Alert archive / Louisiana / Flash Flood Warnings in 2015

Flash Flood Warning 26, NWS Shreveport, LA

May 18, 2015Caddo Parish, Louisiana

NWS Shreveport, LA issued this flash flood warning at May 18, 2015, 5:42 AM CDT for Caddo Parish, Louisiana. It was in force for 93 min. 5 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: May 18, 2015, 5:42 AM CDT (10:42 UTC)
Expired: May 18, 2015, 7:15 AM CDT
In force: 93 min
Issued by: NWS Shreveport, LA
Area: Storm-based polygon
Flood severity: None

County Caddo Parish, LA

What was reported inside it

Time	Report	Where	Remark
May 18, 5:45 AM CDT	FLASH FLOOD	5 N Stonewall, LA	FLOODING IN STREETS AND HOMES KEITHVILLE-KINGSTON RD ON DOMINO DR
May 18, 5:50 AM CDT	FLASH FLOOD	6 Se Shreveport, LA	STREET FLOODING AT MANY LOCATIONS ACROSS THE UNIVERSITY TERRACE SECTIONS OF SE SHREVEPORT.
May 18, 6:30 AM CDT	FLASH FLOOD	Shreveport, LA	1.5-2 FEET OF WATER OVER THE SIDE STREETS OFF OF WILLIAMSON WAY IN FAR SOUTH SHREVEPORT.
May 18, 7:00 AM CDT	FLASH FLOOD	Shreveport, LA	THE ENTRANCE RAMP FROM WEST 70TH STREET ONTO HIGHWAY 3132 WEST NEAR THE NWS OFFICE IS CLOSED DUE TO 1-2 FEET OF WATER OVER THE ROADWAY.
May 18, 7:00 AM CDT	HEAVY RAIN 4.16	Shreveport, LA	24 HOUR RAINFALL FROM A COCORAHS STATION OFF OF WILLIAMSON WAY IN FAR SOUTH SHREVEPORT. 4.02 INCHES OF THIS TOTAL FELL BETWEEN 130-630 AM THIS MORNING.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 5 storm reports to this flash flood warning; the first came 3 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Shreveport, LA (KBAD), launched 00:00Z, 10.7 hours before the alert went out and 4 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 445 J/kg
Mixed-layer CIN: -87 J/kg
Mixed-layer LCL: 956 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: -2 m²/s²
0-3 km storm-relative helicity: -41 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

198 
WGUS54 KSHV 181042
FFWSHV
LAC017-181215-
/O.NEW.KSHV.FF.W.0026.150518T1042Z-150518T1215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
542 AM CDT MON MAY 18 2015

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHWESTERN CADDO PARISH IN NORTHWESTERN LOUISIANA...

* UNTIL 715 AM CDT
    
* AT 541 AM CDT...DOPPLER RADAR INDICATED A THUNDERSTORM PRODUCING
  HEAVY RAIN ACROSS THE WARNED AREA. FLASH FLOODING IS EXPECTED.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  SHREVEPORT...GREENWOOD...SPRING RIDGE...FORBING...KEITHVILLE AND
  CROSS LAKE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING.

TURN AROUND...DONT DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD
DEATHS OCCUR IN VEHICLES.

&&

LAT...LON 3247 9403 3258 9377 3257 9375 3255 9377
      3255 9373 3254 9373 3254 9377 3248 9369
      3246 9370 3242 9367 3242 9369 3240 9369
      3239 9366 3241 9366 3234 9365 3233 9374
      3235 9377 3233 9381 3231 9404

$$

12

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Shreveport, LA wrote its last area forecast discussion before this flash flood warning went out at May 18, 4:04 AM CDT, 1 hour 38 minutes earlier.

Area forecast discussion, May 18, 4:04 AM CDT, 1 hour 38 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
404 AM CDT MON MAY 18 2015

.DISCUSSION...
THUNDERSTORMS CONTINUE TO DEVELOP OVER DEEP EAST TEXAS INTO
NORTHWEST LOUISIANA THIS MORNING ALONG A STALLED OUTFLOW BOUNDARY.
EXPECT BRIEF GUSTY WIND AND VERY HEAVY RAIN...BUT STORMS SHOULD
REMAIN BELOW SEVERE LIMITS. MAIN PROBLEM WILL BE FLASH FLOODING...
AS RAINFALL RATES EXPECTED TO REACH 2 INCHES AN HOUR DUE TO HIGH
PWS...COMBINED WITH TRAINING OF STORMS OVER THE STALLED BOUNDARY.
HAVE EXTENDED THE FFA THROUGH 00Z...AND ADDED SOME SOUTHERN ZONES
AS THE BOUNDARY SAGS SOUTH BY THE AFTERNOON. WILL ALSO CANCEL SOME
NORTHERN ZONES DUE TO THE SCATTERED NATURE OF EXPECTED CONVECTION
IN THIS AREA TODAY.

