739
FXUS65 KBOU 202340
AFDBOU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
540 PM MDT SUN OCT 20 2024
KEY MESSAGES
- LIGHT TO MODERATE SNOW WILL OCCUR IN THE MOUNTAINS TONIGHT AND
MONDAY MORNING WITH A FEW INCHES OF ACCUMULATION MAINLY ON THE
WESTERN SLOPE OF THE FRONT RANGE MOUNTAINS. RAIN SHOWERS WILL BE
POSSIBLE ACROSS THE FOOTHILLS AND I-25 CORRIDOR MONDAY MORNING.
- WINDY CONDITIONS WITH GUSTS UP TO 40 MPH POSSIBLE MONDAY
AFTERNOON ACROSS ALL OF OUR FORECAST AREA.
- DRY WITH ABOVE NORMAL TEMPERATURES TUESDAY THROUGH SUNDAY.
SHORT TERM /THROUGH MONDAY/
ISSUED AT 258 PM MDT SUN OCT 20 2024
SATELLITE SHOWS A STRONG CUT-OFF TROUGH DIRECTLY OVER THE FOUR
CORNERS THIS AFTERNOON. MOST OF OUR FORECAST AREA HAS BEEN UNDER
CLEAR SKIES AND MILD CONDITIONS TODAY. TEMPERATURES HAVE REACHED THE
LOW 70S WITH SOME BREEZY SOUTHERLY WINDS ESPECIALLY ACROSS THE
PALMER DIVIDE AND EAST-CENTRAL PLAINS.
TONIGHT, THE CUT-OFF TROUGH WILL MOVE OVER CENTRAL COLORADO AND THE
INSTABILITY WITHIN THIS TROUGH WILL HELP TO CREATE SCATTERED SHOWERS
AND WEAK THUNDERSTORMS ACROSS THE HIGHER TERRAIN. HIGH RESOLUTION
MODEL GUIDANCE INDICATES THAT THE COVERAGE OF THESE SHOWERS AND
STORMS MAY BE ON THE LOWER SIDE AND THERE IS SOME UNCERTAINTY WITH
SNOWFALL AMOUNTS ACROSS THE HIGHER TERRAIN TONIGHT. THERE MAY
ALSO BE A FEW RAIN SHOWERS OVER THE FAR EASTERN PLAINS MAINLY IN
LINCOLN AND WASHINGTON COUNTIES. THESE WON'T AMOUNT TO MUCH.
MONDAY MORNING, THE TROUGH WILL MOVE OVER THE NORTHEAST PLAINS OF
COLORADO AND THERE WILL BE INCREASING NORTHWEST FLOW OVER OUR ENTIRE
FORECAST AREA. A DEFORMATION ZONE OF THE NORTHWEST SIDE OF THE
TROUGH ALONG WITH UPSLOPE, NORTHWESTERLY FLOW WILL GENERATE MODERATE
SNOW OVER THE WESTERN SLOPE OF THE FRONT RANGE MOUNTAINS. SNOW LEVEL
WILL BE DOWN TO ABOUT 9,000 FEET AND SNOW WILL ACCUMULATE ABOVE THAT
ELEVATION. MOST OF THE AREA WILL SEE 1-4 INCHES BUT THE HIGHER
SLOPES ALONG THE CONTINENTAL DIVIDE MAY SEE UP TO 7 INCHES OF
SNOW. THIS COULD CREATE SOME ROAD IMPACTS ESPECIALLY ON BERTHOUD
PASS AND I-70 NEAR THE TUNNEL. BUT SINCE THE IMPACTS WILL REMAIN
LIMITED, NO HIGHLIGHTS WERE ISSUED.
THE BACK END OF THE TROUGH MAY BE UNSTABLE ENOUGH TO PRODUCE SOME
SHOWERS AND WEAK STORMS OVER THE FOOTHILLS AND I-25 CORRIDOR. THERE
IS SOME SKEPTICISM ABOUT THE AMOUNT OF RAIN THESE SHOWERS MAY
PRODUCE DUE TO THE DOWNSLOPE, NORTHWESTERLY WINDS. HOWEVER, THERE
ARE SOME ENSEMBLE MEMBERS THAT HAVE SOMEWHAT SIGNIFICANT RAINFALL
OVER THE I-25 CORRIDOR OF AROUND HALF AN INCH. THESE TYPES OF
STRONG TROUGHS WILL OFTEN PRODUCE MORE PRECIPITATION THAN EXPECTED
SO POPS WERE INCREASED. IF THERE WERE TO BE MORE RAINFALL OVER
THE I-25 CORRIDOR, IT WOULD NOT HAVE MUCH OF AN IMPACT AND PEOPLE
WOULD LIKELY WELCOME IT.
