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000
FXUS63 KDVN 191758
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1158 AM CST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 316 AM CST FRI DEC 19 2014

LATEST SFC ANALYSIS WAS INDICATING LARGE RIDGE AXIS HOLDING FIRM
FROM ACRS ONTARIO NORTH OF LK SUPERIOR...ALL THE WAY DOWN INTO THE
MID TO LOWER MS RVR VALLEY. LIGHT LLVL RETURN FLOW PATTERN TO THE
WEST OF IT ACRS THE CENTRAL AND NORTHERN PLAINS. EXTENSIVE STRATUS
DECK UNDER THE WEST HALF OF THE RIDGE AND INTO THE EASTERN PLAINS
IN RETURN FLOW INTERACTION ZONE...OPEN SKY SWATH FROM SOUTHWEST
OF DBQ SOUTHEASTWARD THRU THE QUAD CITES/EASTERN I80 CORRIDOR
WILL LOOK TO FILL BACK IN EARLY THIS MORNING. ALOFT...00Z UPPER
AIR ANALYSIS AND CURRENT WATER VAPOR LOOP INDICATED A VORT WING
MOVING ACRS EASTERN SD INTO SOUTHEASTERN MN...TAILING DOWN ACRS
CENTRAL INTO EASTERN IA ATTM. THIS FEATURE IS PRODUCING LIGHT SNOW
ACRS MN...AND MAY BE INDUCING THE PATCHY LIGHT FREEZING DRIZZLE
CURRENTLY OUT ACRS CENTRAL IA. NEG VORTICITY IS MOVING OUT OF EASTERN
NEB INTO WESTERN IA BEHIND THIS MAIN VORT. A FURTHER UPSTREAM VORT
NOTED ACRS WY...AND A MORE VIGOROUS VORT MAX NOTED ACRS SOUTHERN
ALBERTA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST FRI DEC 19 2014

TODAY...BULK OF HIRES MODELS SUGGEST HIGH PRESSURE COMPLEX TO
HAVE IT/S EFFECT THIS MORNING MAINTAINING HIGHER CLOUD CIGS FOR
AWHILE...BEFORE AXIS STARTS TO SLIDE EASTWARD MIDDAY INTO THE
AFTERNOON ALLOWING THE LOWER DECK OUT WEST TO SEEP EASTWARD. AREA
OF LIGHT DRIZZLE/FREEZING DRIZZLE ACRS CENTRAL IA MOVING
NORTHEASTWARD AND MAY GET CLOSE TO THE NORTHWESTERN PORTION OF THE
CWA THIS MORNING...BUT WILL BANK ON DIURNAL EFFECTS AND THE RIDGE
STILL IN PLACE TO DEFLECT/EAT AWAY AT THIS PROCESS AND KEEP THE
DRIZZLE JUST TO THE WEST AND NORTHWEST OF THE CWA THIS MORNING...
ALTHOUGH IT WILL BE CLOSE AND WILL HAVE TO WATCH FOR UPDATES. THEN
EXPECT NVA OUT OF WESTERN IA FOR MUCH OF THE DAY WITH ONGOING CLOUDY
TO MOSTLY CLOUDY SKIES. SOME LIGHT SOUTHEAST SFC FLOW THIS AFTERNOON
TO HELP TEMPS MAKE IT A FEW DEGREES MILDER THAN YESTERDAY. THEN THE
UPSTREAM VORT NOTED ABOVE CURRENTLY ACRS WY WILL LOOK TO DIG ACRS
THE IA/MO BORDER BY LATE AFTERNOON AND EARLY EVENING. WITH RATHER
SHALLOW MOISTURE LAYER TRAPPED IN THE LOW LEVELS MAINLY UNDER H8
MB...THIS INCOMING WAVE MAY START TO PRODUCE SPOTTY DRIZZLE AGAIN
AS OPPOSED TO FLURRIES ACRS MO INTO CENTRAL IA...BUT AGAIN WILL BANK
ON ANY PRECIP REACHING THE SFC TO REMAIN WEST OF THE CWA LATE THIS
AFTERNOON AND INTO THE EVENING.

TONIGHT...EXPECT TEMPS TO HOLD STEADY IN THE MID TO UPPER 20S UNDER
STRATUS DECK AND CONTINUING LIGHT SOUTHEASTERLY SFC FLOW. AS THE
FIRST WEAK WAVE CONTINUES TO MOVE EAST ACRS THE SOUTH HALF OF IA
INTO IL DURING THE EVENING...THERE MAY BE A CHC FOR SOME SPOTTY LIGHT
DRIZZLE/FREEZING DRIZZLE TO BREAK OUT BUT WILL KEEP THE FCST DRY
THROUGH 06Z FOR NOW. A BETTER CHC AFTER MIDNIGHT AS THE STRONGER
WAVE ARRIVES OUT OF ALBERTA AND DIGS ACRS THE SOUTHWESTERN HALF OF
IA. MOISTURE DEPTH AND EXTENT OF LIFT STILL AT QUESTION...BUT WILL
INTRODUCE AT LEAST PATCHY LIGHT FREEZING DRIZZLE OUT OF THE
MOISTURE TRAPPED UNDER THE INVERSION ALOFT ACRS THE WESTERN CWA
AFTER MIDNIGHT. HOPEFULLY IT WILL BE SPOTTY AND LIGHT ENOUGH NOT TO
WARRANT SOME TYPE OF HEADLINE...BUT DAY SHIFT WILL HAVE TO REASSESS
AS WELL AS THE POSSIBILITY TO ADD SPOTTY CHC/S IN THE EVENING BEFORE
MIDNIGHT.    ..12..

.LONG TERM...(SATURDAY THROUGH NEXT THURSDAY)
ISSUED AT 316 AM CST FRI DEC 19 2014

THE LONG TERM WILL BEGIN WITH THE SAME CLOUDY AND DAMP REGIME WE
HAVE SEEN MANY TIMES OVER THIS PAST MONTH. TONIGHTS DRIZZLE...FOG
AND LOW CLOUDS LOOK TO REMAIN IN PLACE FOR SATURDAY THROUGH SUNDAY
NIGHT...WITH THE MAIN IMPACTS GREATLY DEPENDING ON HOURLY
TEMPERATURES. SHORT LIVED SUBSIDENCE SATURDAY BEHIND THE MID LEVEL
SHORT WAVE LATER TONIGHT WILL HOPEFULLY OFFER A LULL IN ANY
DRIZZLE...SO AFTER A MILD DAY IN THE MID TO UPPER 30S...WE WILL SET
UP FOR ANOTHER DRIZZLE/FZDZ EVENT BY SATURDAY NIGHT. THE DOMESTIC
MODELS ARE OFFERING COLD SURFACE CONDITIONS FOR SATURDAY
NIGHT...WHILE THE ECMWF IS MUCH MORE MILD. I BELIEVE THE ECMWF IS
MORE ON TARGET HERE AS THERE IS ALMOST NO REASON FOR COLD
SUBFREEZING AIR TO LINGER UNDER THIS STRATUS DECK. IN ANY
CASE...DESPITE LOWS IN THE LOWER 30S...ROADS AND SURFACES WILL NOT
BE ABLE TO RADIATE OUT SATURDAY NIGHT UNDER THE LOW CLOUDS WHICH
WILL ACTUALLY GIVE OFF LONG WAVE RADIATION TO THE SURFACES AS
WELL...LIKELY KEEPING ANY FZDZ MINIMALLY PROBLEMATIC. STILL...SINCE
WE ARE CLOSE ENOUGH TO 32 MUCH OF THE NIGHT IN THE NORTH...I WILL
MENTION IT IN THE GRIDS...BUT HOPEFULLY THIS IS NOT AN ADVISORY
EVENT. SHOULD THE ECMWF RISING TEMPERATURES BE CORRECT AS I
SUSPECT...WE SHOULD BE ABOVE FREEZING DURING THE TIME DRIZZLE OCCURS
SATURDAY NIGHT. THE DZ EVENT MAY LINGER THROUGH THE DAY SUNDAY...AND
AS MORE NOTABLE FORCING ARRIVES...IT MAY BECOME A INTERMITTENT LIGHT
RAIN IN THE NORTH...AND WILL ALLOW POPS TO BE MENTIONED AT THAT
TIME. IN THE END...IF THE DRIZZLE IS HEAVY ENOUGH...IT WILL NEED
MUCH HIGHER POPS FOR CONTINUALLY WETTING SURFACES ANYWAY.

SUNDAY NIGHT...WAA WILL BE RATHER STRONG AS THE COMPLICATED
NORTHWEST FLOW LOW PRESSURE SYSTEM ARRIVES. A SLOW MOVING SURFACE
LOW IS FORECAST NEAR IOWA...AS THE MAIN ENERGY DIVES WELL
SOUTH...CARVING OUT WHAT MAY BE INTENSE LOW PRESSURE OVER THE OHIO
VALLEY TOWARDS TUESDAY NIGHT. AS THIS OCCURS...BOUTS OF LIGHT RAIN
ARE LIKELY...EVENTUALLY CHANGING TO LIGHT SNOW BY LATER TUESDAY WHEN
THE SYSTEM BEGINS TO RAMP UP TO THE EAST. IN THE END...SUNDAY NIGHT
THROUGH MONDAY NIGHT MAY JUST BE A CONTINUATION OF THE RELATIVELY
MILD AND DAMP CONDITIONS WE HAVE BEEN QUITE FAMILIAR WITH THIS MONTH.

TUESDAY NIGHT INTO WEDNESDAY...WHILE LIGHT SNOW IS POSSIBLE DUE TO
ENERGY DIVING INTO THE RAPIDLY STRENGTHENING STORM TO THE EAST...OUT
BIGGEST SENSIBLE WEATHER WILL BE WIND...STRONG WINDS OF 20 TO 30 MPH
APPEAR LIKELY...WITH GUSTS OVER 35 POSSIBLE WEDNESDAY AFTERNOON AS
THE LOW TO THE EAST POTENTIALLY DEEPENS TO AROUND 970MB PER 00Z ECMWF

FOLLOWING THIS...AFTER A PERIOD OF COLD ADVECTION LASTING INTO
WEDNESDAY NIGHT...MODELS ARE GREATLY DIVERGENT. THE 00Z GFS OFFERS
NORTHWEST FLOW WITH NO SIGNIFICANT ARCTIC AIR...BUT LITTLE PCPN
THREATS. THE 00Z ECMWF HAS A PROGRESSIVE DEEP SYNOPTIC TROF MOVING
INTO THE LOWER ROCKIES BY DECEMBER 26...SPAWNING CYCLOGENESIS IN THE
WESTERN PLAINS. THAT SYSTEM WOULD IMPACT THE MIDWEST WITH MORE
CLOUDS/RAIN/POSSIBLE WINTER PCPN LATER ON THE 26/27. THERE IS NO
CONSISTENCY ON THIS SYSTEM FROM MODEL TO MODEL...OR IN RUN TO RUN OF ANY
MODEL...SO MENTION OF A TRACK OF THAT POSSIBLE STORM SEEMS VERY
PREMATURE AT THIS TIME.   ERVIN

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1158 AM CST FRI DEC 19 2014

BREAKS IN STRATUS WILL RESULT IN SOME PERIODS OF VFR AT
KCID...KMLI...AND KBRL THIS AFTN. LOW-LEVEL STRATOCUMULUS HAS ALREADY
FORMED IN AREAS THAT HAVE RECEIVED SUNSHINE...WHICH WILL KNOCK CIGS
DOWN TO 1500-2000 FT AGL. THIS WILL LIKELY OCCUR AT KMLI EARLY THIS
AFTN AND HOLD OFF LONGER AT KCID AND KBRL. GENERAL TREND AFTER
06Z-09Z/SATURDAY IS FOR DETERIORATING CONDITIONS TO IFR AS CIGS LOWER
TO BELOW 1000 FT AGL AND VSBYS DROP BELOW 3 SM. POTENTIAL FOR SOME
PATCHY -FZDZ TONIGHT...DID NOT MENTION IN TAFS DUE TO LOW CONFIDENCE.

&&

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

$$

SYNOPSIS...12
SHORT TERM...12
LONG TERM...ERVIN
AVIATION...UTTECH






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000
FXUS63 KDMX 191743
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1143 AM CST FRI DEC 19 2014

.SHORT TERM /TODAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

LOW LEVEL MOISTURE SURGE IS LIFTING NORTHEAST ACROSS CENTRAL IOWA
THIS MORNING. WEAK FORCING WITHIN THIS SATURATED LAYER HAS PRODUCED
A MIX OF LIGHT FREEZING DRIZZLE OR FLURRIES WITH SATURATION TOPS
CURRENTLY BETWEEN -7C AND -9C WHICH IS ON THE EDGE BETWEEN GOOD ICE
INTRODUCTION AND SUPER COOLED DROPLETS. THE SATURATION DEPTHS
DECREASE FROM THE TOP OF THE LAYER THROUGH THE MORNING AND THUS
SHOULD DECREASE THE AMOUNT OF ICE INTRODUCTION WHICH WOULD LEAD TO
MORE FREEZING DRIZZLE PROCESSES. NOT EXPECTING A WIDESPREAD IMPACT
THOUGH LOCALIZED ICY PATCHES COULD OCCUR ON ROADWAYS AND WALKWAYS.
SKY CONDITIONS WILL REMAIN CLOUDY TODAY AND WILL HOLD TEMPERATURES
IN THE 20S TO LOWER 30S ONCE AGAIN.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

WE HAVE MUCH TO DISCUSS.

THIS WEEKEND WILL BE CHARACTERIZED BY GENERAL STRATUS AND
HAZE/FOG WITHIN A BROAD WARM AIR/MOISTURE ADVECTION REGIME IN
LIGHT SOUTHERLY SURFACE FLOW. THIS WILL ALSO LEAD TO A SLOW
WARMING TREND...WITH HIGH TEMPERATURES IN THE MID 30S TO LOWER 40S
BY SUNDAY. DURING THE NIGHTTIME AND EARLY MORNING HOURS...BOTH
FROM FRIDAY NIGHT INTO SATURDAY AND FROM SATURDAY NIGHT INTO
SUNDAY...THERE WILL BE INCREASING CHANCES FOR FOG AND DRIZZLE AS
THE NEAR SURFACE CLOUD LAYER GRADUALLY SATURATES AND DEEPENS. ON
FRIDAY NIGHT THE LAYER DEPTHS ARE STILL MARGINAL FOR DRIZZLE AND
THERE IS NO DISCERNIBLE SOURCE OF LIFT TO GENERATE THIS LIGHT
PRECIPITATION. HOWEVER...EVEN EARLY THIS MORNING /FRIDAY/ AND THE
PREVIOUS NIGHT WE HAVE SEEN PATCHY FREEZING DRIZZLE AROUND THE
AREA AND THE SATURATION...WHILE SHALLOW...SEEMS EVEN BETTER ON
FRIDAY NIGHT. GIVEN THE PERSISTENCE OF THE PATTERN...HAVE OPTED TO
INCLUDE DRIZZLE ACROSS THE AREA BETWEEN ABOUT MIDNIGHT AND
SUNRISE. TEMPERATURES WILL BE BELOW FREEZING DURING THIS PERIOD SO
ANY DRIZZLE THAT DOES FORM MAY CAUSE TRAVEL
IMPACTS...HOWEVER...CONFIDENCE IN OCCURRENCE IS EASILY TOO LOW TO
WARRANT ANY HEADLINE CONSIDERATION AT THIS TIME. ON SATURDAY NIGHT
A STRONG SURGE OF THETA E ADVECTION WILL MOVE ACROSS THE
AREA...MAINLY AFTER MIDNIGHT...WITH AN ATTENDANT INCREASE IN THE
DEPTH OF THE WARM CLOUD LAYER. THIS LEADS TO A CONSIDERABLY HIGHER
CONFIDENCE IN DRIZZLE OCCURRENCE LATE SATURDAY NIGHT INTO SUNDAY.
HOWEVER...BY THEN TEMPERATURES WILL BE NEAR OR ABOVE FREEZING IN
MANY AREAS SO IT IS DIFFICULT TO DIFFERENTIATE WHERE THE DRIZZLE
WILL FREEZE AND WHERE IT IS NOT...WITH THE BEST CHANCES FOR
FREEZING DRIZZLE ACROSS THE NORTHERN HALF OR SO OF THE FORECAST
AREA. COMPLICATING THIS FURTHER...FORECAST SOUNDINGS AND
CONCEPTUAL MODELS SUGGEST THAT THE ADVECTION SURGE THAT WILL
TRIGGER DRIZZLE GENERATION MAY PUSH TEMPERATURES FROM BELOW
FREEZING TO ABOVE FREEZING AND IT IS DIFFICULT TO TELL HOW QUICKLY
THIS WILL BE REFLECTED IN SURFACE/ROAD TEMPERATURES. IN ANY
EVENT...THOSE TRAVELING THIS WEEKEND SHOULD KEEP AN EYE ON THE
FORECAST FOR UPDATES ON THE POTENTIAL FOR FREEZING DRIZZLE DURING
THE NIGHTTIME/MORNING HOURS THIS WEEKEND.

BY SUNDAY NIGHT OUR MUCH ANTICIPATED LARGER STORM SYSTEM WILL BE
APPROACHING IN THE FORM OF A 500 MB SHORTWAVE AND ASSOCIATED
SURFACE LOW PRESSURE CENTER MOVING QUICKLY SOUTHEAST ACROSS THE
DAKOTAS. AS THIS SYSTEM REACHES IOWA WE WILL SEE PRECIPITATION
BREAK OUT ACROSS THE STATE FROM WEST TO EAST...MAINLY AFTER
MIDNIGHT SUNDAY NIGHT AND INTO MONDAY. TEMPERATURES WILL BE ABOVE
FREEZING LEADING TO RAIN ACROSS MOST OF THE AREA...WITH THE
EXCEPTION BEING IN OUR FAR NORTH WHERE TEMPERATURES NEAR FREEZING
MAY LEAD TO A WINTRY MIX OF PRECIPITATION BUT WITH LITTLE TO NO
SNOW OR ICE ACCUMULATION THROUGH MONDAY. THE STACKED LOW PRESSURE
CENTER SHOULD BE LOCATED OVER NORTHERN IOWA/SOUTHERN MINNESOTA BY
MONDAY NIGHT...THEREAFTER OCCLUDING AND MOVING SLOWLY TO THE EAST.
THIS WILL LEAD TO A RAIN TO SNOW TRANSITION FROM WEST TO EAST ON
MONDAY NIGHT...FOLLOWED BY A DAY OR TWO OF LIGHT SNOW WITHIN THE
LARGE CLOUD AND PRECIP SHIELD ON THE BACKSIDE OF THE SYSTEM. WHILE
CHANCES FOR SNOWFLAKES ARE HIGH ACROSS MUCH OF THE AREA FROM
MONDAY NIGHT THROUGH TUESDAY...GIVEN THAT THE LOW WILL BE SLOWLY
FILLING AND MOVING AWAY THE QPF IS FAIRLY LOW AND ANY SNOWFALL
AMOUNTS WILL PROBABLY BE LIGHT. THIS MAY STILL PRODUCE SOME TRAVEL
IMPACTS BUT THESE ARE VERY DIFFICULT TO DIAGNOSE AT THIS RANGE. WE
WILL CONTINUE TO CLOSELY MONITOR THIS SYSTEM IN THE COMING DAYS.

THE LIGHT SNOW TRAILING THE EARLY WEEK SYSTEM SHOULD CLEAR OUT OF
THE AREA ROUGHLY AROUND TUESDAY NIGHT OR POSSIBLY WEDNESDAY. IT
DOES APPEAR THAT ANOTHER STORM SYSTEM WILL APPROACH OUR AREA FROM
THE WEST LATE NEXT WEEK...JUST BEYOND THE CURRENT SEVEN DAY
FORECAST...WITH SOME CHANCE FOR PRECIPITATION POSSIBLY IN THE FORM
OF ADDITIONAL SNOWFALL.

&&

.AVIATION...19/18Z
ISSUED AT 1143 AM CST FRI DEC 19 2014

LOW CIGS CONTINUE TO BE AN ISSUE WITH SEVERAL LOCATIONS REPORTING
IFR CIGS AND MVFR VSBYS ACROSS THE AREA. LOW CIGS MAY LIFT SOME
THIS AFTERNOON TO MVFR...BUT ARE EXPECTED TO DROP AGAIN OVERNIGHT
TONIGHT. KOTM REMAINS VFR...BUT MAY LOWER THROUGHOUT THE PERIOD.
WINDS WILL REMAIN LIGHT OUT OF THE SOUTHEAST. OTHER ISSUE IS THE
POTENTIAL FOR VERY LIGHT FZDZ OR FLURRIES TONIGHT INTO EARLY
SATURDAY. STILL SOME UNCERTAINTY...BUT GIVEN THE CONDITIONS
PRODUCED SOME LIGHT PRECIP THIS MORNING AND LOOK EVEN BETTER
TONIGHT WILL LIKELY HAVE TO ADD A MENTION IN IN SUBSEQUENT TAF
ISSUANCES.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...BEERENDS




000
FXUS63 KDMX 191743
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1143 AM CST FRI DEC 19 2014

.SHORT TERM /TODAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

LOW LEVEL MOISTURE SURGE IS LIFTING NORTHEAST ACROSS CENTRAL IOWA
THIS MORNING. WEAK FORCING WITHIN THIS SATURATED LAYER HAS PRODUCED
A MIX OF LIGHT FREEZING DRIZZLE OR FLURRIES WITH SATURATION TOPS
CURRENTLY BETWEEN -7C AND -9C WHICH IS ON THE EDGE BETWEEN GOOD ICE
INTRODUCTION AND SUPER COOLED DROPLETS. THE SATURATION DEPTHS
DECREASE FROM THE TOP OF THE LAYER THROUGH THE MORNING AND THUS
SHOULD DECREASE THE AMOUNT OF ICE INTRODUCTION WHICH WOULD LEAD TO
MORE FREEZING DRIZZLE PROCESSES. NOT EXPECTING A WIDESPREAD IMPACT
THOUGH LOCALIZED ICY PATCHES COULD OCCUR ON ROADWAYS AND WALKWAYS.
SKY CONDITIONS WILL REMAIN CLOUDY TODAY AND WILL HOLD TEMPERATURES
IN THE 20S TO LOWER 30S ONCE AGAIN.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

WE HAVE MUCH TO DISCUSS.

THIS WEEKEND WILL BE CHARACTERIZED BY GENERAL STRATUS AND
HAZE/FOG WITHIN A BROAD WARM AIR/MOISTURE ADVECTION REGIME IN
LIGHT SOUTHERLY SURFACE FLOW. THIS WILL ALSO LEAD TO A SLOW
WARMING TREND...WITH HIGH TEMPERATURES IN THE MID 30S TO LOWER 40S
BY SUNDAY. DURING THE NIGHTTIME AND EARLY MORNING HOURS...BOTH
FROM FRIDAY NIGHT INTO SATURDAY AND FROM SATURDAY NIGHT INTO
SUNDAY...THERE WILL BE INCREASING CHANCES FOR FOG AND DRIZZLE AS
THE NEAR SURFACE CLOUD LAYER GRADUALLY SATURATES AND DEEPENS. ON
FRIDAY NIGHT THE LAYER DEPTHS ARE STILL MARGINAL FOR DRIZZLE AND
THERE IS NO DISCERNIBLE SOURCE OF LIFT TO GENERATE THIS LIGHT
PRECIPITATION. HOWEVER...EVEN EARLY THIS MORNING /FRIDAY/ AND THE
PREVIOUS NIGHT WE HAVE SEEN PATCHY FREEZING DRIZZLE AROUND THE
AREA AND THE SATURATION...WHILE SHALLOW...SEEMS EVEN BETTER ON
FRIDAY NIGHT. GIVEN THE PERSISTENCE OF THE PATTERN...HAVE OPTED TO
INCLUDE DRIZZLE ACROSS THE AREA BETWEEN ABOUT MIDNIGHT AND
SUNRISE. TEMPERATURES WILL BE BELOW FREEZING DURING THIS PERIOD SO
ANY DRIZZLE THAT DOES FORM MAY CAUSE TRAVEL
IMPACTS...HOWEVER...CONFIDENCE IN OCCURRENCE IS EASILY TOO LOW TO
WARRANT ANY HEADLINE CONSIDERATION AT THIS TIME. ON SATURDAY NIGHT
A STRONG SURGE OF THETA E ADVECTION WILL MOVE ACROSS THE
AREA...MAINLY AFTER MIDNIGHT...WITH AN ATTENDANT INCREASE IN THE
DEPTH OF THE WARM CLOUD LAYER. THIS LEADS TO A CONSIDERABLY HIGHER
CONFIDENCE IN DRIZZLE OCCURRENCE LATE SATURDAY NIGHT INTO SUNDAY.
HOWEVER...BY THEN TEMPERATURES WILL BE NEAR OR ABOVE FREEZING IN
MANY AREAS SO IT IS DIFFICULT TO DIFFERENTIATE WHERE THE DRIZZLE
WILL FREEZE AND WHERE IT IS NOT...WITH THE BEST CHANCES FOR
FREEZING DRIZZLE ACROSS THE NORTHERN HALF OR SO OF THE FORECAST
AREA. COMPLICATING THIS FURTHER...FORECAST SOUNDINGS AND
CONCEPTUAL MODELS SUGGEST THAT THE ADVECTION SURGE THAT WILL
TRIGGER DRIZZLE GENERATION MAY PUSH TEMPERATURES FROM BELOW
FREEZING TO ABOVE FREEZING AND IT IS DIFFICULT TO TELL HOW QUICKLY
THIS WILL BE REFLECTED IN SURFACE/ROAD TEMPERATURES. IN ANY
EVENT...THOSE TRAVELING THIS WEEKEND SHOULD KEEP AN EYE ON THE
FORECAST FOR UPDATES ON THE POTENTIAL FOR FREEZING DRIZZLE DURING
THE NIGHTTIME/MORNING HOURS THIS WEEKEND.

BY SUNDAY NIGHT OUR MUCH ANTICIPATED LARGER STORM SYSTEM WILL BE
APPROACHING IN THE FORM OF A 500 MB SHORTWAVE AND ASSOCIATED
SURFACE LOW PRESSURE CENTER MOVING QUICKLY SOUTHEAST ACROSS THE
DAKOTAS. AS THIS SYSTEM REACHES IOWA WE WILL SEE PRECIPITATION
BREAK OUT ACROSS THE STATE FROM WEST TO EAST...MAINLY AFTER
MIDNIGHT SUNDAY NIGHT AND INTO MONDAY. TEMPERATURES WILL BE ABOVE
FREEZING LEADING TO RAIN ACROSS MOST OF THE AREA...WITH THE
EXCEPTION BEING IN OUR FAR NORTH WHERE TEMPERATURES NEAR FREEZING
MAY LEAD TO A WINTRY MIX OF PRECIPITATION BUT WITH LITTLE TO NO
SNOW OR ICE ACCUMULATION THROUGH MONDAY. THE STACKED LOW PRESSURE
CENTER SHOULD BE LOCATED OVER NORTHERN IOWA/SOUTHERN MINNESOTA BY
MONDAY NIGHT...THEREAFTER OCCLUDING AND MOVING SLOWLY TO THE EAST.
THIS WILL LEAD TO A RAIN TO SNOW TRANSITION FROM WEST TO EAST ON
MONDAY NIGHT...FOLLOWED BY A DAY OR TWO OF LIGHT SNOW WITHIN THE
LARGE CLOUD AND PRECIP SHIELD ON THE BACKSIDE OF THE SYSTEM. WHILE
CHANCES FOR SNOWFLAKES ARE HIGH ACROSS MUCH OF THE AREA FROM
MONDAY NIGHT THROUGH TUESDAY...GIVEN THAT THE LOW WILL BE SLOWLY
FILLING AND MOVING AWAY THE QPF IS FAIRLY LOW AND ANY SNOWFALL
AMOUNTS WILL PROBABLY BE LIGHT. THIS MAY STILL PRODUCE SOME TRAVEL
IMPACTS BUT THESE ARE VERY DIFFICULT TO DIAGNOSE AT THIS RANGE. WE
WILL CONTINUE TO CLOSELY MONITOR THIS SYSTEM IN THE COMING DAYS.

THE LIGHT SNOW TRAILING THE EARLY WEEK SYSTEM SHOULD CLEAR OUT OF
THE AREA ROUGHLY AROUND TUESDAY NIGHT OR POSSIBLY WEDNESDAY. IT
DOES APPEAR THAT ANOTHER STORM SYSTEM WILL APPROACH OUR AREA FROM
THE WEST LATE NEXT WEEK...JUST BEYOND THE CURRENT SEVEN DAY
FORECAST...WITH SOME CHANCE FOR PRECIPITATION POSSIBLY IN THE FORM
OF ADDITIONAL SNOWFALL.

&&

.AVIATION...19/18Z
ISSUED AT 1143 AM CST FRI DEC 19 2014

LOW CIGS CONTINUE TO BE AN ISSUE WITH SEVERAL LOCATIONS REPORTING
IFR CIGS AND MVFR VSBYS ACROSS THE AREA. LOW CIGS MAY LIFT SOME
THIS AFTERNOON TO MVFR...BUT ARE EXPECTED TO DROP AGAIN OVERNIGHT
TONIGHT. KOTM REMAINS VFR...BUT MAY LOWER THROUGHOUT THE PERIOD.
WINDS WILL REMAIN LIGHT OUT OF THE SOUTHEAST. OTHER ISSUE IS THE
POTENTIAL FOR VERY LIGHT FZDZ OR FLURRIES TONIGHT INTO EARLY
SATURDAY. STILL SOME UNCERTAINTY...BUT GIVEN THE CONDITIONS
PRODUCED SOME LIGHT PRECIP THIS MORNING AND LOOK EVEN BETTER
TONIGHT WILL LIKELY HAVE TO ADD A MENTION IN IN SUBSEQUENT TAF
ISSUANCES.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...BEERENDS




000
FXUS63 KDMX 191743
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1143 AM CST FRI DEC 19 2014

.SHORT TERM /TODAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

LOW LEVEL MOISTURE SURGE IS LIFTING NORTHEAST ACROSS CENTRAL IOWA
THIS MORNING. WEAK FORCING WITHIN THIS SATURATED LAYER HAS PRODUCED
A MIX OF LIGHT FREEZING DRIZZLE OR FLURRIES WITH SATURATION TOPS
CURRENTLY BETWEEN -7C AND -9C WHICH IS ON THE EDGE BETWEEN GOOD ICE
INTRODUCTION AND SUPER COOLED DROPLETS. THE SATURATION DEPTHS
DECREASE FROM THE TOP OF THE LAYER THROUGH THE MORNING AND THUS
SHOULD DECREASE THE AMOUNT OF ICE INTRODUCTION WHICH WOULD LEAD TO
MORE FREEZING DRIZZLE PROCESSES. NOT EXPECTING A WIDESPREAD IMPACT
THOUGH LOCALIZED ICY PATCHES COULD OCCUR ON ROADWAYS AND WALKWAYS.
SKY CONDITIONS WILL REMAIN CLOUDY TODAY AND WILL HOLD TEMPERATURES
IN THE 20S TO LOWER 30S ONCE AGAIN.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

WE HAVE MUCH TO DISCUSS.

THIS WEEKEND WILL BE CHARACTERIZED BY GENERAL STRATUS AND
HAZE/FOG WITHIN A BROAD WARM AIR/MOISTURE ADVECTION REGIME IN
LIGHT SOUTHERLY SURFACE FLOW. THIS WILL ALSO LEAD TO A SLOW
WARMING TREND...WITH HIGH TEMPERATURES IN THE MID 30S TO LOWER 40S
BY SUNDAY. DURING THE NIGHTTIME AND EARLY MORNING HOURS...BOTH
FROM FRIDAY NIGHT INTO SATURDAY AND FROM SATURDAY NIGHT INTO
SUNDAY...THERE WILL BE INCREASING CHANCES FOR FOG AND DRIZZLE AS
THE NEAR SURFACE CLOUD LAYER GRADUALLY SATURATES AND DEEPENS. ON
FRIDAY NIGHT THE LAYER DEPTHS ARE STILL MARGINAL FOR DRIZZLE AND
THERE IS NO DISCERNIBLE SOURCE OF LIFT TO GENERATE THIS LIGHT
PRECIPITATION. HOWEVER...EVEN EARLY THIS MORNING /FRIDAY/ AND THE
PREVIOUS NIGHT WE HAVE SEEN PATCHY FREEZING DRIZZLE AROUND THE
AREA AND THE SATURATION...WHILE SHALLOW...SEEMS EVEN BETTER ON
FRIDAY NIGHT. GIVEN THE PERSISTENCE OF THE PATTERN...HAVE OPTED TO
INCLUDE DRIZZLE ACROSS THE AREA BETWEEN ABOUT MIDNIGHT AND
SUNRISE. TEMPERATURES WILL BE BELOW FREEZING DURING THIS PERIOD SO
ANY DRIZZLE THAT DOES FORM MAY CAUSE TRAVEL
IMPACTS...HOWEVER...CONFIDENCE IN OCCURRENCE IS EASILY TOO LOW TO
WARRANT ANY HEADLINE CONSIDERATION AT THIS TIME. ON SATURDAY NIGHT
A STRONG SURGE OF THETA E ADVECTION WILL MOVE ACROSS THE
AREA...MAINLY AFTER MIDNIGHT...WITH AN ATTENDANT INCREASE IN THE
DEPTH OF THE WARM CLOUD LAYER. THIS LEADS TO A CONSIDERABLY HIGHER
CONFIDENCE IN DRIZZLE OCCURRENCE LATE SATURDAY NIGHT INTO SUNDAY.
HOWEVER...BY THEN TEMPERATURES WILL BE NEAR OR ABOVE FREEZING IN
MANY AREAS SO IT IS DIFFICULT TO DIFFERENTIATE WHERE THE DRIZZLE
WILL FREEZE AND WHERE IT IS NOT...WITH THE BEST CHANCES FOR
FREEZING DRIZZLE ACROSS THE NORTHERN HALF OR SO OF THE FORECAST
AREA. COMPLICATING THIS FURTHER...FORECAST SOUNDINGS AND
CONCEPTUAL MODELS SUGGEST THAT THE ADVECTION SURGE THAT WILL
TRIGGER DRIZZLE GENERATION MAY PUSH TEMPERATURES FROM BELOW
FREEZING TO ABOVE FREEZING AND IT IS DIFFICULT TO TELL HOW QUICKLY
THIS WILL BE REFLECTED IN SURFACE/ROAD TEMPERATURES. IN ANY
EVENT...THOSE TRAVELING THIS WEEKEND SHOULD KEEP AN EYE ON THE
FORECAST FOR UPDATES ON THE POTENTIAL FOR FREEZING DRIZZLE DURING
THE NIGHTTIME/MORNING HOURS THIS WEEKEND.

BY SUNDAY NIGHT OUR MUCH ANTICIPATED LARGER STORM SYSTEM WILL BE
APPROACHING IN THE FORM OF A 500 MB SHORTWAVE AND ASSOCIATED
SURFACE LOW PRESSURE CENTER MOVING QUICKLY SOUTHEAST ACROSS THE
DAKOTAS. AS THIS SYSTEM REACHES IOWA WE WILL SEE PRECIPITATION
BREAK OUT ACROSS THE STATE FROM WEST TO EAST...MAINLY AFTER
MIDNIGHT SUNDAY NIGHT AND INTO MONDAY. TEMPERATURES WILL BE ABOVE
FREEZING LEADING TO RAIN ACROSS MOST OF THE AREA...WITH THE
EXCEPTION BEING IN OUR FAR NORTH WHERE TEMPERATURES NEAR FREEZING
MAY LEAD TO A WINTRY MIX OF PRECIPITATION BUT WITH LITTLE TO NO
SNOW OR ICE ACCUMULATION THROUGH MONDAY. THE STACKED LOW PRESSURE
CENTER SHOULD BE LOCATED OVER NORTHERN IOWA/SOUTHERN MINNESOTA BY
MONDAY NIGHT...THEREAFTER OCCLUDING AND MOVING SLOWLY TO THE EAST.
THIS WILL LEAD TO A RAIN TO SNOW TRANSITION FROM WEST TO EAST ON
MONDAY NIGHT...FOLLOWED BY A DAY OR TWO OF LIGHT SNOW WITHIN THE
LARGE CLOUD AND PRECIP SHIELD ON THE BACKSIDE OF THE SYSTEM. WHILE
CHANCES FOR SNOWFLAKES ARE HIGH ACROSS MUCH OF THE AREA FROM
MONDAY NIGHT THROUGH TUESDAY...GIVEN THAT THE LOW WILL BE SLOWLY
FILLING AND MOVING AWAY THE QPF IS FAIRLY LOW AND ANY SNOWFALL
AMOUNTS WILL PROBABLY BE LIGHT. THIS MAY STILL PRODUCE SOME TRAVEL
IMPACTS BUT THESE ARE VERY DIFFICULT TO DIAGNOSE AT THIS RANGE. WE
WILL CONTINUE TO CLOSELY MONITOR THIS SYSTEM IN THE COMING DAYS.

THE LIGHT SNOW TRAILING THE EARLY WEEK SYSTEM SHOULD CLEAR OUT OF
THE AREA ROUGHLY AROUND TUESDAY NIGHT OR POSSIBLY WEDNESDAY. IT
DOES APPEAR THAT ANOTHER STORM SYSTEM WILL APPROACH OUR AREA FROM
THE WEST LATE NEXT WEEK...JUST BEYOND THE CURRENT SEVEN DAY
FORECAST...WITH SOME CHANCE FOR PRECIPITATION POSSIBLY IN THE FORM
OF ADDITIONAL SNOWFALL.

&&

.AVIATION...19/18Z
ISSUED AT 1143 AM CST FRI DEC 19 2014

LOW CIGS CONTINUE TO BE AN ISSUE WITH SEVERAL LOCATIONS REPORTING
IFR CIGS AND MVFR VSBYS ACROSS THE AREA. LOW CIGS MAY LIFT SOME
THIS AFTERNOON TO MVFR...BUT ARE EXPECTED TO DROP AGAIN OVERNIGHT
TONIGHT. KOTM REMAINS VFR...BUT MAY LOWER THROUGHOUT THE PERIOD.
WINDS WILL REMAIN LIGHT OUT OF THE SOUTHEAST. OTHER ISSUE IS THE
POTENTIAL FOR VERY LIGHT FZDZ OR FLURRIES TONIGHT INTO EARLY
SATURDAY. STILL SOME UNCERTAINTY...BUT GIVEN THE CONDITIONS
PRODUCED SOME LIGHT PRECIP THIS MORNING AND LOOK EVEN BETTER
TONIGHT WILL LIKELY HAVE TO ADD A MENTION IN IN SUBSEQUENT TAF
ISSUANCES.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...BEERENDS




000
FXUS63 KDMX 191743
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1143 AM CST FRI DEC 19 2014

.SHORT TERM /TODAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

LOW LEVEL MOISTURE SURGE IS LIFTING NORTHEAST ACROSS CENTRAL IOWA
THIS MORNING. WEAK FORCING WITHIN THIS SATURATED LAYER HAS PRODUCED
A MIX OF LIGHT FREEZING DRIZZLE OR FLURRIES WITH SATURATION TOPS
CURRENTLY BETWEEN -7C AND -9C WHICH IS ON THE EDGE BETWEEN GOOD ICE
INTRODUCTION AND SUPER COOLED DROPLETS. THE SATURATION DEPTHS
DECREASE FROM THE TOP OF THE LAYER THROUGH THE MORNING AND THUS
SHOULD DECREASE THE AMOUNT OF ICE INTRODUCTION WHICH WOULD LEAD TO
MORE FREEZING DRIZZLE PROCESSES. NOT EXPECTING A WIDESPREAD IMPACT
THOUGH LOCALIZED ICY PATCHES COULD OCCUR ON ROADWAYS AND WALKWAYS.
SKY CONDITIONS WILL REMAIN CLOUDY TODAY AND WILL HOLD TEMPERATURES
IN THE 20S TO LOWER 30S ONCE AGAIN.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

WE HAVE MUCH TO DISCUSS.

THIS WEEKEND WILL BE CHARACTERIZED BY GENERAL STRATUS AND
HAZE/FOG WITHIN A BROAD WARM AIR/MOISTURE ADVECTION REGIME IN
LIGHT SOUTHERLY SURFACE FLOW. THIS WILL ALSO LEAD TO A SLOW
WARMING TREND...WITH HIGH TEMPERATURES IN THE MID 30S TO LOWER 40S
BY SUNDAY. DURING THE NIGHTTIME AND EARLY MORNING HOURS...BOTH
FROM FRIDAY NIGHT INTO SATURDAY AND FROM SATURDAY NIGHT INTO
SUNDAY...THERE WILL BE INCREASING CHANCES FOR FOG AND DRIZZLE AS
THE NEAR SURFACE CLOUD LAYER GRADUALLY SATURATES AND DEEPENS. ON
FRIDAY NIGHT THE LAYER DEPTHS ARE STILL MARGINAL FOR DRIZZLE AND
THERE IS NO DISCERNIBLE SOURCE OF LIFT TO GENERATE THIS LIGHT
PRECIPITATION. HOWEVER...EVEN EARLY THIS MORNING /FRIDAY/ AND THE
PREVIOUS NIGHT WE HAVE SEEN PATCHY FREEZING DRIZZLE AROUND THE
AREA AND THE SATURATION...WHILE SHALLOW...SEEMS EVEN BETTER ON
FRIDAY NIGHT. GIVEN THE PERSISTENCE OF THE PATTERN...HAVE OPTED TO
INCLUDE DRIZZLE ACROSS THE AREA BETWEEN ABOUT MIDNIGHT AND
SUNRISE. TEMPERATURES WILL BE BELOW FREEZING DURING THIS PERIOD SO
ANY DRIZZLE THAT DOES FORM MAY CAUSE TRAVEL
IMPACTS...HOWEVER...CONFIDENCE IN OCCURRENCE IS EASILY TOO LOW TO
WARRANT ANY HEADLINE CONSIDERATION AT THIS TIME. ON SATURDAY NIGHT
A STRONG SURGE OF THETA E ADVECTION WILL MOVE ACROSS THE
AREA...MAINLY AFTER MIDNIGHT...WITH AN ATTENDANT INCREASE IN THE
DEPTH OF THE WARM CLOUD LAYER. THIS LEADS TO A CONSIDERABLY HIGHER
CONFIDENCE IN DRIZZLE OCCURRENCE LATE SATURDAY NIGHT INTO SUNDAY.
HOWEVER...BY THEN TEMPERATURES WILL BE NEAR OR ABOVE FREEZING IN
MANY AREAS SO IT IS DIFFICULT TO DIFFERENTIATE WHERE THE DRIZZLE
WILL FREEZE AND WHERE IT IS NOT...WITH THE BEST CHANCES FOR
FREEZING DRIZZLE ACROSS THE NORTHERN HALF OR SO OF THE FORECAST
AREA. COMPLICATING THIS FURTHER...FORECAST SOUNDINGS AND
CONCEPTUAL MODELS SUGGEST THAT THE ADVECTION SURGE THAT WILL
TRIGGER DRIZZLE GENERATION MAY PUSH TEMPERATURES FROM BELOW
FREEZING TO ABOVE FREEZING AND IT IS DIFFICULT TO TELL HOW QUICKLY
THIS WILL BE REFLECTED IN SURFACE/ROAD TEMPERATURES. IN ANY
EVENT...THOSE TRAVELING THIS WEEKEND SHOULD KEEP AN EYE ON THE
FORECAST FOR UPDATES ON THE POTENTIAL FOR FREEZING DRIZZLE DURING
THE NIGHTTIME/MORNING HOURS THIS WEEKEND.

BY SUNDAY NIGHT OUR MUCH ANTICIPATED LARGER STORM SYSTEM WILL BE
APPROACHING IN THE FORM OF A 500 MB SHORTWAVE AND ASSOCIATED
SURFACE LOW PRESSURE CENTER MOVING QUICKLY SOUTHEAST ACROSS THE
DAKOTAS. AS THIS SYSTEM REACHES IOWA WE WILL SEE PRECIPITATION
BREAK OUT ACROSS THE STATE FROM WEST TO EAST...MAINLY AFTER
MIDNIGHT SUNDAY NIGHT AND INTO MONDAY. TEMPERATURES WILL BE ABOVE
FREEZING LEADING TO RAIN ACROSS MOST OF THE AREA...WITH THE
EXCEPTION BEING IN OUR FAR NORTH WHERE TEMPERATURES NEAR FREEZING
MAY LEAD TO A WINTRY MIX OF PRECIPITATION BUT WITH LITTLE TO NO
SNOW OR ICE ACCUMULATION THROUGH MONDAY. THE STACKED LOW PRESSURE
CENTER SHOULD BE LOCATED OVER NORTHERN IOWA/SOUTHERN MINNESOTA BY
MONDAY NIGHT...THEREAFTER OCCLUDING AND MOVING SLOWLY TO THE EAST.
THIS WILL LEAD TO A RAIN TO SNOW TRANSITION FROM WEST TO EAST ON
MONDAY NIGHT...FOLLOWED BY A DAY OR TWO OF LIGHT SNOW WITHIN THE
LARGE CLOUD AND PRECIP SHIELD ON THE BACKSIDE OF THE SYSTEM. WHILE
CHANCES FOR SNOWFLAKES ARE HIGH ACROSS MUCH OF THE AREA FROM
MONDAY NIGHT THROUGH TUESDAY...GIVEN THAT THE LOW WILL BE SLOWLY
FILLING AND MOVING AWAY THE QPF IS FAIRLY LOW AND ANY SNOWFALL
AMOUNTS WILL PROBABLY BE LIGHT. THIS MAY STILL PRODUCE SOME TRAVEL
IMPACTS BUT THESE ARE VERY DIFFICULT TO DIAGNOSE AT THIS RANGE. WE
WILL CONTINUE TO CLOSELY MONITOR THIS SYSTEM IN THE COMING DAYS.

THE LIGHT SNOW TRAILING THE EARLY WEEK SYSTEM SHOULD CLEAR OUT OF
THE AREA ROUGHLY AROUND TUESDAY NIGHT OR POSSIBLY WEDNESDAY. IT
DOES APPEAR THAT ANOTHER STORM SYSTEM WILL APPROACH OUR AREA FROM
THE WEST LATE NEXT WEEK...JUST BEYOND THE CURRENT SEVEN DAY
FORECAST...WITH SOME CHANCE FOR PRECIPITATION POSSIBLY IN THE FORM
OF ADDITIONAL SNOWFALL.

&&

.AVIATION...19/18Z
ISSUED AT 1143 AM CST FRI DEC 19 2014

LOW CIGS CONTINUE TO BE AN ISSUE WITH SEVERAL LOCATIONS REPORTING
IFR CIGS AND MVFR VSBYS ACROSS THE AREA. LOW CIGS MAY LIFT SOME
THIS AFTERNOON TO MVFR...BUT ARE EXPECTED TO DROP AGAIN OVERNIGHT
TONIGHT. KOTM REMAINS VFR...BUT MAY LOWER THROUGHOUT THE PERIOD.
WINDS WILL REMAIN LIGHT OUT OF THE SOUTHEAST. OTHER ISSUE IS THE
POTENTIAL FOR VERY LIGHT FZDZ OR FLURRIES TONIGHT INTO EARLY
SATURDAY. STILL SOME UNCERTAINTY...BUT GIVEN THE CONDITIONS
PRODUCED SOME LIGHT PRECIP THIS MORNING AND LOOK EVEN BETTER
TONIGHT WILL LIKELY HAVE TO ADD A MENTION IN IN SUBSEQUENT TAF
ISSUANCES.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...BEERENDS




000
FXUS63 KDVN 191149
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
549 AM CST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 316 AM CST FRI DEC 19 2014

LATEST SFC ANALYSIS WAS INDICATING LARGE RIDGE AXIS HOLDING FIRM
FROM ACRS ONTARIO NORTH OF LK SUPERIOR...ALL THE WAY DOWN INTO THE
MID TO LOWER MS RVR VALLEY. LIGHT LLVL RETURN FLOW PATTERN TO THE
WEST OF IT ACRS THE CENTRAL AND NORTHERN PLAINS. EXTENSIVE STRATUS
DECK UNDER THE WEST HALF OF THE RIDGE AND INTO THE EASTERN PLAINS
IN RETURN FLOW INTERACTION ZONE...OPEN SKY SWATH FROM SOUTHWEST
OF DBQ SOUTHEASTWARD THRU THE QUAD CITES/EASTERN I80 CORRIDOR
WILL LOOK TO FILL BACK IN EARLY THIS MORNING. ALOFT...00Z UPPER
AIR ANALYSIS AND CURRENT WATER VAPOR LOOP INDICATED A VORT WING
MOVING ACRS EASTERN SD INTO SOUTHEASTERN MN...TAILING DOWN ACRS
CENTRAL INTO EASTERN IA ATTM. THIS FEATURE IS PRODUCING LIGHT SNOW
ACRS MN...AND MAY BE INDUCING THE PATCHY LIGHT FREEZING DRIZZLE
CURRENTLY OUT ACRS CENTRAL IA. NEG VORTICITY IS MOVING OUT OF EASTERN
NEB INTO WESTERN IA BEHIND THIS MAIN VORT. A FURTHER UPSTREAM VORT
NOTED ACRS WY...AND A MORE VIGOROUS VORT MAX NOTED ACRS SOUTHERN
ALBERTA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST FRI DEC 19 2014

TODAY...BULK OF HIRES MODELS SUGGEST HIGH PRESSURE COMPLEX TO
HAVE IT/S EFFECT THIS MORNING MAINTAINING HIGHER CLOUD CIGS FOR
AWHILE...BEFORE AXIS STARTS TO SLIDE EASTWARD MIDDAY INTO THE
AFTERNOON ALLOWING THE LOWER DECK OUT WEST TO SEEP EASTWARD. AREA
OF LIGHT DRIZZLE/FREEZING DRIZZLE ACRS CENTRAL IA MOVING
NORTHEASTWARD AND MAY GET CLOSE TO THE NORTHWESTERN PORTION OF THE
CWA THIS MORNING...BUT WILL BANK ON DIURNAL EFFECTS AND THE RIDGE
STILL IN PLACE TO DEFLECT/EAT AWAY AT THIS PROCESS AND KEEP THE
DRIZZLE JUST TO THE WEST AND NORTHWEST OF THE CWA THIS MORNING...
ALTHOUGH IT WILL BE CLOSE AND WILL HAVE TO WATCH FOR UPDATES. THEN
EXPECT NVA OUT OF WESTERN IA FOR MUCH OF THE DAY WITH ONGOING CLOUDY
TO MOSTLY CLOUDY SKIES. SOME LIGHT SOUTHEAST SFC FLOW THIS AFTERNOON
TO HELP TEMPS MAKE IT A FEW DEGREES MILDER THAN YESTERDAY. THEN THE
UPSTREAM VORT NOTED ABOVE CURRENTLY ACRS WY WILL LOOK TO DIG ACRS
THE IA/MO BORDER BY LATE AFTERNOON AND EARLY EVENING. WITH RATHER
SHALLOW MOISTURE LAYER TRAPPED IN THE LOW LEVELS MAINLY UNDER H8
MB...THIS INCOMING WAVE MAY START TO PRODUCE SPOTTY DRIZZLE AGAIN
AS OPPOSED TO FLURRIES ACRS MO INTO CENTRAL IA...BUT AGAIN WILL BANK
ON ANY PRECIP REACHING THE SFC TO REMAIN WEST OF THE CWA LATE THIS
AFTERNOON AND INTO THE EVENING.

TONIGHT...EXPECT TEMPS TO HOLD STEADY IN THE MID TO UPPER 20S UNDER
STRATUS DECK AND CONTINUING LIGHT SOUTHEASTERLY SFC FLOW. AS THE
FIRST WEAK WAVE CONTINUES TO MOVE EAST ACRS THE SOUTH HALF OF IA
INTO IL DURING THE EVENING...THERE MAY BE A CHC FOR SOME SPOTTY LIGHT
DRIZZLE/FREEZING DRIZZLE TO BREAK OUT BUT WILL KEEP THE FCST DRY
THROUGH 06Z FOR NOW. A BETTER CHC AFTER MIDNIGHT AS THE STRONGER
WAVE ARRIVES OUT OF ALBERTA AND DIGS ACRS THE SOUTHWESTERN HALF OF
IA. MOISTURE DEPTH AND EXTENT OF LIFT STILL AT QUESTION...BUT WILL
INTRODUCE AT LEAST PATCHY LIGHT FREEZING DRIZZLE OUT OF THE
MOISTURE TRAPPED UNDER THE INVERSION ALOFT ACRS THE WESTERN CWA
AFTER MIDNIGHT. HOPEFULLY IT WILL BE SPOTTY AND LIGHT ENOUGH NOT TO
WARRANT SOME TYPE OF HEADLINE...BUT DAY SHIFT WILL HAVE TO REASSESS
AS WELL AS THE POSSIBILITY TO ADD SPOTTY CHC/S IN THE EVENING BEFORE
MIDNIGHT.    ..12..

.LONG TERM...(SATURDAY THROUGH NEXT THURSDAY)
ISSUED AT 316 AM CST FRI DEC 19 2014

THE LONG TERM WILL BEGIN WITH THE SAME CLOUDY AND DAMP REGIME WE
HAVE SEEN MANY TIMES OVER THIS PAST MONTH. TONIGHTS DRIZZLE...FOG
AND LOW CLOUDS LOOK TO REMAIN IN PLACE FOR SATURDAY THROUGH SUNDAY
NIGHT...WITH THE MAIN IMPACTS GREATLY DEPENDING ON HOURLY
TEMPERATURES. SHORT LIVED SUBSIDENCE SATURDAY BEHIND THE MID LEVEL
SHORT WAVE LATER TONIGHT WILL HOPEFULLY OFFER A LULL IN ANY
DRIZZLE...SO AFTER A MILD DAY IN THE MID TO UPPER 30S...WE WILL SET
UP FOR ANOTHER DRIZZLE/FZDZ EVENT BY SATURDAY NIGHT. THE DOMESTIC
MODELS ARE OFFERING COLD SURFACE CONDITIONS FOR SATURDAY
NIGHT...WHILE THE ECMWF IS MUCH MORE MILD. I BELIEVE THE ECMWF IS
MORE ON TARGET HERE AS THERE IS ALMOST NO REASON FOR COLD
SUBFREEZING AIR TO LINGER UNDER THIS STRATUS DECK. IN ANY
CASE...DESPITE LOWS IN THE LOWER 30S...ROADS AND SURFACES WILL NOT
BE ABLE TO RADIATE OUT SATURDAY NIGHT UNDER THE LOW CLOUDS WHICH
WILL ACTUALLY GIVE OFF LONG WAVE RADIATION TO THE SURFACES AS
WELL...LIKELY KEEPING ANY FZDZ MINIMALLY PROBLEMATIC. STILL...SINCE
WE ARE CLOSE ENOUGH TO 32 MUCH OF THE NIGHT IN THE NORTH...I WILL
MENTION IT IN THE GRIDS...BUT HOPEFULLY THIS IS NOT AN ADVISORY
EVENT. SHOULD THE ECMWF RISING TEMPERATURES BE CORRECT AS I
SUSPECT...WE SHOULD BE ABOVE FREEZING DURING THE TIME DRIZZLE OCCURS
SATURDAY NIGHT. THE DZ EVENT MAY LINGER THROUGH THE DAY SUNDAY...AND
AS MORE NOTABLE FORCING ARRIVES...IT MAY BECOME A INTERMITTENT LIGHT
RAIN IN THE NORTH...AND WILL ALLOW POPS TO BE MENTIONED AT THAT
TIME. IN THE END...IF THE DRIZZLE IS HEAVY ENOUGH...IT WILL NEED
MUCH HIGHER POPS FOR CONTINUALLY WETTING SURFACES ANYWAY.

SUNDAY NIGHT...WAA WILL BE RATHER STRONG AS THE COMPLICATED
NORTHWEST FLOW LOW PRESSURE SYSTEM ARRIVES. A SLOW MOVING SURFACE
LOW IS FORECAST NEAR IOWA...AS THE MAIN ENERGY DIVES WELL
SOUTH...CARVING OUT WHAT MAY BE INTENSE LOW PRESSURE OVER THE OHIO
VALLEY TOWARDS TUESDAY NIGHT. AS THIS OCCURS...BOUTS OF LIGHT RAIN
ARE LIKELY...EVENTUALLY CHANGING TO LIGHT SNOW BY LATER TUESDAY WHEN
THE SYSTEM BEGINS TO RAMP UP TO THE EAST. IN THE END...SUNDAY NIGHT
THROUGH MONDAY NIGHT MAY JUST BE A CONTINUATION OF THE RELATIVELY
MILD AND DAMP CONDITIONS WE HAVE BEEN QUITE FAMILIAR WITH THIS MONTH.

TUESDAY NIGHT INTO WEDNESDAY...WHILE LIGHT SNOW IS POSSIBLE DUE TO
ENERGY DIVING INTO THE RAPIDLY STRENGTHENING STORM TO THE EAST...OUT
BIGGEST SENSIBLE WEATHER WILL BE WIND...STRONG WINDS OF 20 TO 30 MPH
APPEAR LIKELY...WITH GUSTS OVER 35 POSSIBLE WEDNESDAY AFTERNOON AS
THE LOW TO THE EAST POTENTIALLY DEEPENS TO AROUND 970MB PER 00Z ECMWF

FOLLOWING THIS...AFTER A PERIOD OF COLD ADVECTION LASTING INTO
WEDNESDAY NIGHT...MODELS ARE GREATLY DIVERGENT. THE 00Z GFS OFFERS
NORTHWEST FLOW WITH NO SIGNIFICANT ARCTIC AIR...BUT LITTLE PCPN
THREATS. THE 00Z ECMWF HAS A PROGRESSIVE DEEP SYNOPTIC TROF MOVING
INTO THE LOWER ROCKIES BY DECEMBER 26...SPAWNING CYCLOGENESIS IN THE
WESTERN PLAINS. THAT SYSTEM WOULD IMPACT THE MIDWEST WITH MORE
CLOUDS/RAIN/POSSIBLE WINTER PCPN LATER ON THE 26/27. THERE IS NO
CONSISTENCY ON THIS SYSTEM FROM MODEL TO MODEL...OR IN RUN TO RUN OF ANY
MODEL...SO MENTION OF A TRACK OF THAT POSSIBLE STORM SEEMS VERY
PREMATURE AT THIS TIME.   ERVIN

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 529 AM CST FRI DEC 19 2014

CHALLENGING CIG FCST FOR THE TAFS TODAY...WITH PULSING OPENINGS OF
CLEAR COMBINED WITH MAINLY VFR LEVEL STRATUS CURRENTLY ACRS THE
LOCAL AREA UNDER A SFC RIDGE AXIS. SOME MVFR FOG POSSIBLE AT MLI
AND CID THROUGH 15Z WHERE THE CLEARING EXISTS WITH LIGHT/VARIABLE
WINDS. THEN...MVFR STRATUS ALREADY POISED TO THE WEST ACRS CENTRAL
IA WILL LOOK TO SEEP EASTWARD ACRS THE TAF SITES THIS AFTERNOON.
BUT A FEW OF THE HIRES SOLUTIONS SUGGEST THAT THE LINGERING RIDGE
AXIS TO MAINTAIN VFR CIGS OR EVEN SOME CLEARING HOLES LOCALLY
UNTIL THE EVENING WHEN THE HIGH PRESSURE SLIDES OFF TO THE EAST. SO
TIMING OF THE INCOMING DROP TO MVFR A CHALLENGE FOR THIS AFTERNOON...
IT MAY COME IN FASTER THAN THE PROGS SUGGEST. FOR TONIGHT...WILL
KEEP THE CIGS DROPPING TO A LOWER CATEGORY OF MVFR AND HOLD THE
IFR CIGS OFF TO THE WEST THROUGH 12Z SAT. INCREASING SFC DPTS MAY
MAKE FOR 5-6SM FOG AGAIN AS THE NIGHT PROGRESSES. OF A BIGGER
IMPACT MAY BE THE PRODUCTION OF SOME LIGHT PATCHY FREEZING
DRIZZLE INTO EASTERN IA ESPECIALLY IN THE VCNTY OF CID AFTER
MIDNIGHT. IF IT DOES FORM...IT MAY ALSO GET CLOSE TO THE BRL SITE.
FOR NOW WILL KEEP OUT MENTION IN THE LATER STAGES OF THE TAF
CYCLE. LIGHT SOUTHEAST SFC WINDS OF 3-5 KTS TONIGHT.   ..12..

&&

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

$$

SYNOPSIS...12
SHORT TERM...12
LONG TERM...ERVIN
AVIATION...12







000
FXUS63 KDVN 191140
AFDDVN

AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
539 AM CST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 316 AM CST FRI DEC 19 2014

LATEST SFC ANALYSIS WAS INDICATING LARGE RIDGE AXIS HOLDING FIRM
FROM ACRS ONTARIO NORTH OF LK SUPERIOR...ALL THE WAY DOWN INTO THE
MID TO LOWER MS RVR VALLEY. LIGHT LLVL RETURN FLOW PATTERN TO THE
WEST OF IT ACRS THE CENTRAL AND NORTHERN PLAINS. EXTENSIVE STRATUS
DECK UNDER THE WEST HALF OF THE RIDGE AND INTO THE EASTERN PLAINS
IN RETURN FLOW INTERACTION ZONE...OPEN SKY SWATH FROM SOUTHWEST
OF DBQ SOUTHEASTWARD THRU THE QUAD CITES/EASTERN I80 CORRIDOR
WILL LOOK TO FILL BACK IN EARLY THIS MORNING. ALOFT...00Z UPPER
AIR ANALYSIS AND CURRENT WATER VAPOR LOOP INDICATED A VORT WING
MOVING ACRS EASTERN SD INTO SOUTHEASTERN MN...TAILING DOWN ACRS
CENTRAL INTO EASTERN IA ATTM. THIS FEATURE IS PRODUCING LIGHT SNOW
ACRS MN...AND MAY BE INDUCING THE PATCHY LIGHT FREEZING DRIZZLE
CURRENTLY OUT ACRS CENTRAL IA. NEG VORTICITY IS MOVING OUT OF EASTERN
NEB INTO WESTERN IA BEHIND THIS MAIN VORT. A FURTHER UPSTREAM VORT
NOTED ACRS WY...AND A MORE VIGOROUS VORT MAX NOTED ACRS SOUTHERN
ALBERTA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST FRI DEC 19 2014

TODAY...BULK OF HIRES MODELS SUGGEST HIGH PRESSURE COMPLEX TO
HAVE IT/S EFFECT THIS MORNING MAINTAINING HIGHER CLOUD CIGS FOR
AWHILE...BEFORE AXIS STARTS TO SLIDE EASTWARD MIDDAY INTO THE
AFTERNOON ALLOWING THE LOWER DECK OUT WEST TO SEEP EASTWARD. AREA
OF LIGHT DRIZZLE/FREEZING DRIZZLE ACRS CENTRAL IA MOVING
NORTHEASTWARD AND MAY GET CLOSE TO THE NORTHWESTERN PORTION OF THE
CWA THIS MORNING...BUT WILL BANK ON DIURNAL EFFECTS AND THE RIDGE
STILL IN PLACE TO DEFLECT/EAT AWAY AT THIS PROCESS AND KEEP THE
DRIZZLE JUST TO THE WEST AND NORTHWEST OF THE CWA THIS MORNING...
ALTHOUGH IT WILL BE CLOSE AND WILL HAVE TO WATCH FOR UPDATES. THEN
EXPECT NVA OUT OF WESTERN IA FOR MUCH OF THE DAY WITH ONGOING CLOUDY
TO MOSTLY CLOUDY SKIES. SOME LIGHT SOUTHEAST SFC FLOW THIS AFTERNOON
TO HELP TEMPS MAKE IT A FEW DEGREES MILDER THAN YESTERDAY. THEN THE
UPSTREAM VORT NOTED ABOVE CURRENTLY ACRS WY WILL LOOK TO DIG ACRS
THE IA/MO BORDER BY LATE AFTERNOON AND EARLY EVENING. WITH RATHER
SHALLOW MOISTURE LAYER TRAPPED IN THE LOW LEVELS MAINLY UNDER H8
MB...THIS INCOMING WAVE MAY START TO PRODUCE SPOTTY DRIZZLE AGAIN
AS OPPOSED TO FLURRIES ACRS MO INTO CENTRAL IA...BUT AGAIN WILL BANK
ON ANY PRECIP REACHING THE SFC TO REMAIN WEST OF THE CWA LATE THIS
AFTERNOON AND INTO THE EVENING.

TONIGHT...EXPECT TEMPS TO HOLD STEADY IN THE MID TO UPPER 20S UNDER
STRATUS DECK AND CONTINUING LIGHT SOUTHEASTERLY SFC FLOW. AS THE
FIRST WEAK WAVE CONTINUES TO MOVE EAST ACRS THE SOUTH HALF OF IA
INTO IL DURING THE EVENING...THERE MAY BE A CHC FOR SOME SPOTTY LIGHT
DRIZZLE/FREEZING DRIZZLE TO BREAK OUT BUT WILL KEEP THE FCST DRY
THROUGH 06Z FOR NOW. A BETTER CHC AFTER MIDNIGHT AS THE STRONGER
WAVE ARRIVES OUT OF ALBERTA AND DIGS ACRS THE SOUTHWESTERN HALF OF
IA. MOISTURE DEPTH AND EXTENT OF LIFT STILL AT QUESTION...BUT WILL
INTRODUCE AT LEAST PATCHY LIGHT FREEZING DRIZZLE OUT OF THE
MOISTURE TRAPPED UNDER THE INVERSION ALOFT ACRS THE WESTERN CWA
AFTER MIDNIGHT. HOPEFULLY IT WILL BE SPOTTY AND LIGHT ENOUGH NOT TO
WARRANT SOME TYPE OF HEADLINE...BUT DAY SHIFT WILL HAVE TO REASSESS
AS WELL AS THE POSSIBILITY TO ADD SPOTTY CHC/S IN THE EVENING BEFORE
MIDNIGHT.    ..12..


.LONG TERM...(SATURDAY THROUGH NEXT THURSDAY)
ISSUED AT 316 AM CST FRI DEC 19 2014

THE LONG TERM WILL BEGIN WITH THE SAME CLOUDY AND DAMP REGIME WE
HAVE SEEN MANY TIMES OVER THIS PAST MONTH. TONIGHTS DRIZZLE...FOG
AND LOW CLOUDS LOOK TO REMAIN IN PLACE FOR SATURDAY THROUGH SUNDAY
NIGHT...WITH THE MAIN IMPACTS GREATLY DEPENDING ON HOURLY
TEMPERATURES. SHORT LIVED SUBSIDENCE SATURDAY BEHIND THE MID LEVEL
SHORT WAVE LATER TONIGHT WILL HOPEFULLY OFFER A LULL IN ANY
DRIZZLE...SO AFTER A MILD DAY IN THE MID TO UPPER 30S...WE WILL SET
UP FOR ANOTHER DRIZZLE/FZDZ EVENT BY SATURDAY NIGHT. THE DOMESTIC
MODELS ARE OFFERING COLD SURFACE CONDITIONS FOR SATURDAY
NIGHT...WHILE THE ECMWF IS MUCH MORE MILD. I BELIEVE THE ECMWF IS
MORE ON TARGET HERE AS THERE IS ALMOST NO REASON FOR COLD
SUBFREEZING AIR TO LINGER UNDER THIS STRATUS DECK. IN ANY
CASE...DESPITE LOWS IN THE LOWER 30S...ROADS AND SURFACES WILL NOT
BE ABLE TO RADIATE OUT SATURDAY NIGHT UNDER THE LOW CLOUDS WHICH
WILL ACTUALLY GIVE OFF LONG WAVE RADIATION TO THE SURFACES AS
WELL...LIKELY KEEPING ANY FZDZ MINIMALLY PROBLEMATIC. STILL...SINCE
WE ARE CLOSE ENOUGH TO 32 MUCH OF THE NIGHT IN THE NORTH...I WILL
MENTION IT IN THE GRIDS...BUT HOPEFULLY THIS IS NOT AN ADVISORY
EVENT. SHOULD THE ECMWF RISING TEMPERATURES BE CORRECT AS I
SUSPECT...WE SHOULD BE ABOVE FREEZING DURING THE TIME DRIZZLE OCCURS
SATURDAY NIGHT. THE DZ EVENT MAY LINGER THROUGH THE DAY SUNDAY...AND
AS MORE NOTABLE FORCING ARRIVES...IT MAY BECOME A INTERMITTENT LIGHT
RAIN IN THE NORTH...AND WILL ALLOW POPS TO BE MENTIONED AT THAT
TIME. IN THE END...IF THE DRIZZLE IS HEAVY ENOUGH...IT WILL NEED
MUCH HIGHER POPS FOR CONTINUALLY WETTING SURFACES ANYWAY.

SUNDAY NIGHT...WAA WILL BE RATHER STRONG AS THE COMPLICATED
NORTHWEST FLOW LOW PRESSURE SYSTEM ARRIVES. A SLOW MOVING SURFACE
LOW IS FORECAST NEAR IOWA...AS THE MAIN ENERGY DIVES WELL
SOUTH...CARVING OUT WHAT MAY BE INTENSE LOW PRESSURE OVER THE OHIO
VALLEY TOWARDS TUESDAY NIGHT. AS THIS OCCURS...BOUTS OF LIGHT RAIN
ARE LIKELY...EVENTUALLY CHANGING TO LIGHT SNOW BY LATER TUESDAY WHEN
THE SYSTEM BEGINS TO RAMP UP TO THE EAST. IN THE END...SUNDAY NIGHT
THROUGH MONDAY NIGHT MAY JUST BE A CONTINUATION OF THE RELATIVELY
MILD AND DAMP CONDITIONS WE HAVE BEEN QUITE FAMILIAR WITH THIS MONTH.

TUESDAY NIGHT INTO WEDNESDAY...WHILE LIGHT SNOW IS POSSIBLE DUE TO
ENERGY DIVING INTO THE RAPIDLY STRENGTHENING STORM TO THE EAST...OUT
BIGGEST SENSIBLE WEATHER WILL BE WIND...STRONG WINDS OF 20 TO 30 MPH
APPEAR LIKELY...WITH GUSTS OVER 35 POSSIBLE WEDNESDAY AFTERNOON AS
THE LOW TO THE EAST POTENTIALLY DEEPENS TO AROUND 970MB PER 00Z ECMWF

FOLLOWING THIS...AFTER A PERIOD OF COLD ADVECTION LASTING INTO
WEDNESDAY NIGHT...MODELS ARE GREATLY DIVERGENT. THE 00Z GFS OFFERS
NORTHWEST FLOW WITH NO SIGNIFICANT ARCTIC AIR...BUT LITTLE PCPN
THREATS. THE 00Z ECMWF HAS A PROGRESSIVE DEEP SYNOPTIC TROF MOVING
INTO THE LOWER ROCKIES BY DECEMBER 26...SPAWNING CYCLOGENESIS IN THE
WESTERN PLAINS. THAT SYSTEM WOULD IMPACT THE MIDWEST WITH MORE
CLOUDS/RAIN/POSSIBLE WINTER PCPN LATER ON THE 26/27. THERE IS NO
CONSISTENCY ON THIS SYSTEM FROM MODEL TO MODEL...OR IN RUN TO RUN OF
ANY MODEL...SO MENTION OF A TRACK OF THAT POSSIBLE STORM SEEMS VERY
PREMATURE AT THIS TIME.    ERVIN

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1118 PM CST THU DEC 18 2014

NEARLY CALM WINDS AND VARIABLE CLOUD COVER WILL REMAIN IN PLACE
THROUGH THE REST OF THE NIGHT AS A RIDGE OF HIGH PRESSURE LINGERS
OVERHEAD. A DECK OF LOWER CLOUDS WITH MVFR CIGS WILL AFFECT
PRIMARILY THE DBQ SITE TONIGHT...BEFORE MORE WIDESPREAD LOWER
CLOUDS LOOMING JUST WEST OF THE RIDGE AXIS SPREAD INTO EASTERN IA
AND NW IL DURING THE DAY FRIDAY. CONFIDENCE IN THE EXACT TIMING OF
THIS TRANSITION TO MVFR CONDITIONS REMAINS LOW...BUT THERE IS A
GOOD LIKELIHOOD THAT ALL SITES HAVE CIGS AT OR BELOW 2500 FT BY 06Z
FRIDAY NIGHT.

&&

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

$$

SYNOPSIS...12
SHORT TERM...12
LONG TERM...ERVIN
AVIATION...SHEETS









000
FXUS63 KDMX 191135
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
535 AM CST FRI DEC 19 2014

.SHORT TERM /TODAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

LOW LEVEL MOISTURE SURGE IS LIFTING NORTHEAST ACROSS CENTRAL IOWA
THIS MORNING. WEAK FORCING WITHIN THIS SATURATED LAYER HAS PRODUCED
A MIX OF LIGHT FREEZING DRIZZLE OR FLURRIES WITH SATURATION TOPS
CURRENTLY BETWEEN -7C AND -9C WHICH IS ON THE EDGE BETWEEN GOOD ICE
INTRODUCTION AND SUPER COOLED DROPLETS. THE SATURATION DEPTHS
DECREASE FROM THE TOP OF THE LAYER THROUGH THE MORNING AND THUS
SHOULD DECREASE THE AMOUNT OF ICE INTRODUCTION WHICH WOULD LEAD TO
MORE FREEZING DRIZZLE PROCESSES. NOT EXPECTING A WIDESPREAD IMPACT
THOUGH LOCALIZED ICY PATCHES COULD OCCUR ON ROADWAYS AND WALKWAYS.
SKY CONDITIONS WILL REMAIN CLOUDY TODAY AND WILL HOLD TEMPERATURES
IN THE 20S TO LOWER 30S ONCE AGAIN.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

WE HAVE MUCH TO DISCUSS.

