Hail in South Dakota, March 21, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
959 PM CDT MON MAR 21 2011

.UPDATE...
NOT MUCH CHANGE TO INHERITED FORECAST. LOW CLOUDS CONTINUE TO
OCCUPY MUCH OF THE CWA...WITH LITTLE IF ANY CHANGE IN HOURLY TEMPS
OR DWPTS. LATEST 88D IMAGE BEGINNING TO SHOW SOME MINOR RETURNS
ACROSS FAR SRN SD...SO CURRENT FCST OF PCPN LOOKS TO BE ON TARGET.
LATEST NAM12 IS VERY BULLISH WITH PCPN FCST FOR ERN CWA THROUGH
12Z WED AS PCPN DEVELOPS ON NOSE OF DEVELOPING 850HPA JET.

HYDRO WISE...NEW FCST FOR JAMES AT COLUMBIA AND BIG SIOUX NORTH OF
WATERTOWN MADE IT NECESSARY TO ISSUE FLOOD WARNING FOR THOSE
SITES. HAVE UPDATED FLOOD STATEMENTS FOR REMAINDER OF SITES ALONG
THE JAMES AND BIG SIOUX BASINS FOR HIGHER CREST FORECASTS.

&&
.PREV DISCUSSION...
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT

A SOMEWHAT ACTIVE PERIOD IN STORE THROUGH WEDNESDAY. FOR TONIGHT
STRONG S/W BEGINS LIFTING NORTHEAST OUT OF WESTERN CONUS TROF.
WARM FRONTAL BOUNDARY OVER SOUTHERN NEBRASKA IS EXPECTED TO LIFT
NORTHEAST INTO SOUTH DAKOTA WITH INCREASING MOISTURE AND
INSTABILITY. MU CAPES HEAD TOWARD 500J/KG ACROSS EASTERN CWA LATE
TONIGHT...AND THUS THUNDER IS CERTAINLY POSSIBLE AFTER MIDNIGHT
AND INTO TUES MORNING...WITH PERHAPS MORE THUNDER OVER THE FAR
EAST TUESDAY AFTERNOON. GIVEN TIME OF YEAR...WOULD NOT BE
SURPRISED TO SEE SOME HAIL WITH ANY CONVECTION THAT DOES DEVELOP.
THERE MAY WELL BE A LULL IN THE ACTIVITY LATER TUESDAY INTO
TUESDAY NIGHT ACROSS ESPECIALLY THE SOUTHWEST CWA UNTIL BAND OF
SNOW SLIDES SOUTHEAST INTO MAINLY THE NORTHERN CWA BEHIND
PROPOGATING UPPER LOW. FOR NOW AM FORECASTING UP TO 4 INCHES OF
WET SNOW IN THE FAR NORTHEAST CWA WITH LESS THAN THAT ELSEWHERE.
SOME TYPE OF WINTER ADVISORY MIGHT BE NEEDED TUESDAY NIGHT INTO
WEDNESDAY BUT WILL HOLD OFF ON THAT FOR NOW. THERE IS ONE CAVEOT
TO THIS FORECAST. THE 12Z ECMWF IS MUCH MORE AGRESSIVE WITH PCPN
TOTALS BOTH TOTAL QPF AND TOTAL SNOW AMOUNTS. SO THIS IS
SOMETHING TO KEEP IN MIND...BUT IS NOT SUPPORTED BY MOST RECENT
GEFS/SREF AND HPC DATA SO FOR NOW WILL BASICALLY IGNORE THAT
MODEL. THE CURRENT QPF FORECAST PROBABLY WOULD NOT CAUSE ANY
SIGNIFICANT ADDITIONAL FLOODING ACROSS THE CWA.

PCPN TYPE WISE IT SHOULD BE ALL RAIN UNTIL LATE TUESDAY INTO
TUESDAY NIGHT. THEN CHANGE OVER TO SNOW AS COLD AIR COMES IN.
WEDNESDAY SHOULD BE ALL SNOW BASED ON PARTIAL THICKNESS AND H85
TEMPS AS WELL AS BUFR SOUNDINGS. TEMPERATURES SHOULD RANGE ON
TUESDAY FROM THE MID 30S ALONG THE ND BORDER...TO 50 OR SO IN THE
SOUTHWEST CWA. LOWS TUESDAY NIGHT SHOULD DIP BACK INTO THE
20S...WITH ONLY SOME MINOR RECOVERY ON WEDNESDAY...ESPECIALLY OVER
THE NORTHEAST CWA.

