Alert archive / Louisiana / Severe Thunderstorm Warnings in 2009
Severe Thunderstorm Warning 110, NWS New Orleans, LA
NWS New Orleans, LA issued this severe thunderstorm warning at May 14, 2009, 2:33 PM CDT for Saint Tammany Parish, Louisiana. It was in force for 57 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
- May 14, 2009, 2:33 PM CDT (19:33 UTC)
- Expired
- May 14, 2009, 3:30 PM CDT
- In force
- 57 min
- Issued by
- NWS New Orleans, LA
- Area
- Storm-based polygon
County Saint Tammany Parish, LA
The nearest sounding before it
Slidell Radar S, LA (KSIL), launched 12:00Z, 7.6 hours before the alert went out and 30 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
- 2255 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 530 m above ground
- 0-6 km bulk shear
- 9 kt
- 0-1 km storm-relative helicity
- -73 m²/s²
- 0-3 km storm-relative helicity
- -43 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 May 14, 8:37 AM CDT, 5 hours 56 minutes earlier.
Area forecast discussion, May 14, 8:37 AM CDT, 5 hours 56 minutes before
AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE NEW ORLEANS LA 837 AM CDT THU MAY 14 2009 .UPDATE... ...SOUNDING DISCUSSION... NO PROBLEMS WITH THE FLIGHT THIS MORNING. EXTREMELY MOIST SOUNDING THIS MORNING THAT COULD BE CONFUSED WITH A PRECIPITATION LOADED SOUNDING IF WE HAD ANY PRECIP IN THE AREA RIGHT NOW. PWATS ARE 1.82 AND THE LI IN IN THE -9 RANGE AGAIN THIS MORNING. SLIGHT SURFACE INVERSION THIS MORNING WITH A LARGER CAP AROUND 800 MB. IF THIS CAP CAN BREAK LATER IN THE DAY THERE ARE PLENTY OF THINGS IN FAVOR OF SOME STRONG TO EVEN SEVERE THUNDERSTORM DEVELOPMENT. IN ADDITION TO THE HIGH PWATS AND UNSTABLE LI...THE 500 MB TEMP IS -12C...THE CAPE IS NEAR 3000 J/KG WITH PLENTY AVAILABLE IN THE HAIL GROWTH ZONE...WHILE THE MID LEVEL LAPSE RATES ARE AT AROUND 7C/KM. WINDS REMAIN LIGHT AND VARIABLE FROM THE SURFACE THROUGH 400 MB SO THAT ANYTHING THAT DOES FORM WILL NOT BE IN A HURRY. 98/SO && .PREV DISCUSSION... /ISSUED 425 AM CDT THU MAY 14 2009/ SHORT TERM... SOME INTERESTING THINGS SHOWING UP IN ALL MODEL SUITES FROM THE NORTH AMERICAN TO THE EUROPEAN. STARTING WITH THE SHORT TERM...A WEAK TROPICAL WAVE IS MOVING WEST THROUGH THE GULF THIS MORNING LOCATED ALONG 90WEST. THIS SHOULD HELP BRING SOME NOCTURNALS ONSHORE THIS MORNING. THE FEATURE HAS ALSO INCREASED THE DEPTH OF MOISTURE IN THE BOUNDARY LAYER. THIS WILL ADD TO THE RAIN CHANCES FOR TODAY. RAIN CHANCES WILL GRADUALLY INCREASE EACH DAY AS AVAILABLE MOISTURE INCREASES IN THE VERTICAL UNTIL THE FRONT PASSES SUN NIGHT. SH/TS WILL DEVELOP TODAY BY WAY OF A WELL DEVELOPED C-BRZ. DUE TO THE INCREASED MOISTURE DEPTH PROVIDED BY THE WAVE...THE C-BRZ SHOULD DEVELOP RATHER QUICKLY LATE THIS MORNING BECOMING THE DOMINANT FORCING FEATURE. MICRO-ENVIRONMENT SHOWS THAT WE SHOULD GET SOME ACTIVITY ALONG COASTAL LOCATIONS THROUGH MID-MORNING WHILE INLAND GETS NEAR ZERO. DURING THE AFTERNOON WE SHOULD SEE MORE ACTIVITY INLAND AND CLOSE TO ZERO ALONG COASTAL LOCATIONS. WILL SEE INCREASED MOISTURE DEPTH EACH DAY SO FRI WHOULD RECEIVE A FEW MORE SH/TS THAN TODAY ETC... LOOKS LIKE THE C-BRZ SHOULD GET ACTIVATED EACH DAY UNTIL SUNDAY WHEN SUPPRESSION AHEAD OF THE FRONT MAY WEAKEN THE FEATURE A LITTLE. LONG TERM... THE LONG WAVE TROUGH THAT WILL BE RESPONSIBLE FOR SUPPORTING THE FRONTS MOVE THROUGH OUR AREA IS JUST NOW COMING INTO THE WEST COAST AT VANCOUVER. AT THE SAME TIME...THE STRONG TROPICAL WAVE MOVING THROUGH THE CARIBBEAN AT ABOUT 68.5W WILL GRADUALLY FIND ITSELF IN THE EASTERN GULF AT THE SAME TIME THAT THE UPPER TROUGH IS DIGGING OVER THE DEEP SOUTH. THE FLOW TO THE EAST OF THE UPPER TROUGH WILL HELP EVACUATE THE NORTHERN PORTION OF THE WAVES COLUMN CAUSING IT TO DEEPEN A LITTLE. THIS OCCURS WHILE THE MID/UPPER LEVEL CUT OFF LOW THAT IS FORMING TRIES TO DEVELOP A WEAK SFC REFLECTION AND WRAPS UNLIMITED MOISTURE AROUND ITS CIRCULATION. THE FRONT SHOULD STALL OFFSHORE WHILE THIS OCCURS PROVIDING SEVERAL DAYS OF SH/TS