Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Austin/San Antonio Texas
707 PM CDT Monday Apr 27 2015
Aviation... /00z taf update/
weak surface boundary about 80 miles east of I-35 should deflect
any surface based convection for this evening...and only a few
elevated showers are expected over central Texas tonight. This is
reflected well in recent hrrr runs...so will not include any
convective influences on taf sites. The cold front will slip
through the area with a gradual northerly wind increase this
evening with not a significant wind shift or dramatic wind
increase. Under the base of the upper low over North Texas resides lower
level saturation through cooler temperatures and light rains...and
this lower category should drag MVFR ceilings into Austin sometime
after midnight and into Sat/ssf by daybreak. Meanwhile...drt
should see better dry low level air mixing through the night and
have VFR ceilings develop if they form at all.
Previous discussion... /issued 259 PM CDT Monday Apr 27 2015/
Short term (tonight through Tuesday night)...
looking at the 27/19z surface observations...a weak frontal boundary
is draped across our far eastern counties...located roughly along
the Highway 77 corridor. Afternoon temperatures were in the 70s and
80s while dew point temperatures ranged from the middle 30s across the
southern Edwards Plateau to near 70 near the coastal plains.
Elsewhere...an upper low is nearly stationary across the Texas
Panhandle into far southwest Oklahoma.
The above mentioned upper low will move eastward along the Red River
overnight. Some weak lift associated with this low will spread into
The Hill Country and northern portions of the I-35 corridor and will
result in a few showers and possibly a stray thunderstorm overnight.
Otherwise...northwesterly surface winds will increase as dry and
cool air spreads across south central Texas. The upper low continues
to move eastward on Tuesday as a trailing trough axis moves into
south central Texas. We/ll keep any rain chances low (20%) and
confined to areas north of a Fredericksburg to Giddings line on
Tuesday. We/ll keep the forecast dry Tuesday night...but would not
be too surprised if some light showers tried to move in from the
north. Given the dry sub-cloud layer...any precipitation would
likely evaporate before reaching the ground.
Long term (wednesday through monday)...
northwest to northerly flow aloft will result in dry weather along
with temperatures remaining below normal for Wednesday through
Saturday. Low temperatures will drop into the 40s and 50s with highs
in the 70s and lower 80s for much of the upcoming work week. The
coolest spots will be across The Hill Country and adjacent portions
of the northern I-35 corridor. We do expect an increase in southerly
flow beginning Saturday and continuing through Monday. This will
bring an increase in low-level moisture back to the region. The flow
aloft will transition from northwest to westerly by early next week.
We/ll keep a slight chance for showers and thunderstorms confined
to the coastal plains on Sunday...with rain chances spreading
across the remainder of the region on Monday.
Preliminary point temps/pops...
Austin Camp Mabry 59 69 52 75 53 / 20 10 - 0 0
Austin Bergstrom international Airport 59 68 46 74 49 / 20 10 - 0 0
New Braunfels Muni Airport 59 71 50 75 52 / - - - 0 0
Burnet Muni Airport 56 64 47 74 52 / 30 20 - 0 0
del Rio International Airport 58 72 52 78 54 / 0 - - 0 0
Georgetown Muni Airport 58 65 48 74 51 / 30 20 - 0 0
Hondo Muni Airport 58 73 49 75 52 / 0 - - 0 0
San Marcos Muni Airport 59 69 49 74 52 / - - - 0 0
La Grange - Fayette regional 61 70 49 74 52 / 20 10 - 0 0
San Antonio International Airport 60 72 51 75 53 / 0 - - 0 0
Stinson Muni Airport 61 73 52 75 54 / 0 - - 0 0
public service/data collection...01