Area Forecast Discussion
Issued by NWS North Platte, NE

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000
FXUS63 KLBF 300901
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
401 AM CDT MON MAR 30 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 401 AM CDT MON MAR 30 2015

TODAY AND TONIGHT...A WEAK PACIFIC COLD FRONT ACROSS THE NRN HIGH
PLAINS AND ATTENDANT SFC LOW PRESSURE ACROSS SASKATCHEWAN MOVES
SOUTHEAST DRIVING THE FRONT THROUGH THE FCST AREA THIS MORNING.

HIGHS TODAY RISE WELL INTO THE 70S WITH NORTHWEST WINDS AND MODEST
COOLING ALOFT. THE FRONT ACTUALLY PRODUCES DEEPER MIXING AND WARMER
HIGHS THAN THE RESIDENT AIR MASS MIGHT SUGGEST.

LOWS TONIGHT FALL INTO 30S TO NEAR 40 AS PACIFIC HIGH PRESSURE MOVES
OVERHEAD.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 401 AM CDT MON MAR 30 2015

TUESDAY AND WEDNESDAY HAVE THE POTENTIAL TO BE SIGNIFICANT IN TERMS
OF LARGE RANGE FIRE GROWTH ACROSS WEST CENTRAL NEBRASKA.  THE
OVERALL SYNOPTIC PATTERN FAVORS THE EASTWARD DEVELOPMENT OF AN UPPER
LEVEL RIDGE ACROSS THE PLAINS ON TUESDAY...BUT THE RIDGE IS SHOWN TO
QUICKLY BREAKDOWN BY EARLY WEDNESDAY WITH THE APPROACH OF A NORTHERN
ROCKIES SHORTWAVE.  IN ADDITION...THE SHORTWAVE WILL BE RESPONSIBLE
FOR PUSHING A STRONG COLD FRONT ACROSS THE CWA DURING THE DAYLIGHT
HOURS ON WEDNESDAY.  AS THE FORECAST SITS RIGHT NOW...THE WARMEST
TEMPERATURES WILL OCCUR TUESDAY AFTERNOON AS STRONG LOWER
TROPOSPHERIC WAA SPREADS EAST ACROSS THE SANDHILLS WITH THE BUILDING
RIDGE.  THE LATEST NUMERICAL AND DETERMINISTIC DATA INDICATE
WIDESPREAD HIGHS IN THE UPPER 70S. HOWEVER AS OF LATE THE GUIDANCE
HAS UNDERESTIMATED THE HEATING POTENTIAL IN THESE SITUATIONS.  THUS
LOWER 80S /IF NOT WARMER/ SEEMS REASONABLE FOR MUCH OF THE FORECAST
AREA.  THE PREDOMINATE LOW LEVEL FLOW WILL BE FROM THE SOUTH AND OR
DOWNSLOPING FROM THE SSW AND LIKE TEMPERATURES...RECENT GUIDANCE HAS
STRUGGLE WITH THE AMOUNT OF DRY AIR.  ESPECIALLY TRUE SINCE WE/VE
HAVEN/T SEEN WIDESPREAD APPRECIABLE QPF IN SOME TIME.  FORECAST TD/S
WERE DERIVED FROM A BLEND OF THE DRIEST NUMERICAL DATA WITH THE
WRF-ARW WHICH HAS SHOWN SOME USEFULNESS IN THESE PATTERNS.  THE T/TD
COMBO DURING PEAK HEATING PROMOTES WIDESPREAD RFW CRITERIA RH.  WIND
SPEED RFW CRITERIA HOWEVER IS LESS CERTAIN.  A SURFACE TROUGH WILL
DEEPEN OFF THE NORTHERN HIGH PLAINS...PROMOTING INCREASING SOUTHERLY
TO SOUTHWESTERLY LOWER TROPOSPHERIC FLOW THROUGH THE DAY.  AT THIS
POINT...WE ARE FORECAST GUSTS THAT ARE JUST BELOW CRITERIA IN OPEN
AREAS ACROSS THE CENTRAL AND NORTHWESTERN SANDHILLS...BUT BASED OFF
OF RECENT RANGE FIRES...NEAR CRITICAL CONDITIONS ARE PRODUCING LARGE
FIRE GROWTH.  ADDITIONAL FIRE HEADLINES ARE ANTICIPATED FOR TUESDAY.

WHAT CANNOT BE OVERLY STRESSED ENOUGH IS THAT RH RECOVERY AT NIGHT
HAS BEEN POOR LATELY.  WITH A FRONT POISED TO ARRIVE ON
WEDNESDAY...WINDS WILL REMAIN ELEVATED OVERNIGHT TUESDAY INTO
WEDNESDAY MORNING HELPING TO KEEP THE LOWER TROPOSPHERE WELL MIXED.
RH RECOVERY IS ANTICIPATED TO BE POOR EARLY WEDNESDAY MORNING.  POOR
RH RECOVERY IS A SIGNIFICANT FACTOR IN LARGE RANGE FIRE SPREAD IN
FINE FUELS THE DAY FOLLOWING.  WILL NEED TO MONITOR THIS CLOSELY AND
SHOULD BE CONSIDERED IN ANY POTENTIAL RFW FOR WEDNESDAY.

