Alert archive / Louisiana / Flash Flood Warnings in 2015

Flash Flood Warning 31, NWS Shreveport, LA

May 18, 20156 parishes in Louisiana; Sabine County, Shelby County, Texas

NWS Shreveport, LA issued this flash flood warning at May 18, 2015, 9:16 AM CDT for 6 parishes in Louisiana; Sabine County, Shelby County, Texas. It was in force for 4 hr. 4 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, 9:16 AM CDT (14:16 UTC)
Expired: May 18, 2015, 1:15 PM CDT
In force: 4 hr
Issued by: NWS Shreveport, LA
Area: Storm-based polygon
Flood severity: None

Counties De Soto Parish, LA, Grant Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Sabine Parish, LA, Winn Parish, LA, Sabine County, TX, Shelby County, TX

What was reported inside it

Time	Report	Where	Remark
May 18, 11:30 AM CDT	FLASH FLOOD	Dry Prong, LA	MULTIPLE ROADS WITH WATER OVER THEM... PARISH WIDE REPORTING 1015 - 115 TIMEFRAME
May 18, 12:04 PM CDT	HEAVY RAIN 5.4	1 Ne Natchitoches, LA	5.4 INCHES FELL BY 1204 PM.... 1.78 INCHES FROM 910 TO 945 AM
May 18, 12:49 PM CDT	FLASH FLOOD	2 W Jena, LA	WATER OVER MCCANN ROAD IN TROUT... HIGH WATER SIGNS ON SITE
May 18, 1:02 PM CDT	FLASH FLOOD	Converse, LA	HIGHWAY 171 NORTH AND SOUTH OF CONVERSE DOWN TO ONE LANE EACH DIRECTION DUE TO FLOODING.

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 3 storm reports to this flash flood warning; the first came 134 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 12:00Z, 2.3 hours before the alert went out and 137 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: 840 J/kg
Mixed-layer CIN: -50 J/kg
Mixed-layer LCL: 899 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 86 m²/s²
0-3 km storm-relative helicity: 105 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.6

Open this sounding in Storm Lab

The text

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

905 
WGUS54 KSHV 181416
FFWSHV
LAC031-043-059-069-085-127-TXC403-419-181815-
/O.NEW.KSHV.FF.W.0031.150518T1416Z-150518T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHERN WINN PARISH IN NORTH CENTRAL LOUISIANA...
  GRANT PARISH IN NORTH CENTRAL LOUISIANA...
  SABINE PARISH IN NORTHWESTERN LOUISIANA...
  LA SALLE PARISH IN NORTH CENTRAL LOUISIANA...
  SOUTH CENTRAL DE SOTO PARISH IN NORTHWESTERN LOUISIANA...
  NATCHITOCHES PARISH IN NORTHWESTERN LOUISIANA...
  EASTERN SHELBY COUNTY IN EASTERN TEXAS...
  NORTH CENTRAL SABINE COUNTY IN EASTERN TEXAS...

* UNTIL 115 PM CDT
    
* AT 915 AM CDT...DOPPLER RADAR INDICATED A THUNDERSTORM PRODUCING
  HEAVY RAIN ACROSS THE WARNED AREA. UP TO TWO INCHES OF RAIN HAVE
  ALREADY FALLEN. FLASH FLOODING IS EXPECTED TO BEGIN SHORTLY.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  NATCHITOCHES...MILAM...JENA...MANY...ZWOLLE...COLFAX...OLLA...
  MONTGOMERY...CONVERSE...PATROON...MIDWAY...SHELBYVILLE...OAK
  GROVE...URANIA...PLEASANT HILL...FLORIEN...PROVENCAL...NATCHEZ...
  POLLOCK AND DRY PRONG.

ADDITIONAL RAINFALL AMOUNTS OF TWO TO THREE INCHES ARE POSSIBLE IN 
THE WARNED AREA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

KEEP CHILDREN AWAY FROM STORM DRAINS...CULVERTS...CREEKS AND STREAMS.
WATER LEVELS CAN RISE RAPIDLY AND SWEEP CHILDREN AWAY.

PLEASE REPORT FLOODING TO YOUR LOCAL LAW ENFORCEMENT AGENCY WHEN YOU
CAN DO SO SAFELY.

&&

LAT...LON 3138 9212 3147 9216 3139 9266 3152 9272
      3135 9295 3136 9339 3133 9342 3166 9414
      3189 9400 3179 9313 3192 9201 3138 9201

$$

VII

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, 7:03 AM CDT, 2 hours 13 minutes earlier.

