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fxus64 kcrp 231725 
afdcrp

Area forecast discussion
National Weather Service Corpus Christi Texas
1125 am CST Fri Feb 23 2018

Discussion...

Warm front finally pushing inland...and relatively quickly. Winds
now out of the southeast for the entire area, though the
temp/moisture increase is still back around Victoria to Alice.
Will see this spread westward through the afternoon. Still some
areas of fog out there, but these should gradually improve as
well. Have adjusted some temps down just a bit, but still
expecting mid to upper 70s southeast and upper 60s to lower 70s
west. Could see some breaks in the clouds this afternoon,
especially along the coast.

&&

Aviation...

Flight conditions improving at the time of this writing, and
should be MVFR for all sites within an hour or so. Some potential
for briefing VFR conditions at crp and lrd this afternoon, but
low confidence in this. Expect deteriorating conditions once again
tonight as low cigs and reduced visbys develop. Think wind will
keep visbys up around 1 mile or higher for the most part. Cigs
could become IFR to LIFR however. Should start to improve
conditions by very late in this period.

&&

Previous discussion... /issued 839 am CST Fri Feb 23 2018/

Discussion...

Warm front continues to be a challenge this morning as light
northwesterly winds are still being observed along the coast. All
of the larger scale models would have the front several miles
inland by 15z. General consensus of mesoscale models bring the
front just inland by 15-16z, so still expect it will begin to make
its move. However...until that happens, fog will continue over
land areas. Have issued a dense fog advisory for northern coastal
Bend and Victoria Crossroads region through 11am. Expect immediate
coastal areas will improve before then, but to cover the entire
area, have the 11am end time. The rest of the coastal Bend and
brush country will continue to see areas of fog and drizzle
through mid/late morning. Will have to keep an eye on temperatures
for today. May need to update if the front doesn't begin to move
inland in the next hour or two.

Previous discussion... /issued 617 am CST Fri Feb 23 2018/

Discussion...

Updated for the 12z aviation discussion.

Aviation...

LIFR/IFR cigs and vsbys this morning, with low cigs expected
through much of the taf period. Cigs expected to gradually lift
to MVFR levels as a warm front moves inland today. Enough warming
may break clouds a bit keeping around 2000-2500 feet but with scattered
conditions. MVFR conditions already exist at lrd and will likely
continue through the end of the taf period. Will see winds
gradually become east then southeast through the day as the front lifts
north, with winds up to 15-20 kts in the afternoon mainly for the
coastal taf sites, while winds speed around 10 kts are expected
for lrd. An increase in isentropic lifting and moisture will lead
to cigs and vsbys falling once again this evening through tonight.

Previous discussion... /issued 359 am CST Fri Feb 23 2018/

Short term (today through saturday)...

Showers and thunderstorms continue to develop skimming the
northeastern cwa, roughly west of I-35 this morning with the aide
of a passing mid level short wave. This short wave is expected to
continue to lift farther to the northeast through this morning
with rain chances expected to diminish and weaken with intensity
as the mid level support exits the region. At the surface, the
stalled cold front along the coast is expected to ride farther
north as a warm front, with patchy light rain along the coast
expected to diminish through the morning hours. Uncertainty
resides with how far inland the warm front will push inland and
how this will affect daytime temperatures. Now the NAM has had a
rather good handle on shallow fronts but stalls the warm front
just east of La Salle and Webb counties today, with the highs
expected to struggle to break out of the 50s for these two
counties. The NAM itself remains an outlier even among the other
short ranged hi-res models, but it's hard to disagree given the
performance after previous frontal boundaries. That said, did
want to continue to bring the front in, but continued to show the
relatively cooler temps out west with up to a 10 degree
difference when compared to coastal regions. Did not want to keep
the drastically lower temps across the western brush country
today as the NAM.

