Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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FXUS64 KHGX 171756

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1156 AM CST Fri Nov 17 2017

The main issue starting out onset of higher winds. The MVFR
ceilings had already lifted to VFR and winds were already
starting to increase at 1730Z. Breezy south winds will probably
gust to between 20 and 23 knots through the afternoon.

The next issue will be the timing of lower ceilings developing
tonight. Latest models and guidance are good with the earlier
forecast timing and expect MVFR conditions to redevelop by 07Z at
the far inland locations, 09Z at the Houston metro sites, and 12Z
at KGLS. Some of the guidance and models are suggesting IFR
conditions are possible as well. Southwesterly winds will develop
by around 15Z as the prefrontal trough moves into the area.



.PREV DISCUSSION... /ISSUED 1025 AM CST Fri Nov 17 2017/

Currently, the only reflectivity on radar imagery is the line of
showers located over the eastern coastal waters. These showers
have looked to have formed over a moisture plume evident in the
mid-levels and also over an area with surface speed convergence
which can be seen in the marine observations. This axis of
showers should remain underneath the strong cap at 850 mb seen in
the forecast soundings, and should continue to shift slowly

A deck of stratus clouds are continuing to build in from the
northwest this morning, which will influence our temperatures and
wind speeds today. Short term guidance keeps these mid-level
clouds over the region through late afternoon before the deck
begins to rise, while attempting to scatter out by early this
evening. High temperatures for your Friday are expected to reach
into the low 80s across the region, with upper 70s along the


WAA strengthening this morning with abundant cloud cover/stratus
and little patchy fog but light southerly winds keeping the fog in
check. A warm day with 10-20mph south and southwesterly winds
today. Yesterday`s surface ridging tailing down into the region
has shifted to MS/AL as the Pineapple Express atmospheric river
dumps copious snow/rain over high terrain in CA thanks in large
part to the upper trough swinging through the Pacific Northwest.
This upper trough will race east swinging a cold front through
SETX Saturday afternoon. Rain chances will remain relatively low
with a strong to very strong cap in place over SETX today and
Saturday. As the front reaches the Highway 59 corridor the rain
chances will be improving getting out from underneath the capping
influence. Doubting we see more than 0.10" of rain out of this
system. Gusty northerly flow in the wake of the cold front will
usher in much drier air Saturday night/Sunday. Slightly elevated
fire weather conditions possible Sunday with RH values dipping
into the lower to mid 20 percent range but with winds gradually
dissipating in the morning and by afternoon when the driest
conditions will occur winds should be 10 knots or less.
Temperatures will drop back closer to normal Sunday and hold for a
few days. Ridging moves east and a warm front draws back north
into the area early Tuesday with a deepening upper trough over
SETX/LA/Wrn Gulf through Thanksgiving. GFS/ECMWF have been
differing on this evolution the last few days and are gradually
converging on a solution that brings back rain chances Tuesday and
Tuesday night. Greater rain chances should be over the southern
half of the area and especially over the Gulf waters. Another cold
front sweeps through Tuesday night which should set the stage for
a Thanksgiving that should be dry and cool...okay not technically
cool as temperatures should right about spot on with climatology
for the date...lows in the mid to upper 40s and highs in the
60s...but cool compared to the month of well above normal


Onshore flow will increase today through Saturday ahead of an
approaching cold front with caution to possibly advisory flags
needed tonight as winds and waves build. Expect a thin band of
showers to develop along the cold front as it pushes off the Upper
Texas Coast Saturday night. Strong offshore flow behind the cold
front will warrant Small Craft Advisories through Sunday and gusts
near gale force will be possible Saturday night before the thermal
gradient behind the cold front relaxes. Light offshore flow becomes
established by Sunday night before veering onshore by Tuesday ahead
of the next cold front.



College Station (CLL)      67  79  45  66  40 /  20  20   0   0   0
Houston (IAH)              69  84  48  66  43 /  10  20   0   0   0
Galveston (GLS)            71  80  55  66  54 /  10  30  10   0   0




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