Flash Flood and Hail in South Dakota, June 10 to 11, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
237 PM CDT SUN JUN 10 2007

.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
MAIN CONCERNS IN THE SHORT TERM CONTINUE TO BE TRYING TO NAIL DOWN
BEST CHANCES FOR CONVECTION WITHIN HIGH INSTABILITY/MARGINAL WIND
SHEAR ENVIRONMENT TONIGHT AND MONDAY LATE AFTERNOON/EVENING.

INSTABILITY HAS BEEN INCREASING ALL DAY WITH DPS NOSING INTO THE
LOW TO MID 60S CWA-WIDE ATTM. CONVECTION ONGOING ACROSS FSD AREA
IS BEGINNING TO BACK-BUILD IN THE DIRECTION OF THIS FORECAST
AREA...WHILE NEW CONVECTION IS DEVELOPING ON THE NOSE OF THE
LOW-LEVEL MOISTURE SURGE ACROSS SOUTHWESTERN MINNESOTA.
MEANWHILE...THE HIGHEST RIBBON OF INSTABILITY APPEARS TO BE
DEVELOPING ALONG AND TO THE EAST OF A DRY LINE ACROSS CENTRAL
NEBRASKA AND SOUTH CENTRAL SOUTH DAKOTA. SPC WILL HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR THE SOUTHERN HALF OF THIS FORECAST
AREA FOR THIS AFTERNOON THROUGH THIS EVENING.

CARRYING HIGH END CHANCE POPS ACROSS THE SOUTHWESTERN ZONES AND
THE SISSETON HILLS THIS EVENING WHERE THE HIGHEST INSTABILITY
RESIDES...THEN TRANSITION TO 20 AND 30 POPS FOR THE REMAINDER OF
THE OVERNIGHT...MAINLY ACROSS CENTRAL AND EASTERN ZONES WHERE LOW
LEVEL JET WILL BE POINTING. IMPRESSIVE MID-LEVEL LAPSE RATES
MAINTAINED OVERNIGHT BY ONGOING MID-LEVEL WAA SEQUENCE...AND WILL
PROBABLY SEE OVERNIGHT ACCUS CLOUDS/ELEVATED SHOWER AND
THUNDERSTORM ACTIVITY PERSIST AND/OR REDEVELOP LATE IN THE NIGHT
AS A RESULT.

STUCK WITH THE IDEA OF NO POPS OR RATHER SMALL POPS FOR MONDAY
AFTERNOON WITH MID-LEVEL CAPPING INVERSION EXPECTED TO HOLD
CONVECTION AT BAY UNTIL LATER MONDAY EVENING. MONDAY NIGHT...HAVE
50 AND 60 POPS SMUSHED UP INTO THE NORTH CENTRAL SODAK ZONES CLOSEST
TO WHERE SURFACE FRONTAL BOUNDARY WILL BE MONDAY EVENING AND
OVERNIGHT.

850HPA THERMAL PROGS IN GFS/NAM SOLUTIONS CONTINUE THE MUCH ABOVE
NORMAL WAA PATTERN THROUGH MONDAY NIGHT. TEMPERATURES THIS
AFTERNOON ARE WARMING INTO THE MID 80S TO LOWER 90S CWA-WIDE AND
SHOULD NOT SEE ANY PROBLEM EXPERIENCING LOW TO MID 90S OVER MUCH
OF THE CWA ON MONDAY...WITH LOW TEMPERATURES TONIGHT AND MONDAY
NIGHT PERSISTING SOME 10 TO 15 DEGREES ABOVE NORMAL AS WELL.

