Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 171133
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
633 AM CDT SUN MAY 17 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CDT SUN MAY 17 2015

UPPER LOW CENTER CURRENTLY LIFTING NORTH NORTHEAST ACROSS NORTH
CENTRAL NEBRASKA WILL SLOWLY TRACK THROUGH THE FORECAST AREA TODAY.
TWO AREAS OF RAIN SHOWERS WITH EMBEDDED THUNDER ARE IMPACTING THE
AREA. THE FIRST BROAD BAND AHEAD OF THE LOW IS TRACKING NORTHWARD
ACROSS OUR EASTERN COUNTIES AHEAD OF THE SURFACE AND UPPER LOW. THE
SECOND AREA OF PRECIPITATION ON THE BACK SIDE OF THE LOW ACROSS
SOUTH CENTRAL INTO EAST CENTRAL SOUTH DAKOTA IS PIVOTING IN A
GENERAL NORTHERLY DIRECTION IN ASSOCIATION WITH MID LEVEL TROWALING.
PRECIPITATION IS EXPECTED TO PERSIST THROUGH THE MORNING ACROSS
THESE AREAS...WITH DRY SLOTTING LIMITING PRECIPITATION TO MORE
SCATTERED ACTIVITY NEAR THE I29 CORRIDOR. THE HRRR AND RUC HAVE A
DECENT HANDLE IN THE TRACK AND TIMING OF PRECIPITATION...SO FOLLOWED
THESE MODELS. AS THE LOW BEGINS PULLING AWAY TO THE NORTH THIS
AFTERNOON...MUCH OF REGION WILL BE IN THE DRY SLOT...WITH ONLY
SCATTERED SHOWERS DIMINISHING FROM SOUTH TO NORTH THROUGH EARLY
EVENING. SEVERE STORMS ARE NOT EXPECTED WITH ACTIVITY TODAY.

CLOUDY SKIES...RAINFALL... AND COOLER AIR WRAPPING BEHIND THE LOW
WILL KEEP TEMPERATURES IN CHECK THIS AFTERNOON. THE MID TO UPPER 60S
ARE EXPECTED WEST OF I29 WITH THE LOW TO MID 70S TO THE EAST WHERE
THE COOLER AIRMASS WILL BE DELAYED AND A BIT MORE SUNSHINE AND DRIER
WEATHER IS EXPECTED. WINDS WILL INCREASE THROUGH THE DAY AS THE
PRESSURE GRADIENT TIGHTENS AS THE LOW LIFTS NORTH OF THE AREA.
SUSTAINED WINDS WILL BE NEAR ADVISORY LEVEL MID TO LATE
AFTERNOON...BUT RIGHT NOW IT LOOKS LIKE THEY WILL REMAIN TOO LOW FOR
HEADLINES. SKIES WILL REMAIN PARTLY TO MOSTLY CLOUDY TONIGHT WITH
MUCH COLDER TEMPERATURES FILTERING INTO THE REGION. LOWS TONIGHT
WILL BE IN THE MID 30S TO MID 40S.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 350 AM CDT SUN MAY 17 2015

WINDY AND COOL STILL LOOKS GOOD FOR MONDAY. THE UPPER LOW WILL BE
FAR ENOUGH NORTHEAST TO PROVIDE LITTLE OR NO DYNAMIC SUPPORT FOR
LIGHT SHOWERS...AND WHILE THERE COULD BE A FEW SPRINKLES WITH THE
LOW CLOUDS...WILL LEAVE OUT FOR NOW. THE LOW CLOUD COVER SHOULD
DOMINATE SKIES OVER THE NORTHEAST TO EAST CENTRAL PART OF THE
FORECAST AREA WITH LESSER CLOUD COVER TO THE SOUTHWEST. TEMPERATURES
WILL BE ON THE VERY CHILLY SIDE WITH HIGHS IN THE MID 40S NORTHEAST
TO THE MID 50S SOUTH.

CLEARING SKIES MONDAY NIGHT WITH HIGH PRESSURE RIDGING INTO THE AREA
AND THIS HIGH WILL ALSO BRING DECREASING WINDS. CHILLY TEMPERATURES
MAY DROP TO FROSTY OR FREEZY LEVELS AND WIND LOOK LIGHT ENOUGH BY
EARLY TUESDAY MORNING TO ALLOW FOR FROST EXCEPT IN PART OF SOUTHWEST
MINNESOTA SO AFTER COORDINATION WILL SO MENTION.

TUESDAY LOOKS FAIRLY SUNNY WITH SOME SLOW INCREASE IN CLOUDS
SOUTHWEST. THIS SLOW CLOUD INCREASE WILL CONTINUE FROM THE SOUTHWEST
TUESDAY NIGHT INTO WEDNESDAY AS AN EJECTED WAVE FROM PACIFIC COAST
TROUGH APPROACHES FROM THE SOUTHWEST. THIS WAVE WILL BE SUPPRESSED
TO SOME DEGREE BY A NORTHWESTERLY UPPER FLOW OVER THE WESTERN GREAT
LAKES. LIGHT RAIN LIKELY SPREADING INTO THE SOUTHWEST CORNER OF THE
AREA LATE TUESDAY NIGHT MAY NOT GET TOO FAR NORTHEAST IF THIS
SUPPRESSION IS STRONG ENOUGH. FOR NOW WILL KEEP SOME MENTION OF
LIGHT RAIN CHANCE WEDNESDAY OVER THE SOUTHWEST HALF OF THE AREA. DO
NOT EXPECT MUCH RAIN IN ANY EVENT AS THE SYSTEM WILL BE STEADILY
WEAKENING WHILE BEING SUPPRESSED BETWEEN THE NORTHWESTERLY FLOW AND A
MODEST SOUTHERN PLAINS RIDGE. TEMPERATURES WILL STILL BE COOL WITH
50S HIGHS TUESDAY AND WEDNESDAY.

THE DEPARTURE OF WHAT IS LEFT OF THE WEAK WAVE WILL ALLOW THE RIDGE
TO BUILD A LITTLE MORE INTO THE AREA AND BRING DRY WEATHER WITH
MODEST WARMING THURSDAY INTO FRIDAY. LATE FRIDAY AND SATURDAY WILL
BRING A CHANCE OF SHOWERS AND STORMS AS THE PACIFIC TROUGH
APPROACHES.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 626 AM CDT SUN MAY 17 2015

SHOWERS WITH EMBEDDED THUNDERSTORMS WILL CONTINUE TO TRACK
NORTHWARD ACROSS THE REGION THIS MORNING...THEN DIMINISH SOUTH TO
NORTH THIS AFTERNOON. MVFR CEILINGS AND VISIBILITY WILL BE
ASSOCIATED WITH RAIN SHOWERS. THE QUESTION IS HOW LONG THE MVFR
CONDITIONS LINGER...AS MODELS VARY WITH CEILING HEIGHTS THIS
AFTERNOON THROUGH TONIGHT. FOR NOW...WILL BRING IN SOME IMPROVE
TO LOW END VFR LATE MORNING AND AFTERNOON AND THEN DROP BACK TO
MVFR THIS EVENING AND TONIGHT AT KFSD AND KHON. KSUX IS LESS
CERTAIN...SO LEFT VFR THERE OVERNIGHT.

&&

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

$$

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



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