Scientific Forecaster Discussion
fxus64 kewx 220546
Area forecast discussion
National Weather Service Austin/San Antonio Texas
1246 am CDT sun Sep 22 2019
MVFR ceilings are developing over San Antonio and will spread to
Austin and then del Rio later tonight. The ceiling at Sat will drop
to IFR for a few hours starting around sunrise. All terminals will
improve to VFR by late morning and be VFR through the afternoon and
evening. Low ceilings will develop again late Sunday night.
Previous discussion... /issued 603 PM CDT Sat Sep 21 2019/
deeper tropical moisture is draped along a Georgetown to Boerne to
Carrizo Springs line late this afternoon per GOES total precipitable
water satellite imagery and have done a quick update to pull
isolated rain chances into The Hill Country and Highway 83 corridor
based on latest radar trends. Aircraft soundings out of Austin and
San Antonio show weak mid-level lapse rates and overall
lightning/thunderstorm potential appears to remain low through the
early evening hours. Given the diurnally driven nature of these
showers, still anticipate loss of daytime heating to result in a
quick dissipation of this activity by 9 PM.
Previous discussion... /issued 246 PM CDT Sat Sep 21 2019/
Short term (tonight through sunday)...
isolated showers are ongoing across portions of the coastal plains
and even extending up into the San Antonio area where a plume of
elevated moisture exists. A few areas have picked up some wetting
rains, with Stinson Airport on the southeast side of San Antonio
receiving a half inch of rain. Temperatures this afternoon are
primarily in the 90s, with a few cooler locations across The Hill
Country and where rain cooled air and increased cloud cover has kept
temperatures tempered. Shower activity should come to an end this
evening with the loss of heating. Expect partly to mostly cloudy
skies tonight with overnight lows in the mid 70s for most locations.
A few streamer showers are possible toward morning. Another
unseasonably warm day is expected on Sunday, with highs reaching the
mid to upper 90s for most locations. There will be another slight
chance for some showers, but the favored area will be pushed a little
bit further east to the coastal plains.
Long term (monday through saturday)...
the mid to upper level high across the southeastern US will
generally stay in place through Monday before shifting further
southeast to the eastern Gulf of Mexico near Florida toward mid week.
An upper level trough is expected to come ashore in the Pacific
northwest by Sunday evening, heading southeast and becoming a well
defined closed mid level low by Tuesday morning near the
California/Arizona/Mexico border. It is expected to generally hang
out in that area before becoming an open wave trough and existing to
the northeast. For US here across south central Texas, not a whole
heck of a lot is expected to change, with south/southeasterly surface
flow and generally weak mid to upper level winds persisting. Slight
chance pops, high temperatures in the mid 90s, and lows in the mid
70s are expected to continue through the period. The climate
prediction center's 6 to 10 and 8 to 14 day outlooks continue to show
high probabilities for warmer than normal temperatures continuing,
and long term models continue to show no cold fronts on the horizon.
Preliminary point temps/pops...
Austin Camp Mabry 98 75 97 74 95 / 10 0 10 10 20
Austin Bergstrom Intl Airport 96 72 95 72 94 / 10 0 10 10 20
New Braunfels Muni Airport 97 72 96 72 94 / 20 0 10 10 10
Burnet Muni Airport 94 71 94 71 91 / 10 0 10 10 20
del Rio Intl Airport 98 75 98 76 99 / - 0 - 10 10
Georgetown Muni Airport 96 72 96 72 94 / 10 0 10 10 20
Hondo Muni Airport 99 73 100 73 97 / 10 - 10 10 10
San Marcos Muni Airport 97 72 96 72 94 / 20 0 10 10 20
La Grange - Fayette regional 96 74 96 72 94 / 20 0 20 - 20
San Antonio Intl Airport 97 75 96 75 94 / 20 - 10 10 10
Stinson Muni Airport 99 75 99 75 96 / 20 - 10 10 10