-- Discussion containing changed information from previous version are highlighted. --
280
FXUS64 KHGX 200520
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1220 AM CDT Thu Jun 20 2024

...New AVIATION...

.UPDATE...
Issued at 726 PM CDT Wed Jun 19 2024

A Tornado Watch is now in effect for Jackson and Matagorda
counties until 7 AM Thursday. This watch also includes Matagorda
Bay and the coastal waters from Freeport to the Matagorda Ship
Channel out 20 NM. Increasing low level shear along the Texas
Coastal bend from Tropical Storm Alberto will provide favorable
conditions for the development of isolated Tornadoes and
Waterspouts.

&&

.SHORT TERM...
(This evening through Thursday Night)
Issued at 103 PM CDT Wed Jun 19 2024

Tropical Storm Alberto continues to bring hazardous conditions
across the SE Texas coast this afternoon. Widespread showers are
expected to continue into portions of Thursday, though rainfall
rates thus far have been manageable. Still, there is a Slight (level
2/4) to Marginal (level 1/4) Risk of excessive rainfall in areas
along and South of the I-10 corridor. Deep gulf moisture and high
precipitation efficiency may still allow for any stronger storms to
produce locally heavy rainfall and flash flooding. A FLood Watch
remains in effect for areas South of the I-10 corridor until 1 AM
Thursday.

While heavy rainfall doesn`t appear to be a considerable threat,
moderate coastal flooding is occuring right now across the
Texas/Louisiana coastline. Numerous reports of innundation have been
received spanning locations from High Island to the Matagorda Ship
Channel. Many roadways have become impassable due to water and
debris. Coastal Flood Warnings will remain in effect until 7 PM
Thursday. Please avoid driving and or walking through flood waters
whenever possible.

Tropical Storm Warnings remain in effect across the Gulf Waters,
including corresponding coastal areas from Jackson County to
Brazoria County. The wind field of Tropical Storm Alberto falls
short of the remaining coastal zones, thus a Wind Advisory continues
to be used in lieu for Galveston, Coastal Harris and Chambers
counties for these strong winds.

Finally, storm spotters reported a waterspout near Jamaica Beach
earlier today. SPC has portions of SE Texas under a Marginal (level
1/5) Risk of isolated Tornadoes/Waterspouts from Tropical Storm
Alberto. Make sure to have multiple ways of receiving warnings, as
we cannot rule out the possibility of additional brief spin-ups
within this Tropical System.

Conditions should begin to improve Thursday Night into Friday as
Tropical Storm Alberto Tracks Westward into Mexico, later
dissipating.

03

&&

.LONG TERM...
(Friday through next Tuesday)
Issued at 103 PM CDT Wed Jun 19 2024

Will remain unsettled through the long term period with a
persistent moderate easterly flow and abundant deep moisture.
Alberto will be long gone but development of a new cyclone is a
good bet in the Bay of Campeche by Friday or Saturday, similar to
what we observed with Alberto. High pressure to the north will
likely keep this next system from tracking N toward the
area...once again keeping the center well S...tracking westward
into Mexico. Unlike Alberto the pressure gradient and associated
winds will not be quite as strong...and size of wind field around
cyclone not quite as large so not looking at a carbon copy...but
do expect breezy conditions with elevated seas and tides even in
the extended range...just not quite as high as we are observing
today. Will have daily rain changes...with higher chances southern
zones...lesser rainfall northern...with drier conditions thanks
to surface ridge and subsidence.

Reilly

&&

.AVIATION...
-- Changed Discussion --
(06Z TAF Issuance)
Issued at 1211 AM CDT Thu Jun 20 2024

As expected, we have reached a lull in the shower activity and so
far, only light isolated showers are currently moving over the
southern and coastal portions of SE TX. This trend is expected to
continue for the rest of the night into early morning hours. E
winds have relax a bit inland but GLS/LBX will likely continue to
see gusts between 20-35 kts. Winds are expected to pick up again
around sunrise, mainly for sites IAH southward. Hi-Res models
continue to indicate a few more rounds of showers and iso storms
starting along the coastal areas during the mid to late morning
timeframe, expanding northward across much of SE TX in the
afternoon to evening hours. Will likely continue the issuance of
AMDs and TEMPOs as the event unfolds moving into the local throughout
the day.

