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Area forecast discussion
National Weather Service Austin/San Antonio Texas
325 am CST Tue Nov 12 2019

Short term (today through wednesday)...
area radars show light returns stretching from The Trans Pecos into
The Hill Country early this morning, coincident with an axis of
frontogenetic forcing between 850-700 mb. Surface observations in
this area are reporting temperatures between 26-32 degrees with
reported weather varying between light rain, sleet, and freezing
rain. Early morning surface analysis shows the freezing line
stretching from Austin to Boerne to Pandale with additional southward
progression of this line expected through the remainder of the
morning hours as Storm Prediction Center mesoanalysis shows surface wet bulb temperatures
below freezing from a del Rio to La Grange line.

Expect light freezing rain to continue shifting towards the south
and east towards the Interstate 10/Highway 90 corridor through 6 am
coincident with the aforementioned frontogenetic band. Short term
guidance continues to indicate an intermittent presence of
conditional symmetric instability... which can produce some temporary
enhancements in precipitation rates. The greatest potential for this
appears to remain across The Hill Country/Edwards Plateau through
this 6 am time frame, which may allow for some additional light ice
accretion (less than 0.05") on overpasses or bridges. The Texas
Department of Transportation is reporting patches of ice on
Interstate 10 between Boerne and Highway 290 and additional roadways
in this area may also experience slick spots before precipitation
ends. The Winter Weather Advisory remains in effect for The Hill
Country and Edwards Plateau through 6 am, but will be evaluated
closer to expiration time if any updates are needed. Farther south
and east, light icing has been reported on elevated and/or exposed
objects like flyovers around the Austin Metro and patio furniture,
light poles, and cars in the San Antonio metros. Strong northerly
winds will also continue through sunrise, remaining gusty through the
morning hours with gusts in the 20-30 miles per hour range possible.

A light rain/sleet or light freezing rain/sleet mix will continue to
spread south of Interstate 10/Highway 90 through the 6-9 am
timeframe with warm ground temperatures limiting the potential for
accumulations. Precipitation chances end by mid-morning as an
increasingly veered wind profile dries out the atmospheric column
with highs generally in the 40s this afternoon. Decreasing cloud
cover this afternoon as mid-level dry air works its way into the
region will quickly be replaced by a dense cirrus canopy as upper
level moisture increases with the approach of a closed low near Baja
California. Dry conditions are again expected overnight, but this
increasing cloud cover will make for a challenging temperature
forecast overnight as the thickness and coverage of it will either
inhibit or aid radiational cooling. For now, expect freezing
temperatures outside of the Rio Grande plains. Will need to monitor
the counties south and southwest of the San Antonio Metro for a
possible freeze warning, but with the aforementioned cloud cover
confidence is too low for issuance at this time. After a cold start
with temperatures in the mid 20s to mid 30s, expect highs to climb
into the mid 40s to low 50s Wednesday afternoon with dry conditions
persisting.

&&

Long term (wednesday night through monday)...
as the closed low translating eastward out of Mexico reaches south
Texas on Wednesday night and opens up, rain chances will increase
west to east across the region. A reinforcing cold front moving into
the region during the day Thursday may enhance coverage along and
behind the boundary for the coastal plains, but will still have to
keep an eye on a potential thunderstorm complex developing off the
Lower/Middle Texas coast to see how much moisture is able to actually
support development farther inland. Cloud cover and rain will keep
below normal temperatures in the forecast for Thursday, with highs in
the low 50s to low 60s. Generally dry conditions and a gradual
warming trend are expected Friday through Monday with highs climbing
into the mid 60s to mid 70s by Monday.

&&

Climate...
record low maximum temperatures and/or record low temperatures will be
possible today and Wednesday for parts of south central Texas. A
listing of these records are included below.

November 12
location record low (year) record low maximum (year)
Austin Bergstrom 26 (1980) 51 (2018)
Austin Camp Mabry 24 (1950) 41 (1907)
San Antonio 26 (1950) 45 (1907)
del Rio 31 (1932) 46 (1907)

November 13
location record low (year) record low maximum (year)
Austin Bergstrom 28 (2014) 42 (2014)
Austin Camp Mabry 27 (1911) 36 (1976)
San Antonio 28 (2018) 37 (1976)
del Rio 31 (1986) 40 (1986)

&&

Preliminary point temps/pops...
Austin Camp Mabry 45 29 50 39 53 / 0 0 - 50 40
Austin Bergstrom Intl Airport 44 25 50 37 53 / 0 0 - 50 50
New Braunfels Muni Airport 46 27 49 38 53 / 10 0 - 50 50
Burnet Muni Airport 44 25 50 36 54 / 0 0 - 30 30
del Rio Intl Airport 50 35 50 39 62 / 20 - 10 30 20
Georgetown Muni Airport 44 24 50 37 54 / 0 0 - 40 40
Hondo Muni Airport 49 30 50 39 59 / 20 0 - 30 40
San Marcos Muni Airport 45 25 50 37 53 / 10 0 - 50 50
La Grange - Fayette regional 44 26 50 39 51 / 10 0 - 40 50
San Antonio Intl Airport 47 30 49 40 54 / 20 0 - 40 50
Stinson Muni Airport 47 31 48 41 54 / 30 0 - 40 50

&&

Ewx watches/warnings/advisories...
Wind Advisory until 6 am CST early this morning for Atascosa-
Bandera-Bastrop-Bexar-blanco-Burnet-Caldwell-Comal-De Witt-Dimmit-
Edwards-Fayette-frio-Gillespie-Gonzales-Guadalupe-Hays-Karnes-
Kendall-Kerr-Kinney-Lavaca-Lee-Llano-Maverick-Medina-real-Travis-
Uvalde-Val Verde-Williamson-Wilson-Zavala.

Winter Weather Advisory until 6 am CST early this morning for
Bandera-blanco-Burnet-Edwards-Gillespie-Kendall-Kerr-Llano-real-Val
Verde.

&&

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