Flash Flood Warning 27, NWS Sioux Falls, SD

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
300 PM CDT MON JUL 5 2010

.DISCUSSION...

SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING PRETTY MUCH AS
EXPECTED...JUST A BIT MORE COVERAGE. EVERY CELL HAS DISPLAYED
ATTRIBUTES OF HEAVY RAINERS VERSUS HAILERS WITH MOST IF NOT ALL OF
THE 50+ DBZ FOUND BELOW 20 KFT. FREEZING LEVEL AROUND 15 KFT. HAVE
ALSO HAD REPORTS OF A FEW FUNNEL CLOUDS FROM DEVELOPING CELLS AND
THIS SEEMS TO MAKE SENSE WITH A SFC TO 3KM CAPE AROUND 150 J/KG AND
A WEAK AXIS OF VORTICITY FROM NW IA INTO SW MN. THE SHALLOW AND DEEP
LAYER SHEAR IS VERY WEAK SO DO NOT EXPECT ANY OF THESE FUNNELS TO
DEVELOP INTO TORNADOES. A COUPLE OF THE CELLS HAVE DISPLAYED A WEAK
ROTATIONAL COUPLET WITH THEM IN THE LOW LEVELS BUT NOTHING WORTH
WARNING ON. SO...WILL KEEP MID RANGE POPS IN PLACE THROUGH THE
AFTERNOON AND EVENING OVER THE SOUTHEAST TWO THIRDS OF THE CWA WITH
A MOIST ATMOSPHERE AND SOME UPPER LEVEL SUPPORT SWINGING THROUGH.
LOWS IN THE LOWER TO MID 60S SEEMS REASONABLE GIVEN EXPECTED CLOUD
COVER AND DEW POINTS. /08

TUESDAY LOOKING PRETTY UNEVENTFUL DURING MUCH OF THE DAY WITH WAVE
EXITING IN THE EAST EARLY IN THE MORNING...LEADING TO PARTLY TO
MOSTLY SUNNY SKIES AND SLIGHTLY WARMER TEMPERATURES...IN THE LOWER
TO MID 80S...AND MODERATE HUMIDITY WITH DEWPOINTS IN THE MID AND
UPPER 60S. WITH A FRONTAL BOUNDARY MEANDERING OVER OUR FAR
WEST...MAY SEE A FEW SHOWERS AND THUNDERSTORMS DEVELOP IN OUR
NORTHWEST BY LATE AFTERNOON. BETTER CHANCE OF STORMS WILL OCCUR BY
TOMORROW EVENING INTO TUESDAY NIGHT AS THETA E ADVECTION AND
CONVERGENCE INCREASES ALONG THE FRONT. COULD SEE A FEW SEVERE STORMS
IN THE LATE AFTERNOON OR EVENING WITH INCREASING SHEAR AND MID LEVEL
LAPSE RATES IN THE VICINITY OF THE FRONT...AND CAPE VALUES AROUND
1500 TO 2000 J/KG OVER THAT AREA. THE BOUNDARY WILL MOVE ONLY VERY
SLOWLY EASTWARD LATE TUESDAY NIGHT INTO WEDNESDAY...AND WITH FORCING
NOT AS GOOD...THERE WILL BE A LESSER CHANCE OF SHOWERS AND
THUNDERSTORMS AS THE SYSTEM TRACKS TO THE EAST. WITH CLOUDS/POSSIBLE
SHOWERS AND THE SLIGHTLY COOLER AIRMASS BEHIND THE FRONT...HIGHS ON
WEDNESDAY WILL BE IN THE UPPER 70S TO LOWER 80S.

THE REMAINDER OF THE WEEK INTO THE EARLY PART OF THE WEEKEND IS
LOOKING TO BE DRY AS THE TROUGH OVER THE CENTRAL U.S. AT MIDWEEK
PUSHES TO THE EAST...PUTTING OUR AREA INTO A NORTHWESTERLY UPPER
LEVEL FLOW. HIGHS FOR THURSDAY AND FRIDAY LOOK TO BE IN THE LOWER
80S WITH LOWS IN THE UPPER 50S TO LOWER 60S. NEXT POSSIBILITY FOR
SHOWERS/THUNDERSTORMS WILL BE LATER ON SATURDAY WITH THE NEXT
SYSTEM...THOUGH MODELS HAVE USUAL TIMING/PLACEMENT ISSUES THIS FAR
OUT.  /JM

&&

.AVIATION...

SCATTERED SHOWERS AND THUNDERSTORMS...BETTER CHANCES AT KFSD AND
KSUX WITH LESSER CHANCES AROUND KHON...WILL CONTINUE THROUGH ABOUT
5Z...BECOMING MUCH MORE ISOLATED THEREAFTER. SKIES SHOULD REMAIN
MAINLY VFR BUT SOME PATCHY FOG AND CEILINGS AROUND 1500 FEET
POSSIBLE AT KFSD AND KSUX AS THE SYSTEM LIFTS OUT THIS EVENING. FOG
SHOULD NOT BE A PROBLEM OVERNIGHT. /08

&&

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

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1121 AM CDT MON JUL 05 2010

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-
1121 AM CDT MON JUL 05 2010

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 ISOLATED THUNDERSTORMS ARE EXPECTED THROUGH
THE DAY...ALTHOUGH MOST ACTIVITY WILL BE SHORT LIVED. A FEW OF
THE STORMS MAY CONTAIN BRIEF HEAVY RAINFALL.

FLOODING...
THE JAMES RIVER WILL REMAIN IN FLOOD FOR THE FORESEEABLE FUTURE.
ELSEWHERE...RIVERS CONTINUE TO FALL. THE FIRESTEEL CREEK NEAR
MOUNT VERNON WILL BE IN FLOOD THIS WEEK...AND THE BIG SIOUX RIVER
NEAR BROOKINGS UNTIL LATE THIS WEEK. THE LITTLE SIOUX RIVER NEAR
LINN GROVE AND CHEROKEE WILL ALSO BE IN FLOOD UNTIL EARLY TO MID
WEEK.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THERE IS ANOTHER CHANCE OF THUNDERSTORMS WITH LOCALLY HEAVY RAIN
MOVING EASTWARD OVER THE AREA TUESDAY NIGHT INTO WEDNESDAY.
SEVERE WEATHER IS NOT EXPECTED AT THE PRESENT TIME.

.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.