Area Forecast Discussion
Issued by NWS Brownsville, TX
Issued by NWS Brownsville, TX
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
635 FXUS64 KBRO 300733 AFDBRO Area Forecast Discussion National Weather Service Brownsville TX 233 AM CDT Tue Apr 30 2024 ...New SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (Today through Wednesday) Issued at 232 AM CDT Tue Apr 30 2024 Low level moisture is surging inland as of this writing with WSR88-D radar showing Isolated to scattered showers over the Lower Texas and Tamaulipas coastal waters. Some of these showers are spreading inland this morning but mostly helping to steadily increase the moisture content of the atmosphere across all of Deep South Texas. Mean pwats of 1.7-1.9 inches are forecast over the region today and Wednesday with increasing instability and a weak cap at best to maintain a low chances (15-30%) of convection. A weak elongated upper level disturbance moving across the south Texas this morning initiates mid to late morning convection across the eastern two- thirds of the County Warning Area (CWA). The next shot of convection is shown for Wednesday afternoon as a stronger disturbance passes over South Central Texas placing the best chance for thunderstorms over the NW portions of the CWA. At this time SPC maintains a general thunderstorm outlook today and Wednesday. Otherwise, plenty of morning and night time cloudiness with breaks in the overcast for the afternoon hours. Temperatures continue to be slightly elevated or above seasonal averages especially the overnight night lows. Highs will range from 80 at the local beaches through the 90s inland. Overnight lows only dip into the mid to upper 70s. General moderate southeast winds with some gusts 0f 20-25 mph can be expected. Finally, the rip current risk remains in the high category today with a residual long period swell continuing to be directed towards the Texas coast. As the pressure gradient continues to weaken over the Gulf the swell train should steadily subside over the next 12-24 hours. && .LONG TERM... (Wednesday night through Monday) Issued at 232 AM CDT Tue Apr 30 2024 The start of the long term forecast will have a tight pressure gradient over Deep South Texas and the Rio Grande Valley as the sustained winds could be around 15-20 mph with some stronger gusts close to 30 mph for Thursday. The real interesting story for the long term forecast period is what will the cold front do. An upper- level trough over the Rockies will be the main driving force for the cold front. By the end of the work week the cold front is expected to stall out over Central Texas. While there is still a little bit of a disagreement in the models on the timing of the front, the models have shown a timing this past run that is a bit closer. Rain chances remain very low through the period as a weak mid-level ridge continues to exert its influence over the area. On top of that, the middle and upper levels of the atmosphere are very dry so there is no moisture aloft for showers and thunderstorms to build up with. With southerly to southeasterly flow persisting over the long term forecast period, warm and humid conditions are expected to be the trend. High temperatures are expected to be in the range of upper 80s along the beaches to the mid 90s for most of the region. The western parts of Starr, Zapata, and Jim Hogg could even be in the upper 90s. Given the amount of humidity in the air and the heat, future shifts will need to watch over the heat index values. As maximum heat index values could be around 105 throughout the period. As for the low temperatures, they are expected to remain in the 70s for all of Deep South Texas and the Rio Grande Valley. && .AVIATION... (06Z TAFS) Issued at 1233 AM CDT Tue Apr 30 2024 NWS Radar is showing scattered small light showers increasing along and east-southeast of the lower Texas coast and NE Mexico. These showers are steadily moving northwest with the general southeast low level winds. Besides a passing shower overnight and through Tuesday morning IFR to MVFR ceilings are expected. Models suggest ceiling to rise to VFR by or shortly after 17-18Z. VFR persist through the afternoon with the marine layer moving inland shortly after sunset with ceilings lowering to MVFR and possibly IFR before midnight. Light to moderate southeast winds persist through the period with occasional gusts 18-22kts. && .MARINE... Issued at 232 AM CDT Tue Apr 30 2024 Tuesday through Wednesday...The pressure gradient continues to weaken over the Gulf of Mexico with a 1020mb surface ridge extending over the Eastern Gulf and lower pressure over NE Mexico. Residual long period swells also are showing signs of lowering with at least another 12-24 hours before the higher swell subside below 5 feet. Local pressure gradient along immediate coast tightens Wednesday with moderate to fresh southeast winds expected over the Laguna Madre. There is a medium chance (40-60%) of a Small Craft Advisory for the Laguna Madre Wednesday afternoon. Wednesday Night through Tuesday..Adverse marine conditions are likely with the tight pressure gradient over the Lower Texas Coast with wind speeds around 15-20 knots. Thus a Small Craft Exercise Caution is likely, but a low end Small Craft Advisory cannot be ruled out. Moving into Friday and the weekend, more favorable conditions will be present. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 89 77 88 77 / 30 0 10 0 HARLINGEN 90 74 91 75 / 30 0 10 0 MCALLEN 92 77 92 77 / 20 0 10 0 RIO GRANDE CITY 93 75 93 77 / 20 0 10 10 SOUTH PADRE ISLAND 81 76 81 76 / 30 10 10 0 BAYVIEW/PORT ISABEL 86 74 87 75 / 30 10 10 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...High Rip Current Risk through this evening for TXZ451-454-455. GM...None. && $$ SHORT TERM...59-GB LONG TERM....64-Katz AVIATION...59-GB