725
FXUS65 KBOU 050420
AFDBOU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1020 PM MDT SUN OCT 4 2026
KEY MESSAGES
- DRY AND UNSEASONABLY WARM THROUGH AT LEAST SATURDAY, WITH
RECORD/NEAR RECORD WARMTH ON MONDAY.
- ISOLATED SHOWERS POSSIBLE (15-30% CHANCE) MOST AFTERNOONS FOR
THE HIGHER ELEVATIONS, HIGHEST TUE. PRECIPITATION, IF ANY, WILL
BE HIGHLY LOCALIZED.
DISCUSSION /THROUGH SUNDAY/
ISSUED AT 1019 PM MDT SUN OCT 4 2026
AN UPPER LEVEL HIGH OVER THE GREAT BASIN WILL WEAKEN A BIT ON
MON. ONCE AGAIN THERE IS SOME MID LEVEL MOISTURE EMBEDDED IN WEAK
NW FLOW ALOFT. AS A RESULT, CAN'T RULE OUT ISOLD HIGH BASED
SHOWERS OVER THE HIGH TERRAIN. MEANWHILE, WITH RISING 850-700 MB
TEMPS ALONG WITH DOWNSLOPE LOW LEVEL FLOW, HIGHS MAY TIE OR BREAK
RECORDS, AS READINGS REACH THE MID 80'S TO AROUND 90 OVER THE
PLAINS.
ON TUE, A WEAK DISTURBANCE WILL AFFECT THE AREA WITH SOME INCREASE
IN MID LEVEL MOISTURE. THUS MAY SEE A SLIGHTLY BETTER CHC OF HIGH
BASED SHOWERS/ISOLD TSTMS OVER THE HIGHER TERAIN IN THE AFTN. SOME
OF THIS ACTIVITY MAY AFFECT PORTIONS OF THE I-25 CORRIDOR BY LATE
AFTN OR EARLY EVENING. OVER THE REST OF NERN CO, IT WILL REMAIN DRY
WITH HIGHS REMAINING 10 TO 15 DEGREES ABOVE NORMAL.
BY WED, THE FLOW ALOFT WILL REMAIN WEAK WNW. THERE WILL STILL BE
SOME LINGERING MID LEVEL MOISTURE OVER THE HIGHER TERRAIN. OVERALL,
WILL KEEP IN A SLIGHT CHC OF HIGH BASED SHOWERS/ISOLD TSTMS. ONCE
AGAIN HIGHS WILL BE 10 TO 15 DEGREES ABOVE NORMAL.
FOR THU AND FRI, THE FLOW ALOFT WILL GRADUALLY BECOME MORE ZONAL BY
FRI. STILL EXPECT MAINLY DRY CONDITIONS BOTH DAYS. THE GFS TRIES
TO BACKDOOR A COOL FRONT INTO NERN CO ON FRI WHILE THE ECMWF HAS
DOWNSLOPE LOW LEVEL FLOW AS A SFC LEE TROUGH IS OVER NERN CO.
OVERALL, STILL BELIEVE HIGHS WILL REMAIN 10 TO 15 DEGREES ABOVE
NORMAL ACROSS THE PLAINS BOTH DAYS.
BY NEXT WEEKEND, THE FLOW ALOFT WILL INCREASE FROM THE WSW AS AN
UPPER LEVEL TROUGH DEVELOPS OVER THE PACIFIC NW ON SAT. SHOULD SEE
ANOTHER DAY OF WARM AND DRY CONDITIONS OVER THE AREA ON SAT.
MEANWHILE, BOTH THE ECMWF AND GFS KEEP THE UPPER LEVEL TROUGH TO THE
NW OF THE AREA THRU SUN. BOTH MODELS SHOW SOME SUBTROPICAL
MOISTURE EMBEDDED IN THE FLOW ALOFT WHICH MAY LEAD TO A SLIGHT CHC
OF SHOWERS OVER PORTIONS OF THE HIGHER TERRAIN BY AFTN. ACROSS
THE PLAINS, IT LOOKS DRY WITH ANOTHER DAY OF ABOVE NORMAL
TEMPERATURES.
FOR LATE SUN THROUGH MON, THERE ARE VARYING SOLUTIONS AS TO HOW FAST
OR SLOW THE UPPER LEVEL TROUGH WILL BE AS IT MOVES EASTWARD. THE GFS
IS FASTER WHILE THE ECMWF IS SLOWER BY AT LEAST 24 HOURS. NATURALLY,
DEPENDING ON THE TIMING AND HOW MUCH IT AMPLIFIES WILL HAVE A
SIGNIFICANT IMPACT ON WEATHER FOR NEXT MON AND TUE.
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
ISSUED AT 533 PM MDT SUN OCT 4 2026
VFR CONDITIONS ARE EXPECTED THROUGH THIS TAF PACKAGE. EASTERLY
WINDS ARE CURRENTLY MAKING THEIR WAY THROUGH DIA WITH SPEEDS
AROUND 12KTS. A BOUNDARY WITH STRONGER SOUTHERLY WINDS BEHIND IT
IS CURRENTLY MOVING NORTH/NORTHWEST TOWARDS KDEN AND KAPA. THIS
BOUNDARY IS EXPECTED TO MOVE INTO KAPA AROUND 01Z AND KDEN AROUND
01Z TO 02Z. WINDS BEHIND THIS BOUNDARY WILL BE 12 TO 15 KTS, WITH
OCCASIONAL GUSTS AROUND 20KTS. THESE BREEZIER WINDS WILL CONTINUE
THROUGH 05Z/06Z, BEFORE WINDS TURN MORE TO THE SOUTHWEST AND
BEGIN TO WEAKEN. OVERNIGHT, EXPECT DRAINAGE WINDS AROUND 7KTS TO
12KTS. TOMORROW MORNING WE'LL SEE A PERIOD OF LIGHT AND VARIABLE
WINDS AGAIN BEFORE THEY TURN MORE TO THE E/NE. AT KBJC, WINDS WILL
GENERALLY BE LIGHT WITH PERIODS OF VARIABLE WINDS THROUGH THE
NEXT 24 HOURS.
BOU WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...RPK
AVIATION...AP
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