Severe Thunderstorm Warning 547, NWS Sioux Falls, SD

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
255 PM CDT FRI OCT 22 2004

.DISCUSSION...

STG LO MOVG OVER AREA THIS EVE WILL TRIGGER SHWRS/TSTMS...SCT TSTMS
E THIS EVE WITH SOME SVR...SHWRS AND TSTMS LIKELY FRTHR W. STILL
LOOKING AT MINUTE BY MINUTE QSTNS ON TSTM DVLPMNT AND SVR POTENTL.
MAIN QSTNSEEMS TO BE MOISTR DEPTH. OF COYRSE EXPCT PRETTY GOOD CVRG
OF ACTVTY TO SPRD OVER AREA DURNG TNGT AS UPPR LO MOVES BY BUT THAT
WONT BE SVR.

LINGRNG SHWRS N/E SHUD EXIT PRETTY QUICKLY SAT MRNG AS SYS MOVES NE
OF AREA...MAKING FOR DECENT SUBSDNCE. SKIES SHUD PRTLY CLR SAT WITH
A BREEZY DAY AND FAIRLY MILD TEMPS. SYS SAT NGT AND SUN WITH WK
CDFNT SLIPPNG THRU AREA STILL EXPCTD TO BE DRY WITH SHWRS STAYING TO
THE N. A LTL WARMNG SUN THEN COOLR SUN NGT AND MON...BUT STILL
FAIRLY NICE WITH RELTVLY DRY AIR OVER AREA. ANOTHER WK SYS TRIES TO
NUDGE CLOSE FROM THE W TUE BUT WILL KEEP SKIES PTCLDY.

EXTENDED SYS DEALS WITH DRY START LEADING TO EFFECTS OF MAJOR TROF
DIGGING INTO WRN U.S. BY MIDWEEK. WILL GO WITH IDEA OF WRMFNTL SHWRS
WED...COPNTG CHC SHWRS THU AS STGR SYS APPCHS AREA UP FRONT SIDE OF
MAJOR TROF AS ON NGT MODELS RUNS. DAY GFS IS SLOWER AND HOLD MORE OF
SYS TO THE W...SUGGESTG CONTD CHC SHWRS FOR FRI. FOR NOW WILL GO
WITH IDEA OF DRY FRI BUT AS USUAL MODELS LIKELY TO DO FLIP FLOPS
THAT FAR AHD. AM BEING VERY CONSERVATIVE ON TEMP CHANGES WITH WARM
SRLY FLOW DVLPG DURG WEEK LIKELY TO BE TEMPERED BY INCRS IN
MOISTR...CUD EVEN TURN OUT SOMETHING LIKE LAST FEW DAYS WITH LOTS OF
LO CLDS/DRZL THO WONT GO FOR THAT FOR NOW. OTRW ON THE OTHER SIDE OF
THINGS...IT CUD GO BACK TO UNSEASONABLY WRM FOR A SPELL.A LTL COOLNG
FRI AGN VERY TAME...AGN IF SYS SLOWS DOWN SO WILL ALL ANTICIPATED
CHANGES.

&&

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

&&

WILLIAMS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SIOUX FALLS SD
340 PM CDT FRI OCT 22 2004

SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098-
IAZ001>003-012>014-020>022-031-032-NEZ013-014-231200-
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-
340 PM CDT FRI OCT 22 2004

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

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS...
AN AREA OF LOW PRESSURE WILL CONTINUE TO SLIDE EAST ACROSS THE
AREA THIS EVENING. A WARM FRONT WILL CONTINUE TO LIFT TO THE
NORTH THROUGH THE EVENING AND MAY PROVIDE THE FOCUS FOR A FEW
STRONG TO SEVERE STORMS LATE THIS AFTERNOON INTO EARLY THIS
EVENING. THE THREAT FOR SEVERE THUNDERSTORMS WILL EXIST ALONG AND
EAST OF A WAGNER TO DE SMET LINE. STORMS THAT FORM DURING THIS
TIME MAY PRODUCE WIND GUSTS TO 70 MPH AND LARGE HAIL. A FEW
TORNADOES ARE ALSO POSSIBLE THROUGH 9 PM...MAINLY EAST OF A DE
SMET TO YANKTON LINE.

A STRONG UPPER LEVEL DISTURBANCE WILL ALSO BEGIN TO AFFECT THE
AREA EARLY THIS EVENING AND OVERNIGHT. SCATTERED THUNDERSTORMS
WILL BEGIN TO FORM AHEAD OF THIS FEATURE WEST OF A MITCHELL TO
TYNDALL LINE AFTER 7 PM. THESE STORMS WILL ORGANIZE INTO A LINE
AND SLIDE EAST ACROSS THE REST OF THE AREA OVERNIGHT. THE PRIMARY
THREAT WITH THESE OVERNIGHT STORMS WILL BE HAIL UP TO THE SIZE OF
NICKELS AND WIND GUSTS TO 70 MPH.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE POSSIBLE AFTER 5 PMALONG AND EAST OF A
BONESTEEL TO STICKNEY TO  DE SMET LINE

&&

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

JRM