Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 260229
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
929 PM CDT WED MAR 25 2015

.UPDATE...
ISSUED AT 921 PM CDT WED MAR 25 2015

TWO ADJUSTMENTS MADE TO GOING FORECAST. FIRST...INCREASED CLOUD
COVER ACROSS OUR NORTHEAST...AS STRATUS IS BUILDING BACK
SOUTHEAST INTO THE REGION. COULD BREAK UP LATER TONIGHT...BUT
MODEL RH AROUND 850 MB SUGGESTS IT VERY WELL COULD STICK AROUND
AND ENCOMPASS MOST OF SOUTHWEST MINNESOTA AND PORTIONS OF
NORTHWEST IOWA BY MORNING. THUS ALSO WENT AHEAD AND BUMPED LOWS UP
A BIT IN THIS AREA.

OTHER CHANGE WAS TO INCREASE POPS IN SOUTH CENTRAL SD ON
THURSDAY. PRETTY GOOD MODEL AGREEMENT THAT A BAND OF PRECIPITATION
WILL DEVELOP AS AN UPPER LEVEL WAVE INTERACTS WITH A MID LEVEL
FRONTAL BOUNDARY. MAIN FOCUS APPEARS TO BE IN GREGORY
COUNTY...WITH SOME LIGHT PRECIP STILL POSSIBLE ANYWHERE WEST OF
THE JAMES AND ALONG THE MISSOURI RIVER CORRIDOR. WARM BOUNDARY
LAYER WOULD MEAN MAINLY LIGHT RAIN...ALTHOUGH WHERE THERE IS A
BRIEF PERIOD OF MORE MODERATE PRECIP...WOULD THINK WE WOULD WET
BULB AND CHANGE TO A PERIOD OF SNOW. AGAIN...MOST LIKELY LOCATION
FOR THIS IS AROUND GREGORY COUNTY...WHERE A QUICK HALF INCH OF
SNOW IS POSSIBLE.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 255 PM CDT WED MAR 25 2015

SUBSIDENCE WITH HIGH PRESSURE MOVING IN IS FINALLY WORKING TO THIN
AND DECREASE THE LOW CLOUDS. DECREASE AND END OF THE DAYTIME HEATING
WILL ADD TO THIS AND ALLOW SKIES TO GO PRETTY CLEAR THIS EVENING.
NORTHWEST WINDS ARE SURE TO DECREASE TOWARD THE END OF THE AFTERNOON
AND FEEL CONFIDENT THE WIND ADVISORY FAR NORTHEAST WILL NOT BE
NEEDED PAST 23Z/5PM CDT...IF THAT LONG.

THE MOSTLY CLEAR SKIES WILL ALLOW FOR DECENT COOLING INTO THE LOW TO
MID 20S TONIGHT. A LEVELING OF AND POSSIBLY A SLIGHT WARMING IS
POSSIBLE TOWARD MORNING SOUTHWEST CORNER AS CLOUDS INCREASE WITH
APPROACHING CLIPPER.

THIS CLIPPER WILL BRING A LIGHT PRECIPITATION THREAT TO THE FAR
WESTERN AND SOUTHERN PARTS OF THE AREA. THE THREAT WILL BEGIN AS
LIGHT SNOW AND TRANSITION TO LIGHT RAIN BY LATE MORNING WITH THE
HEATING,,,GIVEN THAT THE ONLY CONCERN IS AT THE LOWEST LEVELS. THE
POPS WILL BE LOW AT 20/30 MAX AND DO NOT EXPECT MUCH ON AMOUNTS. IF
THE PRECIPITATION DOES DEVELOP IT IS LIKELY TO COOL THE AIR AND
PROBABLY RESULT IN MORE OF IT BEING SNOW THAN INDICATED. THAT IS THE
PROBLEM IN BEING CONSISTENT WITH TEMPERATURES AND PRECIPITATION
TYPE WITH SUCH A LOW THREAT. WITHOUT THE PRECIPITATION...AND WE ONLY
HAVE THOSE LOW POPS...TEMPERATURES WILL WARM PRETTY MUCH AS DEPICTED
WITH A SLIGHT DECREASE FROM PREVIOUS HIGHS MAINLY SOUTH DUE TO THE
CLOUD COVER. RECALLING A CHILLY APRIL DAY EONS AGO IN THE DC AREA
WHEN THE TEMP ROSE TO 46 LATE MORNING...STARTED RAINING...15 MINUTES
LATER IT WAS DOWN TO 34 AND SNOWING.

