Tag Archive for: category 4

Cat-4 Ida Hits Louisiana with 150 MPH Winds and 12-Foot Storm Surge

The forecasts turned out to be accurate. According to Jeff Lindner, Harris County meteorologist, “Hurricane Ida made landfall at 11:55 am today at Port Fourchon, LA with sustained winds of 150 mph and a central pressure of 930mb.” Storm surge at the coast is 12 feet above ground level.

Image from RadarScope Pro from KLIX New Orleans Radar.

Wind Reports

Although Ida’s extreme winds are confined to the inner eyewall, aircraft data indicate that hurricane-force winds extend outward about 45 nautical miles to the northeast of the center. Based on buoy data the tropical-storm-force wind field extends outward about 130 nautical miles northeast of the center. Here are some readings as of 1PM Sunday 8/29/2021.

Grand Isle: 146mph (unconfirmed)

Port Fourchon: 153mph (unconfirmed ship)

West Delta Oil Platform: 149mph (elevated just off the coast)

Wind Forecast

For those with friends and relatives in Louisiana who did not evacuate, the National Weather Service predicts that winds will remain over 100 mph for the next 12 hours, decrease to 60 within 24 hours, the drop to 35 mph within 36 hours. Damaging wind gusts are expected in metropolitan New Orleans.

Misery Not Yet Over

The storm should follow this track.

Ida’s track will take it over portions of Tennessee severely damaged by flash flooding last weekend.
Large portions of SE Louisiana could see 15-20 inches of rain.
Most of the state has a moderate to high risk of flash flooding.

“Ida will continue to produce heavy rainfall today through Monday across the central Gulf Coast from southeast Louisiana, coastal Mississippi, and far southwestern Alabama, resulting in considerable to life-threatening flash and urban flooding and significant river flooding impacts,” says the NHC. “As Ida moves inland, significant flooding impacts are possible across portions of the Lower Mississippi, Tennessee Valley, Upper Ohio Valley, Central Appalachians and the Mid-Atlantic through Wednesday.”

Storm Surge

Storm surge has deadly potential along the coast. NHC calls it, “Extremely life-threatening.” And they say, “Overtopping of local levees … is possible.”

Surge recorded so far:

East Bank Mississippi River (South of New Orleans): 12.15ft (AGL)

Shell Beach: 7.51ft (AGL)

Grand Isle: 6-8 ft (AGL)

Thus far all federal levee protection and floodgates/walls are preforming as expected. Catastrophic impacts will continue inland over southeast Louisiana into tonight.

I was planning on doing a 4-year retrospective on Harvey today, but will postpone that out of deference to the suffering east of us. Thoughts and prayers for our neighbors who provided so much help in our hour of need.

Posted by Bob Rehak on 8/29/2021 based on information from NHC and HCFCD

1161 Days since Hurricane Harvey

Ida Now Hurricane, Predicted to Intensify to Category 4, Take Aim at New Orleans

As of 3 p.m. CDT, the National Hurricane Center indicated Tropical Storm Ida had intensified into a hurricane about to cross over the western tip of Cuba. They warn that it could turn into a category 4 hurricane. It is currently predicted to cross over Louisiana, dump up to 20 inches of rain, and produce 15 feet of storm surge on Sunday.

Warnings Now In Effect

The NHC has also posted several warnings. They include:

  • Storm Surge Warning from Rockefeller Wildlife Refuge in Louisiana to the Mississippi/Alabama border.
  • Hurricane Warning for the coast of Louisiana including Lake Pontchartrain and Metropolitan New Orleans.
  • Tropical Storm Warning from the mouth of the Pearl River to the Mississippi/Alabama border.
  • Tropical Storm Warning for the coast of Louisiana from west of Intracoastal City to Cameron.
Hurricane Ida over the western tip of Cuba as of 3PM Houston time on 8/27/2021

Rapid Intensification

According to the National Hurricane Center, radar indicated a closed eye 24 nautical miles wide. Recon aircraft measured winds at 70 knots – hurricane intensity – at 3 PM Houston time.

Once Ida moves past western Cuba and into the southeastern Gulf of Mexico, it will be moving through very warm waters, low wind shear, and a moist low- to mid-level atmosphere. These conditions should result in rapid strengthening during the next 24 to 36 hours.

In fact, with the higher initial wind speed, the intensity guidance has significantly increased.

Models now predict Ida will reach category 4 intensity. The NHC forecast explicitly calls for rapid intensification during the next 24 to 36 hours.

National Hurricane Center

Some fluctuations in intensity are possible as Ida nears the northern Gulf coast due to possible eyewall replacement cycles. Models also call for Ida’s wind field to expand while it moves over the Gulf of Mexico. As a result, there is higher-than-normal confidence that a large and powerful hurricane will impact portions of the northern Gulf coast by late this weekend and early next week.

