Area Forecast Discussion
Issued by NWS Corpus Christi, TX
FXUS64 KCRP 031128
Area Forecast Discussion
National Weather Service Corpus Christi TX
528 AM CST Sat Dec 3 2016
See aviation discussion below for the 12Z TAFs.
IFR/LIFR conditions due mainly to CIGs this morning are expected
to lift to MVFR late morning into the afternoon. However, numerous
SHRAs and a few TSRA`s are expected through much of the TAF
period which may lead to IFR conditions at times throughout the
day. A warm front this morning along the coast is expected to push
inland today then shift back toward the coast as a cold front. The
frontal boundary is expected to stall across S TX today into
tonight. Where the boundary stalls will determine wind direction.
The better chance for TSRAs will be in the warm sector/generally
eastern areas, but elevated TSRAs will also be possible over the
cold sector/generally western areas.
.PREVIOUS DISCUSSION... /Issued 424 AM CST Sat Dec 3 2016/
SHORT TERM (Today through Sunday)...
Overnight convection has generally moved north of the CWA this
morning in response to a strengthening low level jet that is
producing a weak cap across the area. Am still expecting sct to num
shras along with a chance for thunderstorms today due to abundant
moisture, an approaching upper low and a cold front draped across
the area. However, the better instability will be confined to the
immediate coast and over the gulf waters today. The cap is progged
to diminish and the upper level jet will be favorably positioned
across the region tonight and Sunday. The frontal bdry is progged to
remain across the eastern portions of the CWA tonight, but becomes
more tricky Sunday due to differences in model solns. The GFS is
faster with the front pushing across the coastal waters while the
ECMWF has it along the coast. The 00Z NAM was the slower model which
had the bdry farther inland through Sunday, however the 06Z run is
now faster. Where the bdry is located will determine where the
heaviest rainfall/highest pops will be located. Models all agree
that the low level convergence with the bdry will be strong and
instability ahd of the bdry will be moderate. Also the large scale
ascent with the diffluent flow aloft will also be conducive for
convection through the period. Due to better dynamics coming into
play...especially tonight...some storms could be strong with isol
svr a possibility. The heaviest rainfall amounts are still forecast
to be across East TX with decreasing amounts farther south and west
across S TX. Rainfall amounts today through Sunday are expected to
be 1 to 3 inches with isolated higher amounts possible. The lower
amounts are expected across the Rio Grande Plains and the higher
amounts across the VCT Crossroads. Localized flooding is possible
leading to ponding of low lying areas and minor street flooding.
Due to long period swells and large seas, will continue the High Rip
Current risk through the morning. Winds are expected to become more
southerly and decrease through the afternoon which will minimize the
rip current risk this afternoon. Also, Small Craft Advisories are
expected to lower by late afternoon.
LONG TERM (Sunday Night through Friday)...
GFS/ECMWF/NAM deterministic NWP models predict an upper disturbance
to move across the CWA/MSA Sunday Night/Monday with strong 700-300mb
Q-vector convergence (divergence) Sunday Night (Monday.) The
corresponding surface wave is predicted to remain over the MSA with
the CWA within the cold sector. Anticipate scattered/numerous
showers and isolated/scattered thunderstorms Sunday Night then
ending from west to east Monday (expected convection to be mainly
elevated over the CWA yet surface-based over the MSA near the wave.)
The GFS/ECMWF predicts a polar airmass to enter the NW CONUS Monday
with the associated cold front moving across the CWA/MSA late
Wednesday. GFS deterministic continues to predict increasing onshore
flow/associated moisture Tuesday over the MSA/CWA with PWAT
increasing to around 1 inch over the ERN CWA/MSA late Tuesday.
Anticipate at least isolated convection Wednesday/Wednesday Night
over the eastern CWA/MSA along the foregoing cold front. SCA
conditions expected over the MSA after frontal passage Wednesday
Night/Thursday. Dry Thursday/Friday. Near freezing temperatures
anticipated early Friday morning over sections of the northern CWA.
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 76 62 69 55 68 / 70 90 70 70 40
Victoria 69 56 62 53 64 / 90 90 80 70 50
Laredo 76 59 63 51 69 / 50 80 70 70 10
Alice 76 61 66 53 68 / 70 80 70 70 30
Rockport 74 64 67 57 67 / 80 90 90 70 40
Cotulla 66 54 59 50 66 / 70 80 70 70 10
Kingsville 77 64 72 55 69 / 70 80 70 70 30
Navy Corpus 75 67 72 58 68 / 70 90 80 70 40
TX...High Rip Current Risk until noon CST today For the following
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 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.