River Flood Watch 1, NWS Sioux Falls, SD

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1048 AM CDT TUE MAR 15 2011

.DISCUSSION...
SHOWERS ASSOCIATED WITH A PASSING TROUGH CURRENTLY ALONG THE I 29
CORRIDOR NORTH OF SIOUX FALLS. NOT MUCH HITTING THE GROUND BUT
SEEING A FEW HUNDRETHS BEING MEASURED AT SURFACE OBSERVING
STATIONS. MADE MINOR CHANGES TO THE SHORT TERM FORECAST...MAINLY FOR
FASTER EASTWARD MOVEMENT OF SHOWERS AND LOWERED POPS SOUTH OF
INTERSTATE 90. MOST OF THE MEASURABLE SHOWERS WILL BE ACROSS
SOUTHWEST MN THIS MORNING...ENDING BY EARLY THIS AFTERNOON. SKIES
ALREADY CLEARING FROM THE WEST. WILL SEE MOSTLY SUNNY SKIES ACROSS
THE FORECAST AREA BY MID AFTERNOON.  /97

&&

.AVIATION...
A BRIEF PERIOD OF LIGHT RAIN WILL BE POSSIBLE ACROSS SW MN BEFORE
18Z AS A FRONTAL BOUNDARY/UPPER LEVEL DISTURBANCE PUSHES ACROSS THE
AREA. EVEN SO...VISIBILITIES/CEILINGS EXPECTED TO REMAIN IN THE VFR
RANGE THROUGH THE DAY. SKIES TO CLEAR OUT BEHIND THE TROUGH AXIS.
MAY SEE SOME FOG FORMATION BY LATE TONIGHT.

&&

.PREV DISCUSSION...
WAVE AND ASSOCIATED SURFACE FRONT OVER THE WESTERN DAKOTAS WILL
CONTINUE TO MOVE EAST TODAY AND SHOULD MOVE THROUGH EASTERN CWA BY
EARLY AFTERNOON. PLENTY OF MID AND HIGH CLOUDS SPREADING ACROSS THE
CWA AHEAD OF THIS FEATURE WITH LIGHT RAIN STILL ACROSS WESTERN
SOUTH DAKOTA. SHOULD SEE A CHANCE OF RAIN DEVELOP ACROSS THE CWA
THIS MORNING AS FRONT APPROACHES AND THEN END FROM THE WEST LATE
MORNING INTO AFTERNOON AS UPPER WAVE MOVES TO THE EAST. LOOKS LIKE
THE BEST CHANCE FOR ANY MEASURABLE LIGHT RAIN WILL BE ACROSS THE
NORTHERN CWA SO WILL GO WITH 40 TO 50% NORTH OF I90 WITH ONLY 20 TO
30% TO THE SOUTH. CLOUD COVER WILL HELP TO KEEP TEMPERATURES DOWN A
BIT...BUT WITH SOME SUN EXPECTED ESPECIALLY IN THE
AFTERNOON...TEMPERATURES SHOULD BE ABOVE NORMAL MOST PLACES EXCEPT
ACROSS SOUTHWEST MN WHERE CLOUDS WILL REMAIN MOST OF DAY.

SHOULD BE QUIET ACROSS THE CWA TONIGHT WITH CLEAR TO PARTLY CLOUDY
SKIES. STRONG WAA SHOULD SPREAD ACROSS CWA ON WEDNESDAY WITH GUSTY
SOUTH WINDS EXPECTED. SHOULD GENERALLY SEE HIGHS FROM THE LOWER 50S
OVER THE DEEPER SNOW PACK OF THE NORTHEAST CWA TO NEAR 70 ACROSS THE
SOUTHWEST.

ANOTHER UPPER WAVE TO AFFECT PORTIONS OF THE CWA LATE WEDNESDAY
NIGHT AND THURSDAY WITH A CHANCE OF LIGHT RAIN. MODELS SEEM MORE IN
AGREEMENT WITH KEEPING THE BULK OF THE LIGHT RAIN NORTH OF THE CWA
AND WILL TRIM BACK RAIN CHANCES TO 20 TO 40% AT THE MOST WITH BEST
CHANCE NORTH. IF NORTHERN TRACK CONTINUES...LATER SHIFT MAY BE ABLE
TO REMOVE RAIN CHANCE COMPLETELY FROM THE SOUTH. COLD FRONT
ASSOCIATED WITH THIS FEATURE SHOULD MOVE ACROSS THE CWA THURSDAY
MORNING AND WITH LOW LEVEL CAA BEHIND FRONT...NORTHERN CWA WILL ONLY
CLIMB INTO THE LOWER TO MID 40S FOR HIGHS AND 50S ACROSS THE SOUTH.

YET ANOTHER WEAK WAVE WILL MOVE ACROSS THE CWA LATER THURSDAY NIGHT
AND FRIDAY MORNING AND WILL BRING ANOTHER CHANCE OF LIGHT RAIN OR
LIGHT SNOW DURING THAT TIME PERIOD. WILL BE COOLER ON FRIDAY WITH
THE CLOUDS AND NORTHEAST LOW LEVEL FLOW.

WEEKEND STILL LOOKS UNSETTLED WITH THE BEST CHANCE FOR RAIN SATURDAY
NIGHT INTO SUNDAY NIGHT. COULD EVEN SEE THUNDERSTORMS ACROSS THE
AREA SUNDAY AFTERNOON AND EVENING WITH POTENTIAL FOR A FEW
MARGINALLY SEVERE STORMS ACROSS NORTHWEST IOWA AS NOSE OF 50 KNOT
LOW LEVEL JET INTERACTS WITH QUASI SURFACE WARM FRONT. OF COURSE THE
MAIN CONCERN WILL BE HOW MUCH RAIN WILL OCCUR WITH FLOODING THREAT
LOOMING...AND POTENTIAL DOES EXIST FOR SOME LOCALLY HEAVY RAINS
ESPECIALLY WITH RAPID TRANSPORT OF DEEPER LOW LEVEL MOISTURE WITH
SUCH A STRONG LOW LEVEL JET. RIGHT NOW IT APPEARS THE BEST THREAT
FOR THE HEAVIER RAIN WOULD BE OVER THE SNOW FREE AREAS OF THE
SOUTHEAST CWA AND NOT OVER THE DEEPER SNOW PACK AREAS.

&&

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

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SIOUX FALLS SD
350 AM CDT TUE MAR 15 2011

SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098-
IAZ001>003-012>014-020>022-031-032-NEZ013-014-161200-
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-
350 AM CDT TUE MAR 15 2011

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

.DAY ONE...TODAY AND TONIGHT

FLOODING...
MINOR FLOODING IS EXPECTED FOR THE NEXT FEW DAYS ON THE LITTLE
SIOUX RIVER IN NORTHWEST IOWA.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A STRONG STORM SYSTEM WILL MOVE ACROSS THE PLAINS SATURDAY NIGHT
THROUGH SUNDAY AND MAY PRODUCE LOCALLY HEAVY RAINS ACROSS
PORTIONS OF NORTHWEST IOWA AND FAR SOUTHEAST SOUTH DAKOTA.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT.

&&

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