Area Forecast Discussion
Issued by NWS Houston/Galveston, TX
Issued by NWS Houston/Galveston, TX
591 FXUS64 KHGX 180006 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 706 PM CDT Fri Oct 17 2025 ...New AVIATION... .KEY MESSAGES... - Moderate fire danger remains for majority of Southeast Texas and on Friday due to dry vegetation/fuels. - Unseasonably warm weather continues as high temperatures in the mid 80s to lower 90s persist into early next week. Heat index values on Saturday will peak in the upper 90s. - Chances for isolated to scattered showers and storms continue through late Saturday/early Sunday ahead of an approaching weak cold front. - Drier air and breezy northeasterly winds behind the front leading to moderate to high fire danger rating for Sunday. && .DISCUSSION... Issued at 1139 PM CDT Thu Oct 16 2025 After the summer we had where it seemingly rained everyday, I didn`t imagine that we`d be begging for rain a couple of months later. That led me to do some investigating to see exactly how long it`s been dry. The last day of measurable rainfall for the City of Houston was on September 24th. If you`re reading this on October 16th, that was 22 days ago. Most of y`all are reading this on October 17th, so that was 23 days ago. Three solid weeks of NO measurable rainfall...yeah we need some rain y`all. Thanks to the return of onshore flow bringing in a plume of Gulf moisture (PW values peaking in the 1.6- 1.9" range) and lingering PVA from an embedded shortwave, we will see scattered showers and storms pushing through the area beginning Friday morning and lasting into the afternoon. The highest rain chances will be mainly along and west of I-45. Rainfall totals could pile up a tad bit where showers/storms initially push in in a broken south to north oriented line. This would likely result in 1-2" of rainfall and this looks to be most likely to occur near Matagorda Bay. Thanks to the increased chances of rain, high temperatures will top out in the mid to upper 80s, which if you`re keeping track is still above normal. If you recall from yesterday`s AFD, we discussed that the City of Houston has not had a below normal maximum temperature since September 9th. While there is a "cold" front to talk about, don`t expect that streak to end any time soon. These rain chances stick around going into Saturday as an upper level trough and an associated weak cold front begin to push through Texas. The approaching front will nudge the bulk of the moisture eastward leading to the highest rain chances on Saturday being along and east of I-45. Friday`s rain chances are mainly west of I-45, and Saturday`s rain chances are mainly east of I-45...perfectly balanced as all things should be. One difference for Saturday is that we add in quite a bit more instability and a little bit of shear. The shear will be higher further to the north and east, but a combination of those ingredients does offer the potential for some storms to become strong to severe on Saturday in the Piney Woods area. SPC (as of the 2pm CDT Thursday update) has outlined areas generally east of a Madisonville-Huntsville-Shepherd line in a marginal risk of severe weather (level 1 out of 5). The main hazard will be damaging winds, but we can`t entirely rule out hail or a brief isolated tornado. We`ll also get some warmer 850mb temperatures (90th+ percentile) nudged in our direction on Saturday as well. That`ll lead to temperatures topping out mainly in the low 90s, but it`ll feel hotter than that when you factor in the elevated humidity. Heat index values will peak in the mid to upper 90s, so Hot-ober continues! On Wednesday evening, the 18Z GFS pump faked us with a run that said the front wasn`t going to push through and now it`s back. So, tonight`s deterministic model guidance is in consensus on the frontal boundary pushing through on Sunday morning. There looks to be a broken band of showers/storms associated with the front as it pushes through, but it looks like it`ll push out ahead of the front and move in on late Saturday with most of the convective coverage remaining east of I-45. Drier air filters in on Sunday morning/afternoon, but it`ll be brief. While it`ll still be in the upper 80s to low 90s in the daytime, it`ll be a dry heat compared to Saturday. Model guidance is a bit uncertain on how quickly onshore flow returns, but it will occur by Monday. If it occurs closer to Sunday night/Monday morning, then that`ll have an impact on the low temperatures. As of right now, we have low temperatures ranging