Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 281224
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
724 AM CDT SUN JUN 28 2015

.SYNOPSIS...
ISSUED AT 410 AM CDT SUN JUN 28 2015

WING OF STRONG WARM AIR ADVECTION TRIGGERING AN AREA OF SHOWERS
AND SCATTERED THUNDERSTORMS FROM EASTERN MN/WESTERN WI INTO
NORTHERN/WESTERN IA. THESE SHOWERS AND STORMS WERE MOVING SOUTHEAST.
THIS PRECIPITATION WAS ALSO TIED TO THE AXIS OF HIGHER PWAT`S OF
GREATER THAN 1.30 INCHES. THERE WAS MINIMAL INSTABILITY SO THESE
STORMS WERE GARDEN VARIETY.

AT 3 AM TEMPERATURES IN THE DVN CWA RANGED FROM THE MID 50S TO
LOWER 60S WITH DEWPOINTS IN THE LOWER 50S TO LOWER 60S SO ANOTHER
COMFORTABLE EARLY MORNING IN PROGRESS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT SUN JUN 28 2015

FORECAST FOCUS ON POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON AND
EVENING.

TODAY...OPERATIONAL MODELS SEEM TO BE OVERDOING THE COVERAGE OF
THE INTIAL WARM AIR ADVECTION SHOWERS AND STORMS APPROACHING OUR
FAR NW COUNTIES. BASED ON THIS I BELIEVE THIS TREND OF OVERDOING
THE COVERAGE WILL CONTINUE IN THE MODELS IN THE SHORT TERM. THIS
WILL ALLOW FOR SOME SUNSHINE AT TIMES WHICH SHOULD PUSH TEMPERATURES
HIGHER THAN EARLIER FORECAST. I LIKE THE IDEA OF THE HRRR MODEL
BRINGING WEAKENING SHOWERS AND STORMS ACROSS THE CWA THROUGH MID
MORNING THEN SOMEWHAT OF A LULL LATE MORNING/EARLY AFTERNOON. THIS
SHOULD ALLOW AFTERNOON TEMPERATURES TO RISE INTO THE UPPER 70S TO
LOWER 80S...AND IF EVEN MORE SUN IS OBSERVED THAN EXPECTED THEN
SOME LOCATIONS MAY PUSH INTO THE MID 80S. POPS WILL BE LIKELY
THROUGH MID MORNING THEN CHANCE LATE MORNING/EARLY AFTERNOON...THEN
LIKELY AGAIN LATER THIS AFTERNOON INTO THE EVENING AS VIGOROUS UPPER
LEVEL TROUGH/EMBEDDED LOW DIVES INTO NORTHERN IL BY THIS EVENING.

SEVERE WEATHER DISCUSSION...SPC HAS A SLIGHT RISK OF SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING FOR MUCH OF EASTERN IA...
WESTERN IL AND NORTHEAST MO. MLCAPES WILL INCREASE TO 1000-2000
J/KG WITH DEEP LAYER SHEAR AT 35 TO 45 KT WHICH IS SUFFICIENT FOR
SUPERCELLS DEVELOPING BY MID AFTERNOON. PARAMETERS ALSO COMING
TOGETHER FOR A FEW TORNADOES ESPECIALLY IN OUR FAR WESTERN
COUNTIES AND SOUTHEAST INTO WESTERN IL AND NORTHEAST MO. WITH
FREEZING LEVELS AT 12K LARGE HAIL IS LIKELY. LOCALLY HEAVY
RAINFALL WILL ALSO ACCOMPANY THESE STORMS WITH PWATS INCREASING TO
OVER 1.50 INCHES. NOTE...AS USUAL THE SEVERE THREAT WILL BE
CONDITIONAL ON AMOUNT OF SUNSHINE AND INSTABILITY. THE GREATEST
SEVERE THREAT APPEARS TO BE IN THE 3-10 PM TIME FRAME.

