Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 152130
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
330 PM CST SAT NOV 15 2014

.SYNOPSIS...
ISSUED AT 312 PM CST SAT NOV 15 2014

TOP DOWN SATURATION CONTINUES TO PROGRESS QUICKLY THIS AFTERNOON ACROSS
EASTERN IOWA AND WESTERN ILLINOIS. AN ENHANCED SNOW BAND ASSOCIATED
WITH A NORTHEAST ADVANCING SHORT WAVE IS PUSHING QUICKLY THROUGH
SOUTHEAST IOWA AND FAR WEST CENTRAL ILLINOIS. WEB CAMS INDICATE
LOWER VISIBILITIES AND PARTLY TO MOSTLY SNOW COVERED ROADS IN
THOSE AREAS.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 312 PM CST SAT NOV 15 2014

MAIN FORECAST CHALLENGE IS THE ONGOING EARLY SEASON SNOW. IN THE
INITIAL STAGES...THE EVENT HAS PLAYED OUT AS EXPECTED. AN ENHANCED
SNOW BAND WILL CONTINUE TO PROGRESS NORTHEAST THROUGH THE QUAD
CITIES AREA THROUGH EARLY EVENING. OBS AND WEB CAMS INDICATE
VISIBILITIES DROPPING BELOW A MILE IN THE HIGHER INTENSITY SNOW.
ROAD TEMPERATURES ARE EXPECTED TO DIP QUICKLY BELOW FREEZING LATE
THIS AFTERNOON...SETTING UP THE ANTICIPATED SCENARIO OF VERY SLICK
ROADS.

NO CHANGES TO THE WINTER WEATHER ADVISORY HEADLINES FROM EARLIER
TODAY. THE SOUTHEAST TO NORTHWEST SNOWFALL GRADIENT (HALF INCH OR
LESS SOUTHEAST/INCREASING TO 2-3 INCHES NORTHWEST) STILL LOOKS
REASONABLE. MOST OF THE ACCUMULATING SNOW IS EXPECTED TO OCCUR
THROUGH EARLY TO MID EVENING. OVERNIGHT...THE MAIN UPPER TROUGH
WILL SUPPORT MORE SCATTERED LIGHT SNOW SHOWERS.

SNOW SHOWERS WILL LINGER SUNDAY MORNING...BEFORE PUSHING EAST
DURING THE AFTERNOON HOURS. AN INCREASING WESTERLY WIND COULD
PRODUCE SHOW SHALLOW DRIFTING SNOW ACROSS ROADS. THE MAIN SURGE OF
COLD AIR WILL HOLD OFF UNTIL SUNDAY NIGHT.    RP KINNEY


.LONG TERM...(SUNDAY NIGHT THROUGH NEXT SATURDAY)
ISSUED AT 141 PM CST SAT NOV 15 2014

SUNDAY NIGHT AND MONDAY...ARCTIC AIRMASS SURGE OUT OF CANADA UNDER
HIGH AMPLITUDE COLD CORE L/W TROF STILL ON TRACK THIS PERIOD WITH
THE MAIN SFC FRONT STILL EXPECTED TO SLASH IT/S WAY THROUGH THE CWA
LATE SUNDAY NIGHT INTO EARLY MON MORNING. WILL KEEP FLURRY MENTION
IN THE NORTHEAST MAINLY AFTER MIDNIGHT WITH THIS OCCURRENCE...BUT
TIGHTENING CYCLONIC FLOW IN STOUT COLD AIR ADVECTION REGIME WITH
DIURNAL PROCESSES WILL MAKE FOR A BETTER CHC FOR SCTRD FLURRIES OR
EVEN SNOW SHOWER ACTIVITY FROM LATE MON MORNING THROUGH THE
AFTERNOON AS A VORT SPOKE ROTATES THROUGH. BULK OF THE 12Z RUN
MODELS STILL ARE ADVERTISING RECORD COLD FOR NOVEMBER H85 MB POOL OF
-18C TO -20C TO ROTATE DOWN ACRS THE REGION ON MONDAY...AND AFTER
MONDAY MORNING LOWS OF UPPER SINGLE DIGITS TO MID TEENS...TEMPS WON/T
RECOVER MUCH AS THE DAY PROGRESSES/MID TEENS TO LOWER 20S/. EARLY
MON MORNING WIND CHILLS OF ZERO TO NEAR 8 BELOW...WITH NORTHWESTERLY
SFC WINDS CRANKING UP TO 15 TO 25+ MPH SUSTAINED AND GUSTS OVER 30
MPH AS MON PROGRESSES. POST-UPPER WAVE TROP FOLD TO UNDER 550 MB ALSO
POSSIBLE ON MONDAY HELPING OUT THE LLVL WIND MACHINE. SOME CLEARING
WITH SFC WIND DROP OFF LATE MON NIGHT INTO EARLY TUE MORNING MAY SET
THE STAGE FOR RECORD OR NEAR RECORD COLD FOR NOV 18TH. LIKE THE
PREVIOUS SHIFT MENTIONED...IN AREAS WITH SNOW COVER THERE MAY BE
SOME TEMPS APPROACHING ZERO AND WITH SFC WINDS MAINTAINING FROM 9-15
KTS WIND CHILL ADVISORY CRITERIA MAY BE NEARED ESPECIALLY IN THE
NORTHWESTERN THIRD OF THE DVN CWA TUE AM.

