Special Weather Statement, NWS Shreveport, LA

Area Forecast Discussion
National Weather Service Shreveport LA
1254 PM CDT Tue Jul 6 2021

.AVIATION...
For the 06/18z TAFs, scattered convection is quickly developing
along a band from North Central Texas into Deep East Texas and
Southern Louisiana. This activity will likely affect KTYR, KGGG,
and especially KLFK through 07/02z. Additional isolated showers
and thunderstorms are possible across the remainder of the area,
and VCTS was mentioned in all TAF sites except KTXK. However, rain
chances are much higher in East Texas along and south of
Interstate 20. The convection should gradually dissipate by
07/02z-07/03z. Low clouds and patchy fog will likely result in
MVFR conditions for a few hours around sunrise Wednesday at most
terminals. The clouds should slowly lift after daybreak, but more
showers and thunderstorms are expected to develop late in the
period.

CN

&&

.PREV DISCUSSION... /issued 1041 AM CDT Tue Jul 6 2021/

UPDATE...
A very active sea breeze has already developed with convection
moving north of the Interstate 10 corridor. This northernmost band
should affect portions of Deep East Texas very close to or shortly
after noon local time. Vertical ascent from a broad mid-level
Trough over the Northwest Gulf region is serving to greatly
enhance convective coverage. An increase in showers and
thunderstorms is still expected across most of the forecast area
south of Interstate 30 this afternoon.

Overall, only a few changes were made to the grids for this
update. PoPs were trimmed through 18z and edited slightly for the
early afternoon based on latest radar trends.

CN

PREV DISCUSSION... /issued 348 AM CDT Tue Jul 6 2021/

SHORT TERM.../Today through Wednesday/

Broad upper-level trough across the western Gulf of Mexico
extending into Louisiana to support increased instability across
the region through the short-term period. This combined with weak
frontal/sea breeze boundaries progressing north across the region
during the time of max heating will allow for widespread
diurnally driven convection this afternoon and again on Wednesday
afternoon. Afternoon high temperatures forecast to climb into the
lower 90s both days. Convection forecast to linger into the
evening hours before diminishing by midnight. Overnight low
temperatures tonight forecast to fall into the lower to middle
70s. /05/

LONG TERM.../Wednesday Night through Monday Night/

A favorable environment for convection and wet weather continues for
the Ark-La-Tex as the long term period begins. Aloft, ridging
centered just north of the Gulf of California, and ridging over the
Atlantic Basin, will persist through the rest of this week. The
variations in position of these two ridges (and the flow around
them) will influence the position of troughing and subsequent
convective environments over the Ark-La-Tex, but the main theme of
diurnally-driven showers and thunderstorms remains for each day of
the rest of this week and through the weekend into early next week.
By Thursday, a coastal trough axis will continue its closest
approach, instigating widespread afternoon convection before
weakening. No severe weather is expected, but locally heavy rainfall
is possible where storms do develop.

Slight retrograde motion begins with both western and Atlantic Basin
ridges by Friday, gradually allowing a longwave trough over the
Northern Great Plains to dig further south over the weekend. In the
process of this movement, low-level southerly flow will maintain
Gulf moisture for daily chances of afternoon showers and
thunderstorms.  The aforementioned longwave trough will place
southwesterly flow over the area by Sunday, aiding low-level
convergence and chances for precipitation on Sunday afternoon. By
Monday, the Atlantic Basin ridge becomes the stronger of the two
ridges, displacing the longwave trough (and better convection)
further to our north. That said, persistent southerly flow will
maintain moisture for typical diurnal convection once again on
Monday. Daily high temperatures in the upper 80s to lower 90s are
expected due to afternoon convection, which will moderate the
upper end of the diurnal curve toward the seasonal average. Lows
will remain in the low to mid-70s, also near to just above the
seasonal average. /16/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  93  74  91  73 /  50  30  70  20
MLU  92  73  90  73 /  60  40  80  20
DEQ  93  71  92  72 /  10  10  40  10
TXK  93  74  91  74 /  20  10  40  10
ELD  93  71  91  71 /  30  20  60  10
TYR  92  74  90  74 /  30  20  60  10
GGG  91  72  90  72 /  30  20  60  10
LFK  91  73  90  73 /  70  40  80  20

&&

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

09/26

Hazardous Weather Outlook
National Weather Service Shreveport LA
1144 AM CDT Tue Jul 6 2021

ARZ050-051-059>061-070>073-LAZ001>006-010>014-017>022-OKZ077-
TXZ096-097-108>112-124>126-136>138-149>153-165>167-071645-
Sevier-Howard-Little River-Hempstead-Nevada-Miller-Lafayette-
Columbia-Union-Caddo-Bossier-Webster-Claiborne-Lincoln-De Soto-
Red River-Bienville-Jackson-Ouachita-Sabine-Natchitoches-Winn-
Grant-Caldwell-La Salle-McCurtain-Bowie-Franklin-Titus-Camp-
Morris-Cass-Wood-Upshur-Marion-Smith-Gregg-Harrison-Cherokee-Rusk-
Panola-Nacogdoches-Shelby-Angelina-San Augustine-
1144 AM CDT Tue Jul 6 2021

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

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

Showers and thunderstorms will increase in coverage areawide this
afternoon. Locally heavy rain and brief gusty winds will be
possible in stronger storms.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday...

Showers and thunderstorms will become more widespread and likely
by the middle of the workweek. No organized severe weather is
anticipated at this time, but stronger storms may produce locally
heavy rain and brief gusty winds.

.SPOTTER INFORMATION STATEMENT...

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

Special Weather Statement
National Weather Service Shreveport LA
147 PM CDT Tue Jul 6 2021

LAZ017-TXZ167-061930-
Sabine LA-Sabine TX-
147 PM CDT Tue Jul 6 2021

...SPECIAL WEATHER STATEMENT...

At 145 PM CDT, Doppler radar was tracking a strong thunderstorm 7
miles north of Toledo Bend Dam. This storm was nearly stationary.

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

Locations impacted include...
Florien, Fisher, Columbus and Mount Carmel.

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.

If on or near Toledo Bend Reservoir, get out of the water and move
indoors or inside a vehicle. Remember, lightning can strike out to
10 miles from the parent thunderstorm. If you can hear thunder, you
are close enough to be struck by lightning. Move to safe shelter
now! Do not be caught on the water in a thunderstorm.

&&

LAT...LON 3118 9360 3117 9367 3139 9380 3149 9339
      3137 9329 3136 9339 3128 9344 3128 9353
      3125 9354 3124 9356 3123 9354 3122 9355
      3120 9354 3119 9355 3117 9359
TIME...MOT...LOC 1845Z 142DEG 4KT 3128 9356

09