Area Forecast Discussion
Issued by NWS Houston/Galveston, TX
Issued by NWS Houston/Galveston, TX
403 FXUS64 KHGX 081807 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 107 PM CDT Tue Jul 8 2025 ...New DISCUSSION, AVIATION, MARINE... .KEY MESSAGES... Issued at 107 PM CDT Tue Jul 8 2025 - Scattered to widespread showers and thunderstorms are expected each day through the weekend, and even into early next week though we should see a downward trend in storm coverage by that point. - Isolated strong thunderstorms will lead to gusty winds and localized downpours. If more than one of these storms moves over the same area, or happens to fall over an area of poor drainage, then minor street flooding/ponding will be possible. - Near seasonal temperatures will persist, but seasonal this time of year is still hot. Make sure to take breaks if working outside and stay hydrated. && .DISCUSSION... Issued at 107 PM CDT Tue Jul 8 2025 Numerous showers and storms are already strewn across Southeast Texas early this afternoon, and for the next several days...probably through at least this weekend...today makes a pretty good template for the forecast. Look for convection to follow the typical diurnal pattern - offshore pre-dawn, making its way to the immediate coast in the morning, and spreading inland through the afternoon, generally increasing in intensity until the sun goes down enough that everything fades away for a quiet end to the evening. Temperatures will start from a high floor thanks to typically humid conditions in the 70s and lower 80s, rising to highs in the low to mid 90s. Just how high you get depends on if, when, and how strong any storms you see during the day end up being. Today`s activity is very clearly getting a boost from an upper trough making its way in from across the Gulf. Though that trough will fade out, it`s made a clear weakness in the subtropical ridge over us, and a parade of troughs in the northern stream will take advantage. Expect them to dig a little deeper into this weakness in the subtropical ridge, helping it persist into and likely through the weekend, with the scattered to numerous storms to show for it. This high confidence scenario leads me right into my primary break from the deterministic NBM output, which presents a (rather unrealistic) scenario in which we have high rain chances daily, but also hotter than typical temperatures; even high enough that taken verbatim, might have me worrying about the heat advisory threshold. But obviously, cloud cover and convective activity are going to be a downward pressure on temperatures, so I find it very unlikely that we see both. For instance, at 1 pm, temperatures range from the upper 80s all the way down into the upper 70s! This is definitely not a "Porque no los dos?" situation. And since the current presence of the upper trough and high confidence in the stream of northern stream troughs is here, I`m opting to stick with the higher PoPs. I`ve largely replaced NBM highs with the 50th percentile/median NBM numbers, which puts me much closer to seasonal averages and pulls us back from being unrealistically close to a heat advisory. Of course, seasonable in SE Texas is still potentially dangerous for folks sensitive to heat, and for those who are required to exert themselves strenuously outdoors away from shade. Highs in the lower 90s and a humid environment will still push the heat index above 100, and wet bulb globe temperatures into the high risk range. Fortunately, we should at least have plenty of winners in the "afternoon rain lottery", and a passing shower will help make things more comfortable...at least until the sun comes back. And while we`re on notes of caution, those afternoon storms need one as well. Storms, by definition, carry lightning and means you want to be inside of well-constructed shelter to avoid that threat. But also, "seasonable" storms can also cause localized issues with gusty winds and heavy rain. Overall, each day`s activity will be manageable, but the strongest storms of the day could cause isolated problems if they occur in the wrong spot. && .AVIATION... (18Z TAF Issuance) Issued at 107 PM CDT Tue Jul 8 2025 Main focus of this cycle is to handle timing and impacts of scattered to numerous afternoon storms. Primary change so far is to slide things up to accommodate slightly earlier start to activity, and will continue to keep TAFs in line with actual storms as the afternoon drags on. Also introduced PROB30s for tomorrow`s development in the IAH extended. && .MARINE... Issued at 107 PM CDT Tue Jul 8 2025 Daily shower and thunderstorm chances continue through the end of the week. Though more numerous than usual for the next few days, they should follow the typical daily pattern of beginning over the Gulf waters in the pre-dawn hours, then gradually shifting towards the immediate coast later in the morning and farther inland through the afternoon. Light to moderate winds and low seas are expected through Wednesday. Occasionally higher gusts up to 15 to 20 knots are possible. Winds and seas may increase towards the end of the week. Locally higher winds and seas possible in the vicinity of any thunderstorm that develops over the bays and Gulf waters this week. At the shore, the persistent light to moderate onshore flow will modestly boost tidal levels and risk of rip currents for the next couple of days. Beyond that, the expectation for somewhat higher winds may boost concern about rip current - but, for now, Galveston Beach Patrol reports they are flying yellow flags. && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 74 91 75 93 / 30 30 10 20 Houston (IAH) 76 92 77 94 / 20 60 10 50 Galveston (GLS) 82 90 81 90 / 20 40 20 40 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ DISCUSSION...Luchs AVIATION...Luchs MARINE...Luchs