000
FXUS63 KFSD 242043
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
343 PM CDT FRI MAY 24 2013

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 332 PM CDT FRI MAY 24 2013

SCATTERED SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE CWA WITH
THE MOST CONCENTRATED AREA NORTH OF INTERSTATE 90 AND EAST OF
INTERSTATE 29 THIS EVENING. WITH THE WAVE THAT IS AIDING IN THIS
DEVELOPMENT MOVING NORTHEAST SUSPECT THE TREND TO THE EAST AND
NORTH WITH THIS ACTIVITY WILL CONTINUE. SHEAR AND INSTABILITY NOT
ENOUGH FOR SEVERE THUNDERSTORMS BUT SOME VERY SMALL HAIL POSSIBLE
WITH THE STRONGER STORMS. BETWEEN ABOUT 3Z TO 6Z THE LOW LEVEL JET
INCREASES QUITE A BIT IN CENTRAL NEBRASKA AND BEGINS TO FOCUS THE
BEST CONVERGENCE/ADVECTION TOWARDS THE MISSOURI RIVER ALONG THE
SOUTH DAKOTA NEBRASKA BORDER. THE WEAKEST CIN AND HIGHEST CAPE
VALUES SUGGEST THAT A PARCEL LIFTED FROM ABOUT 850MB TO 800MB WOULD
HAVE ABOUT 1500 J/KG TO WORK WITH. WHILE THE EFFECTIVE SHEAR IS
QUITE WEAK SOME NICKEL TO DIME SIZED HAIL WOULD BE POSSIBLE NEAR THE
MISSOURI RIVER. WITH FAIRLY SLOW STORM MOTION ANY STORMS THAT COULD
DEVELOP WOULD HAVE THE POTENTIAL TO PRODUCE SOME HEAVIER RAINFALL.
WILL KEEP THE HIGHEST POPS ALONG THE MISSOURI RIVER INTO NORTHWEST
IOWA OVERNIGHT WITH A TREND DOWNWARD IN RAIN AND THUNDERSTORM
POTENTIAL ON SATURDAY. OTHER THAN CONVECTIVE BLOW OFF OR SOMETHING
THAT ADVECTS IN IT LOOKS LIKE CAPPING WILL KEEP THUNDERSTORMS AT BAY
MOST OF THE DAY IN MOST LOCATIONS. STILL EXPECTING QUITE A BIT OF
CLOUD COVER AND COOL TEMPERATURES...RANGING FROM THE MID 60S EAST OF
THE BUFFALO RIDGE TO 75 TO 80 IN SOUTH CENTRAL SOUTH DAKOTA.


.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 332 PM CDT FRI MAY 24 2013

MODELS SUGGEST THAT A PAIR OF WAVES MAY BEGIN NOSING INTO BLACK
HILLS AREA SATURDAY AFTERNOON AND AGAIN SUNDAY AFTERNOON...
TRIGGERING CONVECTION TO OUR WEST SATURDAY EVENING AND SOUTHWEST ON
SUNDAY EVENING. WITH A QUASI-STATIONARY BOUNDARY DRAPED ACROSS THE
REGION...VERY HIGH PRECIPITABLE WATER AMOUNTS THROUGHOUT THE REGION
AND A STRENGTHENING LOW LEVEL JET NEAR THE MISSOURI RIVER BOTH
NIGHTS...EXPECT SHOWER AND THUNDERSTORM POTENTIAL TO PEAK DURING THE
EVENING AND OVERNIGHT HOURS. MAIN CONCERN WITH THIS CONVECTION WOULD BE
LOCALLY HEAVY RAINFALL AMOUNTS AND STRONG WIND GUSTS. MARGINALLY
SEVERE HAIL WILL ALSO BE POSSIBLE...HOWEVER THIS THREAT WOULD BE
MAINLY DURING THE EVENING HOURS. PRECIPITATION CHANCES DO DIMINISH
SLIGHTLY DURING THE DAY ON SUNDAY...BUT WILL KEEP SCATTERED MENTION
GOING THROUGH THE DAY WITH SOME TIMING UNCERTAINTY.

VERY ACTIVE AND WET PATTERN IS EXPECTED TO PERSIST THROUGH THE
ENTIRE MID AND LONG RANGE WITH PRECIPITATION IN THE FORECAST EACH
PERIOD...INCLUDING MEMORIAL DAY. STILL SEEING QUITE A BIT OF
UNCERTAINTY WITH TIMING ALL OF THE SHORTWAVES TRACKING THROUGH THE
REGION ALONG THE GENERAL UPPER LEVEL SOUTHWEST FLOW. WEST COAST
TROUGHING STARTS NUDGING FURTHER EAST INTO THE HIGH PLAINS LATE WEEK
NEXT WEEK...HOWEVER THE SLOW MOVING NATURE OF THIS SYSTEM KEEPS
IT...AND PRECIPITATION IN THE FORECAST EVEN THROUGH NEXT WEEKEND.
TEMPERATURES WILL WARM A LITTLE TO SLIGHTLY ABOVE NORMAL READINGS
AROUND MID WEEK BUT WILL START TO COOL A BIT LATE WEEK WITH POTENTIAL
TROUGHING ARRIVING.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1240 PM CDT FRI MAY 24 2013

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OCCURRING OVER SOUTH
DAKOTA WILL GRADUALLY WORK EASTWARD THROUGH THE DAY. COVERAGE
SHOULD NOT BE VERY HIGH SO THE MENTION OF THUNDER HAS BEEN REMOVED
FROM THE TAF FORECASTS. WHILE THERE WILL BE A FEW THUNDERSTORMS
HERE AND THERE COVERAGE WILL BE MINIMAL AND ANY LOCATION THAT DOES
RECEIVE SOME ANY THUNDER IT SHOULD ONLY LAST FOR ABOUT 10 TO 15
MINUTES. SOUTH TO SOUTHEAST WINDS WILL GUSTS TO AROUND 30 MPH AT
TIMES THROUGH SUNSET. OTHERWISE LATE TONIGHT...MAINLY AFTER ABOUT
7Z...SOME MVFR CEILINGS WILL BE POSSIBLE.


&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR SDZ050-052-057-058-
     063-064.

MN...NONE.
IA...NONE.
NE...NONE.
&&

$$

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