Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Austin/San Antonio Texas
1155 PM CDT Thursday Jul 31 2014
Aviation... /issued for 06z tafs/
stability increased over the past 6 hours and reduced the effects
of convection on clouds. Looking at the VAD wind profile...the
front appears to have slightly more winds in a deeper layer than
accounted for...so will shift back the return of I-35 low clouds
for an hour from the previous projections. With still a fair
amount of middle level clouds...it may be possible that portions of
the I-35 corridor see no MVFR ceilings at all. MVFR ceilings are a slight
possibility again late Friday night into Saturday morning.
Previous discussion... /issued 1127 PM CDT Thursday Jul 31 2014/
convection has continued to die off except for some light showers
on the coastal plains. We feel confident enough to remove probability of precipitation
except for this area overnight. The rest of the forecast was
updated to re-trend through 12z Friday.
Previous discussion... /issued 937 PM CDT Thursday Jul 31 2014/
showers and thunderstorms continue to wane with the loss of daytime
heating. The mesoscale models show some chance for development
overnight...so will maintain low probability of precipitation east of the I-35 corridor...
except for also along and south of U.S. 90. Higher probability of precipitation are in the
far southeast counties where moderate convection is ongoing.
Otherwise...we re-trended the forecast variables through 12z
Previous discussion... /issued 313 PM CDT Thursday Jul 31 2014/
Short term (tonight through Friday night)...cold front still
progressing southward and middle afternoon was located from near a
Temple to Fredericksburg to Rocksprings line. Convection has been
meager along the front thus far across the northern County Warning Area.
However...hi resolution models insist convection will expand in
coverage and intensity between 3 PM and 6 PM as the front reaches
a more unstable region across the central County Warning Area...and weak low level
flow ahead of it backs to a more favorable southeast position.
Will continue to carry isolated and scattered probability of precipitation in the forecast
for the late afternoon and evening hours...with the best chances
along and southeast of a Caldwell to south Austin to Medina line.
Potential is still there for strong wind gusts and locally heavy
downpours given the amount of cape currently analyzed...2-2.2
inches of precipitable water...precipitation loading.
Front slows and possibly stalls near the I-10/U.S. 90 corridor
overnight...with best chances for precipitation during this time across
the southeast County Warning Area and Rio Grande near and south of the boundary.
Chances for showers and storms will continue Friday across far
southern areas and up the Rio Grande...closer to deep moisture
axis and low level convergence near the boundary.
Long term (saturday through thursday)...amplified pattern with upper
level ridge axis along The Rockies and trough across the eastern
Continental U.S. Will remain in place over the weekend. Drier low and middle
level flow will filter into the northern and central County Warning Area over the
weekend...with the deeper moisture axis being confined on
Saturday to the Rio Grande and on Sunday to the coastal plains.
Low pop with mention of showers both days and locations...with dry
conditions elsewhere. Temperatures "cool" for August...with highs only in
the upper 80s across The Hill Country and low 90s elsewhere.
Morning lows in the upper 60s across The Hill Country and low to
middle 70s elsewhere.
The upper level ridge to the west will build into the Southern
Plains Monday and Tuesday...with troughs across the Great Basin and
deep south. South-central Texas will remain dry early next week
with gradually warming temperatures back to seasonal norms.
Middle and upper level weakness over the western Gulf is forecast to
move into the coastal plains Wednesday and possibly as far west as
the I-35 corridor on Thursday. Slight increase in moisture could
lead to isolated showers across the east each day.
Preliminary point temps/pops...
Austin Camp Mabry 73 90 72 90 73 / 10 10 10 10 -
Austin Bergstrom international Airport 73 91 70 90 70 / 10 10 10 10 -
New Braunfels Muni Airport 74 92 71 90 72 / 10 10 10 10 -
Burnet Muni Airport 71 89 70 88 70 / 10 - 10 10 -
del Rio International Airport 78 93 76 90 75 / 20 30 30 30 20
Georgetown Muni Airport 70 89 70 89 70 / 10 10 10 10 -
Hondo Muni Airport 75 93 73 92 71 / 20 20 20 20 10
San Marcos Muni Airport 73 92 71 90 71 / 10 10 10 10 -
La Grange - Fayette regional 74 89 71 89 72 / 60 20 10 20 10
San Antonio International Airport 76 92 74 91 74 / 20 10 20 10 10
Stinson Muni Airport 76 92 74 92 73 / 20 20 20 10 10
public service/data collection...00