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000
FXUS63 KDVN 021345
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
745 AM CST MON DEC 2 2013

.UPDATE...
ISSUED AT 735 AM CST MON DEC 2 2013

MID LEVEL CLOUDS ARE DEVELOPING ACROSS IOWA AND RADAR REFLECTS
THIS WITH AN INCREASE IN OVERALL RETURNS. 12Z DVN SOUNDING HAS A
DRY LAYER FROM ROUGHLY 950-850MB WITH SATURATION OCCURRING ABOVE
THAT. THIS DRY LAYER IS NARROWER THAN WHAT ANY OF THE MODELS
INDICATED IN THEIR RESPECTIVE 6 AND 12 HR FORECASTS.

RECENT TRENDS IN THE RAP MODEL GENERALLY SUPPORTS THE CURRENT
FORECAST OF A BAND OF RAIN DEVELOPING AND MOVING ACROSS THE AREA
TODAY. THE ONLY DIFFERENCE IS THAT THE DEVELOPMENT MAY OCCUR A BIT
LATER THAN WHAT THE CURRENT FORECAST HAS. HOWEVER...THE NARROWER
DRY LAYER IN THE MORNING SOUNDING WOULD TAKE LESS TIME TO
SATURATE SO PRECIPITATION MAY START SOONER THAN WHAT THE RAP IS
SUGGESTING.

&&

.SYNOPSIS...
ISSUED AT 316 AM CST MON DEC 2 2013

06Z SFC ANALYSIS HAS WEAK LOWS NEAR KVIH...KRSL...AND KPIR.
DEVELOPING WARM FRONTS RAN ACROSS NORTHEAST KANSAS THROUGH CENTRAL
MISSOURI AND ANOTHER FROM THE DAKOTAS INTO EASTERN NEBRASKA. DEW
POINTS WERE IN THE 20S ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST
WITHS 30S AND HIGHER FROM THE OHIO VALLEY INTO THE DEEP SOUTH AND
SOUTHERN PLAINS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST MON DEC 2 2013

CURRENT RADAR TRENDS SHOW PRECIPITATION DECREASING IN COVERAGE AS
THE FIRST ROUND OF FORCING WEAKENS. THUS MAINLY DRY CONDITIONS
SHOULD BE SEEN THROUGH SUNRISE AND THE FIRST PART OF THE MORNING.

FROM MID TO LATE MORNING FORCING BEGINS TO INCREASE AGAIN WITH THE
APPROACH OF THE NEXT UPPER LEVEL DISTURBANCE. THERE IS REASONABLE
AGREEMENT AMONG THE MODELS THAT AS THE FORCING INCREASES...VERY
LIGHT RAIN SHOULD BREAK OUT FROM CENTRAL IOWA INTO THE WESTERN PARTS
OF THE AREA AND INCREASE IN COVERAGE THROUGH MID DAY.

MOISTURE AVAILABILITY IS LIMITED BUT THE FORCING INCREASES FURTHER
DURING THE AFTERNOON. SO...THERE SHOULD BE A BAND OF LIGHT RAIN THAT
WILL MOVE ACROSS THE AREA FROM LATE MORNING THROUGH THE AFTERNOON.

AS THE UPPER LEVEL DISTURBANCE EXITS THE AREA THIS EVENING THE AREAL
COVERAGE OF THE LIGHT RAIN WILL DECREASE THROUGH MID EVENING. THERE
MAY BE A LULL IN PRECIPITATION FROM MID EVENING THROUGH EARLY
MORNING BEFORE THE NEXT UPPER LEVEL DISTURBANCE ARRIVES. THIS
DISTURBANCE SHOULD EITHER ALLOW A MIX TO PERSIST ACROSS THE NORTH OR
DEVELOP A MIX PRIOR TO SUNRISE ON TUESDAY.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 316 AM CST MON DEC 2 2013

