Flash Flood Warning 40, NWS Shreveport, LA

Area Forecast Discussion
National Weather Service Shreveport LA
820 PM CDT Sat Sep 22 2018

.UPDATE...

Still looking at a large upper level trough spinning across North
Central Texas late this evening. A cold front in association with
this trough was located near or just south of the Arkansas/
Louisiana border to near Mount Pleasant and the DFW Metroplex.
This front may drift a little further south, closer to the I-20
Corridor later tonight but that should just about be it.
Temperatures north of the front are falling a little too close to
fcst min temps so have shaved these #s a little more than
previously thought. The rainfall north of the front will be mostly
light but given the shallow nature of the cooler air in the wake
of the front, cannot rule out some more moderate rainfall
developing overnight across the Flash Flood Watch area.

Given the very tropical nature of the moisture currently in place
ahead of the upper level trough to our west, any organized cells
can produce very heavy rainfall rates, as was the case earlier
this afternoon across Shreveport where we saw rainfall in excess
of 3 inches of rain in less than one hour with numerous urban
flooding reports. These isolated heavier tropical downpours will
be more likely along the frontal boundary itself so for this
reason, will not make any changes to the current Flash Flood Watch
along the I-20 Corridor.

Update out shortly...13.

&&

.PREV DISCUSSION... /issued 527 PM CDT Sat Sep 22 2018/

AVIATION...

Another mix of ceilings across our airspace this evening ranging
from LIFR to VFR. The lower ceilings appear to be north of the
I-20 Corridor, effecting the TXK/ELD terminals where very light
rain continues. Further south towards the corridor, ceilings are
mostly MVFR across NE TX to VFR east of the SHV terminal or
towards the MLU terminal. The same could be said for the LFK
terminal where ceilings are currently VFR. After sunset, we should
see VFR ceilings quickly become at least MVFR and have made note
of this in the 00z TAF package. Feel like LIFR/IFR ceilings should
stay there through the remainder of the night with on and off
light rain continuing.

Have removed mention of VCTS or TSRA from this TAF package as we
have just not had much in the way of lighting today. Instead, have
prevailing light to moderate SHRA through much of the 24 hour TAF
period and tried to trend a slight improvement in ceilings for
most terminals by Sunday Afternoon.

The TXK/ELD terminals should see NE winds overnight less than
10kts while terminals along and south of the I-20 Corridor should
see variable to SE winds less than 10kts overnight.

13

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  71  80  71  86 /  80  70  50  40
MLU  72  81  72  87 /  50  70  50  50
DEQ  64  72  67  82 /  80  80  50  40
TXK  64  73  68  82 /  80  80  50  40
ELD  66  74  69  85 /  80  70  50  50
TYR  71  78  70  85 /  80  70  40  20
GGG  71  79  70  85 /  80  70  50  20
LFK  73  82  71  88 /  80  70  50  20

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...Flash Flood Watch until 7 AM CDT Sunday for ARZ050-051-059>061-
     070>073.

LA...Flash Flood Watch until 7 AM CDT Sunday for LAZ001>004.

OK...Flash Flood Watch until 7 AM CDT Sunday for OKZ077.

TX...Flash Flood Watch until 7 AM CDT Sunday for TXZ096-097-108>112-
     124>126-136>138.

&&

13/13

Hazardous Weather Outlook
National Weather Service Shreveport LA
735 AM CDT Sat Sep 22 2018

ARZ070>073-LAZ001>006-010>014-017>022-TXZ112-124>126-136>138-
149>153-165>167-231100-
Miller-Lafayette-Columbia-Union-Caddo-Bossier-Webster-Claiborne-
Lincoln-De Soto-Red River-Bienville-Jackson-Ouachita-Sabine-
Natchitoches-Winn-Grant-Caldwell-La Salle-Cass-Wood-Upshur-Marion-
Smith-Gregg-Harrison-Cherokee-Rusk-Panola-Nacogdoches-Shelby-
Angelina-San Augustine-
735 AM CDT Sat Sep 22 2018

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...Today and Tonight...

Scattered to numerous showers and thunderstorms will develop and
spread over the area during the day and into the night with a
surface low pressure system along a nearly stationary cold front
across North Louisiana and into North Texas. A few storms will
produce strong gusty winds along with locally heavy rainfall. Some
Flooding in low lying areas will be possible, especially across
Southeast Oklahoma and parts of Northeast Texas into Southwest
Arkansas and to a lessor extent minor flooding across North
Louisiana. No organized hazardous weather is expected.

.DAYS TWO THROUGH SEVEN...Sunday through Friday...

