Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 152103
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
303 PM CST MON DEC 15 2014

.SYNOPSIS...
ISSUED AT 302 PM CST MON DEC 15 2014

AN UPPER LOW...WITH FULL CINNAMON ROLL APPEARANCE AND SMALL DRY
CENTER MAKING AN EYE IS FOUND IN NORTH CENTRAL MISSOURI THIS
AFTERNOON. THIS IMPRESSIVE UPPER SYSTEM IS ESPECIALLY VISUALLY
APPEALING ON SATELLITE AS IT CONTAINS ALMOST AN EQUAL BALANCE OF
BOTH DRY AND MOIST AIR. FOR THE SURFACE...THAT HAS MENT THAT BANDS
OF RAIN HAVE BEEN RATHER TRANSIENT TODAY...WITH ONE THIS MORNING...
FOLLOWED BY SMALL SHOWERS THIS AFTERNOON...AND NOW...SHOWERS AND
HEAVY DRIZZLE. THE DRIZZLE IS WIDESPREAD BETWEEN SHOWER BANDS
NOW...AND WE HAVE UPDATED TO 90+ % POPS THE REMAINDER OF THE
AFTERNOON SINCE ALL LOCATIONS ARE GETTING WETNESS FROM THE SKY.
ERVIN

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 302 PM CST MON DEC 15 2014

THE VERTICALLY STACKED UPPER AND SURFACE LOW WILL PASS OVER THE CWA
THIS EVENING AND OVERNIGHT. AT THE MOMENT WITH DRIZZLE AND SHOWERS
TAKING PLACE UNDER THE LOW...FOG HAS NOT BEEN A PROBLEM.
HOWEVER...WITH CONVERGENT SURFACE FLOW...ANY BREAK IN THE LIGHT
SHOWERY OR DRIZZLY PCPN TONIGHT MAY RESULT IN NEW DENSE FOG
FORMATION. THIS THREAT IS ESPECIALLY TRUE IN THE NORTH HALF...JUST
NORTH OF THE LOW TRACK...AND WILL PLACE AREAS OF FOG INTO THE
FORECAST. DENSE IS NOT GUARANTEED...BUT ENOUGH THREAT IS THERE TO
KEEP THIS PLACE HOLDER IN THE FORECAST.

RAIN SHOWERS WILL CONTINUE TO BE PROBABLE ALL NIGHT...AS THE UPPER
LOW ROTATES OVERHEAD. THE MOST CONTINUOUS FORCING SHOULD PASS
THROUGH THE NORTH HALF OF THE CWA...AND RAIN AMOUNTS WILL BE HIGHEST
THERE. SOME SHALLOW CONVECTION IS LIKELY...BUT LIGHTING HAS BEEN
DECREASING IN MISSOURI TODAY..AND SEEMS UNLIKELY IN EASTERN IOWA
TONIGHT. SO WE ARE STAYING WITH RAIN...THOUGH IT WILL BE THROUGH A
MIX OF SHOWERS AND DRIZZLE.

AFTER 3 AM...COLD AVECTION IS EXPECTED TO BECOME STRONG IN THE
WESTERN CWA...SPREADING THROUGH THE REST OF THE CWA BY MORNING. LOWS
NEAR FREEZING BY MORNING ARE EXPECTED...BUT WITH RAIN ENDING FROM
WEST TO EAST AT THE SAME TIME...ONLY A EXTREMELY LIGHT MIX IS
EXPECTED WITH NO PUBLIC IMPACT. TUESDAY MORNING...THIS SUPER LIGHT
MIX BEFORE ENDING IS EXPECTED FARTHER EAST...AND WITH TEMPERATURES
SLOWLY FALLING AFTER SUN RISES THERE...NO PROBLEMS ARE EXPECTED. BY
AFTERNOON TUESDAY...UNDER CLOUDS AND COLD ADVECTION...FALLING
TEMPERATURES COMBINED WITH NORTHWEST WINDS OF 15 TO 25 MPH TO DROP
WIND CHILLS TO THE 10 TO 20 RANGE FROM WEST TO EAST.  WINTER/S CHILL
WILL DEFINTELY BE BACK BY MID AFTERNOON.
ERVIN

