National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KLBF 110839
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
339 AM CDT TUE MAR 11 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT TUE MAR 11 2014

THE MODEL CONSENSUS SHOWS A STRONG AREA OF 700-500MB
FRONTOGENESIS DEVELOPING ACROSS NERN NEB AROUND 18Z TODAY. THIS
FGEN IS EXPECTED TO PRODUCE A FAIRLY STRONG BAND OF WET SNOW WITH
HOURLY LIQUID RATES OF UP TO 0.10 INCHES. THE NAM RADAR PRODUCT
SHOWS THIS BAND SETTING UP FROM AROUND CHAMBERS TO BROKEN BOW AT
21Z WHICH MOVES QUICKLY EAST OF THE FCST AREA BY 00Z. THE NAM HAS
BEEN WOBBLING SOMEWHAT BUT THE CONCEPT OF FOLDED THETA E AND DEEP
LIFT IN THE DENDRITIC GROWTH ZONE CONTINUES. THE 05Z RAP MODEL
SETS IT UP FROM ONEILL TO SUTHERLAND. THE 00Z ECM FOLLOWS THE NAM
WHICH MATCHES THE MODEL CONSENSUS.

IN GENERAL...THE MODELS ARE CLUSTERING AROUND 0.20 INCHES OF LIQUID
FOR THIS EVENT ALONG HIGHWAY 83 BUT THEN SPREAD OUT TO THE EAST AS
SOME SIGNAL A WETTER EVENT AND OTHERS DRIER.  THE MEDIAN QPF IN
CUSTER COUNTY LOOKS TO BE AROUND 0.30 INCHES.

GIVEN THE STRONG LIFT DEVELOPING...IT IS EXPECTED THERE WILL BE A
PERIOD OF MODERATE TO HEAVY SNOW DEVELOPING LASTING 1 OR 2 HOURS AT
THE MOST. THIS IS ABOUT A 6 HOUR PCPN EVENT WHICH EXITS THE FCST
AREA BY AROUND 00Z. THERE IS A SHORT PERIOD OF RAIN BEFORE CHANGE
OVER TO SNOW IN THE GFS AND NAM MODELS. H700MB TEMPERATURES COOL
VERY RAPIDLY BEHIND THE COLD FRONT MARKING THE ONSET OF PCPN AND
DEEP LIFT WILL AID THE DYNAMIC COOLING PROCESS.

AN 8 TO 1 SNOW WATER RATIO WAS USED UP NORTH DURING THE MORNING
HOURS WHICH WAS REDUCED TO 5 TO 1 DURING THE AFTERNOON. TEMPERATURES
FALL TO THE LOW TO MID 30S DURING THE HEAVIEST SNOW AND THEN WARM UP
ONCE THE SNOW LETS UP OR ENDS. THIS PRODUCED 1 TO 2 INCHES OF WET
SNOW.

THERE IS NO REASON TO UNDER ESTIMATE A SPRING STORM DURING THE 2ND
WEEK OF MARCH AND THE SYSTEM FORECAST TO DEVELOP TODAY IS EXPECTED
TO PRODUCE STRONG NORTH WINDS AS THE SFC LOW DEEPENS ACROSS EAST
CENTRAL KANSAS. ALL MODELS SHOW 500M AGL WINDS INCREASING TO OVER
30 KT WHICH TRANSLATES TO 30 MPH AT THE SFC. THE NAM...GFS
GUIDANCE...HRRR AND RAP MODELS ALL SHOW GUSTS TO NEAR 50 MPH
DEVELOPING ACROSS CNTL NEB NORTH OF THE SFC LOW LOCATED ACROSS KS
BY NOON TODAY. H850 WINDS INCREASE TO 45 TO 55 KT. THE WIND
FORECAST IS A CONSENSUS OF MODEL GUIDANCE OUTPUT AND DETERMINISTIC
SOLNS WHICH FOLLOWS THE MIDDLE ROAD. THE GFS AND THE ECM SPREAD
THESE STRONGER WINDS FURTHER NORTH AND WEST THAN THE OTHER MODELS.

