OG Fall weather for Thanksgiving.
NWS is now progging even cooler than OG in the long-term Nov/Dec forecast with 30s possible up around College Station.
Area Forecast Discussion
National Weather Service Houston/Galveston TX
553 AM CST Mon Nov 20 2023
...New AVIATION...
.SHORT TERM...
(Today through Tuesday Night)
Issued at 351 AM CST Mon Nov 20 2023
Turbulent weather is anticipated today as an upper level trough
digs eastward through the Plains while an associated surface low
sails across the Red River Valley, dragging a cold front with it.
SE Texas is still progged to be on the peripheral of an embedded
upper level jet streak on Monday, with the front right quadrant
grazing the northern half of our CWA during the afternoon, though
the jet streak itself appears slightly further north in comparison
to previous model runs. A 30-40 knot LLJ is anticipated to set up
over portions of SE Texas ahead of the aforementioned surface
low. Bulk shear across the region ranges from 50-75 knots, with
cloud layer shear in excess of 100kts and 3km SRH ranging from
100-250 m2s2. Instability also appears more potent with the latest
suite of high-res model guidance, with mean ML CAPE exceeding
1000 J/KG, 700-500mb lapse rates near 6.5 deg/KM and ML LCL
heights hovering near 650-1000m. The latest HRRR Depicts MU CAPE
reaching upwards of 1900 J/KG at times, with DCAPE around 1000
J/KG as well. CAMs show convective development as early as 15z,
with discrete cells becoming more clustered during the afternoon
hours ahead of the cold front.
All these ingredients indicate the potential for strong to severe
storms over SE Texas today. SPC currently has portions of the
Brazos Valley and Piney Woods area (near College Station and Lake
Livingston) under a Slight (level 2/5) risk of severe weather
today, with the rest of SE Texas under a Marginal (level 1/5)
risk. For timing, the main threat window for severe weather will
be from the late morning through the early evening. Damaging winds
and large hail remain the primary hazards with these storms,
though isolated tornadoes cannot be ruled out completely. Be sure
to keep a close eye on the weather today and stay tuned for
additional forecast updates.
The aforementioned cold front finally arrives in SE Texas early
this evening, with the severe threat waning as instability
diminishes. The cold front will move offshore overnight, with
cool, dry and breezy conditions setting in thereafter.
Lows for
Monday will range from the upper 40s to upper 50s. Breezy
northerly flow and mostly cloudy skies persist into Tuesday,
limiting highs to the upper 50s to mid 60s. Thinning cloud cover
and robust CAA should bring cold conditions for Tuesday night,
with lows progged for the 40s to lower 50s.
03
&&
.LONG TERM...
(Wednesday through Sunday)
Issued at 351 AM CST Mon Nov 20 2023
Starting on Wednesday, surface high to our west will continue to
bring dry and cooler north to northwest winds into the region. Mid
to high clouds will begin to filter in throughout the day as
different impulses of energy embedded in the flow aloft moves
through. Cloud cover and northerly winds will keep highs mainly
into the upper-50s to low-60s. These impulses of energy aloft are
associated with a cutoff low spinning over TX/northern MX
Wednesday into Thursday before being an upper wave over the
Southeastern CONUS. Forecast confidence beyond this period remains
low to moderate as discrepancies between model runs/solutions
continue. Latest deterministic guidance, now including the NAM,
still differ in the evolution/track and timing of this low over
southeast TX, and therefore any significant impacts. The ECMWF and
most of its ensemble means stay consistent in bringing increasing
rain chances for Thanksgiving Day. However, it is not aligned
well with dynamics and moisture. Forecast soundings continue to
suggest a dry low to mid-layer with PWs generally at or below
0.9". The only higher solution is the deterministic ECWMF, showing
PWs around 1.0" over our coastal counties by early Thursday
morning. These values are below the daily mean for this time of
year. With that being said, and in collaboration with surrounding
offices, will continue with PoPs around 20-30% from Wednesday
night into Thursday afternoon. Overall, expect a partly to mostly
cloudy day for Thanksgiving Day with possibly some light rain,
diminishing in the afternoon.
Drier conditions briefly return into the area Thursday night into
Saturday before the arrival of the next cold front. A deep upper-
level shortwave trough will develop over the Rockies, gradually
dragging a cold front across the Southern Plains late in the
weekend. Kept PoPs as NBM guidance suggests with rain chances from
Saturday night into early next week.
Well-below normal temperatures are expected through the long term
with temperatures around 10 degrees cooler than average. Highs
generally in the 50s and 60s. Overnight lows mainly into the
upper- 30s and upper-40s.
JM
&&