THIS WEEKEND WILL BE CHARACTERIZED BY GENERAL STRATUS AND
HAZE/FOG WITHIN A BROAD WARM AIR/MOISTURE ADVECTION REGIME IN
LIGHT SOUTHERLY SURFACE FLOW. THIS WILL ALSO LEAD TO A SLOW
WARMING TREND...WITH HIGH TEMPERATURES IN THE MID 30S TO LOWER 40S
BY SUNDAY. DURING THE NIGHTTIME AND EARLY MORNING HOURS...BOTH
FROM FRIDAY NIGHT INTO SATURDAY AND FROM SATURDAY NIGHT INTO
SUNDAY...THERE WILL BE INCREASING CHANCES FOR FOG AND DRIZZLE AS
THE NEAR SURFACE CLOUD LAYER GRADUALLY SATURATES AND DEEPENS. ON
FRIDAY NIGHT THE LAYER DEPTHS ARE STILL MARGINAL FOR DRIZZLE AND
THERE IS NO DISCERNIBLE SOURCE OF LIFT TO GENERATE THIS LIGHT
PRECIPITATION. HOWEVER...EVEN EARLY THIS MORNING /FRIDAY/ AND THE
PREVIOUS NIGHT WE HAVE SEEN PATCHY FREEZING DRIZZLE AROUND THE
AREA AND THE SATURATION...WHILE SHALLOW...SEEMS EVEN BETTER ON
FRIDAY NIGHT. GIVEN THE PERSISTENCE OF THE PATTERN...HAVE OPTED TO
INCLUDE DRIZZLE ACROSS THE AREA BETWEEN ABOUT MIDNIGHT AND
SUNRISE. TEMPERATURES WILL BE BELOW FREEZING DURING THIS PERIOD SO
ANY DRIZZLE THAT DOES FORM MAY CAUSE TRAVEL
IMPACTS...HOWEVER...CONFIDENCE IN OCCURRENCE IS EASILY TOO LOW TO
WARRANT ANY HEADLINE CONSIDERATION AT THIS TIME. ON SATURDAY NIGHT
A STRONG SURGE OF THETA E ADVECTION WILL MOVE ACROSS THE
AREA...MAINLY AFTER MIDNIGHT...WITH AN ATTENDANT INCREASE IN THE
DEPTH OF THE WARM CLOUD LAYER. THIS LEADS TO A CONSIDERABLY HIGHER
CONFIDENCE IN DRIZZLE OCCURRENCE LATE SATURDAY NIGHT INTO SUNDAY.
HOWEVER...BY THEN TEMPERATURES WILL BE NEAR OR ABOVE FREEZING IN
MANY AREAS SO IT IS DIFFICULT TO DIFFERENTIATE WHERE THE DRIZZLE
WILL FREEZE AND WHERE IT IS NOT...WITH THE BEST CHANCES FOR
FREEZING DRIZZLE ACROSS THE NORTHERN HALF OR SO OF THE FORECAST
AREA. COMPLICATING THIS FURTHER...FORECAST SOUNDINGS AND
CONCEPTUAL MODELS SUGGEST THAT THE ADVECTION SURGE THAT WILL
TRIGGER DRIZZLE GENERATION MAY PUSH TEMPERATURES FROM BELOW
FREEZING TO ABOVE FREEZING AND IT IS DIFFICULT TO TELL HOW QUICKLY
THIS WILL BE REFLECTED IN SURFACE/ROAD TEMPERATURES. IN ANY
EVENT...THOSE TRAVELING THIS WEEKEND SHOULD KEEP AN EYE ON THE
FORECAST FOR UPDATES ON THE POTENTIAL FOR FREEZING DRIZZLE DURING
THE NIGHTTIME/MORNING HOURS THIS WEEKEND.

BY SUNDAY NIGHT OUR MUCH ANTICIPATED LARGER STORM SYSTEM WILL BE
APPROACHING IN THE FORM OF A 500 MB SHORTWAVE AND ASSOCIATED
SURFACE LOW PRESSURE CENTER MOVING QUICKLY SOUTHEAST ACROSS THE
DAKOTAS. AS THIS SYSTEM REACHES IOWA WE WILL SEE PRECIPITATION
BREAK OUT ACROSS THE STATE FROM WEST TO EAST...MAINLY AFTER
MIDNIGHT SUNDAY NIGHT AND INTO MONDAY. TEMPERATURES WILL BE ABOVE
FREEZING LEADING TO RAIN ACROSS MOST OF THE AREA...WITH THE
EXCEPTION BEING IN OUR FAR NORTH WHERE TEMPERATURES NEAR FREEZING
MAY LEAD TO A WINTRY MIX OF PRECIPITATION BUT WITH LITTLE TO NO
SNOW OR ICE ACCUMULATION THROUGH MONDAY. THE STACKED LOW PRESSURE
CENTER SHOULD BE LOCATED OVER NORTHERN IOWA/SOUTHERN MINNESOTA BY
MONDAY NIGHT...THEREAFTER OCCLUDING AND MOVING SLOWLY TO THE EAST.
THIS WILL LEAD TO A RAIN TO SNOW TRANSITION FROM WEST TO EAST ON
MONDAY NIGHT...FOLLOWED BY A DAY OR TWO OF LIGHT SNOW WITHIN THE
LARGE CLOUD AND PRECIP SHIELD ON THE BACKSIDE OF THE SYSTEM. WHILE
CHANCES FOR SNOWFLAKES ARE HIGH ACROSS MUCH OF THE AREA FROM
MONDAY NIGHT THROUGH TUESDAY...GIVEN THAT THE LOW WILL BE SLOWLY
FILLING AND MOVING AWAY THE QPF IS FAIRLY LOW AND ANY SNOWFALL
AMOUNTS WILL PROBABLY BE LIGHT. THIS MAY STILL PRODUCE SOME TRAVEL
IMPACTS BUT THESE ARE VERY DIFFICULT TO DIAGNOSE AT THIS RANGE. WE
WILL CONTINUE TO CLOSELY MONITOR THIS SYSTEM IN THE COMING DAYS.

THE LIGHT SNOW TRAILING THE EARLY WEEK SYSTEM SHOULD CLEAR OUT OF
THE AREA ROUGHLY AROUND TUESDAY NIGHT OR POSSIBLY WEDNESDAY. IT
DOES APPEAR THAT ANOTHER STORM SYSTEM WILL APPROACH OUR AREA FROM
THE WEST LATE NEXT WEEK...JUST BEYOND THE CURRENT SEVEN DAY
FORECAST...WITH SOME CHANCE FOR PRECIPITATION POSSIBLY IN THE FORM
OF ADDITIONAL SNOWFALL.

&&

.AVIATION...19/12Z
ISSUED AT 535 AM CST FRI DEC 19 2014

WIDESPREAD IFR/MVFR STRATUS WILL PERSIST THROUGH MUCH OF THE
PERIOD. THE IFR STRATUS OVER SW IA IS EXPECTED TO SPREAD NORTHEAST
TODAY THROUGH IT SHOULD RAISE A BIT THIS AFTERNOON AND BECOME
BORDERLINE MVFR. PATCHES OF DRIZZLE OR FOG POSSIBLE THROUGH THE
PERIOD BUT SHOULD NOT BE A BIG IMPACT. WINDS WILL REMAIN LIGHT OUT
OF THE SOUTH TO SOUTHEAST.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...DONAVON



000
FXUS63 KDMX 191135
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
535 AM CST FRI DEC 19 2014

.SHORT TERM /TODAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

LOW LEVEL MOISTURE SURGE IS LIFTING NORTHEAST ACROSS CENTRAL IOWA
THIS MORNING. WEAK FORCING WITHIN THIS SATURATED LAYER HAS PRODUCED
A MIX OF LIGHT FREEZING DRIZZLE OR FLURRIES WITH SATURATION TOPS
CURRENTLY BETWEEN -7C AND -9C WHICH IS ON THE EDGE BETWEEN GOOD ICE
INTRODUCTION AND SUPER COOLED DROPLETS. THE SATURATION DEPTHS
DECREASE FROM THE TOP OF THE LAYER THROUGH THE MORNING AND THUS
SHOULD DECREASE THE AMOUNT OF ICE INTRODUCTION WHICH WOULD LEAD TO
MORE FREEZING DRIZZLE PROCESSES. NOT EXPECTING A WIDESPREAD IMPACT
THOUGH LOCALIZED ICY PATCHES COULD OCCUR ON ROADWAYS AND WALKWAYS.
SKY CONDITIONS WILL REMAIN CLOUDY TODAY AND WILL HOLD TEMPERATURES
IN THE 20S TO LOWER 30S ONCE AGAIN.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

WE HAVE MUCH TO DISCUSS.

THIS WEEKEND WILL BE CHARACTERIZED BY GENERAL STRATUS AND
HAZE/FOG WITHIN A BROAD WARM AIR/MOISTURE ADVECTION REGIME IN
LIGHT SOUTHERLY SURFACE FLOW. THIS WILL ALSO LEAD TO A SLOW
WARMING TREND...WITH HIGH TEMPERATURES IN THE MID 30S TO LOWER 40S
BY SUNDAY. DURING THE NIGHTTIME AND EARLY MORNING HOURS...BOTH
FROM FRIDAY NIGHT INTO SATURDAY AND FROM SATURDAY NIGHT INTO
SUNDAY...THERE WILL BE INCREASING CHANCES FOR FOG AND DRIZZLE AS
THE NEAR SURFACE CLOUD LAYER GRADUALLY SATURATES AND DEEPENS. ON
FRIDAY NIGHT THE LAYER DEPTHS ARE STILL MARGINAL FOR DRIZZLE AND
THERE IS NO DISCERNIBLE SOURCE OF LIFT TO GENERATE THIS LIGHT
PRECIPITATION. HOWEVER...EVEN EARLY THIS MORNING /FRIDAY/ AND THE
PREVIOUS NIGHT WE HAVE SEEN PATCHY FREEZING DRIZZLE AROUND THE
AREA AND THE SATURATION...WHILE SHALLOW...SEEMS EVEN BETTER ON
FRIDAY NIGHT. GIVEN THE PERSISTENCE OF THE PATTERN...HAVE OPTED TO
INCLUDE DRIZZLE ACROSS THE AREA BETWEEN ABOUT MIDNIGHT AND
SUNRISE. TEMPERATURES WILL BE BELOW FREEZING DURING THIS PERIOD SO
ANY DRIZZLE THAT DOES FORM MAY CAUSE TRAVEL
IMPACTS...HOWEVER...CONFIDENCE IN OCCURRENCE IS EASILY TOO LOW TO
WARRANT ANY HEADLINE CONSIDERATION AT THIS TIME. ON SATURDAY NIGHT
A STRONG SURGE OF THETA E ADVECTION WILL MOVE ACROSS THE
AREA...MAINLY AFTER MIDNIGHT...WITH AN ATTENDANT INCREASE IN THE
DEPTH OF THE WARM CLOUD LAYER. THIS LEADS TO A CONSIDERABLY HIGHER
CONFIDENCE IN DRIZZLE OCCURRENCE LATE SATURDAY NIGHT INTO SUNDAY.
HOWEVER...BY THEN TEMPERATURES WILL BE NEAR OR ABOVE FREEZING IN
MANY AREAS SO IT IS DIFFICULT TO DIFFERENTIATE WHERE THE DRIZZLE
WILL FREEZE AND WHERE IT IS NOT...WITH THE BEST CHANCES FOR
FREEZING DRIZZLE ACROSS THE NORTHERN HALF OR SO OF THE FORECAST
AREA. COMPLICATING THIS FURTHER...FORECAST SOUNDINGS AND
CONCEPTUAL MODELS SUGGEST THAT THE ADVECTION SURGE THAT WILL
TRIGGER DRIZZLE GENERATION MAY PUSH TEMPERATURES FROM BELOW
FREEZING TO ABOVE FREEZING AND IT IS DIFFICULT TO TELL HOW QUICKLY
THIS WILL BE REFLECTED IN SURFACE/ROAD TEMPERATURES. IN ANY
EVENT...THOSE TRAVELING THIS WEEKEND SHOULD KEEP AN EYE ON THE
FORECAST FOR UPDATES ON THE POTENTIAL FOR FREEZING DRIZZLE DURING
THE NIGHTTIME/MORNING HOURS THIS WEEKEND.

BY SUNDAY NIGHT OUR MUCH ANTICIPATED LARGER STORM SYSTEM WILL BE
APPROACHING IN THE FORM OF A 500 MB SHORTWAVE AND ASSOCIATED
SURFACE LOW PRESSURE CENTER MOVING QUICKLY SOUTHEAST ACROSS THE
DAKOTAS. AS THIS SYSTEM REACHES IOWA WE WILL SEE PRECIPITATION
BREAK OUT ACROSS THE STATE FROM WEST TO EAST...MAINLY AFTER
MIDNIGHT SUNDAY NIGHT AND INTO MONDAY. TEMPERATURES WILL BE ABOVE
FREEZING LEADING TO RAIN ACROSS MOST OF THE AREA...WITH THE
EXCEPTION BEING IN OUR FAR NORTH WHERE TEMPERATURES NEAR FREEZING
MAY LEAD TO A WINTRY MIX OF PRECIPITATION BUT WITH LITTLE TO NO
SNOW OR ICE ACCUMULATION THROUGH MONDAY. THE STACKED LOW PRESSURE
CENTER SHOULD BE LOCATED OVER NORTHERN IOWA/SOUTHERN MINNESOTA BY
MONDAY NIGHT...THEREAFTER OCCLUDING AND MOVING SLOWLY TO THE EAST.
THIS WILL LEAD TO A RAIN TO SNOW TRANSITION FROM WEST TO EAST ON
MONDAY NIGHT...FOLLOWED BY A DAY OR TWO OF LIGHT SNOW WITHIN THE
LARGE CLOUD AND PRECIP SHIELD ON THE BACKSIDE OF THE SYSTEM. WHILE
CHANCES FOR SNOWFLAKES ARE HIGH ACROSS MUCH OF THE AREA FROM
MONDAY NIGHT THROUGH TUESDAY...GIVEN THAT THE LOW WILL BE SLOWLY
FILLING AND MOVING AWAY THE QPF IS FAIRLY LOW AND ANY SNOWFALL
AMOUNTS WILL PROBABLY BE LIGHT. THIS MAY STILL PRODUCE SOME TRAVEL
IMPACTS BUT THESE ARE VERY DIFFICULT TO DIAGNOSE AT THIS RANGE. WE
WILL CONTINUE TO CLOSELY MONITOR THIS SYSTEM IN THE COMING DAYS.

THE LIGHT SNOW TRAILING THE EARLY WEEK SYSTEM SHOULD CLEAR OUT OF
THE AREA ROUGHLY AROUND TUESDAY NIGHT OR POSSIBLY WEDNESDAY. IT
DOES APPEAR THAT ANOTHER STORM SYSTEM WILL APPROACH OUR AREA FROM
THE WEST LATE NEXT WEEK...JUST BEYOND THE CURRENT SEVEN DAY
FORECAST...WITH SOME CHANCE FOR PRECIPITATION POSSIBLY IN THE FORM
OF ADDITIONAL SNOWFALL.

&&

.AVIATION...19/12Z
ISSUED AT 535 AM CST FRI DEC 19 2014

WIDESPREAD IFR/MVFR STRATUS WILL PERSIST THROUGH MUCH OF THE
PERIOD. THE IFR STRATUS OVER SW IA IS EXPECTED TO SPREAD NORTHEAST
TODAY THROUGH IT SHOULD RAISE A BIT THIS AFTERNOON AND BECOME
BORDERLINE MVFR. PATCHES OF DRIZZLE OR FOG POSSIBLE THROUGH THE
PERIOD BUT SHOULD NOT BE A BIG IMPACT. WINDS WILL REMAIN LIGHT OUT
OF THE SOUTH TO SOUTHEAST.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...DONAVON




000
FXUS63 KDMX 190929
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
329 AM CST FRI DEC 19 2014

.SHORT TERM /TODAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

LOW LEVEL MOISTURE SURGE IS LIFTING NORTHEAST ACROSS CENTRAL IOWA
THIS MORNING. WEAK FORCING WITHIN THIS SATURATED LAYER HAS PRODUCED
A MIX OF LIGHT FREEZING DRIZZLE OR FLURRIES WITH SATURATION TOPS
CURRENTLY BETWEEN -7C AND -9C WHICH IS ON THE EDGE BETWEEN GOOD ICE
INTRODUCTION AND SUPER COOLED DROPLETS. THE SATURATION DEPTHS
DECREASE FROM THE TOP OF THE LAYER THROUGH THE MORNING AND THUS
SHOULD DECREASE THE AMOUNT OF ICE INTRODUCTION WHICH WOULD LEAD TO
MORE FREEZING DRIZZLE PROCESSES. NOT EXPECTING A WIDESPREAD IMPACT
THOUGH LOCALIZED ICY PATCHES COULD OCCUR ON ROADWAYS AND WALKWAYS.
SKY CONDITIONS WILL REMAIN CLOUDY TODAY AND WILL HOLD TEMPERATURES
IN THE 20S TO LOWER 30S ONCE AGAIN.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

WE HAVE MUCH TO DISCUSS.

THIS WEEKEND WILL BE CHARACTERIZED BY GENERAL STRATUS AND
HAZE/FOG WITHIN A BROAD WARM AIR/MOISTURE ADVECTION REGIME IN
LIGHT SOUTHERLY SURFACE FLOW. THIS WILL ALSO LEAD TO A SLOW
WARMING TREND...WITH HIGH TEMPERATURES IN THE MID 30S TO LOWER 40S
BY SUNDAY. DURING THE NIGHTTIME AND EARLY MORNING HOURS...BOTH
FROM FRIDAY NIGHT INTO SATURDAY AND FROM SATURDAY NIGHT INTO
SUNDAY...THERE WILL BE INCREASING CHANCES FOR FOG AND DRIZZLE AS
THE NEAR SURFACE CLOUD LAYER GRADUALLY SATURATES AND DEEPENS. ON
FRIDAY NIGHT THE LAYER DEPTHS ARE STILL MARGINAL FOR DRIZZLE AND
THERE IS NO DISCERNIBLE SOURCE OF LIFT TO GENERATE THIS LIGHT
PRECIPITATION. HOWEVER...EVEN EARLY THIS MORNING /FRIDAY/ AND THE
PREVIOUS NIGHT WE HAVE SEEN PATCHY FREEZING DRIZZLE AROUND THE
AREA AND THE SATURATION...WHILE SHALLOW...SEEMS EVEN BETTER ON
FRIDAY NIGHT. GIVEN THE PERSISTENCE OF THE PATTERN...HAVE OPTED TO
INCLUDE DRIZZLE ACROSS THE AREA BETWEEN ABOUT MIDNIGHT AND
SUNRISE. TEMPERATURES WILL BE BELOW FREEZING DURING THIS PERIOD SO
ANY DRIZZLE THAT DOES FORM MAY CAUSE TRAVEL
IMPACTS...HOWEVER...CONFIDENCE IN OCCURRENCE IS EASILY TOO LOW TO
WARRANT ANY HEADLINE CONSIDERATION AT THIS TIME. ON SATURDAY NIGHT
A STRONG SURGE OF THETA E ADVECTION WILL MOVE ACROSS THE
AREA...MAINLY AFTER MIDNIGHT...WITH AN ATTENDANT INCREASE IN THE
DEPTH OF THE WARM CLOUD LAYER. THIS LEADS TO A CONSIDERABLY HIGHER
CONFIDENCE IN DRIZZLE OCCURRENCE LATE SATURDAY NIGHT INTO SUNDAY.
HOWEVER...BY THEN TEMPERATURES WILL BE NEAR OR ABOVE FREEZING IN
MANY AREAS SO IT IS DIFFICULT TO DIFFERENTIATE WHERE THE DRIZZLE
WILL FREEZE AND WHERE IT IS NOT...WITH THE BEST CHANCES FOR
FREEZING DRIZZLE ACROSS THE NORTHERN HALF OR SO OF THE FORECAST
AREA. COMPLICATING THIS FURTHER...FORECAST SOUNDINGS AND
CONCEPTUAL MODELS SUGGEST THAT THE ADVECTION SURGE THAT WILL
TRIGGER DRIZZLE GENERATION MAY PUSH TEMPERATURES FROM BELOW
FREEZING TO ABOVE FREEZING AND IT IS DIFFICULT TO TELL HOW QUICKLY
THIS WILL BE REFLECTED IN SURFACE/ROAD TEMPERATURES. IN ANY
EVENT...THOSE TRAVELING THIS WEEKEND SHOULD KEEP AN EYE ON THE
FORECAST FOR UPDATES ON THE POTENTIAL FOR FREEZING DRIZZLE DURING
THE NIGHTTIME/MORNING HOURS THIS WEEKEND.

BY SUNDAY NIGHT OUR MUCH ANTICIPATED LARGER STORM SYSTEM WILL BE
APPROACHING IN THE FORM OF A 500 MB SHORTWAVE AND ASSOCIATED
SURFACE LOW PRESSURE CENTER MOVING QUICKLY SOUTHEAST ACROSS THE
DAKOTAS. AS THIS SYSTEM REACHES IOWA WE WILL SEE PRECIPITATION
BREAK OUT ACROSS THE STATE FROM WEST TO EAST...MAINLY AFTER
MIDNIGHT SUNDAY NIGHT AND INTO MONDAY. TEMPERATURES WILL BE ABOVE
FREEZING LEADING TO RAIN ACROSS MOST OF THE AREA...WITH THE
EXCEPTION BEING IN OUR FAR NORTH WHERE TEMPERATURES NEAR FREEZING
MAY LEAD TO A WINTRY MIX OF PRECIPITATION BUT WITH LITTLE TO NO
SNOW OR ICE ACCUMULATION THROUGH MONDAY. THE STACKED LOW PRESSURE
CENTER SHOULD BE LOCATED OVER NORTHERN IOWA/SOUTHERN MINNESOTA BY
MONDAY NIGHT...THEREAFTER OCCLUDING AND MOVING SLOWLY TO THE EAST.
THIS WILL LEAD TO A RAIN TO SNOW TRANSITION FROM WEST TO EAST ON
MONDAY NIGHT...FOLLOWED BY A DAY OR TWO OF LIGHT SNOW WITHIN THE
LARGE CLOUD AND PRECIP SHIELD ON THE BACKSIDE OF THE SYSTEM. WHILE
CHANCES FOR SNOWFLAKES ARE HIGH ACROSS MUCH OF THE AREA FROM
MONDAY NIGHT THROUGH TUESDAY...GIVEN THAT THE LOW WILL BE SLOWLY
FILLING AND MOVING AWAY THE QPF IS FAIRLY LOW AND ANY SNOWFALL
AMOUNTS WILL PROBABLY BE LIGHT. THIS MAY STILL PRODUCE SOME TRAVEL
IMPACTS BUT THESE ARE VERY DIFFICULT TO DIAGNOSE AT THIS RANGE. WE
WILL CONTINUE TO CLOSELY MONITOR THIS SYSTEM IN THE COMING DAYS.

THE LIGHT SNOW TRAILING THE EARLY WEEK SYSTEM SHOULD CLEAR OUT OF
THE AREA ROUGHLY AROUND TUESDAY NIGHT OR POSSIBLY WEDNESDAY. IT
DOES APPEAR THAT ANOTHER STORM SYSTEM WILL APPROACH OUR AREA FROM
THE WEST LATE NEXT WEEK...JUST BEYOND THE CURRENT SEVEN DAY
FORECAST...WITH SOME CHANCE FOR PRECIPITATION POSSIBLY IN THE FORM
OF ADDITIONAL SNOWFALL.

&&

.AVIATION...19/06Z
ISSUED AT 1141 PM CST THU DEC 18 2014

LOW STRATUS WILL CONTINUE TO BE WIDESPREAD FOR THE DURATION OF THE
FORECAST. VFR CONDITIONS WILL PERSIST ACRS THE FAR NORTHEAST
THROUGH MUCH OF THE NIGHT BUT THE SLOW NORTH AND EAST PROGRESSION
OF MVFR TO IFR CEILINGS WILL CONTINUE AS SOUTHERLY FLOW BEGINS TO
INCREASE AS SURFACE RIDGE SLIDES SLOWLY EASTWARD. THE MVFR TO IFR
CONDITIONS WILL PERSIST INTO FRIDAY AND FRIDAY EVENING AS THE
MOIST LOW LEVEL FLOW CONTINUES. GFS IS INDICATING SOME -DZ/-FZDZ
BY AFTERNOON ACROSS PORTIONS OF THE FORECAST AREA AS FORCING
INCREASES. HAVE NOT INCLUDED AT THIS TIME BUT WILL HAVE TO BE
MONITORED FOR INCLUSION IN SUBSEQUENT FORECASTS. SURFACE WINDS
WILL BE LIGHT OVERNIGHT BECOMING SOUTHEAST TO SOUTH ON FRIDAY BUT
REMAINING LIGHT.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...COGIL




000
FXUS63 KDMX 190929
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
329 AM CST FRI DEC 19 2014

.SHORT TERM /TODAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

LOW LEVEL MOISTURE SURGE IS LIFTING NORTHEAST ACROSS CENTRAL IOWA
THIS MORNING. WEAK FORCING WITHIN THIS SATURATED LAYER HAS PRODUCED
A MIX OF LIGHT FREEZING DRIZZLE OR FLURRIES WITH SATURATION TOPS
CURRENTLY BETWEEN -7C AND -9C WHICH IS ON THE EDGE BETWEEN GOOD ICE
INTRODUCTION AND SUPER COOLED DROPLETS. THE SATURATION DEPTHS
DECREASE FROM THE TOP OF THE LAYER THROUGH THE MORNING AND THUS
SHOULD DECREASE THE AMOUNT OF ICE INTRODUCTION WHICH WOULD LEAD TO
MORE FREEZING DRIZZLE PROCESSES. NOT EXPECTING A WIDESPREAD IMPACT
THOUGH LOCALIZED ICY PATCHES COULD OCCUR ON ROADWAYS AND WALKWAYS.
SKY CONDITIONS WILL REMAIN CLOUDY TODAY AND WILL HOLD TEMPERATURES
IN THE 20S TO LOWER 30S ONCE AGAIN.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 329 AM CST FRI DEC 19 2014

WE HAVE MUCH TO DISCUSS.

THIS WEEKEND WILL BE CHARACTERIZED BY GENERAL STRATUS AND
HAZE/FOG WITHIN A BROAD WARM AIR/MOISTURE ADVECTION REGIME IN
LIGHT SOUTHERLY SURFACE FLOW. THIS WILL ALSO LEAD TO A SLOW
WARMING TREND...WITH HIGH TEMPERATURES IN THE MID 30S TO LOWER 40S
BY SUNDAY. DURING THE NIGHTTIME AND EARLY MORNING HOURS...BOTH
FROM FRIDAY NIGHT INTO SATURDAY AND FROM SATURDAY NIGHT INTO
SUNDAY...THERE WILL BE INCREASING CHANCES FOR FOG AND DRIZZLE AS
THE NEAR SURFACE CLOUD LAYER GRADUALLY SATURATES AND DEEPENS. ON
FRIDAY NIGHT THE LAYER DEPTHS ARE STILL MARGINAL FOR DRIZZLE AND
THERE IS NO DISCERNIBLE SOURCE OF LIFT TO GENERATE THIS LIGHT
PRECIPITATION. HOWEVER...EVEN EARLY THIS MORNING /FRIDAY/ AND THE
PREVIOUS NIGHT WE HAVE SEEN PATCHY FREEZING DRIZZLE AROUND THE
AREA AND THE SATURATION...WHILE SHALLOW...SEEMS EVEN BETTER ON
FRIDAY NIGHT. GIVEN THE PERSISTENCE OF THE PATTERN...HAVE OPTED TO
INCLUDE DRIZZLE ACROSS THE AREA BETWEEN ABOUT MIDNIGHT AND
SUNRISE. TEMPERATURES WILL BE BELOW FREEZING DURING THIS PERIOD SO
ANY DRIZZLE THAT DOES FORM MAY CAUSE TRAVEL
IMPACTS...HOWEVER...CONFIDENCE IN OCCURRENCE IS EASILY TOO LOW TO
WARRANT ANY HEADLINE CONSIDERATION AT THIS TIME. ON SATURDAY NIGHT
A STRONG SURGE OF THETA E ADVECTION WILL MOVE ACROSS THE
AREA...MAINLY AFTER MIDNIGHT...WITH AN ATTENDANT INCREASE IN THE
DEPTH OF THE WARM CLOUD LAYER. THIS LEADS TO A CONSIDERABLY HIGHER
CONFIDENCE IN DRIZZLE OCCURRENCE LATE SATURDAY NIGHT INTO SUNDAY.
HOWEVER...BY THEN TEMPERATURES WILL BE NEAR OR ABOVE FREEZING IN
MANY AREAS SO IT IS DIFFICULT TO DIFFERENTIATE WHERE THE DRIZZLE
WILL FREEZE AND WHERE IT IS NOT...WITH THE BEST CHANCES FOR
FREEZING DRIZZLE ACROSS THE NORTHERN HALF OR SO OF THE FORECAST
AREA. COMPLICATING THIS FURTHER...FORECAST SOUNDINGS AND
CONCEPTUAL MODELS SUGGEST THAT THE ADVECTION SURGE THAT WILL
TRIGGER DRIZZLE GENERATION MAY PUSH TEMPERATURES FROM BELOW
FREEZING TO ABOVE FREEZING AND IT IS DIFFICULT TO TELL HOW QUICKLY
THIS WILL BE REFLECTED IN SURFACE/ROAD TEMPERATURES. IN ANY
EVENT...THOSE TRAVELING THIS WEEKEND SHOULD KEEP AN EYE ON THE
FORECAST FOR UPDATES ON THE POTENTIAL FOR FREEZING DRIZZLE DURING
THE NIGHTTIME/MORNING HOURS THIS WEEKEND.

BY SUNDAY NIGHT OUR MUCH ANTICIPATED LARGER STORM SYSTEM WILL BE
APPROACHING IN THE FORM OF A 500 MB SHORTWAVE AND ASSOCIATED
SURFACE LOW PRESSURE CENTER MOVING QUICKLY SOUTHEAST ACROSS THE
DAKOTAS. AS THIS SYSTEM REACHES IOWA WE WILL SEE PRECIPITATION
BREAK OUT ACROSS THE STATE FROM WEST TO EAST...MAINLY AFTER
MIDNIGHT SUNDAY NIGHT AND INTO MONDAY. TEMPERATURES WILL BE ABOVE
FREEZING LEADING TO RAIN ACROSS MOST OF THE AREA...WITH THE
EXCEPTION BEING IN OUR FAR NORTH WHERE TEMPERATURES NEAR FREEZING
MAY LEAD TO A WINTRY MIX OF PRECIPITATION BUT WITH LITTLE TO NO
SNOW OR ICE ACCUMULATION THROUGH MONDAY. THE STACKED LOW PRESSURE
CENTER SHOULD BE LOCATED OVER NORTHERN IOWA/SOUTHERN MINNESOTA BY
MONDAY NIGHT...THEREAFTER OCCLUDING AND MOVING SLOWLY TO THE EAST.
THIS WILL LEAD TO A RAIN TO SNOW TRANSITION FROM WEST TO EAST ON
MONDAY NIGHT...FOLLOWED BY A DAY OR TWO OF LIGHT SNOW WITHIN THE
LARGE CLOUD AND PRECIP SHIELD ON THE BACKSIDE OF THE SYSTEM. WHILE
CHANCES FOR SNOWFLAKES ARE HIGH ACROSS MUCH OF THE AREA FROM
MONDAY NIGHT THROUGH TUESDAY...GIVEN THAT THE LOW WILL BE SLOWLY
FILLING AND MOVING AWAY THE QPF IS FAIRLY LOW AND ANY SNOWFALL
AMOUNTS WILL PROBABLY BE LIGHT. THIS MAY STILL PRODUCE SOME TRAVEL
IMPACTS BUT THESE ARE VERY DIFFICULT TO DIAGNOSE AT THIS RANGE. WE
WILL CONTINUE TO CLOSELY MONITOR THIS SYSTEM IN THE COMING DAYS.

THE LIGHT SNOW TRAILING THE EARLY WEEK SYSTEM SHOULD CLEAR OUT OF
THE AREA ROUGHLY AROUND TUESDAY NIGHT OR POSSIBLY WEDNESDAY. IT
DOES APPEAR THAT ANOTHER STORM SYSTEM WILL APPROACH OUR AREA FROM
THE WEST LATE NEXT WEEK...JUST BEYOND THE CURRENT SEVEN DAY
FORECAST...WITH SOME CHANCE FOR PRECIPITATION POSSIBLY IN THE FORM
OF ADDITIONAL SNOWFALL.

&&

.AVIATION...19/06Z
ISSUED AT 1141 PM CST THU DEC 18 2014

LOW STRATUS WILL CONTINUE TO BE WIDESPREAD FOR THE DURATION OF THE
FORECAST. VFR CONDITIONS WILL PERSIST ACRS THE FAR NORTHEAST
THROUGH MUCH OF THE NIGHT BUT THE SLOW NORTH AND EAST PROGRESSION
OF MVFR TO IFR CEILINGS WILL CONTINUE AS SOUTHERLY FLOW BEGINS TO
INCREASE AS SURFACE RIDGE SLIDES SLOWLY EASTWARD. THE MVFR TO IFR
CONDITIONS WILL PERSIST INTO FRIDAY AND FRIDAY EVENING AS THE
MOIST LOW LEVEL FLOW CONTINUES. GFS IS INDICATING SOME -DZ/-FZDZ
BY AFTERNOON ACROSS PORTIONS OF THE FORECAST AREA AS FORCING
INCREASES. HAVE NOT INCLUDED AT THIS TIME BUT WILL HAVE TO BE
MONITORED FOR INCLUSION IN SUBSEQUENT FORECASTS. SURFACE WINDS
WILL BE LIGHT OVERNIGHT BECOMING SOUTHEAST TO SOUTH ON FRIDAY BUT
REMAINING LIGHT.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...COGIL



000
FXUS63 KDVN 190918
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
318 AM CST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 316 AM CST FRI DEC 19 2014

LATEST SFC ANALYSIS WAS INDICATING LARGE RIDGE AXIS HOLDING FIRM
FROM ACRS ONTARIO NORTH OF LK SUPERIOR...ALL THE WAY DOWN INTO THE
MID TO LOWER MS RVR VALLEY. LIGHT LLVL RETURN FLOW PATTERN TO THE
WEST OF IT ACRS THE CENTRAL AND NORTHERN PLAINS. EXTENSIVE STRATUS
DECK UNDER THE WEST HALF OF THE RIDGE AND INTO THE EASTERN PLAINS
IN RETURN FLOW INTERACTION ZONE...OPEN SKY SWATH FROM SOUTHWEST
OF DBQ SOUTHEASTWARD THRU THE QUAD CITES/EASTERN I80 CORRIDOR
WILL LOOK TO FILL BACK IN EARLY THIS MORNING. ALOFT...00Z UPPER
AIR ANALYSIS AND CURRENT WATER VAPOR LOOP INDICATED A VORT WING
MOVING ACRS EASTERN SD INTO SOUTHEASTERN MN...TAILING DOWN ACRS
CENTRAL INTO EASTERN IA ATTM. THIS FEATURE IS PRODUCING LIGHT SNOW
ACRS MN...AND MAY BE INDUCING THE PATCHY LIGHT FREEZING DRIZZLE
CURRENTLY OUT ACRS CENTRAL IA. NEG VORTICITY IS MOVING OUT OF EASTERN
NEB INTO WESTERN IA BEHIND THIS MAIN VORT. A FURTHER UPSTREAM VORT
NOTED ACRS WY...AND A MORE VIGOROUS VORT MAX NOTED ACRS SOUTHERN
ALBERTA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST FRI DEC 19 2014

TODAY...BULK OF HIRES MODELS SUGGEST HIGH PRESSURE COMPLEX TO
HAVE IT/S EFFECT THIS MORNING MAINTAINING HIGHER CLOUD CIGS FOR
AWHILE...BEFORE AXIS STARTS TO SLIDE EASTWARD MIDDAY INTO THE
AFTERNOON ALLOWING THE LOWER DECK OUT WEST TO SEEP EASTWARD. AREA
OF LIGHT DRIZZLE/FREEZING DRIZZLE ACRS CENTRAL IA MOVING
NORTHEASTWARD AND MAY GET CLOSE TO THE NORTHWESTERN PORTION OF THE
CWA THIS MORNING...BUT WILL BANK ON DIURNAL EFFECTS AND THE RIDGE
STILL IN PLACE TO DEFLECT/EAT AWAY AT THIS PROCESS AND KEEP THE
DRIZZLE JUST TO THE WEST AND NORTHWEST OF THE CWA THIS MORNING...
ALTHOUGH IT WILL BE CLOSE AND WILL HAVE TO WATCH FOR UPDATES. THEN
EXPECT NVA OUT OF WESTERN IA FOR MUCH OF THE DAY WITH ONGOING CLOUDY
TO MOSTLY CLOUDY SKIES. SOME LIGHT SOUTHEAST SFC FLOW THIS AFTERNOON
TO HELP TEMPS MAKE IT A FEW DEGREES MILDER THAN YESTERDAY. THEN THE
UPSTREAM VORT NOTED ABOVE CURRENTLY ACRS WY WILL LOOK TO DIG ACRS
THE IA/MO BORDER BY LATE AFTERNOON AND EARLY EVENING. WITH RATHER
SHALLOW MOISTURE LAYER TRAPPED IN THE LOW LEVELS MAINLY UNDER H8
MB...THIS INCOMING WAVE MAY START TO PRODUCE SPOTTY DRIZZLE AGAIN
AS OPPOSED TO FLURRIES ACRS MO INTO CENTRAL IA...BUT AGAIN WILL BANK
ON ANY PRECIP REACHING THE SFC TO REMAIN WEST OF THE CWA LATE THIS
AFTERNOON AND INTO THE EVENING.

TONIGHT...EXPECT TEMPS TO HOLD STEADY IN THE MID TO UPPER 20S UNDER
STRATUS DECK AND CONTINUING LIGHT SOUTHEASTERLY SFC FLOW. AS THE
FIRST WEAK WAVE CONTINUES TO MOVE EAST ACRS THE SOUTH HALF OF IA
INTO IL DURING THE EVENING...THERE MAY BE A CHC FOR SOME SPOTTY LIGHT
DRIZZLE/FREEZING DRIZZLE TO BREAK OUT BUT WILL KEEP THE FCST DRY
THROUGH 06Z FOR NOW. A BETTER CHC AFTER MIDNIGHT AS THE STRONGER
WAVE ARRIVES OUT OF ALBERTA AND DIGS ACRS THE SOUTHWESTERN HALF OF
IA. MOISTURE DEPTH AND EXTENT OF LIFT STILL AT QUESTION...BUT WILL
INTRODUCE AT LEAST PATCHY LIGHT FREEZING DRIZZLE OUT OF THE
MOISTURE TRAPPED UNDER THE INVERSION ALOFT ACRS THE WESTERN CWA
AFTER MIDNIGHT. HOPEFULLY IT WILL BE SPOTTY AND LIGHT ENOUGH NOT TO
WARRANT SOME TYPE OF HEADLINE...BUT DAY SHIFT WILL HAVE TO REASSESS
AS WELL AS THE POSSIBILITY TO ADD SPOTTY CHC/S IN THE EVENING BEFORE
MIDNIGHT.    ..12..


.LONG TERM...(SATURDAY THROUGH NEXT THURSDAY)
ISSUED AT 316 AM CST FRI DEC 19 2014

THE LONG TERM WILL BEGIN WITH THE SAME CLOUDY AND DAMP REGIME WE
HAVE SEEN MANY TIMES OVER THIS PAST MONTH. TONIGHTS DRIZZLE...FOG
AND LOW CLOUDS LOOK TO REMAIN IN PLACE FOR SATURDAY THROUGH SUNDAY
NIGHT...WITH THE MAIN IMPACTS GREATLY DEPENDING ON HOURLY
TEMPERATURES. SHORT LIVED SUBSIDENCE SATURDAY BEHIND THE MID LEVEL
SHORT WAVE LATER TONIGHT WILL HOPEFULLY OFFER A LULL IN ANY
DRIZZLE...SO AFTER A MILD DAY IN THE MID TO UPPER 30S...WE WILL SET
UP FOR ANOTHER DRIZZLE/FZDZ EVENT BY SATURDAY NIGHT. THE DOMESTIC
MODELS ARE OFFERING COLD SURFACE CONDITIONS FOR SATURDAY
NIGHT...WHILE THE ECMWF IS MUCH MORE MILD. I BELIEVE THE ECMWF IS
MORE ON TARGET HERE AS THERE IS ALMOST NO REASON FOR COLD
SUBFREEZING AIR TO LINGER UNDER THIS STRATUS DECK. IN ANY
CASE...DESPITE LOWS IN THE LOWER 30S...ROADS AND SURFACES WILL NOT
BE ABLE TO RADIATE OUT SATURDAY NIGHT UNDER THE LOW CLOUDS WHICH
WILL ACTUALLY GIVE OFF LONG WAVE RADIATION TO THE SURFACES AS
WELL...LIKELY KEEPING ANY FZDZ MINIMALLY PROBLEMATIC. STILL...SINCE
WE ARE CLOSE ENOUGH TO 32 MUCH OF THE NIGHT IN THE NORTH...I WILL
MENTION IT IN THE GRIDS...BUT HOPEFULLY THIS IS NOT AN ADVISORY
EVENT. SHOULD THE ECMWF RISING TEMPERATURES BE CORRECT AS I
SUSPECT...WE SHOULD BE ABOVE FREEZING DURING THE TIME DRIZZLE OCCURS
SATURDAY NIGHT. THE DZ EVENT MAY LINGER THROUGH THE DAY SUNDAY...AND
AS MORE NOTABLE FORCING ARRIVES...IT MAY BECOME A INTERMITTENT LIGHT
RAIN IN THE NORTH...AND WILL ALLOW POPS TO BE MENTIONED AT THAT
TIME. IN THE END...IF THE DRIZZLE IS HEAVY ENOUGH...IT WILL NEED
MUCH HIGHER POPS FOR CONTINUALLY WETTING SURFACES ANYWAY.

SUNDAY NIGHT...WAA WILL BE RATHER STRONG AS THE COMPLICATED
NORTHWEST FLOW LOW PRESSURE SYSTEM ARRIVES. A SLOW MOVING SURFACE
LOW IS FORECAST NEAR IOWA...AS THE MAIN ENERGY DIVES WELL
SOUTH...CARVING OUT WHAT MAY BE INTENSE LOW PRESSURE OVER THE OHIO
VALLEY TOWARDS TUESDAY NIGHT. AS THIS OCCURS...BOUTS OF LIGHT RAIN
ARE LIKELY...EVENTUALLY CHANGING TO LIGHT SNOW BY LATER TUESDAY WHEN
THE SYSTEM BEGINS TO RAMP UP TO THE EAST. IN THE END...SUNDAY NIGHT
THROUGH MONDAY NIGHT MAY JUST BE A CONTINUATION OF THE RELATIVELY
MILD AND DAMP CONDITIONS WE HAVE BEEN QUITE FAMILIAR WITH THIS MONTH.

TUESDAY NIGHT INTO WEDNESDAY...WHILE LIGHT SNOW IS POSSIBLE DUE TO
ENERGY DIVING INTO THE RAPIDLY STRENGTHENING STORM TO THE EAST...OUT
BIGGEST SENSIBLE WEATHER WILL BE WIND...STRONG WINDS OF 20 TO 30 MPH
APPEAR LIKELY...WITH GUSTS OVER 35 POSSIBLE WEDNESDAY AFTERNOON AS
THE LOW TO THE EAST POTENTIALLY DEEPENS TO AROUND 970MB PER 00Z ECMWF

FOLLOWING THIS...AFTER A PERIOD OF COLD ADVECTION LASTING INTO
WEDNESDAY NIGHT...MODELS ARE GREATLY DIVERGENT. THE 00Z GFS OFFERS
NORTHWEST FLOW WITH NO SIGNIFICANT ARCTIC AIR...BUT LITTLE PCPN
THREATS. THE 00Z ECMWF HAS A PROGRESSIVE DEEP SYNOPTIC TROF MOVING
INTO THE LOWER ROCKIES BY DECEMBER 26...SPAWNING CYCLOGENESIS IN THE
WESTERN PLAINS. THAT SYSTEM WOULD IMPACT THE MIDWEST WITH MORE
CLOUDS/RAIN/POSSIBLE WINTER PCPN LATER ON THE 26/27. THERE IS NO
CERTAINTY OF THIS SYSTEM FROM MODEL TO MODEL...OR IN RUN TO RUN OF
ANY MODEL...SO MENTION OF A TRACK OF THAT POSSIBLE STORM SEEMS VERY
PREMATURE AT THIS TIME.    ERVIN

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1118 PM CST THU DEC 18 2014

NEARLY CALM WINDS AND VARIABLE CLOUD COVER WILL REMAIN IN PLACE
THROUGH THE REST OF THE NIGHT AS A RIDGE OF HIGH PRESSURE LINGERS
OVERHEAD. A DECK OF LOWER CLOUDS WITH MVFR CIGS WILL AFFECT
PRIMARILY THE DBQ SITE TONIGHT...BEFORE MORE WIDESPREAD LOWER
CLOUDS LOOMING JUST WEST OF THE RIDGE AXIS SPREAD INTO EASTERN IA
AND NW IL DURING THE DAY FRIDAY. CONFIDENCE IN THE EXACT TIMING OF
THIS TRANSITION TO MVFR CONDITIONS REMAINS LOW...BUT THERE IS A
GOOD LIKELIHOOD THAT ALL SITES HAVE CIGS AT OR BELOW 2500 FT BY 06Z
FRIDAY NIGHT.

&&

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

$$

SYNOPSIS...12
SHORT TERM...12
LONG TERM...ERVIN
AVIATION...SHEETS







000
FXUS63 KDVN 190918
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
318 AM CST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 316 AM CST FRI DEC 19 2014

LATEST SFC ANALYSIS WAS INDICATING LARGE RIDGE AXIS HOLDING FIRM
FROM ACRS ONTARIO NORTH OF LK SUPERIOR...ALL THE WAY DOWN INTO THE
MID TO LOWER MS RVR VALLEY. LIGHT LLVL RETURN FLOW PATTERN TO THE
WEST OF IT ACRS THE CENTRAL AND NORTHERN PLAINS. EXTENSIVE STRATUS
DECK UNDER THE WEST HALF OF THE RIDGE AND INTO THE EASTERN PLAINS
IN RETURN FLOW INTERACTION ZONE...OPEN SKY SWATH FROM SOUTHWEST
OF DBQ SOUTHEASTWARD THRU THE QUAD CITES/EASTERN I80 CORRIDOR
WILL LOOK TO FILL BACK IN EARLY THIS MORNING. ALOFT...00Z UPPER
AIR ANALYSIS AND CURRENT WATER VAPOR LOOP INDICATED A VORT WING
MOVING ACRS EASTERN SD INTO SOUTHEASTERN MN...TAILING DOWN ACRS
CENTRAL INTO EASTERN IA ATTM. THIS FEATURE IS PRODUCING LIGHT SNOW
ACRS MN...AND MAY BE INDUCING THE PATCHY LIGHT FREEZING DRIZZLE
CURRENTLY OUT ACRS CENTRAL IA. NEG VORTICITY IS MOVING OUT OF EASTERN
NEB INTO WESTERN IA BEHIND THIS MAIN VORT. A FURTHER UPSTREAM VORT
NOTED ACRS WY...AND A MORE VIGOROUS VORT MAX NOTED ACRS SOUTHERN
ALBERTA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST FRI DEC 19 2014

TODAY...BULK OF HIRES MODELS SUGGEST HIGH PRESSURE COMPLEX TO
HAVE IT/S EFFECT THIS MORNING MAINTAINING HIGHER CLOUD CIGS FOR
AWHILE...BEFORE AXIS STARTS TO SLIDE EASTWARD MIDDAY INTO THE
AFTERNOON ALLOWING THE LOWER DECK OUT WEST TO SEEP EASTWARD. AREA
OF LIGHT DRIZZLE/FREEZING DRIZZLE ACRS CENTRAL IA MOVING
NORTHEASTWARD AND MAY GET CLOSE TO THE NORTHWESTERN PORTION OF THE
CWA THIS MORNING...BUT WILL BANK ON DIURNAL EFFECTS AND THE RIDGE
STILL IN PLACE TO DEFLECT/EAT AWAY AT THIS PROCESS AND KEEP THE
DRIZZLE JUST TO THE WEST AND NORTHWEST OF THE CWA THIS MORNING...
ALTHOUGH IT WILL BE CLOSE AND WILL HAVE TO WATCH FOR UPDATES. THEN
EXPECT NVA OUT OF WESTERN IA FOR MUCH OF THE DAY WITH ONGOING CLOUDY
TO MOSTLY CLOUDY SKIES. SOME LIGHT SOUTHEAST SFC FLOW THIS AFTERNOON
TO HELP TEMPS MAKE IT A FEW DEGREES MILDER THAN YESTERDAY. THEN THE
UPSTREAM VORT NOTED ABOVE CURRENTLY ACRS WY WILL LOOK TO DIG ACRS
THE IA/MO BORDER BY LATE AFTERNOON AND EARLY EVENING. WITH RATHER
SHALLOW MOISTURE LAYER TRAPPED IN THE LOW LEVELS MAINLY UNDER H8
MB...THIS INCOMING WAVE MAY START TO PRODUCE SPOTTY DRIZZLE AGAIN
AS OPPOSED TO FLURRIES ACRS MO INTO CENTRAL IA...BUT AGAIN WILL BANK
ON ANY PRECIP REACHING THE SFC TO REMAIN WEST OF THE CWA LATE THIS
AFTERNOON AND INTO THE EVENING.

TONIGHT...EXPECT TEMPS TO HOLD STEADY IN THE MID TO UPPER 20S UNDER
STRATUS DECK AND CONTINUING LIGHT SOUTHEASTERLY SFC FLOW. AS THE
FIRST WEAK WAVE CONTINUES TO MOVE EAST ACRS THE SOUTH HALF OF IA
INTO IL DURING THE EVENING...THERE MAY BE A CHC FOR SOME SPOTTY LIGHT
DRIZZLE/FREEZING DRIZZLE TO BREAK OUT BUT WILL KEEP THE FCST DRY
THROUGH 06Z FOR NOW. A BETTER CHC AFTER MIDNIGHT AS THE STRONGER
WAVE ARRIVES OUT OF ALBERTA AND DIGS ACRS THE SOUTHWESTERN HALF OF
IA. MOISTURE DEPTH AND EXTENT OF LIFT STILL AT QUESTION...BUT WILL
INTRODUCE AT LEAST PATCHY LIGHT FREEZING DRIZZLE OUT OF THE
MOISTURE TRAPPED UNDER THE INVERSION ALOFT ACRS THE WESTERN CWA
AFTER MIDNIGHT. HOPEFULLY IT WILL BE SPOTTY AND LIGHT ENOUGH NOT TO
WARRANT SOME TYPE OF HEADLINE...BUT DAY SHIFT WILL HAVE TO REASSESS
AS WELL AS THE POSSIBILITY TO ADD SPOTTY CHC/S IN THE EVENING BEFORE
MIDNIGHT.    ..12..


.LONG TERM...(SATURDAY THROUGH NEXT THURSDAY)
ISSUED AT 316 AM CST FRI DEC 19 2014

THE LONG TERM WILL BEGIN WITH THE SAME CLOUDY AND DAMP REGIME WE
HAVE SEEN MANY TIMES OVER THIS PAST MONTH. TONIGHTS DRIZZLE...FOG
AND LOW CLOUDS LOOK TO REMAIN IN PLACE FOR SATURDAY THROUGH SUNDAY
NIGHT...WITH THE MAIN IMPACTS GREATLY DEPENDING ON HOURLY
TEMPERATURES. SHORT LIVED SUBSIDENCE SATURDAY BEHIND THE MID LEVEL
SHORT WAVE LATER TONIGHT WILL HOPEFULLY OFFER A LULL IN ANY
DRIZZLE...SO AFTER A MILD DAY IN THE MID TO UPPER 30S...WE WILL SET
UP FOR ANOTHER DRIZZLE/FZDZ EVENT BY SATURDAY NIGHT. THE DOMESTIC
MODELS ARE OFFERING COLD SURFACE CONDITIONS FOR SATURDAY
NIGHT...WHILE THE ECMWF IS MUCH MORE MILD. I BELIEVE THE ECMWF IS
MORE ON TARGET HERE AS THERE IS ALMOST NO REASON FOR COLD
SUBFREEZING AIR TO LINGER UNDER THIS STRATUS DECK. IN ANY
CASE...DESPITE LOWS IN THE LOWER 30S...ROADS AND SURFACES WILL NOT
BE ABLE TO RADIATE OUT SATURDAY NIGHT UNDER THE LOW CLOUDS WHICH
WILL ACTUALLY GIVE OFF LONG WAVE RADIATION TO THE SURFACES AS
WELL...LIKELY KEEPING ANY FZDZ MINIMALLY PROBLEMATIC. STILL...SINCE
WE ARE CLOSE ENOUGH TO 32 MUCH OF THE NIGHT IN THE NORTH...I WILL
MENTION IT IN THE GRIDS...BUT HOPEFULLY THIS IS NOT AN ADVISORY
EVENT. SHOULD THE ECMWF RISING TEMPERATURES BE CORRECT AS I
SUSPECT...WE SHOULD BE ABOVE FREEZING DURING THE TIME DRIZZLE OCCURS
SATURDAY NIGHT. THE DZ EVENT MAY LINGER THROUGH THE DAY SUNDAY...AND
AS MORE NOTABLE FORCING ARRIVES...IT MAY BECOME A INTERMITTENT LIGHT
RAIN IN THE NORTH...AND WILL ALLOW POPS TO BE MENTIONED AT THAT
TIME. IN THE END...IF THE DRIZZLE IS HEAVY ENOUGH...IT WILL NEED
MUCH HIGHER POPS FOR CONTINUALLY WETTING SURFACES ANYWAY.

SUNDAY NIGHT...WAA WILL BE RATHER STRONG AS THE COMPLICATED
NORTHWEST FLOW LOW PRESSURE SYSTEM ARRIVES. A SLOW MOVING SURFACE
LOW IS FORECAST NEAR IOWA...AS THE MAIN ENERGY DIVES WELL
SOUTH...CARVING OUT WHAT MAY BE INTENSE LOW PRESSURE OVER THE OHIO
VALLEY TOWARDS TUESDAY NIGHT. AS THIS OCCURS...BOUTS OF LIGHT RAIN
ARE LIKELY...EVENTUALLY CHANGING TO LIGHT SNOW BY LATER TUESDAY WHEN
THE SYSTEM BEGINS TO RAMP UP TO THE EAST. IN THE END...SUNDAY NIGHT
THROUGH MONDAY NIGHT MAY JUST BE A CONTINUATION OF THE RELATIVELY
MILD AND DAMP CONDITIONS WE HAVE BEEN QUITE FAMILIAR WITH THIS MONTH.

TUESDAY NIGHT INTO WEDNESDAY...WHILE LIGHT SNOW IS POSSIBLE DUE TO
ENERGY DIVING INTO THE RAPIDLY STRENGTHENING STORM TO THE EAST...OUT
BIGGEST SENSIBLE WEATHER WILL BE WIND...STRONG WINDS OF 20 TO 30 MPH
APPEAR LIKELY...WITH GUSTS OVER 35 POSSIBLE WEDNESDAY AFTERNOON AS
THE LOW TO THE EAST POTENTIALLY DEEPENS TO AROUND 970MB PER 00Z ECMWF

FOLLOWING THIS...AFTER A PERIOD OF COLD ADVECTION LASTING INTO
WEDNESDAY NIGHT...MODELS ARE GREATLY DIVERGENT. THE 00Z GFS OFFERS
NORTHWEST FLOW WITH NO SIGNIFICANT ARCTIC AIR...BUT LITTLE PCPN
THREATS. THE 00Z ECMWF HAS A PROGRESSIVE DEEP SYNOPTIC TROF MOVING
INTO THE LOWER ROCKIES BY DECEMBER 26...SPAWNING CYCLOGENESIS IN THE
WESTERN PLAINS. THAT SYSTEM WOULD IMPACT THE MIDWEST WITH MORE
CLOUDS/RAIN/POSSIBLE WINTER PCPN LATER ON THE 26/27. THERE IS NO
CERTAINTY OF THIS SYSTEM FROM MODEL TO MODEL...OR IN RUN TO RUN OF
ANY MODEL...SO MENTION OF A TRACK OF THAT POSSIBLE STORM SEEMS VERY
PREMATURE AT THIS TIME.    ERVIN

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1118 PM CST THU DEC 18 2014

NEARLY CALM WINDS AND VARIABLE CLOUD COVER WILL REMAIN IN PLACE
THROUGH THE REST OF THE NIGHT AS A RIDGE OF HIGH PRESSURE LINGERS
OVERHEAD. A DECK OF LOWER CLOUDS WITH MVFR CIGS WILL AFFECT
PRIMARILY THE DBQ SITE TONIGHT...BEFORE MORE WIDESPREAD LOWER
CLOUDS LOOMING JUST WEST OF THE RIDGE AXIS SPREAD INTO EASTERN IA
AND NW IL DURING THE DAY FRIDAY. CONFIDENCE IN THE EXACT TIMING OF
THIS TRANSITION TO MVFR CONDITIONS REMAINS LOW...BUT THERE IS A
GOOD LIKELIHOOD THAT ALL SITES HAVE CIGS AT OR BELOW 2500 FT BY 06Z
FRIDAY NIGHT.

&&

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

$$

SYNOPSIS...12
SHORT TERM...12
LONG TERM...ERVIN
AVIATION...SHEETS







000
FXUS63 KDVN 190918
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
318 AM CST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 316 AM CST FRI DEC 19 2014

LATEST SFC ANALYSIS WAS INDICATING LARGE RIDGE AXIS HOLDING FIRM
FROM ACRS ONTARIO NORTH OF LK SUPERIOR...ALL THE WAY DOWN INTO THE
MID TO LOWER MS RVR VALLEY. LIGHT LLVL RETURN FLOW PATTERN TO THE
WEST OF IT ACRS THE CENTRAL AND NORTHERN PLAINS. EXTENSIVE STRATUS
DECK UNDER THE WEST HALF OF THE RIDGE AND INTO THE EASTERN PLAINS
IN RETURN FLOW INTERACTION ZONE...OPEN SKY SWATH FROM SOUTHWEST
OF DBQ SOUTHEASTWARD THRU THE QUAD CITES/EASTERN I80 CORRIDOR
WILL LOOK TO FILL BACK IN EARLY THIS MORNING. ALOFT...00Z UPPER
AIR ANALYSIS AND CURRENT WATER VAPOR LOOP INDICATED A VORT WING
MOVING ACRS EASTERN SD INTO SOUTHEASTERN MN...TAILING DOWN ACRS
CENTRAL INTO EASTERN IA ATTM. THIS FEATURE IS PRODUCING LIGHT SNOW
ACRS MN...AND MAY BE INDUCING THE PATCHY LIGHT FREEZING DRIZZLE
CURRENTLY OUT ACRS CENTRAL IA. NEG VORTICITY IS MOVING OUT OF EASTERN
NEB INTO WESTERN IA BEHIND THIS MAIN VORT. A FURTHER UPSTREAM VORT
NOTED ACRS WY...AND A MORE VIGOROUS VORT MAX NOTED ACRS SOUTHERN
ALBERTA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST FRI DEC 19 2014

TODAY...BULK OF HIRES MODELS SUGGEST HIGH PRESSURE COMPLEX TO
HAVE IT/S EFFECT THIS MORNING MAINTAINING HIGHER CLOUD CIGS FOR
AWHILE...BEFORE AXIS STARTS TO SLIDE EASTWARD MIDDAY INTO THE
AFTERNOON ALLOWING THE LOWER DECK OUT WEST TO SEEP EASTWARD. AREA
OF LIGHT DRIZZLE/FREEZING DRIZZLE ACRS CENTRAL IA MOVING
NORTHEASTWARD AND MAY GET CLOSE TO THE NORTHWESTERN PORTION OF THE
CWA THIS MORNING...BUT WILL BANK ON DIURNAL EFFECTS AND THE RIDGE
STILL IN PLACE TO DEFLECT/EAT AWAY AT THIS PROCESS AND KEEP THE
DRIZZLE JUST TO THE WEST AND NORTHWEST OF THE CWA THIS MORNING...
ALTHOUGH IT WILL BE CLOSE AND WILL HAVE TO WATCH FOR UPDATES. THEN
EXPECT NVA OUT OF WESTERN IA FOR MUCH OF THE DAY WITH ONGOING CLOUDY
TO MOSTLY CLOUDY SKIES. SOME LIGHT SOUTHEAST SFC FLOW THIS AFTERNOON
TO HELP TEMPS MAKE IT A FEW DEGREES MILDER THAN YESTERDAY. THEN THE
UPSTREAM VORT NOTED ABOVE CURRENTLY ACRS WY WILL LOOK TO DIG ACRS
THE IA/MO BORDER BY LATE AFTERNOON AND EARLY EVENING. WITH RATHER
SHALLOW MOISTURE LAYER TRAPPED IN THE LOW LEVELS MAINLY UNDER H8
MB...THIS INCOMING WAVE MAY START TO PRODUCE SPOTTY DRIZZLE AGAIN
AS OPPOSED TO FLURRIES ACRS MO INTO CENTRAL IA...BUT AGAIN WILL BANK
ON ANY PRECIP REACHING THE SFC TO REMAIN WEST OF THE CWA LATE THIS
AFTERNOON AND INTO THE EVENING.

TONIGHT...EXPECT TEMPS TO HOLD STEADY IN THE MID TO UPPER 20S UNDER
STRATUS DECK AND CONTINUING LIGHT SOUTHEASTERLY SFC FLOW. AS THE
FIRST WEAK WAVE CONTINUES TO MOVE EAST ACRS THE SOUTH HALF OF IA
INTO IL DURING THE EVENING...THERE MAY BE A CHC FOR SOME SPOTTY LIGHT
DRIZZLE/FREEZING DRIZZLE TO BREAK OUT BUT WILL KEEP THE FCST DRY
THROUGH 06Z FOR NOW. A BETTER CHC AFTER MIDNIGHT AS THE STRONGER
WAVE ARRIVES OUT OF ALBERTA AND DIGS ACRS THE SOUTHWESTERN HALF OF
IA. MOISTURE DEPTH AND EXTENT OF LIFT STILL AT QUESTION...BUT WILL
INTRODUCE AT LEAST PATCHY LIGHT FREEZING DRIZZLE OUT OF THE
MOISTURE TRAPPED UNDER THE INVERSION ALOFT ACRS THE WESTERN CWA
AFTER MIDNIGHT. HOPEFULLY IT WILL BE SPOTTY AND LIGHT ENOUGH NOT TO
WARRANT SOME TYPE OF HEADLINE...BUT DAY SHIFT WILL HAVE TO REASSESS
AS WELL AS THE POSSIBILITY TO ADD SPOTTY CHC/S IN THE EVENING BEFORE
MIDNIGHT.    ..12..


.LONG TERM...(SATURDAY THROUGH NEXT THURSDAY)
ISSUED AT 316 AM CST FRI DEC 19 2014

THE LONG TERM WILL BEGIN WITH THE SAME CLOUDY AND DAMP REGIME WE
HAVE SEEN MANY TIMES OVER THIS PAST MONTH. TONIGHTS DRIZZLE...FOG
AND LOW CLOUDS LOOK TO REMAIN IN PLACE FOR SATURDAY THROUGH SUNDAY
NIGHT...WITH THE MAIN IMPACTS GREATLY DEPENDING ON HOURLY
TEMPERATURES. SHORT LIVED SUBSIDENCE SATURDAY BEHIND THE MID LEVEL
SHORT WAVE LATER TONIGHT WILL HOPEFULLY OFFER A LULL IN ANY
DRIZZLE...SO AFTER A MILD DAY IN THE MID TO UPPER 30S...WE WILL SET
UP FOR ANOTHER DRIZZLE/FZDZ EVENT BY SATURDAY NIGHT. THE DOMESTIC
MODELS ARE OFFERING COLD SURFACE CONDITIONS FOR SATURDAY
NIGHT...WHILE THE ECMWF IS MUCH MORE MILD. I BELIEVE THE ECMWF IS
MORE ON TARGET HERE AS THERE IS ALMOST NO REASON FOR COLD
SUBFREEZING AIR TO LINGER UNDER THIS STRATUS DECK. IN ANY
CASE...DESPITE LOWS IN THE LOWER 30S...ROADS AND SURFACES WILL NOT
BE ABLE TO RADIATE OUT SATURDAY NIGHT UNDER THE LOW CLOUDS WHICH
WILL ACTUALLY GIVE OFF LONG WAVE RADIATION TO THE SURFACES AS
WELL...LIKELY KEEPING ANY FZDZ MINIMALLY PROBLEMATIC. STILL...SINCE
WE ARE CLOSE ENOUGH TO 32 MUCH OF THE NIGHT IN THE NORTH...I WILL
MENTION IT IN THE GRIDS...BUT HOPEFULLY THIS IS NOT AN ADVISORY
EVENT. SHOULD THE ECMWF RISING TEMPERATURES BE CORRECT AS I
SUSPECT...WE SHOULD BE ABOVE FREEZING DURING THE TIME DRIZZLE OCCURS
SATURDAY NIGHT. THE DZ EVENT MAY LINGER THROUGH THE DAY SUNDAY...AND
AS MORE NOTABLE FORCING ARRIVES...IT MAY BECOME A INTERMITTENT LIGHT
RAIN IN THE NORTH...AND WILL ALLOW POPS TO BE MENTIONED AT THAT
TIME. IN THE END...IF THE DRIZZLE IS HEAVY ENOUGH...IT WILL NEED
MUCH HIGHER POPS FOR CONTINUALLY WETTING SURFACES ANYWAY.

SUNDAY NIGHT...WAA WILL BE RATHER STRONG AS THE COMPLICATED
NORTHWEST FLOW LOW PRESSURE SYSTEM ARRIVES. A SLOW MOVING SURFACE
LOW IS FORECAST NEAR IOWA...AS THE MAIN ENERGY DIVES WELL
SOUTH...CARVING OUT WHAT MAY BE INTENSE LOW PRESSURE OVER THE OHIO
VALLEY TOWARDS TUESDAY NIGHT. AS THIS OCCURS...BOUTS OF LIGHT RAIN
ARE LIKELY...EVENTUALLY CHANGING TO LIGHT SNOW BY LATER TUESDAY WHEN
THE SYSTEM BEGINS TO RAMP UP TO THE EAST. IN THE END...SUNDAY NIGHT
THROUGH MONDAY NIGHT MAY JUST BE A CONTINUATION OF THE RELATIVELY
MILD AND DAMP CONDITIONS WE HAVE BEEN QUITE FAMILIAR WITH THIS MONTH.

TUESDAY NIGHT INTO WEDNESDAY...WHILE LIGHT SNOW IS POSSIBLE DUE TO
ENERGY DIVING INTO THE RAPIDLY STRENGTHENING STORM TO THE EAST...OUT
BIGGEST SENSIBLE WEATHER WILL BE WIND...STRONG WINDS OF 20 TO 30 MPH
APPEAR LIKELY...WITH GUSTS OVER 35 POSSIBLE WEDNESDAY AFTERNOON AS
THE LOW TO THE EAST POTENTIALLY DEEPENS TO AROUND 970MB PER 00Z ECMWF

FOLLOWING THIS...AFTER A PERIOD OF COLD ADVECTION LASTING INTO
WEDNESDAY NIGHT...MODELS ARE GREATLY DIVERGENT. THE 00Z GFS OFFERS
NORTHWEST FLOW WITH NO SIGNIFICANT ARCTIC AIR...BUT LITTLE PCPN
THREATS. THE 00Z ECMWF HAS A PROGRESSIVE DEEP SYNOPTIC TROF MOVING
INTO THE LOWER ROCKIES BY DECEMBER 26...SPAWNING CYCLOGENESIS IN THE
WESTERN PLAINS. THAT SYSTEM WOULD IMPACT THE MIDWEST WITH MORE
CLOUDS/RAIN/POSSIBLE WINTER PCPN LATER ON THE 26/27. THERE IS NO
CERTAINTY OF THIS SYSTEM FROM MODEL TO MODEL...OR IN RUN TO RUN OF
ANY MODEL...SO MENTION OF A TRACK OF THAT POSSIBLE STORM SEEMS VERY
PREMATURE AT THIS TIME.    ERVIN

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1118 PM CST THU DEC 18 2014

NEARLY CALM WINDS AND VARIABLE CLOUD COVER WILL REMAIN IN PLACE
THROUGH THE REST OF THE NIGHT AS A RIDGE OF HIGH PRESSURE LINGERS
OVERHEAD. A DECK OF LOWER CLOUDS WITH MVFR CIGS WILL AFFECT
PRIMARILY THE DBQ SITE TONIGHT...BEFORE MORE WIDESPREAD LOWER
CLOUDS LOOMING JUST WEST OF THE RIDGE AXIS SPREAD INTO EASTERN IA
AND NW IL DURING THE DAY FRIDAY. CONFIDENCE IN THE EXACT TIMING OF
THIS TRANSITION TO MVFR CONDITIONS REMAINS LOW...BUT THERE IS A
GOOD LIKELIHOOD THAT ALL SITES HAVE CIGS AT OR BELOW 2500 FT BY 06Z
FRIDAY NIGHT.

&&

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

$$

SYNOPSIS...12
SHORT TERM...12
LONG TERM...ERVIN
AVIATION...SHEETS







000
FXUS63 KDVN 190918
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
318 AM CST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 316 AM CST FRI DEC 19 2014

LATEST SFC ANALYSIS WAS INDICATING LARGE RIDGE AXIS HOLDING FIRM
FROM ACRS ONTARIO NORTH OF LK SUPERIOR...ALL THE WAY DOWN INTO THE
MID TO LOWER MS RVR VALLEY. LIGHT LLVL RETURN FLOW PATTERN TO THE
WEST OF IT ACRS THE CENTRAL AND NORTHERN PLAINS. EXTENSIVE STRATUS
DECK UNDER THE WEST HALF OF THE RIDGE AND INTO THE EASTERN PLAINS
IN RETURN FLOW INTERACTION ZONE...OPEN SKY SWATH FROM SOUTHWEST
OF DBQ SOUTHEASTWARD THRU THE QUAD CITES/EASTERN I80 CORRIDOR
WILL LOOK TO FILL BACK IN EARLY THIS MORNING. ALOFT...00Z UPPER
AIR ANALYSIS AND CURRENT WATER VAPOR LOOP INDICATED A VORT WING
MOVING ACRS EASTERN SD INTO SOUTHEASTERN MN...TAILING DOWN ACRS
CENTRAL INTO EASTERN IA ATTM. THIS FEATURE IS PRODUCING LIGHT SNOW
ACRS MN...AND MAY BE INDUCING THE PATCHY LIGHT FREEZING DRIZZLE
CURRENTLY OUT ACRS CENTRAL IA. NEG VORTICITY IS MOVING OUT OF EASTERN
NEB INTO WESTERN IA BEHIND THIS MAIN VORT. A FURTHER UPSTREAM VORT
NOTED ACRS WY...AND A MORE VIGOROUS VORT MAX NOTED ACRS SOUTHERN
ALBERTA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST FRI DEC 19 2014

TODAY...BULK OF HIRES MODELS SUGGEST HIGH PRESSURE COMPLEX TO
HAVE IT/S EFFECT THIS MORNING MAINTAINING HIGHER CLOUD CIGS FOR
AWHILE...BEFORE AXIS STARTS TO SLIDE EASTWARD MIDDAY INTO THE
AFTERNOON ALLOWING THE LOWER DECK OUT WEST TO SEEP EASTWARD. AREA
OF LIGHT DRIZZLE/FREEZING DRIZZLE ACRS CENTRAL IA MOVING
NORTHEASTWARD AND MAY GET CLOSE TO THE NORTHWESTERN PORTION OF THE
CWA THIS MORNING...BUT WILL BANK ON DIURNAL EFFECTS AND THE RIDGE
STILL IN PLACE TO DEFLECT/EAT AWAY AT THIS PROCESS AND KEEP THE
DRIZZLE JUST TO THE WEST AND NORTHWEST OF THE CWA THIS MORNING...
ALTHOUGH IT WILL BE CLOSE AND WILL HAVE TO WATCH FOR UPDATES. THEN
EXPECT NVA OUT OF WESTERN IA FOR MUCH OF THE DAY WITH ONGOING CLOUDY
TO MOSTLY CLOUDY SKIES. SOME LIGHT SOUTHEAST SFC FLOW THIS AFTERNOON
TO HELP TEMPS MAKE IT A FEW DEGREES MILDER THAN YESTERDAY. THEN THE
UPSTREAM VORT NOTED ABOVE CURRENTLY ACRS WY WILL LOOK TO DIG ACRS
THE IA/MO BORDER BY LATE AFTERNOON AND EARLY EVENING. WITH RATHER
SHALLOW MOISTURE LAYER TRAPPED IN THE LOW LEVELS MAINLY UNDER H8
MB...THIS INCOMING WAVE MAY START TO PRODUCE SPOTTY DRIZZLE AGAIN
AS OPPOSED TO FLURRIES ACRS MO INTO CENTRAL IA...BUT AGAIN WILL BANK
ON ANY PRECIP REACHING THE SFC TO REMAIN WEST OF THE CWA LATE THIS
AFTERNOON AND INTO THE EVENING.

