Alert archive / Louisiana / Severe Thunderstorm Warnings in 2009
Severe Thunderstorm Warning 71, NWS New Orleans, LA
NWS New Orleans, LA issued this severe thunderstorm warning at Apr 12, 2009, 9:47 PM CDT for 4 parishes in Louisiana; Pike County, Walthall County, Mississippi. It was in force for 58 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Apr 12, 2009, 9:47 PM CDT (02:47 UTC)
- Expired
- Apr 12, 2009, 10:45 PM CDT
- In force
- 58 min
- Issued by
- NWS New Orleans, LA
- Area
- Storm-based polygon
Counties Livingston Parish, LA, Saint Helena Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA, Pike County, MS, Walthall County, MS
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Apr 12, 8:30 PM CDT | Tornado Watch | SPC | 6 hr |
The nearest sounding before it
Slidell Radar S, LA (KSIL), launched 00:00Z, 2.8 hours before the alert went out and 94 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
- 1395 J/kg
- Mixed-layer CIN
- -4 J/kg
- Mixed-layer LCL
- 497 m above ground
- 0-6 km bulk shear
- 73 kt
- 0-1 km storm-relative helicity
- 485 m²/s²
- 0-3 km storm-relative helicity
- 608 m²/s²
- Significant tornado parameter
- 5.0
- Supercell composite
- 19.5
What forecasters said that day
The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at Apr 12, 9:07 PM CDT, 40 minutes earlier.
Area forecast discussion, Apr 12, 9:07 PM CDT, 40 minutes before
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</html>Hazardous weather outlook, Apr 12, 3:06 PM CDT, 6 hours 41 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE NEW ORLEANS LA 306 PM CDT SUN APR 12 2009 GMZ530-550-555-570-575-LAZ034>040-046>050-056>070-MSZ068>071-077- 080>082-131130- PASCAGOULA TO SW PASS MISSISSIPPI RIVER OUT 20 NM- PASCAGOULA TO SW PASS MISSISSIPPI RIVER 20-60 NM OUT- SW PASS MISSISSIPPI RIVER TO ATCHAFALAYA RIVER OUT 20 NM- SW PASS MISSISSIPPI RIVER TO ATCHAFALAYA RIVER 20-60 NM OUT-AMITE- ASCENSION-ASSUMPTION-EAST BATON ROUGE-EAST FELICIANA-HANCOCK- HARRISON-IBERVILLE-JACKSON-LAKES PONTCHARTRAIN AND MAUREPAS- 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- 306 PM CDT SUN APR 12 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF COASTAL WATERS OF SOUTHEAST LOUISIANA AND SOUTH MISSISSIPPI...SOUTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI. .DAY ONE...THIS AFTERNOON AND TONIGHT SEVERE WEATHER...THERE IS A SLIGHT RISK FOR SEVERE WEATHER THIS AFTERNOON AND TONIGHT ACROSS SOUTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI. ISOLATED TORNADOES ALONG WITH HAIL AND DAMAGING WINDS WILL BE THE GREATEST THREATS AS A POTENT DISTURBANCE MOVES THROUGH THE AREA. MOST OF THIS ACTIVITY WILL OCCUR IN THE AFTERNOON AND INTO THE OVERNIGHT HOURS AS THE STORM SYSTEM PROGRESSES EASTWARD. MARINE...SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE COASTAL WATERS INCLUDING THE TIDAL LAKES. STRONG SOUTHERLY WINDS OF 20 TO 30 KNOTS WITH HIGHER GUSTS CAN BE EXPECTED THROUGH THE DAY AND INTO TONIGHT. WIND GENERATED WAVES AND SWELL OF 1 TO 2 FEET WILL LEAD TO SEAS OF 6 TO 8 FEET OVER THE OFFSHORE WATERS. RIVER FLOODING...THE PEARL RIVER IS EXPECTED TO FALL BELOW FLOOD STAGE TONIGHT AT BOGALUSA BUT REMAIN ABOVE FLOOD STAGE AT PEARL RIVER. RIVER FLOODING CONTINUES ALONG THE ATCHAFALAYA RIVER AT MORGAN CITY. REFER TO THE LATEST RIVER FLOOD STATEMENTS FOR DETAILS. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY THE RISK OF SEVERE WEATHER WILL CONTINUE INTO MONDAY AFTERNOON ALONG EXTREME SOUTHEAST LOUISIANA AND COASTAL MISSISSIPPI WITH ALL STORMS SOUTH OF THE AREA BY MONDAY NIGHT. RIVER FLOODING WILL CONTINUE ALONG THE ATCHAFALAYA RIVER AT MORGAN CITY INTO NEXT WEEK. THE PEARL RIVER AT PEARL RIVER IS EXPECTED TO FALL BELOW FLOOD STAGE TUESDAY AFTERNOON. REFER TO THE LATEST RIVER FLOOD STATEMENTS FOR DETAILS. .SPOTTER INFORMATION STATEMENT... THE ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND EMERGENCY PERSONNEL IN SUPPORT OF SEVERE WEATHER OPERATIONS IS REQUESTED THIS AFTERNOON THROUGH TONIGHT AND POSSIBLY INTO MONDAY MORNING.