A WEAK DISTURBANCE IS SHOWN BY THE MODELS TO MOVE ACROSS THE FCST
AREA TONIGHT. THIS COULD PRODUCE SNOW FLURRIES OR PERHAPS ISOLATED
SNOW SHOWER ACTIVITY AS IT TRANSLATES EAST ACROSS THE FCST AREA.
LAPSE RATES STEEPEN AND REMAIN MOIST SUPPORTING THIS FORECAST.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 339 AM CDT TUE MAR 11 2014

THE SYSTEM BRINGING THE SNOW AND WIND TO THE FORECAST AREA TODAY AND
TONIGHT WILL MOVE EAST AND BE PAST THE LOCAL AREA BY 12Z WEDNESDAY.
THIS WILL PUT NEBRASKA UNDER SUBSIDENT AIR WEDNESDAY AND WITH DRY
AIR ADVECTING IN EXPECTING MOSTLY SUNNY SKIES. ALTHOUGH NOT
EXPECTING ADVISORY LEVEL WINDS WEDNESDAY...SIGNALS ARE COMING
TOGETHER FOR A BREEZY DAY. MODELS ARE SHOWING A SECONDARY PV MAX
DROPPING SOUTH ACROSS CENTRAL NEBRASKA THROUGH THE DAY...TO HELP
ENHANCE WINDS ALOFT AND WITH STEEP SURFACE TO 700MB LAPSE RATES
CONFIDENCE INCREASES ON BREEZY CONDITIONS. SOUNDINGS SHOW THE MIXED
LAYER BETWEEN 700MB AND 800MB AND LOOKING AT MAXIMUM WINDS IN THAT
LAYER UP TO 35KTS SO DECIDED TO INCREASE WINDS DURING THE DAY.
TEMPERATURES ALOFT DON/T CHANGE SIGNIFICANTLY ON WEDNESDAY SO
LOOKING AT AN ADIABATIC PROFILE...HIGHS WOULD BE IN THE 40S FOR MOST
LOCATIONS. HOWEVER...MODELS HAVE BEEN CONSISTENTLY A BIT COOL FOR
TEMPERATURES AND WITH SUNNY SKIES THINK MOST AREAS WILL WARM A BIT
MORE THAN THE DETERMINISTIC MODELS ARE INDICATING.

DRY WEATHER IS EXPECTED THROUGH FRIDAY NIGHT AS NO SIGNIFICANT
SYSTEMS ARE SET TO MOVE ACROSS THE CENTRAL PLAINS. AN UPPER LEVEL
LOW WILL STAY FAIRLY STATIONARY OVER THE SOUTHWEST THROUGH
FRIDAY...WHILE THE NORTHERN STREAM WILL KEEP NORTHWEST FLOW ACROSS
THE AREA. THERE WILL BE AN APPROACHING SHORTWAVE TROUGH ON THURSDAY
AS IT WILL BE MOVING OVER THE NORTHERN ROCKIES. THERE IS A BIT OF
UNCERTAINTY ON HOW AMPLIFIED THIS SHORTWAVE TROUGH WILL BE...WHICH
IMPACTS HOW STRONG THE SURFACE LOW WILL BECOME AND THEN HOW MUCH
WARM AIR CAN BE PULLED NORTHWARD. TOOK A MIDDLE OF THE ROAD APPROACH
FOR HIGH TEMPERATURES THURSDAY...WITH FORECAST HIGHS IN THE UPPER
50S AND 60S. IF THE SYSTEM BECOMES A BIT STRONGER...TEMPERATURES
WILL LIKELY NEED TO BE RAISED FOR THURSDAY.

THE COLD FRONT ASSOCIATED WITH THIS UPPER LEVEL SYSTEM WILL PASS
ACROSS NEBRASKA THURSDAY AFTERNOON AND EVENING. ALTHOUGH THERE
CONTINUES TO BE QUITE A BIT OF DISAGREEMENT IN MODEL SOLUTIONS ON
WHERE THE MAIN ENERGY WITH THIS SYSTEM WILL PASS...IT DOES APPEAR
FAIRLY CERTAIN THAT IT WILL BE WELL NORTH OF THE FORECAST AREA. WITH
THE MAJORITY OF THE MOISTURE ACROSS THE NORTH STAYING NEAR THE LOW
CENTER...FOR PRECIPITATION TO OCCUR WOULD NEED A MOISTURE SOURCE
FROM THE SOUTH TO GET THIS TO HAPPEN AS THE FRONT MOVES THROUGH.
HOWEVER THE UPPER LOW TO THE SOUTHWEST WILL LIKELY PROHIBIT MUCH
MOISTURE TRANSPORT INTO THE AREA FROM THE SOUTH. ONE THING THAT
DOES LOOK POSSIBLE IS STRONG WINDS THURSDAY NIGHT. WITH THE AREA
STAYING IN A LOCATION WITH DRY AIR...WHEN THE AIRMASS BECOMES
SUBSIDENT BEHIND THE FRONT...DOWNWARD MOTION WILL BE PROMOTED.
ALTHOUGH TIMING IS NIGHT...WHICH ISN/T AS FAVORABLE FOR STRONGER
WINDS...WILL NEED TO CONTINUE TO WATCH THIS TIME-FRAME IN THE NEXT
FEW DAYS CONCERNING WINDS.

