Area forecast discussion
National Weather Service Houston/Galveston Texas
1149 PM CDT Monday may 20 2013
Aviation...
expecting mainly MVFR ceilings across the area overnight. Anticipate
ceilings to lift and break tomorrow around middle morning. Continuing
to lean toward the high res models for tomorrow evening's line of
strong/severe thunderstorms and rain that are expected to move into the area. 42
&&
Previous discussion... /issued 350 PM CDT Monday may 20 2013/
Discussion...
with the upper low situated over the ND...SD...and Minnesota border...a
westerly flow aloft was present over southeast Texas this afternoon. As the
main upper low meanders over the upper plains...a strong upper
trough will push across the Southern Plains Tuesday and Tuesday
night with the trough then shearing out over la and eastern Texas on
Wednesday. An upper level ridge will then build over the eastern
part of the state Thursday through Saturday. A more northwesterly
flow then is forecast to develop early next week.
The main forecast problem for the middle week period will be the
impact of the upper trough on Tuesday and Wednesday. The models
have come into more of a consensus and the best chances for
showers and thunderstorms will be Tuesday afternoon and night. The
best rain chances will be over the northern half of the forecast
area...while the best time frame for isolated strong to severe
storms now appears to be Tuesday afternoon and evening over the
northern quarter of the forecast area. Kept the rain chances in
place through Wednesday afternoon due to the lingering shortwave
trough overhead.
A return to daytime high temperatures to around 90 or the lower
90s is likely for the last part of the week through the weekend as
the high pressure ridge builds overhead. Slightly adjusted a
couple of days but the current forecast looked good temperature
wise.
Marine...
moderate (occasionally strong) onshore winds prognosticated to persist the
next couple of days given the tightened pressure gradient (in response-
onse to the strong upper low spinning over the central plains). Not
going to change the scec configuration currently in place. Winds to
decrease over the marine areas Wednesday night as the storm system moves
off to the east and high pressure settles over the region. 41
&&
Preliminary point temps/pops...
College Station (cll) 74 90 73 89 72 / 10 30 40 30 10
Houston (iah) 75 90 73 88 72 / 10 20 30 30 10
Galveston (gls) 76 80 75 81 75 / 10 10 20 20 10
&&
Hgx watches/warnings/advisories...
Texas...none.
GM...small craft should exercise caution until 7 am CDT Tuesday for
the following zones: waters from Freeport to the Matagorda
Ship Channel 20 nm to 60 nm...waters from Freeport to the
Matagorda Ship Channel out 20 nm...waters from High Island
to Freeport 20 to 60 nm...waters from High Island to
Freeport out 20 nm.
&&
$$
Discussion...38
aviation/marine...42
