Area Forecast Discussion
Issued by NWS Des Moines, IA

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000
FXUS63 KDMX 010850
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
350 AM CDT WED JUL 1 2015

.SHORT TERM /TODAY/...
ISSUED AT 334 AM CDT WED JUL 1 2015

MAIN CONCERN TODAY IS PLACEMENT OF PRECIPITATION AS WEAK WAVES
RIPPLE SOUTHEAST ALONG BAROCLINIC ZONE PLACED ALONG THE MISSOURI
RIVER VALLEY.  MAIN AREA OF FLOW LEVEL CONVERGENCE...THETA-E
ADVECTION AND MID LEVEL FORCING REMAINS NEAR THE MISSOURI RIVER THIS
MORNING WHERE CONVECTION CONTINUES JUST WEST AND SOUTH OF THE
FORECAST AREA.  THIS AREA OF CONVERGENCE AND FORCING MOVES LITTLE
THROUGH THE DAY WITH BEST THREAT OF PRECIPITATION REMAINING JUST
WEST OF THE CWA.  HOWEVER...SOME SCATTERED SHOWERS AND A FEW STORMS
ARE STILL EXPECTED IN THE WEST THROUGH THE DAY WITH SUCH CLOSE
PROXIMITY TO THE LOW LEVEL CONVERGENCE AND LIFT.  HAVE DROPPED THE
POPS FARTHER NORTHEAST WITH LITTLE THREAT OF PCPN AS DRIER AIR
ADVECTS INTO THE AREA ON EAST WINDS.  TEMPERATURES WILL BE COOLER
TODAY AS CLOUDINESS WILL BE QUITE EXTENSIVE AND THE THERMAL RIDGE IN
THE PLAINS IS SUPPRESSED FARTHER WEST.

.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 334 AM CDT WED JUL 1 2015

THE OVERALL WEATHER PATTERN HASN`T CHANGED MUCH. WE REMAIN IN
NORTHWEST FLOW THROUGH FRIDAY THEN WE TRANSITION TO MORE OF A
ZONAL FLOW OVER THE WEEKEND INTO NEXT WEEK AS A BROAD LOW PRESSURE
PUSHES ACROSS CANADA. THE TROUGH CREATED BY THAT LOW SUPPRESSES THE
HIGH CREATING THE ZONAL FLOW ACROSS THE U.S. WHICH WILL BRING A
RETURN TO WARMER...AND UNSTABLE...AIR BACK INTO IOWA. SO AFTER
BEING IN THE MID 70S OR SO FOR HIGHS...WE WILL SEE MID 80S NEXT
WEEK.

FROM TONIGHT THROUGH FRIDAY WE WILL CONTINUE TO SEE SEVERAL WEAK
SHORTWAVES PASS ACROSS IOWA BUT WITH MINIMAL INSTABILITY ALL WE
SHOULD SEE WITH EACH WAVE IS A CHANCE FOR SHOWERS WITH ISOLATED
THUNDERSTORMS AND ALMOST NO THREAT OF SEVERE STORMS.

SUNDAY NIGHT THROUGH MONDAY NIGHT THE CANADIAN TROUGH DEEPENS AND
SWINGS THORUGH THE NORTHERN PLAINS DRIVING A SURFACE LOW AND COLD
FRONT EAST ACROSS IOWA. THERE WILL BE DECENT FORCING...INSTABILITY
AND SHEAR WITH THE FRONTAL BOUNDARY AND AS SUCH WE SHOULD SEE OUR
BEST CHANCE FOR STRONG TO SEVERE STORMS MONDAY. THE MODELS ARE A
LITTLE FASTER WITH BRINGING THE FRONT THROUGH BEFORE PEAK HEATING
SO EVEN OUR BEST CHANCE AT SEVERE STORMS ISN`T VERY GOOD...AT
LEAST FOR MOST OF IOWA. THROUGH MID WEEK A RIDGE TRIES TO REBUILD
OVER THE ROCKIES BUT ANOTHER CANADIAN LOW AND UPPER TROUGH
FURTHER EAST OF THE BUILDING RIDGE WILL COUNTER THAT AND KEEP A
MORE ZONAL FLOW ACROSS THE UPPER MIDWEST. THE RESULT WILL BE
WARMER TEMPS AND PERIODIC CHANCES FOR STORMS WITH ANY SHORTWAVES
RIPPLING THROUGH BUT THE MODELS ARE SIMPLY HAVING A DIFFICULT TIME
RESOLVING THE TIMING AND DEVELOPMENT OF THESE SHORTWAVES SO FOR
NOW...GENERALLY LOW CHANCES FOR PRECIP AFTER MONDAY.

&&

.AVIATION...01/06Z
ISSUED AT 1125 PM CDT TUE JUN 30 2015

AREA OF SHOWERS AND SCT THUNDER MAINLY AFFECTING SW IOWA ATTM.
LIFT ASSOCIATED WITH BOUNDARY ALOFT FOCUSING CONVECTION SW OF TAF
SITES AND HAVE LESSENED COVERAGE -SHRA THROUGH 10Z AT KFOD AND
KDSM/KOTM. UPSTREAM MCS OVER NORTH DAKOTA IS EXPECTED TO HOLD
TOGETHER WITH SOME SUPPORT OF NEXT UPSTREAM WAVE IN THE WESTERN
DAKOTAS NOW...THIS SHOULD REACH NORTHWEST AREAS AFT 10Z AND
PROGRESS SOUTHEAST FROM 12Z THROUGH 18Z...MOST LIKELY WEAKENING AS
IT DOES. LIKELY THAT CIGS WILL REMAIN VFR THROUGH 12Z WITH SOME
MVFR DEVELOPING ONCE -SHRA CROSS REGION WED. BY 00Z THU SHOWERS
WILL EXIT SOUTHEAST. WINDS MIX AFT 17Z WITH GUSTS 15KTS AT SOME
LOCATIONS. NORTHEAST SHOULD REMAIN DRY. /REV

&&

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

$$

SHORT TERM...COGIL
LONG TERM...FAB
AVIATION...REV


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