FXUS63 KOAX 142103
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
303 PM CST FRI JAN 14 2011
.SHORT TERM...TONIGHT THROUGH MONDAY
PESKY MIXED PRECIP IS MOVING OUT OF THE AREA...LEAVING A QUIET NIGHT
IN THE MIDST OF AN ACTIVE PATTERN. SUBJECTIVE 12Z UPPER AIR
ANALYSIS INDICATES NWRLY FLOW ACROSS THE CONUS...WITH A TROUGH
EXTENDING FROM SWRN SD THROUGH CO/4 CORNERS TO SRN AZ. STRONG
UPPER-LEVEL JET WAS RACING THROUGH WRN CANADA...WITH 150KT IN AB AND
100KT REACHING THE NRN ROCKIES. CWA WAS EMBEDDED IN A DRY PUNCH AT
850MB UNDER 850MB RIDGING...WHICH HAS ALLOWED PRECIP TO FALL AS
LIQUID ACROSS MUCH OF THE AREA TODAY /AS FREEZING DRIZZLE OR VERY
LIGHT RAIN/. WARM NOSE AT 850MB EXTENDED INTO THE NRN HIGH
PLAINS...INCLUDING NEB/WRN IA...THOUGH MUCH COLDER AIR WAS SITUATED
IN SRN CANADA WITH A STRONG BAROCLINIC ZONE NEAR THE US-CANADA
BORDER. AT THE SURFACE AT 20Z...A TROUGH EXTENDED FROM AROUND KBIS
THROUGH CNTRL SD/CNTRL NEB TOWARD A SFC LOW CENTERED IN THE WRN TX
PANHANDLE. DUE TO DOWNSLOPING AND SUNSHINE...TEMPS IN WRN NEB WERE
REACHING THE 50S BEHIND THE TROUGH...WITH COLDER AIR BACK IN THE WRN
DAKOTAS.
MAIN FORECAST CONCERNS ARE INTERMITTENT LIGHT PRECIP CHANCES THROUGH
MONDAY...INCLUDING COMPLICATED PRECIP TYPE CONCERNS. WEAK TROUGH
WILL MOVE THROUGH THE CWA THIS EVENING/TONIGHT AS FAST-MOVING TROUGH
CROSSES THE PLAINS...WITH SOME COLD AIR ADVECTION BEHIND THE FRONT
INTO SATURDAY. SHOULD REMAIN DRY ACROSS THE CWA TONIGHT...WITH
APPROACHING WEAK EMBEDDED WAVE TOO FAR NW TO GENERATE PRECIP IN THE
CWA. MAY SEE LIGHT PRECIP TOMORROW MORNING...BUT WAVE WILL BE
WEAKENING AND SURFACE RIDGE/SUBSIDENCE WILL BE DEVELOPING...AND HAVE
BACKED OFF ON POPS IN THE AREA AS MEASURABLE PRECIP MAY STRUGGLE TO
DEVELOP. WHATEVER PRECIP CAN DEVELOP WOULD FALL IN THE FORM OF SNOW
AS SATURATION DEEPENS. DID DROP TEMPS A FEW DEGREES
TOMORROW...ESPECIALLY IN THE NORTH...AS CLOUDS WILL LINGER THROUGH
THE DAY AND COLD AIR ADVECTION ALSO WILL SUPPRESS TEMPS. WITH
SURFACE RIDGE AXIS MOVING THROUGH ON SATURDAY EVENING/EARLY SUNDAY
NIGHT...TEMPS COULD DIP DOWN TO QUITE CHILLY READINGS BEFORE
BECOMING STEADY OR REBOUNDING THROUGH THE EARLY MORNING HOURS. IN
WAKE OF THE RIDGE...AS RETURN FLOW DEVELOPS...COULD BE ENOUGH
ISENTROPIC LIFT TO PROMPT PRECIP FROM LATE SATURDAY NIGHT INTO
SUNDAY MORNING. WOULD EXPECT AMOUNTS TO BE LIGHT AGAIN...AND WHILE
SNOW IS CURRENTLY IN THE GRIDS...WOULD NOT RULE OUT BRIEF PERIODS OF
FREEZING DRIZZLE.
