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000
FXUS63 KDMX 142033
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
333 PM CDT TUE MAY 14 2013

.SHORT TERM.../TONIGHT/... I
 ISSUED AT 306 PM CDT TUE MAY 14 2013

AFTER RECORD HEAT AND CENTURY MARK TEMPS TODAY WILL BE LOOKING AT
COOL FRONT DRIFTING SOUTHEAST THIS EVENING AND OVERNIGHT.
CONVECTIVE ELEMENTS TRYING TO GET GOING ALONG THE BOUNDARY AND
CONVERGENCE ZONE OVER NORTHWEST IA AND NORTHEAST NEBRASKA...BUT
HAVING DIFFICULTY WITH CAP AND LACK OF REAL FORCING.  TREND SHOULD
CONTINUE WITH PERHAPS AN ISOLATED SHOWER OR THUNDERSTORM THIS
EVENING IN THE VICINITY OF THE BOUNDARY. AFTER SUNSET THERE IS A
POTENTIAL FOR SOME CONVERGENCE ALOFT AS H850 FLOW INCREASES NEAR AND
JUST SOUTH OF THE BOUNDARY OVERNIGHT. AGAIN...WITH NEARLY PARALLEL
FLOW THE CHANCES REMAIN SLIM THAT MUCH REALLY GETS ORGANIZED. HAVE
INCLUDED SLIGHT CHANCES ALONG THE BOUNDARY OVERNIGHT.  TEMPS WILL
FINALLY COOL WITH PASSAGE OF BOUNDARY AND SHOULD FALL QUICKLY AFTER
01 TO 02Z ONCE SUN SETS AND DIURNAL COOLING COMMENCES.

.LONG TERM.../WEDNESDAY THROUGH TUESDAY/...
 ISSUED AT 306 PM CDT TUE MAY 14 2013

FRONTAL BOUNDARY EXPECTED TO BE SOUTH OF STATE IN NORTHERN
MISSOURI FOR BEGINNING OF PERIOD...WITH CHANCES FOR RAIN/THUNDER
RETURNING ALONG FRONTAL BOUNDARY AS IT STALLS IN NORTHERN
MISSOURI. MOISTURE INCREASES SOMEWHAT INTO WEDNESDAY AFTERNOON
ACROSS THE SOUTH...AND HAVE INCLUDED CHANCES FOR THUNDER
GENERALLY SOUTH OF INTERSTATE 80. HOWEVER...DO HAVE CONCERNS WITH
THE AMOUNT OF MOISTURE AVAILABLE AS MODELS HAVE BEEN OVER
AGGRESSIVE WITH MOISTURE LATELY...AND MAY BE TOO DRY IN LOWER
LEVELS TO SEE PRECIPITATION. HOWEVER...AREA OF LOW PRESSURE WILL
LIFT ACROSS THE DAKOTAS...WITH FRONTAL BOUNDARY ALSO LIFTING
ACROSS REGION FOR LATE THURSDAY...WITH INCREASING MOISTURE IN
SOUTHERLY FLOW AND WAA RETURNING...HAVE KEPT TEMPERATURES WARMER
FOR WEDNESDAY AND THURSDAY...WITH INCREASING THUNDERSTORM CHANCES
THURSDAY. BEST CHANCES LOOK TO BE THURSDAY NIGHT. SYSTEM WILL
SLOWLY LIFT NORTHEAST...WITH LINGERING CHANCES FOR THUNDER
THROUGH FRIDAY. MODELS CONTINUE TO POINT TO A BREAK BETWEEN
SYSTEMS WITH FIRST LOWS INFLUENCE WAINING INTO SATURDAY BEFORE
ANOTHER AREA OF LOW PRESSURE PUSHES EASTWARD FROM THE DAKOTAS.
HAVE TRENDED POPS DOWN FOR FRIDAY NIGHT INTO SATURDAY. THIS
SECONDARY SYSTEM LOOKS TO BE THE BEST POTENTIAL FOR SEVERE
WEATHER...WHILE SOME AREAS OF HIGH CAPE NOTED FOR
SATURDAY...LITTLE SHEAR AS FRONTAL BOUNDARY LAYS WELL TO THE WEST
OF CENTRAL IOWA. HOWEVER...CAPE VALUES INCREASE ALONG WITH SHEAR
FOR SUNDAY AS SYSTEM PUSHES ACROSS IOWA. HAVE INCREASED POPS FOR
SUNDAY AFTERNOON. FRONT PUSHES SOUTH WITH LINGERING POPS FOR EARLY
IN THE WEEK. HIGH PRESSURE WORKING IN FROM CANADA FOR END OF
PERIOD BEHIND SYSTEM AND A RETURN TO CALM WEATHER.
HOWEVER...TEMPERATURES WILL DROP BACK BELOW NORMAL FOR THE END OF
THE PERIOD AS COLDER AIR WORKS IN WITH HIGH.

&&

.AVIATION...14/18Z
 ISSUED AT 1233 PM CDT TUE MAY 14 2013

MAIN CONCERNS THIS PERIOD REMAIN WINDS AND POTENTIAL FOR SOME
THUNDER FOR THE LATE AFTERNOON AND OVERNIGHT HOURS.  WINDS CONTINUE
STRONG NORTHWEST AND NORTH AREAS WHERE MIXED LAYER RAPIDLY REACHING
FULL DEPTH EARLY THIS AFTERNOON. WILL CONTINUE TO SEE STRONG WINDS
THROUGH 23Z DIMINISHING THEREAFTER.  WITH MOISTURE POOLING OVER
PORTIONS OF CENTRAL IOWA...SOME CONCERNS OF INSTABILITY THOUGH NO
FOCUSING MECHANISM UNTIL BOUNDARY APPROACHES THIS EVENING. WITH
BOUNDARY SOUTH OF AREA OVERNIGHT...SOME RETURN FLOW ALOFT SHOWS MORE
PROMISE TO INITIATE SCATTERED CONVECTION OVER THE SOUTH. HAVE
INCLUDED VCSH FOR KDSM AND KOTM...BUT OTHERWISE WILL KEEP DRY FOR
THIS PERIOD UNTIL ANY BETTER ORGANIZATION SHOWS ITS HAND.


&&

.FIRE WEATHER...
ISSUED AT 306 PM CDT TUE MAY 14 2013

RELATIVE HUMIDITY VALUES WILL CONTINUE LOW THROUGH 7PM TODAY OVER
WESTERN AND NORTHERN PORTIONS OF THE FORECAST AREA. RH VALUES
RANGING FROM 13 TO 22 PERCENT AND SUSTAINED WINDS AROUND 25 MPH
THROUGH EARLY EVENING. WILL CONTINUE RED FLAG WARNING THROUGH
EVENING HOURS OR UNTIL WINDS DIMINISH.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR ADAIR-ADAMS-
AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CERRO GORDO-CRAWFORD-DALLAS-
EMMET-FRANKLIN-GREENE-GUTHRIE-HAMILTON-HANCOCK-HUMBOLDT-KOSSUTH-
PALO ALTO-POCAHONTAS-SAC-WEBSTER-WINNEBAGO-WORTH-WRIGHT.

&&

$$

SHORT TERM...REV
LONG TERM...AWB
AVIATION...REV
FIRE WEATHER...REV