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000
FXUS63 KDVN 120238
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
938 PM CDT TUE JUN 11 2013

.UPDATE...
ISSUED AT 858 PM CDT TUE JUN 11 2013

KDVN 00Z RAOB CONTINUES TO SHOW AREA BASKING IN A LOT OF CINH
BENEATH WARM EML. THUS FAR THIS EVE HAVE BEEN WATCHING SOME
POCKETS OF VERY HIGH BASED WEAK CONVECTION MAINLY SHOWERS
(RESULTING IN MOSTLY SPRINKLES AT SFC) OCCURRING ON OUTSKIRTS
OF CWA WITH WEAK WARM ADVECTION. SEEING SOME INCREASE IN THE
COVERAGE AND INTENSITY IN ACTIVITY WITH FEW MORE LIGHTNING
STRIKES SHOWING UP OVER NORTHERN IA. WATER VAPOR APPEARS TO
SHOW IMPULSE PASSING JUST SOUTH OF WOODLAKE MN PROFILER (WDLN5)
ATTIM. WITH APPROACHING IMPULSE THIS TREND MAY CONTINUE REST
OF EVE INTO OVRNGT... THUS AREAS OF NORTHEAST IA AND NORTHWEST
IL (ROUGHLY FROM KIIB-KVYS) NEAR NORTHERN FRINGE OF CAPPING
WILL HAVE BEST CHCS OF SEEING ANY HIGH BASED CONVECTION BY LATE
EVE AND OVRNGT.

STILL WATCHING CONVECTIVE ACTIVITY FURTHER WEST FOR INCREASE
IN COVERAGE AND INTENSITY... AS WELL DEFINED SHORTWAVE EMERGES
FROM ROCKIES INTO PLAIN AND INTERACTS WITH STRENGTHENING LOW
LEVEL JET OF 55-60+ KTS. WHILE CAPPING MAKES FOR SOME
UNCERTAINTY WITH COVERAGE... GIVEN FORCING I WOULD STILL
ANTICIPATE ONE OR MORE CONVECTIVE CLUSTERS DEVELOPING IN SD/NE/NW
IA/SW MN. THIS ACTIVITY TRACKING EWD EVENTUALLY TURNING MORE
SE IN TIME ON FRINGE OF STOUT CAPPING... THUS COULD SEE SOME
ADDITIONAL CONVECTION PROPAGATING AND/OR DEVELOPING BACK ACROSS
MAINLY NORTH OF I-80 LATE TNGT INTO WED AM. THE NEW NAM IS
SIMILAR TO 12Z RUNS OF ECMWF AND UKMET IN SUGGESTING GREATEST
STORM COVERAGE AND SEVERE POTENTIAL WILL BE EVOLVING DURING THE
DAYTIME ON WED ACROSS REGION EXITING TOWARD EVE.

&&

.SYNOPSIS...
ISSUED AT 235 PM CDT TUE JUN 11 2013

A WARM FRONT ORIGINATING IS LOW PRESSURE OVER WESTERN KS AND
EASTERN CO...EXTENDED EAST THROUGH SOUTHERN IOWA AND WEST CENTRAL
IL EARLY THIS AFTERNOON. THE MORNING U/A ANALYSIS SHOWED BROAD H5
RIDGING OVER THE PLAINS AND MISSISSIPPI VALLEY WITH A VIGOROUS S/W
OVER THE CENTRAL ROCKIES. THE H7 ANALYSIS SHOWED VERY WARM AIR
FROM THE CENTRAL AND SOUTHERN PLAINS INTO THE MS VALLEY WITH TEMPS
RANGING FROM AROUND 10C NEAR THE MS RIVER TO THE MID AND UPPER
TEENS IN THE PLAINS. THE MORNING SHRA/TSRA THAT CROSSED THE
SOUTHERN CWA WERE ROOTED ABOVE THE MID LEVEL WARM AIR AND APPEARED
TO BE SUPPORTED BY A SUBTLE S/W THAT MOVE THROUGH UPPER MS VALLEY.
OTHER SHRA/ISOLD TSRA CURRENTLY MOVING INTO SOUTHWEST IOWA AND
NORTHWEST MISSOURI WERE ALSO ELEVATED AND OCCURRING IN AN AREA OF
WEAK MID LEVEL FGEN.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 235 PM CDT TUE JUN 11 2013

