474
FXUS63 KLBF 201114
AFDLBF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
514 AM CST WED NOV 20 2024
KEY MESSAGES
- STRONG NORTHWEST WINDS ARE EXPECTED THIS MORNING AND
AFTERNOON, WITH A THREAT FOR WIND GUSTS UP TO 60 MILES PER
HOUR ALONG AND EAST OF HIGHWAY 83 AND NEAR AND NORTH OF
HIGHWAY 91.
- THE COMBINATION OF VERY DRY AIR AND STRONG NORTHWEST WINDS
WILL LEAD TO CRITICAL FIRE WEATHER CONDITIONS THIS AFTERNOON
ALONG AND EAST OF HIGHWAY 83.
- MORE BENIGN WEATHER CONDITIONS ARE EXPECTED FOR LATE WEEK AND
INTO THE WEEKEND, BEFORE A PATTERN SHIFT NEXT WEEK BRINGS A
RETURN OF BELOW AVERAGE TEMPERATURES AND THE POTENTIAL FOR
WINTRY PRECIPITATION.
SHORT TERM /THROUGH THURSDAY NIGHT/
ISSUED AT 402 AM CST WED NOV 20 2024
CURRENTLY, AN UPPER LEVEL LOW IS CENTERED OVER THE EASTERN
DAKOTAS/WESTERN MINNESOTA, WITH RIDGING POSITIONED UPSTREAM OVER THE
INTERMOUNTAIN WEST. ON THE WESTERN PERIPHERY OF THIS LOW, A
POWERFUL H3 JET STREAK (135-145KTS) STRETCHES FROM EASTERN
MONTANA INTO WYOMING AND PORTIONS OF WESTERN NEBRASKA AND
NORTHWEST KANSAS. AT THE SURFACE, A DEEP SURFACE LOW WAS
CENTERED OVER FAR SOUTHERN MANITOBA, WITH A SURFACE COLD FRONT
STRETCHING SOUTHWARD FROM THIS LOW ACROSS SOUTH DAKOTA AND NEAR
THE SOUTH DAKOTA/NEBRASKA BORDER.
CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED ACROSS MUCH OF CENTRAL
AND NORTH CENTRAL NEBRASKA THIS AFTERNOON. ADDITIONAL DETAILS ARE
CONTAINED IN THE FIRE WEATHER SECTION BELOW.
FOR TODAY, EXPECT CONTINUED STRONG NORTHWESTERLY WINDS AS FLOW
REMAINS STRONG ALOFT AND LARGELY UNIDIRECTIONAL WITH HEIGHT. THIS
WILL LEAD TO A RAPID INCREASE WITH WINDS THIS MORNING, AS MIXING
OCCURS AND THE HIGHER MOMENTUM FLOW IS DIRECTED DOWNWARDS TO THE
SURFACE. WIDESPREAD GUSTS OF 50-55MPH ARE EXPECTED FOR ALL OF
WESTERN AND NORTH CENTRAL NEBRASKA LATE THIS MORNING INTO EARLY THIS
AFTERNOON. THE HIGHEST GUSTS CONTINUE TO BE ADVERTISED ACROSS
PORTIONS OF NORTH CENTRAL NEBRASKA, WHERE GUSTS AROUND 60MPH ARE
EXPECTED TODAY. THIS IS A CONSEQUENCE OF BEING IN CLOSER PROXIMITY
TO THE UPPER DYNAMICS, AND FLOW IN THE LOWEST FEW KILOMETERS IS
STRONGEST FURTHER NORTH AND EAST. SPEAKING OF DYNAMICS, GUIDANCE
CONTINUES TO PAINT A TROPOPAUSE FOLD TRANSLATING ACROSS THE AREA
TODAY, IN CLOSE PROXIMITY TO THE UPPER LEVEL JET CORE. AS THE
PRIMARY PV ANOMALY EJECTS EASTWARD TODAY, THE HIGH MOMENTUM FLOW
WILL BE COMPRESSED DOWNWARDS, AND THIS SHOULD ENABLE A DEEP ENOUGH
MIXING DEPTH TO TAP INTO 55-65KT FLOW IN THE LOWEST FEW KILOMETERS.
WITH THIS IN MIND, HAVE EXPANDED THE HIGH WINDS WARNING SOUTHWARD TO
THE HWY 91 CORRIDOR, WHERE CONFIDENCE IN GUSTS APPROACHING 60MPH HAS
INCREASED.
CONCERNINGLY, AMPLE DRY AIR ALOFT ALSO LOOKS TO BE MIXED
DOWNWARDS THIS AFTERNOON, CRATERING DEWPOINTS INTO THE SINGLE
DIGITS. EVEN THOUGH HIGH TEMPERATURES WILL STRUGGLE TO CLIMB OUT OF
THE LOWER TO MIDDLE 40S AMID CONTINUED COLD ADVECTION, HUMIDITY
VALUES IN THE UPPER TEENS TO LOW 20 PERCENT RANGE ARE EXPECTED.
COMBINED THIS WITH THE VERY STRONG NORTHWEST WINDS, AND CRITICAL
FIRE WEATHER CONDITIONS ARE EXPECTED THIS AFTERNOON, PRIMARILY NEAR
AND EAST OF HIGHWAY 83. THIS IS WHERE THE OVERLAP OF STRONG WINDS
AND LOW HUMIDITY LOOKS TO BE MAXIMIZED. THIS IS WHERE A RED FLAG
WARNING IS IN EFFECT THIS AFTERNOON. FURTHER WEST, THOUGH PERIODS OF
CRITICAL FIRE CONDITIONS ARE POSSIBLE, WINDS LOOK TO BEGIN TO RELAX
LATE AFTERNOON AS HUMIDITY VALUES ARE AT THEIR LOWEST. CONFIDENCE IN
A PROLONGED PERIOD OF RED FLAG CONDITIONS PRECLUDES ANY HEADLINES
ACROSS WESTERN NEBRASKA, THOUGH TRENDS WILL CONTINUE TO BE MONITORED.
