Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 270903
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
403 AM CDT SUN JUL 27 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT SUN JUL 27 2014

WELL-DEFINED UPPER LOW DIVING SOUTHEASTWARD THROUGH NORTHWEST MN
EARLY THIS MORNING. ASSOCIATED STRATOCU FIELD IN THE COLD AIR
WORKING SOUTHWARD THROUGH NORTH DAKOTA...WITH MOST SOLID COVERAGE
ALONG/EAST OF THE JAMES RIVER VALLEY IN FAR EASTERN NORTH DAKOTA.
WITH THE UPPER LOW GRADUALLY PULLING FARTHER EAST...ANTICIPATE THE
GREATER CLOUD COVERAGE WILL BE CONFINED TO AREAS EAST OF I-29 IN THE
LATE MORNING/AFTERNOON. WILL CONTINUE WITH MENTION OF SPRINKLES TO
SLIGHT CHC POPS WITHIN THE CLOUD LAYER MIDDAY THROUGH THE AFTERNOON
BUT GIVEN MEAGER INSTABILITY WITHIN THE CLOUD LAYER...GENERALLY LESS
THAN 50J/KG IN MOST MODELS ACROSS OUR FORECAST AREA...FEEL THUNDER
THREAT WILL BE LIMITED TO AREAS FARTHER EAST. MIXING SHOULD COMMENCE
RATHER QUICKLY THIS MORNING...WITH GUSTY NORTHWEST WINDS ENHANCING
EFFECT OF COOLER/DRIER AIR MASS. STRONGEST OF COLD ADVECTION MOVES
THROUGH THE AREA EARLY THIS MORNING...BUT WITH CONTINUED WEAK COLD
ADVECTION THROUGH THE DAY...WOULD NOT BE SURPRISED TO SEE SOUTHWEST
MN REMAIN IN THE 60S MOST OF THE DAY WITH WHAT IS EXPECTED TO BE
SOMEWHAT SELF-DESTRUCTIVE CU FIELD. REMAINDER OF THE FORECAST AREA
SHOULD HAVE LITTLE PROBLEM CLIMBING INTO THE 70S...WITH SOUTHWEST
AREAS TOPPING OUT AROUND 80 DEGREES.

CONTINUED WEAK COLD ADVECTION INTO THE EVENING WILL NOT ALLOW WINDS
TO COMPLETELY DECOUPLE WITH SUNSET...THOUGH GUSTS SHOULD WANE FAIRLY
QUICKLY. NORTHERLY WINDS SHOULD BECOME LIGHT OVERNIGHT HOWEVER...AS
GRADIENT RELAXES WITH APPROACHING SURFACE RIDGE. A COMFORTABLY COOL
NIGHT EXPECTED WITH TEMPERATURES QUICKLY DROPPING INTO 60S DURING
THE EVENING ON THE WAY TO LOWS IN THE MID TO UPPER 50S.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 400 AM CDT SUN JUL 27 2014

GRADIENT IS MUCH WEAKER ON MONDAY...EVEN ALOFT...BUT ENOUGH THAT
MOST AREAS NEAR/EAST OF I 29 WILL BE NEAR THE 10 TO 15 KNOT RANGE...
AND A BIT LESS TO THE WEST. WHILE OVERALL LARGER SCALE WILL BE
FAIRLY SUBSIDENCE FAVORED...JUST ENOUGH CONCERN ABOUT MINOR SHALLOW
SURFACE BASED CAPE ALONG WITH MOISTURE AXIS WRAPPING IN FROM THE
NORTHEAST THROUGH MAINLY SW MN AND NW IA.  STRONG UNIDIRECTIONAL
WINDS AND UNSTABLE LOWER LEVELS SHOULD LEAD TO SHALLOW CLOUD
STREETS...AND LIKELY THAT WILL BE ENOUGH TO GET SOME ISOLATED
SHOWERS GOING DURING THE LATER MORNING AND ESPECIALLY THE
AFTERNOON. 03Z SREF HAS GONE MORE BULLISH ON THE LIGHT QPF THREAT.
MIXING WOULD SUGGEST MAINLY LOWER TO MID 70S EAST...AND NEAR 80
FAR WEST.


OVERNIGHT LOWS WILL BE ON THE COOL SIDE FOR MONDAY AND TUESDAY
NIGHT GIVEN THE PROXIMITY OF THE RIDGE AXIS...ALTHOUGH CLOUDS
COULD HAVE SOMETHING TO SAY ABOUT HOW COOL PARTS OF THE EAST GET
BY TUESDAY MORNING. HIGHS TUESDAY MAINLY MID 70S EAST TO AROUND 80
WEST. WILL HAVE TO MONITOR THE THREAT FOR ADDITIONAL SMOKE
IMPACTING SKIES BY EARLY WEEK WITH TRAJECTORY RETURNING FROM THE
NORTH.

FOR THE MOST PART...WILL SETTLE IN FOR A COOL AND QUIET WEEK AS
THE LARGER SCALE LOCKS IN PLACE WITH RIDGE TO WEST AND TROUGH TO
EAST...ALTHOUGH THE RIDGE AXIS WILL NUDGE EVER SO SLOWLY EAST BY
NEXT WEEKEND. SEVERAL SOLUTIONS HAVE A LITTLE LOBE SWINGING AROUND
EASTERN UPPER LOW ABOUT THURSDAY...AND POSSIBLE THIS COULD HELP TO
FOCUS A BIT OF MOISTURE ALONG CONVERGENCE AXIS FOR A VERY LOW END
PRECIPITATION THREAT THURSDAY NIGHT/FRIDAY ACROSS THE SOUTH/SOUTHEAST.
OTHER PRECIPITATION ASSOCIATED WITH WEAK WAVES COMING AROUND THE
WESTERN RIDGE SHOULD KEEP ANY PRECIPITATION JUST WEST OF THE CWA
AS IT ROTATES SOUTHEAST ACROSS THE HIGH PLAINS. OTHERWISE...TEMPS
WILL CONTINUE TO FEATURE BELOW NORMAL READINGS AND WINDS WILL BE
ABNORMALLY LIGHT. TEMPERATURES WILL BE FAIRLY PERSISTENT...PERHAPS
NUDGING UP A BIT CLOSER TO NORMAL TOWARD NEXT WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1027 PM CDT SAT JUL 26 2014

VFR CONDITIONS THROUGH THE TAF PERIOD. NORTHWESTERLY WINDS WILL
PICK UP AFTER 14Z ON SUNDAY...GUSTING TO AROUND 25 KTS THROUGH
THE AFTERNOON.


&&

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

$$

SHORT TERM...JH
LONG TERM...CHAPMAN
AVIATION...JM





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