Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 04/04/23
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
636 PM CDT Mon Apr 3 2023
...New AVIATION...
.SHORT TERM...
(Tonight through Tuesday night)
Issued at 146 PM CDT Mon Apr 3 2023
Synopsis/Mesoanalysis: Early afternoon surface observations reveal
weaving northeast from approximately central Val Verde County to
Lampasas. Cumulus development has been noted along and immediately
to the north of our borders with SJT and FWD, likely due to a
combination of lift along the boundary and an area of strong surface
heating/90+ degree surface temperatures evident over our Hill
Country counties and points northwest. We will closely monitor this
area for isolated storm development through the remainder of the
afternoon hours, as any activity that materializes could quickly
become severe. A stationary front has been analyzed to our north in
the TX-OK Panhandles, and extends northeast into the Upper Midwest.
A potent upper low will eject into the Central Plains tomorrow
morning and afternoon, leading to cyclogenesis along this boundary
in the KS-NE border vicinity. The deepening surface cyclone is
forecast to pick up the dryline currently situated to our northwest,
dragging it deeper into the CWA through tomorrow afternoon. A
combination of dry air and gusty winds behind the boundary will
support near-critical to critical fire weather conditions across
portions of Hill Country and the southern Edwards Plateau through
the early evening hours. A trailing cold front will then approach
from the northwest overnight Tuesday into early Wednesday morning,
bringing additional shower and thunderstorm chances. Dry air will
swiftly advect into the region behind the front, combining with
gusty north winds to support additional near-critical to critical
fire weather conditions along and west of Interstate 35. This
potential will likely be realized as early as the predawn hours
Wednesday across our western zones.
This Afternoon: Near-critical fire weather conditions will continue
across Val Verde and Edwards Counties behind the dryline. A
Rangeland Fire Danger Statement remains in effect through 8 PM CDT.
An isolated storm remains possible, particularly across Llano,
Burnet, and Williamson Counties. While storm formation is highly
conditional upon erosion of the capping inversion still evident in
ACARS soundings from Austin and San Antonio, 1500-2500 J/kg of
MUCAPE and 50-60 knots of effective bulk shear would support a
supercellular mode in any development that occurs. This would favor
primarily a large hail threat, though isolated damaging wind gusts
exceeding 60 MPH can`t be ruled out. SPC continues to carry a
marginal (level 1/5) risk for severe storms in its day one
convective outlook in light of this potential.
Tonight: Mild lows in the upper 60s and low 70s are expected. Some
patchy fog is possible closer to daybreak in the Coastal Plains.
Tomorrow Night: Shower and thunderstorm chances will increase after
midnight as the cold front discussed above begins to push into the
area. Strong/severe storms are not expected given strong capping
evident in forecast soundings. Activity will likely continue into
early Wednesday morning/the beginning of the long term period.
&&
.LONG TERM...
(Wednesday through Monday)
Issued at 146 PM CDT Mon Apr 3 2023
An active pattern will bring the best chances for appreciable
rainfall amounts to eastern portions of south-central Texas in quite
some time late this week.
Wednesday morning, models unanimously depict a deepening surface low
in MN just ahead of a positively tilted upper trough. A cold front
will be through much of our region already at 12Z, with some shower
and thunderstorm chances along and just behind it in the AM for the
I-35 corridor and Coastal Plains. No severe weather expected,
instead with concerns on Wednesday focusing on fire weather behind
the front. Very dry air will filter in, with RH in the teens before
sunrise even for the southern Edwards Plateau. Northerly winds
behind the front will initially be high enough such that critical
fire danger is expected in the morning hours and a Fire Weather
Watch has been issued from 09Z to 21Z for the western 2/3rds of the
region. Winds will gradually diminish during the day, limiting the
threat for wildfire spread in the afternoon and early evening.
The frontal boundary will get hung up just offshore over the Gulf
late Wednesday into early Thursday. Aloft, southwesterly flow will
remain in place with occasional shortwave activity, and at least on
Thursday we`ll have some enhanced divergence in the upper levels in
the right entrance region of a SW-NE oriented jet. While higher
PWATs will be relegated to the southeastern half of our area, values
of 1.5-1.8" are expected over the Coastal Plains.