FOR AT LEAST THE COASTAL WATERS AND MAYBE EVEN SOME ONSHORE LOCATIONS THROUGH MUCH OF NEXT WEEK. AVIATION... FOR 12Z ISSUANCE...MVFR CEILINGS AND VISIBILITIES WILL IMPACT THE TAF SITES EARLY THIS MORNING BEFORE IMPROVING TO VFR CONDITIONS FOR THE REMAINDER OF THE DAY. ISOLATED TO POSSIBLY SCATTERED CONVECTION WILL THREATENED EACH TAF SITE DURING THE THE AFTERNOON HOURS...WITH THE BEST CHANCES AT KMCB AND KGPT. AGAIN LATE TONIGHT AND EARLY THURSDAY MORNING MVFR CEILINGS AND VISIBILITIES WILL BE POSSIBLE...ESPECIALLY AT KMCB AND KBTR. 18 MARINE... A SURFACE RIDGE WILL DOMINATE THE CENTRAL GULF COAST REGION THROUGH THE END OF THE WEEK WITH GENERALLY LIGHT TO OCCASIONALLY MODERATE ONSHORE FLOW PREVAILING. A COLD FRONT IS EXPECTED TO ENTER THE COASTAL WATERS SUNDAY OR SUNDAY NIGHT. NORTH WINDS BEHIND THE FRONTAL PASSAGE MAY PROMPT A SMALL CRAFT ADVISORY ON MONDAY. 18 && .PRELIMINARY POINT TEMPS/POPS... MCB 88 68 85 65 / 30 10 40 20 BTR 90 69 86 68 / 30 10 40 20 MSY 88 72 85 70 / 30 10 40 20 GPT 86 71 84 68 / 30 10 40 20 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. &&
Hazardous weather outlook, May 14, 10:34 AM CDT, 3 hours 59 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE NEW ORLEANS LA 1034 AM CDT THU MAY 14 2009 GMZ530-550-555-570-575-LAZ034>040-046>050-056>070-MSZ068>071-077- 080>082-151100- 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- 1034 AM CDT THU MAY 14 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 SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON ACROSS SOUTHERN MISSISSIPPI AND SOUTHEAST LOUISIANA. SOME OF THESE THUNDERSTORMS COULD BECOME STRONG WITH AN ISOLATED SEVERE THUNDERSTORM POSSIBLE...PRODUCING LIGHTNING...HAIL...HEAVY DOWNPOURS...AND GUSTY WINDS. RIVER FLOODING... MINOR RIVER FLOODING WILL CONTINUE ON THE MISSISSIPPI RIVER AT RED RIVER LANDING. THE MISSISSIPPI RIVER IS EXPECTED TO RISE ABOVE FLOOD STAGE AT BATON ROUGE TODAY. PLEASE REFER TO THE LATEST RIVER FLOOD STATEMENTS FOR DETAILS. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY SCATTERED AFTERNOON THUNDERSTORMS WILL BE POSSIBLE THROUGH SUNDAY. SOME OF THESE THUNDERSTORMS COULD BE STRONG TO POSSIBLY SEVERE...PRODUCING LIGHTNING...HAIL...HEAVY DOWNPOURS...AND GUSTY WINDS. A COLD FRONT WILL AFFECT THE REGION SUNDAY AND SUNDAY NIGHT. SEVERAL ROUNDS OF THUNDERSTORMS WILL DEVELOP ALONG AND AHEAD OF THE FRONT. A FEW OF THESE THUNDERSTORMS COULD BECOME SEVERE...PRODUCING VERY HEAVY RAINFALL...FREQUENT LIGHTNING...HAIL...AND DAMAGING WINDS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. 32
In the hours before
Special weather statement, May 14, 12:37 PM CDT, 1 hour 56 minutes before
MSZ077-141830- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW ORLEANS LA 1237 PM CDT THU MAY 14 2009 ...CLUSTER OF STRONG THUNDERSTORMS MOVING NORTHEAST AFFECTING PEARL RIVER COUNTY... AT 1236 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A CLUSTER OF STRONG THUNDERSTORMS 8 MILES WEST OF POPLARVILLE...OR ABOUT 7 MILES EAST OF CROSSROADS...MOVING NORTHEAST AT 5 MPH. THE CLUSTER OF STRONG THUNDERSTORMS WILL BE NEAR... POPLARVILLE BY 130 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. BANNAN
Special weather statement, May 14, 2:26 PM CDT, 7 minutes before
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html>Special weather statement, May 14, 2:33 PM CDT, 0 minutes before
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html>The office that day
Everything else NWS New Orleans, LA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 13, 9:25 PM CDT | River Flood Warning | LIX | Ascension | 27 days |
| May 14, 1:13 PM CDT | Flash Flood Warning | LIX | Saint Tammany | 92 min |
| May 14, 2:04 PM CDT | Severe Thunderstorm Warning | LIX | Orleans | 17 min |
| May 14, 2:41 PM CDT | Severe Thunderstorm Warning | LIX | Saint John the Baptist | 64 min |
| May 14, 3:20 PM CDT | Severe Thunderstorm Warning | LIX | Livingston | 55 min |
Nearby
Severe 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.