782
FXUS64 KCRP 270358
AFDCRP

Area Forecast Discussion
National Weather Service Corpus Christi TX
1058 PM CDT Sun May 26 2024

...New AVIATION...

.SHORT TERM...
(Tonight through Monday night)
Issued at 223 PM CDT Sun May 26 2024

Key Message:

- Dangerous heat continues Memorial Day with a major to extreme
risk of heat-related impacts

- Low chance (20%) of strong to severe showers and thunderstorms
4-9 PM over the Rio Grande Plains and northern Coastal Plains

Cloud coverage has been greater today than previously expected and
fortunately has limited surface heating. Temperatures currently in
the low to mid 90s with dewpoints in the upper 70s are causing
heat index values between 105 to 115. A few more hours this
afternoon will allow for these heat indices to bump up a few
degrees. Therefore, kept the Excessive Heat Warning and Heat
Advisory in effect through tonight and extended through Memorial
Day. Please continue to take heat precautions and follow the
guidance as described in the last paragraph of the long term
discussion.

Dewpoints remaining in the upper 70s to around 80 along with
increasing cloud coverage tonight will likely keep low
temperatures near the same, around 80. Currently, KCRP has
observed 150 hours straight of air temperatures at least 80
degrees, by far the earliest stretch of such length. The last
earliest stretch in the calendar year of at least 150 hours of 80
degree temperatures occurred last year from June 14-21st (166
hours). We don`t anticipate going below 80 until early Tuesday
morning at the earliest. This has led to 5 consecutive days of
record high minimums and 6 consecutive days of record heat
indices set at Corpus Christi. The lack of heat recovery
overnight and heat index values returning to 110-119 tomorrow has
warranted an extension of the heat products through Memorial Day.
Air quality will remain poor as HRRR near-surface smoke model
guidance continues to illustrate smoke ushering in from Central
America agricultural fires early this week.

Maintained the low chance (20%) of showers and thunderstorms late
Monday afternoon through Monday evening mainly for the Rio Grande
Plains and the northern tier counties. SPC has included all of
South Texas with the exception of the Coastal Bend in a marginal
risk for strong to severe storms. Throughout Memorial Day,
environmental conditions may become conducive over the Hill
Country and near the Sierra Madres in the warm sector east of the
dryline and south of stationary front over Central Texas. Any
storms that fire off may act as a lifting mechanism to help
overcome the cap between 4-9pm when cin is weakest. The
strengthening low-level jet and late afternoon sea breeze could
help aid in convection development. Confidence is low as CAMs
differ on keeping the convection over Mexico or persisting into
South Texas. Any isolated storm that does break the cap, has the
potential to bringing damaging winds and large hail with
instability near 5000 J/kg, DCAPE around 1300 J/kg, steep lapse
rates over 8 C/km, and effective shear around 50 knots.

&&

.LONG TERM...
(Tuesday through next Saturday)
Issued at 223 PM CDT Sun May 26 2024

- Low chances (10-25%) of rain chances daily this week

Quasi-zonal flow is expected to prevail in the long term as a weak
upper-level ridge will be parked to our south. Multiple mid-level
shortwave disturbances will move through the region, and with low-
level southeasterly flow in place, we should have plenty of moisture
to trigger low chances for rain and thunderstorms daily through
this week. However, it is a bit tricky to nail down locations and
amounts of rainfall, etc. as the weak ridge aloft won`t exactly
make the setup ideal. Additionally, with 700mb temperatures
remaining on the warm side, there will be decent mid-level capping
in place. Therefore, we are only including a low chance (10-25%)
for precipitation through next Sunday. Some periods of
thunderstorms and locally heavy rain may be possible at times, as
model SBCAPE values show 3000+ J/kg and PWAT values may reach 1.5-
1.75 inches. This is specifically true for Tuesday and Wednesday
as WPC has portions of the Brush Country and the northeast Coastal
Plains in a Marginal Risk (level 1 out of 4) for Excessive
Rainfall.

With the establishment of quasi-zonal flow, combined with slight
rain chances and increased cloud cover, high temperatures are
expected to be "cooler" this upcoming week compared to our recent
warm spell. Daytime highs are set to top out in the low to mid-90s
across the Coastal Plains, with the upper 90s to low 100s
expected farther west. Heat indices will remain generally below
112 degrees. Despite these "cooler" conditions, there remains a
medium to high chances (40-70%) of moderate to major heat-related
impacts, with a low to medium chance (10-40%) of an extreme risk
across portions of the Brush Country and the southern Coastal
Plains. This is due to anticipated poor overnight heat recoveries
that could impact individuals sensitive to heat and those without
adequate cooling measures, as well as some health systems and
heat-sensitive industries and infrastructure.

&&

.AVIATION...
(06Z TAFS)
Issued at 1044 PM CDT Sun May 26 2024

MVFR to IFR ceilings are expected in the eastern TAF sites
overnight. The likely timing of arrival for IFR ceilings will be
around 08-10Z. Some patchy fog could develop and mix in with haze
and further drop visibilities during the morning. COT will be the
only western site expected to briefly drop to MVFR ceilings.
Ceilings should transition to VFR at all sites by 15-18Z. There is
a low chance for showers and thunderstorms in the area during the
later half of the period. This will be reassessed in future TAF
issuances.

&&

.MARINE...
Issued at 223 PM CDT Sun May 26 2024

Weak to moderate south to southeasterly flow will continue through
Monday night. Weak to moderate onshore flow is expected Tuesday
through the end of the work week, with periods of strong 20-25
knot gusts on Friday. Seas will generally be between 4-5 feet,
increasing to 5-6 feet by next weekend. There will be low (10-25%)
chances of showers and thunderstorms each evening.

&&

.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi    93  82  96  79 /  10   0   0  10
Victoria          94  79  97  76 /  10   0   0  20
Laredo           106  82 109  80 /   0   0  20  20
Alice            100  80 101  77 /  10   0  10  10
Rockport          91  82  90  79 /  10   0   0  10
Cotulla          105  82 108  79 /   0   0  20  20
Kingsville        96  81  98  77 /  10   0  10  10
Navy Corpus       91  82  90  82 /  10  10   0  10

&&

.CRP WATCHES/WARNINGS/ADVISORIES...
TX...Excessive Heat Warning until 8 PM CDT Monday for TXZ229-230-
     239>243.

     Heat Advisory until 8 PM CDT Monday for TXZ231>234-244>247-
     342>344-346-347.

GM...None.
&&

$$

SHORT TERM...EMF
LONG TERM....KRS
AVIATION...NP/92