New Flood-Map Timetable and How It Affects New Development

Because of low interest rates, new developments seem to pop up weekly around the Lake Houston Area. The question often arises, “How will the development of new flood maps affect the development of new subdivisions?” Most people by now have heard that City building code revisions now require elevation at least two feet above the .02-percent-annual-chance flood (formerly known as 500-year flood). But does that mean two feet above the old floodplain or the new? Due to a little-known provision in the City’s floodplain regulations, it means the new floodplain even though the new floodplain maps are not official yet.

Developments in various stages in the northeast Houston Area and the City’s ETJ (extra territorial jurisdiction). From City of Houston Plat Tracker Plus.

Timetable for Updating Flood Maps

Here’s what you need to know if you’re concerned that someone may be building future buyouts next to your neighborhood. First the timetable for new flood maps.

Remaining timetable for new Harris County Flood Maps

Even though FEMA won’t release the new flood maps officially for approximately another five years, developers should still be building to the higher standards associated with newly acquired data (in other words, the data on which the new maps are being built). See below.

Floodplain Regs Authorize City Engineer to Use Data Behind New Flood Maps

Section 19-4 of the City’s Floodplain regulations address Use of other flood hazard data to supplement the effective Flood Insurance Rate Map (FIRM). It states, “New elevation and flooding studies are undertaken by or under the auspices of FEMA and local political subdivisions, such as the Harris County Flood Control District. Upon determination that the data generated by such a study appears to be reliable and based upon sound engineering and surveying practices and further that the study’s data indicate that the effective FIRMs are FIRM is materially inaccurate, the city engineer may cause the study data to be administered for purposes of this chapter as though it were a part of the effective FIRM. Any such determination shall be issued in writing and a copy shall be placed on file in the office of the city secretary. The city engineer is authorized to utilize updated information from FIS and floodplain models in administering this chapter.”

Basically, that means even though the new maps have not yet been adopted, the City Engineer can require developers’ plans to reflect the new underlying data as though it were part of the current map. In this case, the new underlying data is already in hand.

MaapNext Website Describes New Data Improvements

Current floodplain maps will change greatly according to Harris County Flood Control. The district has already started releasing information on a new website called MaapNext (Modeling, Assessment and Awareness Project).

Components of the MaapNext program. A $3.5 million FEMA grant made MaapNext possible.

According to the MaapNext site, we now have updated data based on:

  • County-wide impervious data developed from 2018 aerial imagery
  • Completed flood risk reduction projects
  • NOAA’s recently-released Atlas 14
  • Updated terrain data

We also have new and better ways to model that data since the last survey after TS Allison:

  • 2-Dimensional Hydraulic Modeling
  • New hydrology method that better accounts for a watershed’s conveyance capacity
  • Rain-on-Grid analysis that identifies previously unmapped urban flood risk.

And, we are beginning to develop better maps:

  • Modeling results in GIS (Geographic Information Systems)
  • New flood-risk data sets describe results in a variety of useful ways

Reportedly, the City is already requiring developers to act on the new “best available data” instead of waiting five years for the next maps.

Chapter 19 of the City Ordinances deals with dozens of other requirements for building in floodplains. But more on those in future posts.

Posted by Bob Rehak on 8/29/2020

1096 Days (Three Years) since Hurricane Harvey

The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.

Commissioner Ellis Tries to Add New Conditions to Woodridge Deal – Yet Again

In the Harris County Commissioners Court meeting on 8/25/2020, Commissioners again considered the purchase of Woodridge Village from Perry Homes – at least one small aspect of it that would have allowed them to lock in the price while other details are worked out.

For months, the County has considered purchasing the property to create a regional flood detention facility along Taylor Gully. On Tuesday, County Engineer John Blount placed an item on the agenda requesting that Commissioners declare the purchase of the property north of Elm Grove a “public necessity.”

The declaration is a procedural formality that would allow the county to enter into an earnest money contract to lock in the price. The terms of the contract, however, would not have obligated the county to write a check until all conditions placed on the sale had been dealt with satisfactorily. After a half hour of debate, the Court took no action.

Ellis Goes On Attack Again

Once again, Commissioner Rodney Ellis used the opportunity to try to add two new conditions to the purchase. In the process, he exaggerated the cost of the deal and misrepresented the substance of previous votes.

The proposed new conditions were that the City should pay for half of any new lawsuits arising from the property and that the City should pay for half of the maintenance costs.

You can view the thirty minute discussion in the video of the meeting. Click on Departments (Part 2 of 2). Then advance to about 2:00:45 as Mr. Blount introduces Item 1T on the agenda.

Ellis’ Concerns

Ellis starts out by openly worrying that new assets would require additional funds for maintenance and operations. He also worries about:

  • Trusting the City to keep its promises.
  • Completing projects in the bond fund.
  • Committing cash to a deal he doesn’t like.
  • The City’s progress on reshaping regulations tied to Atlas-14 adoption.
  • Whether the City will continue to approve ill-conceived projects in its ETJ.
  • Timing of the commitment relative to a vote on whether to increase taxes.
  • How the project will affect the Flood Control District’s maintenance budget.
  • Whether the City is acting in good faith
  • Detracting from projects in his district
  • Spending taxpayer money in another county (even if it helps people in Harris County).

Previously, Commissioner Ellis introduced motions to make the City:

Highlights of Discussion

The following timecodes are approximate. This is a summary, not a transcript. These portions of the 30-minute discussion stood out because of their importance or inconsistencies.

