Area Forecast Discussion
Issued by NWS North Platte, NE

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KLBF 180856
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
356 AM CDT THU SEP 18 2014

.SYNOPSIS...
ISSUED AT 355 AM CDT THU SEP 18 2014

SURFACE LOW PRESSURE EXTENDS SOUTH FROM ALBERTA CANADA INTO
NEVADA AND WESTERN ARIZONA. SURFACE HIGH PRESSURE CENTER LOCATED
OVER THE NORTHERN GREAT LAKES. STRATUS IS DEVELOPING AND
EXPANDING FROM NWRN KS INTO SWRN NEBR AND THE SOUTHERN NEBRASKA
PANHANDLE EARLY THIS MORNING. PORTIONS OF CENTRAL AND SOUTHWEST
NEBRASKA REPORTING MAINLY LIGHT FOG 3-5SM WITH LOCALLY DENSE FOG
AT THE KBBW ASOS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU SEP 18 2014

NEAR TERM CONCERN IS DEVELOPMENT OF STRATUS AND FOG DEVELOPMENT
ACROSS PORTIONS OF CENTRAL AND SOUTHWEST NEBRASKA. WHILE LOW
VISIBILITY OF 1/4-1/2SM AT KBBW IS POSSIBLE ACROSS THE
AREA...PREVAILING VISIBILITIES SHOULD RANGE FROM 3-5 SM OR
HIGHER. AREAS TO PATCHY FOG IN THE FORECAST UNTIL 15Z.
OTHERWISE...STRATUS IS FORECAST TO QUICKLY EXPAND NORTHWESTWARD
INTO WESTERN NEBRASKA THIS MORNING. MODELS SHOW A NEARLY
SATURATED H9-H85 LAYER PRESENT WITH RELATIVELY DRY AIR ALOFT. THE
STRATUS IS FORECAST TO EXIT MUCH OF THE PANHANDLE BY 18Z...WHILE
POTENTIALLY PERSISTING OVER PORTIONS OF SWRN INTO CENTRAL
NEBRASKA THROUGH THE AFTERNOON. THIS AGREED UPON BY THE NAM AND
06Z RAP MODEL. THE GFS IS LESS AGGRESSIVE WITH CLOUDS WITH MUCH
HIGHER MOS GUIDANCE. USING 00Z SUPERBLEND OUTPUT...BLENDED WITH
THE 00Z MET GUIDANCE TO REFLECT COOLER HIGHS. WHERE CLEARING
OCCURS ACROSS WRN TIER OF COUNTIES...HIGHS IN THE UPPER 80S
ATTAINABLE. MID 70S FORECAST FOR PORTIONS OF CENTRAL AND SERN
ZONES. ALSO INCREASED PERCENT SKY COVER TO REFLECT MOSTLY CLOUDY
SKIES CENTRAL AND SERN ZONES.

STRONG WARM AIR ADVECTION TONIGHT WITH H85 TEMPS UP TO 25C. THIS
WILL CAUSE LINGERING STRATUS THIS EVENING TO QUICKLY LIFT
NORTHEAST AND DISPERSE AFTER 06Z. LOWS TONIGHT WILL BE MILDER
THAN THE PAST SEVERAL NIGHTS RANGING MAINLY IN THE LOWER 60S.
THERE WILL BE A STRONG INVERSION WITH SOUTH WINDS BECOMING
SOUTHWEST LATE.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU SEP 18 2014

FRIDAY WILL BE AN UNSEASONABLE WARM DAY AS A LOW DEVELOPS OVER SW
S DAKOTA ALONG A COLD FRONT STRETCHED FROM THE NORTHERN PLAINS
INTO WYOMING. SOUTHERLY WINDS INCREASE AHEAD OF THE FRONT WHICH
SHOULD MIX OUT ANY BL MOISTURE FOG/STRATUS. 850 MB TEMPS INTO THE
20S C AND MOS GUIDANCE WELL INTO THE 80S AND EVEN SOME LOW 90S.
SHOULD SEE SOME A FEW HIGH CLOUDS FROM STORM SYSTEM TO THE SOUTH
SO KEEP HIGHS CONSERVATIVE. COLD FRONT WILL WILL PUSH ACROSS THE
AREA FRIDAY NIGHT INTO SATURDAY. SOME ELEVATED INSTABILITY
OVERNIGHT...WITH AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS TO
DEVELOP ALONG THE BOUNDARY. THE ADDED CLOUDS SHOULD KEEP TEMPS
MILD OVERNIGHT.