Ida has wobbled a little right of the previous track, but the longer term motion continues to be northwestward at about 14 mph.

Tracking Quickly Toward Louisiana Then Slowing

Steering currents push Ida northwestward across the Gulf this weekend. But Ida after landfall they will also slow northward motion and cause the system to turn northeastward.

Key Messages

However, remember not to focus on the exact details of the track. Storm surge, wind, and rainfall impacts will extend far from the center, says the NHC.

1. Life-threatening storm surge and hurricane conditions will continue through tonight in portions of western Cuba. Life-threatening heavy rains, flash flooding and mudslides are expected across Jamaica, the Cayman Islands, and western Cuba, including the Isle of Youth.

2. There is a danger of life-threatening storm surge inundation Sunday along the coasts of Louisiana and Mississippi within the Storm Surge Warning area. Extremely life-threatening inundation of 10 to 15 feet above ground level is possible within the area from Morgan City, Louisiana, to the Mouth of the Mississippi River. Interests throughout the warning area should follow any advice given by local officials.

3. Ida is expected to be an extremely dangerous major hurricane when it reaches the coast of Louisiana. Hurricane-force winds are expected Sunday along the Louisiana coast, including metropolitan New Orleans, with potentially catastrophic wind damage possible where the core of Ida moves onshore. Actions to protect life and property should be rushed to completion in the warning area.

4. Ida is likely to produce heavy rainfall later Sunday into Monday across the central Gulf Coast from southeast Louisiana to coastal Mississippi and Alabama, resulting in considerable flash, urban, small stream, and riverine flooding impacts. As Ida moves inland, flooding impacts are possible across portions of the Lower Mississippi and Tennessee Valleys.

Story of the Storm in Picture

Confidence in track is increasing. Ida should reach the Louisiana and Mississippi coasts by Sunday afternoon.
…but tropical-storm-force winds should arrive by Sunday morning.
Most of the Houston area only has about a 10-30% chance of experience tropical-storm-force winds.
And we have practically no chance of excessive rainfall that could create flash flooding.
Portions of Louisiana, however, will like see 15-20 inches of rain.
But the biggest threat by far to our neighbors will come from storm surge. Portions of the delta could see as much as 15 feet above ground level.

Prays for our neighbors. And thank God that we’re on the dry side of this storm. It should hit on August 29th, the fourth anniversary of when Hurricane Harvey triggered massive evacuations in the Lake Houston Area.

Posted by Bob Rehak on 8/27/2021

1459 Days since Hurricane Harvey

Delta Blows Up into Cat 4 Sooner than Expected; High Island Now in Forecast Cone

11 AM CDT 10/6/2020 – In the last hour, Delta’s winds have increased from 115 to 130 MPH, according to Harris County Meteorologist Jeff Lindner. “Delta is now an extremely dangerous Category 4 hurricane with the central pressure down to 954mb. It is likely that Delta will continue to intensify and could reach 145-155mph late today before landfalling near Cancun tonight,” says Lindner.

Forecasts Continue Shifting West

Forecasters predict that Delta will cross over the tip of the Yucatan and head north toward the central Gulf Coast. The NHC has shifted the forecast track slightly to the west at their 10:00 AM advisory. “The western edge of the forecast cone is now near High Island,” explained Lindner.

Forecast track for Hurricane Delta as of 11 AM EDT Tuesday October 6. Source: National Hurricane Center

Landfall Still Most Likely in Louisiana

“Forecast models, with the exception of the ECMWF, continue to indicate that Delta will turn toward the north of the NW Gulf of Mexico and likely landfall along the central or SE LA coast late Friday. Given the potential for a stronger hurricane in the southern Gulf of Mexico, it is possible that Delta could approach the US coast as a major hurricane.”

Various model forecasts as of 11 am CDT.

Increasing shear and cooler waters near the northern Gulf coast are expected to cause some reduction in wind speed. But Delta should still be a dangerous hurricane when it nears the northern Gulf coast.

Storm 90 Miles Wide

According to the National Hurricane Center, “Although some weakening is likely when Delta moves over the Yucatan peninsula, re-strengthening is forecast when the hurricane moves over the southern Gulf of Mexico. Hurricane-force winds extend outward up to 25 miles (35 km) from the center. Tropical-storm-force winds extend outward up to 90 miles (150 km).”

Delta continues to exceed expectations. Just last night, forecasters predicted Delta would become a major hurricane by Wednesday, not Tuesday.

Posted by Bob Rehak on 10/6/2020 based on information from the NHC and HCFCD

1134 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