493
FXUS65 KBOU 240310
AFDBOU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
910 PM MDT WED OCT 23 2024
KEY MESSAGES
- DRY AND WINDY THURSDAY WITH NEAR CRITICAL FIRE WEATHER
CONDITIONS DURING THE AFTERNOON.
- A COLD FRONT WILL MOVE ACROSS THE PLAINS THURSDAY WITH SLIGHTLY
COOLER TEMPERATURES CONTINUING INTO FRIDAY, BUT TEMPERATURES
WILL STILL REMAIN A LITTLE ABOVE NORMAL.
- PATTERN CHANGE LIKELY EARLY NEXT WEEK. HIGH PROBABILITIES OF
BELOW NORMAL TEMPERATURES BEYOND TUESDAY (>70%), AND A CHANCE
FOR THE FIRST WINTRY WEATHER ACROSS THE PLAINS BY MID-WEEK.
- WIDESPREAD FREEZE BY EARLY NEXT WEEK?
UPDATE
ISSUED AT 849 PM MDT WED OCT 23 2024
TONIGHT'S FORECAST OF A MILD NIGHT WITH MOSTLY SKIES REMAINS ON
TRACK. THERE WERE THREE FIRE STARTS IN OUR FORECAST AREA TODAY
WHICH INDICATES THE FUELS ARE EXCEPTIONALLY PRIME FOR BURNING.
THERE WAS CONSIDERATION FOR ISSUING A RED FLAG WARNING FOR
TOMORROW DUE TO STRONG WINDS BUT THE DECISION WAS MADE TO HOLD OFF
SINCE RELATIVE HUMIDITY MAY WELL ABOVE THE 15 PERCENT THRESHOLD.
WILL GIVE THE NIGHT SHIFT MORE TIME TO CONSIDER THE CHANCES OF
CRITICAL FIRE WEATHER FOR TOMORROW.
SHORT TERM /THROUGH THURSDAY/
ISSUED AT 145 PM MDT WED OCT 23 2024
THE RIDGE OVERHEAD BREAKS DOWN MOMENTARILY LATER TONIGHT INTO
THURSDAY AS A FAST MOVING, MOISTURE-STARVED TROUGH MOVES ACROSS
THE NORTHERN ROCKIES TONIGHT. THE TROUGH AXIS SHOULD MOVE ACROSS
OUR AREA BY MIDDAY, EXITING COLORADO BY THURSDAY EVENING. THERE IS
PERHAPS JUST ENOUGH MOISTURE COMBINED WITH A QUICK SHOT OF LIFT
AHEAD OF THE TROUGH AXIS FOR LIGHT PRECIPITATION ACROSS THE PARK
AND NORTHERN FRONT RANGES, AND MAYBE NORTH PARK. THAT'S ABOUT IT,
AND EVEN THEN IT'S A 10-25% CHANCE OF MEASURABLE PRECIP. THE BEST
CHANCE OF THIS IS RIGHT AHEAD OF THE TROUGH AXIS BETWEEN 5-10 AM
THURSDAY. SNOW LEVELS WILL REMAIN AROUND 9 KFT, BUT MAY BRIEFLY
DROP TO THE VALLEY FLOOR IN NORTH PARK BEFORE NOON.
