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000
FXUS63 KDVN 041721
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1121 AM CST WED MAR 4 2015

.SYNOPSIS...
ISSUED AT 238 AM CST WED MAR 4 2015

ARCTIC AIR CONTINUES TO SPREAD INTO EASTERN IOWA/NORTHWEST ILLINOIS
EARLY TODAY. AS OF 2 AM...TEMPERATURES HAVE FALLEN TO THE UPPER
SINGLE DIGITS NORTHWEST...WHILE STILL FALLING THROUGH THE UPPER
TEENS SOUTHEAST.  MOST OF THE NORTHERN CWA IS CLEAR...WHILE THE
SOUTH HALF IS STILL CLOSE ENOUGH TO THE MID LEVEL CLOUDS ASSOCIATED
WITH THE SOUTHERN HEAVY RAIN AND SNOW EVENT TO SEE OCCASIONAL
OVERCAST CONDITIONS. THE LAST SURGE OF MID CLOUDS IS ON THE WAY FROM
SOUTHWEST IOWA EARLY TODAY...AND THIS SHOULD CONTINUE TO KEEP OUR
SOUTH HALF AT LEAST MOSTLY CLOUDY THROUGH SUNRISE TODAY.

ERVIN

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 238 AM CST WED MAR 4 2015

COLD...BREEZY...BUT RELATIVELY QUIET WEATHER WILL CONTINUE TODAY.
BY SUNRISE...WE SHOULD BE IN THE ZERO TO 10 RANGE FROM NORTH TO
SOUTH...WHICH WILL MAKE A DAY OF NORTHWEST WINDS AND COLD ADVECTION
CONSISTENT FROM START TO FINISH AS HIGHS STRUGGLE TO REACH THE MID
TEENS NORTH TO UPPER TEENS SOUTH. CLOUDS SHOULD GRADUALLY SETTLE
SOUTH...LEAVING THE AREA MOSTLY CLEAR ENTIRELY BY AFTERNOON.
THUS...TONIGHT...CLEAR SKIES...VERY DRY COLD AIR WILL SET THE STAGE
FOR A VERY UN-MARCH LIKE LOW.  MODELS ARE CONSISTENT SHOWING LOWS OF
ZERO SOUTH TO AROUND -10 NORTH...WHICH IS NEAR RECORDS.  THE SNOW
COVER IS WIDESPREAD...BUT NOT IDEAL FOR PERFECT COOLING...AS IT IS
LARGELY ICE COVERED WHERE IT EXISTS. I HAVE CHOSEN TO GO NEAR THE
MIDDLE OF A GUIDANCE BLEND...WHEN NORMALLY WITH SNOW I WOULD UNDER
CUT IT. USING A DIURNAL CURVE PROVIDED BY THE MODEL BLEND...AND
COMBINED WITH WINDS OF ABOUT 7 MPH LATE TONIGHT...WE ARE FORECASTING
WIND CHILLS OF -15 TO -23 OVER THE NORTHERN 1/2 VERY LATE TONIGHT.
THIS IS WITHIN THE ADVISORY RANGE OF -20...BUT IT IS A VERY LATE
ONSET OF THAT LEVEL OF COLD...AND CONFIDENCE ON THE TEMPERATURE
FORECAST AND WINDS ARE NOT HIGH...THUS WILL NOT ISSUE AT THIS TIME
FOR A MARGINAL WIND CHILL EVENT.  IF THERE IS GOOD NEWS IN THIS...BY
ALL LIKELIHOOD...TONIGHT WILL BE THE COLDEST LOWS UNTIL SOMETIME NEXT
WINTER...AS OUR FORECAST WILL SEE US LOOSING OUR SNOW COVER IN THE
COMING DAYS!

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 238 AM CST WED MAR 4 2015

MAIN FORECAST CONCERN FOR THE LONG TERM FORECAST ARE THE
TEMPERATURES FOR THE PERIOD ALONG WITH ANOTHER CLIPPER SYSTEM THIS
WEEKEND.  TEMPERATURES WILL BEGIN TO RISE STARTING FRIDAY AND RISE
THROUGHOUT THE EXTENDED PERIOD.  TEMPERATURES LOOK TO BE IN THE 50S
AND EVEN NEAR 60 AT THE END OF THE PERIOD.

A SERIES OF IMPULSES ARE PROGGED TO TRANSVERSE THE FLOW THROUGH THE
WEEKEND.  MOST OF THESE IMPULSES RESULT IN NO PRECIP IN OUR AREA.
EXPECT MOSTLY CLOUDS WITH THESE IMPULSES AND MOSTLY CLOUDY SKIES AT
THAT.  12Z RUN OF THE GEM THE WAVE ON SAT/SUN DIGGING DEEPER THAN
THE REST OF THE MODELS. 00Z RUNS OF THE MODEL... WAS LESS IMPRESSIVE
WITH THE CLIPPER.  NOW THERE IS LITTLE TO NO PRECIP IN OUR AREA.
MOST OF THE PRECIP LOOKS TO FALL TO OUR NE IN WI.   DPROG OF THE GFS
SHOW THAT THE MODEL DOES HAVE A SW TREND WITH THE QPF.  SO WE WILL
NEED TO KEEP AN EYE ON THIS...WE COULD END UP WITH SOME SORT OF POPS
OVERNIGHT.  THE POSITIVE TO THIS IS THAT ON SUNDAY...TEMPS ARE WELL
INTO THE 30S AND EVEN 40S....SO IF WE DO GET FROZEN PRECIP SAT NIGHT
IT SHOULD MELT.

NOW ON TO WHAT WE HAVE ALL BEEN WAITING FOR...OUR FIRST REAL WARM
UP!  BOTH THE ECMWF AND GFS HAVE THIS WARM UP.  WE START TO SEE A
LOT..IF NOT THE MAJORITY OF OUR SNOW PACK MELT IN THE LONG TERM
PERIOD...WITH THE EXCEPTION OF DEEP PILES LIKE THOSE IN PARKING
LOTS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1120 AM CST WED MAR 4 2015

VFR CONDITIONS WILL BE SEEN THROUGH 00Z/06 AS ANOTHER ARCTIC HIGH
BUILDS INTO THE MIDWEST.

&&

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

$$

SYNOPSIS...ERVIN
SHORT TERM...ERVIN
LONG TERM...GIBBS
AVIATION...08