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 302013
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
313 PM CDT MON MAR 30 2015

.SYNOPSIS...
ISSUED AT 313 PM CDT MON MAR 30 2015

HIGH AMPLITUDE UPPER RIDGE IN PLACE ACROSS THE WRN STATES AS ONE PV
ANOMALY TRIES TO UNDERCUT IT AS IT MOVES SLOWLY EWD OFF THE BAJA
COAST. MEANWHILE...STRONG PV ANOMALY CRASHES ONTO THE BC COAST.
FURTHER EAST...PV LOBE WITH EMBEDDED ANOMALIES SLIDES SEWD ATOP THE
WRN STATES RIDGE TO NRN MN AND INTO THE UPPER MIDWEST...AND MOVING INTO THE
NERN STATES UPPER TROUGH. CLOSER TO HOME...THE WEAK FRONT ASSOCIATED
WITH THE UPPER MIDWEST PV LOBE IS STRUGGLING TO MAKE SWD PROGRESSION
AS DIURNALLY DRIVEN SFC PRESSURE FALLS OVER ERN KS AND SERN NE
PROVIDE RESISTANCE. BEST PRESSURE RISES NOW LOCATED OVER ERN ND. SFC
RH VALUES CONTINUE TO DROP ACROSS THE NEB SANDHILLS AS TEMPS WARM
IMMEDIATELY BEHIND THE WIND SHIFT.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 313 PM CDT MON MAR 30 2015

RED FLAG WARNING WILL CONTINUE INTO THE EVENING AS RH RECOVERY TAKES
SOME TIME TO OCCUR. HOWEVER...MOST SHORT RANGE FCST SOUNDINGS
SUGGEST A RATHER QUICK DECOUPLING UNDER MAINLY CLEAR SKIES. WINDS
SHOULD QUICKLY DIE OFF...HOWEVER RH INCREASE WILL BE SLOWER.

UPPER RIDGE AXIS PROGRESSES EWD TUESDAY AS STRONG PV ANOMALY MOVES
ONSHORE ACROSS THE PAC NW. THIS BEGINS THE RIDGE BREAKDOWN PROCESS
AND THEREFORE ADDITIONAL FIRE WEATHER CONCERNS INTO MID WEEK. RETURN
FLOW CRANKS UP AS PRESSURES LOWER IN THE LEE OF THE NRN HIGH PLAINS.
UNFORTUNATELY ADDITIONAL LOW LEVEL MOISTURE WILL NOT BE PLENTIFUL
INITALLY SO RH VALUES IN THE TEENS WILL BE EXPECTED ONCE AGAIN
ACROSS THE WRN HALF OF NEBR. ADDITIONAL DISCUSSION ON THIS IN THE
FIRE WEATHER SECTION BELOW. SOME DIFFS NOTED IN AVAILABLE SHORT
RANGE GUIDANCE AND FCST SOUNDINGS AS TO THE DEGREE OF MIXING AND
EVENTUAL WIND SPEEDS BY TUESDAY AFTERNOON. AS MOST CURRENT THINKING
IS 10-20 MPH RANGE SHOULD COVER IT. MAX TEMPS WILL BE 20+ DEGREES
ABOVE AVERAGE ONCE AGAIN.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 313 PM CDT MON MAR 30 2015

TUESDAY NIGHT THROUGH THURSDAY...THE MODELS SUGGEST STRATUS WILL
DEVELOP EARLY WEDNESDAY MORNING AND QUICKLY GET SHUNTED EAST AS A
STRONG 45 TO 55 KT LOW LEVEL JET VEERS OFF EAST. THE RETURN MOISTURE
BENEATH THE STRATUS PUSHES DEWPOINTS INTO THE 40S.

THE ROBUST MOISTURE RETURN EARLY WEDNESDAY MORNING WOULD LIKELY HOLD
LOWS TO NEAR 50 EAST OF HIGHWAY 83. SOUTH WINDS OF 15 TO 20 MPH
CONTINUE ALL NIGHT AROUND AINSWORTH AND ONEILL.