.LONG TERM...TUESDAY THROUGH SUNDAY
MODELS ARE CONVERGING ON A SOLUTION. BOTH GFS AND ECMWF AGREE FOR
THE MOST PART ON HANDLING SOUTH WESTERN ENERGY ON TUESDAY. THEY
BOTH LIFT A CLOSED CENTER ONTO THE PLAINS WITH ONLY A LITTLE
DIFFERENCE IN PLACEMENT. ECMWF IS SLIGHTLY FASTER BUT ALMOST IN
LINE BY WEDNESDAY. FOCUS OF THE LONG TERM IS ON PRECIPITATION
EVENT ON TUESDAY NIGHT INTO WEDNESDAY. HPC QPF GUIDANCE WOULD
SUGGEST SOME AREAS OF GREATER THAN 2 INCHES OF RAIN. MUCH OF THIS
AREA...ESPECIALLY IN THE EAST HAVE HAD EXCESSIVE PRECIPITATION
ALREADY TO WHERE TWO MORE INCHES COULD BE SIGNIFICANT. MOISTURE
RETURN IS ALREADY IN PLACE WITH AREA DEW POINTS INTO THE 50S F
TODAY AROUND 10 F MORE THAN YESTERDAY. PRECIPITABLE WATER VALUES
FROM GFS MODEL SOUNDINGS SHOW AN INCREASE FROM .79 ON THIS
MORNINGS UPPER AIR RUN TO 1.4 INCHES BY THIS EVENING AND TO ALMOST
2 INCHES WEDNESDAY. PRECIPITATION AREA WILL BE HARD TO PIN DOWN
THIS EARLY. MUCH WILL DEPEND ON WHERE THE FRONT STALLS AS IT MOVES
EAST. AT THIS POINT IT SEEMS LIKELY THAT SOME AREA IN THIS
FORECAST AREA WILL RECEIVE HEAVY RAIN TUESDAY AFTERNOON THROUGH
WEDNESDAY MORNING. BEHIND THIS LIFTING ENERGY FROM THE SOUTHWEST A
WESTERN RIDGE WILL SLIDE OVER THE AREA. SMALL WAVES WILL BE
EMBEDDED IN THE FLOW BUT THEY WILL BE VERY DIFFICULT TO FORECAST
ESPECIALLY THIS FAR OUT. DID NOT JUMP HARD ON PRECIPITATION DURING
THIS PERIOD AS THERE DOESNT SEEM TO BE A MAJOR EVENT TO TRY AND
TIME.  TEMPERATURES WERE NOT CHANGED A LOT.

&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH MONDAY MORNING.
SCATTERED COVERAGE OF CLOUDS AOA 5K FEET IS DEVELOPING AND WILL
STICK AROUND THE MID EVENING. ISOLATED TO SCATTERED COVERAGE OF SHOWERS
AND THUNDERSTORMS ARE ALSO DEVELOPING AND WILL PERSIST THROUGH
MID-EVENING. SOME THUNDERSTORMS MAY PRODUCED LARGE HAIL AND RATHER
STRONG WIND GUSTS. FLT CAT DROP TO MVFR IN THUNDERSTORMS
/ISOLATED IFR/ IS ALSO POSSIBLE. AFTER SUNDOWN...THUNDERSTORM
ACTIVITY IS EXPECTED TO DIMINISH...BUT COULD POSSIBLY REDEVELOP
TOWARD MORNING AS ELEVATED RAIN SHOWERS/THUNDERSTORMS WITH CLOUD
BASES AOA 10KFT.

&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&

SHORT TERM...DORN
LONG TERM...KEEFE
AVIATION...DORN

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
313 PM CDT SUN JUN 10 2007

MNZ039-046-SDZ007-008-011-112015-
TRAVERSE-BIG STONE-MARSHALL-ROBERTS-DAY-
313 PM CDT SUN JUN 10 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WEST CENTRAL
MINNESOTA AND NORTHEAST SOUTH DAKOTA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THUNDERSTORMS ARE POSSIBLE THIS EVENING THROUGH THE OVERNIGHT
ACROSS FAR NORTHEASTERN SOUTH DAKOTA AND EXTREME WEST CENTRAL
MINNESOTA. THE MAIN THREAT FROM ANY STORMS WOULD BE LIGHTNING AND
SMALL HAIL. A FEW STRONG STORMS ARE POSSIBLE.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORMS ARE POSSIBLE BEGINNING TUESDAY AND LASTING THROUGH
WEDNESDAY EVENING. SOME STORMS COULD BECOME SEVERE TUESDAY NIGHT
AND WEDNESDAY...WITH HEAVY RAIN AND HAIL POSSIBLE.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE NEEDED AFTER 10 PM CDT...MAINLY ALONG
AND EAST OF INTERSTATE 29.

