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000
FXUS63 KDVN 192309
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
609 PM CDT WED JUN 19 2013

.SYNOPSIS...
ISSUED AT 345 PM CDT WED JUN 19 2013

LATEST SFC ANALYSIS WAS INDICATING GRT LKS HIGH MAINTAINING FAR
ENOUGH WEST TO PROVIDE ANOTHER FAIR WX DAY/COMFORTABLE DPTS ACRS THE
CWA...WHILE LLVL RETURN FLOW WAS ORGANIZING UP THE PLAINS.
PRESSURE FALLS INCREASING IN VCNTY OF INITIAL WARM FRONT ACRS
SOUTHERN SD. ALOFT...WATER VAPOR IMAGERY AND THIS MORNING/S 12Z
UPPER AIR ANALYSIS WAS INDICATING A LARGE TROF/WAVE COMPLEX SLOW
ROLLING ACRS THE WESTERN INTER-MOUNTAIN REGION AND NORTHERN
ROCKIES. COMBINED WITH LINGERING EAST COAST L/W TROFFINESS...THIS
PROCESS PUTTING THE SQUEEZE ON UPPER RIDGE AXIS ACRS THE PLAINS
AND UPPER MS RVR VALLEY.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 345 PM CDT WED JUN 19 2013

TONIGHT...EXPECT A MAINLY DRY NIGHT AS LINGERING RIDGING AND DRY
AIR MASS IN PLACE HAVE THEIR EFFECT. MCS-FORCING TOOL SUGGESTS
CONVECTIVE INDUCING PARAMETERS TAKE PLACE MORE ACRS THE CENTRAL AND
NORTHERN PLAINS INTO MN. MAYBE JUST SOME DEBRIS CLOUDS STREAMING
ACRS THE AREA FROM THE WEST OFF UPSTREAM CONVECTIVE PROCESSES
LATER TONIGHT INTO EARLY THU MORNING. WITH LOW SFC DPTS FROM NORTHEAST-
TO-SOUTHWEST THANKS TO LINGERING WESTERN GRT LKS ANTICYCLONE...WILL
PLAY LOWS IN THE SAME GRADIENT WITH MID 50S IN THE FAR NORTHEAST...TO
THE LOW TO MID 60S IN THE SOUTHWEST. ANOTHER PLEASANT LATE JUNE NIGHT.

THURSDAY...SOME WANING SUPPORT/ELEVATED THTA-E ADVECTION UNDER-
CUTTING CONTINUED UPPER RIDGE AMPLIFICATION PROCESS ALONG AND WEST
OF THE MID TO UPPER MS RVR VALLEY REGION TO POSSIBLY ALLOW SOME
HIGHER BASED SHOWERS AND A FEW STORMS TO DRIFT ACRS THE CWA FROM
THE WEST AT TIMES. CURRENT PROGS SUGGEST THE FAR WEST AND
NORTHWESTERN THIRD OF THE DVN FCST AREA MORE AT RISK OF
EXPERIENCING SOME PRECIP. SOUTH TO SOUTHEASTERLY LLVL RETURN FLOW
TO ADVECT WARMER AIR MASS SUPPORTIVE OF HIGHS WELL IN THE UPPER
80S...BUT WORRIED CONVECTIVE DEBRIS/CLOUDS MAY TEMPER THE WARM UP
POTENTIAL SOME AND WILL GO MORE WITH MID 80S ACRS MUCH OF THE
AREA. HIGHS MAY BE HELD IN THE LOWER 80S IN THE NORTH.   ..12..

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 PM CDT WED JUN 19 2013

RIGHT ON QUE WITH SUMMER SOLSTICE /1205 AM CDT FRIDAY/ THE PATTERN
THROUGHOUT MUCH OF THE PERIOD WILL BE THAT OF A FAIRLY TYPICAL
SUMMERTIME REGIME FEATURING VERY WARM/HOT AND HUMID CONDITIONS
ALONG WITH NEARLY DAILY CHANCES OF STORMS AS PATTERN ALOFT IS
FAIRLY STAGNANT FOR MOST OF THE PERIOD FEATURING MEAN WESTERN
TROUGHING WITH BROAD RIDGING FROM THE GREAT LAKES TO THE GULF COAST.

