Severe Thunderstorm Warning 71, NWS Sioux Falls, SD

548 
WWUS53 KFSD 212039
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
339 PM CDT SAT MAY 21 2011

SDC005-212049-
/O.CAN.KFSD.SV.W.0071.000000T0000Z-110521T2100Z/
BEADLE SD-
339 PM CDT SAT MAY 21 2011

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN BEADLE COUNTY IS
CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN SIOUX FALLS.

LAT...LON 4464 9835 4428 9834 4425 9850 4464 9866
      4464 9865 4464 9854
TIME...MOT...LOC 2039Z 169DEG 30KT 4452 9848

$$

HANKO

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1040 AM CDT SAT MAY 21 2011

.DISCUSSION...
SPOKE OF ENERGY ROTATING AROUND THE UPPER LOW CENTERED TO OUR NORTH
IS EXITING THE AREA TO THE NORTHEAST...WITH ONLY A FEW LINGERING
SHOWERS AND THUNDERSTORMS ALONG OUR FAR EASTERN BORDER REMAINING.
THESE SHOWERS WILL EXIT THE REGION WITHIN THE NEXT HOUR. WATER VAPOR
IMAGERY SUGGESTS THAT DRYING WILL WORK NORTHWARD ACROSS THE CWA THIS
MORNING WHICH IS SUPPORTED BY CLEARING ACROSS THE WEST AND SOUTH
THIS MORNING.  THE NEXT SPOKE OF ENERGY SHOULD BEGIN WORKING INTO
NORTHEASTERN NEBRASKA AND NORTHWESTERN IOWA LATER THIS AFTERNOON.
HRRR GUIDANCE SHOWS SOME SCATTERED SHOWERS AND THUNDERSTORMS
DEVELOPING AFTER 2PM ACROSS THE AREA. STILL LOOKS LIKE BEST
POTENTIAL FOR ANY SEVERE DEVELOPMENT WILL BE ACROSS NORTHWEST
IOWA...HOWEVER THIS POTENTIAL STILL SEEMS RATHER LOW. MADE A QUICK
UPDATE TO INCLUDE THE CURRENT PRECIPITATION ALONG OUR EASTERN BORDER
FOR THE NEXT HOUR OR TWO AND TO INCLUDE THE QUICKER CLEARING OF
SKIES IN THE WEST AND SOUTH. OTHERWISE FORECAST PACKAGE APPEARS ON
TRACK.

&&

.AVIATION...
WIDESPREAD MVFR TO IFR CEILINGS PERSIST MAINLY IN NORTHWEST IOWA AND
THE MISSOURI VALLEY THIS MORNING BUT ARE EXPECTED TO LIFT TO VFR
WITHIN THE NEXT HOUR OR TWO. EXPECT SCATTERED THUNDERSTORMS TO
REDEVELOP AFTER 20Z ACROSS THE REGION.

&&

.PREV DISCUSSION...
MCS ACROSS THE SOUTHERN MISSISSIPPI VALLEY CONTINUES TO IMPEDE
DEEPER MOISTURE TRANSPORT NORTHWARD INTO THE PLAINS. RADAR TRENDS
AND COVERAGE INDICATIVE OF LIMITED MOISTURE AS SHOWERS ACROSS THE
AREA DECREASING IN INTENSITY AND BECOMING MORE SCATTERED IN NATURE.
OF COURSE LOST OF STRONGER FORCING CERTAINLY PLAYING ITS ROLE.
CURRENTLY A LINE OF INSTABILITY SHOWERS FORMING ALONG THE LEADING
EDGE OF MID LEVEL DRYING. WILL CONTINUE TO SEE THIS LINE OF SHOWERS
PUSH NORTH AND EAST OF THE AREA EARLY THIS MORNING. SHOULD NOT BE
MUCH IN THE WAY OF ONGOING PRECIPITATION ACROSS THE CWA AFTER
SUNRISE AS DRY SW FLOW KICKS IN...BUT DO EXPECT REDEVELOPMENT OF
SHOWERS AND THUNDERSTORMS BY THIS AFTERNOON AS ATMOSPHERE AGAIN
DESTABILIZES. POTENTIAL FOR SEVERE THUNDERSTORMS IS LOW TODAY. AS
TYPICAL MODELS APPEAR TO BE OVERDOING THE DEW POINTS THIS AFTERNOON
WHICH FEEDS INTO CAPE. NOT EXPECTING 2000 J/KG SFC CAPE THE NAM IS
PRODUCING ACROSS NW IA LATE TODAY. 1000-1500 J/KG MORE REASONABLE
WITH MIX LAYER CAPE PROBABLY CLOSER TO 1000 J/KG. EXPECTING THE CAP
TO GO RATHER QUICKLY WHEN IT DOES GO...WHICH SUGGESTS A RAPIDLY
RELEASE OF INSTABILITY WHEN SHOWERS AND THUNDERSTORMS FORM. THIS
BEING THE CASE...MAIN CONVECTIVE MODE SHOULD QUICKLY TRANSITION TO
MULTICELLULAR PULSE TYPE. SMALL CHANCES FOR SEVERE STORMS SHOULD BE
CONFINED TO NW IA...BUT THIS WILL ONLY BE A SHORT PERIOD DURING THE
INITIAL DEVELOPMENT OF CONVECTION. MOST LIKELY WITH NOT SEE SEVERE
WEATHER IN THE CWA AS MODEL SHEAR PROFILES ARE NOT SUPPORTIVE OF
SEVERE STORMS WITH WIND SHEAR GENERALLY 20 TO 30 KTS AND THE SHEAR
LARGELY UNIDIRECTIONAL. THUNDERSTORM ACTIVITY WILL WANE AS THE
EVENING PROGRESSES WITH THE LOST OF DAYTIME HEATING. AS SHOWERS AND
THUNDERSTORM DIE OFF THIS EVENING...ANOTHER BATCH OF SHOWERS IS
EXPECTED TO APPROACH FROM THE WEST WITH THE CORE OF THE UPPER LOW
APPROACHING.

