FXUS64 KBRO 210422 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1022 PM CST Wed Jan 20 2021

.DISCUSSION...Updated for latest aviation discussion below.
&&

.AVIATION...Minor adjustments made to the previous suite of TAFs.
Low clouds, light rain, and light fog continue to be anticipated
tonight. Tomorrow, a moderate to breezy onshore flow will create
higher ceilings. A slip into MVFR territory may occur Thursday
evening, especially at MFE, but confidence in this is low.
&&

.PREV DISCUSSION... /issued 532 PM CST Wed Jan 20 2021/

DISCUSSION...Updated for latest aviation discussion below.

AVIATION...Less than ideal aviation conditions are expected
through the overnight hours with low clouds, light rain, and light
fog anticipated. Tomorrow, a re-developing and intensifying
onshore flow will bring warmer air into the region, allowing
ceilings to rise to VFR levels.

PREV DISCUSSION... /issued 246 PM CST Wed Jan 20 2021/

SHORT TERM (Now through Thursday Night): A cold front has worked
its way just west of the immediate coast and lies pretty much along
I-69E. Temperatures are in the 50s to near 60 west of the front and
in the 70s east of the front. Light northwest winds, patches of rain
and drizzle, low clouds and some patchy fog with vsby of 2-5 miles
are being observed west of the frontal boundary. Models suggest the
front remaining stationary or wobbling towards the coastline by
sunrise Thursday before slowly dissipating or moving north Thursday
afternoon. Weak but persistent isentropic upglide overnight and
Thursday morning is expected with warmer 925-850mb southerly winds
overriding the cooler surface condition in response to an upper low
pressure area moving into NW Mexico. Light rain, drizzle, patchy fog
and steady temperatures are expected tonight and Thu morning. As
southerly flow returns and increases Thursday the rain and drizzle
end but plenty of clouds should linger and be slow in lifting and
thinning. Limited sunshine and a delay in the south winds will
likely limit maximum heating so have opted to lower temperatures
below consensus keeping them in the low 70s. Benign weather
continues into Thursday night with mostly cloudy skies, some patchy
fog and mild temperatures in the 60s.

LONG TERM (Friday through Wednesday): Whatever is left of the
Baja Low ejects eastward across Texas on Friday as high pressure
drops out of Central Canada and sends an associated surface front
stalling into Central Texas on Saturday. As a series of 500mb
shortwaves dive south along the Pacific coast, mid level ridging
builds again across Texas late this weekend into next week,
keeping warm southwesterly flow aloft in place through the rest of
the long term. The stalling surface front lifts north as a warm
front on Sunday with breezy to windy conditions along the lower
Texas coast. A coastal trough of low pressure develops across Deep
South Texas Sunday into Monday as a surface low out of
northeastern Mexico drags the next cold front toward the coast on
Monday. The coastal trough and any stalled or leftover frontal
boundaries keep things somewhat unsettled into Wednesday.

The chance of rain remains limited through the long term, with
total QPF amounts into next week remaining below a tenth of an
inch. The best chances of rain remain Saturday afternoon into
Sunday, mainly near the coast, and again on Wednesday near the
coast. Temperatures remain warmer than normal through the period,
potentially 12 to 15 degrees above normal on Sunday. With the
abundance of low level moisture, and light to calm winds, expect
patchy fog again Friday morning, and potentially Saturday morning
too.

MARINE (Now through Thursday night): A stationary front along the
lower and middle Texas coast has weakened the pressure gradient
across the Western Gulf. Light southerly winds and a modest to
slight sea are expected through Thursday morning. The front
dissipates Thursday afternoon with high pressure building over
the eastern Gulf of Mexico. The pressure gradient to gradually
strengthen overnight Thursday as the ridge combines with lowering
pressure over West Texas. Exercise caution conditions may be
warranted over the outer offshore coastal waters after midnight
Thursday.

Friday through Wednesday: High pressure works east across the Gulf
of Mexico through the weekend as coastal low pressure develops
along the lower Texas coast into early next week. The pressure
gradient strengthens on Sunday, building southerly winds and seas
into Monday before a cold front brings a northerly wind shift and
improving seas late Monday through Tuesday. Small Craft Advisories
are likely by Sunday night through Monday afternoon and may be
needed across the bay Sunday afternoon due to winds. Patchy fog is
possible Friday morning, and potentially Saturday morning as well,
across the Laguna Madre and coastal Gulf waters.
&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  65  73  63  77 /  20  20  10  20
BROWNSVILLE          65  75  67  80 /  30  20  10  20
HARLINGEN            60  73  64  80 /  30  20  10  10
MCALLEN              59  74  64  81 /  20  20   0  10
RIO GRANDE CITY      55  74  61  83 /  20  10  10   0
SOUTH PADRE ISLAND   67  70  68  72 /  20  20  10  20
&&

.BRO WATCHES/WARNINGS/ADVISORIES...None.
&&

$$

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