Special Weather Statement, NWS Fort Worth, TX

Area Forecast Discussion
National Weather Service Fort Worth TX
1153 PM CDT Sun Oct 10 2021

...New Short Term, Aviation...

.SHORT TERM... /NEW/
Update:
/Overnight and Monday/

A strong to severe squall line continues to track quickly east
into eastern Central TX and E TX at a good clip, supported by
strong westerly mid level winds aloft. Tornado Watch 518 remains
in effect for a few more hours (through 2 AM CDT) for roughly
those areas along and southeast of a Cooper, to Corsicana, to
Groesbeck, to Cameron line.

Otherwise, a cold front will continue to punch drier air in behind
this squall line through sunrise Monday morning with skies at
least partially clearing, with more plentiful sunshine by Monday
afternoon. West-northwest winds 10 to 15 mph through mid morning
will gradually become north, then northeasterly less than 10 mph
Monday afternoon as a surface ridge takes hold across the area.
Highs will mostly be in the upper 70s and lower 80s, though a few
readings in the mid 80s could pop up along and west of US-281
where good insolation and a return of southerly flow could occur
very late in the day.

05/

Previous Discussion:
/Through Monday/

...Significant Severe Weather Expected This Evening...

A vigorous mid-level trough is on track timing-wise as strong
kinematics and DPVA lift east with 150 kt cyclonically curved
upper jet maximum moving over NW TX/W OK by 9-10 pm. At the
surface, a frontal surface low was situated between Childress and
Abilene, with a strong cold front surging southeast from the
Panhandles and South Plains into the Big Country and NW TX. A
surface dryline extended south-southwest from the frontal low to
just west of Abilene/San Angelo. East of this feature, dew point
temperatures were in the 60s across the entire CWA with even
richer values in the lower 70s surging into eastern Central and E
TX. Current temperatures from the upper 80s to middle 90s were
correlating with this low level moisture surge for MLCAPE to
between 1500-2000 J/KG with CINH lessening to below 100 J/KG as
of 5 pm. Mid-level lapse rates weren't overly steep, but
sufficient enough (between 6.5-7 deg C/km) to maintain deep
updrafts when thunderstorms initiate by or possibly just before 7
pm CDT across far western parts of the CWA.

All things said within that synopsis, the forecast still remains
intact, though we'll be watching areas near the US-281 corridor
closer for possible earlier initiation between 6-7 pm. It's all a
timing deal here, but once both convergence ahead of the surface
low, dryline, and cold front coincide and juxtapose with the
increasing large-scale ascent aloft, strong to severe storms
should un-zipper along the features as the dry air within the
residual elevated mixed layer on the 21z special FWD sounding
rapidly moistens and begins cooling and saturating. With strong SW
winds aloft backing quickly southerly at 850mb, then southeast
within the boundary layer, there is good low-level curvature in
the lower 1-3 km, though LCLs may not be as ideal until you get
into richer low-level moisture along and east of I-35. Bottom
line, damaging winds with a fast-moving squall line or even QLCS
looks likely with the strong crosswind component of the
continually veering mid-level flow, along with the possibility of
a few brief tornadoes. We should remain capped enough well in
advance of the line to limit discrete supercells and more
significant tornadoes, though areas north of HWY 380 to the Red
River would be the most likely candidates to see a discrete storm
or two, especially by nightfall with an increasing LLJ/warm
advection near 50 kts just in advance of the cold front. Though
some larger hail to possibly quarter or half dollar size is
possible, the steeper mid-level lapse rates and greater hail
production area aloft will remain north of our area.

As for timing windows, this will be a VERY progressive event with
most locations only seeing a 1-2 hour severe weather window before
gusty west, then northwest winds 15-20 mph draw in behind the
fast-moving cold front. I look for areas between US-281 and
I-35/35W to be in the 7-9 pm time frame, I-35 corridor in the 9-11
time frame, the areas further east from 10 or 11 pm, through 2 or
3 am. Cooler and breezy conditions in the 50s and 60s will greet
most Monday morning, then some clearing and partial sunshine
should help highs rebound into the upper 70s to mid 80s.

