Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 240435
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1135 PM CDT WED JUL 23 2014

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 313 PM CDT WED JUL 23 2014

TONIGHT...CANADIAN HIGH PRESSURE WILL LOOK TO CONTINUE TO DUMP DOWN
ACRS WI AND THE SOUTHWESTERN GRT LKS THROUGH THU MORNING...WITH
NORTHEASTERLY LLVL FETCH CONTINUING DRY/COOLING INFUSION ACRS THE
REGION. WINDS TO GO LIGHT AND VARIABLE OVERNIGHT...BUT DRYING
INFLUENCE WILL HAVE SETTLED IN WITH UPSTREAM LOW 50 SFC DPTS
ADVECTED IN PORTIONS OF THE AREA. AFTER DIURNAL CELLULAR CU DECAYS
FOR MAINLY CLEAR SKIES...LIGHT WINDS...DRIER SFC DPTS AND COOLING
COLUMN ALL SUPPORT AN UNSEASONABLE COOL NIGHT ACRS THE CWA. THE
ENTIRE FCST AREA TO COOL DOWN INTO THE 50S...WITH SOME LOW TO MID 50S
POSSIBLE ACRS THE NORTHEASTERN HALF OF THE DVN CWA IN LOWER DPT POOL
CLOSER TO RIDGE AXIS. THE H85 MB RIDGE COOL RULE EVEN SUPPORTS SOME
UPPER 40S IN SOME SPOTS SUCH AS COOL AIR DRAINAGE LOCATIONS. WILL BE
ADVERTISING CLOSE TO RECORD LOWS AT MLI...BUT OTHER CLIMATE SITES
THE LOWS SHOULD FALL 3-5+ DEGREES SHORT. WILL KEEP THE PATCHY FOG
WORDING GOING ACRS THE NORTHEASTERN THIRD OR BIT MORE OF THE LOCAL
FCST AREA FOR LATE TONIGHT AFTER 09Z...BUT WONDER IF TODAY/S DRYING
AND LOWERING DPTS MAY ALLEVIATE THAT. FOG MAY BE MORE CONFINED TO
THE RVR VALLEYS.

THURSDAY...THE ANTICYCLONE WILL CONTINUE TO MIGRATE EASTWARD ACRS THE
REGION AND TOWARD THE GRT LKS...WHILE STEERING MID LEVEL NORTHWEST
FLOW ORGANIZES ACRS THE UPPER MS RVR VALLEY TO LEE OF WESTERN PLAINS
UPPER RIDGE AXIS. DESPITE INHERENT WEAKER MIXING REGIME UNDER PASSING
RIDGE AXIS...WILL STILL SIDE WITH THE WARMER OF TEMP GUIDANCE HIGHS
WITH DRY AIR IN PLACE AND MOSTLY SUNNY TO SUNNY SKIES...DEPENDING ON
THE AMOUNT OF CELLULAR CU THAT FORMS AGAIN. PLUS THERE IS THE CHC
THAT THE NORTHWEST FLOW MAY DUMP SOME DEBRIS CIRRUS OFF NORTHERN
PLAINS RIDGE-RIDING CONVECTION DOWN ACRS THE CWA LATER IN THE
AFTERNOON FILTERING THE INSOLATION SOME.    ..12..

.LONG TERM...(THURSDAY NIGHT THROUGH NEXT WEDNESDAY)
ISSUED AT 313 PM CDT WED JUL 23 2014

THE MAIN FORECAST ISSUES IN THE LONG TERM PERIOD ARE CONVECTIVE
TIMING/COVERAGE/INTENSITY THROUGH FRIDAY NIGHT.

MEDIUM RANGE MODEL GUIDANCE IS IN REASONABLE AGREEMENT IN POINTING
TO A POTENTIAL MCS AFFECTING THE FORECAST AREA THURSDAY NIGHT INTO
FRIDAY MORNING. MCS DIAGNOSTIC TOOLS INDICATE A 50 KT LOW LEVEL JET
POINTING INTO THE REGION WITH FAVORABLE UPPER LEVEL DIFFLUENCE AND
PWAT`S AROUND 2 INCHES. STORMS WILL LIKELY BE ELEVATED AND POSE A
LIMITED SEVERE WEATHER THREAT. GENERAL 1/4 TO 3/4 INCH RAINS SEEM
REASONABLE...WITH A FEW LOCATIONS LIKELY IN THE 1 TO 2 INCH RANGE.
WITH DRY CONDITIONS MOST AREAS OF LATE...FLASH FLOODING IS NOT
EXPECTED TO BE AN ISSUE. THE FOCUS OF THE DECAYING MCS IS EXPECTED
TO SHIFT ALONG AND EAST OF THE RIVER FRIDAY MORNING.

LOOKING AHEAD TO STORM POTENTIAL FRIDAY AFTERNOON AND NIGHT...
CONFIDENCE IS NOT AS HIGH FOR A COUPLE OF REASONS. FIRST...THE
IMPACT OF OVERNIGHT CONVECTION ON THE LOCATION OF BOUNDARIES
ACROSS THE FORECAST AREA. SECOND...THE STRENGTH OF THE WARM AIR
ALOFT AND POTENTIAL FOR STRONG CAPPING OVER MOST IF NOT ALL OF THE
FORECAST AREA. FOR NOW...HAVE FAVORED THE FAR NORTH AND EAST
PORTIONS OF THE CWA WITH THE HIGHER CHANCE POPS...CO-LOCATED WITH
THE FRINGE OF SLIGHTLY COOLER 700MB TEMPS.

FOR SATURDAY...EXPECT AFTERNOON DEWPOINTS IN THE LOW TO MID
70S...WITH AFTERNOON HEAT INDICES OF 95 TO 100 DEGREES ALONG/SOUTH
OF HIGHWAY 34. ISOLATED TO SCATTERED STORMS CAN`T BE RULED OUT
SATURDAY NIGHT INTO SUNDAY DUE TO A COMPACT UPPER TROUGH PUSHING
THROUGH THE UPPER MISSISSIPPI VALLEY.

FOR THE REST OF THE LONG TERM PERIOD...LOOK FOR A TRANSITION BACK TO
NORTHWEST FLOW...WITH COOLER AND MAINLY DRY CONDITIONS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1129 PM CDT WED JUL 23 2014

CLEAR TO MOSTLY CLEAR SKIES AND GENERALLY VFR CONDITIONS TO PREVAIL
THROUGH AT LEAST 25/06Z. BASED ON T/TD SPREADS OF 3-7 DEGREES AT 04Z
AND CALM WINDS AND CLEAR SKIES....PATCHY LIGHT AVIATION FOG MAY DEVELOP
TOWARD MORNING WITH MVFR TO HIGHER END IFR CONDITIONS AND ARE INCLUDED
AS A TEMPO GROUP IN TERMINAL FORECASTS. WINDS CALM TO VERY LIGHT EAST
OVERNIGHT...SHIFTING TO THE SOUTHEAST THURSDAY AM. SOME FAIR WEATHER
CUMULUS CLOUDS ONCE AGAIN EXPECTED MID DAY THURSDAY.

&&

.CLIMATE...
ISSUED AT 313 PM CDT WED JUL 23 2014

RECORD LOWS FOR JULY 24...

MOLINE.........54 IN 1957
CEDAR RAPIDS...50 IN 1927
DUBUQUE........51 IN 2003
BURLINGTON.....51 IN 2003

&&

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

&&

$$

SHORT TERM...12
LONG TERM...RP KINNEY
AVIATION...NICHOLS







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