899
FXUS64 KHGX 212010
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
310 PM CDT Fri Jun 21 2024

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

.SHORT TERM...
(This evening through Saturday Night)
Issued at 309 PM CDT Fri Jun 21 2024

Scattered showers have begun to build across the greater Houston
area, with the highest amounts in localized areas being about 0.25
inches. These pop-ups are expected to continue into this evening,
with additional rainfall being less than 0.1 inches. Rain should not
continue overnight with the loss of daytime heating after sunset.
Low temperatures tonight should be in the middle to upper 70s, with
low 80s being possible along the immediate coastline.

The high pressure system over the Gulf coast continues to build
throughout tonight and tomorrow, leading to warmer temperatures
across most of the region. Expect widespread low 90s, with some
middle to high 80s in our coastal counties. With our newest tropical
friend remaining in the Southwestern Gulf, our rain chances for
tomorrow remain low. Some very isolated diurnal thunderstorms are a
possibility in the middle to late afternoon and along the immediate
coast, though will likely be short lived with low rainfall rates.

Ellis/Cady

&&

.LONG TERM...
(Sunday through next Thursday)
Issued at 309 PM CDT Fri Jun 21 2024

Sunday is National Hydration Day, but you`re definitely going to
want to celebrate that throughout the week as temperatures remain
solidly in the low to mid 90s. A mid/upper level high remains in
place over the Southern Plains throughout the weekend and into next
week, which will serve to increase subsidence and thus provide us
with temperatures in the 90s. A slight increase in moisture from a
potentially developing tropical system in the Bay of Campeche early
next week will keep PW values in the 1.7"-2.0" (75th percentile:
~1.87"). That elevated moisture will do two things: for one it`ll
lead to daily rain chances (albeit on the light and scattered side
since there will be subsidence to overcome) and increase humidity
(thus increasing heat index values). Hmmm actually three things!
We`ll likely see an increase in probabilities for patchy fog during
the overnight hours early next week.

Temperatures next week will be mostly in the mid 90s north of I-10
(with isolated instances of upper 90s in the Brazos Valley/Piney
Woods) and low 90s south of I-10. Combine that with dew points
solidly in the upper 70s to near 80F and we have heat index values
that are likely to reach Heat Advisory criteria (108F or greater).
We could be looking at a multi-day stretch of heat index values at
least flirting with advisory criteria. By midweek, the main ridge
axis slides off to the west as an upper level trough sweeps through
the Mississippi River Valley. This places us in northwesterly flow
aloft, so we may catch the tail end of storms moving in from the
northwest ahead of a weak frontal boundary (that front will come
nowhere near us...it`s summer). We are officially in astronomical
summer now, but with an expected multi-day stretch of heat index
values well into the triple digits now would be a good time to brush
up on your heat safety tips. There won`t be much relief during the
overnight hours with low temperatures only bottoming out in the
upper 70s to near 80F.

Batiste

&&

.AVIATION...
(18Z TAF Issuance)
Issued at 1227 PM CDT Fri Jun 21 2024

VFR conditions should generally remain in place throughout the
upcoming TAF period, with E/ESE winds around 10 knots prevailing
through the afternoon before winds become light and variable
overnight. Some scattered showers are expected to develop over the
course of the afternoon, but coverage will not be widespread
enough to warrant anything beyond VCSH wording for the time being.
Tomorrow, mostly clear skies and ESE winds near 10 knots are
expected throughout the day with the precipitation threat minimal.

Cady

&&

.MARINE...
Issued at 309 PM CDT Fri Jun 21 2024

Moderate easterly winds persist this afternoon, but have fallen
below the advisory threshold. Elevated seas persist in the offshore
Gulf waters and are expected to remain around 7 feet through the
late afternoon hours. A Coastal Flood Advisory remains in effect for
coastal areas around Galveston Bay into Saturday afternoon with
water levels forecast to reach around 3 to 3.5 feet above MLLW
during high tide on Saturday. With the next potential tropical
system developing in the Bay of Campeche late this weekend, the
increased risk of rip currents will remain throughout the weekend.
While the weekend will be mostly dry, but beginning early next week
there will be daily chances for showers and storms due to increasing
moisture from a potentially developing tropical system. This
potential tropical system is anticipated to develop in a similar
location to Alberto and also take a similar path. However, we are
not expecting much if any impacts from this system other than
increasing rain chances, continued high risk of rip currents, and
slightly elevated water levels during high tide. Mariners are
advised to keep up to date with the latest forecast and tropical
updates.

Batiste

&&

.TROPICAL...
Issued at 309 PM CDT Fri Jun 21 2024

Latest satellite imagery shows a large area of thunderstorms around
and over the Yucatan Peninsula. This is expected to become a broad
area of low pressure over the Bay of Campeche late Friday night and
could potentially become a tropical depression over the weekend.
This system will take a very similar track as Alberto and drift
westward or west-northwestward into the eastern Mexico coastline. As
far as local impacts go, we`re not expecting anything close to what
we saw with Alberto earlier this week. At most, we`re looking at an
increased risk in rip currents, elevated rain chances due to
increasing moisture, and slightly elevated tide levels during times
of high tide (but not as robust as what we saw with Alberto). The
National Hurricane Center still has the probability of formation
into a tropical cyclone within 2 days at 50% (medium) and at 60%
(medium) within 7 days.

Long story short, this is not Alberto part 2 and we are not going to
see any substantial impacts from this system as it moves into
eastern Mexico late this weekend/early next week.

Please continue to monitor the latest forecasts for any
updates from the National Hurricane Center at www.hurricanes.gov.

Batiste

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  72  94  71  95 /  10   0   0  10
Houston (IAH)  75  93  74  95 /  10   0   0  20
Galveston (GLS)  80  89  81  89 /  20   0  10  30

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Coastal Flood Advisory until 7 PM CDT Saturday for TXZ214-313-
     338-438-439.

     Coastal Flood Advisory until 7 PM CDT this evening for
     TXZ335>337-436-437.

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

GM...Small Craft Should Exercise Caution until 10 PM CDT this evening
     for GMZ350-355.

     Small Craft Advisory until 7 PM CDT this evening for GMZ370-375.

     Small Craft Should Exercise Caution from 7 PM CDT this evening
     through Saturday morning for GMZ370-375.

&&

$$

SHORT TERM...Ellis/Cady
LONG TERM....Batiste
AVIATION...Cady
MARINE...Batiste