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Area Forecast Discussion (AFD)

Issued by Brownsville/Rio Grande Valley, TX (BRO)

FXUS64 KBRO 162050

Area Forecast Discussion
National Weather Service Brownsville TX
250 PM CST Sat Feb 16 2019

.SHORT TERM (Tonight through Sunday Night):It's been another warm day 
across Deep South Texas, despite surface winds shifting to a more 
easterly component, thanks to 500mb heights at 586 to 587 dam and 
sunny skies. Highs so far have been in the lower to mid 80s in most 
locations. A few cities out west from McAllen to Zapata are expected 
to reach the lower 90s in the next hour or so. Other than 
temperatures, there isn't much to talk about until later this 
evening with the potential for fog once again. A diffuse front is 
located across South Texas, with ENE winds noted across the northern 
ranchlands. Winds should lighten tonight ahead of it, with moisture 
pooling across the CWA, as experienced the past couple nights. 
Models indicate areas of fog with possible dense fog if winds can 
lighten just enough. Once the main push from the front moves through 
the area, northerly winds will pick up and bring much drier air into 
the region. This should clear the fog up later in the morning with 
low clouds possibly persisting a bit longer along the coast and in 
the lower RGV. Rain chances will be fairly low with the front with 
the better chances being across the eastern half of the CWA and 
offshore. By Monday morning, coastal troughing looks likely, with 
better rain chances returning going into the long term.

.LONG TERM (Monday through Saturday):The 12Z model package remains
consistent and in generally good agreement with the overall 
Western U.S positively tilted trough and Southeast ridge
placement. This will allow for a cold front to move through the 
RGV and stall over the Western Gulf just southeast of our coastal 
waters. As has been mentioned in the forecast the last several 
days an unsettled cooler and wetter forecast pattern is 
anticipated for much of next week. Deterministic models are 
however beginning to indicate some differences with timing and 
placement of mid level shortwave troughs flowing through the 
broad mid/upper level southwest flow and the subsequent surface 
features influence by the overall pattern. With this said forecast
confidence on general temperatures and pops is beginning to lower
but will not make any significant changes from the previous forecast
package. GFS is trending warmer and not as wet while the EC is 
the most consistent with a cooler and wetter pattern. Highest rain
chances are anticipated near the coast and Lower RGV while Monday,
Wednesday and Thursday will likely be the coolest days of the
coming week.


.MARINE:(Now through Sunday night): The main issue again will be 
the fog potential, particularly across the nearshore waters, where
water temperatures are relatively cooler than the warmer air 
moving up from the south. Satellite shows an area of low clouds 
and possibly fog just south of the International Border, which may
drop visibilities down at times this afternoon. Confidence is 
higher that fog will fill back in overnight tonight into Sunday 
morning ahead of a weak front, with visibilities possibly dropping
to 1 nautical mile or less at times. Outside of fog potential, 
light winds will shift from the SE to E this afternoon with low to
moderate seas. Small Craft Advisories will be possible behind the
front Sunday evening and night.

Monday through Thursday...Northeast flow becomes well established
by early Monday in wake of a Sunday cold front. Seas to build 
with small craft advisory conditions anticipated offshore. A brief
lull Tuesday with low pressure moving close by or over the 
coastal waters than high pressure to rebuild over Texas  
increasing the northerly flow once again for Wednesday and 
Thursday. Marginal small craft conditons are anticipated at this 


BAYVIEW/PORT ISABEL  67  74  59  65 /  10  30  10  30 
BROWNSVILLE          69  79  59  66 /  10  30  10  30 
HARLINGEN            68  80  58  65 /  10  30  10  30 
MCALLEN              69  81  58  68 /  10  20  10  30 
RIO GRANDE CITY      68  83  56  67 /  10  10  10  10 
SOUTH PADRE ISLAND   65  71  61  65 /  10  30  10  30 




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65...Short term
59...Long term