686
FXUS65 KBOU 181926
AFDBOU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
126 PM MDT SUN OCT 18 2026
KEY MESSAGES
- WARM AND DRY CONDITIONS CONTINUING INTO THE UPCOMING WEEK.
- A FEW MOUNTAIN RAIN AND SNOW SHOWERS EARLY IN THE WEEK.
- A MORE ORGANIZED SYSTEM BY LATE WEEK OR NEXT WEEKEND, WITH
LIGHT RAIN/SNOW SHOWERS LIKELY ACROSS THE HIGH COUNTRY.
DISCUSSION /THROUGH SUNDAY/
ISSUED AT 126 PM MDT SUN OCT 18 2026
WATER VAPOR SATELLITE IMAGERY SHOWS TWO WEAK UPPER LEVEL TROUGHS
TO THE SOUTHWEST. THE FIRST TROUGH IS JUST SOUTH OF THE FOUR
CORNERS AND THE SECOND IS NEAR YUMA, ARIZONA. THE FIRST TROUGH
PASSES TO OUR SOUTH TONIGHT BRINGING HIGH CLOUDS. A FEW WEAK
SHOWERS WILL BE POSSIBLE ACROSS SOUTHWEST COLORADO, BUT NOTHING IS
EXPECTED IN OUR FORECAST AREA. TEMPERATURES WILL BE SLIGHTLY
COOLER MONDAY DUE TO INCREASED CLOUD COVER AND SLIGHT COOLING
BEHIND A VERY WEAK COLD FRONT THAT BACKED SOUTH ACROSS THE AREA
TODAY. THE CENTRAL MOUNTAINS COULD SEE ISOLATED RAIN AND SNOW
SHOWERS MONDAY AFTERNOON AND EVENING, OTHERWISE DRY CONDITIONS
WILL CONTINUE. TUESDAY WILL WARM A LITTLE, AND WE'LL SEE A
CONTINUED CHANCE FOR ISOLATED SHOWERS OVER THE CENTRAL MOUNTAINS
DURING THE AFTERNOON AND EVENING. AN UPPER LEVEL RIDGE FORMS OVER
THE REGION TUESDAY NIGHT AND WEDNESDAY AHEAD OF AN UPPER LEVEL LOW
ALONG THE WEST COAST. WE'LL SEE MILD TEMPERATURES WITH HIGHS IN
THE 70S OVER NORTHEAST COLORADO AND DRY CONDITIONS ACROSS THE
AREA.
THE UPPER LEVEL RIDGE SHIFTS EAST OF COLORADO WEDNESDAY NIGHT AS
THE UPPER LEVEL LOW ALONG THE WEST COAST MOVES INLAND OVER
CALIFORNIA. THIS WILL BRING A SOUTHWEST FLOW ALOFT TO COLORADO.
THE FLOW EXTENDS FAR ENOUGH SOUTH TO PICK UP SUBTROPICAL
MOISTURE. ON THURSDAY, THE UPPER LEVEL RIDGE WILL REMAIN OVER THE
MIDDLE PART OF THE COUNTRY. THIS WILL CAUSE THE UPPER LEVEL LOW
TO TRACK NORTHEAST ACROSS THE INTERMOUNTAIN WEST THURSDAY
AND FRIDAY. BY LATE FRIDAY THE UPPER LEVEL LOW (IN A MUCH WEAKER
STATE) IS EXPECTED TO BE NORTH TO NORTHWEST OF COLORADO, SOMEWHERE
OVER WYOMING AND/OR IDAHO. SOUTHWEST FLOW ALOFT AND MOISTURE WILL
INCREASE OVER WESTERN COLORADO UNDER THIS PATTERN ON THURSDAY.
WIDESPREAD RAIN AND MOUNTAIN SNOW ARE EXPECTED OVER THE SOUTHWEST
COLORADO MOUNTAINS. THE MOISTURE EMBEDDED IN THE SOUTHWEST FLOW
ALOFT IS WRUNG OUT OVER THE MOUNTAINS WITH ONLY SCATTERED SHOWERS
EXPECTED FOR THE NORTH CENTRAL MOUNTAINS AND DRY CONDITIONS EAST
OF THE MOUNTAINS THROUGH FRIDAY.
FOR NEXT WEEKEND, MODELS STILL VARY ON SOLUTIONS, BUT AGREE THERE
WON'T BE MUCH LEFT OF THE UPPER LEVEL LOW. THERE IS LOOSE
AGREEMENT THAT UNORGANIZED TROUGHINESS PASSES EASTWARD ACROSS THE
ROCKIES, BUT SOME MODELS EVEN WASH THIS TROUGHINESS OUT, LEAVING
ONLY WESTERLY FLOW ALOFT. TEMPERATURES LIKELY COOL CLOSER TO
NORMAL. REGARDING PRECIPITATION CHANCES, MODEL SPREAD RANGES FROM
DRY CONDITIONS TO A ROUND OF LIGHT RAIN AND MOUNTAIN SNOW
SHOWERS.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1129 AM MDT SUN OCT 18 2026
VFR TO PERSIST THROUGH THE TAF PERIOD WITH INCREASING HIGH CLOUDS.
WINDS ARE CURRENTLY LIGHT AND VARIABLE AND WILL SHIFT TO THE
NORTHEAST AROUND 19Z AND THEN TRANSITION TO THE EAST BY 20Z AT
SPEEDS AROUND 10 KNOTS. GIVEN THE INCREASE IN CLOUD COVER AND THE
SURFACE LOW OVER SOUTHERN COLORADO, DRAINAGE WINDS ARE NOT
EXPECTED TO DEVELOP TONIGHT. WINDS ARE EXPECTED TO BE LIGHT AND
VARIABLE TO LIGHT NORTHERLY TONIGHT AND MONDAY MORNING.
BOU WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...BM
AVIATION...BM
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