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000
FXUS63 KDVN 061134
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
534 AM CST FRI DEC 6 2013

.SYNOPSIS...
ISSUED AT 307 AM CST FRI DEC 6 2013

LATEST SURFACE ANALYSIS INDICATED A SURFACE RIDGE OF HIGH PRESSURE
BUILDING EAST SOUTHEASTWARD INTO IOWA AND ILLINOIS.  A COLD FRONT
WAS DRAPED FROM THE SOUTHERN TIP OF TEXAS NORTHEAST TO NEW YORK.
MID AND HIGH LEVEL CLOUDINESS FROM THE NORTHWEST PERIPHERY OF THE
WINTER STORM SYSTEM TO THE SOUTH AND SOUTHEAST IS SEEN STREAMING
NORTHEAST ACROSS THE CWFA. NORTHWEST WINDS AT 8 TO 15 MPH WERE
OBSERVED AT 3AM...WITH A FEW GUSTS AROUND 20 MPH.  TEMPERATURES
RANGE FROM 7 TO 17 DEGREES...WITH THE WARMER READINGS IN THE
SOUTHEAST...CLOSER TO THE SOUTHERN WINTER STORM.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM CST FRI DEC 6 2013

RELATIVELY QUIET AND COLD CONDITIONS WILL CHARACTERIZE THE WEATHER IN
THE SHORT TERM.  ARCTIC HIGH PRESSURE WILL CONTINUE TO BUILD OVER
THE AREA OVER THE NEXT 24 HOURS.  SOME MID AND HIGH LEVEL CLOUDINESS
WILL CONTINUE TO OVERSPREAD THE AREA FROM THE SOUTHWEST TODAY...WITH
CLEARING CONDITIONS TONIGHT.  FLURRIES MAY BE POSSIBLE ACROSS THE
SOUTHEAST 1/4 OF THE CWFA...BUT OPTED TO LEAVE MENTION OUT OF GRIDS
AT THIS TIME. WINDS WILL REMAIN ON THE BLUSTERY SIDE THROUGH THE
MAJORITY OF THE PERIOD...DIMINISHING UNDER 10 MPH BY SATURDAY
MORNING.  TEMPERATURES LOOK TO BE ON TRACK...WITH HIGHS TODAY
STRUGGLING TO REACH THE TEENS AND LOWER 20S.  LOWERED MINS SAT
MORNING JUST A TAD WITH CLEAR SKIES AND LIGHTER WINDS...WITH MINS IN
THE MINUS 3 TO 8 ABOVE RANGE.  WIND CHILLS THIS MORNING WILL SLIP
INTO THE LOWER SINGLE DIGITS ABOVE ZERO EAST NEAR PRINCETON
ILLINOIS...TO ABOUT MINUS 15 NEAR INDEPENDENCE.  THIS AFTERNOON THEY
WILL BE BETWEEN 5 BELOW AND 10 ABOVE. WITH THE COLDER MINS SATURDAY
MORNING...WIND CHILLS WILL DROP TO BETWEEN 5 BELOW AND 18 BELOW ZERO.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 307 AM CST FRI DEC 6 2013

BELOW NORMAL TEMPERATURES ARE THE RULE THROUGHOUT THE EXTENDED
FORECAST. CHANCES FOR MEASURABLE SNOW CONTINUE FOR SUNDAY AND SUNDAY
NIGHT AS UPPER LEVEL IMPULSE IN THE NEARLY MERIDIONAL FLOW CURRENTLY
ALONG THE PACIFIC NW COAST ROUNDS THE BASE OF THE UPPER LEVEL TROUGH
AND PASSES THROUGH THE FORECAST AREA.

SATURDAY INTO SATURDAY NIGHT WILL BE DRY AND COLD AS HIGH PRESSURE
OVER THE NORTHERN ROCKIES PLAINS MIGRATES SE THROUGH THE AREA. WITH
A SIMILAR AIRMASS IN PLACE AS FRIDAY...HIGHS WILL ONLY MAKE THE
TEENS TO NEAR 20 IN THE FAR SOUTH. CLOUDS THICKEN SATURDAY NIGHT AS
MID AND UPPER LEVEL MOISTURE AND MODEST LIFT INCREASES AHEAD OF THE
APPROACHING SHORTWAVE. A DEVELOPING E-SE FLOW OF DRY AIR FROM THE
SURFACE THROUGH 850 MB SHOULD EFFECTIVELY EAT AWAY AT ANY ICE
CRYSTALS...HOLDING OFF THE ONSET OF FLURRIES UNTIL DAYLIGHT SUNDAY.
THE CLOUD COVER SHOULD KEEP MINIMUM TEMPERATURES WARMER THAN
PREVIOUS NIGHTS...FROM AROUND 10 NORTH TO THE LOWER TEENS ELSEWHERE.

