FXUS64 KHGX 181700 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 1200 PM CDT Fri Sep 18 2026 ...New DISCUSSION, AVIATION, MARINE... .KEY MESSAGES... - Hot and dry, with lower humidity through Saturday. - Humidity returns Sunday along with daily diurnal storm chances into next week. && .DISCUSSION... Issued at 1200 PM CDT Fri Sep 18 2026 Satellite derived PW depicts quite the moisture gradient across Southeast Texas. As of early this afternoon, areas west of I-45 remain with PW values closer to the 75th percentile (~1.80") whereas much drier air near or below the 25th percentile (~1.18") moves in from the east and is currently enveloping areas near and east of I- 45. Your first question (other than how long it'll last...we'll get to that) is probably what impacts will this have on the forecast. Rain chances won't completely go away for areas near Matagorda Bay today where we've already seen spotty showers earlier this morning. Lingering moisture down there will keep isolated showers in the forecast through the early afternoon. High temperatures will still top out in the 90s, but it'll be a drier heat out east versus the typical humid heat out west. All of us will get the dry heat Saturday though! The main impact of this drier air will be felt overnight. Drier air cools more efficiently, so low temperatures (outside of urban and coastal areas) will range from the upper 60s to the low 70s. Upper 60s was not a typo! It won't be a fall-type of feel, but it's the closest we can get for now. Areas around the Houston metro area and along the coast will only bottom out in the mid 70s to low 80s, so we'll have to wait a little bit longer to see near normal low temperatures (low 70s). This did make me wonder when was the last time Houston was below 70 degrees (we won't get below 70 tonight, so don't get excited). The last time we were below 70 degrees was 113 days ago on May 28th. The autumnal equinox is coming up on Tuesday the 22nd, so there is a light at the end of the tunnel...but that light extends past this forecast period. Drier air also heats up efficiently and with PW values remaining near the 25th percentiles on Saturday, expect high temperatures mainly in the mid to upper 90s. Can't entirely rule out some mid morning to early afternoon showers along the coast. Low-level moisture increases on Sunday with a ridge axis sliding in and a developing mid-level high (heatdome) developing overhead around midweek. This means hot and humid conditions will be back on the menu along with daily chances for isolated showers/storms mainly south of I-10 along the seabreeze. I do want to address that some deterministic guidance is showing the potential for a backdoor cold front around Wednesday/Thursday. It's too early to lock in one solution over another, but I can say that even if the front manages to push through it wouldn't be a drastic change in temperatures based on what we're seeing in the ensemble guidance. Take a peek at the forecast for low temperatures after Wednesday and you'll see what I mean. Long story short: even though we're on the cusp of astronomical fall, the hot and humid pattern continues to hold on after our brief period of drier conditions. Batiste && .AVIATION... (18Z TAF Issuance) Issued at 1200 PM CDT Fri Sep 18 2026 VFR conditions will prevail during this TAF cycle. E winds today will become calm and VRB overnight, and then turn SE next morning. MVFR cigs/vis are possible at CXO during the overnight/early morning period, so model trends will continue to be monitored. JMG && .MARINE... Issued at 1200 PM CDT Fri Sep 18 2026 Light to occasionally moderate easterly winds continue to persist today. Expect these winds to transition to southeasterly by Saturday night. Onshore flow will prevail through early next week, then easterly winds make a return around midweek. Daily chances for isolated to scattered showers and storms continue mainly in the overnight to morning hours offshore and late morning to afternoon near the bays. Batiste && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 72 98 73 97 / 0 0 0 0 Houston (IAH) 75 95 76 96 / 0 0 0 20 Galveston (GLS) 83 90 83 90 / 0 10 20 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ DISCUSSION...Batiste AVIATION...JMG MARINE...Batiste