TONIGHT...EXPECT TEMPS TO HOLD STEADY IN THE MID TO UPPER 20S UNDER
STRATUS DECK AND CONTINUING LIGHT SOUTHEASTERLY SFC FLOW. AS THE
FIRST WEAK WAVE CONTINUES TO MOVE EAST ACRS THE SOUTH HALF OF IA
INTO IL DURING THE EVENING...THERE MAY BE A CHC FOR SOME SPOTTY LIGHT
DRIZZLE/FREEZING DRIZZLE TO BREAK OUT BUT WILL KEEP THE FCST DRY
THROUGH 06Z FOR NOW. A BETTER CHC AFTER MIDNIGHT AS THE STRONGER
WAVE ARRIVES OUT OF ALBERTA AND DIGS ACRS THE SOUTHWESTERN HALF OF
IA. MOISTURE DEPTH AND EXTENT OF LIFT STILL AT QUESTION...BUT WILL
INTRODUCE AT LEAST PATCHY LIGHT FREEZING DRIZZLE OUT OF THE
MOISTURE TRAPPED UNDER THE INVERSION ALOFT ACRS THE WESTERN CWA
AFTER MIDNIGHT. HOPEFULLY IT WILL BE SPOTTY AND LIGHT ENOUGH NOT TO
WARRANT SOME TYPE OF HEADLINE...BUT DAY SHIFT WILL HAVE TO REASSESS
AS WELL AS THE POSSIBILITY TO ADD SPOTTY CHC/S IN THE EVENING BEFORE
MIDNIGHT.    ..12..


.LONG TERM...(SATURDAY THROUGH NEXT THURSDAY)
ISSUED AT 316 AM CST FRI DEC 19 2014

THE LONG TERM WILL BEGIN WITH THE SAME CLOUDY AND DAMP REGIME WE
HAVE SEEN MANY TIMES OVER THIS PAST MONTH. TONIGHTS DRIZZLE...FOG
AND LOW CLOUDS LOOK TO REMAIN IN PLACE FOR SATURDAY THROUGH SUNDAY
NIGHT...WITH THE MAIN IMPACTS GREATLY DEPENDING ON HOURLY
TEMPERATURES. SHORT LIVED SUBSIDENCE SATURDAY BEHIND THE MID LEVEL
SHORT WAVE LATER TONIGHT WILL HOPEFULLY OFFER A LULL IN ANY
DRIZZLE...SO AFTER A MILD DAY IN THE MID TO UPPER 30S...WE WILL SET
UP FOR ANOTHER DRIZZLE/FZDZ EVENT BY SATURDAY NIGHT. THE DOMESTIC
MODELS ARE OFFERING COLD SURFACE CONDITIONS FOR SATURDAY
NIGHT...WHILE THE ECMWF IS MUCH MORE MILD. I BELIEVE THE ECMWF IS
MORE ON TARGET HERE AS THERE IS ALMOST NO REASON FOR COLD
SUBFREEZING AIR TO LINGER UNDER THIS STRATUS DECK. IN ANY
CASE...DESPITE LOWS IN THE LOWER 30S...ROADS AND SURFACES WILL NOT
BE ABLE TO RADIATE OUT SATURDAY NIGHT UNDER THE LOW CLOUDS WHICH
WILL ACTUALLY GIVE OFF LONG WAVE RADIATION TO THE SURFACES AS
WELL...LIKELY KEEPING ANY FZDZ MINIMALLY PROBLEMATIC. STILL...SINCE
WE ARE CLOSE ENOUGH TO 32 MUCH OF THE NIGHT IN THE NORTH...I WILL
MENTION IT IN THE GRIDS...BUT HOPEFULLY THIS IS NOT AN ADVISORY
EVENT. SHOULD THE ECMWF RISING TEMPERATURES BE CORRECT AS I
SUSPECT...WE SHOULD BE ABOVE FREEZING DURING THE TIME DRIZZLE OCCURS
SATURDAY NIGHT. THE DZ EVENT MAY LINGER THROUGH THE DAY SUNDAY...AND
AS MORE NOTABLE FORCING ARRIVES...IT MAY BECOME A INTERMITTENT LIGHT
RAIN IN THE NORTH...AND WILL ALLOW POPS TO BE MENTIONED AT THAT
TIME. IN THE END...IF THE DRIZZLE IS HEAVY ENOUGH...IT WILL NEED
MUCH HIGHER POPS FOR CONTINUALLY WETTING SURFACES ANYWAY.

SUNDAY NIGHT...WAA WILL BE RATHER STRONG AS THE COMPLICATED
NORTHWEST FLOW LOW PRESSURE SYSTEM ARRIVES. A SLOW MOVING SURFACE
LOW IS FORECAST NEAR IOWA...AS THE MAIN ENERGY DIVES WELL
SOUTH...CARVING OUT WHAT MAY BE INTENSE LOW PRESSURE OVER THE OHIO
VALLEY TOWARDS TUESDAY NIGHT. AS THIS OCCURS...BOUTS OF LIGHT RAIN
ARE LIKELY...EVENTUALLY CHANGING TO LIGHT SNOW BY LATER TUESDAY WHEN
THE SYSTEM BEGINS TO RAMP UP TO THE EAST. IN THE END...SUNDAY NIGHT
THROUGH MONDAY NIGHT MAY JUST BE A CONTINUATION OF THE RELATIVELY
MILD AND DAMP CONDITIONS WE HAVE BEEN QUITE FAMILIAR WITH THIS MONTH.

TUESDAY NIGHT INTO WEDNESDAY...WHILE LIGHT SNOW IS POSSIBLE DUE TO
ENERGY DIVING INTO THE RAPIDLY STRENGTHENING STORM TO THE EAST...OUT
BIGGEST SENSIBLE WEATHER WILL BE WIND...STRONG WINDS OF 20 TO 30 MPH
APPEAR LIKELY...WITH GUSTS OVER 35 POSSIBLE WEDNESDAY AFTERNOON AS
THE LOW TO THE EAST POTENTIALLY DEEPENS TO AROUND 970MB PER 00Z ECMWF

FOLLOWING THIS...AFTER A PERIOD OF COLD ADVECTION LASTING INTO
WEDNESDAY NIGHT...MODELS ARE GREATLY DIVERGENT. THE 00Z GFS OFFERS
NORTHWEST FLOW WITH NO SIGNIFICANT ARCTIC AIR...BUT LITTLE PCPN
THREATS. THE 00Z ECMWF HAS A PROGRESSIVE DEEP SYNOPTIC TROF MOVING
INTO THE LOWER ROCKIES BY DECEMBER 26...SPAWNING CYCLOGENESIS IN THE
WESTERN PLAINS. THAT SYSTEM WOULD IMPACT THE MIDWEST WITH MORE
CLOUDS/RAIN/POSSIBLE WINTER PCPN LATER ON THE 26/27. THERE IS NO
CERTAINTY OF THIS SYSTEM FROM MODEL TO MODEL...OR IN RUN TO RUN OF
ANY MODEL...SO MENTION OF A TRACK OF THAT POSSIBLE STORM SEEMS VERY
PREMATURE AT THIS TIME.    ERVIN

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1118 PM CST THU DEC 18 2014

NEARLY CALM WINDS AND VARIABLE CLOUD COVER WILL REMAIN IN PLACE
THROUGH THE REST OF THE NIGHT AS A RIDGE OF HIGH PRESSURE LINGERS
OVERHEAD. A DECK OF LOWER CLOUDS WITH MVFR CIGS WILL AFFECT
PRIMARILY THE DBQ SITE TONIGHT...BEFORE MORE WIDESPREAD LOWER
CLOUDS LOOMING JUST WEST OF THE RIDGE AXIS SPREAD INTO EASTERN IA
AND NW IL DURING THE DAY FRIDAY. CONFIDENCE IN THE EXACT TIMING OF
THIS TRANSITION TO MVFR CONDITIONS REMAINS LOW...BUT THERE IS A
GOOD LIKELIHOOD THAT ALL SITES HAVE CIGS AT OR BELOW 2500 FT BY 06Z
FRIDAY NIGHT.

&&

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

$$

SYNOPSIS...12
SHORT TERM...12
LONG TERM...ERVIN
AVIATION...SHEETS







000
FXUS63 KDMX 190548
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1148 PM CST THU DEC 18 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 324 PM CST THU DEC 18 2014

SNOW HAS ENDED OVER THE SOUTHEASTERN CWA AS THE CULPRIT UPPER LEVEL
WAVE HAS RAPIDLY WEAKENED AND DGZ FORCING HAS WANED. BASED ON WEBCAM
IMAGES AND A FEW SPOTTER/COOP REPORTS...MOST AREAS IN THE SOUTHERN
THREE TIERS OF COUNTIES SAW LESS THAN AN INCH OF SNOW. ATTENTION NOW
TURNS UPSTREAM TO A LARGE STRATUS PLUME STRETCHING FROM NORTHWEST
MONTANA TO THE TEXAS PANHANDLE...WITH THE EASTERN FRONT NOW JUST
ABOUT TO ENTER THE WESTERN CWA. LIGHT WEST TO SOUTHWEST FLOW IN THE
LOWEST 1 KM OF THE ATMOSPHERE BEHIND A DEPARTING SURFACE RIDGE
SHOULD ADVECT THIS CLOUD MASS OVER CENTRAL IOWA TONIGHT AND KEEP
SKIES OVERCAST ALL NIGHT AND INTO TOMORROW MORNING. THE CLOUDS
SHOULD ALSO BOLSTER LOW TEMPS TONIGHT COMPARED TO PREVIOUS NIGHTS
AND DIDN`T DEVIATE MUCH FROM GUIDANCE IN THIS RESPECT.

THE BIGGEST UNCERTAINTY FOR TONIGHT IS THE POSSIBILITY OF FLURRIES
OR FREEZING DRIZZLE WEST OF I-35. SHORT-RANGE MODEL SOUNDINGS (RUC
AND HRRR IN PARTICULAR) SATURATE THE LOWEST 5 KFT OF THE ATMOSPHERE
IN THIS REGION TONIGHT WITH NEARLY ISOTHERMAL PROFILES IN THIS LAYER
HOVERING BETWEEN -4 AND -7C. WITH THIS CONDITIONAL ICE PROBABILITY
...WENT WITH A MIX OF OCCASIONAL FLURRIES AND PATCHY FZDZ. FORCING
SHOULD BE MARGINAL AT BEST AND NO ACCUMULATION OF SNOW OR ICE IS
ANTICIPATED. ANY LIFT WITH AN UPPER LEVEL TROUGH ON WATER VAPOR
IMAGERY NW OF THE CWA SHOULD STAY NORTH AND EAST OF THE AREA.
ISENTROPIC UPGLIDE IN THE LOWEST 100MB OF THE ATMOSPHERE IS
PRESENT...BUT AGAIN VERY WEAK.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 324 PM CST THU DEC 18 2014

THE WEATHER IN THE LONG TERM WILL IN GENERAL BE MORE ACTIVE THEN
WHAT WE HAVE SEEN IN A WHILE.  FRIDAY THROUGH SUNDAY THERE WILL BE
NUMEROUS RELATIVELY WEAK SHORT WAVES MOVE ACROSS IOWA IN A GENERALLY
ZONAL FLOW.  THROUGH SATURDAY MOISTURE WILL EITHER BE SPARSE OR
SHALLOW SO I AM NOT EXPECTING MUCH WITH THESE SHORTWAVES IN TERMS OF
SENSIBLE WEATHER EXCEPT FOR CLOUD COVER.  TEMPS SHOULD BE RATHER
MILD FOR MID TO LATE DECEMBER.

SATURDAY NIGHT THROUGH SUNDAY A LITTLE STRONGER SHORT WAVE MOVES IN
AND MOISTURE DEPTH INCREASES SLIGHTLY ALTHOUGH IT IS STILL VERY
SHALLOW.  SOUNDINGS DO NOT INDICATE ICE INTRODUCTION AND WHILE THERE
ARE MODEL DIFFERENCES AS TO WHERE ANY WEAK FORCING MIGHT OCCUR...IT
DOES APPEAR THAT THE NORTHERN HALF OF IOWA IS MORE LIKELY TO SEE
THIS THAN SOUTHERN IOWA.  AS A RESULT I KEPT THE MENTION OF FREEZING
DRIZZLE CONFINED TO THE NORTH.  THE SOUNDING DOES SATURATE
OR BEGIN TO SATURATE SUFFICIENTLY LATE SATURDAY NIGHT THROUGH
SUNDAY MORNING THROUGH THE DENDRITIC ZONE THAT WE COULD TRANSITION
TO SOME LIGHT SNOW UP NORTH...ESPECIALLY SUNDAY MORNING. THAT
SHORTWAVE EXITS DURING THE EARLY AFTERNOON AND TEMPS WARM
SUFFICIENTLY FOR A WINTERY MIX CHANGING TO RAIN ACROSS AT LEAST
SOME OF THE AREA.

SUNDAY NIGHT THROUGH MONDAY A MORE POTENT SHORTWAVE MOVES INTO
IOWA...AFFECTING THE WEST SUNDAY NIGHT AND THE REST OF THE AREA
THROUGH TUESDAY.  HERE MODELS DIVERGE ON HOW TO HANDLE THIS SYSTEM.
THE GFS KEEP THE UPPER LEVEL WAVE OPEN AND DEVELOPS A CLOSED SURFACE
LOW OVER CENTRAL TO NORTHEAST IOWA.  THE EURO DRASTICALLY DEPEND
THE UPPER WAVE TO OUR WEST THEN CONTINUES TO DEVELOP IT INTO A
CLOSED LOW MONDAY NIGHT AND TUESDAY ACROSS EASTERN IOWA.  THE
RESULTANT CLOSED SURFACE LOW IS OVER EASTERN IOWA AS WELL AND
FURTHER SOUTHWEST THAN THE GFS HAS.  THE GFS REALLY DEVELOPS THE QG
FORCING ACROSS CENTRAL IOWA SUNDAY NIGHT THEN IS SIGNIFICANTLY
WEAKER THROUGH TUESDAY.  SOUNDINGS SHOW A PROFILE THAT IS PRETTY
WARM THROUGH MONDAY AFTERNOON WHEN THE PROFILE COOLS TO BELOW
FREEZING.  PRECIP THROUGH EARLY MONDAY AFTERNOON SHOULD BE RAIN WITH
AN OCCASIONAL WINTERY MIX ESPECIALLY UP NORTH.  DURING THE AFTERNOON
WE WILL BE TRANSITIONING TO A RAIN/SNOW MIX BEFORE GOING TO ALL SNOW
MONDAY NIGHT.  IT IS TOO FAR OUT TO CONSIDER SNOWFALL AMOUNTS YET
AND GIVEN THE MODEL DISCREPANCIES IT WOULD BE HARD TO DO AT THIS
POINT.

THAT SYSTEM PULLS OUT BY CHRISTMAS EVE LEAVING US WITH SEASONAL
TEMPS AND MAINLY DRY.  ANOTHER SYSTEM PUSHES IN FOR THURSDAY NIGHT
AND FRIDAY AND GIVEN THE STRENGTH OF THE TROUGH OVER US THAT FAR OUT
WE WILL GET SOME PRECIP OUT OF THE SYSTEM BUT MODEL DISCREPANCIES
ARE TOO BIG TO GIVE MUCH IN THE WAY OF TIMING AND AMOUNT DETAILS.

&&

.AVIATION...19/06Z
ISSUED AT 1141 PM CST THU DEC 18 2014

LOW STRATUS WILL CONTINUE TO BE WIDESPREAD FOR THE DURATION OF THE
FORECAST. VFR CONDITIONS WILL PERSIST ACRS THE FAR NORTHEAST
THROUGH MUCH OF THE NIGHT BUT THE SLOW NORTH AND EAST PROGRESSION
OF MVFR TO IFR CEILINGS WILL CONTINUE AS SOUTHERLY FLOW BEGINS TO
INCREASE AS SURFACE RIDGE SLIDES SLOWLY EASTWARD. THE MVFR TO IFR
CONDITIONS WILL PERSIST INTO FRIDAY AND FRIDAY EVENING AS THE
MOIST LOW LEVEL FLOW CONTINUES. GFS IS INDICATING SOME -DZ/-FZDZ
BY AFTERNOON ACROSS PORTIONS OF THE FORECAST AREA AS FORCING
INCREASES. HAVE NOT INCLUDED AT THIS TIME BUT WILL HAVE TO BE
MONITORED FOR INCLUSION IN SUBSEQUENT FORECASTS. SURFACE WINDS
WILL BE LIGHT OVERNIGHT BECOMING SOUTHEAST TO SOUTH ON FRIDAY BUT
REMAINING LIGHT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...SKOW
LONG TERM...FAB
AVIATION...COGIL



000
FXUS63 KDMX 190548
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1148 PM CST THU DEC 18 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 324 PM CST THU DEC 18 2014

SNOW HAS ENDED OVER THE SOUTHEASTERN CWA AS THE CULPRIT UPPER LEVEL
WAVE HAS RAPIDLY WEAKENED AND DGZ FORCING HAS WANED. BASED ON WEBCAM
IMAGES AND A FEW SPOTTER/COOP REPORTS...MOST AREAS IN THE SOUTHERN
THREE TIERS OF COUNTIES SAW LESS THAN AN INCH OF SNOW. ATTENTION NOW
TURNS UPSTREAM TO A LARGE STRATUS PLUME STRETCHING FROM NORTHWEST
MONTANA TO THE TEXAS PANHANDLE...WITH THE EASTERN FRONT NOW JUST
ABOUT TO ENTER THE WESTERN CWA. LIGHT WEST TO SOUTHWEST FLOW IN THE
LOWEST 1 KM OF THE ATMOSPHERE BEHIND A DEPARTING SURFACE RIDGE
SHOULD ADVECT THIS CLOUD MASS OVER CENTRAL IOWA TONIGHT AND KEEP
SKIES OVERCAST ALL NIGHT AND INTO TOMORROW MORNING. THE CLOUDS
SHOULD ALSO BOLSTER LOW TEMPS TONIGHT COMPARED TO PREVIOUS NIGHTS
AND DIDN`T DEVIATE MUCH FROM GUIDANCE IN THIS RESPECT.

THE BIGGEST UNCERTAINTY FOR TONIGHT IS THE POSSIBILITY OF FLURRIES
OR FREEZING DRIZZLE WEST OF I-35. SHORT-RANGE MODEL SOUNDINGS (RUC
AND HRRR IN PARTICULAR) SATURATE THE LOWEST 5 KFT OF THE ATMOSPHERE
IN THIS REGION TONIGHT WITH NEARLY ISOTHERMAL PROFILES IN THIS LAYER
HOVERING BETWEEN -4 AND -7C. WITH THIS CONDITIONAL ICE PROBABILITY
...WENT WITH A MIX OF OCCASIONAL FLURRIES AND PATCHY FZDZ. FORCING
SHOULD BE MARGINAL AT BEST AND NO ACCUMULATION OF SNOW OR ICE IS
ANTICIPATED. ANY LIFT WITH AN UPPER LEVEL TROUGH ON WATER VAPOR
IMAGERY NW OF THE CWA SHOULD STAY NORTH AND EAST OF THE AREA.
ISENTROPIC UPGLIDE IN THE LOWEST 100MB OF THE ATMOSPHERE IS
PRESENT...BUT AGAIN VERY WEAK.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 324 PM CST THU DEC 18 2014

THE WEATHER IN THE LONG TERM WILL IN GENERAL BE MORE ACTIVE THEN
WHAT WE HAVE SEEN IN A WHILE.  FRIDAY THROUGH SUNDAY THERE WILL BE
NUMEROUS RELATIVELY WEAK SHORT WAVES MOVE ACROSS IOWA IN A GENERALLY
ZONAL FLOW.  THROUGH SATURDAY MOISTURE WILL EITHER BE SPARSE OR
SHALLOW SO I AM NOT EXPECTING MUCH WITH THESE SHORTWAVES IN TERMS OF
SENSIBLE WEATHER EXCEPT FOR CLOUD COVER.  TEMPS SHOULD BE RATHER
MILD FOR MID TO LATE DECEMBER.

SATURDAY NIGHT THROUGH SUNDAY A LITTLE STRONGER SHORT WAVE MOVES IN
AND MOISTURE DEPTH INCREASES SLIGHTLY ALTHOUGH IT IS STILL VERY
SHALLOW.  SOUNDINGS DO NOT INDICATE ICE INTRODUCTION AND WHILE THERE
ARE MODEL DIFFERENCES AS TO WHERE ANY WEAK FORCING MIGHT OCCUR...IT
DOES APPEAR THAT THE NORTHERN HALF OF IOWA IS MORE LIKELY TO SEE
THIS THAN SOUTHERN IOWA.  AS A RESULT I KEPT THE MENTION OF FREEZING
DRIZZLE CONFINED TO THE NORTH.  THE SOUNDING DOES SATURATE
OR BEGIN TO SATURATE SUFFICIENTLY LATE SATURDAY NIGHT THROUGH
SUNDAY MORNING THROUGH THE DENDRITIC ZONE THAT WE COULD TRANSITION
TO SOME LIGHT SNOW UP NORTH...ESPECIALLY SUNDAY MORNING. THAT
SHORTWAVE EXITS DURING THE EARLY AFTERNOON AND TEMPS WARM
SUFFICIENTLY FOR A WINTERY MIX CHANGING TO RAIN ACROSS AT LEAST
SOME OF THE AREA.

SUNDAY NIGHT THROUGH MONDAY A MORE POTENT SHORTWAVE MOVES INTO
IOWA...AFFECTING THE WEST SUNDAY NIGHT AND THE REST OF THE AREA
THROUGH TUESDAY.  HERE MODELS DIVERGE ON HOW TO HANDLE THIS SYSTEM.
THE GFS KEEP THE UPPER LEVEL WAVE OPEN AND DEVELOPS A CLOSED SURFACE
LOW OVER CENTRAL TO NORTHEAST IOWA.  THE EURO DRASTICALLY DEPEND
THE UPPER WAVE TO OUR WEST THEN CONTINUES TO DEVELOP IT INTO A
CLOSED LOW MONDAY NIGHT AND TUESDAY ACROSS EASTERN IOWA.  THE
RESULTANT CLOSED SURFACE LOW IS OVER EASTERN IOWA AS WELL AND
FURTHER SOUTHWEST THAN THE GFS HAS.  THE GFS REALLY DEVELOPS THE QG
FORCING ACROSS CENTRAL IOWA SUNDAY NIGHT THEN IS SIGNIFICANTLY
WEAKER THROUGH TUESDAY.  SOUNDINGS SHOW A PROFILE THAT IS PRETTY
WARM THROUGH MONDAY AFTERNOON WHEN THE PROFILE COOLS TO BELOW
FREEZING.  PRECIP THROUGH EARLY MONDAY AFTERNOON SHOULD BE RAIN WITH
AN OCCASIONAL WINTERY MIX ESPECIALLY UP NORTH.  DURING THE AFTERNOON
WE WILL BE TRANSITIONING TO A RAIN/SNOW MIX BEFORE GOING TO ALL SNOW
MONDAY NIGHT.  IT IS TOO FAR OUT TO CONSIDER SNOWFALL AMOUNTS YET
AND GIVEN THE MODEL DISCREPANCIES IT WOULD BE HARD TO DO AT THIS
POINT.

THAT SYSTEM PULLS OUT BY CHRISTMAS EVE LEAVING US WITH SEASONAL
TEMPS AND MAINLY DRY.  ANOTHER SYSTEM PUSHES IN FOR THURSDAY NIGHT
AND FRIDAY AND GIVEN THE STRENGTH OF THE TROUGH OVER US THAT FAR OUT
WE WILL GET SOME PRECIP OUT OF THE SYSTEM BUT MODEL DISCREPANCIES
ARE TOO BIG TO GIVE MUCH IN THE WAY OF TIMING AND AMOUNT DETAILS.

&&

.AVIATION...19/06Z
ISSUED AT 1141 PM CST THU DEC 18 2014

LOW STRATUS WILL CONTINUE TO BE WIDESPREAD FOR THE DURATION OF THE
FORECAST. VFR CONDITIONS WILL PERSIST ACRS THE FAR NORTHEAST
THROUGH MUCH OF THE NIGHT BUT THE SLOW NORTH AND EAST PROGRESSION
OF MVFR TO IFR CEILINGS WILL CONTINUE AS SOUTHERLY FLOW BEGINS TO
INCREASE AS SURFACE RIDGE SLIDES SLOWLY EASTWARD. THE MVFR TO IFR
CONDITIONS WILL PERSIST INTO FRIDAY AND FRIDAY EVENING AS THE
MOIST LOW LEVEL FLOW CONTINUES. GFS IS INDICATING SOME -DZ/-FZDZ
BY AFTERNOON ACROSS PORTIONS OF THE FORECAST AREA AS FORCING
INCREASES. HAVE NOT INCLUDED AT THIS TIME BUT WILL HAVE TO BE
MONITORED FOR INCLUSION IN SUBSEQUENT FORECASTS. SURFACE WINDS
WILL BE LIGHT OVERNIGHT BECOMING SOUTHEAST TO SOUTH ON FRIDAY BUT
REMAINING LIGHT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...SKOW
LONG TERM...FAB
AVIATION...COGIL




000
FXUS63 KDVN 190518
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1118 PM CST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 311 PM CST THU DEC 18 2014

AT 245 PM CDT...A RIDGE OF SURFACE HIGH PRESSURE REMAINED IN PLACE
ACROSS THE REGION. A FEW LIGHT FLURRIES LINGERED IN PARTS OF EASTERN
IOWA AND WESTERN ILLINOIS...BUT WERE DECREASING IN COVERAGE AS MID
LEVEL LOW PRESSURE PUSHED EAST. MID AFTERNOON TEMPERATURES WERE IN
THE 20S.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 311 PM CST THU DEC 18 2014

THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD IS CLOUD TRENDS
AND IMPACT ON TEMPERATURES OVERNIGHT INTO FRIDAY.

IN THE NEAR TERM...ISOLATED FLURRIES WILL CONTINUE TO DIMINISH IN
COVERAGE AS FORCING FROM A MID-LEVEL SHORT WAVE PUSHES EAST. MODEL
LAYER RH PROGS POINT TO POTENTIAL FOR SOME MOSTLY CLEAR TO PARTY
CLOUDY PERIODS ACROSS NORTHERN AND EASTERN PORTIONS OF THE
FORECAST AREA. THESE AREAS HAVE ONLY RISEN INTO THE 23-38 DEGREE
RANGE THIS AFTERNOON. WITH SOME PARTIAL CLEARING EXPECTED...BELIEVE
UNDERCUTTING GUIDANCE NORTH AND EAST IS THE WAY TO GO. LOW LEVEL
MOISTURE WILL BE GREATEST OVERNIGHT IN THE EXTREME SOUTH...AND
HAVE ADDED PATCHY FOG FROM 09Z THROUGH 14Z FRIDAY.

ON FRIDAY...SURFACE RIDGING AND STAGNANT LOW LEVEL WINDS EXPECTED
TO CONTINUE WITH PERSISTENT CLOUDY TO MOSTLY CLOUDY SKIES. 850MB
TEMPS ARE FORECAST TO BE NEAR TO SLIGHTLY WARMER THAN THURSDAY.
BELIEVE AFTERNOON HIGHS WILL ONLY BE MODESTLY WARMER THAN
TODAY...IN THE UPPER 20S TO LOW 30S...COOLER THAN THE CONSENSUS
BLEND GUIDANCE.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 311 PM CST THU DEC 18 2014

MAIN CONCERN IN THE EXTENDED PERIOD IS THE STORM SYSTEM THAT WILL
AFFECT THE MIDWEST THE END OF THIS WEEKEND THROUGH MIDWEEK NEXT
WEEK.  COMPUTER MODEL SOLUTIONS REGARDING THIS SYSTEM ARE DIFFERENT
AND AS SUCH THIS MAKES FOR A DIFFICULT FORECAST.  AT THIS TIME THE
SYSTEM LOOKS TO BRING SOME RAIN TO THE AREA...CHANGING OVER TO SNOW
AT THE END OF THE FORECAST.  THIS FORECAST IS SUBJECT TO CHANGE AS
GUIDANCE BEGINS TO AGREE ON A SOLUTION.

A SERIES OF SHORTWAVE DISTURBANCES WILL TRANSVERSE THROUGH THE FLOW
THIS WEEKEND.  ON SATURDAY NIGHT INTO SUNDAY...AS WAVE WILL MOVE
THROUGH THE AREA...BRINGING WITH IT THE CHANCE OF FREEZING DRIZZLE
ACROSS NORTHERN PORTIONS OF THE CWA.  TEMPERATURES LOOK TO REBOUND
ABOVE FREEZING ON SUNDAY AFTERNOON.  THIS MEANS THAT ANY IMPACTS
FROM THE FREEZING DRIZZLE SHOULD BE SHORT LIVED.  IN THE WAKE OF THIS
SYSTEM SOUTHWEST FLOW WILL HELP TO WARM TEMPERATURES UNTIL ANOTHER
WAVE MOVES THROUGH ON SUNDAY NIGHT.

ON MONDAY...A MUCH MORE ROBUST SYSTEM WITH BETTER VORTICITY
ADVECTION AND MAGNITUDE WILL MOVE INTO THE CENTRAL CONUS. MODELS ARE
IN GOOD AGREEMENT WITH THE BROAD DETAILS OF THE FORECAST.
HOWEVER...THE SURFACE FEATURES AND SUBSEQUENT SENSIBLE WEATHER ARE
HARD TO NAIL DOWN DUE TO THE MODEL INCONSISTENCIES.  CURRENT BLENDED
GUIDANCE SUGGESTS THAT THIS SYSTEM WILL BE MORE OF A RAIN AND THEN
RAIN/SNOW MIX SYSTEM...WITH SNOW ON THE BACK END OF IT.  LOOKING AT
INDIVIDUAL MODELS AND THE SURFACE FIELD EVOLUTION LEADS ONE TO
REALIZE THERE ARE A LOT MORE THINGS THAT COULD HAPPEN.  FOR
ONE...SOME GUIDANCE DEVELOPS A LOW TO OUR SOUTH OVER THE SOUTHERN
MISSISSIPPI RIVER VALLEY AND THEN ADVECTS IT TO THE NE...MERGING
WITH THE LOW OVER N WI.  THIS LOW COULD ACT TO ROB US OF DEEP
MOISTURE AND LEAD TO AN OUTCOME WITH LOWER CHANCES OF PRECIP AND
OVERALL LESS QPF.  THE GEM MODEL HAS THE INITIAL SURFACE LOW OVER
SOUTHERN CANADA AND DEVELOPS A LOW TO OUR EAST.  THE GFS HAS THE
INITIAL LOW  TO OUR WEST...MOVES IT OVER LA CROSSE AND INTO N
WI...THEN DEVELOPS A SURFACE LOW TO OUR EAST.  THE ECMWF IS SIMILAR
TO THE GFS AND THEN DEVELOPS A SECONDARY LOW EVEN FURTHER TO THE
EAST ACROSS THE ATLANTIC STATES.  WHAT THIS MEANS IS THAT THE
SPECIFICS OF THIS FORECAST WILL CHANGE AND THERE IS LOW CONFIDENCE
IN THE CURRENT FORECAST FOR SENSIBLE WEATHER.  THERE IS HIGH
CONFIDENCE THAT THERE WILL BE A SENSIBLE WEATHER PRODUCING SYSTEM
ACROSS THE MIDWEST EARLY NEXT WEEK.  AS FAR AS THE EVENT BEING ALL
RAIN...RASN...OR SNOW...THIS IS HARD TO NAIL DOWN AND SUBJECT TO
CHANGE.  THOSE PLANNING TRAVEL FOR NEXT WEEK SHOULD PAY ATTENTION TO
LATER FORECASTS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1118 PM CST THU DEC 18 2014

NEARLY CALM WINDS AND VARIABLE CLOUD COVER WILL REMAIN IN PLACE
THROUGH THE REST OF THE NIGHT AS A RIDGE OF HIGH PRESSURE LINGERS
OVERHEAD. A DECK OF LOWER CLOUDS WITH MVFR CIGS WILL AFFECT
PRIMARILY THE DBQ SITE TONIGHT...BEFORE MORE WIDESPREAD LOWER
CLOUDS LOOMING JUST WEST OF THE RIDGE AXIS SPREAD INTO EASTERN IA
AND NW IL DURING THE DAY FRIDAY. CONFIDENCE IN THE EXACT TIMING OF
THIS TRANSITION TO MVFR CONDITIONS REMAINS LOW...BUT THERE IS A
GOOD LIKELIHOOD THAT ALL SITES HAVE CIGS AT OR BELOW 2500 FT BY 06Z
FRIDAY NIGHT.

&&

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

$$

SYNOPSIS...RP KINNEY
SHORT TERM...RP KINNEY
LONG TERM...GIBBS
AVIATION...SHEETS







000
FXUS63 KDVN 190518
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1118 PM CST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 311 PM CST THU DEC 18 2014

AT 245 PM CDT...A RIDGE OF SURFACE HIGH PRESSURE REMAINED IN PLACE
ACROSS THE REGION. A FEW LIGHT FLURRIES LINGERED IN PARTS OF EASTERN
IOWA AND WESTERN ILLINOIS...BUT WERE DECREASING IN COVERAGE AS MID
LEVEL LOW PRESSURE PUSHED EAST. MID AFTERNOON TEMPERATURES WERE IN
THE 20S.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 311 PM CST THU DEC 18 2014

THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD IS CLOUD TRENDS
AND IMPACT ON TEMPERATURES OVERNIGHT INTO FRIDAY.

IN THE NEAR TERM...ISOLATED FLURRIES WILL CONTINUE TO DIMINISH IN
COVERAGE AS FORCING FROM A MID-LEVEL SHORT WAVE PUSHES EAST. MODEL
LAYER RH PROGS POINT TO POTENTIAL FOR SOME MOSTLY CLEAR TO PARTY
CLOUDY PERIODS ACROSS NORTHERN AND EASTERN PORTIONS OF THE
FORECAST AREA. THESE AREAS HAVE ONLY RISEN INTO THE 23-38 DEGREE
RANGE THIS AFTERNOON. WITH SOME PARTIAL CLEARING EXPECTED...BELIEVE
UNDERCUTTING GUIDANCE NORTH AND EAST IS THE WAY TO GO. LOW LEVEL
MOISTURE WILL BE GREATEST OVERNIGHT IN THE EXTREME SOUTH...AND
HAVE ADDED PATCHY FOG FROM 09Z THROUGH 14Z FRIDAY.

ON FRIDAY...SURFACE RIDGING AND STAGNANT LOW LEVEL WINDS EXPECTED
TO CONTINUE WITH PERSISTENT CLOUDY TO MOSTLY CLOUDY SKIES. 850MB
TEMPS ARE FORECAST TO BE NEAR TO SLIGHTLY WARMER THAN THURSDAY.
BELIEVE AFTERNOON HIGHS WILL ONLY BE MODESTLY WARMER THAN
TODAY...IN THE UPPER 20S TO LOW 30S...COOLER THAN THE CONSENSUS
BLEND GUIDANCE.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 311 PM CST THU DEC 18 2014

MAIN CONCERN IN THE EXTENDED PERIOD IS THE STORM SYSTEM THAT WILL
AFFECT THE MIDWEST THE END OF THIS WEEKEND THROUGH MIDWEEK NEXT
WEEK.  COMPUTER MODEL SOLUTIONS REGARDING THIS SYSTEM ARE DIFFERENT
AND AS SUCH THIS MAKES FOR A DIFFICULT FORECAST.  AT THIS TIME THE
SYSTEM LOOKS TO BRING SOME RAIN TO THE AREA...CHANGING OVER TO SNOW
AT THE END OF THE FORECAST.  THIS FORECAST IS SUBJECT TO CHANGE AS
GUIDANCE BEGINS TO AGREE ON A SOLUTION.

A SERIES OF SHORTWAVE DISTURBANCES WILL TRANSVERSE THROUGH THE FLOW
THIS WEEKEND.  ON SATURDAY NIGHT INTO SUNDAY...AS WAVE WILL MOVE
THROUGH THE AREA...BRINGING WITH IT THE CHANCE OF FREEZING DRIZZLE
ACROSS NORTHERN PORTIONS OF THE CWA.  TEMPERATURES LOOK TO REBOUND
ABOVE FREEZING ON SUNDAY AFTERNOON.  THIS MEANS THAT ANY IMPACTS
FROM THE FREEZING DRIZZLE SHOULD BE SHORT LIVED.  IN THE WAKE OF THIS
SYSTEM SOUTHWEST FLOW WILL HELP TO WARM TEMPERATURES UNTIL ANOTHER
WAVE MOVES THROUGH ON SUNDAY NIGHT.

ON MONDAY...A MUCH MORE ROBUST SYSTEM WITH BETTER VORTICITY
ADVECTION AND MAGNITUDE WILL MOVE INTO THE CENTRAL CONUS. MODELS ARE
IN GOOD AGREEMENT WITH THE BROAD DETAILS OF THE FORECAST.
HOWEVER...THE SURFACE FEATURES AND SUBSEQUENT SENSIBLE WEATHER ARE
HARD TO NAIL DOWN DUE TO THE MODEL INCONSISTENCIES.  CURRENT BLENDED
GUIDANCE SUGGESTS THAT THIS SYSTEM WILL BE MORE OF A RAIN AND THEN
RAIN/SNOW MIX SYSTEM...WITH SNOW ON THE BACK END OF IT.  LOOKING AT
INDIVIDUAL MODELS AND THE SURFACE FIELD EVOLUTION LEADS ONE TO
REALIZE THERE ARE A LOT MORE THINGS THAT COULD HAPPEN.  FOR
ONE...SOME GUIDANCE DEVELOPS A LOW TO OUR SOUTH OVER THE SOUTHERN
MISSISSIPPI RIVER VALLEY AND THEN ADVECTS IT TO THE NE...MERGING
WITH THE LOW OVER N WI.  THIS LOW COULD ACT TO ROB US OF DEEP
MOISTURE AND LEAD TO AN OUTCOME WITH LOWER CHANCES OF PRECIP AND
OVERALL LESS QPF.  THE GEM MODEL HAS THE INITIAL SURFACE LOW OVER
SOUTHERN CANADA AND DEVELOPS A LOW TO OUR EAST.  THE GFS HAS THE
INITIAL LOW  TO OUR WEST...MOVES IT OVER LA CROSSE AND INTO N
WI...THEN DEVELOPS A SURFACE LOW TO OUR EAST.  THE ECMWF IS SIMILAR
TO THE GFS AND THEN DEVELOPS A SECONDARY LOW EVEN FURTHER TO THE
EAST ACROSS THE ATLANTIC STATES.  WHAT THIS MEANS IS THAT THE
SPECIFICS OF THIS FORECAST WILL CHANGE AND THERE IS LOW CONFIDENCE
IN THE CURRENT FORECAST FOR SENSIBLE WEATHER.  THERE IS HIGH
CONFIDENCE THAT THERE WILL BE A SENSIBLE WEATHER PRODUCING SYSTEM
ACROSS THE MIDWEST EARLY NEXT WEEK.  AS FAR AS THE EVENT BEING ALL
RAIN...RASN...OR SNOW...THIS IS HARD TO NAIL DOWN AND SUBJECT TO
CHANGE.  THOSE PLANNING TRAVEL FOR NEXT WEEK SHOULD PAY ATTENTION TO
LATER FORECASTS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1118 PM CST THU DEC 18 2014

NEARLY CALM WINDS AND VARIABLE CLOUD COVER WILL REMAIN IN PLACE
THROUGH THE REST OF THE NIGHT AS A RIDGE OF HIGH PRESSURE LINGERS
OVERHEAD. A DECK OF LOWER CLOUDS WITH MVFR CIGS WILL AFFECT
PRIMARILY THE DBQ SITE TONIGHT...BEFORE MORE WIDESPREAD LOWER
CLOUDS LOOMING JUST WEST OF THE RIDGE AXIS SPREAD INTO EASTERN IA
AND NW IL DURING THE DAY FRIDAY. CONFIDENCE IN THE EXACT TIMING OF
THIS TRANSITION TO MVFR CONDITIONS REMAINS LOW...BUT THERE IS A
GOOD LIKELIHOOD THAT ALL SITES HAVE CIGS AT OR BELOW 2500 FT BY 06Z
FRIDAY NIGHT.

&&

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

$$

SYNOPSIS...RP KINNEY
SHORT TERM...RP KINNEY
LONG TERM...GIBBS
AVIATION...SHEETS






000
FXUS63 KDVN 182331
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
531 PM CST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 311 PM CST THU DEC 18 2014

AT 245 PM CDT...A RIDGE OF SURFACE HIGH PRESSURE REMAINED IN PLACE
ACROSS THE REGION. A FEW LIGHT FLURRIES LINGERED IN PARTS OF EASTERN
IOWA AND WESTERN ILLINOIS...BUT WERE DECREASING IN COVERAGE AS MID
LEVEL LOW PRESSURE PUSHED EAST. MID AFTERNOON TEMPERATURES WERE IN
THE 20S.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 311 PM CST THU DEC 18 2014

THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD IS CLOUD TRENDS
AND IMPACT ON TEMPERATURES OVERNIGHT INTO FRIDAY.

IN THE NEAR TERM...ISOLATED FLURRIES WILL CONTINUE TO DIMINISH IN
COVERAGE AS FORCING FROM A MID-LEVEL SHORT WAVE PUSHES EAST. MODEL
LAYER RH PROGS POINT TO POTENTIAL FOR SOME MOSTLY CLEAR TO PARTY
CLOUDY PERIODS ACROSS NORTHERN AND EASTERN PORTIONS OF THE
FORECAST AREA. THESE AREAS HAVE ONLY RISEN INTO THE 23-38 DEGREE
RANGE THIS AFTERNOON. WITH SOME PARTIAL CLEARING EXPECTED...BELIEVE
UNDERCUTTING GUIDANCE NORTH AND EAST IS THE WAY TO GO. LOW LEVEL
MOISTURE WILL BE GREATEST OVERNIGHT IN THE EXTREME SOUTH...AND
HAVE ADDED PATCHY FOG FROM 09Z THROUGH 14Z FRIDAY.

ON FRIDAY...SURFACE RIDGING AND STAGNANT LOW LEVEL WINDS EXPECTED
TO CONTINUE WITH PERSISTENT CLOUDY TO MOSTLY CLOUDY SKIES. 850MB
TEMPS ARE FORECAST TO BE NEAR TO SLIGHTLY WARMER THAN THURSDAY.
BELIEVE AFTERNOON HIGHS WILL ONLY BE MODESTLY WARMER THAN
TODAY...IN THE UPPER 20S TO LOW 30S...COOLER THAN THE CONSENSUS
BLEND GUIDANCE.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 311 PM CST THU DEC 18 2014

MAIN CONCERN IN THE EXTENDED PERIOD IS THE STORM SYSTEM THAT WILL
AFFECT THE MIDWEST THE END OF THIS WEEKEND THROUGH MIDWEEK NEXT
WEEK.  COMPUTER MODEL SOLUTIONS REGARDING THIS SYSTEM ARE DIFFERENT
AND AS SUCH THIS MAKES FOR A DIFFICULT FORECAST.  AT THIS TIME THE
SYSTEM LOOKS TO BRING SOME RAIN TO THE AREA...CHANGING OVER TO SNOW
AT THE END OF THE FORECAST.  THIS FORECAST IS SUBJECT TO CHANGE AS
GUIDANCE BEGINS TO AGREE ON A SOLUTION.

A SERIES OF SHORTWAVE DISTURBANCES WILL TRANSVERSE THROUGH THE FLOW
THIS WEEKEND.  ON SATURDAY NIGHT INTO SUNDAY...AS WAVE WILL MOVE
THROUGH THE AREA...BRINGING WITH IT THE CHANCE OF FREEZING DRIZZLE
ACROSS NORTHERN PORTIONS OF THE CWA.  TEMPERATURES LOOK TO REBOUND
ABOVE FREEZING ON SUNDAY AFTERNOON.  THIS MEANS THAT ANY IMPACTS
FROM THE FREEZING DRIZZLE SHOULD BE SHORT LIVED.  IN THE WAKE OF THIS
SYSTEM SOUTHWEST FLOW WILL HELP TO WARM TEMPERATURES UNTIL ANOTHER
WAVE MOVES THROUGH ON SUNDAY NIGHT.

ON MONDAY...A MUCH MORE ROBUST SYSTEM WITH BETTER VORTICITY
ADVECTION AND MAGNITUDE WILL MOVE INTO THE CENTRAL CONUS. MODELS ARE
IN GOOD AGREEMENT WITH THE BROAD DETAILS OF THE FORECAST.
HOWEVER...THE SURFACE FEATURES AND SUBSEQUENT SENSIBLE WEATHER ARE
HARD TO NAIL DOWN DUE TO THE MODEL INCONSISTENCIES.  CURRENT BLENDED
GUIDANCE SUGGESTS THAT THIS SYSTEM WILL BE MORE OF A RAIN AND THEN
RAIN/SNOW MIX SYSTEM...WITH SNOW ON THE BACK END OF IT.  LOOKING AT
INDIVIDUAL MODELS AND THE SURFACE FIELD EVOLUTION LEADS ONE TO
REALIZE THERE ARE A LOT MORE THINGS THAT COULD HAPPEN.  FOR
ONE...SOME GUIDANCE DEVELOPS A LOW TO OUR SOUTH OVER THE SOUTHERN
MISSISSIPPI RIVER VALLEY AND THEN ADVECTS IT TO THE NE...MERGING
WITH THE LOW OVER N WI.  THIS LOW COULD ACT TO ROB US OF DEEP
MOISTURE AND LEAD TO AN OUTCOME WITH LOWER CHANCES OF PRECIP AND
OVERALL LESS QPF.  THE GEM MODEL HAS THE INITIAL SURFACE LOW OVER
SOUTHERN CANADA AND DEVELOPS A LOW TO OUR EAST.  THE GFS HAS THE
INITIAL LOW  TO OUR WEST...MOVES IT OVER LA CROSSE AND INTO N
WI...THEN DEVELOPS A SURFACE LOW TO OUR EAST.  THE ECMWF IS SIMILAR
TO THE GFS AND THEN DEVELOPS A SECONDARY LOW EVEN FURTHER TO THE
EAST ACROSS THE ATLANTIC STATES.  WHAT THIS MEANS IS THAT THE
SPECIFICS OF THIS FORECAST WILL CHANGE AND THERE IS LOW CONFIDENCE
IN THE CURRENT FORECAST FOR SENSIBLE WEATHER.  THERE IS HIGH
CONFIDENCE THAT THERE WILL BE A SENSIBLE WEATHER PRODUCING SYSTEM
ACROSS THE MIDWEST EARLY NEXT WEEK.  AS FAR AS THE EVENT BEING ALL
RAIN...RASN...OR SNOW...THIS IS HARD TO NAIL DOWN AND SUBJECT TO
CHANGE.  THOSE PLANNING TRAVEL FOR NEXT WEEK SHOULD PAY ATTENTION TO
LATER FORECASTS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 530 PM CST THU DEC 18 2014

A RIDGE OF HIGH PRESSURE REMAINED NEARLY STATIONARY OVER THE
REGION FROM CENTRAL ILLINOIS THROUGH MN TODAY...AND WILL ONLY
SLOWLY ADVANCE EASTWARD OVERNIGHT INTO FRIDAY. MOISTURE TRAPPED
UNDER THIS RIDGE WAS RESULTING IN WIDESPREAD CLOUD COVER...WHICH
WAS PREDOMINANTLY ABOVE MVFR THRESHOLDS OVER EASTERN IA AND NW IL
LATE THIS AFTERNOON. AS THE RIDGE MOVES EAST...AND AREA OF LOWER
CLOUDS OVER THE PLAINS WILL SLOWLY SPREAD EASTWARD. FORECAST
CONFIDENCE IN THE TIMING OF THIS TRANSITION TO LOWER CIGS...FROM
1500 TO 2500 FT AGL REMAINS LOW AND FORECAST MODELS APPEAR TO
HAVE A POOR HANDLE ON THESE TRENDS AS WELL. FOR NOW...HAVE KEPT
VFR CONDITIONS IN PLACE WITH VERY LIGHT SURFACE WINDS
OVERNIGHT...THEN HAVE CIGS LOWERING TO MVFR THRESHOLDS LATE
FRIDAY MORNING AT BRL AND IN THE AFTERNOON AT THE OTHER TAF SITES.

&&

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

$$

SYNOPSIS...RP KINNEY
SHORT TERM...RP KINNEY
LONG TERM...GIBBS
AVIATION...SHEETS






000
FXUS63 KDVN 182331
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
531 PM CST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 311 PM CST THU DEC 18 2014

AT 245 PM CDT...A RIDGE OF SURFACE HIGH PRESSURE REMAINED IN PLACE
ACROSS THE REGION. A FEW LIGHT FLURRIES LINGERED IN PARTS OF EASTERN
IOWA AND WESTERN ILLINOIS...BUT WERE DECREASING IN COVERAGE AS MID
LEVEL LOW PRESSURE PUSHED EAST. MID AFTERNOON TEMPERATURES WERE IN
THE 20S.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 311 PM CST THU DEC 18 2014

THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD IS CLOUD TRENDS
AND IMPACT ON TEMPERATURES OVERNIGHT INTO FRIDAY.

IN THE NEAR TERM...ISOLATED FLURRIES WILL CONTINUE TO DIMINISH IN
COVERAGE AS FORCING FROM A MID-LEVEL SHORT WAVE PUSHES EAST. MODEL
LAYER RH PROGS POINT TO POTENTIAL FOR SOME MOSTLY CLEAR TO PARTY
CLOUDY PERIODS ACROSS NORTHERN AND EASTERN PORTIONS OF THE
FORECAST AREA. THESE AREAS HAVE ONLY RISEN INTO THE 23-38 DEGREE
RANGE THIS AFTERNOON. WITH SOME PARTIAL CLEARING EXPECTED...BELIEVE
UNDERCUTTING GUIDANCE NORTH AND EAST IS THE WAY TO GO. LOW LEVEL
MOISTURE WILL BE GREATEST OVERNIGHT IN THE EXTREME SOUTH...AND
HAVE ADDED PATCHY FOG FROM 09Z THROUGH 14Z FRIDAY.

ON FRIDAY...SURFACE RIDGING AND STAGNANT LOW LEVEL WINDS EXPECTED
TO CONTINUE WITH PERSISTENT CLOUDY TO MOSTLY CLOUDY SKIES. 850MB
TEMPS ARE FORECAST TO BE NEAR TO SLIGHTLY WARMER THAN THURSDAY.
BELIEVE AFTERNOON HIGHS WILL ONLY BE MODESTLY WARMER THAN
TODAY...IN THE UPPER 20S TO LOW 30S...COOLER THAN THE CONSENSUS
BLEND GUIDANCE.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 311 PM CST THU DEC 18 2014

MAIN CONCERN IN THE EXTENDED PERIOD IS THE STORM SYSTEM THAT WILL
AFFECT THE MIDWEST THE END OF THIS WEEKEND THROUGH MIDWEEK NEXT
WEEK.  COMPUTER MODEL SOLUTIONS REGARDING THIS SYSTEM ARE DIFFERENT
AND AS SUCH THIS MAKES FOR A DIFFICULT FORECAST.  AT THIS TIME THE
SYSTEM LOOKS TO BRING SOME RAIN TO THE AREA...CHANGING OVER TO SNOW
AT THE END OF THE FORECAST.  THIS FORECAST IS SUBJECT TO CHANGE AS
GUIDANCE BEGINS TO AGREE ON A SOLUTION.

A SERIES OF SHORTWAVE DISTURBANCES WILL TRANSVERSE THROUGH THE FLOW
THIS WEEKEND.  ON SATURDAY NIGHT INTO SUNDAY...AS WAVE WILL MOVE
THROUGH THE AREA...BRINGING WITH IT THE CHANCE OF FREEZING DRIZZLE
ACROSS NORTHERN PORTIONS OF THE CWA.  TEMPERATURES LOOK TO REBOUND
ABOVE FREEZING ON SUNDAY AFTERNOON.  THIS MEANS THAT ANY IMPACTS
FROM THE FREEZING DRIZZLE SHOULD BE SHORT LIVED.  IN THE WAKE OF THIS
SYSTEM SOUTHWEST FLOW WILL HELP TO WARM TEMPERATURES UNTIL ANOTHER
WAVE MOVES THROUGH ON SUNDAY NIGHT.

ON MONDAY...A MUCH MORE ROBUST SYSTEM WITH BETTER VORTICITY
ADVECTION AND MAGNITUDE WILL MOVE INTO THE CENTRAL CONUS. MODELS ARE
IN GOOD AGREEMENT WITH THE BROAD DETAILS OF THE FORECAST.
HOWEVER...THE SURFACE FEATURES AND SUBSEQUENT SENSIBLE WEATHER ARE
HARD TO NAIL DOWN DUE TO THE MODEL INCONSISTENCIES.  CURRENT BLENDED
GUIDANCE SUGGESTS THAT THIS SYSTEM WILL BE MORE OF A RAIN AND THEN
RAIN/SNOW MIX SYSTEM...WITH SNOW ON THE BACK END OF IT.  LOOKING AT
INDIVIDUAL MODELS AND THE SURFACE FIELD EVOLUTION LEADS ONE TO
REALIZE THERE ARE A LOT MORE THINGS THAT COULD HAPPEN.  FOR
ONE...SOME GUIDANCE DEVELOPS A LOW TO OUR SOUTH OVER THE SOUTHERN
MISSISSIPPI RIVER VALLEY AND THEN ADVECTS IT TO THE NE...MERGING
WITH THE LOW OVER N WI.  THIS LOW COULD ACT TO ROB US OF DEEP
MOISTURE AND LEAD TO AN OUTCOME WITH LOWER CHANCES OF PRECIP AND
OVERALL LESS QPF.  THE GEM MODEL HAS THE INITIAL SURFACE LOW OVER
SOUTHERN CANADA AND DEVELOPS A LOW TO OUR EAST.  THE GFS HAS THE
INITIAL LOW  TO OUR WEST...MOVES IT OVER LA CROSSE AND INTO N
WI...THEN DEVELOPS A SURFACE LOW TO OUR EAST.  THE ECMWF IS SIMILAR
TO THE GFS AND THEN DEVELOPS A SECONDARY LOW EVEN FURTHER TO THE
EAST ACROSS THE ATLANTIC STATES.  WHAT THIS MEANS IS THAT THE
SPECIFICS OF THIS FORECAST WILL CHANGE AND THERE IS LOW CONFIDENCE
IN THE CURRENT FORECAST FOR SENSIBLE WEATHER.  THERE IS HIGH
CONFIDENCE THAT THERE WILL BE A SENSIBLE WEATHER PRODUCING SYSTEM
ACROSS THE MIDWEST EARLY NEXT WEEK.  AS FAR AS THE EVENT BEING ALL
RAIN...RASN...OR SNOW...THIS IS HARD TO NAIL DOWN AND SUBJECT TO
CHANGE.  THOSE PLANNING TRAVEL FOR NEXT WEEK SHOULD PAY ATTENTION TO
LATER FORECASTS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 530 PM CST THU DEC 18 2014

A RIDGE OF HIGH PRESSURE REMAINED NEARLY STATIONARY OVER THE
REGION FROM CENTRAL ILLINOIS THROUGH MN TODAY...AND WILL ONLY
SLOWLY ADVANCE EASTWARD OVERNIGHT INTO FRIDAY. MOISTURE TRAPPED
UNDER THIS RIDGE WAS RESULTING IN WIDESPREAD CLOUD COVER...WHICH
WAS PREDOMINANTLY ABOVE MVFR THRESHOLDS OVER EASTERN IA AND NW IL
LATE THIS AFTERNOON. AS THE RIDGE MOVES EAST...AND AREA OF LOWER
CLOUDS OVER THE PLAINS WILL SLOWLY SPREAD EASTWARD. FORECAST
CONFIDENCE IN THE TIMING OF THIS TRANSITION TO LOWER CIGS...FROM
1500 TO 2500 FT AGL REMAINS LOW AND FORECAST MODELS APPEAR TO
HAVE A POOR HANDLE ON THESE TRENDS AS WELL. FOR NOW...HAVE KEPT
VFR CONDITIONS IN PLACE WITH VERY LIGHT SURFACE WINDS
OVERNIGHT...THEN HAVE CIGS LOWERING TO MVFR THRESHOLDS LATE
FRIDAY MORNING AT BRL AND IN THE AFTERNOON AT THE OTHER TAF SITES.

&&

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

$$

SYNOPSIS...RP KINNEY
SHORT TERM...RP KINNEY
LONG TERM...GIBBS
AVIATION...SHEETS







000
FXUS63 KDMX 182329
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
529 PM CST THU DEC 18 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 324 PM CST THU DEC 18 2014

SNOW HAS ENDED OVER THE SOUTHEASTERN CWA AS THE CULPRIT UPPER LEVEL
WAVE HAS RAPIDLY WEAKENED AND DGZ FORCING HAS WANED. BASED ON WEBCAM
IMAGES AND A FEW SPOTTER/COOP REPORTS...MOST AREAS IN THE SOUTHERN
THREE TIERS OF COUNTIES SAW LESS THAN AN INCH OF SNOW. ATTENTION NOW
TURNS UPSTREAM TO A LARGE STRATUS PLUME STRETCHING FROM NORTHWEST
MONTANA TO THE TEXAS PANHANDLE...WITH THE EASTERN FRONT NOW JUST
ABOUT TO ENTER THE WESTERN CWA. LIGHT WEST TO SOUTHWEST FLOW IN THE
LOWEST 1 KM OF THE ATMOSPHERE BEHIND A DEPARTING SURFACE RIDGE
SHOULD ADVECT THIS CLOUD MASS OVER CENTRAL IOWA TONIGHT AND KEEP
SKIES OVERCAST ALL NIGHT AND INTO TOMORROW MORNING. THE CLOUDS
SHOULD ALSO BOLSTER LOW TEMPS TONIGHT COMPARED TO PREVIOUS NIGHTS
AND DIDN`T DEVIATE MUCH FROM GUIDANCE IN THIS RESPECT.

THE BIGGEST UNCERTAINTY FOR TONIGHT IS THE POSSIBILITY OF FLURRIES
OR FREEZING DRIZZLE WEST OF I-35. SHORT-RANGE MODEL SOUNDINGS (RUC
AND HRRR IN PARTICULAR) SATURATE THE LOWEST 5 KFT OF THE ATMOSPHERE
IN THIS REGION TONIGHT WITH NEARLY ISOTHERMAL PROFILES IN THIS LAYER
HOVERING BETWEEN -4 AND -7C. WITH THIS CONDITIONAL ICE PROBABILITY
...WENT WITH A MIX OF OCCASIONAL FLURRIES AND PATCHY FZDZ. FORCING
SHOULD BE MARGINAL AT BEST AND NO ACCUMULATION OF SNOW OR ICE IS
ANTICIPATED. ANY LIFT WITH AN UPPER LEVEL TROUGH ON WATER VAPOR
IMAGERY NW OF THE CWA SHOULD STAY NORTH AND EAST OF THE AREA.
ISENTROPIC UPGLIDE IN THE LOWEST 100MB OF THE ATMOSPHERE IS
PRESENT...BUT AGAIN VERY WEAK.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 324 PM CST THU DEC 18 2014

THE WEATHER IN THE LONG TERM WILL IN GENERAL BE MORE ACTIVE THEN
WHAT WE HAVE SEEN IN A WHILE.  FRIDAY THROUGH SUNDAY THERE WILL BE
NUMEROUS RELATIVELY WEAK SHORT WAVES MOVE ACROSS IOWA IN A GENERALLY
ZONAL FLOW.  THROUGH SATURDAY MOISTURE WILL EITHER BE SPARSE OR
SHALLOW SO I AM NOT EXPECTING MUCH WITH THESE SHORTWAVES IN TERMS OF
SENSIBLE WEATHER EXCEPT FOR CLOUD COVER.  TEMPS SHOULD BE RATHER
MILD FOR MID TO LATE DECEMBER.

SATURDAY NIGHT THROUGH SUNDAY A LITTLE STRONGER SHORT WAVE MOVES IN
AND MOISTURE DEPTH INCREASES SLIGHTLY ALTHOUGH IT IS STILL VERY
SHALLOW.  SOUNDINGS DO NOT INDICATE ICE INTRODUCTION AND WHILE THERE
ARE MODEL DIFFERENCES AS TO WHERE ANY WEAK FORCING MIGHT OCCUR...IT
DOES APPEAR THAT THE NORTHERN HALF OF IOWA IS MORE LIKELY TO SEE
THIS THAN SOUTHERN IOWA.  AS A RESULT I KEPT THE MENTION OF FREEZING
DRIZZLE CONFINED TO THE NORTH.  THE SOUNDING DOES SATURATE
OR BEGIN TO SATURATE SUFFICIENTLY LATE SATURDAY NIGHT THROUGH
SUNDAY MORNING THROUGH THE DENDRITIC ZONE THAT WE COULD TRANSITION
TO SOME LIGHT SNOW UP NORTH...ESPECIALLY SUNDAY MORNING. THAT
SHORTWAVE EXITS DURING THE EARLY AFTERNOON AND TEMPS WARM
SUFFICIENTLY FOR A WINTERY MIX CHANGING TO RAIN ACROSS AT LEAST
SOME OF THE AREA.

SUNDAY NIGHT THROUGH MONDAY A MORE POTENT SHORTWAVE MOVES INTO
IOWA...AFFECTING THE WEST SUNDAY NIGHT AND THE REST OF THE AREA
THROUGH TUESDAY.  HERE MODELS DIVERGE ON HOW TO HANDLE THIS SYSTEM.
THE GFS KEEP THE UPPER LEVEL WAVE OPEN AND DEVELOPS A CLOSED SURFACE
LOW OVER CENTRAL TO NORTHEAST IOWA.  THE EURO DRASTICALLY DEPEND
THE UPPER WAVE TO OUR WEST THEN CONTINUES TO DEVELOP IT INTO A
CLOSED LOW MONDAY NIGHT AND TUESDAY ACROSS EASTERN IOWA.  THE
RESULTANT CLOSED SURFACE LOW IS OVER EASTERN IOWA AS WELL AND
FURTHER SOUTHWEST THAN THE GFS HAS.  THE GFS REALLY DEVELOPS THE QG
FORCING ACROSS CENTRAL IOWA SUNDAY NIGHT THEN IS SIGNIFICANTLY
WEAKER THROUGH TUESDAY.  SOUNDINGS SHOW A PROFILE THAT IS PRETTY
WARM THROUGH MONDAY AFTERNOON WHEN THE PROFILE COOLS TO BELOW
FREEZING.  PRECIP THROUGH EARLY MONDAY AFTERNOON SHOULD BE RAIN WITH
AN OCCASIONAL WINTERY MIX ESPECIALLY UP NORTH.  DURING THE AFTERNOON
WE WILL BE TRANSITIONING TO A RAIN/SNOW MIX BEFORE GOING TO ALL SNOW
MONDAY NIGHT.  IT IS TOO FAR OUT TO CONSIDER SNOWFALL AMOUNTS YET
AND GIVEN THE MODEL DISCREPANCIES IT WOULD BE HARD TO DO AT THIS
POINT.

THAT SYSTEM PULLS OUT BY CHRISTMAS EVE LEAVING US WITH SEASONAL
TEMPS AND MAINLY DRY.  ANOTHER SYSTEM PUSHES IN FOR THURSDAY NIGHT
AND FRIDAY AND GIVEN THE STRENGTH OF THE TROUGH OVER US THAT FAR OUT
WE WILL GET SOME PRECIP OUT OF THE SYSTEM BUT MODEL DISCREPANCIES
ARE TOO BIG TO GIVE MUCH IN THE WAY OF TIMING AND AMOUNT DETAILS.

&&

.AVIATION...19/00Z
ISSUED AT 529 PM CST THU DEC 18 2014

WIDESPREAD CLOUDINESS IS EXPECTED FOR THE DURATION OF THE FORECAST
WITH LOW MVFR TO IFR STRATUS BECOMING COMMON PLACE LATE TONIGHT
INTO FRIDAY. IN EFFECT...WILL SEE LOW LEVEL WARM ADVECTION VERY
GRADUALLY INCREASE WITH WEAK MOISTURE TRANSPORT ACROSS IOWA
HELPING TO KEEP STATUS PERSISTENT. SURFACE WIND FLOW WILL BE WEAK
AND GRADUALLY BECOME SOUTHEAST TO SOUTH ON FRIDAY. VISIBILITIES
MAY ALSO SEE SOME RESTRICTIONS IN LIGHT FOG LATE TONIGHT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...SKOW
LONG TERM...FAB
AVIATION...COGIL




000
FXUS63 KDMX 182132
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
332 PM CST THU DEC 18 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 324 PM CST THU DEC 18 2014

SNOW HAS ENDED OVER THE SOUTHEASTERN CWA AS THE CULPRIT UPPER LEVEL
WAVE HAS RAPIDLY WEAKENED AND DGZ FORCING HAS WANED. BASED ON WEBCAM
IMAGES AND A FEW SPOTTER/COOP REPORTS...MOST AREAS IN THE SOUTHERN
THREE TIERS OF COUNTIES SAW LESS THAN AN INCH OF SNOW. ATTENTION NOW
TURNS UPSTREAM TO A LARGE STRATUS PLUME STRETCHING FROM NORTHWEST
MONTANA TO THE TEXAS PANHANDLE...WITH THE EASTERN FRONT NOW JUST
ABOUT TO ENTER THE WESTERN CWA. LIGHT WEST TO SOUTHWEST FLOW IN THE
LOWEST 1 KM OF THE ATMOSPHERE BEHIND A DEPARTING SURFACE RIDGE
SHOULD ADVECT THIS CLOUD MASS OVER CENTRAL IOWA TONIGHT AND KEEP
SKIES OVERCAST ALL NIGHT AND INTO TOMORROW MORNING. THE CLOUDS
SHOULD ALSO BOLSTER LOW TEMPS TONIGHT COMPARED TO PREVIOUS NIGHTS
AND DIDN`T DEVIATE MUCH FROM GUIDANCE IN THIS RESPECT.

THE BIGGEST UNCERTAINTY FOR TONIGHT IS THE POSSIBILITY OF FLURRIES
OR FREEZING DRIZZLE WEST OF I-35. SHORT-RANGE MODEL SOUNDINGS (RUC
AND HRRR IN PARTICULAR) SATURATE THE LOWEST 5 KFT OF THE ATMOSPHERE
IN THIS REGION TONIGHT WITH NEARLY ISOTHERMAL PROFILES IN THIS LAYER
HOVERING BETWEEN -4 AND -7C. WITH THIS CONDITIONAL ICE PROBABILITY
...WENT WITH A MIX OF OCCASIONAL FLURRIES AND PATCHY FZDZ. FORCING
SHOULD BE MARGINAL AT BEST AND NO ACCUMULATION OF SNOW OR ICE IS
ANTICIPATED. ANY LIFT WITH AN UPPER LEVEL TROUGH ON WATER VAPOR
IMAGERY NW OF THE CWA SHOULD STAY NORTH AND EAST OF THE AREA.
ISENTROPIC UPGLIDE IN THE LOWEST 100MB OF THE ATMOSPHERE IS
PRESENT...BUT AGAIN VERY WEAK.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 324 PM CST THU DEC 18 2014

THE WEATHER IN THE LONG TERM WILL IN GENERAL BE MORE ACTIVE THEN
WHAT WE HAVE SEEN IN A WHILE.  FRIDAY THROUGH SUNDAY THERE WILL BE
NUMEROUS RELATIVELY WEAK SHORT WAVES MOVE ACROSS IOWA IN A GENERALLY
ZONAL FLOW.  THROUGH SATURDAY MOISTURE WILL EITHER BE SPARSE OR
SHALLOW SO I AM NOT EXPECTING MUCH WITH THESE SHORTWAVES IN TERMS OF
SENSIBLE WEATHER EXCEPT FOR CLOUD COVER.  TEMPS SHOULD BE RATHER
MILD FOR MID TO LATE DECEMBER.

SATURDAY NIGHT THROUGH SUNDAY A LITTLE STRONGER SHORT WAVE MOVES IN
AND MOISTURE DEPTH INCREASES SLIGHTLY ALTHOUGH IT IS STILL VERY
SHALLOW.  SOUNDINGS DO NOT INDICATE ICE INTRODUCTION AND WHILE THERE
ARE MODEL DIFFERENCES AS TO WHERE ANY WEAK FORCING MIGHT OCCUR...IT
DOES APPEAR THAT THE NORTHERN HALF OF IOWA IS MORE LIKELY TO SEE
THIS THAN SOUTHERN IOWA.  AS A RESULT I KEPT THE MENTION OF FREEZING
DRIZZLE CONFINED TO THE NORTH.  THE SOUNDING DOES SATURATE
OR BEGIN TO SATURATE SUFFICIENTLY LATE SATURDAY NIGHT THROUGH
SUNDAY MORNING THROUGH THE DENDRITIC ZONE THAT WE COULD TRANSITION
TO SOME LIGHT SNOW UP NORTH...ESPECIALLY SUNDAY MORNING. THAT
SHORTWAVE EXITS DURING THE EARLY AFTERNOON AND TEMPS WARM
SUFFICIENTLY FOR A WINTERY MIX CHANGING TO RAIN ACROSS AT LEAST
SOME OF THE AREA.

SUNDAY NIGHT THROUGH MONDAY A MORE POTENT SHORTWAVE MOVES INTO
IOWA...AFFECTING THE WEST SUNDAY NIGHT AND THE REST OF THE AREA
THROUGH TUESDAY.  HERE MODELS DIVERGE ON HOW TO HANDLE THIS SYSTEM.
THE GFS KEEP THE UPPER LEVEL WAVE OPEN AND DEVELOPS A CLOSED SURFACE
LOW OVER CENTRAL TO NORTHEAST IOWA.  THE EURO DRASTICALLY DEPEND
THE UPPER WAVE TO OUR WEST THEN CONTINUES TO DEVELOP IT INTO A
CLOSED LOW MONDAY NIGHT AND TUESDAY ACROSS EASTERN IOWA.  THE
RESULTANT CLOSED SURFACE LOW IS OVER EASTERN IOWA AS WELL AND
FURTHER SOUTHWEST THAN THE GFS HAS.  THE GFS REALLY DEVELOPS THE QG
FORCING ACROSS CENTRAL IOWA SUNDAY NIGHT THEN IS SIGNIFICANTLY
WEAKER THROUGH TUESDAY.  SOUNDINGS SHOW A PROFILE THAT IS PRETTY
WARM THROUGH MONDAY AFTERNOON WHEN THE PROFILE COOLS TO BELOW
FREEZING.  PRECIP THROUGH EARLY MONDAY AFTERNOON SHOULD BE RAIN WITH
AN OCCASIONAL WINTERY MIX ESPECIALLY UP NORTH.  DURING THE AFTERNOON
WE WILL BE TRANSITIONING TO A RAIN/SNOW MIX BEFORE GOING TO ALL SNOW
MONDAY NIGHT.  IT IS TOO FAR OUT TO CONSIDER SNOWFALL AMOUNTS YET
AND GIVEN THE MODEL DISCREPANCIES IT WOULD BE HARD TO DO AT THIS
POINT.

THAT SYSTEM PULLS OUT BY CHRISTMAS EVE LEAVING US WITH SEASONAL
TEMPS AND MAINLY DRY.  ANOTHER SYSTEM PUSHES IN FOR THURSDAY NIGHT
AND FRIDAY AND GIVEN THE STRENGTH OF THE TROUGH OVER US THAT FAR OUT
WE WILL GET SOME PRECIP OUT OF THE SYSTEM BUT MODEL DISCREPANCIES
ARE TOO BIG TO GIVE MUCH IN THE WAY OF TIMING AND AMOUNT DETAILS.

&&

.AVIATION...18/18Z
ISSUED AT 1141 AM CST THU DEC 18 2014

SNOW IS WINDING DOWN ACROSS SOUTHERN IOWA THIS AFTERNOON WITH IFR
TO LOW MVFR CEILINGS LINGERING OVER THE AREA. IFR/LOW MVFR STRATUS
IS ALSO HANGING ON ACROSS PORTIONS OF NE IOWA. EXPECT LITTLE
IMPROVEMENT THROUGHOUT THE DAY WITH A LARGE SHIELD OF MVFR TO IFR
STRATUS OVER NEBRASKA AND WESTERN IOWA ADVECTING OVER CENTRAL IOWA
TONIGHT AND LINGERING THROUGH THE END OF THE TAF PERIOD.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...SKOW
LONG TERM...FAB
AVIATION...SKOW



000
FXUS63 KDMX 182132
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
332 PM CST THU DEC 18 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 324 PM CST THU DEC 18 2014

SNOW HAS ENDED OVER THE SOUTHEASTERN CWA AS THE CULPRIT UPPER LEVEL
WAVE HAS RAPIDLY WEAKENED AND DGZ FORCING HAS WANED. BASED ON WEBCAM
IMAGES AND A FEW SPOTTER/COOP REPORTS...MOST AREAS IN THE SOUTHERN
THREE TIERS OF COUNTIES SAW LESS THAN AN INCH OF SNOW. ATTENTION NOW
TURNS UPSTREAM TO A LARGE STRATUS PLUME STRETCHING FROM NORTHWEST
MONTANA TO THE TEXAS PANHANDLE...WITH THE EASTERN FRONT NOW JUST
ABOUT TO ENTER THE WESTERN CWA. LIGHT WEST TO SOUTHWEST FLOW IN THE
LOWEST 1 KM OF THE ATMOSPHERE BEHIND A DEPARTING SURFACE RIDGE
SHOULD ADVECT THIS CLOUD MASS OVER CENTRAL IOWA TONIGHT AND KEEP
SKIES OVERCAST ALL NIGHT AND INTO TOMORROW MORNING. THE CLOUDS
SHOULD ALSO BOLSTER LOW TEMPS TONIGHT COMPARED TO PREVIOUS NIGHTS
AND DIDN`T DEVIATE MUCH FROM GUIDANCE IN THIS RESPECT.

