Flash Flood in Iowa, April 6, 2005

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
350 AM CDT WED APR 6 2005

.DISCUSSION...
CUT OFF STACKED UPPER LOW OVER CENTRAL OKLAHOMA TAKING ITS TIME
VACATING THE AREA RESULTING IN SCATTERED SHOWERS WITH EMBEDDED
THUNDERSTORMS IN A LINE FROM KMWM TO KFSD TO KYKN. CLOUD TOPS
WARMING ACROSS THE AREA...AND AS A RESULT ANTICIPATE STORMS TO FALL
APART AS UPPER LEVEL LOW INCHES OFF TO THE EAST. AS THE DAY
PROGRESSES...EXPECT SKIES TO BECOME MOSTLY CLEAR...ESPECIALLY IN THE
WEST. THIS WILL RESULT IN DECENT MIXING ALLOWING STRONGER WINDS
ALOFT TO REACH THE SURFACE. WINDS FAIRLY UNIDIRECTIONAL OUT OF THE
NORTH WITH 20 TO 25 KNOTS AT 925 MB AND 30 TO 35 KNOTS AT 850 MB.
THESE SPEEDS WILL RESULT IN VALUES BELOW ADVISORY CRITERIA...BUT
CONDITIONS WILL STILL BE BREEZY. SKIES WILL BECOME PRISTINE TONIGHT
AND REMAIN SO ON THURSDAY AS HIGH PRESSURE BUILDS INTO THE AREA.
WARMED TEMPERATURES UP A FEW DEGREES ON THURSDAY WITH GRASSES STILL
DORMANT. WITH THAT SAID...STILL LIMITED THE EXTENT OF THE WARM UP
WITH SOUTH TO SOUTHEAST FLOW AS THESE DIRECTIONS ARE NOT AS
FAVORABLE FOR SIGNIFICANT MIXING. KEPT LOW TEMPS ABOVE AVERAGE BOTH
THURSDAY AND FRIDAY NIGHTS AS LOW LEVEL JET FORMS OVER THE AREA
AHEAD OF A COLD FRONT THAT ATTEMPTS TO MOVE THROUGH THE AREA ON
SATURDAY. PARENT LOW PRESSURE SYSTEM OVER MANITOBA WEAKEN
SIGNIFICANTLY ON SATURDAY AS SECOND LOW PRESSURE SYSTEM UNDERGOES
STRONG CYCLOGENESIS ON THE LEE SIDE OF THE ROCKIES IN EASTERN
COLORADO. SYSTEM IN COLORADO FORMS ON THE NORTHERN EDGE OF THE
SOUTHERN BRANCH OF THE JET AND AS A RESULT IS IN NO HURRY TO MOVE
EAST. THEREFORE...KEPT POPS FROM LATE ON SUNDAY THROUGH TUESDAY.
&&

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

&&

BT

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE SIOUX FALLS SD
538 AM CDT WED APR 06 2005

CORRECTED FORMAT

SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098-IAZ001>003-
012>014-020>022-031-032-NEZ013-014-071200-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-
538 AM CDT WED APR 06 2005

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

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS...
SCATTERED THUNDERSTORMS CAN BE EXPECTED THIS MORNING SOUTH AND
EAST OF A LINE FROM WINDOM MINNESOTA...TO ROCK RAPIDS...TO SIOUX
CITY. A FEW OF THESE STORMS WILL BE CAPABLE OF PRODUCING BRIEF
HEAVY RAINFALL AND HAIL TO THE SIZE OF NICKELS. THESE STORMS ARE
EXPECTED TO MOVE SOUTH AND EAST OF THE AREA BY NOON CDT.

FIRE DANGER...
THE GRASSLAND FIRE DANGER INDEX WILL BE VERY HIGH THIS AFTERNOON
WEST OF A LINE FROM LAKE ANDES TO HURON. THESE CONDITIONS ARE DUE
TO TEMPERATURES IN THE UPPER 50S AND LOWER 60S...COMBINED WITH DEW
POINTS IN THE UPPER 20S AND LOWER 30S...CREATING RELATIVE
HUMIDITIES OF 25 TO 30 PERCENT. IN ADDITION...GUSTY NORTH WINDS
OF 20 TO 30 MPH WILL PERSIST THROUGHOUT MUCH OF THE DAY TODAY. THESE
WINDS ARE EXPECTED TO DIMINISH IN THE LATE AFTERNOON AND EVENING
HOURS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE POSSIBLE THROUGH NOON TODAY.

&&

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

BT