THE TROUGH WILL DEPART THE AREA IN THE AFTERNOON WITH SKIES
CLEARING. THE MAIN IMPACT DURING THE AFTERNOON WILL BE GUSTY WINDS
THAT COULD REACH 40 MPH ACROSS MOST OF OUR FORECAST AREA. OTHERWISE,
HIGHS WILL BE A FEW DEGREES ABOVE NORMAL.
LONG TERM /MONDAY NIGHT THROUGH SUNDAY/
ISSUED AT 258 PM MDT SUN OCT 20 2024
THE WEATHER LOOKS TO BE WARM AND DRY THIS ENTIRE UPCOMING WEEK
AND ON INTO NEXT WEEKEND TOO.
UPPER RIDGING MOVES INTO THE CWA STARTING MONDAY EVENING AND IT IS
PROGGED OVER THE CWA THROUGH WEDNESDAY EVENING. THERE IS LIGHT TO
MODERATE WEST-NORTHWESTERLY FLOW ALOFT ALL FIVE PERIODS. A WEAK
UPPER TROUGH IS PROGGED TO JUST GET INTO WESTERN COLORADO BY 12Z
THURSDAY MORNING. THE QG OMEGA FIELDS HAVE SOME DOWNWARD VERTICAL
VELOCITY OVER THE CWA, MAINLY MONDAY EVENING, THEN BENIGN SYNOPTIC
SCALE ENERGY IS PROGGED THROUGH WEDNESDAY NIGHT. IN THE LOW
LEVELS, THERE IS SOME NORTHWESTERLY DOWNSLOPING WIND PROGGED
MONDAY NIGHT BUT AFTER THAT NORMAL DIURNAL WIND PATTERNS ARE
EXPECTED.
THE CROSS SECTIONS AND PRECIPITABLE WATER FIELDS ARE SHOWING VERY
LITTLE MOISTURE FOR THE FORECAST AREA MONDAY NIGHT THROUGH
WEDNESDAY NIGHT. THERE IS NO CAPE PROGGED FOR THE CWA THROUGH
WEDNESDAY NIGHT. THERE IS NO MEASURABLE PRECIPITATION ON THE QPF
FIELDS THROUGH WEDNESDAY NIGHT. NO POPS. FOR TEMPERATURES, TUESDAY'S
HIGHS LOOK TO BE 2-5 C WARMER THAN MONDAY'S HIGHS, WITH
WEDNESDAY'S READINGS A TAD COOLER THAN TUESDAY'S. READINGS WILL
BE IN THE MID 70S ACROSS THE PLAINS TUESDAY FOR HIGHS, THEN COOL
DOWN INTO THE UPPER 60S TO LOWER 70S ON WEDNESDAY.
FOR THE LATER DAYS, THURSDAY THROUGH SUNDAY, THERE IS A WEAK
LITTLE UPPER TROUGH TO MOVE EASTWARD ACROSS NORTHERN COLORADO
THURSDAY. FLAT UPPER RIDGING IS PROGGED FRIDAY THROUGH NEXT
SUNDAY WITH WEAK TO MODERATE ZONAL TO NORTHWESTERLY FLOW ALOFT.
CROSS SECTIONS SHOW SOME UPPER LEVEL MOISTURE FOR THE CWA, MAINLY
FRIDAY AND FRIDAY NIGHT OTHERWISE IT IS QUITE DRY. NO POPS. ABOVE
NORMAL TEMPERATURES WILL CONTINUE ACCORDING TO THE THICKNESS
FIELDS WITH THURSDAY AND FRIDAY TO BE A BIT WARMER THAN SATURDAY
AND SUNDAY.
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
ISSUED AT 540 PM MDT SUN OCT 20 2024
UPPER LEVEL LOW OVER THE FOUR CORNERS TO BRING GUSTY SOUTH WINDS
THROUGH 06Z. SOUTH WINDS TO CONTINUE OVERNIGHT AND EARLY MONDAY
MORNING. AS THE LOW MOVES OVERHEAD, SCATTERED SHOWERS WILL BE
POSSIBLE, IN THE 13-16Z TIME FRAME. GUSTY WEST OUTFLOW WINDS WILL
ALSO BE POSSIBLE DURING THE TIME. CEILINGS COULD FALL AS LOW AS
5000-6000 FEET. HOWEVER, DOWNSLOPE FLOW SHOULD LIMIT HOW FAR EAST
THE SHOWER ACTIVITY TRAVELS. AFTER 16Z, THE LOW PULLS AWAY FROM
THE AREA BRING DRIER WEST TO NORTHWEST WINDS. STRONGEST WINDS ARE
EXPECTED AFTER 20Z WITH WEST-NORTHWEST GUSTS AROUND 30 KNOTS.
BOU WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...DANIELSON
LONG TERM....RJK
AVIATION...MEIER
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page