Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Austin/San Antonio Texas
935 PM CDT Wednesday Jul 27 2016
except for an area of rain between Bastrop and La Grange that will
dissipate by 10 PM, radars show no rain over south central Texas.
We have removed pops for most of tonight. Precipitable waters around 2 inches,
weak low level jet, and upper level shear axis may allow for some
redevelopment toward morning and gone with less than 20 probability of precipitation after
4 am. Rain cooled air from earlier showers and thunderstorms has
resulted in lower temperatures than forecast and have dropped low
temperatures a degree or two most areas. Also, have reestablished
trends to dewpoints/relative humidities and winds for overnight
into early Thursday. Remainder of the forecast is on track with
Thursday being the last day of rain chances for most of south
central Texas for the next week or so.
Previous discussion... /issued 626 PM CDT Wednesday Jul 27 2016/
Aviation discussion...for 00z taf period...
isolated to scattered showers and thunderstorms continue to be
seen at taf issuance across the region but not threatening any
terminals. Should continue to see this activity diminish as night
A return of MVFR and possibly IFR cigs are expected at the I-35
terminals overnight due to lots of rainfall over both areas today.
Should also result in some MVFR br. Improvement to VFR is expected
by mid morning.
Previous discussion... /issued 236 PM CDT Wednesday Jul 27 2016/
Short term (tonight through Thursday night)...
upper air analysis this morning showed a split in the subtropical
ridge over Texas. The 50mb flow was ill defined and at 250mb there
was weak cyclonic flow. The surface pressure field was also weak
and winds were light and variable. There was plenty of low level
moisture with surface dew point temperatures from the upper 60s to
the middle 70s. The weakness in the upper level ridge is allowing
convection to form across the area. Showers and thunderstorms will
continue into the early evening. Lower chances for showers and
thunderstorms will continue overnight. Precipitable water near two inches will
mean efficient rain producing storms and locally heavy rain is
possible with some storms dropping one to two inches of rain over
an hour or two. Most places should be able to take this much rain
since it has been so dry, however a few places could see some
minor flooding. Rain chances will continue Thursday with the best
chances in the east where moisture is deeper.
Long term (friday through wednesday)...
the subtropical high will build back over Texas from the west and
any rain chances will shift to the southeastern part of the County Warning Area
for Friday through Sunday. Chances will be lower and be confined
to the afternoons and early evenings. Temperatures should begin to
rebound, but still be near normal through the weekend. The
beginning of next week the upper ridge will be back in control and
hot and dry weather will return.
Preliminary point temps/pops...
Austin Camp Mabry 75 96 76 98 76 / 10 30 10 10 0
Austin Bergstrom Intl Airport 74 95 75 97 74 / 10 30 10 10 0
New Braunfels Muni Airport 74 94 74 96 74 / 10 30 10 10 0
Burnet Muni Airport 74 94 74 95 75 / 10 30 10 10 0
del Rio Intl Airport 76 96 77 98 78 / 10 20 10 10 0
Georgetown Muni Airport 75 94 76 96 76 / 10 30 10 10 0
Hondo Muni Airport 74 94 74 95 74 / 10 20 10 - 0
San Marcos Muni Airport 74 94 75 96 74 / 10 30 10 10 0
La Grange - Fayette regional 73 94 76 96 75 / 20 40 10 20 -
San Antonio Intl Airport 75 94 77 95 76 / 10 20 10 10 0
Stinson Muni Airport 76 95 76 97 76 / 10 30 10 10 0
public service/data collection...33