In the hours before
Special weather statement, Apr 12, 5:48 PM CDT, 3 hours 59 minutes before
LAZ034-035-MSZ068-069-122345- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW ORLEANS LA 548 PM CDT SUN APR 12 2009 ...LINE OF STRONG THUNDERSTORMS MOVING EAST AFFECTING POINTE COUPEE PARISH...AMITE COUNTY...WILKINSON COUNTY...WEST FELICIANA PARISH... AT 546 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A LINE OF STRONG THUNDERSTORMS...ALONG A LINE EXTENDING FROM 31 MILES NORTHWEST OF LIBERTY TO 8 MILES EAST OF SIMMESPORT...MOVING EAST AT 20 MPH. THE LINE OF STRONG THUNDERSTORMS WILL BE NEAR... WOODVILLE BY 630 PM... CROSBY BY 640 PM... GLOSTER BY 645 PM... THE PRIMARY THREATS FROM THESE STORMS ARE FREQUENT LIGHTNING AND WIND GUSTS TO NEAR 40 MPH...WHICH COULD DOWN TREE LIMBS AND BLOW AROUND UNSECURED SMALL OBJECTS. SEEK SHELTER IN A SAFE HOME OR BUILDING UNTIL THESE STORMS HAVE PASSED. A TORNADO WATCH REMAINS IN EFFECT UNTIL 900 PM SUNDAY EVENING FOR SOUTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI. 24/RR
Special weather statement, Apr 12, 7:04 PM CDT, 2 hours 43 minutes before
LAZ036>038-046>048-050-MSZ069>071-130130- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW ORLEANS LA 704 PM CDT SUN APR 12 2009 ...CLUSTER OF STRONG THUNDERSTORMS MOVING NORTHEAST AFFECTING IBERVILLE PARISH...EAST FELICIANA PARISH...LIVINGSTON PARISH... TANGIPAHOA PARISH...EAST BATON ROUGE PARISH...ST. HELENA PARISH... WEST BATON ROUGE PARISH...PIKE COUNTY...WALTHALL COUNTY...AMITE COUNTY... AT 701 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A CLUSTER OF STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 8 MILES SOUTHWEST OF MCCOMB TO 6 MILES SOUTH OF CATAHOULA...MOVING NORTHEAST AT 30 MPH. THE CLUSTER OF STRONG THUNDERSTORMS WILL AFFECT AREAS IN AND AROUND...MCCOMB...BAKER...GILLSBERG...MCCOMB AIRPORT...DARLINGTON... PRIDE...BATON ROUGE AIRPORT...MAGNOLIA...PORT ALLEN...EASLEYVILLE... BRUSLY...ADDIS...GARDERE...GREENWELL SPRING...OAK HILLS PLACE...BATON ROUGE...WESTMINSTER...WATSON...KENTWOOD...GREENSBURG...DENHAM SPRINGS AND OSYKA THE PRIMARY THREATS FROM THESE STORMS ARE FREQUENT LIGHTNING AND WIND GUSTS TO NEAR 45 MPH...WHICH COULD DOWN TREE LIMBS AND BLOW AROUND UNSECURED SMALL OBJECTS. SEEK SHELTER IN A SAFE HOME OR BUILDING UNTIL THESE STORMS HAVE PASSED. THESE STORMS COULD PRODUCE RAINFALL AMOUNTS OF ONE TO TWO INCHES IN A SHORT PERIOD OF TIME...RESULTING IN PONDING OF WATER AROUND LOW LYING ROADWAYS. REMEMBER...DO NOT DRIVE YOUR VEHICLE INTO WATER COVERED ROADWAYS. THE DEPTH MAY BE TOO GREAT TO ALLOW A SAFE CROSSING. A TORNADO WATCH REMAINS IN EFFECT UNTIL 900 PM CDT SUNDAY EVENING FOR SOUTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI. 24/RR
