Hail in South Dakota, May 5, 2005

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
250 PM CDT THU MAY 5 2005

.DISCUSSION...
FAIRLY COMPLEX FCST THIS GO AROUND...BOTH IN THE SHORT TERM AND
EXTENDED...WITH THE MAIN CHALLENGE PCPN CHANCES. INTERESTING
PHENOMENA...WE HAD TO ISSUE A RED FLAG WARNING UNTIL 7 PM THIS
EVENING FOR COTTONWOOD AND JACKSON COUNTIES. WITH THE SSW FLOW...
THERE APPEARS TO BE SOME DOWNSLOPE COMPONENT OFF OF THE BUFFALO
RIDGE AND TOWARD THE MN RIVER VALLEY. THIS HAS NOT ALLOWED THE
DEWPTS IN THE ENTIRE AREA FM REDWOOD FALLS...DOWN TO JACKSON MN TO
COME UP AT ALL...WITH MUCH HIGHER READINGS TO THEIR S AND W.
ELSEWHERE...FRONTAL BOUNDARY HAS PULLED INTO SERN ND WITH A SFC TROF
EXTENDING BACK INTO CENTRAL SD...AND DECENT MID LVL WAVE MOVG EWD
OVER THESE SFC FEATURES. THEREFORE SOME ELEVATED ACTIVITY HAS FIRED
UP NEAR THE LOW LVL CONVERGENCE FM W CENTRAL MN...BACK INTO NE SD
AND CENTRAL SD. MUCH OF THIS ACTIVITY WL SLIDE STRAIGHT EWD...
AFFECTING THE NRN THIRD OF THE CWFA AS THE FRONT HAS LITTLE SWD PUSH
MUCH BEYOND NE SD...CLEARLY EVIDENCED BY THE UPPER -DIV Q. ISOLD SVR
TS IS POSSIBLE WITH ANY GIVEN CELL...ALBEIT SHORT LIVED...PULSEY AND
MARGINAL GIVEN THE INSTABILITY PARAMETERS AND AVAILABLE CAPE. LATER
TONIGHT...DECENT LLVL JET BLO H85 IS EVIDENT IN ERN AND CENTRAL NEB
WHICH BEGINS TO INTERACT WITH A SUBTLE H7 SHORTWV IN CENTRAL NEB.
THIS COULD FIRE OFF A FEW TS IN OUR SW AND S CENTRAL CWFA...INTO FRI
MRNG...WHERE LOW TO MID LVL FRONTOGENESIS IS FOUND.

ON FRIDAY...THE CDFNT RETREATS BACK NWD AS A WMFNT...BUT THERE
REALLY ISNT ANYTHING TO HANG YOUR HAT ON FOR FOCUSING MECHANISM FOR
MUCH OF THE DAY FOR PCPN CHCS. GIVEN H85 TEMPS...WL BE WARM AND MOST
GUIDANCE TEMPS LOOK REASONABLE BUT HEDGED ON THE WARMER READINGS.
NOW THE NAM HAS BEEN REMARKABLY CONSISTENT WITH MOVG A MID LVL
SHORTWV THRU THE FA FRI NIGHT...AND PUSHING A SFC TROF INTO THE WRN
PLAINS JUST W OF THE FA. AS PER THE PAST SEVERAL RUNS...THE SHORTWV
MAINLY AFFECTS THE ERN HALF OF THE FA...WITH DECENT INSTABILITY AND
VERY GOOD WIND SHEAR...CERTAINLY DEEP MSTR IS NO PROBLEM. THEREFORE
LIKELY POPS OVR MUCH OF THE E IS WARRANTED.

SAT AND SAT NIGHT LOOK TO BE AN IN-BETWEEN SETUP...WITH REALLY NOT A
LOT GOING ON. DISCREPANCIES EXIST BETWEEN THE MID AND UPPER LOW
BETWEEN THE NAM AND THE GFS...NOT SO MUCH IN PLACEMENT BUT THE NAM
IS MUCH MORE CLOSED WITH IT THAN THE GFS. AT ANY RATE...THE POSITION
IS NOT GOOD FOR THIS FA. SLY FLOW WL CONTINUE AND IT IS VERY WARM
THRU THE WEEKEND...BUT LITTLE IN THE WAY OF FOCUS...BOTH IN THE LOW
LVLS AND ALOFT SAT AND SAT NIGHT. WITH PURE INSTABILITY AND LAPSE
RATES...CANNOT RULE OUT A SLGT CHC ON SATURDAY AT ANY GIVEN
LOCATION...WITH A SLIGHTLY BETTER CHC IN OUR FAR WEST LATE SAT NIGHT
CLOSER TO THE LOW LVL BOUNDARY. ON SUNDAY...WENT WITH THE SLOWER GFS
TIMING FOR FRONTAL POSITION...BUT AGAIN THE MID AND UPPER LOW
PLACEMENT IS NOT GOOD FOR THIS FA. BEST CHCS ON SUNDAY AFTN WL BE
AHEAD OF THE FRONT IN NW IA WHERE WIND SHEAR IS VERY STRONG...AND
POST FRONTAL IN THE WRN CWFA WHERE A TON OF LOW LVL MSTR AND STRATO
CU COULD BE AROUND. SUNDAY EVENING THE CRUX OF THE BOUNDARY MOVES
THRU WITH PLENTY OF DYNAMICS SO GOOD CHCS OF TS EXIST THRU THE
ENTIRE ERN HALF OF THE FA.

