Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX
FXUS64 KEWX 270409 AAA
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
1109 PM CDT THU MAY 26 2016
The forecast has been updated for the early cancellation of WW
#217 where thunderstorm activity has diminished over the last
couple hours. Farther east across the Hill Country, I-35 corridor
and into the Hwy. 77 corridor a new severe thunderstorms watch
(#221) is now in effect until 3 AM CDT. Rain chances have also
been raised significantly for areas generally along and north of
I-10. Complicated surface pattern in place with an outflow
boundary roughly along a Llano to LaGrange line, with stout
southerly flow in the low-levels to the south and southwest of
this boundary. In addition, lone cell over the western Hill
continues to remain severe while moving eastward. This will lead
to additional showers and storms for most areas north of I-10.
.PREV DISCUSSION... /ISSUED 743 PM CDT THU MAY 26 2016/
Please see the 00Z aviation forecast discussion below.
Convection chances will be the main concern across the region
through the remainder of this evening. Based on radar trends, we
have gone with TEMPO groups for TSRA at KAUS and KDRT for the next
couple of hours. We will also include TEMPO groups for SAT/SSF
between 06Z-10Z as activity is expected to move in from the west.
Additional rainfall chances appear in the offing for our I-35
sites late tomorrow afternoon and we`ll mention PROB30 groups to
PREV DISCUSSION... /ISSUED 318 PM CDT THU MAY 26 2016/
In coordination with SPC, we have issued a Severe Thunderstorm
Watch along and northwest of a Junction to Uvalde to Del Rio line.
Showers and thunderstorms continued to develop over the Serranias
del Burro mountains to southwestern Texas. Strong instability and
shear are noted across our area.
PREV DISCUSSION... /ISSUED 232 PM CDT THU MAY 26 2016/
SHORT TERM (Tonight through Friday Night)...
Have issued a Flash Flood Watch for areas along and east of a
Burnet to Boerne to San Antonio to Karnes City line for this
afternoon through late tonight. A surface boundary from morning
rains over Central Texas is slowly drifting south along the I-35
corridor and provided lift to generate showers and thunderstorms.
PWS have risen to near 2 inches across the Hill Country and South
Central Texas tapering to near 1.5 inches along the Rio Grande.
Due to earlier clearing skies allowing convective temperatures to
be reached, showers and thunderstorms have developed out west from
the Serranias del Burro of Mexico across the Big Bend into
southwestern Texas. Expect showers and thunderstorms to continue
across the eastern areas with locally heavy rains causing some
flooding this afternoon into evening. Showers and thunderstorms
out west will organize and move east across our area this evening
into the overnight hours. This will cause another round of locally
heavy rains. With the rains ongoing in the east adding to the
saturated soils...the threat for flooding will continue into the
overnight hours especially across eastern areas. An upper level
trough will move northeast across the plains states on Wednesday
forcing a dryline into the Edwards Plateau and Rio Grande Plains
on Friday. Showers and thunderstorms will develop along and east
of the dryline. More locally heavy rains are possible with PWS
near 1.8 inches east of I-35. CAPEs of 2000 to 4000 j/kg and 0-6
km shear will allow for strong to severe storms this afternoon
through Friday evening.
LONG TERM (Saturday through Thursday)...
A series of upper level impulses will move across the southern
tier of states. A moist and unstable airmass lingers over our area
due to a persistent southeasterly lower flow off the Gulf of
Mexico. As a result, periods of showers and thunderstorms are
expected Saturday through Thursday. Similar to the short term, a
few strong to severe storms and locally heavy rains with flooding
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 73 85 73 90 73 / 90 60 40 30 20
Austin Bergstrom Intl Airport 73 85 72 89 72 / 100 60 40 30 20
New Braunfels Muni Airport 73 87 72 88 73 / 70 60 30 30 20
Burnet Muni Airport 71 85 71 88 71 / 70 60 30 30 20
Del Rio Intl Airport 72 95 71 90 73 / 50 10 10 40 30
Georgetown Muni Airport 72 84 72 89 71 / 70 60 40 30 20
Hondo Muni Airport 73 91 73 90 73 / 60 30 20 30 30
San Marcos Muni Airport 73 86 72 88 72 / 90 60 30 30 20
La Grange - Fayette Regional 75 85 75 88 73 / 90 70 40 30 10
San Antonio Intl Airport 74 87 74 88 73 / 60 40 20 30 20
Stinson Muni Airport 75 90 75 90 75 / 60 40 20 30 20
Flash Flood Watch until 6 AM CDT Friday for the following counties:
Public Service/Data Collection...Treadway