SUNDAY AND SUNDAY NIGHT...LIGHT SNOW WILL OVERSPREAD THE AREA FROM
WEST TO EAST AS THE UPPER LEVEL VORT MAX AND INVERTED SURFACE TROUGH
MOVE THROUGH THE REGION. WHILE THERE ARE STILL MINOR DIFFERENCES
BETWEEN MODELS...THE OVERALL TREND IS TOWARD THE BEST UPPER LEVEL
FORCING PASSING OVERHEAD FROM MIDDAY INTO EARLY EVENING. MODEL QPF
AMOUNTS OF ROUGHLY .05 TO NEARLY .20...ALONG WITH A BRIEF WINDOW OF
LIFT IN THE IDEAL DENDRITIC GROWTH ZONE AND SURFACE TEMPERATURES
ONLY REACHING THE 20S...WOULD SUPPORT WIDESPREAD SNOWFALL AMOUNTS OF
AROUND 1 TO 3 INCHES. THE HIGHER TOTALS WILL LIKELY BE ACROSS THE NW
AND NORTH WITH LIGHTEST AMOUNTS IN THE SOUTHEAST. THE VORT MAX
PASSES TO THE NORTHEAST AFTER MIDNIGHT...ENDING THE LIGHT SNOW.
ALLOWING FOR SOME POSSIBLE FURTHER SLOWING OF THE SYSTEM...HAVE KEPT
CHANCE POPS GOING IN THE WEST...WHILE LIKELY POPS HANG ON IN THE FAR
NORTHEAST THROUGH THE NIGHT.

MONDAY THROUGH THURSDAY...THE FORECAST IS KEPT COLD AND DRY. THERE
WILL HOWEVER BE PERIODIC WEAK CLIPPER SYSTEMS IN THE MAINLY NW FLOW
ALOFT TO PROVIDE AT LEAST LOW CHANCES FOR FLURRIES OR LIGHT SNOW IN
THE VICINITY. AT THIS TIME...MODELS HAVE THE FIRST ONE PASSING TO
THE NORTHEAST ON TUESDAY...WITH ANOTHER AROUND WED OR WED NIGHT
POSSIBLY TAKING A MORE DIRECT PATH...BUT WITH SIGNIFICANTLY
DIFFERENT TIMING BETWEEN THE GFS AND ECMWF NO MENTION OF
PRECIPITATION IS INCLUDED IN THE FORECAST AT THIS TIME. THE BIGGER
STORY WILL BE THE CONTINUED COLD TEMPERATURES AS 850 MB TEMPERATURES
REMAIN IN THE SUB ZERO TEENS. FORECAST HIGHS IN THE TEENS TO MID 20S
AND LOWS IN THE SINGLE DIGITS MON THROUGH WED MAY BE TOO
OPTIMISTIC...ESPECIALLY IF THE SUNDAY SYSTEM LAYS NEW SNOW COVER
ACROSS THE AREA. THURSDAY AND BEYOND...THERE IS INDICATION OF A
WARMING TREND AS A SYSTEM DEVELOPS OUT WEST AND THIS IS REFLECTED
WITH HIGHS IN THE 20S TO POSSIBLY LOWER 30S IN THE SOUTH THURSDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 520 AM CST FRI DEC 6 2013

VFR CONDITIONS WILL PREVAIL THIS TAF CYCLE AS ARCTIC HIGH PRESSURE
CONTINUES TO BUILD INTO THE AREA. MID TO HIGH LEVEL CLOUDS ARE
EXPECTED TO STREAM NORTHEAST ACROSS THE TERMINALS TODAY...WITH
CLEARING EXPECTED TONIGHT. WINDS WILL BE NORTHWEST AT 10 TO 15 KTS
WITH OCCASIONAL HIGHER GUSTS THROUGH EVENING...DIMINISHING TO UNDER
10 KTS AFTER 06Z. VISIBILITIES WILL REMAIN P6SM.

&&

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

$$

SYNOPSIS...14
SHORT TERM...14
LONG TERM...SHEETS
AVIATION...14