Special Weather Statement, NWS Shreveport, LA

Area Forecast Discussion
National Weather Service Shreveport LA
253 PM CDT Sun Jun 13 2021

.SHORT TERM.../Tonight through Monday Night/

For the rest of today...While the chance is fairly low, isolated
showers and thunderstorms will be possible this afternoon, with
the best chances coming for areas along and southeast of a line
from Lufkin, TX to Ringold, LA to near El Dorado, AR. Should
showers and thunderstorms move into this area, there is a threat a
few of them could become strong to severe at times. Already seeing
an uptick of thunderstorms firing across southwest Arkansas and
northwest Louisiana. Meanwhile, satellite imagery from this
afternoon continues to show an increase in cu across the entire
area. In addition, afternoon heat indices could reach the lower
to mid 100s, so continue to use caution if outdoors for an
extended period of time.

Upper-level ridge will continue to control the southwest CONUS
through the short term period and beyond. We could see additional
showers and thunderstorms across the area into the early overnight
hours as the passing backdoor cold front could struggle to clear
the area. Overnight lows will range from the lower to mid 70s once
again across the area. On Monday, additional afternoon showers
and thunderstorms will once again be possible across our far
southern and southwest zones as the remnant frontal boundary
lingers. High temperatures on Monday will once again climb into
the lower to mid 90s across the area with afternoon heat indices
reaching the upper 90s to lower 100s across the area. Monday night
will be slightly "cooler" across our northern zones with lows
falling into the upper 60s, with lower 70s expected elsewhere.
/33/

.LONG TERM.../Tuesday through Sunday/

Large upper ridging anchored from the Desert SW N through the
Rockies/Plains into Srn Saskatchewan/Manitoba will remain in place
Tuesday, with the Ern extent of the ridge expanding E to the MS
Valley. This will maintain hot and dry conditions over the region,
with any isolated convection expected to remain S of the area over
SE TX/S LA. The progs do suggest that the Ern extent of the ridge
may weaken slightly Wednesday over Deep E TX/Cntrl LA, such that
isolated afternoon convection will be possible over these areas,
where slight chance pops were maintained. The ridge to our WNW will
begin to flatten Wednesday afternoon/night in response to upper
troughing traversing E atop the ridge across Cntrl/Srn Canada, with
the ridge again expanded back E to the Lower MS Valley Thursday thus
returning dry conditions areawide. Sfc ridging extending from the
Midwest/OH Valley SW into E TX Tuesday will persist through Tuesday,
which will result in slightly drier air (lower dewpoints in the
mid/upper 60s), which will help lower heat indices despite the above
normal temps in the mid 90s expected. The GFS does depict isolated
afternoon convection develop Thursday over portions of N LA/Lower E
TX in response to a weak shear axis that will sink S through the
Lower MS Valley into N LA/Deep E TX. But given that this is an
outlying solution, and the fact that the NBM maintained dry
conditions, have opted to keep a dry forecast going but will
continue to monitor in the coming days.

The aforementioned troughing aloft will act to further suppress the
ridge Friday as it begins to slide SE through the Great Lakes
Region, although this will have little effect on the sensible
weather here other than maintaining the hot and mostly dry
conditions in place. It is here though that an eye will be needed to
be kept on the tropics, as an area of disturbed weather will emerge
out of the Bay of Campeche and drift N across the Wrn Gulf. General
agreement exists amongst the medium range progs with potential
tropical development as it approaches the SE TX/Srn LA coasts
sometime by mid to late weekend, which will result in a gradual
uptick of wrap-around convection across Deep E TX/N LA Saturday and
moreso Sunday. There still remains considerable uncertainty in
regards to how fast this system will strengthen as well as its
track/impacts on the region, as the GFS and Canadian do suggest a
weak shortwave trough in the NW flow aloft from the Mid MS Valley
into the TN Valley may pick this system up and steer it NE away from
the region. For now (as it is a Day 7 forecast), did remain
conservative with low to mid chance pops across Lower E TX/N
LA/SCntrl AR, tapering to slight chance across the remainder of the
area. The increase in wrap-around cloud cover/increased low level
moisture should also yield slightly cooler temps as well for next
weekend, with readings that are more typical for this time of year.

15

&&

.AVIATION...

