Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 270921
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
321 AM MDT MON JUL 27 2015

.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 321 AM MDT MON JUL 27 2015

STRONG UPPER LEVEL RIDGE WILL REMAIN PARKED OVER THE SOUTHERN PLAINS
TODAY AND TONIGHT. AT THE SAME TIME...AN UPPER LEVEL LOW WILL MOVE
ACROSS THE NORTHERN ROCKIES. SOUTHWEST FLOW ALOFT WILL INCREASE AND
TURN MORE WESTERLY LATE TODAY AND TONIGHT AS THE TROUGH PASSES NORTH
OF COLORADO. A SHORT WAVE ROTATING AROUND THE MAIN LOW WILL TRAVEL
FROM NORTHERN NEVADA THIS MORNING TO NORTHERN WYOMING THIS EVENING.
LIFT FROM THIS WAVE COMBINED WITH A SOMEWHAT MOIST AND UNSTABLE
AIRMASS IS EXPECTED TO PRODUCE ISOLATED TO SCATTERED THUNDERSTORMS
TODAY. PRECIPITABLE WATER VALUES WILL RANGE FROM THREE-QUARTERS OF
AN INCH ALONG THE FRONT RANGE TO AN INCH OVER THE PLAINS THIS
AFTERNOON.

A SURFACE TROUGH/DRY LINE OVER THE EASTERN PLAINS WILL PUSH EAST OF
THE AREA THIS AFTERNOON. EAST OF THE TROUGH WHERE DEW POINTS WILL BE
IN THE 60S AND CAPES WILL CLIMB TO 1000-3000 J/KG. IF THIS TROUGH
SLOWS IT EASTWARD PROGRESSION...PARTS OF THE FAR NORTHEAST PLAINS
COULD SEE SEVERE STORMS. WOULD THINK CONVERGENCE ALONG THE TROUGH
WILL BE A FAVORABLE AREA FOR STORMS TO INITIATE. FOR MOST OF THE
FORECAST AREA WHICH WILL BE WEST OF THE TROUGH...CAPES WILL BE LESS
THAN 500 J/KG TODAY. BRIEF HEAVY RAIN AND STRONG OUTFLOW WINDS WILL
BE THE MAIN THREATS WITH THE THUNDERSTORMS.

HIGHS WILL BE A FEW DEGREES WARMER TODAY WITH MOST AREAS OVER
NORTHEAST COLORADO REACHING THE 90S. AS FLOW ALOFT INCREASES DURING
THE DAY...EXPECT BREEZY CONDITIONS OVER THE HIGH COUNTRY WITH GUSTS
TO 40 MPH POSSIBLE THIS AFTERNOON. AIRMASS WILL QUICKLY DRY LATE
THIS AFTERNOON AND EARLY EVENING FROM WEST TO EAST. SKIES WILL CLEAR
BY MIDNIGHT. A COLD FRONT WILL DROP SOUTH ACROSS THE STATE TONIGHT
AND BRING SLIGHTLY COOLER OVERNIGHT LOWS TONIGHT WITH MOST PLACES
DROPPING INTO THE 50S ACROSS NORTHEAST COLORADO.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 321 AM MDT MON JUL 27 2015

WSW FLOW ALOFT WILL BE OVER THE AREA ON TUE AS A COOL FNT AFFECTS
NERN CO.  THIS FNT WILL INITIALLY BRING IN DRIER AIR ACROSS THE
PLAINS WHICH WILL NEGATE TSTM DEVELOPMENT THRU THE AFTN HOURS.
OVER THE HIGHER TERRAIN THERE WILL BE SOME LIMITED MOISTURE SO
WILL MENTION ISOLD STORMS SOUTH OF I-70. AS FOR HIGHS READINGS
WILL DROP BACK INTO THE 85 TO 90 DEGREE RANGE OVER NERN CO.

BY TUE NIGHT LOW LVL MOISTURE WILL INCREASE OVER THE PALMER DIVIDE
AND SOUTHERN AREAS OF THE FRONT RANGE AS A SECOND SURGE OF COOLER
AIR MOVES ACROSS THE PLAINS.  THIS MAY LEAD TO A SLIGHT CHC OF
STORMS OVERNIGHT.  ON WED THE FLOW ALOFT WILL BE MORE WLY AS AN
UPPER LEVEL HIGH BUILDS FM TEXAS INTO THE SRN ROCKIES. APPEARS
SUBTROPICAL MOISTURE WILL STAY MAINLY OVER SRN CO HOWEVER ECMWF
DOES SHOW SOME OF THIS MOISTURE AFFECTING AREAS SOUTH OF I-70.
FOR NOW WILL KEEP IN LOW POPS OVER THE HIGHER TERRAIN AND ACROSS
THE PALMER DIVIDE. AS FOR HIGHS WILL KEEP READINGS IN THE 80S
ACROSS NERN CO.

FOR THU AND FRI THE UPPER LEVEL HIGH WILL BEGIN TO EXPAND FURTHER
WEST WITH THE FLOW ALOFT BECOMING MORE WNW.  THIS WOULD KEEP MAIN
AXIS OF SUBTROPICAL MOISTURE OVER SRN CO.  MEANWHILE AT THE SFC A
LEE TROUGH WILL BE OVER ERN CO WITH A WK CONVERGENCE ZN OVER
PORTIONS OF THE FAR NERN PLAINS WHERE DEEPER LOW LVL MOISTURE WILL
EXIST. OVERALL TSTM COVERAGE BOTH DAYS LOOKS TO RATHER ISOLD AN
CONFINED TO AREAS OVER THE HIGHER TERRAIN AND OVER THE FAR NERN
PLAINS. AS FOR HIGHS READINGS WILL RISE INTO THE UPPER 80S TO
LOWER 90S ON THU WITH LOWER TO MID 90S BY FRI OVER NERN CO.

BY THE WEEKEND THE FLOW ALOFT WILL REMAIN WNW WITH SOME POTENTIAL
INFLUX OF SUBTROPICAL MOISTURE AROUND THE PERIPHERY OF THE UPPER
LEVEL HIGH ESPECIALLY BY SUN. WILL KEEP TSTM COVERAGE IN THE
ISOLD CATEGORY FOR SAT WITH SLIGHTLY BETTER COVERAGE ON SUN. HIGHS
WILL REMAIN IN THE LOWER TO MID 90S BOTH DAYS ACROSS THE PLAINS.

&&

.AVIATION...(FOR THE TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 321 AM MDT MON JUL 27 2015

THERE WILL BE A SLIGHT CHANCE FOR LOW CLOUDS/FOG THIS
MORNING...THOUGH THE BETTER CHANCE WILL BE OVER THE EASTERN PLAINS.
WILL KEEP THE VCFG IN THE TAF FOR THE LOW CHANCE OF IT OCCURRING.
IF LOW CLOUDS OR FOG FORMS...EXPECT CEILINGS BELOW 1000 FEET.
VISIBILITY COULD FALL BELOW A MILE FOR A SHORT TIME. SCATTERED
THUNDERSTORMS ARE EXPECTED TO FORM AFTER 18Z. THEY WILL QUICKLY
MOVE EASTWARD ACROSS THE AREA AND EXIT THE DENVER AREA BY
00Z...IF NOT A LITTLE SOONER. STRONG OUTFLOW WINDS TO 40 KNOTS
WILL BE POSSIBLE WITH THE THUNDERSTORMS. DRIER WILL MOVE INTO THE
AREA BRINGING MOSTLY CLEAR SKIES BY 06Z.

&&

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

$$

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



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