2:00:45 County Engineer John Blount introduces Item 1T on page 4 of the agenda. It reads:

“Recommendation that the court find a public necessity exists for the Flood Control District to purchase Tracts G503-06-00-01-001.0 and G503-06-00-01-002.0 in Montgomery County from Figure Four Partners, Ltd., in the amount of $14,019,316 plus closing costs for the Woodridge Village stormwater detention basin, and that the Real Property Division Manager or Assistant Division Manager be authorized to sign any agreements or closing documents associated with this transaction.”

Ellis Leads Off Discussion With Leading Questions

2:01:12: Commissioner Ellis says “Judge, I have a few questions…” and the debate begins. As usual, Mr. Ellis begins by asking leading questions. And the answers are usually obvious. On this day he asked whether the purchase would lead to increased maintenance costs.

2:01:40: Russ Poppe, executive director of the Flood Control District replies, “Yes.”

2:01:50: Ellis asks how much the District’s maintenance budget would decrease should the county adopt a “no-new-revenue” tax rate for next year.

2:02:10: Poppe says that he has seen spreadsheets [which have not been made public] that indicate reductions to operations and maintenance budgets could begin next year, but he doesn’t mention a percentage.

2:02:37: Ellis says, “So the costs will go up” and “…It will be a significant increase.” [Editor’s note: the amount of the increase was never mentioned. You need to be a fast listener when Ellis has the floor.] “So my question is, ‘Why would the district proceed with construction of mitigation assets if we don’t know if we may be unable to maintain them?

Would it make more sense – if we adopt the no-new-revenue rate – to pause third and fourth quartile bond projects until revenue is sufficient to maintain?

Rodney Ellis

[Editor’s Note: by accelerating projects in LMI and SVI neighborhoods, Ellis has delayed projects, such as this one, in other precincts.]

Ellis continues. “Why will we keep starting more projects and we have no idea how we’re going to maintain them?” [Editor’s Note: He does not ask the same question of projects in his precinct.]

2:03:27: Poppe replies, “You bring up a concern that I had, too, Commissioner. Because I know our funding is going to have to increase in order for us to take care of all this infrastructure to the level that our residents are going to expect us to make sure that it functions when we need it to function.”

Confusion over Previous Conditions

2:03:40: Ellis asks Blount or Poppe to restate the conditions previously imposed on the deal that should have preceded the County moving forward with the project. [Editor’s note: I submitted a FOIA request to the County asking for the exact text of that motion, approved in open court. The County denied the request. I appealed. The County submitted it to the State Attorney General’s office for review. The attorney general has not yet ruled on the issue.]

2:04:10: Poppe starts his reply by talking about the demand for half the purchase price. “The city has indicated they do not have the cash available to make up their half of the contribution to acquire the site, which is around 14 million dollars. And the city has indicated that they would rather transfer land assets in the value of at least half of the purchase price to us for use as flood-risk reduction projects. That was condition number one.”

“Condition number two was that the City of Houston adopt updated detention and mitigation rates commensurate with the Atlas-14 rainfall rates. And that was both to be adopted inside not only their city of Houston limits, but also their ETJ.”

“And then the third…”

2:04:45 Ellis interrupts. “And have they done that?”

Precinct 1 Commissioner Rodney Ellis

2:04:50: Poppe replies, “No, there’s an ongoing task force or work group for which I think John’s office (County Engineer) and my office both have people who sit in and contribute to those conversations. But no, they have not adopted increased mitigation requirements yet.”

“And then the last piece that has to occur, Commissioner, is we have to execute an inter-local agreement that addresses those issues I just mentioned, as well as other details, as one might imagine, come up as you start developing a site of this magnitude.”

Ellis Reminds Poppe about Getting City to Pay for Half of Construction

2:05:17: Ellis, referring to a second motion to include construction costs in the City’s half of the deal, asks, “And wasn’t that talk about paying for half the cost to do something with it? I thought that was in the motion. And also paying for half the cost in the event there’s a lawsuit … and … a commitment to pay for half of what it takes to maintain?” (Editor’s note: Paying for half the construction costs was in a previous motion. But the motion did NOT include the City paying for half of legal or maintenance costs.)

2:05:54: Poppe replies. “Yes, Commissioner, those were all issues we’ve talked about, but I don’t believe those were actually directed by court. I know that’s your intention and I want to get those issues addressed with the City as part of our inter-local agreement, too, because those are real costs.”

2:06:54: Hidalgo incorrectly states that Ellis’ additional requirements WERE part of previous motions. “And they WERE, Russ. I remember this is about the fourth time we’re going back over what we agreed. Maybe someone ought to just go back and listen to the transcript and send it around, because as I remember, it was that half of both the purchase and whatever happens and then the detention requirements and there could be assets of land. But we’ve had the same discussion quite a few times. I think in the end we agreed.” (Editor’s note: this contradiction may have something to do with why the FOIA request was denied and appealed to the State AG.)

2:07:45: After a long diatribe about how the City can’t be trusted, Ellis states that he can’t support the deal unless there’s an inter-local agreement that specifies objectives IN WRITING. (Editor’s note: Ellis previously insisted that an inter-local agreement was worthless and that the City had to actually comply with all County demands BEFORE the County moved forward.)

Ellis then worries that there won’t be enough money to complete projects in his district.