SHOWERS AND STORMS WILL DIMINISH BY LATE EVENING WITH CHANCE POPS
AFTER MIDNIGHT. MINIMUM TEMPERATURES TONIGHT WILL BE IN THE LOWER
TO MID 60S.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 410 AM CDT SUN JUN 28 2015

NORTHWEST FLOW WILL PERSIST THROUGH LATE WEEK WITH TEMPS NEAR TO BELOW NORMAL
(HIGHS 70S/LOWER 80S AND LOWS 50S/60S). THE FLOW PATTERN WILL REMAIN ACTIVE
WITH PERIODIC RAIN CHANCES WITH THE PASSAGE OF SEVERAL LOW AMPLITUDE
SHORTWAVES IN THE FLOW. WHILE IT WILL BE SOMEWHAT ACTIVE/UNSETTLED THE GOOD
NEWS FOR AREA FARMERS NEEDING SOME DRY WEATHER IS THAT THE THREAT
FOR WIDESPREAD ORGANIZED HEAVY RAINFALL IN THIS PATTERN IS VERY LOW... AND
OVERALL ANTICIPATE MAINLY LIGHT (0.25 INCH OR LESS)TO SOME AREAS OF MODERATE
(0.25-0.5+ INCH) RAIN AMOUNTS BY THE END OF THE WEEK. THE CHALLENGE REMAINS
OF TRYING TO TIME THESE SHORTWAVES AND ATTENDANT RAIN CHANCES GIVEN THE MODELS
GENERALLY POOR RESOLUTION AND SMOOTHING OF THESE SMALLER SCALE PERTURBATIONS.

MONDAY AND MONDAY NIGHT...BELIEVE OPPORTUNITY TO TRIM RAIN CHANCES AS MUCH OF
THE DAY WILL SEE LIMITED FORCING WITH ANY WRAP-AROUND FROM DEPARTING LOW
EXITING EASTERN SECTIONS EARLY ON... THEN MOST MODELS INDICATE WEAK SURFACE
RIDGING. LATE IN THE DAY ANOTHER DISTURBANCE AND MID LEVEL DIVERGENCE SIGNATURE
BEGIN TO APPROACH FROM NORTHWEST WITH RAIN CHANCES THEN INCREASING MONDAY NIGHT
AS THIS ENERGY AND ATTENDANT WEAK SURFACE LOW PASSES.

TUESDAY AND TUESDAY NIGHT...SUGGESTION OF BETTER RAIN CHANCES FAVORING THE
EASTERN CWA INTO EARLY EVENING BEING IN CLOSER PROXIMITY TO STRONGER CYCLONIC FLOW.

THEN MODEL TRENDS SEEM TO BE LEANING TOWARD DRYING ON EASTERLY FLOW POSSIBLY DURING
THE MIDWEEK PERIOD.

LATE WEEK LOOKS TO BRING RETURN OF RAIN CHANCES WITH ADDITIONAL SHORTWAVE ENERGY
RIPPLING DOWN IN NORTHWEST FLOW WITH MID LEVEL BAROCLINIC ZONE IN CLOSE PROXIMITY.

RIGHT NOW MOST OF THE MODELS APPEAR TO BE TRENDING TOWARD DRYING THINGS OUT FOR THE
4THOF JULY... BUT LOWER CONFIDENCE THIS FAR OUT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 723 AM CDT SUN JUN 28 2015

MVFR CONDS IN PERIODS OF SHOWERS AND SCATTERED THUNDERSTORMS WILL
BE ACROSS THE TAF SITES TODAY AND THIS EVENING. SEVERE WEATHER IS
POSSIBLE FROM THE MID AFTERNOON INTO THE EVENING HOURS...WITH THE
ACTIVITY DIMINISHING OR ENDING AFTER 05Z/29. SOUTH WINDS TODAY
THEN BECOMING NORTHWEST TONIGHT BEHIND A WEAK COLD FRONT. WIND
SPEEDS WILL BE 10 TO 20 KNOTS TODAY THEN LESS THAN 10 KNOTS TONIGHT.

&&

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

$$

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


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