A nearly stationary frontal boundary will linger over the
region through the late weekend before lifting back to the
Northeast on Monday as a warm front. Another cold front will move
into the region near mid week followed by another cold front on
Friday. These frontal systems along with disturbances aloft and
available and deep moisture will provide the area with scattered
to numerous showers and thunderstorms. Thunderstorms will be
capable of producing gusty winds and locally heavy rainfall.
Some of the heavier totals of rainfall will be over Northeast
Texas, Southeast Oklahoma, and parts of Southwest Arkansas.
With repeated development of convection ponding of water in
streets and low lying areas and at low water crossings will be
possible. No organized hazardous weather is expected.

.SPOTTER INFORMATION STATEMENT...

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

ARZ050-051-059>061-OKZ077-TXZ096-097-108>111-231100-
Sevier-Howard-Little River-Hempstead-Nevada-McCurtain-Red River-
Bowie-Franklin-Titus-Camp-Morris-
735 AM CDT Sat Sep 22 2018

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

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

...FLASH FLOOD WATCH IN EFFECT THROUGH SATURDAY AFTERNOON...

Scattered to numerous showers and thunderstorms will develop and
spread over the area during the day and into the night with a
surface low pressure system along a nearly stationary cold front
across North Louisiana and into North Texas. Two to five inches
has already occurred and another two to four inches can occur. A
few storms will produce strong gusty winds along with locally
heavy rainfall. Some Flooding in low lying, poor drainage, and low
water crossings will be possible with heavy rainfall training
over the same locations across Southeast Oklahoma and parts of
Northeast Texas into Southwest Arkansas. No organized hazardous
weather is expected.

.DAYS TWO THROUGH SEVEN...Sunday through Friday...

Flash flooding will remain possible across portions of Southeast
Oklahoma and parts of southwest Arkansas and Northeast Texas.
Rainfall totals up to 5 to 7 inches will be possible by the end of
the weekend A nearly stationary frontal boundary will linger over
the region before lifting back to the Northeast on Monday as a
warm front. Another cold front will move into the region near mid
week followed by another cold front on Friday. These frontal
systems along with disturbances aloft and available and deep
moisture will provide the area with scattered to numerous showers
and thunderstorms. Thunderstorms will be capable of producing
gusty winds and locally heavy rainfall. With repeated development
of convection, ponding of water in streets and low lying areas and
at low water crossings will be possible through mid week.

.SPOTTER INFORMATION STATEMENT...

Activation of emergency management personnel, amateur radio
operators, and storm spotters will not be needed through tonight
for severe weather but may be required for high water and
flooding.

06

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
726 PM CDT SAT SEP 22 2018

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

0725 PM     FLASH FLOOD      3 WSW BOSSIER CITY      32.51N 93.76W
09/22/2018                   CADDO              LA   LAW ENFORCEMENT

            FLOODING REPORTED CADDO ST AT COMMON NEAR
            DOWNTOWN SHREVEPORT.

&&

25

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
740 PM CDT SAT SEP 22 2018

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

0737 PM     FLASH FLOOD      3 ENE SHREVEPORT        32.48N 93.75W
09/22/2018                   CADDO              LA   NWS EMPLOYEE

            FLOODING REPORTED, STREET CLOSED AT ST
            VINCENT AVENUE AND FAIRFIELD KINGS.

&&

25

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
748 PM CDT SAT SEP 22 2018

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

0747 PM     FLASH FLOOD      3 WNW BOSSIER CITY      32.54N 93.77W
09/22/2018                   CADDO              LA   LAW ENFORCEMENT

            FLOODING REPORTED AT NORTH HEARNE AND NORTH
            MARKET.

&&

25

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
750 PM CDT SAT SEP 22 2018

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

0749 PM     FLASH FLOOD      3 NNE SHREVEPORT        32.51N 93.77W
09/22/2018                   CADDO              LA   LAW ENFORCEMENT

            STREET FLOODING AT NORMA AND PERRIN IN
            SHREVEPORT.

&&

25

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
801 PM CDT SAT SEP 22 2018

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

0800 PM     FLASH FLOOD      4 WSW SHREVEPORT        32.45N 93.87W
09/22/2018                   CADDO              LA   LAW ENFORCEMENT

            FLOODING REPORTED PINES ROAD AREA NEAR I-20.

&&

25

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
815 PM CDT SAT SEP 22 2018

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

0814 PM     FLASH FLOOD      3 E SHREVEPORT          32.47N 93.74W
09/22/2018                   CADDO              LA   LAW ENFORCEMENT

            FLOODING REPORTED HIGHLAND AVENUE AND DUDLEY
            IN SHREVEPORT.

&&

25