UPPER LOW WILL BE THE MAIN WEATHER FACTOR THE NEXT FEW DAYS AS IT
MAKES IS WAY EAST INTO THE GREAT LAKES BY MONDAY. MODELS HAVE
TRENDED FARTHER SOUTH WITH THE CORE OF THE UPPER LOW...THUS GIVING
BETTER CHANCES OF SHOWERS OVER THE FORECAST AREA THE NEXT FEW DAYS.
THIS ALSO MEANS MORE CLOUD COVER AND COOLER TEMPERATURES. SHAVED A
FEW DEGREES OFF HIGH TEMPERATURES SUNDAY AND MONDAY...HOWEVER WITH
THE OVERALL FARTHER SOUTH SOLUTIONS...SHOULD MEAN SKIES WILL CLEAR
FROM NORTH TO SOUTH ON TUESDAY AND WEDNESDAY...WITH BETTER CHANCES
FOR PRECIPITATION SOUTH OF THE FORECAST AREA. THIS ALSO MEANS
TEMPERATURES SHOULD REBOUND A BIT FASTER GOING INTO MID WEEK WITH
DRY AIR AND LOTS OF SUNSHINE IN PLACE.  /97

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1113 AM CDT SAT MAY 21 2011

SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098-
IAZ001>003-012>014-020>022-031-032-NEZ013-014-221200-
AURORA-BEADLE-BON HOMME-BROOKINGS-BRULE-BUENA VISTA IA-
CHARLES MIX-CHEROKEE IA-CLAY-CLAY IA-COTTONWOOD MN-DAKOTA NE-
DAVISON-DICKINSON IA-DIXON NE-DOUGLAS-GREGORY-HANSON-HUTCHINSON-
IDA IA-JACKSON MN-JERAULD-KINGSBURY-LAKE-LINCOLN-LINCOLN MN-
LYON IA-LYON MN-MCCOOK-MINER-MINNEHAHA-MOODY-MURRAY MN-NOBLES MN-
OBRIEN IA-OSCEOLA IA-PIPESTONE MN-PLYMOUTH IA-ROCK MN-SANBORN-
SIOUX IA-TURNER-UNION-WOODBURY IA-YANKTON-
1113 AM CDT SAT MAY 21 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST SOUTH DAKOTA...
SOUTHWEST MINNESOTA...NORTHWEST IOWA...AND NORTHEAST NEBRASKA.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS...
SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE AREA
THIS AFTERNOON BEFORE DYING OFF THIS EVENING. SEVERE
THUNDERSTORMS ARE NOT EXPECTED TODAY...ALTHOUGH A FEW STRONGER
STORMS MAY PRODUCE SMALL HAIL.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL AGAIN BE
POSSIBLE SUNDAY AND MONDAY...BUT SEVERE THUNDERSTORMS AREA NOT
ANTICIPATED.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT.

&&

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT
WWW.WEATHER.GOV/SIOUXFALLS. THIS INCLUDES THE GRAPHICAL HAZARDOUS
WEATHER OUTLOOK.