FXUS63 KOAX 311913
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
113 PM CST FRI DEC 31 2010
.UPDATE...
SNOW CONTINUES TO DECREASE AS DEFORMATION ZONE LIFTS NORTH AND DRY
AIR ALOFT MOVES IN. WINTER STORM WARNING AND ADVISORY AREAS WERE
CANCELLED. AFTER TALKING THINGS OVER HERE...CONSENSUS WAS TO ISSUE
A WIND CHILL ADVISORY FOR NORTHEAST NEBRASKA AREA THAT WAS IN
PREVIOUS WARNING AREA. WEB CAMS SHOW CONDITIONS MUCH IMPROVED.
&&
.PREV DISCUSSION... /ISSUED 1204 PM CST FRI DEC 31 2010/
UPDATE...
UPDATED PRODUCTS EARLIER BUT SYSTEM CONTINUES TO DEVELOP ABOUT AS
EXPECTED. NO CHANGES TO HEADLINES AND ONLY MINOR CHANGES OTHERWISE.
DISCUSSION...
LOW PRESSURE AT THE SURFACE WILL CONTINUE TO TRACK NORTH OVER IOWA
THIS AFTERNOON AND THEN INTO MINNESOTA. 12Z KOAX SOUNDING SHOWED
THE WARM LAYER BETWEEN ABOUT 850 MB AND 750 MB. MODEL SHOW THIS
COOLING THE REST OF TODAY AS COLDER AIR MOVES IN FROM THE WEST
AND NORTHWEST. VERY WARM AIR CONTINUES TO FEED NORTH ACROSS IOWA
AND MISSOURI.
PREV DISCUSSION... /ISSUED 400 AM CST FRI DEC 31 2010/
DISCUSSION...
MAIN CONCERN IS THE IMPENDING WINTER STORM THAT WILL AFFECT THE
REGION OVER THE NEXT 12 TO 18 HOURS...WITH ALL WEATHER TYPES
EXPECTED...RANGING FROM ALL SNOW IN NORTHEAST NEBRASKA...A SNOW
AND SLEET MIX IN THE TRANSITION ZONE...AND NEARLY ALL FREEZING
RAIN IN EXTREME SOUTHEAST NEBRASKA AND SOUTHWEST IOWA WITH EVEN A
CHANCE OF THUNDER THIS MORNING.
MODELS ARE IN FAIR AGREEMENT THIS MORNING...TAKING A SURFACE LOW
THAT IS LOCATED ACROSS CENTRAL OKLAHOMA AT 09Z...TO NORTHWEST
MISSOURI BY 18Z AND SOUTHEASTERN MINNESOTA BY 00Z. THUS...ITS A
QUICK MOVING SYSTEM...WHICH WILL HELP TO LIMIT PRECIP AMOUNTS AS
WELL. WITH THE ALL SNOW AREA...BASED ON MODEL QPF AND SPEED OF THE
SYSTEM...EXPECTING 6 TO 8 INCHES OF SNOW...NORTHWEST OF A LINE
FROM COLUMBUS TO WAYNE. THERE WILL BE SOME WINDS WITH THIS...BUT
CERTAINLY NOT BLIZZARD CRITERIA WINDS...AND A WINTER STORM WARNING
IS IN EFFECT FOR THIS AREA. HAVE CONSIDERED EXPANDING THE STORM
WARNING THOUGH ONE TIER OF COUNTIES SOUTHEAST FROM PREVIOUS AREAL
EXTENT. IN THE TRANSITION ZONE FROM FAIRBURY TO LINCOLN TO
OMAHA...MOSTLY SLEET IS EXPECTED BEFORE CHANGING TO SNOW...BUT BY
THEN...THE BEST CHANCE FOR ACCUMULATING SNOW WILL HAVE PASSED TO
THE NORTH...THUS ONLY FORECASTING AROUND AN INCH OF SLEET/SNOW
COMBINATION...WITH THE TRACTION PROPERTIES OF SLEET...AND THE
OVERALL LIGHT AMOUNTS...A WINTER WEATHER ADVISORY STILL SEEMS
APPROPRIATE IN THIS AREA TODAY...AND DUE TO THE QUICK ENDING
NATURE...CONDITIONS SHOULD SIGNIFICANTLY IMPROVE THIS AFTERNOON
FROM SOUTH TO NORTHEAST. FROM FALLS CITY TO CLARINDA...ITS MORE OF
A FREEZING RAIN THREAT THIS MORNING...ALSO WITH A CHANCE FOR
THUNDER WITH SOME DEFINITE INSTABILITY NOTED ABOVE ABOUT H85.
