396
FXUS63 KLBF 181132
AFDLBF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
532 AM CST WED DEC 18 2024
KEY MESSAGES
- A CLIPPER SYSTEM WILL BRING STRONG WINDS TO THE AREA THURSDAY,
WITH GUSTS TO AROUND 50 MPH POSSIBLE IN NORTH CENTRAL NE.
- HIGH FORECAST CONFIDENCE CONTINUES TOWARD WARMER THAN NORMAL
TEMPERATURES SATURDAY THROUGH TUESDAY.
- DRY CONDITIONS OVER THE NEXT 7 DAYS.
SYNOPSIS
ISSUED AT 348 AM CST WED DEC 18 2024
AN UPPER TROUGH WAS CURRENTLY MOVING INTO THE PACIFIC NORTHWEST
WITH AN UPPER RIDGE DOWNSTREAM OVER THE NORTHERN AND CENTRAL
ROCKIES. FURTHER EAST AN UPPER LOW WAS LOCATED OVER HUDSON BAY
CANADA WITH AN UPPER THROUGH EXTENDING SOUTH THROUGH THE GREAT
LAKES BACK INTO CENTRAL TEXAS.
AT THE SURFACE, HIGH PRESSURE WAS OVER THE DAKOTAS, NEBRASKA,
SOUTH INTO THE SOUTHERN HIGH PLAINS. TEMPERATURES RANGED FROM
THE MID TEENS ACROSS THE WESTERN AND CENTRAL SANDHILLS TO THE
LOW TO MID 20S IN THE EAST, WHERE LOW CLOUDINESS LINGERED.
SHORT TERM /THROUGH THURSDAY/
ISSUED AT 348 AM CST WED DEC 18 2024
TODAY, A SHORTWAVE TROUGH WILL MOVE INTO CENTRAL MONTANA AND
WESTERN WYOMING. THIS WILL DEEPEN A LEESIDE SURFACE TROUGH AND
BRING WARM AIR ADVECTION TO WESTERN AND CENTRAL NEBRASKA AS
SOUTHWESTERLY H85 WINDS INCREASE TO 35KTS. SURFACE WINDS WEST OF
HIGHWAY 83 WILL INCREASE TO 10 TO 20 MPH, TO A SOUTHERLY
DIRECTION 5 TO 15 MPH FURTHER EAST. HIGHS REMAIN NEAR THE
PREVIOUS FORECAST FROM THE UPPER 40S TO LOWER 50S WEST OF
HIGHWAY 83, TO UPPER 30S TO MID 40S TO THE EAST. SKIES REMAIN
MOSTLY SUNNY TODAY.
TONIGHT, A CLIPPER SYSTEM WILL DEVELOP ACROSS THE DAKOTAS, AS
WESTERLY WINDS FROM 40 TO 50KTS AT H85 TURN NORTHWEST.
SOUTHWESTERLY SURFACE WINDS THIS EVENING WILL BECOME WESTERLY
OVERNIGHT AND INCREASE TO 15 TO 25 MPH. THIS WILL AID IN KEEPING
THE BOUNDARY LAYER MIXED, WITH TEMPERATURES HOLDING IN THE LOW
TO MID 30S.
THURSDAY, THE CLIPPER SYSTEM WILL MOVE FROM EASTERN SOUTH DAKOTA
INTO EASTERN IOWA DRIVING A COLD FRONT QUICKLY THROUGH THE
FORECAST AREA IN THE MORNING. MODIFIED ARCTIC AIR WILL EVEN MOVE
INTO EASTERN PORTIONS OF NORTH CENTRAL NEBRASKA IN THE
AFTERNOON. BECOMING VERY WINDY, ESPECIALLY ACROSS NORTH CENTRAL
NEBRASKA. THE LATEST NAM12 AND GFS BUFKIT SOUNDINGS CONTINUE TO
INDICATE WINDS ABOVE 50KTS AT THE TOP OF THE MIXED LAYER. THIS
SUPPORTS SURFACE WIND GUSTS TO AROUND 50 MPH ALONG A CORRIDOR
FROM VALENTINE TO BROKEN BOW AND LOCATIONS TO THE EAST. THIS IS
WHERE THE STRONGEST COLD AIR ADVECTION AND 3-HOURLY PRESSURE
RISES TO AROUND 3 MILLIBARS. USED A 50/50 BLEND OF THE NBM AND
NBM 90TH PERCENTILE FOR WINDS/WIND GUSTS RESULTING IN GUSTS OF
45 TO TO AROUND 50 MPH, IN CLOSE AGREEMENT WITH BUFKIT
SOUNDINGS. DEEP MIXING WILL ALLOW HIGHS TO REACH THE LOW 40S FAR
NORTHERN NEBRASKA BY EARLY AFTERNOON, FOLLOWED BY FALLING
TEMPERATURES TO THE UPPER 30S MID AFTERNOON AND UPPER 20S LATE
AFTERNOON. HIGHS REACH 50 TO AROUND 55 ACROSS THE SOUTH.
