310 
FXUS64 KBRO 290930
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
330 AM CST Sat Feb 29 2020

.SHORT TERM (Now through Sunday): Wind will increasingly be the 
concern in this portion of the forecast. Surface high pressure over 
the northwest Gulf of Mexico will shift east as low pressure drops 
into the Central Plains. The increasing interaction between these 
two systems will produce breezy winds today and windy conditions 
tomorrow. As a result, a Wind Advisory may be needed for the three 
coastal counties of the BRO CWFA on Sunday. Meanwhile, a nearly 
zonal 500 mb flow over Deep South Texas and the Rio Grande Valley 
will produce dry weather with limited cloud cover during the 
weekend, while the aforementioned high pressure system maintains an 
onshore flow that will rocket daytime high temperatures into well 
above normal levels. 

.LONG TERM (Sunday Night through Friday): As the mid-level ridge, 
along with the surface high pressure, shift off to the east, Deep 
South Texas and the Rio Grande Valley will be under the influence of 
a nearly zonal flow aloft and strengthening southerly winds at the 
surface at the start of the long term. This pattern will allow for a 
warming trend to continue through Tuesday with increasing low-level 
moisture in advance of the next weak cold front expected sometime 
Tuesday afternoon into early Wednesday. 

Even though modest timing discrepancies between models for the 
frontal passage continue with the new model runs, there is still 
good agreement on the trend for strengthening southerly winds 
heading into early next week and strong north-northwesterly winds 
behind the front late Tuesday into Wednesday. The timing and 
strength of these stronger winds will need to be adjusted as models 
come into better agreement with future runs. With modest low level 
moisture moving into the region ahead of the front, there is a 
slight chance that some showers could develop due to isentropic lift 
along the leading edge of the front Tuesday night in the northern 
ranchlands, and there could be enough instability to produce some 
embedded thunderstorms within these showers. The biggest impact of 
this front will likely not be a dramatic drop in temperatures, but 
rather the very dry air and the moderate to strong northerly winds 
it brings into the region, increasing fire weather concerns on 
Wednesday.

Beyond the frontal passage mid-week next week, model solutions 
continue to diverge, but overall, surface high pressure and mid-
level ridging behind this system will allow subsidence to take over 
with mostly sunny to partly cloudy skies and near normal 
temperatures expected through the end of the workweek and into next 
weekend.

&&

.MARINE: 
Now through Sunday...Buoy 42020 reported south winds around 14 
knots gusting to around 16 knots with seas slightly under 1.5 feet
with a period of 3 seconds at 250 CST/850 UTC. Increasingly 
adverse marine conditions are expected along the Lower Texas Coast
with high pressure over the Gulf of Mexico interacting with low 
pressure over the Central Plains. A Small Craft Advisory will be 
in effect for the Laguna Madre and Gulf of Mexico waters today 
and/or tonight, with additional Advisories likely for Sunday. 

Sunday Night through Friday...Marine conditions are expected to 
remain hazardous through mid week due to strong winds and elevated
seas. The first part of the week will experience moderate to 
strong southerly winds as the pressure gradient increases between 
high pressure over the Gulf and low pressure developing to our 
west over the southwestern plains and northeastern Mexico. There 
may be a brief lull in the winds, but not sufficient to allow seas
to recover before strong north-northwesterly winds move in behind
a cold front late Tuesday into Wednesday. Winds and seas will 
gradually improve to more favorable conditions by Thursday as high
pressure once again settles overhead. 

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  75  63  79  67 /   0   0   0   0 
BROWNSVILLE          76  63  80  67 /   0   0   0   0 
HARLINGEN            78  60  83  66 /   0   0   0   0 
MCALLEN              78  62  85  66 /   0   0   0   0 
RIO GRANDE CITY      81  58  88  63 /   0   0   0   0 
SOUTH PADRE ISLAND   71  65  73  68 /   0   0   0   0 

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Advisory from 1 PM this afternoon to 4 AM CST Sunday 
     for GMZ130-132-135.

     Small Craft Advisory from 6 PM this evening to 6 AM CST Sunday 
     for GMZ150-155-170-175.

&&

$$

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

Short Term...66/Tomaselli
Long Term...69/Farris
Upper Air...63/Caceres