COOLER BEHIND THE FRONT WITH PRECIP EXPECTED TO BE PUSHING EAST
IN THE MORNING. SOME SUN BEHIND THE FRONT AND TEMPS REBOUND TO
AROUND 80 ON SATURDAY.

COOL HIGH PRESSURE BUILDS IN OVER THE REST OF THE WEEKEND INTO
EARLY NEXT WEEK WITH TEMPS TO SLOWLY TREND DOWN THROUGH MONDAY.
MEANWHILE A DISTURBANCE WILL RIDE ALONG THE FRONT RANGE...HOWEVER
MODELS GENERALLY KEEP PRECIP WEST OF THE CWA.

NEXT WEEK THE HIGH SLIDES EAST WITH RETURN SOUTHERLY FLOW TO
BRING A RETURN OF MORE MOISTURE. A DISTURBANCE SHOULD RIDE ACROSS
THE CENTRAL ROCKIES EARLY MONDAY WITH A CHANCE FOR PRECIP LIFTING
ACROSS THE CWA MONDAY INTO TUESDAY. ALTHOUGH 850 TEMPS ON THE
RISE...CLOUDS /ASSOCIATED WITH THE DISTURBANCE/ LIKELY TO KEEP
TEMPS FROM JUMPING UP TO MUCH. GUIDANCE SUGGEST SEASONAL MID
70S...WHICH SEEMS REASONABLE AT THIS TIME.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1143 PM CDT WED SEP 17 2014

ONCE AGAIN...THE FORECAST ISSUE TONIGHT AND EARLY THURSDAY IS THE
LIKELIHOOD OF CEILING AND/OR VISIBILITY BELOW INSTRUMENT
THRESHOLDS. CONSENSUS AMONG THE SHORT RANGE MODEL OUTPUT IS THAT
INSTRUMENT OR LOW INSTRUMENT METEOROLOGICAL CONDITIONS ARE LIKELY
IN A LARGE PART OF WESTERN NEBRASKA ALONG AND SOUTH-WEST OF A
VTN-ANW-BBW LINE. THOUGH IT MAKES LITTLE DIFFERENCE IN THE FLIGHT
CATEGORY...THE OTHER QUESTION IS...FOG OR STRATUS? CURRENT
INDICATIONS ARE THAT THE WIND SPEED WILL BE 5-10KT AND THAT WOULD
FAVOR LOW STRATUS VERSUS FOG. THEREFORE...OUR CONFIDENCE IS HIGH
THAT CEILING AT OR BELOW 500 FEET AGL WILL DEVELOP AFTER 09Z FOR
MHN...OGA AND LBF AND CONFIDENCE IS NOT HIGH THAT INSTRUMENT
CONDITIONS WILL DEVELOP FOR VTN...TIF AND BBW. FOR THIS FORECAST
ISSUANCE...WE WILL INCLUDE CEILING BELOW 500 FEET AND VISIBILITY
2-3SM FOR LBF AND CEILING JUST ABOVE 1000 FEET AGL AND VISIBILITY
3-5SM FOR VTN. THE LOW CLOUDS WILL BE SLOW TO SCATTER OUT.
CURRENT INDICATIONS FROM SHORT RANGE MODELS AND CONDITIONAL
CLIMATOLOGY WOULD INDICATE SCATTERING BETWEEN 16Z AND 18Z.

THOUGH THIS IS BEYOND THE 24 HOUR FORECAST WINDOW...INSTRUMENT
METEOROLOGICAL CONDITIONS ARE AGAIN POSSIBLE THURSDAY NIGHT.

&&

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

&&

$$

SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...MASEK
AVIATION...SPRINGER





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.