.LONG TERM...THURSDAY THROUGH MONDAY
NO CHANGES PLANNED TO THE LONG TERM AT THIS TIME. MODELS STILL
PREDICTING SEVERAL S/W TROUGHS TO WORK THROUGH THE REGION. TRICKY
FORECAST AS IT APPEARS THAT THE DAKOTAS WILL BE THE ZONE WHERE A
SPLIT FLOW PATTERN MERGES BACK INTO ONE PREDOMINANT WESTERLY
JET STREAM...WHICH INTRODUCES THE POTENTIAL FOR WEATHER SYSTEMS TO
PERHAPS BE SHUNTED A BIT SOUTH OF THIS CWA AS THEY WORK EAST
THROUGH THE PLAINS STATES. HIGHEST POPS...BY FAR...ARE CENTERED ON
THURSDAY NIGHT INTO FRIDAY MORNING. BEYOND THAT...POPS BECOME LESS
IN PERCENTAGE AND COVERAGE...UNTIL IT IS A DRY FORECAST BY SUNDAY
NIGHT. PREVIOUS THINKING OF BELOW NORMAL TEMPS STILL STICKS...AS
HIGH PRESSURE SETS UP OVER THIS CWA BY THURSDAY AND BASICALLY
REMAINS THROUGH THE WEEKEND. THIS SURFACE PATTERN SHOULD SUPPORT
THE USHERING OF COLDER AIR OUT OF CANADA INTO THIS AREA...WHICH
SHOULD THEN STICK AROUND FOR SEVERAL DAYS. ANY WARMING TREND WOULD
BE DUE TO AIRMASS MODERATION.

&&

.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS

MVFR/IFR CIGS WILL CONTINUE THROUGH FORECAST PERIOD. LOOK FOR
-RA/RA TO DEVELOP IN VCNTY OF KPIR TERMINAL BY 06Z...AND REMAINDER
OF TERMINALS BY 10Z. SOME ISOLD -TSRA IS PSBL IN THE KATY TERMINAL
AFT 08Z...BUT LOW CONFIDENCE IN AREAL COVERAGE AND ACTUAL
OCCURRENCE PREVENTED MENTION IN TERMINAL FCST ATTM.

&&

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

UPDATE...HINTZ
SHORT TERM...TDK
LONG TERM...DORN
AVIATION...HINTZ

WEATHER.GOV/ABERDEEN

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE ABERDEEN SD
726 AM CDT MON MAR 21 2011

SDZ003>005-009-010-015>017-033>037-045-048-051-221230-
CORSON-CAMPBELL-MCPHERSON-WALWORTH-EDMUNDS-DEWEY-POTTER-FAULK-
STANLEY-SULLY-HUGHES-HYDE-HAND-JONES-LYMAN-BUFFALO-
726 AM CDT MON MAR 21 2011 /626 AM MDT MON MAR 21 2011/

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

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

PRECIPITATION AHEAD OF A DEVELOPING STORM SYSTEM WILL BEGIN TO
REACH THE REGION LATE MONDAY NIGHT/TUESDAY MORNING...WITH
WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY. THUNDERSTORMS ARE NOT
EXPECTED TO BE SEVERE...HOWEVER RAINFALL DURING THE DAY TUESDAY
COULD EXACERBATE ANY ONGOING FLOOD ISSUES. PRECIPITATION WILL
CHANGE OVER TO SNOW STARTING AT THE NORTH DAKOTA BORDER DURING
MID DAY TUESDAY...PROGRESSING SOUTH THROUGH THE AFTERNOON AND
EVENING...WITH THE ENTIRE CWA UNDER A COLD ENOUGH AIRMASS FOR
ACCUMULATING SNOW BY WEDNESDAY MORNING. IMPROVING CONDITIONS
EXPECTED LATE WEDNESDAY INTO EARLY THURSDAY...HOWEVER LOCATIONS IN
THE NORTHERN SISSETON HILLS/WEST CENTRAL MINNESOTA COULD SEE AS
MUCH AS 4" OF SNOW. LOWER AMOUNTS ARE EXPECTED ELSEWHERE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT.

MNZ039-046-SDZ006>008-011-018>023-221230-
TRAVERSE-BIG STONE-BROWN-MARSHALL-ROBERTS-DAY-SPINK-CLARK-
CODINGTON-GRANT-HAMLIN-DEUEL-
726 AM CDT MON MAR 21 2011

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

.DAY ONE...TODAY AND TONIGHT

MORNING FOG IS EXPECTED FOR LOCATIONS LOCATED IN THE JAMES VALLEY
AND SISSETON HILLS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

PRECIPITATION AHEAD OF A DEVELOPING STORM SYSTEM WILL BEGIN TO
REACH THE REGION LATE MONDAY NIGHT/TUESDAY MORNING...WITH
WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY. THUNDERSTORMS ARE NOT
EXPECTED TO BE SEVERE...HOWEVER RAINFALL DURING THE DAY TUESDAY
COULD EXACERBATE ANY ONGOING FLOOD ISSUES. PRECIPITATION WILL
CHANGE OVER TO SNOW STARTING AT THE NORTH DAKOTA BORDER DURING
MID DAY TUESDAY...PROGRESSING SOUTH THROUGH THE AFTERNOON AND
EVENING...WITH THE ENTIRE CWA UNDER A COLD ENOUGH AIRMASS FOR
ACCUMULATING SNOW BY WEDNESDAY MORNING. IMPROVING CONDITIONS
EXPECTED LATE WEDNESDAY INTO EARLY THURSDAY...HOWEVER LOCATIONS IN
THE NORTHERN SISSETON HILLS/WEST CENTRAL MINNESOTA COULD SEE AS
MUCH AS 4" OF SNOW. LOWER AMOUNTS ARE EXPECTED ELSEWHERE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT.

CONNELLY