Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Austin/San Antonio Texas
623 PM CST Sat Jan 31 2015
Steady rain showers have ended at drt and will move through the
I-35 taf sites over the next few hours. Conditions will fluctuate
between IFR/MVFR for the next several hours at all sites. Expect
visibilities to gradually fall to IFR conditions at all sites between
4-6z with drt and Sat/ssf deteriorating to LIFR between 10-11z as
nice advection and radiation fog event sets up. Less confident
that aus will have LIFR visibilities since rain may redevelop over Hill
Country and prevent fog from settling in...but have mentioned a
tempo group for them between 11-15z. Fog should rapidly lift with
initial wind shift around 15-16z at all sites and VFR conditions
should prevail by 18-19z. Wind gusts up to 25-30 kts will be
possible at Sat/ssf/aus after cold front passes around 21-00z.
Previous discussion... /issued 254 PM CST Sat Jan 31 2015/
Short term (tonight through Sunday night)...
an upper level disturbance over the Baja California peninsula is forecast to
push southward this evening as another upper level disturbance
pushes across the northern rockies. Latest water vapor channel
photos are showing plenty of upper level moisture arriving to south
central Texas from the southwest. At lower level...a southeasterly
flow is pushing Gulf moisture across the area with dewpoints in
the lower to middle 50s. A low level jet around 5kft of 40 to 50 miles per hour
based on Storm Prediction Center mesoscale analysis Page...is forecast to prevail
across the area through tonight. This will combine with a new
upper level wave of instability moving across northeast Mexico
later this afternoon and evening. As the wave nears...expect
rain showers to increase in areal coverage...first affecting the
Rio Grande plains and then the I-35 corridor this evening. This
wave could bring a round of moderate rain showers and isolated
thunderstorms. Highest rainfall amounts could range from one
quarter to one half inch with few locations getting up to three
quarter inch. Once this waves pushes through late tonight...will
have a break from the moderate rains with some lingering light
rain/drizzle mainly over The Hill Country and eastern zones.
Included patchy fog across the southwest counties and parts of the
Rio Grande plains for the dawn hours. However...this will be
closely monitor for other areas.
A cold front is forecast to push across south central Texas
Sunday afternoon. Rain chances increase along the front with
rain showers and isolated thunderstorms possible mainly along and
east of Highway 281. In the wake of the front...a cooler airmass
and breezy northerly winds are expected with gusts up to 30 miles per hour.
Overnight lows will drop to the lower 30s across The Hill
Country...middle to upper 30s along the I-35 and lower 40s over the
Long term (monday through saturday)...
dry and cool on Monday with high only in the 50s. By
Tuesday...surface southerly flow returns and an upper level
disturbance (mentioned above) will finally track eastward and move
across the area. This will bring rain showers and even few
thunderstorms across the area late Tuesday into Wednesday.
Weather conditions dry out by Wednesday afternoon and remain
through next weekend.
Preliminary point temps/pops...
Austin Camp Mabry 57 68 36 51 37 / 70 40 10 - -
Austin Bergstrom international Airport 56 69 37 51 33 / 70 40 10 - -
New Braunfels Muni Airport 57 71 38 53 36 / 70 40 10 - -
Burnet Muni Airport 53 64 32 50 34 / 70 30 10 - -
del Rio International Airport 52 69 41 56 40 / 30 10 10 - -
Georgetown Muni Airport 56 65 33 49 34 / 70 40 10 - -
Hondo Muni Airport 54 73 39 56 37 / 60 20 10 - -
San Marcos Muni Airport 56 69 37 51 35 / 70 40 10 - -
La Grange - Fayette regional 58 70 38 51 36 / 60 50 10 - -
San Antonio International Airport 56 70 39 54 38 / 70 30 10 - -
Stinson Muni Airport 56 73 40 55 38 / 70 30 10 - -
public service/data collection...00