Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 140247
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
947 PM CDT SUN JUL 13 2014

.UPDATE...
ISSUED AT 940 PM CDT SUN JUL 13 2014

FEW SHOWERS NW IA DRIFTING SEWD AHEAD OF MAIN FRONT AND SURGE OF
COOLER DRIER AIR... AND WILL SEE CHC OF SHOWERS OVRNGT INTO EARLY MON
AM ESPECIALLY SOUTHWEST 1/3-1/2 OF CWA AHEAD OF THIS FRONT. GIVEN
DEGREE OF MOISTURE POOLING SOUTH OF FRONT WITH DEWPTS IN 60S DO HAVE
SOME CONCERNS GOING PCPN CHCS MAY BE TOO LOW. ALSO...AN ISOLD
STORM NOT OUT OF QUESTION. WILL CONTINUE TO MONITOR TRENDS AND UPDATE
IF NEEDED.

&&

.SYNOPSIS...
ISSUED AT 323 PM CDT SUN JUL 13 2014

DVN RADAR SHOWED SCATTERED SHOWERS BREAKING OUT ALONG A LINE ROUGHLY
FROM BELLEVUE TO BELLE PLAINE AT 20Z. THESE WERE IN AN AREA OF
ELEVATED CONVERGENCE AHEAD OF THE MAIN COLD FRONT...THAT REACHED
FROM PRAIRIE DU CHIEN WI TO FORT DODGE IA. AHEAD OF THIS
BOUNDARY...SKIES WERE MOSTLY CLEAR OVER THE FORECAST AREA WITH
TEMPERATURES IN THE LOWER 80S AND DEWPOINTS IN THE UPPER 60S TO
AROUND 70. NORTH OF THE FRONT...TEMPERATURES WERE IN THE 70S WITH
DEWPOINTS IN THE 50S...TAPERING BACK TO THE 40S ACROSS NORTHERN MN
AND ND. THIS BOUNDARY WAS THE LEADING EDGE OF A COOL AIRMASS BEING
DRIVEN SOUTH BY A LARGE COLD CORE UPPER LEVEL VORTEX OVER SW
ONTARIO. THIS FEATURE WILL CONTINUE TO BUILD SOUTHWARD...ALLOWING
A NEARLY MERIDIONAL FLOW TO POUR COOL CANADIAN AIR INTO THE REGION
FOR THE FIRST HALF OF THE WORK WEEK.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 323 PM CDT SUN JUL 13 2014

TEMPERATURES AND CHANCES FOR LIGHT PRECIPITATION ARE THE PRIMARY
CHALLENGES IN THE NEAR TERM. TONIGHT...THE LINE OF SHOWERS AND
POSSIBLE ISOLATED THUNDERSTORMS WILL SEE A DIURNAL DIE OFF IN THE
EVENING. FOCUS THEN TURNS TO LATER TONIGHT...WHERE MAINLY THE
AMERICAN MODELS DEPICT A WAVE OF FRONTOGENESIS ALONG THE NORTHERN
EDGE OF THE RETREATING MOISTURE AT 850 MB AND BEHIND THE SURFACE
BOUNDARY THAT IS PROGGED TO REACH N CENTRAL IL INTO FAR NE MO BY
SUNRISE. THIS LOOKS LARGELY OVERDONE AND WILL SIDE TOWARD THE
ECMWF AND GEM AND KEEP ONLY A SLIGHT CHANCE FOR LIGHT RAIN OR
SPRINKLES AFTER MIDNIGHT WITH THIS FEATURE. OTHERWISE...CLEARING
SKIES AND LOWERING DEWPOINTS SHOULD LEAD TO A COOLER NIGHT WITH
LOWS FROM THE UPPER 50S NORTH TO MID 60S SOUTH.