TUESDAY AND WEDNESDAY...COLD DAY IN THE TEENS AND 20S FOR TUE...THEN
EYES TURN TO A CLIPPER TYPE SYSTEM FOR TUE NIGHT RIPPLING DOWN INTO
BROADENING L/W TROF BASE WHICH SHOULD BE ENGULFING MUCH OF THE
EASTERN HALF OF THE CONUS BY THEN. MANY 12Z RUN SOLUTIONS HAVE
TRENDED FURTHER SOUTH WITH THIS FEATURE/S SFC WAVE AND ASSOCIATED
PRE-SYSTEM WING OF WAA SNOWS. MOST SYSTEMS NOW CLIP THE FAR NORTH
TO NORTHEASTERN CWA WITH A DUSTING OF SNOW LATE TUE NIGHT INTO WED
MORNING...WHILE THE MORE BULLISH 12Z GFS PRODUCES A HALF INCH TO
NEAR AND INCH OF NEW SNOW DOWN TO I80. FOR NOW WILL KEEP THE FCST
DRY AND AWAIT FURTHER MODEL RUNS FOR SOME CONSISTENCY WITH THIS
FEATURE. PRE-WAVE WARM DRAW MAY MAKE FOR WARMING TEMPS TUE NIGHT
INTO WED ESPECIALLY IF THE SNOW STAYS OFF TO THE NORTH. MODERATING
TEMPS CONTINUE INTO WED.

THURSDAY THROUGH NEXT SATURDAY...LESS CONFIDENCE THIS PERIOD AS
MEDIUM RANGE SOLUTIONS HAVING TROUBLE WITH COMPLEX REX BLOCK JUST
OFF THE WEST COAST AND CANADIAN UPPER JET ENERGY TRYING TO DIG DOWN
AND RE-ENFORCE EASTERN CONUS TROFFINESS. THE 12Z RUN ECMWF SUGGESTS
ENOUGH INTERACTION AHEAD OF THIS DIGGING TROF/WAVE ENOUGH TO ROLL OUT
A SOUTHERN STREAM SYSTEM FAR ENOUGH TO THE NORTH THAT IT MAY
PRODUCE OVERRUNNING SNOWS ACRS AT LEAST SOUTHEASTERN THIRD LAT THU AN
THU NIGHT...WHILE THE 12Z GFS IS DRY WITH DOMINATING MS RVR VALLEY
RIDING THU INTO FRI. THE EURO THEN COLD DUMPS WITH ANOTHER STRONG
HIGH ACRS THE MIDWEST FRO A DRY FRI INTO EARLY SAT...WHILE THE GFS
TRIES TO PHASE AN UPSTREAM L/W TROF ACRS THE ROCKIES INTO THE
PLAINS WHICH MAY BRING A MIXED BAG OF PRECIP OUT AHEAD OF IT INTO
THE LOCAL AREA LATE FRI NIGHT INTO SAT. FEEL THE EVENTUAL SOLUTION
WILL BE IN-BETWEEN AND WILL CARRY SLIGHT CHC POPS FOR RAIN OR SNOW ON
SAT IN THE SOUTHEASTERN HALF OF THE DVN CWA.    ..12..

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1220 PM CST SAT NOV 15 2014

18Z TAFS UPDATED FOR MINOR ADJUSTMENTS TO TIMING AND PEAK SNOWFALL
INTENSITY. IN GENERAL...EXPECTING PERIODS OF IFR CIGS/VSBY IN
POCKETS OF HIGHER INTENSITY SNOW. FROM 23-01Z...SNOWFALL EXPECTED
TO DIMINISH TO FLURRIES OR LIGHT SNOW SHOWERS WITH MVFR VSBYS.
CIGS BELOW 1000FT AGL LIKELY OVERNIGHT INTO SUNDAY MORNING.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL 3 AM CST SUNDAY FOR CEDAR-CLINTON-
     DES MOINES-DUBUQUE-JACKSON-JONES-LOUISA-MUSCATINE-SCOTT.

     WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR BENTON-
     BUCHANAN-DELAWARE-HENRY IA-IOWA-JEFFERSON-JOHNSON-KEOKUK-
     LEE-LINN-VAN BUREN-WASHINGTON.

IL...WINTER WEATHER ADVISORY UNTIL 3 AM CST SUNDAY FOR CARROLL-
     HENDERSON-HENRY IL-JO DAVIESS-MERCER-ROCK ISLAND-STEPHENSON-
     WHITESIDE.

MO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CLARK-
     SCOTLAND.

&&

$$

SYNOPSIS...RP KINNEY
SHORT TERM...RP KINNEY
LONG TERM...12
AVIATION...RP KINNEY








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