FOR MOST OF THE PERIOD THE AREA WILL RESIDE IN OR NEAR THE ACTIVE MCS
ZONE OR RING OF FIRE... WITH CWA CONCEPTUALLY IN OR NEAR FAVORED
18C TO 24C 850 MB THERMAL GRADIENT FOR GENESIS AND TRACK OF CONVECTIVE
COMPLEXES. WHILE PRECIPITATION CHANCES CANT BE RULED OUT AT ABOUT
ANY TIME THERE WILL BE PLENTY OF DRY HOURS... BUT IN THIS REGIME
THE BEST CHANCES OF CONVECTION FAVOR THE NIGHTTIME AND EARLY AM HOURS.
UNFORTUNATELY CANNOT GET AWAY FROM BROAD-BRUSH 20-40 POPS THROUGH GOOD
PORTION OF FORECAST FOR NOW AS CONFIDENCE LOW WITH TIMING OF FEATURES
AND DUE TO CHALLENGES OF WHERE CONVECTION FIRES AT NIGHT WILL AFFECT
WHERE IT DEVELOPS THE FOLLOWING DAY AND THIS NOT EVIDENT OFTEN UNTIL
6-12 HRS PRIOR. TEMPS GENERALLY ABOVE NORMAL WITH MAINLY RANGE OF 86-93F
ON HIGHS AND 67-74F ON LOWS. HEAT INDICES LIKELY APPROACHING 100 DEGS IN
SOME LOCATIONS FOR SEVERAL DAYS BY SAT THROUGH TUE.

MODELS GENERALLY DEPICT THE STAGNANT PATTERN BREAKING DOWN AROUND THE
MIDDLE OF NEXT WEEK... WITH THE RETROGRESSION OF THE UPPER RIDGE
/HEAT DOME/ OUT WEST ALLOWING FOR BROAD TROUGHING OVER THE EASTERN CONUS.
THIS SHOULD EVENTUALLY RESULT IN RETURN OF MORE PLEASANT CONDITIONS...
WITH THE EXACT TIMING STILL IN QUESTION. THE 12Z HI-RES ECMWF HAS
SPED UP THE NEXT COLD FRONT TO WED. IF THIS TREND PERSISTS THEN WILL
NEED TO REALLY LOWER TEMPS FOR NEXT WED.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 605 PM CDT WED JUN 19 2013

SURFACE HIGH PRESSURE WILL GRADUALLY MOVE EAST ALLOWING SOUTHEAST
WINDS TO BE STRENGTHEN TO AROUND 12 KTS BY 15Z/20. SKIES SHOULD
BE PRIMARILY CLEAR OVERNIGHT...WITH SCATTERED HIGH BASED
ALTOCUMULUS AT TIMES. THUS...A SCATTERED CLOUD GROUP AROUND 12000
FT IS INCLUDED THROUGHOUT THE ENTIRE PERIOD. THERE MAY BE A FEW
SCATTERED SHOWERS OR THUNDERSTORMS FROM 18Z/20 TO 00Z/21...BUT
COVERAGE IS EXPECTED TO BE VERY SCATTERED...IF NOT ISOLATED.
THUS...I HAVE LEFT ANY MENTION OF SHOWERS AND STORMS OUT OF THE
TERMINAL FORECASTS AT THIS TIME. SHOULD A SHOWER OCCUR...A BRIEF
REDUCTION IN VISIBILITY DUE TO RAIN IS THE PRIMARY THREAT.
ERVIN

&&

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

$$

SYNOPSIS...12
SHORT TERM...12
LONG TERM...05
AVIATION...ERVIN