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000
FXUS63 KDMX 121758
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1255 PM CDT WED JUN 12 2013

.UPDATE...
ISSUED AT 637 AM CDT WED JUN 12 2013

MAJORITY OF STORMS HAVE MOVED THROUGH THE CWA...WITH THE LINE TO
THE NORTH PUSHING MORE EAST AND DIMINISHING SOME. THEREFORE HAVE
UPDATED TO REFINE POPS FOR THE EARLY MORNING/MORNING HOURS...WITH
CURRENT ACTIVITY EXPECTED TO REMAIN RELATIVELY BENIGN. FOCUS THEN
TURNS TO REDEVELOPMENT EXPECTED LATER THIS MORNING ACROSS THE
NORTH...AND BY EARLY AFTERNOON ACROSS THE EAST/SOUTH AS THE UPPER
WAVE AND ASSOCIATED SURFACE LOW MOVE THROUGH THE AREA.

&&

.SHORT TERM.../TODAY /...
ISSUED AT 315 AM CDT WED JUN 12 2013

PRECIPITATION CHANCES THE MAIN FORECAST CONCERN TODAY...WITH A SFC
LOW CURRENTLY CENTERED OVER SC NE/NC KS AND ASSOCIATED UPPER LEVEL
WAVE MOVING INTO WESTERN SD. THE UPPER LEVEL WAVE WILL SLIDE EAST
SOUTHEAST THROUGH THE AREA TODAY...WITH THE SFC LOW TRACKING
EXPECTED TO BE CENTERED OVER SOUTHWEST IA BY 15Z..AND SLIDE EASTWARD
THROUGH SOUTHERN IOWA THROUGH LATE AFTERNOON. THIS WILL ALLOW FOR
CHANCES OF PRECIPITATION ACROSS MUCH OF THE CWA...AND ESPECIALLY THE
NORTH/EASTERN CWA THROUGH THE DAY. CURRENTLY HAVE A LINE OF JUST
MOVING INTO THE NORTHERN/WESTERN CWA. THIS ACTIVITY BEING FUELED BY
WAA AND STRONG PUSH OF MOISTURE TRANSPORT INTO ERN NE/NRN IA.
ACTIVITY EXPECTED TO CONTINUE TO TRANSLATE EASTWARD ACROSS THE CWA
THROUGH 12Z AND THEN MOVE EAST OF THE CWA. NOT A WHOLE LOT OF
EFFECTIVE DEEP LAYER SHEAR ACROSS THE AREA...SO SEVERE THREAT IS
SOMEWHAT CONDITIONAL.

SECONDARY AREA OF ACTIVITY MORE OF CONCERN EXPECTED TO POSSIBLY
REACH THE NORTHERN CWA BY MID MORNING. ACTIVITY HAS BEEN MAINLY
TRACKING DUE EAST...BUT THIS AREA IS ASSOCIATED WITH THE UPPER LEVEL
WAVE MOVING THROUGH ALOFT. CURRENT PROJECTIONS INDICATE IT
BEGINNING TO MOVE ESE OR EXPAND SOUTHWARD ACROSS THE NORTHERN CWA
THIS MORNING. AS THE SFC LOW APPROACHES TO THE SOUTHWEST...AND THE
UPPER LEVEL WAVE APPROACHES ALOFT DEEP LAYER SHEAR SHOULD
INCREASE...THUS ALLOWING CHANCE FOR A SEVERE WIND GUST ACROSS THE
NORTHERN CWA TOWARD MORNING IF THE AREA OF STORMS HOLD
TOGETHER/INTENSIFIES. ADDITIONAL POSSIBILITY OF STORM DEVELOPMENT IN
VICINITY OF THE SFC LOW/SFC WARM FRONT TOWARD MID-DAY/EARLY
AFTERNOON AS MID LEVEL TEMPS COOL IN ADVANCE OF THE APPROACHING
UPPER LEVEL WAVE ALLOWING THE AREA TO BECOME UNCAPPED TOWARD 18Z
MAINLY ALONG AND EAST OF I-35/SOUTH OF HWY 20. THESE STORMS COULD
ALSO POSE A SEVERE THREAT...BUT WILL BE DEPENDED ON TIME OF
INITIATION AS THE SFC LOW IS QUICKLY MOVING THROUGH THE AREA AND
COULD END UP WITH CONVECTIVE INITIATION JUST EAST OF THE CWA.
OTHERWISE HAVE CONTINUED POPS ON THE BACKSIDE OF THE SYSTEM THROUGH
THE LATE AFTERNOON HOURS...AS MORE WEAK THUNDERSTORM/SCATTERED
SHOWERS STILL POSSIBLE INTO THE LATE AFTERNOON HOURS ON THE COOL
SIDE OF THE SYSTEM.

