535
FXUS64 KHGX 262035
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
335 PM CDT Fri Jul 26 2024

...New SHORT TERM, LONG TERM, MARINE...

.SHORT TERM...
(This evening through Saturday Night)
Issued at 246 PM CDT Fri Jul 26 2024

The heavier rains of this morning have yielded to a "cool" and
cloudy afternoon featuring scattered showers. Temperatures are
fighting to surpass 80 degrees in some areas. A typical late July
afternoon ranges from low 90s near the coast to mid/upper 90s
inland. So the mid 70s to low 80s we are experiencing today could be
described as "cool" in relative terms. Perhaps we will establish a
few record low max temperatures today. The current shower activity
is expected to diminish as the late afternoon progresses into the
evening.

A well defined mid/upper trough can be seen over Texas via WV
imagery and 500MB RAP analysis. SE Texas is located between the
trough to our west and a mid/upper ridge over Florida. Moist
Tropical Pacific oriented SW flow aloft between the two features is
pushing a continuous stream a mid-level shortwaves up the Texas
Coast. These features in the upper-levels combined with deep LL
tropical moisture and some modest instability will keep the chance
of scattered to widespread showers and thunderstorms in the forecast
for your Saturday. Models indicate increasing PVA tonight into
tomorrow morning. However, there is some disagreement on the timing
of when lift becomes sufficient for shower/thunderstorm development.
Global models suggest we could have showers/storms develop across
our coastal counties as early as midnight. But hi-res CAMs guidance
suggest it may take until the pre-dawn hours before we begin to see
showers and thunderstorms develop. Though most of the CWA has a shot
at receiving rainfall on Saturday, the best chance of receiving
moderate to heavy showers and thunderstorms will be across our
southern and coastal counties during the morning hours. Considering
the saturated antecedent soil conditions, we have opted to extend
the Flood Watch through early afternoon tomorrow across our southern
and coastal zones. Saturday afternoon may end up like today with
overcast skies and scattered residual showers. Afternoon highs are
expected to be in the low/mid 80s. But we cannot rule out some areas
struggling to reach 80 again due to rainfall.

The pattern eventually becomes hotter and less rainy. But I`ll leave
that part of the discussion to the long range forecaster.

Self

&&

.LONG TERM...
(Sunday through next Thursday)
Issued at 246 PM CDT Fri Jul 26 2024

The transition to a more typical summertime pattern will begin on
Sunday as the robust midlevel trough in place across the South
Central CONUS will finally begin to shift to the northeast. Steady
rainfall should begin to taper off on Sunday morning as this
occurs, and over the course of the day broad surface high pressure
will once again become situated across the Eastern Gulf. The
resultant onshore flow regime promoted by this pattern, along with
the presence of a mid/upper ridge that will build into the central
third of the country by Monday morning, will result in decreased
rainfall chances over the course of the upcoming week given the
lack of available synoptic forcing. Rainfall chances through mid-
week will be confined mainly to diurnal heating, as well as the
inland propagation of the sea/bay breezes each afternoon. Have
generally maintained 20-40% PoP values in this forecast package,
with the highest rain chances concentrated along and south of the
Interstate 10 corridor. Rain chances decrease further towards the
end of the week with high pressure solidly overhead.

As one may expect with the transition to a more typical summertime
pattern, temperatures will steadily increase heading into next
week with highs returning to more normal values (mid-90s). With
onshore moisture transport once again keeping dew points elevated,
we could be looking at Heat Index values near 110 and thus will
need to monitor for the potential for Heat Advisories during this
time.

&&

.AVIATION...
(18Z TAF Issuance)
Issued at 1228 PM CDT Fri Jul 26 2024

Scattered SHRA with isolated TSRA expected through the afternoon.
Mention of TS was removed from most TAFs this afternoon. But
afternoon TS chances are not zero, and amendments may be needed of
TS development occurs in the vicinity of terminals. Mostly VFR
with areas of MVFR cigs/vis expected this afternoon. A transition
to more MVFR to IFR conditions are expected overnight into
tomorrow morning. SHRA/TSRA chance begin to increase late
overnight into the morning hours. Best chance of TS activity
appears to be from IAH to the coast. Uncertainty exists regarding
TS timing along with how far inland TS activity will extend
tomorrow late tonight and tomorrow morning.

&&

.MARINE...
Issued at 246 PM CDT Fri Jul 26 2024

Periods of rain, heavy at times, will impact the coastal waters on
both Saturday and Sunday during the earlier parts of the day. Any
stronger storms may produce strong wind gusts and locally elevated
seas. Rainfall chances diminish on Monday as high pressure settles
into the area, promoting the return of a steady onshore flow
regime. Winds and seas should generally remain below caution
thresholds over this time.

Cady

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  73  83  73  87 /  30  50  20  60
Houston (IAH)  74  83  75  87 /  60  70  40  70
Galveston (GLS)  77  86  80  86 /  60  80  50  60

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Flood Watch through Saturday afternoon for TXZ200-213-214-226-
     227-235>238-300-313-335>338-436>439.

GM...None.
&&

$$

SHORT TERM...Self
LONG TERM....Cady
AVIATION...Self
MARINE...Cady