FXUS63 KOAX 160918
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
318 AM CST SUN JAN 16 2011
.DISCUSSION...
PRECIPITATION AMOUNTS AND TYPE THROUGH MONDAY REMAIN FORECAST
CHALLENGE/FOCUS.
WEAK WAVE DROPPING SE THRU CNTRL NEBRASKA EARLY THIS MORNING WAS
APPARENTLY WEAKENING PER ENHANCED CLOUDS ON OBSERVED STLT IMAGERY...
BUT SYSTEM HAD SPREAD AN AREA OF LIGHT SNOW ACROSS CWA WITH
LEADING EDGE APPROACHING KOMA/KLNK AT 0830Z. SINCE WAVE WAS
WEAKENING WL JUST MENTION LINGERING FLURRIES FIRST HALF OF THIS
MORNING SERN ZONES. OTHERWISE CIGS SEEM TO IMPROVE A BIT AFT SNOW
ENDS AND WITH SFC RIDGE BUILDING SWD ACRS ERN NEBR WOULD THINK
BETTER LOW LVL MOISTURE AND ANY FZDZ WOULD HOLD OFF UNTIL AT LEAST
THIS AFTN IF NOT LATER. ALTHOUGH IT IS SOMETIMES DANGEROUS TO
PULL IT AFT A WEAK AREA OF SNOW MOVES ACROSS IN THIS TYPE OF
SCENARIO. WITH SFC WARM ADVCTN WEAK TODAY AND DELAYED TILL MORE IN
THE AFTN TRIMMED BACK TEMPS AS SNOWPACK ENHANCES LOW LVL
INVERSION. THIS CONTS TO MAKE PCPN TYPE TRICKY TONIGHT AS STRONG
WARM ADVCTN ABOVE INVERSION SETS UP AS A STRONGER WAVE STRENGTHENS
AS IT MOVS INTO ERN SD EARLY MONDAY. FCST SOUNDINGS INDICATED
MAINLY AN IP TRANSITIONING TO A FZRA EVENT TNGT...ALTHOUGH GFS
WARMS WRN SECTIONS UP TO A BIT ABOVE FREEZING BFR 12Z...WITH SNOW
MAIN TYPE JUST TO OUR ENE. ADJUSTED GRIDS A BIT TO KEEP SNOW
MENTION E OF OMA BUT EXPECT SNOW COVER AIDING IN KEEPING SFC TEMPS
BELOW FREEZING TNGT. NO HEADLINES ATTM AS AMOUNTS QUESTIONABLE
AND IF IP REMAINS MAIN TYPE CONDS WOULD NOT BECOME AS BAD AS THEY
WOULD IF PCPN WAS MOSTLY ZR. ISENTROPIC LIFT/LOWER CONDENSATION
PRESSURE DEFICITS KEY ON WRN IA ZONES AND WL HIT THAT AREA HARDEST
WITH POPS. STILL APPEARS GENERALLY RISING TEMPS TNGT SPCLY SINCE
MAX TEMPS TDA PROBABLY A BIT COOLER THAN EARLIER THOUGHT.
NO BIG CHANGE FM MODELS ON FORECAST SFC LOW TRACK ON MONDAY...PROBABLY
JUST FAR ENOUGH INTO OR NE OF NERN NEBR TO PULL MOST AREAS ABOVE
FREEZING. QUESTION IS HOW QUICKLY. PLAYED THINGS ON THE COOL SIDE
AND KEPT PCPN TYPE AS FREEZING RAIN MOST AREAS MONDAY MORNING BUT COULD
SEE PCPN EITHER ENDING OR GOING OVER TO DRIZZLE/FZ DZ PRETTY
QUICKLY...SPCLY SWRN ZONES. ADJUSTED MENTION IN AFTN TO TRACE
DRIZZLE OR FREEZING DRIZZLE MUCH OF THE S AS FORCING...MAINLY
WARM ADVCTN DRIVEN...SHIFTS FARTHER ENE. AS COLD AIR CRASHES SWD
BHND FRONT COULD SEE EITHER PCPN CHANGING TO LIGHT SNOW OR
FLURRIES AFTER A BRIEF PD OF FZDZ AND MADE SOME ADJUSTMENTS THERE.
DID NOT ESPECIALLY LIKE NAM WHICH REALLY SLOWED COLD PUSH AND
APPEARED TOO WARM MON NGT INTO TUE. HOWEVER...EVEN 00Z GFS/ECMWF
KEPT THE DOUBLE DIGIT BELOW ZERO H85 TEMPS AND 522 DM H100-H5
THICKNESS N OF NEBRASKA THRU 12Z TUE...AND EVEN MUCH OF TUE...
SUGGESTING THE TRULY ARCTIC AIR MAY REMAIN MOSTLY TO OUR N.
ALTHOUGH GFS DID LEAK IT INTO THE CWA LATE TUE INTO WED. FCST
SOUNDINGS SHOWED SOME FLURRIES OR LGT SNOW POSSIBLE MON NGT AS
COLD AIR BECOMES DEEPER AND INCLUDED. ALSO SMOOTHED TEMPS UP A
BIT WHILE GENERALLY REMAINING ON COOL SIDE OF MEX.
SNOW CHCS STILL APPEARED OK ON WED ALTHOUGH GFS/ECM FOCUSED IT
MORE ON SWRN ZONES...BUT NO CHANGES MADE TO BLANKET CHC POPS ATTM.
WAVE TRAIN CONTINUES INTO AND BEYOND EXTENDED PD SO APPEARS WE
WILL BE DEALING WITH NUISANCE TYPE SYSTEMS UFN.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
VFR TO MVFR CONDITIONS ARE EXPECTED IN THE BEGINNING OF THE PD WITH
SCATTERED LIGHT SNOW AT BOTH KOFK AND KOMA THRU 12Z. MVFR CONDITIONS
ARE EXPECTED FOR MUCH OF THE REMAINDER OF THE TAF PD WITH -FZDZ
BECOMING MORE LIKELY LATE IN THE PD WITH CONDITIONS BEING REDUCED TO
IFR AFTER 00Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
CHERMOK/KERN