Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 291731
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1231 PM CDT WED OCT 29 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM CDT WED OCT 29 2014

MODELS IN GOOD AGREEMENT IN THE NEAR TERM TODAY. HAVE GOOD
CONFIDENCE IN THE FORECAST. UPPER LOW HAS MOVED TO SOUTHERN HUDSON
BAY ALLOWING RIDGE TO BUILD INTO THE NORTHERN PLAINS. 1023MB SURFACE
HIGH OVER SOUTHEAST NEBRASKA THIS MORNING. WESTERN NEBRASKA WILL BE
ON THE BACKSIDE OF THIS HIGH TODAY WITH SOUTHWEST WINDS BECOMING
WESTERLY DOWN SLOPE WINDS THIS AFTERNOON. STATIONARY BOUNDARY TO THE
WEST OVER THE EASTERN PLAINS OF WYOMING AND COLORADO WILL MOVE EAST
TODAY AS A WARM FRONT. WARM DRY AIR WILL MOVE EAST OVER WESTERN
NEBRASKA. HAVE UPPED TEMPERATURES A COUPLE OF DEGREES OVER GUIDANCE
ESPECIALLY OVER SOUTHWEST NEBRASKA WITH GOOD DOWN SLOPE FLOW. NORTH
CENTRAL NEBRASKA WILL REMAIN COOL BUT STILL SHOULD SEE TEMPERATURES
APPROACHING 60 THIS AFTERNOON WITH FULL SUN AND SOUTHERLY FLOW.
HEIGHTENED FIRE WEATHER OVER SOUTHWEST NEBRASKA THIS AFTERNOON AS
MINIMUM RELATIVE HUMIDITY FALLS TO AROUND 14%. WINDS SHOULD REMAIN
BELOW CRITICAL FIRE WEATHER CRITERIA BUT MAY HAVE UNDER DONE WINDS
WITH CRAIG HIGH. CLEAR SKIES CONTINUE TONIGHT WITH INCREASING
NORTHWEST FLOW THROUGH THE EARLY MORNING AS A BACKDOOR FRONT MOVES
SOUTH INTO NORTHERN NEBRASKA. WINDS WILL STAY UP AND KEEP THE
BOUNDARY LAYER MIXED WITH TEMPERATURES GENERALLY IN THE 30S. DRY.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 351 AM CDT WED OCT 29 2014

PRIMARY FORECAST CONCERNS ARE TEMPERATURES AND WINDS FOR THURSDAY
THROUGH SATURDAY...THEN WITH PRECIPITATION CHANCES CENTERED ON
MONDAY.

MODELS ARE IN FAIR AGREEMENT THROUGH SATURDAY...THEN BEGIN DIVERGING
AS THE UPPER LEVEL SYSTEM NOW OVER THE GULF OF ALASKA PROGRESSES
FROM THE WESTERN PART OF THE CONUS EAST THROUGH THE PLAINS.

THE UPPER LEVEL SHORTWAVE TROUGH THAT IS CURRENTLY OVER THE
PACIFIC NORTHWEST WILL HAVE JUST PASSED ACROSS NEBRASKA WITHIN THE
NORTHWEST FLOW ALOFT AS THE DAY BEGINS ON THURSDAY. THE SURFACE
COLD FRONT WILL HAVE MOVED ACROSS THE REGION BY THURSDAY MORNING
BUT COLD AIR ADVECTION WILL BE ONGOING THROUGH THE DAY BEHIND THE
SYSTEM. WITH STRONG SUBSIDENCE AND DRY AIR PUSHING INTO THE AREA
AS WELL...LOOKING FOR STEEP LAPSE RATES IN THE LOW LEVELS WITH
MIXING TO AROUND 850-800MB INTO THE AFTERNOON. THIS WILL PROVIDE
BREEZY CONDITIONS DUE TO WINDS OF 20 TO 30 KTS AT THE TOP OF THE
MIXED LAYER BEING ABLE TO MIX DOWN TO THE SURFACE. WITH THE COLDER
AIR MOVING INTO THE REGION DID MAKE SOME ADJUSTMENTS TO HIGH
TEMPERATURES THURSDAY...ESPECIALLY ACROSS NORTHERN NEBRASKA. MODELS
ARE TRENDING LOWER FOR TEMPERATURES AND FEEL THIS IS APPROPRIATE
WITH 850MB TEMPERATURES DROPPING TO AROUND 0C OVER PARTS OF NORTH
CENTRAL NEBRASKA BY THE END OF THE AFTERNOON.

CANADIAN HIGH PRESSURE BUILDS INTO THE NORTHERN AND CENTRAL PLAINS
THURSDAY NIGHT. DEWPOINTS LOOK TO FALL INTO THE LOW AND MID 20S
AND WITH CLEAR SKIES AND LIGHT WINDS EXPECT TEMPERATURES TO FALL
INTO THE MID AND UPPER 20S.