WEDNESDAY IS CONDITIONAL...THE RH RECOVERY IS FORECAST TO BE POOR
THE NIGHT BEFORE...HOWEVER A FRONT IS FORECAST TO CROSS THE REGION
LATE MORNING TO EARLY AFTERNOON.  THE TIMING OF THE FRONT WILL BE
KEY TO THE FIRE POTENTIAL.  LATER ARRIVAL EQUALS GREATER HEATING &
LOWER RH...WHEREAS THE EARLY ARRIVAL WOULD ALLOW FOR THE OPPOSITE.
WHAT IS CERTAIN IS GUSTY CONDITIONS WOULD ACCOMPANY THE FRONT WITH A
WIND SHIFT.  THIS MAY BE A CASE WHERE A RFW IS ISSUED FOR DROUGHT
CONDITIONS WITH A SIGNIFICANT FRONTAL PASSAGE.  WEDNESDAY COULD BE A
BIG DAY.

A FEW HIGH BASED THUNDERSTORMS MAY BE POSSIBLE WITH THE FRONT ACROSS
OUR FAR NORTHEAST WEDNESDAY AFTERNOON.  A DRY LOWER TROPOSPHERE
WOULD LIMIT RAINFALL POTENTIAL...WIDESPREAD DRY LIGHTNING IS NOT
FORECAST...BUT A FEW RAIN CHALLENGED STRIKES ARE.  IT SHOULD BE
NOTED THE EC RUN LIGHTS UP OUR EASTERN ZONES LATE AFTERNOON
WEDNESDAY WITH CONVECTION AND QPF...BUT THE DRIER GFS AND NAM REMAIN
FAVORED.

WEDNESDAY NIGHT THROUGH FRIDAY...THE NEXT DISTURBANCE DROPS INTO THE
SOUTHWEST AND WILL EVENTUALLY INCREASE THE CHANCE OF PRECIPITATION
ACROSS OUR AREA.  THE PRECIPITATION IS KEYING ON A MIDLEVEL FGEN
BAND AND FAVORABLE ULJ DYNAMICS.  SUFFICIENT COOLING TAKES PLACE
SUCH THAT IF MOISTURE IS AVAILABLE...A MIX OR A CHANGE OVER TO ALL
SNOW IS POSSIBLE.  UNFORTUNATELY AT THIS POINT ENOUGH VARIABILITY IN
THE LONG RANGE MODELS WILL KEEP CONFIDENCE IN WIDESPREAD QPF LOW.
WILL KEEP POPS AT 40% OR LESS FOR NOW.  AFTER A COOLDOWN LATE
WEEK...TEMPERATURES WILL WARM FOR THE WEEKEND WITH CLEARING SKIES
DOWNSLOPING WINDS RETURNING.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1153 PM CDT SUN MAR 29 2015

FOR BOTH THE KLBF AND KVTN TERMINALS...EXPECT SCATTERED HIGH
CLOUDINESS AON 25000 FT AGL OVERNIGHT WITH CLEARING MONDAY
MORNING. SOME HIGH CLOUDS ARE POSSIBLE MONDAY EVENING AT THE KVTN
TERMINAL WITH SCATTERED CLOUDS AON 25000 FT AGL. WINDS OVERNIGHT
WILL BE LIGHT FROM THE SOUTHWEST AT UNDER 10 KTS. WINDS WILL
BECOME NORTHWESTERLY AND INCREASE TO 10 TO 20 KTS MONDAY AFTERNOON
WITH GUSTS APPG 25 KTS AT THE KVTN TERMINAL. WINDS WILL DIMINISH
TO UNDER 10 KTS AFTER SUNDOWN MONDAY EVENING.

&&

.FIRE WEATHER...
ISSUED AT 401 AM CDT MON MAR 30 2015

THE ONLY CHANCE OF RAIN IS WEDNESDAY NIGHT THROUGH FRIDAY AS A
DISTURBANCE MOVES THROUGH THE ROCKIES. THE SERIES OF PACIFIC COLD
FRONTS MOVING THROUGH THE CENTRAL PLAINS IS WIPING OUT RETURN FLOW
FROM THE GULF OR ANYWHERE MOIST FOR THAT MATTER. THE LATEST MODEL
DATA INDICATE DRY WEATHER MAY CONTINUE ACROSS NCNTL NEB FOR THE NEXT
7 DAYS. WPC SUGGESTS LESS THAN 1/4 INCH OF RAIN ACROSS SOUTHWEST NEB
WEDNESDAY NIGHT THROUGH FRIDAY.

A WEAK PACIFIC COLD FRONT ACROSS THE NRN HIGH PLAINS AND ATTENDANT
SFC LOW PRESSURE ACROSS SASKATCHEWAN MOVES SOUTHEAST DRIVING THE
FRONT THROUGH THE FCST AREA THIS MORNING.

CRITICAL FIRE DANGER TODAY...THE HRRR AND RAP MODELS SHOW VERY DEEP
MIXING ALONG THE FRONT WITH DEWPOINTS FALLING INTO THE TEENS TO
AROUND 20. SOME RECOVERY OCCURS BEHIND THE FRONT ACROSS NORTHWEST
NEB BUT IN GENERAL HUMIDITY SHOULD FALL BELOW 15 PERCENT ACROSS MOST
OF THE FCST AREA USING THESE MODELS. SIMILARLY...WIND GUSTS TO 25
AND 30 MPH SHOULD BE COMMON ALONG AND NORTH OF INTERSTATE 80
SUPPORTING A RED FLAG WARNING FOR ALL AREAS NORTH OF THE INTERSTATE.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 11 AM CDT /10 AM MDT/ THIS MORNING TO 9 PM
CDT /8 PM MDT/ THIS EVENING FOR NEZ204-206-208-209.

&&

$$

SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CLB
FIRE WEATHER...CDC







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