THE BIGGEST UNCERTAINTY FOR TONIGHT IS THE POSSIBILITY OF FLURRIES
OR FREEZING DRIZZLE WEST OF I-35. SHORT-RANGE MODEL SOUNDINGS (RUC
AND HRRR IN PARTICULAR) SATURATE THE LOWEST 5 KFT OF THE ATMOSPHERE
IN THIS REGION TONIGHT WITH NEARLY ISOTHERMAL PROFILES IN THIS LAYER
HOVERING BETWEEN -4 AND -7C. WITH THIS CONDITIONAL ICE PROBABILITY
...WENT WITH A MIX OF OCCASIONAL FLURRIES AND PATCHY FZDZ. FORCING
SHOULD BE MARGINAL AT BEST AND NO ACCUMULATION OF SNOW OR ICE IS
ANTICIPATED. ANY LIFT WITH AN UPPER LEVEL TROUGH ON WATER VAPOR
IMAGERY NW OF THE CWA SHOULD STAY NORTH AND EAST OF THE AREA.
ISENTROPIC UPGLIDE IN THE LOWEST 100MB OF THE ATMOSPHERE IS
PRESENT...BUT AGAIN VERY WEAK.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 324 PM CST THU DEC 18 2014

THE WEATHER IN THE LONG TERM WILL IN GENERAL BE MORE ACTIVE THEN
WHAT WE HAVE SEEN IN A WHILE.  FRIDAY THROUGH SUNDAY THERE WILL BE
NUMEROUS RELATIVELY WEAK SHORT WAVES MOVE ACROSS IOWA IN A GENERALLY
ZONAL FLOW.  THROUGH SATURDAY MOISTURE WILL EITHER BE SPARSE OR
SHALLOW SO I AM NOT EXPECTING MUCH WITH THESE SHORTWAVES IN TERMS OF
SENSIBLE WEATHER EXCEPT FOR CLOUD COVER.  TEMPS SHOULD BE RATHER
MILD FOR MID TO LATE DECEMBER.

SATURDAY NIGHT THROUGH SUNDAY A LITTLE STRONGER SHORT WAVE MOVES IN
AND MOISTURE DEPTH INCREASES SLIGHTLY ALTHOUGH IT IS STILL VERY
SHALLOW.  SOUNDINGS DO NOT INDICATE ICE INTRODUCTION AND WHILE THERE
ARE MODEL DIFFERENCES AS TO WHERE ANY WEAK FORCING MIGHT OCCUR...IT
DOES APPEAR THAT THE NORTHERN HALF OF IOWA IS MORE LIKELY TO SEE
THIS THAN SOUTHERN IOWA.  AS A RESULT I KEPT THE MENTION OF FREEZING
DRIZZLE CONFINED TO THE NORTH.  THE SOUNDING DOES SATURATE
OR BEGIN TO SATURATE SUFFICIENTLY LATE SATURDAY NIGHT THROUGH
SUNDAY MORNING THROUGH THE DENDRITIC ZONE THAT WE COULD TRANSITION
TO SOME LIGHT SNOW UP NORTH...ESPECIALLY SUNDAY MORNING. THAT
SHORTWAVE EXITS DURING THE EARLY AFTERNOON AND TEMPS WARM
SUFFICIENTLY FOR A WINTERY MIX CHANGING TO RAIN ACROSS AT LEAST
SOME OF THE AREA.

SUNDAY NIGHT THROUGH MONDAY A MORE POTENT SHORTWAVE MOVES INTO
IOWA...AFFECTING THE WEST SUNDAY NIGHT AND THE REST OF THE AREA
THROUGH TUESDAY.  HERE MODELS DIVERGE ON HOW TO HANDLE THIS SYSTEM.
THE GFS KEEP THE UPPER LEVEL WAVE OPEN AND DEVELOPS A CLOSED SURFACE
LOW OVER CENTRAL TO NORTHEAST IOWA.  THE EURO DRASTICALLY DEPEND
THE UPPER WAVE TO OUR WEST THEN CONTINUES TO DEVELOP IT INTO A
CLOSED LOW MONDAY NIGHT AND TUESDAY ACROSS EASTERN IOWA.  THE
RESULTANT CLOSED SURFACE LOW IS OVER EASTERN IOWA AS WELL AND
FURTHER SOUTHWEST THAN THE GFS HAS.  THE GFS REALLY DEVELOPS THE QG
FORCING ACROSS CENTRAL IOWA SUNDAY NIGHT THEN IS SIGNIFICANTLY
WEAKER THROUGH TUESDAY.  SOUNDINGS SHOW A PROFILE THAT IS PRETTY
WARM THROUGH MONDAY AFTERNOON WHEN THE PROFILE COOLS TO BELOW
FREEZING.  PRECIP THROUGH EARLY MONDAY AFTERNOON SHOULD BE RAIN WITH
AN OCCASIONAL WINTERY MIX ESPECIALLY UP NORTH.  DURING THE AFTERNOON
WE WILL BE TRANSITIONING TO A RAIN/SNOW MIX BEFORE GOING TO ALL SNOW
MONDAY NIGHT.  IT IS TOO FAR OUT TO CONSIDER SNOWFALL AMOUNTS YET
AND GIVEN THE MODEL DISCREPANCIES IT WOULD BE HARD TO DO AT THIS
POINT.

THAT SYSTEM PULLS OUT BY CHRISTMAS EVE LEAVING US WITH SEASONAL
TEMPS AND MAINLY DRY.  ANOTHER SYSTEM PUSHES IN FOR THURSDAY NIGHT
AND FRIDAY AND GIVEN THE STRENGTH OF THE TROUGH OVER US THAT FAR OUT
WE WILL GET SOME PRECIP OUT OF THE SYSTEM BUT MODEL DISCREPANCIES
ARE TOO BIG TO GIVE MUCH IN THE WAY OF TIMING AND AMOUNT DETAILS.

&&

.AVIATION...18/18Z
ISSUED AT 1141 AM CST THU DEC 18 2014

SNOW IS WINDING DOWN ACROSS SOUTHERN IOWA THIS AFTERNOON WITH IFR
TO LOW MVFR CEILINGS LINGERING OVER THE AREA. IFR/LOW MVFR STRATUS
IS ALSO HANGING ON ACROSS PORTIONS OF NE IOWA. EXPECT LITTLE
IMPROVEMENT THROUGHOUT THE DAY WITH A LARGE SHIELD OF MVFR TO IFR
STRATUS OVER NEBRASKA AND WESTERN IOWA ADVECTING OVER CENTRAL IOWA
TONIGHT AND LINGERING THROUGH THE END OF THE TAF PERIOD.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...SKOW
LONG TERM...FAB
AVIATION...SKOW



000
FXUS63 KDMX 182132
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
332 PM CST THU DEC 18 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 324 PM CST THU DEC 18 2014

SNOW HAS ENDED OVER THE SOUTHEASTERN CWA AS THE CULPRIT UPPER LEVEL
WAVE HAS RAPIDLY WEAKENED AND DGZ FORCING HAS WANED. BASED ON WEBCAM
IMAGES AND A FEW SPOTTER/COOP REPORTS...MOST AREAS IN THE SOUTHERN
THREE TIERS OF COUNTIES SAW LESS THAN AN INCH OF SNOW. ATTENTION NOW
TURNS UPSTREAM TO A LARGE STRATUS PLUME STRETCHING FROM NORTHWEST
MONTANA TO THE TEXAS PANHANDLE...WITH THE EASTERN FRONT NOW JUST
ABOUT TO ENTER THE WESTERN CWA. LIGHT WEST TO SOUTHWEST FLOW IN THE
LOWEST 1 KM OF THE ATMOSPHERE BEHIND A DEPARTING SURFACE RIDGE
SHOULD ADVECT THIS CLOUD MASS OVER CENTRAL IOWA TONIGHT AND KEEP
SKIES OVERCAST ALL NIGHT AND INTO TOMORROW MORNING. THE CLOUDS
SHOULD ALSO BOLSTER LOW TEMPS TONIGHT COMPARED TO PREVIOUS NIGHTS
AND DIDN`T DEVIATE MUCH FROM GUIDANCE IN THIS RESPECT.

THE BIGGEST UNCERTAINTY FOR TONIGHT IS THE POSSIBILITY OF FLURRIES
OR FREEZING DRIZZLE WEST OF I-35. SHORT-RANGE MODEL SOUNDINGS (RUC
AND HRRR IN PARTICULAR) SATURATE THE LOWEST 5 KFT OF THE ATMOSPHERE
IN THIS REGION TONIGHT WITH NEARLY ISOTHERMAL PROFILES IN THIS LAYER
HOVERING BETWEEN -4 AND -7C. WITH THIS CONDITIONAL ICE PROBABILITY
...WENT WITH A MIX OF OCCASIONAL FLURRIES AND PATCHY FZDZ. FORCING
SHOULD BE MARGINAL AT BEST AND NO ACCUMULATION OF SNOW OR ICE IS
ANTICIPATED. ANY LIFT WITH AN UPPER LEVEL TROUGH ON WATER VAPOR
IMAGERY NW OF THE CWA SHOULD STAY NORTH AND EAST OF THE AREA.
ISENTROPIC UPGLIDE IN THE LOWEST 100MB OF THE ATMOSPHERE IS
PRESENT...BUT AGAIN VERY WEAK.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 324 PM CST THU DEC 18 2014

THE WEATHER IN THE LONG TERM WILL IN GENERAL BE MORE ACTIVE THEN
WHAT WE HAVE SEEN IN A WHILE.  FRIDAY THROUGH SUNDAY THERE WILL BE
NUMEROUS RELATIVELY WEAK SHORT WAVES MOVE ACROSS IOWA IN A GENERALLY
ZONAL FLOW.  THROUGH SATURDAY MOISTURE WILL EITHER BE SPARSE OR
SHALLOW SO I AM NOT EXPECTING MUCH WITH THESE SHORTWAVES IN TERMS OF
SENSIBLE WEATHER EXCEPT FOR CLOUD COVER.  TEMPS SHOULD BE RATHER
MILD FOR MID TO LATE DECEMBER.

SATURDAY NIGHT THROUGH SUNDAY A LITTLE STRONGER SHORT WAVE MOVES IN
AND MOISTURE DEPTH INCREASES SLIGHTLY ALTHOUGH IT IS STILL VERY
SHALLOW.  SOUNDINGS DO NOT INDICATE ICE INTRODUCTION AND WHILE THERE
ARE MODEL DIFFERENCES AS TO WHERE ANY WEAK FORCING MIGHT OCCUR...IT
DOES APPEAR THAT THE NORTHERN HALF OF IOWA IS MORE LIKELY TO SEE
THIS THAN SOUTHERN IOWA.  AS A RESULT I KEPT THE MENTION OF FREEZING
DRIZZLE CONFINED TO THE NORTH.  THE SOUNDING DOES SATURATE
OR BEGIN TO SATURATE SUFFICIENTLY LATE SATURDAY NIGHT THROUGH
SUNDAY MORNING THROUGH THE DENDRITIC ZONE THAT WE COULD TRANSITION
TO SOME LIGHT SNOW UP NORTH...ESPECIALLY SUNDAY MORNING. THAT
SHORTWAVE EXITS DURING THE EARLY AFTERNOON AND TEMPS WARM
SUFFICIENTLY FOR A WINTERY MIX CHANGING TO RAIN ACROSS AT LEAST
SOME OF THE AREA.

SUNDAY NIGHT THROUGH MONDAY A MORE POTENT SHORTWAVE MOVES INTO
IOWA...AFFECTING THE WEST SUNDAY NIGHT AND THE REST OF THE AREA
THROUGH TUESDAY.  HERE MODELS DIVERGE ON HOW TO HANDLE THIS SYSTEM.
THE GFS KEEP THE UPPER LEVEL WAVE OPEN AND DEVELOPS A CLOSED SURFACE
LOW OVER CENTRAL TO NORTHEAST IOWA.  THE EURO DRASTICALLY DEPEND
THE UPPER WAVE TO OUR WEST THEN CONTINUES TO DEVELOP IT INTO A
CLOSED LOW MONDAY NIGHT AND TUESDAY ACROSS EASTERN IOWA.  THE
RESULTANT CLOSED SURFACE LOW IS OVER EASTERN IOWA AS WELL AND
FURTHER SOUTHWEST THAN THE GFS HAS.  THE GFS REALLY DEVELOPS THE QG
FORCING ACROSS CENTRAL IOWA SUNDAY NIGHT THEN IS SIGNIFICANTLY
WEAKER THROUGH TUESDAY.  SOUNDINGS SHOW A PROFILE THAT IS PRETTY
WARM THROUGH MONDAY AFTERNOON WHEN THE PROFILE COOLS TO BELOW
FREEZING.  PRECIP THROUGH EARLY MONDAY AFTERNOON SHOULD BE RAIN WITH
AN OCCASIONAL WINTERY MIX ESPECIALLY UP NORTH.  DURING THE AFTERNOON
WE WILL BE TRANSITIONING TO A RAIN/SNOW MIX BEFORE GOING TO ALL SNOW
MONDAY NIGHT.  IT IS TOO FAR OUT TO CONSIDER SNOWFALL AMOUNTS YET
AND GIVEN THE MODEL DISCREPANCIES IT WOULD BE HARD TO DO AT THIS
POINT.

THAT SYSTEM PULLS OUT BY CHRISTMAS EVE LEAVING US WITH SEASONAL
TEMPS AND MAINLY DRY.  ANOTHER SYSTEM PUSHES IN FOR THURSDAY NIGHT
AND FRIDAY AND GIVEN THE STRENGTH OF THE TROUGH OVER US THAT FAR OUT
WE WILL GET SOME PRECIP OUT OF THE SYSTEM BUT MODEL DISCREPANCIES
ARE TOO BIG TO GIVE MUCH IN THE WAY OF TIMING AND AMOUNT DETAILS.

&&

.AVIATION...18/18Z
ISSUED AT 1141 AM CST THU DEC 18 2014

SNOW IS WINDING DOWN ACROSS SOUTHERN IOWA THIS AFTERNOON WITH IFR
TO LOW MVFR CEILINGS LINGERING OVER THE AREA. IFR/LOW MVFR STRATUS
IS ALSO HANGING ON ACROSS PORTIONS OF NE IOWA. EXPECT LITTLE
IMPROVEMENT THROUGHOUT THE DAY WITH A LARGE SHIELD OF MVFR TO IFR
STRATUS OVER NEBRASKA AND WESTERN IOWA ADVECTING OVER CENTRAL IOWA
TONIGHT AND LINGERING THROUGH THE END OF THE TAF PERIOD.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...SKOW
LONG TERM...FAB
AVIATION...SKOW



000
FXUS63 KDMX 182132
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
332 PM CST THU DEC 18 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 324 PM CST THU DEC 18 2014

SNOW HAS ENDED OVER THE SOUTHEASTERN CWA AS THE CULPRIT UPPER LEVEL
WAVE HAS RAPIDLY WEAKENED AND DGZ FORCING HAS WANED. BASED ON WEBCAM
IMAGES AND A FEW SPOTTER/COOP REPORTS...MOST AREAS IN THE SOUTHERN
THREE TIERS OF COUNTIES SAW LESS THAN AN INCH OF SNOW. ATTENTION NOW
TURNS UPSTREAM TO A LARGE STRATUS PLUME STRETCHING FROM NORTHWEST
MONTANA TO THE TEXAS PANHANDLE...WITH THE EASTERN FRONT NOW JUST
ABOUT TO ENTER THE WESTERN CWA. LIGHT WEST TO SOUTHWEST FLOW IN THE
LOWEST 1 KM OF THE ATMOSPHERE BEHIND A DEPARTING SURFACE RIDGE
SHOULD ADVECT THIS CLOUD MASS OVER CENTRAL IOWA TONIGHT AND KEEP
SKIES OVERCAST ALL NIGHT AND INTO TOMORROW MORNING. THE CLOUDS
SHOULD ALSO BOLSTER LOW TEMPS TONIGHT COMPARED TO PREVIOUS NIGHTS
AND DIDN`T DEVIATE MUCH FROM GUIDANCE IN THIS RESPECT.

THE BIGGEST UNCERTAINTY FOR TONIGHT IS THE POSSIBILITY OF FLURRIES
OR FREEZING DRIZZLE WEST OF I-35. SHORT-RANGE MODEL SOUNDINGS (RUC
AND HRRR IN PARTICULAR) SATURATE THE LOWEST 5 KFT OF THE ATMOSPHERE
IN THIS REGION TONIGHT WITH NEARLY ISOTHERMAL PROFILES IN THIS LAYER
HOVERING BETWEEN -4 AND -7C. WITH THIS CONDITIONAL ICE PROBABILITY
...WENT WITH A MIX OF OCCASIONAL FLURRIES AND PATCHY FZDZ. FORCING
SHOULD BE MARGINAL AT BEST AND NO ACCUMULATION OF SNOW OR ICE IS
ANTICIPATED. ANY LIFT WITH AN UPPER LEVEL TROUGH ON WATER VAPOR
IMAGERY NW OF THE CWA SHOULD STAY NORTH AND EAST OF THE AREA.
ISENTROPIC UPGLIDE IN THE LOWEST 100MB OF THE ATMOSPHERE IS
PRESENT...BUT AGAIN VERY WEAK.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 324 PM CST THU DEC 18 2014

THE WEATHER IN THE LONG TERM WILL IN GENERAL BE MORE ACTIVE THEN
WHAT WE HAVE SEEN IN A WHILE.  FRIDAY THROUGH SUNDAY THERE WILL BE
NUMEROUS RELATIVELY WEAK SHORT WAVES MOVE ACROSS IOWA IN A GENERALLY
ZONAL FLOW.  THROUGH SATURDAY MOISTURE WILL EITHER BE SPARSE OR
SHALLOW SO I AM NOT EXPECTING MUCH WITH THESE SHORTWAVES IN TERMS OF
SENSIBLE WEATHER EXCEPT FOR CLOUD COVER.  TEMPS SHOULD BE RATHER
MILD FOR MID TO LATE DECEMBER.

SATURDAY NIGHT THROUGH SUNDAY A LITTLE STRONGER SHORT WAVE MOVES IN
AND MOISTURE DEPTH INCREASES SLIGHTLY ALTHOUGH IT IS STILL VERY
SHALLOW.  SOUNDINGS DO NOT INDICATE ICE INTRODUCTION AND WHILE THERE
ARE MODEL DIFFERENCES AS TO WHERE ANY WEAK FORCING MIGHT OCCUR...IT
DOES APPEAR THAT THE NORTHERN HALF OF IOWA IS MORE LIKELY TO SEE
THIS THAN SOUTHERN IOWA.  AS A RESULT I KEPT THE MENTION OF FREEZING
DRIZZLE CONFINED TO THE NORTH.  THE SOUNDING DOES SATURATE
OR BEGIN TO SATURATE SUFFICIENTLY LATE SATURDAY NIGHT THROUGH
SUNDAY MORNING THROUGH THE DENDRITIC ZONE THAT WE COULD TRANSITION
TO SOME LIGHT SNOW UP NORTH...ESPECIALLY SUNDAY MORNING. THAT
SHORTWAVE EXITS DURING THE EARLY AFTERNOON AND TEMPS WARM
SUFFICIENTLY FOR A WINTERY MIX CHANGING TO RAIN ACROSS AT LEAST
SOME OF THE AREA.

SUNDAY NIGHT THROUGH MONDAY A MORE POTENT SHORTWAVE MOVES INTO
IOWA...AFFECTING THE WEST SUNDAY NIGHT AND THE REST OF THE AREA
THROUGH TUESDAY.  HERE MODELS DIVERGE ON HOW TO HANDLE THIS SYSTEM.
THE GFS KEEP THE UPPER LEVEL WAVE OPEN AND DEVELOPS A CLOSED SURFACE
LOW OVER CENTRAL TO NORTHEAST IOWA.  THE EURO DRASTICALLY DEPEND
THE UPPER WAVE TO OUR WEST THEN CONTINUES TO DEVELOP IT INTO A
CLOSED LOW MONDAY NIGHT AND TUESDAY ACROSS EASTERN IOWA.  THE
RESULTANT CLOSED SURFACE LOW IS OVER EASTERN IOWA AS WELL AND
FURTHER SOUTHWEST THAN THE GFS HAS.  THE GFS REALLY DEVELOPS THE QG
FORCING ACROSS CENTRAL IOWA SUNDAY NIGHT THEN IS SIGNIFICANTLY
WEAKER THROUGH TUESDAY.  SOUNDINGS SHOW A PROFILE THAT IS PRETTY
WARM THROUGH MONDAY AFTERNOON WHEN THE PROFILE COOLS TO BELOW
FREEZING.  PRECIP THROUGH EARLY MONDAY AFTERNOON SHOULD BE RAIN WITH
AN OCCASIONAL WINTERY MIX ESPECIALLY UP NORTH.  DURING THE AFTERNOON
WE WILL BE TRANSITIONING TO A RAIN/SNOW MIX BEFORE GOING TO ALL SNOW
MONDAY NIGHT.  IT IS TOO FAR OUT TO CONSIDER SNOWFALL AMOUNTS YET
AND GIVEN THE MODEL DISCREPANCIES IT WOULD BE HARD TO DO AT THIS
POINT.

THAT SYSTEM PULLS OUT BY CHRISTMAS EVE LEAVING US WITH SEASONAL
TEMPS AND MAINLY DRY.  ANOTHER SYSTEM PUSHES IN FOR THURSDAY NIGHT
AND FRIDAY AND GIVEN THE STRENGTH OF THE TROUGH OVER US THAT FAR OUT
WE WILL GET SOME PRECIP OUT OF THE SYSTEM BUT MODEL DISCREPANCIES
ARE TOO BIG TO GIVE MUCH IN THE WAY OF TIMING AND AMOUNT DETAILS.

&&

.AVIATION...18/18Z
ISSUED AT 1141 AM CST THU DEC 18 2014

SNOW IS WINDING DOWN ACROSS SOUTHERN IOWA THIS AFTERNOON WITH IFR
TO LOW MVFR CEILINGS LINGERING OVER THE AREA. IFR/LOW MVFR STRATUS
IS ALSO HANGING ON ACROSS PORTIONS OF NE IOWA. EXPECT LITTLE
IMPROVEMENT THROUGHOUT THE DAY WITH A LARGE SHIELD OF MVFR TO IFR
STRATUS OVER NEBRASKA AND WESTERN IOWA ADVECTING OVER CENTRAL IOWA
TONIGHT AND LINGERING THROUGH THE END OF THE TAF PERIOD.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...SKOW
LONG TERM...FAB
AVIATION...SKOW



000
FXUS63 KDVN 182111
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
311 PM CST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 246 PM CST THU DEC 18 2014

AT 245 PM CDT...A RIDGE OF SURFACE HIGH PRESSURE REMAINED IN PLACE
ACROSS THE REGION. A FEW LIGHT FLURRIES LINGERED IN PARTS OF EASTERN
IOWA AND WESTERN ILLINOIS...BUT WERE DECREASING IN COVERAGE AS MID
LEVEL LOW PRESSURE PUSHED EAST. MID AFTERNOON TEMPERATURES WERE IN
THE 20S.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 246 PM CST THU DEC 18 2014

THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD IS CLOUD TRENDS
AND IMPACT ON TEMPERATURES OVERNIGHT INTO FRIDAY.

IN THE NEAR TERM...ISOLATED FLURRIES WILL CONTINUE TO DIMINISH IN
COVERAGE AS FORCING FROM A MID-LEVEL SHORT WAVE PUSHES EAST. MODEL
LAYER RH PROGS POINT TO POTENTIAL FOR SOME MOSTLY CLEAR TO PARTY
CLOUDY PERIODS ACROSS NORTHERN AND EASTERN PORTIONS OF THE
FORECAST AREA. THESE AREAS HAVE ONLY RISEN INTO THE 23-38 DEGREE
RANGE THIS AFTERNOON. WITH SOME PARTIAL CLEARING EXPECTED...BELIEVE
UNDERCUTTING GUIDANCE NORTH AND EAST IS THE WAY TO GO. LOW LEVEL
MOISTURE WILL BE GREATEST OVERNIGHT IN THE EXTREME SOUTH...AND
HAVE ADDED PATCHY FOG FROM 09Z THROUGH 14Z FRIDAY.

ON FRIDAY...SURFACE RIDGING AND STAGNANT LOW LEVEL WINDS EXPECTED
TO CONTINUE WITH PERSISTENT CLOUDY TO MOSTLY CLOUDY SKIES. 850MB
TEMPS ARE FORECAST TO BE NEAR TO SLIGHTLY WARMER THAN THURSDAY.
BELIEVE AFTERNOON HIGHS WILL ONLY BE MODESTLY WARMER THAN
TODAY...IN THE UPPER 20S TO LOW 30S...COOLER THAN THE CONSENSUS
BLEND GUIDANCE.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 246 PM CST THU DEC 18 2014

MAIN CONCERN IN THE EXTENDED PERIOD IS THE STORM SYSTEM THAT WILL
AFFECT THE MIDWEST THE END OF THIS WEEKEND THROUGH MIDWEEK NEXT
WEEK.  COMPUTER MODEL SOLUTIONS REGARDING THIS SYSTEM ARE DIFFERENT
AND AS SUCH THIS MAKES FOR A DIFFICULT FORECAST.  AT THIS TIME THE
SYSTEM LOOKS TO BRING SOME RAIN TO THE AREA...CHANGING OVER TO SNOW
AT THE END OF THE FORECAST.  THIS FORECAST IS SUBJECT TO CHANGE AS
GUIDANCE BEGINS TO AGREE ON A SOLUTION.

A SERIES OF SHORTWAVE DISTURBANCES WILL TRANSVERSE THROUGH THE FLOW
THIS WEEKEND.  ON SATURDAY NIGHT INTO SUNDAY...AS WAVE WILL MOVE
THROUGH THE AREA...BRINGING WITH IT THE CHANCE OF FREEZING DRIZZLE
ACROSS NORTHERN PORTIONS OF THE CWA.  TEMPERATURES LOOK TO REBOUND
ABOVE FREEZING ON SUNDAY AFTERNOON.  THIS MEANS THAT ANY IMPACTS
FROM THE FREEZING DRIZZLE SHOULD BE SHORT LIVED.  IN THE WAKE OF THIS
SYSTEM SOUTHWEST FLOW WILL HELP TO WARM TEMPERATURES UNTIL ANOTHER
WAVE MOVES THROUGH ON SUNDAY NIGHT.

ON MONDAY...A MUCH MORE ROBUST SYSTEM WITH BETTER VORTICITY
ADVECTION AND MAGNITUDE WILL MOVE INTO THE CENTRAL CONUS. MODELS ARE
IN GOOD AGREEMENT WITH THE BROAD DETAILS OF THE FORECAST.
HOWEVER...THE SURFACE FEATURES AND SUBSEQUENT SENSIBLE WEATHER ARE
HARD TO NAIL DOWN DUE TO THE MODEL INCONSISTENCIES.  CURRENT BLENDED
GUIDANCE SUGGESTS THAT THIS SYSTEM WILL BE MORE OF A RAIN AND THEN
RAIN/SNOW MIX SYSTEM...WITH SNOW ON THE BACK END OF IT.  LOOKING AT
INDIVIDUAL MODELS AND THE SURFACE FIELD EVOLUTION LEADS ONE TO
REALIZE THERE ARE A LOT MORE THINGS THAT COULD HAPPEN.  FOR
ONE...SOME GUIDANCE DEVELOPS A LOW TO OUR SOUTH OVER THE SOUTHERN
MISSISSIPPI RIVER VALLEY AND THEN ADVECTS IT TO THE NE...MERGING
WITH THE LOW OVER N WI.  THIS LOW COULD ACT TO ROB US OF DEEP
MOISTURE AND LEAD TO AN OUTCOME WITH LOWER CHANCES OF PRECIP AND
OVERALL LESS QPF.  THE GEM MODEL HAS THE INITIAL SURFACE LOW OVER
SOUTHERN CANADA AND DEVELOPS A LOW TO OUR EAST.  THE GFS HAS THE
INITIAL LOW  TO OUR WEST...MOVES IT OVER LA CROSSE AND INTO N
WI...THEN DEVELOPS A SURFACE LOW TO OUR EAST.  THE ECMWF IS SIMILAR
TO THE GFS AND THEN DEVELOPS A SECONDARY LOW EVEN FURTHER TO THE
EAST ACROSS THE ATLANTIC STATES.  WHAT THIS MEANS IS THAT THE
SPECIFICS OF THIS FORECAST WILL CHANGE AND THERE IS LOW CONFIDENCE
IN THE CURRENT FORECAST FOR SENSIBLE WEATHER.  THERE IS HIGH
CONFIDENCE THAT THERE WILL BE A SENSIBLE WEATHER PRODUCING SYSTEM
ACROSS THE MIDWEST EARLY NEXT WEEK.  AS FAR AS THE EVENT BEING ALL
RAIN...RASN...OR SNOW...THIS IS HARD TO NAIL DOWN AND SUBJECT TO
CHANGE.  THOSE PLANNING TRAVEL FOR NEXT WEEK SHOULD PAY ATTENTION TO
LATER FORECASTS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 246 PM CST THU DEC 18 2014

LIGHT SNOW/FLURRIES WILL DIMINISH THROUGH LATE AFTERNOON. KDBQ/KBRL
MAY BE IMPACTED BY CIGS AROUND 1500FT AGL INTO THE EVENING...BUT
CONFIDENCE IS LOW ON HOW THE LOW CLOUDS WILL EVOLVE OVERNIGHT AT
THESE LOCATIONS. CONFIDENCE IS HIGHER FRIDAY MORNING REGARDING LOW LEVEL
MOISTURE EXPECTED TO INCREASE AT KBRL/KCID WITH MVFR CIGS AFTER
14Z.

&&

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

$$

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






000
FXUS63 KDVN 182111
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
311 PM CST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 246 PM CST THU DEC 18 2014

AT 245 PM CDT...A RIDGE OF SURFACE HIGH PRESSURE REMAINED IN PLACE
ACROSS THE REGION. A FEW LIGHT FLURRIES LINGERED IN PARTS OF EASTERN
IOWA AND WESTERN ILLINOIS...BUT WERE DECREASING IN COVERAGE AS MID
LEVEL LOW PRESSURE PUSHED EAST. MID AFTERNOON TEMPERATURES WERE IN
THE 20S.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 246 PM CST THU DEC 18 2014

THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD IS CLOUD TRENDS
AND IMPACT ON TEMPERATURES OVERNIGHT INTO FRIDAY.

IN THE NEAR TERM...ISOLATED FLURRIES WILL CONTINUE TO DIMINISH IN
COVERAGE AS FORCING FROM A MID-LEVEL SHORT WAVE PUSHES EAST. MODEL
LAYER RH PROGS POINT TO POTENTIAL FOR SOME MOSTLY CLEAR TO PARTY
CLOUDY PERIODS ACROSS NORTHERN AND EASTERN PORTIONS OF THE
FORECAST AREA. THESE AREAS HAVE ONLY RISEN INTO THE 23-38 DEGREE
RANGE THIS AFTERNOON. WITH SOME PARTIAL CLEARING EXPECTED...BELIEVE
UNDERCUTTING GUIDANCE NORTH AND EAST IS THE WAY TO GO. LOW LEVEL
MOISTURE WILL BE GREATEST OVERNIGHT IN THE EXTREME SOUTH...AND
HAVE ADDED PATCHY FOG FROM 09Z THROUGH 14Z FRIDAY.

ON FRIDAY...SURFACE RIDGING AND STAGNANT LOW LEVEL WINDS EXPECTED
TO CONTINUE WITH PERSISTENT CLOUDY TO MOSTLY CLOUDY SKIES. 850MB
TEMPS ARE FORECAST TO BE NEAR TO SLIGHTLY WARMER THAN THURSDAY.
BELIEVE AFTERNOON HIGHS WILL ONLY BE MODESTLY WARMER THAN
TODAY...IN THE UPPER 20S TO LOW 30S...COOLER THAN THE CONSENSUS
BLEND GUIDANCE.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 246 PM CST THU DEC 18 2014

MAIN CONCERN IN THE EXTENDED PERIOD IS THE STORM SYSTEM THAT WILL
AFFECT THE MIDWEST THE END OF THIS WEEKEND THROUGH MIDWEEK NEXT
WEEK.  COMPUTER MODEL SOLUTIONS REGARDING THIS SYSTEM ARE DIFFERENT
AND AS SUCH THIS MAKES FOR A DIFFICULT FORECAST.  AT THIS TIME THE
SYSTEM LOOKS TO BRING SOME RAIN TO THE AREA...CHANGING OVER TO SNOW
AT THE END OF THE FORECAST.  THIS FORECAST IS SUBJECT TO CHANGE AS
GUIDANCE BEGINS TO AGREE ON A SOLUTION.

A SERIES OF SHORTWAVE DISTURBANCES WILL TRANSVERSE THROUGH THE FLOW
THIS WEEKEND.  ON SATURDAY NIGHT INTO SUNDAY...AS WAVE WILL MOVE
THROUGH THE AREA...BRINGING WITH IT THE CHANCE OF FREEZING DRIZZLE
ACROSS NORTHERN PORTIONS OF THE CWA.  TEMPERATURES LOOK TO REBOUND
ABOVE FREEZING ON SUNDAY AFTERNOON.  THIS MEANS THAT ANY IMPACTS
FROM THE FREEZING DRIZZLE SHOULD BE SHORT LIVED.  IN THE WAKE OF THIS
SYSTEM SOUTHWEST FLOW WILL HELP TO WARM TEMPERATURES UNTIL ANOTHER
WAVE MOVES THROUGH ON SUNDAY NIGHT.

ON MONDAY...A MUCH MORE ROBUST SYSTEM WITH BETTER VORTICITY
ADVECTION AND MAGNITUDE WILL MOVE INTO THE CENTRAL CONUS. MODELS ARE
IN GOOD AGREEMENT WITH THE BROAD DETAILS OF THE FORECAST.
HOWEVER...THE SURFACE FEATURES AND SUBSEQUENT SENSIBLE WEATHER ARE
HARD TO NAIL DOWN DUE TO THE MODEL INCONSISTENCIES.  CURRENT BLENDED
GUIDANCE SUGGESTS THAT THIS SYSTEM WILL BE MORE OF A RAIN AND THEN
RAIN/SNOW MIX SYSTEM...WITH SNOW ON THE BACK END OF IT.  LOOKING AT
INDIVIDUAL MODELS AND THE SURFACE FIELD EVOLUTION LEADS ONE TO
REALIZE THERE ARE A LOT MORE THINGS THAT COULD HAPPEN.  FOR
ONE...SOME GUIDANCE DEVELOPS A LOW TO OUR SOUTH OVER THE SOUTHERN
MISSISSIPPI RIVER VALLEY AND THEN ADVECTS IT TO THE NE...MERGING
WITH THE LOW OVER N WI.  THIS LOW COULD ACT TO ROB US OF DEEP
MOISTURE AND LEAD TO AN OUTCOME WITH LOWER CHANCES OF PRECIP AND
OVERALL LESS QPF.  THE GEM MODEL HAS THE INITIAL SURFACE LOW OVER
SOUTHERN CANADA AND DEVELOPS A LOW TO OUR EAST.  THE GFS HAS THE
INITIAL LOW  TO OUR WEST...MOVES IT OVER LA CROSSE AND INTO N
WI...THEN DEVELOPS A SURFACE LOW TO OUR EAST.  THE ECMWF IS SIMILAR
TO THE GFS AND THEN DEVELOPS A SECONDARY LOW EVEN FURTHER TO THE
EAST ACROSS THE ATLANTIC STATES.  WHAT THIS MEANS IS THAT THE
SPECIFICS OF THIS FORECAST WILL CHANGE AND THERE IS LOW CONFIDENCE
IN THE CURRENT FORECAST FOR SENSIBLE WEATHER.  THERE IS HIGH
CONFIDENCE THAT THERE WILL BE A SENSIBLE WEATHER PRODUCING SYSTEM
ACROSS THE MIDWEST EARLY NEXT WEEK.  AS FAR AS THE EVENT BEING ALL
RAIN...RASN...OR SNOW...THIS IS HARD TO NAIL DOWN AND SUBJECT TO
CHANGE.  THOSE PLANNING TRAVEL FOR NEXT WEEK SHOULD PAY ATTENTION TO
LATER FORECASTS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 246 PM CST THU DEC 18 2014

LIGHT SNOW/FLURRIES WILL DIMINISH THROUGH LATE AFTERNOON. KDBQ/KBRL
MAY BE IMPACTED BY CIGS AROUND 1500FT AGL INTO THE EVENING...BUT
CONFIDENCE IS LOW ON HOW THE LOW CLOUDS WILL EVOLVE OVERNIGHT AT
THESE LOCATIONS. CONFIDENCE IS HIGHER FRIDAY MORNING REGARDING LOW LEVEL
MOISTURE EXPECTED TO INCREASE AT KBRL/KCID WITH MVFR CIGS AFTER
14Z.

&&

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

$$

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







000
FXUS63 KDVN 181804
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1204 PM CST THU DEC 18 2014

.UPDATE...
ISSUED AT 1017 AM CST THU DEC 18 2014

MORNING UPDATE TO FINE TUNE POPS AND SNOWFALL AMOUNTS...WITH A
SLIGHT INCREASE NORTH TOWARDS SIGOURNEY AND WILLIAMSBURG. LATEST
NAM/RAP BUFKIT SOUNDINGS INDICATE SOME POTENTIAL FOR SOME PATCHY
FREEZING DRIZZLE AT THE TAIL END OF THE EVENT THIS AFTERNOON
ACROSS THE EXTREME SOUTH.

&&

.SYNOPSIS...
ISSUED AT 321 AM CST THU DEC 18 2014

SNOW FAIRLY WIDESPREAD FROM WESTERN MO INTO NE AND KS AHEAD OF AN
UPPER LEVEL SHORTWAVE OVER THE PLAINS. REPORTS OF ACCUMS FROM
1-3 INCHES FROM NORTHERN KS THROUGH THE KC METRO WITH OBS SUGGESTING
THE LEADING EDGE OF SNOW BETWEEN CHILLICOTHE MO AND KC METRO
MOVING N/E. TRENDS SUPPORT SYSTEM AND ATTENDANT SNOW TO GRADUALLY
WEAKEN TODAY AS IT ENCOUNTERS RIDGING OVER THE REGION... BUT
BEFORE DOING SO IS EXPECTED BRING SOME LIGHT ACCUMS TO SOUTHERN
PORTIONS OF CWA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU DEC 18 2014

SHORTWAVE WILL MOVE ACROSS REGION TODAY AND DEAMPLIFY/WEAKEN WHILE
RUNNING INTO THE RIDGE. THIS ALONG WITH COPIOUS DRY AIR PER 00Z
DVN AND ILX RAOBS SHOULD RESULT IN STEADY WEAKENING OF SNOW AS IT
SPREADS INTO FAR SOUTHERN CWA THIS AM. FORCING PEAKS OVER NORTHERN
MO 10Z-15Z THEN QUICKLY DIMINISHING THROUGH 18Z. OVERALL GOING
WITH 0.05 TO 0.1 INCH OF LIQUID QPF WITH SLR OF 12-14:1 TO YIELD
AROUND AN INCH OR SO OF ACCUM VERY FAR SOUTHERN CWA MAINLY NORTHEAST
MO INTO PORTIONS OF WEST CENTRAL IL TAPERING OFF TO TRACE HWY 34.
GIVEN DRY AIR AND ALIGNMENT OF FORCING COULD ENVISION SCENARIO
WHEREBY THIS OCCURS OVER MUCH SHORTER DISTANCE OF 25+ MILES NORTHEAST
MO. CANT RULE OUT POSSIBILITY OF SOME FREEZING DRIZZLE FAR SOUTH
FOR A WHILE THIS AFTERNOON IF CLOUD BEARING LAYER BECOMES SUFFICIENTLY
SHALLOW/WARM.. BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE MENTION
ATTIM. ASIDE FROM THE LIGHT SNOW FAR SOUTHERN CWA... EXPECT PTSUNNY
TO CLOUDY SKIES TODAY WITH TEMPS SIMILAR TO THOSE OF YSTDY IN
RELATIVELY NEUTRAL THERMAL ENVIRONMENT... WITH READINGS MAINLY IN
UPPER 20S TO LOWER 30S. WINDS NEGLIGIBLE AND GENERALLY 5 MPH OR LESS
WITH SURFACE RIDGING.

TONIGHT... GENERALLY PT-MOCDLY SKIES WITH SFC RIDGING BECOMING
RE-ESTABLISHED AS THE DOMINANT FEATURE. BANKING ON SUFFICIENT
CLOUDINESS TO PRECLUDE TEMPS FROM BOTTOMING OUT DESPITE NEAR
CALM/CALM WINDS... AND EXPECT GENERALLY UPPER TEENS TO MID 20S FOR
LOWS. SHOULD SOME AREAS SEE MORE IN WAY OF CLEARING THEN POTENTIAL
TO BE IN MID TEENS FOR LOWS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU DEC 18 2014

FORECAST FOCUS ON ACTIVE WEATHER PATTERN ESPECIALLY CHRISTMAS WEEK.

FRIDAY THROUGH SUNDAY...ZONAL FLOW OVER THE REGION WITH A SERIES OF
SHORT WAVES MOVING ACROSS. THIS LOOKS TO BE ANOTHER RATHER CLOUDY
PERIOD WITH FORECAST SOUNDINGS INDICATING WEAK LOW LEVEL WARM
ADVECTION AND A STRONG INVERSION SETTING UP AROUND 850 MB...WITH MOISTURE
TRAPPED BELOW. SATURDAY NIGHT I HAVE INTRODUCED A SLIGHT CHANCE OF
FREEZING DRIZZLE IN OUR FAR NW CWA...AS A SHORT WAVE/VORT MAX
TRAVERSES NORTHERN IA. FORECAST SOUNDINGS INDICATE A WARM LAYER JUST
ABOVE FREEZING WITH DRY AIR IN THE MID LEVELS WITH MOISTURE BELOW.
MAXIMUM TEMPERATURES DURING THIS PERIOD WILL BE IN THE 30S TO NEAR
40 WITH LOWS IN THE 20S TO NEAR 30.

MONDAY THROUGH WEDNESDAY...THIS IS WHEN THE WEATHER GETS ACTIVE BUT
ALSO COMPLICATED AND CHALLENGING. UPPER LOW DEEPENS AS IT TRACKS
FROM THE NORTHERN PLAINS (MONDAY) INTO EASTERN IA (TUESDAY) AND THEN
LIFTING INTO THE WESTERN GREAT LAKES (WEDNESDAY). THE PATH OF THIS
SYSTEM WOULD SUGGEST MAINLY A RAIN/SNOW MIX BUT WILL NEED TO KEEP AN
EYE ON TUESDAY WHERE IT MAY CHANGE TO ALL SNOW...GIVEN THE COLD
POCKET ALOFT AND DYNAMIC COOLING. WAY TOO EARLY TO OFFER ANY
ACCUMULATION AMOUNTS IF ANY. MAXIMUM TEMPERATURES ON MONDAY SHOULD
PUSH INTO THE 40S FROM ABOUT I-80 SOUTHWARD...AND IN THE 30S TUESDAY
AND WEDNESDAY. THE ECMWF HAS NOW THROWN A CURVE BALL IN REGARD TO
THE WHOPPER STORM EARLIER INDICATED TO BE IN THE GREAT LAKES REGION
CHRISTMAS EVE. IT NOW IS NOT QUITE THE BOMB SHOWN THE PAST COUPLE
RUNS AND IS ALSO INTENSIFYING THE CYCLONE FARTHER EAST...IN NEW
ENGLAND! THIS IS WHAT THE GFS HAS BEEN INDICATING ALL ALONG. SUFFICE
TO SAY CONFIDENCE IS LOW AS PHASING ISSUES CONTINUE TO HAUNT THE
MODELS. SO MORE CHANGES IN THE MODELS CAN BE EXPECTED OVER THE NEXT
SEVERAL DAYS AND THE IMPACTS IF ANY ON OUR AREA REMAIN TO BE SEEN.

CHRISTMAS DAY AND FRIDAY...MANY UNCERTAINTIES REGARDING THE
POTENTIAL WINTER STORM OFFERED BY THE ECMWF ON FRIDAY. DEPENDING ON
WHERE THE HUGE UPPER LOW TO OUR NORTHEAST IS LOCATED WILL PLAY A
ROLE IN THE STRONG ENERGY COMING OUT OF THE SOUTHWEST. CONFIDENCE IN
THE TRACK/TIMING/INTENSITY OF THIS SYSTEM IS LOW BUT CERTAINLY THERE
IS THE POTENTIAL FOR A WINTER STORM SOMEWHERE IN THE MIDWEST...SO
ANYONE TRAVELING AROUND CHRISTMAS DAY OR THEREAFTER SHOULD CONTINUE
TO MONITOR LATER FORECASTS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1153 AM CST THU DEC 18 2014

LIGHT SNOW WILL TAPER OFF ACROSS SOUTHEAST IOWA AND NEARBY AREAS
THIS AFTERNOON...WITH PERIODS OF MVFR CIGS AT KBRL THROUGH EARLY
AFTERNOON. LOW VFR CIGS WILL DEVELOP AT ALL SITES OVERNIGHT. LOW
LEVEL MOISTURE WILL INCREASE ACROSS EASTERN IOWA FRIDAY MORNING
WITH MVFR CIGS EXPECTED AT KBRL/KCID AFTER 14Z.

&&

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

$$

UPDATE...RP KINNEY
SYNOPSIS...05
SHORT TERM...05
LONG TERM...HAASE
AVIATION...RP KINNEY






000
FXUS63 KDVN 181804
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1204 PM CST THU DEC 18 2014

.UPDATE...
ISSUED AT 1017 AM CST THU DEC 18 2014

MORNING UPDATE TO FINE TUNE POPS AND SNOWFALL AMOUNTS...WITH A
SLIGHT INCREASE NORTH TOWARDS SIGOURNEY AND WILLIAMSBURG. LATEST
NAM/RAP BUFKIT SOUNDINGS INDICATE SOME POTENTIAL FOR SOME PATCHY
FREEZING DRIZZLE AT THE TAIL END OF THE EVENT THIS AFTERNOON
ACROSS THE EXTREME SOUTH.

&&

.SYNOPSIS...
ISSUED AT 321 AM CST THU DEC 18 2014

SNOW FAIRLY WIDESPREAD FROM WESTERN MO INTO NE AND KS AHEAD OF AN
UPPER LEVEL SHORTWAVE OVER THE PLAINS. REPORTS OF ACCUMS FROM
1-3 INCHES FROM NORTHERN KS THROUGH THE KC METRO WITH OBS SUGGESTING
THE LEADING EDGE OF SNOW BETWEEN CHILLICOTHE MO AND KC METRO
MOVING N/E. TRENDS SUPPORT SYSTEM AND ATTENDANT SNOW TO GRADUALLY
WEAKEN TODAY AS IT ENCOUNTERS RIDGING OVER THE REGION... BUT
BEFORE DOING SO IS EXPECTED BRING SOME LIGHT ACCUMS TO SOUTHERN
PORTIONS OF CWA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU DEC 18 2014

SHORTWAVE WILL MOVE ACROSS REGION TODAY AND DEAMPLIFY/WEAKEN WHILE
RUNNING INTO THE RIDGE. THIS ALONG WITH COPIOUS DRY AIR PER 00Z
DVN AND ILX RAOBS SHOULD RESULT IN STEADY WEAKENING OF SNOW AS IT
SPREADS INTO FAR SOUTHERN CWA THIS AM. FORCING PEAKS OVER NORTHERN
MO 10Z-15Z THEN QUICKLY DIMINISHING THROUGH 18Z. OVERALL GOING
WITH 0.05 TO 0.1 INCH OF LIQUID QPF WITH SLR OF 12-14:1 TO YIELD
AROUND AN INCH OR SO OF ACCUM VERY FAR SOUTHERN CWA MAINLY NORTHEAST
MO INTO PORTIONS OF WEST CENTRAL IL TAPERING OFF TO TRACE HWY 34.
GIVEN DRY AIR AND ALIGNMENT OF FORCING COULD ENVISION SCENARIO
WHEREBY THIS OCCURS OVER MUCH SHORTER DISTANCE OF 25+ MILES NORTHEAST
MO. CANT RULE OUT POSSIBILITY OF SOME FREEZING DRIZZLE FAR SOUTH
FOR A WHILE THIS AFTERNOON IF CLOUD BEARING LAYER BECOMES SUFFICIENTLY
SHALLOW/WARM.. BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE MENTION
ATTIM. ASIDE FROM THE LIGHT SNOW FAR SOUTHERN CWA... EXPECT PTSUNNY
TO CLOUDY SKIES TODAY WITH TEMPS SIMILAR TO THOSE OF YSTDY IN
RELATIVELY NEUTRAL THERMAL ENVIRONMENT... WITH READINGS MAINLY IN
UPPER 20S TO LOWER 30S. WINDS NEGLIGIBLE AND GENERALLY 5 MPH OR LESS
WITH SURFACE RIDGING.

TONIGHT... GENERALLY PT-MOCDLY SKIES WITH SFC RIDGING BECOMING
RE-ESTABLISHED AS THE DOMINANT FEATURE. BANKING ON SUFFICIENT
CLOUDINESS TO PRECLUDE TEMPS FROM BOTTOMING OUT DESPITE NEAR
CALM/CALM WINDS... AND EXPECT GENERALLY UPPER TEENS TO MID 20S FOR
LOWS. SHOULD SOME AREAS SEE MORE IN WAY OF CLEARING THEN POTENTIAL
TO BE IN MID TEENS FOR LOWS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU DEC 18 2014

FORECAST FOCUS ON ACTIVE WEATHER PATTERN ESPECIALLY CHRISTMAS WEEK.

FRIDAY THROUGH SUNDAY...ZONAL FLOW OVER THE REGION WITH A SERIES OF
SHORT WAVES MOVING ACROSS. THIS LOOKS TO BE ANOTHER RATHER CLOUDY
PERIOD WITH FORECAST SOUNDINGS INDICATING WEAK LOW LEVEL WARM
ADVECTION AND A STRONG INVERSION SETTING UP AROUND 850 MB...WITH MOISTURE
TRAPPED BELOW. SATURDAY NIGHT I HAVE INTRODUCED A SLIGHT CHANCE OF
FREEZING DRIZZLE IN OUR FAR NW CWA...AS A SHORT WAVE/VORT MAX
TRAVERSES NORTHERN IA. FORECAST SOUNDINGS INDICATE A WARM LAYER JUST
ABOVE FREEZING WITH DRY AIR IN THE MID LEVELS WITH MOISTURE BELOW.
MAXIMUM TEMPERATURES DURING THIS PERIOD WILL BE IN THE 30S TO NEAR
40 WITH LOWS IN THE 20S TO NEAR 30.

MONDAY THROUGH WEDNESDAY...THIS IS WHEN THE WEATHER GETS ACTIVE BUT
ALSO COMPLICATED AND CHALLENGING. UPPER LOW DEEPENS AS IT TRACKS
FROM THE NORTHERN PLAINS (MONDAY) INTO EASTERN IA (TUESDAY) AND THEN
LIFTING INTO THE WESTERN GREAT LAKES (WEDNESDAY). THE PATH OF THIS
SYSTEM WOULD SUGGEST MAINLY A RAIN/SNOW MIX BUT WILL NEED TO KEEP AN
EYE ON TUESDAY WHERE IT MAY CHANGE TO ALL SNOW...GIVEN THE COLD
POCKET ALOFT AND DYNAMIC COOLING. WAY TOO EARLY TO OFFER ANY
ACCUMULATION AMOUNTS IF ANY. MAXIMUM TEMPERATURES ON MONDAY SHOULD
PUSH INTO THE 40S FROM ABOUT I-80 SOUTHWARD...AND IN THE 30S TUESDAY
AND WEDNESDAY. THE ECMWF HAS NOW THROWN A CURVE BALL IN REGARD TO
THE WHOPPER STORM EARLIER INDICATED TO BE IN THE GREAT LAKES REGION
CHRISTMAS EVE. IT NOW IS NOT QUITE THE BOMB SHOWN THE PAST COUPLE
RUNS AND IS ALSO INTENSIFYING THE CYCLONE FARTHER EAST...IN NEW
ENGLAND! THIS IS WHAT THE GFS HAS BEEN INDICATING ALL ALONG. SUFFICE
TO SAY CONFIDENCE IS LOW AS PHASING ISSUES CONTINUE TO HAUNT THE
MODELS. SO MORE CHANGES IN THE MODELS CAN BE EXPECTED OVER THE NEXT
SEVERAL DAYS AND THE IMPACTS IF ANY ON OUR AREA REMAIN TO BE SEEN.

CHRISTMAS DAY AND FRIDAY...MANY UNCERTAINTIES REGARDING THE
POTENTIAL WINTER STORM OFFERED BY THE ECMWF ON FRIDAY. DEPENDING ON
WHERE THE HUGE UPPER LOW TO OUR NORTHEAST IS LOCATED WILL PLAY A
ROLE IN THE STRONG ENERGY COMING OUT OF THE SOUTHWEST. CONFIDENCE IN
THE TRACK/TIMING/INTENSITY OF THIS SYSTEM IS LOW BUT CERTAINLY THERE
IS THE POTENTIAL FOR A WINTER STORM SOMEWHERE IN THE MIDWEST...SO
ANYONE TRAVELING AROUND CHRISTMAS DAY OR THEREAFTER SHOULD CONTINUE
TO MONITOR LATER FORECASTS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1153 AM CST THU DEC 18 2014

LIGHT SNOW WILL TAPER OFF ACROSS SOUTHEAST IOWA AND NEARBY AREAS
THIS AFTERNOON...WITH PERIODS OF MVFR CIGS AT KBRL THROUGH EARLY
AFTERNOON. LOW VFR CIGS WILL DEVELOP AT ALL SITES OVERNIGHT. LOW
LEVEL MOISTURE WILL INCREASE ACROSS EASTERN IOWA FRIDAY MORNING
WITH MVFR CIGS EXPECTED AT KBRL/KCID AFTER 14Z.

&&

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

$$

UPDATE...RP KINNEY
SYNOPSIS...05
SHORT TERM...05
LONG TERM...HAASE
AVIATION...RP KINNEY






000
FXUS63 KDVN 181804
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1204 PM CST THU DEC 18 2014

.UPDATE...
ISSUED AT 1017 AM CST THU DEC 18 2014

MORNING UPDATE TO FINE TUNE POPS AND SNOWFALL AMOUNTS...WITH A
SLIGHT INCREASE NORTH TOWARDS SIGOURNEY AND WILLIAMSBURG. LATEST
NAM/RAP BUFKIT SOUNDINGS INDICATE SOME POTENTIAL FOR SOME PATCHY
FREEZING DRIZZLE AT THE TAIL END OF THE EVENT THIS AFTERNOON
ACROSS THE EXTREME SOUTH.

&&

.SYNOPSIS...
ISSUED AT 321 AM CST THU DEC 18 2014

SNOW FAIRLY WIDESPREAD FROM WESTERN MO INTO NE AND KS AHEAD OF AN
UPPER LEVEL SHORTWAVE OVER THE PLAINS. REPORTS OF ACCUMS FROM
1-3 INCHES FROM NORTHERN KS THROUGH THE KC METRO WITH OBS SUGGESTING
THE LEADING EDGE OF SNOW BETWEEN CHILLICOTHE MO AND KC METRO
MOVING N/E. TRENDS SUPPORT SYSTEM AND ATTENDANT SNOW TO GRADUALLY
WEAKEN TODAY AS IT ENCOUNTERS RIDGING OVER THE REGION... BUT
BEFORE DOING SO IS EXPECTED BRING SOME LIGHT ACCUMS TO SOUTHERN
PORTIONS OF CWA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU DEC 18 2014

SHORTWAVE WILL MOVE ACROSS REGION TODAY AND DEAMPLIFY/WEAKEN WHILE
RUNNING INTO THE RIDGE. THIS ALONG WITH COPIOUS DRY AIR PER 00Z
DVN AND ILX RAOBS SHOULD RESULT IN STEADY WEAKENING OF SNOW AS IT
SPREADS INTO FAR SOUTHERN CWA THIS AM. FORCING PEAKS OVER NORTHERN
MO 10Z-15Z THEN QUICKLY DIMINISHING THROUGH 18Z. OVERALL GOING
WITH 0.05 TO 0.1 INCH OF LIQUID QPF WITH SLR OF 12-14:1 TO YIELD
AROUND AN INCH OR SO OF ACCUM VERY FAR SOUTHERN CWA MAINLY NORTHEAST
MO INTO PORTIONS OF WEST CENTRAL IL TAPERING OFF TO TRACE HWY 34.
GIVEN DRY AIR AND ALIGNMENT OF FORCING COULD ENVISION SCENARIO
WHEREBY THIS OCCURS OVER MUCH SHORTER DISTANCE OF 25+ MILES NORTHEAST
MO. CANT RULE OUT POSSIBILITY OF SOME FREEZING DRIZZLE FAR SOUTH
FOR A WHILE THIS AFTERNOON IF CLOUD BEARING LAYER BECOMES SUFFICIENTLY
SHALLOW/WARM.. BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE MENTION
ATTIM. ASIDE FROM THE LIGHT SNOW FAR SOUTHERN CWA... EXPECT PTSUNNY
TO CLOUDY SKIES TODAY WITH TEMPS SIMILAR TO THOSE OF YSTDY IN
RELATIVELY NEUTRAL THERMAL ENVIRONMENT... WITH READINGS MAINLY IN
UPPER 20S TO LOWER 30S. WINDS NEGLIGIBLE AND GENERALLY 5 MPH OR LESS
WITH SURFACE RIDGING.

TONIGHT... GENERALLY PT-MOCDLY SKIES WITH SFC RIDGING BECOMING
RE-ESTABLISHED AS THE DOMINANT FEATURE. BANKING ON SUFFICIENT
CLOUDINESS TO PRECLUDE TEMPS FROM BOTTOMING OUT DESPITE NEAR
CALM/CALM WINDS... AND EXPECT GENERALLY UPPER TEENS TO MID 20S FOR
LOWS. SHOULD SOME AREAS SEE MORE IN WAY OF CLEARING THEN POTENTIAL
TO BE IN MID TEENS FOR LOWS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU DEC 18 2014

FORECAST FOCUS ON ACTIVE WEATHER PATTERN ESPECIALLY CHRISTMAS WEEK.

FRIDAY THROUGH SUNDAY...ZONAL FLOW OVER THE REGION WITH A SERIES OF
SHORT WAVES MOVING ACROSS. THIS LOOKS TO BE ANOTHER RATHER CLOUDY
PERIOD WITH FORECAST SOUNDINGS INDICATING WEAK LOW LEVEL WARM
ADVECTION AND A STRONG INVERSION SETTING UP AROUND 850 MB...WITH MOISTURE
TRAPPED BELOW. SATURDAY NIGHT I HAVE INTRODUCED A SLIGHT CHANCE OF
FREEZING DRIZZLE IN OUR FAR NW CWA...AS A SHORT WAVE/VORT MAX
TRAVERSES NORTHERN IA. FORECAST SOUNDINGS INDICATE A WARM LAYER JUST
ABOVE FREEZING WITH DRY AIR IN THE MID LEVELS WITH MOISTURE BELOW.
MAXIMUM TEMPERATURES DURING THIS PERIOD WILL BE IN THE 30S TO NEAR
40 WITH LOWS IN THE 20S TO NEAR 30.

MONDAY THROUGH WEDNESDAY...THIS IS WHEN THE WEATHER GETS ACTIVE BUT
ALSO COMPLICATED AND CHALLENGING. UPPER LOW DEEPENS AS IT TRACKS
FROM THE NORTHERN PLAINS (MONDAY) INTO EASTERN IA (TUESDAY) AND THEN
LIFTING INTO THE WESTERN GREAT LAKES (WEDNESDAY). THE PATH OF THIS
SYSTEM WOULD SUGGEST MAINLY A RAIN/SNOW MIX BUT WILL NEED TO KEEP AN
EYE ON TUESDAY WHERE IT MAY CHANGE TO ALL SNOW...GIVEN THE COLD
POCKET ALOFT AND DYNAMIC COOLING. WAY TOO EARLY TO OFFER ANY
ACCUMULATION AMOUNTS IF ANY. MAXIMUM TEMPERATURES ON MONDAY SHOULD
PUSH INTO THE 40S FROM ABOUT I-80 SOUTHWARD...AND IN THE 30S TUESDAY
AND WEDNESDAY. THE ECMWF HAS NOW THROWN A CURVE BALL IN REGARD TO
THE WHOPPER STORM EARLIER INDICATED TO BE IN THE GREAT LAKES REGION
CHRISTMAS EVE. IT NOW IS NOT QUITE THE BOMB SHOWN THE PAST COUPLE
RUNS AND IS ALSO INTENSIFYING THE CYCLONE FARTHER EAST...IN NEW
ENGLAND! THIS IS WHAT THE GFS HAS BEEN INDICATING ALL ALONG. SUFFICE
TO SAY CONFIDENCE IS LOW AS PHASING ISSUES CONTINUE TO HAUNT THE
MODELS. SO MORE CHANGES IN THE MODELS CAN BE EXPECTED OVER THE NEXT
SEVERAL DAYS AND THE IMPACTS IF ANY ON OUR AREA REMAIN TO BE SEEN.

CHRISTMAS DAY AND FRIDAY...MANY UNCERTAINTIES REGARDING THE
POTENTIAL WINTER STORM OFFERED BY THE ECMWF ON FRIDAY. DEPENDING ON
WHERE THE HUGE UPPER LOW TO OUR NORTHEAST IS LOCATED WILL PLAY A
ROLE IN THE STRONG ENERGY COMING OUT OF THE SOUTHWEST. CONFIDENCE IN
THE TRACK/TIMING/INTENSITY OF THIS SYSTEM IS LOW BUT CERTAINLY THERE
IS THE POTENTIAL FOR A WINTER STORM SOMEWHERE IN THE MIDWEST...SO
ANYONE TRAVELING AROUND CHRISTMAS DAY OR THEREAFTER SHOULD CONTINUE
TO MONITOR LATER FORECASTS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1153 AM CST THU DEC 18 2014

LIGHT SNOW WILL TAPER OFF ACROSS SOUTHEAST IOWA AND NEARBY AREAS
THIS AFTERNOON...WITH PERIODS OF MVFR CIGS AT KBRL THROUGH EARLY
AFTERNOON. LOW VFR CIGS WILL DEVELOP AT ALL SITES OVERNIGHT. LOW
LEVEL MOISTURE WILL INCREASE ACROSS EASTERN IOWA FRIDAY MORNING
WITH MVFR CIGS EXPECTED AT KBRL/KCID AFTER 14Z.

&&

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

$$

UPDATE...RP KINNEY
SYNOPSIS...05
SHORT TERM...05
LONG TERM...HAASE
AVIATION...RP KINNEY






000
FXUS63 KDVN 181804
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1204 PM CST THU DEC 18 2014

.UPDATE...
ISSUED AT 1017 AM CST THU DEC 18 2014

MORNING UPDATE TO FINE TUNE POPS AND SNOWFALL AMOUNTS...WITH A
SLIGHT INCREASE NORTH TOWARDS SIGOURNEY AND WILLIAMSBURG. LATEST
NAM/RAP BUFKIT SOUNDINGS INDICATE SOME POTENTIAL FOR SOME PATCHY
FREEZING DRIZZLE AT THE TAIL END OF THE EVENT THIS AFTERNOON
ACROSS THE EXTREME SOUTH.

&&

.SYNOPSIS...
ISSUED AT 321 AM CST THU DEC 18 2014

SNOW FAIRLY WIDESPREAD FROM WESTERN MO INTO NE AND KS AHEAD OF AN
UPPER LEVEL SHORTWAVE OVER THE PLAINS. REPORTS OF ACCUMS FROM
1-3 INCHES FROM NORTHERN KS THROUGH THE KC METRO WITH OBS SUGGESTING
THE LEADING EDGE OF SNOW BETWEEN CHILLICOTHE MO AND KC METRO
MOVING N/E. TRENDS SUPPORT SYSTEM AND ATTENDANT SNOW TO GRADUALLY
WEAKEN TODAY AS IT ENCOUNTERS RIDGING OVER THE REGION... BUT
BEFORE DOING SO IS EXPECTED BRING SOME LIGHT ACCUMS TO SOUTHERN
PORTIONS OF CWA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU DEC 18 2014

SHORTWAVE WILL MOVE ACROSS REGION TODAY AND DEAMPLIFY/WEAKEN WHILE
RUNNING INTO THE RIDGE. THIS ALONG WITH COPIOUS DRY AIR PER 00Z
DVN AND ILX RAOBS SHOULD RESULT IN STEADY WEAKENING OF SNOW AS IT
SPREADS INTO FAR SOUTHERN CWA THIS AM. FORCING PEAKS OVER NORTHERN
MO 10Z-15Z THEN QUICKLY DIMINISHING THROUGH 18Z. OVERALL GOING
WITH 0.05 TO 0.1 INCH OF LIQUID QPF WITH SLR OF 12-14:1 TO YIELD
AROUND AN INCH OR SO OF ACCUM VERY FAR SOUTHERN CWA MAINLY NORTHEAST
MO INTO PORTIONS OF WEST CENTRAL IL TAPERING OFF TO TRACE HWY 34.
GIVEN DRY AIR AND ALIGNMENT OF FORCING COULD ENVISION SCENARIO
WHEREBY THIS OCCURS OVER MUCH SHORTER DISTANCE OF 25+ MILES NORTHEAST
MO. CANT RULE OUT POSSIBILITY OF SOME FREEZING DRIZZLE FAR SOUTH
FOR A WHILE THIS AFTERNOON IF CLOUD BEARING LAYER BECOMES SUFFICIENTLY
SHALLOW/WARM.. BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE MENTION
ATTIM. ASIDE FROM THE LIGHT SNOW FAR SOUTHERN CWA... EXPECT PTSUNNY
TO CLOUDY SKIES TODAY WITH TEMPS SIMILAR TO THOSE OF YSTDY IN
RELATIVELY NEUTRAL THERMAL ENVIRONMENT... WITH READINGS MAINLY IN
UPPER 20S TO LOWER 30S. WINDS NEGLIGIBLE AND GENERALLY 5 MPH OR LESS
WITH SURFACE RIDGING.

TONIGHT... GENERALLY PT-MOCDLY SKIES WITH SFC RIDGING BECOMING
RE-ESTABLISHED AS THE DOMINANT FEATURE. BANKING ON SUFFICIENT
CLOUDINESS TO PRECLUDE TEMPS FROM BOTTOMING OUT DESPITE NEAR
CALM/CALM WINDS... AND EXPECT GENERALLY UPPER TEENS TO MID 20S FOR
LOWS. SHOULD SOME AREAS SEE MORE IN WAY OF CLEARING THEN POTENTIAL
TO BE IN MID TEENS FOR LOWS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU DEC 18 2014

FORECAST FOCUS ON ACTIVE WEATHER PATTERN ESPECIALLY CHRISTMAS WEEK.

FRIDAY THROUGH SUNDAY...ZONAL FLOW OVER THE REGION WITH A SERIES OF
SHORT WAVES MOVING ACROSS. THIS LOOKS TO BE ANOTHER RATHER CLOUDY
PERIOD WITH FORECAST SOUNDINGS INDICATING WEAK LOW LEVEL WARM
ADVECTION AND A STRONG INVERSION SETTING UP AROUND 850 MB...WITH MOISTURE
TRAPPED BELOW. SATURDAY NIGHT I HAVE INTRODUCED A SLIGHT CHANCE OF
FREEZING DRIZZLE IN OUR FAR NW CWA...AS A SHORT WAVE/VORT MAX
TRAVERSES NORTHERN IA. FORECAST SOUNDINGS INDICATE A WARM LAYER JUST
ABOVE FREEZING WITH DRY AIR IN THE MID LEVELS WITH MOISTURE BELOW.
MAXIMUM TEMPERATURES DURING THIS PERIOD WILL BE IN THE 30S TO NEAR
40 WITH LOWS IN THE 20S TO NEAR 30.

MONDAY THROUGH WEDNESDAY...THIS IS WHEN THE WEATHER GETS ACTIVE BUT
ALSO COMPLICATED AND CHALLENGING. UPPER LOW DEEPENS AS IT TRACKS
FROM THE NORTHERN PLAINS (MONDAY) INTO EASTERN IA (TUESDAY) AND THEN
LIFTING INTO THE WESTERN GREAT LAKES (WEDNESDAY). THE PATH OF THIS
SYSTEM WOULD SUGGEST MAINLY A RAIN/SNOW MIX BUT WILL NEED TO KEEP AN
EYE ON TUESDAY WHERE IT MAY CHANGE TO ALL SNOW...GIVEN THE COLD
POCKET ALOFT AND DYNAMIC COOLING. WAY TOO EARLY TO OFFER ANY
ACCUMULATION AMOUNTS IF ANY. MAXIMUM TEMPERATURES ON MONDAY SHOULD
PUSH INTO THE 40S FROM ABOUT I-80 SOUTHWARD...AND IN THE 30S TUESDAY
AND WEDNESDAY. THE ECMWF HAS NOW THROWN A CURVE BALL IN REGARD TO
THE WHOPPER STORM EARLIER INDICATED TO BE IN THE GREAT LAKES REGION
CHRISTMAS EVE. IT NOW IS NOT QUITE THE BOMB SHOWN THE PAST COUPLE
RUNS AND IS ALSO INTENSIFYING THE CYCLONE FARTHER EAST...IN NEW
ENGLAND! THIS IS WHAT THE GFS HAS BEEN INDICATING ALL ALONG. SUFFICE
TO SAY CONFIDENCE IS LOW AS PHASING ISSUES CONTINUE TO HAUNT THE
MODELS. SO MORE CHANGES IN THE MODELS CAN BE EXPECTED OVER THE NEXT
SEVERAL DAYS AND THE IMPACTS IF ANY ON OUR AREA REMAIN TO BE SEEN.

CHRISTMAS DAY AND FRIDAY...MANY UNCERTAINTIES REGARDING THE
POTENTIAL WINTER STORM OFFERED BY THE ECMWF ON FRIDAY. DEPENDING ON
WHERE THE HUGE UPPER LOW TO OUR NORTHEAST IS LOCATED WILL PLAY A
ROLE IN THE STRONG ENERGY COMING OUT OF THE SOUTHWEST. CONFIDENCE IN
THE TRACK/TIMING/INTENSITY OF THIS SYSTEM IS LOW BUT CERTAINLY THERE
IS THE POTENTIAL FOR A WINTER STORM SOMEWHERE IN THE MIDWEST...SO
ANYONE TRAVELING AROUND CHRISTMAS DAY OR THEREAFTER SHOULD CONTINUE
TO MONITOR LATER FORECASTS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1153 AM CST THU DEC 18 2014

LIGHT SNOW WILL TAPER OFF ACROSS SOUTHEAST IOWA AND NEARBY AREAS
THIS AFTERNOON...WITH PERIODS OF MVFR CIGS AT KBRL THROUGH EARLY
AFTERNOON. LOW VFR CIGS WILL DEVELOP AT ALL SITES OVERNIGHT. LOW
LEVEL MOISTURE WILL INCREASE ACROSS EASTERN IOWA FRIDAY MORNING
WITH MVFR CIGS EXPECTED AT KBRL/KCID AFTER 14Z.

&&

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

$$

UPDATE...RP KINNEY
SYNOPSIS...05
SHORT TERM...05
LONG TERM...HAASE
AVIATION...RP KINNEY






000
FXUS63 KDMX 181745
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1145 AM CST THU DEC 18 2014

.UPDATE...
ISSUED AT 920 AM CST THU DEC 18 2014

BASED ON INCOMING COOP SNOWFALL REPORTS AND RADAR TRENDS...HAVE
LOWERED SNOWFALL AMOUNTS BY SEVERAL TENTHS OF AN INCH AND REMOVED
SNOW NORTH OF I-80 FOR THE REST OF TODAY. DRY LAYER VERY PROMINENT
ON THE 12Z 0AX SOUNDING IS RESULTING IN A SHARP CUTOFF IN THE
PRECIP BAND JUST SOUTH OF DSM. IT IS QUITE POSSIBLE THAT THE
METRO MAY SEE ONLY FLURRIES BY THE TIME THIS EVENT IS ALL SAID
AND DONE WITH THE BEST DGZ FORCING ALREADY SHIFTING TOWARDS SE
IOWA AND RADAR ECHOS DECREASING OVER THE SW CWA.

&&

.SHORT TERM /TODAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

AN UPPER LEVEL SHORT WAVE IS MOVING ACROSS MISSOURI THIS MORNING
WITH THE NORTHERN FRINGE OF KINEMATIC FORCING REACHING INTO SOUTHERN
IOWA. A BRANCH OF THE WARM CONVEYOR BELT IS WRAPPING AROUND THE
NORTH SIDE WITH MOISTURE OVERRUNNING THE SURFACE COLDER AIR. THE
COMBINATION OF MOISTURE AND FORCING HAS RESULTED IN A BAND OF SNOW
LIFTING NORTHEAST THROUGH NORTHEAST KANSAS AND NORTHERN MISSOURI.
THIS BAND OF SNOW WILL MOVE INTO SOUTHERN IOWA EARLY THIS MORNING
HOWEVER ITS NORTHEAST EXTENT WILL BE LIMITED BY DRY AIR ASSOCIATED
WITH A RIDGE OF HIGH PRESSURE SITUATED OVER NORTHEAST IOWA. IN
ADDITION...FORCING WILL WEAKEN AS THE UPPER LEVEL SYSTEM DEPARTS TO
THE EAST AND LEAVES THE SNOW BAND BEHIND TO DIMINISH. SNOWFALL
AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE OVER THE SOUTHERN 2 TIERS OF
COUNTIES WITH MINOR ACCUMULATIONS OF A FEW TENTHS POSSIBLE AS FAR
NORTH AS INTERSTATE 80. POTENTIAL FOR FREEZING DRIZZLE BY THIS
AFTERNOON IS LOW. MOISTURE DEPTHS WITH RELATIVE HUMIDITIES GREATER
THAN 75 PERCENT REMAIN RELATIVELY HIGH AND COLD FOR ICE TO REMAIN
INTRODUCED AND RESULTING IN LIGHT SNOW OR FLURRIES COMPARED TO
FZDZ.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

OUR WEATHER PATTERN IS SET TO BECOME MORE ACTIVE OVER THE COMING
DAYS. INITIALLY A SERIES OF 500 MB TROUGHS WILL CROSS THE
REGION...THE FIRST AROUND FRIDAY NIGHT AND ANOTHER AROUND
SATURDAY NIGHT/SUNDAY...GRADUALLY CARVING OUT BROAD CYCLONIC FLOW
ACROSS THE CENTRAL U.S. CONCURRENT WITH A LARGE 500 MB HIGH
PRESSURE DOME DEVELOPING OVER THE EASTERN PACIFIC. WITH THE FIRST
TROUGH PASSAGE OVER IOWA ON FRIDAY NIGHT THERE IS A POTENTIAL FOR
SOME STRATUS AND DRIZZLE...BUT FORECAST SOUNDINGS INDICATE THAT
LOW LEVEL MOISTURE AND LIFT WILL PROBABLY BE INSUFFICIENT TO
GENERATE PRECIPITATION. WITH THE SECOND TROUGH ON SATURDAY NIGHT
INTO SUNDAY THERE IS A BETTER SIGNAL FOR SOME LIGHT
PRECIPITATION...PROBABLY IN THE FORM OF DRIZZLE OR FREEZING
DRIZZLE. IT IS LIKELY THAT TEMPERATURES WILL FALL BELOW FREEZING
SATURDAY NIGHT...HOWEVER...DEWPOINTS AND TEMPERATURES MAY RECOVER
TO JUST ABOVE FREEZING BEFORE DRIZZLE DEVELOPS.
NEVERTHELESS...GIVEN THE POSSIBILITY OF FREEZING DRIZZLE AND ITS
ASSOCIATED IMPACTS HAVE ADDED A CHANCE INTO THE OUTGOING FORECAST
PACKAGE. WE WILL BE CLOSELY MONITORING THIS POSSIBILITY OVER THE
NEXT COUPLE OF DAYS.

