Alert archive / Mississippi / Severe Thunderstorm Warnings in 2009
Severe Thunderstorm Warning 170, NWS New Orleans, LA
NWS New Orleans, LA issued this severe thunderstorm warning at Aug 21, 2009, 6:24 PM CDT for Washington Parish, Louisiana; Pike County, Walthall County, Mississippi. It was in force for 51 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
- Aug 21, 2009, 6:24 PM CDT (23:24 UTC)
- Expired
- Aug 21, 2009, 7:15 PM CDT
- In force
- 51 min
- Issued by
- NWS New Orleans, LA
- Area
- Storm-based polygon
Counties Washington Parish, LA, Pike County, MS, Walthall County, MS
The nearest sounding before it
Slidell Radar S, LA (KSIL), launched 12:00Z, 11.4 hours before the alert went out and 101 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
- 3891 J/kg
- Mixed-layer CIN
- -2 J/kg
- Mixed-layer LCL
- 565 m above ground
- 0-6 km bulk shear
- 9 kt
- 0-1 km storm-relative helicity
- -11 m²/s²
- 0-3 km storm-relative helicity
- 36 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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 Aug 21, 4:11 PM CDT, 2 hours 13 minutes earlier.
Area forecast discussion, Aug 21, 4:11 PM CDT, 2 hours 13 minutes before
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</html>Hazardous weather outlook, Aug 21, 11:38 AM CDT, 6 hours 46 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE NEW ORLEANS LA 1138 AM CDT FRI AUG 21 2009 GMZ530-550-555-570-575-LAZ034>040-046>050-056>070-MSZ068>071-077- 080>082-221100- LAKE PONTCHARTRAIN AND LAKE MAUREPAS- COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO LOWER ATCHAFALAYA RIVER LA OUT 20 NM- COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM- COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO LOWER ATCHAFALAYA RIVER LA FROM 20 TO 60 NM- COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM-POINTE COUPEE-WEST FELICIANA- EAST FELICIANA-ST. HELENA-TANGIPAHOA-WASHINGTON-ST. TAMMANY- IBERVILLE-WEST BATON ROUGE-EAST BATON ROUGE-ASCENSION-LIVINGSTON- ASSUMPTION-ST. JAMES-ST. JOHN THE BAPTIST-UPPER LAFOURCHE- ST. CHARLES-UPPER JEFFERSON-ORLEANS-UPPER PLAQUEMINES- UPPER ST. BERNARD-UPPER TERREBONNE-LOWER TERREBONNE- LOWER LAFOURCHE-LOWER JEFFERSON-LOWER PLAQUEMINES- LOWER ST. BERNARD-WILKINSON-AMITE-PIKE-WALTHALL-PEARL RIVER- HANCOCK-HARRISON-JACKSON- 1138 AM CDT FRI AUG 21 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 NUMEROUS THUNDERSTORMS...AND ISOLATED STRONG TO MARGINALLY SEVERE STORMS ARE EXPECTED THROUGH THIS EVENING IN ADVANCE OF A COLD FRONT THAT WILL BE MOVING ACROSS THE OUTLOOK AREA FROM THE NORTHWEST TONIGHT AND SATURDAY MORNING. THE PRIMARY THREAT WILL BE GUSTY TO DAMAGING WIND GUSTS AND FREQUENT TO CONTINUOUS LIGHTNING. THERE IS ALSO A RISK OF TORRENTIAL DOWNPOURS WHICH COULD LEAD TO RAINFALL AMOUNTS OF UP TO TWO INCHES. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... THE ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND EMERGENCY MANAGEMENT PERSONNEL IN SUPPORT OF SEVERE WEATHER OPERATIONS IS NOT ANTICIPATED THROUGH THURSDAY...AUGUST 27TH. 22/TD
In the hours before
Special weather statement, Aug 21, 1:49 PM CDT, 4 hours 35 minutes before
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</html>Special weather statement, Aug 21, 1:53 PM CDT, 4 hours 31 minutes before
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</html>Special weather statement, Aug 21, 2:09 PM CDT, 4 hours 15 minutes before
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</html>Local storm report, Aug 21, 2:18 PM CDT, 4 hours 6 minutes before
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</html>Local storm report, Aug 21, 2:21 PM CDT, 4 hours 3 minutes before
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</html>Special weather statement, Aug 21, 6:12 PM CDT, 12 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 |
|---|---|---|---|---|
| Aug 21, 1:23 PM CDT | Special Marine Warning | LIX | 52 min | |
| Aug 21, 1:40 PM CDT | Areal Flood Advisory | LIX | Jefferson, Orleans, Saint Bernard, Saint Charles, Saint John the Baptist | 110 min |
| Aug 21, 1:43 PM CDT | Special Marine Warning | LIX | 62 min |
Nearby
Severe Thunderstorm Warnings in Mississippi, 2009Severe Thunderstorm Warnings in Louisiana, 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.