Alert archive / Louisiana / Flash Flood Warnings in 1998
Flash Flood Warning 42, NWS New Orleans, LA
NWS New Orleans, LA issued this flash flood warning at Sep 18, 1998, 3:40 PM CDT for Jefferson Parish, Plaquemines Parish, Louisiana. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Sep 18, 1998, 3:40 PM CDT (20:40 UTC)
- Expired
- Sep 18, 1998, 6:00 PM CDT
- In force
- 2 hr
- Issued by
- NWS New Orleans, LA
- Area
- Whole counties
Counties Jefferson Parish, LA, Plaquemines Parish, LA
The nearest sounding before it
Slidell Radar S, LA (KSIL), launched 12:00Z, 8.7 hours before the alert went out and 75 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.
- Mixed-layer CAPE
- 422 J/kg
- Mixed-layer CIN
- -9 J/kg
- Mixed-layer LCL
- 606 m above ground
- 0-6 km bulk shear
- 10 kt
- 0-1 km storm-relative helicity
- -2 m²/s²
- 0-3 km storm-relative helicity
- 14 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KNEW 182039 FFWNEW LAC051-075-182300- BULLETIN - IMMEDIATE BROADCAST REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE NEW ORLEANS LA 340 PM CDT FRI SEP 18 1998 THE NATIONAL WEATHER SERVICE IN NEW ORLEANS LA HAS ISSUED A... * FLASH FLOOD WARNING FOR - LOWER JEFFERSON PARISH IN SOUTHEASTERN LOUISIANA - CENTRAL AND LOWER PLAQUEMINES PARISH IN SOUTHEASTERN LOUISIANA * UNTIL 600 PM CDT * AT 330 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED SHOWERS AND THUNDERSTORMS PRODUCING TORRENTIAL RAINFALL AT THE RATE OF 2 TO 4 INCHES PER HOUR OVER PORTIONS OF LOWER PLAQUEMINES PARISH JUST WEST OF PORT SULPHUR AND EMPIRE...WITH LITTLE MOVEMENT NOTED. VERY HEAVY RAIN WILL CONTINUE OVER THE SAME AREA THROUGH AT LEAST 5 PM WITH HIGH WATER PERSISTING UNTIL AT LEAST 6 PM. THE HEAVY RAIN AREA WILL EXPAND ACROSS CENTRAL AND LOWER PLAQUEMINES INTO LOWER JEFFERSON PARISH FROM LAFITTE SOUTHWARD. FLOODING OF SECTIONS OF HIGHWAY 23 CAN BE EXPECTED WITH FLOODING OF STREETS AND LOW LYING AREAS LIKELY IN COMMUNITIES FROM BURAS TO POINTE A LA HACHE TO LAFITTE. 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.
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.
In the hours before
Special weather statement, Sep 18, 11:40 AM CDT, 4 hours before
LAZ034>040-046>050-056>070-MSZ068>071-077-080>082-191730- THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE NEW ORLEANS LA 1140 AM CDT FRI SEP 18 1998 MOISTURE WILL CONTINUE TO INCREASE ACROSS THE LOCAL REGION UNDER UNSTABLIZING AIR MASS. AREA COVERAGE OF SHOWERS WILL GRADUALLY INCREASE THROUGH TONIGHT AND SATURDAY. A FEW THUNDERSTORMS ARE EXPECTED WITH LOCALLY HEAVY DOWNPOURS THROUGH SATURDAY. HOWEVER...SEVERE THUNDERSTORMS ARE NOT EXPECTED.
Special weather statement, Sep 18, 11:40 AM CDT, 4 hours before
LAZ034>040-046>050-056>070-MSZ068>071-077-080>082-191730- THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE NEW ORLEANS LA 1140 AM CDT FRI SEP 18 1998 MOISTURE WILL CONTINUE TO INCREASE ACROSS THE LOCAL REGION UNDER UNSTABLIZING AIR MASS. AREA COVERAGE OF SHOWERS WILL GRADUALLY INCREASE THROUGH TONIGHT AND SATURDAY. A FEW THUNDERSTORMS ARE EXPECTED WITH LOCALLY HEAVY DOWNPOURS THROUGH SATURDAY. HOWEVER...SEVERE THUNDERSTORMS ARE NOT EXPECTED.
The office that day
Everything else NWS New Orleans, LA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 18, 1:37 PM CDT | Flash Flood Warning | LIX | Saint Charles | 113 min |
| Sep 18, 4:33 PM CDT | Flash Flood Warning | LIX | Lafourche, Terrebonne | 3 hr |
Nearby
Flash Flood Warnings in Louisiana, 1998Every flash flood warning in 1998
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.