THE COLD FRONT WEDNESDAY IS ON TRACK TO SWEEP ACROSS INTERSTATE 80
AROUND 18Z. THE NAM AND GFS TIMING IS THE SAME AS PREVIOUS MODEL
RUNS BUT WITH A SLIGHTLY STRONGER PUSH OF COOLER AIR WHICH WOULD
HOLD HIGHS DOWN IN THE 60S ACROSS NRN SHERIDAN COUNTY. 70S STILL
LOOK REASONABLE SOUTH AND EAST THROUGH ONEILL AND NORTH PLATTE. THE
STRATUS SHOULD HAVE MINIMAL IMPACT ON HIGHS WITH BURN OFF EXPECTED
AROUND 15Z.

THE NAM SUGGESTS K INDICES AROUND 30C EAST OF HIGHWAY 83 WEDNESDAY
AFTN AND EVENING. FARTHER WEST...THE MODEL SHOWS DEEP LIFT FROM
700MB TO 500MB AND LIGHT QPF SUGGESTING SHOWERS AND PERHAPS A HIGH
BASED THUNDERSTORM. ALTHOUGH THE STRONGER WINDS ALOFT WOULD REMAIN
NORTH OF THIS AREA GUSTY WINDS COULD MIX DOWN WITH THESE SHOWERS
PRODUCING GUSTS TO PERHAPS 40 OR 45 MPH. SO THE FORECAST IS FOR
MAINLY ISOLATED SHOWERS AND THUNDERSTORMS ACROSS SWRN NEB EAST
THROUGH BROKEN BOW AND ONEILL WHICH COULD BE CAPABLE OF GUSTY
WINDS.

AN UPPER LEVEL DISTURBANCE WILL FOLLOW ON THE HEALS OF THE COLD
FRONT WEDNESDAY PRODUCING A CHANCE OF LIGHT RAIN THURSDAY ACROSS
SOUTHWESTERN NEBRASKA. THE MODEL BLEND SUGGESTED ONLY A FEW
HUNDREDTHS OF AN INCH OF QPF ACROSS SOUTHWEST NEB FROM THE
DISTURBANCE WHICH WILL MAINLY AFFECT COLORADO AND KANSAS. WPC
FORECAST MORE QPF...BUT STILL LESS THAN 1/4 INCH. H850 MB
TEMPERATURES THURSDAY ARE IN THE SINGLE DIGITS CELSIUS SUPPORTING
HIGHS IN THE 50S TO NEAR 60 WHICH MIGHT BE TOO WARM GIVEN SKIES MAY
BE OVERCAST OR MOSTLY CLOUDY THURSDAY. THE NAM AND GFS BUFFER
SOUNDINGS SHOWED HIGHS IN THE UPPER 40S TO LOWER 50S AT NORTH PLATTE
AND VALENTINE. THE COOLER HIGHS WOULD BE DEPENDENT ON CLOUD COVER.

THURSDAY NIGHT INTO FRIDAY...THE POSITIVELY TILTED UPPER TROUGH WILL
CROSS THE ROCKIES THURSDAY NIGHT AND MOVE ACROSS THE CENTRAL PLAINS
FRIDAY. AT THE BASE OF THIS UPPER TROUGH...AN H3 JET MAX UP TO
120KT WILL EXTEND ACROSS SRN CO INTO KS. THIS WILL PROVIDE SOME
UPPER LEVEL DIVERGENCE ACROSS NRN CO INTO SWRN NEBR. WITH MUCH
COLDER AIR ALOFT AND NEAR THE SURFACE...A MIX OF RAIN OR SNOW IS
SUPPORTED INTO THE WRN SANDHILLS AND SWRN NEBR THURSDAY NIGHT INTO
FRIDAY MORNING. NO EXPECTING ANY SNOW ACCUMULATIONS ATTM...HOWEVER
IT THERE ARE LIGHT ACCUMULATIONS...IT WOULD BE ACROSS THE SRN PNHDL
INTO FAR SWRN NEBR. HIGHS FRIDAY FCST TO REACH THE LOWER 50S WEST TO
NEAR 55 EAST.

