Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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000
FXUS63 KFSD 081959
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
259 PM CDT TUE JUL 8 2014

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 258 PM CDT TUE JUL 8 2014

BREEZY NORTHWEST WINDS WILL CONTINUE THROUGH THE LATE AFTERNOON
HOURS DUE TO MECHANICAL MIXING.  SHOULD SEE THE GUSTS DECREASE
FAIRLY MARKEDLY THIS EVENING...BUT MAY HANG ON TO SLIGHTLY STRONGER
WINDS THAN ANTICIPATED THROUGH THE EVENING DUE TO LINGERING LOW
LEVEL COLD AIR ADVECTION IN THE EAST.  COULD ALSO HAVE AN
AFTERNOON/EARLY EVENING SHOWER IN EASTERN CWA WITH NEARLY UNCAPPED
ENVIRONMENT.  SHEAR PROFILES ARE VERY LINEAR...SO ANY STORMS THAT
DEVELOP WOULD LIKELY STRUGGLE TO BECOME ORGANIZED.

SURFACE HIGH PRESSURE REMAINS ACROSS THE AREA ON WEDNESDAY. WITH
MIXING...WILL LIKELY DEVELOP A LIGHT NORTHWEST WIND...ESPECIALLY
ACROSS THE EASTERN HALF OF THE FORECAST AREA THAT WILL LINGER
THROUGH THE DAY.  WITH DRY ATMOSPHERE...KEPT DRY FORECAST GOING WITH
SLIGHTLY BELOW NORMAL TEMPERATURES.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 258 PM CDT TUE JUL 8 2014

THE CHANCES FOR SHOWERS AND THUNDERSTORMS NOT VERY GOOD ON WEDNESDAY
NIGHT AS THE SLIGHTLY MORE UNSTABLE AIR LOOKS TO REMAIN SOUTH AND
WEST OF THE AREA. AND WITH LOW LEVEL FLOW MAINLY SOUTHEAST THE
ADVECTION OF THIS MORE UNSTABLE AIR NOT OCCURRING. WILL MAINTAIN
SOME SMALL POPS IN THE WESTERN CWA AS A WEAK WAVE MOVES THROUGH.

BY THURSDAY A STRONGER WAVE WILL MOVE EAST ALONG THE ND/SD BORDER
WHICH WILL TURN WINDS A LITTLE MORE SOUTHERLY AND
SOUTHWESTERLY...AIDING IN CONVERGENCE AND DESTABILIZATION. THIS WILL
BRING THE NEED FOR INCREASED POPS BUT THE CHANCE FOR SEVERE PRETTY
SLIM WITH GENERALLY LESS THAN 1000 J/KG OF SKINNY CAPE. THIS THREAT
WILL CONTINUE INTO THURSDAY NIGHT AND EXIT TO THE EAST LATE THURSDAY
NIGHT AND FRIDAY MORNING.

ANOTHER WEAKER WAVE WILL MOVE THROUGH ON FRIDAY AND WILL NEED SOME
LOWER END POPS TO COVER THIS THREAT. ONCE AGAIN INSTABILITY MARGINAL
SO THE SEVERE THREAT ALSO MARGINAL.

IN THE OUTER PERIODS(FRIDAY THROUGH TUESDAY)...MODELS STILL TRENDING
AND CONVERGING TOWARDS A CHILLY SUMMERTIME PATTERN. A DEEP LARGE
SCALE TROUGH/LOW PRESSURE IS EXPECTED TO DIG INTO THE GREAT LAKES
REGION SUNDAY INTO MONDAY BRINGING MUCH COOLER AIR TO THE REGION. A
FEW OF THE RUNS ARE COOL ENOUGH THAT THE NORTHEAST THIRD OF THE CWA
MIGHT NOT MAKE IT TO 70 DEGREES. THIS PATTERN SUGGESTS TEMPERATURES
MUCH BELOW NORMAL FOR MONDAY AND TUESDAY. STATISTICAL GUIDANCE
SOMEWHAT SUPPORTIVE OF THIS WITH THE MEX NUMBERS BELOW CLIMATOLOGY
AND THE ENSEMBLE MEAN EVEN COOLER. A COUPLE OF WEAK WAVES WILL MOVE
THROUGH OVER THE WEEKEND WHICH COULD BRING A FEW SHOWERS AND
THUNDERSTORMS BUT MONDAY AND TUESDAY SHOULD SEE MAINLY COOL AND
STABLE AIR WITH LOWER PROBABILITIES OF RAINFALL.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1239 PM CDT TUE JUL 8 2014

GUSTY NORTHWEST WINDS WILL PREVAIL THROUGH THE AFTERNOON AND
EVENING HOURS. WINDS WILL DROP RAPIDLY TOWARDS SUNSET. WINDS WILL
REMAIN LIGHT THROUGH THE MORNING HOURS ON WEDNESDAY...MIXING OUT
TO NORTHWEST THROUGHOUT THE DAY. SCATTERED CUMULUS AROUND 4-5K
FEET WILL DIE AWAY THIS EVENING...WITH MOSTLY CLEAR SKIES EXPECTED
OVERNIGHT THROUGH WEDNESDAY MORNING.

&&

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

$$

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






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