TONIGHT...RAINFALL SHOULD TAPER OFF WITH ONLY SCATTERED ACTIVITY
EXPECTED TUESDAY AS SLIGHT RIDGING DEVELOPS OVER THIS REGION. THEN
BY LATE TUESDAY AFTERNOON INTO TUESDAY NIGHT...ANOTHER SHORTWAVE
MOVING INTO THE RED RIVER VALLEY WILL BRING ANOTHER ROUND OF SHOWERS
AND TSTMS.

BY LATE WEEK...ANOTHER LOW WILL FOLLOW THE EARLY WEEK SYSTEM...MOVING
INTO CA BY FRIDAY. THIS SYSTEM WILL TRACK NE INTO THE NORTHERN PLAINS
BY EARLY NEXT WEEK. THIS WILL RESULT IN CONTINUED SW FLOW ALOFT
OVER THE REGION AND A PACIFIC MOISTURE FETCH THROUGH THE REMAINDER
OF THE SEVEN DAY FORECAST. TEMPERATURES THROUGHOUT THE PERIOD WILL
REMAIN FAIRLY CONSISTENT...WITH LOWS IN THE 60S TO LOWER 70S AND HIGHS
IN THE 80S. MAIN INFLUENCE ON DAILY TEMPERATURES WILL CONTINUE BE
THE CLOUDS AND RAIN.

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  81  69  85  70 /  80  30  30  30
MLU  81  68  85  70 /  80  30  40  30
DEQ  83  66  81  67 /  40  30  30  30
TXK  82  67  82  67 /  70  30  30  30
ELD  79  67  83  68 /  80  30  30  30
TYR  82  69  83  70 /  60  20  30  20
GGG  81  68  84  69 /  70  20  30  20
LFK  82  70  85  71 /  80  20  40  20

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH THIS EVENING FOR ARZ072-073.

LA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR LAZ001>006-010>014-
     017>022.

OK...NONE.
TX...FLASH FLOOD WATCH THROUGH THIS EVENING FOR TXZ136>138-149>153-
     165>167.

&&

14

Hazardous weather outlook, May 18, 4:40 AM CDT, 1 hour 2 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SHREVEPORT LA
440 AM CDT MON MAY 18 2015

ARZ050-051-059>061-070-071-OKZ077-TXZ096-097-108>112-124>126-
181700-
SEVIER-HOWARD-LITTLE RIVER-HEMPSTEAD-NEVADA-MILLER-LAFAYETTE-
MCCURTAIN-RED RIVER-BOWIE-FRANKLIN-TITUS-CAMP-MORRIS-CASS-WOOD-
UPSHUR-MARION-
440 AM CDT MON MAY 18 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
ARKANSAS...SOUTHEAST OKLAHOMA AND NORTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT...

THERE IS A CHANCE OF THUNDERSTORMS ACROSS THE AREA TODAY AND
TONIGHT. SEVERE STORMS ARE NOT EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...

THUNDERSTORM CHANCES WILL CONTINUE ACROSS THE AREA THROUGH SUNDAY.
NO WIDESPREAD SEVERE WEATHER IS EXPECTED.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

ARZ072-073-LAZ001>006-010>014-017>022-TXZ136>138-149>153-165>167-
181700-
COLUMBIA-UNION-CADDO-BOSSIER-WEBSTER-CLAIBORNE-LINCOLN-DE SOTO-
RED RIVER-BIENVILLE-JACKSON-OUACHITA-SABINE-NATCHITOCHES-WINN-
GRANT-CALDWELL-LA SALLE-SMITH-GREGG-HARRISON-CHEROKEE-RUSK-PANOLA-
NACOGDOCHES-SHELBY-ANGELINA-SAN AUGUSTINE-
440 AM CDT MON MAY 18 2015

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...

NUMEROUS SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP OVER
THE AREA AND SPREAD NORTHEAST TODAY. HEAVY RAINFALL AND LOCALLY
GUSTY WINDS WILL BE POSSIBLE WITH THE STRONGER STORMS. THE MAIN
HAZARD WILL BE FLASH FLOODING...WITH ADDITIONAL RAINFALL AMOUNTS
OF ONE TO THREE INCHES POSSIBLE IN A SHORT PERIOD OF TIME.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...

