000
FXUS63 KDMX 232338
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
638 PM CDT THU MAY 23 2013

.SHORT TERM.../TONIGHT /...
ISSUED AT 310 PM CDT THU MAY 23 2013

LITTLE OF CONCERN TONIGHT WITH IA BETWEEN HIGH PLAINS RIDGE AND
DEPARTING GREAT LAKES TROUGH.  ALTHOUGH SKIES WILL BE CLEAR WITH
LIGHT WINDS AS SURFACE HIGH PRESSURE CROSSES THE UPPER MS
VALLEY...OVERNIGHT LOWS SHOULD ONLY DIP INTO THE UPPER 30S NORTHEAST
KEEPING FROST CONCERNS AT BAY.

.LONG TERM.../FRIDAY THROUGH THURSDAY/...
ISSUED AT 310 PM CDT THU MAY 23 2013

ACTIVE PERIOD SETTING UP FOR THE HOLIDAY WEEKEND INTO NEXT
WEEK...WITH MAIN ISSUED SURROUNDING CHANCES FOR THUNDERSTORMS AND
POTENTIAL FOR HEAVY RAIN. HIGH PRESSURE INITIALLY OVER THE AREA
FRIDAY WITH DRY CONDITIONS EXPECTED...HOWEVER THE SFC HIGH QUICKLY
SHOVES EAST WITH WAA AND MOISTURE ADVECTION BACK INTO WESTERN IOWA
BY LATE FRIDAY AFTERNOON. THIS WILL ALLOW FOR SOME POTENTIAL
THUNDERSTORMS ACROSS WESTERN IOWA LATE IN THE AFTERNOON. CHANCES FOR
THUNDERSTORMS TO BECOME MORE WIDESPREAD ACROSS THE CWA AS WEAK
SHORTWAVES PUSH EASTWARD THROUGH THE UPPER LEVEL RIDGE EXPECTED TO
REMAIN IN PLACE THROUGH THE WEEKEND. THUNDERSTORM CHANCES WILL
REMAIN WITH THE CLIMATOLOGICAL FAVORED TIMES IN THIS TYPE OF
PATTERN...MAINLY IN THE EVENING TO OVERNIGHT HOURS AND LINGERING
INTO THE MORNING. WITH THE EXTENDED CHANCES FOR THUNDERSTORMS AND
RAINFALL...FLASH FLOODING AND RIVER FLOODING BECOMES A CONCERN.
MOISTURE TRANSPORT ORIENTED INTO IOWA FOR MUCH OF THE HOLIDAY
WEEKEND...PWATS WELL ABOVE AVERAGE INCREASING INTO THE 1.3 TO 1.5
INCH RANGE...AND FZ LVL QUITE HIGH SUGGESTING EFFICIENT RAIN
PRODUCTION THROUGH THE WEEKEND. WIDESPREAD RAINFALL AMOUNTS OF 1
TO 2 INCHES WITH LOCALLY HIGHER AMOUNTS ARE POSSIBLE THROUGH THE
HOLIDAY WEEKEND. SEVERE PARAMETERS NOT THAT GREAT...SO WIDESPREAD
SEVERE WEATHER IS NOT ANTICIPATED.

UPPER LEVEL RIDGE BEGINS TO SHIFT EAST SLIGHTLY AND DAMPEN
SOME...WITH A SFC WARM FRONT EXPECTED TO LIFT NORTHWARD THROUGH THE
STATE TUESDAY. AN UPPER LEVEL CLOSED LOW DIGS INTO THE DESERT
SOUTHWEST WITH IMPULSES EJECTING OUT AHEAD OF THE MAIN SYSTEM
THROUGH THE REGION. WITH THE WARM FRONT STALLING OUT ACROSS THE CWA
TUESDAY INTO WEDNESDAY...AND THE ENERGY LIFTING THROUGH THE
AREA...THUNDERSTORM CHANCES CONTINUE INTO NEXT WEEK ACROSS THE AREA.
WARMER TEMPERATURES ALSO EXPECTED WITH THE WARM FRONT LIFTING
NORTH...WITH MUCH OF THE AREA RETURNING TO 70S AND 80S BY THE MIDDLE
OF NEXT WEEK.

&&

.AVIATION...24/00Z
 ISSUED AT 637 PM CDT THU MAY 23 2013

FEW CONCERNS THIS PERIOD. HIGH REMAINS OVER THE AREA THROUGH
OVERNIGHT HOURS AS TROUGH OF LOW PRESSURE OVER THE WESTERN PLAINS
DRIFTS EAST FRIDAY. IN RESPONSE SOME HIGH AND MID LEVEL CLOUDS
WILL INCREASE FOR KFOD AND KDSM 15-22Z. WINDS WILL INCREASE FROM
THE SOUTH SOUTHEAST AT KFOD AND KDSM AS WELL FROM 14Z-00Z WITH
GUSTS TO 20KT AFT 16-20Z. NIL WX UNTIL SYSTEM ARRIVES AFT 00Z WITH
NOCTURNAL THUNDER LIKELY BECOMING MORE PROBLEMATIC FOR CIGS AND VSBYS
AFT 04Z...AND WILL INCLUDE MORE DETAILS NEXT UPDATE.

&&

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

$$

SHORT TERM...SMALL
LONG TERM...BEERENDS
AVIATION...REV