Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Austin/San Antonio Texas
828 PM CDT Thursday Jul 28 2016
heavy precipitation has ended for the evening across south central
Texas. Light to moderate rain will continue from Maverick County,
east to Dimmit and frio counties with a few embedded lightning
strikes for the next few hours. An isolated shower is also
possible across portions of the coastal plains, areas east of
Interstate 35 and north of the Austin Metro area through late this
evening due to the various remnant boundaries that are still
moving across the area. Adjusted pops to reflect current radar
trends with activity diminishing by midnight per the high
Thanks to the rain and outflows from the storms temperatures
across much of the area (i-35 and east) are already down to near
80 or below. Areas that did not see rain are still in the mid to
upper 80s. Temperatures will continue to cool through the evening.
Have re-trended the hourly temperature grids to reflect this.
For the most part south central Texas is in for a cloudy, dry, and
mild night after midnight. A few areas could see some breaks in
the clouds late tonight before status forms tomorrow morning.
Previous discussion... /issued 645 PM CDT Thursday Jul 28 2016/
convection at the area airports has ended for now. The only
possibility for another round is in the San Antonio, because there
is an area of thunderstorms about 25 miles south of ssf which is
moving slowly northward. At the same time these storms are
dissipating and I don't think they will make it that far north.
So, all the tafs are VFR for the rest of the evening. Expecting
cigs to lower to MVFR in Austin and San Antonio by around 08z and
at drt by around 14z. Cigs in San Antonio will drop to IFR by
around 10z. Improvement to VFR will come by late morning Friday.
Previous discussion... /issued 251 PM CDT Thursday Jul 28 2016/
Short term (tonight through Friday night)...
showers and thunderstorms were developing along and east of the
Interstate 35 corridor this afternoon and moving northward. Storm Prediction Center
mesoanalysis continues to show peak precipitable water values of well over 2"
with high precip efficiency in this area along with MUCAPE values
of 2000+ j/kg. As a result...the potentiality of isolated heavy
rainfall resulting in quick accumulations over an inch are
possible throughout the rest of the afternoon along and east of
the 35 corridor. Also seeing development along the crp/ewx border
and Rio Grande this afternoon, however this activity is moving
northward into a slightly less favorable environment of lower
instability and deep layer moisture. Hi-res models have kept this
area (on the escarpment) for the most part dry. Outflows from the
eastern activity could develop a few isolated cells however, so
kept at least slight chance pops in out west.
Activity should wane quickly at or shortly after 00z. A return of
low clouds overnight will keep tomorrow morning mostly cloudy
through day break. Rain chances begin to wane considerably
beginning tomorrow and into the weekend while temperatures rise
with building high pressure aloft.
Long term (saturday through thursday)...
aforementioned high pressure will work to build over the central
US and dry out/thicken the atmosphere through the weekend. A
gradual decrease in moisture and increase in temperatures
throughout the next week will be in store. Due to the rainfall
over the last few days and today, surface moisture should linger
perhaps through Sunday but drop off considerably by Monday. Relative humidity
analysis shows min relative humidity values starting to drop into the 20 percent
range by Monday and Tuesday resulting in likely the typical
scenario of elevated fire weather conditions in the west and
elevated heat indices (105-110) east and southeast. These should
be the primary weather concerns next week as far as hazards are
Preliminary point temps/pops...
Austin Camp Mabry 95 76 97 76 98 / 50 10 - 0 10
Austin Bergstrom Intl Airport 95 74 96 74 96 / 60 10 - 0 10
New Braunfels Muni Airport 95 75 95 74 96 / 50 10 - - 10
Burnet Muni Airport 96 74 95 74 95 / 30 20 - 0 -
del Rio Intl Airport 96 76 97 77 99 / 20 20 10 0 10
Georgetown Muni Airport 96 76 96 75 96 / 40 20 - - -
Hondo Muni Airport 95 74 94 74 95 / 30 20 10 0 -
San Marcos Muni Airport 95 75 95 74 95 / 60 10 - - 10
La Grange - Fayette regional 92 76 96 75 97 / 60 20 10 - 10
San Antonio Intl Airport 93 76 94 76 95 / 40 10 - 0 10
Stinson Muni Airport 95 76 96 76 96 / 40 20 - 0 10
public service/data collection...33