Also, please prepare now and be ready to take safety tonight and
do not get hung on severity, as that's not in question. What I
have noticed a lot of folks getting hung up on "Which SPC risk
area am I in?" and having that drive their awareness and
preparation. That's not the important thing here. Please DO NOT
do so and regardless of whether you are in an Enhanced, Slight, or
Marginal Risk, have your severe weather plan in place and where
you plan to shelter when things go bad. Though the greatest coverage
of severe weather is expected to be along/N of I-20, any storms
that happen will be capable of producing all modes of severe
weather, including a few tornadoes.

05/Marty

&&

.LONG TERM... /Issued 241 PM CDT Sun Oct 10 2021/
/Monday Night through Next Weekend/

The extended portion of the forecast features daily rain/storm
chances through Friday followed by a nice, dry, and cooler weekend.
As the Sunday night storm system continues to lift to the northeast,
another strong upper-level trough will move from the west into the
Four Corners region. At the surface, a warm frontal boundary will
begin to lift northward from the Texas Coast, bringing another
surge of moisture into North and Central TX. Scattered showers and
storms will be possible during the day on Tuesday. Severe weather
appears low at this time, but we can't rule out a few strong
storms.

Precipitation chances will increase Tuesday night through Thursday
as strong/large scale ascent and deeper moisture increases across
our region. Most guidance agrees that the southwesterly flow in
the wake of the upper low will allow the surface cold front to
weaken and stall just to our west Wednesday and Thursday. Pacific
moisture is expected to be advected into Texas associated with
Tropical Depression 16 over the Eastern Pacific. Models also
suggest that we will positioned under the divergence and ascent
entrance region of the jet. As we bring all these pieces together
into a conceptual model, we notice that it matches the Pacific-
Texas PREs (Predecessor Rain Events) pattern. What this means is
that convection over Texas will likely be enhanced provided that
low-level moisture is also available. Forecast PWs in the
1.6-2.5" range depicts that low level moisture will reside over
the region. With that in mind...confidence is increasing that
there will be periods of heavy rainfall as a large band of rain
oriented NE-SW develops along and ahead of the cold front during
this time period. It is still too early to pinpoint the exact
location of the heaviest precipitation, but it appears that the
majority of the region will receive rainfall totals between 1-3
inches. If the forecast continues to follow this pattern, we
could see some locations receiving significantly higher rainfall
amounts. We will continue to refine the details in the upcoming
days, but it important to highlight the potential for some
flooding concerns later in the week.

The cold front will finally push through our area on Friday bringing
cooler and drier air into the weekend. Tuesday through Thursday's
temperatures will range from the upper 70s to upper 80s due to
rain chances and clouds, but next weekend highs will stay in the
70s!

Sanchez

&&

.AVIATION... /NEW/
/06z TAFs/

Winds continue to veer southwesterly at 10 to 15 kts behind the
departing squall line across all airports. VCSH will be
maintained a few more hours across the D10, with some VCTS holding
on at Waco Regional through 06z.

Otherwise, VFR conditions should prevail in behind a Pacific FROPA
expected across all terminals by 12z Monday. IR satellite does
show some MVFR cigs rotating within cyclonic low level flow from
Hwy 380 into S OK and it possible these could clip northern D10
terminals between 06z-12z, but for now have left out of the
forecast.

W-NW winds 10-15 knots should continue through 15z to 18z Monday,
before becoming N-NE less than 10 knots afterwards. Some minor
west crosswind issues may occur at DFW through 15z Monday, but
don't expect significant issues. TS will continue to impact
NBND/EBND traffic, as well as the BYP/CQY cornerposts through 12z
Monday.

05/

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    62  82  64  86  72 / 100   0   5  60  40
Waco                60  82  65  87  73 /  80   0   5  40  20
Paris               62  78  58  82  70 /  90   0   5  50  30
Denton              58  82  59  85  68 / 100   0   5  60  50
McKinney            61  81  60  84  71 /  90   0   5  60  40
Dallas              64  82  66  87  74 /  90   0   5  50  40
Terrell             61  81  60  86  70 /  90   0   5  50  20
Corsicana           62  82  65  87  72 /  80   0  10  40  20
Temple              61  84  66  87  72 /  80   0   5  40  20
Mineral Wells       57  82  60  86  68 / 100   0   5  50  50

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&

Hazardous Weather Outlook...UPDATED
National Weather Service Fort Worth TX
1035 PM CDT Sun Oct 10 2021

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-111200-
Montague-Cooke-Grayson-Fannin-Lamar-Young-Jack-Wise-Denton-Collin-
Hunt-Delta-Hopkins-Stephens-Palo Pinto-Parker-Tarrant-Dallas-
Rockwall-Kaufman-Van Zandt-Rains-Eastland-Erath-Hood-Somervell-
Johnson-Ellis-Henderson-Comanche-Mills-Hamilton-Bosque-Hill-Navarro-
Freestone-Anderson-Lampasas-Coryell-Bell-McLennan-Falls-Limestone-
Leon-Milam-Robertson-
1035 PM CDT Sun Oct 10 2021

This Hazardous Weather Outlook is for North and Central Texas.

