Hail in Iowa, June 26, 2014

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
638 AM CDT THU JUN 26 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 323 AM CDT THU JUN 26 2014

MESSY FORECAST TODAY AS LATEST SATELLITE AND RADAR DATA HINTS AT A
PAIR OF MCVS IN CENTRAL SOUTH DAKOTA...ALTHOUGH AS OF 300 AM BOTH
WERE SHOWING SIGNS OF WEAKENING. THE NORTHERN MCV WAS MOVING TOWARDS
THE FAR NORTHWEST CORNER OF THE CWA WHILE THE SOUTHERN MCV WAS
MOVING INTO NORTH CENTRAL NEBRASKA. BOTH ARE MOVING INTO RELATIVELY
MORE STABLE AIR BUT NOT STABLE ENOUGH TO EASILY BRING THE THREAT FOR
SHOWERS AND THUNDERSTORMS TO AN END. THEREFOR WILL NEED TO CARRY A
SMALL CHANCE THROUGH MUCH OF THE DAY. SOUTHEAST FLOW WILL CONTINUE
IN THE LOW LEVELS THROUGH THE DAY AND NIGHT AND THIS FLOW WILL
CONTINUE TO ADVECT IN SLIGHTLY MORE STABLE AIR WHICH MAY KEEP MUCH
OF THE AFTERNOON AND EARLY EVENING ACTIVITY TO THE NORTH AND WEST OF
THE AREA. HOWEVER AS THE NIGHT WEARS ON THE THREAT FOR THIS ACTIVITY
TO ADVECT INTO THE AREA WILL INCREASE...WITH THE BETTER CHANCES IN
THE NORTH AND WESTERN CWA. WHILE SEVERE WEATHER WILL NOT BE
IMPOSSIBLE IT SEEMS A BIT UNLIKELY AT THIS TIME. HIGHS TODAY MAINLY
IN THE 80S WITH TONIGHTS LOWS IN THE MID TO UPPER 60S AS CLOUDS AND
A DECENT SOUTHEAST WIND KEEP TEMPERATURES FAIRLY WARM.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 323 AM CDT THU JUN 26 2014

A RATHER ACTIVE WEEKEND IS IN STORE FOR THE REGION WITH THE
POTENTIAL FOR STRONG TO SEVERE STORMS ALONG WITH AN ELEVATED RISK
FOR EXCESSIVE RAINFALL.  WE MAY START OUT FRIDAY WITH SCATTERED
SHOWERS AND THUNDERSTORMS ACROSS THE REGION...AS A MERIDIONAL 35-40
KNOT LLJ AND MINOR SHORTWAVE LIFT NORTH ACROSS THE AREA.  HOWEVER
HIGHER RAIN CHANCES ARE EXPECTED TO HOLD OFF UNTIL LATE FRIDAY INTO
FRIDAY NIGHT AS A NEGATIVELY TILTED UPPER TROUGH PIVOTS THROUGH THE
PLAINS. DEPENDING ON THE AMOUNT OF CONVECTIVE DEBRIS ACROSS THE
AREA...A MODERATELY UNSTABLE ENVIRONMENT SHOULD FORM ALONG AND EAST
OF A NORTH-SOUTH ORIENTED SFC BOUNDARY ACROSS WEST CENTRAL SOUTH
DAKOTA AND NEBRASKA. AS THE MID-LEVEL WAVE ENTERS THE PLAINS LATE IN
THE AFTERNOON...CONVECTION SHOULD INITIATE AHEAD OF THIS BOUNDARY.
SHEAR IS NOT OVERLY IMPRESSIVE...WHICH WOULD TEND TO FAVOR
MULTICELLULAR CLUSTERS OF CONVECTION DEVELOPING AND LIFTING NORTHEAST
WITH THE WAVE. DUE TO THE NORTHWARD TRACK OF THE SHORTWAVE...HEAVIEST
RAIN CHANCES SHOULD REMAIN ALONG AND WEST OF THE JAMES RIVER VALLEY.

