000
FXUS64 KBRO 132352 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
652 PM CDT Tue Apr 13 2021

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

&&

.AVIATION...The daytime heating and low level mixing is resulting
in VFR conditions across the RGV airports. However, this will
likely be pretty short lived as low level moisture advecting in
from the Gulf of Mex will likely produce another round of low
clds/IFR conditions after sunset through Wed morning. In addition,
short term model guidance is indicating that some of the marine
fog may advect/spread inland mainly impacting the BRO/HRL airports
overnight. As the surface winds shift around from the S-SE after
sunrise tomorrow, expect enough low level mixing to occur to allow
a return of VFR conditions. The better conv chcs will likely
remain confined to the north of RGV airports over the northern
Ranchlands. So will not mention any conv for the 00Z RGV TAFS.

&&

.PREV DISCUSSION... /issued 255 PM CDT Tue Apr 13 2021/

SHORT TERM (Now through Wednesday Night): Nearly-zonal mid level
flow will continue over the area while a cold front drifts very
slowly southward across southern Texas. Some light showers have
occurred today as a result of some warm air advection and slight
surface convergence providing just enough lift. Surface moisture
will continue to increase as a result of prolonged onshore flow
which will lead to fog yet again overnight and tomorrow morning in
coastal areas as well as eastern portions of the inland CWA.
Temperatures will remain slightly above normal through the short
term as persistent lower level clouds keep diurnal temperature
variations relatively small. Chances for showers can be expected
again on Wednesday as the front slowly approaches the CWA leading
to additional surface convergence and warm air advection. Highs
tomorrow will be fairly similar to today, ranging from the middle
to upper 80s in eastern areas to the middle 90s out west. The
immediate coast will also remain similar with highs in the upper
70s to near 80 tomorrow.

LONG TERM (Thursday through Tuesday): A stalled frontal boundary
will lie across the area on Thursday, under a zonal flow aloft.
As the front edges south, conditions appear slightly drier now on
Friday than before, and rain chances were lowered slightly from
the previous forecast. Saturday, especially Saturday morning,
still looks promising for a half inch of rain in light to moderate
showers as a surge of high pressure undercuts the zonal flow
aloft. Both long term models do keep rain chances going into at
least Sunday and likely into Monday under overcast skies, waiting
for a mid level short wave trough to clear the area before drier
conditions return on Tuesday. The GFS is still cooler than the
ECWMF Saturday through Monday by around 5 or a bit more degrees,
but the two models seem to be converging. Continued to use a blend
for temperatures through the period.

MARINE:
Now through Wednesday Night: TABS Buoys continue to indicate a
low sea state occurring over the lower Texas coastal waters. Aside
from patchy marine fog later this evening and Wednesday night as
well, marine conditions are expected to remain generally favorable
through the short term. The slowly approaching cold front will
help maintain light to moderate southeast winds across the waters
along with relatively low wave heights. A few showers will also be
possible as the front approaches but no significant convection is
expected at this time.

Thursday through Sunday Night...Light to moderate east to
southeast winds and low to moderate seas will prevail from
Thursday through early Saturday. A surge of high pressure will
arrive on Saturday, with moderate to strong northeast winds and
elevated seas through Sunday night. Small craft exercise caution
conditions will develop on the Laguna Madre, with small craft
advisory conditions coming about on the Gulf due to high seas.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  73  89  74  85 /  10  20  10  10
BROWNSVILLE          74  90  76  89 /  10  20  10  10
HARLINGEN            74  94  75  91 /  10  20  10  10
MCALLEN              75  95  76  93 /  10  20  10  10
RIO GRANDE CITY      74  97  75  96 /  10  20  10  20
SOUTH PADRE ISLAND   73  80  73  77 /  10  20  10  10

&&

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

$$

This product is also available on the web at:
HTTP://WEATHER.GOV/RGV

Short Term/Aviation...60-Speece
Long Term/Upper Air...68-McGinnis/52-Goldsmith