Experimental ERO on day 4 (Thursday) does depict a Slight Risk of
excessive rainfall for much of the Coastal Plains, and a Marginal
Risk across the I-35 corridor including Austin and San Antonio. As a
reminder, these are tied to probabilities of exceeding Flash Flood
Guidance within 25 miles of a point, with Marginal corresponding to
at least a 5% chance and Slight to a 15% chance. Given latest ECM
Ensemble/GEFS indicate PWATs some 150-200% of normal late Thursday
through Saturday morning for the I-35 Corridor and eastward into the
entire Coastal Plains, the concern for flash flooding is at a
heightened state. Friday also features an Marginal Risk for day 5
(Friday) over the Coastal Plains, with the threat for additional
locally heavy rainfall over the eastern 1/3rd of the area. A stalled
out frontal boundary will be the primary culprit, which at this
point, we will thankfully take, given the lack of appreciable
rainfall in quite some time over South-Central Texas. Ensemble
guidance from the ECM, GFS, and NBM indicate a 90% chance for at
least 1-2" from the I-35 Corridor and points eastward by the time
the heavier rains wrap up on Saturday. In fact, the latest NBM
indicates upwards of 4-5" possible over the Coastal Plains by
Saturday evening. We won`t hold our breath for that outcome, but we
will certainly take any rainfall as drought continues for much of
the area.
The weekend looks messy with lingering showers and storms possible
through Sunday for various parts of the area. Temperatures should
slowly rebound from highs in the 60s Thursday and Friday, to highs
back into the 70s and 80s Saturday and Sunday.
&&
.AVIATION...
(00Z TAFS)
Issued at 636 PM CDT Mon Apr 3 2023
At the I-35 sites, VFR conditions this evening. Stratus with low end
MVFR, perhaps briefly IFR, CIGs will develop overnight, then mix to
VFR later Tuesday morning. S to SE winds of 7 to 15 KTs will prevail
with a few daytime wind gusts on Tuesday up to 25 KTs possible.
At KDRT, VFR conditions prevail. SE winds up to 9 KTs return this
evening, then shift to W, or perhaps become variable, Tuesday
afternoon.
&&
.FIRE WEATHER...
Issued at 146 PM CDT Mon Apr 3 2023
Periods of near-critical to critical fire weather conditions are
forecast tomorrow and Wednesday. Relative humidities will drop into
the teens and single digits across portions of the Rio Grande Plains
and southern Edwards Plateau behind the dryline during the
afternoon. This will support widespread elevated to near-critical
fire weather conditions in these locations on Tuesday, as winds are
forecast to remain at or below 15 MPH. Winds will be stronger in Val
Verde County, where the afternoon update depicts sustained winds
approaching and exceeding 20 MPH. Gusts in excess of 30 MPH will
accompany the sustained winds. Combined with dry to critically dry
fuels, this has prompted the issuance of a Red Flag Warning for Val
Verde County, effective from 1 to 7 PM Tuesday afternoon. A
Rangeland Fire Danger Statement may be needed to address the near-
critical fire weather concerns in some of the other aforementioned
locations (particularly Edwards County). Subsequent shifts will
evaluate the potential need for the product following the expiration
of the Rangeland Fire Danger Statement currently in effect for Val
Verde and Edwards Counties.
Fire weather concerns continue into Wednesday as the cold front
discussed in the synopsis departs South-Central Texas. Relative
humidities in the teens and single digits are forecast along and
west of Interstate 35, and will be accompanied by sustained 15-25
MPH northerly winds. Given these conditions, and an area of much
broader dry to critically dry fuels forecast by the Texas A&M Forest
Service, we have elected to issue a Fire Weather Watch for all
locations along and west of Interstate 35, effective from 4 AM to 4
PM CDT Wednesday. Individuals are urged to avoid any activities that
could inadvertently lead to the ignition and spread of wildfires
both tomorrow and on Wednesday.