COOLED TEMPS A BIT ACROSS THE NORTH WITH CLOUDS/PRECIP EXPECTED TO
BE IN THE AREA MUCH OF THE DAY AND CAA EXPECTED THIS AFTERNOON.
OTHERWISE WARMEST AREA IN WARM SECTOR AHEAD OF THE LOW WITH THE
SOUTHEASTERN CWA WARMING BACK INTO THE MID TO UPPER 80S BEFORE COLD
FRONT/SFC LOW PASS THROUGH THE AREA BY MID/LATE AFTERNOON.

.LONG TERM.../TONIGHT THROUGH MONDAY/...
ISSUED AT 315 AM CDT WED JUN 12 2013

SYSTEM WILL BE DEPARTING TO THE EAST THIS EVENING WITH ANY
LINGERING PCPN ENDING BY MIDNIGHT. SUBSIDENCE AND DRIER AIR WILL
OVERSPREAD THE STATE DURING THE NIGHT WITH CLEARING ALONG WITH
COOLER TEMPERATURES. RELATIVELY TRANQUIL WEATHER IS EXPECTED ON
THURSDAY AS WEAK SURFACE RIDGING PASSES OVERHEAD. BY THURSDAY
NIGHT...INCREASING WARM ADVECTION AND THETA-E ADVECTION IS
EXPECTED IN WESTERN IOWA. ELEVATED CONVECTION IS EXPECTED TO
DEVELOP ALONG THE MISSOURI RIVER VALLEY OVERNIGHT AND SLOWLY PUSH
EAST INTO THE WESTERN FORECAST AREA. THIS AREA SHOULD PERSIST INTO
FRIDAY AND EASE ACROSS CENTRAL IOWA DURING THE DAY AS THE BEST
MOISTURE ADVECTION MOVES EASTWARD. ADDITIONAL DEVELOPMENT IS
EXPECTED INTO FRIDAY EVENING AND NIGHT...PRIMARILY IN THE NORTH
AND EAST WHERE BEST LOW LEVEL INFLOW WILL BE FOCUS.

ADDITIONAL CHANCES FOR CONVECTION ARE EXPECTED INTO THE WEEKEND AS
WESTERN TROF MOVES EAST AND FLATTENS THE UPPER RIDGE ACROSS THE
CENTRAL U.S. ASSOCIATED SURFACE FRONT WILL GRADUALLY PUSH SOUTH
ACROSS IOWA INTO EARLY NEXT WEEK PROVIDING THE FOCUS FOR THE
THUNDERSTORMS THIS WEEKEND. THERE DOES APPEAR TO BE SOME BREAK IN
THE ACTIVITY INTO EARLY NEXT WEEK AS WEAK SURFACE RIDGING SLIDES
INTO THE REGION.

&&

.AVIATION...12/18Z
ISSUED AT 1255 PM CDT TUE JUN 11 2013

UNSTABLE ATMOSPHERE IN PLACE WITH A SURFACE LOW SHIFTING EAST ACROSS
SOUTHERN IOWA AND A WARM FRONT ALONG THE HIGHWAY 20 CORRIDOR.
THUNDERSTORMS WILL ERUPT ALONG AND NORTH OF THIS BOUNDARY AND BECOME
STRONG VERY QUICKLY.  THE PRIMARY AREA WILL BE OVER KALO WITH KMCW
ON THE FRINGE THEN AS THE LOW SHIFTS FURTHER KOTM MAY SEE SOME
STRONG STORMS.  STRONG STORMS SHOULD BE OUT OF CENTRAL IOWA BY 00Z
BUT POST FRONTAL STORMS COULD LINGER THROUGH 03Z IN ABOUT THE SAME
AREA.  MVFR CONDITIONS EXPECTED IN THUNDERSTORMS BECOMING VFR AFT
06Z.  SFC FLOW WILL BE SW AT 10G25KT AND STRONG IN STORMS BUT WILL
BECOME NORTH AT 5G15KT AFT 06Z.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

UPDATE...BEERENDS
SHORT TERM...BEERENDS
LONG TERM...COGIL
AVIATION...FAB