Alert archive / Louisiana / Flash Flood Warnings in 2004

Flash Flood Warning 39, NWS New Orleans, LA

October 10, 2004Lafourche Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Oct 10, 2004, 6:25 AM CDT for Lafourche Parish, Louisiana. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Oct 10, 2004, 6:25 AM CDT (11:25 UTC)
Expired
Oct 10, 2004, 10:30 AM CDT
In force
4 hr
Issued by
NWS New Orleans, LA
Area
Counties, with a storm outline in the text

County Lafourche Parish, LA

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

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

Slidell Radar S, LA (KSIL), launched 00:00Z, 11.4 hours before the alert went out and 102 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, Slidell Radar S, LA at 00:00Z on 2004-10-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 330 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, Slidell Radar S, LA at 00:00Z on 2004-10-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 78 square meters per square second.19395878Sfc1 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
330 J/kg
Mixed-layer CIN
-54 J/kg
Mixed-layer LCL
521 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
78 m²/s²
0-3 km storm-relative helicity
125 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.2

Open this sounding in Storm Lab

The text

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

000 
WGUS54 KLIX 101128
FFWNEW
LAC057-101530-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
625 AM CDT SUN OCT 10 2004

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  LAFOURCHE PARISH IN SOUTHEAST LOUISIANA
  THIS INCLUDES THE CITY OF LAROSE

* UNTIL 1030 AM CDT

* AT 620 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  FLASH FLOODING FROM A THUNDERSTORM NEAR LAROSE...OR ABOUT OVER
  LAROSE...MOVING NORTH AT 25 MPH.

* THE STORM PRODUCING FLASH FLOODING WILL OTHERWISE REMAIN OVER
  MAINLY RURAL AREAS OF THE INDICATED PARISH.

ADDITIONAL RAINFALL AMOUNTS OF 2 TO 3 INCHES ARE POSSIBLE IN THE 
WARNED AREA.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY.
MOVE TO HIGHER GROUND.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN NEW
ORLEANS.

LAT...LON 2950 9047 2950 9037 2969 9031 2971 9049

$$

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 New Orleans, LA wrote its last area forecast discussion before this flash flood warning went out at Oct 10, 3:56 AM CDT, 2 hours 29 minutes earlier.

Area forecast discussion, Oct 10, 3:56 AM CDT, 2 hours 29 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS/BATON ROUGE LA
345 AM SUN OCT 10 2004

.DISCUSSION
NOT MUCH CHANGE TO THE FORECAST PACKAGE THIS MORNING.  TROPICAL
STORM MATTHEW CONTINUES TO PULL NORTHWARD TOWARD THE LOUISIANA
COASTLINE.  THIS TREND WILL CONTINUE THIS MORNING...WITH THE SYSTEM
MOVING THROUGH SOUTHEAST LOUISIANA AND SOUTHWEST MISSISSIPPI DURING
THE DAY.  THE STORM WILL REMAIN POORLY ORGANIZED AS DEEP
SOUTHWESTERLY SHEAR ASSOCIATED WITH AN UPPER LEVEL LOW IN WEST TEXAS
REMAINS OVER THE SYSTEM.  THE HEAVIEST RAINS WILL REMAIN WELL EAST
OF THE CENTER OF CIRCULATION.  KEPT POPS UP OVER COASTAL MISSISSIPPI
COUNTIES AS A RESULT.  HOWEVER...DO NOT EXPECT WIDESPREAD HEAVY
RAINFALL TODAY IN OUR REGION.  TONIGHT...EXPECT POPS TO DROP
SHARPLY...AS A DRY SLOT WRAPS AROUND THE STORM.  MID AND UPPER
LEVELS WILL DRY SIGNIFICANTLY...BUT BOUNDARY LAYER WILL REMAIN
MOIST.  EXPECT LOW STRATUS DECK TO REMAIN IN PLACE THROUGH THE
NIGHT.  THE UPPER LOW OVER TEXAS WILL BEGIN TO LIFT OUT TOMORROW AND
TOMORROW NIGHT...PUSHING THE REMAINS OF MATTHEW NORTH INTO THE MID
MISSISSIPPI VALLEY.  EXPECT CONDITIONS TO DRY OUT AND CLOUD COVER TO
DIMINISH RAPIDLY TOMORROW.  HOWEVER...A JET STREAK LOOKS TO PASS
OVER CENTRAL MISSISSIPPI TUESDAY NIGHT.  A FEW MORE CLOUDS COULD
DEVELOP OVER OUR NORTHERN CWA AS A RESULT.  HOWEVER...DO NOT EXPECT
ANY PRECIP TO DEVELOP.  MIDWEEK LOOKS STABLE...AS STRONG SUBSIDENCE
IN WAKE OF LOW INFLUENCES REGION.

