677
FXUS63 KLBF 212332
AFDLBF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
532 PM CST FRI FEB 21 2020
SYNOPSIS
ISSUED AT 328 PM CST FRI FEB 21 2020
H5 ANALYSIS THIS MORNING HAS A TROUGH OF LOW PRESSURE
EXTENDING FROM NEWFOUNDLAND CANADA SOUTHWEST INTO NORTHERN ALABAMA.
FURTHER WEST, A LOW AMPLITUDE RIDGE EXTENDED FROM NORTHERN NEW
MEXICO NORTHWEST INTO SOUTHERN IDAHO. FURTHER WEST OF THIS FEATURE,
A CLOSED LOW WAS LOCATED ROUGHLY 500 MILES WEST OF LOS ANGELES
CALIFORNIA. THIS FEATURE SHOWS UP NICELY ON WV IMAGERY THIS
AFTERNOON. A LARGE PLUME OF PACIFIC MOISTURE WAS SOUTH OF THIS
FEATURE, AND EXTENDED NORTHEAST INTO THE SWRN CONUS. AT THE SURFACE,
HIGH PRESSURE WAS ANCHORED OVER THE ARKLATEX INTO THE TENNESSEE
VALLEY. NORTH OF THIS FEATURE, A SURFACE TROUGH OF LOW PRESSURE
EXTENDED FROM EASTERN NORTH DAKOTA INTO CENTRAL NEBRASKA. ACROSS
WESTERN AND NORTH CENTRAL NEBRASKA, VISIBLE SATELLITE IMAGERY HAS A
BROAD AREA OF SNOW COVER EXTENDING FROM GARDEN COUNTY INTO THE
SANDHILLS, EAST NORTHEAST INTO HOLT COUNTY. SKIES WERE CLEAR THIS
AFTERNOON AND TEMPERATURES AS OF 2 PM CST RANGED FROM 41 IN O'NEILL
TO 59 AT VALENTINE.
SHORT TERM
(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 328 PM CST FRI FEB 21 2020
THE MAIN FORECAST CHALLENGES IN
THE NEAR TERM ARE TEMPERATURES AND WIND. ANOTHER TRICKY ELEMENT IN
THE FORECAST OVER THE NEXT 24 HOURS IS SOME FIRE WEATHER CONCERNS IN
THE FAR SOUTHWESTERN FORECAST AREA SATURDAY AFTERNOON. FOR TONIGHT,
SKIES WILL REMAIN MOSTLY CLEAR WITH THE EXCEPTION OF SOME HIGH
CLOUDS ACROSS NORTHERN NEBRASKA. THIS IS IN ADVANCE OF A VERY WEAK
SHORTWAVE WHICH ENTERS THE WESTERN DAKOTAS EARLY SATURDAY MORNING.
LOWS WILL RANGE FROM THE UPPER TEENS TO LOWER 20S. THE BEFORE
MENTIONED TROUGH WILL FORCE A SURFACE TROUGH THROUGH THE FORECAST
AREA ON SATURDAY. THIS WILL BE LITTLE MORE THAN A SMALL WIND SHIFT
FROM THE WEST TO NORTH AS IT PASSES. AS FOR HIGHS SATURDAY: THERE
WAS SOME DECENT SPREAD IN THE NUMERICAL GUIDANCE WITH THIS MORNING'S
MODEL RUNS. THE MAV SOLN IS WARMEST WITH THE MET BEING THE COOLEST.
