Flash Flood Warning 33, NWS Shreveport, LA

Area Forecast Discussion
National Weather Service Shreveport LA
557 AM CDT Sun Jun 21 2020

.AVIATION...
Patchy MVFR/IFR cigs/vsbys will continue to be possible mainly
across E TX terminals, with VFR conditions to return in the mid
to late morning. Tstms to develop n of I-20 by mid morning, and
will continue through much of today. Convection to be more isold
in nature across srn areas, so will only keep VCTS for the aftn.
Convection to diminish around or just after sunset. Otherwise,
expect sly to swly winds around 10 kts or less through the pd.
/12/

&&

.PREV DISCUSSION... /issued 301 AM CDT Sun Jun 21 2020/

SHORT TERM.../Today through Monday Night/

Nw flow pattern continues across our region, as longwave trof axis
remains fixed across the central CONUS. A series of disturbances
in nw flow aloft will bring multiple rounds of convection through
the short-term and beyond. The first in the series is currently
movg sewd along the Red River of N TX/southern OK, with associated
convection ongoing. This disturbance will continue esewd along a
weak boundary stalled across SE OK/SW AR. Convection is fcst to
spread esewd into our area by later this morning to areas mainly
n of I-20. Although widespread severe weather does not appear
likely, a damaging wind gust or two cannot be ruled out with ample
instability and localized shear associated with the shortwave.
Convection should wind down after sunset.

As is common in June nw flow regimes, another impulse will barrel
sewd late tonight/early Monday morning into our nwrn areas, which
could bring an isold severe threat to these areas. The associated
MCS is fcst to decay by around or just after sunrise, likely
laying up an outflow boundary across our region. This boundary
will serve as a focus for sct aftn convection to redevelop.

By Monday evening, yet another impulse will send another round of
convection sewd towards our nrn areas early Tuesday morning,
again posing an isold severe risk. /12/

LONG TERM.../Tuesday through Saturday Night/

A series of upper troughs will move across Southern Canada/the
Northern U.S. combined with an upper ridge over the Western CONUS
will keep northwesterly flow in place for much of the long-term
forecast period. As a result, unsettled weather will persist.
Another MCS will enter the area from the northwest Tuesday morning.
A frontal boundary should accompany the storms but is expected to
from the Arkansas/Louisiana border and southwest across East Texas.
Diurnal instability and a passing shortwave trough should result in
redevelopment along the front and any remnant outflow boundaries,
especially along and south of Interstate 20. With the front
remaining quasi-stationary across the area, showers and
thunderstorms are likely across much of Louisiana and East Texas
Wednesday and Thursday.

The front will generally become more diffuse Thursday night. Rain
chances will diminish somewhat for Friday and Saturday. However, a
mid-level trough will develop near the Big Bend of the Rio Grande
late in the week. While the daily parade of MCSs from the northwest
will end, the resulting deep southerly flow should result in daily
chances for scattered diurnal convection across the entire area.
PoPs should begin to decrease on Saturday as the mid-level trough
quickly moves northeast of the region. /09/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  92  75  91  74 /  30  10  30  10
MLU  93  72  91  74 /  30  20  50  20
DEQ  87  69  89  69 /  70  30  30  50
TXK  87  72  89  73 /  60  10  20  30
ELD  89  70  89  71 /  60  20  40  30
TYR  91  75  92  74 /  20   0  20  10
GGG  92  74  92  74 /  30  10  20  10
LFK  93  75  91  74 /  20  10  40  10

&&

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

12/09

Hazardous Weather Outlook
National Weather Service Shreveport LA
612 AM CDT Sun Jun 21 2020

ARZ050-051-059>061-070>073-LAZ001>006-012>014-OKZ077-TXZ096-097-
108>112-124>126-136>138-221100-
Sevier-Howard-Little River-Hempstead-Nevada-Miller-Lafayette-
Columbia-Union-Caddo-Bossier-Webster-Claiborne-Lincoln-Bienville-
Jackson-Ouachita-McCurtain-Red River-Bowie-Franklin-Titus-Camp-
Morris-Cass-Wood-Upshur-Marion-Smith-Gregg-Harrison-
612 AM CDT Sun Jun 21 2020

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

.DAY ONE...Today and Tonight...

A complex of thunderstorms may move east-southeast across the
area today from Southern Oklahoma and North Central Texas, mainly
affecting locations along and north of Interstate 20. A couple of
isolated severe thunderstorms cannot be completely ruled out.
Damaging winds will be the primary threat.

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

Thunderstorms will remain possible every day from Monday through
Saturday. Widespread thunderstorms are expected Tuesday and
Wednesday. A few severe storms cannot be completely ruled out.
Damaging winds will be the primary threat. In addition, locally
heavy rainfall could lead to isolated flooding.

.SPOTTER INFORMATION STATEMENT...

Activation of emergency management personnel...amateur radio
operators...and storm spotters may be needed today. Please relay
any information about observed severe weather to the NWS while
following all local, state, and CDC guidelines.

LAZ010-011-017>022-TXZ149>153-165>167-221100-
De Soto-Red River-Sabine-Natchitoches-Winn-Grant-Caldwell-
La Salle-Cherokee-Rusk-Panola-Nacogdoches-Shelby-Angelina-
San Augustine-
612 AM CDT Sun Jun 21 2020

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

.DAY ONE...Today and Tonight...

Isolated to widely scattered thunderstorms will be possible today.
The strongest storms may produce gusty winds and brief heavy
rainfall.

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

Thunderstorms will remain possible every day from Monday through
Saturday. Widespread thunderstorms are expected Tuesday and
Wednesday. A few severe storms cannot be completely ruled out.
Damaging winds will be the primary threat. In addition, locally
heavy rainfall could lead to isolated flooding.

.SPOTTER INFORMATION STATEMENT...

Activation of emergency management personnel...amateur radio
operators...and storm spotters is not anticipated through tonight.

09

Special Weather Statement
National Weather Service Shreveport LA
830 AM CDT Sun Jun 21 2020

OKZ077-211415-
McCurtain OK-
830 AM CDT Sun Jun 21 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN MCCURTAIN COUNTY UNTIL
915 AM CDT...

At 829 AM CDT, Doppler radar was tracking a strong thunderstorm 10
miles northwest of Broken Bow, or 31 miles west of De Queen, moving
northeast at 20 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Broken Bow, Glover, Hochatown, Bethel, Oak Hill, Mount Herman,
Sherwood and Golden.

LAT...LON 3425 9447 3420 9447 3398 9483 3415 9507
      3450 9485
TIME...MOT...LOC 1329Z 227DEG 18KT 3411 9488

20

Special Weather Statement
National Weather Service Shreveport LA
915 AM CDT Sun Jun 21 2020

OKZ077-211500-
McCurtain OK-
915 AM CDT Sun Jun 21 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN MCCURTAIN COUNTY UNTIL
1000 AM CDT...

At 914 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 11 miles east of Cloudy to 15 miles northwest
of Broken Bow. Movement was northeast at 10 mph.

Half inch hail and winds in excess of 40 mph will be possible with
these storms.

Locations impacted include...
Plunketville, Smithville, Hochatown, Watson, Bethel, Battiest,
Pickens, Mount Herman and Sherwood.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3451 9467 3445 9446 3432 9447 3414 9467
      3424 9512 3425 9505 3451 9505
TIME...MOT...LOC 1414Z 223DEG 11KT 3429 9507 3423 9484

20