Hail and Damaging Wind in Iowa, June 20, 2014

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
146 PM CDT FRI JUN 20 2014

.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 1038 AM CDT FRI JUN 20 2014

FOR A CHANGE NOT MUCH GOING ON IN THE SHORT TERM OTHER THAN A FEW
ACCAS -TSRA ACROSS INTERSTATE 29 FROM SIOUX FALLS TO BROOKINGS.
EXPECT LIGHTNING TO BE THE ONLY ISSUE WITH THE STORMS AS THEY MOVE
EAST AND WEAKEN. A LITTLE CONCERNED WITH STORMS ACROSS PORTIONS OF
NEBRASKA AT THE PRESENT TIME AND WHAT THAT MEANS FOR THE SOUTHERN
SECTIONS OF OUR CWA LATER TODAY AND THIS EVENING. MODELS ARE NOT
DOING WELL WITH FORECAST POSITION OF THE BOUNDARY...SO MODELS
SEVERE WEATHER INDICES HAVE ALSO BEEN AFFECTED. EXPECT STORMS TO
BE POSSIBLE ACROSS THE SOUTHERN AREA...MAINLY KSUX...BUT ONLY
THINK WIDELY SCATTERED AND NOT THE WIDESPREAD VARIETY AS WE HAVE
SEEN LATELY. STORMS THAT DO DEVELOP WILL HAVE THE POSSIBILITY OF
PRODUCING LARGE HAIL AND PERIODS OF MODERATE RAINFALL. DONT EXPECT
RAINFALL TO IMPACT CURRENT FLOODING ACROSS THE AREA AS THE
RAINFALL WILL BE FAIRLY LOCALIZED. CURRENT EHWO AND FORECAST HAS
MENTION OF STORMS IN THOSE AREAS...SO WILL LET IT RIDE FOR NOW.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 422 AM CDT FRI JUN 20 2014

CONDITIONS ON SATURDAY WILL LARGELY BE MARKED BY IMPACT OF EARLY
DAY ELEVATED CONVECTION...OR LACK OF IT...ACROSS THE CWA. ADVANCE
OF THE STEEP MID LEVEL LAPSE RATES AND THE LOCATION OF QG FORCING
WOULD SUGGEST WOULD STILL BE DEALING WITH A GREATER THREAT FOR
LINGERING SHOWERS/THUNDER ACROSS NW IA...AND MORE ISOLATED CHANCE
ELSEWHERE. THIS WOULD PRIMARILY BE A MORNING THREAT...UNLESS FAITH
PUT IN THE GFS/CANADIAN GLOBAL SOLUTION...WHICH IS MUCH DIFFERENT
DYNAMICALLY THAN OTHER SOLUTIONS...MORE PERSISTENT WITH PRECIPITATION
AND CLOUDS THROUGH THE DAY. AT THIS TIME...MUCH FAVOR SHOWN TOWARD
THE MASS OF OTHER SOLUTIONS. CONTINUED RETURN OF MOISTURE...
DAYTIME HEATING...AND THE STEEPENING MID LEVEL LAPSE RATES WILL
PRODUCE MODEST INSTABILITY BY LATER IN THE AFTERNOON ACROSS THE
AREA.  WITH LARGER SCALE NOT IN FAVOR OF LIFT...AND THE ONLY
BOUNDARY AROUND LIKELY TO BE A RESULT OF THE EARLIER NIGHT/MORNING
CONVECTION...WILL LOOK WESTWARD TO THE BETTER THREAT OF
DEVELOPMENT NEAR WEAK CONVERGENCE AXIS ACROSS CENTRAL AND WESTERN
DAKOTAS. WOULD LIKELY BE INITIATION POINT FOR MAJORITY OF
CONVECTION DURING THE LATER AFTERNOON HOURS...WHICH WOULD THEN
PROPAGATE EASTWARD THROUGH THE CWA OVERNIGHT. PRE CONVECTIVE
ENVIRONMENT ACROSS THE CENTRAL PORTIONS OF SD INDICATE 30 TO 35
KNOTS OF 0-6KM SHEAR...AND HODOGRAPHS ARE INDICATIVE OF FAVORING
SPLIT TO LEFT MOVER. LIFT SHOULD BE ENHANCE BY WEAK JET IMPULSE
SLIDING TO NORTH... AND EXPECT CONVECTION TO TRACK STEADILY
EASTWARD ALONG WITH THE VEERING BUT SOMEWHAT WEAK LOW LEVEL JET. A
FEW SEVERE STORMS WOULD CERTAINLY APPEAR TO BE IN THE MIX STARTING
DURING THE EVENING WEST OF THE JAMES VALLEY...WITH THE THREAT
WOULD LIKELY BE LIMITED TO LARGE HAIL AND DAMAGING WINDS...MORE
TOWARD THE LATTER AS STORMS ORGANIZE INTO SMALL SEGMENTS BY LATER
EVENING. PROGRESSION SHOULD KEEP RAINFALL AMOUNTS FROM BEING TOO
EXCESSIVE...BUT MANY AREA LIKELY TO SEE A HALF INCH TO INCH
RAINFALL...ESPECIALLY AREAS I29 AND WEST.

