Alert archive / Louisiana / Special Weather Statements in 2015

Special Weather Statement, NWS New Orleans, LA

May 19, 2015West Feliciana Parish, Louisiana

NWS New Orleans, LA issued this special weather statement at May 19, 2015, 7:31 PM CDT for West Feliciana Parish, Louisiana. It was in force for 14 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
May 19, 2015, 7:31 PM CDT (00:31 UTC)
Expired
May 19, 2015, 7:45 PM CDT
In force
14 min
Issued by
NWS New Orleans, LA

County West Feliciana Parish, LA

The radar

The Ft Polk radar (KPOE), 125 km from the middle of the area, began a volume at 00:32 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 0.5 hours before the alert went out and 172 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-pSkew-T log-p diagram, Lake Charles Mun, LA at 00:00Z on 2015-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1640 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lake Charles Mun, LA at 00:00Z on 2015-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -25 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
1640 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
969 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-25 m²/s²
0-3 km storm-relative helicity
-14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

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What forecasters said that day

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

NWS New Orleans, LA wrote its last area forecast discussion before this special weather statement went out at May 19, 3:33 PM CDT, 3 hours 58 minutes earlier.

Area forecast discussion, May 19, 3:33 PM CDT, 3 hours 58 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
333 PM CDT TUE MAY 19 2015

.DISCUSSION...

A VERY SUMMER-LIKE PATTERN IS IN PLACE OVER THE CENTRAL GULF COAST
STATES WITH SEASONABLY WARM AND HUMID DAYS AND NO DAY BEING
COMPLETELY DRY ACROSS THE FORECAST AREA. THUNDERSTORM DEVELOPMENT
TODAY HAS BEEN FOCUSED SOUTH OF THE TIDAL LAKES. THUNDERSTORM
ACTIVITY WILL DECREASE SHORTLY AFTER DARK WITH LOSS OF DAYTIME
HEATING. TONIGHT...WITH CALM WINDS...PATCHY FOG MAY DEVELOP AFTER
MIDNIGHT WITH MOS GUIDANCE SHOWING 1 MILE AT KMCB. AFTER THE FOG
DISSIPATES...DAYTIME HEATING ON WEDNESDAY SHOULD ALSO GENERATE
ISOLATED THUNDERSTORMS FOCUSED ON SEA BREEZE BOUNDARIES. ONCE
AGAIN...WE WILL BE WATCHING FOR FOG TO DEVELOP EARLY THURSDAY
MORNING WITH SREF PROBABILITIES HIGHEST OVER SOUTHWEST MISSISSIPPI AND
SOUTHEAST LOUISIANA.

ON THURSDAY...UPPER LEVEL ENERGY ALONG WITH A SLOW SOUTHWARD MOVING
COLD FRONT WILL PROVIDE FOR A BETTER OPPORTUNITY FOR THUNDERSTORMS
OVER THE AREA. PRECIPITABLE WATER VALUES WILL RANGE FROM 1.5 TO 2.0
INCHES AND WITH RECENT RAINFALL MAY HAVE TO BE MINDFUL OF SOME OF
THE RIVER LEVELS. SCATTERED THUNDERSTORMS WILL REMAIN IN THE
FORECAST AS THE FRONT STALLS OVER THE AREA FRIDAY AND LIFTS BACK
NORTHWARD ON SATURDAY AND SUNDAY. AS WE GET INTO NEXT WORK
WEEK...UPPER LEVEL DISTURBANCE SHOULD PROMOTE SCATTERED
THUNDERSTORMS AS IT APPROACHES THE AREA ON MONDAY AND SLOWLY CROSS
THE AREA TUESDAY AND WEDNESDAY.

ANSORGE

&&

.AVIATION...

MUCH LESS CONVECTION TODAY COMPARED THE THE LAST FEW. THE MAJORITY
OF STORMS THIS AFTERNOON ARE ALONG AND SOUTH OF INTERSTATE 10.
NEW/MSY AND HUM THE MOST LIKELY TO SEE IMPACTS WITH VIS DROPPING
DOWN TO 1-2 MILES DURING THE MOST INTENSE STORMS. ACTIVITY SHOULD
BEGIN TO WANE AROUND SUNSET WITH LITTLE TO NO RAIN OVERNIGHT. WILL
BRING CEILINGS BACK IN OVERNIGHT TONIGHT AT AROUND 300 TO 500 FEET
AFTER 06Z WITH THE POTENTIAL FOR LIGHT TO POSSIBLY MODERATE FOG.

