000
FXUS64 KHGX 202104
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
404 PM CDT Sat Apr 20 2024

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

.SHORT TERM...
(This evening through Sunday Night)
Issued at 404 PM CDT Sat Apr 20 2024

Latest radar imagery and surface analysis show scattered showers and
thunderstorms developing and moving north-northeast across SE TX,
and a quasi-stationary boundary, roughly extending along the I-10
corridor. Most of this activity is developing along a maximized
frontogenesis at 1000:925 mb layer, along with increasing PWATs at
or above 1.7 inches. The environment remains favorable for periods
of showers and thunderstorms (a few strong to marginally severe)
this afternoon into the overnight hours. In fact, latest guidance
continues to show increasing PV advection as a strong shortwave
moves through this evening. Strong low level convergence, high
precipitable waters and decent instability will enhance the risk of
training of storms, capable of producing rainfall rates into the 2+
in/hr range. The greatest potential for moderate to heavy rain
continues to be along and north of a line from Columbus to NW Harris
County to Livingston. Total rainfall amounts of 2 to 4 inches can be
expected over these areas. With models continuing to show another
band of frontogenesis in the 925:850mb layer, isolated higher
amounts of 5+ inches will be possible through late night. A Flood
Watch has been issued for the northern half of our counties from
4pm this afternoon through late night. Excessive rainfall may
result in street flooding, especially in low-lying or poor drainage
ares. Flooding of rivers and creeks will also be possible. In
terms of severe weather, decent deep layer shear will be enough to
produce organized updrafts/cells capable of producing up to
quarter sized hail and strong winds, now through this evening.

Shortwave(s) aloft and surface boundary will gradually move out of
the region overnight; though light rain chances may persist through
early Sunday. Behind the boundary, drier and breezy northerly winds
will filter in on Sunday. Clouds will slowly scatter out in the
afternoon, resulting in a comfortable day with highs mainly in the
60s. North-northwest winds, a drier airmass and mostly clear skies
will result in a cool night Sunday night into Monday morning with
lows from the low 40s to mid 50s.

JM

&&

.LONG TERM...
(Monday through next Friday)
Issued at 404 PM CDT Sat Apr 20 2024

Enjoy the start of the upcoming week before a warming temperature and
humidity trend sets in. Highs on Monday will be in the low to mid 70s,
and humidities will be on the low side. An upswing in both temperatures
and humidities will begin on Tuesday as high pressure moves off to the
east. This change will bring southeast winds back to the area, and this
flow will persist and gradually strengthen as the week progresses resulting
in the warming temperatures and increasing humidities. Partly cloudy
skies by midweek will become partly to mostly cloudy by the end of the
week, and rising moisture levels could bring some showers/storms to
parts of our northern counties on Friday afternoon. The entire area
will notice the increase in winds beginning Thursday afternoon and continuing
on into Friday under a tightening pressure gradient (high pressure to
our east and strengthening low pressure off to our northwest and north).

For temperatures, highs on Tuesday will be in an upper 70s to low 80s
range, and by Friday we will have mid to upper 80s. Lows on Tuesday
morning in an upper 40s to mid 50s range will be warming into an upper
60s to low 70s range by Friday.

42

&&

.AVIATION...
(18Z TAF Issuance)
Issued at 1243 PM CDT Sat Apr 20 2024

Scattered showers will continue to develop and move north-
northeast across the terminals this afternoon. Thunderstorms will
be possible in the next hour or so with the best chances by
mid/late afternoon. Showers and storms will continue this evening
into the overnight hours. Rain may become heavy at times,
resulting in lower ceilings and reduced visibility. A few strong
storms may also produce erratic wind gusts. Overall, MVFR ceilings
this afternoon will gradually deteriorate to IFR conditions this
evening through early Sunday. Winds will shift to the north late
this evening as the surface boundary finally moves offshore.

JM

&&

.MARINE...
Issued at 404 PM CDT Sat Apr 20 2024

Onshore winds will persist until a cold front moves off the coast late
tonight, resulting in a shift to moderate to occasionally strong and
gusty north to northeast winds. Showers and thunderstorms will develop
along and ahead of the front, impacting the bays and coastal waters
between later this afternoon and especially this evening through early
Sunday morning. A Small Craft Advisory will be in effect Sunday morning
behind the front. Winds will relax by Monday with onshore flow redeveloping
on Tuesday. Look for gradually increasing southeast winds and seas
as the week progresses.

42

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  53  65  46  71 /  90  20   0   0
Houston (IAH)  57  68  51  74 /  80  30   0   0
Galveston (GLS)  61  70  58  70 /  60  30   0   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Flood Watch through late tonight for TXZ163-164-176>179-195>199-
     210>212.

GM...Small Craft Advisory from 7 AM to 1 PM CDT Sunday for GMZ330-335.

     Small Craft Advisory from 7 AM Sunday to 1 AM CDT Monday for
     GMZ350-355-370-375.

&&

$$

SHORT TERM...JM
LONG TERM....42
AVIATION...JM
MARINE...42