.LONG TERM...(TUESDAY NIGHT THROUGH NEXT MONDAY)
ISSUED AT 302 PM CST MON DEC 15 2014

TUESDAY NIGHT THROUGH THURSDAY...ALTHOUGH THE 12Z MODEL RUNS CONTINUE
TO ADVERTISE A RATHER STRONG SFC RIDGE NOSING DOWN OUT OF CANADA
AND ACRS THE MO/MS RVR VALLEYS...SECONDARY UPPER LOW PIVOTING
EAST-SOUTHEASTWARD DOWN ACRS THE WESTERN GRT LKS WILL LOOK TO
CONTINUE WRAP AROUND CLOUD SHIELD ACRS MUCH OF THE NORTHERN HALF
TO 2/3S OF THE DVN CWA/IF NOT THE ENTIRE FCST AREA/ TUE NIGHT
THROUGH WED. ALTHOUGH MOISTURE DEPTH/LAYER CURRENTLY NOT EXPECTED
TO BE DEEP ENOUGH FOR A STRONG/VIGOROUS VORT MAX ALONG AND NORTH
OF THE CWA TO WRING OUT FLURRIES LATE TUE NIGHT AND WED...THE
CLOUD DECK MAY MAKE FOR A MORE UNIFORM TEMP REGIME ACRS THE
AREA/BOTH HIGHS AND LOWS/ THROUGH MID WEEK. SOME POST-WAVE
SUBSIDENCE BREAKS MAY OCCUR WED AFTERNOON FROM WEST-TO-EAST THOUGH
WHICH COULD ALLOW FOR WARMER TEMPS THAN WILL BE ADVERTISED FOR
WED. THE 12Z RUN MEDIUM RANGE SOLUTIONS AND ENSEMBLES STILL
ADVERTISE A SEMI-SPLIT DISORGANIZED STEERING FLOW ACRS THE UPPER
MIDWEST AND GRT LKS INTO THU...WHILE THE SOUTHERN STREAM ACTIVATES
AND BECOMES MORE DOMINATE. OVERRUNNING ISENTROPIC EVENT TRYING TO
SPILL LIGHT PRECIP OUT OF THE SOUTHERN PLAINS AND TOWARD THE
SOUTHERN CWA LATE WED NIGHT INTO THU...BUT WITH EXTENT OF DRY
RIDGE IN PLACE WOULD BE SURPRISED IF MUCH MORE THAN A FEW FLURRIES
MAKE IT ACRS THE FAR SOUTHERN CWA. OVERRUNNING CLOUDS THOUGH
EXPECTED UP TO AT LEAST I80 FROM THE SOUTH AND WITH COLD LAYER
TRAPPED AT THE SURFACE HIGH TEMPS ON THU MAY BE HELD IN THE UPPER
20S TO LOWER 30S. AREAS WITH MORE SUN/INSOLATION MAY TREND CLOSER
TO THE MID 30S. COLD/BELOW NORMAL TEMP REGIME EXTENDS INTO FRI
MORNING.

FRIDAY THROUGH NEXT MONDAY...BULK OF 12Z RUN MEDIUM RANGE MODELS
HAVE TRENDED TOWARD THE ECMWF RUNS OF THE PAST FEW DAYS IN
SUGGESTING LESS PHASED/WITH ANY NORTHERN STREAM WAVE/ WILL RESULT IN
A SOUTHEAST TX/LA LOW ON FRI THAT WILL CONTINUE TO ROLL ALONG THE
EASTERN GULF COAST THRU SAT...MISSING THE CWA WELL TO THE SOUTH
WITH ANY DEF ZONE TYPE PRECIP IT CAN MUSTER UP. WILL CONTINUE TO CUT
BACK POPS OUT OF THE SOUTH WITH THESE MODEL TRENDS FRI INTO SAT
MORNING...WITH NEAR NORMAL TO SOMEWHAT BELOW NORMAL TEMPS ADVERTISED
THROUGH THE WEEKEND UNDER THE INFLUENCE OF CANADIAN AIRMASS/NORTHERN
STREAM. SLIGHT TEMP MODERATION WITH NO SNOW COVER INTO SUNDAY AND
ESPECIALLY MONDAY...WITH MONDAY POSSIBLY SEEING A GOOD TEMP REBOUND
IF SOUTH TO SOUTHEASTERLY RETURN FLOW ACCELERATES AHEAD OF THE NEXT
L/W PHASING PROCESS ACRS THE PLAINS TO LEE OF BUILDING WEST COAST
OMEGA BLOCK. IF L/W TROF FORMS AND MIGRATES ACRS THE MIDWEST...
POSSIBLY NEXT PRECIP EVENT AT END OF LONG RANGE OR JUST PAST BY MID
NEXT WEEK. COLDER INFLUX INTO THE TROF BASE ACRS THE UPPER MS RVR
VALLEY ALSO POSSIBLE THIS PRE HOLIDAY PERIOD IF ENSEMBLES ARE
TRENDING RIGHT.   ..12..

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1117 AM CST MON DEC 15 2014

PERSISTENT LOW STRATUS WILL CONTINUE THROUGH TUESDAY
AFTERNOON...AS A SURFACE AND UPPER LOW SLOWLY MOVE DIRECTLY OVER
EASTERN IOWA. PERIODS OF LIGHT RAIN AND DRIZZLE...ALONG WITH FOG
WILL LOWER VISIBILITY FREQUENTLY TO THE 1 TO 4 MILE RANGE THROUGH
TONIGHT...WITH CIGS GENERALLY VARIABLE BETWEEN 300 FT NORTH TO
AROUND 1000 FT SOUTH. THIS IFR TO OCCASIONAL LIFR WEATHER WILL
BECOME MAINLY MVFR BY MORNING AS A COLD FRONT SWEEPS THROUGH THE
REGION. WINDS WILL INITIALLY SWITCH FROM SOUTHEAST TO NORTHWEST IN
NORTHEAST IOWA AROUND 06Z/16...AND AFTER 14Z TUESDAY...LOOK FOR
NORTHWEST WINDS OF 15 TO 20 KTS AND CIGS AROUND 1500 TO 3000 FT.

&&

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

$$

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






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