260
FXUS64 KHGX 100854
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
354 AM CDT Fri May 10 2024

...New SYNOPSIS, SHORT TERM, LONG TERM, MARINE, CLIMATE...

.SYNOPSIS...
Issued at 354 AM CDT Fri May 10 2024

Storms have come to an end for the night, and with a weak front
passing through, we should see a short break of fair weather
through the early weekend. Showers and storms return Sunday into
Monday, however. This next bout will bring another chance for
locally heavy rain, and perhaps strong to severe storms as well.
There are plenty of details to iron out, but at this stage, here
are a few main thoughts:
- The weak front moving through early this morning will not
  meaningfully scour out moisture, and we`ll see moisture quickly
  work back in for this next round of storms. WPC highlights most
  of the area in a slight risk for excessive rain (threat level 2
  of 4) on Sunday, and the eastern half of the area continues at
  that threat level on Monday. On both days, the remaining area
  not covered by the slight risk will be in a marginal risk
  (threat level 1 of 4) for excessive rain.
- Recent heavy rainfall will continue to have some influence on
  the most vulnerable locations, as those spots will still have
  relatively more saturated grounds. Thresholds of concern for
  flash flooding will be lowest in the vicinity of Lake
  Livingston. Some area rivers and streams are still swollen,
  including ongoing flooding on the Trinity and Brazos rivers.
- The potential for severe thunderstorms also exists, but
  specifics are less clear at this time than the potential for
  heavy rain. SPC highlights the western half of our area with a
  marginal risk (threat level 1 of 5) on Sunday. There is not yet
  enough confidence to highlight a threat area for any severe
  storms for Monday, but keep checking updated forecasts, as one
  may emerge if confidence in a particular scenario increases.

&&

.SHORT TERM...
(Today through Saturday Night)
Issued at 354 AM CDT Fri May 10 2024

The midnight shift will take credit for killing off the day`s
storms, as they pretty quickly moved off or came to an end not too
long after we arrived! It`s also totally me, and not some modestly
cooler and drier air filtering in behind a weak front, that will
make for fair weather through virtually all of this portion of the
forecast.

Speaking of that front, it is getting to be that time of year
where we call them cold fronts by convention, but the incoming
airmass is already so heavily moderated by the time it gets here,
that there is little to no change in afternoon highs, and even the
nighttime lows don`t get to take too much of a nudge downward as
we`re not even getting a big dip in dewpoints, either. But...this
front has at least enough oomph from high pressure drifting across
the Great Plains that it should clear the area entirely, and make
it out onto the open waters of the Gulf of Mexico before stalling
out, buying us at least a short break of fair weather that is a
little bit cooler and drier.

With the front still in the process of making its way through,
that bit of cooler air today will be largely limited to the
northernmost strip of the forecast area. Good news for Caldwell,
B/CS, Madisonville, and Crockett. Not so good news for those
closer to the Gulf on the coastal plain. Today should see a good
amount of sun, helping daytime temps rise more effectively through
the day, so highs still look to end up right around 90 degrees. At
least dewpoints will be on their way down, so peak heat index
values look to stay below 100 degrees. Tonight looks to be
modestly cooler, and those away from the Gulf should see highs
slip below 70 degrees, setting us up for a slightly cooler day
Saturday, where highs look to only make it into the lower to
middle 80s.

Saturday isn`t all great news, though. The Plains surface high
keeps on moving east into the Southeastern US, and that means the
return of onshore flow. This will pretty quickly erase all trace
of this nice little post-frontal stretch, and precipitable water
values look to spend their time Saturday night increasing back
above the 90th percentile. This is mostly table setting for Sunday
and what my shift partner will be talking about in the next
section of the discussion. But, in case things are a bit on the
progressive side, I do bring in some slight chances of PoPs in the
15 to 20 percent range late Saturday night.

