Area Forecast Discussion
Issued by NWS Corpus Christi, TX
FXUS64 KCRP 021112
Area Forecast Discussion
National Weather Service Corpus Christi TX
512 AM CST Fri Dec 2 2016
See aviation discussion below for the 12Z TAFs.
Conditions are expected to deteriorate today as abundant moisture
moves into the area and lowers CIGs and increases rain chances.
Mainly SHRA`s are expected today and tonight, however a few
TSRA`s are possible. Have TSRA`s mentioned in PROB groups for the
latter part of the TAF period due to better dynamics increasing
late tonight into early Sat as a warm front moves across S TX.
Generally expecting MVFR conditions through much of the TAF period
with IFR at times due to convection.
.PREVIOUS DISCUSSION... /Issued 428 AM CST Fri Dec 2 2016/
SHORT TERM (Today through Saturday)...
Rain chances expected to increase significantly today through
Saturday in response to abundant moisture advecting into S TX and a
developing coastal trough. In addition, a large area of diffluent
flow aloft and an approaching upper level low pressure system will
also aid in convection. Initially a cap will hinder convection from
becoming too deep. High helicity values are progged today and
tonight, however CAPE values will be rather low with some CIN in
place. The upper level jet will be well to the NW of the area
today...but will approach the region tonight through Sat. Models are
hinting at possibly some dry slotting tonight along with a
strengthening low level jet. This will keep the best rain chances
across the northern CWA tonight. For now am expecting mainly SHRA`s
with a slight chance of TSRA`s today and tonight. The sfc trough is
progged to shift inland tonight and Saturday as a warm front, which
will provide strong low level convergence across S TX. Where the sfc
trough is located will determine where the heaviest rainfall will be
located. Models also prog CAPE values to increase on Sat and the
upper level jet to approach S TX, therefore am expecting the better
chances for TSRA`s to be Sat. In a nutshell, the best chance is
expected to be across the eastern CWA today due to the developing
coastal trough, then shifting north and NW tonight due to the trough
beginning to move inland and the approaching upper low from the
west. The highest rain chances will be Sat and will shift to the
NE as the better dynamics shift that direction. The Storms
Prediction Center has S TX in a marginal risk for SVR weather
today through Sat, but feel the better chances would be Sat.
Due to a mod to strong long easterly fetch across the gulf waters
today, the rip current risk will be moderate. This may also elevate
tide levels with tides possibly reaching around 1.8FT abv MSL at the
time of high tide early this evening.
LONG TERM (Saturday Night through Thursday)...
Deterministic output and GFS ensemble mean suggest that an upper
level disturbance will move slowly across the SW CONUS and the
CWA/MSA Saturday Night through Monday. In the interim...a surface
wave/associated front moves slowly across the CWA Saturday
Night/Sunday then offshore. Further...very moist atmospheric
conditions are expected over the CWA Saturday Night (NAM
deterministic.) The combination of moisture and surface/upper
forcing will contribute to at least scattered/numerous shower
activity Saturday Night/Sunday. Anticipate primarily isolated
thunderstorm activity given limited SBCAPE (NAM deterministic.)
Caveat...upper forcing Sunday (upper jet dynamics) and Sunday Night
(upper jet dynamics/700-300mb Q-vector convergence) may result in at
least scattered elevated thunderstorm activity. Drier conditions
expected to develop from west to east across the CWA/MSA Monday. Dry
conditions Tuesday. A slight increase in moisture anticipated
Wednesday in advance of a cold front. Isolated showers may occur
over portions of the Coastal Bend/MSA near the front. Much colder/
drier conditions are expected after frontal passage Wednesday
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 78 70 78 64 69 / 70 70 60 70 60
Victoria 70 64 73 57 61 / 70 80 90 80 70
Laredo 76 67 79 58 63 / 40 70 40 60 60
Alice 77 69 78 61 66 / 60 60 60 70 60
Rockport 74 69 74 63 67 / 70 70 80 80 70
Cotulla 71 63 74 54 59 / 50 80 70 70 60
Kingsville 78 70 80 64 72 / 60 60 50 60 60
Navy Corpus 75 72 76 66 72 / 70 70 60 70 70
GM...Small Craft Advisory from 9 AM this morning to 6 PM CST this
evening For the following zones: Coastal waters from Port
Aransas to Matagorda Ship Channel out 20 NM...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.