000
FXUS63 KDMX 200505
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1205 AM CDT THU JUN 20 2013

.UPDATE...
ISSUED AT 937 PM CDT WED JUN 19 2013

HAVE LOWERED POPS THIS EVENING WITH NOTHING OF NOTE IN SATELLITE
IMAGERY AFTER DIURNAL LOSS OF CU. WEAK LIFT ASSOCIATED WITH
ELONGATED MN/IA/MO SHORT WAVE AXIS IS PRODUCING NOTHING BEYOND BKN
MID/HIGH CLOUDS AND EXITING THE FORECAST AREA. RAP OBJECTIVE
ANALYSIS DOES SHOW THETA-E ADVECTION THROUGH THE MO VALLEY...BUT
MOISTURE MUST BE LIMITED FOR NOW AS SKIES ARE MOSTLY CLEAR. WARM
ADVECTION DOES CONTINUE OVERNIGHT SO GRADUALLY RE-INTRODUCED POPS
WEST AND NORTH LATE IN CASE THIS THERMODYNAMIC FORCING EVENTUALLY
MATURES AND IS REALIZED.

&&

.SHORT TERM.../TONIGHT/...
ISSUED AT 413 PM CDT WED JUN 19 2013

MAIN FORECAST CONCERN IS WITH SMALL CHANCES OF ISOLATED STORMS
ACROSS THE WEST AND NORTH THIS AFTERNOON THROUGH THURSDAY MORNING.
LEANED TOWARD A BLEND OF THE HI-RES MODELS FOR TRENDS TONIGHT INTO
THURSDAY MORNING.

THE ARW-WEST AND LATEST HRRR HAVE SOME ISOLATED THUNDERSTORMS
DEVELOPING THIS AFTERNOON INTO THE EARLY EVENING ACROSS WESTERN TO
NORTHERN PORTIONS OF THE FORECAST AREA. CAP SEEMS TO BE WINNING ATTM
AND CUT BACK ON POPS TO MAINLY THE FAR WEST EVEN THOUGH SURFACE
BASED CAPE AROUND 1000-1500 J/KG WITH MUCAPE SLIGHTLY HIGHER. THERE
IS VERY LITTLE...IF ANY SHEAR PRESENT THROUGH THE EVENING HOURS..SO
NOT ANTICIPATING ANYTHING LONG-LIVED. WEAK THETA-E ADVECTION MOVES
INTO WESTERN IOWA PAST 06Z AS A BROAD AREA OF VORTICITY CUTS THROUGH
THE REGION TONIGHT. TRANSITIONED CHANCE POPS FURTHER EAST OVERNIGHT
AND MAINLY KEPT HIGHEST POPS ACROSS NORTHERN IOWA PAST 06Z THURSDAY
WHERE BEST FORCING IS PRESENT.

.LONG TERM.../THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 413 PM CDT WED JUN 19 2013

UPPER LEVEL LOW CONTINUES SLOWLY MOVE OVER THE PACIFIC NORTHWEST
TODAY AND WILL MOVE LITTLE THROUGH SATURDAY BEFORE BEGINNING TO
LIFT NORTHEAST INTO CANADA ON SUNDAY. WEAK RIDGING OVER IOWA WILL
SLOWLY SHIFT EAST DURING THIS TIME AS WELL AND WILL FOCUS
SOUTHWEST FLOW INTO THE UPPER MIDWEST. NUMEROUS SHORT WAVES ARE
STILL EXPECTED TO RIPPLE THROUGH THIS FLOW AND IMPACT MAINLY
NORTHERN IOWA AND AREAS TO THE NORTH DURING THE PERIOD WHILE WARM
AIR ALOFT DRIVES A CAP INTO CENTRAL AND SOUTHERN IOWA FRIDAY INTO
SATURDAY.

SURFACE LOW PRESSURE WILL LIFT NORTH THROUGH KANSAS AND NEBRASKA
THURSDAY AND THURSDAY NIGHT WITH A SECONDARY WARM FRONT MOVING
NORTH THROUGH THE STATE. WHILE THE PRIMARY FRONTAL BOUNDARY WILL
BE NORTH INTO MINNESOTA DURING THE AFTERNOON...THE POTENTIAL FOR
THE SECONDARY BOUNDARY TO LIFT INTO WEST CENTRAL DURING THE
AFTERNOON. SOME MIXED LAYER CIN WILL BE IN PLACE THROUGH A WEAK
SHORT WAVE IS EXPECTED TO MOVE ACROSS THE AREA WITH MID LEVEL
COOLING THAT MAY BE ENOUGH TO KICK OFF A FEW STORMS. IF STORMS
FIRE...CERTAINLY A FEW SUPERCELLS WOULD BE POSSIBLE. STILL SOME
HINTS THAT A DAKOTAS MCS COULD DROP INTO NORTHERN IOWA THURSDAY
NIGHT AND COULD BRING AN ADDITIONAL CHANCE FOR SEVERE WEATHER.

MUCH OF THE AREA OVER THE CENTRAL AND SOUTH BECOMES CAPPED FRIDAY
INTO THE WEEKEND AND HAVE BEGUN TO DROP POPS ACROSS THESE AREAS
WITH THE PRIMARY FOCUS BEING ACROSS THE NORTH. A VERY WARM AND
HUMID AIR MASS WILL LIFT INTO THE AREA WITH HIGH TEMPERATURES IN
HIGHS IN THE UPPER 80S TO MID 90S AND DEWPOINTS RISING INTO THE
70S. THE SUBTROPICAL HIGH CONTINUES TO EXERT ITSELF OVER THE
SOUTHERN PLAINS INTO EARLY NEXT WEEK AND BUILDING NORTH. THE RING
OF FIRE MAY CLIP INTO NORTHERN IOWA DURING END OF THE PERIOD BY
THE PRIMARY FOCUS WILL BE TO THE NORTH WITH SUMMER IN PLACE OVER
IOWA.

&&

.AVIATION...20/06Z
ISSUED AT 1204 AM CDT THU JUN 20 2013

VFR CONDITIONS STATEWIDE AT 06Z WITH NOTHING MORE THAN SCT
MID/HIGH CLOUDS EAST. THERE IS SOME CONCERN THAN MVFR VSBYS MAY
BRIEFLY DEVELOP BEFORE DAYBREAK...BUT NOT ENOUGH TO INCLUDE AT THE
MOMENT WITH SELY WINDS NOT DECOUPLING. VARIOUS MODELS AND
ENSEMBLES SHOW CHANCES FOR CONVECTION FROM THE AFTERNOON INTO THE
EVENING...BUT CONFIDENCE IN LOCATION AND TIMING IS NOT THERE TO
INCLUDE YET. OPTED FOR NO MENTION RATHER THAN 18 HOUR VCSH BROAD
BRUSH.

&&

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

&&

$$

UPDATE...SMALL
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...SMALL