MONDAY...MODELS SPREAD THIS AXIS OF INCREASING FRONTOGENESIS
SOUTHWARD...THEN BREAK OUT SOME INSTABILITY SHOWERS OVER ESPECIALLY
THE NORTH IN THE AFTERNOON AS COOLER AIR ALOFT SPILLS SOUTHWARD.
WILL CONTINUE WITH SLIGHT TO LOW END CHANCE POPS TO COVER THESE
FEATURES. USING MIX DOWN TOOLS AND CURRENT THERMAL TRENDS IN THE
AIRMASS BEHIND THE FRONT...HAVE KEPT HIGHS FROM AROUND 70 NORTH TO
THE UPPER 70S SOUTH. DEWPOINTS WILL LOWER IN THE 50S BY
AFTERNOON...PROVIDING COMFORTABLE HUMIDITY LEVELS OVER THE AREA.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 323 PM CDT SUN JUL 13 2014

FORECAST FOCUS ON POTENTIAL FOR RECORD LOWS MONDAY NIGHT AND TUESDAY
NIGHT...OTHERWISE PLEASANT WEATHER FOR THE NEW WORK WEEK. THUNDERSTORM
CHANCES RETURN NEXT WEEKEND ALONG WITH THE WARMTH AND HUMIDITY.

MONDAY NIGHT THROUGH FRIDAY...PLEASANT STRETCH OF WEATHER WITH
COMFORTABLE TEMPERATURES AND HUMIDITY LEVELS. THE ONLY CHANCE FOR
RAIN IS TUESDAY UNDER THE COLD POCKET ASSOCIATED WITH THE DEEP
VORTEX IN THE GREAT LAKES REGION. THE STEEPEST LAPSE RATES AND
CYCLONIC FLOW IS IN OUR NW IL COUNTIES...BUT MOISTURE IS VERY
LIMITED SO I WILL CONTINUE WITH ONLY SLIGHT CHANCES.  OTHERWISE...
THE WEEK WILL BE DOMINATED BY SPRAWLING CANADIAN HIGH PRESSURE. THE
COOLEST NIGHTS SHOULD BE MONDAY NIGHT AND TUESDAY NIGHT WHEN RECORD
LOWS ARE IN JEOPARDY. MUCH OF THE WORK WEEK WILL HAVE MAXIMUM
TEMPERATURES IN THE 70S WITH LOWS MAINLY IN THE 50S.

NEXT WEEKEND...THE HIGH WILL SHIFT WELL TO OUR EAST WHILE ANOTHER
UPPER LEVEL TROUGH PUSHES ACROSS THE MIDWEST. AHEAD OF THE TROUGH
TEMPERATURES WILL WARM INTO THE 80S WITH DEWPOINTS RISING WELL INTO
THE 60S TO AROUND 70. THIS SYSTEM WILL ALSO SPARK SOME THUNDERSTORMS
SATURDAY NIGHT AND SUNDAY. OPERATIONAL MODELS HINTING AT SUMMER HEAT
TAKING HOLD ACROSS THE PLAINS AND TRYING TO SPREAD INTO THE MIDWEST
FOR THE FOLLOWING WEEK...AS UPPER LEVEL RIDGE INTENSIFIES. TIME WILL
TELL THOUGH.

HAASE

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 648 PM CDT SUN JUL 13 2014

COOL FRONT WILL PASS THROUGH KBRL NEXT HOUR WITH CHANCE OF SHOWER
FOLLOWING THEREAFTER FOR A SHORT WHILE. MAY SEE MORE SHOWERS
DEVELOP LATE TONIGHT INTO MON AM MAINLY SOUTH OF I-80 WITH BAND
OF MID LEVEL FRONTOGENESIS AHEAD OF A DIGGING UPPER TROUGH. THEN...
SCATTERED POPCORN INSTABILITY SHOWERS POSSIBLE BY MID TO LATE
AFTERNOON ESPECIALLY NORTHEAST THIRD TO HALF OF CWA WITH POCKET OF
COLD AIR ALOFT. MIXING SUPPORTS GUSTY NORTHWEST WINDS BY AFTERNOON
AT 15-25 KTS.


&&

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

$$

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






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