AS MENTIONED EARLIER...BY THE LATTER PART OF THE WEEKEND A BROAD
500 MB TROUGH WILL HAVE BEEN CARVED OUT OVER THE CENTRAL U.S. A
COMPACT BUT ENERGETIC SHORTWAVE WILL THEN OVERTOP THE EASTERN
PACIFIC RIDGE AND ROCKET SOUTHEASTWARD OVER THE NORTHERN ROCKIES
ON SUNDAY...SUBSEQUENTLY DIGGING AND CLOSING OFF AS A LOW OVER
MINNESOTA AND IOWA BY MONDAY NIGHT. THIS LOW WILL THEN WOBBLE OVER
THE REGION...OR SLIGHTLY TO THE EAST OVER WISCONSIN AND LAKE
MICHIGAN...BEFORE FINALLY EJECTING EASTWARD AROUND CHRISTMAS EVE.
IN TERMS OF SENSIBLE WEATHER...THE INITIAL APPROACH OF THE LOW ON
WILL SPREAD A SWATH OF WARM ADVECTION REGIME PRECIPITATION ACROSS
IOWA ON SUNDAY NIGHT INTO MONDAY...THEN AS THE LOW MOVES NEARBY OR
OVERHEAD A LARGE STRATUS AND PRECIPITATION SHIELD WILL AFFECT MOST
OF THE REGION AND EVENTUALLY CHANGE OVER TO SNOW. THERE IS STILL
SOME UNCERTAINTY AS TO THE LOCATION OF THE LOW PRESSURE CENTER AND
ATTENDANT TEMPERATURE FIELDS...BUT IT SEEMS LIKELY THAT INITIALLY
THE PRECIPITATION WILL BE MOSTLY IN THE FORM OF RAIN WITH A WINTRY
MIX ACROSS NORTHERN IOWA...THEN BECOME LIGHTER BY THE TIME A
CHANGE TO SNOW OCCURS LATER IN THE EVENT. THIS WILL LIMIT SNOW
ACCUMULATIONS ACROSS MOST OF IOWA...BUT IN THE NORTH THERE COULD
BE SOME DECENT AMOUNTS DEPENDING ON HOW THE TEMPERATURES SET UP.
CERTAINLY TOO EARLY FOR ANY HEADLINE DIAGNOSIS BUT CERTAINLY ALL
EYES WILL BE ON THIS LARGE STORM SYSTEM IN THE COMING DAYS.

&&

.AVIATION...18/18Z
ISSUED AT 1141 AM CST THU DEC 18 2014

SNOW IS WINDING DOWN ACROSS SOUTHERN IOWA THIS AFTERNOON WITH IFR
TO LOW MVFR CEILINGS LINGERING OVER THE AREA. IFR/LOW MVFR STRATUS
IS ALSO HANGING ON ACROSS PORTIONS OF NE IOWA. EXPECT LITTLE
IMPROVEMENT THROUGHOUT THE DAY WITH A LARGE SHIELD OF MVFR TO IFR
STRATUS OVER NEBRASKA AND WESTERN IOWA ADVECTING OVER CENTRAL IOWA
TONIGHT AND LINGERING THROUGH THE END OF THE TAF PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...SKOW
SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...SKOW




000
FXUS63 KDMX 181745
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1145 AM CST THU DEC 18 2014

.UPDATE...
ISSUED AT 920 AM CST THU DEC 18 2014

BASED ON INCOMING COOP SNOWFALL REPORTS AND RADAR TRENDS...HAVE
LOWERED SNOWFALL AMOUNTS BY SEVERAL TENTHS OF AN INCH AND REMOVED
SNOW NORTH OF I-80 FOR THE REST OF TODAY. DRY LAYER VERY PROMINENT
ON THE 12Z 0AX SOUNDING IS RESULTING IN A SHARP CUTOFF IN THE
PRECIP BAND JUST SOUTH OF DSM. IT IS QUITE POSSIBLE THAT THE
METRO MAY SEE ONLY FLURRIES BY THE TIME THIS EVENT IS ALL SAID
AND DONE WITH THE BEST DGZ FORCING ALREADY SHIFTING TOWARDS SE
IOWA AND RADAR ECHOS DECREASING OVER THE SW CWA.

&&

.SHORT TERM /TODAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

AN UPPER LEVEL SHORT WAVE IS MOVING ACROSS MISSOURI THIS MORNING
WITH THE NORTHERN FRINGE OF KINEMATIC FORCING REACHING INTO SOUTHERN
IOWA. A BRANCH OF THE WARM CONVEYOR BELT IS WRAPPING AROUND THE
NORTH SIDE WITH MOISTURE OVERRUNNING THE SURFACE COLDER AIR. THE
COMBINATION OF MOISTURE AND FORCING HAS RESULTED IN A BAND OF SNOW
LIFTING NORTHEAST THROUGH NORTHEAST KANSAS AND NORTHERN MISSOURI.
THIS BAND OF SNOW WILL MOVE INTO SOUTHERN IOWA EARLY THIS MORNING
HOWEVER ITS NORTHEAST EXTENT WILL BE LIMITED BY DRY AIR ASSOCIATED
WITH A RIDGE OF HIGH PRESSURE SITUATED OVER NORTHEAST IOWA. IN
ADDITION...FORCING WILL WEAKEN AS THE UPPER LEVEL SYSTEM DEPARTS TO
THE EAST AND LEAVES THE SNOW BAND BEHIND TO DIMINISH. SNOWFALL
AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE OVER THE SOUTHERN 2 TIERS OF
COUNTIES WITH MINOR ACCUMULATIONS OF A FEW TENTHS POSSIBLE AS FAR
NORTH AS INTERSTATE 80. POTENTIAL FOR FREEZING DRIZZLE BY THIS
AFTERNOON IS LOW. MOISTURE DEPTHS WITH RELATIVE HUMIDITIES GREATER
THAN 75 PERCENT REMAIN RELATIVELY HIGH AND COLD FOR ICE TO REMAIN
INTRODUCED AND RESULTING IN LIGHT SNOW OR FLURRIES COMPARED TO
FZDZ.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

OUR WEATHER PATTERN IS SET TO BECOME MORE ACTIVE OVER THE COMING
DAYS. INITIALLY A SERIES OF 500 MB TROUGHS WILL CROSS THE
REGION...THE FIRST AROUND FRIDAY NIGHT AND ANOTHER AROUND
SATURDAY NIGHT/SUNDAY...GRADUALLY CARVING OUT BROAD CYCLONIC FLOW
ACROSS THE CENTRAL U.S. CONCURRENT WITH A LARGE 500 MB HIGH
PRESSURE DOME DEVELOPING OVER THE EASTERN PACIFIC. WITH THE FIRST
TROUGH PASSAGE OVER IOWA ON FRIDAY NIGHT THERE IS A POTENTIAL FOR
SOME STRATUS AND DRIZZLE...BUT FORECAST SOUNDINGS INDICATE THAT
LOW LEVEL MOISTURE AND LIFT WILL PROBABLY BE INSUFFICIENT TO
GENERATE PRECIPITATION. WITH THE SECOND TROUGH ON SATURDAY NIGHT
INTO SUNDAY THERE IS A BETTER SIGNAL FOR SOME LIGHT
PRECIPITATION...PROBABLY IN THE FORM OF DRIZZLE OR FREEZING
DRIZZLE. IT IS LIKELY THAT TEMPERATURES WILL FALL BELOW FREEZING
SATURDAY NIGHT...HOWEVER...DEWPOINTS AND TEMPERATURES MAY RECOVER
TO JUST ABOVE FREEZING BEFORE DRIZZLE DEVELOPS.
NEVERTHELESS...GIVEN THE POSSIBILITY OF FREEZING DRIZZLE AND ITS
ASSOCIATED IMPACTS HAVE ADDED A CHANCE INTO THE OUTGOING FORECAST
PACKAGE. WE WILL BE CLOSELY MONITORING THIS POSSIBILITY OVER THE
NEXT COUPLE OF DAYS.

AS MENTIONED EARLIER...BY THE LATTER PART OF THE WEEKEND A BROAD
500 MB TROUGH WILL HAVE BEEN CARVED OUT OVER THE CENTRAL U.S. A
COMPACT BUT ENERGETIC SHORTWAVE WILL THEN OVERTOP THE EASTERN
PACIFIC RIDGE AND ROCKET SOUTHEASTWARD OVER THE NORTHERN ROCKIES
ON SUNDAY...SUBSEQUENTLY DIGGING AND CLOSING OFF AS A LOW OVER
MINNESOTA AND IOWA BY MONDAY NIGHT. THIS LOW WILL THEN WOBBLE OVER
THE REGION...OR SLIGHTLY TO THE EAST OVER WISCONSIN AND LAKE
MICHIGAN...BEFORE FINALLY EJECTING EASTWARD AROUND CHRISTMAS EVE.
IN TERMS OF SENSIBLE WEATHER...THE INITIAL APPROACH OF THE LOW ON
WILL SPREAD A SWATH OF WARM ADVECTION REGIME PRECIPITATION ACROSS
IOWA ON SUNDAY NIGHT INTO MONDAY...THEN AS THE LOW MOVES NEARBY OR
OVERHEAD A LARGE STRATUS AND PRECIPITATION SHIELD WILL AFFECT MOST
OF THE REGION AND EVENTUALLY CHANGE OVER TO SNOW. THERE IS STILL
SOME UNCERTAINTY AS TO THE LOCATION OF THE LOW PRESSURE CENTER AND
ATTENDANT TEMPERATURE FIELDS...BUT IT SEEMS LIKELY THAT INITIALLY
THE PRECIPITATION WILL BE MOSTLY IN THE FORM OF RAIN WITH A WINTRY
MIX ACROSS NORTHERN IOWA...THEN BECOME LIGHTER BY THE TIME A
CHANGE TO SNOW OCCURS LATER IN THE EVENT. THIS WILL LIMIT SNOW
ACCUMULATIONS ACROSS MOST OF IOWA...BUT IN THE NORTH THERE COULD
BE SOME DECENT AMOUNTS DEPENDING ON HOW THE TEMPERATURES SET UP.
CERTAINLY TOO EARLY FOR ANY HEADLINE DIAGNOSIS BUT CERTAINLY ALL
EYES WILL BE ON THIS LARGE STORM SYSTEM IN THE COMING DAYS.

&&

.AVIATION...18/18Z
ISSUED AT 1141 AM CST THU DEC 18 2014

SNOW IS WINDING DOWN ACROSS SOUTHERN IOWA THIS AFTERNOON WITH IFR
TO LOW MVFR CEILINGS LINGERING OVER THE AREA. IFR/LOW MVFR STRATUS
IS ALSO HANGING ON ACROSS PORTIONS OF NE IOWA. EXPECT LITTLE
IMPROVEMENT THROUGHOUT THE DAY WITH A LARGE SHIELD OF MVFR TO IFR
STRATUS OVER NEBRASKA AND WESTERN IOWA ADVECTING OVER CENTRAL IOWA
TONIGHT AND LINGERING THROUGH THE END OF THE TAF PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...SKOW
SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...SKOW



000
FXUS63 KDVN 181647
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1047 AM CST THU DEC 18 2014

.UPDATE...
ISSUED AT 1017 AM CST THU DEC 18 2014

MORNING UPDATE TO FINE TUNE POPS AND SNOWFALL AMOUNTS...WITH A
SLIGHT INCREASE NORTH TOWARDS SIGOURNEY AND WILLIAMSBURG. LATEST
NAM/RAP BUFKIT SOUNDINGS INDICATE SOME POTENTIAL FOR SOME PATCHY
FREEZING DRIZZLE AT THE TAIL END OF THE EVENT THIS AFTERNOON
ACROSS THE EXTREME SOUTH.

&&

.SYNOPSIS...
ISSUED AT 321 AM CST THU DEC 18 2014

SNOW FAIRLY WIDESPREAD FROM WESTERN MO INTO NE AND KS AHEAD OF AN
UPPER LEVEL SHORTWAVE OVER THE PLAINS. REPORTS OF ACCUMS FROM
1-3 INCHES FROM NORTHERN KS THROUGH THE KC METRO WITH OBS SUGGESTING
THE LEADING EDGE OF SNOW BETWEEN CHILLICOTHE MO AND KC METRO
MOVING N/E. TRENDS SUPPORT SYSTEM AND ATTENDANT SNOW TO GRADUALLY
WEAKEN TODAY AS IT ENCOUNTERS RIDGING OVER THE REGION... BUT
BEFORE DOING SO IS EXPECTED BRING SOME LIGHT ACCUMS TO SOUTHERN
PORTIONS OF CWA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU DEC 18 2014

SHORTWAVE WILL MOVE ACROSS REGION TODAY AND DEAMPLIFY/WEAKEN WHILE
RUNNING INTO THE RIDGE. THIS ALONG WITH COPIOUS DRY AIR PER 00Z
DVN AND ILX RAOBS SHOULD RESULT IN STEADY WEAKENING OF SNOW AS IT
SPREADS INTO FAR SOUTHERN CWA THIS AM. FORCING PEAKS OVER NORTHERN
MO 10Z-15Z THEN QUICKLY DIMINISHING THROUGH 18Z. OVERALL GOING
WITH 0.05 TO 0.1 INCH OF LIQUID QPF WITH SLR OF 12-14:1 TO YIELD
AROUND AN INCH OR SO OF ACCUM VERY FAR SOUTHERN CWA MAINLY NORTHEAST
MO INTO PORTIONS OF WEST CENTRAL IL TAPERING OFF TO TRACE HWY 34.
GIVEN DRY AIR AND ALIGNMENT OF FORCING COULD ENVISION SCENARIO
WHEREBY THIS OCCURS OVER MUCH SHORTER DISTANCE OF 25+ MILES NORTHEAST
MO. CANT RULE OUT POSSIBILITY OF SOME FREEZING DRIZZLE FAR SOUTH
FOR A WHILE THIS AFTERNOON IF CLOUD BEARING LAYER BECOMES SUFFICIENTLY
SHALLOW/WARM.. BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE MENTION
ATTIM. ASIDE FROM THE LIGHT SNOW FAR SOUTHERN CWA... EXPECT PTSUNNY
TO CLOUDY SKIES TODAY WITH TEMPS SIMILAR TO THOSE OF YSTDY IN
RELATIVELY NEUTRAL THERMAL ENVIRONMENT... WITH READINGS MAINLY IN
UPPER 20S TO LOWER 30S. WINDS NEGLIGIBLE AND GENERALLY 5 MPH OR LESS
WITH SURFACE RIDGING.

TONIGHT... GENERALLY PT-MOCDLY SKIES WITH SFC RIDGING BECOMING
RE-ESTABLISHED AS THE DOMINANT FEATURE. BANKING ON SUFFICIENT
CLOUDINESS TO PRECLUDE TEMPS FROM BOTTOMING OUT DESPITE NEAR
CALM/CALM WINDS... AND EXPECT GENERALLY UPPER TEENS TO MID 20S FOR
LOWS. SHOULD SOME AREAS SEE MORE IN WAY OF CLEARING THEN POTENTIAL
TO BE IN MID TEENS FOR LOWS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU DEC 18 2014

FORECAST FOCUS ON ACTIVE WEATHER PATTERN ESPECIALLY CHRISTMAS WEEK.

FRIDAY THROUGH SUNDAY...ZONAL FLOW OVER THE REGION WITH A SERIES OF
SHORT WAVES MOVING ACROSS. THIS LOOKS TO BE ANOTHER RATHER CLOUDY
PERIOD WITH FORECAST SOUNDINGS INDICATING WEAK LOW LEVEL WARM
ADVECTION AND A STRONG INVERSION SETTING UP AROUND 850 MB...WITH MOISTURE
TRAPPED BELOW. SATURDAY NIGHT I HAVE INTRODUCED A SLIGHT CHANCE OF
FREEZING DRIZZLE IN OUR FAR NW CWA...AS A SHORT WAVE/VORT MAX
TRAVERSES NORTHERN IA. FORECAST SOUNDINGS INDICATE A WARM LAYER JUST
ABOVE FREEZING WITH DRY AIR IN THE MID LEVELS WITH MOISTURE BELOW.
MAXIMUM TEMPERATURES DURING THIS PERIOD WILL BE IN THE 30S TO NEAR
40 WITH LOWS IN THE 20S TO NEAR 30.

MONDAY THROUGH WEDNESDAY...THIS IS WHEN THE WEATHER GETS ACTIVE BUT
ALSO COMPLICATED AND CHALLENGING. UPPER LOW DEEPENS AS IT TRACKS
FROM THE NORTHERN PLAINS (MONDAY) INTO EASTERN IA (TUESDAY) AND THEN
LIFTING INTO THE WESTERN GREAT LAKES (WEDNESDAY). THE PATH OF THIS
SYSTEM WOULD SUGGEST MAINLY A RAIN/SNOW MIX BUT WILL NEED TO KEEP AN
EYE ON TUESDAY WHERE IT MAY CHANGE TO ALL SNOW...GIVEN THE COLD
POCKET ALOFT AND DYNAMIC COOLING. WAY TOO EARLY TO OFFER ANY
ACCUMULATION AMOUNTS IF ANY. MAXIMUM TEMPERATURES ON MONDAY SHOULD
PUSH INTO THE 40S FROM ABOUT I-80 SOUTHWARD...AND IN THE 30S TUESDAY
AND WEDNESDAY. THE ECMWF HAS NOW THROWN A CURVE BALL IN REGARD TO
THE WHOPPER STORM EARLIER INDICATED TO BE IN THE GREAT LAKES REGION
CHRISTMAS EVE. IT NOW IS NOT QUITE THE BOMB SHOWN THE PAST COUPLE
RUNS AND IS ALSO INTENSIFYING THE CYCLONE FARTHER EAST...IN NEW
ENGLAND! THIS IS WHAT THE GFS HAS BEEN INDICATING ALL ALONG. SUFFICE
TO SAY CONFIDENCE IS LOW AS PHASING ISSUES CONTINUE TO HAUNT THE
MODELS. SO MORE CHANGES IN THE MODELS CAN BE EXPECTED OVER THE NEXT
SEVERAL DAYS AND THE IMPACTS IF ANY ON OUR AREA REMAIN TO BE SEEN.

CHRISTMAS DAY AND FRIDAY...MANY UNCERTAINTIES REGARDING THE
POTENTIAL WINTER STORM OFFERED BY THE ECMWF ON FRIDAY. DEPENDING ON
WHERE THE HUGE UPPER LOW TO OUR NORTHEAST IS LOCATED WILL PLAY A
ROLE IN THE STRONG ENERGY COMING OUT OF THE SOUTHWEST. CONFIDENCE IN
THE TRACK/TIMING/INTENSITY OF THIS SYSTEM IS LOW BUT CERTAINLY THERE
IS THE POTENTIAL FOR A WINTER STORM SOMEWHERE IN THE MIDWEST...SO
ANYONE TRAVELING AROUND CHRISTMAS DAY OR THEREAFTER SHOULD CONTINUE
TO MONITOR LATER FORECASTS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 536 AM CST THU DEC 18 2014

WEAKENING STORM SYSTEM WILL SPREAD LIGHT SNOW ACROSS NORTHEAST MO...
FAR SOUTHEAST IA AND PORTIONS OF WEST CENTRAL IL THROUGH MIDDAY
BEFORE DIMINISHING. LIGHT SNOW COULD BRUSH THE BRL TERMINAL 15Z-18Z
BUT LOW CONFIDENCE DUE TO DRY AIR AND WEAKENING SYSTEM THUS ONLY
HAVE MENTION OF FLURRIES WITH VSBYS AOA 6SM. OTHERWISE... EXPECT
VFR CONDITIONS WITH MID/HIGH CLOUDINESS AND LIGHT WINDS. THE
POTENTIAL EXISTS FOR PATCHY FOG WITH MVFR TO LOCALIZED IFR VSBYS
LATE TONIGHT... BUT WITH MID/HIGH CLOUDINESS NOT CONFIDENT ENOUGH
ON DEVELOPMENT/IMPACT AT TERMINALS FOR MENTION AT THIS TIME.


&&

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

$$

UPDATE...RP KINNEY
SYNOPSIS...05
SHORT TERM...05
LONG TERM...HAASE
AVIATION...05







000
FXUS63 KDVN 181647
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1047 AM CST THU DEC 18 2014

.UPDATE...
ISSUED AT 1017 AM CST THU DEC 18 2014

MORNING UPDATE TO FINE TUNE POPS AND SNOWFALL AMOUNTS...WITH A
SLIGHT INCREASE NORTH TOWARDS SIGOURNEY AND WILLIAMSBURG. LATEST
NAM/RAP BUFKIT SOUNDINGS INDICATE SOME POTENTIAL FOR SOME PATCHY
FREEZING DRIZZLE AT THE TAIL END OF THE EVENT THIS AFTERNOON
ACROSS THE EXTREME SOUTH.

&&

.SYNOPSIS...
ISSUED AT 321 AM CST THU DEC 18 2014

SNOW FAIRLY WIDESPREAD FROM WESTERN MO INTO NE AND KS AHEAD OF AN
UPPER LEVEL SHORTWAVE OVER THE PLAINS. REPORTS OF ACCUMS FROM
1-3 INCHES FROM NORTHERN KS THROUGH THE KC METRO WITH OBS SUGGESTING
THE LEADING EDGE OF SNOW BETWEEN CHILLICOTHE MO AND KC METRO
MOVING N/E. TRENDS SUPPORT SYSTEM AND ATTENDANT SNOW TO GRADUALLY
WEAKEN TODAY AS IT ENCOUNTERS RIDGING OVER THE REGION... BUT
BEFORE DOING SO IS EXPECTED BRING SOME LIGHT ACCUMS TO SOUTHERN
PORTIONS OF CWA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU DEC 18 2014

SHORTWAVE WILL MOVE ACROSS REGION TODAY AND DEAMPLIFY/WEAKEN WHILE
RUNNING INTO THE RIDGE. THIS ALONG WITH COPIOUS DRY AIR PER 00Z
DVN AND ILX RAOBS SHOULD RESULT IN STEADY WEAKENING OF SNOW AS IT
SPREADS INTO FAR SOUTHERN CWA THIS AM. FORCING PEAKS OVER NORTHERN
MO 10Z-15Z THEN QUICKLY DIMINISHING THROUGH 18Z. OVERALL GOING
WITH 0.05 TO 0.1 INCH OF LIQUID QPF WITH SLR OF 12-14:1 TO YIELD
AROUND AN INCH OR SO OF ACCUM VERY FAR SOUTHERN CWA MAINLY NORTHEAST
MO INTO PORTIONS OF WEST CENTRAL IL TAPERING OFF TO TRACE HWY 34.
GIVEN DRY AIR AND ALIGNMENT OF FORCING COULD ENVISION SCENARIO
WHEREBY THIS OCCURS OVER MUCH SHORTER DISTANCE OF 25+ MILES NORTHEAST
MO. CANT RULE OUT POSSIBILITY OF SOME FREEZING DRIZZLE FAR SOUTH
FOR A WHILE THIS AFTERNOON IF CLOUD BEARING LAYER BECOMES SUFFICIENTLY
SHALLOW/WARM.. BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE MENTION
ATTIM. ASIDE FROM THE LIGHT SNOW FAR SOUTHERN CWA... EXPECT PTSUNNY
TO CLOUDY SKIES TODAY WITH TEMPS SIMILAR TO THOSE OF YSTDY IN
RELATIVELY NEUTRAL THERMAL ENVIRONMENT... WITH READINGS MAINLY IN
UPPER 20S TO LOWER 30S. WINDS NEGLIGIBLE AND GENERALLY 5 MPH OR LESS
WITH SURFACE RIDGING.

TONIGHT... GENERALLY PT-MOCDLY SKIES WITH SFC RIDGING BECOMING
RE-ESTABLISHED AS THE DOMINANT FEATURE. BANKING ON SUFFICIENT
CLOUDINESS TO PRECLUDE TEMPS FROM BOTTOMING OUT DESPITE NEAR
CALM/CALM WINDS... AND EXPECT GENERALLY UPPER TEENS TO MID 20S FOR
LOWS. SHOULD SOME AREAS SEE MORE IN WAY OF CLEARING THEN POTENTIAL
TO BE IN MID TEENS FOR LOWS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU DEC 18 2014

FORECAST FOCUS ON ACTIVE WEATHER PATTERN ESPECIALLY CHRISTMAS WEEK.

FRIDAY THROUGH SUNDAY...ZONAL FLOW OVER THE REGION WITH A SERIES OF
SHORT WAVES MOVING ACROSS. THIS LOOKS TO BE ANOTHER RATHER CLOUDY
PERIOD WITH FORECAST SOUNDINGS INDICATING WEAK LOW LEVEL WARM
ADVECTION AND A STRONG INVERSION SETTING UP AROUND 850 MB...WITH MOISTURE
TRAPPED BELOW. SATURDAY NIGHT I HAVE INTRODUCED A SLIGHT CHANCE OF
FREEZING DRIZZLE IN OUR FAR NW CWA...AS A SHORT WAVE/VORT MAX
TRAVERSES NORTHERN IA. FORECAST SOUNDINGS INDICATE A WARM LAYER JUST
ABOVE FREEZING WITH DRY AIR IN THE MID LEVELS WITH MOISTURE BELOW.
MAXIMUM TEMPERATURES DURING THIS PERIOD WILL BE IN THE 30S TO NEAR
40 WITH LOWS IN THE 20S TO NEAR 30.

MONDAY THROUGH WEDNESDAY...THIS IS WHEN THE WEATHER GETS ACTIVE BUT
ALSO COMPLICATED AND CHALLENGING. UPPER LOW DEEPENS AS IT TRACKS
FROM THE NORTHERN PLAINS (MONDAY) INTO EASTERN IA (TUESDAY) AND THEN
LIFTING INTO THE WESTERN GREAT LAKES (WEDNESDAY). THE PATH OF THIS
SYSTEM WOULD SUGGEST MAINLY A RAIN/SNOW MIX BUT WILL NEED TO KEEP AN
EYE ON TUESDAY WHERE IT MAY CHANGE TO ALL SNOW...GIVEN THE COLD
POCKET ALOFT AND DYNAMIC COOLING. WAY TOO EARLY TO OFFER ANY
ACCUMULATION AMOUNTS IF ANY. MAXIMUM TEMPERATURES ON MONDAY SHOULD
PUSH INTO THE 40S FROM ABOUT I-80 SOUTHWARD...AND IN THE 30S TUESDAY
AND WEDNESDAY. THE ECMWF HAS NOW THROWN A CURVE BALL IN REGARD TO
THE WHOPPER STORM EARLIER INDICATED TO BE IN THE GREAT LAKES REGION
CHRISTMAS EVE. IT NOW IS NOT QUITE THE BOMB SHOWN THE PAST COUPLE
RUNS AND IS ALSO INTENSIFYING THE CYCLONE FARTHER EAST...IN NEW
ENGLAND! THIS IS WHAT THE GFS HAS BEEN INDICATING ALL ALONG. SUFFICE
TO SAY CONFIDENCE IS LOW AS PHASING ISSUES CONTINUE TO HAUNT THE
MODELS. SO MORE CHANGES IN THE MODELS CAN BE EXPECTED OVER THE NEXT
SEVERAL DAYS AND THE IMPACTS IF ANY ON OUR AREA REMAIN TO BE SEEN.

CHRISTMAS DAY AND FRIDAY...MANY UNCERTAINTIES REGARDING THE
POTENTIAL WINTER STORM OFFERED BY THE ECMWF ON FRIDAY. DEPENDING ON
WHERE THE HUGE UPPER LOW TO OUR NORTHEAST IS LOCATED WILL PLAY A
ROLE IN THE STRONG ENERGY COMING OUT OF THE SOUTHWEST. CONFIDENCE IN
THE TRACK/TIMING/INTENSITY OF THIS SYSTEM IS LOW BUT CERTAINLY THERE
IS THE POTENTIAL FOR A WINTER STORM SOMEWHERE IN THE MIDWEST...SO
ANYONE TRAVELING AROUND CHRISTMAS DAY OR THEREAFTER SHOULD CONTINUE
TO MONITOR LATER FORECASTS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 536 AM CST THU DEC 18 2014

WEAKENING STORM SYSTEM WILL SPREAD LIGHT SNOW ACROSS NORTHEAST MO...
FAR SOUTHEAST IA AND PORTIONS OF WEST CENTRAL IL THROUGH MIDDAY
BEFORE DIMINISHING. LIGHT SNOW COULD BRUSH THE BRL TERMINAL 15Z-18Z
BUT LOW CONFIDENCE DUE TO DRY AIR AND WEAKENING SYSTEM THUS ONLY
HAVE MENTION OF FLURRIES WITH VSBYS AOA 6SM. OTHERWISE... EXPECT
VFR CONDITIONS WITH MID/HIGH CLOUDINESS AND LIGHT WINDS. THE
POTENTIAL EXISTS FOR PATCHY FOG WITH MVFR TO LOCALIZED IFR VSBYS
LATE TONIGHT... BUT WITH MID/HIGH CLOUDINESS NOT CONFIDENT ENOUGH
ON DEVELOPMENT/IMPACT AT TERMINALS FOR MENTION AT THIS TIME.


&&

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

$$

UPDATE...RP KINNEY
SYNOPSIS...05
SHORT TERM...05
LONG TERM...HAASE
AVIATION...05







000
FXUS63 KDVN 181647
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1047 AM CST THU DEC 18 2014

.UPDATE...
ISSUED AT 1017 AM CST THU DEC 18 2014

MORNING UPDATE TO FINE TUNE POPS AND SNOWFALL AMOUNTS...WITH A
SLIGHT INCREASE NORTH TOWARDS SIGOURNEY AND WILLIAMSBURG. LATEST
NAM/RAP BUFKIT SOUNDINGS INDICATE SOME POTENTIAL FOR SOME PATCHY
FREEZING DRIZZLE AT THE TAIL END OF THE EVENT THIS AFTERNOON
ACROSS THE EXTREME SOUTH.

&&

.SYNOPSIS...
ISSUED AT 321 AM CST THU DEC 18 2014

SNOW FAIRLY WIDESPREAD FROM WESTERN MO INTO NE AND KS AHEAD OF AN
UPPER LEVEL SHORTWAVE OVER THE PLAINS. REPORTS OF ACCUMS FROM
1-3 INCHES FROM NORTHERN KS THROUGH THE KC METRO WITH OBS SUGGESTING
THE LEADING EDGE OF SNOW BETWEEN CHILLICOTHE MO AND KC METRO
MOVING N/E. TRENDS SUPPORT SYSTEM AND ATTENDANT SNOW TO GRADUALLY
WEAKEN TODAY AS IT ENCOUNTERS RIDGING OVER THE REGION... BUT
BEFORE DOING SO IS EXPECTED BRING SOME LIGHT ACCUMS TO SOUTHERN
PORTIONS OF CWA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU DEC 18 2014

SHORTWAVE WILL MOVE ACROSS REGION TODAY AND DEAMPLIFY/WEAKEN WHILE
RUNNING INTO THE RIDGE. THIS ALONG WITH COPIOUS DRY AIR PER 00Z
DVN AND ILX RAOBS SHOULD RESULT IN STEADY WEAKENING OF SNOW AS IT
SPREADS INTO FAR SOUTHERN CWA THIS AM. FORCING PEAKS OVER NORTHERN
MO 10Z-15Z THEN QUICKLY DIMINISHING THROUGH 18Z. OVERALL GOING
WITH 0.05 TO 0.1 INCH OF LIQUID QPF WITH SLR OF 12-14:1 TO YIELD
AROUND AN INCH OR SO OF ACCUM VERY FAR SOUTHERN CWA MAINLY NORTHEAST
MO INTO PORTIONS OF WEST CENTRAL IL TAPERING OFF TO TRACE HWY 34.
GIVEN DRY AIR AND ALIGNMENT OF FORCING COULD ENVISION SCENARIO
WHEREBY THIS OCCURS OVER MUCH SHORTER DISTANCE OF 25+ MILES NORTHEAST
MO. CANT RULE OUT POSSIBILITY OF SOME FREEZING DRIZZLE FAR SOUTH
FOR A WHILE THIS AFTERNOON IF CLOUD BEARING LAYER BECOMES SUFFICIENTLY
SHALLOW/WARM.. BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE MENTION
ATTIM. ASIDE FROM THE LIGHT SNOW FAR SOUTHERN CWA... EXPECT PTSUNNY
TO CLOUDY SKIES TODAY WITH TEMPS SIMILAR TO THOSE OF YSTDY IN
RELATIVELY NEUTRAL THERMAL ENVIRONMENT... WITH READINGS MAINLY IN
UPPER 20S TO LOWER 30S. WINDS NEGLIGIBLE AND GENERALLY 5 MPH OR LESS
WITH SURFACE RIDGING.

TONIGHT... GENERALLY PT-MOCDLY SKIES WITH SFC RIDGING BECOMING
RE-ESTABLISHED AS THE DOMINANT FEATURE. BANKING ON SUFFICIENT
CLOUDINESS TO PRECLUDE TEMPS FROM BOTTOMING OUT DESPITE NEAR
CALM/CALM WINDS... AND EXPECT GENERALLY UPPER TEENS TO MID 20S FOR
LOWS. SHOULD SOME AREAS SEE MORE IN WAY OF CLEARING THEN POTENTIAL
TO BE IN MID TEENS FOR LOWS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU DEC 18 2014

FORECAST FOCUS ON ACTIVE WEATHER PATTERN ESPECIALLY CHRISTMAS WEEK.

FRIDAY THROUGH SUNDAY...ZONAL FLOW OVER THE REGION WITH A SERIES OF
SHORT WAVES MOVING ACROSS. THIS LOOKS TO BE ANOTHER RATHER CLOUDY
PERIOD WITH FORECAST SOUNDINGS INDICATING WEAK LOW LEVEL WARM
ADVECTION AND A STRONG INVERSION SETTING UP AROUND 850 MB...WITH MOISTURE
TRAPPED BELOW. SATURDAY NIGHT I HAVE INTRODUCED A SLIGHT CHANCE OF
FREEZING DRIZZLE IN OUR FAR NW CWA...AS A SHORT WAVE/VORT MAX
TRAVERSES NORTHERN IA. FORECAST SOUNDINGS INDICATE A WARM LAYER JUST
ABOVE FREEZING WITH DRY AIR IN THE MID LEVELS WITH MOISTURE BELOW.
MAXIMUM TEMPERATURES DURING THIS PERIOD WILL BE IN THE 30S TO NEAR
40 WITH LOWS IN THE 20S TO NEAR 30.

MONDAY THROUGH WEDNESDAY...THIS IS WHEN THE WEATHER GETS ACTIVE BUT
ALSO COMPLICATED AND CHALLENGING. UPPER LOW DEEPENS AS IT TRACKS
FROM THE NORTHERN PLAINS (MONDAY) INTO EASTERN IA (TUESDAY) AND THEN
LIFTING INTO THE WESTERN GREAT LAKES (WEDNESDAY). THE PATH OF THIS
SYSTEM WOULD SUGGEST MAINLY A RAIN/SNOW MIX BUT WILL NEED TO KEEP AN
EYE ON TUESDAY WHERE IT MAY CHANGE TO ALL SNOW...GIVEN THE COLD
POCKET ALOFT AND DYNAMIC COOLING. WAY TOO EARLY TO OFFER ANY
ACCUMULATION AMOUNTS IF ANY. MAXIMUM TEMPERATURES ON MONDAY SHOULD
PUSH INTO THE 40S FROM ABOUT I-80 SOUTHWARD...AND IN THE 30S TUESDAY
AND WEDNESDAY. THE ECMWF HAS NOW THROWN A CURVE BALL IN REGARD TO
THE WHOPPER STORM EARLIER INDICATED TO BE IN THE GREAT LAKES REGION
CHRISTMAS EVE. IT NOW IS NOT QUITE THE BOMB SHOWN THE PAST COUPLE
RUNS AND IS ALSO INTENSIFYING THE CYCLONE FARTHER EAST...IN NEW
ENGLAND! THIS IS WHAT THE GFS HAS BEEN INDICATING ALL ALONG. SUFFICE
TO SAY CONFIDENCE IS LOW AS PHASING ISSUES CONTINUE TO HAUNT THE
MODELS. SO MORE CHANGES IN THE MODELS CAN BE EXPECTED OVER THE NEXT
SEVERAL DAYS AND THE IMPACTS IF ANY ON OUR AREA REMAIN TO BE SEEN.

CHRISTMAS DAY AND FRIDAY...MANY UNCERTAINTIES REGARDING THE
POTENTIAL WINTER STORM OFFERED BY THE ECMWF ON FRIDAY. DEPENDING ON
WHERE THE HUGE UPPER LOW TO OUR NORTHEAST IS LOCATED WILL PLAY A
ROLE IN THE STRONG ENERGY COMING OUT OF THE SOUTHWEST. CONFIDENCE IN
THE TRACK/TIMING/INTENSITY OF THIS SYSTEM IS LOW BUT CERTAINLY THERE
IS THE POTENTIAL FOR A WINTER STORM SOMEWHERE IN THE MIDWEST...SO
ANYONE TRAVELING AROUND CHRISTMAS DAY OR THEREAFTER SHOULD CONTINUE
TO MONITOR LATER FORECASTS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 536 AM CST THU DEC 18 2014

WEAKENING STORM SYSTEM WILL SPREAD LIGHT SNOW ACROSS NORTHEAST MO...
FAR SOUTHEAST IA AND PORTIONS OF WEST CENTRAL IL THROUGH MIDDAY
BEFORE DIMINISHING. LIGHT SNOW COULD BRUSH THE BRL TERMINAL 15Z-18Z
BUT LOW CONFIDENCE DUE TO DRY AIR AND WEAKENING SYSTEM THUS ONLY
HAVE MENTION OF FLURRIES WITH VSBYS AOA 6SM. OTHERWISE... EXPECT
VFR CONDITIONS WITH MID/HIGH CLOUDINESS AND LIGHT WINDS. THE
POTENTIAL EXISTS FOR PATCHY FOG WITH MVFR TO LOCALIZED IFR VSBYS
LATE TONIGHT... BUT WITH MID/HIGH CLOUDINESS NOT CONFIDENT ENOUGH
ON DEVELOPMENT/IMPACT AT TERMINALS FOR MENTION AT THIS TIME.


&&

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

$$

UPDATE...RP KINNEY
SYNOPSIS...05
SHORT TERM...05
LONG TERM...HAASE
AVIATION...05







000
FXUS63 KDVN 181647
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1047 AM CST THU DEC 18 2014

.UPDATE...
ISSUED AT 1017 AM CST THU DEC 18 2014

MORNING UPDATE TO FINE TUNE POPS AND SNOWFALL AMOUNTS...WITH A
SLIGHT INCREASE NORTH TOWARDS SIGOURNEY AND WILLIAMSBURG. LATEST
NAM/RAP BUFKIT SOUNDINGS INDICATE SOME POTENTIAL FOR SOME PATCHY
FREEZING DRIZZLE AT THE TAIL END OF THE EVENT THIS AFTERNOON
ACROSS THE EXTREME SOUTH.

&&

.SYNOPSIS...
ISSUED AT 321 AM CST THU DEC 18 2014

SNOW FAIRLY WIDESPREAD FROM WESTERN MO INTO NE AND KS AHEAD OF AN
UPPER LEVEL SHORTWAVE OVER THE PLAINS. REPORTS OF ACCUMS FROM
1-3 INCHES FROM NORTHERN KS THROUGH THE KC METRO WITH OBS SUGGESTING
THE LEADING EDGE OF SNOW BETWEEN CHILLICOTHE MO AND KC METRO
MOVING N/E. TRENDS SUPPORT SYSTEM AND ATTENDANT SNOW TO GRADUALLY
WEAKEN TODAY AS IT ENCOUNTERS RIDGING OVER THE REGION... BUT
BEFORE DOING SO IS EXPECTED BRING SOME LIGHT ACCUMS TO SOUTHERN
PORTIONS OF CWA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU DEC 18 2014

SHORTWAVE WILL MOVE ACROSS REGION TODAY AND DEAMPLIFY/WEAKEN WHILE
RUNNING INTO THE RIDGE. THIS ALONG WITH COPIOUS DRY AIR PER 00Z
DVN AND ILX RAOBS SHOULD RESULT IN STEADY WEAKENING OF SNOW AS IT
SPREADS INTO FAR SOUTHERN CWA THIS AM. FORCING PEAKS OVER NORTHERN
MO 10Z-15Z THEN QUICKLY DIMINISHING THROUGH 18Z. OVERALL GOING
WITH 0.05 TO 0.1 INCH OF LIQUID QPF WITH SLR OF 12-14:1 TO YIELD
AROUND AN INCH OR SO OF ACCUM VERY FAR SOUTHERN CWA MAINLY NORTHEAST
MO INTO PORTIONS OF WEST CENTRAL IL TAPERING OFF TO TRACE HWY 34.
GIVEN DRY AIR AND ALIGNMENT OF FORCING COULD ENVISION SCENARIO
WHEREBY THIS OCCURS OVER MUCH SHORTER DISTANCE OF 25+ MILES NORTHEAST
MO. CANT RULE OUT POSSIBILITY OF SOME FREEZING DRIZZLE FAR SOUTH
FOR A WHILE THIS AFTERNOON IF CLOUD BEARING LAYER BECOMES SUFFICIENTLY
SHALLOW/WARM.. BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE MENTION
ATTIM. ASIDE FROM THE LIGHT SNOW FAR SOUTHERN CWA... EXPECT PTSUNNY
TO CLOUDY SKIES TODAY WITH TEMPS SIMILAR TO THOSE OF YSTDY IN
RELATIVELY NEUTRAL THERMAL ENVIRONMENT... WITH READINGS MAINLY IN
UPPER 20S TO LOWER 30S. WINDS NEGLIGIBLE AND GENERALLY 5 MPH OR LESS
WITH SURFACE RIDGING.

TONIGHT... GENERALLY PT-MOCDLY SKIES WITH SFC RIDGING BECOMING
RE-ESTABLISHED AS THE DOMINANT FEATURE. BANKING ON SUFFICIENT
CLOUDINESS TO PRECLUDE TEMPS FROM BOTTOMING OUT DESPITE NEAR
CALM/CALM WINDS... AND EXPECT GENERALLY UPPER TEENS TO MID 20S FOR
LOWS. SHOULD SOME AREAS SEE MORE IN WAY OF CLEARING THEN POTENTIAL
TO BE IN MID TEENS FOR LOWS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU DEC 18 2014

FORECAST FOCUS ON ACTIVE WEATHER PATTERN ESPECIALLY CHRISTMAS WEEK.

FRIDAY THROUGH SUNDAY...ZONAL FLOW OVER THE REGION WITH A SERIES OF
SHORT WAVES MOVING ACROSS. THIS LOOKS TO BE ANOTHER RATHER CLOUDY
PERIOD WITH FORECAST SOUNDINGS INDICATING WEAK LOW LEVEL WARM
ADVECTION AND A STRONG INVERSION SETTING UP AROUND 850 MB...WITH MOISTURE
TRAPPED BELOW. SATURDAY NIGHT I HAVE INTRODUCED A SLIGHT CHANCE OF
FREEZING DRIZZLE IN OUR FAR NW CWA...AS A SHORT WAVE/VORT MAX
TRAVERSES NORTHERN IA. FORECAST SOUNDINGS INDICATE A WARM LAYER JUST
ABOVE FREEZING WITH DRY AIR IN THE MID LEVELS WITH MOISTURE BELOW.
MAXIMUM TEMPERATURES DURING THIS PERIOD WILL BE IN THE 30S TO NEAR
40 WITH LOWS IN THE 20S TO NEAR 30.

MONDAY THROUGH WEDNESDAY...THIS IS WHEN THE WEATHER GETS ACTIVE BUT
ALSO COMPLICATED AND CHALLENGING. UPPER LOW DEEPENS AS IT TRACKS
FROM THE NORTHERN PLAINS (MONDAY) INTO EASTERN IA (TUESDAY) AND THEN
LIFTING INTO THE WESTERN GREAT LAKES (WEDNESDAY). THE PATH OF THIS
SYSTEM WOULD SUGGEST MAINLY A RAIN/SNOW MIX BUT WILL NEED TO KEEP AN
EYE ON TUESDAY WHERE IT MAY CHANGE TO ALL SNOW...GIVEN THE COLD
POCKET ALOFT AND DYNAMIC COOLING. WAY TOO EARLY TO OFFER ANY
ACCUMULATION AMOUNTS IF ANY. MAXIMUM TEMPERATURES ON MONDAY SHOULD
PUSH INTO THE 40S FROM ABOUT I-80 SOUTHWARD...AND IN THE 30S TUESDAY
AND WEDNESDAY. THE ECMWF HAS NOW THROWN A CURVE BALL IN REGARD TO
THE WHOPPER STORM EARLIER INDICATED TO BE IN THE GREAT LAKES REGION
CHRISTMAS EVE. IT NOW IS NOT QUITE THE BOMB SHOWN THE PAST COUPLE
RUNS AND IS ALSO INTENSIFYING THE CYCLONE FARTHER EAST...IN NEW
ENGLAND! THIS IS WHAT THE GFS HAS BEEN INDICATING ALL ALONG. SUFFICE
TO SAY CONFIDENCE IS LOW AS PHASING ISSUES CONTINUE TO HAUNT THE
MODELS. SO MORE CHANGES IN THE MODELS CAN BE EXPECTED OVER THE NEXT
SEVERAL DAYS AND THE IMPACTS IF ANY ON OUR AREA REMAIN TO BE SEEN.

CHRISTMAS DAY AND FRIDAY...MANY UNCERTAINTIES REGARDING THE
POTENTIAL WINTER STORM OFFERED BY THE ECMWF ON FRIDAY. DEPENDING ON
WHERE THE HUGE UPPER LOW TO OUR NORTHEAST IS LOCATED WILL PLAY A
ROLE IN THE STRONG ENERGY COMING OUT OF THE SOUTHWEST. CONFIDENCE IN
THE TRACK/TIMING/INTENSITY OF THIS SYSTEM IS LOW BUT CERTAINLY THERE
IS THE POTENTIAL FOR A WINTER STORM SOMEWHERE IN THE MIDWEST...SO
ANYONE TRAVELING AROUND CHRISTMAS DAY OR THEREAFTER SHOULD CONTINUE
TO MONITOR LATER FORECASTS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 536 AM CST THU DEC 18 2014

WEAKENING STORM SYSTEM WILL SPREAD LIGHT SNOW ACROSS NORTHEAST MO...
FAR SOUTHEAST IA AND PORTIONS OF WEST CENTRAL IL THROUGH MIDDAY
BEFORE DIMINISHING. LIGHT SNOW COULD BRUSH THE BRL TERMINAL 15Z-18Z
BUT LOW CONFIDENCE DUE TO DRY AIR AND WEAKENING SYSTEM THUS ONLY
HAVE MENTION OF FLURRIES WITH VSBYS AOA 6SM. OTHERWISE... EXPECT
VFR CONDITIONS WITH MID/HIGH CLOUDINESS AND LIGHT WINDS. THE
POTENTIAL EXISTS FOR PATCHY FOG WITH MVFR TO LOCALIZED IFR VSBYS
LATE TONIGHT... BUT WITH MID/HIGH CLOUDINESS NOT CONFIDENT ENOUGH
ON DEVELOPMENT/IMPACT AT TERMINALS FOR MENTION AT THIS TIME.


&&

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

$$

UPDATE...RP KINNEY
SYNOPSIS...05
SHORT TERM...05
LONG TERM...HAASE
AVIATION...05







000
FXUS63 KDMX 181523
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
923 AM CST THU DEC 18 2014

.UPDATE...
ISSUED AT 920 AM CST THU DEC 18 2014

BASED ON INCOMING COOP SNOWFALL REPORTS AND RADAR TRENDS...HAVE
LOWERED SNOWFALL AMOUNTS BY SEVERAL TENTHS OF AN INCH AND REMOVED
SNOW NORTH OF I-80 FOR THE REST OF TODAY. DRY LAYER VERY PROMINENT
ON THE 12Z 0AX SOUNDING IS RESULTING IN A SHARP CUTOFF IN THE
PRECIP BAND JUST SOUTH OF DSM. IT IS QUITE POSSIBLE THAT THE
METRO MAY SEE ONLY FLURRIES BY THE TIME THIS EVENT IS ALL SAID
AND DONE WITH THE BEST DGZ FORCING ALREADY SHIFTING TOWARDS SE
IOWA AND RADAR ECHOS DECREASING OVER THE SW CWA.

&&

.SHORT TERM /TODAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

AN UPPER LEVEL SHORT WAVE IS MOVING ACROSS MISSOURI THIS MORNING
WITH THE NORTHERN FRINGE OF KINEMATIC FORCING REACHING INTO SOUTHERN
IOWA. A BRANCH OF THE WARM CONVEYOR BELT IS WRAPPING AROUND THE
NORTH SIDE WITH MOISTURE OVERRUNNING THE SURFACE COLDER AIR. THE
COMBINATION OF MOISTURE AND FORCING HAS RESULTED IN A BAND OF SNOW
LIFTING NORTHEAST THROUGH NORTHEAST KANSAS AND NORTHERN MISSOURI.
THIS BAND OF SNOW WILL MOVE INTO SOUTHERN IOWA EARLY THIS MORNING
HOWEVER ITS NORTHEAST EXTENT WILL BE LIMITED BY DRY AIR ASSOCIATED
WITH A RIDGE OF HIGH PRESSURE SITUATED OVER NORTHEAST IOWA. IN
ADDITION...FORCING WILL WEAKEN AS THE UPPER LEVEL SYSTEM DEPARTS TO
THE EAST AND LEAVES THE SNOW BAND BEHIND TO DIMINISH. SNOWFALL
AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE OVER THE SOUTHERN 2 TIERS OF
COUNTIES WITH MINOR ACCUMULATIONS OF A FEW TENTHS POSSIBLE AS FAR
NORTH AS INTERSTATE 80. POTENTIAL FOR FREEZING DRIZZLE BY THIS
AFTERNOON IS LOW. MOISTURE DEPTHS WITH RELATIVE HUMIDITIES GREATER
THAN 75 PERCENT REMAIN RELATIVELY HIGH AND COLD FOR ICE TO REMAIN
INTRODUCED AND RESULTING IN LIGHT SNOW OR FLURRIES COMPARED TO
FZDZ.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

OUR WEATHER PATTERN IS SET TO BECOME MORE ACTIVE OVER THE COMING
DAYS. INITIALLY A SERIES OF 500 MB TROUGHS WILL CROSS THE
REGION...THE FIRST AROUND FRIDAY NIGHT AND ANOTHER AROUND
SATURDAY NIGHT/SUNDAY...GRADUALLY CARVING OUT BROAD CYCLONIC FLOW
ACROSS THE CENTRAL U.S. CONCURRENT WITH A LARGE 500 MB HIGH
PRESSURE DOME DEVELOPING OVER THE EASTERN PACIFIC. WITH THE FIRST
TROUGH PASSAGE OVER IOWA ON FRIDAY NIGHT THERE IS A POTENTIAL FOR
SOME STRATUS AND DRIZZLE...BUT FORECAST SOUNDINGS INDICATE THAT
LOW LEVEL MOISTURE AND LIFT WILL PROBABLY BE INSUFFICIENT TO
GENERATE PRECIPITATION. WITH THE SECOND TROUGH ON SATURDAY NIGHT
INTO SUNDAY THERE IS A BETTER SIGNAL FOR SOME LIGHT
PRECIPITATION...PROBABLY IN THE FORM OF DRIZZLE OR FREEZING
DRIZZLE. IT IS LIKELY THAT TEMPERATURES WILL FALL BELOW FREEZING
SATURDAY NIGHT...HOWEVER...DEWPOINTS AND TEMPERATURES MAY RECOVER
TO JUST ABOVE FREEZING BEFORE DRIZZLE DEVELOPS.
NEVERTHELESS...GIVEN THE POSSIBILITY OF FREEZING DRIZZLE AND ITS
ASSOCIATED IMPACTS HAVE ADDED A CHANCE INTO THE OUTGOING FORECAST
PACKAGE. WE WILL BE CLOSELY MONITORING THIS POSSIBILITY OVER THE
NEXT COUPLE OF DAYS.

AS MENTIONED EARLIER...BY THE LATTER PART OF THE WEEKEND A BROAD
500 MB TROUGH WILL HAVE BEEN CARVED OUT OVER THE CENTRAL U.S. A
COMPACT BUT ENERGETIC SHORTWAVE WILL THEN OVERTOP THE EASTERN
PACIFIC RIDGE AND ROCKET SOUTHEASTWARD OVER THE NORTHERN ROCKIES
ON SUNDAY...SUBSEQUENTLY DIGGING AND CLOSING OFF AS A LOW OVER
MINNESOTA AND IOWA BY MONDAY NIGHT. THIS LOW WILL THEN WOBBLE OVER
THE REGION...OR SLIGHTLY TO THE EAST OVER WISCONSIN AND LAKE
MICHIGAN...BEFORE FINALLY EJECTING EASTWARD AROUND CHRISTMAS EVE.
IN TERMS OF SENSIBLE WEATHER...THE INITIAL APPROACH OF THE LOW ON
WILL SPREAD A SWATH OF WARM ADVECTION REGIME PRECIPITATION ACROSS
IOWA ON SUNDAY NIGHT INTO MONDAY...THEN AS THE LOW MOVES NEARBY OR
OVERHEAD A LARGE STRATUS AND PRECIPITATION SHIELD WILL AFFECT MOST
OF THE REGION AND EVENTUALLY CHANGE OVER TO SNOW. THERE IS STILL
SOME UNCERTAINTY AS TO THE LOCATION OF THE LOW PRESSURE CENTER AND
ATTENDANT TEMPERATURE FIELDS...BUT IT SEEMS LIKELY THAT INITIALLY
THE PRECIPITATION WILL BE MOSTLY IN THE FORM OF RAIN WITH A WINTRY
MIX ACROSS NORTHERN IOWA...THEN BECOME LIGHTER BY THE TIME A
CHANGE TO SNOW OCCURS LATER IN THE EVENT. THIS WILL LIMIT SNOW
ACCUMULATIONS ACROSS MOST OF IOWA...BUT IN THE NORTH THERE COULD
BE SOME DECENT AMOUNTS DEPENDING ON HOW THE TEMPERATURES SET UP.
CERTAINLY TOO EARLY FOR ANY HEADLINE DIAGNOSIS BUT CERTAINLY ALL
EYES WILL BE ON THIS LARGE STORM SYSTEM IN THE COMING DAYS.

&&

.AVIATION...18/12Z
ISSUED AT 555 AM CST THU DEC 18 2014

BAND OF SNOW MOVING INTO SOUTHERN IOWA WILL DROP VISIBILITIES TO
MVFR AT TIMES AT KOTM/KDSM THIS MORNING BEFORE DIMINISHING. CIGS
WILL DROP TO MVFR AS WELL IN THAT AREA. PRIMARILY VFR CONDITIONS
AT OTHER SITES THROUGH MUCH OF THE DAY. CIGS ARE EXPECTED TO LOWER
LATE TODAY AND THROUGH TONIGHT WITH WIDESPREAD MVFR OVERNIGHT.
LIGHT WINDS ARE EXPECTED THROUGH THE PERIOD.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...SKOW
SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...DONAVON




000
FXUS63 KDMX 181523
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
923 AM CST THU DEC 18 2014

.UPDATE...
ISSUED AT 920 AM CST THU DEC 18 2014

BASED ON INCOMING COOP SNOWFALL REPORTS AND RADAR TRENDS...HAVE
LOWERED SNOWFALL AMOUNTS BY SEVERAL TENTHS OF AN INCH AND REMOVED
SNOW NORTH OF I-80 FOR THE REST OF TODAY. DRY LAYER VERY PROMINENT
ON THE 12Z 0AX SOUNDING IS RESULTING IN A SHARP CUTOFF IN THE
PRECIP BAND JUST SOUTH OF DSM. IT IS QUITE POSSIBLE THAT THE
METRO MAY SEE ONLY FLURRIES BY THE TIME THIS EVENT IS ALL SAID
AND DONE WITH THE BEST DGZ FORCING ALREADY SHIFTING TOWARDS SE
IOWA AND RADAR ECHOS DECREASING OVER THE SW CWA.

&&

.SHORT TERM /TODAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

AN UPPER LEVEL SHORT WAVE IS MOVING ACROSS MISSOURI THIS MORNING
WITH THE NORTHERN FRINGE OF KINEMATIC FORCING REACHING INTO SOUTHERN
IOWA. A BRANCH OF THE WARM CONVEYOR BELT IS WRAPPING AROUND THE
NORTH SIDE WITH MOISTURE OVERRUNNING THE SURFACE COLDER AIR. THE
COMBINATION OF MOISTURE AND FORCING HAS RESULTED IN A BAND OF SNOW
LIFTING NORTHEAST THROUGH NORTHEAST KANSAS AND NORTHERN MISSOURI.
THIS BAND OF SNOW WILL MOVE INTO SOUTHERN IOWA EARLY THIS MORNING
HOWEVER ITS NORTHEAST EXTENT WILL BE LIMITED BY DRY AIR ASSOCIATED
WITH A RIDGE OF HIGH PRESSURE SITUATED OVER NORTHEAST IOWA. IN
ADDITION...FORCING WILL WEAKEN AS THE UPPER LEVEL SYSTEM DEPARTS TO
THE EAST AND LEAVES THE SNOW BAND BEHIND TO DIMINISH. SNOWFALL
AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE OVER THE SOUTHERN 2 TIERS OF
COUNTIES WITH MINOR ACCUMULATIONS OF A FEW TENTHS POSSIBLE AS FAR
NORTH AS INTERSTATE 80. POTENTIAL FOR FREEZING DRIZZLE BY THIS
AFTERNOON IS LOW. MOISTURE DEPTHS WITH RELATIVE HUMIDITIES GREATER
THAN 75 PERCENT REMAIN RELATIVELY HIGH AND COLD FOR ICE TO REMAIN
INTRODUCED AND RESULTING IN LIGHT SNOW OR FLURRIES COMPARED TO
FZDZ.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

OUR WEATHER PATTERN IS SET TO BECOME MORE ACTIVE OVER THE COMING
DAYS. INITIALLY A SERIES OF 500 MB TROUGHS WILL CROSS THE
REGION...THE FIRST AROUND FRIDAY NIGHT AND ANOTHER AROUND
SATURDAY NIGHT/SUNDAY...GRADUALLY CARVING OUT BROAD CYCLONIC FLOW
ACROSS THE CENTRAL U.S. CONCURRENT WITH A LARGE 500 MB HIGH
PRESSURE DOME DEVELOPING OVER THE EASTERN PACIFIC. WITH THE FIRST
TROUGH PASSAGE OVER IOWA ON FRIDAY NIGHT THERE IS A POTENTIAL FOR
SOME STRATUS AND DRIZZLE...BUT FORECAST SOUNDINGS INDICATE THAT
LOW LEVEL MOISTURE AND LIFT WILL PROBABLY BE INSUFFICIENT TO
GENERATE PRECIPITATION. WITH THE SECOND TROUGH ON SATURDAY NIGHT
INTO SUNDAY THERE IS A BETTER SIGNAL FOR SOME LIGHT
PRECIPITATION...PROBABLY IN THE FORM OF DRIZZLE OR FREEZING
DRIZZLE. IT IS LIKELY THAT TEMPERATURES WILL FALL BELOW FREEZING
SATURDAY NIGHT...HOWEVER...DEWPOINTS AND TEMPERATURES MAY RECOVER
TO JUST ABOVE FREEZING BEFORE DRIZZLE DEVELOPS.
NEVERTHELESS...GIVEN THE POSSIBILITY OF FREEZING DRIZZLE AND ITS
ASSOCIATED IMPACTS HAVE ADDED A CHANCE INTO THE OUTGOING FORECAST
PACKAGE. WE WILL BE CLOSELY MONITORING THIS POSSIBILITY OVER THE
NEXT COUPLE OF DAYS.

AS MENTIONED EARLIER...BY THE LATTER PART OF THE WEEKEND A BROAD
500 MB TROUGH WILL HAVE BEEN CARVED OUT OVER THE CENTRAL U.S. A
COMPACT BUT ENERGETIC SHORTWAVE WILL THEN OVERTOP THE EASTERN
PACIFIC RIDGE AND ROCKET SOUTHEASTWARD OVER THE NORTHERN ROCKIES
ON SUNDAY...SUBSEQUENTLY DIGGING AND CLOSING OFF AS A LOW OVER
MINNESOTA AND IOWA BY MONDAY NIGHT. THIS LOW WILL THEN WOBBLE OVER
THE REGION...OR SLIGHTLY TO THE EAST OVER WISCONSIN AND LAKE
MICHIGAN...BEFORE FINALLY EJECTING EASTWARD AROUND CHRISTMAS EVE.
IN TERMS OF SENSIBLE WEATHER...THE INITIAL APPROACH OF THE LOW ON
WILL SPREAD A SWATH OF WARM ADVECTION REGIME PRECIPITATION ACROSS
IOWA ON SUNDAY NIGHT INTO MONDAY...THEN AS THE LOW MOVES NEARBY OR
OVERHEAD A LARGE STRATUS AND PRECIPITATION SHIELD WILL AFFECT MOST
OF THE REGION AND EVENTUALLY CHANGE OVER TO SNOW. THERE IS STILL
SOME UNCERTAINTY AS TO THE LOCATION OF THE LOW PRESSURE CENTER AND
ATTENDANT TEMPERATURE FIELDS...BUT IT SEEMS LIKELY THAT INITIALLY
THE PRECIPITATION WILL BE MOSTLY IN THE FORM OF RAIN WITH A WINTRY
MIX ACROSS NORTHERN IOWA...THEN BECOME LIGHTER BY THE TIME A
CHANGE TO SNOW OCCURS LATER IN THE EVENT. THIS WILL LIMIT SNOW
ACCUMULATIONS ACROSS MOST OF IOWA...BUT IN THE NORTH THERE COULD
BE SOME DECENT AMOUNTS DEPENDING ON HOW THE TEMPERATURES SET UP.
CERTAINLY TOO EARLY FOR ANY HEADLINE DIAGNOSIS BUT CERTAINLY ALL
EYES WILL BE ON THIS LARGE STORM SYSTEM IN THE COMING DAYS.

&&

.AVIATION...18/12Z
ISSUED AT 555 AM CST THU DEC 18 2014

BAND OF SNOW MOVING INTO SOUTHERN IOWA WILL DROP VISIBILITIES TO
MVFR AT TIMES AT KOTM/KDSM THIS MORNING BEFORE DIMINISHING. CIGS
WILL DROP TO MVFR AS WELL IN THAT AREA. PRIMARILY VFR CONDITIONS
AT OTHER SITES THROUGH MUCH OF THE DAY. CIGS ARE EXPECTED TO LOWER
LATE TODAY AND THROUGH TONIGHT WITH WIDESPREAD MVFR OVERNIGHT.
LIGHT WINDS ARE EXPECTED THROUGH THE PERIOD.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...SKOW
SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...DONAVON



000
FXUS63 KDMX 181155
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
555 AM CST THU DEC 18 2014

.SHORT TERM /TODAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

AN UPPER LEVEL SHORT WAVE IS MOVING ACROSS MISSOURI THIS MORNING
WITH THE NORTHERN FRINGE OF KINEMATIC FORCING REACHING INTO SOUTHERN
IOWA. A BRANCH OF THE WARM CONVEYOR BELT IS WRAPPING AROUND THE
NORTH SIDE WITH MOISTURE OVERRUNNING THE SURFACE COLDER AIR. THE
COMBINATION OF MOISTURE AND FORCING HAS RESULTED IN A BAND OF SNOW
LIFTING NORTHEAST THROUGH NORTHEAST KANSAS AND NORTHERN MISSOURI.
THIS BAND OF SNOW WILL MOVE INTO SOUTHERN IOWA EARLY THIS MORNING
HOWEVER ITS NORTHEAST EXTENT WILL BE LIMITED BY DRY AIR ASSOCIATED
WITH A RIDGE OF HIGH PRESSURE SITUATED OVER NORTHEAST IOWA. IN
ADDITION...FORCING WILL WEAKEN AS THE UPPER LEVEL SYSTEM DEPARTS TO
THE EAST AND LEAVES THE SNOW BAND BEHIND TO DIMINISH. SNOWFALL
AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE OVER THE SOUTHERN 2 TIERS OF
COUNTIES WITH MINOR ACCUMULATIONS OF A FEW TENTHS POSSIBLE AS FAR
NORTH AS INTERSTATE 80. POTENTIAL FOR FREEZING DRIZZLE BY THIS
AFTERNOON IS LOW. MOISTURE DEPTHS WITH RELATIVE HUMIDITIES GREATER
THAN 75 PERCENT REMAIN RELATIVELY HIGH AND COLD FOR ICE TO REMAIN
INTRODUCED AND RESULTING IN LIGHT SNOW OR FLURRIES COMPARED TO
FZDZ.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

OUR WEATHER PATTERN IS SET TO BECOME MORE ACTIVE OVER THE COMING
DAYS. INITIALLY A SERIES OF 500 MB TROUGHS WILL CROSS THE
REGION...THE FIRST AROUND FRIDAY NIGHT AND ANOTHER AROUND
SATURDAY NIGHT/SUNDAY...GRADUALLY CARVING OUT BROAD CYCLONIC FLOW
ACROSS THE CENTRAL U.S. CONCURRENT WITH A LARGE 500 MB HIGH
PRESSURE DOME DEVELOPING OVER THE EASTERN PACIFIC. WITH THE FIRST
TROUGH PASSAGE OVER IOWA ON FRIDAY NIGHT THERE IS A POTENTIAL FOR
SOME STRATUS AND DRIZZLE...BUT FORECAST SOUNDINGS INDICATE THAT
LOW LEVEL MOISTURE AND LIFT WILL PROBABLY BE INSUFFICIENT TO
GENERATE PRECIPITATION. WITH THE SECOND TROUGH ON SATURDAY NIGHT
INTO SUNDAY THERE IS A BETTER SIGNAL FOR SOME LIGHT
PRECIPITATION...PROBABLY IN THE FORM OF DRIZZLE OR FREEZING
DRIZZLE. IT IS LIKELY THAT TEMPERATURES WILL FALL BELOW FREEZING
SATURDAY NIGHT...HOWEVER...DEWPOINTS AND TEMPERATURES MAY RECOVER
TO JUST ABOVE FREEZING BEFORE DRIZZLE DEVELOPS.
NEVERTHELESS...GIVEN THE POSSIBILITY OF FREEZING DRIZZLE AND ITS
ASSOCIATED IMPACTS HAVE ADDED A CHANCE INTO THE OUTGOING FORECAST
PACKAGE. WE WILL BE CLOSELY MONITORING THIS POSSIBILITY OVER THE
NEXT COUPLE OF DAYS.

AS MENTIONED EARLIER...BY THE LATTER PART OF THE WEEKEND A BROAD
500 MB TROUGH WILL HAVE BEEN CARVED OUT OVER THE CENTRAL U.S. A
COMPACT BUT ENERGETIC SHORTWAVE WILL THEN OVERTOP THE EASTERN
PACIFIC RIDGE AND ROCKET SOUTHEASTWARD OVER THE NORTHERN ROCKIES
ON SUNDAY...SUBSEQUENTLY DIGGING AND CLOSING OFF AS A LOW OVER
MINNESOTA AND IOWA BY MONDAY NIGHT. THIS LOW WILL THEN WOBBLE OVER
THE REGION...OR SLIGHTLY TO THE EAST OVER WISCONSIN AND LAKE
MICHIGAN...BEFORE FINALLY EJECTING EASTWARD AROUND CHRISTMAS EVE.
IN TERMS OF SENSIBLE WEATHER...THE INITIAL APPROACH OF THE LOW ON
WILL SPREAD A SWATH OF WARM ADVECTION REGIME PRECIPITATION ACROSS
IOWA ON SUNDAY NIGHT INTO MONDAY...THEN AS THE LOW MOVES NEARBY OR
OVERHEAD A LARGE STRATUS AND PRECIPITATION SHIELD WILL AFFECT MOST
OF THE REGION AND EVENTUALLY CHANGE OVER TO SNOW. THERE IS STILL
SOME UNCERTAINTY AS TO THE LOCATION OF THE LOW PRESSURE CENTER AND
ATTENDANT TEMPERATURE FIELDS...BUT IT SEEMS LIKELY THAT INITIALLY
THE PRECIPITATION WILL BE MOSTLY IN THE FORM OF RAIN WITH A WINTRY
MIX ACROSS NORTHERN IOWA...THEN BECOME LIGHTER BY THE TIME A
CHANGE TO SNOW OCCURS LATER IN THE EVENT. THIS WILL LIMIT SNOW
ACCUMULATIONS ACROSS MOST OF IOWA...BUT IN THE NORTH THERE COULD
BE SOME DECENT AMOUNTS DEPENDING ON HOW THE TEMPERATURES SET UP.
CERTAINLY TOO EARLY FOR ANY HEADLINE DIAGNOSIS BUT CERTAINLY ALL
EYES WILL BE ON THIS LARGE STORM SYSTEM IN THE COMING DAYS.

&&

.AVIATION...18/12Z
ISSUED AT 555 AM CST THU DEC 18 2014

BAND OF SNOW MOVING INTO SOUTHERN IOWA WILL DROP VISIBILITIES TO
MVFR AT TIMES AT KOTM/KDSM THIS MORNING BEFORE DIMINISHING. CIGS
WILL DROP TO MVFR AS WELL IN THAT AREA. PRIMARILY VFR CONDITIONS
AT OTHER SITES THROUGH MUCH OF THE DAY. CIGS ARE EXPECTED TO LOWER
LATE TODAY AND THROUGH TONIGHT WITH WIDESPREAD MVFR OVERNIGHT.
LIGHT WINDS ARE EXPECTED THROUGH THE PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...DONAVON



000
FXUS63 KDMX 181155
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
555 AM CST THU DEC 18 2014

.SHORT TERM /TODAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

AN UPPER LEVEL SHORT WAVE IS MOVING ACROSS MISSOURI THIS MORNING
WITH THE NORTHERN FRINGE OF KINEMATIC FORCING REACHING INTO SOUTHERN
IOWA. A BRANCH OF THE WARM CONVEYOR BELT IS WRAPPING AROUND THE
NORTH SIDE WITH MOISTURE OVERRUNNING THE SURFACE COLDER AIR. THE
COMBINATION OF MOISTURE AND FORCING HAS RESULTED IN A BAND OF SNOW
LIFTING NORTHEAST THROUGH NORTHEAST KANSAS AND NORTHERN MISSOURI.
THIS BAND OF SNOW WILL MOVE INTO SOUTHERN IOWA EARLY THIS MORNING
HOWEVER ITS NORTHEAST EXTENT WILL BE LIMITED BY DRY AIR ASSOCIATED
WITH A RIDGE OF HIGH PRESSURE SITUATED OVER NORTHEAST IOWA. IN
ADDITION...FORCING WILL WEAKEN AS THE UPPER LEVEL SYSTEM DEPARTS TO
THE EAST AND LEAVES THE SNOW BAND BEHIND TO DIMINISH. SNOWFALL
AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE OVER THE SOUTHERN 2 TIERS OF
COUNTIES WITH MINOR ACCUMULATIONS OF A FEW TENTHS POSSIBLE AS FAR
NORTH AS INTERSTATE 80. POTENTIAL FOR FREEZING DRIZZLE BY THIS
AFTERNOON IS LOW. MOISTURE DEPTHS WITH RELATIVE HUMIDITIES GREATER
THAN 75 PERCENT REMAIN RELATIVELY HIGH AND COLD FOR ICE TO REMAIN
INTRODUCED AND RESULTING IN LIGHT SNOW OR FLURRIES COMPARED TO
FZDZ.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

OUR WEATHER PATTERN IS SET TO BECOME MORE ACTIVE OVER THE COMING
DAYS. INITIALLY A SERIES OF 500 MB TROUGHS WILL CROSS THE
REGION...THE FIRST AROUND FRIDAY NIGHT AND ANOTHER AROUND
SATURDAY NIGHT/SUNDAY...GRADUALLY CARVING OUT BROAD CYCLONIC FLOW
ACROSS THE CENTRAL U.S. CONCURRENT WITH A LARGE 500 MB HIGH
PRESSURE DOME DEVELOPING OVER THE EASTERN PACIFIC. WITH THE FIRST
TROUGH PASSAGE OVER IOWA ON FRIDAY NIGHT THERE IS A POTENTIAL FOR
SOME STRATUS AND DRIZZLE...BUT FORECAST SOUNDINGS INDICATE THAT
LOW LEVEL MOISTURE AND LIFT WILL PROBABLY BE INSUFFICIENT TO
GENERATE PRECIPITATION. WITH THE SECOND TROUGH ON SATURDAY NIGHT
INTO SUNDAY THERE IS A BETTER SIGNAL FOR SOME LIGHT
PRECIPITATION...PROBABLY IN THE FORM OF DRIZZLE OR FREEZING
DRIZZLE. IT IS LIKELY THAT TEMPERATURES WILL FALL BELOW FREEZING
SATURDAY NIGHT...HOWEVER...DEWPOINTS AND TEMPERATURES MAY RECOVER
TO JUST ABOVE FREEZING BEFORE DRIZZLE DEVELOPS.
NEVERTHELESS...GIVEN THE POSSIBILITY OF FREEZING DRIZZLE AND ITS
ASSOCIATED IMPACTS HAVE ADDED A CHANCE INTO THE OUTGOING FORECAST
PACKAGE. WE WILL BE CLOSELY MONITORING THIS POSSIBILITY OVER THE
NEXT COUPLE OF DAYS.

