Red Flag Warning 1, NWS Austin/San Antonio, TX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
245 AM CDT Sat Mar 28 2020

.SHORT TERM (Today through Sunday)...

Area radars show light showers along the I-35 corridor near the
right entrance region of an upper level jet with showers developing
over the Edwards Plateau near the Pacific front. The parent upper
level trough will move out across the Plains today forcing the front
across our area this morning into early afternoon. The showers will
translate to the east along with the jet and front, moving east of
our area around midday. Some instability will allow for isolated
thunderstorms with a small hail a possibility.

In the wake of the front, strong northwest winds of 15 to 25 mph
with gusts up to 35 mph are expected mainly over the Rio Grande
Plains due to mixing with the stronger winds aloft. In addition, a
very dry airmass filters into our area bringing very low relative
humidities this afternoon. This combination will generate critical
fire weather conditions over the Rio Grande Plains. As a result, the
Fire Weather Watch will be upgraded to a Red Flag Warning. East of
the Rio Grande Plains to I-35/I-37 corridors, although winds will be
lighter and humidities higher, elevated to near critical fire
weather conditions are expected .

Surface high settles over our area tonight with much cooler low
temperatures due to lighter winds and low dewpoints. Surface begins
to drift off to the east on Sunday as another upper level trough
currently off the Pacific Northwest Coast moves onshore into
California. Southeasterly winds return to all areas by evening with
a slow increase in moisture.

&&

.LONG TERM (Sunday Night through Friday)...

Relatively stable and seasonal temperatures are expected through the
long term with afternoon highs in the 70s/lows in the 50s north and
east and highs in the 80s/lows 56-65 south and west, with the
coolest lows coming Wednesday morning. Precip chances will come
Monday into Monday night, then return as early as Thursday although
the picture becomes a little murky late in the week.

Sunday evening, an upper level trough over the Four Corners region
will begin to move to the southern Plains and finally begin to break
down the persistent ridging over the Gulf of Mexico. Could start to
see some isolated shower activity just before sunrise Monday as weak
isentropic upglide begins. WAA and moisture return will build
instability ahead of the cold front, and showers and a few
thunderstorms are likely during the day. This activity will be
primarily focused over the eastern 2/3rds of the area and forcing
will be strongest north. There may be a slight chance for a strong
storm in the afternoon and evening as the pre-frontal trough crosses
the I-35 corridor with CAPE perhaps exceeding 1000 J/kg and deep
shear near 50 knots. The best chance for this will come along and
east of the I-35 corridor. The highest QPF of up to 0.5" with
locally up to 1", is expected north of Austin.

Moisture will quickly exit as the front approaches and showers
should end Monday night. Weak ridging will then keep us mainly dry
through Wednesday night. Despite models beginning to diverge after
Wednesday and quite a bit of run-to-run change over this period,
long-wave northern stream troughing is expected over the east CONUS,
perhaps closing off over the Great Lakes, while split flow may
develop over the western CONUS. In addition to indications of a
shortwave trough and perhaps some moist isentropic ascent Thursday,
the longwave troughing should send another back-door front our
direction by Thursday night/Friday morning. Beginning 12Z Thursday,
have introduced slight chance POPs through the end of the period as
the model blend initialization came in dry. Looks like that period,
and especially into next weekend, has the potential to be very wet,
and CPC has highlighted the above normal precipitation chances in
their 6-14 day outlook products and the week 2 hazards. At this early
juncture, models are showing low instability availability but will
continue to refine the forecast over the coming days.

&&

.PREV DISCUSSION... /ISSUED 1243 AM CDT Sat Mar 28 2020/

AVIATION...
MVFR conditions, -RA/VCSH, and S to SE winds of 5 to 10 KTs have
developed at the I-35 sites and will continue until mid Saturday
morning. Although ISOLD TSRA are possible, will hold off mention due
to low chances. However, will monitor radar trends for possible
updates to mention. A frontal passage will end the -RA/VCSH and any
TSRA along with a rapid improvement to VFR on NW winds 10 to 15 KTs.
Wind speeds gradually decrease to 5 KTs Saturday night.

SHRA are expected in the VCNTY of KDRT until frontal passage early
Saturday morning. VFR skies will prevail with SE winds around 5 KTs,
shifting to NW with the frontal passage and increasing to 15 to 25
KTs with gusts around 30 KTs. Wind speeds decrease to near 5 KTs
Saturday night.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              78  52  78  60  75 /  60   0  -   20  80
Austin Bergstrom Intl Airport  77  51  78  60  76 /  60   0  -   20  80
New Braunfels Muni Airport     80  49  78  60  77 /  60   0  -   20  70
Burnet Muni Airport            76  48  74  58  71 /  40   0  -   20  90
Del Rio Intl Airport           80  50  83  61  84 /   0   0   0  10  10
Georgetown Muni Airport        78  48  77  59  72 /  50   0  -   20  90
Hondo Muni Airport             83  49  81  62  80 /  20   0  -   20  70
San Marcos Muni Airport        78  49  78  60  77 /  60   0  -   20  80
La Grange - Fayette Regional   76  51  79  62  80 /  60   0  -   20  60
San Antonio Intl Airport       82  52  78  61  77 /  50   0  -   20  70
Stinson Muni Airport           83  54  80  63  79 /  50   0  -   20  70

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 11 AM this morning to 6 PM CDT this evening
for Dimmit-Kinney-Maverick-Uvalde-Val Verde-Zavala.

&&

Short-Term/Aviation...04
Long-Term...KCW

Hazardous Weather Outlook...UPDATED
National Weather Service Austin/San Antonio TX
311 PM CDT Fri Mar 27 2020

TXZ171>173-184>194-204>209-219>225-282000-
Llano-Burnet-Williamson-Edwards-Real-Kerr-Bandera-Gillespie-
Kendall-Blanco-Hays-Travis-Bastrop-Lee-Medina-Bexar-Comal-
Guadalupe-Caldwell-Fayette-Frio-Atascosa-Wilson-Karnes-Gonzales-
De Witt-Lavaca-
311 PM CDT Fri Mar 27 2020

This Hazardous Weather Outlook is for South-Central Texas..

.DAY ONE...This Afternoon And Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

A strong storm or two is possible Monday afternoon and evening
near and east of the I-35 corridor ahead of a Pacific cold front.

Otherwise, no hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.

TXZ183-202-203-217-218-228-282000-
Val Verde-Kinney-Uvalde-Maverick-Zavala-Dimmit-
311 PM CDT Fri Mar 27 2020

This Hazardous Weather Outlook is for South-Central Texas..

.DAY ONE...This Afternoon And Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Near critical to critical fire weather conditions are possible
near the Rio Grande on Saturday as gusty winds and low relative
humidity develop.

Otherwise, no hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.