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/
ISSUED AT 348 AM CST WED DEC 18 2024
THURSDAY NIGHT, ARCTIC HIGH PRESSURE WILL BECOME CENTERED FROM
THE DAKOTAS INTO NEBRASKA WITH CLEAR SKIES. NORTHERLY WINDS TO
DIMINISH OVERNIGHT, LEADING TO COLD LOWS 5 TO 10 ABOVE ACROSS
THE EAST, AND 10 TO 15 ABOVE WEST AND SOUTHWEST. WIND CHILLS IN
THE EAST WILL ALSO BE AS LOW AS 2 BELOW TO 5 ABOVE.
FRIDAY, NORTHWEST FLOW ALOFT WITH A RETURN SOUTHERLY WIND OF 10
TO 20 MPH IN THE AFTERNOON. THIS WILL BE THE COOLEST/COLDEST
DAY. HIGHS ONLY NEAR 25 IN THE FAR NORTHEAST, NEAR 40 ALONG
HIGHWAY 83, TO AROUND 45 FAR WESTERN COUNTIES.
A PERSISTENT WARMUP BEGINS SATURDAY AND PERSISTS THROUGH TUESDAY
(CHRISTMAS EVE DAY). AN UPPER RIDGE BRIEFLY BUILDS IN SATURDAY
AS AN UPPER TROUGH AND CLOSED LOWS MOVES INTO THE DAKOTAS ON
SUNDAY. THIS SHOULD KEEP DRY CONDITIONS OVER WESTERN NEBRASKA,
AND NOT PULL IN ANY MEANINGFUL COOLER AIR.
FAIRLY ZONAL FLOW MONDAY, AS A BROAD TROUGH TRAVERSES THE
CENTRAL U.S. MONDAY NIGHT INTO TUESDAY. THIS WILL MAINTAIN A
FAIRLY MILD PACIFIC AIRMASS.
HIGHS SATURDAY CONTRAST FROM 35 TO 40 IN THE NORTHEAST, TO 48 TO
55 WEST. 50S ARE FORECAST SUNDAY THROUGH TUESDAY ACROSS MUCH OF
THE AREA.
LOOKING BEYOND DAY 7, WARM CONDITIONS EXPECTED NEXT WEDNESDAY (CHRISTMAS
DAY) WITH HIGHS IN THE 50S STILL PROBABLE. WILL NEED TO MONITOR
AN UPPER TROUGH WEDNESDAY INTO THURSDAY SHOWN BY DETERMINISTIC
GFS, ECMWF, AND CANADIAN MODELS, AND THEIR RESPECTIVE ENSEMBLES.
THIS COULD BRING AT LEAST LOW CHANCES FOR PRECIPITATION,
INITIALLY FAVORING RAIN.
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 521 AM CST WED DEC 18 2024
STRATUS/FOG WITH MVFR/IFR CONDITIONS OVER PORTIONS OF NORTH
CENTRAL NEBRASKA (KBWW, KONL, KTIF) WILL GRADUALLY IMPROVE TO
VFR SHORTLY AFTER SUNRISE. THE STRATUS DECK HAS BEGUN TO NUDGE
SOUTH TOWARDS KVTN, HOWEVER, GUIDANCE SUGGESTS THAT IT WILL
REMAIN OUT OF THE TERMINAL. FUTURE AMMENDMENTS MAY BE NEEDED
SHOULD THE STRATUS PUSH FURTHER SOUTH THAN ORIGINALLY THOUGHT.
OTHERWISE, EXPECT WIDESPREAD VFR CONDITIONS FOR ALL SITES
THROUGH THE END OF THE PERIOD. A STRONG CLIPPER SYSTEM WILL
APPROACH THE REGION LATE THIS EVENING, FORCING A COLD FRONT
THROUGH THE AREA OVERNIGHT. INCREASED SURFACE FLOW WILL SUPPORT
A PERIOD OF WEST TO NORTHWESTERLY LLWS OF 35 TO 50 KTS. SURFACE
WINDS WILL REMAIN OUT OF THE SOUTH THROUGH MUCH OF THE DAY,
VEERING AND INCREASING OUT OF THE NORTHWEST WITH GUSTS OF 20 TO
30 MPH BEHIND THE FRONT LATE THIS EVENING/TONIGHT.
LBF WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...ROBERG
AVIATION...VIKEN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page