IN THE EXTENDED...00Z AND 06Z GFS...COUPLED WITH THE ECMWF AND DGEX
ARE IN FAIRLY GOOD AGREEMENT WITH THE LARGE SCALE FEATURES. THE
AFOREMENTIONED CDFNT EXITS THE ERN CWFA MON MORNING...WITH SHORTWV
RIDGING DOMINATING MON AND MON NIGHT. ON TUE AND TUE NIGHT...ANOTHER
LARGE UPPER LOW MOVES INTO THE AREA TO OUR WEST...THEN THERE APPEARS
TO BE A VERY STRONG WMFNT MOVG NWD THRU THIS FA AHEAD OF IT ON TUE
NIGHT AND WED. THAT WL BE OUR FOCUS FOR TS.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...RED FLAG WARNING THRU 7 PM FOR MNZ081 AND MNZ090.
IA...NONE.
NE...NONE.

&&

MJF/08

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SIOUX FALLS SD
157 PM CDT THU MAY 05 2005

SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098-
IAZ001>003-012>014-020>022-031-032-NEZ013-014-061200-
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-
157 PM CDT THU MAY 05 2005

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

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS...
A FEW THUNDERSTORMS COULD DEVELOP NORTH OF INTERSTATE 90 LATE
THIS AFTERNOON...AND ADDITIONAL THUNDERSTORMS COULD DEVELOP LATE
TONIGHT ALONG THE MISSOURI RIVER VALLEY. ANY THUNDERSTORMS THAT
DEVELOP ARE EXPECTED TO DISSIPATE BY ABOUT 900 PM CDT NORTH OF
INTERSTATE 90. NONE OF THESE STORMS ARE EXPECTED TO BECOME
SEVERE...ALTHOUGH SOME SMALL HAIL WILL BE POSSIBLE.

FIRE DANGER...
A RED FLAG WARNING IS IN EFFECT FOR COTTONWOOD AND JACKSON
COUNTIES IN SOUTHWEST MINNESOTA THROUGH 700 PM CDT. SOUTHWEST
WINDS OF 20 TO 30 MPH ALONG WITH RELATIVE HUMIDITIES NEAR 20
PERCENT WILL CREATE VERY DANGEROUS BURNING CONDITIONS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

SCATTERED THUNDERSTORMS SHOULD DEVELOP NEAR THE MISSOURI RIVER BY
LATE FRIDAY AFTERNOON...AND THEN MOVE NORTHEAST OVER THE TRI
STATE AREA FRIDAY NIGHT. THE BEST CHANCE FOR THUNDERSTORMS SHOULD
FALL AFTER 1000 PM CDT. LARGE HAIL IS THE MAIN THREAT FROM THESE
STORMS...ALTHOUGH SOME LOCALLY HEAVY RAINFALL WILL BE POSSIBLE.

SCATTERED THUNDERSTORMS COULD AGAIN DEVELOP FROM SOUTH CENTRAL
SOUTH DAKOTA TO NEAR BROOKINGS AND MARSHALL BY LATE SATURDAY
AFTERNOON...THEN MOVE EAST THROUGH THE REST OF AREA SATURDAY
NIGHT. AT THIS TIME...CONDITIONS ALOFT ARE NOT EXTREMELY
FAVORABLE FOR WIDESPREAD THUNDERSTORM ACTIVITY.

THUNDERSTORMS MAY AGAIN DEVELOP SUNDAY AFTERNOON IN THE
AREA...MAINLY EAST OF INTERSTATE 29 AHEAD OF COLD FRONT. THESE
STORMS COULD ALSO BECOME SEVERE...BUT MOST OF THE SEVERE ACTIVITY
SHOULD REMAIN EAST OF THE AREA.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT.

&&

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

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