Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Corpus Christi Texas
528 am CST Tuesday Dec 10 2013
Discussion...update for 12z aviation below.
Aviation...at 12z skies have cleared along and north of a
cot-ali-vct line. Clouds will continue to erode farther south at
lrd and crp over the next couple of hours...with VFR conditions
by 14z. VFR conditions then persisting across all of south Texas
through the day and evening. North wind gusting 15 to 25 kts
across eastern taf sites through 15z...then gradually diminishing
into the afternoon.
Previous discussion... /issued 355 am CST Tuesday Dec 10 2013/
Short term (today through wednesday)...the secondary surge of
high pressure has arrived into south Texas. Downglide has
commenced with clearing across the northern counties having already
occurred...clearing across southern counties towards daybreak.
Still the potential for a light freeze across northern counties so
will maintain the freeze warning (may not be widespread two hours
or more though). Have cancelled the Wind Chill Advisory for the
western County Warning Area where wind speeds have diminished. Still the potential
to reach 25 degree wind chill across the eastern County Warning Area through the
early morning hours as temperatures bottom out and before higher
wind speeds diminish. Otherwise mostly sunny conditions and drying
but cool today. Another light freeze possible late tonight into
Wednesday morning across northern areas and some isolated
locations of the southern brush country. Weak isentropic upglide
will develop Wednesday morning...resulting in a gradual increase
in cloud cover from south to north.
Long term (wednesday night through monday)...two main features of
this forecast period...reinforcing surface ridge on Thursday...and
cold front on Friday night. Ahead of reinforcing ridge...low level
moisture begins streaming back into the area with warming
temperatures and increasing dewpoints. As the surface ridge
strengthens...moisture in lowest layers decreases temporarily...but
just above the surface moisture will remain...and isentropic upglide
increases. This will bring chances for precipitation back for Friday.
Guidance indicates a pretty fair upglide situation for the daytime
Friday with 30 to 40 knots winds at the 300k surface (approximately
800mb)...with conditions pressure deficits in the coastal Bend down to
10-20mb. Have expanded 40 probability of precipitation to much of the coastal Bend...with
30s through much of the brush country. In western areas moisture is
a bit less and will stick with just 20s. Timing of the weekend cold
front has moved up a bit...and appears a bit stronger. Initial wind
shift to the west would occur early Friday night with the real front
pushing through by 12z Saturday. Will maintain 20-30 probability of precipitation ahead of
and along the front...but new model runs would indicate a fairly
rapid clearing behind the front during the day on Saturday with a
deeper airmass change and north to northwest flow up to around 700mb
level. Confidence in temperatures Sat through Monday not great with
changing frontal timing. Have decreased maximum T on Sunday...quicker
frontal passage...but if sun comes out this could offset the cold air advection and
allow temperatures to warm in the afternoon. Would also expect cooler min
temperatures for Sat and sun nights. We should finally be broken out of the
recent cloudy/cool pattern by late in the weekend and into early
next week. Surface winds shifting east will begin to pull low level
moisture back in early next week.
Preliminary point temps/pops...
Corpus Christi 37 55 43 54 46 / 0 10 10 10 20
Victoria 30 57 40 53 41 / 0 10 10 10 20
Laredo 36 57 44 53 46 / 0 10 10 10 10
Alice 33 54 42 54 44 / 0 10 10 10 20
Rockport 37 54 44 53 49 / 0 10 10 10 20
Cotulla 32 57 41 51 43 / 0 10 10 10 20
Kingsville 35 55 43 53 46 / 0 10 10 10 20
Navy corpus 40 54 46 55 50 / 0 10 10 10 20
Texas...Wind Chill Advisory until 9 am CST this morning for the
following zones: Aransas...Bee...Calhoun...Goliad...Jim
Freeze warning until 8 am CST this morning for the following
zones: Bee...Goliad...La Salle...Live Oak...McMullen...
GM...Small Craft Advisory until 6 PM CST this evening for the
following zones: waters from Baffin Bay to Port Aransas
from 20 to 60 nm...waters from Port Aransas to Matagorda
Ship Channel from 20 to 60 nm.
Small Craft Advisory until noon CST today for the following
zones: bays and waterways from Baffin Bay to Port Aransas...
bays and waterways from Port Aransas to Port O'Connor.
Small Craft Advisory until 3 PM CST this afternoon for the
following zones: coastal waters from Baffin Bay to Port
Aransas out 20 nm...coastal waters from Port Aransas to
Matagorda Ship Channel out 20 nm.