Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 190904
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
304 AM CST WED NOV 19 2014

.SYNOPSIS...
ISSUED AT 303 AM CST WED NOV 19 2014

A MOISTURE STARVED CLIPPER TYPE SYSTEM IS STREAMING SOUTHEAST
THROUGH THE UPPER MIDWEST EARLY THIS MORNING. THIS IS BRINGING A
BAND OF LIGHT SNOW TO MINNESOTA AND WISCONSIN...BUT ITS SOUTHERN
PERIPHERY OF SATURATION SEEMS TO BE FAR NORTHERN IOWA. A FLURRY IS
BEING REPORTED AT MASON CITY IOWA AS OF 2 AM. WARM ADVECTION HAS
EXPUNGED THE BITTERLY COLD AIR FROM EASTERN IOWA...AND THE MILD AIR
IS ONLY SHORT DRIVE AWAY IN NORTHWEST MISSOURI. HOWEVER...THE COLD
FRONT...WITH MORE ARCTIC AIR BEHIND IT...IS ALREADY SWEEPING THROUGH
WESTERN IOWA...AND SHOULD ARRIVE ALONG THE MISSISSIPPI RIVER TODAY
AROUND 7 AM.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 303 AM CST WED NOV 19 2014

TODAY WILL BE COLD AND WINDY...AGAIN. SAME STORY...DIFFERENT DAY IT
SEEMS. COLD ADVECTION WILL BRING CLOUDS...AND SOME SCATTERED
FLURRIES AS MIX INTO A SHALLOW DENDRITIC GROWTH ZONE AROUND 2500
FEET BEHIND THE FRONT. HIGHS TODAY WILL BE EARLY IN THE
PERIOD...AROUND 7 TO 10 AM...FOLLOWED BY VERY SLOWLY FALLING OR
STEADY TEMPERATURES. WINDS SHOULD SUSTAIN AROUND 18 MPH BY LATE
MORNING...WITH GUSTS TO 35 MPH AT TIMES.  WITH MOST LOCATIONS IN THE
LOWER TO MID 20S DURING THE AFTERNOON...UNDER CLOUDS...THE WIND
CHILLS WILL ONCE AGAIN BE IN THE 5 TO 15 RANGE. WHILE NOT
HAZARDOUS...TODAYS WEATHER WILL CERTAINLY BE A COLD WIND IN THE
FACE.

CLOUDS BECOME A CHALLENGE TONIGHT...AS MOST MODELS INDICATE CLEARING
BY EARLY TO MID EVENING. HOWEVER...WITH WIDESPREAD STRATUS UPSTREAM
AND CONTINUED COLD ADVECTION...IT SEEMS LIKELY THAT WE REMAIN PARTLY
TO MOSTLY CLOUDY THROUGH THE NIGHT. SOME CLEARING...IF IT DOES
OCCUR...IS MOST POSSIBLE AFTER MIDNIGHT. TEMPERATURES BASED ON CAA
ALONE...SHOULD FALL TO THE UPPER SINGLE DIGITS NORTH TO LOWER TEENS
ALONG INTERSTATE 80...AND MID TEENS SOUTH. SHOULD WE BE CLEAR...AS
SOME MODELS INDICATE...TEMPERATURES COULD BE ABOUT 5 DEGREES COLDER.
WIND CHILLS TONIGHT MAY DROP AS LOW AS -5 TO +5F AFTER 2 AM.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 303 AM CST WED NOV 19 2014

FORECAST FOCUS ON A CHANCE OF FREEZING RAIN FRIDAY NIGHT THEN
INTENSE STORM SYSTEM TO BRING WIDESPREAD RAIN AND WARMER
TEMPERATURES THIS WEEKEND. ECMWF HAS BEEN THE MOST CONSISTENT MODEL
BUT EVEN THE GFS/GEM ARE FOR THE MOST PART FAIRLY SIMILAR.

THURSDAY THROUGH FRIDAY...HIGH PRESSURE OVER THE REGION THURSDAY AND
THURSDAY NIGHT WILL GRADUALLY SHIFT TO THE OHIO VALLEY ON FRIDAY.
THIS WILL BE A COLD BUT DRY PERIOD WITH MAXIMUM TEMPERATURES IN THE
20S TO LOWER 30S WITH LOWS IN THE SINGLE DIGITS AND TEENS.

FRIDAY NIGHT...SOUTHERLY RETURN FLOW WILL BEGIN TO INCREASE MOISTURE
LEADING TO THE POTENTIAL FOR LIGHT PRECIPITATION BEGINNING FRIDAY
EVENING IN OUR SOUTHERN CWA AND QUICKLY SPREADING NORTHWARD ON
STRENGTHENING WARM AIR ADVECTION/MOISTURE TRANSPORT. THERMAL
PROFILES INDICATE AN INCREASING WARM LAYER ALOFT BUT DRY AIR IN THE
MID LEVELS INITIALLY. THE PROBLEM IS THAT SURFACE AND GROUND
TEMPERATURES WILL STILL BE BELOW FREEZING AND THERE IS THE THREAT OF
FREEZING DRIZZLE. AS THE NIGHT PROGRESSES CONTINUED WARM AIR
ADVECTION SHOULD RAISE TEMPERATURES ABOVE FREEZING IN OUR FAR
SOUTHERN CWA TO CHANGE OVER TO PLAIN RAIN. HOWEVER...ROUGHLY ALONG
AND NORTH OF HIGHWAY 34 FREEZING RAIN/FREEZING DRIZZLE SHOULD
CONTINUE TO BE A PROBLEM. WHILE QPF AMOUNTS SHOULD ONLY BE A COUPLE
OF HUNDREDTHS OF AN INCH ANY FREEZING PRECIPITATION WOULD CAUSE
SLICK ROADS AS SURFACE/GROUND TEMPERATURES REMAIN BELOW FREEZING.
WE WILL CONTINUE TO MONITOR THIS SITUATION.

