Area Forecast Discussion
Issued by NWS Corpus Christi, TX
FXUS64 KCRP 270244 AAC
Area Forecast Discussion...UPDATED
National Weather Service Corpus Christi TX
944 PM CDT THU MAY 26 2016
.DISCUSSION...Based on radar and satellite trends, lowered rain
chances even more, but did keep a chance in for the west and north
(30 POPs), based on previous discussion of better "forecast"
moisture advection overnight. However, cap is coming back and
winds not impressive (4 KM models also do not have much, but they
have not been doing well either). Satellite looks like best
diffluence will remain northwest of area. Thus, for all these
reasons, have lowered rain chances again. Updates are out.
.PREVIOUS DISCUSSION... /Issued 845 PM CDT THU MAY 26 2016/
DISCUSSION...Lowered POPs for this evening and a bit overnight,
but keeping chance pops west and extreme north this evening and
overnight. Confidence is waning on convection developing out west,
and 4 KM models have been VERY misleading (synoptic models have
not fared all that better either). Thus, am trending toward a
drier forecast for this evening and overnight, but still keeping a
chance for showers/thunder (much lower than what guidance has been
providing). Synoptic models are showing that the best mid
level/850mb theta-e air will be to the north (where convection is
occurring) through 06Z, but more favorable moisture advection may
(and I do say `may` as models have not done very well) occur
between 09Z-21Z Friday (which is why I am not going even lower on
POPs especially since there is some hint of weak diffluence
overnight). Will continue to monitor, but at this time, prefer to
reduce the chances for rain. Also, greatly lowered QPF values
through tonight. Not much change to other parameters needed at
MARINE...Marine forecast overall is doing fine but did increase
wave heights somewhat especially tonight as BOY020 is already at 7
feet. Lowered rain chances as well, with best moisture
availability remaining inland through the early morning hours.
PREVIOUS DISCUSSION... /Issued 621 PM CDT THU MAY 26 2016/
DISCUSSION...See 00Z aviation discussion below.
AVIATION...First, confidence in convection developing over the
mountains of Mexico this evening is waning, as KLRD winds are more
SSE than SE (or even better ESE). However, will maintain a VCTS
for 03Z time frame as there is still some suggestion that
moisture advection may be proximate enough and cap may weaken (and
winds back a bit more) to bring convection to the area. Elsewhere,
will not mention showers/thunder tonight with only VCSH overnight
at KVCT where some energy from upper trough could impact area.
Otherwise, as usual winds diminish slowly and veer overnight with
MVFR ceilings developing again this evening and overnight eastern
terminals. Am not sure we will see MVFR ceilings at KLRD so for
now went with a tempo group toward 12Z. For Friday, will maintain
or put in showers at KCRP for the morning, and thunder at KVCT
for the late morning and afternoon, although thunder by late
afternoon may be well to the north and east. Looking at the
pressure gradient for Friday, am expecting gusty SSE winds KCRP
and KVCT after sunrise, with less wind and more south at KLRD.
Will keep some gusts in KALI for 15Z and beyond, although winds
could diminish enough by 21Z as surface trough approaches the
terminal and weakens gradient.
PREVIOUS DISCUSSION... /Issued 358 PM CDT THU MAY 26 2016
by National Weather Service Austin/San Antonio TX/
SHORT TERM (Tonight through Friday night)...Majority of
convection this morning and afternoon has remained to the
northeast of the region with a backbuilding MCS located over
southeast Texas. Another impulse is progged to move off upper low
as it moves further east tonight. Confidence is still lower in
thunderstorms making it into the region again tonight. Convection
has been developing well west of the region over the Sierra Madres
and could push further in from the west overnight. High CAPE
values remain over the region, and if convection does make it into
the region, could see some strong storms with hail and gusty winds
develop. However, overall better dynamics still remain to the
north of the region. Tomorrow confidence is a little better as
upper low lifts northeast over the panhandles. A dryline will push
in from the west and diffluent region of upper jet noses into
south Texas, with the majority of the convection concentrated
across our eastern zones. Kept a mention of slight chance PoPs
through Friday night for any lingering convection. PWAT values
remain well above normal for the time of year tonight, but
higher moisture will decrease Friday afternoon into Friday night.
South southeast winds have strengthened in response to tightening
pressure gradient from surface low over northwest Texas. Seas will
build in response to persistent onshore flow, and a small craft
advisory has been issued for the middle Texas coastal waters
through tomorrow night.
LONG TERM (Saturday through Wednesday)...Chances for showers and
thunderstorms will continue for much of the extended. Upper level
ridge will build northward this weekend. However, moisture will
remain adequate across South Texas that daytime heating may result
in additional convection. Moisture levels will be most favorable
across the western zones on Saturday as PW values approach 2 inches.
Pops will remain in the 20 to 40 percent on Saturday with highest
chances over the Rio Grande Plains. Moisture decreases slightly on
Sunday but still sufficient to warrant 20 and 30 pops. A slow moving
upper level trough across the Desert Southwest will slide eastward
during the early to middle part of next week. Upper system will
still be to the west of the area by Wednesday. Several impulses will
approach area during the Monday through Wednesday time frame. This
will result in daily chances of showers and thunderstorms across
South Texas. Pops were capped at 50 percent for the Tuesday and
Wednesday, but may need to be raised in later forecasts.
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 80 89 79 90 78 / 20 40 20 20 10
Victoria 77 85 77 89 76 / 30 60 40 30 10
Laredo 77 96 77 98 77 / 20 20 20 40 30
Alice 78 92 77 93 76 / 20 40 20 30 10
Rockport 80 86 80 88 79 / 20 50 20 20 10
Cotulla 75 95 75 95 75 / 30 20 20 30 30
Kingsville 79 91 78 92 78 / 20 40 20 20 10
Navy Corpus 81 87 80 88 79 / 20 40 20 20 10
GM...Small Craft Advisory until 7 PM 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 until 1 AM CDT Friday For the following
zones: Bays and Waterways from Baffin Bay to Port Aransas...
Bays and Waterways from Port Aransas to Port OConnor.