Tornado Warning 14, NWS Houston/Galveston, TX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
702 PM CDT Mon Mar 21 2022

.AVIATION [00Z TAF Issuance]...

Widespread showers will continue to move quickly (from south to
north) with the help of the deep onshore flow that has been pre-
sent over the area today. These 40 to 60kt winds just above the
surface are expected to persist a little longer and so too will
the 30 to 35kt gusts this evening. CIGS are going to remain at/
around MVFR/IFR. Otherwise, a line of strong to severe thunder-
storms moving in from the W could make it into the CLL terminal
in the next couple of hours before slowly sagging E/SE and then
stalling by midnight. This scenario could keep TS in place over
the Houston metro for several hours before the main front moves
into the CWA from the west. Expect other severe weather hazards
with these storms during the overnight hours such as hail, very
heavy downpours, strong damaging wind, lightning and possibly a
few isolated tornadoes. Current timing has the front moving off
the coast/east of the area by 13-15Z. 41

&&

.PREV DISCUSSION... /ISSUED 355 PM CDT Mon Mar 21 2022/

SHORT TERM [Tonight Through Tuesday Night]...

Southeast Texas is still on track for severe weather this evening
and through the overnight hours as a potent cold front pushes
through our area. A strong 55-65 kt low level jet has increased
our local dewpoints rapidly and into the low 70s. Some of these
winds have been mixing down to the surface with areas across
Southeast Texas seeing gusts over 35kts. Therefore, our CWA
remains under a Wind Advisory until 10PM this evening. A recent
18Z sounding from Texas A&M showed impressive low level shear from
this jet with 0-1 km SRH over 500 and 0-3km SRH over 700. There
appears to be a little CIN remaining at 700 mb, but that should
continue to erode over the next few hours as temps/moisture
continue to climb. Hi res models are still showing discrete
supercells forming out ahead of the front at around sunset for our
northwestern counties. Therefore, a tornado watch is in effect
until 10PM for these areas. By midnight, the convective mode will
transition into a more linear pattern as these storms organize in
a line roughly stretching from Trinity County to Jackson County
and filling in across the Brazos Valley.

Severe weather hazards off all types are possible throughout the
evening and through the overnight hours which include hail,
damaging winds, frequent lightning, tornadoes, and flooding. Once
these storms transition into a linear convective mode, the risk
for flooding increases for areas north of I-10 and east of College
Station as training storms could develop. With PWs sampled near
the 90th percentile for this time of year and diffluence aloft,
heavy rainfall amounts of 2-4 inches are possible for these areas
and up to 2 inches can be expected elsewhere. Keep in mind that
isolated higher amounts are still possible should storms continue
to move over the same area. This line of storms will slowly drift
to the southeast from midnight and onwards until it reaches
Liberty/Chambers county a few hours before sunrise. This front
will continue to push out of the area by mid morning and be out of
our CWA by early afternoon.

Southeast Texas should remain weather aware throughout the night.
Make sure you have a safety plan in place and have multiple ways
to receive warnings.

By tomorrow afternoon, high pressure will begin to quickly fill in
behind the front, leading to mostly clear skies, highs in the low
to mid 70s and lows in the 40s.

Lenninger

LONG TERM [Wednesday Through Sunday]...

Very pleasant and benign weather. Upper level troughing over and to
the east with the departing storm system will bring drying and
relatively mild early Spring weather. Dewpoints will be falling and
afternoon temperatures Wed-Sun will be bouncing around in the 68-76
degree range for the most part. A reinforcing weak cold front
arrives Friday night or Saturday morning...keeping the weather dry
and mild. On Sunday high pressure slides away to the east into the
Gulf and southerly flow begins to establish and strengthen
ultimately tapping into some increasing moisture Sunday night.

45

MARINE...

Unsettled weather to start off with...Gale warning continues this
evening for the 20-60nm waters and have dropped it at 6 pm for the
bays and nearshore waters replaced with an SCA. The onshore flow
will continue until the above much discussed cold front pushes into
the coastal waters around sunrise and then through the coastal
waters before or by noon. Seas have built to 8-9 feet already and
with the strong WAA should continue to build this evening. Platform
level winds well out in the Western Gulf are showing 30-35kt winds
with higher gusts so expect those associated waves to overspread the
region tonight. Seas may reach 10-12 feet well offshore and 8-9 in
the nearshore before winds relax near the front. Rough conditions
will persist across the UTCW well into Tuesday as seas will be very
slow to diminish. NW flow in the wake of the front in the 10-20 knot
range should continue into Tue evening. Beyond that into Wed winds
diminishing as well as seas.

Tide levels are high and will continue to be high through Tuesday
morning which will amplify the tidal currents and combined with the
strong winds/large swells/wind waves will continue the rip dangers
overnight and then gradually improving Tuesday during the day.

Strong to severe thunderstorms will be possible with this cold
frontal passage with wind gusts in excess of 40 knots, hail, and
even a waterspout as the band of storms along the front pushes
through.

45

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)      61  68  42  66  41 /  90  20   0   0   0
Houston (IAH)              65  74  45  67  46 /  90  80   0   0   0
Galveston (GLS)            66  73  51  65  55 /  50  70   0   0   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Wind Advisory until 10 PM CDT this evening for the following
     zones: Austin...Bolivar Peninsula...Brazoria Islands...
     Brazos...Burleson...Chambers...Coastal Brazoria...Coastal
     Galveston...Coastal Harris...Coastal Jackson...Coastal
     Matagorda...Colorado...Fort Bend...Galveston Island...
     Grimes...Houston...Inland Brazoria...Inland Galveston...
     Inland Harris...Inland Jackson...Inland Matagorda...
     Madison...Matagorda Islands...Montgomery...Northern
     Liberty...Polk...San Jacinto...Southern Liberty...Trinity...
     Walker...Waller...Washington...Wharton.

     Flood Watch through Tuesday morning for the following zones:
     Coastal Harris...Grimes...Houston...Inland Harris...
     Madison...Montgomery...Northern Liberty...Polk...San
     Jacinto...Southern Liberty...Trinity...Walker...Waller.

     High Rip Current Risk through Tuesday afternoon for the
     following zones: Bolivar Peninsula...Brazoria Islands...
     Galveston Island...Matagorda Islands.

     Coastal Flood Advisory until 1 PM CDT Tuesday for the following
     zones: Bolivar Peninsula...Brazoria Islands...Galveston
     Island...Matagorda Islands.

GM...Small Craft Advisory until 11 PM CDT this evening for the
     following zones: Galveston Bay...Matagorda Bay.

     Small Craft Advisory until 1 PM CDT Tuesday for the following
     zones: Coastal waters from Freeport to Matagorda Ship
     Channel TX out 20 NM...Coastal waters from High Island to
     Freeport TX out 20 NM.

     Small Craft Advisory from 11 PM this evening to 1 PM CDT Tuesday
     for the following zones: Waters from Freeport to Matagorda
     Ship Channel TX from 20 to 60 NM...Waters from High Island
     to Freeport TX from 20 to 60 NM.

     Gale Warning until 11 PM CDT this evening for the following
     zones: Waters from Freeport to Matagorda Ship Channel TX
     from 20 to 60 NM...Waters from High Island to Freeport TX
     from 20 to 60 NM.

&&