000
FXUS63 KDVN 221216
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
616 AM CST THU JAN 22 2015

.SYNOPSIS...
ISSUED AT 300 AM CST THU JAN 22 2015

AT 3 AM CST...A WEAK SURFACE TROUGH EXTENDED FROM CENTRAL
ILLINOIS...TO NEAR THE IOWA/MISSOURI BORDER. SCATTERED FLURRIES
CONTINUES OVER PORTIONS OF EASTERN IOWA AND NORTHWEST ILLINOIS.
EARLY MORNING TEMPERATURES WERE IN THE UPPER 20S TO LOW 30S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CST THU JAN 22 2015

THE MAIN FORECAST ISSUES IN THE SHORT TERM PERIOD ARE POTENTIAL
FOR A SLICK MORNING COMMUTE WITH FLURRIES/FREEZING DRIZZLE...AND
TEMPERATURE CHALLENGES WITH CLEARING TRENDS TODAY.

EARLY THIS MORNING...LINGERING MOISTURE FREEZING ON ROADS...AS WELL
AS OVERNIGHT FLURRIES AND FREEZING DRIZZLE...ARE ALL CONTRIBUTING
TO SLICK CONDITIONS ON UNTREATED ROADS...RESIDENTIAL STREETS AND
SIDEWALKS. WILL BE ISSUING A SPECIAL WEATHER STATEMENT THROUGH
THE MORNING COMMUTE TO HIGHLIGHT WEATHER/HAZARDS. CLOUD TRENDS
WILL BE TRICKY TODAY. FLURRIES/FREEZING DRIZZLE EXPECTED TO
CONTINUE MAINLY EAST HALF OF FORECAST AREA THROUGH AT LEAST MID
MORNING. BANKING ON SOME AFTERNOON CLEARING ACROSS THE NORTHWEST
HALF...LINGERING CLOUDS SOUTHEAST HALF. COOLEST TEMPS OF 30-34
EXPECTED ALONG AND EAST OF THE MISSISSIPPI RIVER.

FOR TONIGHT...CLOUDS EXPECTED TO CLEAR OUT OF THE SOUTHEAST
HALF...WHICH COULD BE THE COLDEST AREA OVERNIGHT DUE TO THE
STAGNANT SURFACE WINDS...SLIGHTLY WARMER IN EASTERN IOWA WITH A
BIT STRONGER SOUTHWEST FLOW.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 300 AM CST THU JAN 22 2015

OVERVIEW...SPLIT UPPER-LEVEL FLOW WILL BRING QUIET WEATHER TO THE
MIDWEST THROUGH SATURDAY. MID-LEVEL RIDGE OVER THE WESTERN CONUS
WILL LEAD TO WARMING 850 TEMPS ACROSS THE PLAINS WHICH WILL REMAIN
ABOVE 0 C. EVEN WITH A SFC FLOW OUT OF THE NW...RELATIVELY MILD
TEMPS ARE FORECAST THROUGH THE WEEKEND. A CLIPPER SYSTEM MAY BRING
LIGHT PRECIPITATION TO IOWA/ILLINOIS SUNDAY. HOWEVER...TEMPS MAY BE
MILD ENOUGH FOR A RAIN/SNOW MIX OR ALL RAIN ACROSS PARTS OF THE CWA.

FRIDAY...THE CENTRAL MIDWEST WILL BE IN BETWEEN SYSTEMS DURING THIS
PERIOD WITH A SFC LOW TRAVERSING THE HUDSON BAY REGION AND ANOTHER
ONE THROUGH THE MID-ATLANTIC/EAST COAST.

A LARGE AREA OF +8 C 850 MB TEMPS/ELEVATED MIXED LAYER...FORMING
WITHIN A DOWNSLOPING WIND REGIME OVER ALBERTA AND
SASKATCHEWAN...WILL ADVECT ACROSS THE PLAINS STATES TODAY AND THEN
NOSE INTO IOWA BY FRI. THESE ABOVE GROUND TEMPS WILL MODIFY TO
AROUND +1/+2 C. FRI SFC TEMPS SHOULD REACH THE UPPER 30S/MID 40S
WITH THE USUAL NE TO SW GRADIENT ACROSS THE FORECAST AREA. PARTLY
SUNNY SKIES AND A STEADY SW WIND SHOULD AID IN PUSHING TEMPS UP IN
THIS ROUGHLY 10 DEGREE ABOVE AVG RANGE.

