609
FXUS64 KEWX 280806
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
306 AM CDT Tue May 28 2024

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

.SHORT TERM...
(Today through Wednesday)
Issued at 305 AM CDT Tue May 28 2024

* Level 2 to 3 out of 5 risk for severe storms from this evening
  through tonight across all of South-Central Texas. Greatest
  concerns are damaging straight line winds and large hail.

* Heavy rainfall expected with a level 2 out of 4 risk for flash
  flooding, especially for our northern and northeastern most
  counties.

* Dangerous heat lingers for one more afternoon with peak heat
  indices as high as 110 degrees across our southern most areas.

Today starts off very warm and humid once again with returning
clouds and hazy skies. Couldn`t rule out some patchy fog early as
well. Additionally, it should start off quiet on the radar with
rain/storm chances not expected to arrive until this evening and
into tonight. With majority of the latest CAM guidance indicating
the slower arrival of any storms and outflow towards the evening
hours, a concern for dangerous heat will linger today despite
greater cloud coverage compared to recent afternoons. Highs will
likely reach the mid to upper 90s for locations along and east of
the I-35 corridor and near/above 100 degrees in the Rio Grande
Plains. Heat indices are likely to peak in the 104 to 112 degree
range and this will prompt a Heat Advisory across our southern most
rows of counties.

A shortwave embedded within the west-northwesterly mid-level flow
along with the placement of a stationary front over Central Texas
will help initiate several regions of convection this afternoon
across the Texas panhandle, portions of North and West Texas and
into the higher terrain of Mexico. Convection will likely congeal
into one large organized singular MCS moving south-southeastward
and/or a couple of separate individual clusters. As activity is
advancing towards and across our region from this evening through
tonight, it likely will be mainly cold pool driven. This favors
damaging straight line winds as the greatest concern regarding
severe weather where gusts of 65 to 75 mph or greater may be
possible. Large to very large hail (1-2+" in diameter) will be a
secondary concern with the largest hail favoring from the Hill
Country and points north. An isolated tornado or two will be
possible as well.

This MCS and/or complexes will also result in heavy rainfall and
some concern for flooding will exist across the region. Latest 24h
HREF ensemble probability matched mean (PPM) guidance shows the
potential for 1 to 3 inches of heavy rain with locally higher
amounts where the MCS and/or complexes transverse across. At the
time of this forecast discussion, the most favored area stretches
from our northern/northeastern counties and into the SJT/FWD/HGX
CWAs. Rainfall will be more sparse outside of these convective
complexes.

Wednesday should escape the dangerous heat we have seen over the
past week with cooler outflow driven air in wake of the convective
complexes. High temperatures range from the mid 80s across our
northern/eastern counties into the mid 90s along the Rio Grande.
Rain chances will be low to start off the day but gradually return
towards late in the day and into Wednesday evening. While a few
strong to severe storms are possible, it`s a less of a concern
compared to this evening/tonight`s threat.

&&

.LONG TERM...
(Wednesday night through Monday)
Issued at 305 AM CDT Tue May 28 2024

A possible active period continues for much of the long-term portion
of the forecast. The forecast for Wednesday night will be somewhat
dependent on what occurs today and tomorrow afternoon, but if
convection does move through the area during the short-term a
boundary will likely be setup over the area by Wednesday night. If
this does occur we will likely see some scattered convection ongoing
at the beginning of the long-term period Wednesday evening across
the Edwards Plateau. This activity would then move southeast before
likely dissipating by midnight. Instability amounts would support
the possibility of a strong to severe storm. The new Day 2 outlook
from SPC has most of the area in a level 1 out of 5 (marginal) risk
for severe storms to cover this threat. Isolated to scattered
convection will continue to be possible mainly during the afternoon
periods. It will remain difficult to truly pinpoint location and
timing as much of what occurs each day will be highly dependent on
what occurs during the previous day or two as boundary interactions
remain a key role in thunderstorm development. Have undercut NBM
PoPs slightly through the period as they seem a bit too high at
times. High temperatures through Friday will range from near 90 in
the northern CWA to near 100 degrees in the Rio Grande Plains with
lows in the 70s. Upper heights will rise a bit for the weekend which
will begin to lower the overall rain chances by Sunday or Monday.
This will also allow temperatures to slightly increase as well with
highs Monday likely back in the middle 90s to near 104 degrees near
the Rio Grande.

&&

.AVIATION...
(06Z TAFS)
Issued at 1225 AM CDT Tue May 28 2024

MVFR flight conditions generally prevails overnight through Tuesday
morning at the I-35 TAF sites (KAUS, KSAT, and KSSF). This continues
to include some reduced visibility from haze or some combination of
haze and patchy fog. KDRT likely remains VFR into and through much
of Tuesday. Convective potential returns and increases from late
Tuesday afternoon into Tuesday night as convection likely arrives in
the form of a large complex or individual clusters out of north and
west Texas. The confidence remains low regarding the exact timing,
placement, and intensity of activity as it advances through the
area. However, there is potential for storms to become severe with
large hail, and strong damaging winds. The southeasterly winds that
occur outside of any convective influences are to diminish overnight
before becoming breezy again through Tuesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              95  72  88  73 /  20  60  40  30
Austin Bergstrom Intl Airport  94  72  88  72 /  20  50  40  30
New Braunfels Muni Airport     98  74  91  73 /  20  50  30  20
Burnet Muni Airport            92  69  85  71 /  30  60  40  30
Del Rio Intl Airport          100  76  98  78 /  30  30  20  20
Georgetown Muni Airport        91  69  86  71 /  20  60  40  30
Hondo Muni Airport             98  72  93  73 /  20  50  20  20
San Marcos Muni Airport        96  72  90  72 /  20  50  30  20
La Grange - Fayette Regional   95  74  88  73 /  20  50  40  20
San Antonio Intl Airport       97  74  91  75 /  20  60  30  20
Stinson Muni Airport           98  75  93  76 /  20  50  20  20

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from noon today to 7 PM CDT this evening for Atascosa-
De Witt-Dimmit-Frio-Gonzales-Karnes-Lavaca-Maverick-Wilson-Zavala.

&&

$$

Short-Term...Brady
Long-Term...29
Aviation...Brady