WHAT THIS TROUGH LACKS IN MOISTURE IS MADE UP WITH THE WIND. THE
FIRST AREAS TO SEE THE WIND WILL BE ALONG THE RIDGE TOPS AND EAST
ACROSS THE EASTERN FOOTHILLS AND ADJACENT PLAINS. 50 KTS OF CROSS
BARRIER FLOW WILL BE IN PLACE FOR SEVERAL HOURS STARTING AROUND 5
AM. THERE IS SOME UPWARD MOTION INITIALLY WHICH WOULD KEEP THE
STRONGEST WINDS ABOVE 8,000 FT OR SO. BUT BETWEEN 8AM - 12 PM
LAPSE RATES TANK ABOVE RIDGETOP WHILE THE 50 KT CROSS BARRIER FLOW
HANGS ON. THE POST TROUGH SUBSIDENCE ALSO KICKS IN RIGHT AROUND
THIS TIME. THIS WOULD RESULT IN GUSTS PROBABLY OVER 50 MPH FROM
THE EAST SLOPE FOOTHILLS DOWN TO THE BOULDER-ARVADA-GOLDEN WIND
CORRIDOR DURING THE LATE MORNING HOURS. THERE IS A 30 CHANCE OF
EXCEEDING 60 MPH IN THE FAVORED WIND AREAS. WINDS ALOFT DECREASE
BY THE AFTERNOON AND SUCH THAT THE STRONGEST WINDS FROM THE
MOUNTAINS TO EASTERN FOOTHILLS TO WEST OF I-25 SHOULD WEAKEN
SIGNIFICANTLY DURING THE AFTERNOON HOURS. OVERALL WE EXPECT A
SHORT LIVED MOUNTAIN WAVE EVENT. THE MOUNTAIN VALLEYS WILL
LIKEWISE SEE A SHORT WINDOW (LATE MORNING TO MIDDAY) OF GUSTS
25-35 MPH BEFORE THOSE WINDS WEAKEN. FURTHER EAST, THE STORY IS A
LITTLE DIFFERENT BECAUSE THE WINDS ARE DRIVEN BY THE NEAR-SURFACE
PRESSURE GRADIENT AND A FAST MOVING COLD FRONT. AS THE TROUGH AXIS
AT 700 MB MOVES EAST, IT WILL HELP FORCE A COLD FRONT SOUTH OUT
OF WYOMING THAT WILL TRAVERSE OUR PLAINS. IT SHOULD REACH FORT
COLLINS-GREELEY BETWEEN 8-9 AM, DENVER BY 9-10 AM, AND EXIT
LINCOLN COUNTY BY 11 AM OR SO. WINDS EAST OF A LINE FROM FORT
COLLINS TO DIA TO LIMON WILL GUST 20-40 MPH AFTER FRONTAL PASSAGE,
AND CONTINUE TO GUST 30+ MPH ALL AFTERNOON BEFORE WEAKENING BY
THE EVENING. AS FOR TEMPERATURES, IT WILL BE QUITE WARM PRIOR TO
FROPA, WITH TEMPS WARMING INTO THE 60S TO AROUND 70 WITH DOWNSLOPE
WINDS. AFTER FROPA, TEMPERATURES WILL REMAIN STEADY IN THE 60S
ALL AFTERNOON OR EVEN DROP A FEW DEGREES. THE COOLEST SPOTS WILL
BE ALONG AND NORTH OF US-34 WHERE THE FRONT WILL MOVE THROUGH
SOONEST. THE MOUNTAIN VALLEYS SHOULD BE COOLER TOO WITH THE TROUGH
MOVING OVERHEAD, WHERE THEY WILL REACH THE 50S.
LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/
ISSUED AT 145 PM MDT WED OCT 23 2024
WOO WOO WOO! ALL ABOARD THE SNOW TRAIN, LEAVING THE STATION EARLY
NEXT WEEK OR, JUST COLDER TEMPERATURES AND MAYBE OUR FIRST
WIDESPREAD FREEZE EVENT, IT'S STILL A TOSS UP. I MEAN WE'VE BEEN IN
THIS SPOT BEFORE, SOMETHING LOOKS SOOOOO GOOD AT DAY 7-8 AND THEN
DAY 1 IT'S A SKUNK ALL THE WHILE GIVING YOU FALSE HOPE. WITH WEATHER
FORECASTING WE'RE IN THE MARKETING DEPARTMENT, NOT PRODUCTION...
BETWEEN NOW AND EARLY NEXT WEEK WE STILL HAVE WEATHER TO CONTEND
WITH, JUST NOT THE MOIST KIND, IT'S THE EXACT OPPOSITE
UNFORTUNATELY. FIRE WEATHER CONCERNS CONTINUE TO BE THE MAIN STORY
THROUGH THE WEEKEND AS TEMPERATURES REMAIN ABOVE SEASONAL AVERAGES,
WINDS REMAIN ELEVATED, NOT TOO STRONG UNTIL SUNDAY AND MONDAY, AND
WE REMAIN DRY. AT THIS TIME MONDAY LOOKS TO HAVE THE STRONGEST WINDS
AND THE WARMEST TEMPERATURES AHEAD OF THE UPCOMING TROUGH. JUST A
TYPICAL COLORADO BIG WARM UP BEFORE THE PLUNGE.
