Area Forecast Discussion
Issued by NWS Houston/Galveston, TX
Issued by NWS Houston/Galveston, TX
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669 FXUS64 KHGX 200444 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 1144 PM CDT Thu Sep 19 2024 ...New LONG TERM, AVIATION, MARINE... .SHORT TERM... (This evening through Friday Night) Issued at 218 PM CDT Thu Sep 19 2024 Upper level ridging centered over the TX Big Bend/northern MX remains strong, resulting in little weather pattern change across SE TX. At the surface, high pressure system continues overhead, leading to light to occasionally moderate warm and humid onshore flow. Overall, this pattern will keep us under a mostly dry, humid and hot pattern in the next few days. Highs will generally range into the low to mid 90s. Continue practicing heat safety as afternoon heat indices into the 100 to 107 degF range can be expected. A few showers will continue to develop along the coast, more towards the Matagorda/Palacios area. Decent moisture convergence (more likely due to sea breeze), and PW values into the 1.8 - 2.1 inch range are resulting in these light showers today and then again on Friday. Mild nights with mostly clear skies can be expected. Light winds and residual moisture will once again lead to areas of fog, some locally dense, across portions of the region. Most of this activity will be patchy and/or low-lying and should persist through mid Friday morning. JM && .LONG TERM... (Sunday through next Thursday) Issued at 1136 PM CDT Thu Sep 19 2024 Hot and humid weather will continue on Sunday as the upper-level ridge remains centered over the Western Gulf Coast. Afternoon high temperatures will again be in the low to mid 90s along and north of the US-59 corridor, and then mid to upper 80s along the coast with heat indices rising into the upper 90s and into the triple digits for much of the area. The ridge of high pressure will continue to limit any afternoon shower or thunderstorm development. This high pressure will gradually move further east into the Gulf through the week, and possibly weaken - but guidance is rather uncertain on the future strength of this ridge. With the weakening subsidence aloft, we will see a very gradual lowering of temperatures through the week - but still above normal. High temperatures on Monday will be about 1-2 degrees cooler than Sunday, then dropping another 1-2 degrees by Wednesday and Thursday with much of the area getting high temperatures in the upper 80s to low 90s. Not much of a cool down, but its something. The overnight temperatures will still continue to be much above normal with lows in the low to mid 70s for much of the area, and then mid to upper 70s in the Houston Metro and along the coast. The lower heights aloft will also allow for the return of afternoon showers and thunderstorms to develop, especially along the seabreeze. So there is a slight chance to a chance of rainfall each afternoon generally along and south of I-45. NHC continues to monitor a tropical wave in the Caribbean and gives it a Medium, 40%, chance of development within the next 7 days as it approaches the Yucatan. There is still much uncertainty with this system, which hasn`t even formed yet, and the upper level pattern as we go into the end of next week. Main takeaway is just continue to follow the official forecasts from the NHC through the next several days. Fowler && .AVIATION... (06Z TAF Issuance) Issued at 1136 PM CDT Thu Sep 19 2024 Confidence is increasing that there will be areas of MVFR cigs and vis during the morning hours on Friday. However, there continues to be some question regarding how widespread the reduced vis/cigs will be, as well as uncertainty regarding if these lower cigs/vis can push into Houston`s urban core and impact IAH and HOU. The urban heat island in hot air masses can often help spare the urban terminals from sub VFR conditions (especially regarding fog). Therefore, we remain somewhat apprehensive to jumping on the prevailing MVFR bandwagon at IAH and HOU. That being said, we have added a higher end MVFR 10-13Z TEMPO group for IAH while lowering the prevailing HOU vis down to 6SM BR for the same time period. Cannot rule out needing to amend the forecast if trends more strongly point towards sub VFR in the city. Any MVFR conditions should lift by mid- morning, with VFR conditions and light winds prevailing through the rest of the day. Sea breeze could bring SE winds over 10 knots between the coast and Houston later in the day. && .MARINE... Issued at 1136 PM CDT Thu Sep 19 2024 Light to occasionally moderate onshore flow (5-10kt during the day, then 10-15kt during the overnight and early morning hours) and low seas (1-3ft) will continue through the weekend and into next week. There will be increased chances of scattered showers and thunderstorms over the coastal waters beginning Sunday night and continue through at least midweek next week. Fowler && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 98 75 97 73 / 0 0 0 0 Houston (IAH) 96 77 96 76 / 0 0 0 0 Galveston (GLS) 90 80 89 80 / 10 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ SHORT TERM...JM LONG TERM....Fowler AVIATION...Self MARINE...Fowler