341
FXUS63 KLBF 161743
AFDLBF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1243 PM CDT WED OCT 16 2013
.SYNOPSIS...
ISSUED AT 400 AM CDT WED OCT 16 2013
A BROAD TROUGH OF LOW PRESSURE ALOFT CONTINUES ACROSS MOST OF THE
CONUS TONIGHT WITH A TANDEM OF SHORTWAVES NOTED ACROSS THE UPPER
MISSISSIPPI VALLEY AND ACROSS THE SOUTHERN ROCKIES IN THE
VICINITY OF THE FOUR CORNERS. ABUNDANT CLOUD COVER EXTENDED FROM
THE UPPER MISSISSIPPI VALLEY WSW INTO NORTHERN NEBRASKA AND THE
INTERMOUNTAIN WEST TONIGHT. THE ABUNDANT CLOUD COVER OVER CENTRAL
AND NORTHERN NEBRASKA HAS HELD TEMPERATURES IN THE MID TO UPPER
30S...WHILE OVER SOUTHWESTERN NEBRASKA...CLEAR SKIES AND DRY AIR
HAS ALLOWED TEMPERATURES TO DIP INTO THE UPPER 20S TO AROUND 30
DEGREES. SURFACE ANALYSIS AS OF 2 AM CDT...HAS WEAK HIGH PRESSURE
OVER NWRN KS/FAR SWRN NEBRASKA...WITH LOW PRESSURE NOTED OVER THE
UP OF MICHIGAN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT WED OCT 16 2013
THE MAIN FORECASTING CHALLENGE OVER THE NEXT 24 HOURS IS
TEMPERATURES. FOR TODAY...THE BEFOREMENTIONED UPPER LEVEL
SHORTWAVE TROUGH...WILL TRACK SOUTH OF THE FORECAST AREA INTO
KANSAS...CLEARING SKIES FROM NORTH TO SOUTH. AS FOR HIGHS THIS
AFTERNOON...BASED ON H85 TEMPS RANGING FROM AROUND 4C IN THE
NORTHEAST TO 8C IN THE FAR SOUTHWEST...AFTERNOON HIGHS ARE
EXPECTED TO RANGE FROM THE MID 50S IN THE NORTHEAST...TO THE
UPPER 50S IN THE WEST AND SOUTHWEST. TEMPS MAY GET TRICKY IN THE
SOUTHWEST TDY HOWEVER AS LINGERING CLOUD COVER MAY HOLD BACK
TEMPS. FOR NOW...BASED ON THE NAM AND GFS SOLNS...ENOUGH CLEARING
IS EXPECTED THIS AFTERNOON...SO THE FCST OF UPPER 50S LOOKS ON
TRACK ATTM. FOR TONIGHT...LOW AMPLITUDE RIDGING WILL BUILD INTO
COLORADO AND NEBRASKA IN ADVANCE OF ANOTHER UPPER LEVEL SHORTWAVE
TROUGH OF LOW PRESSURE. THIS TROUGH WILL APPROACH THE DAKOTAS AND
NORTHERN PANHANDLE TOWARD 12Z THURSDAY...WITH A DECENT COLD FRONT
EXPECTED TO IMPACT THE FORECAST AREA ON THURSDAY. IN ADVANCE OF
THE UPPER LEVEL TROUGH...MOSTLY CLEAR SKIES...DRY AIR AND LIGHT
WESTERLY WINDS WILL ALLOW TEMPERATURES TO DROP INTO THE UPPER 20S
TO LOWER 30S BY THURSDAY MORNING. WITH LIGHT WESTERLY DRAINAGE
WINDS EXPECTED...DECIDED TO UNDERCUT GUIDANCE...IN THE PLATTE
RIVER VALLEY...WHERE MID 20S ARE FORECAST FOR LOWS TONIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 400 AM CDT WED OCT 16 2013
THURSDAY WILL SEE THE COLD FRONT PUSH ACROSS THE AREA. TEMPS
