NWS Brownsville, TX wrote its last area forecast discussion before the first event at Jan 8, 12:04 PM CST, 33 minutes earlier.
Area forecast discussion, Jan 8, 12:04 PM CST, 33 minutes before
Area Forecast Discussion
National Weather Service Brownsville TX
1204 PM CST Mon Jan 8 2024
...New UPDATE, AVIATION, MARINE, FIRE WEATHER...
.UPDATE...
Issued at 1149 AM CST Mon Jan 8 2024
While the wind advisory was removed earlier this morning for the
IH-69C corridor of Brooks/Hidalgo a bit east into Kenedy, it was
retained across the lower Valley and now extended until 2 PM as
daytime heating and the last vestiges of the 50 knot jet are
combining to tighten the gradient...which has caused speeds to
increase to 30 to 37 mph with gusts exceeding 50 mph at Harlingen,
Brownsville over to the west side of Laguna Madre. At the edge of
High Wind Warning with a peak gust of 63 mph at Brownsville/South
Padre and gusts in the lower 50s at Harlingen and Bayview/Cameron
County Airport.
Expect breezy to windy conditions to continue after the advisory
expires but at more reasonable speeds as the LLJ continues to
progress eastward.
Decisions on a second wind advisory mainly for the Brush
Country/Rio Grande Plains will be considered soon.
&&
.SHORT TERM...
(Today through Tuesday)
Issued at 255 AM CST Mon Jan 8 2024
The main concern in this portion of the total forecast remains
wind. The most recent surface analysis indicated low pressure
along the Texas/New Mexico border, with a cold front, warm front,
and dryline all extended from that feature. The interaction
between this system and high pressure over the Gulf of Mexico will
create strong winds within Deep South Texas and the Rio Grande
Valley today, and a Wind Advisory remains in effect for the five
easternmost counties from a few hours before dawn this morning
until midday. Based on inherited wind grids, the timing of the end
of the Wind Advisory appears appropriate, so will allow the
successive shift to extend the Advisory a few more hours into this
afternoon, if needed. Inherited wind grids also suggest the
possible need for another Wind Advisory tonight, but in order to
prevent confusing wording with one Advisory ending and another
starting, and to give more time for new model analysis, will also
punt this decision to the successive shift.
Additionally, with seas elevated due to the approach and passage of
the aforementioned cold front, have extended the High Risk of rip
currents at the local beaches until sunset Tuesday.
&&
.LONG TERM...
(Tuesday night through Sunday)
Issued at 255 AM CST Mon Jan 8 2024
Improved conditions are expected to start out for the long term
forecast period on Tuesday night. Surface winds are expected to be
lighter and turn towards the south over the course of Tuesday night
into Wednesday. This will allow for a slight warming trend to occur
over the next several days into Friday, which will be the day that
the next cold front will push through Deep South Texas and the Rio
Grande Valley. More on that cold front later on. While the southerly
winds are expected to pick up slightly on Wednesday, they will not
be as strong as the winds that are impacting the area today.
Meanwhile, zonal flow will be in place in the upper levels of the
atmosphere and surface high pressure will be in the Gulf of Mexico
to help give the region some pleasant weather for the next couple of
days.
However, getting into Friday, a mid-level trough will swing by and
with it the next cold front that will impact the area. Current model
analysis has this cold front lack any form of precipitation with it.
But, this cold front will bring some cooler and drier air to the
region. Expect the surface winds to shift towards the north after
the front passes through. While the winds do not appear to be strong
enough to warrant a Wind Advisory, but combination of them with the
dry air behind the front and there are some concerns for Fire
Weather. More on that in the Fire Weather section of this
discussion. Moving into Saturday, the surface winds will quickly
turn back towards the southeast as center of an area of high
pressure moves into the Central Gulf Coast. Resulting in a pleasant
weekend with mostly clear skies.
As for the temperatures, starting with the low temperatures. Tuesday
night, lows are expected to be in the 40s. However, there will be a
slight warming of the low temperatures for Wednesday and Thursday
night with lows in the 50s mostly for both nights. Friday night low
temperatures will be cooler thanks to the cold front that will have
passed through that day, as such the lows are expected to be in the
40s. The low temperatures for Saturday night are not expected to
warm up by much with most of Deep South Texas and the Rio Grande
Valley will still be in the 40s, but parts of the Mid to Lower Rio
Grande Vally could be in the 50s. Sunday night lows, will be just a
tad warmer with most of the region in the 50s, but some parts of the
Northern Ranchlands could still be in the upper 40s. Moving on to
the highs, the high temperatures for Wednesday are expected to be in
the 70s. Then for Thursday the highs will warm up to the being
mostly in the lower 80s. Friday highs will cool down thanks to the
cold front with highs in the 70s. Saturday high temperatures will be
even slightly cooler as more of the cold air moves into the region
with highs in the range of upper 60s to low 70s. Finally, on Sunday,
the highs are expected to be in the 70s for Deep South Texas and the
Rio Grand Valley.
&&
.AVIATION...
