720
FXUS65 KBOU 151950
AFDBOU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
150 PM MDT MON SEP 15 2025
KEY MESSAGES
- A SLIGHT CHANCE OF A WEAK AFTERNOON SHOWER OR THUNDERSTORM
THROUGH THIS EVENING.
- MORE UNSETTLED AND COOLER TUESDAY THROUGH THURSDAY, WITH
SCATTERED TO WIDESPREAD SHOWERS AND THUNDERSTORMS EXPECTED.
DISCUSSION /THROUGH MONDAY/
ISSUED AT 150 PM MDT MON SEP 15 2025
WATER VAPOR SATELLITE IMAGERY SHOWING A LARGE UPPER LEVEL TROUGH
OVER THE NORTHWEST PART OF THE COUNTRY WITH DRIER AIR AND WEAK
RIDGING OVER COLORADO. OTHER THAN A COUPLE HIGH BASED SHOWERS, DRY
CONDITIONS ARE EXPECTED THROUGH TONIGHT. SATELLITE IMAGERY IS
ALSO SHOWING A STRONG SHORTWAVE TROUGH SPINNING NEAR THE
IDAHO/WYOMING BORDER WITHIN THE LARGE UPPER LEVEL TROUGH. THERE IS
ALSO A SECOND WEAKER SHORTWAVE TROUGH NEAR THE WASHINGTON/OREGON
BORDER. THIS SECOND ONE WILL TRACK SOUTHEAST BRINGING SCATTERED
SHOWERS AND THUNDERSTORMS TUESDAY AFTERNOON AND EVENING. A WEAK
COLD ASSOCIATED WITH THIS SYSTEM WILL BRING COOLER TEMPERATURES
TUESDAY. THE COLD FRONT STALLS OVER FAR EASTERN COLORADO TUESDAY.
ALONG AND EAST OF THIS CAPE REACHES 2000 J/KG, WHICH MAY LEAD TO A
FEW STRONG TO SEVERE THUNDERSTORMS. ON WEDNESDAY, THIS TROUGH
CLOSES OFF SOMEWHERE OVER NORTHEAST COLORADO TO WESTERN NEBRASKA
AND BECOMES PART OF THE LARGER UPPER LEVEL TROUGH OVER THE CENTRAL
PART OF THE COUNTRY. FOR WEDNESDAY, TEMPERATURES COOL MORE WITH
SHOWERS LIKELY. SBCAPE IS REACHES UP TO 500 J/KG, SO WE SHOULD SEE
ISOLATED TO SCATTERED STORMS DURING THE AFTERNOON AND EARLY
EVENING.
COME THURSDAY WE WILL SEE A BROAD UPPER LEVEL LOW OVER THE
NORTHERN AND CENTRAL PLAINS AND RIDGING TO THE WEST. ACROSS
COLORADO, A NORTH TO NORTHWEST FLOW ALOFT WILL PREVAIL. COOL
TEMPERATURES WILL PERSIST AGAIN WITH HIGHS IN THE 60S ACROSS
NORTHEAST COLORADO. SCATTERED SHOWERS WILL BE POSSIBLE THURSDAY,
BUT RAINFALL AMOUNTS SHOULD BE LIGHT.
THE RIDGING OFF TO THE WEST SLIDES EASTWARD FRIDAY AND SHOULD BE
CENTERED OVER COLORADO LATE IN THE DAY. EXPECT DRY CONDITIONS TO
RETURN TO THE AREA WITH TEMPERATURES WARMING INTO THE 70S OVER
NORTHEAST COLORADO.
FOR THE WEEKEND MODELS TREND TOWARDS A ZONAL FLOW, BUT DIFFER ON
THE PLACEMENT ON THE SHORTWAVE TROUGHS AND RIDGES. CHANCES FOR
PRECIPITATION LOOK LOW UNDER THIS PATTERN, SO WILL KEEP THE
FORECAST MOSTLY DRY. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE
NORMAL WITH HIGHS IN THE UPPER 70S TO MID 80S OVER NORTHEAST
COLORADO. FOR EARLY NEXT WEEK, MODELS INDICATE RIDGING BUILDS OVER
THE SOUTHWEST PART OF THE COUNTRY AND COULD EXTEND EASTWARD INTO
THE ROCKIES. EXPECT DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES
UNDER THIS PATTERN.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1126 AM MDT MON SEP 15 2025
LIGHT WINDS TO PREVAIL TODAY WITH A GENERAL SOUTH TO SOUTHEAST
DIRECTION. VFR TO PREVAIL THROUGH TONIGHT AND TUESDAY. CAN'T RULE
OUT A WEAK SHOWER 21-01Z THAT PRODUCES A WIND SHIFT, BUT CHANCES
FOR THIS ARE LOW (10-15)%. A RETURN TO A SOUTHERLY DRAINAGE
DIRECTION WILL OCCUR THIS EVENING. THERE MAY BE A BRIEF TURN TO
THE NORTH OVERNIGHT AS A WEAK FRONT MOVES THROUGH. WE WILL SEE A
STEADY NORTH TO NORTHEAST COME LATE TUESDAY MORNING. THE CHANCE
FOR SHOWERS AND THUNDERSTORMS RETURNS AFTER 22Z TUESDAY.
BOU WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...MEIER
AVIATION...MEIER
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page