THUNDERSTORM CHANCES WILL CONTINUE ACROSS THE AREA THROUGH SUNDAY.
NO WIDESPREAD SEVERE WEATHER IS EXPECTED.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS POSSIBLE TODAY...MAINLY DUE TO FLOODING.

In the hours before

Special weather statement, May 18, 5:08 AM CDT, 34 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
508 AM CDT MON MAY 18 2015

TXZ138-150-151-181100-
RUSK TX-HARRISON TX-PANOLA TX-
508 AM CDT MON MAY 18 2015

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN RUSK...EASTERN
HARRISON AND NORTHWESTERN PANOLA COUNTIES UNTIL 600 AM CDT...

AT 507 AM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM OVER
TATUM...OR 15 MILES NORTHWEST OF CARTHAGE...MOVING NORTHEAST AT 40
MPH.

NICKEL SIZE HAIL AND WIND GUSTS UP TO 50 MPH WILL BE POSSIBLE WITH
THIS STORM.

LOCATIONS IMPACTED INCLUDE...
MARSHALL...WASKOM...TATUM...BECKVILLE...ELYSIAN FIELDS...KARNACK...
SCOTTSVILLE...JONESVILLE...LEIGH...DARCO AND STEWART.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

&&

LAT...LON 3270 9419 3251 9404 3238 9405 3217 9459
      3229 9468
TIME...MOT...LOC 1007Z 236DEG 33KT 3229 9455

12

The office that day

Everything else NWS Shreveport, LA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 17, 7:55 PM CDT	Special Weather Statement	SHV	Ouachita	65 min
May 17, 8:13 PM CDT	Areal Flood Advisory	SHV	Caldwell, Grant, LaSalle, Ouachita, Union	3 hr
May 18, 3:21 AM CDT	Flash Flood Warning	SHV	Bossier, Caddo, De Soto, Webster	2 hr
May 18, 6:02 AM CDT	Flash Flood Warning	SHV	Bienville, Caldwell, Jackson, Lincoln, Ouachita	3 hr
May 18, 6:52 AM CDT	Special Weather Statement	SHV	Natchitoches	38 min
May 18, 7:13 AM CDT	Flash Flood Warning	SHV	Bienville, Caldwell, Jackson, Natchitoches, Red River, Winn	3 hr
May 18, 8:21 AM CDT	Special Weather Statement	SHV	Natchitoches	54 min
May 18, 8:59 AM CDT	Flash Flood Warning	SHV	Bienville, Caldwell, Jackson, Lincoln, Ouachita	2 hr
May 18, 9:16 AM CDT	Flash Flood Warning	SHV	De Soto, Grant, LaSalle, Natchitoches, Sabine, Winn	4 hr
May 18, 9:58 AM CDT	Special Weather Statement	SHV	Natchitoches	47 min
May 18, 10:28 AM CDT	Flash Flood Warning	SHV	Bienville, Bossier, Caddo, De Soto, Jackson, Natchitoches and 4 more	4 hr
May 18, 10:37 AM CDT	Flash Flood Warning	SHV	Caldwell, Jackson, LaSalle, Winn	3 hr
May 18, 10:57 AM CDT	Areal Flood Advisory	SHV	Bienville, Caldwell, Jackson, Lincoln, Ouachita, Union	3 hr
May 18, 11:15 AM CDT	River Flood Warning	SHV	Bienville, Bossier, Caddo, Natchitoches, Red River	47 days
May 18, 11:15 AM CDT	River Flood Warning	SHV	Grant, Natchitoches, Red River	49 days
May 18, 11:21 AM CDT	River Flood Warning	SHV	Bienville, Bossier, Red River, Webster	12 days
May 18, 11:43 AM CDT	River Flood Warning	SHV	Caldwell, Grant, LaSalle, Winn	9 days
May 18, 1:14 PM CDT	Flash Flood Warning	SHV	De Soto, Grant, LaSalle, Natchitoches, Sabine, Winn	2 hr
May 18, 1:29 PM CDT	Flash Flood Warning	SHV	Caldwell, Jackson, LaSalle, Winn	3 hr
May 18, 1:34 PM CDT	River Flood Warning	SHV	De Soto	11 days
May 18, 3:27 PM CDT	Areal Flood Advisory	SHV	Caldwell, Grant, LaSalle	2 hr

Nearby

Flash Flood Warnings in Louisiana, 2015 Every flash flood warning in 2015

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive.