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000
FXUS63 KDVN 011753
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1153 AM CST SAT MAR 1 2014

.SYNOPSIS...
ISSUED AT 331 AM CST SAT MAR 1 2014

THE SURFACE COLD FRONT AT 3 AM WAS ROUGHLY FROM CHICAGO TO QUINCY
WITH A 1038 HIGH PRESSURE IN ITS WAKE BUILDING INTO WESTERN ND. AREA
RADARS AND SURFACE REPORTS SHOWED A POST FRONTAL BAND OF LIGHT
SNOW...ENHANCED BY MID LEVEL FRONTOGENETICAL FORCING...IN A NE TO SW
AXIS MOVING OVER NORTHERN IL THROUGH BUREAU AND PUTNAM COUNTIES.
ANOTHER AXIS OF SNOW WAS DEVELOPING OVER THE CENTRAL PLAINS UNDER
THE NEXT ROUND OF FRONTOGENETICAL FORCING ADVANCING OUT OF THE
CENTRAL ROCKIES. THIS WAS ASSOCIATED WITH A JET COUPLET BETWEEN A
STRONG JET ALONG THE U.S./CANADIAN BORDER AND ANOTHER ADVANCING OUT
OF THE BASE OF THE UPPER LOW OFF THE CA COAST. THIS FEATURE WILL
CONTINUE EASTWARD...SPREADING THE NEXT ROUND OF SNOW ACROSS THE AREA
THIS AFTERNOON THROUGH SUNDAY MORNING.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CST SAT MAR 1 2014

CHALLENGES CENTER ON SNOW AMOUNTS AND YET ANOTHER ROUND OF BITTER
COLD WIND CHILLS.

HEADLINES...THE ONLY CHANGE THIS MORNING WAS TO EXPAND THE WINTER
WEATHER ADVISORY NORTHWARD TO COVER THE NORTHERN TIER OF COUNTIES
ALONG THE HIGHWAY 20 CORRIDOR. WHILE SNOWFALL TOTALS IN THIS AREA
WILL BE MARGINAL...AROUND 2 TO 3 INCHES...THE COMBINATION OF
SUFFICIENT WINDS FOR DRIFTING SNOW AND WIND CHILLS DROPPING NEAR OR
BELOW -20 TONIGHT...WILL WARRANT THE ADVISORY FOR THE COMBINED
WINTER HAZARDS.

FORECAST MODELS ARE IN DECENT AGREEMENT SPREADING THE NORTHERN
NEBRASKA AND SD AXIS OF MID LEVEL FRONTOGENETICAL FORCING EASTWARD
INTO EASTERN IA AND NW IL THIS AFTERNOON. THIS THEN SETTLES
SOUTHWARD OVER THE ENTIRE AREA BY EVENING...THEN SHIFTING TO
PRIMARILY THE FAR SOUTH AND SE BY SUNDAY MORNING AS THE INITIAL
UPPER LEVEL JET COUPLET OVER THE ROCKIES TRANSITIONS TO A RIGHT
ENTRANCE REGION OF THE PRIMARY JET MOVING INTO THE UPPER GREAT
LAKES. THIS LIFT WILL HAVE A STRONG BAROCLINIC AXIS AT 850 MB TO
WORK WITH AS THE -20 C ISOTHERM SHIFTS SOUTH TO ALONG THE IA/MN
BORDER...WHILE THE ZERO LINE MAY BE AS CLOSE AS STL BY SUNDAY
MORNING. AT THE SURFACE...COLD AIR ADVECTION AND PRESSURE RISES
ASSOCIATED WITH THE ARCTIC HIGH BUILDING INTO THE DAKOTAS WILL
RESULT IN BITTER COLD TEMPERATURES AND BRISK NORTH WINDS TODAY AND
TONIGHT.

SNOW AMOUNTS...DESPITE DEEP MODERATE FORCING...MOISTURE WILL BE
LIMITED IN THE ARCTIC AIRMASS AND AVERAGE MODEL QPF AMOUNTS ROUGHLY IN THE
RANGE OF ROUGHLY .20 NORTH TO NEAR A HALF INCH IN THE FAR SOUTH LOOK
REASONABLE FOR THE EVENT FROM THIS AFTERNOON THROUGH SUNDAY MORNING.
USING CONSERVATIVE 14:1 TO NEAR 16:1 SNOW TO LIQUID RATIOS...
SNOWFALL TOTALS WOULD AMOUNT TO AROUND 2 TO 3 INCHES NORTH OF
HIGHWAY 30...3 TO 5 FROM THERE SOUTH TO ROUGHLY HIGHWAY 34...AND 5
OR 6 ACROSS THE SOUTHERN 2 ROWS OF COUNTIES. THIS SNOW WILL
OVERSPREAD THE AREA THIS AFTERNOON AND AT THIS TIME LOOKS TO BE
HEAVIEST IN THE LATE AFTERNOON AND EARLY EVENING HOURS ACROSS
CENTRAL PORTIONS OF THE FORECAST AREA...THEN MAINLY SOUTH OF I-80
AFTER MIDNIGHT. NORTH WINDS FROM 10 TO 20 MPH WITH HIGHER GUSTS AT
TIMES WILL CAUSE SOME DRIFTING THROUGHOUT.

COLD AIR ADVECTION...CLOUD COVER...AND DEVELOPING SNOW WILL HOLD
TEMPERATURES TO A RANGE FROM AROUND 10 NORTH TO THE LOWER 20S OVER
THE FAR SOUTH...OVER 20 DEGREES BELOW TYPICAL EARLY MARCH VALUES.
TONIGHT...COLD AIR ADVECTION CONTINUES...BUT BASED ON RECENT MODEL
BIASES...HAVE STAYED CLOSER TO WARMER MOS NUMBERS WITH TEMPERATURES
COOLING TO AROUND 5 BELOW ZERO NORTH...TO AROUND 5 ABOVE IN THE FAR
SOUTH AND SOUTHEAST. RESULTING WIND CHILLS OF -20 TO NEAR -25 ACROSS
EAST CENTRAL IA INTO FAR NW IL WILL BE MENTIONED IN THE WINTER
WEATHER ADVISORY.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 331 AM CST SAT MAR 1 2014

THE SNOW WILL BE EXITING THE SOUTHERN COUNTIES SUNDAY. THE
QUESTION IS HOW FAST TO END THE SNOW. THE GFS SUGGESTS THE SNOW
WILL BE SOUTH OF THE FORECAST AREA BY 18Z SUNDAY BUT THE ECM HOLDS
ON TO PRECIP THROUGH THE AFTERNOON. WITH THE MODELS SHOWING THE
ENTRANCE REGION OF AN H3 JET REMAINING OVER THE AREA DURING THE
DAY...THE FORECAST WAS SKEWED TOWARD THE SLOWER ECM SOLUTION...WITH
LIKELY POPS SOUTH SUNDAY MORNING AND CHANCE TO SLIGHT CHANCE POPS
DURING THE AFTERNOON INTO THE EVENING. THE LINGERING SNOW SUNDAY
COULD ACCOUNT FOR ANOTHER INCH OR SO OF ACCUMULATION ACROSS THE
FAR SOUTH.

SUNDAY NIGHT STRONG HIGH PRESSURE IS EXPECTED TO MOVE INTO WESTERN
IA SETTING THE REGION UP FOR RECORD LOW TEMPERATURE POTENTIAL.
THERE IS SOME UNCERTAINTY ABOUT CLOUD COVER OVERNIGHT WITH THE
SYSTEM DEPARTING TO OUR EAST AND ANOTHER H3 JET STREAK APPROACHING
FROM THE NORTHWEST WHICH COULD SPREAD HIGH CLOUDS OVER THE AREA BY
MONDAY MORNING. THE POTENTIAL FOR CLEARING AND GOOD RADIATIONAL
COOLING WILL BE THE BEST OVER THE WESTERN CWFA SO WENT WITH LOWS IN
THE -9 TO -16 RANGE AND HELD MINS CLOSER TO 0 IN THE EAST WHERE
CLEARING IS LESS CERTAIN.  IF WE DO SEE A PROLONGED PERIOD OF CLEAR
SKIES THEN TEMPERATURES COULD BOTTOM OUT.  SOME GUIDANCE IS
SUGGESTING MINS AS LOW AS -20 OVER THE NORTHWEST CWFA.  IF THE
FORECAST VERIFIES FOR MONDAYS MIN TEMPERATURES THAN MOST SITES WILL
HAVE RECORD BREAKING LOW TEMPERATURES.  ALSO IF THE COLDER GUIDANCE
WOULD VERIFY THEN CEDAR RAPIDS AND DUBUQUE/S RECORD LOW FOR THE
MONTH OF MARCH WOULD ALSO BE IN JEOPARDY. SEE THE CLIMATE SECTION
BELOW FOR MARCH 3RD RECORD LOWS AND RECORD LOWS FOR THE MONTH OF MARCH.
GIVEN THE BITTERLY COLD TEMPERATURES AND LIGHT WIND...DANGEROUS
WIND CHILLS ARE EXPECTED OVER MUCH OF THE AREA.