Area forecast discussion, May 18, 7:03 AM CDT, 2 hours 13 minutes before

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

.AVIATION...
TSTMS EXPECTED TO CONTINUE AT LEAST INTERMITTENTLY THROUGHOUT THE
PD...WITH N LA TERMINALS MOST PRONE TO BE AFFECTED. LOW CIGS/VSBYS
ALONG WITH GUSTY WINDS WILL BE POSSIBLE IN THE VC OF ANY
CONVECTION. AFTER 06Z...LIGHT WINDS AND MOIST SOILS FROM PREVIOUS
RAINS WILL ALLOW FOR SOME PATCHY FOG DEVELOPMENT...ESPECIALLY
WHERE CLOUDS ARE ABLE TO THIN OUT. ADDITIONALLY...PATCHY MVFR
STRATUS WILL BE POSSIBLE AT A FEW OF THE TERMINALS AS WELL.
OTHERWISE...EXPECT SLY WINDS LESS THAN 10 KTS THROUGHOUT THE PD.
/12/

&&

.PREV DISCUSSION... /ISSUED 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
PWATS...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.

&&

12

Hazardous weather outlook, May 18, 4:40 AM CDT, 4 hours 36 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

Local storm report, May 18, 8:51 AM CDT, 25 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
851 AM CDT MON MAY 18 2015

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

0640 AM     FLASH FLOOD      4 SW BROWNSVILLE-BAWCOM 32.44N  92.21W
05/18/2015                   OUACHITA           LA   BROADCAST MEDIA

            SUNSHINE ESTATES MOBILE HOME PARK FLOODED.

&&

EVENT NUMBER SHV1500478

20

Local storm report, May 18, 8:53 AM CDT, 23 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
853 AM CDT MON MAY 18 2015

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

0700 AM     HEAVY RAIN       4 NNW COLUMBIA          32.16N  92.10W
05/18/2015  M7.24 INCH       CALDWELL           LA   COCORAHS

            STILL RAINING.

&&

EVENT NUMBER SHV1500479

15

Local storm report, May 18, 8:57 AM CDT, 19 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
857 AM CDT MON MAY 18 2015

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

0800 AM     HEAVY RAIN       2 NW RUSTON             32.55N  92.66W
05/18/2015  M5.66 INCH       LINCOLN            LA   COCORAHS

            STILL RAINING.

&&

EVENT NUMBER SHV1500480

15

Local storm report, May 18, 8:58 AM CDT, 18 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
858 AM CDT MON MAY 18 2015

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

0755 AM     HEAVY RAIN       1 S BIENVILLE           32.35N  92.98W
05/18/2015  M4.44 INCH       BIENVILLE          LA   COCORAHS

            STILL RAINING.

&&

EVENT NUMBER SHV1500481

15

Local storm report, May 18, 9:02 AM CDT, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
902 AM CDT MON MAY 18 2015

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

0700 AM     HEAVY RAIN       10 SW WEST MONROE       32.41N  92.27W
05/18/2015  M4.21 INCH       OUACHITA           LA   COCORAHS

            COCORAHS STATION 4.3 MILES SOUTH SOUTHEAST OF THE
            COMMUNITY OF CALHOUN. STILL RAINING.

&&

EVENT NUMBER SHV1500482

15

Local storm report, May 18, 9:09 AM CDT, 7 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
909 AM CDT MON MAY 18 2015

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

0800 AM     FLASH FLOOD      4 SW BROWNSVILLE-BAWCOM 32.44N  92.21W
05/18/2015                   OUACHITA           LA   AMATEUR RADIO

            FLOODING AT THE INTERSECTION OF HWY 3033 AND TIDWELL
            ROAD. WATER FLOW NEAR 10 INCHES DEEP.

&&

EVENT NUMBER SHV1500483

20

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, 5:42 AM CDT	Flash Flood Warning	SHV	Caddo	93 min
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, 9:58 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
May 18, 5:08 AM CDT	Special Weather Statement	SHV	Harrison	52 min
May 18, 8:40 AM CDT	Flash Flood Warning	SHV	Angelina, Cherokee, Nacogdoches, San Augustine	3 hr
May 18, 10:08 AM CDT	Special Weather Statement	SHV	Sabine	52 min
May 18, 10:17 AM CDT	Special Weather Statement	SHV	Panola	43 min
May 18, 11:46 AM CDT	Flash Flood Warning	SHV	Angelina, Cherokee, Nacogdoches, San Augustine	119 min

Nearby

Flash Flood Warnings in Louisiana, 2015 Flash Flood Warnings in Texas, 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.