GOING INTO THE EXTENDED PERIOD...ECMWF...UKMET...AND GFS ARE ALL IN
GOOD AGREEMENT WITH A MAJOR COOL DOWN FOR THE AREA.  LOOKS LIKE A
STRONG HUDSON BAY LOW PRESSURE SYSTEM WILL DEVELOP THIS WEEKEND.  AS
THE LOW DEEPENS...A STRONG COLD FRONT WILL SWEEP DOWN FROM THE
PLAINS OF CANADA THROUGH OUR REGION LATE WEDNESDAY INTO EARLY
THURSDAY.  IT APPEARS THIS FRONT WILL BE MOISTURE STARVED...AS
RETURN FLOW WILL HAVE LITTLE TIME TO REESTABLISH.  EXPECT LIMITED
POPS WITH THE FRONT AS IT MOVES THROUGH.  GOING INTO THE
WEEKEND...ANOTHER REINFORCING SHOT OF COOL AIR IS EXPECTED...AS A
LOW PRESSURE SYSTEM AND FRONT DIVES INTO THE REGION FROM THE
NORTHEAST ROCKIES...ON THE BACK SIDE OF A DEEP UPPER LEVEL TROUGH.
GOING INTO THE MIDDLE OF NEXT WEEK...A HINT AT A MORE ZONAL FLOW
DEVELOPS...AS THE RIDGE IN THE WEST DEAMPLIFIES.

&&

.PRELIMINARY POINT TEMP/POPS...
MCB 71 64 79 62 / 80 30 10 10
BTR 75 67 82 64 / 70 20 00 00
MSY 76 69 84 67 / 70 20 00 00
GPT 75 68 83 65 / 80 40 10 00

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...TROPICAL STORM WARNING IN EFFECT FOR LAZ038-040- 050-056>070.
FLOOD WATCH IN EFFECT FOR FOLLOWING SE LA
PARISHES...LAZ038>040-050-056>070.
MS...TROPICAL STORM WARNING IN EFFECT MSZ080>082.
FLOOD WATCH IN EFFECT FOR FOLLOWING MS COUNTIES...MSZ070-071
-077-080>082.
SE LA AND MS COASTAL WATERS...TROPICAL STORM WARNING IN EFFECT FROM
PASCAGOULA TO ATCHAFALAYA RIVER INCLUDING LAKES MAUREPAS AND
PONTCHARTRAIN.

&&

32
Hazardous weather outlook, Oct 9, 11:16 PM CDT, 7 hours 9 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1116 PM CDT SAT OCT 9 2004

LAZ034>040-046>050-056>070-MSZ068>071-077-080>082-101030-
AMITE-ASCENSION-ASSUMPTION-EAST BATON ROUGE-EAST FELICIANA-HANCOCK-
HARRISON-IBERVILLE-JACKSON-LIVINGSTON-LOWER JEFFERSON-
LOWER LAFOURCHE-LOWER PLAQUEMINES-LOWER ST BERNARD-LOWER TERREBONNE-
ORLEANS-PEARL RIVER-PIKE-POINTE COUPEE-ST CHARLES-ST HELENA-ST JAMES-
ST JOHN THE BAPTIST-ST TAMMANY-TANGIPAHOA-UPPER JEFFERSON-
UPPER LAFOURCHE-UPPER PLAQUEMINES-UPPER ST BERNARD-UPPER TERREBONNE-
WALTHALL-WASHINGTON-WEST BATON ROUGE-WEST FELICIANA-WILKINSON-
1116 PM CDT SAT OCT 9 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL AND SOUTHEAST
LOUISIANA AND EXTREME SOUTHWEST...SOUTH CENTRAL AND COASTAL
MISSISSIPPI.

