Flash Flood Warning 13, NWS Shreveport, LA

539 
WGUS74 KSHV 112005
FFSSHV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
305 PM CDT SUN JUL 11 2010

ARC099-112100-
/O.CON.KSHV.FF.W.0013.000000T0000Z-100711T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEVADA AR-
305 PM CDT SUN JUL 11 2010

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 400 PM CDT FOR
NEVADA COUNTY...

AT 302 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THAT MOST OF THE HEAVY RAINFALL HAS MOVED EASTWARD INTO OUACHITA 
COUNTY ARKANSAS. WHILE THE HEAVY RAINFALL HAS ENDED ACROSS NEVADA 
COUNTY...RUNOFF IS LIKELY NOT COMPLETE FROM THE EXCESSIVE HEAVY
RAINFALL THAT FELL ACROSS THE COUNTY EARLIER. THEREFORE...THE FLASH
FLOOD WARNING WILL CONTINUE UNTIL EXPIRATION. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ENCOUNTER FLOODED ROADWAYS...TURN AROUND...DON'T DROWN. TO 
REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN
SHREVEPORT.

&&

LAT...LON 3374 9347 3371 9311 3349 9311 3349 9347

$$

13

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
1134 AM CDT SUN JUL 11 2010

.DISCUSSION...
WATCHING A SUBTLE SHORTWAVE DROP SE ACROSS WRN AR/EXTREME SE OK/EXTREME
NE TX THIS MORNING PER WATER VAPOR LOOP...AROUND THE FLAT UPPER RIDGE
WHICH HAS ACTUALLY SHIFTED E A TAD INTO SW TX. CONSIDERABLE AC EXISTS
ACROSS ALL OF SW AR/EXTREME NRN LA AHEAD OF THIS APPROACHING
SHORTWAVE...WHICH HAS LIMITED THE WARMUP OVER THESE AREAS.
MEANWHILE...CU FIELD IS JUST NOW BEGINNING TO DEVELOP ACROSS E TX/N
LA...WHICH HAS RESULTED IN TEMPS WARMING TO THE UPPER 80S/NEAR 90
ALREADY AS OF 16Z. THIS HAS RESULTED IN A LARGE INSTABILITY AREA
DEVELOPING ACROSS THESE AREAS...WITH SFC BASED CAPES NEARING/EXCEEDING
2500 J/KG. SCT CONVECTION HAS ALREADY DEVELOPED ACROSS SE OK/SW AR
ALONG THE SHORTWAVE AXIS/ATTENDANT THETA-E RIDGE ITSELF...BUT AM
EXPECTING ADDITIONAL CONVECTION TO DEVELOP THIS AFTERNOON DURING PEAK
HEATING...ESPECIALLY AS IT TRAVERSES THE HIGHER INSTABILITY AXIS.
GIVEN THE VERY TROPICAL AIR MASS STILL IN PLACE PER THE 12Z KSHV
RAOB...WITH PW/S OF 2.28"...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE IN
THE STRONGER STORMS AS WELL. HOWEVER...THE 12Z SHORT TERM PROGS HAVE
BACKED OFF A BIT ON CONVECTIVE DEVELOPMENT...THUS CONFIDENCE IS NOT
HIGH ENOUGH TO INSERT MENTION IN THE FORECAST ATTM. WILL MAINTAIN
MENTION IN THE HWO FOR NOW...ALTHOUGH LOCALIZED FLOODING WILL BE
POSSIBLE ONCE AGAIN ESPECIALLY WHERE REDEVELOPMENT/TRAINING OCCURS.

ONLY MADE MINOR TWEAKS TO THE CURRENT FORECAST POPS...MAINLY TO LOWER
POPS A TAD ACROSS MCCURTAIN CO/ADJACENT SW AR...WHERE THE SHORTWAVE IS
PUSHING THROUGH ALREADY...AND ADDITIONAL CONVECTION WILL BE MORE
WIDELY SCATTERED AT BEST ONCE THE AIR MASS HAS TIME TO DESTABILIZE.
OTHERWISE...WILL MAINTAIN CHANCE POPS...WITH THE HIGHEST POPS OVER
SCNTRL AR/NCNTRL LA. ALSO MADE MINOR TWEAKS TO FORECAST MAX TEMPS PER
CURRENT TRENDS...MAINLY TO RAISE TEMPS A TAD OVER THE CURRENTLY CLOUD
FREE AREAS. DID INCLUDE HEAT INDEX MENTION AS WELL AS DEWPOINTS ARE
NOT MIXING OUT ATTM UNDER OUR CURRENT AIR MASS...WITH INDICES RANGING
FROM 100-106 DEGREES.