THE INHERITED FORECAST WAS WEIGHTED MORE TOWARD THE COOLER MET
GUIDANCE FOR HIGHS SATURDAY. DECIDED TO INCREASE HIGHS FOR SATURDAY
UTILIZING A BLEND OF PERSISTENCE AND MAV GUIDANCE. BASED ON BUFKIT
SOUNDINGS, THE NAM, SEEMS TO NOT MIX AS HIGH SATURDAY AFTERNOON,
THUS THE COOLER TEMPS. BELIEVE THE GFS IS A BETTER SOLUTION HERE
GIVEN THE EXPECTED FULL SUN AND DRY SOUNDING FORECAST WHICH
FACILITATES BETTER MIXING SATURDAY AFTERNOON. ONE LAST POSSIBLE
IMPACT TO TEMPERATURES IS SNOW COVER ACROSS THE SANDHILLS. FOR NOW,
WILL FORECAST HIGHS ON THE NOTION THAT THIS SNOWCOVER WILL BE GONE
SATURDAY. THIS NOTION SEEMS VERY PLAUSIBLE GIVEN THE FULL SUN TODAY,
VERY DRY LOW LEVELS AS EVIDENCED BY THE 0.05 PWAT IN THE 12Z KLBF
RAOB THIS MORNING, AND THE VERY DRY NATURE OF THE SNOW. UPPER LEVEL
LOW PRESSURE WILL TRACK INTO THE FOUR CORNERS SATURDAY NIGHT.
DOWNSTREAM OF THIS FEATURE, MID TO HIGH CLOUDINESS WILL SPREAD
NORTHEAST INTO THE FORECAST AREA OVERNIGHT SATURDAY NIGHT. WITH THE
APPROACHING SYSTEM AND DEEPENING LOW PRESSURE OVER FAR NORTHEASTERN
NEW MEXICO, WINDS WILL INCREASE OVERNIGHT. THE INCREASING WINDS,
COUPLED WITH INCREASED CLOUDINESS, SHOULD LEAD TO MILD LOWS FOR
SATURDAY NIGHT. THE GUIDANCE HAD LOWS IN THE TEENS AND LOWER 20S.
DECIDED TO TREND THESE HIGHER INTO THE 20S.
LONG TERM
(SUNDAY THROUGH FRIDAY)
ISSUED AT 328 PM CST FRI FEB 21 2020
THE EXTENDED FORECAST IS HIGHLIGHTED BY TWO
WEATHER SYSTEMS, FOLLOWED BY SEASONAL TEMPERATURES LATE NEXT WEEK.
FOR SUNDAY AND SUNDAY NIGHT: THE UPPER LEVEL LOW OVER THE FOUR
CORNERS SUNDAY MORNING WILL TRACK EAST ALONG THE NEW MEXICO/COLORADO
BORDER, EMERGING IN THE VICINITY OF THE OKLAHOMA PANHANDLE BY 00Z
MONDAY. THE MODELS ARE IN DECENT AGREEMENT WITH THE TRACK OF THE H5
LOW WITH THIS SYSTEM AS THE PREFERRED TRACK IS ACROSS SOUTHWEST
KANSAS/NORTHWEST OKLAHOMA SUNDAY EVENING INTO EAST CENTRAL KANSAS
AND NW MISSOURI BY 12Z MONDAY. THE 12Z NAM SOLN HAS NOW COME INTO
AGREEMENT WITH THE GFS, ECMWF AND CANADIAN SOLUTIONS WITH A MORE
SOUTHERN TRACK TO THIS SYSTEM. YESTERDAY, THE 12Z NAM TRACKED THE
LOW ACROSS NORTHERN KANSAS. THIS WOULD HAVE FAVORED DECENT POPS IN
THE SOUTHERN HALF OF THE FORECAST AREA. WITH THE MORE SOUTHERN TREND
OF THE MODELS, POPS WERE LOWERED ACROSS THE BOARD. UTILIZING THE
NBM, POPS WERE LOWERED 20 TO 30 PERCENT ACROSS THE BOARD FROM THE
PVS FORECAST. EVEN THAT MAY NOT BE ENOUGH AS IT IS LOOKING PRETTY
DRY FOR ALL OF THE FORECAST AREA WITH THE EXCEPTION OF CHASE, HAYES
