FXUS63 KLBF 112240 CCA
AFDLBF
AREA FORECAST DISCUSSION...CORRECTED FORMATTING
NATIONAL WEATHER SERVICE NORTH PLATTE NE
353 PM CST FRI DEC 11 2009
...A BRIEF WARMUP SATURDAY FOLLOWED BY ANOTHER ARCTIC SURGE SUNDAY
AND MONDAY...
SHORT TERM DISCUSSION...
NOT AS COLD TONIGHT. RIDGE OF SFC HIGH PRESSURE WILL BREAK DOWN
TONIGHT WITH WEAK LOW PRESSURE DEVELOPING OVER THE BLACK HILLS
REGION. WIND TONIGHT WILL BE LIGHT AND VARIABLE MOST AREAS WITH ONLY
SCATTERED HIGH CLOUDS. LOWS TO MAINLY BE AROUND 5 ABOVE...EXCEPT
NEARER TO ZERO IN FAVORED VALLEYS AND LOW AREAS. 12Z GFS AND NAM
SIMILAR WITH OVERALL UPPER FLOW BECOMING ZONAL BY 12Z SATURDAY. THIS
WILL BRING A PACIFIC AIRMASS EAST INTO PLAINS...WITH THE ARCTIC AIR
RETREATING INTO THE GREAT LAKES AND NORTHEAST U.S. TEMPERATURES WILL
CONTINUE TO MODERATE SATURDAY...WITH BOTH GFS AND NAM H925 TEMPS
SUPPORTING UPPER 30S TO LOWER 40S ACROSS SOUTHWEST NEB ON BOTH
SATURDAY. OF COURSE WITH PLENTY OF SNOW COVER...AND LACK OF DEEP
MIXING WITH ONLY LIGHT WEST/SOUTHWEST WINDS WILL GO ABOUT 3 TO 5
DEGREES BELOW COLDEST MET GUIDANCE SATURDAY. YESTERDAYS ECMWF SHOWED
ARCTIC AIR BACKDOORING WRN NEBR AND NOW TODAYS 12Z ECMWF/NAM AND TO
LESSER DEGREE 12Z GFS ALL INDICATE THIS. THUS...HAVE COOLER HIGHS
CONSIDERABLY INTO THE UPR TEENS NORTHEAST TO THE LOWER 30S ACROSS
ERN PNHDL AND SOUTHWEST. WINDS SUNDAY WILL TURN EAST AND SOUTHEAST
DURING AFTN AS SFC LOW PRESSURE DEEPENS IN NERN CO. WEAK SHORTWAVE
APPROACH SUNDAY WILL BRING AN INCREASE IN MID/HIGH CLOUDS AND SLIGHT
CHC FOR -SN TO NORTHWEST BY LATE AFTN. CHANCES FOR -SN HAS BEEN
INCREASED TO LOW CHC POPS (30 PERCENT) MOST OF NCTRL AND SLIGHT CHC
SOUTH TO NEAR AN OSHKOSH AND BURWELL LINE. ALSO MUST POINT OUT
POTENTIAL FOR -FZDZ SUNDAY NIGHT INTO MONDAY MORNING MAINLY SOUTH OF
HWYS 2 AND 91. TIME FRAME LOOKS TO FOCUS FROM 06Z TIL 15Z MONDAY.
NAM BUFR AND BUFKIT SOUNDING INDICATE NEAR SATURATION UP TO ABOUT
H85 MB. WILL NOT INCLUDE IN FCST ATTM ALTHOUGH SHOULD MONITOR NEXT
FCST SHIFTS TO INCLUDE IF MODELS CONTINUE TO INDICATE. DO NOT FEEL
THIS SHOULD BE ANYTHING MORE THAN PATCHY THOUGH.
CONTINUED COLDER MONDAY AS ARCTIC AIR CONTINUES TO PUSH IN. HIGHS TO
BE 10-15 ABOVE NCTRL TO 20-25 SOUTHWEST. ALSO A SLIGHT CHC FOR SNOW
NCTRL AND WEAK SHORTWAVE PASSES EAST.
&&
.EXTENDED DISCUSSION...
ECMWF AND GFS INDICATE THERE SHOULD BE A SLIGHT WARMUP TUESDAY FROM
MID TEENS NORTHEAST TO MID/UPPER 20S SOUTHWEST AS ARCTIC AIR
RETREATS FURTHER EAST. UPPER RIDGE WILL BUILD ACROSS THE
INTERMOUNTAIN WEST THROUGH FRIDAY BRINGING MILDER TEMPERATURES NEAR
NORMAL WEDNESDAY AND POSSIBLY ABOVE NORMAL IN THE LOWER TO MID 40S
BY THURSDAY/FRIDAY. EXTENDED TO BE DRY AS WELL.
&&
AVIATION...
VFR CONDITIONS WILL REMAIN IN PLACE AGAIN OVERNIGHT UNDER FEW-SCT250
AND UNLIMITED VSBYS. WITH STRONG INVERSION EXPECTED AGAIN WINDS
SHOULD BE FAIRLY LIGHT. LLWS IS NOT EXPECTED WITH WINDS THROUGH AND
ABOVE INVERSION EXPECTED TO REMAIN UNDER 15KTS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...ROBERG
AVIATION...MASEK