THUNDER HAS MOVED AS FAR NORTH AS EMPORIA KS EARLY THIS
MORNING...AND MOVING OUR WAY. THIS MOSTLY APPEARS TO BE POSSIBLE
EAST OF THE OMAHA METRO AREA...BUT IT COULD BE VERY CLOSE LATER
THIS MORNING. OVERALL ICING AMOUNTS IN THIS AREA SHOULD BE
LIGHT...UP TO 1/10 INCH...WITH LITTLE IF ANY SNOWFALL...AND
PERHAPS ONLY A VERY SMALL WINDOW FOR SOME SLEET LATER THIS MORNING
AS WELL. DUE TO THE MIXTURE OF WINTRY PRECIPITATION...WINTER
WEATHER ADVISORY LOOKS GOOD HERE TOO.
THE WINTRY WEATHER DOES TRANSITION NORTHWARD FAIRLY QUICKLY THIS
AFTERNOON...ALTHOUGH THERE SHOULD STILL BE SOME SNOW OCCURRING IN
NORTHEAST NEBRASKA THIS EVENING...WITHIN THE EXTREME SOUTHERN EDGE
OF THE TROWAL...WITH A MUCH BIGGER IMPACT ACROSS SOUTH DAKOTA AND
MINNESOTA. HOWEVER...DUE TO THE COLD NATURE OF THE ATMOSPHERE...WITH
DENDRITIC TEMPS AT H7...COMBINED WITH SOME LINGERING RH...THERE
PROBABLY WILL STILL BE A FEW NON ACCUMULATING FLURRIES ALONG/NORTH
OF I80 ESPECIALLY IN THE EVENING. DUE TO THE SNOW/BLOWING SNOW
POSSIBILITY IN EXTREME NORTHEAST NEBRASKA...EXTENDED THE WINTER
STORM WARNING THERE THROUGH MIDNIGHT.
WEATHER BEYOND TONIGHT WILL BE DRY...AND SLOWLY MODERATING...
ALTHOUGH IT WILL BE A COLD NIGHT SATURDAY NIGHT WHERE THE SNOW
ACCUMULATES WITH SUB ZERO READINGS. DID NOT HAVE MUCH TIME TO LOOK
AT THE FORECAST BEYOND MONDAY/TUESDAY AND MADE NO SUBSTANTIAL
CHANGES.
DEWALD
AVIATION...
06Z TAFS
VERY STRONG SYSTEM LIFTING THRU THE CNTRL PLAINS WILL RESULT IN
POTENTIALLY HAZARDOUS CONDITIONS AT ALL TERMINALS THIS MORNING.
INTENSE COLD FRONT ASSOC WITH SFC LOW IN MN HAS MOVED THRU ERN NEB
INTO KS/NRN MO. MAIN CONCERN IS PCPN MIX AT KOMA/KLNK. EXPECT AREA
OF PCPN CURRENTLY MOVING NNE THRU KS WILL BRING -SNPL MIX AT KLNK
AROUND 10Z...AND 11Z AT KOMA. CHANGE OVER TO -SN TWD 14Z AT
KLNK...16Z AT KOMA. BEST FORCING WILL MOVE INTO THE DAKOTAS/UPPER
MID WEST LATE THIS AFTN WITH -SN COMING TO AN END. TOTAL SN ACCUM AT
KOMA/KLNK 1-2 INCHES. FOR KOFK...ACTIVITY CONSISTING OF SN/BLSN
BTWN 31/11Z-20Z...WITH POTENTIAL ACCUM AROUND 5 INCHES.
ALSO...OVERRUNNING SITUATION CREATING ICING POTENTIAL FL020-030 AGL
AT ALL TERMINALS THRU AT LEAST 31/15Z. ALL SITES....CONDITIONS
IMPROVING FROM MVFR/IFR TO VFR AROUND 01/01Z. THREAT FOR CROSS
WIND ACTIVITY WHEN WINDS SHIFT FROM N TO W AROUND 01/00Z AND
CONTINUING THRU THE FCST PD.
DEE
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND CHILL ADVISORY UNTIL 6 AM CST SATURDAY FOR NEZ011-012-
016>018-030>032-042.
IA...NONE.
&&
$$
SHORT TERM...MILLER