Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Corpus Christi Texas
1121 am CST Wednesday Nov 25 2015
Discussion...light rain and drizzle in warm advection pattern
growing more strongly so will send out a quick forecast update for
the afternoon. Expect little rainfall accumulation.
Aviation...isentropic upglide reinforcing multilayered St/SC
deck. Expect most places to remain VFR through the afternoon with
isolated pockets of MVFR ceilings/visibilities in -radzbr. Ceilings lower to MVFR
after sunset and will remain so through the end of the
period...especially eastern terminals where visibility restrictions in
light rain are more likely. Southeast surface winds will pick up
as well Thursday morning.
Previous discussion... /issued 549 am CST Wednesday Nov 25 2015/
Discussion...updated for the 12z aviation discussion.
Aviation...VFR early with broken at 6k feet. But persistent upglide
will lead to lowering ceilings briefly this middle morning to MVFR
levels. Satellite is currently showing clear skies at lrd...but
will expect MVFR ceilings to fill in with heating shortly around
sunrise. Should see ceilings lifting back to VFR by 18z yet remain
sct-bkn. Southeast wind 15-20 kts is expected by late morning/afternoon before
decoupling this evening. Patchy -ra with a few -shras will be
possible today mainly across the eastern taf sites of ali-crp-vct.
Increased moisture in the lowest levels may allow for MVFR ceilings to
develop once again late tonight.
Previous discussion... /issued 458 am CST Wednesday Nov 25 2015/
Short term (today through thursday)...onshore flow will
strengthen today through Thursday as low pressure develops across
the southern High Plains. This will lead to precipitable waters of 1.2-1.4
inches today increasing to near 1.7 inches Thursday. An
overrunning pattern combined with the moisture will lead to the
continuation of light rain and a few showers being picked up on
the radar. Will expect a continued upglide pattern to keep clouds
around today through Thursday. Broad ridging in the midlevels
remains across the western Gulf with warming from 850 mb-700 mb over
south Texas. But with moisture trapped beneath the cap...should
expect to see light rain/showers to continue Thursday as well.
Boundary layer instability increases slightly Thursday which may
allow for an isolated thunderstorm or two. Temperatures will
gradually warm into the lower 80s by Thursday.
As for the coastal Flood Advisory...the persistent onshore flow
and increasing swells/swell periods will lead to minor tidal
overflow along the southern coastal Bend from Port Aransas to bob
Hall pier this afternoon during time of high tide. Minor coastal
flooding may likely develop once again Thursday during high tide.
The onshore flow...and increasing swells/swell periods will also
lead to a moderate risk for rip currents along local beaches of
the coastal Bend.
Long term (thursday night through tuesday)...GFS/ECMWF generally
consistent with an upper pattern characterized by a strong upper system
moving slowly across the southwestern Continental U.S. Then across the plains Sunday/Monday.
Another weaker upper system near the U.S./Canadian border is
predicted to force a cold front southward across the plains and into the County Warning Area
Saturday (gfs ensemble mean.) The GFS/NAM predict precipitable water values
approaching 2 inches Friday over the County Warning Area/msa in advance of the
front. Upper forcing associated with the southwestern/plains system is
expected to remain north of the cwa/msa. Nevertheless...anticipate
that greater moisture will contribute to isolated/scattered convection
over the County Warning Area/msa Friday. Will increase the probability of precipitation Saturday owing to the
proximity of the front/copious moisture. Drier conditions are
anticipated for Sunday/Monday after frontal passage. The synoptic pattern
based on the GFS ensemble mean suggest isentropic lift. The GFS
deterministic predicts such for Monday/Tuesday. Will forecast isolated
shower activity Monday night/Tuesday.
Preliminary point temps/pops...
Corpus Christi 78 70 82 72 81 / 30 10 20 30 40
Victoria 78 67 80 70 78 / 20 10 40 40 50
Laredo 79 71 84 72 84 / 10 10 10 30 40
Alice 80 68 84 71 82 / 30 10 20 30 40
Rockport 80 70 80 71 78 / 30 10 30 30 40
Cotulla 79 68 82 70 79 / 20 10 20 40 50
Kingsville 80 71 84 73 82 / 30 10 20 30 40
Navy corpus 80 72 80 73 78 / 30 10 20 30 40
Texas...coastal Flood Advisory until 9 PM CST this evening for the
following zones: Kleberg...Nueces...San Patricio.