FXUS64 KHGX 201121
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
621 AM CDT Sun Sep 20 2026

...New AVIATION...

.KEY MESSAGES...

  - Hot with a daily risk of isolated showers and thunderstorms
    along the sea breeze boundary.

  - Chance of late afternoon / evening thunderstorms has increased
    for our northern counties on Monday. 

  - Slightly less hot later in the week. 
    

&&

.DISCUSSION...
Issued at 1200 AM CDT Sun Sep 20 2026

Overall, the general expected synoptic pattern over the next few
days has not changed. Persistent, yet weakening, ridging should
dominate the Lone Star State. The ridge will be influential enough
to help skew temperatures hotter than normal. But it shouldn't be
suppressive enough to prevent diurnally forced isolated showers
and thunderstorms. We suspect there will be a daily risk of 
isolated showers/storms, particularly in our southern and coastal 
counties. However, the guidance is suggesting the high may erode a
little more on Monday, allowing PVA from a shortwave to sneak 
into our region by the afternoon and evening. 00Z HRRR is even 
going as far as showing thunderstorm activity in our northern 
counties by late Monday afternoon. For this reason, I decided to 
add some low PoPs in our northern counties late Monday afternoon 
evening. We'll monitor trends in case we need to bump up PoPs 
during that time frame. Inland afternoon temperatures are expected
to average in the mid / upper 90s through the mid-week (upper 80s
to low 90s at the coast) 

Not much has changed regarding expectations in the late week
pattern. Guidance still suggests a deepening E CONUS trough with
ridging aloft over central CONUS. This signals a continuation of
hot weather, but there may be a backdoor frontal boundary that at
least brings lower humidity and perhaps drops temperatures a few
degrees. 

Self 

&&

.AVIATION...
(12Z TAF Issuance)
Issued at 620 AM CDT Sun Sep 20 2026

Light winds this morning will strengthen and become southeasterly 
during the afternoon. Isolated showers will be possible as well, 
though chances and coverage are currently forecast to be too low to 
warrant a mention with the current TAF cycle. Winds become light and 
variable this evening. Cloud decks lower to around 2000-3000 ft 
overnight into Monday morning. Outside of brief patchy fog in spots, 
VFR conditions should largely prevail throughout the TAF period. 

03

&&

.MARINE...
Issued at 1200 AM CDT Sun Sep 20 2026

Light to occasionally moderate east to southeast winds, should
become more consistently moderate and from the east to northeast
by the middle to later part of the week. There will be a daily
risk of an isolated shower or thunderstorm through mid-week. Gulf
seas are expected to be in the 1-3 foot range. However, seas may
increase somewhat later in the week, possibly nearing 5 feet
well offshore by Thursday. 

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)	  97  75  98  75 /  10   0  20  20 
Houston (IAH)			  96  77  96  78 /  20   0  20  10 
Galveston (GLS)			  90  83  91  82 /  20  10  10  10 

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&

$$

DISCUSSION...Self
AVIATION...03
MARINE...Self