Severe Thunderstorm Warning 178, NWS Sioux Falls, SD

000 
WWUS53 KFSD 280017
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
717 PM CDT FRI JUN 27 2008

SDC027-135-280027-
/O.CAN.KFSD.SV.W.0178.000000T0000Z-080628T0030Z/
YANKTON SD-CLAY SD-
717 PM CDT FRI JUN 27 2008

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN CLAY AND EASTERN
YANKTON COUNTIES IS CANCELLED...

THE STORM HAS WEAKENED AND IS NO LONGER SEVERE.

LAT...LON 4291 9703 4287 9735 4317 9746 4317 9723
TIME...MOT...LOC 0017Z 325DEG 33KT 4297 9722

$$

08

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
212 PM CDT FRI JUN 27 2008

.DISCUSSION...
LAST LN OF SHRA/ISOLD TSRA ASSCD WITH LEADING EDGE OF MID LVL COLDER
AIR APPROACHING BKX TO FSD TO YKN LN AT 20Z. THIS LINE WILL MOVE ESE
THRU SWRN MN AND NWRN IA WHERE ISOLD DECENT TSTMS ARE STILL PSBL
THRU 01Z OR SO...FLWD BY CLRG AND DRYING WITH WNWLY FLOW. WRAPAROUND
WITH SC DECK AND SLGT CHCS OF -SHRA/ISOLD TSRA THEN MOVE INTO NWRN
TO FAR NRN CWA LATE TNGT AS PER PREV FCST. SHOULD BE A PERIOD OF
DECOUPLING AND LIGHTER WINDS TNGT BEFORE WNWLY GRADIENT AND MIXING
REALLY KICK IN FM NW TO SE IN CWA LATER TNGT.

UNSEASONABLY COLD UPPER LEVEL LOW...WITH COLDEST 500MB TEMPS ON THE
ORDER OF -20C...SWINGS EAST THROUGH THE CWA SATURDAY MORNING...WITH
CYCLONIC CURVATURE ON THE BACKSIDE PROVIDING WEAK LIFT/INSTABILITY
ACROSS THE NORTHEAST HALF OF OUR FORECAST AREA THRU THE AFTERNOON.
CORE OF COLDEST UPPER LEVEL TEMPS SHIFTS EAST OF US INTO THE UPPER
MISSISSIPPI VALLEY BY LATE AFTERNOON...WITH 500MB TEMPS BACK UP TO
AROUND -12C BY 21Z-00Z. THIS SHOULD HELP KEEP ANY THUNDERSTORMS IN
CHECK AND THINK THREAT OF SEVERE IS LIMITED THIS FAR WEST. WILL BE
QUITE WINDY EVEN WITHOUT TSRA THOUGH...WITH 25-30MPH SUSTAINED AND
GUSTS APPROACHING 40MPH IN THE AFTERNOON. MAY HAVE TO WATCH FAVORED
ELEVATION AREAS FOR WIND ADVISORY...BUT LOOKS MARGINAL...SO WILL
HOLD OFF ISSUING AT THIS TIME. WITH COLD POCKET JUST EAST OF THE
AREA SATURDAY AFTERNOON...WILL BE LOOKING AT HIGHS 10-15 DEGREES
BELOW NORMAL ALONG AND EAST OF I-29.

WINDS WILL DECREASE TOWARD SUNSET SATURDAY...THOUGH COULD REMAIN
BREEZY ACROSS SOUTHWEST MN MUCH OF THE NIGHT. WINDS WILL PICK UP
AGAIN ON SUNDAY WITH DEEP NORTH-NORTHWEST FLOW FAVORING STRONG
MIXING. NOT AS STRONG AS SATURDAY...BUT STILL LOOKING AT 15-25 MPH
ACROSS THE EASTERN HALF OF THE AREA IN THE AFTERNOON. SLOW RECOVERY
IN TEMPS THROUGH MONDAY...THOUGH STILL ON THE COOL SIDE OF NORMAL...
EVEN WITH MORE WIDEPSREAD SUNSHINE AS THE UPPER LOW BEGINS TO PULL
EAST AND HIGH PRESSURE BUILDS INTO THE AREA.

COLD UPPER LOW IS A LITTLE SLOWER TO MOVE EAST EARLY NEXT WEEK...SO
DECENT MOISTURE ALSO SLOWER TO RETURN. STILL SHOULD SEE BEGINNING OF
WARMUP ON TUESDAY...THOUGH NOT QUITE AS AGGRESSIVE SO HAVE COOLED A
FEW DEGREES FROM PREVIOUS FORECAST. STILL SEEING A WEAK WAVE DROP
THROUGH THE NORTHWEST FLOW OVER EASTERN ND AND MN TUESDAY NIGHT...
THOUGH MOISTURE PROFILES NOT IMPRESSIVE AND HAVE PULLED POPS FROM
THAT PERIOD. BETTER CHANCE OF PRECIP WITH DEEPER MOISTURE RETURN AS
BOUNDARY PUSHES SOUTH THROUGH THE FORECAST AREA WEDNESDAY AND
WEDNESDAY NIGHT. MODELS DIFFER IN HANDLING THIS BOUNDARY...WITH
ECMWF CONSISTENT IN ITS MORE AGGRESSIVE PUSH OF THE BOUNDARY SOUTH
INTO THE CENTRAL PLAINS FOR LATE NEXT WEEK...WHILE THE 00Z-06Z GFS
RUNS HANG THE BOUNDARY UP NORTH OF OUR AREA. CANADIAN FAVORS ECMWF
SOLUTION...AS DOES MOST RECENT 12Z GFS...AND HAVE TRENDED IN THIS
DIRECTION IN KEEPING THURSDAY AND FRIDAY DRY AND SEASONABLE FOR NOW.
BEARS WATCHING OVER THE NEXT FEW DAYS THOUGH...WITH FRIDAY THE START
OF THE HOLIDAY WEEKEND.

&&

.AVIATION...
GENERALLY VFR EXPCD. ISOLD MVFR CIGS AND VSBYS PSBL IN ISOLD TSRA
MOVG EAST OF I29 THRU 01Z...THEN BORDERLINE MVFR CIGS MOVG SEWD INTO
AREA NORTH OF I90 FM 12Z TO 16Z.

&&

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

&&

 JH/RSR

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1012 AM CDT FRI JUN 27 2008

SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098-
IAZ001>003-012>014-020>022-031-032-NEZ013-014-281200-
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-
1012 AM CDT FRI JUN 27 2008

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 WEST OF THE JAMES RIVER THIS
MORNING...WILL MOVE EAST OVER THE AREA THIS AFTERNOON. MOST
THUNDERSTORMS SHOULD STAY BELOW SEVERE LIMITS. HOWEVER...THERE IS
THE CHANCE OF ISOLATED HAIL REACHING PENNY SIZE AND LOCALIZED
WIND GUSTS UP TO 45 MPH...MAINLY ALONG AND EAST OF INTERSTATE 29
THIS AFTERNOON.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

SHOWERS AND A FEW THUNDERSTORMS WILL PROBABLY DEVELOP ALONG AND
EAST OF THE JAMES RIVER VALLEY ON SATURDAY. A FEW STORMS IN THE
AFTERNOON COULD HAVE MARGINALLY SEVERE HAIL AND BRIEF WIND GUSTS
TO 40 TO 60 MPH.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE POSSIBLE AFTER 2 PM CDT...MAINLY ALONG
AND EAST OF INTERSTATE 29.

&&

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

RSR