OTHERWISE...THE CURRENT FORECAST REMAINS ON TRACK.

UPDATE ALREADY OUT.

15

&&

.AVIATION...
WIDELY SCATTERED SHOWERS AND A FEW THUNDERSTORMS CONTINUE ACROSS
SOUTHERN AND SOUTHWEST ARKANSAS IN ASSOCIATION WITH A WEAK SHEAR
AXIS AND THETAE RIDGING. CLOUD COVER IS NOT AS PREVALENT TODAY AS
WAS THE CASE ON SATURDAY BUT MOISTURE REMAINS PLENTIFUL AS EVIDENT
FROM SHV 12Z SOUNDING. CURRENTLY SEEING VFR CEILINGS AOA 10KFT AT
MLU AND ELD TERMINALS WITH SCATTERED AC DECK ACROSS MOST OTHER
TERMINAL SITES. EXPECTING CU FIELD TO BEGIN DEVELOPING RAPIDLY OVER
THE NEXT HOUR AND GIVEN THE AMPLE HEATING EXPECTED TODAY...SHOULD
SEE SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS ACROSS
A LARGE PORTION OF THE AREA. BEST CHANCES FOR PRECIPITATION WILL BE
ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR OF NORTHEAST TEXAS AND
NORTHERN LOUISIANA WHICH INCLUDES MOST TERMINAL LOCATIONS. WILL KEEP
VFR CONDITIONS ACROSS THE REGION WITH THE UNDERSTANDING THAT WHEN AN
AIRPORT ENCOUNTERS CONVECTION...EXPECT BRIEF MVFR/IFR CONDITIONS
WITH BOTH CEILING AND VSBY. WIND GUSTS TO NEAR 30KTS WILL ALSO BE
POSSIBLE WITH THE STRONGER STORMS THIS AFTERNOON. /13/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  93  77  95  77  96 /  40  20  20  10  20
MLU  93  75  96  75  97 /  50  20  20  10  30
DEQ  89  72  93  74  93 /  50  20  20  40  30
TXK  90  75  94  76  94 /  40  20  20  30  30
ELD  89  74  95  75  96 /  50  20  20  20  30
TYR  95  75  94  75  94 /  30  10  20  20  20
GGG  94  74  95  76  95 /  30  10  20  20  20
LFK  96  74  96  75  96 /  20  10  20  10  20

&&

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

15/13

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SHREVEPORT LA
1215 PM CDT SUN JUL 11 2010

ARZ050-051-059>061-070>073-LAZ001>006-010>014-017>022-OKZ077-
TXZ096-097-108>112-124>126-136>138-149>153-165>167-121100-
SEVIER-HOWARD-LITTLE RIVER-HEMPSTEAD-NEVADA-MILLER-LAFAYETTE-
COLUMBIA-UNION AR-CADDO-BOSSIER-WEBSTER-CLAIBORNE-LINCOLN-
UNION LA-DE SOTO-RED RIVER-BIENVILLE-JACKSON-OUACHITA-SABINE LA-
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-SABINE TX-
1215 PM CDT SUN JUL 11 2010

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...

AN UPPER LEVEL DISTURBANCE OVER EXTREME SOUTHEAST OKLAHOMA...WESTERN
ARKANSAS...AND EXTREME NORTHEAST TEXAS...WILL SHIFT SOUTHEAST INTO
NORTHCENTRAL LOUISIANA AND EXTREME EASTERN TEXAS THIS AFTERNOON DURING
PEAK HEATING. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP AND
SPREAD EAST SOUTHEAST THIS AFTERNOON OVER THE AREA...BEFORE
DIMINISHING THIS EVENING WITH THE LOSS OF DAYTIME HEATING AND THE
DEPARTURE OF THE UPPER LEVEL DISTURBANCE. GIVEN THE VERY TROPICAL NATURE
OF THE AIR MASS IN PLACE THIS AFTERNOON...AND THE EXTENT OF INSTABILITY
PRESENT...ISOLATED STRONG STORMS WILL BE POSSIBLE...CAPABLE OF
PRODUCING WIND GUSTS UP TO 40 MPH...FREQUENT LIGHTNING...AND LOCALLY
HEAVY RAINFALL. ANY INSTANCES OF HEAVY RAINFALL WILL OCCUR OVER AREAS
THAT HAVE SEEN ONE TO TWO INCHES OF RAIN IN THE LAST WEEK...WITH
HOURLY RAIN RATES OF ONE TO IN EXCESS OF TWO INCHES POSSIBLE. ANY
PROLONGED HEAVY RAINFALL WILL QUICKLY RUNOFF...AND COULD RESULT IN
MINOR FLOODING OF LOW LYING...POOR DRAINAGE AREAS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY...