SATURDAY REMAINS A VERY TRICKY FORECAST...WITH HIGH UNCERTAINTY ONCE
AGAIN WITH CONVECTIVE DEBRIS AND IMPACTS ON POTENTIAL INSTABILITY
ALONG AN EASTWARD ADVANCING COLD FRONT. LATEST GUIDANCE HAS TRENDED
TOWARDS LESS INSTABILITY DUE TO LINGERING CLOUD COVER...BUT WOULD
NOT DISCOUNT THE POTENTIAL FOR A NARROW CORRIDOR OR POCKETS OF
MODERATE INSTABILITY FORMING AHEAD OF THIS BOUNDARY.  A SECONDARY
SHORTWAVE...AND MID-LEVEL 60 KNOT JETLET...WILL LIFT THROUGH THE
AREA IN THE AFTERNOON AND MAY AGAIN SPARK A FEW STRONG TO SEVERE
THUNDERSTORMS. THIS ACTIVITY SHOULD PUSH EAST OF THE AREA QUICKLY
SATURDAY EVENING LEAVING MUCH OF THE CWA DRY OVERNIGHT.

ONE FINAL ROUND OF CONVECTION POSSIBLE SUNDAY AS UPPER TROUGH ACROSS
SOUTHERN CANADA BEGINS TO PIVOT AND TURN SOUTHWARD INTO THE
NORTHERN PLAINS. WITH NO STRONG COLD FRONT SCOURING OUT LOW-LVL
MOISTURE SATURDAY NIGHT...FAIRLY QUICK RECOVERY SHOULD TAKE PLACE ON
SUNDAY AS A STRONGER FRONTAL BOUNDARY DROPS THROUGH THE AREA IN THE
AFTERNOON.  A LARGE RESERVOIR OF CAPE APPROACHING 3000 J/KG IS
ANTICIPATED ALONG AND SOUTHEAST OF THIS BOUNDARY.  A STRONG UPPER
JET WILL NOSE INTO THE PLAINS SUNDAY AFTERNOON...INCREASING
EFFECTIVE SHEAR INTO THE 40-50 KNOT RANGE. WHILE THIS TIME PERIOD IS
STILL A FEW DAYS OUT...TONIGHT'S GUIDANCE PARAMETERS LINE UP FOR
ALL MODES OF SEVERE STORMS SUNDAY AFTERNOON...MAINLY FOR THE FAR
EAST/SOUTHEAST COUNTIES IN THE CWA.

QPF THROUGH THE WEEKEND COULD BE PROBLEMATIC.  STRONG MOISTURE
TRANSPORT WHICH BEGINS TODAY WILL PUSH PWAT VALUES AROUND 1.8" BY
FRIDAY NIGHT/SATURDAY...AND CLIMATOLOGICALLY SPEAKING BETWEEN 2-3 SD
ABOVE NORMAL.  WOULD ANTICIPATE THE POTENTIAL FOR SEVERAL INCHES OF RAIN
FOR SOME FOLKS BY TIME MONDAY ARRIVES.

THE GOOD NEWS IS THAT WE'LL HAVE A FAIRLY SUBSTANTIAL PATTERN SHIFT
BEGINNING MONDAY AS UPPER TROUGHING SWINGS THROUGH THE GREAT
LAKES...LIKELY THE PRECEDING STEPS TO THE FORMATION OF A TYPICAL
SUMMER RIDGE BY EARLY JULY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 635 AM CDT THU JUN 26 2014

SCATTERED THUNDERSTORMS WILL BE POSSIBLE THROUGH ABOUT 16Z...THEN
ISOLATED THUNDERSTORMS WILL BE POSSIBLE MOST OF THE REMAINDER OF
THE DAYLIGHT HOURS. AFTER ABOUT 5Z THE THUNDERSTORM THREAT WILL
INCREASE AGAIN FROM THE NORTHWEST. OTHERWISE...OUTSIDE OF THE
THUNDERSTORMS VFR CONDITIONS ARE EXPECTED.

&&

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

SHORT TERM...08
LONG TERM...DUX
AVIATION...08