Area Forecast Discussion
Issued by NWS Sioux Falls, SD

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KFSD 272102
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
402 PM CDT SAT SEP 27 2014

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 401 PM CDT SAT SEP 27 2014

UPPER LOW OVER THE AREA RESPONSIBLE FOR CU ACROSS OUR FAR EASTERN
CWA...BUT MOST OF THE ISOLATED SHOWER ACTIVITY SEEMS TO BE STAYING
OFF TO THE EAST. OTHERWISE WILL BE A SUNNY...WARM AND BREEZY
REMAINDER OF THE AFTERNOON. DO SEE LOW LEVEL MOISTURE AND
CONVERGENCE INCREASE A BIT TONIGHT AS THE LOW LEVEL JET GETS GOING.
COULD BE ENOUGH TO GET SOME SCATTERED MID LEVEL CLOUDINESS...AND
POTENTIALLY AN ISOLATED THUNDERSTORM LATE TONIGHT OR TOMORROW
MORNING. SOUNDINGS DO SUGGEST A RELATIVELY UNCAPPED ATMOSPHERE IF WE
CAN SATURATE AND LIFT A PARCEL FROM AROUND 800 OR 850 MB...ALTHOUGH
UNCERTAIN IF THIS CAN HAPPEN AND LARGE SCALE SUBSIDENCE OVERHEAD
WILL BE ANOTHER NEGATIVE. THUS OVERALL FEEL THREAT IS TOO LOW TO
WARRANT MENTION IN THE FORECAST...BUT SOMETHING TO WATCH. OTHERWISE
ANOTHER MILD NIGHT WITH LOWS IN THE UPPER 50S TO AROUND 60.

SUNDAY WILL BE ANOTHER NICE DAY WITH WELL ABOVE NORMAL TEMPERATURES
CONTINUING. MAY HAVE A BIT MORE CLOUD COVER...BUT SHOULD NOT HAVE AN
IMPACT ON TEMPERATURES. THERMAL PROFILES VERY SIMILAR TO TODAY...AND
THUS THINKING MOST LOCATIONS WILL BE PLUS OR MINUS A DEGREE FROM
TODAY. MODEL GUIDANCE CONTINUES TO HAVE A COUPLE DEGREE COOL
BIAS...SO WENT AHEAD AND RAISED HIGHS ABOVE GUIDANCE...TO AROUND
WHAT WE ARE SEEING THIS AFTERNOON...GENERALLY LOW TO MID 80S.
BOUNDARY WILL BE DROPPING SOUTH THROUGH THE DAY AND COULD SEE
ISOLATED SHOWERS AND THUNDERSTORMS ON THE COOL SIDE OF THIS BOUNDARY
LATER IN THE DAY...BUT SEEMS LIKE THIS WILL STAY NORTH OF THE CWA
THROUGH 0Z.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 401 PM CDT SAT SEP 27 2014

MODELS GENERALLY SHOWING GOOD AGREEMENT IN THE TIMING OF THE DEEP UPPER
LEVEL PACIFIC TROUGH LIFTING NORTHEASTWARD INTO THE CENTRAL AND
NORTHERN HIGH PLAINS ON MONDAY. STRONG RIDGING OVER THE UPPER
MISSISSIPPI VALLEY WILL SLOW ITS EASTWARD PROGRESSION...KEEPING
PRECIPITATION LARGELY CONFINED TO WESTERN AND CENTRAL SOUTH DAKOTA
THROUGH THE DAY. MODELS CONTINUE TO SLOW THE PROGRESSION A BIT...WITH
THE GFS SLIGHTLY FASTER THAN THE OTHER MODELS. BY MONDAY EVENING...THE
WAVE LIFTS INTO SOUTHWEST SOUTH DAKOTA...WITH SHOWERS AND THUNDERSTORMS
BECOMING LIKELY OVERNIGHT IN SOUTH CENTRAL. CYCLOGENESIS IN THE CENTRAL
HIGH PLAINS WILL TRACK NORTHEASTWARD ON TUESDAY INTO SOUTH CENTRAL
NORTH DAKOTA...WITH A TRAILING FRONT STALLING ACROSS THE FORECAST AREA
THROUGH MID WEEK. SHOWER AND THUNDERSTORM CHANCES SHIFT EASTWARD ACROSS
THE WESTERN AND CENTRAL FORECAST AREA ON TUESDAY WITH MORE SCATTERED
ACTIVITY IN THE EAST. INITIALLY...PRECIPITATION WILL BE MAINLY RAIN
SHOWERS...BUT SOME WEAK ELEVATED INSTABILITY WILL ALLOW FOR SOME
THUNDERSTORM ACTIVITY TO BECOME MORE PREVALENT IN THE AFTERNOON AND
EVENING.

A SECOND MID LEVEL WAVE LIFTS THROUGH THE CENTRAL PLAINS INTO THE
UPPER MIDWEST WEDNESDAY AFTERNOON INTO THURSDAY...AND WILL KEEP WET
CONDITIONS IN THE PICTURE. THE COLD FRONT BEGINS ADVANCING AGAIN DURING
THE DAY ON WEDNESDAY...WITH ONLY WEAK CONVERGENCE ASSOCIATED WITH IT.
BUT GIVEN THE MARGINAL SHEAR AND DECENT CAPE DEVELOPING EAST OF
INTERSTATE 29 - MAINLY ACROSS NORTHWEST IOWA...WE COULD SEE AN ISOLATED
SEVERE THREAT HERE WITH THE FRONTAL PASSAGE.

WITH CLOUDS AND PERIODIC RAIN SETTLING IN TUESDAY THROUGH
FRIDAY...TEMPERATURES WILL COOL BACK INTO THE LOW TO MID 70S TUESDAY
AND WEDNESDAY...BUT COOL FURTHER INTO THE 60S THURSDAY AND THE
50S ON FRIDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1224 PM CDT SAT SEP 27 2014

VFR CONDITIONS EXPECTED THROUGH THE PERIOD. WILL BE BREEZY
TODAY...WITH SOUTHERLY WINDS GUSTING 20 TO 25 KTS THROUGH SUNSET.
COULD POTENTIALLY SEE AN ISOLATED THUNDERSTORM TONIGHT...BUT
CHANCES TOO LOW TO WARRANT MENTION IN TAFS.


&&

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

$$

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



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.