000
FXUS63 KDVN 072333
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
533 PM CST SAT DEC 7 2013

.SYNOPSIS...
ISSUED AT 244 PM CST SAT DEC 7 2013

ANALYSIS AT 2 PM SHOWS ARCTIC HIGH PRESSURE OVER NW IOWA MOVING
EAST AT 20-25 MPH. INCREASING STREAM OF DEVELOPING HIGH/MID CLOUDS
OVER CENTRAL PLAINS IN RESPONSE TO SHORT WAVE EJECTING NE IN AZ/NM
ON FAST 120+ KT JET. CLOUDS TO INCREASE NEXT 6-12 HOURS WITH CLOUDY
SKIES OVER ALL AREA. AREA TEMPERATURES RUNNING IN THE TEENS AT 2
PM WITH LIGHT WINDS. INITIALIZATION AND VERIFICATION SUPPORT MINOR
CHANGES TO CURRENT FORECAST.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 244 PM CST SAT DEC 7 2013

TONIGHT...SKIES TO BECOME CLOUDY BY OVERNIGHT HOURS WITH INCREASING
HIGH CLOUDS THAT WILL LOWER BY MORNING. MOST LOWS TO OCCUR BY LATE
EVENING AND SLOWLY RISING BY DAYBREAK. LIGHT SNOW OR FLURRIES WILL
ARRIVE FAR WESTERN SECTIONS BY 12Z. LOWS HIGH SINGLE DIGITS NORTH
TO 11-14 DEGREES SOUTH.

SUNDAY...LIGHT SNOW WILL OVERSPREAD ALL THE REGION BY EARLY AFTERNOON
WITH UPPER FORCING WHICH IS MODEST AT BEST SUPPORTING BEST LIFT OVER
NW 1/2 OR SO OF AREA. COMBINED WITH LOW PW/S AND QUITE COLD
TEMPERATURES SUGGEST MOST AREA TO SEE LIGHT AMOUNTS. RAIN/SNOW
RATIOS SHOULD BE AROUND 15:1 OVER SE SECTIONS AND 20+:1 OVER NW
SECTIONS. THIS WITH LIFT SUPPORTS 1 INCH OR LESS FAR SE TO AROUND 3
INCHES NW SECTIONS WITH LOCALLY HIGH AMOUNTS BEFORE ENDING IN NW
SECTIONS. THIS WILL BE A POWDERY DRY SNOW WITH WINDS MOSTLY 5 TO 15
MPH FOR LITTLE OR NO DRIFTING. LIMITED FORCING SUPPORTS LIGHT
SNOWFALL RATES OF INTENSITY OF A FEW TENTHS AN HOUR. NORTHWEST
SECTIONS MAY SEE AN HOUR OF UP TO A HALF INCH IN AN HOURS.
OVERALL...THIS SNOWFALL EVENT WILL TEND TO MINOR IMPACTS DUE TO DRY
NATURE...LIGHT WIND AND LIGHT SNOWFALL RATES. WILL GO AHEAD AND
HOIST A WINTER WEATHER ADVISORY FOR SUNDAY AND SUNDAY EVENING
LOCATIONS NW OF A DBQ-CID LINE FOR 3-4 INCH AMOUNTS. HIGHS WILL
RANGE IN THE MID 20S SE SECTIONS TO NEAR 20 FAR NW SECTIONS.

SUNDAY NIGHT...LIGHT SNOW SHOULD DIMINISH TO FLURRIES AND END BY MID
TO LATE EVENING WITH MOST LOCATIONS TO PICK UP ONLY AN ADDITIONAL
FEW TENTHS OF AN INCH OR LESS. SOME PARTIAL CLEARING TOWARD MORNING
WITH WESTERLY WINDS OF 10 TO 15 MPH THAT SHOULD ALSO LIMIT ANY
DRIFTING. AREA LOWS IN THE UPPER SINGE DIGITS NW SECTIONS TO MIDDLE
TEENS EAST SECTIONS.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 244 PM CST
SAT DEC 7 2013

FORECAST FOCUS ON WELL BELOW NORMAL TEMPERATURES EARLY TO MID
WEEK THEN SOME MODERATION TO NEAR NORMAL BY THE END OF THE WORK
WEEK. NORTHWEST FLOW ALOFT WITH THE STORM TRACK TO OUR NORTH AND
WELL TO OUR SOUTH KEEPING MAINLY DRY CONDITIONS ACROSS THE DVN CWA.

