Severe Weather - Monday, April 4, 2011

A lot of information on this post, so we'll start with the high points:

• Severe weather will affect the Mississippi Delta area today from around Noon through 6:00pm tonight
• Greatest risk of severe weather will be north of Interstate 20
• Damaging winds up to 75 MPH, and large (golfball size) hail are possible
• The risk of tornadoes also exists with individual storm cells
• Western Delta counties (Bolivar, Washington, Sunflower, Humphreys, Leflore) should see the weather between Noon and 3:00pm today
• Eastern Delta counties (Carroll, Holmes, Montgomery, Attala) will see there weather generally between 3:00pm and 6:00pm this evening.
• 1 to 2 inches of rain can be expected with this storm system.  The higher amounts of rainfall are expected for Leflore, Carroll, Montgomery, and Holmes counties.
• A Wind Advisory is in effect until 4:00pm today.  Sustained winds of 20-30 MPH, with gusts of 40-45 MPH are possible, separate from storm-related winds.

These storms will move through the area very rapidly.  You are strongly encouraged to maintain a constant awareness of changing weather conditions.  Monitor local broadcast media and NOAA Weather  Radio for up-to-the-minute information and warnings.

The following statement is from the NWS Storm Prediction Center in Norman, Oklahoma:

PUBLIC SEVERE WEATHER OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0405 AM CDT MON APR 04 2011
   
   ...WIDESPREAD SEVERE THUNDERSTORMS EXPECTED OVER PARTS OF THE LOWER
   MISSISSIPPI VALLEY INTO TENNESSEE VALLEY TODAY INTO TONIGHT...
   
   THE NWS STORM PREDICTION CENTER IN NORMAN OK IS FORECASTING THE
   DEVELOPMENT OF WIDESPREAD DAMAGING WINDS AND POSSIBLY A FEW
   TORNADOES OVER PARTS OF THE LOWER MISSISSIPPI VALLEY INTO TENNESSEE
   VALLEY TODAY INTO TONIGHT.
   
   THE AREAS MOST LIKELY TO EXPERIENCE THIS ACTIVITY INCLUDE
   
          NORTHERN ALABAMA
          NORTHERN AND CENTRAL MISSISSIPPI
          WESTERN AND MIDDLE TENNESSEE
   
   ELSEWHERE...SEVERE STORMS ARE ALSO POSSIBLE FROM THE UPPER OHIO
   VALLEY TO THE GULF COAST STATES.
   
   A STRONG UPPER-LEVEL STORM SYSTEM WITH ASSOCIATED JET STREAM WINDS
   GREATER THAN 100 MPH WILL PROGRESS FROM THE GREAT PLAINS THROUGH THE
   OHIO AND TENNESSEE VALLEYS AND GULF COAST STATES TODAY AND TONIGHT. 
   A COLD FRONT WILL ACCOMPANY THE UPPER-AIR STORM SYSTEM WITH THIS
   FEATURE PROVIDING THE FOCUS FOR SEVERE THUNDERSTORMS IT SURGES
   EASTWARD THROUGH THE REGION.  
   
   THROUGH THE REMAINDER OF THE MORNING...EXPECT LOCATIONS FROM THE MID
   MISSISSIPPI VALLEY SOUTHWESTWARD INTO ARKANSAS...EASTERN TEXAS AND
   LOUISIANA TO BE IMPACTED BY A FEW SEVERE STORMS.  BY AFTERNOON...THE
   FRONT WILL ENCOUNTER A WARMER AND MORE HUMID AIR MASS STREAMING
   NORTHWARD FROM THE GULF OF MEXICO THROUGH THE LOWER MISSISSIPPI
   VALLEY INTO TENNESSEE VALLEY.  THIS WILL RESULT IN A MARKED INCREASE
   IN SEVERE THUNDERSTORMS ALONG THE COLD FRONT.  THESE STORMS WILL BE
   CAPABLE OF WIDESPREAD DAMAGING WINDS AND PERHAPS A FEW TORNADOES AS
   THEY ADVANCE ACROSS THE TENNESSEE VALLEY AND GULF COAST STATES TODAY
   INTO TONIGHT.
   
   STATE AND LOCAL EMERGENCY MANAGERS ARE MONITORING THIS DEVELOPING
   SITUATION. THOSE IN THE THREATENED AREA ARE URGED TO REVIEW SEVERE
   WEATHER SAFETY RULES AND TO LISTEN TO RADIO...TELEVISION...AND NOAA
   WEATHER RADIO FOR POSSIBLE WATCHES...WARNINGS...AND STATEMENTS LATER
   TODAY.

The following statement is today's Hazardous Weather Outlook from NWS Jackson, MS:

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
555 AM CDT MON APR 4 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EXTREME SOUTHEAST ARKANSAS AND
PORTIONS OF NORTHEAST LOUISIANA AND WESTERN MISSISSIPPI.

.DAY ONE...TODAY AND TONIGHT

A SEVERE WEATHER OUTBREAK IS EXPECTED TODAY ACROSS THE ARKLAMISS.
THERE WILL BE A RISK FOR WIDESPREAD DAMAGING WINDS UP TO 70 MPH...
TORNADOES...AND LARGE HAIL UP TO THE SIZE OF GOLFBALLS. THE MOST
LIKELY TIME FOR THESE STORMS TO OCCUR WILL BE FROM NOON TO 3PM.

VERY STRONG WIND SHEAR AND A VERY MOIST AND UNSTABLE AIRMASS WILL BE
IN PLACE OVER THE ARKLAMISS AHEAD OF A COLD FRONT. AS THE FRONT
MOVES ACROSS THE AREA...A BROKEN LINE OF STORMS WILL DEVELOP AND FORM
INTO A SQUALL LINE. SUPERCELL THUNDERSTORMS WILL BE POSSIBLE WITHIN
AND JUST AHEAD OF THE SQUALL LINE AS IT MOVES SOUTHEAST ACROSS THE
AREA...POTENTIALLY RESULTING IN A MORE ENHANCED RISK FOR TORNADOES
DURING THE LATE MORNING AND EARLY AFTERNOON. THE RISK FOR SEVERE
WEATHER SHOULD DIMINISH OVER NORTHWEST PORTIONS OF THE ARKLAMISS
DURING THE LATE AFTERNOON. IN ADDITION...INTENSE RAINFALL RATES COULD
BE EXPECTED TO PRODUCE A QUICK ONE TO TWO INCHES OF RAINFALL. THIS
MAY RESULT IN SOME PONDING OF WATER.

OUTSIDE OF STORMS...A WIND ADVISORY IS IN EFFECT FOR THE ENTIRE
OUTLOOK AREA THROUGH LATE AFTERNOON. SOUTH TO SOUTHWEST WINDS OF 20
TO 30 MPH WITH GUSTS UP TO 40 TO 45 MPH CAN BE EXPECTED. WINDS OF
THIS MAGNITUDE ARE CAPABLE OF BRINGING DOWN TREES AND POWERLINES.