Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 09/15/22
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
618 PM CDT Wed Sep 14 2022
...New AVIATION...
.SHORT TERM...
(Tonight through Thursday night)
Issued at 240 PM CDT Wed Sep 14 2022
Low clouds are taking longer than expected to burn off as of early
this afternoon, however, clouds are forecast to scattered out/burn
off by mid to late afternoon (some of it lingers around all day).
When looking at water vapor satellite imagery (check out GOES Image
Viewer website), there is a great signal of a dry air mass over
eastern Texas. That air mass is forecast to be transported to our
local area for the rest of this afternoon into Thursday morning.
SPC Mesoscale Analysis product as of 1 PM CDT shows pwat values in
the 0.8 to 0.9 inch range along and east of Highway 77, which is
well below our daily mean. To make sure all of this is correct,
looked at an aircraft sounding from IAH (Houston-George Bush
International Airport) with valid time of 18Z (1 PM) with pwat value
of 0.81 inch. Therefore, dry air is definitely in place. So, what`s
driving that air mass to the east? An east to southeast wind flow
around 850 to 500 mb. And what else we can expect with this dry air?
Well, less humidity with dewpoints in the 40 and 50s across parts of
the Hill Country and I-35 later tonight. Also, this means cooler
temperatures for the overnight hours into Thursday morning.
Overnight lows are expected to drop to the lower 60s across the Hill
Country with mid 60s along the I-35 corridor and upper 60s to the
lower 70s for the coastal plains and the Rio Grande, where slightly
higher dewpoints are forecasted.
Some morning clouds are expected along the I-35 corridor and the
coastal plains for the Thursday morning period. There could be a
period where clouds scattered out around noon or so, but increased
moisture arrives across the coastal plains and then pushes to the
northwest and north into areas along and east of I-35 as a mid to
upper level inverted trough moves over east Texas. Pwats are
forecast to jump into the 1.4 to 1.6 inch range. So just like that,
rain chances return for the coastal plains area on Thursday
afternoon. All of the shower and isolated thunderstorm activity
enhanced by the sea breeze is expected to come to an end by sunset.
As far as high temperatures for Thursday, expect upper 80s to mid
90s with heat index values in the upper 90s for portions of the
coastal plains. Mostly cloudy skies are expected for Thursday
evening with lows coming back up to climate normal as moisture
spreads across the area. Therefore, expect lows in upper 60s to mid
70s.
&&
.LONG TERM...
(Friday through Wednesday)
Issued at 240 PM CDT Wed Sep 14 2022
Friday into the weekend will trend warm but also more humid given
higher dew points and low-level moisture levels with the onshore
flow coming off the Gulf. The heat indices could climb to above 100
degrees for several hours each afternoon, especially across the
locations to the east of I-35. Shower and storm chances will also
likely be best Friday afternoon where PoPs range from 20 percent
along or just to the west of the I-35 corridor to as high as 50
percent across portions of the coastal plains. Rain and storm
chances will be possible Saturday and Sunday but will primarily
focus east of I-35. Activity should gradually diminish around or
just after sunset each day.
Upper level ridging intensifies across the state from late this
weekend through early next week. The building ridge will yield to
even hotter afternoons where high temperatures become well above
climatological average. However with the building ridge, expect
drier air with below average precipitable water values to filter
into South-Central Texas. This will not only suppress the rain
chances for early next week but will help to keep conditions more
comfortable during the afternoons as well with lower heat index
values and less stickiness.
&&
.AVIATION...
(00Z TAFS)
Issued at 618 PM CDT Wed Sep 14 2022
VFR conditions are expected through much of the period at all
terminals, with the exception for a few hours of MVFR cigs being likely
at the I-35 terminals mid-tomorrow morning. These clouds should lift
and scatter by around 17Z, with fair skies expected through the
remainder of the period. A few isolated showers may be found near the
I-35 terminals tomorrow afternoon, however confidence is too low for
mention in the TAFs at this time. Winds will be light through the
period and mainly east-southeasterly.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 66 92 72 93 / 0 10 0 20
Austin Bergstrom Intl Airport 64 93 72 92 / 0 10 0 20
New Braunfels Muni Airport 66 94 72 93 / 0 10 0 20
Burnet Muni Airport 66 92 71 92 / 0 0 0 10
Del Rio Intl Airport 70 90 72 92 / 0 0 0 10
Georgetown Muni Airport 64 92 71 92 / 0 0 0 20
Hondo Muni Airport 67 93 73 93 / 0 10 10 20
San Marcos Muni Airport 65 93 71 93 / 0 10 0 20
La Grange - Fayette Regional 67 93 71 92 / 0 20 0 30
San Antonio Intl Airport 68 92 73 92 / 0 10 10 20
Stinson Muni Airport 69 93 74 93 / 0 10 10 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Short-Term...17
Long-Term...Brady
Aviation...Gale