000
FXUS63 KDMX 182341
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
641 PM CDT TUE JUN 18 2013

.SHORT TERM.../TONIGHT/...
ISSUED AT 410 PM CDT TUE JUN 18 2013

WEAK BOUNDARY MOVING THROUGH THE EASTERN CWA...DENOTED BY WIND SHIFT
FROM NORTHWEST TO NORTHEAST/EAST BEHIND THE BOUNDARY. THIS WAS
ASSOCIATED WITH A WEAK UPPER LEVEL DISTURBANCE DROPPING THROUGH THE
REGION EARLIER TODAY. SEEING A FEW RADAR ECHOES GO UP NEAR THE
BOUNDARY IN AREA OF ENHANCED CU OVER THE EAST/SOUTHEASTERN CWA.
LATEST MESOANALYSIS SUGGESTING DECENT CAPE AND SOME SHEAR ACROSS THE
FAR SOUTHEASTERN CWA. THEREFORE MAY CONTINUE TO SEE A COUPLE
ISOLATED CELLS THROUGH THE REMAINDER OF THE AFTERNOON HOURS. EXPECT
ANY ACTIVITY TO DIE OFF WITH SUNSET AND THE CURRENT CU FIELD TO
CLEAR AS SFC HIGH PRESSURE SKIRTS THE AREA TO THE EAST. UPPER LEVEL
RIDGING WILL BUILD IN ALOFT FROM THE WEST...WITH RETURN FLOW SETTING
UP ACROSS THE WESTERN CWA LATE TONIGHT. THETA-E ADVECTION BEGINS
ALOFT IN SOUTHWEST/WESTERLY FLOW TOWARD 09-12Z. THIS MAY RESULT IN
SOME MID LEVEL CLOUD COVER DEVELOPING ACROSS THE WESTERN CWA TOWARD
SUNRISE WEDNESDAY. MOISTURE PUSH NOT ALL THAT STRONG...SO STUCK WITH
INCREASING CLOUD COVER AND A DRY FORECAST. MAY SEE A LITTLE LIGHT
FOG DEVELOP WITH THE CLEAR SKIES AND LIGHT WINDS ACROSS THE EASTERN
CWA...BUT VISIBILITIES EXPECTED TO REMAIN IN THE 3-5 MILE RANGE SO
DID NOT MENTION FOG IN THE GRIDS.

.LONG TERM.../WEDNESDAY THROUGH TUESDAY/...
ISSUED AT 410 PM CDT TUE JUN 18 2013

UPPER LEVEL RIDGE WILL GRADUALLY SETTLE OVER THE MIDWEST THE NEXT
SEVERAL DAYS AS AN UPPER LOW CHURNS OVER THE PACIFIC NORTHWEST.
NUMEROUS SHORT WAVES WILL RIPPLE THROUGH THE SOUTHWEST FLOW AND
OVER TOP THE RIDGE INTO THE WEEKEND BEFORE THE UPPER LOW LIFTS
NORTH INTO CANADA AND A SUBTROPICAL HIGH BEGINS TO BUILD NORTH
INTO THE NATIONS MID SECTION. THE INITIAL SHORT WAVE ARRIVES OVER
WESTERN IOWA BY WEDNESDAY AFTERNOON ACCOMPANIED BY INCREASING
THETA-E ADVECTION INTO THE OVERNIGHT. A BETTER CHANCE FOR
CONVECTION ARRIVES THURSDAY AS THE THETA-E ADVECTION CONTINUES AND
THE LOW LEVEL JET BECOMES MORE FOCUSED INTO WESTERN IOWA. SOME
SEVERE WEATHER MAY ACCOMPANY EACH SYSTEM THROUGH A BETTER CHANCE
APPEARS LATE THURSDAY INTO THURSDAY NIGHT. MODELS SUGGESTING THE
POTENTIAL FOR A COMPLEX TO DEVELOP OVER NORTH DAKOTA THEN FOLLOW
THE CORFIDI VECTORS DOWN THE INSTABILITY AXIS AND DROP SOUTH INTO
THE FORECAST AREA.

THE PATTERN DOES NOT CHANGE MUCH UNTIL SUNDAY AS THE SYSTEM PULLS
NORTHEAST INTO CANADA. TEMPERATURES THROUGH THE PERIOD WILL
GRADUALLY WARM AND SHOULD BE IN THE THE MID 80S TO LOWER 90S. THE
THERMAL RIDGE BEGINS TO ARRIVE TOWARD THE END OF THE PERIOD WITH
THE 700 MB CAP OF +12C TO +16C ARRIVING. THIS WOULD LEAD TO HIGHS
WELL INTO THE 90S. HAVE NOT GONE QUITE THIS HIGH YET BUT HAVE
TRENDED WARMER.

&&

.AVIATION...19/00Z
ISSUED AT 640 PM CDT TUE JUN 18 2013

VFR CU CONTINUES TO LIFT AND DISSIPATE AND THAT SHOULD BE THE
TREND THROUGH THE EVENING HOURS. ONLY CONCERN THROUGH THE PERIOD
WILL BE WHETHER MVFR FOG COULD DEVELOP EARLY WED MORNING. TEMPS
AND DEWPOINTS ARE A BIT LOWER/HIGHER RESPECTIVELY FROM THIS TIME
YESTERDAY SO THERE IS THAT POTENTIAL WITH LIGHT SE WIND. HAVE ADDED
MENTION IN CLIMATOLOGICALLY FAVORED LOCATIONS WHICH ARE ALSO
SUPPORTED BY MOS GUIDANCE...WHICH ENDS UP TO BE EVERYWHERE
OUTSIDE OF KDSM.

&&

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

&&

$$

SHORT TERM...BEERENDS
LONG TERM...DONAVON
AVIATION...SMALL