974
FXUS65 KBOU 242037
AFDBOU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
237 PM MDT THU OCT 24 2024
KEY MESSAGES
- CRITICAL FIRE WEATHER FOOTHILLS AND PLAINS; INCREASING HUMIDITY
WITH DECREASING WINDS BY EVENING.
- WIDESPREAD FROST WILL OCCUR LATE TONIGHT THROUGH MID MORNING ON
FRIDAY ACROSS MOST OF THE PLAINS AND PALMER DIVIDE.
- A LITTLE COOLER THROUGH FRIDAY, BUT WELL ABOVE NORMAL
TEMPERATURES RETURN FOR THE WEEKEND. NEAR RECORD WARMTH EXPECTED
SUNDAY AND MONDAY.
- PATTERN CHANGE IS STILL ON TRACK 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.
SHORT TERM /THROUGH FRIDAY/
ISSUED AT 237 PM MDT THU OCT 24 2024
COLD FRONT HAS PUSHED ACROSS NORTHEASTERN COLORADO. THERE WAS A
BAND OF DUST RIGHT BEHIND THE FRONT, BUT THERE'S MUCH LESS FURTHER
BACK. SO FAR THE WINDS ARE HANGING ON PRETTY WELL, WITH GUSTS IN
THE 40-50 MPH RANGE ACROSS MOST OF THE PLAINS. WE ARE STARTING TO
SEE SOME DECREASE IN SOUTHEAST WYOMING NOW, SO THE IDEA OF A
DECREASE AND TURNING TO NORTHEAST CLOSE TO THE MOUNTAINS DURING
THE LATE AFTERNOON STILL LOOKS GOOD.
WE ONLY MADE MINOR CHANGES TO TONIGHT'S LOW TEMPERATURES. THERE
WILL STILL BE A LITTLE WIND IN PLACES THAT NORMALLY HAVE IT
(RIDGES, DRAINAGE AREAS) BUT LOW LYING AREAS WILL WIND UP CLEAR
AND CALM LATER TONIGHT WITH DRYING AIR. WE NUDGED TEMPERATURES A
LITTLE COOLER AROUND THE EDGES OF OUR FROST ADVISORY, AROUND DIA
AND LONGMONT. THOSE AREAS SHOULD STAY ABOVE FREEZING BUT MIGHT
HAVE FROST DEPENDING ON WHETHER THEY KEEP A LITTLE WIND. FURTHER
WEST FOR DENVER AND ITS SUBURBS AND THE CITY OF BOULDER IT SHOULD
BE SEVERAL DEGREES WARMER.
FRIDAY WILL BE A QUIET DAY WITH SOUTHERLY WINDS DEVELOPING ON THE
PLAINS HELPING TEMPERATURES RECOVER AFTER A COOL START. WITH FULL
SUN, DRY AIR, AND THE BREEZE WE NUDGED FRIDAY'S HIGH TEMPERATURES
UP JUST A DEGREE OR TWO.
LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/
ISSUED AT 237 PM MDT THU OCT 24 2024
A LARGE, FLAT RIDGE BUILDS ACROSS THE CENTRAL AND SOUTHERN
ROCKIES AND THROUGH SUNDAY. WEST/SOUTHWEST FLOW ALOFT DEVELOPS
ACROSS THE FORECAST AREA WITH PERSISTENT WARM ADVECTION. THIS,
COMBINED WITH AN INCREASED WESTERLY FLOW ALOFT, WILL SUPPORT
TEMPERATURES WARMING TO THE 80 DEGREE MARK ACROSS MOST OF THE
PLAINS AND I-25 CORRIDOR. WITH SUFFICIENT DOWNSLOPE, WE THINK THE
POTENTIAL OF RECORD/NEAR RECORD TEMPERATURES ARE INCREASING
SLIGHTLY FOR SUNDAY AND MONDAY. RECORD HIGHS ARE 83F AND 82F IN
DENVER, RESPECTIVELY FOR THOSE DAYS. WHETHER WE HIT RECORDS OR
NOT, HIGH TEMPERATURES WILL BE UNSEASONABLY WARM. IN ADDITION,
HUMIDITIES WILL BE LOW AND WINDS ARE EXPECTED TO BE MARGINAL
SUNDAY, BUT INCREASE MONDAY WHEN THERE IS HIGHER CONFIDENCE OF
CRITICAL FIRE WEATHER CONDITIONS DEVELOPING.
