853
FXUS64 KCRP 141717
AFDCRP

Area Forecast Discussion
National Weather Service Corpus Christi TX
1217 PM CDT Sat Sep 14 2024

...New AVIATION...

.SHORT TERM...
(Today through Sunday)
Issued at 319 AM CDT Sat Sep 14 2024

Key Messages:

- Moderate to major risk of heat related impacts across the northern
Brush Country, and minor to moderate across the remainder of South
Texas, Today.

- Sunday, Minor to moderate risk of heat related impacts across
South Texas.

- Low (20-30%) chance of showers and thunderstorms Sunday.

Today, The 500 mb ridge that has been bringing the return to the hot
weather of the summer, the last day or two, continues to be blocked
by the rex block made up of the ridge in the Lower Great Lakes and
500 mb low, which are the remnants of Francine. So the main concern
is the heat as the temperatures range from around 90 near the coast
to at or just above 100 around Cotulla and LaSalle county. Minimum
relative humidity levels will remain around 40% in the Rio Grande
Plains to near 80% at the Coastal Bend. The best heat indices would
then end up in the inland portions of Kleberg and Nueces counties
with 105-110 heat index values expected.

Tonight, clouds begin to move into the region as moisture moves in
from the west over the mountains, and also from the southeast, along
the Rio Grande Valley toward the sfc lying along the leeside of the
Rocky Mountains and into West Texas.

For Sunday, the models have been all over the place with how the
thunderstorms would evolve. Over the last few nights, the models
have been back and forth with what to do about about tropical storm
Ileana in the Pacific. A couple of nights ago the GFS explicitly
pulled the energy east over the mountains and into South Texas. Last
night, it looked like it would take the energy north, but pull the
moisture east. While most of the models have been showing that
Ileana moves north dissipates, and some of the moisture moves east-
southeast, and mainly in to Deep South Texas. So tonight, the
GFS and the ECMWF have brought the two solutions together. Most of
the energy moves north into Arizona, but a vort max at 500 mb
seems to make it into the Rio Grande Plains of Mexico, with most
of the moisture of Ileana moving over the mountains into Mexico.
So some of the remnants of Ileana meet up with the moisture in the
Rio Grande Plains which seems to be drawn north by a sfc trough
in the lee of the Rocky Mountains and West Texas. The sfc trough
initiates the convection in the Rio Grande Valley Sunday morning,
and spreads them east toward the southern Coastal Bend (Kleberg
and Nueces Counties)with isolated to scattered (15-35% chance)
showers and thunderstorms in southern Brush Country. The models
are all pretty much on board with the rain heading southeast into
Deep South Texas in the afternoon. Thought the NBM was a little
underdone, so blended the 00z ARW/GFS/ECMWF to boost the western
and southern pops a bit. So the expectation is for
showers/thunderstorms to fire off in Mexico and travel down the
rio Grande Plains and out of our area. Temperatures look to remain
into the lower to mid 90s from the cloud cover and the bit of
rain that falls over the southern Brush Country. Heat index values
are expected to remain between 100-105.

&&

.LONG TERM...
(Sunday night through next Friday)
Issued at 319 AM CDT Sat Sep 14 2024

Key Messages:

- Low to medium (20-35%) chance of showers and thunderstorms Sunday
night into Monday.

- Moderate to Major risk of heat related impacts across the Brush
Country, and Minor to Moderate across the remainder of South Texas
through the end of the work week.

Low to medium rain/storm chances start off the Extended period owing
to the combination of moisture advection from what it currently is
Tropical Storm Ileana over the Baja Peninsula and associated mid-
level energy. Although the highest precip chances can be expected
across western zones Sunday night into Monday, an approaching weak
frontal boundary from the northeast may bring some activity to the
Crossroads area in the evening hours of Sunday. PWATs will climb to
around 2.0-2.4 inches during the aforementioned timeframe, remaining
at around 1.5-1.8 inches through the remainder of the work week.
However, by Tuesday high pressure is expected to settle back over
the region with drier air filtering in at the mid-levels, confining
moisture to the lower layers. A few showers will still be possible
through the end of the week (mainly along the seabreeze), but PoPs
will stay below 25%.

Temperatures are forecast to be on the warm side through the period,
with highs generally in the mid 80s to around 100 all week. With
such high moisture expected over the area along with the warmer
temps, heat index values will be in the 100-109 range throughout this
upcoming week. The risk for experiencing heat related illnesses will
be at Moderate to Major levels over the Brush Country all week, with
generally a Minor to Moderate risk elsewhere. Overnight lows will
range in the 70s nightly.

&&

.AVIATION...
(18Z TAFS)
Issued at 1201 PM CDT Sat Sep 14 2024

Conditions have improved to VFR across South Texas early this
afternoon and will persist through majority of the period.
Southeasterly winds will be rather light at 10-15 knots sustained
and gusts up to 20 knots through this evening before decreasing
to below 10 knots overnight. Patchy fog and MVFR ceilings over the
Coastal Plains will be a concern for ALI/VCT from 10-14Z.
Tropical Storm Ileana just offshore of the western coast of
Mexico will eject mid-level lift support eastward towards the Rio
Grande. This disturbance will allow for the low chance (30%) of
showers and storms over the Rio Grande Plains overnight into
Sunday. Only included a prob30 at LRD as it contains the greatest
chances of receiving showers or thunderstorms but left COT out due
to low confidence.

&&

.MARINE...
Issued at 319 AM CDT Sat Sep 14 2024

A weak to moderate south to southeast flow is expected today through
Sunday. Isolated showers and thunderstorms are possible in the
nearshore waters near Baffin Bay, Sunday as a disturbance moves into
Deep South Texas. Weak to moderate south to southeasterly flow
will persist through mid week. There is a low (10-20%) chance of
showers and thunderstorms daily.

&&

.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi    96  77  90  76 /   0   0  20  10
Victoria          97  74  95  74 /   0  10  10  10
Laredo           101  79  93  76 /  20  30  40  20
Alice             98  76  94  74 /   0  10  20  10
Rockport          89  78  91  77 /   0   0  10  10
Cotulla          101  78  97  76 /   0  10  10  10
Kingsville        97  77  92  76 /   0  10  20  10
Navy Corpus       90  80  87  79 /   0   0  20  10

&&

.CRP WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&

$$

SHORT TERM...JSL
LONG TERM....ANM
AVIATION...EMF/94