.DAY ONE...Overnight.

A line of strong to severe storms will continue moving rapidly to
the east across areas primarily east of a line from Bonham, to
Dallas, to Waco and Temple through 3 AM CDT. Some storms may be
severe with damaging winds and small hail.

A few brief, spin-up tornadoes remain possible within this line of
storms. This line of severe storms should exit out of far eastern
parts of North and Central Texas before sunrise Monday morning.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Storm chances return late Tuesday and continue through the end of the
week. Some strong storms will be possible along with locally heavy
rain. More details regarding the Tuesday through Friday activity
should become known by early in the work week.

.SPOTTER INFORMATION STATEMENT...
Limited spotter activation will remain possible across eastern
portions of North and Central Texas into the early pre-dawn hours.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FORT WORTH TX
825 PM CDT SUN OCT 10 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0820 PM     TSTM WND GST     MINERAL WELLS           32.82N 98.08W
10/10/2021  M60 MPH          PALO PINTO         TX   ASOS

            MINERAL WELLS ASOS REPORTED 60 MPH WINDS AT
            8:20PM.

&&

JH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FORT WORTH TX
908 PM CDT SUN OCT 10 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0903 PM     TSTM WND GST     ANNETTA SOUTH           32.67N 97.67W
10/10/2021  E60 MPH          PARKER             TX   PUBLIC

            60 MPH GUSTS REPORTED IN ANNETTA SOUTH.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FORT WORTH TX
931 PM CDT SUN OCT 10 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0910 PM     TSTM WND GST     PONDER                  33.18N 97.29W
10/10/2021  M60 MPH          DENTON             TX   TRAINED SPOTTER

            60 MPH WINDS REPORTED IN PONDER BY WEATHER
            SPOTTER.

&&

JH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FORT WORTH TX
1031 PM CDT SUN OCT 10 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0924 PM     TSTM WND DMG     DENTON                  33.22N 97.13W
10/10/2021                   DENTON             TX   PUBLIC

            DELAYED REPORT: SOCIAL MEDIA REPORTS SEVERAL
            BROKEN LARGE TREE BRANCHES IN DENTON, TX.

&&

JH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FORT WORTH TX
1033 PM CDT SUN OCT 10 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0935 PM     TSTM WND DMG     1 WSW GUNTER            33.45N 96.75W
10/10/2021                   GRAYSON            TX   PUBLIC

            POWER POLES SNAPPED EAST OF 289 ON FM121 IN
            GUNTER.

&&

JH

Special Weather Statement
National Weather Service Fort Worth TX
1157 PM CDT Sun Oct 10 2021

TXZ122-135-146>148-162-110600-
Van Zandt TX-Anderson TX-Leon TX-Freestone TX-Henderson TX-
Navarro TX-
1157 PM CDT Sun Oct 10 2021

...Strong thunderstorms will impact portions of Freestone,
southeastern Van Zandt, northeastern Leon, Henderson, Anderson and
southeastern Navarro Counties through 100 AM CDT...

At 1155 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Canton to Groesbeck. Movement was east at
35 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Palestine, Athens, Canton, Teague, Fairfield, Chandler, Van,
Malakoff, Frankston, Brownsboro, Eustace, Berryville, Trinidad, Edom,
Coffee City, Caney City, Fairfield Lake State Park, Log Cabin,
Murchison and Oakwood.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

A Tornado Watch remains in effect until 200 AM CDT for central and
north central Texas.

&&

LAT...LON 3151 9574 3147 9627 3170 9643 3255 9583
      3255 9559 3248 9560 3235 9545 3227 9545
      3223 9549 3218 9546 3215 9548 3208 9542
      3196 9545 3193 9542
TIME...MOT...LOC 0455Z 258DEG 32KT 3253 9577 3152 9651

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

Stalley