Area Forecast Discussion
Issued by NWS Brownsville, TX
Issued by NWS Brownsville, TX
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449 FXUS64 KBRO 121712 AAB AFDBRO Area Forecast Discussion...UPDATED National Weather Service Brownsville TX 1212 PM CDT Wed Jun 12 2024 ...New AVIATION... .SHORT TERM... (Today through Thursday) Issued at 237 AM CDT Wed Jun 12 2024 The relentless grip of oppressive 500 mb high pressure will be loosened a bit for the BRO CWFA during this period. As the mid- level ridge remains centered generally over southern New Mexico, broad 500 mb low pressure will be in place over the western Gulf of Mexico and along the Texas coastline. When combined with precipitable water values that may increase to, and hover around, 2 inches, the result will be mainly isolated convection across the BRO CWFA today through tomorrow, with the greatest areal coverage of showers and thunderstorms anticipated for Thursday. Temperature-wise, the relative absence of the 500 mb high, increased cloud cover, and the opportunity for precipitation will result in above normal temperatures through the period, and not well above normal for a change. This will result in a HEAT ADVISORY not likely for today and Thursday, and will instead manage the heat indices with a SPECIAL WEATHER STATEMENT on both of those days. && .LONG TERM... (Thursday night through Tuesday) Issued at 237 AM CDT Wed Jun 12 2024 While the mid-level ridge looks to hold strong going into the weekend and continue to exert its influence over Deep South Texas and the Rio Grande Valley. It does actually start to weaken a bit as a shortwave swings across the Great Basin and through the Plains. While this is occurring, an inverted trough axis will develop over the eastern and central Gulf. At this current time and based on the latest model analysis, Saturday could see some limited isolated showers and thunderstorms. However, these showers and thunderstorms are limited to the Lower Rio Grande Valley. GFS guidance does indicate that starting on Saturday, the middle and upper levels of the atmosphere will become more moist. However, that is a bit dependent upon the previously mentioned inverted trough. The current GFS shows the atmosphere remaining very moist for the remainder of the long term forecast period. While there is plenty of potential for rain and even periods of heavy rain. All this rainfall would be very welcomed here in Deep South Texas with the ongoing drought. As for the temperatures for the long term forecast period, are expected to be mostly in the range of 90s to triple digits. However, the further into the long term forecast period one goes, the high temperatures actually start to become a few degrees cooler. Thus by Tuesday, the high temperatures are in the 90s for Deep South Texas and the Rio Grande Valley. The heat indices continue to be rather high, but below Heat Advisory through the long term forecast period as well. As for the low temperatures, for the most part the overnight lows are expected to be in the 70s, though some parts of the region particularly the extreme southern areas could see some low 80s creep in. Shifting over to the tropics, there is the potential for some tropical activity early next week. However the model guidance is still holds some disagreements, but there are signs of some form of either a Tropical Depression or a weak Tropical Storm. However, it would seem that the most likely landfall at this time would be well to our south around Veracruz. Further forecast shifts will need to continue to monitor the model trends and see if they can come into a better agreement. Climatological trends do show that the Bay of Campeche is a good area for development of Tropical Cyclones, so there is good reason to lean into the potential for the development of a system in that region. Also considering that high pressure over the central and eastern Gulf also adds to the notion of a southerly development area. Further forecast shifts will also need to watch for any sort of trends in the models that could see a northern reformation that has occurred before with weak western Gulf systems. For those that are planning to make a trip to the beach during the long term forecast period, early next week there is an expected increase in the risk of rip currents along with some coastal flooding as well due to the building swells coming from an elevated pressure gradient creating a strong southeast flow. && .AVIATION... (18Z TAFS) Issued at 1157 AM CDT Wed Jun 12 2024 VFR conditions at the TAF sites now with light to moderate east southeast winds. As was the case yesterday, low level cumulus streets (4 to 4.5 kft) cover the eastern 2/3 of the CWA. There is a bit more low level moisture today, and the sea breeze is already underway, pushing a convergence line and enhanced low level cumulus into the coastal counties. May see few to sct mid to upper clouds later today as viewed moving south on satellite. Radar has been quiet this morning. For the rest of the day and tonight, will plan on continued VFR conditions with a weak pressure gradient. Some of the guidance hints at brief coastal MVFR mid tomorrow morning, but this would be brief and will not emphasize in the new TAF set. && .MARINE... Issued at 237 AM CDT Wed Jun 12 2024 Today through Thursday...Surface high pressure centered generally over Louisiana will remain extended over the western Gulf of Mexico through the period. This will produce light to moderate winds and low to moderate seas along the Lower Texas Coast, with neither Small Craft Should Exercise Caution nor Small Craft Advisory anticipated to be needed. Thursday Night through Tuesday...Light to moderate easterly winds and low to moderate seas are expected with Tuesday night through most of the weekend. Showers and thunderstorm chances start to increase moving into the weekend, and could bring in some locally elevated winds and seas, as an inverted trough axis approaches the Lower Texas Coast. Moving into the early parts of next week, the pressure gradient will become more enhanced leading to adverse and hazardous conditions. A combination of Small Craft Exercise Caution and Small Craft Advisory will be needed through Tuesday due to the larger swell. There is potential for a tropical cyclone to develop in the Bay of Campeche, which could mean that winds and seas could actually be higher than what is current forecasted depending on how that system develops. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 96 80 94 78 / 10 10 30 10 HARLINGEN 97 76 96 74 / 10 0 30 0 MCALLEN 100 79 97 77 / 10 0 20 0 RIO GRANDE CITY 100 79 97 77 / 10 10 10 0 SOUTH PADRE ISLAND 88 82 87 82 / 10 10 30 10 BAYVIEW/PORT ISABEL 92 79 92 78 / 10 10 30 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ SHORT TERM...54-BHM LONG TERM....80-MB AVIATION...54-BHM