For tonight, the weak trough should transition into an area of
low pressure across northeastern Mexico which should aide in
bringing the warmer and moist air farther inland into the brush
country. Temperatures tonight are expected to be on the verge of
10-15 degrees warmer than this morning. Increased isentropic lift
will keep light rain/showers for tonight, with slightly greater
chances across the northern tier from Cotulla to Victoria. Did
begin a transition to thunder overnight through Saturday morning
with diffluent flow aloft with the jet stream.

Rain chances continue through Saturday but should gradually shift
east and lift north as drier air begins to move in with the next
frontal boundary. Not expecting much of a temperature change, just
drier air moving in, as h925 temps vary little.

Marine...

Sea fog continues to plague the middle Texas coast, with areas of
dense fog across the nearshore waters and bays roughly from Port
Aransas and northward. With warm moist air expected to continue
flow over the cool shelf waters today, have extended the marine
dense fog advisory through noon today. Expecting the fog to break
up some this afternoon yet remain patchy as temperatures warm.
However, as temperatures cool again tonight, areas of fog are
expected to redevelop across the region.

Long term (saturday night through thursday)...

Best rain chances in this package appear to be late Saturday
night/Sunday morning then again late Wednesday/Wednesday night.
Saturday night pops are tricky over the northwest areas as drier air does
try to come in on Saturday but moisture may get pulled in back northwest as
upper disturbance comes across. Really feel that the rain chances
over the northwest areas are quite limited as I think the drier air will
win out for now, but it could be close did include some potential
over the southern areas but kept most of La Salle County dry for
now. Front comes down on Sunday morning, and the GFS and European model (ecmwf) agree
of having some sort of coastal trough over the Rio Grande Valley
during the day as some additional energy from the upper trough moves
in from the southwest. With projected pwats at or above 1.5 inches and
enough forcing, did go with good chance/likely pops for Sunday
morning then diminish them a bit in the afternoon (just a bit). For
Sunday night, am expecting the rain to be offshore (850 Theta-E
ridge shifts that way with drier air inland) so will not mention
rain for inland areas Sunday night. With not a vast difference
between model solutions Saturday night through Sunday night, went
with a blend of model and MOS consensus and bias-corrected
temperatures and moisture grids, Bud did adjust some high
temperatures on Sunday to fall more in line with the superblend as
some temperatures to the west appear too warm while some over the
southeast appear a bit too cool.

After that, models try to bring the moisture back (again) along with
the rain chances (again) Monday and Monday night. There could be
some isentropic upglide late Monday over the southern areas but will
pull back on the rain chances at this time as it appears the more
isentropic pattern will come about Monday night (and still am going
to undercut rain chances 10 percent). Did mention rain Monday night
and Tuesday but did lower pops 10 percent as it is isentropic
upglide generated and that can often be over-done W.R.T. Measurable
rain chances. Better chances for rainfall appear to be Wednesday and
Wednesday night with the upper disturbance and front (better
Wednesday night since we will be on the southern periphery of the
upper trough with the boundary the main focus), then it should be
dry on Thursday with maybe some lingering rain over the Gulf waters.
For temperatures Monday and beyond, did not sway too far from the
superblend.

&&

Preliminary point temps/pops...
Corpus Christi 69 82 61 68 53 / 20 20 50 50 10
Victoria 67 79 57 66 48 / 30 20 30 60 10
Laredo 65 82 56 72 50 / 20 10 20 10 0
Alice 68 84 59 68 51 / 20 20 50 50 10
Rockport 68 77 61 66 55 / 20 20 50 50 10
Cotulla 63 79 52 73 46 / 30 10 10 10 0
Kingsville 69 86 61 69 53 / 20 20 50 50 10
Navy corpus 68 77 62 69 57 / 20 20 50 50 10

&&

Crp watches/warnings/advisories...
Texas...none.
GM...dense fog advisory until noon CST today for the following zones:
bays and waterways from Baffin Bay to Port Aransas...bays
and waterways from Port Aransas to Port O'Connor...coastal
waters from Baffin Bay to Port Aransas out 20 nm...coastal
waters from Port Aransas to Matagorda Ship Channel out 20
nm.

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