Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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FXUS64 KHGX 250505

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1205 AM CDT Wed Apr 25 2018

Challenging forecast unfolding for the 06Z TAFs where model
guidance has struggled to capture the development of a 25-30 know
low level jet that has developed across the region. Surface
analysis shows the sea breeze has lifted near to just north of
IAH with a weak enough surface pressure gradient in the vicinity
of this feature to produce calm to nearly calm winds at the
terminals near and north of Interstate 10. This, coupled with an
expected decreasing trend in surface winds at the terminals south
of there, has resulted in the addition of LLWS in the TAF as a
result through 08Z and will monitor trends for updates. The veered
nature of the jet raises concerns that MVFR ceilings that develop
near Matagorda Bay overnight per latest trends in the HRRR may
advect near the terminals. Not confident at all in this solution
but have added a FEW020 group to highlight potential for IAH, HOU,
SGR, LBX, and GLS. Elevated low level winds may delay or inhibit
fog development tonight, but brief MVFR visibility drops may be
possible at CXO and LBX. Regional radar mosaic shows outflow
associated with storms over West Central Texas may serve as a
focus for an isolated shower or two early this morning and
potentially a brief northerly wind shift at CLL but have not
included any mention of this in the 06Z TAF due to low confidence.

Expect VFR conditions to prevail at all terminals after 16Z with
winds becoming south to southwest around 5-8 knots ahead of an
approaching cold front. Will have to keep an eye on the remnant
outflow boundary during the morning hours for additional SHRA
development near CLL, but expect the TAF sites to remain dry until
after FROPA Wednesday afternoon and evening. Northerly winds near
10 knots will become established behind the front with a brief
window for a few elevated SHRA possible Wednesday evening before
drier air moves in Wednesday night.



.PREV DISCUSSION... /ISSUED 951 PM CDT Tue Apr 24 2018/

Storms near a Breckenridge/San Angelo line showing a weakening
trend. Abundant high clouds should stream off these and traverse
the northern counties around 1 am through 3 am. Lower level clouds
should develop near PSX/BYY after 3 am with some patchy fog mainly
across the southern counties toward morning. Very minor changes to
the current forecast. Lower end rain chances still look reasonable
for the area Wednesday night/Thursday morning.


College Station (CLL)      60  83  54  76  54 /   0  10  30  10  10
Houston (IAH)              62  85  59  78  56 /   0  10  40  10  10
Galveston (GLS)            67  74  64  76  64 /   0  10  40  10  10




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