ANOTHER UPPER LEVEL DISTURBANCE WILL DROP SOUTHEAST ACROSS THE
SOUTHERN PLAINS MONDAY AFTERNOON AND NIGHT...TRIGGERING SCATTERED
SHOWERS AND THUNDERSTORMS MONDAY AFTERNOON ACROSS CENTRAL AND EASTERN
OKLAHOMA...AND INTO NORTHERN ARKANSAS. SOME OF THESE SHOWERS AND
THUNDERSTORMS MAY BUILD SOUTHEAST INTO EXTREME NORTHEAST TEXAS...SOUTHEAST
OKLAHOMA AND SOUTHWEST ARKANSAS MONDAY NIGHT AND TUESDAY MORNING. SOME
OF THESE STORMS MAY BE STRONG AND PRODUCE WIND GUSTS OF 40 TO 50 MPH...FREQUENT
LIGHTNING...AND LOCALLY HEAVY RAINFALL...BEFORE THEY BEGIN TO DIMINISH
TUESDAY MORNING. HOWEVER...ADDITIONAL REDEVELOPMENT WILL BE POSSIBLE
THROUGHOUT TUESDAY...AS THE UPPER LEVEL DISTURBANCE INTERACTS WITH
STRONG HEATING AND THE RESULTANT INSTABILITY...ESPECIALLY OVER EXTREME
EASTERN TEXAS...SOUTHERN ARKANSAS...AND NORTHERN LOUISIANA. THESE
SHOWERS AND THUNDERSTORMS SHOULD DIMINISH TUESDAY NIGHT WITH THE LOSS
OF HEATING.

AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION BY
MID TO LATE WEEK...RESULTING IN AN INCREASE IN THE HEAT...AND VERY
MINIMAL...IF ANY...ISOLATED SHOWERS AND THUNDERSTORMS.

.SPOTTER INFORMATION STATEMENT...

ACTIVATION OF EMERGENCY MANAGERS...SKYWARN NETWORKS...AND HAM RADIO
OPERATORS...MAY BE NEEDED THIS AFTERNOON FOR LOCALIZED INSTANCES OF
FLOODING THAT MAY OCCUR ACROSS EXTREME EASTERN TEXAS...SOUTHWEST
ARKANSAS...AND NORTH LOUISIANA.

15

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
837 AM CDT SUN JUL 11 2010

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

0424 PM     HEAVY RAIN       MARSHALL                32.54N 94.35W
07/10/2010  M2.10 INCH       HARRISON           TX   EMERGENCY MNGR

            RAINFALL OVER TWO INCHES IN A SHORT PERIOD OF TIME
            RESULTED IN HIGH WATER ACROSS PORTIONS OF TOWN. THE WATER
            CLOSED A FEW CITY STREETS IN USUAL FLOOD PRONE AREAS. ONE
            OF THESE INCLUDED WEST HOUSTON STREET.

&&

MBERRY

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
152 PM CDT SUN JUL 11 2010

ARZ061-111945-
NEVADA-
152 PM CDT SUN JUL 11 2010

...SIGNIFICANT WEATHER ADVISORY...

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A SIGNIFICANT
WEATHER ADVISORY...EFFECTIVE UNTIL 230 PM CDT...FOR THE FOLLOWING
COUNTY...

IN SOUTHWEST ARKANSAS...
     NEVADA...

INCLUDING THE FOLLOWING LOCATIONS...
     BLUFF CITY AND ROSSTON...

AT 152 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE
DETECTING A STRONG THUNDERSTORM NEAR ROSSTON...OR 13 MILES SOUTHEAST
OF PRESCOTT...MOVING EAST AT 25 MPH.

PEA SIZE HAIL...AND WINDS 40 TO 50 MPH ARE EXPECTED WITH THIS STORM.
EXPECT LOCALLY HEAVY RAINFALL AMOUNTS OF NEAR 2 INCHES PER HOUR WITH
THIS STORM AS WELL.

13