Area Forecast Discussion
Issued by NWS Houston/Galveston, TX
Issued by NWS Houston/Galveston, TX
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432 FXUS64 KHGX 152033 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 333 PM CDT Sun Sep 15 2024 ...New SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (This evening through Monday Night) Issued at 307 PM CDT Sun Sep 15 2024 Latest surface analysis indicates the presence of a weak surface boundary over the northeastern portion of the area, running roughly along a line from just north of Madisonville towards Livingston as of 3 PM CDT. With robust surface moisture in place and marginal but nonetheless present surface instability, the development of scattered thunderstorms is possible over the next 3-6 hours. Radar imagery at the time of publication shows a cluster of storms over Leon County, with additional activity beginning to develop just northeast of Huntsville. A southwestward expansion in storm coverage is anticipated as the afternoon/early evening draws on, with the storm threat shifting to the northern portions Greater Houston by 5-6 PM. High resolution guidance remains split on how far southward of an expansion we will see, but the bulk of activity should remain confined to areas north of I-10. While severe impacts are not expected, a few stronger wind gusts and isolated brief downpours may accompany any convection. Storm activity will begin to diminish after sunset, with a partly cloudy and calm night anticipated as winds shift to the northwest behind the aforementioned boundary. These conditions could drive the development of patchy fog through the early morning hours of Monday. Overnight lows will generally sit in the 70s, perhaps remaining at 80 along the immediate coast. A less active day is expected on Monday as we begin to transition into a pronounced mid/upper level blocking pattern that will keep conditions warm but otherwise benign for several days. Look for highs in the low to mid 90s, lows in the low to mid 70s, and slightly lower dew points thanks to the transition to a light W/NW wind. Cady && .LONG TERM... (Tuesday through next Saturday) Issued at 307 PM CDT Sun Sep 15 2024 500mb analysis shows a classic omega blocking pattern setting up for the majority of the week as a tropical low moves inland on the east coast, and a series of low pressure systems move towards the Four Corners/Central CONUS from the Pacific NW, resulting in a ridge and ridge axis over the Great Plains/Texas area. This setup will keep SE Texas relatively dry and subsidence will bring daytime temperatures to normal and above normal temperatures for this time of year. Despite the high pressure setup, southerly surface winds and low- level moisture (particularly in the coastal areas) could result in isolated showers/storms developing along the sea breeze Thursday and Friday. Low pressure from the Pacific NW will continue to move E this weekend, with high pressure being forced southward into Mexico. The area of low pressure along the E CONUS will come into close proximity with an area of high pressure in the NE CONUS, resulting in a rex block pattern. Here in SE Texas, there will be an increase in mid- upper level PVA as a surface frontal boundary approaches. The combination of PVA and forcing from the incoming frontal boundary will result in an increase in rain chances going into this coming weekend. Have maintained PoPs near the previous forecast as it is still a bit far out in the long-range. && .AVIATION... (18Z TAF Issuance) Issued at 1258 PM CDT Sun Sep 15 2024 While VFR conditions will generally prevail for the TAF period, will need to keep a close eye on the development of scattered storms along and north of the I-10 corridor later this afternoon. Latest high resolution models point to a potential window of around 22Z through 02Z, during which scattered storms could produce a few gusty winds and/or periods of reduced visibility in addition to lightning. The storm threat will diminish overnight, though light winds and relatively high moisture levels may favor some patchy fog development, perhaps reducing visibility to MVFR levels for a brief period. Tomorrow, light W/NW winds develop behind an advancing boundary. Cady && .MARINE... Issued at 307 PM CDT Sun Sep 15 2024 Winds will briefly shift to the north-northwest this evening/tonight ahead of a passing weak boundary. Isolated showers/storms will also be possible during this time frame. Light to occasionally onshore winds resume by Monday afternoon. Winds will vary between southwesterly and southeasterly throughout the day each day. Isolated rain/storms are also possible with the best chances towards the end of the week and into the weekend. && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 73 95 72 95 / 30 0 0 0 Houston (IAH) 76 95 75 94 / 30 0 0 0 Galveston (GLS) 78 86 77 86 / 10 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ SHORT TERM...Cady LONG TERM....Adams AVIATION...Cady MARINE...Adams