Area Forecast Discussion
Issued by NWS Corpus Christi, TX
FXUS64 KCRP 231130 AAA
Area Forecast Discussion...UPDATED
National Weather Service Corpus Christi TX
630 AM CDT Thu Mar 23 2017
.DISCUSSION...See Aviation section for 12Z TAFs.
.AVIATION...Satellite imagery shows broken stratus over portions
of the Brush Country while fog has formed on the eastern edge of
this stratus deck along a line from south of Alice to Beeville.
MVFR ceilings from 1500-2000 feet will be prevalent through 15Z
over the Brush Country. Fog with IFR/LIFR vsbys will continue
until 14Z from ALI-BEA. Ceilings will lift to around 2500 feet by
15Z with winds increasing. Low pressure deepening over West Texas
will lead to strong gusty winds over the region today with gusts
over 30 knots this afternoon for most areas. Gusts to 35 knots are
expected over the Coastal Bend. VFR conditions are expected by
17Z. MVFR ceilings will return the VCT area by this evening with
winds decreasing but remaining gusty. Low level jet of 45 knots
will bring an increase in low level moisture with stratus/MVFR
ceilings covering all of south Texas by 08Z.
.PREVIOUS DISCUSSION... /Issued 420 AM CDT Thu Mar 23 2017/
SHORT TERM (Today through Friday)...
Satellite imagery shows the upper level trough moving through the
Great Basin early this morning. The upper trough will move across
the Four Corners region today and become a closed low. The upper
low will move east to central Kansas/north-central Oklahoma by
Surface low pressure will deepen over West Texas today as the
upper level trough approaches. This will tighten the pressure
gradient over the region with windy conditions expected for the
entire area. Winds speeds will reach advisory criteria over the
southern Coastal Bend this afternoon.
Low level jet will increase to 45 knots tonight but moisture will
be slow to increase in depth. Models depict 85H moisture axis will
move into the region in advance of the front/dryline Friday
morning. A strong 100 knot west-southwesterly jet at 25h will move
across central Texas Friday afternoon with the right entrance
region of the jet impacting the northeast portion of the forecast
area in the afternoon. Forecast soundings show the mid level
inversion will gradually erode through the afternoon. Mixed layer
CAPE values are forecast to be around 1000-1200 J/kg over the
coastal plains with 0-6 km shear around 50 knots in the afternoon.
Expect scattered thunderstorms will develop by mid morning in
advance of the front/dryline and increase in strength in the
afternoon. 00Z 4km ARW and NMM along with latest Tech WRF suggest
line of possibly strong thunderstorms moving across the coastal
plains in the afternoon. Will mention in the HWO possibility of
isolated severe storms possible in line with latest SPC outlook
showing a Marginal threat for areas northeast of Interstate 37.
LONG TERM (Friday Night through Wednesday)...
The upper low will be shifting NE Friday night with rain chances
exiting to the east and northeast through Sat morning. A weak cold
front is progged to enter the CWA late Fri night leading to slightly
cooler mn temps across the north and western CWA by Sat morning. A
weak northerly flow will be short-lived as onshore flow quickly
returns Sat resulting in another warm day. Warm dry conditions
continue through Sun as the CWA is between systems. A slight chc of
rain returns to the NE CWA Mon ahead of a second upper disturbance.
Rain chcs increase through mid week as a third upper low approaches
the region. Moisture is progged to deepen through mid week ahead of
the upper level system and combine with an unstable airmass to bring
a chc of convection to the area.
Onshore flow will steadily increase today as the low pressure area
to the west deepens. The winds will reach SCA levels for the
southern bays this afternoon. Winds will ramp up over the Gulf
waters tonight. SCA is in effect through the night for the Gulf
waters and will probably need to be extended into portions of
Friday. Wind speeds will diminish some as the front/dryline
approaches the coastal plains but seas will be slow to decline.
Isolated to scattered storms could affect the coastal waters also
with some of the storms becoming strong.
Southerly flow Friday night is expected to weaken with weak to
mod onshore flow Saturday and Saturday night. Onshore flow is
expected to strengthen to moderate levels Sunday ahead of the
next system and may reach advisory levels by Sunday afternoon and
night. Winds relax Mon and Tue then begin to restrengthen to
possible advisory levels by late Tue into Wed ahead of the third
Relative humidity levels will diminish to 35-40 percent over the
inland portions of the southern Coastal Bend and near 30 percent
over the western Brush Country this afternoon. With wind speeds
increasing to 25 to 35 mph with higher gusts, elevated fire danger
conditions will exist over the southern Coastal Bend to the
southern portions of the western Brush Country this afternoon.
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 85 70 85 67 86 / 0 10 40 10 10
Victoria 84 68 83 61 84 / 0 10 50 20 10
Laredo 90 68 91 63 92 / 0 10 10 0 0
Alice 90 67 89 63 90 / 0 10 30 10 10
Rockport 83 71 81 70 82 / 0 10 40 20 10
Cotulla 89 66 89 57 90 / 0 10 20 0 0
Kingsville 88 69 87 65 90 / 0 10 30 10 10
Navy Corpus 82 71 82 69 81 / 0 10 30 20 10
TX...Wind Advisory from noon today to 6 PM CDT this evening For the
following zones: Kleberg...Nueces...San Patricio.
GM...Small Craft Advisory from 7 PM this evening to 6 AM CDT Friday
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...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 from noon today to 6 AM CDT Friday For the
following zones: Bays and Waterways from Baffin Bay to Port