THE ROCKIES S/W WILL MOVE EAST INTO WESTERN IOWA BY EARLY
WEDNESDAY AFTERNOON WITH THE PLAINS SURFACE LOW REACHING EAST
CENTRAL IOWA. THE AIRMASS AHEAD OF THESE FEATURES WILL REMAIN VERY
UNSTABLE. THUNDERSTORM DEVELOPMENT AHEAD OF THE SYSTEM WILL BE
LIMITED DUE TO THE STRONG CAP OVER THE REGION. THE BIGGEST
CHALLENGE WILL BE DETERMINING WHERE AND WHEN THE STORMS WILL BE ABLE
TO OVERCOME THE SUPPRESSION.

THE ELEVATED SHRA/ISOLATED TSRA ONGOING TO THE WEST WILL HAVE TO
BE WATCHED TO SEE IF IT CAN HOLD TOGETHER LONG ENOUGH TO BRUSH THE
SOUTHERN CWFA LATE THIS AFTERNOON AND EARLY THIS EVENING. THE
PRECIP APPEARS TO BE TIED TO MID LEVEL FGEN THAN MODELS SHOW
SLIDING OFF TO THE SOUTHEAST AND WEAKENING BY 00Z. IF THIS
VERIFIES THEN MOST OF THE PRECIP SHOULD MISS THE CWFA. OTHERWISE
MAINTAINED SOME LOW POPS NORTH...NORTH OF THE WARM FRONT THIS
EVENING FOR ANY ISOLATED STORMS THAT ARE ABLE TO DEVELOP.  THE
BETTER THREAT OF THUNDERSTORMS SHOULD ARRIVE LATE TONIGHT VIA AN
MCS EXPECTED TO TAKE SHAPE OVER THE NORTHERN PLAINS THIS EVENING.
THE MCS SHOULD MOVE ALONG THE EDGE OF THE CAP THROUGH NORTHERN
IA/SRN MN AFTER MIDNIGHT WITH THE POTENTIAL FOR SOME STORMS TO
BUILD SOUTH TOWARD THE CWFA BY TUESDAY MORNING. THERE IS A SEVERE
HAIL AND WIND THREAT WITH THESE STORMS. EVEN THOUGH THE STORMS
WILL BE TAPPING AIR WITH 1.5 INCH PLUS P/W/S THE THREAT OF HEAVY
RAIN WILL BE LIMITED SINCE THE STORMS SHOULD BE PROGRESSIVE.

A GREATER THREAT OF SEVERE WEATHER WILL EXIST WEDNESDAY WITH THE
ARRIVAL OF THE UPPER WAVE AND SURFACE LOW. THE LATEST RUNS SUGGEST
THAT THE THREAT WILL BE GREATEST DURING THE AFTERNOON EAST OF THE
MISSISSIPPI RIVER WHICH LOOKS REASONABLE. MODELS SHOW THE CAP
WEAKENING JUST AHEAD OF THE UPPER TROF WHICH SUGGESTS A NARROW
WINDOW FOR SIGNIFICANT SEVERE STORMS DURING THE LATE MORNING AND
EARLY AFTERNOON WEST IF THE RIVER WITH THE BETTER FORCING AND
INSTABILITY PHASING EAST OF THE RIVER DURING THE AFTERNOON. THE
SEVERE THREAT WILL INCLUDE ISOLATED TORNADOES...WIND AND HAIL
EARLY IN THE AFTERNOON WHEN THE STORM MODE IS EXPECTED TO BE SUPER
CELLS...THEN TRANSITIONING TO MAINLY WIND AND HAIL AS THE
AFTERNOON PROGRESSES AND STORMS BECOME MORE LINEAR.

DLF

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 235 PM CDT TUE JUN 11 2013

WEDNESDAY NIGHT THROUGH NEXT TUESDAY...
FORECAST FOCUS ON ACTIVE WEATHER FOR MOST OF THIS PERIOD.

