Area forecast discussion
National Weather Service Corpus Christi Texas
104 PM CDT Thursday may 23 2013
Discussion...update for 18z aviation below.
&&
Aviation...with the exception of MVFR ceilings near the coast
through 19-20z...VFR conditions through the afternoon with scattered
to at times broken ceilings around 4000 feet. Haze from smoke
originating in Mexico will produce 6-7sm visibilities at some
locations during the afternoon (3-4sm visibilities at some
offshore locations). Stratus expected to move back into the
coastal plains by 03-04z and lrd by 07z. Generally MVFR in
stratus...with a few locations tempo IFR. Southeast winds 10-15 kts
with a few gusts near 20 kts at some locations through the
afternoon.
&&
Previous discussion... /issued 406 am CDT Thursday may 23 2013/
Short term (today through friday)...the middle level ridge axis from
Mexico into West Texas will move east over south Texas later today.
Morning stratus will scatter in the afternoon. Areas of smoke/haze
over the Gulf will continue to affect the region also. Area of
low pressure will remain in New Mexico during the period so do not
expect wind speeds to increase above moderate levels. The middle level
ridge axis shifts to the east into the western Gulf of Mexico on
Friday and the 850 mb Theta-E ridge axis will remain along the Rio
Grande. There is a slim possibility of a weak short wave trough
moving out of northeast Mexico in the afternoon. This could
generate convection on the higher terrain that could move close to
the river by late afternoon. Confidence is not that high at the
moment...so will keep probability of precipitation at 10 percent and leave out wording
in the forecast.
Long term (friday night through wednesday)...models are in fair
agreement with an upper low developing across West Texas and slowly moving east Friday
night/Sat. Models are also in agreement with precipitation across the West County warning area
or at least close to the area by Sat morning. Models also show the
capping inversion weakening on Sat. Airmass is forecasted to be unstable
and pwat's are forecasted to increase to above 1.5 inches across the West County warning area.
NAM MOS guidance for cot has around 50 percent chance of precipitation.
However...the GFS MOS is only 20 percent. Have introduced a 20 pop
for the western County Warning Area for Sat but did not want to go any higher as
upper dynamics are not that impressive and there's little in the way
of low level forcing other than some weak speed convergence across
the West County warning area. Models keep an upper level trough axis draped across southeast and
S Texas Sat night/Sunday...but the deeper moisture remains across the
Rio Grande plains on the less favorable west side of the trough. A drier
airmass is prgd to be across the east County Warning Area and Gulf waters through the
weekend. Kept a silent 10 pop across the west for Sunday due to the
deeper moisture and instability forecasted to be across mex and the Rio
Grande plains. Ridging aloft then takes hold Monday/Tuesday with little to
no precipitation expected. Warmer temperatures also expected for Monday/Tuesday
timeframe. Both the European model (ecmwf) and GFS show the ridge shifting east as a low
swings across the west U.S. Resulting in deeper moisture being advected
into S Texas by Wednesday. For now went with silent 10 probability of precipitation for Wednesday but if
this scenario pans out...probability of precipitation may need to be increased. As for
winds...went with a blend of models. Winds are expected to
strengthen by next Tuesday in response to the upper level system
approaching from the west.
&&
Preliminary point temps/pops...
Corpus Christi 76 87 76 91 74 / 10 10 10 10 10
Victoria 73 88 73 89 72 / 10 10 10 10 10
Laredo 77 97 77 97 77 / 10 10 10 20 10
Alice 75 91 75 92 73 / 10 10 10 10 10
Rockport 76 84 76 84 76 / 10 10 10 10 10
Cotulla 74 95 73 97 73 / 10 10 10 20 10
Kingsville 76 90 75 92 73 / 10 10 10 10 10
Navy corpus 77 84 76 84 76 / 10 10 10 10 10
&&
Crp watches/warnings/advisories...
Texas...none.
GM...none.
&&
$$
Jr/76...aviation