Mostly MVFR to VFR conditions are expected, however, stronger
showers could result in brief moments of IFR vis/cigs as well as
stronger wind gusts. Small quick vortices and areas of llvl wind
shear are also not out of the question.

24
-- End Changed Discussion --

&&

.MARINE...
Issued at 103 PM CDT Wed Jun 19 2024

Hazardous marine conditions are expected to persist into Thursday as
Tropical Storm Alberto continues to approach the coast of Eastern
Mexico. Overnight and into tomorrow, tropical storm force winds are
expected to continue across Matagorda Bay and the SE TX coastal
waters. Winds of 25-35 knots with gusts of up to 50 knots are
possible, along with seas of 10 to 17 feet. Across Galveston Bay,
winds of 25 to 30 knots with gusts as high as 40 knots are possible.
As a result, a Small Craft Advisory remains in effect. Conditions
will begin to gradually improve on Thursday as Alberto makes
landfall in Mexico and pushes inland.

In addition to the hazardous marine conditions, this system is
expected to continue to result in flooding along the SE TX coastline
through tomorrow`s high tide. Inundation of 2-4 ft (locally higher)
is expected to impact the immediate coast. Finally, the strong
onshore winds associated with Alberto will produce strong rip
currents through at least Friday morning.

Cady/Ellis

&&

.TROPICAL...
Issued at 103 PM CDT Wed Jun 19 2024

As of 1 PM CDT, the center of what is now Tropical Storm Alberto
was located approximately 295 miles south-southeast of
Brownsville, or just over 400 miles southwest of Matagorda Bay.
Despite how far the center of circulation is from the SE TX coast,
the unusually large swath of tropical storm-force winds extending
from the system will continue to produce impacts across the area.
The primary concern overnight and into tomorrow morning`s high
tide will continue to be coastal flooding, where 2-4 ft (locally
higher) of inundation are possible along the immediate coast.
Coastal flooding has already resulted in impacts to many of our
coastal communities, including Galveston, Jamaica Beach, Surfside
Beach, and Sargent. In addition to this, some brief heavy
downpours may produce pockets of isolated flash flooding through
the remainder of the afternoon and into the evening, with the
highest risk for this across locations surrounding Matagorda Bay.
Tropical storm force winds will continue to remain a possibility
along portions of the SE TX coast, in addition to our coastal
waters (not including Galveston Bay). Gusts as high as 50-55 mph
will remain a possibility at times. Finally, an isolated
waterspout/tornado associated with advancing rainbands can`t
totally be ruled out...earlier today, we received visual
confirmation of a waterspout just offshore of Jamaica Beach.

Conditions should begin to improve on Thursday afternoon as Alberto
pushes inland along the Eastern Mexico coastline.

Cady/Ellis

&&

.PRELIMINARY POINT TEMPS/POPS...
-- Changed Discussion --
College Station (CLL)  73  93  73  94 /  10  10   0   0
Houston (IAH)  74  91  74  94 /  20  30   0  10
Galveston (GLS)  81  88  81  88 /  30  40  10  20
-- End Changed Discussion --

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
TX...Tropical Storm Warning for TXZ335>337-436-437.

     Coastal Flood Warning until 7 PM CDT this evening for TXZ214-313-
     335>338-436>439.

     Wind Advisory until 7 AM CDT this morning for TXZ214-238-313-338-
     438-439.

     Flood Watch until 1 AM CDT early this morning for TXZ338.

     High Rip Current Risk through this evening for TXZ436>439.

GM...Tropical Storm Warning for GMZ330-350-355-370-375.

     Small Craft Advisory until 7 AM CDT this morning for GMZ335.
-- End Changed Discussion --

&&

$$

SHORT TERM...03
LONG TERM....Reilly
AVIATION...Cotto (24)
MARINE...Cady