from the low 50s to low 60s (low 70s along the coast). As onshore flow returns early next week, mid to upper level high pressure expands over northern Mexico towards the western Gulf coast. Another trough sweeping through the Central Plains midweek may allow another front to approach the area, but I`m not entirely convinced on that one since the associated trough and upper level low pushes through the Northern Plains into the Great Lakes region. That would leave us under control of the ridge albeit with the main ridge axis to our west. If you hate math (specifically statistics), you should probably go ahead and stop reading right here. To get an indication of the uncertainty of next week`s front, let`s take a look at some box and whisker plots! Going into midweek, there is a notable increase in the low temperature spread. That comes to tune of a 10+F difference between the upper quartile and the lower quartile. There are a few ensemble members that bring upper 50s/low 60s to the metro area around midweek, but there are quite a few more that keep us in the upper 60s/low 70s. The latest run of the NBM is now leaning towards the FROPA-less solution as it keeps low temperatures next week generally in the 60s...and we`ll see if that upward trend continues. See, math DOES have real world application! *insert nerd emoji here* Batiste && .AVIATION... (00Z TAF Issuance) Issued at 634 PM CDT Fri Oct 17 2025 VFR conditions will continue through this evening, but moist onshore flow will bring a period of MVFR CIGs to the area late tonight into the mid-morning hours on Saturday with ceilings around 1500-2500ft. Wind speeds during the overnight hours will generally be between 4-8kt, and then increase to 7-12kt by the mid-morning hours on Saturday and persist through the evening. The increase in moisture will also lead to scattered showers and eventually thunderstorms during the day tomorrow. Isolated shower activity will begin near the coast near dawn, then spreading in coverage through most of the area by the afternoon hours. Scattered, pop-up thunderstorms will develop by the late morning to afternoon hours with the greatest chances being CXO southwards. There will be a lull in the activity during the evening to early overnight hours, but a weak boundary approaching from the northwest will bring additional rain chances late Saturday night into Sunday morning. This is beyond the end of this TAF package, but expected a broken line of showers and storms to move through after 6z with a period of northwesterly winds developing behind it. Fowler && .MARINE... Issued at 1139 PM CDT Thu Oct 16 2025 Onshore flow persists leading to the gradual increase of moisture heading into the weekend. Expect chances for showers and storms to gradually increase going into Friday and Saturday. Wind speeds may approach the caution flag threshold on Friday night into Saturday morning to go along with seas elevating to around 4 ft. This increased onshore flow will lead to an increased risk in rip currents late Friday into the weekend. Chances for isolated to scattered showers and storms will persist until a frontal boundary pushes through on Sunday. Expecting a brief period of northerly to northeasterly winds behind the front on Sunday, but southeasterly winds make a quick return by Monday. Batiste && .FIRE WEATHER... Issued at 1139 PM CDT Thu Oct 16 2025 Although moisture is on the rise, dry vegetation/fuels remain especially in portions of the Brazos Valley and the Piney Woods. As a result, the fire danger rating for Friday is still moderate for most of Southeast Texas. The increased moisture means an increase in rain chances, especially for Friday and Saturday ahead of a weak cold front that looks to push through on Sunday. On Sunday, we could see an overlap of drier air (minimum RH values 25-35%) and breezy northeasterly winds, which would create another day of elevated fire weather conditions. We are currently looking at a moderate to high fire danger rating for Sunday with those outlined in a high fire danger rating generally north of I-10. Lastly, the vast majority of the counties in Southeast Texas now have a burn ban in place. The only counties that do not have a burn ban as of Thursday night are Brazoria and Galveston Counties. Batiste && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 70 91 65 83 / 0 30 30 0 Houston (IAH) 72 89 70 84 / 0 50 30 10 Galveston (GLS) 78 85 74 84 / 10 20 20 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ DISCUSSION...Batiste AVIATION...Fowler MARINE...Batiste