SDZ003>006-009-010-112015-
CORSON-CAMPBELL-MCPHERSON-BROWN-WALWORTH-EDMUNDS-
313 PM CDT SUN JUN 10 2007 /213 PM MDT SUN JUN 10 2007/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL
SOUTH DAKOTA AND NORTHEAST SOUTH DAKOTA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A FEW THUNDERSTORMS ARE POSSIBLE THIS EVENING ACROSS PORTIONS OF NORTH
CENTRAL AND NORTHEASTERN SOUTH DAKOTA. ACTIVITY WILL REMAIN
ISOLATED TO WIDELY SCATTERED IF ANY STORMS CAN DEVELOP. A STRONG
STORM OR TWO MAY FORM WITH SMALL HAIL AND GUSTY WINDS BEING THE
MAIN THREATS. THUNDERSTORMS ARE ALSO POSSIBLE LATER TONIGHT...BUT
ACTIVITY SHOULD REMAIN BELOW SEVERE LIMITS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORMS ARE POSSIBLE MONDAY EVENING ACROSS CENTRAL SOUTH
DAKOTA. SOME STORMS COULD BECOME SEVERE WITH HAIL AND GUSTY WINDS
BEING THE MAIN THREATS. CHANCES FOR STORMS WILL CONTINUE INTO MID
WEEK WITH HEAVY RAIN POSSIBLE IN SOME LOCATIONS.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE NEEDED...MAINLY BETWEEN 8 PM CDT AND
MIDNIGHT CDT...AND MAINLY ALONG AND SOUTH OF A LINE FROM MOBRIDGE
TO HECLA.

SDZ015>018-033>037-045-048-051-112015-
DEWEY-POTTER-FAULK-SPINK-STANLEY-SULLY-HUGHES-HYDE-HAND-JONES-
LYMAN-BUFFALO-
313 PM CDT SUN JUN 10 2007 /213 PM MDT SUN JUN 10 2007/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL SOUTH
DAKOTA...NORTH CENTRAL SOUTH DAKOTA AND NORTHEAST SOUTH DAKOTA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

SEVERE THUNDERSTORM WATCH 377 IN EFFECT UNTIL 10 PM CDT THIS
EVENING...WITH LARGE HAIL AND DAMAGING WINDS THE MAIN THREATS FROM
ANY SEVERE STORMS THAT DEVELOP.

ADDITIONAL THUNDERSTORM REDEVELOPMENT IS POSSIBLE LATE TONIGHT BUT
IS NOT EXPECTED TO BE SEVERE.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORMS ARE POSSIBLE MONDAY EVENING ACROSS CENTRAL SOUTH
DAKOTA. SOME STORMS COULD BECOME SEVERE WITH HAIL AND GUSTY WINDS
BEING THE MAIN THREATS. CHANCES FOR STORMS WILL CONTINUE INTO MID
WEEK WITH HEAVY RAIN POSSIBLE IN SOME LOCATIONS.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS REQUESTED UNTIL 10 PM CDT...MAINLY ALONG AND
SOUTH OF A LINE FROM EAGLE BUTTE TO MELLETE. PLEASE REMAIN
VIGILANT. REPORT ANY OBSERVED SEVERE WEATHER TO THE NATIONAL
WEATHER SERVICE OR YOUR LOCAL LAW ENFORCEMENT AGENCY.

SDZ019>023-112015-
CLARK-CODINGTON-GRANT-HAMLIN-DEUEL-
313 PM CDT SUN JUN 10 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST SOUTH
DAKOTA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

SEVERE THUNDERSTORM WATCH 377 IN EFFECT UNTIL 10 PM CDT THIS
EVENING...WITH LARGE HAIL AND DAMAGING WINDS THE MAIN THREATS FROM
ANY SEVERE STORMS THAT DEVELOP.

ADDITIONAL THUNDERSTORM REDEVELOPMENT IS POSSIBLE LATE TONIGHT BUT
IS NOT EXPECTED TO BE SEVERE.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORMS ARE POSSIBLE BEGINNING TUESDAY AND LASTING THROUGH
WEDNESDAY EVENING. SOME STORMS COULD BECOME SEVERE TUESDAY NIGHT
AND WEDNESDAY...WITH HEAVY RAIN AND HAIL POSSIBLE.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS REQUESTED UNTIL 10 PM CDT...MAINLY ALONG AND
SOUTH OF A LINE FROM BRADLEY TO MILBANK. PLEASE REMAIN VIGILANT.
REPORT ANY OBSERVED SEVERE WEATHER TO THE NATIONAL WEATHER
SERVICE OR YOUR LOCAL LAW ENFORCEMENT AGENCY.

DORN