SPEAKING OF THE PLUNGE, WE DO HAVE HIGHER CONFIDENCE IN THE MUCH
COOLER TEMPERATURES MOVING IN TUESDAY AND WEDNESDAY OF NEXT WEEK
WITH A TROUGH PASSAGE AND STRONGER COLD FRONT. THIS IS CURRENTLY
SHAPING UP TO BE OUR FIRST WIDESPREAD FREEZE WEDNESDAY MORNING. AS
FOR THE SNOWFALL AND REALLY ANY MOISTURE, IT'S STILL EARLY TO LOCK
SOMETHING IN, SEE FIRST PARAGRAPH LINE 3. WE'RE TRYING TO BE
OPTIMISTIC AS WE COULD USE A NICE SOAKING AND THE SNOW TO FLATTEN
THE TALLER GRASSES, BUT A FEW MILES HERE AND THERE MAKE AN ENORMOUS
DIFFERENCE. KEEP READING OVER THE NEXT SEVERAL DAYS!
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 537 PM MDT WED OCT 23 2024
VFR CONDITIONS THROUGH THE TAF PERIOD. STRONGER THAN NORMAL
DRAINAGE WINDS ARE EXPECTED TONIGHT DUE TO AN INCREASING PRESSURE
GRADIENT. THURSDAY MORNING, A COLD FRONT WILL MOVE ACROSS THE
TERMINALS. THIS WILL INITIALLY INCREASE WESTERLY WINDS BETWEEN
14-15Z AND THEN THE BOUNDARY WILL MOVE THROUGH BETWEEN 16-17Z AT
ALL TERMINALS. IMMEDIATELY BEHIND THIS BOUNDARY, WIND GUSTS COULD
REACH 35 KNOTS OUT OF THE NORTHWEST. BY THE EARLY AFTERNOON,
WINDS MAY RELAX A BIT AND GUSTS SHOULD STAY BELOW 30 KNOTS. BY THE
LATE AFTERNOON, WINDS WILL START TO VEER TO THE NORTHEAST AND
THEN EAST BY AROUND SUNSET.
FIRE WEATHER
ISSUED AT 145 PM MDT WED OCT 23 2024
THERE WILL BE A CONSIDERABLE AMOUNT OF WIND ON THURSDAY WITH NEAR
CRITICAL FIRE CONDITIONS ACROSS THE PLAINS SOUTH OF I-76. FIRST,
DOWNSLOPE WINDS ASSOCIATED WITH A DRY TROUGH WILL OCCUR ACROSS THE
MOUNTAINS, EASTERN FOOTHILLS, AND ADJACENT PLAINS WHERE MOUNTAIN
WAVE ENHANCEMENT MAY RESULT IN GUSTS GREATER THAN 50 MPH. FURTHER
EAST, A COLD FRONT WILL SHIFT WINDS TO THE NORTH LATE MORNING AND
WE EXPECT GUSTS 20-40 MPH ALL AFTERNOON. RH SHOULD REMAIN ABOVE
20-25 PERCENT FOR MOST AREAS OTHER THAN SOUTHERN WASHINGTON,
ELBERT, AND LINCOLN COUNTIES WHERE RH MAY BE CLOSE TO 15%. EVEN
THOUGH RFW CONDITIONS ARE NOT EXPECTED TO BE MET, IT WOULD BE A
BAD IDEA TO BURN TOMORROW JUST ABOUT ANYWHERE.
BEYOND THURSDAY, WE REMAIN ON THE DRIER SIDE WITH A FEW BOUTS OF
STRONGER WINDS, MAINLY SUNDAY AND MONDAY. RELATIVE HUMIDITY VALUES
DROP INTO THE TEENS EACH AFTERNOON FROM THE FOOTHILLS EASTWARD
(SUNDAY AND MONDAY THAT IS) AND WITH STRONGER WINDS IN PLACE,
THESE ARE OUR TWO ELEVATED FIRE WEATHER DAYS AFTER THURSDAY.
BOU WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...DANIELSON
SHORT TERM...SCHLATTER
LONG TERM...HEAVENER
AVIATION...DANIELSON
FIRE WEATHER...SCHLATTER/HEAVENER
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page