Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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000
FXUS65 KBOU 202109
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
309 PM MDT MON OCT 20 2014

.SHORT TERM...(THIS AFTERNOON THROUGH TUESDAY)
ISSUED AT 309 PM MDT MON OCT 20 2014

ANOTHER WARM DAY AS THE UPPER RIDGE JUST TO OUR EAST BRINGS IN
WARM SOUTH-SOUTHWESTERLY FLOW ALOFT. A DEEPENING SURFACE TROUGH ON
THE LEE OF THE ROCKIES IS INCREASING SOUTHERLY SURFACE WINDS WITH
GUSTS IN THE 20-30 MPH RANGE OVER THE EASTERN PLAINS. EXPECT THE
SOUTH WINDS TO CONTINUE ALTHOUGH AT WEAKER SPEEDS THROUGH THE
NIGHT. ISOLATED SHOWERS OVER THE HIGH COUNTRY WILL INCREASE
SLIGHTLY IN COVERAGE THIS AFTERNOON...AND WILL CONTINUE INTO THE
EARLY EVENING WITH A SLIGHT CHANCE OF A THUNDERSTORM OR TWO. SOME
OF THE HIGH RES MODELS DEPICT SOME OF THESE MOVING NORTHEAST ONTO
THE FOOTHILLS AND POSSIBLY OVER THE URBAN CORRIDOR. BELIEVE THE
AIRMASS DOWN BELOW IS TOO STABLE AND THE ONLY EFFECT MAY BE GUSTY
OUTFLOW. HIGHER DEWPOINTS SHOULD MOVE NORTH INTO THE AREA
OVERNIGHT TO BRING AREAS OF FOG OVER THE EASTERN PLAINS...MAINLY
OVER LINCOLN AND SOUTHERN WASHINGTON COUNTIES. THE WRF SIMULATED
FOG PRODUCT SHOWS THIS NICELY...SHOWING UP AFTER MIDNIGHT.

AN UPPER TROUGH OVER THE GREAT BASIN WILL MOVE TOWARD THE STATE
TUESDAY TO SPREAD SHOWERS OVER THE MOUNTAINS DURING THE MORNING
THEN OVER THE FOOTHILLS AND POSSIBLY OVER THE URBAN CORRIDOR BY
LATE AFTERNOON. WEAK CAPE AND UPWARD QG VERTICAL VELOCITIES MAY
ALLOW FOR A FEW THUNDERSTORMS DURING THE AFTERNOON. TEMPERATURES
OVER THE PLAINS WILL BE CLOSE OR SLIGHTLY WARMER THAN
TODAY...WHILE THE INCREASE CLOUD COVER AND AN APPROACHING COLD
FRONT WILL PRODUCE NEAR OR SLIGHTLY COOLER TEMPERATURES OVER THE
MOUNTAINS.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 309 PM MDT MON OCT 20 2014

THE UPPER LEVEL TROUGH WILL TRANSITION INTO SOUTHERN MONTANA BY
TUESDAY EVENING BRINGING ADDITIONAL MOISTURE INTO THE REGION. THIS
TRAILING MOISTURE WILL COMBINE WITH TROPICAL MOISTURE INFLUENCE
FROM THE SOUTH TO BRING SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS TUESDAY EVENING AND SHOWERS OVERNIGHT OVER MUCH OF
THE PLAINS AND FOOTHILLS. WITH THE COOLER AIR AND INCREASED
MOISTURE OVER THE MOUNTAINS...SNOWSHOWERS WILL FALL TO 9000FT
WHERE A FEW INCHES IN ACCUMULATION IS POSSIBLE OVER THE HIGH
COUNTRY.

A COLD FRONT WILL MOVE OVER NE COLORADO EARLY WEDNESDAY BRINGING
ANOTHER SHOT OF MOISTURE THAT WILL AID IN SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS FOR THE PLAINS AND FOOTHILLS WEDNESDAY
AFTERNOON. WITH INCREASED CAPE AND DECENT QG...CHANCES FOR
THUNDERSTORMS ARE BETTER ON WEDNESDAY BUT WILL STILL BE ISOLATED
IN NATURE. WITH COLD FRONTAL PASSAGE TEMPERATURES ON WEDNESDAY
WILL BE COOLER THAN THE PRECEDING FEW DAYS AND RETURN TO SEASONAL
NORMALS. THE SYSTEM WILL TRANSITION QUICKLY OUT OF THE REGION WITH
SUBSIDENCE AND WARMING BEHIND IT AS ANOTHER RIDGE MOVES IN FROM
THE WEST.

FOR THURSDAY THROUGH SUNDAY AN UPPER LEVEL RIDGE WILL BUILD BACK
IN WITH PREDOMINANT WNW FLOW. THIS FLOW COMBINED WITH A LEE SIDE
TROUGH SETUP WILL AID IN INCREASING TEMPERATURES INTO THE UPPER
70S AND LOWER 80S WHICH COULD BRING RECORD BREAKING TEMPERATURES FOR
BOTH FRIDAY AND SATURDAY.

FOR SUNDAY EVENING AND BEYOND...EXTENDED MODELS ARE BRINGING DOWN
AN UPPER LEVEL TROUGH THAT WILL JUST BE ENTERING THE NW REGION OF
THE STATE BY SUNDAY EVENING. THIS WILL BE THE NEXT OPPORTUNITY FOR
PRECIP AND COOLER TEMPERATURES.

&&

.AVIATION...(FOR THE TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 309 PM MDT MON OCT 20 2014

VFR CONDITIONS OVER THE NEXT 24 HRS. SSELY WINDS THIS
AFTN/EVNG WILL BACK TO SSWLY AFTER 06Z TONIGHT. CONTINUE TO SEE GUSTS
TO AROUND 20 KTS AT KDEN AND KAPA UNTIL 03Z ...WHERE KBJC WILL
BE LIGHTER. THERE IS A SLIGHT CHANCE OUTFLOW GUSTS FROM CONVECTIVE
ACTIVITY OVER THE MOUNTAINS COULD TURN WINDS AROUND TO THE WEST AS
SOME RECENT HIGH RES MODELS SHOW. NOT CONFIDENT THIS WILL HAPPEN
AT THIS POINT...SO WILL KEEP WINDS SLY IN THE TAFS. WINDS WILL
LIKELY STILL BE SLY TUESDAY...BUT LIGHTER SPEEDS. SYNTHETIC
SATELLITE HINTS AT SOME STRATUS/FOG DEVELOPMENT TOWARDS 12Z
TUESDAY MORNING...BUT WELL TO THE EAST AND SOUTHEAST OF KDEN.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...KRIEDERMAN
LONG TERM...BOWEN
AVIATION...KRIEDERMAN



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