Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 06/18/23
Area Forecast Discussion
National Weather Service Fort Worth TX
650 PM CDT Sat Jun 17 2023
...New Aviation, Short Term...
.SHORT TERM... /NEW/
Update:
Convection is underway across the Big Country within a highly
unstable airmass east of a West Texas dryline. This supercellular
activity is expected to grow upscale to an extent, which should
cause it to push eastward with time as cold pools consolidate and
storm mode transitions to one or more linear segments. The big
question mark is still areal coverage, and it`s possible a large
section of our CWA does not experience storms this evening. This
would be due to some weak capping as indicated by afternoon North
Texas AMDAR soundings, but strong elevated instability may still
allow existing convection to maintain itself as it advances east
despite encountering increasing MLCIN. This modest capping may
also explain why recent CAM runs have trended downward with
evening convection in both coverage and intensity, but with a
volatile and amply sheared airmass in place, these solutions may
be underdone. The main threats with any organized activity this
evening will be damaging gusts and large hail. Overnight,
additional upstream convection (currently in progress in NW
Oklahoma) will move southeastward, likely impacting our
north/northeastern zones around or after 3-4 AM. This activity
could also be severe, and winds would probably be the primary
threat.
Additional severe convection is possible again tomorrow afternoon
along a weak front/trough axis which should be positioned though
Central/East Texas during peak heating.
-Stalley
Previous Discussion:
/This Afternoon through Sunday Night/
Visible satellite imagery shows an expanding cumulus field across
the region at this hour as a diffuse frontal boundary meanders
northward in the vicinity of the I-20 corridor. This boundary is
best delineated by the gradient in surface theta-e which is
sharpest across the northern parts of the Metroplex thanks to an
appreciable drop in dewpoints closer and just north of the Red
River. A broad area of modest surface convergence is also noted in
the latest objective analysis across this boundary. Despite this,
aircraft soundings indicate that the moisture rich boundary layer
is still strongly capped across North Texas, and it`ll likely be
several more hours before this cap can erode sufficiently for
thunderstorm development.
By late afternoon, a dryline will spread out of far West Texas
into northwest Texas, extending southward into the Big Country.
As it does, a modest mid level shortwave (currently across draped
across New Mexico on water vapor imagery) will move across West
Texas and into the Southern Plains by early evening. Regional VAD
wind profiles show mid level winds currently around 20-30 kt but
these will increase to 50-60 kt by this evening as large scale
forcing for ascent spreads into the region. The uptick in deep
layer shear above a strongly buoyant airmass will set the stage
for rapid severe thunderstorm development late this afternoon into
the late evening hours. Strong insolation combined with
increasing ascent and focused convergence along the dryline should
allow any remaining convective inhibition to be overcome by late
afternoon. Thunderstorms should develop along the dryline to the
west of our area between 4-6 pm and quickly move east/northeast
through the late evening hours. The hot boundary layer airmass
will result in slightly higher based convection with an increasing
threat for damaging winds, especially if any organized cold pool
can develop. MLCAPE in excess of 4000 J/kg along with ample deep
layer shear will also support a very large (baseball size or
greater) hail threat into the late evening hours. Hodographs from
forecast soundings across our west/northwest counties favor
splitting supercells initially, with left movers accelerating off
to the northeast around 40 kt. This activity is expected to
quickly spread east along the I-20 corridor into our northeast
counties closer to midnight. In addition, we`ll be watching a
potential complex of thunderstorms racing across Oklahoma, as this
could spread across the Red River into our northeast counties
during the overnight hours. PoPs will top out around 60% for areas
west/northwest of the Metroplex this evening.
Lingering convection should wind down late tonight as the
shortwave moves into the mid-Mississippi River Valley by early
Sunday morning. As it does, a weak front will slide southward into
North Texas resulting in ever so slightly cooler and drier air for
Sunday afternoon. We`ll leave the current Excessive Heat
Warnings/Heat Advisories in place how they`re configured despite a
slightly cooler Sunday, as temperatures will quickly rebound
for the start of next week.
Dunn
&&
.LONG TERM... /Issued 127 PM CDT Sat Jun 17 2023/
/Monday Into Next Weekend/
Chances for showers and thunderstorms (and, therefore, severe
weather) will finally taper off during the upcoming week. However,
the hottest temperatures of the meteorological summer thus far
will likely occur Monday and Tuesday, as widespread triple digit
heat is expected across the region. Unfortunately, the return of
southerly winds on Monday will result in an increase in moisture
with dew points climbing well into the 70s. While we would
typically expect dew points to mix out by the afternoon hours,
weak boundary layer winds will continue to discourage vertical
mixing, keeping us very humid throughout the day. As a result,
stifling heat is expected both Monday and Tuesday as heat index
values soar to 110-115 degrees across a rather large portion of
the area both days, and perhaps even higher in some locations.
This should require an extension of our current heat headlines in
the near future.
By mid to late week, an upper ridge will build further north and
east. While fewer locations will reach the century mark on
Wednesday, continued high humidity will result in heat index
values between 100-115 degrees. We should finally see high
temperatures return to the 90s by late week, which will be much
closer to normal values for mid to late June. Rain chances should
remain very low, but we`ll still be somewhat on the periphery of
the upper ridge with the potential for a few passing mid-level
impulses. Therefore, we can`t completely discount another chance
for showers and thunderstorms, especially late in the week. We`ll
continue to monitor this potential over the next few days.
Barnes
&&
.AVIATION... /NEW/
/00z TAFs/
Convective impacts are expected across parts of North Texas this
evening as thunderstorm activity arrives from the west. Areal
coverage remains uncertain at this time, and it is possible that
thunderstorms do not directly impact the TAF sites. However, will
maintain a fairly aggressive TAF given the highly unstable
airmass in place. Greatest thunderstorm chances at the D10
airports will be roughly 02-04z, but additional convection is
possible across the northern fringes of the area into the
overnight hours as well.
Otherwise, there is a low chance for a couple hours of MVFR cigs
tomorrow morning. A weak surface front/trough will arrive around
midday, shifting winds to the northwest where they will remain
through the rest of the period. There are convective chances in
parts of East/Central Texas tomorrow afternoon, but this activity
would likely occur southeast of the TAF sites.
-Stalley
&&
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 75 95 74 100 79 / 40 10 0 0 5
Waco 76 99 75 102 77 / 20 20 5 0 5
Paris 70 89 68 93 73 / 70 40 0 0 5
Denton 70 95 69 100 76 / 50 5 0 0 5
McKinney 71 92 70 96 76 / 50 10 0 0 5
Dallas 74 96 73 100 79 / 40 10 0 0 5
Terrell 73 94 71 98 76 / 40 20 5 0 5
Corsicana 77 98 76 99 79 / 30 20 10 0 5
Temple 77 102 76 103 77 / 20 20 5 0 5
Mineral Wells 71 95 71 103 76 / 40 5 0 0 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM CDT Sunday for TXZ104>107-118>123-
131>134-142>145.
Excessive Heat Warning until 8 PM CDT Sunday for TXZ135-146>148-
156>162-174-175.
&&
$$