Area Forecast Discussion
Issued by NWS Houston/Galveston, TX
Issued by NWS Houston/Galveston, TX
857 FXUS64 KHGX 011755 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 1255 PM CDT Mon Sep 1 2025 ...New DISCUSSION, MARINE... .KEY MESSAGES... Issued at 1234 PM CDT Mon Sep 1 2025 - Scattered to numerous storms, along with a threat of localized heavy rain will continue today. A marginal risk of excessive rain (threat level 1 of 4) is in place for most of the area. - Tranquil conditions are expected Wednesday into Friday as drier air filters into the region. - High temperatures will rise back into the mid 90s by mid-week. The drier air will lead to cooler temperatures at night, as lows gradually slide through the 70s and into the upper 60s inland. && .DISCUSSION... Issued at 1234 PM CDT Mon Sep 1 2025 A few more rounds of showers and thunderstorms are expected this afternoon and evening as diurnal heating and instability increases while PWs remain between 2.2-2.4 inches and the weak frontal boundary that pushed through yesterday meanders over the coastal waters. Locations near and south of I-10 will be more susceptible to shower and thunderstorm development today, although there is a chance for isolated showers and thunderstorms everywhere else. With the amount of moisture in place from the surface to mid- levels, it will be of no surprise if stronger storms once again produce heavy rainfall with rain rates of 2-3 inches per hour. Also, the speed at which these storms move will be a significant factor regarding the potential for higher accumulations over a short time period (similar to what occurred yesterday). This could lead to flooding issues along roadways as well as low lying and poor drainage areas, in particular over the more urban regions that received good amounts of rainfall yesterday. Now, the good news is that our southern locations did not receive as much accumulations as other locations, thus, the soils are not yet saturated. However, we will need to keep an eye on storms that develop in and near the Houston metro area given that some roads and underpasses are quick to flood when high rainfall rates occur over a certain amount of time as witnessed yesterday afternoon. WPC has continued a Marginal Risk for excessive rainfall (level 1 of 4) for today and tonight for all of Southeast TX except the Piney Woods region. Make sure to check the radar imagery and traffic conditions before you begin your commute this holiday weekend. Strong storms will be capable of also producing frequent lightning and gusty winds...make sure to have an alternative option for outdoors activities today. Remember, when thunder roars, head indoors and never cross flooded roadways. Conditions will improve tonight as diurnal heating and instability decreases and drier air begins to move into the Brazos Valley and Piney Woods region. Some isolated showers may still occasionally affect the coastal locations during the overnight to early morning hours. On Tuesday, a weak mid-level shortwave will move across TX and could help fire up a few more showers and thunderstorms in the morning and afternoon. The most likely areas to see activity will be over areas south of the Brazos Valley and Piney Woods region given that the higher moisture will be closer to the coast. A drier weather pattern will begin Tuesday night as dry air continues to push towards the coast and the weak boundary continues further into the Gulf as a reinforcing front approaches our northern counties. Tranquil conditions will persist into the end of the work week. Rain chances are expected to return this weekend with the potential for another frontal boundary passing through Southeast TX. The high temperatures will mostly be in the upper 80s to lower 90s today and Tuesday. The highs will rise back into the mid 90s by Thursday and Friday. Temperatures may lower again this weekend, depending on rain and cloud coverage. As for the low temperatures, we are expecting those cooler nighttime temperatures Tuesday night into Thursday night with lows dipping into the upper 60s over areas north of I-10, the lower 70s over areas near and south of I-10, and the upper 70s along the coasts by Wednesday night. Cotto && .AVIATION... (12Z TAF Issuance) Issued at 651 AM CDT Mon Sep 1 2025 Weak seabreeze trying to push inland is setting up a weak convergent zone and an area where we`ll see some continued shra/tstm development this afternoon. Further inland, lingering 2.1" PW`s (per GOES Total Precip product) and daytime heating is allowing for sct shra development. We could see a storm or two emerge there as well this afternoon. Most activity will diminish toward early evening with the loss of heating. Conditions will mainly be VFR, but localized heavy rain rates in the stronger cells will produce some visibility reductions and short lived MVFR cigs. Fairly quiet overnight, but cannot rule out some patchy fog at outlying/grassy locations considering the light winds. Probably see some sct shra redevelopment near the beaches and offshore toward morning. 47 && .MARINE... Issued at 1234 PM CDT Mon Sep 1 2025 The weak frontal boundary stalled over the coastal waters will bring scattered showers and thunderstorms Tuesday and will then push deeper into the Gulf Tuesday night. Strong winds, frequent lightning, and elevated seas may occur in and near stronger storms. Otherwise, light and variable winds with seas of 2 feet or less can be expected through next weekend. Drier conditions are expected mid-week into the end of the work week as a drier airmass moves into Southeast TX. Rain chances return next weekend. Cotto && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 72 91 71 92 / 10 10 0 0 Houston (IAH) 75 91 74 93 / 20 20 0 10 Galveston (GLS) 79 89 79 91 / 40 40 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ DISCUSSION...Cotto AVIATION...47 MARINE...Cotto