000
FXUS63 KLBF 090512 AAC
AFDLBF

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1112 PM CST SUN DEC 8 2013

.SYNOPSIS...
ISSUED AT 326 PM CST SUN DEC 8 2013

H5 ANALYSIS FROM THIS MORNING HAS A HIGHLY AMPLIFIED
PATTERN ACROSS NOAM THIS MORNING WITH A RIDGE EXTENDING INTO THE
GULF OF ALASKA. A CLOSED LOW WAS OVER WESTERN PORTIONS OF THE HUDSON
BAY WITH A DEEP TROUGH OF LOW PRESSURE EXTENDING SSWD INTO THE
ROCKIES AND SWRN US. NUMEROUS EMBEDDED SHORTWAVES WERE NOTED ACROSS
THE WESTERN CONUS THIS MORNING. THE FIRST OVER SWRN WYOMING...WHICH
IS CROSSING CENTRAL COLORADO AND IS EMERGING ONTO THE FRONT RANGES
JUST SOUTH OF DENVER...PER SATELLITE AND RADAR IMAGERY. ANOTHER
SHORTWAVE WAS LOCATED OVER SWRN SASKATCHEWAN AND SRN ALBERTA...AND A
THIRD WAS NOTED OFF THE NRN CALIFORNIA COAST. AT THE SURFACE...AN
AREA OF SNOW IN ASSOCIATION WITH THE FIRST SHORTWAVE...EXTENDED FROM
AROUND LIMON COLORADO...NEWD TO FAR SOUTHWESTERN NEBRASKA. THE
HEAVIEST SNOW PER RADAR IMAGERY EXTENDED FROM NEAR LIMON COLORADO TO
NEAR IMPERIAL. THIS ACTIVITY HAS BEEN MOVING TO THE EAST NORTHEAST
AND IS EXPECTED TO REMAIN MAINLY SOUTH OF THE FORECAST AREA THIS
AFTERNOON. THE EXCEPTION IS ACROSS THE FAR SOUTHWESTERN COUNTIES
WHERE 1 TO 2 INCHES IS POSSIBLE THIS AFTERNOON. ELSEWHERE...ANY
ACCUMULATIONS ARE EXPECTED TO BE AN INCH OR LESS. AS OF 3 PM
CST...UNDER PARTLY TO MOSTLY CLOUDY SKIES...TEMPERATURES RANGED FROM
11 AT VALENTINE TO 17 AT OGALLALA.

&&

.UPDATE...
ISSUED AT 729 PM CST SUN DEC 8 2013

THE RAP AND HRRR TEMPERATURE AND WIND CHILL FORECASTS APPEAR TO BE
ON TRACK WITH KVTN SHOWING A WIND CHILL OF -26F AT 7 PM CST.

THERE ARE SOME MID CLOUDS MOVING IN FROM WY WHICH WILL LIMIT THE
AMOUNT OF TIME FOR RADIATIONAL COOLING. THUS CONDITIONS ARE NOT
FAVORABLE FOR ROCK BOTTOM LOWS BUT -10F TO -20F SHOULD DEVELOP
ALONG AND WEST OF HIGHWAY 83 TONIGHT.

TEMPS HAVE BEEN LOWERED IN THE NORTH AND A WIND CHILL WARNING IS
IN PLACE FROM VALENTINE WEST TO GORDON.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 326 PM CST SUN DEC 8 2013

SHORT WAVE MOVING ACROSS THE NEB/KS BORDER...WHICH MODELS HAVE
HANDLED FAIRLY WELL. LIGHT SNOW WILL BE TAPERING TO FLURRIES ACROSS
PORTIONS OF SOUTHWEST AND CENTRAL NEBRASKA BEFORE ENDING LATER THIS
EVENING. ADDITIONAL SNOWFALL COULD REACH UP TO THREE QUARTERS OF AN
INCH...HOWEVER MOST AREAS IN THE SE CWA TO SEE A COUPLE OF TENTHS.
CLEARING SKIES ARE ALREADY SEEN ON VISIBLE SAT ACROSS THE PANHANDLE
AND NW NEB. HIGH PRESSURE WILL BEGIN TO NOSE DOWN INTO THE AREA
TONIGHT...WHICH WILL COMBINE WITH THE SNOW PACK TO ALLOW FOR GOOD
RADIATIONAL COOLING. RECENT LOWS HAVE BEEN BELOW GUIDANCE WHEN SKIES
HAVE CLEARED...SO TOOK COOLER MAV GUIDANCE AND DROPPED A COUPLE OF
DEGREES...WHICH MAYBE CONSERVATIVE FOR PORTIONS OF THE NW
CWA...WHERE MORE THAN HALF A FOOT OF SNOW REMAINS ON THE GROUND.
THIS PLACES LOWS IN THE -5 TO -15 DEGREE RANGE. NORTHWEST WINDS
MOVING IN WITH THE CLEARING...ALTHOUGH THEY WILL BE DIMINISHING. THE
COMBINATION OF LIGHT WINDS AND BITTER COLD TEMPS WILL ALLOW FOR WIND
CHILLS TO FALL INTO THE -20 TO -30 RANGE...LOCALLY LOWER ACROSS NW
ZONES. WILL GO WITH A WIND CHILL ADVISORY FOR ENTIRE CWA.