THE MODELS REALLY BEGIN TO DIVERGE BEGINNING SATURDAY AS THEY SEEM
TO BE HAVING PROBLEMS HANDLING THE SOUTHWEST UPPER LOW. ONE THING
THEY DO ALL AGREE ON IS THAT STRONG RIDGING WILL BUILD
IN...SOMEWHERE ACROSS THE WESTERN HALF OF THE COUNTRY INTO THE FIRST
PART OF NEXT WEEK.

DESPITE THE MODEL DIFFERENCES...THEY ALSO ARE INDICATING THE PATTERN
ALOFT BECOMING MORE AMPLIFIED AND DIG A SHORTWAVE TROUGH SOUTH ALONG
THE LEE-SIDE OF THE ROCKY MOUNTAINS OVER THE WEEKEND. CONTINUE TO
HAVE PRECIPITATION CHANCES THROUGH MUCH OF THE WEEKEND...WITH BOTH
RAIN AND SNOW LOOKING POSSIBLE. TEMPERATURE PROFILES SHOW
PRECIPITATION TYPE AS RAIN ON SATURDAY...THEN SWITCHING TO RAIN/SNOW
AND SNOW SATURDAY NIGHT...THEN BACK TO RAIN ON SUNDAY. THIS MAY NOT
BE REAL LIKELY...AS THERE WON/T BE THAT GREAT AMOUNT OF TIME WITH
RAIN AND SNOW...BUT WITH CONCERN OVER TIMING AND LOCATION OF THE
PRECIPITATION...DID NOT HAVE THE CONFIDENCE YET TO NAIL DOWN A
PARTICULAR PRECIPITATION TYPE.

THE VERY END OF THE FORECAST PERIOD LOOKS INTERESTING...WITH A
STRONG COLD FRONT TO PASS MONDAY NIGHT AND TUESDAY. DYNAMICS WITH
THIS SYSTEM ARE PRETTY STRONG...WHICH COULD LEAD TO VERY WARM
TEMPERATURES MONDAY...THEN CHANCES FOR PRECIPITATION MONDAY NIGHT
AND TUESDAY...AND STRONG WINDS TUESDAY. DIDN/T GO TOO WARM WITH
TEMPERATURES FOR MONDAY AT THIS TIME AS CONFIDENCE ON FORECASTING
THE HIGHS THE DETERMINISTIC MODELS SHOW AT THIS TIME IS QUITE
LOW...BUT IT BEARS WATCHING OVER THE COMING DAYS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1220 AM CDT TUE MAR 11 2014

A BANDED AREA OF IFR/LIFR IN SNOW IS EXPECTED TO DEVELOP ACROSS
THE NORTH TOWARD 12Z TUESDAY. THIS BAND OF IFR/LIFR IS EXPECTED
MOVE SOUTH THROUGH THE FCST AREA DURING THE LATE MORNING AND
AFTERNOON WITH FLIGHT CONDITIONS IMPROVING IN THE NORTH DURING THE
AFTN.

SCATTERED MVFR IS POSSIBLE TUESDAY EVENING AS A WEAK DISTURBANCE
MOVES ACROSS THE FCST AREA. ISOLATED FLURRIES MAY ACCOMPANY THE
DISTURBANCE AND PRODUCE MVFR CIGS.


&&

.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM CDT /9 AM MDT/ THIS MORNING TO 8 PM CDT
/7 PM MDT/ THIS EVENING FOR NEZ025>029-036>038-057>059-069>071.

&&

$$

SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...CDC