AND FRONTIER COUNTIES. IN THESE AREAS QPF'S WILL BE LOW AND THE 30
TO 40 POPS IN THESE AREAS ARE VERY "OPTIMISTIC" AT THIS JUNCTURE. A
SECOND WEATHER SYSTEM WILL TAKE AIM AT THE FORECAST AREA MONDAY INTO
TUESDAY EVENING. THIS WILL BE IN THE FORM OF A NORTHWESTERLY
SHORTWAVE TROUGH, WHICH DEPENDING ON MODEL CHOICE, ACTUALLY CLOSES
OFF OVER THE CENTRAL PLAINS MONDAY NIGHT INTO TUESDAY. PRECIPITATION
IN ASSOCIATION WITH THIS FEATURE WILL START OFF AS RAIN ON MONDAY,
FOLLOWED BY A QUICK CHANGEOVER TO SNOW AS COLDER AIR IS DRAWN INTO
THE SYSTEM FROM THE NORTH. UNLIKE THE FIRST SYSTEM SUNDAY, THIS
SYSTEM WILL HAVE PLENTY OF ARCTIC AIR TO WORK WITH, SO SNOW WILL BE
THE PREDOMINANT PTYPE WITH THIS SYSTEM. ATTM, SNOWFALL WITH THIS
SYSTEM APPEARS MOST PROBABLE ACROSS THE PINE RIDGE INTO NORTH
CENTRAL NEBRASKA. WILL CONTINUE TO MESSAGE THE SNOW/COLD THREAT IN
THE HWO. BEYOND TUESDAY NIGHT, DRY CONDITIONS ARE FORECAST.
WEDNESDAY WILL BE COOL WITH A GRADUAL WARMUP INTO THE END OF THE
WEEK. BY FRIDAY, HIGHS WILL REACH BACK INTO 40S.
AVIATION
(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 530 PM CST FRI FEB 21 2020
VFR AND CLEAR SKIES SHOULD PREVAIL THE NEXT 24 HRS ACROSS WESTERN
AND NORTH CENTRAL NEBRASKA. WINDS WILL BE LIGHT TONIGHT, THEN
INCREASE TO AROUND 10 KT FROM THE NORTHWEST DURING THE DAY
SATURDAY.
FIRE WEATHER
ISSUED AT 328 PM CST FRI FEB 21 2020
FIRE WEATHER FORECAST CONCERNS WILL BECOME ELEVATED
ON SATURDAY ACROSS FAR SOUTHWESTERN NEBRASKA OVER ZONE 210. DRY
CONDITIONS CONTINUE IN THIS ZONE WHICH MISSED OUT ON THE SNOWFALL
EARLIER IN THE WEEK. HIGHS WILL REACH THE LOWER 60S IN THIS AREA
SATURDAY AFTERNOON WITH MINIMUM RH REACHING AROUND 20 PERCENT.
LOOKING AT NUMERICAL GUIDANCE, FORECAST WIND SPEEDS FOR IMPERIAL ARE
WELL BELOW CRITICAL CRITERIA FOR A RED FLAG WARNING. HOWEVER, GFS
BUFKIT SOUNDINGS FOR IMPERIAL INDICATE A SMALL WINDOW WHERE WIND
GUSTS COULD REACH AROUND 20 MPH SATURDAY AFTERNOON UNDER FULL
MIXING. CONDITIONS WILL BE CLOSE TO RED FLAG CRITERIA TOMORROW
AFTERNOON BUT NOT QUITE THERE JUST YET. AFTER CONVERSING WITH LOCAL
FIRE OFFICIALS IN ZONE 210, THEY INDICATED FUELS WERE READY TO BURN.
DECIDED TO CONTACT FIRE PARTNERS IN FAR SW NEBRASKA AND GIVE THEM A
HEADS UP ON THE ELEVATED FIRE WEATHER CONDITIONS SATURDAY AFTERNOON.
LBF WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...BUTTLER
SHORT TERM...BUTTLER
LONG TERM...BUTTLER
AVIATION...TAYLOR
FIRE WEATHER...BUTTLER
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