FORECAST CONFIDENCE STARTS TO WANE HEADING TOWARD SUNDAY AND
BEYOND WITH MODEL SOLUTIONS POLLUTED BY PERIODS OF INTERNAL
CONVECTIVE DEVELOPMENT. SEVERAL SOLUTIONS POINT TOWARD A STRONGER
WAVE SLIDING INTO THE REGION. CONVECTIVELY REINFORCED BOUNDARY
WILL BE SLIPPING TOWARD SW MN AND NW IA DURING THE DAY...AND
EXPECT A RESURGENCE IN CONVECTION...AND DEPENDING ON THE DEGREE
OF DESTABILIZATION...A THREAT FOR A FEW SEVERE STORMS AGAIN
ACROSS THE EAST...AS WELL AS SOME SPOTTY HEAVIER RAINFALL...
AS AMPLIFYING TROUGH IN THE NORTHERN PLAINS LIFTS EAST/NORTHEAST.

FOCUS FOR PRECIPITATION WILL GRADUALLY SETTLE SOUTHWARD EARLY IN
THE WEEK...AND SHOULD GET A PERIOD OF 24-48 HOURS OF DRY WEATHER.
CERTAINLY WILL BE A TOUCH COOLER OVERALL AS FLOW DIVERTS BEHIND
WAVE TO NORTH TO NORTHEAST FOR A FEW DAYS. MAY START TO GET A
LITTLE THUNDER THREAT RETURNING TOWARD SOUTH CENTRAL SD TOWARD
LATER WEDNESDAY...AND HAVE A SMALL CHANCE FOR PRECIPITATION ON
THURSDAY ONCE LOWER LEVEL RETURN FLOW BECOMES REESTABLISHED AND
MID LEVEL INSTABILITY SPREADS BACK ACROSS THE AREA UNDER BUILDING
RIDGE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 142 PM CDT FRI JUN 20 2014

VFR CIGS FOR MOST OF THE PERIOD AND TAF LOCATIONS. CHANCE FOR
SCATTERED -TSRA AT KSUX BETWEEN 23Z & 03Z AS BOUNDARY APPRAOCHES
FROM THE SOUTH. ANOTHER CHANCE FOR SCATTERED -TSRA AS FAR NORTH AS
KFSD BUT CHANCES ARE MUCH BETTER FURTHER SOUTH. OTHERWISE...VFR
CIGS TO CONTINUE THROUGH PERIOD.

