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Area forecast discussion 
National Weather Service Austin/San Antonio Texas
921 PM CDT Sat Apr 19 2014

Update...
update issued this evening to make subtle changes to sky...
temperature...and weather grids through 15z Sunday. Chance category probability of precipitation
continue into late tonight for the southern Edwards Plateau...as
lighting activity extends deep into northern Mexico. For this
reason...slight chance probability of precipitation were nudged eastward slightly over the
Rio Grande plains. Slightly drier surface area analyzed this
evening suggests fog may be less extensive over SW and NE
counties. The rest of the afternoon forecast package remains in
good shape.

&&

Previous discussion... /issued 642 PM CDT Sat Apr 19 2014/

Aviation...
VFR conditions will prevail through this evening. Convective
activity across West Texas this evening will move eastward...but
should remain north of south central Texas taf locations. Additional
isolated-scattered rain showers/thunderstorms and rain is possible across the region through the rest
of taf period...but coverage is too low to warrant explicit mention
at this time. Southerly surface winds will allow moisture to continue
to advect into the region this evening...enabling a stratus deck to
develop overnight. Latest model runs continue to suggest the
potential for ceilings to fall to borderline IFR/LIFR in the near
sunrise hours at I-35 taf sites. Patchy fog will also develop
mainly across eastern portions of the region overnight...but visibilities
are expected to mostly be MVFR or better...with patchy reductions
to IFR around daybreak. Persistent moist southerly flow will keep low
ceilings through the early morning hours with a gradual improvement
during the late morning/early afternoon. There is the possibility
for ceilings to remain MVFR through the afternoon hours...but have
gone with a more optimistic solution of a few hours of VFR during
the afternoon.

Previous discussion... /issued 327 PM CDT Sat Apr 19 2014/

Short term (tonight through Sunday night)...
low level moisture continues to increase across south central
Texas this afternoon as surface high pressure ridge over the
eastern half of the nation pushes to the northeast. Also...
middle to upper level moisture from the eastern Pacific persists
across the area as the sub-tropical jet moves across the southern
states/Gulf of Mexico area. Isolated showers and even an isolated
thunderstorm is possible across Val Verde County through late this
afternoon as an upper level short-wave moves from northeast Mexico
into central Texas. This activity could expand to the east this
evening affecting portions of the southern Rio Grande plains and
Edwards Plateau. Rainfall amounts are expected to be light or few
hundredths of an inch at most. Overnight lows will range from the
upper 50s across The Hill Country to middle 60s in southern Rio
Grande plains.

Another but stronger upper level short-wave trough is forecast to
push across central Texas midday/early afternoon Sunday. With surface
dewpoints in the upper 50s to lower 60s and the passage of the
upper wave (for upper level support)...expect a slight chance of
showers and thunderstorms across most areas with better chances
for thunderstorms out west...especially west of a Rocksprings to
del Rio line. Some of these storms could become strong to even
severe in the afternoon/early evening with large hail and damaging
winds as main hazards. Once again...quantitative precipitation forecast values are anticipated to
be light or from a trace to several hundredths of an inch.

Long term (monday through saturday)...
an upper level low pressure system over southwest Arizona this
afternoon is forecast to push to the northeast and into the
Central Plains by Monday. At the surface...a weak cold front is
expected to push across south central Texas around midday/early
afternoon with dewpoints in the lower to middle 60s. At the same
time...a vorticity maximum is expected to be moving at the bottom of the
upper trough with area forecast soundings showing cape of 2000 to
3000 j/kg and lifted index values of -6 to -7. With these atmospheric
conditions...any storm that does develop has the potential to become
strong to severe. As of now...Storm Prediction Center day3 severe thunderstorm outlook
has The Hill Country (northeast of a Rocksprings to Kerrville to
Georgetown line) with a slight risk of severe thunderstorms. Large
and damaging winds are expected to be the main hazards for this
event.

Storms will come to an end Monday night as the cold front pushes
across the area and upper level northwest winds develop. Tuesday and
Wednesday of next week expect typical Spring days over the area
with 90s over the west and upper 80s east of Highway 281. Another
upper level trough is forecast to push across the area on Thursday
for a chance of rain mainly over the I-35 corridor.

&&

Preliminary point temps/pops...
Austin Camp Mabry 59 79 62 83 64 / 10 20 10 20 20
Austin Bergstrom international Airport 56 79 60 83 62 / 10 20 10 20 20
New Braunfels Muni Airport 57 79 61 84 61 / 10 20 10 20 20
Burnet Muni Airport 59 76 62 82 63 / 10 20 10 30 20
del Rio International Airport 64 81 66 88 66 / 30 30 10 20 10
Georgetown Muni Airport 58 78 62 82 64 / 10 20 10 20 20
Hondo Muni Airport 63 81 65 88 65 / 10 20 10 20 10
San Marcos Muni Airport 57 78 60 83 61 / 10 20 10 20 20
La Grange - Fayette regional 59 81 62 82 63 / 10 20 10 20 20
San Antonio International Airport 61 79 63 85 64 / 10 20 10 20 20
Stinson Muni Airport 61 81 63 87 64 / 10 20 10 10 20

&&

Ewx watches/warnings/advisories...
none.
&&

$$

Mesoscale/aviation...25
synoptic/grids...18
public service/data collection...33