WEDNESDAY NIGHT...POTENTIAL FOR SEVERE WEATHER IN THE FORM OF A
DAMAGING DERECHO WILL BE QUICKLY MOVING EAST OF THE DVN CWA DURING
THE EVENING. WILL HAVE LIKELY POPS FOR OUR EASTERN CWA THEN ONLY
SMALL POPS IN OUR FAR EASTERN COUNTIES AFTER MIDNIGHT.

THURSDAY THROUGH FRIDAY...A BRIEF RESPITE AS HIGH PRESSURE RIDGE
BUILDS INTO THE WESTERN GREAT LAKES/MIDWEST. MAXIMUM TEMPERATURES
WILL BE IN THE MID 70S TO LOWER 80S BUT DEW POINTS WILL BE MORE
COMFORTABLE...IN THE 50S TO LOWER 60S.

FRIDAY NIGHT THROUGH SUNDAY...ACTIVE PATTERN WITH THE BOUNDARY LIFTING
NORTHWARD INTO THE DVN CWA AND STALLING OUT. THE MORE LIKELY TIME
FRAME FOR MCS DEVELOPMENT WILL BE FRIDAY NIGHT INTO SATURDAY AND
AGAIN SATURDAY NIGHT INTO SUNDAY. THIS WILL OCCUR AS LOW LEVEL JET
STRENGTHENS AS SHORT WAVES RIDE THE TOP OF THE RIDGE...AND THE DVN
CWA ON THE EDGE OF A CAP. THERE WILL BE A RISK FOR SEVERE WEATHER AS
WELL AS HEAVY RAINFALL.

EARLY NEXT WEEK...DRY PATTERN WITH A NORTHWEST FLOW WITH HIGHS IN
THE 70S TO AROUND 80.

HAASE

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 649 PM CDT TUE JUN 11 2013

STRONG CAP OR ELEVATED LAYER OF VERY WARM AIR STILL IN PLACE ATTIM.
SCATTERED VERY WEAK HIGH BASED SHOWERS OVER CENTRAL IA WILL
CONTINUE TO FESTER ON ELEVATED WARM ADVECTION AND MAY DRIFT
INTO PORTIONS OF EASTERN IA THIS EVE MAINLY SOUTH OF INTERSTATE 80.
MAIN FOCUS FOR STORM DEVELOPMENT THIS EVENING APPEARS TO BE TO OUR
WEST AND NORTHWEST OVER PORTIONS NE/SD/NW IA/SW MN WHERE STRONG
UPPER LEVEL DISTURBANCE AND LOW LEVEL JET WILL BE CONVERGING TO
LIKELY SPAWN STORMS. IF THESE STORMS MANAGE TO BECOME SURFACE
BASED AND GROW UPSCALE INTO MCS THEN PROPAGATION VECTORS ARE
FAVORABLE FOR MOVEMENT INTO PORTIONS OF EASTERN IA AND NORTHWEST
IL LATE TONIGHT AND WED AM ESPECIALLY NEAR TO NORTH OF I 80 WITH
STRONG GUSTY WINDS A POSSIBILITY. COULD ALSO SEE WARM ADVECTION WING
OF SCATTERED SHOWERS AND STORMS DEVELOP AFTER 06Z NORTH OF I 80
AHEAD OF MAIN COMPLEX OF STORMS TO OUR WEST. ON WEDNESDAY...STORMS
LIKELY TO IMPACT TERMINALS WITH TIMING THE MAIN CHALLENGE. POTENTIAL
FOR CONVECTIVE COMPLEX TO AFFECT NORTHERN SITES EARLY IN DAY OR
POSSIBLY LATER IF DELAYED ONSET TONIGHT. REDEVELOPMENT ALSO IS
EXPECTED DURING THE AFTERNOON. RISK OF SEVERE STORMS EXISTS ACROSS
THE AREA WITH LARGE HAIL AND DAMAGING WINDS.

BOTTOM LINE IS THUNDERSTORM CHANCES WILL BE ON THE INCREASE LATE
TONIGHT AND WEDNESDAY AT THE TERMINALS... WITH RISK OF SEVERE STORMS.
MAINLY VFR CONDITIONS TONIGHT INTO WED WITH MVFR TO IFR CONDITIONS
WITH STORMS.


&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

UPDATE...05
SYNOPSIS...DLF
SHORT TERM...DLF
LONG TERM...HAASE
AVIATION...05