STRONGER WAVE IS PROGGED TO MOVE THROUGH THE CNTRL PLAINS SUNDAY
NIGHT/MONDAY...DRAGGING A COLD FRONT THROUGH THE AREA AND GENERATING
MORE WIDESPREAD PRECIP. MODEL CONSENSUS BRINGS A WARM NOSE AT 850MB
BACK INTO NEB/IA /PARTICULARLY THE SRN HALF OF THE AREA/ UNTIL THE
COLD FRONT PASSES THROUGH LATE ON MONDAY. WARM AIR ADVECTION/SRLY
FLOW AT THE SURFACE WILL HELP BOOST TEMPS INTO THE 30S DURING THE
DAY ON MONDAY...ESPECIALLY IN THE SRN CWA...BUT FOR MOST OF THE DAY
AND IN MOST PLACES...SFC TEMPS REMAIN BELOW FREEZING AND CURRENT
PROGS INDICATE FZRA/FZDZ AS THE MOST LIKELY PRECIP TYPE. HAVE
ALLOWED FZRA MENTION TO BE THE PRIMARY PRECIP TYPE IN THE GRIDS.
RIGHT NOW...AMOUNTS LOOK LIGHT AS SYSTEM INTENSIFIES JUST TO OUR
EAST.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
PATTERN REMAINS ACTIVE THROUGH THE PERIOD WITH TROUGH DIGGING INTO
THE EASTERN CONUS AND VERY COLD AIR PLUNGING INTO THE CENTRAL PLAINS
AT THE START...FOLLOWED BY DEVELOPMENT OF SPLIT FLOW BY WEDNESDAY
INTO THURSDAY WITH MORE COLD AIR DROPPING INTO THE REGION FROM
CANADA. SOME UNCERTAINTY ON INTENSITY OF SOUTHERN STREAM WAVE THAT
THE EURO DEVELOPS AND MOVES INTO THE SOUTHERN TIER OF STATES BY LATE
IN THE PERIOD. TRENDED TOWARD THE HPC BLEND OF GUIDANCE WITH EURO THE
PRIMARY MODEL. DID NOT GO QUITE AS COLD AS GUIDANCE WOULD SUGGEST
FOR FRIDAY MORNING WITH TREND TOWARD A BLEND WITH SURROUNDING
OFFICES. HPC HAD REMOVED POPS FOR WEDNESDAY PERIOD WITH MORNING
GUIDANCE BUT NEW EURO AND GFS SUGGEST SOME CHANCE SO REENTERED
SLIGHT POPS.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
VFR CONDITIONS ARE EXPECTED THROUGH ABOUT 12Z SATURDAY...THEN MVFR
CIGS AND POSSIBLY -SN COULD AFFECT EASTERN NEBRASKA TAF SITES. ONE
SYSTEM MOVING EAST THROUGH EASTERN NEBRASKA WILL EXIT EASTERN
NEBRASKA BY LATE FRIDAY AFTERNOON. SIGNIFICANT ICING IS POSSIBLE
THROUGH 00Z ESPECIALLY NORTH OF KOMA AND EAST OF KOFK BEFORE AN AREA
OF FREEZING RAIN AND SNOW MOVES INTO WESTERN IOWA. ANOTHER SYSTEM
WILL DROP SOUTHEAST FRIDAY NIGHT...DRIVING A COLD FRONT INTO
NORTHEAST NEBRASKA BY 06Z. A WIND SHIFT TO NORTH WILL OCCUR WITH THE
FRONT...WITH MVFR CIGS BETWEEN FL015 AND FL025 LAGGING THE FRONT BY
ABOUT 6 OR 8 HOURS. EXPECT MVFR CIGS AND AREAS OF LIGHT SNOW NEAR
KOFK BY 12Z...WITH THE SAME CONDITIONS SPREADING TO KOMA AND KLNK
BETWEEN 15Z AND 18Z SATURDAY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
MAYES/FOBERT/DERGAN