AS MENTIONED EARLIER...BY THE LATTER PART OF THE WEEKEND A BROAD
500 MB TROUGH WILL HAVE BEEN CARVED OUT OVER THE CENTRAL U.S. A
COMPACT BUT ENERGETIC SHORTWAVE WILL THEN OVERTOP THE EASTERN
PACIFIC RIDGE AND ROCKET SOUTHEASTWARD OVER THE NORTHERN ROCKIES
ON SUNDAY...SUBSEQUENTLY DIGGING AND CLOSING OFF AS A LOW OVER
MINNESOTA AND IOWA BY MONDAY NIGHT. THIS LOW WILL THEN WOBBLE OVER
THE REGION...OR SLIGHTLY TO THE EAST OVER WISCONSIN AND LAKE
MICHIGAN...BEFORE FINALLY EJECTING EASTWARD AROUND CHRISTMAS EVE.
IN TERMS OF SENSIBLE WEATHER...THE INITIAL APPROACH OF THE LOW ON
WILL SPREAD A SWATH OF WARM ADVECTION REGIME PRECIPITATION ACROSS
IOWA ON SUNDAY NIGHT INTO MONDAY...THEN AS THE LOW MOVES NEARBY OR
OVERHEAD A LARGE STRATUS AND PRECIPITATION SHIELD WILL AFFECT MOST
OF THE REGION AND EVENTUALLY CHANGE OVER TO SNOW. THERE IS STILL
SOME UNCERTAINTY AS TO THE LOCATION OF THE LOW PRESSURE CENTER AND
ATTENDANT TEMPERATURE FIELDS...BUT IT SEEMS LIKELY THAT INITIALLY
THE PRECIPITATION WILL BE MOSTLY IN THE FORM OF RAIN WITH A WINTRY
MIX ACROSS NORTHERN IOWA...THEN BECOME LIGHTER BY THE TIME A
CHANGE TO SNOW OCCURS LATER IN THE EVENT. THIS WILL LIMIT SNOW
ACCUMULATIONS ACROSS MOST OF IOWA...BUT IN THE NORTH THERE COULD
BE SOME DECENT AMOUNTS DEPENDING ON HOW THE TEMPERATURES SET UP.
CERTAINLY TOO EARLY FOR ANY HEADLINE DIAGNOSIS BUT CERTAINLY ALL
EYES WILL BE ON THIS LARGE STORM SYSTEM IN THE COMING DAYS.

&&

.AVIATION...18/12Z
ISSUED AT 555 AM CST THU DEC 18 2014

BAND OF SNOW MOVING INTO SOUTHERN IOWA WILL DROP VISIBILITIES TO
MVFR AT TIMES AT KOTM/KDSM THIS MORNING BEFORE DIMINISHING. CIGS
WILL DROP TO MVFR AS WELL IN THAT AREA. PRIMARILY VFR CONDITIONS
AT OTHER SITES THROUGH MUCH OF THE DAY. CIGS ARE EXPECTED TO LOWER
LATE TODAY AND THROUGH TONIGHT WITH WIDESPREAD MVFR OVERNIGHT.
LIGHT WINDS ARE EXPECTED THROUGH THE PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...DONAVON




000
FXUS63 KDVN 181152
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
552 AM CST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 321 AM CST THU DEC 18 2014

SNOW FAIRLY WIDESPREAD FROM WESTERN MO INTO NE AND KS AHEAD OF AN
UPPER LEVEL SHORTWAVE OVER THE PLAINS. REPORTS OF ACCUMS FROM
1-3 INCHES FROM NORTHERN KS THROUGH THE KC METRO WITH OBS SUGGESTING
THE LEADING EDGE OF SNOW BETWEEN CHILLICOTHE MO AND KC METRO
MOVING N/E. TRENDS SUPPORT SYSTEM AND ATTENDANT SNOW TO GRADUALLY
WEAKEN TODAY AS IT ENCOUNTERS RIDGING OVER THE REGION... BUT
BEFORE DOING SO IS EXPECTED BRING SOME LIGHT ACCUMS TO SOUTHERN
PORTIONS OF CWA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU DEC 18 2014

SHORTWAVE WILL MOVE ACROSS REGION TODAY AND DEAMPLIFY/WEAKEN WHILE
RUNNING INTO THE RIDGE. THIS ALONG WITH COPIOUS DRY AIR PER 00Z
DVN AND ILX RAOBS SHOULD RESULT IN STEADY WEAKENING OF SNOW AS IT
SPREADS INTO FAR SOUTHERN CWA THIS AM. FORCING PEAKS OVER NORTHERN
MO 10Z-15Z THEN QUICKLY DIMINISHING THROUGH 18Z. OVERALL GOING
WITH 0.05 TO 0.1 INCH OF LIQUID QPF WITH SLR OF 12-14:1 TO YIELD
AROUND AN INCH OR SO OF ACCUM VERY FAR SOUTHERN CWA MAINLY NORTHEAST
MO INTO PORTIONS OF WEST CENTRAL IL TAPERING OFF TO TRACE HWY 34.
GIVEN DRY AIR AND ALIGNMENT OF FORCING COULD ENVISION SCENARIO
WHEREBY THIS OCCURS OVER MUCH SHORTER DISTANCE OF 25+ MILES NORTHEAST
MO. CANT RULE OUT POSSIBILITY OF SOME FREEZING DRIZZLE FAR SOUTH
FOR A WHILE THIS AFTERNOON IF CLOUD BEARING LAYER BECOMES SUFFICIENTLY
SHALLOW/WARM.. BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE MENTION
ATTIM. ASIDE FROM THE LIGHT SNOW FAR SOUTHERN CWA... EXPECT PTSUNNY
TO CLOUDY SKIES TODAY WITH TEMPS SIMILAR TO THOSE OF YSTDY IN
RELATIVELY NEUTRAL THERMAL ENVIRONMENT... WITH READINGS MAINLY IN
UPPER 20S TO LOWER 30S. WINDS NEGLIGIBLE AND GENERALLY 5 MPH OR LESS
WITH SURFACE RIDGING.

TONIGHT... GENERALLY PT-MOCDLY SKIES WITH SFC RIDGING BECOMING
RE-ESTABLISHED AS THE DOMINANT FEATURE. BANKING ON SUFFICIENT
CLOUDINESS TO PRECLUDE TEMPS FROM BOTTOMING OUT DESPITE NEAR
CALM/CALM WINDS... AND EXPECT GENERALLY UPPER TEENS TO MID 20S FOR
LOWS. SHOULD SOME AREAS SEE MORE IN WAY OF CLEARING THEN POTENTIAL
TO BE IN MID TEENS FOR LOWS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU DEC 18 2014

FORECAST FOCUS ON ACTIVE WEATHER PATTERN ESPECIALLY CHRISTMAS WEEK.

FRIDAY THROUGH SUNDAY...ZONAL FLOW OVER THE REGION WITH A SERIES OF
SHORT WAVES MOVING ACROSS. THIS LOOKS TO BE ANOTHER RATHER CLOUDY
PERIOD WITH FORECAST SOUNDINGS INDICATING WEAK LOW LEVEL WARM
ADVECTION AND A STRONG INVERSION SETTING UP AROUND 850 MB...WITH MOISTURE
TRAPPED BELOW. SATURDAY NIGHT I HAVE INTRODUCED A SLIGHT CHANCE OF
FREEZING DRIZZLE IN OUR FAR NW CWA...AS A SHORT WAVE/VORT MAX
TRAVERSES NORTHERN IA. FORECAST SOUNDINGS INDICATE A WARM LAYER JUST
ABOVE FREEZING WITH DRY AIR IN THE MID LEVELS WITH MOISTURE BELOW.
MAXIMUM TEMPERATURES DURING THIS PERIOD WILL BE IN THE 30S TO NEAR
40 WITH LOWS IN THE 20S TO NEAR 30.

MONDAY THROUGH WEDNESDAY...THIS IS WHEN THE WEATHER GETS ACTIVE BUT
ALSO COMPLICATED AND CHALLENGING. UPPER LOW DEEPENS AS IT TRACKS
FROM THE NORTHERN PLAINS (MONDAY) INTO EASTERN IA (TUESDAY) AND THEN
LIFTING INTO THE WESTERN GREAT LAKES (WEDNESDAY). THE PATH OF THIS
SYSTEM WOULD SUGGEST MAINLY A RAIN/SNOW MIX BUT WILL NEED TO KEEP AN
EYE ON TUESDAY WHERE IT MAY CHANGE TO ALL SNOW...GIVEN THE COLD
POCKET ALOFT AND DYNAMIC COOLING. WAY TOO EARLY TO OFFER ANY
ACCUMULATION AMOUNTS IF ANY. MAXIMUM TEMPERATURES ON MONDAY SHOULD
PUSH INTO THE 40S FROM ABOUT I-80 SOUTHWARD...AND IN THE 30S TUESDAY
AND WEDNESDAY. THE ECMWF HAS NOW THROWN A CURVE BALL IN REGARD TO
THE WHOPPER STORM EARLIER INDICATED TO BE IN THE GREAT LAKES REGION
CHRISTMAS EVE. IT NOW IS NOT QUITE THE BOMB SHOWN THE PAST COUPLE
RUNS AND IS ALSO INTENSIFYING THE CYCLONE FARTHER EAST...IN NEW
ENGLAND! THIS IS WHAT THE GFS HAS BEEN INDICATING ALL ALONG. SUFFICE
TO SAY CONFIDENCE IS LOW AS PHASING ISSUES CONTINUE TO HAUNT THE
MODELS. SO MORE CHANGES IN THE MODELS CAN BE EXPECTED OVER THE NEXT
SEVERAL DAYS AND THE IMPACTS IF ANY ON OUR AREA REMAIN TO BE SEEN.

CHRISTMAS DAY AND FRIDAY...MANY UNCERTAINTIES REGARDING THE
POTENTIAL WINTER STORM OFFERED BY THE ECMWF ON FRIDAY. DEPENDING ON
WHERE THE HUGE UPPER LOW TO OUR NORTHEAST IS LOCATED WILL PLAY A
ROLE IN THE STRONG ENERGY COMING OUT OF THE SOUTHWEST. CONFIDENCE IN
THE TRACK/TIMING/INTENSITY OF THIS SYSTEM IS LOW BUT CERTAINLY THERE
IS THE POTENTIAL FOR A WINTER STORM SOMEWHERE IN THE MIDWEST...SO
ANYONE TRAVELING AROUND CHRISTMAS DAY OR THEREAFTER SHOULD CONTINUE
TO MONITOR LATER FORECASTS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 536 AM CST THU DEC 18 2014

WEAKENING STORM SYSTEM WILL SPREAD LIGHT SNOW ACROSS NORTHEAST MO...
FAR SOUTHEAST IA AND PORTIONS OF WEST CENTRAL IL THROUGH MIDDAY
BEFORE DIMINISHING. LIGHT SNOW COULD BRUSH THE BRL TERMINAL 15Z-18Z
BUT LOW CONFIDENCE DUE TO DRY AIR AND WEAKENING SYSTEM THUS ONLY
HAVE MENTION OF FLURRIES WITH VSBYS AOA 6SM. OTHERWISE... EXPECT
VFR CONDITIONS WITH MID/HIGH CLOUDINESS AND LIGHT WINDS. THE
POTENTIAL EXISTS FOR PATCHY FOG WITH MVFR TO LOCALIZED IFR VSBYS
LATE TONIGHT... BUT WITH MID/HIGH CLOUDINESS NOT CONFIDENT ENOUGH
ON DEVELOPMENT/IMPACT AT TERMINALS FOR MENTION AT THIS TIME.

&&

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

$$

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







000
FXUS63 KDVN 181152
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
552 AM CST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 321 AM CST THU DEC 18 2014

SNOW FAIRLY WIDESPREAD FROM WESTERN MO INTO NE AND KS AHEAD OF AN
UPPER LEVEL SHORTWAVE OVER THE PLAINS. REPORTS OF ACCUMS FROM
1-3 INCHES FROM NORTHERN KS THROUGH THE KC METRO WITH OBS SUGGESTING
THE LEADING EDGE OF SNOW BETWEEN CHILLICOTHE MO AND KC METRO
MOVING N/E. TRENDS SUPPORT SYSTEM AND ATTENDANT SNOW TO GRADUALLY
WEAKEN TODAY AS IT ENCOUNTERS RIDGING OVER THE REGION... BUT
BEFORE DOING SO IS EXPECTED BRING SOME LIGHT ACCUMS TO SOUTHERN
PORTIONS OF CWA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU DEC 18 2014

SHORTWAVE WILL MOVE ACROSS REGION TODAY AND DEAMPLIFY/WEAKEN WHILE
RUNNING INTO THE RIDGE. THIS ALONG WITH COPIOUS DRY AIR PER 00Z
DVN AND ILX RAOBS SHOULD RESULT IN STEADY WEAKENING OF SNOW AS IT
SPREADS INTO FAR SOUTHERN CWA THIS AM. FORCING PEAKS OVER NORTHERN
MO 10Z-15Z THEN QUICKLY DIMINISHING THROUGH 18Z. OVERALL GOING
WITH 0.05 TO 0.1 INCH OF LIQUID QPF WITH SLR OF 12-14:1 TO YIELD
AROUND AN INCH OR SO OF ACCUM VERY FAR SOUTHERN CWA MAINLY NORTHEAST
MO INTO PORTIONS OF WEST CENTRAL IL TAPERING OFF TO TRACE HWY 34.
GIVEN DRY AIR AND ALIGNMENT OF FORCING COULD ENVISION SCENARIO
WHEREBY THIS OCCURS OVER MUCH SHORTER DISTANCE OF 25+ MILES NORTHEAST
MO. CANT RULE OUT POSSIBILITY OF SOME FREEZING DRIZZLE FAR SOUTH
FOR A WHILE THIS AFTERNOON IF CLOUD BEARING LAYER BECOMES SUFFICIENTLY
SHALLOW/WARM.. BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE MENTION
ATTIM. ASIDE FROM THE LIGHT SNOW FAR SOUTHERN CWA... EXPECT PTSUNNY
TO CLOUDY SKIES TODAY WITH TEMPS SIMILAR TO THOSE OF YSTDY IN
RELATIVELY NEUTRAL THERMAL ENVIRONMENT... WITH READINGS MAINLY IN
UPPER 20S TO LOWER 30S. WINDS NEGLIGIBLE AND GENERALLY 5 MPH OR LESS
WITH SURFACE RIDGING.

TONIGHT... GENERALLY PT-MOCDLY SKIES WITH SFC RIDGING BECOMING
RE-ESTABLISHED AS THE DOMINANT FEATURE. BANKING ON SUFFICIENT
CLOUDINESS TO PRECLUDE TEMPS FROM BOTTOMING OUT DESPITE NEAR
CALM/CALM WINDS... AND EXPECT GENERALLY UPPER TEENS TO MID 20S FOR
LOWS. SHOULD SOME AREAS SEE MORE IN WAY OF CLEARING THEN POTENTIAL
TO BE IN MID TEENS FOR LOWS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU DEC 18 2014

FORECAST FOCUS ON ACTIVE WEATHER PATTERN ESPECIALLY CHRISTMAS WEEK.

FRIDAY THROUGH SUNDAY...ZONAL FLOW OVER THE REGION WITH A SERIES OF
SHORT WAVES MOVING ACROSS. THIS LOOKS TO BE ANOTHER RATHER CLOUDY
PERIOD WITH FORECAST SOUNDINGS INDICATING WEAK LOW LEVEL WARM
ADVECTION AND A STRONG INVERSION SETTING UP AROUND 850 MB...WITH MOISTURE
TRAPPED BELOW. SATURDAY NIGHT I HAVE INTRODUCED A SLIGHT CHANCE OF
FREEZING DRIZZLE IN OUR FAR NW CWA...AS A SHORT WAVE/VORT MAX
TRAVERSES NORTHERN IA. FORECAST SOUNDINGS INDICATE A WARM LAYER JUST
ABOVE FREEZING WITH DRY AIR IN THE MID LEVELS WITH MOISTURE BELOW.
MAXIMUM TEMPERATURES DURING THIS PERIOD WILL BE IN THE 30S TO NEAR
40 WITH LOWS IN THE 20S TO NEAR 30.

MONDAY THROUGH WEDNESDAY...THIS IS WHEN THE WEATHER GETS ACTIVE BUT
ALSO COMPLICATED AND CHALLENGING. UPPER LOW DEEPENS AS IT TRACKS
FROM THE NORTHERN PLAINS (MONDAY) INTO EASTERN IA (TUESDAY) AND THEN
LIFTING INTO THE WESTERN GREAT LAKES (WEDNESDAY). THE PATH OF THIS
SYSTEM WOULD SUGGEST MAINLY A RAIN/SNOW MIX BUT WILL NEED TO KEEP AN
EYE ON TUESDAY WHERE IT MAY CHANGE TO ALL SNOW...GIVEN THE COLD
POCKET ALOFT AND DYNAMIC COOLING. WAY TOO EARLY TO OFFER ANY
ACCUMULATION AMOUNTS IF ANY. MAXIMUM TEMPERATURES ON MONDAY SHOULD
PUSH INTO THE 40S FROM ABOUT I-80 SOUTHWARD...AND IN THE 30S TUESDAY
AND WEDNESDAY. THE ECMWF HAS NOW THROWN A CURVE BALL IN REGARD TO
THE WHOPPER STORM EARLIER INDICATED TO BE IN THE GREAT LAKES REGION
CHRISTMAS EVE. IT NOW IS NOT QUITE THE BOMB SHOWN THE PAST COUPLE
RUNS AND IS ALSO INTENSIFYING THE CYCLONE FARTHER EAST...IN NEW
ENGLAND! THIS IS WHAT THE GFS HAS BEEN INDICATING ALL ALONG. SUFFICE
TO SAY CONFIDENCE IS LOW AS PHASING ISSUES CONTINUE TO HAUNT THE
MODELS. SO MORE CHANGES IN THE MODELS CAN BE EXPECTED OVER THE NEXT
SEVERAL DAYS AND THE IMPACTS IF ANY ON OUR AREA REMAIN TO BE SEEN.

CHRISTMAS DAY AND FRIDAY...MANY UNCERTAINTIES REGARDING THE
POTENTIAL WINTER STORM OFFERED BY THE ECMWF ON FRIDAY. DEPENDING ON
WHERE THE HUGE UPPER LOW TO OUR NORTHEAST IS LOCATED WILL PLAY A
ROLE IN THE STRONG ENERGY COMING OUT OF THE SOUTHWEST. CONFIDENCE IN
THE TRACK/TIMING/INTENSITY OF THIS SYSTEM IS LOW BUT CERTAINLY THERE
IS THE POTENTIAL FOR A WINTER STORM SOMEWHERE IN THE MIDWEST...SO
ANYONE TRAVELING AROUND CHRISTMAS DAY OR THEREAFTER SHOULD CONTINUE
TO MONITOR LATER FORECASTS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 536 AM CST THU DEC 18 2014

WEAKENING STORM SYSTEM WILL SPREAD LIGHT SNOW ACROSS NORTHEAST MO...
FAR SOUTHEAST IA AND PORTIONS OF WEST CENTRAL IL THROUGH MIDDAY
BEFORE DIMINISHING. LIGHT SNOW COULD BRUSH THE BRL TERMINAL 15Z-18Z
BUT LOW CONFIDENCE DUE TO DRY AIR AND WEAKENING SYSTEM THUS ONLY
HAVE MENTION OF FLURRIES WITH VSBYS AOA 6SM. OTHERWISE... EXPECT
VFR CONDITIONS WITH MID/HIGH CLOUDINESS AND LIGHT WINDS. THE
POTENTIAL EXISTS FOR PATCHY FOG WITH MVFR TO LOCALIZED IFR VSBYS
LATE TONIGHT... BUT WITH MID/HIGH CLOUDINESS NOT CONFIDENT ENOUGH
ON DEVELOPMENT/IMPACT AT TERMINALS FOR MENTION AT THIS TIME.

&&

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

$$

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







000
FXUS63 KDVN 181152
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
552 AM CST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 321 AM CST THU DEC 18 2014

SNOW FAIRLY WIDESPREAD FROM WESTERN MO INTO NE AND KS AHEAD OF AN
UPPER LEVEL SHORTWAVE OVER THE PLAINS. REPORTS OF ACCUMS FROM
1-3 INCHES FROM NORTHERN KS THROUGH THE KC METRO WITH OBS SUGGESTING
THE LEADING EDGE OF SNOW BETWEEN CHILLICOTHE MO AND KC METRO
MOVING N/E. TRENDS SUPPORT SYSTEM AND ATTENDANT SNOW TO GRADUALLY
WEAKEN TODAY AS IT ENCOUNTERS RIDGING OVER THE REGION... BUT
BEFORE DOING SO IS EXPECTED BRING SOME LIGHT ACCUMS TO SOUTHERN
PORTIONS OF CWA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU DEC 18 2014

SHORTWAVE WILL MOVE ACROSS REGION TODAY AND DEAMPLIFY/WEAKEN WHILE
RUNNING INTO THE RIDGE. THIS ALONG WITH COPIOUS DRY AIR PER 00Z
DVN AND ILX RAOBS SHOULD RESULT IN STEADY WEAKENING OF SNOW AS IT
SPREADS INTO FAR SOUTHERN CWA THIS AM. FORCING PEAKS OVER NORTHERN
MO 10Z-15Z THEN QUICKLY DIMINISHING THROUGH 18Z. OVERALL GOING
WITH 0.05 TO 0.1 INCH OF LIQUID QPF WITH SLR OF 12-14:1 TO YIELD
AROUND AN INCH OR SO OF ACCUM VERY FAR SOUTHERN CWA MAINLY NORTHEAST
MO INTO PORTIONS OF WEST CENTRAL IL TAPERING OFF TO TRACE HWY 34.
GIVEN DRY AIR AND ALIGNMENT OF FORCING COULD ENVISION SCENARIO
WHEREBY THIS OCCURS OVER MUCH SHORTER DISTANCE OF 25+ MILES NORTHEAST
MO. CANT RULE OUT POSSIBILITY OF SOME FREEZING DRIZZLE FAR SOUTH
FOR A WHILE THIS AFTERNOON IF CLOUD BEARING LAYER BECOMES SUFFICIENTLY
SHALLOW/WARM.. BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE MENTION
ATTIM. ASIDE FROM THE LIGHT SNOW FAR SOUTHERN CWA... EXPECT PTSUNNY
TO CLOUDY SKIES TODAY WITH TEMPS SIMILAR TO THOSE OF YSTDY IN
RELATIVELY NEUTRAL THERMAL ENVIRONMENT... WITH READINGS MAINLY IN
UPPER 20S TO LOWER 30S. WINDS NEGLIGIBLE AND GENERALLY 5 MPH OR LESS
WITH SURFACE RIDGING.

TONIGHT... GENERALLY PT-MOCDLY SKIES WITH SFC RIDGING BECOMING
RE-ESTABLISHED AS THE DOMINANT FEATURE. BANKING ON SUFFICIENT
CLOUDINESS TO PRECLUDE TEMPS FROM BOTTOMING OUT DESPITE NEAR
CALM/CALM WINDS... AND EXPECT GENERALLY UPPER TEENS TO MID 20S FOR
LOWS. SHOULD SOME AREAS SEE MORE IN WAY OF CLEARING THEN POTENTIAL
TO BE IN MID TEENS FOR LOWS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU DEC 18 2014

FORECAST FOCUS ON ACTIVE WEATHER PATTERN ESPECIALLY CHRISTMAS WEEK.

FRIDAY THROUGH SUNDAY...ZONAL FLOW OVER THE REGION WITH A SERIES OF
SHORT WAVES MOVING ACROSS. THIS LOOKS TO BE ANOTHER RATHER CLOUDY
PERIOD WITH FORECAST SOUNDINGS INDICATING WEAK LOW LEVEL WARM
ADVECTION AND A STRONG INVERSION SETTING UP AROUND 850 MB...WITH MOISTURE
TRAPPED BELOW. SATURDAY NIGHT I HAVE INTRODUCED A SLIGHT CHANCE OF
FREEZING DRIZZLE IN OUR FAR NW CWA...AS A SHORT WAVE/VORT MAX
TRAVERSES NORTHERN IA. FORECAST SOUNDINGS INDICATE A WARM LAYER JUST
ABOVE FREEZING WITH DRY AIR IN THE MID LEVELS WITH MOISTURE BELOW.
MAXIMUM TEMPERATURES DURING THIS PERIOD WILL BE IN THE 30S TO NEAR
40 WITH LOWS IN THE 20S TO NEAR 30.

MONDAY THROUGH WEDNESDAY...THIS IS WHEN THE WEATHER GETS ACTIVE BUT
ALSO COMPLICATED AND CHALLENGING. UPPER LOW DEEPENS AS IT TRACKS
FROM THE NORTHERN PLAINS (MONDAY) INTO EASTERN IA (TUESDAY) AND THEN
LIFTING INTO THE WESTERN GREAT LAKES (WEDNESDAY). THE PATH OF THIS
SYSTEM WOULD SUGGEST MAINLY A RAIN/SNOW MIX BUT WILL NEED TO KEEP AN
EYE ON TUESDAY WHERE IT MAY CHANGE TO ALL SNOW...GIVEN THE COLD
POCKET ALOFT AND DYNAMIC COOLING. WAY TOO EARLY TO OFFER ANY
ACCUMULATION AMOUNTS IF ANY. MAXIMUM TEMPERATURES ON MONDAY SHOULD
PUSH INTO THE 40S FROM ABOUT I-80 SOUTHWARD...AND IN THE 30S TUESDAY
AND WEDNESDAY. THE ECMWF HAS NOW THROWN A CURVE BALL IN REGARD TO
THE WHOPPER STORM EARLIER INDICATED TO BE IN THE GREAT LAKES REGION
CHRISTMAS EVE. IT NOW IS NOT QUITE THE BOMB SHOWN THE PAST COUPLE
RUNS AND IS ALSO INTENSIFYING THE CYCLONE FARTHER EAST...IN NEW
ENGLAND! THIS IS WHAT THE GFS HAS BEEN INDICATING ALL ALONG. SUFFICE
TO SAY CONFIDENCE IS LOW AS PHASING ISSUES CONTINUE TO HAUNT THE
MODELS. SO MORE CHANGES IN THE MODELS CAN BE EXPECTED OVER THE NEXT
SEVERAL DAYS AND THE IMPACTS IF ANY ON OUR AREA REMAIN TO BE SEEN.

CHRISTMAS DAY AND FRIDAY...MANY UNCERTAINTIES REGARDING THE
POTENTIAL WINTER STORM OFFERED BY THE ECMWF ON FRIDAY. DEPENDING ON
WHERE THE HUGE UPPER LOW TO OUR NORTHEAST IS LOCATED WILL PLAY A
ROLE IN THE STRONG ENERGY COMING OUT OF THE SOUTHWEST. CONFIDENCE IN
THE TRACK/TIMING/INTENSITY OF THIS SYSTEM IS LOW BUT CERTAINLY THERE
IS THE POTENTIAL FOR A WINTER STORM SOMEWHERE IN THE MIDWEST...SO
ANYONE TRAVELING AROUND CHRISTMAS DAY OR THEREAFTER SHOULD CONTINUE
TO MONITOR LATER FORECASTS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 536 AM CST THU DEC 18 2014

WEAKENING STORM SYSTEM WILL SPREAD LIGHT SNOW ACROSS NORTHEAST MO...
FAR SOUTHEAST IA AND PORTIONS OF WEST CENTRAL IL THROUGH MIDDAY
BEFORE DIMINISHING. LIGHT SNOW COULD BRUSH THE BRL TERMINAL 15Z-18Z
BUT LOW CONFIDENCE DUE TO DRY AIR AND WEAKENING SYSTEM THUS ONLY
HAVE MENTION OF FLURRIES WITH VSBYS AOA 6SM. OTHERWISE... EXPECT
VFR CONDITIONS WITH MID/HIGH CLOUDINESS AND LIGHT WINDS. THE
POTENTIAL EXISTS FOR PATCHY FOG WITH MVFR TO LOCALIZED IFR VSBYS
LATE TONIGHT... BUT WITH MID/HIGH CLOUDINESS NOT CONFIDENT ENOUGH
ON DEVELOPMENT/IMPACT AT TERMINALS FOR MENTION AT THIS TIME.

&&

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

$$

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







000
FXUS63 KDVN 181152
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
552 AM CST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 321 AM CST THU DEC 18 2014

SNOW FAIRLY WIDESPREAD FROM WESTERN MO INTO NE AND KS AHEAD OF AN
UPPER LEVEL SHORTWAVE OVER THE PLAINS. REPORTS OF ACCUMS FROM
1-3 INCHES FROM NORTHERN KS THROUGH THE KC METRO WITH OBS SUGGESTING
THE LEADING EDGE OF SNOW BETWEEN CHILLICOTHE MO AND KC METRO
MOVING N/E. TRENDS SUPPORT SYSTEM AND ATTENDANT SNOW TO GRADUALLY
WEAKEN TODAY AS IT ENCOUNTERS RIDGING OVER THE REGION... BUT
BEFORE DOING SO IS EXPECTED BRING SOME LIGHT ACCUMS TO SOUTHERN
PORTIONS OF CWA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU DEC 18 2014

SHORTWAVE WILL MOVE ACROSS REGION TODAY AND DEAMPLIFY/WEAKEN WHILE
RUNNING INTO THE RIDGE. THIS ALONG WITH COPIOUS DRY AIR PER 00Z
DVN AND ILX RAOBS SHOULD RESULT IN STEADY WEAKENING OF SNOW AS IT
SPREADS INTO FAR SOUTHERN CWA THIS AM. FORCING PEAKS OVER NORTHERN
MO 10Z-15Z THEN QUICKLY DIMINISHING THROUGH 18Z. OVERALL GOING
WITH 0.05 TO 0.1 INCH OF LIQUID QPF WITH SLR OF 12-14:1 TO YIELD
AROUND AN INCH OR SO OF ACCUM VERY FAR SOUTHERN CWA MAINLY NORTHEAST
MO INTO PORTIONS OF WEST CENTRAL IL TAPERING OFF TO TRACE HWY 34.
GIVEN DRY AIR AND ALIGNMENT OF FORCING COULD ENVISION SCENARIO
WHEREBY THIS OCCURS OVER MUCH SHORTER DISTANCE OF 25+ MILES NORTHEAST
MO. CANT RULE OUT POSSIBILITY OF SOME FREEZING DRIZZLE FAR SOUTH
FOR A WHILE THIS AFTERNOON IF CLOUD BEARING LAYER BECOMES SUFFICIENTLY
SHALLOW/WARM.. BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE MENTION
ATTIM. ASIDE FROM THE LIGHT SNOW FAR SOUTHERN CWA... EXPECT PTSUNNY
TO CLOUDY SKIES TODAY WITH TEMPS SIMILAR TO THOSE OF YSTDY IN
RELATIVELY NEUTRAL THERMAL ENVIRONMENT... WITH READINGS MAINLY IN
UPPER 20S TO LOWER 30S. WINDS NEGLIGIBLE AND GENERALLY 5 MPH OR LESS
WITH SURFACE RIDGING.

TONIGHT... GENERALLY PT-MOCDLY SKIES WITH SFC RIDGING BECOMING
RE-ESTABLISHED AS THE DOMINANT FEATURE. BANKING ON SUFFICIENT
CLOUDINESS TO PRECLUDE TEMPS FROM BOTTOMING OUT DESPITE NEAR
CALM/CALM WINDS... AND EXPECT GENERALLY UPPER TEENS TO MID 20S FOR
LOWS. SHOULD SOME AREAS SEE MORE IN WAY OF CLEARING THEN POTENTIAL
TO BE IN MID TEENS FOR LOWS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU DEC 18 2014

FORECAST FOCUS ON ACTIVE WEATHER PATTERN ESPECIALLY CHRISTMAS WEEK.

FRIDAY THROUGH SUNDAY...ZONAL FLOW OVER THE REGION WITH A SERIES OF
SHORT WAVES MOVING ACROSS. THIS LOOKS TO BE ANOTHER RATHER CLOUDY
PERIOD WITH FORECAST SOUNDINGS INDICATING WEAK LOW LEVEL WARM
ADVECTION AND A STRONG INVERSION SETTING UP AROUND 850 MB...WITH MOISTURE
TRAPPED BELOW. SATURDAY NIGHT I HAVE INTRODUCED A SLIGHT CHANCE OF
FREEZING DRIZZLE IN OUR FAR NW CWA...AS A SHORT WAVE/VORT MAX
TRAVERSES NORTHERN IA. FORECAST SOUNDINGS INDICATE A WARM LAYER JUST
ABOVE FREEZING WITH DRY AIR IN THE MID LEVELS WITH MOISTURE BELOW.
MAXIMUM TEMPERATURES DURING THIS PERIOD WILL BE IN THE 30S TO NEAR
40 WITH LOWS IN THE 20S TO NEAR 30.

MONDAY THROUGH WEDNESDAY...THIS IS WHEN THE WEATHER GETS ACTIVE BUT
ALSO COMPLICATED AND CHALLENGING. UPPER LOW DEEPENS AS IT TRACKS
FROM THE NORTHERN PLAINS (MONDAY) INTO EASTERN IA (TUESDAY) AND THEN
LIFTING INTO THE WESTERN GREAT LAKES (WEDNESDAY). THE PATH OF THIS
SYSTEM WOULD SUGGEST MAINLY A RAIN/SNOW MIX BUT WILL NEED TO KEEP AN
EYE ON TUESDAY WHERE IT MAY CHANGE TO ALL SNOW...GIVEN THE COLD
POCKET ALOFT AND DYNAMIC COOLING. WAY TOO EARLY TO OFFER ANY
ACCUMULATION AMOUNTS IF ANY. MAXIMUM TEMPERATURES ON MONDAY SHOULD
PUSH INTO THE 40S FROM ABOUT I-80 SOUTHWARD...AND IN THE 30S TUESDAY
AND WEDNESDAY. THE ECMWF HAS NOW THROWN A CURVE BALL IN REGARD TO
THE WHOPPER STORM EARLIER INDICATED TO BE IN THE GREAT LAKES REGION
CHRISTMAS EVE. IT NOW IS NOT QUITE THE BOMB SHOWN THE PAST COUPLE
RUNS AND IS ALSO INTENSIFYING THE CYCLONE FARTHER EAST...IN NEW
ENGLAND! THIS IS WHAT THE GFS HAS BEEN INDICATING ALL ALONG. SUFFICE
TO SAY CONFIDENCE IS LOW AS PHASING ISSUES CONTINUE TO HAUNT THE
MODELS. SO MORE CHANGES IN THE MODELS CAN BE EXPECTED OVER THE NEXT
SEVERAL DAYS AND THE IMPACTS IF ANY ON OUR AREA REMAIN TO BE SEEN.

CHRISTMAS DAY AND FRIDAY...MANY UNCERTAINTIES REGARDING THE
POTENTIAL WINTER STORM OFFERED BY THE ECMWF ON FRIDAY. DEPENDING ON
WHERE THE HUGE UPPER LOW TO OUR NORTHEAST IS LOCATED WILL PLAY A
ROLE IN THE STRONG ENERGY COMING OUT OF THE SOUTHWEST. CONFIDENCE IN
THE TRACK/TIMING/INTENSITY OF THIS SYSTEM IS LOW BUT CERTAINLY THERE
IS THE POTENTIAL FOR A WINTER STORM SOMEWHERE IN THE MIDWEST...SO
ANYONE TRAVELING AROUND CHRISTMAS DAY OR THEREAFTER SHOULD CONTINUE
TO MONITOR LATER FORECASTS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 536 AM CST THU DEC 18 2014

WEAKENING STORM SYSTEM WILL SPREAD LIGHT SNOW ACROSS NORTHEAST MO...
FAR SOUTHEAST IA AND PORTIONS OF WEST CENTRAL IL THROUGH MIDDAY
BEFORE DIMINISHING. LIGHT SNOW COULD BRUSH THE BRL TERMINAL 15Z-18Z
BUT LOW CONFIDENCE DUE TO DRY AIR AND WEAKENING SYSTEM THUS ONLY
HAVE MENTION OF FLURRIES WITH VSBYS AOA 6SM. OTHERWISE... EXPECT
VFR CONDITIONS WITH MID/HIGH CLOUDINESS AND LIGHT WINDS. THE
POTENTIAL EXISTS FOR PATCHY FOG WITH MVFR TO LOCALIZED IFR VSBYS
LATE TONIGHT... BUT WITH MID/HIGH CLOUDINESS NOT CONFIDENT ENOUGH
ON DEVELOPMENT/IMPACT AT TERMINALS FOR MENTION AT THIS TIME.

&&

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

$$

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







000
FXUS63 KDVN 181152
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
552 AM CST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 321 AM CST THU DEC 18 2014

SNOW FAIRLY WIDESPREAD FROM WESTERN MO INTO NE AND KS AHEAD OF AN
UPPER LEVEL SHORTWAVE OVER THE PLAINS. REPORTS OF ACCUMS FROM
1-3 INCHES FROM NORTHERN KS THROUGH THE KC METRO WITH OBS SUGGESTING
THE LEADING EDGE OF SNOW BETWEEN CHILLICOTHE MO AND KC METRO
MOVING N/E. TRENDS SUPPORT SYSTEM AND ATTENDANT SNOW TO GRADUALLY
WEAKEN TODAY AS IT ENCOUNTERS RIDGING OVER THE REGION... BUT
BEFORE DOING SO IS EXPECTED BRING SOME LIGHT ACCUMS TO SOUTHERN
PORTIONS OF CWA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU DEC 18 2014

SHORTWAVE WILL MOVE ACROSS REGION TODAY AND DEAMPLIFY/WEAKEN WHILE
RUNNING INTO THE RIDGE. THIS ALONG WITH COPIOUS DRY AIR PER 00Z
DVN AND ILX RAOBS SHOULD RESULT IN STEADY WEAKENING OF SNOW AS IT
SPREADS INTO FAR SOUTHERN CWA THIS AM. FORCING PEAKS OVER NORTHERN
MO 10Z-15Z THEN QUICKLY DIMINISHING THROUGH 18Z. OVERALL GOING
WITH 0.05 TO 0.1 INCH OF LIQUID QPF WITH SLR OF 12-14:1 TO YIELD
AROUND AN INCH OR SO OF ACCUM VERY FAR SOUTHERN CWA MAINLY NORTHEAST
MO INTO PORTIONS OF WEST CENTRAL IL TAPERING OFF TO TRACE HWY 34.
GIVEN DRY AIR AND ALIGNMENT OF FORCING COULD ENVISION SCENARIO
WHEREBY THIS OCCURS OVER MUCH SHORTER DISTANCE OF 25+ MILES NORTHEAST
MO. CANT RULE OUT POSSIBILITY OF SOME FREEZING DRIZZLE FAR SOUTH
FOR A WHILE THIS AFTERNOON IF CLOUD BEARING LAYER BECOMES SUFFICIENTLY
SHALLOW/WARM.. BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE MENTION
ATTIM. ASIDE FROM THE LIGHT SNOW FAR SOUTHERN CWA... EXPECT PTSUNNY
TO CLOUDY SKIES TODAY WITH TEMPS SIMILAR TO THOSE OF YSTDY IN
RELATIVELY NEUTRAL THERMAL ENVIRONMENT... WITH READINGS MAINLY IN
UPPER 20S TO LOWER 30S. WINDS NEGLIGIBLE AND GENERALLY 5 MPH OR LESS
WITH SURFACE RIDGING.

TONIGHT... GENERALLY PT-MOCDLY SKIES WITH SFC RIDGING BECOMING
RE-ESTABLISHED AS THE DOMINANT FEATURE. BANKING ON SUFFICIENT
CLOUDINESS TO PRECLUDE TEMPS FROM BOTTOMING OUT DESPITE NEAR
CALM/CALM WINDS... AND EXPECT GENERALLY UPPER TEENS TO MID 20S FOR
LOWS. SHOULD SOME AREAS SEE MORE IN WAY OF CLEARING THEN POTENTIAL
TO BE IN MID TEENS FOR LOWS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU DEC 18 2014

FORECAST FOCUS ON ACTIVE WEATHER PATTERN ESPECIALLY CHRISTMAS WEEK.

FRIDAY THROUGH SUNDAY...ZONAL FLOW OVER THE REGION WITH A SERIES OF
SHORT WAVES MOVING ACROSS. THIS LOOKS TO BE ANOTHER RATHER CLOUDY
PERIOD WITH FORECAST SOUNDINGS INDICATING WEAK LOW LEVEL WARM
ADVECTION AND A STRONG INVERSION SETTING UP AROUND 850 MB...WITH MOISTURE
TRAPPED BELOW. SATURDAY NIGHT I HAVE INTRODUCED A SLIGHT CHANCE OF
FREEZING DRIZZLE IN OUR FAR NW CWA...AS A SHORT WAVE/VORT MAX
TRAVERSES NORTHERN IA. FORECAST SOUNDINGS INDICATE A WARM LAYER JUST
ABOVE FREEZING WITH DRY AIR IN THE MID LEVELS WITH MOISTURE BELOW.
MAXIMUM TEMPERATURES DURING THIS PERIOD WILL BE IN THE 30S TO NEAR
40 WITH LOWS IN THE 20S TO NEAR 30.

MONDAY THROUGH WEDNESDAY...THIS IS WHEN THE WEATHER GETS ACTIVE BUT
ALSO COMPLICATED AND CHALLENGING. UPPER LOW DEEPENS AS IT TRACKS
FROM THE NORTHERN PLAINS (MONDAY) INTO EASTERN IA (TUESDAY) AND THEN
LIFTING INTO THE WESTERN GREAT LAKES (WEDNESDAY). THE PATH OF THIS
SYSTEM WOULD SUGGEST MAINLY A RAIN/SNOW MIX BUT WILL NEED TO KEEP AN
EYE ON TUESDAY WHERE IT MAY CHANGE TO ALL SNOW...GIVEN THE COLD
POCKET ALOFT AND DYNAMIC COOLING. WAY TOO EARLY TO OFFER ANY
ACCUMULATION AMOUNTS IF ANY. MAXIMUM TEMPERATURES ON MONDAY SHOULD
PUSH INTO THE 40S FROM ABOUT I-80 SOUTHWARD...AND IN THE 30S TUESDAY
AND WEDNESDAY. THE ECMWF HAS NOW THROWN A CURVE BALL IN REGARD TO
THE WHOPPER STORM EARLIER INDICATED TO BE IN THE GREAT LAKES REGION
CHRISTMAS EVE. IT NOW IS NOT QUITE THE BOMB SHOWN THE PAST COUPLE
RUNS AND IS ALSO INTENSIFYING THE CYCLONE FARTHER EAST...IN NEW
ENGLAND! THIS IS WHAT THE GFS HAS BEEN INDICATING ALL ALONG. SUFFICE
TO SAY CONFIDENCE IS LOW AS PHASING ISSUES CONTINUE TO HAUNT THE
MODELS. SO MORE CHANGES IN THE MODELS CAN BE EXPECTED OVER THE NEXT
SEVERAL DAYS AND THE IMPACTS IF ANY ON OUR AREA REMAIN TO BE SEEN.

CHRISTMAS DAY AND FRIDAY...MANY UNCERTAINTIES REGARDING THE
POTENTIAL WINTER STORM OFFERED BY THE ECMWF ON FRIDAY. DEPENDING ON
WHERE THE HUGE UPPER LOW TO OUR NORTHEAST IS LOCATED WILL PLAY A
ROLE IN THE STRONG ENERGY COMING OUT OF THE SOUTHWEST. CONFIDENCE IN
THE TRACK/TIMING/INTENSITY OF THIS SYSTEM IS LOW BUT CERTAINLY THERE
IS THE POTENTIAL FOR A WINTER STORM SOMEWHERE IN THE MIDWEST...SO
ANYONE TRAVELING AROUND CHRISTMAS DAY OR THEREAFTER SHOULD CONTINUE
TO MONITOR LATER FORECASTS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 536 AM CST THU DEC 18 2014

WEAKENING STORM SYSTEM WILL SPREAD LIGHT SNOW ACROSS NORTHEAST MO...
FAR SOUTHEAST IA AND PORTIONS OF WEST CENTRAL IL THROUGH MIDDAY
BEFORE DIMINISHING. LIGHT SNOW COULD BRUSH THE BRL TERMINAL 15Z-18Z
BUT LOW CONFIDENCE DUE TO DRY AIR AND WEAKENING SYSTEM THUS ONLY
HAVE MENTION OF FLURRIES WITH VSBYS AOA 6SM. OTHERWISE... EXPECT
VFR CONDITIONS WITH MID/HIGH CLOUDINESS AND LIGHT WINDS. THE
POTENTIAL EXISTS FOR PATCHY FOG WITH MVFR TO LOCALIZED IFR VSBYS
LATE TONIGHT... BUT WITH MID/HIGH CLOUDINESS NOT CONFIDENT ENOUGH
ON DEVELOPMENT/IMPACT AT TERMINALS FOR MENTION AT THIS TIME.

&&

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

$$

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






000
FXUS63 KDMX 180936
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
336 AM CST THU DEC 18 2014

.SHORT TERM /TODAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

AN UPPER LEVEL SHORT WAVE IS MOVING ACROSS MISSOURI THIS MORNING
WITH THE NORTHERN FRINGE OF KINEMATIC FORCING REACHING INTO SOUTHERN
IOWA. A BRANCH OF THE WARM CONVEYOR BELT IS WRAPPING AROUND THE
NORTH SIDE WITH MOISTURE OVERRUNNING THE SURFACE COLDER AIR. THE
COMBINATION OF MOISTURE AND FORCING HAS RESULTED IN A BAND OF SNOW
LIFTING NORTHEAST THROUGH NORTHEAST KANSAS AND NORTHERN MISSOURI.
THIS BAND OF SNOW WILL MOVE INTO SOUTHERN IOWA EARLY THIS MORNING
HOWEVER ITS NORTHEAST EXTENT WILL BE LIMITED BY DRY AIR ASSOCIATED
WITH A RIDGE OF HIGH PRESSURE SITUATED OVER NORTHEAST IOWA. IN
ADDITION...FORCING WILL WEAKEN AS THE UPPER LEVEL SYSTEM DEPARTS TO
THE EAST AND LEAVES THE SNOW BAND BEHIND TO DIMINISH. SNOWFALL
AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE OVER THE SOUTHERN 2 TIERS OF
COUNTIES WITH MINOR ACCUMULATIONS OF A FEW TENTHS POSSIBLE AS FAR
NORTH AS INTERSTATE 80. POTENTIAL FOR FREEZING DRIZZLE BY THIS
AFTERNOON IS LOW. MOISTURE DEPTHS WITH RELATIVE HUMIDITIES GREATER
THAN 75 PERCENT REMAIN RELATIVELY HIGH AND COLD FOR ICE TO REMAIN
INTRODUCED AND RESULTING IN LIGHT SNOW OR FLURRIES COMPARED TO
FZDZ.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

OUR WEATHER PATTERN IS SET TO BECOME MORE ACTIVE OVER THE COMING
DAYS. INITIALLY A SERIES OF 500 MB TROUGHS WILL CROSS THE
REGION...THE FIRST AROUND FRIDAY NIGHT AND ANOTHER AROUND
SATURDAY NIGHT/SUNDAY...GRADUALLY CARVING OUT BROAD CYCLONIC FLOW
ACROSS THE CENTRAL U.S. CONCURRENT WITH A LARGE 500 MB HIGH
PRESSURE DOME DEVELOPING OVER THE EASTERN PACIFIC. WITH THE FIRST
TROUGH PASSAGE OVER IOWA ON FRIDAY NIGHT THERE IS A POTENTIAL FOR
SOME STRATUS AND DRIZZLE...BUT FORECAST SOUNDINGS INDICATE THAT
LOW LEVEL MOISTURE AND LIFT WILL PROBABLY BE INSUFFICIENT TO
GENERATE PRECIPITATION. WITH THE SECOND TROUGH ON SATURDAY NIGHT
INTO SUNDAY THERE IS A BETTER SIGNAL FOR SOME LIGHT
PRECIPITATION...PROBABLY IN THE FORM OF DRIZZLE OR FREEZING
DRIZZLE. IT IS LIKELY THAT TEMPERATURES WILL FALL BELOW FREEZING
SATURDAY NIGHT...HOWEVER...DEWPOINTS AND TEMPERATURES MAY RECOVER
TO JUST ABOVE FREEZING BEFORE DRIZZLE DEVELOPS.
NEVERTHELESS...GIVEN THE POSSIBILITY OF FREEZING DRIZZLE AND ITS
ASSOCIATED IMPACTS HAVE ADDED A CHANCE INTO THE OUTGOING FORECAST
PACKAGE. WE WILL BE CLOSELY MONITORING THIS POSSIBILITY OVER THE
NEXT COUPLE OF DAYS.

AS MENTIONED EARLIER...BY THE LATTER PART OF THE WEEKEND A BROAD
500 MB TROUGH WILL HAVE BEEN CARVED OUT OVER THE CENTRAL U.S. A
COMPACT BUT ENERGETIC SHORTWAVE WILL THEN OVERTOP THE EASTERN
PACIFIC RIDGE AND ROCKET SOUTHEASTWARD OVER THE NORTHERN ROCKIES
ON SUNDAY...SUBSEQUENTLY DIGGING AND CLOSING OFF AS A LOW OVER
MINNESOTA AND IOWA BY MONDAY NIGHT. THIS LOW WILL THEN WOBBLE OVER
THE REGION...OR SLIGHTLY TO THE EAST OVER WISCONSIN AND LAKE
MICHIGAN...BEFORE FINALLY EJECTING EASTWARD AROUND CHRISTMAS EVE.
IN TERMS OF SENSIBLE WEATHER...THE INITIAL APPROACH OF THE LOW ON
WILL SPREAD A SWATH OF WARM ADVECTION REGIME PRECIPITATION ACROSS
IOWA ON SUNDAY NIGHT INTO MONDAY...THEN AS THE LOW MOVES NEARBY OR
OVERHEAD A LARGE STRATUS AND PRECIPITATION SHIELD WILL AFFECT MOST
OF THE REGION AND EVENTUALLY CHANGE OVER TO SNOW. THERE IS STILL
SOME UNCERTAINTY AS TO THE LOCATION OF THE LOW PRESSURE CENTER AND
ATTENDANT TEMPERATURE FIELDS...BUT IT SEEMS LIKELY THAT INITIALLY
THE PRECIPITATION WILL BE MOSTLY IN THE FORM OF RAIN WITH A WINTRY
MIX ACROSS NORTHERN IOWA...THEN BECOME LIGHTER BY THE TIME A
CHANGE TO SNOW OCCURS LATER IN THE EVENT. THIS WILL LIMIT SNOW
ACCUMULATIONS ACROSS MOST OF IOWA...BUT IN THE NORTH THERE COULD
BE SOME DECENT AMOUNTS DEPENDING ON HOW THE TEMPERATURES SET UP.
CERTAINLY TOO EARLY FOR ANY HEADLINE DIAGNOSIS BUT CERTAINLY ALL
EYES WILL BE ON THIS LARGE STORM SYSTEM IN THE COMING DAYS.

&&

.AVIATION...18/06Z
ISSUED AT 1140 PM CST WED DEC 17 2014

SYSTEM ACROSS PLAINS WILL CONTINUE TO LIFT NORTHEAST THROUGH
THURSDAY. CLOUDS WILL MOVE INTO IOWA WITH PRIMARILY MID AND HIGH
CLOUDINESS OVERNIGHT AND VFR CONDITIONS. AS DEEPER SATURATION
APPROACHES FROM THE SOUTH TOWARD DAYBREAK...MVFR TO IFR CONDITIONS
NEAR THE MISSOURI BORDER ARE EXPECTED ALTHOUGH DRIER LOW LEVEL AIR
WILL KEEP LOCATIONS FARTHER NORTH VFR. THERE WILL BE SOME LOW
LEVEL CLOUDS NEAR KMCW OVERNIGHT NEAR RIDGE AXIS AND THIS MAY
LINGER INTO THURSDAY MORNING AS FLOW REMAINS QUITE LIGHT. WITH
PASSAGE OF SYSTEM ON THURSDAY...THREAT OF PRECIPITATION IN THE
SOUTH WILL END AFTER MIDDAY. HOWEVER...LOW TO MID LEVEL MOISTURE
WILL REMAIN WITH WIDESPREAD STATUS EXPECTED TO PERSIST THROUGH THE
END OF THE FORECAST.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...COGIL



000
FXUS63 KDMX 180936
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
336 AM CST THU DEC 18 2014

.SHORT TERM /TODAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

AN UPPER LEVEL SHORT WAVE IS MOVING ACROSS MISSOURI THIS MORNING
WITH THE NORTHERN FRINGE OF KINEMATIC FORCING REACHING INTO SOUTHERN
IOWA. A BRANCH OF THE WARM CONVEYOR BELT IS WRAPPING AROUND THE
NORTH SIDE WITH MOISTURE OVERRUNNING THE SURFACE COLDER AIR. THE
COMBINATION OF MOISTURE AND FORCING HAS RESULTED IN A BAND OF SNOW
LIFTING NORTHEAST THROUGH NORTHEAST KANSAS AND NORTHERN MISSOURI.
THIS BAND OF SNOW WILL MOVE INTO SOUTHERN IOWA EARLY THIS MORNING
HOWEVER ITS NORTHEAST EXTENT WILL BE LIMITED BY DRY AIR ASSOCIATED
WITH A RIDGE OF HIGH PRESSURE SITUATED OVER NORTHEAST IOWA. IN
ADDITION...FORCING WILL WEAKEN AS THE UPPER LEVEL SYSTEM DEPARTS TO
THE EAST AND LEAVES THE SNOW BAND BEHIND TO DIMINISH. SNOWFALL
AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE OVER THE SOUTHERN 2 TIERS OF
COUNTIES WITH MINOR ACCUMULATIONS OF A FEW TENTHS POSSIBLE AS FAR
NORTH AS INTERSTATE 80. POTENTIAL FOR FREEZING DRIZZLE BY THIS
AFTERNOON IS LOW. MOISTURE DEPTHS WITH RELATIVE HUMIDITIES GREATER
THAN 75 PERCENT REMAIN RELATIVELY HIGH AND COLD FOR ICE TO REMAIN
INTRODUCED AND RESULTING IN LIGHT SNOW OR FLURRIES COMPARED TO
FZDZ.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

OUR WEATHER PATTERN IS SET TO BECOME MORE ACTIVE OVER THE COMING
DAYS. INITIALLY A SERIES OF 500 MB TROUGHS WILL CROSS THE
REGION...THE FIRST AROUND FRIDAY NIGHT AND ANOTHER AROUND
SATURDAY NIGHT/SUNDAY...GRADUALLY CARVING OUT BROAD CYCLONIC FLOW
ACROSS THE CENTRAL U.S. CONCURRENT WITH A LARGE 500 MB HIGH
PRESSURE DOME DEVELOPING OVER THE EASTERN PACIFIC. WITH THE FIRST
TROUGH PASSAGE OVER IOWA ON FRIDAY NIGHT THERE IS A POTENTIAL FOR
SOME STRATUS AND DRIZZLE...BUT FORECAST SOUNDINGS INDICATE THAT
LOW LEVEL MOISTURE AND LIFT WILL PROBABLY BE INSUFFICIENT TO
GENERATE PRECIPITATION. WITH THE SECOND TROUGH ON SATURDAY NIGHT
INTO SUNDAY THERE IS A BETTER SIGNAL FOR SOME LIGHT
PRECIPITATION...PROBABLY IN THE FORM OF DRIZZLE OR FREEZING
DRIZZLE. IT IS LIKELY THAT TEMPERATURES WILL FALL BELOW FREEZING
SATURDAY NIGHT...HOWEVER...DEWPOINTS AND TEMPERATURES MAY RECOVER
TO JUST ABOVE FREEZING BEFORE DRIZZLE DEVELOPS.
NEVERTHELESS...GIVEN THE POSSIBILITY OF FREEZING DRIZZLE AND ITS
ASSOCIATED IMPACTS HAVE ADDED A CHANCE INTO THE OUTGOING FORECAST
PACKAGE. WE WILL BE CLOSELY MONITORING THIS POSSIBILITY OVER THE
NEXT COUPLE OF DAYS.

AS MENTIONED EARLIER...BY THE LATTER PART OF THE WEEKEND A BROAD
500 MB TROUGH WILL HAVE BEEN CARVED OUT OVER THE CENTRAL U.S. A
COMPACT BUT ENERGETIC SHORTWAVE WILL THEN OVERTOP THE EASTERN
PACIFIC RIDGE AND ROCKET SOUTHEASTWARD OVER THE NORTHERN ROCKIES
ON SUNDAY...SUBSEQUENTLY DIGGING AND CLOSING OFF AS A LOW OVER
MINNESOTA AND IOWA BY MONDAY NIGHT. THIS LOW WILL THEN WOBBLE OVER
THE REGION...OR SLIGHTLY TO THE EAST OVER WISCONSIN AND LAKE
MICHIGAN...BEFORE FINALLY EJECTING EASTWARD AROUND CHRISTMAS EVE.
IN TERMS OF SENSIBLE WEATHER...THE INITIAL APPROACH OF THE LOW ON
WILL SPREAD A SWATH OF WARM ADVECTION REGIME PRECIPITATION ACROSS
IOWA ON SUNDAY NIGHT INTO MONDAY...THEN AS THE LOW MOVES NEARBY OR
OVERHEAD A LARGE STRATUS AND PRECIPITATION SHIELD WILL AFFECT MOST
OF THE REGION AND EVENTUALLY CHANGE OVER TO SNOW. THERE IS STILL
SOME UNCERTAINTY AS TO THE LOCATION OF THE LOW PRESSURE CENTER AND
ATTENDANT TEMPERATURE FIELDS...BUT IT SEEMS LIKELY THAT INITIALLY
THE PRECIPITATION WILL BE MOSTLY IN THE FORM OF RAIN WITH A WINTRY
MIX ACROSS NORTHERN IOWA...THEN BECOME LIGHTER BY THE TIME A
CHANGE TO SNOW OCCURS LATER IN THE EVENT. THIS WILL LIMIT SNOW
ACCUMULATIONS ACROSS MOST OF IOWA...BUT IN THE NORTH THERE COULD
BE SOME DECENT AMOUNTS DEPENDING ON HOW THE TEMPERATURES SET UP.
CERTAINLY TOO EARLY FOR ANY HEADLINE DIAGNOSIS BUT CERTAINLY ALL
EYES WILL BE ON THIS LARGE STORM SYSTEM IN THE COMING DAYS.

&&

.AVIATION...18/06Z
ISSUED AT 1140 PM CST WED DEC 17 2014

SYSTEM ACROSS PLAINS WILL CONTINUE TO LIFT NORTHEAST THROUGH
THURSDAY. CLOUDS WILL MOVE INTO IOWA WITH PRIMARILY MID AND HIGH
CLOUDINESS OVERNIGHT AND VFR CONDITIONS. AS DEEPER SATURATION
APPROACHES FROM THE SOUTH TOWARD DAYBREAK...MVFR TO IFR CONDITIONS
NEAR THE MISSOURI BORDER ARE EXPECTED ALTHOUGH DRIER LOW LEVEL AIR
WILL KEEP LOCATIONS FARTHER NORTH VFR. THERE WILL BE SOME LOW
LEVEL CLOUDS NEAR KMCW OVERNIGHT NEAR RIDGE AXIS AND THIS MAY
LINGER INTO THURSDAY MORNING AS FLOW REMAINS QUITE LIGHT. WITH
PASSAGE OF SYSTEM ON THURSDAY...THREAT OF PRECIPITATION IN THE
SOUTH WILL END AFTER MIDDAY. HOWEVER...LOW TO MID LEVEL MOISTURE
WILL REMAIN WITH WIDESPREAD STATUS EXPECTED TO PERSIST THROUGH THE
END OF THE FORECAST.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...COGIL



000
FXUS63 KDMX 180936
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
336 AM CST THU DEC 18 2014

.SHORT TERM /TODAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

AN UPPER LEVEL SHORT WAVE IS MOVING ACROSS MISSOURI THIS MORNING
WITH THE NORTHERN FRINGE OF KINEMATIC FORCING REACHING INTO SOUTHERN
IOWA. A BRANCH OF THE WARM CONVEYOR BELT IS WRAPPING AROUND THE
NORTH SIDE WITH MOISTURE OVERRUNNING THE SURFACE COLDER AIR. THE
COMBINATION OF MOISTURE AND FORCING HAS RESULTED IN A BAND OF SNOW
LIFTING NORTHEAST THROUGH NORTHEAST KANSAS AND NORTHERN MISSOURI.
THIS BAND OF SNOW WILL MOVE INTO SOUTHERN IOWA EARLY THIS MORNING
HOWEVER ITS NORTHEAST EXTENT WILL BE LIMITED BY DRY AIR ASSOCIATED
WITH A RIDGE OF HIGH PRESSURE SITUATED OVER NORTHEAST IOWA. IN
ADDITION...FORCING WILL WEAKEN AS THE UPPER LEVEL SYSTEM DEPARTS TO
THE EAST AND LEAVES THE SNOW BAND BEHIND TO DIMINISH. SNOWFALL
AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE OVER THE SOUTHERN 2 TIERS OF
COUNTIES WITH MINOR ACCUMULATIONS OF A FEW TENTHS POSSIBLE AS FAR
NORTH AS INTERSTATE 80. POTENTIAL FOR FREEZING DRIZZLE BY THIS
AFTERNOON IS LOW. MOISTURE DEPTHS WITH RELATIVE HUMIDITIES GREATER
THAN 75 PERCENT REMAIN RELATIVELY HIGH AND COLD FOR ICE TO REMAIN
INTRODUCED AND RESULTING IN LIGHT SNOW OR FLURRIES COMPARED TO
FZDZ.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

OUR WEATHER PATTERN IS SET TO BECOME MORE ACTIVE OVER THE COMING
DAYS. INITIALLY A SERIES OF 500 MB TROUGHS WILL CROSS THE
REGION...THE FIRST AROUND FRIDAY NIGHT AND ANOTHER AROUND
SATURDAY NIGHT/SUNDAY...GRADUALLY CARVING OUT BROAD CYCLONIC FLOW
ACROSS THE CENTRAL U.S. CONCURRENT WITH A LARGE 500 MB HIGH
PRESSURE DOME DEVELOPING OVER THE EASTERN PACIFIC. WITH THE FIRST
TROUGH PASSAGE OVER IOWA ON FRIDAY NIGHT THERE IS A POTENTIAL FOR
SOME STRATUS AND DRIZZLE...BUT FORECAST SOUNDINGS INDICATE THAT
LOW LEVEL MOISTURE AND LIFT WILL PROBABLY BE INSUFFICIENT TO
GENERATE PRECIPITATION. WITH THE SECOND TROUGH ON SATURDAY NIGHT
INTO SUNDAY THERE IS A BETTER SIGNAL FOR SOME LIGHT
PRECIPITATION...PROBABLY IN THE FORM OF DRIZZLE OR FREEZING
DRIZZLE. IT IS LIKELY THAT TEMPERATURES WILL FALL BELOW FREEZING
SATURDAY NIGHT...HOWEVER...DEWPOINTS AND TEMPERATURES MAY RECOVER
TO JUST ABOVE FREEZING BEFORE DRIZZLE DEVELOPS.
NEVERTHELESS...GIVEN THE POSSIBILITY OF FREEZING DRIZZLE AND ITS
ASSOCIATED IMPACTS HAVE ADDED A CHANCE INTO THE OUTGOING FORECAST
PACKAGE. WE WILL BE CLOSELY MONITORING THIS POSSIBILITY OVER THE
NEXT COUPLE OF DAYS.

AS MENTIONED EARLIER...BY THE LATTER PART OF THE WEEKEND A BROAD
500 MB TROUGH WILL HAVE BEEN CARVED OUT OVER THE CENTRAL U.S. A
COMPACT BUT ENERGETIC SHORTWAVE WILL THEN OVERTOP THE EASTERN
PACIFIC RIDGE AND ROCKET SOUTHEASTWARD OVER THE NORTHERN ROCKIES
ON SUNDAY...SUBSEQUENTLY DIGGING AND CLOSING OFF AS A LOW OVER
MINNESOTA AND IOWA BY MONDAY NIGHT. THIS LOW WILL THEN WOBBLE OVER
THE REGION...OR SLIGHTLY TO THE EAST OVER WISCONSIN AND LAKE
MICHIGAN...BEFORE FINALLY EJECTING EASTWARD AROUND CHRISTMAS EVE.
IN TERMS OF SENSIBLE WEATHER...THE INITIAL APPROACH OF THE LOW ON
WILL SPREAD A SWATH OF WARM ADVECTION REGIME PRECIPITATION ACROSS
IOWA ON SUNDAY NIGHT INTO MONDAY...THEN AS THE LOW MOVES NEARBY OR
OVERHEAD A LARGE STRATUS AND PRECIPITATION SHIELD WILL AFFECT MOST
OF THE REGION AND EVENTUALLY CHANGE OVER TO SNOW. THERE IS STILL
SOME UNCERTAINTY AS TO THE LOCATION OF THE LOW PRESSURE CENTER AND
ATTENDANT TEMPERATURE FIELDS...BUT IT SEEMS LIKELY THAT INITIALLY
THE PRECIPITATION WILL BE MOSTLY IN THE FORM OF RAIN WITH A WINTRY
MIX ACROSS NORTHERN IOWA...THEN BECOME LIGHTER BY THE TIME A
CHANGE TO SNOW OCCURS LATER IN THE EVENT. THIS WILL LIMIT SNOW
ACCUMULATIONS ACROSS MOST OF IOWA...BUT IN THE NORTH THERE COULD
BE SOME DECENT AMOUNTS DEPENDING ON HOW THE TEMPERATURES SET UP.
CERTAINLY TOO EARLY FOR ANY HEADLINE DIAGNOSIS BUT CERTAINLY ALL
EYES WILL BE ON THIS LARGE STORM SYSTEM IN THE COMING DAYS.

&&

.AVIATION...18/06Z
ISSUED AT 1140 PM CST WED DEC 17 2014

SYSTEM ACROSS PLAINS WILL CONTINUE TO LIFT NORTHEAST THROUGH
THURSDAY. CLOUDS WILL MOVE INTO IOWA WITH PRIMARILY MID AND HIGH
CLOUDINESS OVERNIGHT AND VFR CONDITIONS. AS DEEPER SATURATION
APPROACHES FROM THE SOUTH TOWARD DAYBREAK...MVFR TO IFR CONDITIONS
NEAR THE MISSOURI BORDER ARE EXPECTED ALTHOUGH DRIER LOW LEVEL AIR
WILL KEEP LOCATIONS FARTHER NORTH VFR. THERE WILL BE SOME LOW
LEVEL CLOUDS NEAR KMCW OVERNIGHT NEAR RIDGE AXIS AND THIS MAY
LINGER INTO THURSDAY MORNING AS FLOW REMAINS QUITE LIGHT. WITH
PASSAGE OF SYSTEM ON THURSDAY...THREAT OF PRECIPITATION IN THE
SOUTH WILL END AFTER MIDDAY. HOWEVER...LOW TO MID LEVEL MOISTURE
WILL REMAIN WITH WIDESPREAD STATUS EXPECTED TO PERSIST THROUGH THE
END OF THE FORECAST.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...COGIL



000
FXUS63 KDMX 180936
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
336 AM CST THU DEC 18 2014

.SHORT TERM /TODAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

AN UPPER LEVEL SHORT WAVE IS MOVING ACROSS MISSOURI THIS MORNING
WITH THE NORTHERN FRINGE OF KINEMATIC FORCING REACHING INTO SOUTHERN
IOWA. A BRANCH OF THE WARM CONVEYOR BELT IS WRAPPING AROUND THE
NORTH SIDE WITH MOISTURE OVERRUNNING THE SURFACE COLDER AIR. THE
COMBINATION OF MOISTURE AND FORCING HAS RESULTED IN A BAND OF SNOW
LIFTING NORTHEAST THROUGH NORTHEAST KANSAS AND NORTHERN MISSOURI.
THIS BAND OF SNOW WILL MOVE INTO SOUTHERN IOWA EARLY THIS MORNING
HOWEVER ITS NORTHEAST EXTENT WILL BE LIMITED BY DRY AIR ASSOCIATED
WITH A RIDGE OF HIGH PRESSURE SITUATED OVER NORTHEAST IOWA. IN
ADDITION...FORCING WILL WEAKEN AS THE UPPER LEVEL SYSTEM DEPARTS TO
THE EAST AND LEAVES THE SNOW BAND BEHIND TO DIMINISH. SNOWFALL
AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE OVER THE SOUTHERN 2 TIERS OF
COUNTIES WITH MINOR ACCUMULATIONS OF A FEW TENTHS POSSIBLE AS FAR
NORTH AS INTERSTATE 80. POTENTIAL FOR FREEZING DRIZZLE BY THIS
AFTERNOON IS LOW. MOISTURE DEPTHS WITH RELATIVE HUMIDITIES GREATER
THAN 75 PERCENT REMAIN RELATIVELY HIGH AND COLD FOR ICE TO REMAIN
INTRODUCED AND RESULTING IN LIGHT SNOW OR FLURRIES COMPARED TO
FZDZ.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 336 AM CST THU DEC 18 2014

OUR WEATHER PATTERN IS SET TO BECOME MORE ACTIVE OVER THE COMING
DAYS. INITIALLY A SERIES OF 500 MB TROUGHS WILL CROSS THE
REGION...THE FIRST AROUND FRIDAY NIGHT AND ANOTHER AROUND
SATURDAY NIGHT/SUNDAY...GRADUALLY CARVING OUT BROAD CYCLONIC FLOW
ACROSS THE CENTRAL U.S. CONCURRENT WITH A LARGE 500 MB HIGH
PRESSURE DOME DEVELOPING OVER THE EASTERN PACIFIC. WITH THE FIRST
TROUGH PASSAGE OVER IOWA ON FRIDAY NIGHT THERE IS A POTENTIAL FOR
SOME STRATUS AND DRIZZLE...BUT FORECAST SOUNDINGS INDICATE THAT
LOW LEVEL MOISTURE AND LIFT WILL PROBABLY BE INSUFFICIENT TO
GENERATE PRECIPITATION. WITH THE SECOND TROUGH ON SATURDAY NIGHT
INTO SUNDAY THERE IS A BETTER SIGNAL FOR SOME LIGHT
PRECIPITATION...PROBABLY IN THE FORM OF DRIZZLE OR FREEZING
DRIZZLE. IT IS LIKELY THAT TEMPERATURES WILL FALL BELOW FREEZING
SATURDAY NIGHT...HOWEVER...DEWPOINTS AND TEMPERATURES MAY RECOVER
TO JUST ABOVE FREEZING BEFORE DRIZZLE DEVELOPS.
NEVERTHELESS...GIVEN THE POSSIBILITY OF FREEZING DRIZZLE AND ITS
ASSOCIATED IMPACTS HAVE ADDED A CHANCE INTO THE OUTGOING FORECAST
PACKAGE. WE WILL BE CLOSELY MONITORING THIS POSSIBILITY OVER THE
NEXT COUPLE OF DAYS.

AS MENTIONED EARLIER...BY THE LATTER PART OF THE WEEKEND A BROAD
500 MB TROUGH WILL HAVE BEEN CARVED OUT OVER THE CENTRAL U.S. A
COMPACT BUT ENERGETIC SHORTWAVE WILL THEN OVERTOP THE EASTERN
PACIFIC RIDGE AND ROCKET SOUTHEASTWARD OVER THE NORTHERN ROCKIES
ON SUNDAY...SUBSEQUENTLY DIGGING AND CLOSING OFF AS A LOW OVER
MINNESOTA AND IOWA BY MONDAY NIGHT. THIS LOW WILL THEN WOBBLE OVER
THE REGION...OR SLIGHTLY TO THE EAST OVER WISCONSIN AND LAKE
MICHIGAN...BEFORE FINALLY EJECTING EASTWARD AROUND CHRISTMAS EVE.
IN TERMS OF SENSIBLE WEATHER...THE INITIAL APPROACH OF THE LOW ON
WILL SPREAD A SWATH OF WARM ADVECTION REGIME PRECIPITATION ACROSS
IOWA ON SUNDAY NIGHT INTO MONDAY...THEN AS THE LOW MOVES NEARBY OR
OVERHEAD A LARGE STRATUS AND PRECIPITATION SHIELD WILL AFFECT MOST
OF THE REGION AND EVENTUALLY CHANGE OVER TO SNOW. THERE IS STILL
SOME UNCERTAINTY AS TO THE LOCATION OF THE LOW PRESSURE CENTER AND
ATTENDANT TEMPERATURE FIELDS...BUT IT SEEMS LIKELY THAT INITIALLY
THE PRECIPITATION WILL BE MOSTLY IN THE FORM OF RAIN WITH A WINTRY
MIX ACROSS NORTHERN IOWA...THEN BECOME LIGHTER BY THE TIME A
CHANGE TO SNOW OCCURS LATER IN THE EVENT. THIS WILL LIMIT SNOW
ACCUMULATIONS ACROSS MOST OF IOWA...BUT IN THE NORTH THERE COULD
BE SOME DECENT AMOUNTS DEPENDING ON HOW THE TEMPERATURES SET UP.
CERTAINLY TOO EARLY FOR ANY HEADLINE DIAGNOSIS BUT CERTAINLY ALL
EYES WILL BE ON THIS LARGE STORM SYSTEM IN THE COMING DAYS.

