Area Forecast Discussion
Issued by NWS Houston/Galveston, TX
Issued by NWS Houston/Galveston, TX
025 FXUS64 KHGX 281049 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 549 AM CDT Sat Jun 28 2025 ...New AVIATION... .KEY MESSAGES... Issued at 1209 AM CDT Sat Jun 28 2025 - Plume of moisture from a tropical disturbance to enhance rainfall chances on Sunday and possibly Monday. - Plume of mid-level Saharan Dust to bring hazy skies next week. - Temperatures are expected to be somewhat hotter next week. && .DISCUSSION... Issued at 1209 AM CDT Sat Jun 28 2025 Saturday`s weather is expected to behave much like the last few days. So if very humid conditions with a side of widely scattered showers and thunderstorms is what you crave, then enjoy your Saturday! Once again, not every location will receive a shower or thunderstorm. By Sunday and Monday, our attention will turn towards an atmospheric battle of sorts. Behold...the battle of the plumes! You`ll notice in the key points section above that the word `plume` was used not once, but twice. Indeed, we have two atmospheric plumes on route to SE Texas. The first being a plume of dense tropical moisture, brought forth to our region thanks to a tropical disturbance moving into the Bay of Campeche. Plume number two refers to the approaching dry and dusty air in the mid-levels currently over the Caribbean. We can thank the Saharan Desert for this plume. The moisture plume will tend to increase the chance and coverage of shower and thunderstorm activity. Meanwhile, the presence of the Saharan Dust would warm up and dry out the mid-levels, acting to suppress rain chances. So which one will win the great battle? For now, the evidence suggests the moisture will win (at least over the southern half of the CWA) on Sunday. The evidence in this case being the computer models and what we can see on TPW imagery with our own eyes. Let`s start with the current PWAT situation. MIMIC-TPW imagery clearly shows the tropical moisture plume outrunning the Saharan Air Layer. The axis of highest TPW is already entering the southern Gulf, while the dry mid-level air lags over the Caribbean. At this time, there is no reason to believe that this lag will not continue. The models agree with this assessment as well. Therefore, our forecast features increasing rain/thunderstorm chances on Sunday (some could be heavy) especially across our southern counties. Where things get a little tricky is Monday. The low-levels will remain rich in tropical moisture. But the increasing presence of Saharan Air aloft may act as a suppressive force against convective development. Therefore, we are expecting less (though not zero) shower/thunderstorm activity on Monday (plume battle depending). Beyond Monday, mid/upper ridging is expected to build while Saharan Dust lingers in the mid-levels. If you guessed that these trends support lower PoPs and higher temps, you would not be wrong. But the mid to late week atmosphere isn`t looking suppressive enough to bring PoPs down to zero. In addition, the mid-level dust can block enough solar radiation to limit warming. Current temperature outlook for Tuesday-Friday range from upper 80s to low 90s near the coast, to mid 90s inland (upper 90s in a few spots). So the forecast is hot, but not as hot as it can be. Self && .AVIATION... (12Z TAF Issuance) Issued at 549 AM CDT Sat Jun 28 2025 Patchy fog, mainly across more rural/non-metro areas should burn off a few hours after sunrise. Otherwise, VFR conditions will prevail today. There will be some spotty afternoon shra/tstms around, but overall coverage should be lower than past days and am not currently planning to add the mention in the 12z TAFs attm. 47 && .MARINE... Issued at 1209 AM CDT Sat Jun 28 2025 The marine weather outlook through next week features a continuation of light to moderate onshore flow, 2-4 foot seas, and a daily risk of isolated to scattered showers and thunderstorms. The exception to this will be Sunday into Monday, when a tropical disturbances passes the region to the south. Despite its southward track, the system is expected to bring increasing rain chances along with a modest increase in winds and waves. Seas offshore are expected to approach 5 feet, with some possibility of reaching 6 feet well offshore on Sunday into Monday. As per the National Hurricane Center, the system has a 30 percent chance of development into a tropical depression before moving into Mexico on Monday. Self && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 93 74 91 75 / 10 0 30 0 Houston (IAH) 92 77 89 77 / 30 0 80 10 Galveston (GLS) 89 81 89 82 / 10 20 70 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$