For the 13/18z TAFs...Satellite imagery continues to show an
increase in cu this afternoon across much of the area. Surface
observations under the increasing clouds are showing SCT to BKN
around 3500 ft. VFR conditions will continue to control the
airspace above all terminals through the remainder of this TAF
package, with the exception of KLFK where some MVFR conditions and
BR are possible around 14/11z. That being said, one move caveat
for flight conditions this afternoon, there remains a non-zero
chance of some afternoon showers thunderstorms to develop across
portions of the area. Confidence is low that any of these storms
will impact any terminal at this time, so have left any mention of
them out. Should any develop around a terminal, will amend as
needed. /33/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  75  96  72  96 /  20   0   0   0
MLU  74  93  72  95 /  30  10   0   0
DEQ  71  95  69  95 /   0   0   0   0
TXK  74  94  71  94 /   0   0   0   0
ELD  72  95  69  95 /  20   0   0   0
TYR  75  94  74  95 /   0   0   0   0
GGG  74  94  72  95 /  10   0   0   0
LFK  74  96  75  96 /  10  10   0  10

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&

33/15/33

Hazardous Weather Outlook...CORRECTED
National Weather Service Shreveport LA
115 PM CDT Sun Jun 13 2021

ARZ050-051-059>061-070-OKZ077-TXZ096-097-108>112-124>126-136>138-
149-150-141200-
Sevier-Howard-Little River-Hempstead-Nevada-Miller-McCurtain-
Red River-Bowie-Franklin-Titus-Camp-Morris-Cass-Wood-Upshur-
Marion-Smith-Gregg-Harrison-Cherokee-Rusk-
115 PM CDT Sun Jun 13 2021

This Hazardous Weather Outlook is for portions of southwest
Arkansas, southeast Oklahoma and northeast Texas.

.DAY ONE...This Afternoon and Tonight...

Isolated showers and thunderstorms will be possible late this
afternoon and evening across portions of East Texas and Southwest
Arkansas. In addition, temperatures will climb into the lower and
mid 90s, and when combined with the humidity, will result in heat
indices ranging from 100 to 105 degrees.

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

Hot and dry conditions are expected for much of this week across
the region, as an upper level ridge of high pressure builds back
east into the area.

.SPOTTER INFORMATION STATEMENT...

Activation of emergency management personnel...amateur radio
operators...and storm spotters will not be be needed through
tonight.

ARZ071>073-LAZ001>006-010>014-017>022-TXZ151>153-165>167-141200-
Lafayette-Columbia-Union-Caddo-Bossier-Webster-Claiborne-Lincoln-
De Soto-Red River-Bienville-Jackson-Ouachita-Sabine-Natchitoches-
Winn-Grant-Caldwell-La Salle-Panola-Nacogdoches-Shelby-Angelina-
San Augustine-
115 PM CDT Sun Jun 13 2021

This Hazardous Weather Outlook is for portions of south central
Arkansas, southwest Arkansas, north central Louisiana, northwest
Louisiana, east Texas and northeast Texas.

.DAY ONE...This Afternoon and Tonight...

Scattered showers and thunderstorms are expected to develop by mid
and late afternoon across Northcentral Louisiana and Lower East
Texas, and spread west southwest across these areas during the
evening in advance of an approaching upper level disturbance.
Given the extent of instability that has developed, some of these
storms may be strong to severe, with damaging winds and brief
heavy rainfall possible. These storms should gradually diminish late
tonight with reduced instability. In addition, afternoon
temperatures will climb into the lower to mid 90s across much of the
region. When combined with the humidity, heat indices will range
from 101 to 105 degrees, with some locations briefly exceeding 105
degrees.

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

Isolated to widely scattered showers and thunderstorms will be
possible Monday afternoon and evening over the southern sections
of Northcentral Louisiana and Deep East Texas, before mostly dry
conditions return Tuesday through much of the coming work week.
Moisture should begin to increase by Saturday to support the
return of at least isolated showers and thunderstorms for next
weekend.

.SPOTTER INFORMATION STATEMENT...

Activation of emergency management personnel...amateur radio
operators...and storm spotters may be needed this afternoon and
evening.

15

Special Weather Statement
National Weather Service Shreveport LA
616 PM CDT Sun Jun 13 2021

LAZ021-022-140000-
Caldwell LA-La Salle LA-
616 PM CDT Sun Jun 13 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN CALDWELL AND NORTHERN LA
SALLE PARISHES UNTIL 700 PM CDT...

At 616 PM CDT, Doppler radar was tracking a strong thunderstorm near
Columbia, moving south at 30 mph.

Winds in excess of 30 mph will be possible with this storm.

Locations impacted include...
Columbia, Jena, Olla, Clarks, Grayson, Midway, Urania, Tullos,
Spaulding, Riverton, Standard, Kelly, Zenoria and Burlington.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3209 9189 3207 9193 3204 9190 3193 9191
      3193 9201 3164 9201 3171 9237 3173 9236
      3174 9236 3176 9234 3178 9235 3178 9236
      3219 9211 3218 9198 3217 9198 3217 9194
      3216 9190 3214 9190 3213 9188
TIME...MOT...LOC 2316Z 010DEG 25KT 3206 9202

09