Ellis Likens Project to Buying Brooklyn Bridge

2:16:46: Ellis likens the Woodridge Village project to acquiring the Brooklyn Bridge.

2:17:00 Poppe explains that the County provided an inter-local agreement to the City that addresses all the issues under discussion.

“We are still waiting to hear back from them to actually sit down and have a negotiation meeting to make sure that they’re on the same page as us with those initial concepts and the inter-local agreement.”

Russ Poppe, Exec Director, HCFCD

2:17:38: Hidalgo says, “So we can take no action on this item?”

County Attorney’s Office and Cagle Clarify Earnest Money Contract

2:18:43: Robert Soard from the County Attorney’s Office clarifies the purpose of the earnest money contract. It:

  • Commits the seller to the price.
  • Gives the County 120 days to work out an inter-local agreement with the City.
  • Specifically says the inter-local agreement has to be approved by Commissioners Court before the court has to buy the property.

2:24:05: Commissioner Jack Cagle says, “This is not nearly as complicated as we’re trying to make it. We have people in Harris County that are at risk of flooding because of the property that’s upstream. We have a chance to lock in a very good price to be able to acquire property to help people that live in Harris County.”

“Understand that we have all the criteria that have been added to the initial idea. And the ball has moved a little bit since our very first meeting. But with all of that in place, to be able to at least lock in the price – as opposed to letting that price float with someone on the other side who is trying to decide what they want to do – I think is a reasonable thing.”

“And if we can’t meet the three criteria or the five criteria or the seven criteria that might come down the pike, then we don’t meet those. But at least let’s give ourselves a locked-in price and a set of targets to move towards. These are people in Harris County that we’re trying to help in times when they’re concerned with things that are coming in to our area with regard to water – tropical storms, hurricanes, flooding.”

Ellis Drops New Bomb; Commissioners Take No Action

2:25:40: Ellis says that he won’t support the declaration of necessity because it raises “false hope that we’re going to do it,” meaning purchase the property. He also says, “And the city is telling us that they are not going to make a decision on those policy matters [Atlas-14 implementation], but they would like us to commit to this 50 to 70 million dollars.” During this part of the discussion, Ellis doubles previous estimates and ignores the fact that the City would be paying for half, but no one corrects him. He couples the Woodridge-Village purchase with setting the tax rate, as if he’s getting ready to blame a tax increase on Elm Grove.

And then he drops the big one. He admits, “those people who have gotten water in neighborhoods where there were no equity standards will be left out.”

Rodney Ellis, Harris County PRECINCT 1 COMMISSIONER

The reference to equity has to do with the application of poverty standards to the prioritization of bond funds. He explicitly states that if your neighborhood doesn’t meet LMI or SVI criteria – his definition of equity – you won’t benefit from the $2.5 billion bond fund.

The discussion ended shortly thereafter.

Commissioners decided to take no action and defer the motion to a later date.

Again, please don’t just accept my summary of Tuesday’s meeting; view the video yourself. The discussion was rambling, disjointed, and filled with “memory lapses.” But I believe this summary captures the main points.

Breaking a Golden Rule of Conflict Negotiation

It’s clear from Cagle’s cynical comment about the three, five, or seven conditions, that he despairs this deal will ever be finalized. Every time it comes up, Ellis tries to add more conditions. Most distressing is the fact that he’s also trying to redefine motions that the Court previously agreed to. And that the county refuses to produce the text of after a valid FOIA request.

Harris County Commissioners Court has a real transparency issue.

Ellis is diverting money to projects in his district with new conditions that evolve in each meeting.

A golden rule of conflict resolution states that if you agree to a deal three times and someone still keeps trying to add conditions, you should disengage. That person is just not being honest with you.

Posted by Bob Rehak on 8/27/2020

1094 Days since Hurricane Harvey and 343 since Imelda

The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.

How Close Was Laura?

After a week of worry! After adrenaline-fueled prep for two back-to-back hurricanes that could have wreaked havoc on Houston…I woke up refreshed this morning, walked to my weather window, and saw…nothing unusual. What happened? I checked my weather gauge. It read 0.00 inches of rain. Max winds since midnight: 3 mph.

It would appear the Houston Area dodged Laura’s silver bullet. But why? According to Harris County Meteorologist, Jeff Linder, two things spared us the wrath of Laura. First, Laura shifted slightly east. Second, as Laura intensified, the wind field pulled in tighter. That diminished feeder bands on the western side of the storm.

How Close Laura Came

Here are some radar and satellite images that show how close the storm came.

From Weather Live App at 5:55 am Thursday 8/27/2020
From the National Hurricane Center at 5:56 am. Houston is the bright spot on the SW side of the swirl.
From the National Weather Service at 1:53 CDT as Laura came ashore.
From Lake Charles Louisiana radar at 12:46 am CDT. (This and following images from RadarScope Pro app.)

The shot above and the radar loop below show dramatically how the storm shifted east last night. The National Hurricane Center had predicted eye of the storm to move up the Sabine River near Port Arthur, about 40 miles west.

