Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/31/18
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
909 PM CDT Fri Mar 30 2018
Just sent an update to re-trend variables through 15Z Saturday. While
there is no major change to the previous forecast, recent HRRR and
RAP13 runs suggest a bit more coverage with patchy fog after 11Z in
the San Antonio metro area. So that is now reflected in the forecast.
.PREV DISCUSSION... /ISSUED 703 PM CDT Fri Mar 30 2018/
VFR conditions will continue through the evening, with winds veering
from more easterly headings to southerly overnight to cause low-level
moisture to return at all sites. MVFR ceilings should develop by 9Z
at DRT where southeasterly winds are already gusting to 20-25 knots,
but they will be delayed to 11-12Z at SAT/SSF where winds be lighter
around 5-10 knots. IFR ceilings are possible at those three sites,
but winds will probably be too strong at DRT and IFR ceilings at SAT
should be short-lived. VFR conditions are most likely at AUS where
moisture will be a bit slower to return, but MVFR ceilings above 2000
feet are still possible. All sites should improve to VFR around 17Z,
with southerly wind gusts to 20-25 knots expected as the pressure
gradient increases due to a surface low in the Texas panhandle.
PREV DISCUSSION... /ISSUED 319 PM CDT Fri Mar 30 2018/
SHORT TERM (Tonight through Saturday Night)...
Surface high pressure is currently in place across south central
Texas, with mid-afternoon temperatures in the mid 60s and 70s.
Surface high pressure will shift eastward tonight, allowing winds to
become southeasterly overnight. Given the pressure gradient, winds
will be a little stronger along the Rio Grande with mainly 10-15 mph
expected. Farther east into the coastal plains and Highway 77
corridor, winds will be lighter. These lighter winds along with wet
grounds and clear skies should allow some patchy fog to develop south
of I-10/east of I-35 late tonight into early Saturday morning. On
Saturday, breezy south winds are in store for all areas, along with a
warming trend. Highs Saturday should range from near 80 in the Hill
Country to the mid 80s along the Rio Grande. While we could see
additional fog development Saturday night across the coastal plains,
wind speeds around 10 mph may limit the fog potential and we will not
mention in the forecast at this time.
LONG TERM (Sunday through Friday)...
The warm temperatures along with breezy south winds will continue on
Sunday. Most areas can expect highs in the 80s. For Sunday night, the
flow aloft begins to become a little more active as the models show a
few weak upper disturbances moving across south Texas. This should be
enough to generate a few showers for the I-35 corridor and Hill
Country areas Sunday night. Southwest flow aloft continues on Monday
and with highs mainly in the 80s and adequate moisture, can`t rule
out some isolated showers and thunderstorms. Most activity should
occur during the late afternoon and early evening hours during peak
heating. An upper level trough axis to our west will sharpen and
begin to move into far southwest Texas through Tuesday morning. The
dryline will mix eastward into the southern Edwards Plateau during
the afternoon hours and could serve as a focus for thunderstorm
development. Thunderstorm development will likely continue into
Tuesday night as a cold front moves in from the north. The models are
beginning to show better agreement with the timing of the front and
show the front should clear our area by early Wednesday morning. Dry
weather is expected behind the front on Wednesday and Thursday.
Moisture returns quickly Thursday night and Friday and with a weak,
broad upper trough axis over the southern U.S. Plains, we will
mention a low chance for convection across south central Texas.
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 56 82 62 81 64 / 0 0 - 10 20
Austin Bergstrom Intl Airport 53 81 61 81 64 / 0 0 - 10 20
New Braunfels Muni Airport 55 82 60 81 64 / 0 0 0 10 20
Burnet Muni Airport 53 80 60 81 62 / 0 0 0 0 20
Del Rio Intl Airport 62 85 62 86 67 / - - 0 0 10
Georgetown Muni Airport 53 81 61 81 62 / 0 0 0 - 20
Hondo Muni Airport 57 83 60 83 65 / 0 10 0 - 20
San Marcos Muni Airport 55 81 60 81 64 / 0 0 - 10 20
La Grange - Fayette Regional 54 82 62 81 65 / 0 0 - 0 10
San Antonio Intl Airport 58 81 62 82 65 / 0 - 0 10 20
Stinson Muni Airport 58 82 62 83 66 / 0 0 0 10 20
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
759 PM EDT Fri Mar 30 2018
A weak frontal boundary approaches the west coast of Florida this
evening. Latest radar is showing a weakening trend with the
rainshowers as they approach the coastline. Latest HRRR guidance
appears to be slightly over doing the strength of the showers and
storms as they make their way over the coastline. It appears that
most of the showers will move onshore from Tampa Bay northward along
the nature coast with southwest Florida only seeing a slight chance
of showers this evening. Most of the weather will move through by
early Saturday morning, with mostly cloudy skies lingering through
the morning hours. Temperatures will remain seasonal tonight and
again on Saturday with upper 50`s to mid 60`s tonight and upper 70`s
to low 80`s on Saturday. Forecast looks good for now with no
significant changes needed.
31/00Z TAFs. The frontal boundary continues to move toward the west
coast of Florida. VCSH can be expected over the next several hours
for KTPA/KPIE/KLAL/KSRQ with SHRA beginning around 03-04Z for
KTPA/KPIE/KLAL through 07Z. With this front, mostly VFR conditions
can be expected with CIGs around 040. As the front shifts south late
tonight into Saturday morning, some brief MVFR CIGs are possible at
KPGD/KFMY/KRSW early Saturday morning. As the front moves over
southern Florida late morning, conditions will be VFR for the
remainder of the period. Winds will shift from the west-northwest
this evening to the northeast tomorrow, but generally staying 10
knots or less.
A cold front eases south of the waters through this evening with a
few heavy rainshowers and locally higher winds and seas. In addition
there may be patchy sea fog near the southwest coast late overnight.
The front exits tonight taking the showers and any sea fog with it.
High pressure builds in over the weekend with some perhaps robust
winds...then tracks east during early next week with diminishing and
veering winds. No other marine impacts expected.
.Preliminary Point Temps/PoPs...
TPA 63 79 63 81 / 40 20 0 20
FMY 66 82 65 83 / 10 30 10 20
GIF 63 79 62 84 / 30 20 10 30
SRQ 64 79 64 78 / 20 20 10 20
BKV 58 78 57 82 / 40 10 0 20
SPG 65 77 64 81 / 30 10 0 20