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Area forecast discussion 
National Weather Service Austin/San Antonio Texas
1253 am CDT Tuesday Jul 7 2015

Aviation... /06z taf update/

A general persistence trend is expected with skies over the taf
sites for the next 24 hours. Instability over northwest Texas could spread
southeast into the drt area after daybreak...and a few strong storms
could generate gusty outflows. A wide window for timing and most
of the activity expected to stay west of the area will keep this
taf update from including thunder. A fairly tight surface pressure
gradient should keep daytime and evening winds gusting up to
around 27 knots. The well mixed air should keep morning stratus
layers mainly MVFR.

&&

Previous discussion... /issued 917 PM CDT Monday Jul 6 2015/

Update...
small batch of convection formed over the far western sections of
Val Verde County earlier this evening. Much of that convection is
now gone but will keep the mention of chance pop out west across
mainly Val Verde County as the latest hrrr does show some sh/ts
development later on. This scenario is not consistent across the
board with the various mesoscale models...but with large cluster of
storms across northwest Texas...and obvious middle to upper level energy
over Texas...will keep the pop in place. Elsewhere across south
central Texas...should see an increase in cloud cover as cirrus
blowoff from storms to the north make their way down to our area.
Winds still remain gusty in many locations and the ongoing
convection over northwest Texas may keep them a bit stronger overnight or
at least delay a decrease in speeds late this evening. Did some
minor tweaks to the current grids but no major changes.

Previous discussion... /issued 651 PM CDT Monday Jul 6 2015/

Aviation.../00z taf cycle/

VFR conditions prevail across the region with few/sct050 fair
weather cumulus clouds. Off to the northwest of the region...stronger thunderstorms and rain
is aiding in cirrus blowoff and this will shift over kdrt first and
then rest of region overnight. While thunderstorms and rain/rain showers is not expected to
impact any taf sites...lower MVFR ceilings will once again develop 05-
08z across central sites and fall to low MVFR with some patchy areas
of IFR possible. Hrrr indicates some chances at ceilings reducing to 600-
900 feet at times 09-14z but feel overall low MVFR ceilings will
prevail. Ceilings will increase through the middle to late morning similar
to today. Gusty winds this late afternoon will slowly calm overnight
but remain near 10-15 knots and pick back up Tuesday with gusts to 25
knots by the late morning and through the afternoon.

Previous discussion... /issued 303 PM CDT Monday Jul 6 2015/

Short term (tonight through Tuesday night)...
precipitation chances through the short term portion of the forecast
will remain favored across the southern Edwards Plateau and portions
of the Rio Grande plains. A pronounced middle-level Theta-E ridge axis
currently over West Texas and Chihuahua Mexico will gradually shift
eastward over the next 48 hours...with rain chances likely peaking
Tuesday afternoon. We/ll keep rain chances highest (40%) across
western Val Verde County with chances decreasing to 20% along a del
Rio to Rocksprings line. Slow moving cells along with deep moisture
could result in some locally heavy rains across portions of Val
Verde and Edwards counties on Tuesday. Elsewhere...dry and warm
weather can be expected across south central Texas. We/ll need to
monitor for an isolated shower developing along the sea breeze. At
this time...prefer to keep the forecast dry with temperatures near
or just below climatological normal values.

Long term (wednesday through monday)...
on Wednesday...we/ll keep a mention of isolated showers and
thunderstorms across far western Val Verde County as the above
mentioned middle-level Theta-E ridge axis gradually weakens. The medium
range models agree in showing a strengthening subtropical ridge
across the southern U.S. Plains through the remainder of the
forecast period. This will result in dry and warm weather across
almost all of south central Texas. The models are beginning to show
some consistency with an increase in moisture across the coastal
plains on Saturday. We have introduced a 20% chance for showers and
thunderstorms for the coastal plains and Highway 77 corridor on
Saturday. Temperatures will gradually climb as soils dry out and
subsidence increases. This will result in near normal temperatures
with highs warming into the lower 90s across The Hill Country to
near 100 along the Rio Grande plains for the upcoming weekend into
early next week.

&&

Preliminary point temps/pops...
Austin Camp Mabry 75 93 75 92 74 / 0 0 - 0 0
Austin Bergstrom international Airport 75 92 74 93 73 / 0 0 - 0 0
New Braunfels Muni Airport 74 92 74 92 73 / 0 0 - 0 0
Burnet Muni Airport 74 91 73 92 71 / 0 0 0 0 0
del Rio International Airport 77 95 76 95 74 / 20 10 0 0 0
Georgetown Muni Airport 75 92 74 92 73 / 0 0 0 0 0
Hondo Muni Airport 74 93 73 93 73 / 0 0 0 0 0
San Marcos Muni Airport 75 92 74 92 73 / 0 0 - 0 0
La Grange - Fayette regional 76 92 75 92 74 / 0 0 0 0 0
San Antonio International Airport 75 92 74 92 74 / 0 0 - 0 0
Stinson Muni Airport 74 92 75 92 74 / 0 0 - 0 0

&&

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

$$

Mesoscale/aviation...Oaks
synoptic/grids...runyen

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