&&

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

SHORT TERM...HEITKAMP
LONG TERM...CHAPMAN
AVIATION...HEITKAMP

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SIOUX FALLS SD
648 AM CDT FRI JUN 20 2014

IAZ001>003-012>014-MNZ071-072-080-081-089-090-097-098-SDZ038>040-
050-052>070-211200-
LYON-OSCEOLA-DICKINSON-SIOUX-OBRIEN-CLAY-LINCOLN-MURRAY-
COTTONWOOD-NOBLES-JACKSON-PIPESTONE-ROCK-BEADLE-KINGSBURY-
BROOKINGS-GREGORY-JERAULD-SANBORN-MINER-LAKE-MOODY-BRULE-AURORA-
DAVISON-HANSON-MCCOOK-MINNEHAHA-CHARLES MIX-DOUGLAS-HUTCHINSON-
TURNER-BON HOMME-YANKTON-
648 AM CDT FRI JUN 20 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST
IOWA...SOUTHWEST MINNESOTA...EAST CENTRAL SOUTH DAKOTA...SOUTH
CENTRAL SOUTH DAKOTA AND SOUTHEAST SOUTH DAKOTA.

.DAY ONE...TODAY AND TONIGHT
THERE IS A SMALL CHANCE OF THUNDERSTORMS MAINLY NEAR AND SOUTH OF
INTERSTATE 90 TONIGHT...BUILDING NORTH OF INTERSTATE 90 TOWARD
SATURDAY MORNING. NO SEVERE STORMS ARE EXPECTED.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY
A FEW MORNING THUNDERSTORMS ARE POSSIBLE ON SATURDAY...AND ARE NOT
EXPECTED TO BE SEVERE. A BETTER CHANCE FOR THUNDERSTORMS WILL
SPREAD IN ON SATURDAY EVENING WEST OF THE JAMES RIVER...WITH
STORMS CAPABLE OF HAIL UP TO GOLF BALL SIZE WITH WINDS GUSTS UP
TO 70 MPH. AS STORMS SPREAD EAST TOWARD SOUTHWEST MINNESOTA AND
NORTHWEST IOWA...THE THREAT BE HAIL TO HALF DOLLAR SIZE AND WINDS
TO 70 MPH. ISOLATED POCKETS OF HEAVY RAINFALL ARE POSSIBLE AFTER
MIDNIGHT ON SATURDAY NIGHT ACROSS SOUTHWEST MINNESOTA AND
NORTHWEST IOWA.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT.

IAZ020>022-031-032-NEZ013-014-SDZ071-211200-
PLYMOUTH-CHEROKEE-BUENA VISTA-WOODBURY-IDA-DIXON-DAKOTA-UNION-
648 AM CDT FRI JUN 20 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST
IOWA...NORTHEAST NEBRASKA AND SOUTHEAST SOUTH DAKOTA.

.DAY ONE...TODAY AND TONIGHT
PATCHY DENSE FOG IS EXPECTED TO DISSIPATE BY AROUND 8 AM...
GENERALLY EAST OF A LINE FROM SPENCER TO CORRECTIONVILLE.

ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED BY LATE
AFTERNOON THROUGH THE LOWER MISSOURI VALLEY...CONTINUING THROUGH
THE EVENING AND OVERNIGHT HOURS. A FEW STORMS MAY PRODUCE HAIL UP
TO QUARTER SIZE. THERE IS A SMALL CHANCE THAT REDEVELOPMENT OF
STORMS ACROSS THE AREA COULD PRODUCE SPOTTY HEAVY RAINFALL FROM
EXTREME NORTHEAST NEBRASKA EASTWARD ALONG HIGHWAY 20 IN NORTHWEST
IOWA.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY
A FEW MORNING THUNDERSTORMS ARE POSSIBLE ON SATURDAY...BUT ARE
NOT EXPECTED TO BE SEVERE. WHILE AN ISOLATED THUNDERSTORM IS
POSSIBLE ON SATURDAY EVENING...A BETTER CHANCE FOR THUNDERSTORMS
WILL SPREAD IN AFTER MIDNIGHT...WITH STORMS CAPABLE OF HAIL UP TO
GOLF BALL SIZE WITH WINDS GUSTS UP TO 70 MPH. ISOLATED POCKETS OF
HEAVY RAINFALL ARE POSSIBLE AS WELL.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL BE POSSIBLE AFTER 600 PM CDT.