Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Austin/San Antonio Texas
1238 am CDT Tuesday Apr 28 2015
currently all taf sites are VFR and should remain that way for the
next few hours. By 09z at aus and 12z elsewhere MVFR stratus will
move down from the north. The deck will be persistent through
much of the morning and afternoon hours...rising to VFR by late in
The cold front is pushing south across south central Texas
currently. Winds are already out of the north and northwest. Winds
will gradually increase in speed overnight and into tomorrow with
gusts up to 25 knots possible tomorrow during the morning and
afternoon hours. Winds will begin to decrease as we get into the
evening and overnight hours Tuesday.
Previous discussion... /issued 937 PM CDT Monday Apr 27 2015/
isolated storms across central Texas are pushing to the east
southeast ahead of a weak cold front. Some of these storms are
expected to affect the northern portion of Llano and Burnet
counties tonight. Strongest storms could produce pea to dime sized
hail. Otherwise...a cool night is in store for The Hill Country
and southern Edwards Plateau with lows in the middle 50s to the upper
50s and lower 60s elsewhere.
Previous discussion... /issued 707 PM CDT Monday Apr 27 2015/
Aviation... /00z taf update/
weak surface boundary about 80 miles east of I-35 should deflect
any surface based convection for this evening...and only a few
elevated showers are expected over central Texas tonight. This is
reflected well in recent hrrr runs...so will not include any
convective influences on taf sites. The cold front will slip
through the area with a gradual northerly wind increase this
evening with not a significant wind shift or dramatic wind
increase. Under the base of the upper low over North Texas resides lower
level saturation through cooler temperatures and light rains...and
this lower category should drag MVFR ceilings into Austin sometime
after midnight and into Sat/ssf by daybreak. Meanwhile...drt
should see better dry low level air mixing through the night and
have VFR ceilings develop if they form at all.
Previous discussion... /issued 259 PM CDT Monday Apr 27 2015/
Short term (tonight through Tuesday night)...
looking at the 27/19z surface observations...a weak frontal boundary
is draped across our far eastern counties...located roughly along
the Highway 77 corridor. Afternoon temperatures were in the 70s and
80s while dew point temperatures ranged from the middle 30s across the
southern Edwards Plateau to near 70 near the coastal plains.
Elsewhere...an upper low is nearly stationary across the Texas
Panhandle into far southwest Oklahoma.
The above mentioned upper low will move eastward along the Red River
overnight. Some weak lift associated with this low will spread into
The Hill Country and northern portions of the I-35 corridor and will
result in a few showers and possibly a stray thunderstorm overnight.
Otherwise...northwesterly surface winds will increase as dry and
cool air spreads across south central Texas. The upper low continues
to move eastward on Tuesday as a trailing trough axis moves into
south central Texas. We/ll keep any rain chances low (20%) and
confined to areas north of a Fredericksburg to Giddings line on
Tuesday. We/ll keep the forecast dry Tuesday night...but would not
be too surprised if some light showers tried to move in from the
north. Given the dry sub-cloud layer...any precipitation would
likely evaporate before reaching the ground.
Long term (wednesday through monday)...
northwest to northerly flow aloft will result in dry weather along
with temperatures remaining below normal for Wednesday through
Saturday. Low temperatures will drop into the 40s and 50s with highs
in the 70s and lower 80s for much of the upcoming work week. The
coolest spots will be across The Hill Country and adjacent portions
of the northern I-35 corridor. We do expect an increase in southerly
flow beginning Saturday and continuing through Monday. This will
bring an increase in low-level moisture back to the region. The flow
aloft will transition from northwest to westerly by early next week.
We/ll keep a slight chance for showers and thunderstorms confined
to the coastal plains on Sunday...with rain chances spreading
across the remainder of the region on Monday.
Preliminary point temps/pops...
Austin Camp Mabry 69 52 75 53 79 / 10 - 0 0 0
Austin Bergstrom international Airport 68 46 74 49 78 / 10 - 0 0 0
New Braunfels Muni Airport 71 50 75 52 79 / - - 0 0 0
Burnet Muni Airport 64 47 74 52 77 / 20 - 0 0 0
del Rio International Airport 72 52 78 54 84 / - - 0 0 0
Georgetown Muni Airport 65 48 74 51 77 / 20 - 0 0 0
Hondo Muni Airport 73 49 75 52 80 / - - 0 0 0
San Marcos Muni Airport 69 49 74 52 78 / - - 0 0 0
La Grange - Fayette regional 70 49 74 52 77 / 10 - 0 0 0
San Antonio International Airport 72 51 75 53 79 / - - 0 0 0
Stinson Muni Airport 73 52 75 54 80 / - - 0 0 0