-- Discussion containing changed information from previous version are highlighted. --
468
FXUS64 KHGX 212325
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
625 PM CDT Tue May 21 2024

...New AVIATION...

.SHORT TERM...
(This evening through Wednesday Night)
Issued at 1257 PM CDT Tue May 21 2024

With no major changes to the synoptic pattern expected in the
immediate term as upper ridging continues to remain the main feature
over the South Central CONUS, the warm and humid pattern is expected
to prevail through the remainder of the week and into the weekend.
As such, the main weather story for the time being remains the
potential for elevated heat impacts. Latest observations show some
heat index values breaking into the triple digits this afternoon, a
trend that is expected to continue for the foreseeable future. With
this being an early season heat event and thus heat acclimation
being relatively low, it will remain important to consider heat
safety actions if performing any sort of strenuous outdoor activity.
Experimental HeatRisk values, which take into account the departure
from climatological normal temperatures, remain at a Moderate level
today and will generally remain at this level tomorrow. The heat
impacts of highs near 90 today and tomorrow will be compounded
further by very high dew point values, generally sitting in the
upper 70s across most of the area. Overnight lows will sit in the
upper 70s to near 80.

Some isolated showers and storms are possible tomorrow across the
far northern zones as a series of weak midlevel shortwaves pass to
our north. While most of the resultant precipitation should fall
closer to the D/FW metro area, an isolated storm or two can`t be
ruled out across positions of the Brazos Valley/Piney Woods tomorrow
afternoon.

&&

.LONG TERM...
(Thursday through next Monday)
Issued at 1257 PM CDT Tue May 21 2024

UL ridging will continue to dominate the pattern through at least
the weekend. Thursday`s conditions are forecast to be very similar
to Tuesday/Wednesday. Temperatures are likely to become hotter by
Friday and especially this weekend as LL cyclogenesis over
Oklahoma veers the 850-700MB flow to the southwest. The resulting
WAA aloft will boost 850MB temps several degrees centigrade by
week`s end. Friday afternoon temps are expected to average in the
low 90s. Western, inland counties could make a run for the mid 90s
while the immediate coast remains in the mid/upper 80s. But by
Saturday and Sunday, much of the inland CWA could be in the mid
90s while coastal areas approach the 90 degree mark. Weak
shortwaves aloft along with plentiful LL moisture will be fighting
a stout cap thanks to the ridge. Therefore, PoPs are very low
this weekend (0-10%). Best chance of an isolated rogue shower will
be in our northernmost counties. A frontal boundary associated
with a potential developing low over Oklahoma may approach the
region by Monday or Tuesday of next week. But my confidence in a
front (even a week front) making it down here early next week is
pretty low. For now, the early outlook for Memorial Day is quite
hot (widespread mid 90s) and humid. Heat index values this weekend
and early next week could approach heat advisory criteria.
Experimental HeatRisk values suggest Major (Level 3 of 4) to
Extreme (Level 4 of 4) Risk over the weekend into Monday. For
those of you planning to spend your holiday weekend outside, be
advised that temperatures and humidity may be quite high, even for
Houston late May standards. Overnight lows are expected to fall
into the mid 70s to low 80s. Low PoPs (10-20%) are introduced
north of I-10 Monday evening/night due to the potential
aforementioned frontal boundary.

&&

.AVIATION...
-- Changed Discussion --
(00Z TAF Issuance)
Issued at 619 PM CDT Tue May 21 2024

Ceilings will continue to gradually drop to MVFR conditions this
evening and will persist through mid/late Wednesday morning.
Brief periods of IFR conditions will be possible, especially
around terminals north of IAH. VFR conditions can be expected by
Wed afternoon, but MVFR cigs may persist along the coast. Winds
will remain from the SE, SSE at around 10 knots or less tonight,
strengthening up to 15 knots by Wednesday afternoon.

JM
-- End Changed Discussion --

&&

.MARINE...
Issued at 1257 PM CDT Tue May 21 2024

A persistent, generally moderate southeasterly flow regime is
likely to continue through the weekend. At times, winds will be
strong enough to warrant caution flags and possibly small craft
advisories. Offshore seas are expected to average 3 to 5 feet.
However, seas could occasionally reach 6-7 feet offshore. Rain
chances remain low through the forecast period. Heat and humidity
will be higher than normal through at least the weekend, if not
early next week.

&&

.HYDROLOGY...
Issued at 306 AM CDT Tue May 21 2024

Minor to major river flooding continues for parts of Southeast
Texas, particularly along portions of the Trinity and Brazos
rivers. The following river points are either currently in flood
stage or are forecast to reach flood stage (as of early Tuesday
morning):

MAJOR//
-------
- Trinity River (Liberty): Major

MODERATE//
----------
- Trinity River (Goodrich): Moderate
- Trinity River (Riverside): Moderate
- Trinity River (Moss Bluff): Moderate
- Brazos River (West Columbia): Moderate (forecast)

MINOR//
-------
- East Fork San Jacinto (New Caney): Minor
- Brazos River (Richmond): Minor
- Brazos River (Rosharon): Minor
- Brazos River (Sugar Land): Minor

Remember to heed any instructions from your local officials and to
never travel through ANY flooded areas or roadways. TURN AROUND,
DON`T DROWN. Please monitor updated forecasts via the NWS AHPS
website and/or the new NWS NWPS webpage (https://water.noaa.gov/) as
the river flood threat persists.

Batiste

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  77  89  75  91 /  10  10  10  10
Houston (IAH)  78  87  76  90 /  10  10   0   0
Galveston (GLS)  79  83  78  84 /   0   0   0   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
TX...High Rip Current Risk through Wednesday evening for TXZ436>439.

GM...None.
-- End Changed Discussion --
&&

$$

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