Monday Analysis on Tropical Storm Harvey and Outlook for Texas/Louisiana

This continues to be, by far the main weather story in the US. Harvey continues to produce historic catastrophic flash flooding in the Houston Metro area as well as other parts of Southeast Texas and now intensifying in Southwest Louisiana as the center of the tropical cyclone drifts offshore.

11 am CDT radar showing center of circulation moving offshore and rain bands continuing to circulate and pound Houston and the surrounding communities with moderate to heavy rainfall.
Main feeder band stretched out far from Harvey’s center pounding Lafayette and surrounding SW Louisiana with rainfall rates of up to 3+ inches/hr. Flash flooding is likely as the band somewhat “trains” shifting slowly north-northeast as it forms off the Gulf.(11:05 am CDT)

Massive amounts of rain have fallen as a result of Harvey.

Storm total precipitation from Harvey as of 7 am CDT Monday. (NWS)

Observed maximum precipitation since Friday ranges from 25-40 inches! The Houston Metro has been the center of the bullseye, resulting in catastrophic flooding, thousands recused by police and US Coast Guard and so many more still in need of help as waters are still expected to rise. Another 15-25 inches. Yes…the potential for over 50 inches of storm total rainfall exists. Over 30 inches may fall in parts of Southwest LA when all is said and done.
NWS Weather Prediction Center graphic on Harvey issued after 11 am CDT.

As you can see, the center of Harvey will continue to shift more offshore before pulling back for a historic *third* landfall on the Texas Coast near Galveston Wednesday. Because of the current structure of Harvey (lack of inner core) it’s not expected to rapidly intensify over the open coastal waters, however it will likely strengthen some and a 45-50 mph intensity is possible by Wed.

Thunderstorm activity (the brighter yellow in this image) recently firing up near center of circulation as Harvey begins to gain greater heat energy the open Gulf waters offshore SE Texas. Image at 11:15 am CDT

In the end, the maintenance or mild intensification of winds within the cyclone matter not so much as the structural survival of the system and its position as a “pump” from which to machine gun Southeast TX and Southwest LA with intense to horrific amounts of rain causing significant to catastrophic flooding the rest of the week until the system finally gets the steering currents to come far inland. This will be a major problem for awhile.

And if that wasn’t enough we have a potential new system initiating tropical storm watches for North Carolina and continued high heat and dryness out West and on the Northern High Plains. I’ll have more on the drought situation later today or tomorrow.

Photos from Houston this weekend…

From Rockport, TX where Harvey made landfall as a Category 4 hurricane-

-Meteorologist Nick Humphrey


Author: Meteorologist Nick Humphrey

Meteorologist and geoscientist in Lincoln, NE. Seattle, WA native. Love weather, storm chasing/photography and planetary science.

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