AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 1108 PM CST Wed Jan 29 2025 ...New AVIATION... .SHORT TERM... (This evening through Thursday Night) Issued at 242 PM CST Wed Jan 29 2025 For the time being, we will remain in the overcast, damp, and foggy pattern of the last several days ahead of the approach of a cold front on Thursday. The synoptic regime has undergone some changes from yesterday, namely the eastward shift of a robust upper level low over the Four Corners region and resultant tightening of the surface pressure gradient to our SW as an area of low pressure deepens slightly. As such, we have seen an increase in the strength of the SE winds in place across the area today, a trend which will continue into the evening. With these steady onshore winds providing increased WAA, overnight lows will generally sit in the low to mid 60s with the SW zones in the upper 60s. Despite elevated winds overnight, relatively cold coastal waters will continue to promote the development of sea fog which should advect inland over the course of the evening. This, combined with the potential for inland radiation fog, will result in reduced visibilities across SE TX overnight and into tomorrow morning. Dense fog will be possible at time, and as such those traveling tomorrow morning should be cognizant of local road conditions. Fog will likely linger into the morning hours as a cold front approaches the area. Some scattered showers ahead of the front will be possible, but rainfall rates/coverage should at first remain low. A surface cold front remains on track to move into the area from the NW beginning tomorrow morning in the Brazos Valley/Piney Woods, reaching the Inner Loop by early afternoon and the coast by the late afternoon. Accompanying this front will be a line of showers with isolated thunderstorms. Environmental parameters present a very conditional severe weather picture. While effective shear will be abundant (40-50kt), instability will be quite limited. The morning HREF indicates only a 20-30% probability of SB CAPE reaching 500 J/kg or greater for portions of the area, and as such the prospect of a severe storm is nonzero but not particularly high. Still, a few embedded stronger storm could result in a few instances of gusty winds and locally heavier rainfall rates. General rainfall totals should range from 0.5 - 1", with a few locally higher amounts. As the front moves offshore tomorrow night, expect a gradual clearing through early Friday with winds shifting to the NW. Overnight lows should generally sit in the upper 40s to near 50 as cool, dry air moves in behind the boundary. Cady && .LONG TERM... (Friday through next Tuesday) Issued at 242 PM CST Wed Jan 29 2025 In the wake of the cold front on Friday and going into the weekend surface high pressure will build into the region. High temperatures on Friday will reach the mid 60s to low 70s. Friday night still looks to be our coldest night for this period with min temps from the upper 30s far north to near 50 at the coast. A benign weather pattern will be in place through early next week with zonal flow aloft. We will see a gradual warmup with above normal temperatures beginning this weekend. Onshore flow will quickly return this weekend which will also allow moisture levels to rise through the period. Although moisture levels rise, no significant chances of rain due to high pressure dominating the forecast. A slight chance of showers is expected just after the period around mid-week due to a weak upper level disturbance. Wood && .AVIATION... (06Z TAF Issuance) Issued at 1041 PM CST Wed Jan 29 2025 IFR to LIFR conditions will persist through the morning with CIGs around 300-600ft across the region and dense fog developing along the coast (with patches of dense fog elsewhere). Conditions won`t really improve until the passage of an anticipated cold front that will move through the region during the late morning through the afternoon. There will be some isolated prefrontal showers overnight tonight through Thursday morning, and then a thin line of showers and storms expected with the passage of the front. Southeasterly winds of 7-12kt with occasional gusts to 20-25kt will persist through the morning, then switch westerly and northwesterly following the FROPA. VFR conditions are expected for most of the region by the evening hours, however lingering moisture may lead to MVFR CIGs and patchy fog along the coast until Friday morning. Fowler && .MARINE... Issued at 242 PM CST Wed Jan 29 2025 Sea fog will continue to be the primary marine hazard over the next couple of days until a cold front pushes offshore by Thursday evening. Will be continuing a dense fog advisory for the nearshore waters and Galveston bay into tomorrow morning. Dense fog continues this afternoon over the nearshore waters and dense fog will likely return to most of Galveston bay this evening. However, visibilities may not get as low as they did this morning due to wind speeds increasing late tonight ahead of the approaching storm system. Onshore flow will strengthen throughout Thursday leading to an upward trend in winds and seas. As a result, there will be a mixture of caution flags and advisories for the Gulf waters beginning tonight and extending into Thursday night. Winds subside rather quickly behind the front with light to moderate northwesterly winds prevailing, but seas may take until Friday morning to recede below the caution flag threshold. Benign marine conditions are expected over most of the weekend, but onshore flow returns by Saturday night. So, the chance of sea fog will return as dew points begin to surge back into the lower 60s late this weekend. Wood && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 61 71 46 68 / 70 90 0 0 Houston (IAH) 64 73 51 68 / 30 90 0 0 Galveston (GLS) 58 66 52 64 / 10 80 30 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...Dense Fog Advisory until 8 AM CST Thursday for TXZ214-313-338- 436>439. GM...Dense Fog Advisory until 9 AM CST Thursday for GMZ330-335-350- 355. Small Craft Should Exercise Caution through Thursday evening for GMZ350-355. Small Craft Should Exercise Caution until midnight CST tonight for GMZ370-375. Small Craft Advisory until midnight CST Thursday night for GMZ370-375. && $$