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 272109
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
409 PM CDT MON APR 27 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 408 PM CDT MON APR 27 2015

WITH THE UPPER LEVEL RIDGE AXIS OVERHEAD AND SURFACE HIGH PRESSURE
SLIDING OFF TO OUR EAST...VERY PLEASANT WEATHER CONDITIONS WILL
CONTINUE INTO THE EVENING. LIGHT WINDS AND MOSTLY CLEAR SKIES WILL
ABOUND...HOWEVER CLOUDS ARE EXPECTED TO BEGIN BUILDING INTO OUR
WESTERN BORDER IN THE EARLY MORNING HOURS WITH THE ARRIVAL OF SHORT
WAVE IN THE NORTHERN PLAINS AND AN ASSOCIATED FRONTAL BOUNDARY. THE
FRONT WILL TRACK ACROSS THE FORECAST AREA THROUGH MIDDAY...BUT
WITHOUT MUCH FANFARE. WITH THE STRONGER DYNAMIC SUPPORT WELL NORTH
OF THE FORECAST AREA AND LIMITED LOW AND MID LEVEL MOISTURE...RAIN
WILL BE SPARSE. WILL CONTINUE WITH THE MENTION OF A FEW SPRINKLES
TRACKING SOUTHEAST THROUGH THE MID AFTERNOON. SUPPORT WANES EVEN
FURTHER IN THE LATE AFTERNOON AND SHOULD ALLOW THE BAND OF
STRATOCUMULUS TO THIN AND ANY REMAINING SPRINKLES TO DISSIPATE.
WINDS ON TUESDAY WILL BE A LITTLE STRONGER THAN TODAY...BUT
GENERALLY LESS THAN 15 MPH.

TEMPERATURES WILL FALL INTO THE MID 30S TO LOWER 40S. GIVEN THE
LIGHT WINDS AND THE FACT THAT THE MODELS HAVE BEEN TOO WARM WITH
LOWS RECENTLY...HEDGED A BIT COOLER WITH THE LOWS. HIGHS WILL REACH
THE MID 60S TO LOWER 70S.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 408 PM CDT MON APR 27 2015

COULD STILL BE A COUPLE OF ROGUE SPRINKLES ACROSS THE SOUTHEASTERN
CWA TUESDAY EVENING AS LAST OF SHEARING MID LEVEL BOUNDARY QUICKLY
EXITS THE AREA. ONLY A SLIGHT COOLING OF THE AIRMASS...AS
NORTHERLY FLOW WEAKENS OVERNIGHT WITH EXTENSION OF SURFACE RIDGE
AXIS BUILDING INTO THE NORTHERN/WESTERN CWA. AS WITH RECENT
SIMILAR NIGHTS...WOULD SUGGEST LOWEST SIDE OF GUIDANCE...SO HAVE
SOME LOWS GETTING TOWARD MID 30S IN THE NORTHERN/WESTERN CWA.
SURFACE RIDGE HOVERS NEAR THE CWA ON WEDNESDAY...AND WILL PROBABLY
END UP AS ONE OF THE NICER SPRING DAYS WITH SUNSHINE AND LIGHT
WINDS. AREAS AHEAD OF THE RIDGE AXIS ACROSS NORTHWEST IOWA AND
SOUTHWEST MINNESOTA WILL MIX DOWN A BIT MORE NORTH TO NORTHEAST
WIND...PERHAPS A BIT OVER 10 MPH AT TIMES. DRY AIR AND LINGERING
WEAKER GRADIENT IN THE EAST MAY AGAIN OPEN THE WINDOW FOR SOME
COOLER LOWS ACROSS NORTHWEST IOWA ON THURSDAY MORNING.

AS RIDGE SHIFTS EAST THURSDAY...AND WAVE MOVING ACROSS THE
NORTHERN ROCKIES PUSHES INTO THE WESTERN PLAINS LATE DAY...
SOUTHERLY GRADIENT WILL INCREASE...AND SO WILL CONCERN FOR FIRE
DANGER. WARM TEMPERATURES IN THE 70S TO NEAR 80 AND LACK OF
SIGNIFICANT MOISTURE RETURN WILL ALLOW AFTERNOON HUMIDITY TO REACH
20 TO 30 PERCENT...AND BRING A VERY HIGH FIRE DANGER TO MUCH OF
THE AREA. WILL HAVE TO WATCH POTENTIAL FOR A WEDGE OF MORE
SIGNIFICANT DRYING RIGHT AHEAD OF APPROACHING FRONTAL BOUNDARY
INTO LOWER BRULE AREAS.

AS FRONT PUSHES THROUGH THURSDAY NIGHT...MARGINAL MOISTURE WILL
MAKE FOR A MEAGER AMOUNT OF INSTABILITY...BUT TAIL END OF BETTER
DYNAMICS DOES DRAG THROUGH THE CWA LATER THURSDAY NIGHT INTO
FRIDAY...SUPPORTING A LEAST A LOWER CHANCE MENTION. AS FAST AS THE
BOUNDARY MOVES IN...IT MOVES OUT TAKING THE LOWER THREAT OF RAIN
WITH IT...AND LACK OF FLOW AMPLITUDE KEEPING ANY THERMAL CHANGES
MINIMAL.

THINGS GET A BIT MORE UNCERTAIN BY THE WEEKEND AND ESPECIALLY THE
LAST COUPLE DAYS. LARGE SCALE PATTERN BECOMES MUCH MORE ZONAL
AFTER LATE WEEK WAVES...AND TIMING OF FEATURES ALONG WITH
UNCERTAIN NORTH/SOUTH LOCATION OF MORE SIGNIFICANT BOUNDARIES WILL
MAKE PLACING BETTER PRECIPITATION CHANCES A MORE DIFFICULT TASK.
BEST PRECIPITATION THREAT WOULD APPEAR TO BE ON SUNDAY INTO SUNDAY
NIGHT...TIMING AROUND A MORE SIGNIFICANT FRONTAL PASSAGE. SUNDAY
PARTICULARLY INTERESTING...AS SOME SOLUTIONS INDICATED TIMING OF
FRONTAL PASSAGE THROUGH CWA TO MATCH WELL WITH DIURNAL CYCLE. IF
CAN BREAK OUT CLOUD DEBRIS AND WARM MORE THAN EXPECTED...WITH
INDICATED LOW LEVEL JET AND MOISTURE RETURN...MAY GET A BETTER
THREAT FOR MORE SIGNIFICANT THUNDERSTORMS. MONDAY...THREAT WILL
SHIFT MORE TO THE SOUTH WITH PUSH OF COOLER AND DRIER AIR FROM THE
NORTH.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1208 PM CDT MON APR 27 2015

VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD.

&&

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

$$

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


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