&&
.CLIMATE...
Issued at 146 PM CDT Mon Apr 3 2023
Record Highs for Tuesday April 4th:
ATT: 92 in 2019
AUS: 92 in 1958
DRT: 94 in 1964
SAT: 93 in 1893
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 71 90 62 77 / 10 0 50 20
Austin Bergstrom Intl Airport 70 90 63 76 / 10 0 50 30
New Braunfels Muni Airport 70 92 63 79 / 10 0 30 20
Burnet Muni Airport 68 89 57 75 / 20 0 40 10
Del Rio Intl Airport 71 99 62 82 / 0 0 0 0
Georgetown Muni Airport 70 89 60 74 / 20 0 60 20
Hondo Muni Airport 69 94 65 80 / 10 0 20 10
San Marcos Muni Airport 69 91 62 77 / 10 0 40 30
La Grange - Fayette Regional 70 86 63 74 / 0 0 40 50
San Antonio Intl Airport 70 92 64 79 / 10 0 30 20
Stinson Muni Airport 71 94 67 81 / 10 0 20 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
&&
$$
Short-Term...Quigley
Long-Term...MMM
Aviation...04
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
737 PM EDT Mon Apr 3 2023
...New UPDATE, AVIATION...
.UPDATE...
Issued at 727 PM EDT Mon Apr 3 2023
While a couple isolated storms have been quite active along the FL
East Coast, West Central and SWFL has remained largely quiet, with
drier and more stable air over our portion of the peninsula
compared to the east coast. ACARs data from the east coast
suggests more moisture pooling has been taking place, along with
added surface convergence along the sea breeze boundaries.
The rest of the evening should be pretty quiet, with mostly clear
skies and light winds. The setup is favorable for early morning
fog/low clouds. Don`t be surprised to see some fog first thing
tomorrow morning. That should quickly clear out, with a sunny and
warm day in store. Late afternoon to early evening conditions
potentially support a couple isolated storms later tomorrow
afternoon to evening across West Central and SWFL. Some CAMs are
hinting at this possibility, but forecaster intuition also
suggests this is possible. So a 20% POP remains for late tomorrow
afternoon and into the evening.
Overall, the current forecast remains on track.
&&
.AVIATION...
(00Z TAFS)
Issued at 727 PM EDT Mon Apr 3 2023
Some guidance and the overall setup continues to favor IFR to LIFR
conditions tomorrow morning, associated with low clouds and/or fog.
The potential exists during the morning hours, especially from 11-
13Z, for LIFR impacts at all terminals, but forecast confidence for
most is not high enough to explicitly forecast at this time. While
this quickly dissipates as the sun rises and VFR returns, a
shower or thunderstorm cannot be ruled out late tomorrow. With
POPs of only 20% tomorrow afternoon, have opted not to mention in
TAFs at this time, but inland terminals like KLAL, KFMY, and KRSW
could have a brief window for TSRA impacts, likely after 21Z.
&&
.MARINE...
Issued at 300 PM EDT Mon Apr 3 2023
High pressure will build over the gulf waters with southeast flow
through the week, except becoming onshore near the coast each
afternoon due to the sea breeze. Relatively benign conditions are
expected through the week with winds less than 15 knots and seas
3 feet or less.
&&
.FIRE WEATHER...
Issued at 300 PM EDT Mon Apr 3 2023
A few areas could see relative humidity values drop into the mid
30s over inland areas during the next few afternoons, but no Red
Flag conditions are expected. Some areas of late night and early
morning fog are also anticipated over the next few days.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 70 89 71 92 / 0 10 10 0
FMY 70 93 69 94 / 0 10 20 0
GIF 65 92 68 93 / 0 20 20 0
SRQ 68 87 69 91 / 0 10 10 0
BKV 62 93 64 95 / 0 0 10 0
SPG 71 86 73 88 / 0 0 10 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...None.
Gulf waters...None.
&&
$$
UPDATE/AVIATION...Flannery
PREVIOUS DISCUSSION...MARINE/FIRE WEATHER...Close