Flash Flood Warning 4, NWS Shreveport, LA

Area Forecast Discussion
National Weather Service Shreveport LA
114 PM CDT Sun Apr 7 2019

.UPDATE...
Zones will be updated shortly for the inclusion of Severe
Thunderstorm Watch #42.

See below for 07/18z Aviation Discussion.

&&

.AVIATION...
For the 07/18z TAFs, strong to severe convection will once again
affect all of the TAF sites and most terminals along and south of
Interstate 30 during the period. Scattered convection is already
impacting much of Southern Arkansas and Louisiana, including KTXK,
KELD, and KMLU. A much strong convective complex will arrive from
Southeast Texas beginning around 07/20z and will move northeast
across the area through the evening hours. Thunderstorms will
likely persist at many of the TAF sites before finally tapering
off from west to east beginning around 08/10z. Flight conditions
will continue to vary, but IFR/LIFR conditions along with variable
and gusty winds should be expected with any storms.

CN

&&

.PREV DISCUSSION... /issued 1131 AM CDT Sun Apr 7 2019/

UPDATE...
A line of thunderstorms continues to move northward across
Northeast Texas and Southern Arkansas, and will eventually move
into Southeast Oklahoma and extreme Southwest Arkansas. CAPE
values in this area are generally between 500-1000 J/kg. A threat
for marginally severe hail will continue with this activity, but
the biggest risk for be for locally heavy rainfall. Rain rates in
excess of 2 inches per hour have been observed, and flash flooding
has already been occurring in Union County.

Farther south, the atmosphere is quickly recovering over East
Texas and Louisiana south of Interstate 20. Mesoanalysis shows
instability has already built to between 2000-3000 J/kg. Combined
with the deep layer shear already in place, this will be more than
sufficient for severe convection later this afternoon.

The linear convective complex that extends from east of Austin TX,
south-southeast and off the coast near Matagorda Bay is expected
to lift northeast later this afternoon as a surface low rapidly
strengthens in Southeast Texas. The potential for a widespread
damaging wind event south of Interstate 20 this afternoon and into
this evening has increased. Thus, SPC has upgraded to an Enhanced
Risk of severe weather across that portion of our area in the
latest Day 1 Convective Outlook. The potential also exists for
embedded QLCS tornadoes, especially if surface winds become more
backed in response to the developing surface low.

PoPs were adjusted somewhat to better account for radar trends.
Some edits were also made to the temperature grids to better
account for the latest observations and some of the cooling
effects of ongoing convection.

CN

PREV DISCUSSION... /issued 525 AM CDT Sun Apr 7 2019/

SHORT TERM.../Sunday through Monday/

A huge range of 60s this morning with light and variable winds.
Skies are cloudy and less than half sites at this time are seeing
any patchy fog issue, mainly in E TX where rains have just lifted
across I-20 and continue Northward. We had some decent totals
yesterday with another 1 to 3 inches possible today and tonight.

The SPC continues a large slight risk area for today and hail
continues to be primary threat today and this evening. Tomorrow
their marginal area will lie over the Eastern edge of our cwa.
The models show the upper low flying right overhead with a weak
surface reflection focusing all the activity on the Eastern half.
Pollen continues to just give up. We will continue with near
average temps through Monday. /24/

LONG TERM.../Monday Night through Sunday/

Despite the semi-closed nature of the upper trough by tonight and
Monday, the majority of the progs have trended with a faster
movement of the low/trough into the Lower MS Valley Monday evening,
with the exception of the NAM, which is considerably slower with
the low over Wrn LA early Monday evening. Have trended more with a
blend of the models but a bit faster than the NAM (considering
consistency in the models for the past couple of days), with some
isolated -SHRA possibly lingering in the evening near the trough/low
center over Scntrl AR/Ern sections of Ncntrl LA. Thus, have re-
inserted slight chance pops for these areas Monday evening, before
drying/subsidence just behind the departing system should end any
residual -SHRA by 06Z Tuesday. Otherwise, a dry NW flow aloft will
commence late Monday night in wake of the departing trough, allowing
for drier air to spill SE into the region. Weak sfc ridging will
build into the region as well, with enhanced subsidence within the
dry air mass in place expected to result in above normal temps as
readings climb into the lower to mid 80s.

