Area Forecast Discussion
Issued by NWS Brownsville, TX
Issued by NWS Brownsville, TX
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221 FXUS64 KBRO 301930 AFDBRO Area Forecast Discussion National Weather Service Brownsville TX 230 PM CDT Tue Apr 30 2024 ...New SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (Tonight through Wednesday night) Issued at 223 PM CDT Tue Apr 30 2024 With no frontal boundaries expected to move over the local forecast area, the short-term forecast period will feature a continued steady state (status quo) pattern of warmth, humidity, and mainly dry weather conditions. Overcast skies will remain in place particularly during the morning and nighttime hours with some breaks in the overcast during the afternoon hours. Forecast models are signaling at the potential for an isolated/rogue shower or thunderstorm on Wednesday given the robust instability parameters, yet little to no lifting mechanism to support. The best chance for any shower or storm will be located over the northern half of the area (i.e. Northern Ranchlands) as a shortwave is expected to track north of our CWA (i.e. CRP Corpus Christi and EWX Austin/San Antonio`s area). The Storm Prediction Center (SPC) in Norman, Oklahoma has a general outlook/risk for thunderstorms over the northern half of our local forecast area for Wednesday. Tonight and Wednesday night will remain warm and muggy with overnight low temperatures ranging between the mid to upper 70s with similar dewpoint temperatures. There is low, but non-zero probability of some mist/fog development tonight with copious amounts of low level moisture in place. A lot will depend on how strong/weak the winds become tonight. Daytime high temperatures tomorrow (Wednesday) are expected to be in the upper 80s to mid 90s across Deep South Texas and the Rio Grande Valley (near 80F over/along the coastal areas). && .LONG TERM... (Thursday through next Tuesday) Issued at 223 PM CDT Tue Apr 30 2024 The long-term forecast period will feature a continuation, steady state pattern of warm, humid, and mainly dry conditions. Towards the end of the extended (i.e. Sunday-Tuesday timeframe), we could see hot conditions (i.e. triple digit heating) developing over parts of the local forecast area as 500mb geopotential heights increase and a ~591 dam sub-tropical heat dome builds northward into our CWA. Thursday through Sunday, daytime highs are expected to be in the upper 80s to mid 90s across Deep South Texas and the Rio Grande Valley (lower 80s along/near the coast). Nighttime lows are expected to range from the mid to upper 70s. On Monday, daytime highs are expected to rise into the lower 90s to near 100F across the region with the hottest temperatures being located over our far western sections (i.e. Zapata and Starr Counties). Max heat indices are expected to range from 100F-105F with coverage being over the western 2/3rds of the forecast area. Tuesday is expected to be the hottest day of the long-term period with highs in the low/mid 90s to lower 100s. There will be more coverage in mid 90s to near 100F degrees with the hottest temps again being over our western sections. Widespread heat indices between 100-109F are expected over Deep South Texas and the Rio Grande Valley. The NWS HeatRisk tool is suggesting mostly moderate risks to heat related impacts through the long-term period with minor risks confined mainly along the coastal areas. By the time we get into Monday-Tuesday of next week, we`ll need to monitor trends to see if the risk increases into the moderate to major categories (with triple digit heat and heat indices expected). This ultimately will depend on how strong the aforementioned sub-tropical heat dome gets. && .AVIATION... (18Z TAFS) Issued at 1215 PM CDT Tue Apr 30 2024 Through 18z Wednesday....VFR to MVFR conditons were taking place at the terminals as of this update under a BKN-OVC deck of cumulus clouds with ceilings ranging between 2,500-3,000 feet AGL and unrestricted visibilities. Due to the copious amounts of low level moisture in place and continuous onshore flow, low level clouds will remain in play through the 18z TAF period. As we shift into this evening/tonight, expectations are for more MVFR clouds to take over with lower MVFR ceilings possible later tonight. During the day on Wednesday, cloud bases should gradually increase but may still remain in MVFR territory through 18z Wednesday. Winds will remain out of the southeast between 10-15 kts. During the day on Wednesday southeast winds are expected to gusts 20-25 kts. && .MARINE... Issued at 223 PM CDT Tue Apr 30 2024 Tonight through Wednesday night....Moderate winds and seas are expected through Wednesday night. Wave heights over the Gulf are expected to range between 4-5 feet. Thursday through Tuesday....Moderate winds and seas are expected to continue Thursday through next Tuesday. Wave heights are expected to range between 4-6 feet. Small Craft Exercise Caution (SCEC) conditions are possible at times during this timeframe (especially over the offshore Gulf waters). && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 77 88 77 89 / 0 10 0 0 HARLINGEN 74 91 76 92 / 0 10 0 0 MCALLEN 77 92 78 94 / 10 10 0 10 RIO GRANDE CITY 76 92 76 95 / 10 10 10 10 SOUTH PADRE ISLAND 76 81 77 81 / 0 0 0 0 BAYVIEW/PORT ISABEL 75 87 75 87 / 0 10 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...High Rip Current Risk until 7 PM CDT this evening for TXZ451-454- 455. GM...None. && $$ SHORT TERM...23-Evbuoma LONG TERM....23-Evbuoma AVIATION...23-Evbuoma