A STRONG ARCTIC FRONT WILL SWEEP THROUGH THE MIDWEST...BRINGING A
RETURN TO BRISK COLD TEMPERATURE FOR THE REMAINDER OF THE WEEK.
WHEN THIS BEGINS...THE FROPA...REMAINS A GIANT TROUBLESOME
DIFFERENCE IN THE 00Z GUIDANCE SUITE. THE PERIOD THIS DIFFERENCE WILL
AFFECT IS WEDNESDAY. THERE ARE TWO CAMPS...THE FASTER
NAM/GFS...WHICH MOVE THE FRONT INTO THE CWA TUESDAY NIGHT...AND THE
FAR SLOWER UKMET AND ECMWF WHICH MOVE THE FRONT THROUGH THE CWA
WEDNESDAY AFTERNOON. THIS ROUGHLY 12 HOUR DIFFERENCE CREATES
POTENTIAL FOR A 20 DEGREE BUST ON TEMPS FOR WEDNESDAY. WE COULD
CONCEIVABLY BEGIN THE DAY IN THE MID 30S TO MID 40S...AND FALL LIKE
A ROCK ALL DAY...OR SHOULD THE SLOWER SOLUTIONS WORK OUT...AN
AFTERNOON HIGHS WELL INTO THE 50S COULD BE SEEN IN ILLINOIS. GIVEN
THE POSITIVELY TILTED UPPER TROF...I STILL FEEL THE FASTER SOLUTIONS
ARE NOT OUT OF THE QUESTION. THUS...I WILL GO A BIT MILDER WEDNESDAY
THAN THE FAST/COLD NAM...BUT MUCH COOLER THAN THE SLOW ECMWF. IN
ALL...THIS DAY STILL DOES NOT OFFER MUCH CHANCE FOR SIGNIFICANT
RAIN/SNOW...BUT A SMALL POP FOR 0.01 OR SO REMAINS IN THE FORECAST
WITH THE FRONT.

TEMPERATURES TUESDAY WILL BE QUITE MILD...WARM SECTORED...WITH 40S
NORTH TO MID AND UPPER 50S CENTRAL AND SOUTH. THIS AIR HANGS ON
UNTIL THE FROPA...LEADING TO THE POTENTIAL CHALLENGE OF WEDNESDAYS
HIGHS AND HOURLY TEMPERATURES. BEHIND THE FRONT...TEMPERATURES WILL
CERTAINLY CRASH...TO THE 20S AND TEENS INITIALLY...BUT BY THURSDAY
NIGHT THROUGH THE WEEKEND...LOWS IN THE SINGLE DIGITS ARE CERTAINLY
LIKELY. HIGHS IN THE UPPER TEENS TO LOWER 20S WILL FINISH OUT THE
WEEK.  WIND CHILLS OF -10 TO +5 WILL BE FOUND EACH NIGHT FROM
THURSDAY NIGHT THROUGH SATURDAY NIGHT.

LOW POPS ARE RETAINED IN THE SOUTH FOR THE NORTH EDGE OF A POSSIBLE
OVER RUNNING LIGHT SNOW EVENT THURSDAY INTO FRIDAY. OTHERWISE...THE
NEXT MORE LIKELY OVER RUNNING LIGHT SNOW EVENT APPEARS SET FOR
SUNDAY AND MONDAY.
ERVIN

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 537 AM CST MON DEC 2 2013

MVFR VSBYS MAY BRIEFLY IMPROVE TO VFR PRIOR TO 18Z/02. HOWEVER...
AN APPROACHING DISTURBANCE WILL DEVELOP WIDESPREAD MVFR CONDITIONS
AROUND 18Z/02 WITH RAIN. THE POSSIBILITY DOES EXIST THAT BRIEF
PERIODS OF IFR CONDITIONS MAY DEVELOP IN THE RAIN PRIOR TO 00Z/03.
AFTER 00Z/03 MVFR/IFR CONDITIONS WILL PERSIST WITH SOME
IMPROVEMENT TO VFR ACROSS SOUTHEAST IOWA FOLLOWING THE FRONTAL
PASSAGE.


&&

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

$$

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