Radar Loop showing Laura coming onshore that started at 11:28pm 8/26/2020.
Little Rock, Arkansas radar at 5:41 am CDT as Laura approaches

6 A.M. Update from NHC

At this instant, Laura has diminished to a Cat 2 storm. An update issued by the NHC at 6:00 a.m. says,

  • HURRICANE CONDITIONS SPREADING FARTHER INLAND ACROSS SOUTHWESTERN LOUISIANA…
  • CATASTROPHIC STORM SURGE, HURRICANE FORCE WINDS, AND FLASH FLOODING WILL CONTINUE THIS MORNING…
  • Fort Polk, Louisiana recently reported a sustained wind of 45 mph (72 km/h) and a wind gust of 70 mph (113 km/h). SUMMARY OF 600 AM CDT…1100 UTC…
INFORMATION
  • LOCATION…30.9N 93.3W ABOUT 55 MI…90 KM N OF LAKE CHARLES LOUISIANA
  • MAXIMUM SUSTAINED WINDS…105 MPH…170 KM/H
  • PRESENT MOVEMENT…N OR 355 DEGREES AT 15 MPH…24 KM/H
  • MINIMUM CENTRAL PRESSURE…964 MB…28.47 INCHES

Hurricane Guilt

After Hurricane Rita, which dodged Houston like Laura, I coined a term called “hurricane guilt.” It’s that feeling of elation you get when you realize the storm missed you…followed closely by the realization that it destroyed innocent lives elsewhere.

That’s what I feel right now. As I write this, the sun is rising and birds are singing. Soon images of Laura’s destruction will start to pour in. Only then will we know how lucky we were.

Posted by Bob Rehak at 6:45 am on 8/27/2020 based on information from NWS, NHC, RadarScope, and Jeff Lindner, Harris County Meteorologist

1094 Days since Hurricane Harvey

As of 1 p.m., Laura Now Category 4 Hurricane, Moving at 16 mph

Based on recent Hurricane Hunter aircraft measurements, the National Hurricane Center reported at 1 p.m. that Hurricane Laura’s maximum sustained winds have increased to near 140 mph with higher gusts. Laura is an extremely dangerous Category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Maximum winds could reach 145 mph.

Laura is forecast to remain a category 4 hurricane through landfall tonight.

National Hurricane Center

350 Miles Across

Rapid weakening is expected after Laura reaches land. However, Hurricane-force winds extend outward up to 70 miles from the center and tropical-storm-force winds extend outward up to 175 miles (280 km). That’s 350 miles across!

Storm surge and tropical-storm-force winds will arrive within the warning areas well in advance of Laura’s center.

All preparations to protect life and property should be rushed to completion in the next few hours.

Louisiana Already Feeling Tropical-Storm-Force Winds

Tropical-storm-force winds have already reached the coast of Louisiana. An observing site at Eugene Island recently measured sustained winds of 39 mph (63 km/h) and a gust to 64 mph (104 km/h). The latest minimum central pressure estimated from reconnaissance aircraft data is 952 mb (28.11 inches). Very low!

20-Foot-High Storm Surge Could Reach 30 Miles Inland

According to the NHC, unsurvivable storm surge with large and destructive waves will cause catastrophic damage from Sea Rim State Park, Texas, to Intracoastal City, Louisiana, including Calcasieu and Sabine Lakes. This storm surge could penetrate up to 30 miles inland from the immediate coastline in southwestern Louisiana and far southeastern Texas.

Warnings in Effect

STORM-SURGE WARNING IS IN EFFECT FOR FREEPORT TEXAS TO THE MOUTH OF THE MISSISSIPPI RIVER

HURRICANE-WARNING IS IN EFFECT FOR SAN LUIS PASS TEXAS TO INTRACOASTAL CITY LOUISIANA

TROPICAL-STORM WARNING IN EFFECT FOR SARGENT TEXAS TO SAN LUIS PASS AND EAST OF INTRACOASTAL CITY LOUISIANA TO THE MOUTH OF THE MISSISSIPPI RIVER

Key Messages

1. Unsurvivable storm surge with large and destructive waves will cause catastrophic damage from Sea Rim State Park, Texas, to Intracoastal City, Louisiana, including Calcasieu and Sabine Lakes. This surge could penetrate up to 30 miles inland from the immediate coastline. Only a few hours remain to protect life and property and all actions should be rushed to completion.

2. Hurricane-force winds are expected tonight in portions of the hurricane warning area from San Luis Pass, Texas, to west of Morgan City, Louisiana, with catastrophic wind damage expected where Laura’s eyewall makes landfall. Hurricane-force winds and widespread damaging wind gusts will spread well inland across portions of eastern Texas and western Louisiana early Thursday.

3. Widespread flash flooding along small streams, urban areas, and roadways is expected to begin this afternoon into Thursday from far eastern Texas, across Louisiana and Arkansas. This will also lead to minor to isolated moderate freshwater river flooding. The heavy rainfall threat and localized flash and urban flooding potential will spread northeastward into the middle-Mississippi, lower Ohio and Tennessee Valleys Friday night and Saturday.

Posted by Bob Rehak at 2 p.m. CDT on 8/26/2020 based on input from National Hurricane Center and Jeff Lindner, Harris County Meteorologist

1093 Days after Hurricane Harvey

Impact Corridor of Hurricanes Much Wider than Cone of Uncertainty

Many people mistake the cone of uncertainty associated with a hurricane as the width of a storm. It’s not. It merely shows likely paths the hurricane’s eye could take as it comes ashore. There’s an equal probability of any path within the cone. Cones expand with more distant projections because uncertainty increases. But as forecasters always warn us, the impact of a major hurricane extends far beyond the cone of uncertainty.

Difference Visualized

Compare these two pictures to fully understand the difference.

Cone of uncertainty for Laura as of Wed. morning, 8/26/2020 at 10 a.m. CDT.
Satellite image of Laura taken at about the same time the cone image above was produced.