This sfc ridge should shift E of the region Tuesday night, with the
pressure gradient tightening across the Srn Plains and much of our
region Wednesday in response to deepening sfc cyclogenesis that will
occur over portions of Wrn and Cntrl KS ahead of an amplifying upper
trough that will cross the Rockies. Despite the increasing Srly low
level flow, moisture will be hard to come by, which should result in
much above normal temps by afternoon as they climb into the mid and
possibly upper 80s. The SWrly LLJ will persist Wednesday night which
should maintain sfc winds overnight and thus milder min temps, with
the low level moisture field finally beginning to deepen somewhat
after 12Z Thursday ahead of an associated cold front that will enter
extreme SE Ok/SW AR/NE TX after daybreak. The GFS/Canadian continue
to suggest that the potential for isolated convection developing by
afternoon just ahead of the cold front over Scntrl AR/much of N LA,
with the ECMWF finally on board with isolated convection developing
as well. Have maintained slight chance pops over these areas through
Thursday evening, with the front still expected to exit the region
by 06Z Friday. Cooler (more seasonal temps) and drier air will spill
SE in wake of the fropa, with sfc ridging expected to build S to the
coast Friday. SW flow aloft will persist in wake of the fropa
though, ahead of an amplifying longwave trough that will dig through
the Desert SW Saturday and into the Srn Rockies and eventually Srn
Plains Saturday night/Sunday. This should result in increasing
overrunning convection as it spreads NE across the region Saturday
through Sunday. For now, have carried mid chance pops areawide with
the potential for pops to be increased in subsequent forecasts.

/15/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  73  61  77  57 /  80  80  40  10
MLU  77  63  76  57 /  90  80  60  20
DEQ  74  59  78  51 /  50  60  30   0
TXK  73  60  77  55 /  70  70  40  10
ELD  76  60  75  54 /  80  80  60  20
TYR  70  60  78  56 /  80  70  30   0
GGG  71  60  79  55 /  80  70  30   0
LFK  73  61  79  57 /  90  80  30   0

&&

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

09/07

Hazardous Weather Outlook...UPDATED
National Weather Service Shreveport LA
128 PM CDT Sun Apr 7 2019

LAZ001>006-010>014-017>022-TXZ138-149>153-165>167-081100-
Caddo-Bossier-Webster-Claiborne-Lincoln-Union-De Soto-Red River-
Bienville-Jackson-Ouachita-Sabine-Natchitoches-Winn-Grant-
Caldwell-La Salle-Harrison-Cherokee-Rusk-Panola-Nacogdoches-
Shelby-Angelina-San Augustine-
128 PM CDT Sun Apr 7 2019

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

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

A Severe Thunderstorm Watch is in effect until 9 PM CDT tonight.

Thunderstorms are already ongoing across the area. This activity
will begin to increase as a complex of strong to severe
thunderstorms moves in from the south by late afternoon to early
evening. Damaging winds, large hail, and isolated tornadoes will
be the primary threats. In addition, locally heavy rainfall may
lead to isolated flash flooding. The severe weather threat will
gradually diminish late tonight. However, the threat for locally
heavy rainfall will linger through the overnight hours.

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

Showers and isolated thunderstorms will begin to diminish from
west to east Monday, as the storm system continues to shift east
out of the area. While much warmer and drier conditions are
expected for much of this week, showers and a few embedded
thunderstorms will increase across the region Saturday.

.SPOTTER INFORMATION STATEMENT...

Activation of emergency managers, spotter networks, and amateur
radio operators, will likely be needed during mainly the evening
hours.

ARZ060-061-070>073-TXZ112-126-136-137-081100-
Hempstead-Nevada-Miller-Lafayette-Columbia-Union-Cass-Marion-
Smith-Gregg-
128 PM CDT Sun Apr 7 2019

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

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

Thunderstorms are already ongoing across the area. This activity
will begin to increase as a complex of strong to severe
thunderstorms moves in from the south by late afternoon to early
evening. Damaging winds, large hail, and isolated tornadoes will
be the primary threats. In addition, locally heavy rainfall may
lead to isolated flash flooding. The severe weather threat will
gradually diminish late tonight. However, the threat for locally
heavy rainfall will linger through the overnight hours.

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

Showers and isolated thunderstorms will begin to diminish from
west to east Monday, as the storm system continues to shift east
out of the area. While much warmer and drier conditions are
expected for much of this week, showers and a few embedded
thunderstorms will increase across the region Saturday.

.SPOTTER INFORMATION STATEMENT...