MONDAY THROUGH TUESDAY...ASSUMING A FRESH LAYER OF NEW SNOW ACROSS
THE CWA THIS WILL KEEP THE CWA IN THE DEEP FREEZE. HAVE LOWERED
TEMPERATURES SEVERAL MORE DEGREES FROM PREVIOUS FORECAST WITH
READINGS WELL BELOW NORMAL FOR EARLY DECEMBER...BUT NOT ANYWHERE
CLOSE TO RECORDS. WILL HAVE MAXIMUM TEMPERATURES ON MONDAY RANGING
FROM NEAR 10 IN OUR FAR NW CWA TO THE LOWER 20S SE. MINIMUM READINGS
MONDAY NIGHT ZERO TO 2 BELOW NW TO SINGLE DIGITS ABOVE ELSEWHERE.
HIGHS ON TUESDAY UPPER TEENS FAR NORTH TO UPPER 20S FAR SOUTH.

ADDING INSULT TO INJURY WILL BE A CLIPPER SYSTEM MOVING FROM THE
UPPER MIDWEST INTO THE NORTHERN GREAT LAKES REGION. THE GRADIENT
WILL TIGHTEN BETWEEN THAT SYSTEM AND HIGH PRESSURE TO OUR SOUTH.
WIND GUSTS LATE MONDAY NIGHT AND TUESDAY WILL BE 25 TO 30 MPH. THIS
WILL SEND WIND CHILLS BELOW ZERO AT ALL LOCATIONS WITH 15 TO 20
BELOW ALONG HIGHWAY 20...ESPECIALLY ON MONDAY NIGHT.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...WEAK SHORT WAVE IN THE FLOW
TRACKS ACROSS THE UPPER MIDWEST TUESDAY NIGHT. ECMWF/GFS/GEM
INDICATE VERY LIGHT QPF IN THE FORM OF FLURRIES IN OUR NORTHERN CWA.
AIRMASS WILL BE QUITE DRY FOR ANYTHING MORE THAN THAT. BEHIND THE
WAVE ANOTHER CHUNK OF REINFORCING ARCTIC AIR ARRIVES WITH A 1040 MB
HIGH SETTLING INTO THE MIDWEST.

THURSDAY THROUGH FRIDAY NIGHT...RETURN FLOW AROUND THE DEPARTING
ARCTIC HIGH SHOULD BRING MODERATING TEMPERATURES. SOUTHWEST TO SOUTH
WINDS WILL PUSH READINGS INTO THE 20S TO AROUND 30 ON THURSDAY WITH
HIGHS IN THE 30S AT MOST LOCATIONS ON FRIDAY. HOWEVER...THIS WARM-UP
WILL BE ONLY BRIEF.

NEXT WEEKEND...ANOTHER TROUGH SWINGS THROUGH THE MIDWEST BY SATURDAY
BUT ONCE AGAIN THE AIRMASS IS QUITE DRY SO LITTLE IF ANY SNOW WITH
THIS FEATURE. THIS WILL BE FOLLOWED BY ANOTHER CANADIAN HIGH
PRESSURE BUT THIS ONE IS NOT AS STRONG. TEMPERATURES WILL BE COLD
BUT NOT AS EXTREME AS WE HAVE SEEN RECENTLY.

WEEK 2...NAO/AO TRENDS POSITIVE WITH THE UPPER FLOW ACROSS THE LOWER
48 BEING MORE ZONAL. THIS SHOULD BRING NORMAL TEMPERATURES AND
PRECIPITATION TO THE DVN CWA FOR THE WEEK OF DECEMBER 15-21.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 525 PM CST SAT DEC 7 2013

HIGH PRESSURE WILL MOVE NORTHEAST OUT OF THE AREA THIS EVENING.
WEAK LOW PRESSURE OVER THE PLAINS WILL MOVE OUT OF THE SOUTHERN
PLAINS INTO MISSOURI BY SUNDAY AFTERNOON. THIS WEAK SYSTEM WILL
SPREAD SNOW OVER THE AREA SUNDAY AND SUNDAY EVENING. VFR
CONDITIONS WILL REMAIN OVER THE AREA TONIGHT WITH CONDITIONS
LOWERING TO MVFR DUE CIGS AND VSBYS IN LIGHT SNOW FROM WEST TO EAST
BETWEEN 12Z AND 18Z SUNDAY. SUNDAY AFTERNOON CONDITIONS SOUTH OF
I80 SHOULD REMAIN PREDOMINANTLY MVFR WITH IFR CONDITIONS EXPECTED
NORTH OF THE INTERSTATE.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY
     NIGHT FOR BENTON-BUCHANAN-DELAWARE-DUBUQUE-LINN.

IL...NONE.
MO...NONE.
&&

$$

SYNOPSIS...NICHOLS
SHORT TERM...NICHOLS
LONG TERM...HAASE
AVIATION...DLF