Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Austin/San Antonio Texas
1102 PM CST Monday Mar 2 2015
Aviation discussion...for 06z taf package...
extremely poor aviation conditions for this taf period. Dense fog
advisory for most of the state of Texas and much of the southeast Continental U.S.
For that matter. As such...LIFR visible is expected throughout the
night and at least until middle day tomorrow. As return flow only
further enhances the already moist low level
atmosphere...conditions will only continue to worsen and Airport
minimums are expected overnight and through the morning.
Again...LIFR conditions are expected to prevail with extremely
poor conditions prevailing. Expect Airport minimums to be reached
during the majority of the first 12 hours of the taf period.
Previous discussion... /issued 646 PM CST Monday Mar 2 2015/
visibilities are dropping across the area with San Antonio
International Airport already at 1/4 of a mile. This trend should
continue with winds becoming weak and from the south aiding in
increasing warm/moist advection at the surface. Issued a dense fog
advisory until 10 am tomorrow for all but the western counties
where visibilities should remain above 1/4 of a mile. Products
have been sent.
Previous discussion... /issued 532 PM CST Monday Mar 2 2015/
Aviation discussion...for 00z taf package...
poor aviation conditions will continue through this taf period.
Similar to previous tafs...IFR/LIFR conditions are expected
throughout the period due to a saturated low level atmosphere.
Surface winds will shift to the southeast overnight and visible will
lower as a result...as will ceilings. Thus included LIFR fog and ceilings
to kaus/ksat/kssf overnight.
Previous discussion... /issued 334 PM CST Monday Mar 2 2015/
Short term (tonight through Tuesday night)...
cloudy skies...northerly winds and cool temperatures are still
intact across all of south central Texas as of late this afternoon.
Temperatures as of 02/20z were generally in the upper 30s to upper
40s across the region. For tonight...cloud cover will remain thick
as low-level winds gradually transition to a more southerly
direction. With an increased moist...southerly flow in the
low-levels...we/ll maintain a 20-30% chance for rain across most
areas tonight. Finally...areas of fog can also be expected as cool
and moist air along with light winds dominate the boundary layer.
Fog continues into Tuesday morning along with a slight chance of
showers through the day. Temperatures will warm tomorrow given the
increase in southerly flow. Most of the model guidance appears too
warm as we expect mostly cloudy to cloudy skies tomorrow. We/ll
trend toward the lower side of guidance with high temperatures
mainly in the 60s on Tuesday. The weather pattern begins to turn a
little more interesting Tuesday night as an upper level trough moves
into the Desert Southwest. We/ll mention a 20-30% chance for rain
along with an isolated thunderstorm possible mainly north of U.S.
Long term (wednesday through monday)...
the above mentioned upper level trough continues to approach on
Wednesday. A Pacific cold front will move in from the west during
the morning hours...quickly followed by an Arctic cold front moving
in from the north. The cold front will bring sharply cooler
temperatures along with gusty north winds during the afternoon and
evening hours. Concerns for wintry precipitation will be on the
increase during the evening hours across The Hill Country and
southern Edwards Plateau. Forecast soundings favor a freezing rain
and sleet mix given the shallow...cold air in the low-levels along
with a pronounced warm layer just above the low-level cold air.
During the early morning hours on Thursday...the wintry
precipitation threat will drop southward to just north of a del
Rio...San Antonio...La Grange line. Again...most areas can expect a
freezing rain and sleet mix...with some snow possible across the
southern Edwards Plateau...Hill Country and I-35 Corridor North of
San Antonio. By early Thursday afternoon...temperatures should rise
above freezing with the precipitation type transitioning back to all
Cool temperatures remain in the forecast on Friday with highs
generally in the 40s. Temperatures warm slightly on Saturday but
remain below normal. The medium range models also suggest an upper
level trough will move in from the west on Saturday. We/ll maintain
a 20-30% chance for showers across most areas on Saturday...with
precipitation shifting east into the coastal plains on Sunday.
Preliminary point temps/pops...
Austin Camp Mabry 44 64 56 57 30 / 30 20 30 60 70
Austin Bergstrom international Airport 43 65 56 58 30 / 30 20 20 60 70
New Braunfels Muni Airport 46 65 57 59 32 / 30 20 20 40 70
Burnet Muni Airport 41 64 53 53 27 / 30 20 30 70 70
del Rio International Airport 51 70 54 65 32 / 10 10 20 40 50
Georgetown Muni Airport 42 63 55 57 28 / 30 20 30 70 70
Hondo Muni Airport 49 65 55 61 33 / 20 20 20 40 60
San Marcos Muni Airport 45 65 56 59 31 / 30 20 20 50 70
La Grange - Fayette regional 47 70 60 62 33 / 30 20 30 60 70
San Antonio International Airport 47 64 57 61 32 / 30 20 20 40 70
Stinson Muni Airport 47 65 57 61 33 / 30 20 20 30 70
dense fog advisory until 10 am CST Tuesday for the following
public service/data collection...00