872
FXUS65 KBOU 160534
AFDBOU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1134 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 /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1128 PM MDT MON SEP 15 2025
VFR CONDITIONS WILL PREVAIL FOR ALL TERMINALS THROUGH AT LEAST 06Z
WED. SOUTHERLY DRAINAGE FLOW THIS MORNING WILL BE INTERRUPTED
16-17Z WITH A FRONTAL PASSAGE, BRINGING A SHIFT TO N AND NE WINDS
AT 10-15 KTS THAT SHOULD PERSIST INTO EARLY AFTERNOON.
NEAR 21Z, +/- 1 HR, -SHRA AND -TSRA WILL DEVELOP OVER THE DENVER
METRO AND PUSH EAST. COVERAGE LOOKS MARGINALLY SUFFICIENT TO
SUPPORT TEMPO GROUP FOR THE TERMINALS, FAVORING 21-01Z. MORE
ISOLATED CONVECTIVE SHOWERS MAY LINGER BEYOND THAT THROUGH THE
LATE EVENING HOURS. GUSTY OUTFLOWS TO ~30 KTS WILL BE POSSIBLE IN
THE VICINITY OF ANY -TSRA.
WINDS SHOULD BECOME CONSIDERABLY LIGHTER OVERNIGHT, GENERALLY
RETAINING A NW COMPONENT BUT WITH SOME DIRECTIONAL VARIABILITY
LIKELY AT TIMES. IN COMBINATION WITH POST-FRONTAL MOISTURE, THIS
MAY PROMOTE ARRIVAL OF LOW STRATUS WITH BASES 010-015 BY EARLY WED
AM, PARTICULARLY FOR KBJC AND KDEN. VIS RESTRICTIONS ARE MORE
UNCERTAIN GIVEN ANTICIPATED BASES.
BOU WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...MEIER
AVIATION...RODRIGUEZ
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