TOMORROW MODELS HOLD 850 MB TEMPS FAIRLY STEADY...AND WITH MOSTLY
SUNNY SKIES EXPECT HIGHS TO REBOUND A LITTLE WARMER THAN
TODAY...HIGHS SHOULD REBOUND INTO THE TEENS TO NEAR 20.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 326 PM CST SUN DEC 8 2013

MONDAY NIGHT THROUGH WEDNESDAY...THE MAIN FORECASTING
CHALLENGES ARE TEMPERATURES...THEN LOW PRECIPITATION CHANCES FOR
TUESDAY NIGHT. ON MONDAY NIGHT...A SURFACE TROUGH OF LOW PRESSURE
WILL TRACK FROM THE CENTRAL PLAINS EAST INTO THE UPPER MIDWEST.
LIMITED CAA WILL ACCOMPANY PASSAGE OF THE TROUGH. HOWEVER...IT WILL
HELP TO KEEP THE LOW LEVEL WINDS MIXED ON MONDAY NIGHT...THUS MILDER
TEMPERATURES ARE EXPECTED. ALBEIT...LOWS WILL STILL BE COLD WITH
READINGS IN THE SINGLE DIGITS. ON TUESDAY...WESTERLY DOWNSLOPE WINDS
WILL CONTINUE INCREASE SOMEWHAT TO 10 TO 15 MPH. DECIDED TO UNDERCUT
GUIDANCE FOR HIGHS TUESDAY...BASED ON SNOW COVER AND LIMITED MIXING
POTENTIAL. THIS LED TO HIGHS MAINLY IN THE 20S...WITH SOME TEMPS
NEAR THE FREEZING MARK ACROSS THE FAR SOUTHWEST. ON TUESDAY
NIGHT...AN ARCTIC COLD FRONT WILL BACK INTO NORTHERN AND
NORTHEASTERN NEBRASKA WITH A NICE PV MAX ARRIVING OVERNIGHT. CROSS
SECTIONS ACROSS NORTHERN NEBRASKA ARE INDICATIVE OF SOME WEAK LIFT
IN THE DENDRITIC LAYER WHICH MAXES OUT AROUND 06Z WEDNESDAY. TOP
DOWN SATURATION WILL HAVE TO OCCUR WITH ANY PCPN WHICH MAY FALL...SO
WILL LIMIT POP MENTION TO SLIGHTS FOR NOW...AND KEEP POPS ACROSS THE
NRN CWA AS CROSS SECTIONS NEVER MOISTEN UP ACROSS THE SRN CWA. ON
WEDNESDAY SURFACE HIGH PRESSURE WILL BUILD INTO THE MID MISSOURI
VALLEY. WINDS WILL SHIFT TO THE SOUTHWEST DURING THE AFTERNOON
HOURS...AND WILL RECYCLE COLD AIR ACROSS THE FORECAST AREA. HIGHS
WILL BE COLD...RANGING FROM THE MIDDLE TEENS IN THE NORTHEAST...TO
THE UPPER 20S IN THE FAR SOUTHWEST.

WEDNESDAY NIGHT THROUGH SUNDAY...THE MID RANGE MODEL SOLUTIONS
CONTINUE TO INDICATE LOW AMPLITUDE WEST NORTHWESTERLY FLOW ACROSS
THE CONUS FOR THE END OF THE WEEK INTO EARLY NEXT WEEK. BOTH THE
ECMWF AND GFS SOLNS ARE TRENDING TOWARD THE DEVELOPMENT OF AN UPPER
LEVEL TROUGH EMBEDDED IN THE SRN STREAM TOWARD FRIDAY. BOTH SOLNS
LIFT THIS ENERGY SOUTH OF THE AREA...SO A DRY FORECAST CONTINUES.
AFTER TEMPERATURES TREND HIGHER FOR THURSDAY AND FRIDAY WITH HIGHS
IN THE 30S...COOLER TEMPERATURES WILL ARRIVE ON FRIDAY NIGHT AS AN
ARCTIC COLD FRONT BACKS INTO THE FORECAST AREA. HIGHS WILL BE COOLER
IN THE 20S AND LOWER 30S SATURDAY...FOLLOWED BY 30S AND LOWER 40S FOR
SUNDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1112 PM CST SUN DEC 8 2013

VFR IS EXPECTED ALL AREAS TONIGHT THROUGH MONDAY EVENING. SCATTERED
TO BROKEN COVERAGE OF MID AND HIGH LEVEL CLOUDS WILL CONTINUE
ACROSS THE FCST AREA DURING THIS PERIOD.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST /11 AM MST/ MONDAY FOR NEZ007-
009-010-022>029-035>038-056>059-069>071.

WIND CHILL WARNING UNTIL NOON CST /11 AM MST/ MONDAY FOR
NEZ004>006-008-094.

&&

$$

UPDATE...CDC
SYNOPSIS...CLB
SHORT TERM...MASEK
LONG TERM...CLB
AVIATION...CDC