A WEAK SFC BOUNDARY WILL MOVE THROUGH FRI NIGHT. ASIDE FROM A SLIGHT
CHANCE FOR PATCHY DRIZZLE/FZ DRIZZLE IT WILL PASS THROUGH QUIETLY.

SATURDAY...NOT MUCH CHANGE. ALTHOUGH WILL SEE AN INCREASE IN CLOUD
COVER OUT IN ADVANCE OF A COMPACT SHORTWAVE TROUGH PUSHING INTO
MINNESOTA AND W IOWA. 1000-500 MB THICKNESSES STILL FORECAST TO BE
AROUND 540 DAM.

SATURDAY NIGHT AND SUNDAY...THE TROUGH PROGGED TO MOVE THROUGH THE
MIDWEST DURING THIS PERIOD IS IMPRESSIVE FROM A DYNAMICAL
STANDPOINT. A STRONG +150 KT JET WILL ENTER INTO NEBRASKA SAT NIGHT.
THE ORIENTATION OF THE LEFT EXIT REGION WITH RESPECT TO THE TROUGH
SUGGESTS SIGNIFICANT DIGGING/LOWERING OF HEIGHTS WITH TIME VIA ITS
THERMALLY INDIRECT CIRCULATION.

STILL PLENTY OF UNCERTAINTY WITH THE EXACT TRACK OF THE SFC LOW
ATTENDANT TO THIS TROUGH. THE GFS HAS A TRACK JUST TO THE NE OF THE
DVN CWA ACROSS NE ILLINOIS AND THE GEM IS NORTH OF THIS. THE ECMWF
IS NOW FURTHER TO THE SW OVER E IOWA. A MORE NE TRACK WOULD MEAN
MORE OF A LIGHT RAIN/SNOW MIX OR ALL LIGHT RAIN ACROSS MUCH OF THE
FORECAST AREA WHILE A TRACK FURTHER TO THE SW COULD RESULT IN LIGHT
SNOW ACCUMULATIONS...STAY TUNED.

GIVEN THE RELATIVELY WARM ANTECEDENT CONDITIONS IN THE DAYS LEADING
UP TO THIS EVENT WOULD NOT BE SURPRISED IF A MORE NE TRACK VERIFIES
AS THE LOW-LEVEL BAROCLINIC ZONE FOCUSES TO THE NORTH...BUT WILL
HAVE TO WAIT AND SEE HOW MODELS CONVERGE OVER NEXT FEW RUNS.

MONDAY...COLDER NW FLOW WILL DROP 850 MB TEMPS TO AROUND -8 C AND
HIGHS WILL COME DOWN SLIGHTLY TO NEAR OR SLIGHTLY ABOVE AVG. STILL
NO SIGNS OF ARCTIC AIR AS 1000-500 MB THICKNESSES ONLY FALL TO ABOUT
~528 DAM. A FEW SNOW SHOWERS WILL BE POSSIBLE.

TUESDAY...STRONG SW TO NE TEMP GRADIENT LOOKS TO SET UP ACROSS THE
MIDWEST WITH LOWER 60S POSSIBLE AS CLOSE AS W MISSOURI. CONSENSUS
BLEND GIVE NEAR 50 F IN THE SW DVN CWA TO THE MID 30S NEAR FREEPORT.
THERE MAY ALSO BE A CLIPPER SYSTEM TO DEAL WITH PER THE 00Z/1.22
GFS. FOR NOW ONLY INTRODUCED SLIGHT CHANCE FOR LIGHT SNOW OVER THE
EASTERN FORECAST AREA.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 607 AM CST THU JAN 22 2015

LIGHT FREEZING DRIZZLE AND FLURRIES WILL PERSIST UNTIL 14-15Z THIS
MORNING AT KDBQ/KMLI. OTHERWISE...EXPECT IFR/MVFR CEILINGS AND
MVFR VISIBILITIES. CEILINGS WILL GRADUALLY LIFT FROM NORTHWEST TO
SOUTHEAST ACROSS THE AREA DURING THE LATE MORNING AND AFTERNOON.
HAVE TIMED THE CLEARING TREND LATER THAN WHAT MODEL RH PROGS WOULD
SUGGEST.

&&

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

$$

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