Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 210925
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
325 AM MDT TUE OCT 21 2014

.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 325 AM MDT TUE OCT 21 2014

UPPER LEVEL TROUGH IS CURRENTLY OVER NORTHWEST NEVADA AND WILL LIFT
INTO MONTANA BY THIS EVENING. THIS WILL TAKE THE MAJORITY OF LIFT
AND MOISTURE WITH IT. EXPECT WEAK LIFT TO MOVE ACROSS COLORADO THIS
AFTERNOON AND TONIGHT...MAINLY FROM QG ASCENT AND A PACIFIC COLD
FRONT. AIRMASS WILL ALSO BE SLIGHTLY UNSTABLE WITH CAPES MAINLY
UNDER 300 J/KG. ALSO...LAPSE RATES WILL BE STEEPER THAN 7 J/KG FROM
THE SURFACE TO 400MB. NOTHING GREAT BUT ENOUGH FOR SCATTERED SHOWERS
AND PERHAPS A FEW WEAK THUNDERSTORMS.

PACIFIC MOISTURE WILL INCREASE THIS AFTERNOON OVER THE MOUNTAINS.
THIS COMBINED WITH THE LIFT AND INSTABILITY SHOULD PRODUCE SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON. MEANWHILE FOR THE
FRONT RANGE AND EASTERN PLAINS...IT WILL BE MOSTLY SUNNY AND WARM
THROUGH MID AFTERNOON WITH HIGHS IN THE 70S. THE CLOUDS AND
CONVECTION WILL SPREAD EAST ONTO THE FRONT RANGE LATE THIS AFTERNOON
AND THIS EVENING. MOISTURE AND LIFT IS LIMITED WITH THIS SYSTEM SO
WILL KEEP POPS GENERALLY SCATTERED OR LESS ACROSS EASTERN COLORADO.
THE MOUNTAINS WILL HAVE THE BEST CHANCE AT RECEIVING PRECIPITATION
WITH POPS IN THE 40 TO 70 PERCENT RANGE. THIS SYSTEM WILL CONTINUE
TO MOVE EASTWARD TONIGHT. THE BEST CHANCE FOR RAIN OVER THE
NORTHEAST CORNER WILL OCCUR AFTER MIDNIGHT. DUE TO CLOUDY SKIES
TONIGHT...EXPECT MILD OVERNIGHT LOWS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 325 AM MDT TUE OCT 21 2014

A WK UPPER LEVEL TROUGH WILL MOVE EAST OF THE AREA ON WED WITH WLY
FLOW ALOFT.  THERE IS SOME WK MID LVL QG ASCENT IN THE MORNING OVER
THE PLAINS WHICH MAY PRODUCE A CHC OF SHOWERS.  IN THE MTNS WK
OROGRAPHICS COMBINED WITH SOME LINGERING MOISTURE WILL LEAD TO A CHC
OF SHOWERS AS WELL THRU THE AFTN HOURS.  BY AFTN THERE MAY BE ENOUGH
INSTABILITY OVER NERN CO FOR A SLIGHT CHC OF SHOWERS/TSTMS.  AS FOR
HIGHS WILL KEEP READINGS IN THE UPPER 60S TO NEAR 70 OVER THE PLAINS.

BY THU AN UPPER LEVEL RIDGE WILL BEGIN TO BUILD ACROSS THE SRN
ROCKIES AND THEN EXPAND NORTHWARD INTO THE AREA ON FRI.  THIS WILL
LEAD TO A DRY WX PTRN WITH A WARMING TREND.  HIGHS ON THU WILL RISE
INTO THE MID TO UPPER 70S OVER NERN CO WITH UPPER 70S TO LOWER 80S
POSSIBLE ON FRI.

ON SAT THE UPPER LEVEL RIDGE WILL SHIFT A BIT FURTHER EAST WITH
INCREASING SWLY FLOW ALOFT.  THIS WILL LEAD TO ANOTHER DRY DAY WITH
ABV NORMAL TEMPS CONTINUING AS READINGS ONCE AGAIN RISE INTO THE
UPPER 70S TO LOWER 80S ACROSS NERN CO.  FOR SUN INTO SUN NIGHT BOTH
THE ECMWF AND GFS SHOW AN UPPER LEVEL TROUGH MAY AFFECT THE AREA.
THE ECMWF IS STRONGER WITH THIS FEATURE VS THE GFS.  FOR NOW WILL
MENTION A CHC OF PCPN IN THE MTNS WITH A SLIGHT CHC OVER THE REST OF
THE AREA WITH THE MAIN FOCUS LATE SUN AFTN THRU SUN NIGHT.  A WEAK
FNT MAY MOVE INTO NERN CO ON SUN WHICH MAY DROP TEMPS BACK INTO THE
UPPER 60S TO LOWER 70S.

FOR MON THE ECMWF STILL HAS THE UPPER LEVEL TROUGH AFFECTING THE
AREA WHILE THE GFS MOVES IT EAST OF THE AREA.  FOR NOW WILL JUST
MENTION SOME LOW POPS.  MEANWHILE BOTH MODELS DO SHOW ANOTHER SHOT
OF COOLER AIR WHICH WOULD DROP HIGHS BACK TO OR SLIGHTLY BLO NORMAL
OVER NERN CO.

&&

.AVIATION...(FOR THE TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 325 AM MDT TUE OCT 21 2014

SOUTHERLY WIND WITH GUSTS TO 25 KNOTS AT KDEN WILL DECREASE AFTER
12Z...BUT REMAIN SOUTHERLY. BY 18Z WINDS...MAY TURN SOUTHEASTERLY.
MOSTLY SUNNY SKIES WILL PREVAIL THROUGH 21Z. CLOUDS WILL THEN
INCREASE AS A PACIFIC SYSTEM MOVES INTO COLORADO. THIS SYSTEM WILL
BRING MOSTLY CLOUDY SKIES AND SCATTERED SHOWERS AFTER 22Z AND INTO
TUESDAY. NOT MUCH LOW LEVEL MOISTURE WITH THIS SYSTEM...SO EXPECT
CEILINGS TO REMAIN ABOVE 6000 FEET THROUGH TONIGHT. A COLD FRONT
WILL PUSH ACROSS THE DENVER AREA AROUND 00Z...CAUSING WINDS TO TURN
WEST TO NORTHWESTERLY.

&&

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

$$

SHORT TERM...MEIER
LONG TERM...RPK
AVIATION...MEIER



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