&&

.AVIATION...18/06Z
ISSUED AT 1140 PM CST WED DEC 17 2014

SYSTEM ACROSS PLAINS WILL CONTINUE TO LIFT NORTHEAST THROUGH
THURSDAY. CLOUDS WILL MOVE INTO IOWA WITH PRIMARILY MID AND HIGH
CLOUDINESS OVERNIGHT AND VFR CONDITIONS. AS DEEPER SATURATION
APPROACHES FROM THE SOUTH TOWARD DAYBREAK...MVFR TO IFR CONDITIONS
NEAR THE MISSOURI BORDER ARE EXPECTED ALTHOUGH DRIER LOW LEVEL AIR
WILL KEEP LOCATIONS FARTHER NORTH VFR. THERE WILL BE SOME LOW
LEVEL CLOUDS NEAR KMCW OVERNIGHT NEAR RIDGE AXIS AND THIS MAY
LINGER INTO THURSDAY MORNING AS FLOW REMAINS QUITE LIGHT. WITH
PASSAGE OF SYSTEM ON THURSDAY...THREAT OF PRECIPITATION IN THE
SOUTH WILL END AFTER MIDDAY. HOWEVER...LOW TO MID LEVEL MOISTURE
WILL REMAIN WITH WIDESPREAD STATUS EXPECTED TO PERSIST THROUGH THE
END OF THE FORECAST.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...DONAVON
LONG TERM...LEE
AVIATION...COGIL



000
FXUS63 KDVN 180930
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
330 AM CST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 321 AM CST THU DEC 18 2014

SNOW FAIRLY WIDESPREAD FROM WESTERN MO INTO NE AND KS AHEAD OF AN
UPPER LEVEL SHORTWAVE OVER THE PLAINS. REPORTS OF ACCUMS FROM
1-3 INCHES FROM NORTHERN KS THROUGH THE KC METRO WITH OBS SUGGESTING
THE LEADING EDGE OF SNOW BETWEEN CHILLICOTHE MO AND KC METRO
MOVING N/E. TRENDS SUPPORT SYSTEM AND ATTENDANT SNOW TO GRADUALLY
WEAKEN TODAY AS IT ENCOUNTERS RIDGING OVER THE REGION... BUT
BEFORE DOING SO IS EXPECTED BRING SOME LIGHT ACCUMS TO SOUTHERN
PORTIONS OF CWA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU DEC 18 2014

SHORTWAVE WILL MOVE ACROSS REGION TODAY AND DEAMPLIFY/WEAKEN WHILE
RUNNING INTO THE RIDGE. THIS ALONG WITH COPIOUS DRY AIR PER 00Z
DVN AND ILX RAOBS SHOULD RESULT IN STEADY WEAKENING OF SNOW AS IT
SPREADS INTO FAR SOUTHERN CWA THIS AM. FORCING PEAKS OVER NORTHERN
MO 10Z-15Z THEN QUICKLY DIMINISHING THROUGH 18Z. OVERALL GOING
WITH 0.05 TO 0.1 INCH OF LIQUID QPF WITH SLR OF 12-14:1 TO YIELD
AROUND AN INCH OR SO OF ACCUM VERY FAR SOUTHERN CWA MAINLY NORTHEAST
MO INTO PORTIONS OF WEST CENTRAL IL TAPERING OFF TO TRACE HWY 34.
GIVEN DRY AIR AND ALIGNMENT OF FORCING COULD ENVISION SCENARIO
WHEREBY THIS OCCURS OVER MUCH SHORTER DISTANCE OF 25+ MILES NORTHEAST
MO. CANT RULE OUT POSSIBILITY OF SOME FREEZING DRIZZLE FAR SOUTH
FOR A WHILE THIS AFTERNOON IF CLOUD BEARING LAYER BECOMES SUFFICIENTLY
SHALLOW/WARM.. BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE MENTION
ATTIM. ASIDE FROM THE LIGHT SNOW FAR SOUTHERN CWA... EXPECT PTSUNNY
TO CLOUDY SKIES TODAY WITH TEMPS SIMILAR TO THOSE OF YSTDY IN
RELATIVELY NEUTRAL THERMAL ENVIRONMENT... WITH READINGS MAINLY IN
UPPER 20S TO LOWER 30S. WINDS NEGLIGIBLE AND GENERALLY 5 MPH OR LESS
WITH SURFACE RIDGING.

TONIGHT... GENERALLY PT-MOCDLY SKIES WITH SFC RIDGING BECOMING
RE-ESTABLISHED AS THE DOMINANT FEATURE. BANKING ON SUFFICIENT
CLOUDINESS TO PRECLUDE TEMPS FROM BOTTOMING OUT DESPITE NEAR
CALM/CALM WINDS... AND EXPECT GENERALLY UPPER TEENS TO MID 20S FOR
LOWS. SHOULD SOME AREAS SEE MORE IN WAY OF CLEARING THEN POTENTIAL
TO BE IN MID TEENS FOR LOWS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU DEC 18 2014

FORECAST FOCUS ON ACTIVE WEATHER PATTERN ESPECIALLY CHRISTMAS WEEK.

FRIDAY THROUGH SUNDAY...ZONAL FLOW OVER THE REGION WITH A SERIES OF
SHORT WAVES MOVING ACROSS. THIS LOOKS TO BE ANOTHER RATHER CLOUDY
PERIOD WITH FORECAST SOUNDINGS INDICATING WEAK LOW LEVEL WARM
ADVECTION AND A STRONG INVERSION SETTING UP AROUND 850 MB...WITH MOISTURE
TRAPPED BELOW. SATURDAY NIGHT I HAVE INTRODUCED A SLIGHT CHANCE OF
FREEZING DRIZZLE IN OUR FAR NW CWA...AS A SHORT WAVE/VORT MAX
TRAVERSES NORTHERN IA. FORECAST SOUNDINGS INDICATE A WARM LAYER JUST
ABOVE FREEZING WITH DRY AIR IN THE MID LEVELS WITH MOISTURE BELOW.
MAXIMUM TEMPERATURES DURING THIS PERIOD WILL BE IN THE 30S TO NEAR
40 WITH LOWS IN THE 20S TO NEAR 30.

MONDAY THROUGH WEDNESDAY...THIS IS WHEN THE WEATHER GETS ACTIVE BUT
ALSO COMPLICATED AND CHALLENGING. UPPER LOW DEEPENS AS IT TRACKS
FROM THE NORTHERN PLAINS (MONDAY) INTO EASTERN IA (TUESDAY) AND THEN
LIFTING INTO THE WESTERN GREAT LAKES (WEDNESDAY). THE PATH OF THIS
SYSTEM WOULD SUGGEST MAINLY A RAIN/SNOW MIX BUT WILL NEED TO KEEP AN
EYE ON TUESDAY WHERE IT MAY CHANGE TO ALL SNOW...GIVEN THE COLD
POCKET ALOFT AND DYNAMIC COOLING. WAY TOO EARLY TO OFFER ANY
ACCUMULATION AMOUNTS IF ANY. MAXIMUM TEMPERATURES ON MONDAY SHOULD
PUSH INTO THE 40S FROM ABOUT I-80 SOUTHWARD...AND IN THE 30S TUESDAY
AND WEDNESDAY. THE ECMWF HAS NOW THROWN A CURVE BALL IN REGARD TO
THE WHOPPER STORM EARLIER INDICATED TO BE IN THE GREAT LAKES REGION
CHRISTMAS EVE. IT NOW IS NOT QUITE THE BOMB SHOWN THE PAST COUPLE
RUNS AND IS ALSO INTENSIFYING THE CYCLONE FARTHER EAST...IN NEW
ENGLAND! THIS IS WHAT THE GFS HAS BEEN INDICATING ALL ALONG. SUFFICE
TO SAY CONFIDENCE IS LOW AS PHASING ISSUES CONTINUE TO HAUNT THE
MODELS. SO MORE CHANGES IN THE MODELS CAN BE EXPECTED OVER THE NEXT
SEVERAL DAYS AND THE IMPACTS IF ANY ON OUR AREA REMAIN TO BE SEEN.

CHRISTMAS DAY AND FRIDAY...MANY UNCERTAINTIES REGARDING THE
POTENTIAL WINTER STORM OFFERED BY THE ECMWF ON FRIDAY. DEPENDING ON
WHERE THE HUGE UPPER LOW TO OUR NORTHEAST IS LOCATED WILL PLAY A
ROLE IN THE STRONG ENERGY COMING OUT OF THE SOUTHWEST. CONFIDENCE IN
THE TRACK/TIMING/INTENSITY OF THIS SYSTEM IS LOW BUT CERTAINLY THERE
IS THE POTENTIAL FOR A WINTER STORM SOMEWHERE IN THE MIDWEST...SO
ANYONE TRAVELING AROUND CHRISTMAS DAY OR THEREAFTER SHOULD CONTINUE
TO MONITOR LATER FORECASTS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1123 PM CST WED DEC 17 2014

A WEAK UPPER LEVEL SYSTEM WILL SPREAD LIGHT SNOW ACROSS MO INTO
CENTRAL IL ON THURSDAY. THIS MAY BRUSH THE BRL SITE...WHERE A
SEVERAL HOUR WINDOW OF MVFR CIGS/VISBYS IS FORECAST THURSDAY MORNING.
ELSEWHERE...SURFACE HIGH PRESSURE AND LIGHT NORTHWEST WINDS WILL
PROVIDE VFR CONDITIONS THROUGHOUT. FORECAST MODELS CONTINUE TO
SUGGEST A POTENTIAL FOR MVFR FOG LATE TONIGHT INTO MID MORNING
THURSDAY...WHICH HAS YET TO MATERIALIZE. WITH UNFAVORABLE
CONDITIONS DUE TO DRY AIR...DRY SURFACE CONDITIONS AND THICKENING
HIGH CLOUD COVER...THIS FOG HAS BEEN DISCOUNTED AND NOT INCLUDED IN THE
FORECASTS AT THIS TIME.

&&

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

$$

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






000
FXUS63 KDVN 180930
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
330 AM CST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 321 AM CST THU DEC 18 2014

SNOW FAIRLY WIDESPREAD FROM WESTERN MO INTO NE AND KS AHEAD OF AN
UPPER LEVEL SHORTWAVE OVER THE PLAINS. REPORTS OF ACCUMS FROM
1-3 INCHES FROM NORTHERN KS THROUGH THE KC METRO WITH OBS SUGGESTING
THE LEADING EDGE OF SNOW BETWEEN CHILLICOTHE MO AND KC METRO
MOVING N/E. TRENDS SUPPORT SYSTEM AND ATTENDANT SNOW TO GRADUALLY
WEAKEN TODAY AS IT ENCOUNTERS RIDGING OVER THE REGION... BUT
BEFORE DOING SO IS EXPECTED BRING SOME LIGHT ACCUMS TO SOUTHERN
PORTIONS OF CWA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU DEC 18 2014

SHORTWAVE WILL MOVE ACROSS REGION TODAY AND DEAMPLIFY/WEAKEN WHILE
RUNNING INTO THE RIDGE. THIS ALONG WITH COPIOUS DRY AIR PER 00Z
DVN AND ILX RAOBS SHOULD RESULT IN STEADY WEAKENING OF SNOW AS IT
SPREADS INTO FAR SOUTHERN CWA THIS AM. FORCING PEAKS OVER NORTHERN
MO 10Z-15Z THEN QUICKLY DIMINISHING THROUGH 18Z. OVERALL GOING
WITH 0.05 TO 0.1 INCH OF LIQUID QPF WITH SLR OF 12-14:1 TO YIELD
AROUND AN INCH OR SO OF ACCUM VERY FAR SOUTHERN CWA MAINLY NORTHEAST
MO INTO PORTIONS OF WEST CENTRAL IL TAPERING OFF TO TRACE HWY 34.
GIVEN DRY AIR AND ALIGNMENT OF FORCING COULD ENVISION SCENARIO
WHEREBY THIS OCCURS OVER MUCH SHORTER DISTANCE OF 25+ MILES NORTHEAST
MO. CANT RULE OUT POSSIBILITY OF SOME FREEZING DRIZZLE FAR SOUTH
FOR A WHILE THIS AFTERNOON IF CLOUD BEARING LAYER BECOMES SUFFICIENTLY
SHALLOW/WARM.. BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE MENTION
ATTIM. ASIDE FROM THE LIGHT SNOW FAR SOUTHERN CWA... EXPECT PTSUNNY
TO CLOUDY SKIES TODAY WITH TEMPS SIMILAR TO THOSE OF YSTDY IN
RELATIVELY NEUTRAL THERMAL ENVIRONMENT... WITH READINGS MAINLY IN
UPPER 20S TO LOWER 30S. WINDS NEGLIGIBLE AND GENERALLY 5 MPH OR LESS
WITH SURFACE RIDGING.

TONIGHT... GENERALLY PT-MOCDLY SKIES WITH SFC RIDGING BECOMING
RE-ESTABLISHED AS THE DOMINANT FEATURE. BANKING ON SUFFICIENT
CLOUDINESS TO PRECLUDE TEMPS FROM BOTTOMING OUT DESPITE NEAR
CALM/CALM WINDS... AND EXPECT GENERALLY UPPER TEENS TO MID 20S FOR
LOWS. SHOULD SOME AREAS SEE MORE IN WAY OF CLEARING THEN POTENTIAL
TO BE IN MID TEENS FOR LOWS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU DEC 18 2014

FORECAST FOCUS ON ACTIVE WEATHER PATTERN ESPECIALLY CHRISTMAS WEEK.

FRIDAY THROUGH SUNDAY...ZONAL FLOW OVER THE REGION WITH A SERIES OF
SHORT WAVES MOVING ACROSS. THIS LOOKS TO BE ANOTHER RATHER CLOUDY
PERIOD WITH FORECAST SOUNDINGS INDICATING WEAK LOW LEVEL WARM
ADVECTION AND A STRONG INVERSION SETTING UP AROUND 850 MB...WITH MOISTURE
TRAPPED BELOW. SATURDAY NIGHT I HAVE INTRODUCED A SLIGHT CHANCE OF
FREEZING DRIZZLE IN OUR FAR NW CWA...AS A SHORT WAVE/VORT MAX
TRAVERSES NORTHERN IA. FORECAST SOUNDINGS INDICATE A WARM LAYER JUST
ABOVE FREEZING WITH DRY AIR IN THE MID LEVELS WITH MOISTURE BELOW.
MAXIMUM TEMPERATURES DURING THIS PERIOD WILL BE IN THE 30S TO NEAR
40 WITH LOWS IN THE 20S TO NEAR 30.

MONDAY THROUGH WEDNESDAY...THIS IS WHEN THE WEATHER GETS ACTIVE BUT
ALSO COMPLICATED AND CHALLENGING. UPPER LOW DEEPENS AS IT TRACKS
FROM THE NORTHERN PLAINS (MONDAY) INTO EASTERN IA (TUESDAY) AND THEN
LIFTING INTO THE WESTERN GREAT LAKES (WEDNESDAY). THE PATH OF THIS
SYSTEM WOULD SUGGEST MAINLY A RAIN/SNOW MIX BUT WILL NEED TO KEEP AN
EYE ON TUESDAY WHERE IT MAY CHANGE TO ALL SNOW...GIVEN THE COLD
POCKET ALOFT AND DYNAMIC COOLING. WAY TOO EARLY TO OFFER ANY
ACCUMULATION AMOUNTS IF ANY. MAXIMUM TEMPERATURES ON MONDAY SHOULD
PUSH INTO THE 40S FROM ABOUT I-80 SOUTHWARD...AND IN THE 30S TUESDAY
AND WEDNESDAY. THE ECMWF HAS NOW THROWN A CURVE BALL IN REGARD TO
THE WHOPPER STORM EARLIER INDICATED TO BE IN THE GREAT LAKES REGION
CHRISTMAS EVE. IT NOW IS NOT QUITE THE BOMB SHOWN THE PAST COUPLE
RUNS AND IS ALSO INTENSIFYING THE CYCLONE FARTHER EAST...IN NEW
ENGLAND! THIS IS WHAT THE GFS HAS BEEN INDICATING ALL ALONG. SUFFICE
TO SAY CONFIDENCE IS LOW AS PHASING ISSUES CONTINUE TO HAUNT THE
MODELS. SO MORE CHANGES IN THE MODELS CAN BE EXPECTED OVER THE NEXT
SEVERAL DAYS AND THE IMPACTS IF ANY ON OUR AREA REMAIN TO BE SEEN.

CHRISTMAS DAY AND FRIDAY...MANY UNCERTAINTIES REGARDING THE
POTENTIAL WINTER STORM OFFERED BY THE ECMWF ON FRIDAY. DEPENDING ON
WHERE THE HUGE UPPER LOW TO OUR NORTHEAST IS LOCATED WILL PLAY A
ROLE IN THE STRONG ENERGY COMING OUT OF THE SOUTHWEST. CONFIDENCE IN
THE TRACK/TIMING/INTENSITY OF THIS SYSTEM IS LOW BUT CERTAINLY THERE
IS THE POTENTIAL FOR A WINTER STORM SOMEWHERE IN THE MIDWEST...SO
ANYONE TRAVELING AROUND CHRISTMAS DAY OR THEREAFTER SHOULD CONTINUE
TO MONITOR LATER FORECASTS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1123 PM CST WED DEC 17 2014

A WEAK UPPER LEVEL SYSTEM WILL SPREAD LIGHT SNOW ACROSS MO INTO
CENTRAL IL ON THURSDAY. THIS MAY BRUSH THE BRL SITE...WHERE A
SEVERAL HOUR WINDOW OF MVFR CIGS/VISBYS IS FORECAST THURSDAY MORNING.
ELSEWHERE...SURFACE HIGH PRESSURE AND LIGHT NORTHWEST WINDS WILL
PROVIDE VFR CONDITIONS THROUGHOUT. FORECAST MODELS CONTINUE TO
SUGGEST A POTENTIAL FOR MVFR FOG LATE TONIGHT INTO MID MORNING
THURSDAY...WHICH HAS YET TO MATERIALIZE. WITH UNFAVORABLE
CONDITIONS DUE TO DRY AIR...DRY SURFACE CONDITIONS AND THICKENING
HIGH CLOUD COVER...THIS FOG HAS BEEN DISCOUNTED AND NOT INCLUDED IN THE
FORECASTS AT THIS TIME.

&&

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

$$

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





000
FXUS63 KDMX 180541
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1141 PM CST WED DEC 17 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 245 PM CST WED DEC 17 2014

A QUIET AFTERNOON IS IN STORE FOR THE CWA WITH SURFACE HIGH PRESSURE
ANCHORED ALONG THE MISSOURI RIVER VALLEY. A SHARP 300 MB SHORTWAVE
TROUGH CURRENTLY EJECTING FROM THE FOUR CORNERS REGION WILL ENTER
SOUTHWEST IOWA BY 12Z THURSDAY. NAM/GFS ARE TOO SLOW WITH RETURNING
MID-LEVEL MOISTURE (MANIFESTING ITSELF AS AN ALTOSTRATUS DECK) NOW
WELL INTO SW IOWA AS WELL AS WITH PRECIP COVERAGE WITH THIS SYSTEM
IN OKLAHOMA. THE HRRR BEST REFLECTS REALITY IN TERMS OF PRECIP
COVERAGE BUT IS ABOUT 3 HOURS BEHIND THE CURVE WITH CLOUD PLACEMENT.
HAVE SUBSEQUENTLY MANUALLY INCREASED CLOUD COVER OVER THE SW HALF OF
THE CWA AND USED THE HRRR FOR TIMING THE ONSET OF SNOW IN THE
SOUTHWESTERN CWA. LOW TEMPERATURES TONIGHT...ESPECIALLY OVER THE
NORTH...WILL BE DEPENDENT ON HOW QUICKLY CLOUDS CAN ADVECT OVERHEAD.
THESE WILL NEED TO BE MONITORED THIS EVENING AND ADJUSTED UPWARD
SHOULD THE CLOUDS ADVANCE FASTER THAN CURRENTLY FORECAST.

THE FASTER MOISTURE RETURN THROWS JUST ANOTHER WRENCH IN TIMING AND
AMOUNTS OF SNOWFALL IN SOUTHERN IOWA LATE TONIGHT. 12/18Z MODEL BUFR
SOUNDINGS DEPICT A STOUT 925-850MB DRY WEDGE ATTENDANT WITH THE
SURFACE RIDGE...BUT THIS MIDLEVEL MOISTURE MAY SATURATE THE COLUMN
FASTER THAN PROGGED AND LEAD TO HIGHER SNOWFALL TOTALS. OVERALL MADE
LITTLE CHANGES TO THE FORECAST IN THIS RESPECT...BUT DID TIGHTEN THE
POP GRADIENT AS IT ADVANCES NORTHEAST FROM 09 TO 12Z THINKING THAT
THE LOW LEVEL DRY AIR WILL RESULT IN A SHARP CUTOFF IN ACCUMULATING
SNOW.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 245 PM CST WED DEC 17 2014

A FEW CHALLENGES OVER THE EXTENDED PERIOD...WITH A NUMBER OF WEAK
SYSTEMS TO AFFECT PORTIONS OF THE AREA THROUGH THE PERIOD. SPLIT
FLOW CONTINUES TO BE THE MAIN DRIVING FORCE BEHIND THE RATHER
QUIESCENT WEATHER FOR MID DECEMBER. RATHER HIGH AMPLITUDE RIDGE OF
HIGH PRESSURE STILL ANCHORED FROM THE NORTHERN PLAINS TO THE GULF
COAST NEXT FEW DAYS. FIRST WAVE CURRENTLY OVER THE SOUTHERN
PLAINS TODAY AND SHOULD MOVE NORTHEAST THROUGH THU MORNING. AHEAD
OF THE WEAK SYSTEM WARM AIR ADVECTION AND LIMITED MOISTURE WILL BE
FORCED UPWARD IN AN AREA OF ISENTROPIC LIFT OVER SOUTHERN IOWA
THURSDAY. THE LIFT AND MOISTURE WILL BE ATTEMPTING TO OVERCOME THE
DRY AIRMASS CURRENTLY IN PLACE...LIMITING OVERALL AMOUNTS. THIS
WILL RESULT IN SOME RATHER LIGHT SNOW DURING THE MORNING HOURS
WITH MINOR ACCUMULATIONS GENERALLY LESS THAN AN INCH. DURING THE
EARLY AFTERNOON HOURS...BUFR SOUNDINGS SHOW THAT WE LOSE ICE
INTRODUCTION ACROSS THE SOUTHWEST AND SOUTH. HAVE INTRODUCED SOME
PATCHY FREEZING DRIZZLE ALONG WITH VERY LIGHT SNOW DURING THE
AFTERNOON HOURS...THOUGH EXPECTATIONS ARE THAT ANY PRECIPITATION
BY THAT TIME WILL BE VERY LIGHT AND LITTLE IF ANY ICE ACCUMULATION
IS EXPECTED. NEXT SYSTEM ARRIVES BY SUNDAY AND MONDAY AND EXTENDS
INTO TUESDAY. LOWER CONFIDENCE MOVING FORWARD WITH A CONSENSUS
SOLUTION AS THE GFS IS QUITE MILD WHILE THE EURO IS NOW SUGGESTING
A SOLUTION WITH MORE SIGNIFICANT DYNAMIC COOLING AS THE PRECIP
ARRIVES INTO MONDAY. THE EURO SUGGESTS MORE SNOW THAN RAIN/SNOW
MIX. GIVEN THE EVENT IS STILL 5 DAYS AWAY...WILL HOLD ONTO CURRENT
MIX TRENDS FOR NOW...AND MONITOR DURING SUBSEQUENT MODEL PACKAGES.
THE ONE TREND THAT IS BEGINNING TO EMERGE IS COLDER AIR AS NEXT
WEEK PROGRESSES. AS A STRONG PACNW STREAM WAVE ADVANCES EAST INTO
THE WESTERN STATES...MIDWEST RIDGE FINALLY BEGINS TO BREAK DOWN
AND BECOME DISPLACED BY A LONG WAVE TROUGH. THIS SHOULD SPELL A
TRANSITION TO A MORE ACTIVE AND COLDER PATTERN TOWARD THE END OF
THE EXTENDED. AS THE WAVE TUESDAY DEEPENS...A RATHER STRONG SFC
WAVE WILL EJECT NORTH NORTHEAST OUT OF EASTERN TEXAS TO EASTERN
MICHIGAN WEDNESDAY. GIVEN THE CURRENT GFS/EURO PACKAGES...THE MAIN
H850 MOISTURE PLUME...BETTER FORCING...AND HIGHER PRECIPITATION
AMOUNTS WILL PROBABLY END UP EAST OF THE REGION. WILL MONITOR FOR
GENERAL WESTWARD DRIFT NEXT SEVERAL PACKAGES...THIS SOMETIMES
OCCURS WITH WINTER STORM EVOLUTION IN MODEL PACKAGES...FIRST
PROJECTING THE EVENT TOO FAR EAST THEN PULLING IT BACK AS THE
EVENT NEARS.

&&

.AVIATION...18/06Z
ISSUED AT 1140 PM CST WED DEC 17 2014

SYSTEM ACROSS PLAINS WILL CONTINUE TO LIFT NORTHEAST THROUGH
THURSDAY. CLOUDS WILL MOVE INTO IOWA WITH PRIMARILY MID AND HIGH
CLOUDINESS OVERNIGHT AND VFR CONDITIONS. AS DEEPER SATURATION
APPROACHES FROM THE SOUTH TOWARD DAYBREAK...MVFR TO IFR CONDITIONS
NEAR THE MISSOURI BORDER ARE EXPECTED ALTHOUGH DRIER LOW LEVEL AIR
WILL KEEP LOCATIONS FARTHER NORTH VFR. THERE WILL BE SOME LOW
LEVEL CLOUDS NEAR KMCW OVERNIGHT NEAR RIDGE AXIS AND THIS MAY
LINGER INTO THURSDAY MORNING AS FLOW REMAINS QUITE LIGHT. WITH
PASSAGE OF SYSTEM ON THURSDAY...THREAT OF PRECIPITATION IN THE
SOUTH WILL END AFTER MIDDAY. HOWEVER...LOW TO MID LEVEL MOISTURE
WILL REMAIN WITH WIDESPREAD STATUS EXPECTED TO PERSIST THROUGH THE
END OF THE FORECAST.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...SKOW
LONG TERM...REV
AVIATION...COGIL



000
FXUS63 KDMX 180541
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1141 PM CST WED DEC 17 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 245 PM CST WED DEC 17 2014

A QUIET AFTERNOON IS IN STORE FOR THE CWA WITH SURFACE HIGH PRESSURE
ANCHORED ALONG THE MISSOURI RIVER VALLEY. A SHARP 300 MB SHORTWAVE
TROUGH CURRENTLY EJECTING FROM THE FOUR CORNERS REGION WILL ENTER
SOUTHWEST IOWA BY 12Z THURSDAY. NAM/GFS ARE TOO SLOW WITH RETURNING
MID-LEVEL MOISTURE (MANIFESTING ITSELF AS AN ALTOSTRATUS DECK) NOW
WELL INTO SW IOWA AS WELL AS WITH PRECIP COVERAGE WITH THIS SYSTEM
IN OKLAHOMA. THE HRRR BEST REFLECTS REALITY IN TERMS OF PRECIP
COVERAGE BUT IS ABOUT 3 HOURS BEHIND THE CURVE WITH CLOUD PLACEMENT.
HAVE SUBSEQUENTLY MANUALLY INCREASED CLOUD COVER OVER THE SW HALF OF
THE CWA AND USED THE HRRR FOR TIMING THE ONSET OF SNOW IN THE
SOUTHWESTERN CWA. LOW TEMPERATURES TONIGHT...ESPECIALLY OVER THE
NORTH...WILL BE DEPENDENT ON HOW QUICKLY CLOUDS CAN ADVECT OVERHEAD.
THESE WILL NEED TO BE MONITORED THIS EVENING AND ADJUSTED UPWARD
SHOULD THE CLOUDS ADVANCE FASTER THAN CURRENTLY FORECAST.

THE FASTER MOISTURE RETURN THROWS JUST ANOTHER WRENCH IN TIMING AND
AMOUNTS OF SNOWFALL IN SOUTHERN IOWA LATE TONIGHT. 12/18Z MODEL BUFR
SOUNDINGS DEPICT A STOUT 925-850MB DRY WEDGE ATTENDANT WITH THE
SURFACE RIDGE...BUT THIS MIDLEVEL MOISTURE MAY SATURATE THE COLUMN
FASTER THAN PROGGED AND LEAD TO HIGHER SNOWFALL TOTALS. OVERALL MADE
LITTLE CHANGES TO THE FORECAST IN THIS RESPECT...BUT DID TIGHTEN THE
POP GRADIENT AS IT ADVANCES NORTHEAST FROM 09 TO 12Z THINKING THAT
THE LOW LEVEL DRY AIR WILL RESULT IN A SHARP CUTOFF IN ACCUMULATING
SNOW.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 245 PM CST WED DEC 17 2014

A FEW CHALLENGES OVER THE EXTENDED PERIOD...WITH A NUMBER OF WEAK
SYSTEMS TO AFFECT PORTIONS OF THE AREA THROUGH THE PERIOD. SPLIT
FLOW CONTINUES TO BE THE MAIN DRIVING FORCE BEHIND THE RATHER
QUIESCENT WEATHER FOR MID DECEMBER. RATHER HIGH AMPLITUDE RIDGE OF
HIGH PRESSURE STILL ANCHORED FROM THE NORTHERN PLAINS TO THE GULF
COAST NEXT FEW DAYS. FIRST WAVE CURRENTLY OVER THE SOUTHERN
PLAINS TODAY AND SHOULD MOVE NORTHEAST THROUGH THU MORNING. AHEAD
OF THE WEAK SYSTEM WARM AIR ADVECTION AND LIMITED MOISTURE WILL BE
FORCED UPWARD IN AN AREA OF ISENTROPIC LIFT OVER SOUTHERN IOWA
THURSDAY. THE LIFT AND MOISTURE WILL BE ATTEMPTING TO OVERCOME THE
DRY AIRMASS CURRENTLY IN PLACE...LIMITING OVERALL AMOUNTS. THIS
WILL RESULT IN SOME RATHER LIGHT SNOW DURING THE MORNING HOURS
WITH MINOR ACCUMULATIONS GENERALLY LESS THAN AN INCH. DURING THE
EARLY AFTERNOON HOURS...BUFR SOUNDINGS SHOW THAT WE LOSE ICE
INTRODUCTION ACROSS THE SOUTHWEST AND SOUTH. HAVE INTRODUCED SOME
PATCHY FREEZING DRIZZLE ALONG WITH VERY LIGHT SNOW DURING THE
AFTERNOON HOURS...THOUGH EXPECTATIONS ARE THAT ANY PRECIPITATION
BY THAT TIME WILL BE VERY LIGHT AND LITTLE IF ANY ICE ACCUMULATION
IS EXPECTED. NEXT SYSTEM ARRIVES BY SUNDAY AND MONDAY AND EXTENDS
INTO TUESDAY. LOWER CONFIDENCE MOVING FORWARD WITH A CONSENSUS
SOLUTION AS THE GFS IS QUITE MILD WHILE THE EURO IS NOW SUGGESTING
A SOLUTION WITH MORE SIGNIFICANT DYNAMIC COOLING AS THE PRECIP
ARRIVES INTO MONDAY. THE EURO SUGGESTS MORE SNOW THAN RAIN/SNOW
MIX. GIVEN THE EVENT IS STILL 5 DAYS AWAY...WILL HOLD ONTO CURRENT
MIX TRENDS FOR NOW...AND MONITOR DURING SUBSEQUENT MODEL PACKAGES.
THE ONE TREND THAT IS BEGINNING TO EMERGE IS COLDER AIR AS NEXT
WEEK PROGRESSES. AS A STRONG PACNW STREAM WAVE ADVANCES EAST INTO
THE WESTERN STATES...MIDWEST RIDGE FINALLY BEGINS TO BREAK DOWN
AND BECOME DISPLACED BY A LONG WAVE TROUGH. THIS SHOULD SPELL A
TRANSITION TO A MORE ACTIVE AND COLDER PATTERN TOWARD THE END OF
THE EXTENDED. AS THE WAVE TUESDAY DEEPENS...A RATHER STRONG SFC
WAVE WILL EJECT NORTH NORTHEAST OUT OF EASTERN TEXAS TO EASTERN
MICHIGAN WEDNESDAY. GIVEN THE CURRENT GFS/EURO PACKAGES...THE MAIN
H850 MOISTURE PLUME...BETTER FORCING...AND HIGHER PRECIPITATION
AMOUNTS WILL PROBABLY END UP EAST OF THE REGION. WILL MONITOR FOR
GENERAL WESTWARD DRIFT NEXT SEVERAL PACKAGES...THIS SOMETIMES
OCCURS WITH WINTER STORM EVOLUTION IN MODEL PACKAGES...FIRST
PROJECTING THE EVENT TOO FAR EAST THEN PULLING IT BACK AS THE
EVENT NEARS.

&&

.AVIATION...18/06Z
ISSUED AT 1140 PM CST WED DEC 17 2014

SYSTEM ACROSS PLAINS WILL CONTINUE TO LIFT NORTHEAST THROUGH
THURSDAY. CLOUDS WILL MOVE INTO IOWA WITH PRIMARILY MID AND HIGH
CLOUDINESS OVERNIGHT AND VFR CONDITIONS. AS DEEPER SATURATION
APPROACHES FROM THE SOUTH TOWARD DAYBREAK...MVFR TO IFR CONDITIONS
NEAR THE MISSOURI BORDER ARE EXPECTED ALTHOUGH DRIER LOW LEVEL AIR
WILL KEEP LOCATIONS FARTHER NORTH VFR. THERE WILL BE SOME LOW
LEVEL CLOUDS NEAR KMCW OVERNIGHT NEAR RIDGE AXIS AND THIS MAY
LINGER INTO THURSDAY MORNING AS FLOW REMAINS QUITE LIGHT. WITH
PASSAGE OF SYSTEM ON THURSDAY...THREAT OF PRECIPITATION IN THE
SOUTH WILL END AFTER MIDDAY. HOWEVER...LOW TO MID LEVEL MOISTURE
WILL REMAIN WITH WIDESPREAD STATUS EXPECTED TO PERSIST THROUGH THE
END OF THE FORECAST.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...SKOW
LONG TERM...REV
AVIATION...COGIL




000
FXUS63 KDVN 180523
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1123 PM CST WED DEC 17 2014

.UPDATE...
ISSUED AT 1123 PM CST WED DEC 17 2014

SKIES HAVE REMAINED MOSTLY CLEAR OVER ALL BUT THE FAR SOUTH AND
EXTREME NORTHEAST THIS EVENING. THIS...ALONG WITH VERY DRY
AIR AND LIGHT WINDS HAS ALLOWED TEMPERATURES TO DROP INTO THE MID
TEENS OVER ALL BUT THE FAR SOUTH. OVER THE PAST HOUR...SATELLITE
SHOWED HIGH CLOUDS SPREADING NORTHEAST AHEAD OF THE UPPER LEVEL
SYSTEM MOVING INTO THE CENTRAL PLAINS. THIS SHOULD END THE
TEMPERATURE PLUNGE AND PREVIOUSLY UPDATED LOW...FROM AROUND 12
NORTHWEST TO THE LOWER 20S SOUTH OF HIGHWAY 34 SHOULD HOLD. THE
LEADING EDGE OF THE LIGHT SNOW IS STILL WELL SOUTH OF THE I-70
CORRIDOR IN MO AND WITH THE DRY AIR ALOFT...NOT LIKELY TO REACH
INTO OUR NE MO COUNTIES UNTIL AFTER 12Z AS MENTIONED IN THE
PREVIOUS DISCUSSION.

&&

.SYNOPSIS...
ISSUED AT 325 PM CST WED DEC 17 2014

12Z UA ANALYSIS HAS AN 850MB RIDGE RUNNING FROM THE GULF COAST INTO
THE NORTHERN PLAINS. A STORM SYSTEM WAS OVER SOUTHERN CANADA WITH A
LLJ RUNNING FROM WEST TEXAS INTO THE CENTRAL PLAINS. SATELLITE
TRENDS THROUGH MID AFTERNOON SHOW CLEARING SKIES ACROSS THE AREA
WITH CLOUDS FROM THE NEXT SYSTEM OVER THE CENTRAL AND SOUTHERN
PLAINS.

18Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE NORTHERN PLAINS AND
UPPER MIDWEST. A WEAK LOW WAS IN SOUTHEAST COLORADO WITH AN IMPLIED
BOUNDARY RUNNING FROM THE LOW INTO SOUTHWEST ARKANSAS. DEW POINTS
WERE IN THE SINGLE DIGITS AND TEENS ACROSS THE NORTHERN PLAINS AND
UPPER MIDWEST WITH 20S AND 30S FROM THE OHIO VALLEY INTO THE
SOUTHERN PLAINS.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 325 PM CST WED DEC 17 2014

QUIET CONDITIONS WITH CLEAR OR CLEARING SKIES WILL BE SEEN ACROSS
THE AREA THROUGH LATE AFTERNOON. DRY CONDITIONS WILL THEN BE SEEN
TONIGHT AND INTO THE PRE-DAWN HOURS WITH INCREASING CLOUDS. SNOW
WILL DEVELOP AND SPREAD NORTHEAST THROUGH KANSAS AND MISSOURI.
HOWEVER...DRY AIR ACROSS THE AREA WILL PREVENT ANY SNOW FROM
REACHING THE EXTREME SOUTH PRIOR TO 6 AM THURSDAY.

LOWS TONIGHT SHOULD DROP QUICKLY AFTER SUNSET AND THEN MAY BECOME
STEADY OR RISE SLIGHTLY AS CLOUDS MOVE BACK INTO THE AREA.

ON THURSDAY...STRONG FORCING WILL GO INTO SATURATING THE DRY AIR AT
THE LOW LEVELS AND ALLOW SNOW TO MOVE INTO THE FAR SOUTHERN AREAS.
THE FORCING RAPIDLY COLLAPSES BY LATE MORNING WITH MINIMAL FORCING
IN THE SATURATED ATMOSPHERE ACROSS THE SOUTH THIRD DURING THE
AFTERNOON.

THUS THE OPPORTUNITY FOR ACCUMULATING SNOW WILL OCCUR THURSDAY
MORNING IN A 4-6 HOUR WINDOW. THE BEST CHANCES FOR ANY ACCUMULATING
SNOW APPEAR TO BE SOUTH OF A KCNC...KFSW...TO KBMI LINE OR SOUTH OF
A CHARITON IOWA TO BLOOMINGTON ILLINOIS LINE. ACCUMULATIONS WILL BE
UNDER AN INCH BUT AMOUNTS APPROACHING AN INCH MAY BE SEEN ACROSS THE
EXTREME SOUTHERN PARTS OF SCOTLAND/CLARK COUNTIES IN MISSOURI AND
POSSIBLY THE SOUTHWEST CORNER OF HANCOCK COUNTY ILLINOIS.

DATA DOES SUGGEST THE POTENTIAL FOR A NARROW BAND OF SNOW IN STRONG
FORCING TO SET UP NEAR A KIRK TO KUIN LINE. A NORTHWARD SHIFT OF
THIS BAND WOULD PLACE IT ACROSS THE EXTREME SOUTHERN PARTS OF THE
AREA WITH THE POTENTIAL FOR SLIGHTLY HIGHER AMOUNTS.

HOWEVER...IF THE DRY AIR IS DEEPER THAN DEPICTED IN THE MODELS...
THEN THE SNOW BAND WOULD BE MUCH FURTHER SOUTH OF THE AREA AND SNOW
AMOUNTS ACROSS THE EXTREME SOUTH WOULD BE MUCH LESS.

THE KEY POINT IS THAT THERE WILL BE A VERY SHARP GRADIENT BETWEEN NO
SNOW AND ACCUMULATING SNOW ON THURSDAY.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 325 PM CST WED DEC 17 2014

OVERVIEW...ZONAL 500 MB FLOW WILL KEEP THINGS QUIET THROUGH SUNDAY.
UPPER LEVEL DISTURBANCE ASSOCIATED WITH THE SUBTROPICAL JET WILL
EJECT OUT OF NORTHERN MEXICO AND TRACK ACROSS THE SOUTHERN U.S.
THROUGH THE WEEKEND...REMAINING WELL SOUTH OF IOWA. A LARGE PACIFIC
JET STREAK WILL CARVE OUT A TROUGH OVER THE CENTRAL U.S. BEGINNING
MONDAY AND PERSISTING THROUGH NEXT WEEK. LIGHT RAIN AND SNOW WILL BE
POSSIBLE ON MONDAY ACROSS THE AREA.

FRIDAY AND SATURDAY...VERY QUIET PERIOD WITH HIGH TEMPS IN THE 30S
ALONG WITH DRY WEATHER. A WEAKENING TROUGH AXIS WILL MOVE THROUGH
FRIDAY NIGHT INTO SATURDAY MORNING WHICH HAS DECREASING DEFINITION
FORM THE MID-LEVELS TO THE SFC. PERIOD OF WEAK NEGATIVE OMEGA IS
FORECAST SATURDAY MORNING AS DCVA MOVES THROUGH BUT LAYER JUST BELOW
THE LIFT AT 600 MB IS VERY DRY DURING THIS TIME WITH RH NEAR 30%.

SUNDAY...SFC WINDS WILL BEGIN TO INCREASE OUT OF THE SE IN RESPONSE
TO A LEE-SIDE SFC LOW ORGANIZING OVER E MONTANA AND THE DAKOTAS.
HIGHS WILL ONCE AGAIN BE IN THE MID 30S TO NEAR 40 F.

MONDAY...PERIOD OF RAIN AND SNOW POSSIBLE AS LOW PRESSURE CENTER
REMAINS NW OF THE AREA ACROSS SW MINNESOTA AND N IOWA...NOT A
FAVORABLE LOCATION FOR MUCH ACCUMULATING SNOW TO OCCUR ACROSS THE
DVN FORECAST AREA.

TIMING AND P-TYPE ISSUE EXISTS BETWEEN THE GFS/ECMWF. ECMWF IS
COOLER AND ~6-12 HOURS SLOWER (THAN THE GFS)...IT HAS THE 850 MB 0 C
ISOTHERM TO THE SOUTH OF THE CWA INTO THE NIGHTTIME HOURS WITH
PRECIP LINGERING PAST 00Z/TUESDAY. THE GFS HAS 850 MB 0 C ISOTHERM
OVER NORTHERN CWA AND HAS MOST PRECIP OVER WITH BY THE AFTN. ECMWF
HAS LOW-LEVEL WAA RAISING 925 MB TEMPS TO +1 TO +3 C BY THE EVENING
AND BOTH MODELS FORECAST 2 METER MAX TEMPS IN THE MID TO UPPER 30S.

FORECAST SOUNDINGS HAVE WARMEST TEMPS IN THE LOWER PORTION OF THE
BOUNDARY LAYER WHICH ACTUALLY SLOWLY INCREASE THROUGH THE DAY.
THEREFORE MAY HAVE -RA/-SN MIX OR -SN TRANSITION TO -RA THROUGH THE
EVENT WITH BEST CHANCES FOR -SN ACROSS THE NORTH.

TUESDAY AND WEDNESDAY...A STRONG LOW WILL LIKELY FORM DURING THIS
TIME ALONG A DEVELOPING BAROCLINIC ZONE OVER THE SOUTHERN U.S./OHIO
VALLEY AND THEN MOVE INTO THE GREAT LAKES AREA. MODEL CONSENSUS FOR
THE DVN CWA IS COLDER AND BREEZY WITH SCT SNOW SHOWERS.

THE ECMWF IS SHOWING A STRONG LOW PRESSURE SYSTEM DEVELOPING ACROSS
ALABAMA AND TENNESSEE TUESDAY NIGHT AND THEN LIFTING NORTHWARD TO
LAKE HURON BY WEDNESDAY NIGHT WITH A CENTRAL PRESSURE DOWN TO 961
MB. THE GFS BRINGS IT TO THE SAME AREA BUT IS FURTHER SE DURING THE
CYCLOGENESIS PHASE. IT WILL BE INTERESTING TO SEE THE MODELS WORK
OUT THE POLAR-SUBTROPICAL JET PHASING ISSUES OVER THE NEXT FEW DAYS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1123 PM CST WED DEC 17 2014

A WEAK UPPER LEVEL SYSTEM WILL SPREAD LIGHT SNOW ACROSS MO INTO
CENTRAL IL ON THURSDAY. THIS MAY BRUSH THE BRL SITE...WHERE A
SEVERAL HOUR WINDOW OF MVFR CIGS/VISBYS IS FORECAST THURSDAY MORNING.
ELSEWHERE...SURFACE HIGH PRESSURE AND LIGHT NORTHWEST WINDS WILL
PROVIDE VFR CONDITIONS THROUGHOUT. FORECAST MODELS CONTINUE TO
SUGGEST A POTENTIAL FOR MVFR FOG LATE TONIGHT INTO MID MORNING
THURSDAY...WHICH HAS YET TO MATERIALIZE. WITH UNFAVORABLE
CONDITIONS DUE TO DRY AIR...DRY SURFACE CONDITIONS AND THICKENING
HIGH CLOUD COVER...THIS FOG HAS BEEN DISCOUNTED AND NOT INCLUDED IN THE
FORECASTS AT THIS TIME.

&&

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

$$

UPDATE...SHEETS
SYNOPSIS...08
SHORT TERM...08
LONG TERM...UTTECH
AVIATION...SHEETS







000
FXUS63 KDVN 180523
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1123 PM CST WED DEC 17 2014

.UPDATE...
ISSUED AT 1123 PM CST WED DEC 17 2014

SKIES HAVE REMAINED MOSTLY CLEAR OVER ALL BUT THE FAR SOUTH AND
EXTREME NORTHEAST THIS EVENING. THIS...ALONG WITH VERY DRY
AIR AND LIGHT WINDS HAS ALLOWED TEMPERATURES TO DROP INTO THE MID
TEENS OVER ALL BUT THE FAR SOUTH. OVER THE PAST HOUR...SATELLITE
SHOWED HIGH CLOUDS SPREADING NORTHEAST AHEAD OF THE UPPER LEVEL
SYSTEM MOVING INTO THE CENTRAL PLAINS. THIS SHOULD END THE
TEMPERATURE PLUNGE AND PREVIOUSLY UPDATED LOW...FROM AROUND 12
NORTHWEST TO THE LOWER 20S SOUTH OF HIGHWAY 34 SHOULD HOLD. THE
LEADING EDGE OF THE LIGHT SNOW IS STILL WELL SOUTH OF THE I-70
CORRIDOR IN MO AND WITH THE DRY AIR ALOFT...NOT LIKELY TO REACH
INTO OUR NE MO COUNTIES UNTIL AFTER 12Z AS MENTIONED IN THE
PREVIOUS DISCUSSION.

&&

.SYNOPSIS...
ISSUED AT 325 PM CST WED DEC 17 2014

12Z UA ANALYSIS HAS AN 850MB RIDGE RUNNING FROM THE GULF COAST INTO
THE NORTHERN PLAINS. A STORM SYSTEM WAS OVER SOUTHERN CANADA WITH A
LLJ RUNNING FROM WEST TEXAS INTO THE CENTRAL PLAINS. SATELLITE
TRENDS THROUGH MID AFTERNOON SHOW CLEARING SKIES ACROSS THE AREA
WITH CLOUDS FROM THE NEXT SYSTEM OVER THE CENTRAL AND SOUTHERN
PLAINS.

18Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE NORTHERN PLAINS AND
UPPER MIDWEST. A WEAK LOW WAS IN SOUTHEAST COLORADO WITH AN IMPLIED
BOUNDARY RUNNING FROM THE LOW INTO SOUTHWEST ARKANSAS. DEW POINTS
WERE IN THE SINGLE DIGITS AND TEENS ACROSS THE NORTHERN PLAINS AND
UPPER MIDWEST WITH 20S AND 30S FROM THE OHIO VALLEY INTO THE
SOUTHERN PLAINS.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 325 PM CST WED DEC 17 2014

QUIET CONDITIONS WITH CLEAR OR CLEARING SKIES WILL BE SEEN ACROSS
THE AREA THROUGH LATE AFTERNOON. DRY CONDITIONS WILL THEN BE SEEN
TONIGHT AND INTO THE PRE-DAWN HOURS WITH INCREASING CLOUDS. SNOW
WILL DEVELOP AND SPREAD NORTHEAST THROUGH KANSAS AND MISSOURI.
HOWEVER...DRY AIR ACROSS THE AREA WILL PREVENT ANY SNOW FROM
REACHING THE EXTREME SOUTH PRIOR TO 6 AM THURSDAY.

LOWS TONIGHT SHOULD DROP QUICKLY AFTER SUNSET AND THEN MAY BECOME
STEADY OR RISE SLIGHTLY AS CLOUDS MOVE BACK INTO THE AREA.

ON THURSDAY...STRONG FORCING WILL GO INTO SATURATING THE DRY AIR AT
THE LOW LEVELS AND ALLOW SNOW TO MOVE INTO THE FAR SOUTHERN AREAS.
THE FORCING RAPIDLY COLLAPSES BY LATE MORNING WITH MINIMAL FORCING
IN THE SATURATED ATMOSPHERE ACROSS THE SOUTH THIRD DURING THE
AFTERNOON.

THUS THE OPPORTUNITY FOR ACCUMULATING SNOW WILL OCCUR THURSDAY
MORNING IN A 4-6 HOUR WINDOW. THE BEST CHANCES FOR ANY ACCUMULATING
SNOW APPEAR TO BE SOUTH OF A KCNC...KFSW...TO KBMI LINE OR SOUTH OF
A CHARITON IOWA TO BLOOMINGTON ILLINOIS LINE. ACCUMULATIONS WILL BE
UNDER AN INCH BUT AMOUNTS APPROACHING AN INCH MAY BE SEEN ACROSS THE
EXTREME SOUTHERN PARTS OF SCOTLAND/CLARK COUNTIES IN MISSOURI AND
POSSIBLY THE SOUTHWEST CORNER OF HANCOCK COUNTY ILLINOIS.

DATA DOES SUGGEST THE POTENTIAL FOR A NARROW BAND OF SNOW IN STRONG
FORCING TO SET UP NEAR A KIRK TO KUIN LINE. A NORTHWARD SHIFT OF
THIS BAND WOULD PLACE IT ACROSS THE EXTREME SOUTHERN PARTS OF THE
AREA WITH THE POTENTIAL FOR SLIGHTLY HIGHER AMOUNTS.

HOWEVER...IF THE DRY AIR IS DEEPER THAN DEPICTED IN THE MODELS...
THEN THE SNOW BAND WOULD BE MUCH FURTHER SOUTH OF THE AREA AND SNOW
AMOUNTS ACROSS THE EXTREME SOUTH WOULD BE MUCH LESS.

THE KEY POINT IS THAT THERE WILL BE A VERY SHARP GRADIENT BETWEEN NO
SNOW AND ACCUMULATING SNOW ON THURSDAY.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 325 PM CST WED DEC 17 2014

OVERVIEW...ZONAL 500 MB FLOW WILL KEEP THINGS QUIET THROUGH SUNDAY.
UPPER LEVEL DISTURBANCE ASSOCIATED WITH THE SUBTROPICAL JET WILL
EJECT OUT OF NORTHERN MEXICO AND TRACK ACROSS THE SOUTHERN U.S.
THROUGH THE WEEKEND...REMAINING WELL SOUTH OF IOWA. A LARGE PACIFIC
JET STREAK WILL CARVE OUT A TROUGH OVER THE CENTRAL U.S. BEGINNING
MONDAY AND PERSISTING THROUGH NEXT WEEK. LIGHT RAIN AND SNOW WILL BE
POSSIBLE ON MONDAY ACROSS THE AREA.

FRIDAY AND SATURDAY...VERY QUIET PERIOD WITH HIGH TEMPS IN THE 30S
ALONG WITH DRY WEATHER. A WEAKENING TROUGH AXIS WILL MOVE THROUGH
FRIDAY NIGHT INTO SATURDAY MORNING WHICH HAS DECREASING DEFINITION
FORM THE MID-LEVELS TO THE SFC. PERIOD OF WEAK NEGATIVE OMEGA IS
FORECAST SATURDAY MORNING AS DCVA MOVES THROUGH BUT LAYER JUST BELOW
THE LIFT AT 600 MB IS VERY DRY DURING THIS TIME WITH RH NEAR 30%.

SUNDAY...SFC WINDS WILL BEGIN TO INCREASE OUT OF THE SE IN RESPONSE
TO A LEE-SIDE SFC LOW ORGANIZING OVER E MONTANA AND THE DAKOTAS.
HIGHS WILL ONCE AGAIN BE IN THE MID 30S TO NEAR 40 F.

MONDAY...PERIOD OF RAIN AND SNOW POSSIBLE AS LOW PRESSURE CENTER
REMAINS NW OF THE AREA ACROSS SW MINNESOTA AND N IOWA...NOT A
FAVORABLE LOCATION FOR MUCH ACCUMULATING SNOW TO OCCUR ACROSS THE
DVN FORECAST AREA.

TIMING AND P-TYPE ISSUE EXISTS BETWEEN THE GFS/ECMWF. ECMWF IS
COOLER AND ~6-12 HOURS SLOWER (THAN THE GFS)...IT HAS THE 850 MB 0 C
ISOTHERM TO THE SOUTH OF THE CWA INTO THE NIGHTTIME HOURS WITH
PRECIP LINGERING PAST 00Z/TUESDAY. THE GFS HAS 850 MB 0 C ISOTHERM
OVER NORTHERN CWA AND HAS MOST PRECIP OVER WITH BY THE AFTN. ECMWF
HAS LOW-LEVEL WAA RAISING 925 MB TEMPS TO +1 TO +3 C BY THE EVENING
AND BOTH MODELS FORECAST 2 METER MAX TEMPS IN THE MID TO UPPER 30S.

FORECAST SOUNDINGS HAVE WARMEST TEMPS IN THE LOWER PORTION OF THE
BOUNDARY LAYER WHICH ACTUALLY SLOWLY INCREASE THROUGH THE DAY.
THEREFORE MAY HAVE -RA/-SN MIX OR -SN TRANSITION TO -RA THROUGH THE
EVENT WITH BEST CHANCES FOR -SN ACROSS THE NORTH.

TUESDAY AND WEDNESDAY...A STRONG LOW WILL LIKELY FORM DURING THIS
TIME ALONG A DEVELOPING BAROCLINIC ZONE OVER THE SOUTHERN U.S./OHIO
VALLEY AND THEN MOVE INTO THE GREAT LAKES AREA. MODEL CONSENSUS FOR
THE DVN CWA IS COLDER AND BREEZY WITH SCT SNOW SHOWERS.

THE ECMWF IS SHOWING A STRONG LOW PRESSURE SYSTEM DEVELOPING ACROSS
ALABAMA AND TENNESSEE TUESDAY NIGHT AND THEN LIFTING NORTHWARD TO
LAKE HURON BY WEDNESDAY NIGHT WITH A CENTRAL PRESSURE DOWN TO 961
MB. THE GFS BRINGS IT TO THE SAME AREA BUT IS FURTHER SE DURING THE
CYCLOGENESIS PHASE. IT WILL BE INTERESTING TO SEE THE MODELS WORK
OUT THE POLAR-SUBTROPICAL JET PHASING ISSUES OVER THE NEXT FEW DAYS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1123 PM CST WED DEC 17 2014

A WEAK UPPER LEVEL SYSTEM WILL SPREAD LIGHT SNOW ACROSS MO INTO
CENTRAL IL ON THURSDAY. THIS MAY BRUSH THE BRL SITE...WHERE A
SEVERAL HOUR WINDOW OF MVFR CIGS/VISBYS IS FORECAST THURSDAY MORNING.
ELSEWHERE...SURFACE HIGH PRESSURE AND LIGHT NORTHWEST WINDS WILL
PROVIDE VFR CONDITIONS THROUGHOUT. FORECAST MODELS CONTINUE TO
SUGGEST A POTENTIAL FOR MVFR FOG LATE TONIGHT INTO MID MORNING
THURSDAY...WHICH HAS YET TO MATERIALIZE. WITH UNFAVORABLE
CONDITIONS DUE TO DRY AIR...DRY SURFACE CONDITIONS AND THICKENING
HIGH CLOUD COVER...THIS FOG HAS BEEN DISCOUNTED AND NOT INCLUDED IN THE
FORECASTS AT THIS TIME.

&&

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

$$

UPDATE...SHEETS
SYNOPSIS...08
SHORT TERM...08
LONG TERM...UTTECH
AVIATION...SHEETS







000
FXUS63 KDVN 180523
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1123 PM CST WED DEC 17 2014

.UPDATE...
ISSUED AT 1123 PM CST WED DEC 17 2014

SKIES HAVE REMAINED MOSTLY CLEAR OVER ALL BUT THE FAR SOUTH AND
EXTREME NORTHEAST THIS EVENING. THIS...ALONG WITH VERY DRY
AIR AND LIGHT WINDS HAS ALLOWED TEMPERATURES TO DROP INTO THE MID
TEENS OVER ALL BUT THE FAR SOUTH. OVER THE PAST HOUR...SATELLITE
SHOWED HIGH CLOUDS SPREADING NORTHEAST AHEAD OF THE UPPER LEVEL
SYSTEM MOVING INTO THE CENTRAL PLAINS. THIS SHOULD END THE
TEMPERATURE PLUNGE AND PREVIOUSLY UPDATED LOW...FROM AROUND 12
NORTHWEST TO THE LOWER 20S SOUTH OF HIGHWAY 34 SHOULD HOLD. THE
LEADING EDGE OF THE LIGHT SNOW IS STILL WELL SOUTH OF THE I-70
CORRIDOR IN MO AND WITH THE DRY AIR ALOFT...NOT LIKELY TO REACH
INTO OUR NE MO COUNTIES UNTIL AFTER 12Z AS MENTIONED IN THE
PREVIOUS DISCUSSION.

&&

.SYNOPSIS...
ISSUED AT 325 PM CST WED DEC 17 2014

12Z UA ANALYSIS HAS AN 850MB RIDGE RUNNING FROM THE GULF COAST INTO
THE NORTHERN PLAINS. A STORM SYSTEM WAS OVER SOUTHERN CANADA WITH A
LLJ RUNNING FROM WEST TEXAS INTO THE CENTRAL PLAINS. SATELLITE
TRENDS THROUGH MID AFTERNOON SHOW CLEARING SKIES ACROSS THE AREA
WITH CLOUDS FROM THE NEXT SYSTEM OVER THE CENTRAL AND SOUTHERN
PLAINS.

18Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE NORTHERN PLAINS AND
UPPER MIDWEST. A WEAK LOW WAS IN SOUTHEAST COLORADO WITH AN IMPLIED
BOUNDARY RUNNING FROM THE LOW INTO SOUTHWEST ARKANSAS. DEW POINTS
WERE IN THE SINGLE DIGITS AND TEENS ACROSS THE NORTHERN PLAINS AND
UPPER MIDWEST WITH 20S AND 30S FROM THE OHIO VALLEY INTO THE
SOUTHERN PLAINS.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 325 PM CST WED DEC 17 2014

QUIET CONDITIONS WITH CLEAR OR CLEARING SKIES WILL BE SEEN ACROSS
THE AREA THROUGH LATE AFTERNOON. DRY CONDITIONS WILL THEN BE SEEN
TONIGHT AND INTO THE PRE-DAWN HOURS WITH INCREASING CLOUDS. SNOW
WILL DEVELOP AND SPREAD NORTHEAST THROUGH KANSAS AND MISSOURI.
HOWEVER...DRY AIR ACROSS THE AREA WILL PREVENT ANY SNOW FROM
REACHING THE EXTREME SOUTH PRIOR TO 6 AM THURSDAY.

LOWS TONIGHT SHOULD DROP QUICKLY AFTER SUNSET AND THEN MAY BECOME
STEADY OR RISE SLIGHTLY AS CLOUDS MOVE BACK INTO THE AREA.

ON THURSDAY...STRONG FORCING WILL GO INTO SATURATING THE DRY AIR AT
THE LOW LEVELS AND ALLOW SNOW TO MOVE INTO THE FAR SOUTHERN AREAS.
THE FORCING RAPIDLY COLLAPSES BY LATE MORNING WITH MINIMAL FORCING
IN THE SATURATED ATMOSPHERE ACROSS THE SOUTH THIRD DURING THE
AFTERNOON.

THUS THE OPPORTUNITY FOR ACCUMULATING SNOW WILL OCCUR THURSDAY
MORNING IN A 4-6 HOUR WINDOW. THE BEST CHANCES FOR ANY ACCUMULATING
SNOW APPEAR TO BE SOUTH OF A KCNC...KFSW...TO KBMI LINE OR SOUTH OF
A CHARITON IOWA TO BLOOMINGTON ILLINOIS LINE. ACCUMULATIONS WILL BE
UNDER AN INCH BUT AMOUNTS APPROACHING AN INCH MAY BE SEEN ACROSS THE
EXTREME SOUTHERN PARTS OF SCOTLAND/CLARK COUNTIES IN MISSOURI AND
POSSIBLY THE SOUTHWEST CORNER OF HANCOCK COUNTY ILLINOIS.

DATA DOES SUGGEST THE POTENTIAL FOR A NARROW BAND OF SNOW IN STRONG
FORCING TO SET UP NEAR A KIRK TO KUIN LINE. A NORTHWARD SHIFT OF
THIS BAND WOULD PLACE IT ACROSS THE EXTREME SOUTHERN PARTS OF THE
AREA WITH THE POTENTIAL FOR SLIGHTLY HIGHER AMOUNTS.

HOWEVER...IF THE DRY AIR IS DEEPER THAN DEPICTED IN THE MODELS...
THEN THE SNOW BAND WOULD BE MUCH FURTHER SOUTH OF THE AREA AND SNOW
AMOUNTS ACROSS THE EXTREME SOUTH WOULD BE MUCH LESS.

THE KEY POINT IS THAT THERE WILL BE A VERY SHARP GRADIENT BETWEEN NO
SNOW AND ACCUMULATING SNOW ON THURSDAY.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 325 PM CST WED DEC 17 2014

OVERVIEW...ZONAL 500 MB FLOW WILL KEEP THINGS QUIET THROUGH SUNDAY.
UPPER LEVEL DISTURBANCE ASSOCIATED WITH THE SUBTROPICAL JET WILL
EJECT OUT OF NORTHERN MEXICO AND TRACK ACROSS THE SOUTHERN U.S.
THROUGH THE WEEKEND...REMAINING WELL SOUTH OF IOWA. A LARGE PACIFIC
JET STREAK WILL CARVE OUT A TROUGH OVER THE CENTRAL U.S. BEGINNING
MONDAY AND PERSISTING THROUGH NEXT WEEK. LIGHT RAIN AND SNOW WILL BE
POSSIBLE ON MONDAY ACROSS THE AREA.

FRIDAY AND SATURDAY...VERY QUIET PERIOD WITH HIGH TEMPS IN THE 30S
ALONG WITH DRY WEATHER. A WEAKENING TROUGH AXIS WILL MOVE THROUGH
FRIDAY NIGHT INTO SATURDAY MORNING WHICH HAS DECREASING DEFINITION
FORM THE MID-LEVELS TO THE SFC. PERIOD OF WEAK NEGATIVE OMEGA IS
FORECAST SATURDAY MORNING AS DCVA MOVES THROUGH BUT LAYER JUST BELOW
THE LIFT AT 600 MB IS VERY DRY DURING THIS TIME WITH RH NEAR 30%.

SUNDAY...SFC WINDS WILL BEGIN TO INCREASE OUT OF THE SE IN RESPONSE
TO A LEE-SIDE SFC LOW ORGANIZING OVER E MONTANA AND THE DAKOTAS.
HIGHS WILL ONCE AGAIN BE IN THE MID 30S TO NEAR 40 F.

MONDAY...PERIOD OF RAIN AND SNOW POSSIBLE AS LOW PRESSURE CENTER
REMAINS NW OF THE AREA ACROSS SW MINNESOTA AND N IOWA...NOT A
FAVORABLE LOCATION FOR MUCH ACCUMULATING SNOW TO OCCUR ACROSS THE
DVN FORECAST AREA.

TIMING AND P-TYPE ISSUE EXISTS BETWEEN THE GFS/ECMWF. ECMWF IS
COOLER AND ~6-12 HOURS SLOWER (THAN THE GFS)...IT HAS THE 850 MB 0 C
ISOTHERM TO THE SOUTH OF THE CWA INTO THE NIGHTTIME HOURS WITH
PRECIP LINGERING PAST 00Z/TUESDAY. THE GFS HAS 850 MB 0 C ISOTHERM
OVER NORTHERN CWA AND HAS MOST PRECIP OVER WITH BY THE AFTN. ECMWF
HAS LOW-LEVEL WAA RAISING 925 MB TEMPS TO +1 TO +3 C BY THE EVENING
AND BOTH MODELS FORECAST 2 METER MAX TEMPS IN THE MID TO UPPER 30S.

FORECAST SOUNDINGS HAVE WARMEST TEMPS IN THE LOWER PORTION OF THE
BOUNDARY LAYER WHICH ACTUALLY SLOWLY INCREASE THROUGH THE DAY.
THEREFORE MAY HAVE -RA/-SN MIX OR -SN TRANSITION TO -RA THROUGH THE
EVENT WITH BEST CHANCES FOR -SN ACROSS THE NORTH.

TUESDAY AND WEDNESDAY...A STRONG LOW WILL LIKELY FORM DURING THIS
TIME ALONG A DEVELOPING BAROCLINIC ZONE OVER THE SOUTHERN U.S./OHIO
VALLEY AND THEN MOVE INTO THE GREAT LAKES AREA. MODEL CONSENSUS FOR
THE DVN CWA IS COLDER AND BREEZY WITH SCT SNOW SHOWERS.

THE ECMWF IS SHOWING A STRONG LOW PRESSURE SYSTEM DEVELOPING ACROSS
ALABAMA AND TENNESSEE TUESDAY NIGHT AND THEN LIFTING NORTHWARD TO
LAKE HURON BY WEDNESDAY NIGHT WITH A CENTRAL PRESSURE DOWN TO 961
MB. THE GFS BRINGS IT TO THE SAME AREA BUT IS FURTHER SE DURING THE
CYCLOGENESIS PHASE. IT WILL BE INTERESTING TO SEE THE MODELS WORK
OUT THE POLAR-SUBTROPICAL JET PHASING ISSUES OVER THE NEXT FEW DAYS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1123 PM CST WED DEC 17 2014

A WEAK UPPER LEVEL SYSTEM WILL SPREAD LIGHT SNOW ACROSS MO INTO
CENTRAL IL ON THURSDAY. THIS MAY BRUSH THE BRL SITE...WHERE A
SEVERAL HOUR WINDOW OF MVFR CIGS/VISBYS IS FORECAST THURSDAY MORNING.
ELSEWHERE...SURFACE HIGH PRESSURE AND LIGHT NORTHWEST WINDS WILL
PROVIDE VFR CONDITIONS THROUGHOUT. FORECAST MODELS CONTINUE TO
SUGGEST A POTENTIAL FOR MVFR FOG LATE TONIGHT INTO MID MORNING
THURSDAY...WHICH HAS YET TO MATERIALIZE. WITH UNFAVORABLE
CONDITIONS DUE TO DRY AIR...DRY SURFACE CONDITIONS AND THICKENING
HIGH CLOUD COVER...THIS FOG HAS BEEN DISCOUNTED AND NOT INCLUDED IN THE
FORECASTS AT THIS TIME.

&&

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

$$

UPDATE...SHEETS
SYNOPSIS...08
SHORT TERM...08
LONG TERM...UTTECH
AVIATION...SHEETS







000
FXUS63 KDVN 180523
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1123 PM CST WED DEC 17 2014

.UPDATE...
ISSUED AT 1123 PM CST WED DEC 17 2014

SKIES HAVE REMAINED MOSTLY CLEAR OVER ALL BUT THE FAR SOUTH AND
EXTREME NORTHEAST THIS EVENING. THIS...ALONG WITH VERY DRY
AIR AND LIGHT WINDS HAS ALLOWED TEMPERATURES TO DROP INTO THE MID
TEENS OVER ALL BUT THE FAR SOUTH. OVER THE PAST HOUR...SATELLITE
SHOWED HIGH CLOUDS SPREADING NORTHEAST AHEAD OF THE UPPER LEVEL
SYSTEM MOVING INTO THE CENTRAL PLAINS. THIS SHOULD END THE
TEMPERATURE PLUNGE AND PREVIOUSLY UPDATED LOW...FROM AROUND 12
NORTHWEST TO THE LOWER 20S SOUTH OF HIGHWAY 34 SHOULD HOLD. THE
LEADING EDGE OF THE LIGHT SNOW IS STILL WELL SOUTH OF THE I-70
CORRIDOR IN MO AND WITH THE DRY AIR ALOFT...NOT LIKELY TO REACH
INTO OUR NE MO COUNTIES UNTIL AFTER 12Z AS MENTIONED IN THE
PREVIOUS DISCUSSION.

&&

.SYNOPSIS...
ISSUED AT 325 PM CST WED DEC 17 2014

12Z UA ANALYSIS HAS AN 850MB RIDGE RUNNING FROM THE GULF COAST INTO
THE NORTHERN PLAINS. A STORM SYSTEM WAS OVER SOUTHERN CANADA WITH A
LLJ RUNNING FROM WEST TEXAS INTO THE CENTRAL PLAINS. SATELLITE
TRENDS THROUGH MID AFTERNOON SHOW CLEARING SKIES ACROSS THE AREA
WITH CLOUDS FROM THE NEXT SYSTEM OVER THE CENTRAL AND SOUTHERN
PLAINS.

18Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE NORTHERN PLAINS AND
UPPER MIDWEST. A WEAK LOW WAS IN SOUTHEAST COLORADO WITH AN IMPLIED
BOUNDARY RUNNING FROM THE LOW INTO SOUTHWEST ARKANSAS. DEW POINTS
WERE IN THE SINGLE DIGITS AND TEENS ACROSS THE NORTHERN PLAINS AND
UPPER MIDWEST WITH 20S AND 30S FROM THE OHIO VALLEY INTO THE
SOUTHERN PLAINS.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 325 PM CST WED DEC 17 2014

QUIET CONDITIONS WITH CLEAR OR CLEARING SKIES WILL BE SEEN ACROSS
THE AREA THROUGH LATE AFTERNOON. DRY CONDITIONS WILL THEN BE SEEN
TONIGHT AND INTO THE PRE-DAWN HOURS WITH INCREASING CLOUDS. SNOW
WILL DEVELOP AND SPREAD NORTHEAST THROUGH KANSAS AND MISSOURI.
HOWEVER...DRY AIR ACROSS THE AREA WILL PREVENT ANY SNOW FROM
REACHING THE EXTREME SOUTH PRIOR TO 6 AM THURSDAY.

LOWS TONIGHT SHOULD DROP QUICKLY AFTER SUNSET AND THEN MAY BECOME
STEADY OR RISE SLIGHTLY AS CLOUDS MOVE BACK INTO THE AREA.

ON THURSDAY...STRONG FORCING WILL GO INTO SATURATING THE DRY AIR AT
THE LOW LEVELS AND ALLOW SNOW TO MOVE INTO THE FAR SOUTHERN AREAS.
THE FORCING RAPIDLY COLLAPSES BY LATE MORNING WITH MINIMAL FORCING
IN THE SATURATED ATMOSPHERE ACROSS THE SOUTH THIRD DURING THE
AFTERNOON.

THUS THE OPPORTUNITY FOR ACCUMULATING SNOW WILL OCCUR THURSDAY
MORNING IN A 4-6 HOUR WINDOW. THE BEST CHANCES FOR ANY ACCUMULATING
SNOW APPEAR TO BE SOUTH OF A KCNC...KFSW...TO KBMI LINE OR SOUTH OF
A CHARITON IOWA TO BLOOMINGTON ILLINOIS LINE. ACCUMULATIONS WILL BE
UNDER AN INCH BUT AMOUNTS APPROACHING AN INCH MAY BE SEEN ACROSS THE
EXTREME SOUTHERN PARTS OF SCOTLAND/CLARK COUNTIES IN MISSOURI AND
POSSIBLY THE SOUTHWEST CORNER OF HANCOCK COUNTY ILLINOIS.

DATA DOES SUGGEST THE POTENTIAL FOR A NARROW BAND OF SNOW IN STRONG
FORCING TO SET UP NEAR A KIRK TO KUIN LINE. A NORTHWARD SHIFT OF
THIS BAND WOULD PLACE IT ACROSS THE EXTREME SOUTHERN PARTS OF THE
AREA WITH THE POTENTIAL FOR SLIGHTLY HIGHER AMOUNTS.

HOWEVER...IF THE DRY AIR IS DEEPER THAN DEPICTED IN THE MODELS...
THEN THE SNOW BAND WOULD BE MUCH FURTHER SOUTH OF THE AREA AND SNOW
AMOUNTS ACROSS THE EXTREME SOUTH WOULD BE MUCH LESS.