...A TROPICAL STORM WARNING IS IN EFFECT FOR THE MISSISSIPPI COAST
AND THE ENTIRE SOUTHEAST LOUISIANA COAST TO INTRACOASTAL CITY
INCLUDING THE TIDAL LAKES...
...A FLOOD WATCH IS IN EFFECT FOR ALL PARISHES AND COUNTIES EAST OF
A LINE FROM SUMMIT MISSISSIPPI TO MORGAN CITY LOUISIANA...

.DAY ONE...TONIGHT

TROPICAL WEATHER...
REFER TO THE LATEST LOCAL ACTION STATEMENTS REGARDING TROPICAL STORM
MATTHEW FOR INFORMATION PERTAINING TO YOUR PARISH OR COUNTY.

HEAVY RAINS AND FLOODING...
THERE REMAINS A THREAT OF PERSISTENT MODERATE TO HEAVY RAINS
OVERSPREADING THE OUTLOOK AREA WITH THE APPROACH AND LANDFALL OF
TROPICAL STORM MATTHEW SUNDAY MORNING. AN ADDITIONAL 2 TO 4 INCHES
OF RAINFALL IS LIKELY THROUGH SUNDAY WITH SOME LOCALLY HIGHER
AMOUNTS MAINLY NEAR THE COAST.

SEVERE THUNDERSTORMS...
AN ISOLATED SEVERE THUNDERSTORM IS POSSIBLE TONIGHT...MAINLY NEAR
THE SOUTHEAST LOUISIANA COAST. THE MAIN HAZARD WILL BE STRONG
DAMAGING WINDS AND POSSIBLY AN ISOLATED TORNADO. OTHERWISE...ONLY
ISOLATED THUNDERSTORMS ARE EXPECTED THROUGH TONIGHT ACROSS MOST LAND
AREAS. THESE THUNDERSTORMS WILL BE CAPABLE OF PRODUCING OCCASIONAL
LIGHTNING...HEAVY RAINFALL...AND WIND GUSTS TO 40 MPH IN TROPICAL
SQUALLS.

MARINE...
SMALL CRAFT REMAIN IN PORT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

TROPICAL...
THE AFFECTS FROM TROPICAL STORM MATTHEW WILL GRADUALLY DIMINISH
THROUGHOUT THE DAY SUNDAY. TIDES WILL REMAIN HIGH THROUGH MUCH OF
SUNDAY BEFORE RECEDING LATE SUNDAY EVENING...PARTICULARLY IN THE
TIDAL LAKES.

MARINE...
SMALL CRAFT SHOULD REMAIN IN PORT SUNDAY UNTIL WINDS AND SEAS
SUBSIDE.

.SPOTTER INFORMATION STATEMENT...

THE ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS AND EMERGENCY
MANAGEMENT PERSONNEL...IN SUPPORT OF SEVERE WEATHER OPERATIONS...IS
NOT REQUESTED AT THIS TIME. HOWEVER...ANY SIGNIFICANT RAINFALL
REPORTS OR OBSERVED FLOODING PLEASE CONTACT YOUR LOCAL LAW
ENFORCEMENT OR NATIONAL WEATHER SERVICE OFFICE.

24

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 10, 4:50 AM CDTTornado WarningLIXLafourche25 min
Oct 10, 5:19 AM CDTTornado WarningLIXLafourche, Terrebonne26 min
Oct 10, 5:43 AM CDTTornado WarningLIXLafourche32 min
Oct 10, 6:14 AM CDTTornado WarningLIXJefferson, Lafourche, Saint Charles31 min

Nearby

Flash Flood Warnings in Louisiana, 2004Every flash flood warning in 2004

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.