Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX
FXUS64 KEWX 051118
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
518 AM CST Mon Dec 5 2016
.AVIATION DISCUSSION...FOR 12Z TAF PERIOD...
Upper low still positioned west of KDRT at TAF issuance. Thus,
rain chances will continue for all terminals through the morning
hours. KDRT will improve first, with CIGs rising to VFR by early
afternoon. -RA will continue for the I-35 terminals along with
CIGs fluctuating around the 1kft height through much of the day.
Improvement to MVFR is expected by early evening and quickly to
VFR after dark. Amendments will likely be needed for fluctuating
IFR/MVFR CIGs through the morning hours. Included TEMPO groups to
account and to reduce amendments.
.PREV DISCUSSION... /ISSUED 306 AM CST Mon Dec 5 2016/
SHORT TERM (Today through Tuesday)...
The upper low is finally beginning to move to the east this
morning which signals the beginning of the end of the rain which
has been around for 3 days. This rain event ended up bringing 2-7
inches of rain to most of the region and the lakes and aquifers
have risen accordingly. At the present time, periods of rain can
be expected through the morning hours. As the upper low nears the
CWA, a dry slot in the mid-levels of the atmosphere should enter
the region and begin to dry things out around mid-day with all of
the precipitation ending by the late afternoon hours. Broke down
the PoP grids today in 3 hour increments to show this drying trend
a bit better. Additional rainfall amounts should be less than 1/4
of an inch across most locations. The current Flash Flood Watch
expires at 6 am and will let it ride for the 3 hours. However, the
threat of flash flooding is low given the rain rates, but numerous
low-water crossing remain closed at this time. High temperatures
today will once again be in the 50s to the lower 60s which is a
bit warmer than previous days due to a few peaks of the sun by the
late afternoon hours.
After today, the main weather story was the cold front expected
for the end of the work week. However, there should be an initial
front which should move through the area on Tuesday afternoon.
This front will have a decent push of colder air behind it with
40s possible by 00z Tuesday evening for the Hill Country.
LONG TERM (Tuesday Night through Sunday)...
Northerly flow will continue Tuesday night behind the front with
low temperatures dipping into the 40s across the region. Winds
will be light and easterly on Wednesday ahead of the next cold
front. Models have pushed back the timing a bit of this stronger
front into the Wednesday night time frame. Thursday will be
outright cold across South-Central Texas. Temperatures in the
afternoon will be in the 30s across portions of the Hill Country
and the 40s elsewhere. Wind speeds will be in the 15-25 MPH range
as well which would lead to wind chill values dipping into the
teens and 20s. Wind speeds will become less than 10 mph by Friday
morning which should be low enough for temperatures to drop below
freezing across much of the CWA.
Highs Friday will remain in the 40s areawide with continued
lighter winds. Southerly flow returns on Saturday with another
possible freeze Saturday morning before the warm-air advection
really gets going. The strong southerly flow could lead to
isolated showers across the eastern counties on Saturday and will
continue to show the 20 PoP. Temperatures will warm back into the
60s on Sunday as models have backed off on another front moving
into the region and now keep southerly flow in place.
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 53 46 64 44 62 / 80 0 0 0 10
Austin Bergstrom Intl Airport 53 43 65 45 62 / 80 0 0 0 10
New Braunfels Muni Airport 55 45 68 45 62 / 80 0 0 0 20
Burnet Muni Airport 50 43 62 44 61 / 80 - 0 0 10
Del Rio Intl Airport 59 44 68 44 65 / 50 0 0 0 0
Georgetown Muni Airport 51 43 63 44 61 / 80 - 0 0 10
Hondo Muni Airport 58 43 71 44 64 / 60 0 0 0 10
San Marcos Muni Airport 54 44 66 45 62 / 80 0 0 0 20
La Grange - Fayette Regional 54 45 68 48 65 / 80 0 0 - 20
San Antonio Intl Airport 56 47 69 44 63 / 70 0 0 0 10
Stinson Muni Airport 57 45 71 46 64 / 60 0 0 0 10
Flash Flood Watch until 6 AM CST early this morning for the
following counties: Bandera...Bastrop...Bexar...Caldwell...Comal...