SATURDAY THROUGH MONDAY...AN UPPER RIDGE WILL BUILD BACK INTO THE
CENTRAL CONUS AS AN UPPER TROUGH DIGS INTO THE WEST CAST AND
INTERMOUNTAIN WEST. HIGHS WILL RETURN TO THE 60S SATURDAY AND THE
70S SUNDAY AND MONDAY. WITH DRY CONDITIONS AND WARMING
TEMPERATURES...ELEVATED FIRE CONDITIONS WILL ONCE AGAIN RETURN.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1252 PM CDT MON MAR 30 2015

VFR CONDITIONS ACROSS THE AREA THROUGH 18Z TUESDAY.

UPPER PV ANOMALY MOVING ACROSS THE UPPER MIDWEST CURRENTLY. ATTENDANT
WEAK FRONT HAS MOVED INTO THE NORTH CENTRAL ZONES AND LEADING EDGE
OF SFC PRESSURE RISES SHOWS A STEADY SEWD PROGRESSION. VTN HAS
GUSTED TO 30KTS AND WOULD EXPECT THIS TO BE THE HIGHER EDGE OF THE
ENVELOPE FOR THE REMAINDER OF THE AFTERNOON ACROSS THE NORTHERN
AND EASTERN ZONES...INCLUDING KVTN. FURTHER S...WINDS WILL
INCREASE AND BE GUSTY...BUT SOMEWHAT LESS THAN FURTHER N. FCST
SOUNDINGS SUGGEST A QUICK DECOUPLING NEAR SUNSET AND HAVE TRENDED
WIND FCST IN THAT MANNER.


&&

.FIRE WEATHER...
ISSUED AT 313 PM CDT MON MAR 30 2015

RED FLAG WARNING REMAINS FOR THE EVENING HOURS FOR AREAS MAINLY
ALONG AND NORTH OF INTERSTATE 80 TO THE SOUTH DAKOTA BORDER. DESPITE
A SUGGESTED QUICK DECOUPLING OF WINDS AROUND SUNSET BY FCST
SOUNDINGS...RH RECOVERY WILL BE SLOW. THIS SLOW RH RECOVERY AT NIGHT
HAS BEEN FREQUENT THIS SPRING AND CONTINUES TO ENHANCE LARGE FIRE
GROWTH POTENTIAL.

THEN...RH VALUES ARE PROGGED BY MODELS /ESPECIALLY ARW/ TO FALL INTO
THE TEENS BY LATE AFTERNOON TUESDAY. SWRLY COMPONENT TO WINDS ARE
CONCERNING AS THESE TYPE OF EVENT PRIOR TO AND DURING RIDGE
BREAKDOWN ARE NOTORIOUS FOR BRINGING DRIER AIR INTO THE ERN
PANHANDLE AND WRN SANDHILLS THAN MODELS SUGGEST. WINDS AS OF NOW
LOOK TO REMAIN BELOW CRITERIA FOR RED FLAG...BUT WITH ANOMALOUS
700/850 MB TEMPERATURES ACROSS THE HIGH PLAINS...WEATHER CONDITIONS
SUPPORTING EXTREME FIRE GROWTH ARE STILL POSSIBLE. FURTHER
RE-EVALUATION FOR ADDITIONAL FIRE WEATHER HIGHLIGHTS WILL CONTINUE
THIS EVENING FOR POSSIBLE HEADLINES TUESDAY.

FURTHER SEWD PROGRESSION OF THE STRONG PV ANOAMLY WILL OCCUR WED.
PRIOR TO THIS...A PRONOUNCED LOW LEVEL JET WILL DEVELOP ACROSS THE
PLAINS TUESDAY NIGHT AHEAD OF THE ADVANCING SYSTEM. NORMALLY THIS
WOULD BRING ADDITIONAL LOW LEVEL MOISTURE INTO THE REGION /AND WILL
EVENTUALLY/ HOWEVER IN THE BEGINNING PHASE WILL ACTUALLY KEEP THE
ATMOSPHERE MIXED OVER PORTIONS OF THE ERN PANHANDLE AND WESTERN
SANDHILLS. THIS WILL LEAD TO POOR RH RECOVERY TUESDAY NIGHT AND
EARLY WED MORNING. THIS LEADS TO ADDITIONAL CONCERNS WED.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR
NEZ204-206-208-209.

&&

$$

SYNOPSIS...JWS
SHORT TERM...JWS
LONG TERM...ROBERG
AVIATION...JWS
FIRE WEATHER...JWS







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