I have arbitrarily assigned the term “impact corridor” to the area between the two lines to help describe the difference. (No one uses this term but me, although they probably should.)

Of course, as you go further from the center of the storm, the intensity decreases and so do negative impacts.

Currently (12:30 pm CDT, 8/26/2020), hurricane-force winds extend outward up to 70 miles from the center and tropical-storm-force winds extend outward up to 175 miles. That’s 350 miles across!

Interesting Facts About Hurricanes

As you ride this one out with your children or grandchildren, make it a learning experience. Here are some interesting facts about hurricanes taken from Weather.gov.

  • Each year, an average of ten tropical storms develop over the Atlantic Ocean, Carribean Sea, and Gulf of Mexico. Many of these remain over the ocean. Six of these storms become hurricanes each year. In an average 3-year period, roughly five hurricanes strike the United States coastline, killing approximately 50 to 100 people anywhere from Texas to Maine. Of these, two are typically major hurricanes (winds greater than 110 mph).
  • Typical hurricanes are about 300 miles wide although they can vary considerably in size.
  • The eye at a hurricane’s center is a relatively calm, clear area approximately 20-40 miles across.
  • The eyewall surrounding the eye is composed of dense clouds that contain the highest winds in the storm.
  • The storm’s outer rainbands (often with hurricane or tropical storm-force winds) are made up of dense bands of thunderstorms ranging from a few miles to tens of miles wide and 50 to 300 miles long.
  • Hurricane-force winds can extend outward to about 25 miles in a small hurricane and to more than 150 miles for a large one. Tropical storm-force winds can stretch out as far as 300 miles from center of a large hurricane.
  • Frequently, the right side of a hurricane is the most dangerous in terms of storm surge, winds, and tornadoes.
  • A hurricane’s speed and path depend on complex ocean and atmospheric interactions, including the presence or absence of other weather patterns. This complexity of the flow makes it very difficult to predict the speed and direction of a hurricane.
  • Do not focus on the eye or the track. Hurricanes are immense systems that can move in complex patterns that are difficult to predict. Be prepared for changes in size, intensity, speed and direction.

What Hurricanes Need to Grow

Weather.gov lists six widely accepted conditions for hurricane development:

1. The first condition is that ocean waters must be above 79 degrees Fahrenheit. Below this threshold temperature, hurricanes will not form or will weaken rapidly. Ocean temperatures in the tropics routinely surpass this threshold.

2. The second ingredient is the Coriolis Force. Without the spin of the earth and the resulting Coriolis force, hurricanes would not form. Coriolis force causes a counterclockwise spin to low pressure systems, such as hurricanes, in the Northern Hemisphere and a clockwise spin to low pressure in the Southern Hemisphere.

3. The third ingredient is that of a saturated lapse rate gradient near the center of rotation of the storm. A saturated lapse rate insures latent heat will be released at a maximum rate. Hurricanes are warm core storms. The heat hurricanes generate is from the condensation of water vapor as it convectively rises around the eye wall. The lapse rate must be unstable around the eyewall to insure rising parcels of air will continue to rise and condense water vapor.

4. The fourth and one of the most important ingredients is that of a low vertical wind shear, especially in the upper level of the atmosphere. Wind shear is a change in wind speed with height. Strong upper level winds destroy the storms structure by displacing the warm temperatures above the eye and limiting the vertical accent of air parcels. Hurricanes will not form when the upper level winds are too strong.

5. The fifth ingredient is high relative humidity values from the surface to the mid levels of the atmosphere. Dry air in the mid levels of the atmosphere impedes hurricane development in two ways. First, dry air causes evaporation of liquid water. Since evaporation is a cooling process, it reduces the warm core structure of the hurricane and limits vertical development of convection. Second, dry air in the mid levels can create what is known as a trade wind inversion. This inversion is similar to sinking air in a high pressure system. The trade wind inversion produces a layer of warm temperatures and dryness in the mid levels of the atmosphere due to the sinking and adiabatic warming of the mid level air. This inhibits deep convection and produces a stable lapse rate.

6. The sixth ingredient is that of a tropical wave. Often hurricanes in the Atlantic begin as a thunderstorm complex that moves off the coast of Africa. It becomes what is known as a midtropospheric wave. If this wave encounters favorable conditions such as stated in the first five ingredients, it will amplify and evolve into a tropical storm or hurricane. Hurricanes in the East Pacific can develop by a midtropospheric wave or by what is known as a monsoonal trough.

Posted by Bob Rehak on 8/26/2020 based on data from Weather.gov.

1093 Days since Hurricane Harvey

NWS Predicts Local Impacts to Lake Houston Area from Hurricane Laura

The National Weather Service (NWS) Southern Region has produced an interactive map that lets users click on their location and produce estimates of danger from Hurricane Laura.

For the Lake Houston Area, NWS predicts potential for moderate flooding rain

Click one a location near you and review the threat potential.

Potential Impacts Include:

  • Moderate rainfall flooding may prompt several evacuations and rescues.
  • Rivers and tributaries may quickly become swollen with swifter currents and overspill their banks in a few places, especially in usually vulnerable spots. Small streams, creeks, canals, and ditches overflow.
  • Flood waters can enter some structures or weaken foundations. Several places may experience expanded areas of rapid inundation at underpasses, low-lying spots, and poor drainage areas. Some streets and parking lots take on moving water as storm drains and retention ponds overflow. Driving conditions become hazardous. Some road and bridge closures.

