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Tropical Storm Beta Discussion Number  18
NWS National Hurricane Center Miami FL       AL222020
1000 PM CDT Mon Sep 21 2020
 
There has been a recent increase in convection along the Texas
coast just to the north of Beta's center this evening.  A blend
of flight-level and SFMR winds from an Air Force Reserve
reconnaissance aircraft indicate that Beta's peak intensity
remains around 40 kt. The aircraft has reported a minimum central
pressure of around 999 mb, which is unchanged from earlier today.
West-southwesterly vertical wind shear and land interaction should
gradually weaken the cyclone over the next couple of days.  The NHC
intensity forecast is a little above model guidance through 24
hours since a significant portion of the circulation is forecast
to remain over water.  Strong vertical wind shear is expected
to prevent re-strengthening when Beta moves near or just offshore of
the Upper Texas coast in a couple of days.
 
Beta is moving northwestward or 325/3 kt.  The tropical storm
should move just inland along the central Texas coast overnight, but
it is expected to become nearly stationary on Tuesday as steering
currents collapse.  A weak trough over the south-central United
States should begin to steer Beta east-northeastward Tuesday night
and Wednesday, and a northeastward motion at a slightly faster
forward speed should continue until dissipation in 72-96 hours.
The latest NHC track forecast is very similar to the previous
advisory and is a blend of the latest GFS and ECMWF models.
 
Key Messages:
 
1. The expected slow motion of Beta will produce a long duration 
rainfall event from the middle Texas coast to southeast Louisiana. 
Flash, urban, and minor river flooding is likely. Rainfall will also 
spread northward into the ArkLaTex region and east into the Lower 
Mississippi Valley and portions of the Southeast through the end of 
the week. Flash, urban, and isolated minor river flooding is 
possible.
 
2. There is the danger of life-threatening storm surge near times of
high tide through Tuesday along portions of the Texas and Louisiana
coasts within the storm surge warning areas. Residents in these
areas should follow advice given by local officials.
 
3. Tropical-storm-force winds will spread westward across the Texas
coast through Tuesday.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  22/0300Z 28.4N  96.3W   40 KT  45 MPH
 12H  22/1200Z 28.6N  96.3W   35 KT  40 MPH...INLAND
 24H  23/0000Z 28.8N  96.0W   35 KT  40 MPH...INLAND
 36H  23/1200Z 29.1N  95.0W   30 KT  35 MPH...OVER WATER
 48H  24/0000Z 29.5N  93.8W   30 KT  35 MPH...OVER WATER
 60H  24/1200Z 30.4N  92.3W   25 KT  30 MPH...INLAND
 72H  25/0000Z 31.7N  90.7W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  26/0000Z...DISSIPATED
 
$$
Forecaster Brown
 
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