Local storm report, Apr 12, 8:26 PM CDT, 1 hour 21 minutes before
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</html>Local storm report, Apr 12, 9:04 PM CDT, 43 minutes before
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</html>Local storm report, Apr 12, 9:15 PM CDT, 32 minutes before
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</html>The office that day
Everything else NWS New Orleans, LA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 12, 7:26 PM CDT | Severe Thunderstorm Warning | LIX | East Baton Rouge, West Baton Rouge | 21 min |
| Apr 12, 8:32 PM CDT | Severe Thunderstorm Warning | LIX | East Feliciana | 15 min |
| Apr 12, 11:36 PM CDT | Special Marine Warning | LIX | 24 min | |
| Apr 13, 12:17 AM CDT | Special Marine Warning | LIX | 43 min | |
| Apr 13, 12:25 AM CDT | Severe Thunderstorm Warning | LIX | Saint Tammany | 35 min |
| Apr 13, 6:33 AM CDT | Dense Fog Advisory | LIX | Assumption, East Baton Rouge, East Feliciana, Iberville, Pointe Coupee, Saint Helena and 5 more | 2 hr |
| Apr 13, 8:57 AM CDT | Special Marine Warning | LIX | 63 min | |
| Apr 13, 9:52 AM CDT | River Flood Warning | LIX | Tangipahoa | 4 days |
| Apr 13, 9:58 AM CDT | Special Marine Warning | LIX | 92 min | |
| Apr 13, 9:59 AM CDT | River Flood Warning | LIX | Saint Tammany | 5 days |
| Apr 13, 11:27 AM CDT | Special Marine Warning | LIX | 93 min | |
| Apr 13, 1:19 PM CDT | Special Marine Warning | LIX | 86 min | |
| Apr 13, 2:05 PM CDT | Special Marine Warning | LIX | 85 min | |
| Apr 13, 3:44 PM CDT | Small Craft Advisory | LIX | 18 hr | |
| Apr 13, 3:54 PM CDT | Severe Thunderstorm Warning | LIX | Washington | 66 min |
| Apr 13, 4:33 PM CDT | Severe Thunderstorm Warning | LIX | West Feliciana | 61 min |
| Apr 12, 7:36 PM CDT | Severe Thunderstorm Warning | LIX | Amite, Pike, Walthall | 54 min |
| Apr 12, 7:46 PM CDT | Flash Flood Warning | LIX | Amite, Pike | 2 hr |
| Apr 12, 11:43 PM CDT | Severe Thunderstorm Warning | LIX | Pearl River | 62 min |
| Apr 13, 3:14 AM CDT | Severe Thunderstorm Warning | LIX | Harrison | 23 min |
| Apr 13, 9:52 AM CDT | River Flood Warning | LIX | Pike | 11 hr |
| Apr 13, 1:44 PM CDT | River Flood Warning | LIX | Harrison | 34 hr |
Nearby
Severe Thunderstorm Warnings in Louisiana, 2009Severe Thunderstorm Warnings in Mississippi, 2009Every severe thunderstorm warning in 2009
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.