Special Weather Statement, NWS Houston/Galveston, TX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
742 PM CDT Thu Apr 8 2021

.DISCUSSION...

Updated to add a chc of thunderstorms for NW areas for the next 3
hours as a severe thunderstorm in central Texas moves southeast
toward the area. With the loss of heating, the storm could weaken
as it approaches Brazos/Madison counties between 830 and 930 PM.

Wood

&&

.PREV DISCUSSION... /ISSUED 636 PM CDT Thu Apr 8 2021/

AVIATION [00Z TAF Issuance]...

VFR conditions will continue through the evening across the area.
Patchy fog and low ceilings will again becoming an issue tonight.
CIGs will be between 1500-2500ft with occasional drops to 700ft
starting at midnight and lasting through the midmorning. Fog
tonight will much more isolated than last night due to the warmer
ground (temperatures this afternoon got into the upper 80s which
may have allowed the ground to absorb enough heat to keep
the near surface air from saturating enough for fog development).
Did keep the mention fog in at CXO, LBX, SGR, and GLS as the
potential is still there. CIGs will gradually improve through the
morning with VFR conditions expected HOU northward. LBX and GLS
may deal with 2500-3500 CIGs through the entire day. Cloud cover
returns tomorrow evening as a cold front approaches from the
northwest.

Fowler

PREV DISCUSSION /Issued 333 PM CDT Thu Apr 8 2021/...

SHORT TERM [Tonight Through Friday Night]...

Onshore winds are returning to the area today, and this is helping to
boost temperatures into the low to mid 80s. Could see values go up a
couple more degrees before the area starts to cool down this evening.
There will not be much of a cool down overnight as the south winds actually
begin to strengthen in response to a tightening pressure gradient. Deepening
moisture with this flow will result in increasing cloud cover this evening
and overnight, and temperatures should only fall into the mid to upper
60s. We are seeing some models that have showers/thunderstorms edging
close to Houston County overnight, and we'll keep an eye on how this
all unfolds. Forecast confidence/uncertainty increases significantly
Friday through Friday night regarding area rain chances and the potential
for strong/severe thunderstorm development. We are seeing a variety
of different model solutions, some of which are showing possible late
afternoon, evening and overnight activity moving across the area and
some of which are showing little to no development at all. If the cap
breaks, the wetter and more active solutions could pan out with the
potential for strong/severe storms per SPC's Day 2 Severe Weather Outlook.
If the cap holds, the little or no development solutions will win. For
now, will continue to keep shower and thunderstorm chances in the forecast
with the higher numbers Friday evening through Friday night. A lot of
uncertainty exists in the potential, timing and location of the possible
storms, and it is recommended people pay close attention to the forecast/
discussions/radar on Friday and Friday night to see how this all unfolds.

42

LONG TERM [Saturday Through Thursday]...

Will continue to carry some low POPs in for Sat morning as the main
cold front finally moves across the FA (mainly E/SE locations). High
pressure building in behind the boundary will clear skies and bring
a cooler/drier air mass into the region by the afternoon. And given
that this rather progressive pattern of late will be continuing, we
will see this surface high pressure move out quickly Sat night with
light E/SE winds returning by Sun. High temperatures on Sat will be
in the upper 70s to lower 80s...then warming into the lower/mid 80s
on Sun. Lows Sat night are forecast to range from around 50 for the
far northern counties to the upper 50s/low 60s at the coast.

Per extended global models, next week looks to be a somewhat unsett-
led one. A persistent E/SE at the lower levels along with a stalled
boundary (warm front?) lingering over the area and a series of weak
upper level shortwaves moving in from the west will keep at least a
low chance of POPs in for Mon through Thur. Progged PWs from 1.5 to
1.7" do seem to support this possible activity for much of the CWA.
(PWs even approaching 1.8-2" over the Gulf waters!) These increased
rain chances/clouds should help to keep high temperatures in the up-
per 70s and lower 80s for this timeframe...with lows slightly above
normals in the mid to upper 60s. 41

MARINE...

South winds will return to the area today and tonight and then strengthen
on Friday and Friday night. Caution or advisory flags might be needed
for the strengthening winds and associated building seas. The onshore
flow along with a potential for fog will persist until a cold front
pushes through late Friday night or early Saturday morning. There could
be some showers and thunderstorms too before or with the passage of
the front. A mainly easterly flow can be expected for the first half
of next week.  42

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)      66  89  61  79  51 /  30  20  20   0   0
Houston (IAH)              68  86  67  81  57 /  10  10  30  10   0
Galveston (GLS)            68  78  69  81  65 /  10  10  30  20   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

Discussion...33

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
903 PM CDT THU APR 8 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0850 PM     HAIL             2 SSW LAKE BRYAN        30.70N 96.49W
04/08/2021  M1.25 INCH       BRAZOS             TX   TRAINED SPOTTER

&&

JPF

Special Weather Statement
National Weather Service Houston/Galveston TX
946 PM CDT Thu Apr 8 2021

TXZ196-198-199-212-090330-
Brazos TX-Grimes TX-Waller TX-Montgomery TX-
946 PM CDT Thu Apr 8 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN GRIMES...EASTERN
BRAZOS...WEST CENTRAL MONTGOMERY AND NORTHEASTERN WALLER COUNTIES
UNTIL 1030 PM CDT...

At 945 PM CDT, Doppler radar was tracking a strong thunderstorm over
Anderson, or 8 miles northeast of Navasota, moving southeast at 35
mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Navasota, Montgomery, Millican, Anderson, Todd Mission,
Plantersville, Dobbin and Dacus.

LAT...LON 3050 9622 3060 9603 3041 9560 3019 9586
TIME...MOT...LOC 0245Z 302DEG 29KT 3049 9601