THIS WEEKEND...ECMWF CONSISTENT IN TAKING AN INTENSE CYCLONE/NEGATIVELY
TILTED UPPER LEVEL TROUGH FROM THE SOUTHERN PLAINS TO THE GREAT
LAKES. THE SURFACE LOW IS PROGGED TO DEEPEN TO 979 MB AS IT TRACKS
TO NORTHERN IL ON SUNDAY THEN TO 974 MB HEADING TO LAKE SUPERIOR
SUNDAY NIGHT. WHILE THERE WILL BE A CHANCE OF RAIN ON SATURDAY THE
MORE WIDESPREAD/HEAVIER RAIN SHOULD BE ON SUNDAY. OPERATIONAL MODELS
ARE FAIRLY SIMILAR IN SHOWING A NICE WARM CONVEYOR BELT FROM THE
GULF OF MEXICO INTO THE CWA WITH WIDESPREAD LIGHT TO MODERATE RAIN
ON SUNDAY. HAVE RAISED POPS SOME MORE BUT WITH PLENTY OF ROOM TO GO
EVEN HIGHER AS WE GET CLOSER TO THE EVENT. CERTAINLY POTENTIAL FOR
AN INCH OF RAIN. THIS SYSTEM WILL BRING A SURGE OF MUCH WARMER AIR
INTO THE AREA WITH HIGHS IN THE 40S TO NEAR 50 THIS WEEKEND.

EARLY NEXT WEEK...COLDER AIR ON THE BACKSIDE OF THE SYSTEM SHOULD
ALLOW FOR LIGHT SNOW MONDAY AND MONDAY NIGHT WITH SOME LIGHT
ACCUMULATION POSSIBLE. MAXIMUM TEMPERATURES ON TUESDAY TO BE BACK
DOWN IN THE 20S TO LOWER 30S.

HAASE


&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1116 PM CST TUE NOV 18 2014

AN UPPER LEVEL DISTURBANCE AND SFC WARM FRONT ARRIVING OVERNIGHT WILL
BRING A CHANCE OF LIGHT SNOW AND MVFR CONDITIONS. SATURATION IS
THE MAIN CHALLENGE GIVEN PLENTY OF DRY AIR AND MODELS A BIT OVERDONE
WITH MOISTURE. BEST WARM ADVECTION/ISENTROPIC ASCENT AIMED INTO
NORTHEAST IA AND ESPECIALLY NORTHERN IL AND SOUTHERN WI 09Z-14Z
WITH CHANCE OF BRIEF PD OF SNOW WITH VSBYS 2-6SM AT KDBQ. WITH
SYSTEM ORGANIZING WHILE PASSING... EXPECT LOCATIONS EAST OF
TERMINALS ACROSS NORTHEAST IL AND SOUTHEAST WI TO STAND BEST CHANCE
OF LIGHT SNOW AND IFR/MVFR PERIOD WED AM. OUTSIDE OF THIS POTENTIAL
FOR SNOW...REST OF TERMINALS SHOULD GENERALLY SEE VFR CONDITIONS
THROUGH 12Z. WINDS AT TERMINALS WILL VEER FROM SOUTHEAST TO SOUTHWEST
AROUND 10 KTS THROUGH 12Z WITH SOME LOCAL GUSTS POSSIBLE. COLD FRONT
TO THEN FOLLOW AND PASS BY 15Z WITH WINDS BECOMING WEST/NORTHWEST
AND GUSTY 15-30 KTS. FLURRIES OR VERY LIGHT SNOW ALONG WITH MVFR
CIGS ANTICIPATED TO DEVELOP ACROSS THE TERMINALS BY LATE AM THROUGH
PM WITH STEEP LOW LEVEL LAPSE RATES EXTENDING INTO THE DENDRITIC
GROWTH ZONE. MODEL GUIDANCE SUGGESTS CLEARING OR IMPROVEMENT TO
VFR BY 00Z THU... BUT GIVEN EXTENT OF CLOUDINESS IN COLD AIR ATTIM
AND DEGREE OF COLD ADVECTION/CYCLONIC FLOW HAVE OPTED TO STAY ON THE
PESSIMISTIC SIDE AND MAINTAIN MVFR CIGS THROUGH WED EVE WITH WINDS
STAYING AT OR ABOVE 10 KTS AND GUSTY AT TIMES.


&&

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

$$

SYNOPSIS...ERVIN
SHORT TERM...ERVIN
LONG TERM...HAASE
AVIATION...05





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