(18Z TAFS)
Issued at 1149 AM CST Mon Jan 8 2024
Wind is the word for this forecast, with gusts exceeding 35 knots
until 2 PM at Harlingen/Brownsville before dipping back closer to
25 knots as the core of the jet slides farther east. Will update
the AWW until 2 PM to account at both Harlingen and Brownsville.
Winds may lay down briefly between 4 and 7 PM before resurging
from the northwest following the initial front. Following the
front, speeds should be in check as the stronger mix-down doesn't
arrive until later at night...at the same time cold air advection
and some surface stability is in play. Did nudge speeds up a touch
for the midnight/late night period, then dropped back a bit
toward daybreak before raising a bit once again after sunrise and
some warming/better mixing begins.
As for sky cover? Clear/mostly clear through the afternoon with
perhaps a brief period of MVFR ceilings at Brownsville/Harlingen
as the front passes betwee 5 and 7/8 PM. Ceilings could continue
an hour or two post-front before strong dry air advection clears
things out.
&&
.MARINE...
Issued at 1149 AM CST Mon Jan 8 2024
Update: As mentioned yesterday, we're now seeing that brief period
of Gale Force gusts across the lower Laguna Madre and likely
sneaking into the nearshore Gulf waters. With conditions only
expected to last up to three hours in any one location and the
"larger" Gale Warning now in effect beginning soon after sunset,
will handle with a marine weather statement through 4 PM.
Otherwise, the more widespread Gale force gusts from the northwest
should kick in this evening. Latest model guidance suggests a
delay perhaps until after 9 PM...but did not want to get to
specific at this point.
Prior discussion:
Today through Tuesday...A Small Craft Advisory remains in effect
for the Laguna Madre and Gulf of Mexico waters from 0 to 60
nautical miles offshore. Once the Advisory ends around sunset this
evening, a Gale Watch will be in effect for the Laguna Madre and
Gulf of Mexico waters from 0 to 60 nautical miles offshore until
around sunset Tuesday. However, inherited wind grids suggest that
Gale conditions might not actually commence along the Lower Texas
Coast until a couple of hours before midnight tonight. Thus, will
leave the Gale Watch in place for now, and allow the successive
shift to assess new model guidance and weather observations to
hone the Small Craft Advisory/Gale Warning threshold.
Tuesday Night through Sunday...Improving marine conditions
are expected for Tuesday night with light to moderate onshore flow
and moderate seas. These conditions are expected to last until early
Friday when the cold front will push through the Lower Texas Coast.
Elevated northerly winds are expected in the wake of this cold front
that will likely require Small Craft Advisory. However conditions
are expected to improve to being favorable in time for the weekend
and should remain that way for the rest of the period.
&&
.FIRE WEATHER...
Issued at 1149 AM CST Mon Jan 8 2024
Update: Still making decision on Red Flag Warning. Latest guidance
in good agreement with previous Watch area with multiple critical
timings with initial plunge of overnight RH and some mix-down of
the 50 knot northwest flow...but more of a "slam dunk" on Tuesday
with combination of wind, (though slightly lower, still critical),
RH in the 15-20 percent range, and forecast "dry" fuel dryness as
well as rapid drying of 10-hour (grass) fuels.
Previous discussion...
Today through Tuesday...A Fire Weather Watch is currently in
effect for all of Deep South Texas and the Rio Grande Valley,
except the island portions of Cameron, Willacy, and Kenedy
counties, from a couple of hours after sunset this evening until
around sunset Tuesday. However, it was noted in a previous
forecast discussion that a Fire Danger Statement would be an
option if conditions fell short of Red Flag Warning criteria in
some areas. Thus, since the Fire Weather Watch initiates after
sunset this evening, will allow the successive shift to consider
observations at the surface related to the passage of the cold
front, and either upgrade the Watch to a Warning, or downgrade it
to a Statement.
Friday...In the wake of the cold front that is expected to
move through Deep South Texas and the Rio Grande Valley. Elevated
northerly winds with 20-foot winds in the range of 15 to 20 knots
with some higher gusts and dry air will surge into the region. With
the minimum relative humidity in the upper teens for the western
half of the CWA and the lower 20s for the eastern half. This will
more than likely need a Fire Danger Statement issued and possible a
Fire Weather Watch.
&&
.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE 81 52 67 47 / 10 20 0 0
HARLINGEN 85 47 67 42 / 10 20 0 0
MCALLEN 88 49 68 44 / 10 10 0 0
RIO GRANDE CITY 87 50 67 42 / 0 0 0 0
SOUTH PADRE ISLAND 75 55 63 56 / 10 30 0 0
BAYVIEW/PORT ISABEL 81 50 66 47 / 10 30 0 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Fire Weather Watch from 8 PM CST this evening through Tuesday
afternoon for TXZ248>255-351-353>355.
Wind Advisory until 2 PM CST this afternoon for TXZ254-255-354-
355.
High Rip Current Risk through Tuesday afternoon for TXZ451-454-
455.
GM...Small Craft Advisory until 6 PM CST this evening for GMZ130-132-
135-150-155-170-175.
Gale Warning from 6 PM this evening to noon CST Tuesday for
GMZ130-132-135-150-155-170-175.
&&
SHORT TERM/FIRE WEATHER/AVIATION/MARINE Updates...52-Goldsmith