Area Forecast Discussion
Issued by NWS Brownsville, TX
Issued by NWS Brownsville, TX
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522 FXUS64 KBRO 062011 AFDBRO Area Forecast Discussion National Weather Service Brownsville TX 311 PM CDT Thu Jun 6 2024 ...New SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (Tonight through Friday night) Issued at 311 PM CDT Thu Jun 6 2024 Key Messages: * The heat continues, but subtle relief arrives in terms of slightly drier air and lower late night/early morning temperatures * Heat Risk also improves a little bit on Friday with more areas in Moderate (level 2 of 4) range * Unhealthy air quality persists into at least Friday morning with some minor improvement by afternoon * The surf finally becomes more favorable for more swimmers by Friday. At long last...some modest relief in terms of apparent temperatures is headed to the Valley and the ranchlands as nuanced dry air slides in associated with the core of the upper level ridge which builds across all of Texas and noses across all of south Texas. While daytime temperatures will change little...humidity will drop by 10- 15 percent as afternoon dewpoints fall into the mid 60s (Brush Country/Rio Grande Plains) to lower 70s (along/east of I69C/US 281) which will keep apparent, or "feels like", temperatures in the more "average" range of 103 to 108. This means we break the four-day streak of continuous advisories (and a few warnings) that began on Monday. The only minor item to consider this evening is a quick shot of potential convection sliding in from the Sierra Madre...most likely to impact southern Zapata through southern/central Starr County. Confidence is not very high...but the GFS and some CAMs are hinting at the possibility...and the Weather Prediction Center has introduced a pocket of 0.05 to 0.4 inches of rain in these areas. Not expecting anything severe...but one can never rule out small hail and gusts to 40 mph in such a situation. For now, have used 20 percent chances to cover the potential...only through 10 PM. Otherwise...expect another round of yucky haze overnight into early Friday as remaining pollutants are held in place by the inversion and light to calm winds. Air Quality rebounded (badly) to unhealthy levels overnight through this afternoon...and would not be surprised to see a short period of very unhealthy (index values 200 or a bit higher) later tonight into mid morning Friday. For Friday night...expect mainly clear skies with slightly higher east southeast winds which may be enough to keep mentionable haze out of the forecast. More importantly...for people looking for overnight temperature "relief" they`ll finally get it as post- midnight temperatures should fall below 80 just about everywhere...with 70-73 likely by daybreak for all but urban centers and the coast. Nobody will complain about these more seasonable temperatures after so many mornings remaining at or above 80 in most areas. Finally...this afternoon remains tricky for beach goers as waves are more inviting but the longshore continues to make swimming a bit difficult. We`ve had a number of drownings/rescues on afternoons like today (Thursday)...so vigilance is important. By Friday...waves recede and all currents should dip to low...allowing decent swimming conditions for most compared with recent weeks. && .LONG TERM... (Saturday through next Thursday) Issued at 311 PM CDT Thu Jun 6 2024 Key Messages: *Above normal high and low temperatures *Very low rain chances The mid-level ridge continues to be the star of the weather for Deep South Texas and the Rio Grande Valley. As such the middle and upper levels of the atmosphere are expected to be dry and stable thanks to the subsidence from the ridge. This will be a hindrance for any showers and thunderstorms that try to develop. However, it is possible that a rogue shower or thunderstorm could impact the region around Monday or Tuesday, but confidence is not high at this time. As for the heat, above normal temperatures will continue to persist through the long term forecast period. However, the temperatures will be slightly cooler than they have been with the the most recent event. Even though there will still be plenty of humid air in the region thanks to the southeasterly flow at the surface, Heat Advisories are not likely to occur everyday. With the heat indices under 111, Special Weather Statements are sufficient enough to cover for them. && .AVIATION... (18Z TAFS) Issued at 1243 PM CDT Thu Jun 6 2024 Persistent smoke/soot from the last of agricultural burning in southeast Mexico...as well as Central American wildfires...combined with increasing low level inversion(s) and lighter winds associated with surface high pressure ridge settling over the Valley have brought back visibility-reducing haze/smog that was fairly thick this morning as pockets of IFR visibility developed. That, along with potential for IFR ceilings...is the primary concern for the overnight. Persistence, therefore, is the best option for the overnight and early Friday morning forecast. After the usual brief uptick in easterly winds late this afternoon/early this evening, which should keep haze at bay, expect haze to return as winds lay down soon after sunrise. Despite a bit more easterly component aloft (as well as across the smokier areas to our south), stagnant air is still here (note another day of "Unhealthy" air quality) so have lowered visibility to the edge of IFR (3 statute miles) especially for the Lower Valley terminals, mainly after 1 AM. Ceilings will form up as well but there is some uncertainty on the duration of such...and exactly how low they drop to. High IFR/low MVFR seems the best bet (900 to 1500 feet) which should continue through 8 or 9 AM...then lift to high MVFR/low VFR to close out the forecast window. Winds will increase a little but still remain below 10 knots through late morning. This should be enough to improve visibility but not by too much...and would not surprise to see 6 miles continue through lunchtime. && .MARINE... Issued at 311 PM CDT Thu Jun 6 2024 Tonight through Friday night...After many difficult boating days dominated by persistent wind waves a chop...the arrival of surface high pressure parking over the lower Texas Gulf waters will bring much calmer conditions for this period. Light east winds and slight seas (falling to 2 feet) will be the rule through the period. Tonight through Thursday Night...Light to moderate southeasterly winds with moderate seas are expected to occur along the Lower Texas Coast through Thursday Night as high pressure remains in control over the Gulf of Mexico. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 80 96 79 95 / 0 0 0 10 HARLINGEN 76 97 75 96 / 0 0 0 0 MCALLEN 79 100 77 99 / 10 0 0 0 RIO GRANDE CITY 78 99 75 98 / 20 0 0 0 SOUTH PADRE ISLAND 81 87 81 87 / 0 0 0 10 BAYVIEW/PORT ISABEL 79 91 78 91 / 0 0 0 10 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...Heat Advisory until 8 PM CDT this evening for TXZ248>255-351- 353>355. GM...None. && $$ SHORT TERM...52-Goldsmith LONG TERM....64-Katz AVIATION...52-Goldsmith