Scientific Forecaster Discussion
fxus64 kcrp 130451
Area forecast discussion
National Weather Service Corpus Christi Texas
1051 PM CST Thu Dec 12 2019
Updated for 06z aviation discussion.
MVFR ceilings have begun to move in tonight at crp and vct.
Ceilings will transition to MVFR through the night. Expect fog to
begin to develop across the coastal plains and Victoria
Crossroads in the next hour or two dropping visibilities to drop
to IFR, with some LIFR visibilities through mid morning. Fog and
ceilings will lift by mid morning with VFR conditions expected
through the rest of the taf period.
Previous discussion... /issued 526 PM CST Thu Dec 12 2019/
Updated for 00z aviation discussion.
VFR conditions prevail this evening and much of tonight, with only
brief periods of MVFR ceilings later in the evening. As we
approach dawn, expect light winds and higher humidities to aid in
the development of fog. Vct, crp, and ali can expect visibilities
to drop to IFR, with the possibility of LIFR visibilities through
the mid morning. Fog will lift by mid morning, with VFR conditions
expected through the rest of the taf period.
Previous discussion... /issued 345 PM CST Thu Dec 12 2019/
Short term (tonight through Friday night)...
Concur with the deterministic NAM and European model (ecmwf) that an upper level
disturbance will move slowly eastward across the region during the
period and maintain subsidence/drying conditions. Owing in part to
drying aloft, anticipate a thermodynamic profile conducive to the
development of radiation fog overnight/early Friday morning.
NAM deterministic soundings at select locations suggest fog over
much of the County Warning Area. Yet, sref probabilities suggest that fog will be
restricted to the eastern County Warning Area. Integrated the foregoing to predict
patchy/areas of fog over the County Warning Area. Unsure whether dense fog will
occur with an areal coverage sufficient for dense fog advisory
conditions. Will defer to later shifts. Water levels at bob Hall
pier recently reached 2ft msl, which is likely due to a
combination of ekman forcing (owing to persistent north/NE flow over
the coastal waters) and the astronomical tide. Issued a cfw for
the islands until 04z Friday.
Long term (saturday through thursday)...
Upper level ridging on Saturday will become more zonal through
Monday. A weak front will move through Saturday morning shifting
winds briefly to the north. By afternoon, winds will return to the
south with warm air advection. Southwest winds at 850mb and
southerly surface winds will help temperatures to continue to warm
on Sunday. Highs will reach the mid 80s, about 15 degrees above
normal for mid December. Early next week an upper level trough
moving across the plains will send a cold front through south Texas.
Southerly winds ahead of the front will bring enough moisture for
showers Sunday night into Monday ahead of and along the front. Most
of the rain will stay over the coastal waters with 40-50% for the
Victoria Crossroads on Monday. Have continued the slight chance of
thunder as well. Models have come into better agreement with timing
of the front around 18z on Monday. Drier air will lag the front a
bit, but dewpoints will fall to the 20s and 30s by Tuesday morning.
Highs will only reach the upper 50s to near 60 on Tuesday, then will
drop to the low to mid 30s Tuesday night.
The GFS keeps the broad trough moving off to the east on Tuesday,
but the European model (ecmwf) has a piece of the trough break off, sharpen and move
across south Texas on Wednesday. Both models have surface high
pressure and dry air move in behind the front and temperatures will
moderate to the upper 60s by Thursday.
Based on recent observations/wave watch output with regard to seas,
decided to extend the mww until 00z Friday. A weak disturbance
may generate isolated showers over mainly the offshore coastal
waters this evening/early tonight, before drying conditions
develop later tonight through Friday as the upper system moves
east. A weak front will shift winds to the north Saturday morning
but offshore flow will redevelop by Saturday afternoon. Offshore
flow will increase to moderate to strong levels Saturday night
through early Monday morning ahead of an upper disturbance. Small
Craft Advisory conditions are likely at times Saturday night
through Monday morning, before a cold front Monday afternoon
delivers strong northerly winds with potential for gale conditions
Monday night and Tuesday. Some showers and a few thunderstorms
are likely on Monday with the front.
Preliminary point temps/pops...
Corpus Christi 49 77 50 78 60 / 10 0 0 0 0
Victoria 48 75 45 75 55 / 10 0 0 0 0
Laredo 45 78 51 83 56 / 0 0 0 0 0
Alice 47 80 48 82 57 / 0 0 0 0 0
Rockport 53 73 54 73 62 / 10 0 0 0 0
Cotulla 41 78 46 82 51 / 0 0 0 0 0
Kingsville 47 79 48 82 59 / 0 0 0 0 0
Navy corpus 54 73 55 73 64 / 10 0 0 0 0