For Lake Houston Area, NWS Predicts Winds from 58 to 73 mph

Potential wind threats from Laura and protective actions for people in the Lake Houston Area

Potential Impacts Include:

  • Some damage to roofing and siding materials, along with damage to porches, awnings, carports, and sheds. A few buildings experiencing window, door, and garage door failures. Mobile homes damaged, especially if unanchored. Unsecured lightweight objects become dangerous projectiles.
  • Several large trees snapped or uprooted, but with greater numbers in places where trees are shallow rooted. Several fences and roadway signs blown over.
  • Some roads impassable from large debris, and more within urban or heavily wooded places. A few bridges, causeways, and access routes impassable.
  • Scattered power and communications outages, but more prevalent in areas with above ground lines.

…TROPICAL STORM WARNING REMAINS IN EFFECT…

West of Lake Houston, the threat level decreases. Between Dayton and Liberty, it increases.

For those closer to the coast, the map also includes storm surge warnings. Also check out the estimates of tornado threats.

The latest satellite images show Laura just off the coast. The storm is moving north at about 15 miles per hour.

Hurricane Laura as of 11 am 8/26/2020

No Lake Conroe Release Anticipated Before Storm

In other hurricane related news, the SJRA just issued a press release stating that:

“SJRA is operating under standard protocols for a severe weather event and will be onsite at Lake Conroe throughout the night and into Thursday. 
Lake Conroe remains about 15 inches low, and based on the current forecast, no reservoir releases are expected.

Posted by Bob Rehak on 8/26/2020 at 11:00 a.m. based on estimates from the National Weather Service.

1093 Days since Hurricane Harvey

As of 7 a.m., Laura Predicted to Make Landfall at Sabine Pass as Cat 4 Hurricane

This update on Hurricane Laura is based on information from Harris County Meteorologist Jeff Lindner and the National Hurricane Center based on their 4 a.m. and 7 a.m. updates on Wednesday 8/26/2020.

Laura rapidly strengthening…now a 115 mph Category 3 hurricane, predicted to reach Cat 4.

Extremely dangerous hurricane will make landfall near Sabine Pass tonight with catastrophic impacts.

All preparations must be completed by 6:00 p.m. this evening.

Conditions will begin to deteriorate late this afternoon and evening over the region.

Rainfall predictions for the Lake Houston Area increased overnight. We could now receive up to six inches.

The Lake Houston Area now has a 60-80% chance of experiencing topical-storm-force winds from Laura.
Tropical-storm-force winds could arrive as early as mid-afternoon.
The most likely time, however, for the arrival of tropical-storm-force winds is later this evening.

Discussion 

Laura became a large and dangerous hurricane overnight with expansion of the wind field. USAF missions indicate the central pressure continues to fall. Winds are increasing. And Laura has experienced a 40 knot increase in winds in the last 24 hours. (A knot = 1.15 mph.) The eye of the hurricane is starting to clear out. Further rapid intensification is likely today.

The cone of uncertainty now shows Houston will NOT experience a direct hit from the storm, but we will still feel it. Effects from the Laura extend well outward from the center.
Track

The center of Laura should cross the coast near Sabine Pass, TX, near the Texas/Louisiana Border. Models have tightly clustered just either side of the state line. There is high confidence that Laura will make landfall in the areas between Sea Rim State Park and Cameron LA early Thursday morning. The hurricane should move rapidly northward, up the Sabine River Valley on Thursday. 

Given the fast forward motion, significant wind impacts will extend well inland along the track of Laura with wind damage likely extending 100-200 miles inland over eastern Texas and western Louisiana.

Intensity: 

Laura will pass over warm Gulf waters today and upper air conditions that favor intensification through landfall. The National Hurricane Center forecasts a category 4, 130 mph hurricane at landfall.

Hurricane force winds extend outward 70 miles from the center and tropical storm force winds 175 miles.

Wind damage and storm surge impacts will extend well beyond the center.

Jeff Lindner, Harris County meteorologist

Impacts

Storm Surge: 

Expect a catastrophic storm surge event over extreme SE TX and much of coastal Louisiana.

Strong north winds tonight may drive water levels along the north side of Galveston Island and Bolivar to elevated levels and water levels in the NW part of Galveston Bay may fall well below normal.

The following values are above ground level:

Galveston Bay: 1-3 ft

Bolivar: 2-5 ft

High Island to Sea Rim State Park: 6-9 ft

Sea Rim State Park to Intracoastal City (Including Beaumont and Lake Charles): 10-15 ft.

Large destructive waves will accompany storm surge.

Winds: 

West of I-45: 30-40mph

East of I-45: 45-55mph

Chambers, Liberty, Polk Counties: 50-65mph

Jefferson, Orange Counties and Lake Charles: 110-120mph

Higher gusts will occur in squalls. 

Hurricane-force winds currently extend outward up to 70 miles from the center and tropical-storm- force winds extend outward up to 175 miles.

The Harris County line is 75 miles from Sabine Pass; Lake Houston 80 miles.

Rainfall: 

West of I-45: 1-2 inches

East of I-45: 2-6 inches, isolated totals up to 8 inches.

Sabine River Valley: 8-12 inches

Overnight, rainfall predictions for the Lake Houston Area increased 2 inches. The six inches now predicted roughly equals the amount of rain the Lake Houston Area received on May 7th last year. Elm Grove residents: Please note: the volume of detention ponds now on Woodridge Village should be enough to protect you unless there is a design flaw.