&&

.LONG TERM...
(Sunday through Thursday)
Issued at 354 AM CDT Fri May 10 2024

A stalled boundary offshore will lift northward on Sunday,
enhancing LL convergence and bringing ample LL Gulf moisture.
Meanwhile aloft, a mid/upper trough will move from SW CONUS into W
Texas, ejecting a 50-60 knot 500mb jet over our region along with
a pesky train of vort maxes embedded in the flow. Trough induced
lee-side LL cyclogenesis over Oklahoma will enhance deep LL
moisture advection. Sunday`s PWATs are expected to easily exceed
2.0 inches. Global ensembles are aggressive with widespread 2.0+
inch PWATs while deterministic guidance suggest the possibility of
over 3.0 inches near the aforementioned boundary as it pushes
north. Therefore, it is no surprise that model guidance is
indicating widespread showers and thunderstorms on Sunday. Given
the moisture and synoptic parameters, areas of heavy rainfall will
unfortunately lead to another risk of flooding. The Weather
Prediction Center has placed most of our region under a Slight
Risk (Level 2 of 4) of excessive rainfall, with the highest risk
of heavy rainfall being north of I- 10. Widespread totals are
expected to be on the order of 1 to 4 inches. But locally much
heavier totals will be possible given the very high PWAT values.
We also cannot rule out isolated strong to severe thunderstorms.
Storm Prediction Center has most of our region under a Marginal
Risk (Level 1 of 5) of severe thunderstorms. The primary concerns
are damaging wind gusts and hail.

The sfc low over Oklahoma pushes eastward Monday. An associated
weak, trailing cold front will push southward, keeping a chance of
showers and thunderstorms in the forecast. Guidance is generally
less aggressive with PWATs on Monday. However, there still appears
to be potential for PWATs to exceed 2.0 inches near the boundary.
Therefore, locally heavy showers and thunderstorms will be possible
on Monday as well. We finally dry things out on Tuesday. But this
may be short-lived due to another round of UL disturbances progged
to influence our atmosphere during the second half of the week.

Regarding temperatures, most of the long term is expected to skew a
little hotter than averages with inland afternoon highs well into
the 80s (possibly around 90) when not rain cooled. Sunday may
feature enough rain and clouds to keep our northern counties in the
70s while our southern counties only make it into the low 80s.
Overnight lows are expected to average in the upper 60s to low
70s.

&&

.AVIATION...
(06Z TAF Issuance)
Issued at 1156 PM CDT Thu May 9 2024

Scattered thunderstorms have dissipated, with north winds now
beginning to develop behind an advancing boundary. Periods of MVFR
to IFR cigs are expected overnight with drier air behind the front
only just beginning to filter in. In general, the risk for IFR
conditions will be higher to the south of the I-10 corridor.
Moderate north winds develop tomorrow morning as cigs lift to VFR.
Sustained winds of 10-15 knots with some gusts in excess of 20
knots are possible tomorrow afternoon. Winds become light and
variable tomorrow night.

Cady

&&

.MARINE...
Issued at 354 AM CDT Fri May 10 2024

Winds will increase from the northeast behind a passing frontal
boundary today. Patchy fog and areas of haze are possible through
this afternoon. Winds will veer easterly and increase further on
Saturday, resulting in a corresponding increase in seas. Winds veer
to a southeasterly direction by Sunday. Caution flags will likely be
warranted on Saturday and possibly needed on Sunday. Showers and
thunderstorms are possible on Sunday into Monday. Brief period of
offshore flow possible on Tuesday before onshore flow returns by
Tuesday night. Shower and thunderstorm activity may return during
the second half of the upcoming week.

&&

.CLIMATE...
Issued at 354 AM CDT Fri May 10 2024

For the third day in a row, a daily record high minimum
temperature record has fallen at Hobby. Yesterday`s low
temperature of 79 degrees breaks the old record of 78 degrees.
That record dates back to 2022.

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  84  65  83  67 /   0   0  10  20
Houston (IAH)  88  68  85  69 /   0   0  10  20
Galveston (GLS)  85  74  81  74 /  10   0  10  20

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Should Exercise Caution until 4 AM CDT early this
     morning for GMZ370-375.

&&

$$

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