Red Flag Warning 4, NWS Brownsville, TX

677 
WWUS84 KBRO 082213
RFWBRO

URGENT - FIRE WEATHER MESSAGE
National Weather Service Brownsville TX
413 PM CST Fri Mar 8 2024

...AN ELEVATED FIRE WEATHER THREAT CONTINUES THIS AFTERNOON...

.In the wake of a dry line passage, conditions remain favorable
for enhanced wildfire growth and spread. 

TXZ248>250-252-253-353-082315-
/O.EXP.KBRO.FW.W.0004.000000T0000Z-240308T2200Z/
Zapata-Jim Hogg-Brooks-Starr-Southern Hidalgo-Northern Hidalgo-
413 PM CST Fri Mar 8 2024

...RED FLAG WARNING HAS EXPIRED FOR FOR THE COMBINATION OF LOW HUMIDITY, STRONG NORTHWEST 
WINDS, AND DRYING FUELS FOR ZAPATA, STARR, JIM HOGG, BROOKS AND
HIDALGO COUNTIES...

The red flag warning has been allowed to expire. Nonetheless,
conditions will remain favorable for enhanced wildfire growth and
spread for a few more hours this afternoon.

$$

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1037 PM CST Thu Mar 7 2024

...New AVIATION...

.SHORT TERM...
(Tonight through Friday night)
Issued at 236 PM CST Thu Mar 7 2024

At upper levels, a troughing pattern has settled over the region and
will continue to support extensive cloud cover overnight. At the
surface, elevated southeast winds this evening, especially near the
coast, will diminish to a light south-southwesterly breeze across
the Rio Grande Valley (RGV) with minimum temperatures ranging from
the upper 60s to the north and low 70s to the south. Some fog is
possible tomorrow morning, but will be short lived as the winds
enhance.

Throughout the morning tomorrow, winds will turn from the west and
then from the north beginning in the Rio Grande Plains and reaching
the coast by noon as the pre-frontal trough/cold front passes from
west to east across the RGV. Behind the front, a dry air mass will
be ushered in and clouds will decrease steadily from west to east,
relative humidity (RH) values will drop rapidly and wind speeds will
become enhanced across the whole area, but will be most notable west
of the Interstate 69 corridor, where RH values of 25% or less and
sustained winds of at least 15 mph, with gusts to 25 mph (or higher)
are expected. This combination of low RH values and winds is a
recipe for spreading wild fires for tomorrow across the RGV. See the
Fire Weather Discussion for more details.

Although a drier air mass will settle across the region,
temperatures will still remain above average with day time highs
reaching into the mid-to-upper 80s across the RGV with some
locations nearing 90 and upper 70s near the coast. Going into Friday
evening, clouds will build again and winds will subside to a light
northerly breeze for most of the night, but begin to pick up closer
to sunrise, beginning in the northern counties of the RGV as a
secondary cold front arrives tomorrow night. Friday night lows will
range from the low-to-mid 50s for much of the region with low 60s
for the lower RGV and near the coast.

&&

.LONG TERM...
(Saturday through next Thursday)
Issued at 236 PM CST Thu Mar 7 2024

The start of the long term forecast period will see the after
effects of the cold front passage. Breezy northerly winds at the
surface are expected to last through the weekend, and then a return
to onshore flow is expected to occur during the day on Monday. Once
the onshore flow returns, the winds are expected to be generally out
of the south for the rest of the long term forecast period. The
onshore flow will bring in some low level moisture to Deep South
Texas and the Rio Grande Valley, however, not expecting any rain to
occur during the period. Meanwhile in the upper levels of the
atmosphere, a series of disturbances will pass to the north of the
region, but will act to maintain a mostly southwesterly flow aloft.
This is will result in more dry air in the mid-levels throughout the
long term period.

As for the temperatures, a fairly consistent warming trend will
occur over the long term forecast period. Starting off with the low
temperatures, Saturday night lows will be in the range of upper 40s
in the Northern Ranchlands to low to mid 50s in in the Lower Rio
Grande Valley. By next Thursday, the low temperatures are expected
to be in the mid to upper 60s for Deep South Texas and the Rio
Grande Valley. On the other hand, the high temperatures, will start
off in the low to mid 70s for the area, then by end of the the
period will have increased to upper 80s and low 90s. With the
hotter temperatures being found in the western half of the CWA.

&&

.AVIATION...
(06Z TAFS)
Issued at 1023 PM CST Thu Mar 7 2024

All sites have dropped to MVFR late this evening. Winds are light
to moderate southeast, but light fog has nonetheless been able to
cut visibility down a bit. Not much change to the previous TAF
thinking, however. Low clouds will thicken and spread ahead of an
approaching upstream cold front. Ceilings may still drop to IFR
at all sites overnight, and will then remain there well into
Friday. There will be an initial punch of dry air from the west
Friday afternoon which may serve to lift ceilings, but coverage
will remain significant. Cooler air from the north will arrive
Friday night, again not helping to clear skies. I don't expect
significant, if any, rain during the TAF period.

&&

.MARINE...
Issued at 236 PM CST Thu Mar 7 2024

Tonight through Friday night...Light to moderate southeasterly winds
will transition to light southerly winds overnight into tomorrow
morning. As a initial cold front arrives to the coast late morning
and continues eastward over the Gulf waters into the afternoon,
winds will shift to westerly and then north-northeasterly by evening
and remain light. By late night, a secondary cold front will enter
the northern coastal waters and continue southward. Northerly winds
will quickly pick up to a fresh to strong breeze with building seas.
Small Craft Advisories are likely to be issued.

Saturday through Next Thursday...Hazardous marine conditions are
expected for the weekend due to elevated winds and seas in the wake
of a cold front moving through the Lower Texas Coast. Small Craft
Advisory will be needed through most of the weekend. Conditions will
start to improve on Sunday and are expected to become favorable by
Sunday night. By Monday, light to moderate onshore with low to
moderate seas will return resulting in favorable conditions
persisting through the rest of the period.

&&

.FIRE WEATHER...
Issued at 236 PM CST Thu Mar 7 2024

Friday...The post frontal environment across the western half of
Deep South Texas Friday will be supportive of rapid fire growth
and spread. Probabilities have increased medium to high chances
(60- 90%)for the overlap of relative humidity values of 15-25
percent and sustained 20 foot winds 15-20 mph with some gusts as
high as 30 mph to yield a window of heighten wildfire threat.
SPC's Day 2 fire weather outlook indicates elevated risk along the
Rio Grande Plains and spreading into the Upper and Mid Rio Grande
Valley. A Fire weather watch has been issued for areas along and
west of the Interstate Highway 69C corridor from 11 AM to 4 PM
Friday covering this increased fire threat. Relative humidity
remains low after 4 PM with limited recovery Friday night while
winds to steadily relax.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             81  72  87  62 /   0   0   0   0
HARLINGEN               84  69  89  58 /   0   0   0   0
MCALLEN                 88  71  89  58 /   0   0   0   0
RIO GRANDE CITY         90  68  88  56 /   0   0   0   0
SOUTH PADRE ISLAND      74  69  76  60 /   0   0   0   0
BAYVIEW/PORT ISABEL     81  69  84  59 /  10   0   0   0

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Fire Weather Watch from Friday morning through Friday afternoon
     for TXZ248>250-252-253-353.

GM...None.
&&

SHORT TERM...54-BHM
LONG TERM....56-Hallman
AVIATION...54-BHM