The main rainfall threat comes from rapid, intense rains which can cause street flooding.

Actions

Complete all preparations by 6:00 pm this evening. Earlier the better.

If in evacuation areas, evacuate immediately…especially in the Beaumont and Lake Charles area.

Lake Report

Lake Houston as of 6:30 a.m. was at 41.17 feet (full pool 42.4). The Coastal Water Authority will continue releasing water from Lake Houston until it reaches 41 feet.

Lake Conroe is not releasing water and stands at 199.72 feet (full pool is 201).

For More Up-to-the-Minute Information

For the most up-to-date rainfall totals and water levels in bayous, creeks, and rivers, visit www.harriscountyfws.org. This system relies on a network of gage stations that have been strategically placed throughout Harris and surrounding counties.

Also visit the National Hurricane Center and the National Weather Service.

Posted by Bob Rehak at 7:12 a.m. on 8/26/2020 based on input from the National Hurricane Center and Jeff Lindner, Harris County Meteorologist.

1093 Days after Hurricane Harvey

Lake Houston Level Now Being Lowered in Advance of Hurricane Laura

Mayor Pro Tem Dave Martin announced at 4:31 p.m. Tuesday that Houston Public Works will initiate the temporary lowering of Lake Houston within the hour. The City made this decision after taking into account the fast-changing nature of Hurricane Laura. The Coastal Water Authority will lower Lake Houston to 41.0 ft from 41.59, another six tenths of a foot, which is 18 inches below full pool.

Laura should arrive late tomorrow or early Thursday as a Category 3 storm. Hurricane conditions are expected in Chambers and Liberty County – with 45-60 mph winds east of I-45 throughout the Lake Houston Area.

Floodgates on Lake Houston Dam photographed on 6/16/2020.

2 to 4 Inches Expected

The National Hurricane Center predicts that Hurricane Laura will bring 2 – 4 inches of rain to the Lake Houston Area in the next few days. Isolated areas could receive 6 inches. These rainfall amounts exceed the 3 inch trigger to lower Lake Houston, said Martin. 

Lake to Be Lowered Another 7.2 inches

As a result of these predicted rainfall amounts in addition to the rainfall that will be accumulated to our east, the Lake will be lowered gradually overnight from the current level, which is 41.6 ft down to an elevation of 41.0 ft. Six tenths of a foot is 7.2 inches.

The Lake will be maintained at a level of approximately 41.0 ft while there is an immediate inclement weather threat. Once that weather has moved out of our area, the Lake will be allowed to naturally refill from the storm’s runoff.

Some fluctuations in Lake level can be attributed to high winds so please keep that in mind when checking Lake levels.

Secure Shoreline Property NOW If You Have Not Already

Property owners were given notice Friday afternoon to secure property along the shoreline for a potential temporary lowering of Lake Houston. If you have not already done so now is the time to take action to secure your shoreline property.

Dave Martin, Mayor Pro Tem

The lake will be lowered at a cautious rate so as to not impact those living downstream. At the completion of this temporary lowering effort the total reduction in the level of Lake Houston from normal pool of 42.5 ft to 41.0 ft will be 1.5 feet. 

For More Information

Residents may monitor the lowering of Lake Houston by visiting the Coastal Water Authority website or visiting Mayor Pro Tem Martin’s Facebook page for updates from the District E office.

No Mention of SJRA

Martin’s press release made no mention of the SJRA or Lake Conroe. Lake Conroe, which is farther west should receive less rain than Lake Houston from Laura.

Posted by Bob Rehak on 8/25/2020 at 6 pm, based on a press release from Houston Mayor Pro Tem Dave Martin.

1092 Days after Hurricane Harvey

Laura Intensifying into Major Hurricane; Prepare for Big Winds, Power Outages

These warnings were just issued by Jeff Lindner, Harris County Meteorologist, the National Hurricane Center, and City of Houston:

Hurricane warnings issued from San Luis Pass into Louisiana.

Landfall of a devastating hurricane likely between Galveston Bay and Sabine Pass tomorrow night.

Rush to complete preparations to protect life and property.

Heed all evacuation recommendations.

Discussion

Laura – now a hurricane with sustained winds of 75mph – is continuing to intensify. The hurricane will likely rapidly intensify over the next 24-36 hours, right up to landfall along the upper TX coast. The National Hurricane Center predicts Laura will become a major hurricane with sustained winds over 110 mph by tomorrow night or early Thursday morning when it makes landfall somewhere between Galveston Bay and Sabine Pass.

Track: 

Everyone should be planning for the landfall of a very serious hurricane between Galveston Bay and Sabine Pass on the Louisiana border. Additional shifts in the track are possible that could bring the core of Laura into Galveston Bay and Harris/Galveston Counties.

The large wind field will result in strong winds likely 100-150 miles inland across east Texas.

Prepare for power outages extending well inland along with significant wind damage and extended outages.  

Intensity:

Prepare for the impact of a major hurricane (cat 3 or higher). Once the inner core of Laura forms, significant intensification is likely, and conditions look very favorable for intensification. 

Tropical Storm force winds will begin along the coast at around 8:00 pm Wednesday evening.

