Area Forecast Discussion
Issued by NWS Des Moines, IA

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011
FXUS63 KDMX 112209
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
409 PM CST THU FEB 11 2016

.SHORT TERM /TONIGHT/...
ISSUED AT 409 PM CST THU FEB 11 2016

THE NEXT IN A SERIES OF QUICK MOVING CLIPPER SYSTEM WILL PASS
SOUTHEAST THROUGH THE STATE TONIGHT.  SYSTEMS HAVE BEEN RIDING TIGHT
TEMPERATURE GRADIENT ALONG POLAR BOUNDARY WITH GOOD ISENTROPIC AND
QG FORCING ON THE COLD SIDE OF THE FRONT.  SNOW HAS ALREADY SPREAD
INTO NORTHWEST AND WEST CENTRAL IOWA BY MID AFTERNOON AND THIS WILL
CONTINUE TO INCREASE IN COVERAGE AS LIFT MAXIMIZES ACROSS THE AREA
EARLY THIS EVENING.  SNOW LIKELY NOT AS FLUFFY AS THE WEDNESDAY
MORNING SNOWFALL AS MUCH OF THE SATURATED LOW LEVEL PROFILE REMAINS
ABOVE THE DENDRITIC GROWTH ZONE.  HOWEVER...DURATION SHOULD BE
SUFFICIENT FOR AN INCH OR TWO IN THE HEAVIEST BAND CENTERED FROM SAC
CITY TO ADEL TO BLOOMFIELD.  THE FAR NORTHEAST NEAR MASON CITY AND
WATERLOO SHOULD ONLY SEE A LIGHTER DUSTING OF SNOWFALL AS WELL AS
THE EXTREME SOUTHWEST NEAR BEDFORD.  WINDS WILL REMAIN LIGHT FOR
MUCH OF THE NIGHT AS THE SURFACE WAVE PASSES BUT STRENGTHENING WILL
BEGIN IN THE NORTH TOWARD DAYBREAK WHERE COLD ADVECTION IS EXPECTED
TO INTENSIFY.  TEMPERATURES WILL BE RELATIVELY STEADY THIS EVENING
BUT BEGIN TO DROP...ESPECIALLY IN THE NORTH LATE AS COLD ADVECTION
INTENSIFIES TOWARD DAYBREAK.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 409 PM CST THU FEB 11 2016

A COLD FRONT WILL PASS THROUGH IOWA ON FRIDAY AND BRING GUSTY
NORTHERLY WINDS TO IOWA DURING THE DAY WITH GUSTS OVER 30 MPH AT
TIMES. EXPECT AREAS OF BLOWING SNOW TO DEVELOP THOUGH NOT TO THE
EXTENT THAT WOULD REQUIRE HEADLINES. AREAS OF BLOWING SNOW WILL
CAUSE ROADWAYS TO BECOME SNOW COVERED AND ICY IN
AREAS...ESPECIALLY ACROSS THE NORTH. WILL CONTINUE TO HIGHLIGHT
TRAVEL IMPACTS VIA SOCIAL MEDIA AND THE WEATHER STORY. VERY COLD
TEMPERATURES STILL EXPECTED FRIDAY NIGHT. READINGS MAY NOT TRULY
BOTTOM OUT WITH WINDS REMAINING BREEZY INTO THE EVENING BEFORE
DROPPING OFF LATE AND POTENTIAL FOR HIGH LEVEL CLOUDS LATE. STILL
HAVE LOWS OF 10 TO 15 BELOW ZERO ACROSS THE NORTH WITH WIND CHILLS
DROPPING TO AROUND 30 BELOW. EXPECT WIND CHILL HEADLINES WILL BE
NEEDED. SATURDAY WILL REMAIN COOL AHEAD OF THE NEXT SYSTEM.

THETA-E ADVECTION WILL ARRIVE SATURDAY NIGHT WITH SNOW DEVELOPING
FROM NORTHWEST TO SOUTHEAST. HAVE INCREASED POPS SIGNIFICANTLY
OVER THE NORTHEAST HALF OF THE AREA SATURDAY NIGHT INTO SUNDAY
MORNING. SHOULD HAVE AN INCREASE AGAIN IN SNOW SUNDAY MORNING AS
THE UPPER LEVEL KINEMATIC FORCING ARRIVES. SNOWFALL RATIOS WILL BE
NEAR TO ABOVE CLIMO AND IN THE MID TEENS WITH PERIODS OF GOOD
DENDRITIC GROWTH. SNOWFALL AMOUNTS OF 2 TO 5 INCHES ARE POSSIBLE
FROM CENTRAL TO THE NORTHEAST FORECAST AREA WITH THE GREATER
AMOUNTS ON THE NORTHEAST SIDE. BLOWING SNOW AND DRIFTING OF SNOW
WILL BE POSSIBLE WITH WINDS OF 15 TO 25 MPH WITH HIGHER GUSTS.

WARMER CONDITIONS WILL FOLLOW MONDAY AND TUESDAY. HAVE LOWERED
HIGH TEMPERATURES OVER NORTHERN IOWA FOR WEDNESDAY WITH COLDER AIR
MAKING A BRIEF REAPPEARANCE FOLLOWED BY THE POTENTIAL FOR MUCH
WARMER TO END NEXT WEEK.

&&

.AVIATION...11/18Z
ISSUED AT 1134 AM CST THU FEB 11 2016

CLIPPER SYSTEM WILL AFFECT AVIATION WEATHER DURING THIS FORECAST
PERIOD WITH LOW CEILINGS INCREASING ACROSS CENTRAL IOWA THIS
AFTERNOON AS WARM ADVECTION INCREASES. CEILINGS WILL INITIALLY BE
VFR BUT DROP TO MVFR/IFR AS SNOW APPROACHES AND THEN OCCURS OVER
MUCH OF THE AREA LATE THIS AFTERNOON INTO THIS EVENING. THE WORST
AVIATION CONDITIONS WILL BE FROM 00-06Z ACROSS CENTRAL IOWA WITH
REDUCTIONS TO BOTH VISIBILITIES AND CEILINGS DUE TO FALLING SNOW.
WINDS WILL REMAIN RELATIVELY LIGHT DURING THIS TIME LIMITING AND
BLOWING SNOW POTENTIAL. SNOW WILL END BY LATE TONIGHT WITH LOW
CEILINGS REMAINING BUT VISIBILITIES INCREASING. STRONG COLD
ADVECTION WILL ARRIVE ON FRIDAY MORNING WITH STRONG NORTHWEST
WINDS LEADING TO BLOWING SNOW BY LATE MORNING.


&&

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

$$

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



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