THE SURFACE HIGH DRIFTS EAST DURING THE DAY FRIDAY...WHILE RIDGING
ALOFT BEGINS TO BUILD INTO THE PLAINS. THAT BEING SAID...THE
WARMER AIR IS SLOW TO MOVE IN AND TEMPERATURES ALOFT END UP
STAYING COOLER THAN ON THURSDAY AS THE AREA REMAINS UNDER MORE OF
AN INFLUENCE FROM THE SURFACE HIGH AND UPPER LEVEL LOW SYSTEM TO
THE EAST. WILL START TO SEE WINDS SWITCH AROUND TO THE SOUTH BY
THE END OF THE DAY...BUT AGAIN WITH THE COOLER AIR IN PLACE DID
DROP HIGHS A FEW DEGREES. HIGHS NOW LOOKING TO BE IN THE 40S TO
LOW 50S. GOING INTO FRIDAY NIGHT...THE PRESSURE GRADIENT TIGHTENS
AS LOW PRESSURE DEVELOPS OVER THE ROCKIES SO LOOKING AT WINDS
STAYING A LITTLE HIGHER OVERNIGHT. NOT EXPECTING STRONG
WINDS...BUT 10-15KTS SO ENOUGH TO KEEP A STRONG INVERSION FROM
DEVELOPING AND KEEPING TEMPERATURES FROM DROPPING TOO FAR. MAY SEE
A BIT MORE RADIATIONAL COOLING AND THE SET UP OF AN INVERSION
GOING FURTHER EAST ACROSS NEBRASKA WHERE OVERNIGHT TEMPERATURES
ARE APPROPRIATELY COOLER.

THE UPPER LEVEL RIDGE WILL BE OVERHEAD ON SATURDAY WHILE THE LARGE
LOW PRESSURE SYSTEM CURRENTLY OVER THE GULF OF ALASKA WILL HAVE
MOVED ONSHORE AND BE MOVING TOWARDS THE ROCKY MOUNTAINS. THIS WILL
BRING ABOUT FURTHER STRENGTHENING OF THE SURFACE LOW ON THE LEE
SIDE OF THE ROCKIES AND THUS WILL FURTHER TIGHTEN THE PRESSURE
GRADIENT LOCALLY. IN ADDITION TO THE SOUTHERLY SURFACE
WINDS...LOOKING UP AT 850MB...WINDS ARE FAIRLY STRONG AT 30 TO
40KTS SO EVEN A LITTLE MIXING SHOULD HELP TO CREATE BREEZY TO
WINDY CONDITIONS AT TIMES. WARM AIR ADVECTION WILL BE OCCURRING
THROUGH THE DAY SO EXPECTING A SLIGHT WARMING TREND...HOWEVER
HIGHS ARE CURRENTLY STILL EXPECTED TO BE BELOW NORMAL FOR ALL
OF THE FORECAST AREA WITH THE EXCEPTION OF THE EASTERN PANHANDLE
INTO FAR SOUTHWEST NEBRASKA.

AS WAS MENTIONED EARLIER...THE MODELS DO BEGIN DIVERGING WITH THE
SOLUTIONS OF HOW THE SYSTEM OVER THE ROCKIES WILL PROGRESS INTO
THE CENTRAL PART OF THE COUNTRY FROM THE LATE WEEKEND INTO THE
EARLY PART OF THE WORK WEEK. THE ECMWF AND GFS ARE SLIGHTLY
SIMILAR BRINGING THE MAIN ENERGY FROM THE SYSTEM UP OVER THE
DAKOTAS THROUGH MONDAY...WITH A SECOND PIECE OF ENERGY REMAINING
OVER THE DESERT SOUTHWEST. HOWEVER THEY ARE NOT IN AGREEMENT ON
THE SPEED OF THIS OCCURRING...AND THE GFS STRENGTHENS THE UPPER
LEVEL SYSTEM A BIT MORE. THE GEM IS IN A DIFFERENT CAMP...KEEPING
THE MAJORITY OF THE SYSTEM TOGETHER AND HAVING IT PASS ACROSS
NEBRASKA. EITHER WAY...WILL HAVE RAIN CHANCES ON MONDAY...BUT
CONFIDENCE ON HOW MUCH AND THE AREAL EXTENT IS LOW AT THIS TIME.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1231 PM CDT WED OCT 29 2014

VFR ANTICIPATED ACROSS ALL WESTERN AND NORTH CENTRAL NEBRASKA
TERMINALS THROUGH THE 18Z TAF PERIOD.  LIGHT SOUTHERLY FLOW WILL
TRANSITION TO WESTERLY /FOR THE WESTERN SANDHILLS AND SOUTHWEST
NEBRASKA/ THIS AFTERNOON...THEN NORTHERLY /ALL LOCATIONS/ OVERNIGHT
BEHIND A PASSING BOUNDARY...BUT WIND SPEEDS WILL REMAIN LIGHT
THROUGH MOST OF THE FORECAST PERIOD. GUIDANCE DOES INDICATE A
SLIGHT UPTICK IN SPEEDS LATE IN THE FORECAST PERIOD THURSDAY
/AFTER 15Z/. MODEL AGREEMENT IS STRONG...THUS FORECAST CONFIDENCE
IS HIGH.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...POWER
LONG TERM...BROOKS
AVIATION...JACOBS







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