MEFFER

&&

.MARINE...

RATHER LIGHT WIND REGIME THE NEXT DAY OR SO OVER MUCH OF
THE COASTAL WATERS BUT A WEAK NOCTURNAL JET OVER THE MS SOUND AND
JUST TO THE SOUTH WILL LIKELY DEVELOP THE NEXT FEW NIGHTS WITH
WINDS AROUND 10 KTS. BY FRI HIGH PRESSURE WILL GENERALLY BE IN
CONTROL WITH LIGHT WINDS AGAIN. THERE WILL BE A WEAK NRLY
COMPONENT AS A WEAK FRONT TRIES TO PUSH INTO THE COASTAL WATERS.
HIGH PRESSURE WILL QUICKLY SHIFT EAST AND MODERATE ONSHORE FLOW
WILL DEVELOP THIS WEEKEND. /CAB/

&&

.DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...NONE.

DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN  = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE   = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
         VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
         WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
         TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED    = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
         TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  68  87  70  85 /  40  30  20  50
BTR  71  88  71  87 /  40  30  20  40
ASD  72  87  72  86 /  20  30  20  40
MSY  73  88  73  87 /  30  30  20  40
GPT  73  86  74  86 /  20  30  20  40
PQL  72  86  73  86 /  20  30  20  40

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.

&&
Hazardous weather outlook, May 19, 6:34 PM CDT, 57 minutes before
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In the hours before

Special weather statement, May 19, 3:33 PM CDT, 3 hours 58 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
333 PM CDT TUE MAY 19 2015

LAZ056-057-059-065-192115-
ASSUMPTION LA-ST. JAMES LA-UPPER LAFOURCHE LA-UPPER TERREBONNE LA-
333 PM CDT TUE MAY 19 2015

...SPECIAL WEATHER STATEMENT...

AT 333 PM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR
SCHRIEVER...OR NEAR THIBODAUX...MOVING NORTH AT 5 MPH.

HALF INCH HAIL AND WINDS IN EXCESS OF 30 MPH WILL BE POSSIBLE WITH
THIS STORM.

LOCATIONS IMPACTED INCLUDE...
THIBODAUX...LABADIEVILLE...SOUTH VACHERIE...SUPREME...CHACKBAY...
SCHRIEVER AND GRAY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

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.

&&

LAT...LON 3003 9099 2992 9067 2989 9066 2990 9063
      2988 9061 2989 9059 2987 9053 2962 9097
      2977 9107
TIME...MOT...LOC 2033Z 192DEG 5KT 2975 9090
Special weather statement, May 19, 5:50 PM CDT, 1 hour 41 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
550 PM CDT TUE MAY 19 2015

LAZ048-192315-
EAST BATON ROUGE-
550 PM CDT TUE MAY 19 2015

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL EAST BATON ROUGE
PARISH...

AT 550 PM CDT...A STRONG THUNDERSTORM WAS OVER PORT ALLEN...MOVING
NORTHEAST AT 5 MPH.

WINDS IN EXCESS OF 30 MPH AND PEA SIZE HAIL ARE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
BATON ROUGE...ZACHARY...BAKER...PORT ALLEN...BROWNFIELDS...
MERRYDALE...MONTICELLO AND BATON ROUGE AIRPORT.

LAT...LON 3066 9121 3053 9098 3049 9097 3043 9118
      3044 9120 3051 9120 3052 9121 3052 9122
TIME...MOT...LOC 2250Z 213DEG 5KT 3047 9118

24/RR
Local storm report, May 19, 7:29 PM CDT, 2 minutes before
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Special weather statement, May 19, 7:31 PM CDT, 0 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
May 20, 1:20 PM CDTSpecial Weather StatementLIXEast Baton Rouge, East Feliciana40 min
May 20, 1:59 PM CDTSpecial Weather StatementLIXAscension31 min
May 20, 2:26 PM CDTSpecial Weather StatementLIXHarrison34 min
May 20, 3:00 PM CDTSpecial Weather StatementLIXPike30 min
May 20, 3:02 PM CDTSpecial Weather StatementLIXHarrison28 min

Nearby

Special Weather Statements in Louisiana, 2015Every special weather statement 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.