THE PRECIPITATION WILL TRANSLATE EAST SOUTHEAST AND TENS TO HUG
THE MISSOURI RIVER LATE IN THE DAY. DO NOT EXPECT IT TO GET UP TO
MHE/FSD AND POINTS EAST AND NORTH IN ANY EVENT.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 255 PM CDT WED MAR 25 2015

A COMBINATION OF WEAK UPPER LEVEL SUPPORT DROPPING SOUTH AND
INCREASING LOWER TO MID LEVEL MOISTURE WILL BRING A SMALL CHANCE FOR
PRECIPITATION FRIDAY NIGHT INTO SATURDAY NIGHT. FOR NOW NOT PLANNING
ON ANYTHING OTHER THAN LOW POPS. THIS INCREASE IN CLOUD COVER DOES
MAKE FOR SOMEWHAT TRICKY LOW TEMPERATURES THURSDAY NIGHT AS DRIER
AIR AND LIGHTER WINDS WILL BE IN PLACE BUT CLOUDS WILL BE ON THE
INCREASE FROM WEST TO EAST. WILL AIM FOR MID TO UPPER 20S IN SOUTH
CENTRAL SOUTH DAKOTA TO UPPER TEENS IN SOUTHWEST MINNESOTA.

WENT AHEAD AND BACKED OFF ON HIGHS A BIT FRIDAY AS SOUTH TO
SOUTHEAST FLOW AND FAIRLY WIDESPREAD CLOUD COVER SHOULD KEEP FROM
WARMING MUCH. STILL NOT EXPECTING MUCH MORE THAN SPRINKLES OR VERY
LIGHT SNOW SHOWERS OVER MAINLY THE EASTERN CWA FRIDAY NIGHT. HIGHS
FRIDAY FROM NEAR 40 ACROSS SOUTHWEST MINNESOTA INTO NORTHWEST IOWA
WITH MID 50S IN GREGORY COUNTY.

BY SATURDAY THE WARMING WILL SURGE A LITTLER FARTHER EAST SO EXPECT
WARMER READINGS. HOWEVER STRONG SOUTH TO SOUTHEAST WINDS WILL MAKE
IT FEEL A BIT COLDER. HIGHS FROM NEAR 50 IN SOUTHWEST MINNESOTA AND
NORTHWEST IOWA TO NEAR 70 IN SOUTH CENTRAL SOUTH DAKOTA.

ANOTHER WAVE WILL QUICKLY MOVE THROUGH THE AREA SATURDAY NIGHT BUT
NOT EXPECTING MUCH SO ONLY LOW POPS.

IN THE OUTER PERIODS(SUNDAY THROUGH WEDNESDAY)...A FAIRLY STRONG
WAVE WILL BE EXITING THE AREA ON SUNDAY WITH RELATIVELY FAST WEST TO
WEST NORTHWEST FLOW ALOFT DEVELOP THROUGH MID WEEK. THIS SHOULD
ALLOW FOR A MILD PERIOD WITH FAIRLY HIGH CONFIDENCE IN ABOVE NORMAL
TEMPERATURES. RIGHT NOW WEDNESDAY IS THE DAY THAT IS MOST UP IN THE
AIR. THE ECMWF IS MUCH FASTER AND FARTHER SOUTH WITH A PIECE OF
ENERGY WHILE THE GFS IS SLOWER. SO THE MAIN DIFFERENCE WILL BE
COOLER TEMPERATURES AND A CHANCE FOR RAIN VIA THE ECMWF WHILE THE
GFS WOULD BE MUCH WARMER. THE GEM IS NOT MUCH HELP AS IT IS ABOUT ON
PAR WITH A CONSENSUS BETWEEN THE ECMWF AND GFS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 629 PM CDT WED MAR 25 2015

WINDS WILL DISSIPATE THIS EVENING WITH VFR CONDITIONS CONTINUING.
MAY SEE SOME MVFR STRATOCU REDEVELOPMENT AFTER SUNRISE...BUT THE
BEST CHANCE SEEMS TO BE EAST OF INTERSTATE 29...SO WILL LEAVE OUT
OF THE TAFS. A BIT OF LIGHT RAIN..POSSIBLY MIXED WITH SNOW...IS
POSSIBLE THURSDAY AFTERNOON WEST OF THE JAMES RIVER AND ALONG THE
MISSOURI RIVER CORRIDOR. COULD SEE A BRIEF PERIOD OF MVFR CIGS AND
VIS IN THIS ACTIVITY...BUT MOST OF THIS SHOULD REMAIN SOUTHWEST OF
THE TAF SITES.


&&

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

$$

UPDATE...CHENARD
SHORT TERM...
LONG TERM...08
AVIATION...CHENARD


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