Advice from City, Lake Status

“Rainfall amounts in the Lake Houston Watershed over the next six days are expected to be 2 – 4 inches with isolated accumulation of 6 inches possible,” said Dave Martin. “Currently, the Lake Houston Watershed is dry and the projected impact to our area will be to our east with the largest possible impact expected along the East Fork of the San Jacinto River. Lake Houston is already down one foot from normal pool with the possibility of being lowered additionally, if necessary. Please make sure all property along the shoreline is secured in the event additional lowering is ordered.”

“Regardless of where this storm lands,” said Martin, “it is important all residents prepare themselves and have a plan. Hurricane Laura will likely be similar to Ike with severe wind impacts and power outages. The City of Houston has prepared resources to help you get ready for upcoming disasters and make sure you are prepared for this one. Please visit www.readyhoustontx.gov to learn more.

Actions

  • Prepare for the landfall of a major hurricane along the SE TX coast
  • Bring in anything in your yard, such as lawn furniture, that could become airborne.
  • All preparations will be to be competed by 6:00 p.m. Wednesday evening.
  • Heed all evacuation orders. 

For hurricane preparation tips from the National Weather Service, click here.

Posted by Bob Rehak on 8/24/2020 based on input from the National Hurricane Center and Jeff Lindner, Harris County Meteorologist.

1091 Days after Hurricane Harvey

Laura Upgraded to Hurricane; Will Intensify Through Landfall; Mandatory Evacuation for Galveston Island

Overnight, Laura turned into a hurricane. At 5:25 this morning, Jeff Lindner, Harris County Meteorologist, issued the following:

Hurricane Watches extended west to San Luis Pass…now include Harris and Galveston Counties

Major hurricane forecast in the NW Gulf of Mexico Wednesday

Enact hurricane plans now. Follow all recommendations from local officials.

At 7:00 a.m., he issued another warning saying that:

Laura upgraded to a hurricane…intensification will continue through landfall.

Mandatory evacuation order for Galveston Island effective immediately.

Discussion 

Laura is now over the SE Gulf of Mexico and moving toward the WNW after having jogged westward overnight. Deep convection has developed over and near the center this morning. Some light northerly system continues to impact Laura, which continues to track to the south of predictions. 

Track: 

The steering pattern that will bring Laura to the NW Gulf of Mexico remains somewhat in flux this morning. Laura will turn northwest and then north. But uncertainty remains as to when Laura will make this turn. Overnight model guidance now delays this turn a little longer and brings Laura more toward the upper Texas coast. NHC may have to shift their forecast track a bit more westward later this morning.

Forecast track shifted back west overnight bringing Houston into cone of uncertainty. Track forecast could shift further westward later this morning, bringing Houston closer to center of storm.

While uncertainty remains in the eventual outcome of Laura, preparations for landfall of a major hurricane along the upper TX coast should be well underway.

Jeff Lindner, Harris County Meteorologist

Tropical storm force winds will begin to arrive along the coast Wednesday evening and spread inland Wednesday night into Thursday morning.

Intensity: 

A central core is starting to form with Laura and overall circulation of the system is looking better defined. Conditions in the central Gulf today favor a period of rapid intensification. Laura is forecast to make landfall as a major hurricane along the SE TX/SW LA coast late Wednesday.

Laura is a fairly large storm and impacts will be far reaching from the impact point extending both west and east.

Tropical-storm-force winds currently extend outward up to 175 miles (280 km) from the center.

Impacts

Rainfall:

Will rainfall forecast at 2-4 inches east of I-45 and 1-3 inches west of I-45, but this may need to be increased later today. WPC has placed areas east of I-45 in a slight risk for flash flooding.

Most of Houston falls into the light and dark green bands on the left, predicted to get 1-4 inches of rain.
NHC how gives the Houston Area a slight chance of flash flooding (10-20%).
Storm Surge: 

Still looking at 2-4 feet above ground level in Galveston Bay and 4-6 feet on Bolivar with levels of 7-11 feet east of High Island into Louisiana. Should the track shift more west, these values around Galveston Bay would potentially need to be increased significantly.  

Wind: 

Tropical storm force winds will be moving into the area Wednesday evening. Expect winds of 40-50mph across Harris County northward along I-45 with hurricane conditions becoming increasingly likely over Liberty and Chambers Counties. Any additional shift westward in the track will bring stronger winds across the area.

Be prepared for power outages starting Wednesday evening. 

Actions

Enact hurricane plans now.

Follow all recommendation on evacuation from local officials.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT

The National Hurricane Center advises that:

Storm Surge Watch is in effect for San Luis Pass Texas to Ocean Springs Mississippi.

  • High Island TX to Morgan City LA including Sabine Lake, Calcasieu Lake, and Vermilion Bay…7-11 ft
  • Port Bolivar TX to High Island TX…4-6 ft
  • San Luis Pass TX to Port Bolivar TX…2-4 ft
  • Galveston Bay…2-4 ft

Hurricane Watch is in effect for San Luis Pass Texas to west of Morgan City Louisiana

Tropical Storm Watch is in effect for…

  • San Luis Pass to Freeport Texas
  • Morgan City Louisiana to the Mouth of the Mississippi River

A Storm Surge Watch means there is a possibility of life-threatening inundation, from rising water moving inland from the coastline, in the indicated locations during the next 48 hours.

A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous.

For inland watches and warnings, monitor the local National Weather Service forecast office.

Posted by Bob Rehak on 8/25/2020 with input from CoH, Harris County, National Hurricane Center, National Weather Service, and ReadyHarris.

1092 Days After Hurricane Harvey