THE KEY POINT IS THAT THERE WILL BE A VERY SHARP GRADIENT BETWEEN NO
SNOW AND ACCUMULATING SNOW ON THURSDAY.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 325 PM CST WED DEC 17 2014

OVERVIEW...ZONAL 500 MB FLOW WILL KEEP THINGS QUIET THROUGH SUNDAY.
UPPER LEVEL DISTURBANCE ASSOCIATED WITH THE SUBTROPICAL JET WILL
EJECT OUT OF NORTHERN MEXICO AND TRACK ACROSS THE SOUTHERN U.S.
THROUGH THE WEEKEND...REMAINING WELL SOUTH OF IOWA. A LARGE PACIFIC
JET STREAK WILL CARVE OUT A TROUGH OVER THE CENTRAL U.S. BEGINNING
MONDAY AND PERSISTING THROUGH NEXT WEEK. LIGHT RAIN AND SNOW WILL BE
POSSIBLE ON MONDAY ACROSS THE AREA.

FRIDAY AND SATURDAY...VERY QUIET PERIOD WITH HIGH TEMPS IN THE 30S
ALONG WITH DRY WEATHER. A WEAKENING TROUGH AXIS WILL MOVE THROUGH
FRIDAY NIGHT INTO SATURDAY MORNING WHICH HAS DECREASING DEFINITION
FORM THE MID-LEVELS TO THE SFC. PERIOD OF WEAK NEGATIVE OMEGA IS
FORECAST SATURDAY MORNING AS DCVA MOVES THROUGH BUT LAYER JUST BELOW
THE LIFT AT 600 MB IS VERY DRY DURING THIS TIME WITH RH NEAR 30%.

SUNDAY...SFC WINDS WILL BEGIN TO INCREASE OUT OF THE SE IN RESPONSE
TO A LEE-SIDE SFC LOW ORGANIZING OVER E MONTANA AND THE DAKOTAS.
HIGHS WILL ONCE AGAIN BE IN THE MID 30S TO NEAR 40 F.

MONDAY...PERIOD OF RAIN AND SNOW POSSIBLE AS LOW PRESSURE CENTER
REMAINS NW OF THE AREA ACROSS SW MINNESOTA AND N IOWA...NOT A
FAVORABLE LOCATION FOR MUCH ACCUMULATING SNOW TO OCCUR ACROSS THE
DVN FORECAST AREA.

TIMING AND P-TYPE ISSUE EXISTS BETWEEN THE GFS/ECMWF. ECMWF IS
COOLER AND ~6-12 HOURS SLOWER (THAN THE GFS)...IT HAS THE 850 MB 0 C
ISOTHERM TO THE SOUTH OF THE CWA INTO THE NIGHTTIME HOURS WITH
PRECIP LINGERING PAST 00Z/TUESDAY. THE GFS HAS 850 MB 0 C ISOTHERM
OVER NORTHERN CWA AND HAS MOST PRECIP OVER WITH BY THE AFTN. ECMWF
HAS LOW-LEVEL WAA RAISING 925 MB TEMPS TO +1 TO +3 C BY THE EVENING
AND BOTH MODELS FORECAST 2 METER MAX TEMPS IN THE MID TO UPPER 30S.

FORECAST SOUNDINGS HAVE WARMEST TEMPS IN THE LOWER PORTION OF THE
BOUNDARY LAYER WHICH ACTUALLY SLOWLY INCREASE THROUGH THE DAY.
THEREFORE MAY HAVE -RA/-SN MIX OR -SN TRANSITION TO -RA THROUGH THE
EVENT WITH BEST CHANCES FOR -SN ACROSS THE NORTH.

TUESDAY AND WEDNESDAY...A STRONG LOW WILL LIKELY FORM DURING THIS
TIME ALONG A DEVELOPING BAROCLINIC ZONE OVER THE SOUTHERN U.S./OHIO
VALLEY AND THEN MOVE INTO THE GREAT LAKES AREA. MODEL CONSENSUS FOR
THE DVN CWA IS COLDER AND BREEZY WITH SCT SNOW SHOWERS.

THE ECMWF IS SHOWING A STRONG LOW PRESSURE SYSTEM DEVELOPING ACROSS
ALABAMA AND TENNESSEE TUESDAY NIGHT AND THEN LIFTING NORTHWARD TO
LAKE HURON BY WEDNESDAY NIGHT WITH A CENTRAL PRESSURE DOWN TO 961
MB. THE GFS BRINGS IT TO THE SAME AREA BUT IS FURTHER SE DURING THE
CYCLOGENESIS PHASE. IT WILL BE INTERESTING TO SEE THE MODELS WORK
OUT THE POLAR-SUBTROPICAL JET PHASING ISSUES OVER THE NEXT FEW DAYS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1123 PM CST WED DEC 17 2014

A WEAK UPPER LEVEL SYSTEM WILL SPREAD LIGHT SNOW ACROSS MO INTO
CENTRAL IL ON THURSDAY. THIS MAY BRUSH THE BRL SITE...WHERE A
SEVERAL HOUR WINDOW OF MVFR CIGS/VISBYS IS FORECAST THURSDAY MORNING.
ELSEWHERE...SURFACE HIGH PRESSURE AND LIGHT NORTHWEST WINDS WILL
PROVIDE VFR CONDITIONS THROUGHOUT. FORECAST MODELS CONTINUE TO
SUGGEST A POTENTIAL FOR MVFR FOG LATE TONIGHT INTO MID MORNING
THURSDAY...WHICH HAS YET TO MATERIALIZE. WITH UNFAVORABLE
CONDITIONS DUE TO DRY AIR...DRY SURFACE CONDITIONS AND THICKENING
HIGH CLOUD COVER...THIS FOG HAS BEEN DISCOUNTED AND NOT INCLUDED IN THE
FORECASTS AT THIS TIME.

&&

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

$$

UPDATE...SHEETS
SYNOPSIS...08
SHORT TERM...08
LONG TERM...UTTECH
AVIATION...SHEETS







000
FXUS63 KDVN 172336
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
536 PM CST WED DEC 17 2014

.SYNOPSIS...
ISSUED AT 325 PM CST WED DEC 17 2014

12Z UA ANALYSIS HAS AN 850MB RIDGE RUNNING FROM THE GULF COAST INTO
THE NORTHERN PLAINS. A STORM SYSTEM WAS OVER SOUTHERN CANADA WITH A
LLJ RUNNING FROM WEST TEXAS INTO THE CENTRAL PLAINS. SATELLITE
TRENDS THROUGH MID AFTERNOON SHOW CLEARING SKIES ACROSS THE AREA
WITH CLOUDS FROM THE NEXT SYSTEM OVER THE CENTRAL AND SOUTHERN
PLAINS.

18Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE NORTHERN PLAINS AND
UPPER MIDWEST. A WEAK LOW WAS IN SOUTHEAST COLORADO WITH AN IMPLIED
BOUNDARY RUNNING FROM THE LOW INTO SOUTHWEST ARKANSAS. DEW POINTS
WERE IN THE SINGLE DIGITS AND TEENS ACROSS THE NORTHERN PLAINS AND
UPPER MIDWEST WITH 20S AND 30S FROM THE OHIO VALLEY INTO THE
SOUTHERN PLAINS.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 325 PM CST WED DEC 17 2014

QUIET CONDITIONS WITH CLEAR OR CLEARING SKIES WILL BE SEEN ACROSS
THE AREA THROUGH LATE AFTERNOON. DRY CONDITIONS WILL THEN BE SEEN
TONIGHT AND INTO THE PRE-DAWN HOURS WITH INCREASING CLOUDS. SNOW
WILL DEVELOP AND SPREAD NORTHEAST THROUGH KANSAS AND MISSOURI.
HOWEVER...DRY AIR ACROSS THE AREA WILL PREVENT ANY SNOW FROM
REACHING THE EXTREME SOUTH PRIOR TO 6 AM THURSDAY.

LOWS TONIGHT SHOULD DROP QUICKLY AFTER SUNSET AND THEN MAY BECOME
STEADY OR RISE SLIGHTLY AS CLOUDS MOVE BACK INTO THE AREA.

ON THURSDAY...STRONG FORCING WILL GO INTO SATURATING THE DRY AIR AT
THE LOW LEVELS AND ALLOW SNOW TO MOVE INTO THE FAR SOUTHERN AREAS.
THE FORCING RAPIDLY COLLAPSES BY LATE MORNING WITH MINIMAL FORCING
IN THE SATURATED ATMOSPHERE ACROSS THE SOUTH THIRD DURING THE
AFTERNOON.

THUS THE OPPORTUNITY FOR ACCUMULATING SNOW WILL OCCUR THURSDAY
MORNING IN A 4-6 HOUR WINDOW. THE BEST CHANCES FOR ANY ACCUMULATING
SNOW APPEAR TO BE SOUTH OF A KCNC...KFSW...TO KBMI LINE OR SOUTH OF
A CHARITON IOWA TO BLOOMINGTON ILLINOIS LINE. ACCUMULATIONS WILL BE
UNDER AN INCH BUT AMOUNTS APPROACHING AN INCH MAY BE SEEN ACROSS THE
EXTREME SOUTHERN PARTS OF SCOTLAND/CLARK COUNTIES IN MISSOURI AND
POSSIBLY THE SOUTHWEST CORNER OF HANCOCK COUNTY ILLINOIS.

DATA DOES SUGGEST THE POTENTIAL FOR A NARROW BAND OF SNOW IN STRONG
FORCING TO SET UP NEAR A KIRK TO KUIN LINE. A NORTHWARD SHIFT OF
THIS BAND WOULD PLACE IT ACROSS THE EXTREME SOUTHERN PARTS OF THE
AREA WITH THE POTENTIAL FOR SLIGHTLY HIGHER AMOUNTS.

HOWEVER...IF THE DRY AIR IS DEEPER THAN DEPICTED IN THE MODELS...
THEN THE SNOW BAND WOULD BE MUCH FURTHER SOUTH OF THE AREA AND SNOW
AMOUNTS ACROSS THE EXTREME SOUTH WOULD BE MUCH LESS.

THE KEY POINT IS THAT THERE WILL BE A VERY SHARP GRADIENT BETWEEN NO
SNOW AND ACCUMULATING SNOW ON THURSDAY.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 325 PM CST WED DEC 17 2014

OVERVIEW...ZONAL 500 MB FLOW WILL KEEP THINGS QUIET THROUGH SUNDAY.
UPPER LEVEL DISTURBANCE ASSOCIATED WITH THE SUBTROPICAL JET WILL
EJECT OUT OF NORTHERN MEXICO AND TRACK ACROSS THE SOUTHERN U.S.
THROUGH THE WEEKEND...REMAINING WELL SOUTH OF IOWA. A LARGE PACIFIC
JET STREAK WILL CARVE OUT A TROUGH OVER THE CENTRAL U.S. BEGINNING
MONDAY AND PERSISTING THROUGH NEXT WEEK. LIGHT RAIN AND SNOW WILL BE
POSSIBLE ON MONDAY ACROSS THE AREA.

FRIDAY AND SATURDAY...VERY QUIET PERIOD WITH HIGH TEMPS IN THE 30S
ALONG WITH DRY WEATHER. A WEAKENING TROUGH AXIS WILL MOVE THROUGH
FRIDAY NIGHT INTO SATURDAY MORNING WHICH HAS DECREASING DEFINITION
FORM THE MID-LEVELS TO THE SFC. PERIOD OF WEAK NEGATIVE OMEGA IS
FORECAST SATURDAY MORNING AS DCVA MOVES THROUGH BUT LAYER JUST BELOW
THE LIFT AT 600 MB IS VERY DRY DURING THIS TIME WITH RH NEAR 30%.

SUNDAY...SFC WINDS WILL BEGIN TO INCREASE OUT OF THE SE IN RESPONSE
TO A LEE-SIDE SFC LOW ORGANIZING OVER E MONTANA AND THE DAKOTAS.
HIGHS WILL ONCE AGAIN BE IN THE MID 30S TO NEAR 40 F.

MONDAY...PERIOD OF RAIN AND SNOW POSSIBLE AS LOW PRESSURE CENTER
REMAINS NW OF THE AREA ACROSS SW MINNESOTA AND N IOWA...NOT A
FAVORABLE LOCATION FOR MUCH ACCUMULATING SNOW TO OCCUR ACROSS THE
DVN FORECAST AREA.

TIMING AND P-TYPE ISSUE EXISTS BETWEEN THE GFS/ECMWF. ECMWF IS
COOLER AND ~6-12 HOURS SLOWER (THAN THE GFS)...IT HAS THE 850 MB 0 C
ISOTHERM TO THE SOUTH OF THE CWA INTO THE NIGHTTIME HOURS WITH
PRECIP LINGERING PAST 00Z/TUESDAY. THE GFS HAS 850 MB 0 C ISOTHERM
OVER NORTHERN CWA AND HAS MOST PRECIP OVER WITH BY THE AFTN. ECMWF
HAS LOW-LEVEL WAA RAISING 925 MB TEMPS TO +1 TO +3 C BY THE EVENING
AND BOTH MODELS FORECAST 2 METER MAX TEMPS IN THE MID TO UPPER 30S.

FORECAST SOUNDINGS HAVE WARMEST TEMPS IN THE LOWER PORTION OF THE
BOUNDARY LAYER WHICH ACTUALLY SLOWLY INCREASE THROUGH THE DAY.
THEREFORE MAY HAVE -RA/-SN MIX OR -SN TRANSITION TO -RA THROUGH THE
EVENT WITH BEST CHANCES FOR -SN ACROSS THE NORTH.

TUESDAY AND WEDNESDAY...A STRONG LOW WILL LIKELY FORM DURING THIS
TIME ALONG A DEVELOPING BAROCLINIC ZONE OVER THE SOUTHERN U.S./OHIO
VALLEY AND THEN MOVE INTO THE GREAT LAKES AREA. MODEL CONSENSUS FOR
THE DVN CWA IS COLDER AND BREEZY WITH SCT SNOW SHOWERS.

THE ECMWF IS SHOWING A STRONG LOW PRESSURE SYSTEM DEVELOPING ACROSS
ALABAMA AND TENNESSEE TUESDAY NIGHT AND THEN LIFTING NORTHWARD TO
LAKE HURON BY WEDNESDAY NIGHT WITH A CENTRAL PRESSURE DOWN TO 961
MB. THE GFS BRINGS IT TO THE SAME AREA BUT IS FURTHER SE DURING THE
CYCLOGENESIS PHASE. IT WILL BE INTERESTING TO SEE THE MODELS WORK
OUT THE POLAR-SUBTROPICAL JET PHASING ISSUES OVER THE NEXT FEW DAYS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 536 PM CST WED DEC 17 2014

A WEAK UPPER LEVEL SYSTEM WILL SPREAD LIGHT SNOW ACROSS MO INTO
CENTRAL IL ON WEDNESDAY. THIS MAY BRUSH THE BRL SITE...WHERE A
SEVERAL HOUR WINDOW OF MVFR CIGS/VISBYS IS FORECAST WEDNESDAY
MORNING. ELSEWHERE...SURFACE HIGH PRESSURE AND LIGHT NORTHWEST
WINDS WILL PROVIDE VFR CONDITIONS THROUGHOUT.

&&

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

$$

SYNOPSIS...08
SHORT TERM...08
LONG TERM...UTTECH
AVIATION...SHEETS







000
FXUS63 KDVN 172336
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
536 PM CST WED DEC 17 2014

.SYNOPSIS...
ISSUED AT 325 PM CST WED DEC 17 2014

12Z UA ANALYSIS HAS AN 850MB RIDGE RUNNING FROM THE GULF COAST INTO
THE NORTHERN PLAINS. A STORM SYSTEM WAS OVER SOUTHERN CANADA WITH A
LLJ RUNNING FROM WEST TEXAS INTO THE CENTRAL PLAINS. SATELLITE
TRENDS THROUGH MID AFTERNOON SHOW CLEARING SKIES ACROSS THE AREA
WITH CLOUDS FROM THE NEXT SYSTEM OVER THE CENTRAL AND SOUTHERN
PLAINS.

18Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE NORTHERN PLAINS AND
UPPER MIDWEST. A WEAK LOW WAS IN SOUTHEAST COLORADO WITH AN IMPLIED
BOUNDARY RUNNING FROM THE LOW INTO SOUTHWEST ARKANSAS. DEW POINTS
WERE IN THE SINGLE DIGITS AND TEENS ACROSS THE NORTHERN PLAINS AND
UPPER MIDWEST WITH 20S AND 30S FROM THE OHIO VALLEY INTO THE
SOUTHERN PLAINS.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 325 PM CST WED DEC 17 2014

QUIET CONDITIONS WITH CLEAR OR CLEARING SKIES WILL BE SEEN ACROSS
THE AREA THROUGH LATE AFTERNOON. DRY CONDITIONS WILL THEN BE SEEN
TONIGHT AND INTO THE PRE-DAWN HOURS WITH INCREASING CLOUDS. SNOW
WILL DEVELOP AND SPREAD NORTHEAST THROUGH KANSAS AND MISSOURI.
HOWEVER...DRY AIR ACROSS THE AREA WILL PREVENT ANY SNOW FROM
REACHING THE EXTREME SOUTH PRIOR TO 6 AM THURSDAY.

LOWS TONIGHT SHOULD DROP QUICKLY AFTER SUNSET AND THEN MAY BECOME
STEADY OR RISE SLIGHTLY AS CLOUDS MOVE BACK INTO THE AREA.

ON THURSDAY...STRONG FORCING WILL GO INTO SATURATING THE DRY AIR AT
THE LOW LEVELS AND ALLOW SNOW TO MOVE INTO THE FAR SOUTHERN AREAS.
THE FORCING RAPIDLY COLLAPSES BY LATE MORNING WITH MINIMAL FORCING
IN THE SATURATED ATMOSPHERE ACROSS THE SOUTH THIRD DURING THE
AFTERNOON.

THUS THE OPPORTUNITY FOR ACCUMULATING SNOW WILL OCCUR THURSDAY
MORNING IN A 4-6 HOUR WINDOW. THE BEST CHANCES FOR ANY ACCUMULATING
SNOW APPEAR TO BE SOUTH OF A KCNC...KFSW...TO KBMI LINE OR SOUTH OF
A CHARITON IOWA TO BLOOMINGTON ILLINOIS LINE. ACCUMULATIONS WILL BE
UNDER AN INCH BUT AMOUNTS APPROACHING AN INCH MAY BE SEEN ACROSS THE
EXTREME SOUTHERN PARTS OF SCOTLAND/CLARK COUNTIES IN MISSOURI AND
POSSIBLY THE SOUTHWEST CORNER OF HANCOCK COUNTY ILLINOIS.

DATA DOES SUGGEST THE POTENTIAL FOR A NARROW BAND OF SNOW IN STRONG
FORCING TO SET UP NEAR A KIRK TO KUIN LINE. A NORTHWARD SHIFT OF
THIS BAND WOULD PLACE IT ACROSS THE EXTREME SOUTHERN PARTS OF THE
AREA WITH THE POTENTIAL FOR SLIGHTLY HIGHER AMOUNTS.

HOWEVER...IF THE DRY AIR IS DEEPER THAN DEPICTED IN THE MODELS...
THEN THE SNOW BAND WOULD BE MUCH FURTHER SOUTH OF THE AREA AND SNOW
AMOUNTS ACROSS THE EXTREME SOUTH WOULD BE MUCH LESS.

THE KEY POINT IS THAT THERE WILL BE A VERY SHARP GRADIENT BETWEEN NO
SNOW AND ACCUMULATING SNOW ON THURSDAY.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 325 PM CST WED DEC 17 2014

OVERVIEW...ZONAL 500 MB FLOW WILL KEEP THINGS QUIET THROUGH SUNDAY.
UPPER LEVEL DISTURBANCE ASSOCIATED WITH THE SUBTROPICAL JET WILL
EJECT OUT OF NORTHERN MEXICO AND TRACK ACROSS THE SOUTHERN U.S.
THROUGH THE WEEKEND...REMAINING WELL SOUTH OF IOWA. A LARGE PACIFIC
JET STREAK WILL CARVE OUT A TROUGH OVER THE CENTRAL U.S. BEGINNING
MONDAY AND PERSISTING THROUGH NEXT WEEK. LIGHT RAIN AND SNOW WILL BE
POSSIBLE ON MONDAY ACROSS THE AREA.

FRIDAY AND SATURDAY...VERY QUIET PERIOD WITH HIGH TEMPS IN THE 30S
ALONG WITH DRY WEATHER. A WEAKENING TROUGH AXIS WILL MOVE THROUGH
FRIDAY NIGHT INTO SATURDAY MORNING WHICH HAS DECREASING DEFINITION
FORM THE MID-LEVELS TO THE SFC. PERIOD OF WEAK NEGATIVE OMEGA IS
FORECAST SATURDAY MORNING AS DCVA MOVES THROUGH BUT LAYER JUST BELOW
THE LIFT AT 600 MB IS VERY DRY DURING THIS TIME WITH RH NEAR 30%.

SUNDAY...SFC WINDS WILL BEGIN TO INCREASE OUT OF THE SE IN RESPONSE
TO A LEE-SIDE SFC LOW ORGANIZING OVER E MONTANA AND THE DAKOTAS.
HIGHS WILL ONCE AGAIN BE IN THE MID 30S TO NEAR 40 F.

MONDAY...PERIOD OF RAIN AND SNOW POSSIBLE AS LOW PRESSURE CENTER
REMAINS NW OF THE AREA ACROSS SW MINNESOTA AND N IOWA...NOT A
FAVORABLE LOCATION FOR MUCH ACCUMULATING SNOW TO OCCUR ACROSS THE
DVN FORECAST AREA.

TIMING AND P-TYPE ISSUE EXISTS BETWEEN THE GFS/ECMWF. ECMWF IS
COOLER AND ~6-12 HOURS SLOWER (THAN THE GFS)...IT HAS THE 850 MB 0 C
ISOTHERM TO THE SOUTH OF THE CWA INTO THE NIGHTTIME HOURS WITH
PRECIP LINGERING PAST 00Z/TUESDAY. THE GFS HAS 850 MB 0 C ISOTHERM
OVER NORTHERN CWA AND HAS MOST PRECIP OVER WITH BY THE AFTN. ECMWF
HAS LOW-LEVEL WAA RAISING 925 MB TEMPS TO +1 TO +3 C BY THE EVENING
AND BOTH MODELS FORECAST 2 METER MAX TEMPS IN THE MID TO UPPER 30S.

FORECAST SOUNDINGS HAVE WARMEST TEMPS IN THE LOWER PORTION OF THE
BOUNDARY LAYER WHICH ACTUALLY SLOWLY INCREASE THROUGH THE DAY.
THEREFORE MAY HAVE -RA/-SN MIX OR -SN TRANSITION TO -RA THROUGH THE
EVENT WITH BEST CHANCES FOR -SN ACROSS THE NORTH.

TUESDAY AND WEDNESDAY...A STRONG LOW WILL LIKELY FORM DURING THIS
TIME ALONG A DEVELOPING BAROCLINIC ZONE OVER THE SOUTHERN U.S./OHIO
VALLEY AND THEN MOVE INTO THE GREAT LAKES AREA. MODEL CONSENSUS FOR
THE DVN CWA IS COLDER AND BREEZY WITH SCT SNOW SHOWERS.

THE ECMWF IS SHOWING A STRONG LOW PRESSURE SYSTEM DEVELOPING ACROSS
ALABAMA AND TENNESSEE TUESDAY NIGHT AND THEN LIFTING NORTHWARD TO
LAKE HURON BY WEDNESDAY NIGHT WITH A CENTRAL PRESSURE DOWN TO 961
MB. THE GFS BRINGS IT TO THE SAME AREA BUT IS FURTHER SE DURING THE
CYCLOGENESIS PHASE. IT WILL BE INTERESTING TO SEE THE MODELS WORK
OUT THE POLAR-SUBTROPICAL JET PHASING ISSUES OVER THE NEXT FEW DAYS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 536 PM CST WED DEC 17 2014

A WEAK UPPER LEVEL SYSTEM WILL SPREAD LIGHT SNOW ACROSS MO INTO
CENTRAL IL ON WEDNESDAY. THIS MAY BRUSH THE BRL SITE...WHERE A
SEVERAL HOUR WINDOW OF MVFR CIGS/VISBYS IS FORECAST WEDNESDAY
MORNING. ELSEWHERE...SURFACE HIGH PRESSURE AND LIGHT NORTHWEST
WINDS WILL PROVIDE VFR CONDITIONS THROUGHOUT.

&&

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

$$

SYNOPSIS...08
SHORT TERM...08
LONG TERM...UTTECH
AVIATION...SHEETS






000
FXUS63 KDMX 172335
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
535 PM CST WED DEC 17 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 245 PM CST WED DEC 17 2014

A QUIET AFTERNOON IS IN STORE FOR THE CWA WITH SURFACE HIGH PRESSURE
ANCHORED ALONG THE MISSOURI RIVER VALLEY. A SHARP 300 MB SHORTWAVE
TROUGH CURRENTLY EJECTING FROM THE FOUR CORNERS REGION WILL ENTER
SOUTHWEST IOWA BY 12Z THURSDAY. NAM/GFS ARE TOO SLOW WITH RETURNING
MID-LEVEL MOISTURE (MANIFESTING ITSELF AS AN ALTOSTRATUS DECK) NOW
WELL INTO SW IOWA AS WELL AS WITH PRECIP COVERAGE WITH THIS SYSTEM
IN OKLAHOMA. THE HRRR BEST REFLECTS REALITY IN TERMS OF PRECIP
COVERAGE BUT IS ABOUT 3 HOURS BEHIND THE CURVE WITH CLOUD PLACEMENT.
HAVE SUBSEQUENTLY MANUALLY INCREASED CLOUD COVER OVER THE SW HALF OF
THE CWA AND USED THE HRRR FOR TIMING THE ONSET OF SNOW IN THE
SOUTHWESTERN CWA. LOW TEMPERATURES TONIGHT...ESPECIALLY OVER THE
NORTH...WILL BE DEPENDENT ON HOW QUICKLY CLOUDS CAN ADVECT OVERHEAD.
THESE WILL NEED TO BE MONITORED THIS EVENING AND ADJUSTED UPWARD
SHOULD THE CLOUDS ADVANCE FASTER THAN CURRENTLY FORECAST.

THE FASTER MOISTURE RETURN THROWS JUST ANOTHER WRENCH IN TIMING AND
AMOUNTS OF SNOWFALL IN SOUTHERN IOWA LATE TONIGHT. 12/18Z MODEL BUFR
SOUNDINGS DEPICT A STOUT 925-850MB DRY WEDGE ATTENDANT WITH THE
SURFACE RIDGE...BUT THIS MIDLEVEL MOISTURE MAY SATURATE THE COLUMN
FASTER THAN PROGGED AND LEAD TO HIGHER SNOWFALL TOTALS. OVERALL MADE
LITTLE CHANGES TO THE FORECAST IN THIS RESPECT...BUT DID TIGHTEN THE
POP GRADIENT AS IT ADVANCES NORTHEAST FROM 09 TO 12Z THINKING THAT
THE LOW LEVEL DRY AIR WILL RESULT IN A SHARP CUTOFF IN ACCUMULATING
SNOW.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 245 PM CST WED DEC 17 2014

A FEW CHALLENGES OVER THE EXTENDED PERIOD...WITH A NUMBER OF WEAK
SYSTEMS TO AFFECT PORTIONS OF THE AREA THROUGH THE PERIOD. SPLIT
FLOW CONTINUES TO BE THE MAIN DRIVING FORCE BEHIND THE RATHER
QUIESCENT WEATHER FOR MID DECEMBER. RATHER HIGH AMPLITUDE RIDGE OF
HIGH PRESSURE STILL ANCHORED FROM THE NORTHERN PLAINS TO THE GULF
COAST NEXT FEW DAYS. FIRST WAVE CURRENTLY OVER THE SOUTHERN
PLAINS TODAY AND SHOULD MOVE NORTHEAST THROUGH THU MORNING. AHEAD
OF THE WEAK SYSTEM WARM AIR ADVECTION AND LIMITED MOISTURE WILL BE
FORCED UPWARD IN AN AREA OF ISENTROPIC LIFT OVER SOUTHERN IOWA
THURSDAY. THE LIFT AND MOISTURE WILL BE ATTEMPTING TO OVERCOME THE
DRY AIRMASS CURRENTLY IN PLACE...LIMITING OVERALL AMOUNTS. THIS
WILL RESULT IN SOME RATHER LIGHT SNOW DURING THE MORNING HOURS
WITH MINOR ACCUMULATIONS GENERALLY LESS THAN AN INCH. DURING THE
EARLY AFTERNOON HOURS...BUFR SOUNDINGS SHOW THAT WE LOSE ICE
INTRODUCTION ACROSS THE SOUTHWEST AND SOUTH. HAVE INTRODUCED SOME
PATCHY FREEZING DRIZZLE ALONG WITH VERY LIGHT SNOW DURING THE
AFTERNOON HOURS...THOUGH EXPECTATIONS ARE THAT ANY PRECIPITATION
BY THAT TIME WILL BE VERY LIGHT AND LITTLE IF ANY ICE ACCUMULATION
IS EXPECTED. NEXT SYSTEM ARRIVES BY SUNDAY AND MONDAY AND EXTENDS
INTO TUESDAY. LOWER CONFIDENCE MOVING FORWARD WITH A CONSENSUS
SOLUTION AS THE GFS IS QUITE MILD WHILE THE EURO IS NOW SUGGESTING
A SOLUTION WITH MORE SIGNIFICANT DYNAMIC COOLING AS THE PRECIP
ARRIVES INTO MONDAY. THE EURO SUGGESTS MORE SNOW THAN RAIN/SNOW
MIX. GIVEN THE EVENT IS STILL 5 DAYS AWAY...WILL HOLD ONTO CURRENT
MIX TRENDS FOR NOW...AND MONITOR DURING SUBSEQUENT MODEL PACKAGES.
THE ONE TREND THAT IS BEGINNING TO EMERGE IS COLDER AIR AS NEXT
WEEK PROGRESSES. AS A STRONG PACNW STREAM WAVE ADVANCES EAST INTO
THE WESTERN STATES...MIDWEST RIDGE FINALLY BEGINS TO BREAK DOWN
AND BECOME DISPLACED BY A LONG WAVE TROUGH. THIS SHOULD SPELL A
TRANSITION TO A MORE ACTIVE AND COLDER PATTERN TOWARD THE END OF
THE EXTENDED. AS THE WAVE TUESDAY DEEPENS...A RATHER STRONG SFC
WAVE WILL EJECT NORTH NORTHEAST OUT OF EASTERN TEXAS TO EASTERN
MICHIGAN WEDNESDAY. GIVEN THE CURRENT GFS/EURO PACKAGES...THE MAIN
H850 MOISTURE PLUME...BETTER FORCING...AND HIGHER PRECIPITATION
AMOUNTS WILL PROBABLY END UP EAST OF THE REGION. WILL MONITOR FOR
GENERAL WESTWARD DRIFT NEXT SEVERAL PACKAGES...THIS SOMETIMES
OCCURS WITH WINTER STORM EVOLUTION IN MODEL PACKAGES...FIRST
PROJECTING THE EVENT TOO FAR EAST THEN PULLING IT BACK AS THE
EVENT NEARS.

&&

.AVIATION...18/00Z
ISSUED AT 520 PM CST WED DEC 17 2014

SYSTEM IN PLAINS WILL CONTINUE TO LIFT NORTHEAST AND WEAKEN
TONIGHT INTO THURSDAY. INITIALLY...VFR CEILINGS WILL SPREAD ACROSS
IOWA TONIGHT BUT WITH DRY LOW LEVELS...CLOUDS WILL REMAIN MID TO
HIGH LEVEL. DEEPER SATURATION OCCURS NEAR THE MISSOURI BORDER AND
SOME MVFR CEILINGS WITH LIGHT SNOW WILL BE POSSIBLE NEAR THE
MISSOURI BORDER BY DAYBREAK ON THURSDAY. HOWEVER...MUCH OF THE
FORECAST AREA WILL REMAIN WITH VFR CONDITIONS THROUGH THURSDAY
WITH THE POSSIBLE EXCEPTION OF KOTM. SURFACE WINDS WILL REMAIN
GENERALLY LIGHT AND VARIABLE FOR THE DURATION OF THE FORECAST.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...SKOW
LONG TERM...REV
AVIATION...COGIL




000
FXUS63 KDMX 172335
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
535 PM CST WED DEC 17 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 245 PM CST WED DEC 17 2014

A QUIET AFTERNOON IS IN STORE FOR THE CWA WITH SURFACE HIGH PRESSURE
ANCHORED ALONG THE MISSOURI RIVER VALLEY. A SHARP 300 MB SHORTWAVE
TROUGH CURRENTLY EJECTING FROM THE FOUR CORNERS REGION WILL ENTER
SOUTHWEST IOWA BY 12Z THURSDAY. NAM/GFS ARE TOO SLOW WITH RETURNING
MID-LEVEL MOISTURE (MANIFESTING ITSELF AS AN ALTOSTRATUS DECK) NOW
WELL INTO SW IOWA AS WELL AS WITH PRECIP COVERAGE WITH THIS SYSTEM
IN OKLAHOMA. THE HRRR BEST REFLECTS REALITY IN TERMS OF PRECIP
COVERAGE BUT IS ABOUT 3 HOURS BEHIND THE CURVE WITH CLOUD PLACEMENT.
HAVE SUBSEQUENTLY MANUALLY INCREASED CLOUD COVER OVER THE SW HALF OF
THE CWA AND USED THE HRRR FOR TIMING THE ONSET OF SNOW IN THE
SOUTHWESTERN CWA. LOW TEMPERATURES TONIGHT...ESPECIALLY OVER THE
NORTH...WILL BE DEPENDENT ON HOW QUICKLY CLOUDS CAN ADVECT OVERHEAD.
THESE WILL NEED TO BE MONITORED THIS EVENING AND ADJUSTED UPWARD
SHOULD THE CLOUDS ADVANCE FASTER THAN CURRENTLY FORECAST.

THE FASTER MOISTURE RETURN THROWS JUST ANOTHER WRENCH IN TIMING AND
AMOUNTS OF SNOWFALL IN SOUTHERN IOWA LATE TONIGHT. 12/18Z MODEL BUFR
SOUNDINGS DEPICT A STOUT 925-850MB DRY WEDGE ATTENDANT WITH THE
SURFACE RIDGE...BUT THIS MIDLEVEL MOISTURE MAY SATURATE THE COLUMN
FASTER THAN PROGGED AND LEAD TO HIGHER SNOWFALL TOTALS. OVERALL MADE
LITTLE CHANGES TO THE FORECAST IN THIS RESPECT...BUT DID TIGHTEN THE
POP GRADIENT AS IT ADVANCES NORTHEAST FROM 09 TO 12Z THINKING THAT
THE LOW LEVEL DRY AIR WILL RESULT IN A SHARP CUTOFF IN ACCUMULATING
SNOW.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 245 PM CST WED DEC 17 2014

A FEW CHALLENGES OVER THE EXTENDED PERIOD...WITH A NUMBER OF WEAK
SYSTEMS TO AFFECT PORTIONS OF THE AREA THROUGH THE PERIOD. SPLIT
FLOW CONTINUES TO BE THE MAIN DRIVING FORCE BEHIND THE RATHER
QUIESCENT WEATHER FOR MID DECEMBER. RATHER HIGH AMPLITUDE RIDGE OF
HIGH PRESSURE STILL ANCHORED FROM THE NORTHERN PLAINS TO THE GULF
COAST NEXT FEW DAYS. FIRST WAVE CURRENTLY OVER THE SOUTHERN
PLAINS TODAY AND SHOULD MOVE NORTHEAST THROUGH THU MORNING. AHEAD
OF THE WEAK SYSTEM WARM AIR ADVECTION AND LIMITED MOISTURE WILL BE
FORCED UPWARD IN AN AREA OF ISENTROPIC LIFT OVER SOUTHERN IOWA
THURSDAY. THE LIFT AND MOISTURE WILL BE ATTEMPTING TO OVERCOME THE
DRY AIRMASS CURRENTLY IN PLACE...LIMITING OVERALL AMOUNTS. THIS
WILL RESULT IN SOME RATHER LIGHT SNOW DURING THE MORNING HOURS
WITH MINOR ACCUMULATIONS GENERALLY LESS THAN AN INCH. DURING THE
EARLY AFTERNOON HOURS...BUFR SOUNDINGS SHOW THAT WE LOSE ICE
INTRODUCTION ACROSS THE SOUTHWEST AND SOUTH. HAVE INTRODUCED SOME
PATCHY FREEZING DRIZZLE ALONG WITH VERY LIGHT SNOW DURING THE
AFTERNOON HOURS...THOUGH EXPECTATIONS ARE THAT ANY PRECIPITATION
BY THAT TIME WILL BE VERY LIGHT AND LITTLE IF ANY ICE ACCUMULATION
IS EXPECTED. NEXT SYSTEM ARRIVES BY SUNDAY AND MONDAY AND EXTENDS
INTO TUESDAY. LOWER CONFIDENCE MOVING FORWARD WITH A CONSENSUS
SOLUTION AS THE GFS IS QUITE MILD WHILE THE EURO IS NOW SUGGESTING
A SOLUTION WITH MORE SIGNIFICANT DYNAMIC COOLING AS THE PRECIP
ARRIVES INTO MONDAY. THE EURO SUGGESTS MORE SNOW THAN RAIN/SNOW
MIX. GIVEN THE EVENT IS STILL 5 DAYS AWAY...WILL HOLD ONTO CURRENT
MIX TRENDS FOR NOW...AND MONITOR DURING SUBSEQUENT MODEL PACKAGES.
THE ONE TREND THAT IS BEGINNING TO EMERGE IS COLDER AIR AS NEXT
WEEK PROGRESSES. AS A STRONG PACNW STREAM WAVE ADVANCES EAST INTO
THE WESTERN STATES...MIDWEST RIDGE FINALLY BEGINS TO BREAK DOWN
AND BECOME DISPLACED BY A LONG WAVE TROUGH. THIS SHOULD SPELL A
TRANSITION TO A MORE ACTIVE AND COLDER PATTERN TOWARD THE END OF
THE EXTENDED. AS THE WAVE TUESDAY DEEPENS...A RATHER STRONG SFC
WAVE WILL EJECT NORTH NORTHEAST OUT OF EASTERN TEXAS TO EASTERN
MICHIGAN WEDNESDAY. GIVEN THE CURRENT GFS/EURO PACKAGES...THE MAIN
H850 MOISTURE PLUME...BETTER FORCING...AND HIGHER PRECIPITATION
AMOUNTS WILL PROBABLY END UP EAST OF THE REGION. WILL MONITOR FOR
GENERAL WESTWARD DRIFT NEXT SEVERAL PACKAGES...THIS SOMETIMES
OCCURS WITH WINTER STORM EVOLUTION IN MODEL PACKAGES...FIRST
PROJECTING THE EVENT TOO FAR EAST THEN PULLING IT BACK AS THE
EVENT NEARS.

&&

.AVIATION...18/00Z
ISSUED AT 520 PM CST WED DEC 17 2014

SYSTEM IN PLAINS WILL CONTINUE TO LIFT NORTHEAST AND WEAKEN
TONIGHT INTO THURSDAY. INITIALLY...VFR CEILINGS WILL SPREAD ACROSS
IOWA TONIGHT BUT WITH DRY LOW LEVELS...CLOUDS WILL REMAIN MID TO
HIGH LEVEL. DEEPER SATURATION OCCURS NEAR THE MISSOURI BORDER AND
SOME MVFR CEILINGS WITH LIGHT SNOW WILL BE POSSIBLE NEAR THE
MISSOURI BORDER BY DAYBREAK ON THURSDAY. HOWEVER...MUCH OF THE
FORECAST AREA WILL REMAIN WITH VFR CONDITIONS THROUGH THURSDAY
WITH THE POSSIBLE EXCEPTION OF KOTM. SURFACE WINDS WILL REMAIN
GENERALLY LIGHT AND VARIABLE FOR THE DURATION OF THE FORECAST.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...SKOW
LONG TERM...REV
AVIATION...COGIL




000
FXUS63 KDMX 172335
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
535 PM CST WED DEC 17 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 245 PM CST WED DEC 17 2014

A QUIET AFTERNOON IS IN STORE FOR THE CWA WITH SURFACE HIGH PRESSURE
ANCHORED ALONG THE MISSOURI RIVER VALLEY. A SHARP 300 MB SHORTWAVE
TROUGH CURRENTLY EJECTING FROM THE FOUR CORNERS REGION WILL ENTER
SOUTHWEST IOWA BY 12Z THURSDAY. NAM/GFS ARE TOO SLOW WITH RETURNING
MID-LEVEL MOISTURE (MANIFESTING ITSELF AS AN ALTOSTRATUS DECK) NOW
WELL INTO SW IOWA AS WELL AS WITH PRECIP COVERAGE WITH THIS SYSTEM
IN OKLAHOMA. THE HRRR BEST REFLECTS REALITY IN TERMS OF PRECIP
COVERAGE BUT IS ABOUT 3 HOURS BEHIND THE CURVE WITH CLOUD PLACEMENT.
HAVE SUBSEQUENTLY MANUALLY INCREASED CLOUD COVER OVER THE SW HALF OF
THE CWA AND USED THE HRRR FOR TIMING THE ONSET OF SNOW IN THE
SOUTHWESTERN CWA. LOW TEMPERATURES TONIGHT...ESPECIALLY OVER THE
NORTH...WILL BE DEPENDENT ON HOW QUICKLY CLOUDS CAN ADVECT OVERHEAD.
THESE WILL NEED TO BE MONITORED THIS EVENING AND ADJUSTED UPWARD
SHOULD THE CLOUDS ADVANCE FASTER THAN CURRENTLY FORECAST.

THE FASTER MOISTURE RETURN THROWS JUST ANOTHER WRENCH IN TIMING AND
AMOUNTS OF SNOWFALL IN SOUTHERN IOWA LATE TONIGHT. 12/18Z MODEL BUFR
SOUNDINGS DEPICT A STOUT 925-850MB DRY WEDGE ATTENDANT WITH THE
SURFACE RIDGE...BUT THIS MIDLEVEL MOISTURE MAY SATURATE THE COLUMN
FASTER THAN PROGGED AND LEAD TO HIGHER SNOWFALL TOTALS. OVERALL MADE
LITTLE CHANGES TO THE FORECAST IN THIS RESPECT...BUT DID TIGHTEN THE
POP GRADIENT AS IT ADVANCES NORTHEAST FROM 09 TO 12Z THINKING THAT
THE LOW LEVEL DRY AIR WILL RESULT IN A SHARP CUTOFF IN ACCUMULATING
SNOW.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 245 PM CST WED DEC 17 2014

A FEW CHALLENGES OVER THE EXTENDED PERIOD...WITH A NUMBER OF WEAK
SYSTEMS TO AFFECT PORTIONS OF THE AREA THROUGH THE PERIOD. SPLIT
FLOW CONTINUES TO BE THE MAIN DRIVING FORCE BEHIND THE RATHER
QUIESCENT WEATHER FOR MID DECEMBER. RATHER HIGH AMPLITUDE RIDGE OF
HIGH PRESSURE STILL ANCHORED FROM THE NORTHERN PLAINS TO THE GULF
COAST NEXT FEW DAYS. FIRST WAVE CURRENTLY OVER THE SOUTHERN
PLAINS TODAY AND SHOULD MOVE NORTHEAST THROUGH THU MORNING. AHEAD
OF THE WEAK SYSTEM WARM AIR ADVECTION AND LIMITED MOISTURE WILL BE
FORCED UPWARD IN AN AREA OF ISENTROPIC LIFT OVER SOUTHERN IOWA
THURSDAY. THE LIFT AND MOISTURE WILL BE ATTEMPTING TO OVERCOME THE
DRY AIRMASS CURRENTLY IN PLACE...LIMITING OVERALL AMOUNTS. THIS
WILL RESULT IN SOME RATHER LIGHT SNOW DURING THE MORNING HOURS
WITH MINOR ACCUMULATIONS GENERALLY LESS THAN AN INCH. DURING THE
EARLY AFTERNOON HOURS...BUFR SOUNDINGS SHOW THAT WE LOSE ICE
INTRODUCTION ACROSS THE SOUTHWEST AND SOUTH. HAVE INTRODUCED SOME
PATCHY FREEZING DRIZZLE ALONG WITH VERY LIGHT SNOW DURING THE
AFTERNOON HOURS...THOUGH EXPECTATIONS ARE THAT ANY PRECIPITATION
BY THAT TIME WILL BE VERY LIGHT AND LITTLE IF ANY ICE ACCUMULATION
IS EXPECTED. NEXT SYSTEM ARRIVES BY SUNDAY AND MONDAY AND EXTENDS
INTO TUESDAY. LOWER CONFIDENCE MOVING FORWARD WITH A CONSENSUS
SOLUTION AS THE GFS IS QUITE MILD WHILE THE EURO IS NOW SUGGESTING
A SOLUTION WITH MORE SIGNIFICANT DYNAMIC COOLING AS THE PRECIP
ARRIVES INTO MONDAY. THE EURO SUGGESTS MORE SNOW THAN RAIN/SNOW
MIX. GIVEN THE EVENT IS STILL 5 DAYS AWAY...WILL HOLD ONTO CURRENT
MIX TRENDS FOR NOW...AND MONITOR DURING SUBSEQUENT MODEL PACKAGES.
THE ONE TREND THAT IS BEGINNING TO EMERGE IS COLDER AIR AS NEXT
WEEK PROGRESSES. AS A STRONG PACNW STREAM WAVE ADVANCES EAST INTO
THE WESTERN STATES...MIDWEST RIDGE FINALLY BEGINS TO BREAK DOWN
AND BECOME DISPLACED BY A LONG WAVE TROUGH. THIS SHOULD SPELL A
TRANSITION TO A MORE ACTIVE AND COLDER PATTERN TOWARD THE END OF
THE EXTENDED. AS THE WAVE TUESDAY DEEPENS...A RATHER STRONG SFC
WAVE WILL EJECT NORTH NORTHEAST OUT OF EASTERN TEXAS TO EASTERN
MICHIGAN WEDNESDAY. GIVEN THE CURRENT GFS/EURO PACKAGES...THE MAIN
H850 MOISTURE PLUME...BETTER FORCING...AND HIGHER PRECIPITATION
AMOUNTS WILL PROBABLY END UP EAST OF THE REGION. WILL MONITOR FOR
GENERAL WESTWARD DRIFT NEXT SEVERAL PACKAGES...THIS SOMETIMES
OCCURS WITH WINTER STORM EVOLUTION IN MODEL PACKAGES...FIRST
PROJECTING THE EVENT TOO FAR EAST THEN PULLING IT BACK AS THE
EVENT NEARS.

&&

.AVIATION...18/00Z
ISSUED AT 520 PM CST WED DEC 17 2014

SYSTEM IN PLAINS WILL CONTINUE TO LIFT NORTHEAST AND WEAKEN
TONIGHT INTO THURSDAY. INITIALLY...VFR CEILINGS WILL SPREAD ACROSS
IOWA TONIGHT BUT WITH DRY LOW LEVELS...CLOUDS WILL REMAIN MID TO
HIGH LEVEL. DEEPER SATURATION OCCURS NEAR THE MISSOURI BORDER AND
SOME MVFR CEILINGS WITH LIGHT SNOW WILL BE POSSIBLE NEAR THE
MISSOURI BORDER BY DAYBREAK ON THURSDAY. HOWEVER...MUCH OF THE
FORECAST AREA WILL REMAIN WITH VFR CONDITIONS THROUGH THURSDAY
WITH THE POSSIBLE EXCEPTION OF KOTM. SURFACE WINDS WILL REMAIN
GENERALLY LIGHT AND VARIABLE FOR THE DURATION OF THE FORECAST.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...SKOW
LONG TERM...REV
AVIATION...COGIL




000
FXUS63 KDMX 172335
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
535 PM CST WED DEC 17 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 245 PM CST WED DEC 17 2014

A QUIET AFTERNOON IS IN STORE FOR THE CWA WITH SURFACE HIGH PRESSURE
ANCHORED ALONG THE MISSOURI RIVER VALLEY. A SHARP 300 MB SHORTWAVE
TROUGH CURRENTLY EJECTING FROM THE FOUR CORNERS REGION WILL ENTER
SOUTHWEST IOWA BY 12Z THURSDAY. NAM/GFS ARE TOO SLOW WITH RETURNING
MID-LEVEL MOISTURE (MANIFESTING ITSELF AS AN ALTOSTRATUS DECK) NOW
WELL INTO SW IOWA AS WELL AS WITH PRECIP COVERAGE WITH THIS SYSTEM
IN OKLAHOMA. THE HRRR BEST REFLECTS REALITY IN TERMS OF PRECIP
COVERAGE BUT IS ABOUT 3 HOURS BEHIND THE CURVE WITH CLOUD PLACEMENT.
HAVE SUBSEQUENTLY MANUALLY INCREASED CLOUD COVER OVER THE SW HALF OF
THE CWA AND USED THE HRRR FOR TIMING THE ONSET OF SNOW IN THE
SOUTHWESTERN CWA. LOW TEMPERATURES TONIGHT...ESPECIALLY OVER THE
NORTH...WILL BE DEPENDENT ON HOW QUICKLY CLOUDS CAN ADVECT OVERHEAD.
THESE WILL NEED TO BE MONITORED THIS EVENING AND ADJUSTED UPWARD
SHOULD THE CLOUDS ADVANCE FASTER THAN CURRENTLY FORECAST.

THE FASTER MOISTURE RETURN THROWS JUST ANOTHER WRENCH IN TIMING AND
AMOUNTS OF SNOWFALL IN SOUTHERN IOWA LATE TONIGHT. 12/18Z MODEL BUFR
SOUNDINGS DEPICT A STOUT 925-850MB DRY WEDGE ATTENDANT WITH THE
SURFACE RIDGE...BUT THIS MIDLEVEL MOISTURE MAY SATURATE THE COLUMN
FASTER THAN PROGGED AND LEAD TO HIGHER SNOWFALL TOTALS. OVERALL MADE
LITTLE CHANGES TO THE FORECAST IN THIS RESPECT...BUT DID TIGHTEN THE
POP GRADIENT AS IT ADVANCES NORTHEAST FROM 09 TO 12Z THINKING THAT
THE LOW LEVEL DRY AIR WILL RESULT IN A SHARP CUTOFF IN ACCUMULATING
SNOW.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 245 PM CST WED DEC 17 2014

A FEW CHALLENGES OVER THE EXTENDED PERIOD...WITH A NUMBER OF WEAK
SYSTEMS TO AFFECT PORTIONS OF THE AREA THROUGH THE PERIOD. SPLIT
FLOW CONTINUES TO BE THE MAIN DRIVING FORCE BEHIND THE RATHER
QUIESCENT WEATHER FOR MID DECEMBER. RATHER HIGH AMPLITUDE RIDGE OF
HIGH PRESSURE STILL ANCHORED FROM THE NORTHERN PLAINS TO THE GULF
COAST NEXT FEW DAYS. FIRST WAVE CURRENTLY OVER THE SOUTHERN
PLAINS TODAY AND SHOULD MOVE NORTHEAST THROUGH THU MORNING. AHEAD
OF THE WEAK SYSTEM WARM AIR ADVECTION AND LIMITED MOISTURE WILL BE
FORCED UPWARD IN AN AREA OF ISENTROPIC LIFT OVER SOUTHERN IOWA
THURSDAY. THE LIFT AND MOISTURE WILL BE ATTEMPTING TO OVERCOME THE
DRY AIRMASS CURRENTLY IN PLACE...LIMITING OVERALL AMOUNTS. THIS
WILL RESULT IN SOME RATHER LIGHT SNOW DURING THE MORNING HOURS
WITH MINOR ACCUMULATIONS GENERALLY LESS THAN AN INCH. DURING THE
EARLY AFTERNOON HOURS...BUFR SOUNDINGS SHOW THAT WE LOSE ICE
INTRODUCTION ACROSS THE SOUTHWEST AND SOUTH. HAVE INTRODUCED SOME
PATCHY FREEZING DRIZZLE ALONG WITH VERY LIGHT SNOW DURING THE
AFTERNOON HOURS...THOUGH EXPECTATIONS ARE THAT ANY PRECIPITATION
BY THAT TIME WILL BE VERY LIGHT AND LITTLE IF ANY ICE ACCUMULATION
IS EXPECTED. NEXT SYSTEM ARRIVES BY SUNDAY AND MONDAY AND EXTENDS
INTO TUESDAY. LOWER CONFIDENCE MOVING FORWARD WITH A CONSENSUS
SOLUTION AS THE GFS IS QUITE MILD WHILE THE EURO IS NOW SUGGESTING
A SOLUTION WITH MORE SIGNIFICANT DYNAMIC COOLING AS THE PRECIP
ARRIVES INTO MONDAY. THE EURO SUGGESTS MORE SNOW THAN RAIN/SNOW
MIX. GIVEN THE EVENT IS STILL 5 DAYS AWAY...WILL HOLD ONTO CURRENT
MIX TRENDS FOR NOW...AND MONITOR DURING SUBSEQUENT MODEL PACKAGES.
THE ONE TREND THAT IS BEGINNING TO EMERGE IS COLDER AIR AS NEXT
WEEK PROGRESSES. AS A STRONG PACNW STREAM WAVE ADVANCES EAST INTO
THE WESTERN STATES...MIDWEST RIDGE FINALLY BEGINS TO BREAK DOWN
AND BECOME DISPLACED BY A LONG WAVE TROUGH. THIS SHOULD SPELL A
TRANSITION TO A MORE ACTIVE AND COLDER PATTERN TOWARD THE END OF
THE EXTENDED. AS THE WAVE TUESDAY DEEPENS...A RATHER STRONG SFC
WAVE WILL EJECT NORTH NORTHEAST OUT OF EASTERN TEXAS TO EASTERN
MICHIGAN WEDNESDAY. GIVEN THE CURRENT GFS/EURO PACKAGES...THE MAIN
H850 MOISTURE PLUME...BETTER FORCING...AND HIGHER PRECIPITATION
AMOUNTS WILL PROBABLY END UP EAST OF THE REGION. WILL MONITOR FOR
GENERAL WESTWARD DRIFT NEXT SEVERAL PACKAGES...THIS SOMETIMES
OCCURS WITH WINTER STORM EVOLUTION IN MODEL PACKAGES...FIRST
PROJECTING THE EVENT TOO FAR EAST THEN PULLING IT BACK AS THE
EVENT NEARS.

&&

.AVIATION...18/00Z
ISSUED AT 520 PM CST WED DEC 17 2014

SYSTEM IN PLAINS WILL CONTINUE TO LIFT NORTHEAST AND WEAKEN
TONIGHT INTO THURSDAY. INITIALLY...VFR CEILINGS WILL SPREAD ACROSS
IOWA TONIGHT BUT WITH DRY LOW LEVELS...CLOUDS WILL REMAIN MID TO
HIGH LEVEL. DEEPER SATURATION OCCURS NEAR THE MISSOURI BORDER AND
SOME MVFR CEILINGS WITH LIGHT SNOW WILL BE POSSIBLE NEAR THE
MISSOURI BORDER BY DAYBREAK ON THURSDAY. HOWEVER...MUCH OF THE
FORECAST AREA WILL REMAIN WITH VFR CONDITIONS THROUGH THURSDAY
WITH THE POSSIBLE EXCEPTION OF KOTM. SURFACE WINDS WILL REMAIN
GENERALLY LIGHT AND VARIABLE FOR THE DURATION OF THE FORECAST.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...SKOW
LONG TERM...REV
AVIATION...COGIL




000
FXUS63 KDVN 172125
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
325 PM CST WED DEC 17 2014

.SYNOPSIS...
ISSUED AT 323 PM CST WED DEC 17 2014

12Z UA ANALYSIS HAS AN 850MB RIDGE RUNNING FROM THE GULF COAST INTO
THE NORTHERN PLAINS. A STORM SYSTEM WAS OVER SOUTHERN CANADA WITH A
LLJ RUNNING FROM WEST TEXAS INTO THE CENTRAL PLAINS. SATELLITE
TRENDS THROUGH MID AFTERNOON SHOW CLEARING SKIES ACROSS THE AREA
WITH CLOUDS FROM THE NEXT SYSTEM OVER THE CENTRAL AND SOUTHERN
PLAINS.

18Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE NORTHERN PLAINS AND
UPPER MIDWEST. A WEAK LOW WAS IN SOUTHEAST COLORADO WITH AN IMPLIED
BOUNDARY RUNNING FROM THE LOW INTO SOUTHWEST ARKANSAS. DEW POINTS
WERE IN THE SINGLE DIGITS AND TEENS ACROSS THE NORTHERN PLAINS AND
UPPER MIDWEST WITH 20S AND 30S FROM THE OHIO VALLEY INTO THE
SOUTHERN PLAINS.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 323 PM CST WED DEC 17 2014

QUIET CONDITIONS WITH CLEAR OR CLEARING SKIES WILL BE SEEN ACROSS
THE AREA THROUGH LATE AFTERNOON. DRY CONDITIONS WILL THEN BE SEEN
TONIGHT AND INTO THE PRE-DAWN HOURS WITH INCREASING CLOUDS. SNOW
WILL DEVELOP AND SPREAD NORTHEAST THROUGH KANSAS AND MISSOURI.
HOWEVER...DRY AIR ACROSS THE AREA WILL PREVENT ANY SNOW FROM
REACHING THE EXTREME SOUTH PRIOR TO 6 AM THURSDAY.

LOWS TONIGHT SHOULD DROP QUICKLY AFTER SUNSET AND THEN MAY BECOME
STEADY OR RISE SLIGHTLY AS CLOUDS MOVE BACK INTO THE AREA.

ON THURSDAY...STRONG FORCING WILL GO INTO SATURATING THE DRY AIR AT
THE LOW LEVELS AND ALLOW SNOW TO MOVE INTO THE FAR SOUTHERN AREAS.
THE FORCING RAPIDLY COLLAPSES BY LATE MORNING WITH MINIMAL FORCING
IN THE SATURATED ATMOSPHERE ACROSS THE SOUTH THIRD DURING THE
AFTERNOON.

THUS THE OPPORTUNITY FOR ACCUMULATING SNOW WILL OCCUR THURSDAY
MORNING IN A 4-6 HOUR WINDOW. THE BEST CHANCES FOR ANY ACCUMULATING
SNOW APPEAR TO BE SOUTH OF A KCNC...KFSW...TO KBMI LINE OR SOUTH OF
A CHARITON IOWA TO BLOOMINGTON ILLINOIS LINE. ACCUMULATIONS WILL BE
UNDER AN INCH BUT AMOUNTS APPROACHING AN INCH MAY BE SEEN ACROSS THE
EXTREME SOUTHERN PARTS OF SCOTLAND/CLARK COUNTIES IN MISSOURI AND
POSSIBLY THE SOUTHWEST CORNER OF HANCOCK COUNTY ILLINOIS.

DATA DOES SUGGEST THE POTENTIAL FOR A NARROW BAND OF SNOW IN STRONG
FORCING TO SET UP NEAR A KIRK TO KUIN LINE. A NORTHWARD SHIFT OF
THIS BAND WOULD PLACE IT ACROSS THE EXTREME SOUTHERN PARTS OF THE
AREA WITH THE POTENTIAL FOR SLIGHTLY HIGHER AMOUNTS.

HOWEVER...IF THE DRY AIR IS DEEPER THAN DEPICTED IN THE MODELS...
THEN THE SNOW BAND WOULD BE MUCH FURTHER SOUTH OF THE AREA AND SNOW
AMOUNTS ACROSS THE EXTREME SOUTH WOULD BE MUCH LESS.

THE KEY POINT IS THAT THERE WILL BE A VERY SHARP GRADIENT BETWEEN NO
SNOW AND ACCUMULATING SNOW ON THURSDAY.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 323 PM CST WED DEC 17 2014

OVERVIEW...ZONAL 500 MB FLOW WILL KEEP THINGS QUIET THROUGH SUNDAY.
UPPER LEVEL DISTURBANCE ASSOCIATED WITH THE SUBTROPICAL JET WILL
EJECT OUT OF NORTHERN MEXICO AND TRACK ACROSS THE SOUTHERN U.S.
THROUGH THE WEEKEND...REMAINING WELL SOUTH OF IOWA. A LARGE PACIFIC
JET STREAK WILL CARVE OUT A TROUGH OVER THE CENTRAL U.S. BEGINNING
MONDAY AND PERSISTING THROUGH NEXT WEEK. LIGHT RAIN AND SNOW WILL BE
POSSIBLE ON MONDAY ACROSS THE AREA.

FRIDAY AND SATURDAY...VERY QUIET PERIOD WITH HIGH TEMPS IN THE 30S
ALONG WITH DRY WEATHER. A WEAKENING TROUGH AXIS WILL MOVE THROUGH
FRIDAY NIGHT INTO SATURDAY MORNING WHICH HAS DECREASING DEFINITION
FORM THE MID-LEVELS TO THE SFC. PERIOD OF WEAK NEGATIVE OMEGA IS
FORECAST SATURDAY MORNING AS DCVA MOVES THROUGH BUT LAYER JUST BELOW
THE LIFT AT 600 MB IS VERY DRY DURING THIS TIME WITH RH NEAR 30%.

SUNDAY...SFC WINDS WILL BEGIN TO INCREASE OUT OF THE SE IN RESPONSE
TO A LEE-SIDE SFC LOW ORGANIZING OVER E MONTANA AND THE DAKOTAS.
HIGHS WILL ONCE AGAIN BE IN THE MID 30S TO NEAR 40 F.

MONDAY...PERIOD OF RAIN AND SNOW POSSIBLE AS LOW PRESSURE CENTER
REMAINS NW OF THE AREA ACROSS SW MINNESOTA AND N IOWA...NOT A
FAVORABLE LOCATION FOR MUCH ACCUMULATING SNOW TO OCCUR ACROSS THE
DVN FORECAST AREA.

TIMING AND P-TYPE ISSUE EXISTS BETWEEN THE GFS/ECMWF. ECMWF IS
COOLER AND ~6-12 HOURS SLOWER (THAN THE GFS)...IT HAS THE 850 MB 0 C
ISOTHERM TO THE SOUTH OF THE CWA INTO THE NIGHTTIME HOURS WITH
PRECIP LINGERING PAST 00Z/TUESDAY. THE GFS HAS 850 MB 0 C ISOTHERM
OVER NORTHERN CWA AND HAS MOST PRECIP OVER WITH BY THE AFTN. ECMWF
HAS LOW-LEVEL WAA RAISING 925 MB TEMPS TO +1 TO +3 C BY THE EVENING
AND BOTH MODELS FORECAST 2 METER MAX TEMPS IN THE MID TO UPPER 30S.

FORECAST SOUNDINGS HAVE WARMEST TEMPS IN THE LOWER PORTION OF THE
BOUNDARY LAYER WHICH ACTUALLY SLOWLY INCREASE THROUGH THE DAY.
THEREFORE MAY HAVE -RA/-SN MIX OR -SN TRANSITION TO -RA THROUGH THE
EVENT WITH BEST CHANCES FOR -SN ACROSS THE NORTH.

TUESDAY AND WEDNESDAY...A STRONG LOW WILL LIKELY FORM DURING THIS
TIME ALONG A DEVELOPING BAROCLINIC ZONE OVER THE SOUTHERN U.S./OHIO
VALLEY AND THEN MOVE INTO THE GREAT LAKES AREA. MODEL CONSENSUS FOR
THE DVN CWA IS COLDER AND BREEZY WITH SCT SNOW SHOWERS.

THE ECMWF IS SHOWING A STRONG LOW PRESSURE SYSTEM DEVELOPING ACROSS
ALABAMA AND TENNESSEE TUESDAY NIGHT AND THEN LIFTING NORTHWARD TO
LAKE HURON BY WEDNESDAY NIGHT WITH A CENTRAL PRESSURE DOWN TO 961
MB. THE GFS BRINGS IT TO THE SAME AREA BUT IS FURTHER SE DURING THE
CYCLOGENESIS PHASE. IT WILL BE INTERESTING TO SEE THE MODELS WORK
OUT THE POLAR-SUBTROPICAL JET PHASING ISSUES OVER THE NEXT FEW DAYS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1133 AM CST WED DEC 17 2014

MVFR CIGS WILL SLOWLY CLEAR ACROSS EASTERN IOWA AND NORTHERN
ILLINOIS THROUGH 00Z/18 AS HIGH PRESSURE BUILDS INTO THE MIDWEST.
AFT 00Z/18 VFR CONDITIONS ARE EXPECTED THROUGH 12Z/18. AFT 12Z/18
SNOW WILL SLOWLY MOVE INTO SOUTHEAST IOWA PRODUCING MVFR AND
POSSIBLY IFR CONDITIONS.


&&

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

$$

SYNOPSIS...08
SHORT TERM...08
LONG TERM...UTTECH
AVIATION...08






000
FXUS63 KDVN 172125
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
325 PM CST WED DEC 17 2014

.SYNOPSIS...
ISSUED AT 323 PM CST WED DEC 17 2014

12Z UA ANALYSIS HAS AN 850MB RIDGE RUNNING FROM THE GULF COAST INTO
THE NORTHERN PLAINS. A STORM SYSTEM WAS OVER SOUTHERN CANADA WITH A
LLJ RUNNING FROM WEST TEXAS INTO THE CENTRAL PLAINS. SATELLITE
TRENDS THROUGH MID AFTERNOON SHOW CLEARING SKIES ACROSS THE AREA
WITH CLOUDS FROM THE NEXT SYSTEM OVER THE CENTRAL AND SOUTHERN
PLAINS.

18Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE NORTHERN PLAINS AND
UPPER MIDWEST. A WEAK LOW WAS IN SOUTHEAST COLORADO WITH AN IMPLIED
BOUNDARY RUNNING FROM THE LOW INTO SOUTHWEST ARKANSAS. DEW POINTS
WERE IN THE SINGLE DIGITS AND TEENS ACROSS THE NORTHERN PLAINS AND
UPPER MIDWEST WITH 20S AND 30S FROM THE OHIO VALLEY INTO THE
SOUTHERN PLAINS.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 323 PM CST WED DEC 17 2014

QUIET CONDITIONS WITH CLEAR OR CLEARING SKIES WILL BE SEEN ACROSS
THE AREA THROUGH LATE AFTERNOON. DRY CONDITIONS WILL THEN BE SEEN
TONIGHT AND INTO THE PRE-DAWN HOURS WITH INCREASING CLOUDS. SNOW
WILL DEVELOP AND SPREAD NORTHEAST THROUGH KANSAS AND MISSOURI.
HOWEVER...DRY AIR ACROSS THE AREA WILL PREVENT ANY SNOW FROM
REACHING THE EXTREME SOUTH PRIOR TO 6 AM THURSDAY.

LOWS TONIGHT SHOULD DROP QUICKLY AFTER SUNSET AND THEN MAY BECOME
STEADY OR RISE SLIGHTLY AS CLOUDS MOVE BACK INTO THE AREA.

ON THURSDAY...STRONG FORCING WILL GO INTO SATURATING THE DRY AIR AT
THE LOW LEVELS AND ALLOW SNOW TO MOVE INTO THE FAR SOUTHERN AREAS.
THE FORCING RAPIDLY COLLAPSES BY LATE MORNING WITH MINIMAL FORCING
IN THE SATURATED ATMOSPHERE ACROSS THE SOUTH THIRD DURING THE
AFTERNOON.

THUS THE OPPORTUNITY FOR ACCUMULATING SNOW WILL OCCUR THURSDAY
MORNING IN A 4-6 HOUR WINDOW. THE BEST CHANCES FOR ANY ACCUMULATING
SNOW APPEAR TO BE SOUTH OF A KCNC...KFSW...TO KBMI LINE OR SOUTH OF
A CHARITON IOWA TO BLOOMINGTON ILLINOIS LINE. ACCUMULATIONS WILL BE
UNDER AN INCH BUT AMOUNTS APPROACHING AN INCH MAY BE SEEN ACROSS THE
EXTREME SOUTHERN PARTS OF SCOTLAND/CLARK COUNTIES IN MISSOURI AND
POSSIBLY THE SOUTHWEST CORNER OF HANCOCK COUNTY ILLINOIS.

DATA DOES SUGGEST THE POTENTIAL FOR A NARROW BAND OF SNOW IN STRONG
FORCING TO SET UP NEAR A KIRK TO KUIN LINE. A NORTHWARD SHIFT OF
THIS BAND WOULD PLACE IT ACROSS THE EXTREME SOUTHERN PARTS OF THE
AREA WITH THE POTENTIAL FOR SLIGHTLY HIGHER AMOUNTS.

HOWEVER...IF THE DRY AIR IS DEEPER THAN DEPICTED IN THE MODELS...
THEN THE SNOW BAND WOULD BE MUCH FURTHER SOUTH OF THE AREA AND SNOW
AMOUNTS ACROSS THE EXTREME SOUTH WOULD BE MUCH LESS.

THE KEY POINT IS THAT THERE WILL BE A VERY SHARP GRADIENT BETWEEN NO
SNOW AND ACCUMULATING SNOW ON THURSDAY.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 323 PM CST WED DEC 17 2014

OVERVIEW...ZONAL 500 MB FLOW WILL KEEP THINGS QUIET THROUGH SUNDAY.
UPPER LEVEL DISTURBANCE ASSOCIATED WITH THE SUBTROPICAL JET WILL
EJECT OUT OF NORTHERN MEXICO AND TRACK ACROSS THE SOUTHERN U.S.
THROUGH THE WEEKEND...REMAINING WELL SOUTH OF IOWA. A LARGE PACIFIC
JET STREAK WILL CARVE OUT A TROUGH OVER THE CENTRAL U.S. BEGINNING
MONDAY AND PERSISTING THROUGH NEXT WEEK. LIGHT RAIN AND SNOW WILL BE
POSSIBLE ON MONDAY ACROSS THE AREA.

FRIDAY AND SATURDAY...VERY QUIET PERIOD WITH HIGH TEMPS IN THE 30S
ALONG WITH DRY WEATHER. A WEAKENING TROUGH AXIS WILL MOVE THROUGH
FRIDAY NIGHT INTO SATURDAY MORNING WHICH HAS DECREASING DEFINITION
FORM THE MID-LEVELS TO THE SFC. PERIOD OF WEAK NEGATIVE OMEGA IS
FORECAST SATURDAY MORNING AS DCVA MOVES THROUGH BUT LAYER JUST BELOW
THE LIFT AT 600 MB IS VERY DRY DURING THIS TIME WITH RH NEAR 30%.

SUNDAY...SFC WINDS WILL BEGIN TO INCREASE OUT OF THE SE IN RESPONSE
TO A LEE-SIDE SFC LOW ORGANIZING OVER E MONTANA AND THE DAKOTAS.
HIGHS WILL ONCE AGAIN BE IN THE MID 30S TO NEAR 40 F.

MONDAY...PERIOD OF RAIN AND SNOW POSSIBLE AS LOW PRESSURE CENTER
REMAINS NW OF THE AREA ACROSS SW MINNESOTA AND N IOWA...NOT A
FAVORABLE LOCATION FOR MUCH ACCUMULATING SNOW TO OCCUR ACROSS THE
DVN FORECAST AREA.

TIMING AND P-TYPE ISSUE EXISTS BETWEEN THE GFS/ECMWF. ECMWF IS
COOLER AND ~6-12 HOURS SLOWER (THAN THE GFS)...IT HAS THE 850 MB 0 C
ISOTHERM TO THE SOUTH OF THE CWA INTO THE NIGHTTIME HOURS WITH
PRECIP LINGERING PAST 00Z/TUESDAY. THE GFS HAS 850 MB 0 C ISOTHERM
OVER NORTHERN CWA AND HAS MOST PRECIP OVER WITH BY THE AFTN. ECMWF
HAS LOW-LEVEL WAA RAISING 925 MB TEMPS TO +1 TO +3 C BY THE EVENING
AND BOTH MODELS FORECAST 2 METER MAX TEMPS IN THE MID TO UPPER 30S.

FORECAST SOUNDINGS HAVE WARMEST TEMPS IN THE LOWER PORTION OF THE
BOUNDARY LAYER WHICH ACTUALLY SLOWLY INCREASE THROUGH THE DAY.
THEREFORE MAY HAVE -RA/-SN MIX OR -SN TRANSITION TO -RA THROUGH THE
EVENT WITH BEST CHANCES FOR -SN ACROSS THE NORTH.

TUESDAY AND WEDNESDAY...A STRONG LOW WILL LIKELY FORM DURING THIS
TIME ALONG A DEVELOPING BAROCLINIC ZONE OVER THE SOUTHERN U.S./OHIO
VALLEY AND THEN MOVE INTO THE GREAT LAKES AREA. MODEL CONSENSUS FOR
THE DVN CWA IS COLDER AND BREEZY WITH SCT SNOW SHOWERS.

THE ECMWF IS SHOWING A STRONG LOW PRESSURE SYSTEM DEVELOPING ACROSS
ALABAMA AND TENNESSEE TUESDAY NIGHT AND THEN LIFTING NORTHWARD TO
LAKE HURON BY WEDNESDAY NIGHT WITH A CENTRAL PRESSURE DOWN TO 961
MB. THE GFS BRINGS IT TO THE SAME AREA BUT IS FURTHER SE DURING THE
CYCLOGENESIS PHASE. IT WILL BE INTERESTING TO SEE THE MODELS WORK
OUT THE POLAR-SUBTROPICAL JET PHASING ISSUES OVER THE NEXT FEW DAYS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1133 AM CST WED DEC 17 2014

MVFR CIGS WILL SLOWLY CLEAR ACROSS EASTERN IOWA AND NORTHERN
ILLINOIS THROUGH 00Z/18 AS HIGH PRESSURE BUILDS INTO THE MIDWEST.
AFT 00Z/18 VFR CONDITIONS ARE EXPECTED THROUGH 12Z/18. AFT 12Z/18
SNOW WILL SLOWLY MOVE INTO SOUTHEAST IOWA PRODUCING MVFR AND
POSSIBLY IFR CONDITIONS.


&&

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

$$

SYNOPSIS...08
SHORT TERM...08
LONG TERM...UTTECH
AVIATION...08





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