Area Forecast Discussion
Issued by NWS Corpus Christi, TX
FXUS64 KCRP 290308
Area Forecast Discussion
National Weather Service Corpus Christi TX
1008 PM CDT Fri Apr 28 2017
No major changes needed to the forecast at this point. Reason for
the update was to align forecast based on latest trends/obs. Some
convection developed over the higher terrain over Mexico early
this evening, but storms have been weakening and should dissipate
before reach the border. Main story overnight will be the strong
winds, especially over the marine zones. A small craft advisory
remains in effect through tomorrow. Also, observed tides are above
predicted values and this could create some issues around high
tide tomorrow morning. A short-fused coastal flood advisory may
become necessary later tonight into early Saturday morning as tide
levels approach 2.0 feet above MSL. Otherwise, overnight lows
will be on the mild side and temps should pretty much hold in the
middle and upper 70s. Cold front still looks on track for late
Saturday night into early Sunday morning.
.PREVIOUS DISCUSSION... /Issued 709 PM CDT Fri Apr 28 2017/
Updated for 00z aviation.
Winds will remain up through most of the period at ALI/CRP/VCT.
VFR conditions initially this evening will transition to MVFR
levels within a couple hours at ALI/CRP/VCT, and later tonight
into early Saturday morning at LRD. Winds may stay up through the
night at CRP/VCT and have removed LLWS for now, but may subside
enough at ALI and have retained LLWS remarks. Confidence is not
great enough to include IFR ceilings just yet, but may need to be
added/amended later on. A return to VFR will occur at LRD by 18z
and perhaps not until the afternoon hours at the other taf sites.
Strong SE/SSE will continue on Saturday at ALI/CRP/VCT with gusts
between 25 and 30 knots at times. Winds won`t be as strong at LRD
as sfc trough/dryline pushes eastward into the Brush Country.
PREVIOUS DISCUSSION... /Issued 317 PM CDT Fri Apr 28 2017/
SHORT TERM (Tonight through Saturday night)...
WV imagery/NWP model output depict a strong upper level
disturbance approaching the SWRN CONUS. 6-hr (valid 18 UTC Today)
GFS dynamic tropopause (1.5 PVU) descent to around 500-mb
coincident with red color in the SPoRT Air Mass RGB, suggestive of
intrusion of stratospheric air/rapid cyclogenesis. Deterministic
GFS/ECMWF predict this system to slowly approach TX from the W/NW
Tonight/Saturday. In response, strong onshore flow expected over
the MSA Tonight/Saturday and will maintain the SCA. NAM
deterministic predict PWAT values to increase to near/above normal
over the ERN CWA by Saturday afternoon. NAM/GFS deterministic
predict 4500-5000 J/KG SBCAPE values over the ERN CWA for Saturday
afternoon, yet both models predict greater CIN values than 12z
run yesterday. Will forecast isolated convection Saturday
afternoon yet confined to the NERN section owing to expected
smaller CIN values and considering GFS ensemble QPF output. Some
discrete cells may become strong. Saturday night...expect the
combination of strong upper dynamics/corresponding surface
front/sufficient moisture and instability to contribute to at
least isolated/scattered convection over the CNTRL/ERN CWA. Some
storms may become strong.
LONG TERM (Sunday through Friday)...
Drier and cooler air build into the region Sunday in wake of the
exiting fropa. Strong northerly winds will develop most noticeably
across the waters with SCA conditions expected. Offshore flow is
expected to diminish Sunday afternoon/evening and become onshore
Monday as surface high pressure quickly enters and exits the region.
Temperatures Sunday are expected to drop back to near seasonal
normal with a warming trend through the work week. Development and
deepening of surface low pressure across west Texas will lead to a
moderate southeast flow and a return of moisture Tuesday. This may
lead to slight chances for rain returning to portions of South Texas
beginning as early as Tuesday night. Models are in somewhat
agreement with the passage of another cold front to move through the
region Wednesday night into Thursday. Latest runs now have the ECMWF
running a bit faster than the GFS as compared to the previous run
where the GFS was faster. In either scenario, both models continue
to develop precip along the front with much drier conditions
developing in wake of the front.
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 78 93 67 83 59 / 10 10 30 10 0
Victoria 77 88 63 78 53 / 10 20 60 10 0
Laredo 75 102 63 84 58 / 10 10 10 10 0
Alice 76 101 65 85 54 / 10 10 20 10 0
Rockport 78 85 66 81 64 / 10 10 40 10 0
Cotulla 74 98 60 83 54 / 10 10 20 10 0
Kingsville 77 100 66 85 56 / 10 10 20 10 0
Navy Corpus 78 87 68 83 65 / 10 10 20 10 0
GM...Small Craft Advisory until 7 PM CDT Saturday 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...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.