ATTENTION THEN TURNS TO NEXT TUESDAY AND WEDNESDAY, WITH A FAIRLY
SIGNIFICANT PATTERN CHANGE IS EXPECTED. GUIDANCE REMAINS REASONABLY
CONSISTENT IN PUSHING A STRONG TROUGH THROUGH THE REGION TUESDAY
INTO WEDNESDAY, WHICH WILL ALMOST CERTAINLY BRING MUCH COOLER
TEMPERATURES. IT WAS INTERESTING TO NOTE THERE WAS STILL A LARGE
SPREAD IN HIGH TEMPERATURES TUESDAY DUE TO THE TIMING OF THE
FRONT AND TROUGH, BUT BETTER AGREEMENT BY WEDNESDAY WITH 25TH-75TH
PERCENTILES SHOWING HIGHS WELL BELOW NORMAL (IN THE MID TO UPPER 40S
FOR THE PLAINS AND I-25 CORRIDOR! IT DOES APPEAR FROM DETERMINISTIC
FORECASTS THAT COLDER RUNS WOULD SHOW A POTENTIAL FOR SNOW BY
LATE TUESDAY NIGHT AND WEDNESDAY DOWN ONTO THE I-25 CORRIDOR AND
PLAINS. WHAT'S MORE UNCERTAIN IS HOW THE WEATHER PATTERNS EVOLVE
AND WHETHER OR NOT THE COLD AIR CAN LINK UP WITH THE
PRECIPITATION. SPEAKING OF PRECIPITATION, SO FAR THE ENSEMBLES ARE
IN STRONG AGREEMENT THAT THE MAIN FORCING WITH THE UPPER LEVEL
TROUGH WILL STAY TO OUR NORTH, AND THUS MUCH OF NORTHEAST COLORADO
SEES ONLY LIGHT PRECIPITATION AMOUNTS. THIS WAS WELL REPRESENTED
IN THE ENSEMBLE GUIDANCE SHOWING THE 25-75TH PERCENTILES ONLY IN
THE ZERO TO 0.4 INCH RANGE, AND ONLY A FEW OUTLIERS WITH AMOUNTS
GREATER THAN 0.5 INCH.
BY THURSDAY, THERE IS RATHER REMARKABLE AGREEMENT THAT THE FIRST
TROUGH PUSHES TO THE EAST AND WE'LL BE UNDER THE INFLUENCE OF A
FLAT RIDGE. THUS, MAINLY DRY CONDITIONS ARE EXPECTED TO REDEVELOP
WITH TEMPERATURES RETURNING CLOSER TO NORMAL FOR THE LAST DAY OF
OCTOBER. GIVEN OUR RECENT WARMTH, SOME MAY BE SURPRISED THAT OUR
NORMAL HIGHS BY THEN ARE ONLY IN THE UPPER 50S.
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/
ISSUED AT 425 AM MDT THU OCT 24 2024
WINDS WERE SSW EARLY THIS MORNING BUT SHOULD BECOME WSW BY 14Z.
BY 16Z, WINDS MAY HAVE A MORE WESTERLY COMPONENT WITH GUSTS
UP TO 30 MPH. A COLD FRONT WILL MOVE ACROSS BY 18Z WITH GUSTY
NNW WINDS BEHIND IT. GUSTS BETWEEN 18Z AND 22Z WILL BE AROUND
40 MPH WITH A 30% CHANCE OF A FEW HIGHER GUSTS FROM 45 TO 50 MPH
AT DIA. BY 22Z WINDS WILL BECOME MORE NNE AND SLOWLY DECREASE
THRU 00Z. AFTER 00Z WINDS WILL BE MORE EASTERLY WITH LIGHTER
SPEEDS AND TRANSITION TO SE BY 05Z.
VFR CONDITIONS ARE EXPECTED TODAY AND TONIGHT, HOWEVER CAN'T RULE
OUT SOME BLOWING DUST WITH VISIBILITY DOWN TO 6 MILES OR SO
BETWEEN 18Z AND 22Z AT DIA.
FIRE WEATHER
ISSUED AT 237 PM MDT THU OCT 24 2024
HUMIDITIES WILL BE RISING BEHIND A COLD FRONT THIS AFTERNOON, UP
TO AROUND 30 PERCENT BY LATE AFTERNOON. STRONG WINDS GUSTING INTO
THE 40-50 MPH RANGE WILL CONTINUE ACROSS MOST OF THE PLAINS
THROUGH MID AFTERNOON THEN DIMINISH.
BOU WATCHES/WARNINGS/ADVISORIES
RED FLAG WARNING UNTIL 6 PM MDT THIS EVENING FOR COZ215-216-
238>251.
FROST ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM MDT FRIDAY FOR
COZ038-041>051.
SHORT TERM...GIMMESTAD
LONG TERM...BARJENBRUCH
AVIATION...RPK
FIRE WEATHER...GIMMESTAD
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