TRICKY FOR THE DAY AS TIMING OF FRONT AS IT MOVES OVER THE CWA IS
EXPECTED DURING THE DAYTIME. MANY AREAS LIKELY TO SEE TEMPS STALL
OR FALL FOR THE AFTERNOON HOURS. TEMPS ALOFT COOL AS ARCTIC HIGH
PRESSURE BUILDS IN BEHIND THE FRONT. STEEP LAPSE RATES BEHIND THE
FRONT TO BRING A SLIGHT CHANCE SOME SHOWERS...MAINLY IN THE NW
ZONES. MODELS IN AGREEMENT WITH DRY AIR ACROSS MUCH OF THE CWA TO
LIMIT PRECIP REACHING THE GROUND. THE CHANCE FOR PRECIP CONTINUES
THURSDAY NIGHT...MAINLY ACROSS THE HIGHER TERRAIN...SHIFTING MORE
TO THE SW ZONES. MODELS SHOW SOME BETTER LIFT IN THIS REGION
AIDED BY THE RIGHT ENTRANCE TO THE 250 MB JET STREAK. THE PRECIP
IS INITIALLY LIQUID...HOWEVER SFC TEMPS TO FALL INTO THE LOWER
AND MID 30S OVERNIGHT...WHILE 850 MB TEMPS FALL TO ZERO TO 1 C.
THIS SHOULD BE ENOUGH TO MIX A FEW SNOW FLAKES IN WITH THE RAIN.
A SECOND FRONTAL BOUNDARY TO QUICKLY PUSH INTO THE REGION ON
FRIDAY. LIMITED MOISTURE BUT SOME STEEP LAPSE RATES FOR SOME WEAK
INSTABILITY SHOWERS...GENERALLY ACROSS THE NW BEHIND THE FRONT
DURING THE DAY. TEMPS WARM BENEATH THE CLOUDS INTO THE UPPER 30S
TO THE UPPER 40S...WHICH SHOULD BE ENOUGH FOR GENERALLY LIQUID
PRECIP.
AFTER THE SECOND FRONT ON FRIDAY...QUIET AND DRY FOR THE
WEEKEND...BENEATH NW FLOW. TEMPS REBOUND SOME DUE TO THE MAINLY
SUNNY SKIES...ALTHOUGH NIGHTS TO COOL INTO THE 30S. THESE TEMPS
ARE MORE SEASONAL FOR MID OCTOBER. MODELS BRING A WEAK FRONT
ACROSS THE AREA MONDAY...HOWEVER STILL SEEING SOME TIMING ISSUES
BETWEEN THE MODELS. THERE IS AGREEMENT THAT MOISTURE WILL BE
LIMITED AND FORECAST WILL REMAIN DRY FOR NOW. MIGHT NEED TO
ADJUST TEMPS LOWER BEHIND THE FRONT...ALTHOUGH NOT MOS GUIDANCE
DID NOT DROP BUT A COUPLE DEGREES. WILL NEED TO MONITOR CLOUDS TO
SEE IF TEMPS NEED TO DROP MORE AS MORE CLOUDS WILL LIMIT HEATING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1233 PM CDT WED OCT 16 2013
A COLD FRONT WILL MOVE SOUTHEAST ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA THURSDAY MORNING. MODELS ARE HINTING THAT SOME STARTUS
MAY DEVELOP JUST BEHIND THE FRONT OVER PORTIONS OF NORTHWEST
NEBRASKA. WILL INTRODUCE THIS INTO THE KVTN TAF...BUT ONLY HAVE A
SCATTERED MENTION AT THIS TIME AS CONFIDENCE IS LOW. OTHERWISE
SCATTERED MID AND HIGH LEVEL CLOUDS ARE EXPECTED...WITH VFR
CONDITIONS PREVAILING. NORTHWEST WINDS WILL INCREASE 15 TO 20 KTS
AFTER THE FRONTAL PASSAGE THURSDAY MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...CLB
LONG TERM...MASEK
AVIATION...TAYLOR