401
FXUS64 KHGX 011747
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1247 PM CDT Wed May 1 2024

...New AVIATION...

.SHORT TERM...
(Today through Thursday Night)
Issued at 243 AM CDT Wed May 1 2024

Active weather pattern returns today and Thursday with periods of
showers and thunderstorms, especially during the overnight hours
through Thursday.

In the near term, stratus and patchy fog will continue to develop
across portions of SE TX early this morning. Fog is not expected to
be as widespread as yesterday, and is expected to burn early this
morning. Low clouds/stratus, on the other hand, will continue
through the day, with just some improvement in the afternoon.
Increasing warm air advection, and daytime heating will help to
spark isolated to scattered showers and thunderstorms late this
morning into the afternoon hours.

The primary concerns in the short term portion of the forecast
revolve around excessive rainfall and convection risks this evening
into Thursday. Model guidance continues to support scattered to
numerous thunderstorms developing across north central Texas and
into Southeast TX later today as a strong upper-level trough moves
through on the nose of a strengthening LLJ. West to southwest flow
aloft, strong forcing and instability and 0-6 km bulk shear around
25-40 knots will support strong updrafts with these storms. There is
a moderate to high probability that this activity will initiate with
a supercellular development to our west, eventually evolving into a
linear MCS as storms move over our forecast area. Damaging winds
will be the primary threat with any strong to severe thunderstorms.
This system is progged to be progressive; but latest trends continue
to show excessive rainfall over areas where recently had significant
rainfall/flooding. For this reason, WPC placed us under a Moderate
Risk (level 3 of 4) and a Slight Risk (level 2 of 4)of excessive
rainfall today/tonight in their Day 1 Outlook and in a Slight Risk
in their Day 2 (Thursday). Most of this activity is progged to be
north of I-10. Widespread rainfall totals of 2 to 4 inches can be
expected north of I-10, with isolated higher amounts of 5 to 8
inches possible. Up to an inch of rain will be possible for areas
south of I-10 (lower amounts towards the coast). The greatest threat
of heavy rainfall and strong to severe storms should gradually
diminish on Thursday during the day.

A Flood Watch has been issued generally for counties north of the
Houston metro area from late this evening through Thursday evening.
Those living in areas prone to flooding should be prepared to take
action should flooding develop.

JM

&&

.LONG TERM...
(Friday through Tuesday)
Issued at 243 AM CDT Wed May 1 2024

Several mid to upper level disturbances embedded in the
quasi zonal flow aloft will continue to move over the region
through early this weekend. During the early morning hours on
Friday, another pulse of low level moisture will move in from the
Gulf waters maintaining PWs between 1.5 to 1.8 inches, in
particular over the Piney Woods region. In addition, there`s the
indication of mid level vort maxes moving over the northern half
of Southeast Texas on Friday. Another thing to note is that
although the low level jet is at its strongest on Thursday, it may
still be present on Friday. Based on this set up, confidence of
seeing a few more rounds of showers and thunderstorms on Friday is
increasing. For now, the best chances for showers and storms
would be Friday morning into early afternoon. Models show very dry
air along the mid levels moving into the region in the afternoon
and could help suppress some of the rainfall, however, good
instability and low level moisture remains throughout the day and
could combine with the vort maxes to help maintain isolated to
scattered storms over portions of Southeast Texas through late
afternoon or early evening. A lull in activity can be expected
Friday night and Saturday morning, although we will need to keep
an eye on a few more vort maxes that are to pass through Saturday
morning. On Saturday afternoon, another round of storms look to
develop mainly over the Brazos Valley and Piney Woods region,
where moisture and instability remains highest. There will be some
capping in place, thus, hopefully PoPs may not be as high as they
are currently forecasted (~30-50%).

One important thing to note is that the higher PoPs are once
again located along and east of I-45 and north of I-10. With the
expected rainfall to occur today and Thursday (in particularly
over the Brazos Valley and Piney Woods region) along with the
potential for localized flash flooding and river flooding, the
additional rainfall on Friday and Saturday could aggravate the
situation even more. Remember, rivers can see water levels
increasing several hours to days after the main rainfall event.
Please continue to monitor the latest forecast and have multiple
ways to receive warnings.

By early next week, fairly tranquil conditions can be expected as
mid to upper level riding dominates the local weather pattern. This
will result in dry but warmer conditions with highs reaching the
upper 80s to low 90s early next week (some locations may reach
the mid 90s). PWs will range between 1.4 to 1.8 inches and with
dewpoints mainly in the low 70s, conditions will feel even warmer
as well as muggy.

24

&&

.AVIATION...
(18Z TAF Issuance)
Issued at 1236 PM CDT Wed May 1 2024

Mixture of VFR/MVFR conditions ongoing this afternoon. GLS
currently at IFR with low CIGs. Expect primarily MVFR this
afternoon with periods of IFR possible. Isolated to scattered
showers and storms will be possible overnight through Thursday
morning. Gusty winds and reduced VSBYs will be possible with any
stronger storms. SE winds will strengthen this afternoon to around
10 to 15 knots.

&&

.MARINE...
Issued at 243 AM CDT Wed May 1 2024

Moderate onshore winds are expected through much of the forecast
period. Winds may flirt with Advisory levels on Thursday. Seas
will generally range between 4 to 6 feet over the offshore waters
and 2 to 5 feet over the nearshore waters. Also, strong rip
currents could occur across the Gulf facing beaches over the next
few days. Periods of showers and storms can be expected through
the end of the work week.

24

&&

.HYDROLOGY...
Issued at 243 AM CDT Wed May 1 2024

River flooding continues, particularly along portions of the
Trinity and San Jacinto rivers. The following river points
continue to remain at or above flood stage as of this morning:

- Trinity River (Goodrich): Major Flood Stage
- Trinity River (Liberty): Moderate Flood Stage, rising to Major
  Flood Stage today
- Trinity River (Riverside): Moderate Flood Stage
- Trinity River (Romayor): Action Stage, rising to Minor Flood
  Stage today
- Trinity River (Moss Bluff): Minor Flood Stage
- Menard Creek (Rye): Moderate Flood Stage
- San Jacinto (New Caney): Major Flood Stage

Additional rainfall over the next few days, both over the area and
upstream, may result in further water level rises and prolonged
river flooding. Remember to heed any instructions from your
local officials and to never travel through flooded areas or
roadways. 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 continues.

24

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  85  70  83  72 /  40  70  60  30
Houston (IAH)  84  72  84  72 /  30  40  40  30
Galveston (GLS)  80  73  80  73 /  30  20  20  30

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Flood Watch from 10 PM CDT this evening through Thursday evening
     for TXZ163-164-176>179-195>200-210>212-300.

GM...None.
&&

$$

SHORT TERM...JM
LONG TERM....24
AVIATION...Adams
MARINE...24