BY THIS EVENING, THE PARENT UPPER LOW WILL BEGIN TO PULL AWAY FROM
THE AREA INTO THE GREAT LAKES. AS THE ASSOCIATED SURFACE FEATURES
EXIT AS WELL, THE SURFACE PRESSURE GRADIENT FINALLY RELAXES ACROSS
THE AREA. IN RESPONSE, WINDS QUICKLY WEAKEN FROM SOUTHWEST TO
NORTHEAST THIS EVENING, BECOMING LIGHT OVERNIGHT ACROSS WESTERN
NEBRASKA. THE CLEAR SKIES AND LIGHTER WINDS WILL ALLOW FOR
TEMPERATURES TO QUICKLY FALL INTO THE TEENS TONIGHT ACROSS THE
ENTIRE AREA.
LONG TERM /FRIDAY THROUGH TUESDAY/
ISSUED AT 402 AM CST WED NOV 20 2024
HEIGHTS RISE ALOFT IN THE WAKE OF THE DEPARTING LOW AND UPPER
RIDGING AMPLIFIES ACROSS THE ROCKIES. THE UPPER RIDGE WILL SLOWLY
TRANSLATE EASTWARD INTO THE WEEKEND, WITH TEMPERATURES MODERATING
LOCALLY BACK INTO THE UPPER 40S AND 50S. AS WE HEAD INTO EARLY NEXT
WEEK, WILL BE WATCHING AN AMPLIFYING UPPER RIDGE OVER THE GULF OF
ALASKA. THIS WILL LEAD TO DEEP NORTHWESTERLY FLOW ALOFT UPSTREAM
ACROSS MUCH OF WESTERN CANADA AND THE CENTRAL CONUS. GUIDANCE
CONTINUES TO SUGGEST MUCH COLDER AIR FILTERING SOUTHWARD INTO THE
CONUS TOWARDS THE BUSY HOLIDAY TRAVEL PERIOD LATE NEXT WEEK.
SOLUTIONS DIVERGE WITH RESPECT TO PRECIPITATION THREATS, WITH WIDE
VARIANCE IN HANDLING OF SYNOPTIC FEATURES. STILL, THERMAL PROFILES
WILL BE SUPPORTIVE OF WINTRY PRECIPITATION AND TRENDS WILL NEED TO
BE MONITORED, ESPECIALLY DURING THE BUSY HOLIDAY TRAVEL PERIOD.
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 514 AM CST WED NOV 20 2024
VFR IS ANTICIPATED THROUGH THE FORECAST PERIOD FOR WESTERN AND
NORTH CENTRAL NEBRASKA TERMINALS, BUT WIND WILL BE A BIG
AVIATION WEATHER CONCERN. LOW LEVEL WIND SHEAR CONDITIONS WILL
CONTINUE THROUGH MID-MORNING, THEN STRONG NORTHWEST WINDS WILL
BE REALIZED THROUGHOUT THE DAY. THIS INCLUDES GUSTS OF 40+ KTS
FOR NORTHERN TERMINALS (VTN) AND 30+ KTS SOUTH (LBF). WINDS
BEGIN TO RELAX AFTER SUNSET, EVENTUALLY BECOMING LIGHT IN
SOUTHWEST NEBRASKA TONIGHT.
FIRE WEATHER
ISSUED AT 402 AM CST WED NOV 20 2024
A POWERFUL LOW PRESSURE OVER THE UPPER MIDWEST AND A TRAILING COLD
FRONT THAT WILL ENTER NEBRASKA WILL SET THE STAGE FOR WIDESPREAD
NEAR CRITICAL AND LOCALLY CRITICAL FIRE WEATHER CONDITIONS TODAY.
VERY STRONG NORTHWEST WINDS WILL GUST TO 60 MPH AT TIMES ACROSS
PORTIONS OF NORTHERN NEBRASKA (EASTERN ZONE 208, NORTHERN ZONES
206 AND 209). ADDITIONALLY, A CORE OF DRY AIR NEAR THE FRONT WILL
RESULT IN LOW HUMIDITY. CONFIDENCE IN HUMIDITY VALUES REACHING OR
COMING WITHIN 5% OF CRITICAL THRESHOLDS GENERALLY LINES UP FROM
NEAR VALENTINE TO NEAR BROKEN BOW. FOR FAR NORTH CENTRAL NEB
(O'NEILL), HUMIDITY VALUES SHOULD REMAIN AT LEAST 10% ABOVE
CRITICAL THRESHOLDS, AND CONCERN IS LOWER WHERE SUBSTANTIAL RAIN
FELL A COUPLE DAYS AGO. TO THE WEST (PANHANDLE AND FAR SOUTHWEST
NEB), THE STRONGEST WINDS WILL OCCUR DURING THE MORNING AND EARLY
AFTERNOON, WHICH LIMITS THE MATCH-UP WITH PEAK HEATING AND LOWEST
HUMIDITY. NEVERTHELESS, WINDS WILL BE CAPABLE OF RAPID FIRE SPREAD
THROUGHOUT THE REGION.
LBF WATCHES/WARNINGS/ADVISORIES
HIGH WIND WARNING UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ005>010-026>029-094.
RED FLAG WARNING FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
NEZ206-208-209-219.
SHORT TERM...BROWN
LONG TERM...BROWN
AVIATION...SNIVELY
FIRE WEATHER...SNIVELY
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page