WITH LITTLE MIXING DURING THE DAY MONDAY AND FRESH SNOW COVER...TEMPERATURES
SHOULD ONLY RECOVER INTO THE SINGLE DIGITS TO AROUND 10 DEGREES.

MODELS ARE STILL SHOWING MORE OF AN ACTIVE ZONAL PATTERN FOR MUCH OF
THE UPCOMING WEEK.  THIS WILL RESULT IN LOW POPS FOR SNOW TUESDAY
INTO  WEDNESDAY NIGHT AS WEAK IMPULSES MOVE THROUGH THE WESTERLY
FLOW.  LOW POPS WERE ALSO INCLUDED FOR FRIDAY WITH THE GFS BRINGING
SOME PRECIP INTO THE AREA AHEAD OF A MID LEVEL TROF CROSSING THE
NORTHERN PLAINS.  THE ECM WAS SIMILAR BUT WITH SLOWER TIMING.
THERMAL PROFILES SUPPORT A RAIN/SNOW MIX.  TEMPERATURES THROUGH THE
WEEK WILL BE MODERATING SLOWLY BUT WILL REMAIN BELOW NORMAL AT LEAST
THROUGH THURSDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1145 AM CST SAT MAR 1 2014

SNOW WITH MVFR/IFR CONDITIONS AND AREAS OF LIFR/VLIFR WILL BE FOCUSED
VICINITY OF KDBQ AND KCID OR ROUGHLY NEAR AND ESPECIALLY NORTH OF
HWY 30 MUCH OF THIS AFTERNOON WITHIN BAND OF STRONG MID LEVEL
FRONTOGENETICAL FORCING. LATE THIS AFTERNOON AND EVENING THE SNOW
AND DETERIORATING CONDITIONS IS EXPECTED TO SPREAD OR DEVELOP
SOUTHWARD ACROSS THE REST OF THE AREA. SNOW IS EXPECTED TO DIMINISH
OVERNIGHT THROUGH SUNDAY MORNING WITH CONDITIONS IMPROVING TO VFR FROM
NORTH TO SOUTH. WINDS WILL REMAIN NORTHERLY 10-15 KTS WITH OCCASIONAL
GUSTS NEAR 20 KTS.

&&

.CLIMATE...
ISSUED AT 331 AM CST SAT MAR 1 2014

RECORD LOWS FOR MARCH 3...

BURLINGTON..... -3 IN 1913
CEDAR RAPIDS... -9 IN 1913
DUBUQUE........ -10 IN 2002
MOLINE......... -8 IN 1884

MARCH RECORD LOWS...

BURLINGTON..... -13 03/05/1960
CEDAR RAPIDS... -20 03/01/1962
DUBUQUE........ -20 03/01/1962
MOLINE......... -19 03/06/1960

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL 6 AM CST SUNDAY FOR BENTON-
     BUCHANAN-DELAWARE-DUBUQUE-JACKSON-JONES-LINN.

     WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST
     SUNDAY FOR DES MOINES-HENRY IA-JEFFERSON-LEE-VAN BUREN.

     WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 6 AM CST
     SUNDAY FOR CEDAR-CLINTON-IOWA-JOHNSON-KEOKUK-LOUISA-
     MUSCATINE-SCOTT-WASHINGTON.

IL...WINTER WEATHER ADVISORY UNTIL 6 AM CST SUNDAY FOR CARROLL-JO
     DAVIESS-STEPHENSON.

     WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST
     SUNDAY FOR BUREAU-HANCOCK-HENDERSON-HENRY IL-MCDONOUGH-
     MERCER-PUTNAM-WARREN.

     WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 6 AM CST
     SUNDAY FOR ROCK ISLAND-WHITESIDE.

MO...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST
     SUNDAY FOR CLARK-SCOTLAND.

&&

$$

SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...FERRY
AVIATION...05
CLIMATE...FERRY