Activation of emergency managers, spotter networks, and amateur
radio operators, will likely be needed during mainly the evening
hours.

ARZ050-051-059-OKZ077-TXZ096-097-108>111-124-125-081100-
Sevier-Howard-Little River-McCurtain-Red River-Bowie-Franklin-
Titus-Camp-Morris-Wood-Upshur-
128 PM CDT Sun Apr 7 2019

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

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

Widely scattered showers and thunderstorms across the area may
increase in coverage and intensity later in the day.
There will be a threat for isolated strong to severe
thunderstorms, consisting of strong to possible damaging winds,
large hail, and locally heavy rainfall. Where the heavier rains
move repeatedly over the same areas, isolated minor flooding
will be possible. Any severe weather or heavy rain threat will
diminish later this evening.

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

Showers and isolated thunderstorms will quickly diminish Monday
morning the parent storm system continues to shift east out of
the area. While much warmer and drier conditions are expected for
much of this week, showers and a few embedded thunderstorms will
increase across the region Saturday.

.SPOTTER INFORMATION STATEMENT...

Activation of emergency managers, spotter networks, and amateur
radio operators, are not anticipated at this time across the area
due to the isolated nature of any severe storms or heavy rain.

09

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
945 AM CDT SUN APR 7 2019

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

0708 AM     HAIL             7 SSE MARIETTA          33.08N 94.50W
04/07/2019  E1.00 INCH       CASS               TX   PUBLIC

            QUARTER SIZE HAIL FELL ABOUT 10 MILES
            NORTHEAST OF HUGHES SPRINGS. REPORT VIA
            FACEBOOK.

&&

15

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
953 AM CDT SUN APR 7 2019

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

0428 AM     HAIL             BERNICE                 32.82N 92.66W
04/07/2019  E0.75 INCH       UNION              LA   LAW ENFORCEMENT

            PENNY SIZE HAIL FELL IN BERNICE.

&&

15

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
1007 AM CDT SUN APR 7 2019

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

0841 AM     FLASH FLOOD      EL DORADO               33.22N 92.66W
04/07/2019                   UNION              AR   PUBLIC

            VIDEO OF FLASH FLOODING ON SOCIAL MEDIA.
            REPORTS OF MULTIPLE ROADS FLOODED.

&&

CN

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
1030 AM CDT SUN APR 7 2019

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

0930 AM     FLASH FLOOD      EL DORADO               33.22N 92.66W
04/07/2019                   UNION              AR   PUBLIC

            CORRECTS PREVIOUS FLASH FLOOD REPORT FROM EL
            DORADO. VIDEO OF FLASH FLOODING ON SOCIAL
            MEDIA. REPORTS OF MULTIPLE ROADS FLOODED.

&&

15

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
1043 AM CDT SUN APR 7 2019

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

1040 AM     FLASH FLOOD      5 SSE MAGNOLIA          33.20N 93.21W
04/07/2019                   COLUMBIA           AR   LAW ENFORCEMENT

            PORTIONS OF HIGHWAY 79 SOUTH OF MAGNOLIA ARE
            UNDERWATER. SEVERAL COUNTY ROADS ARE
            UNDERWATER. MAIN STREET AND DUDNEY STREET,
            AS WELL AS OTHER CITY STREETS IN MAGNOLA ARE
            FLOODED.

&&

15

Special Weather Statement
National Weather Service Shreveport LA
123 PM CDT Sun Apr 7 2019

ARZ073-LAZ004-006-071915-
Union AR-Union LA-Claiborne LA-
123 PM CDT Sun Apr 7 2019

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN UNION COUNTY...
NORTHWESTERN UNION AND NORTHEASTERN CLAIBORNE PARISHES UNTIL 215 PM
CDT...

At 122 PM CDT, Doppler radar was tracking a strong thunderstorm near
Homer, moving northeast at 15 mph.

Wind gusts up to 50 mph will be possible with this storm.

Locations impacted include...
Homer, Junction City, Lisbon, Lillie, Hew Hope, Three Creeks, Corney
Lake, Lockhart, Antioch, Summerfield and Lake Clairborne.

A Severe Thunderstorm Watch remains in effect until 900 PM CDT for
north central and northwestern Louisiana.

LAT...LON 3271 9288 3280 9308 3313 9294 3302 9257
TIME...MOT...LOC 1822Z 207DEG 13KT 3283 9295

Duplantis