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000
FXUS65 KBOU 180300
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
900 PM MDT THU APR 17 2014

.UPDATE...
ISSUED AT 840 PM MDT THU APR 17 2014

THERE IS A BIT OF LEE WAVE CLOUDINESS OVER THE DIVIDE MOUNTAINS AND
FOOTHILLS THIS EVENING. THERE IS LITTLE TO CHANCE.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 312 PM MDT THU APR 17 2014

UPPER RIDGE BUILDING INTO COLORADO FROM THE GREAT BASIN.
NORTHWEST FLOW STILL OVER REGION WITH UPPER TROUGH ACROSS NORTHERN
AND CENTRAL PLAIN STATES. SOUTHERLY SURFACE WINDS A BIT GUSTY FAR
EASTERN PLAINS. AIRMASS GENERALLY DRY AND STABLE BUT ENOUGH LOW
LEVEL MOISTURE FOR SOME CUMULUS TO FORM IN A CONVERGENCE AREA
SOUTHEAST OF DENVER. RIDGE WILL CONTINUE TO BUILD INTO COLORADO
TONIGHT WITH AXIS ALONG WESTERN COLORADO BORDER. WINDS TO DECREASE
ACROSS PLAINS AS SOUTHERLY GRADIENT WEAKENS. SOME INCREASE IN HIGH
LEVEL MOISTURE OVERNIGHT. WARM AIR ADVECTION OCCURS
TONIGHT...SHOULD KEEP TEMPERATURES ABOVE FREEZING MOST LOCATIONS
ACROSS THE PLAINS. ON FRIDAY...UPPER RIDGE TO BE OVER COLORADO
WITH A WARMER AIRMASS IN PLACE. SURFACE LEE TROUGH FORMS ALONG THE
FOOTHILLS DURING THE AFTERNOON. THE SOUTHERLY SURFACE WINDS WILL
HELP WITH WARMUP...WITH HIGHS IN THE 70S ACROSS THE PLAINS. IT
SHOULD BE RATHER BALMY IN THE HIGH COUNTRY DESPITE PERSISTENT SNOW
PACK...WITH HIGHS POSSIBLY GETTING INTO THE 50S. MODEL CROSS
SECTIONS INDICATE SOME MOISTURE SPREADING INTO THE MOUNTAINS LATE
AFTERNOON. THERE APPEARS TO BE ENOUGH LIFT AND WEAK INSTABILITY TO
GENERATE A FEW HIGH BASED SHOWERS ACROSS THE PARK AND GORE RANGES
OF WESTERN JACKSON COUNTY AND SOUTH PARK. THE STABILITY LOOKS
LIMITED SO WILL NOT MENTION THUNDER.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 312 PM MDT THU APR 17 2014

FRIDAY EVENING WILL SEE AN INCREASE IN MID AND UPPER LEVEL
MOISTURE...BUT CROSS SECTIONS SHOW IT ALL ABOVE 600 MB AND MID
LEVEL INSTABILITY IS MINIMAL. THEREFORE...ANY CHANCE OF SHOWERS
FOR THAT TIME WILL LIKELY BE CONFINED TO THE MOUNTAINS.

BY SATURDAY AFTERNOON...UPPER LEVEL SUPPORT...MOISTURE...AND
INSTABILITY WILL BE INCREASING AS UPPER TROUGH SWINGS ACROSS THE
DESERT SOUTHWEST. THIS WILL RESULT IN A BETTER CHANCE OF
SHOWERS...AS WELL AS A FEW THUNDERSTORMS WITH INCREASED
INSTABILITY AND CAPES OF 100-500 J/KG. HIGHEST COVERAGE SHOULD
OCCUR IN MOUNTAINS...FOOTHILLS...AND NEAR THE HIGHER TERRAIN WHERE
INSTABILITY IS MAXIMIZED. CONVECTION WILL GRADUALLY DECREASE
SATURDAY EVENING WITH THE PASSAGE OF UPPER LEVEL TROUGH. BY
SUNDAY...MOISTURE DECREASES A LITTLE BUT SURFACE HEATING AND
INSTABILITY WILL ALLOW A FEW MORE SHOWERS AND STORMS TO DEVELOP
IN/NEAR THE HIGHER TERRAIN OF THE FRONT RANGE SUNDAY AFTERNOON AND
EVENING.

ON MONDAY...UPPER LEVEL RIDGE WILL BUILD ACROSS THE CENTRAL
ROCKIES. THIS WILL BRING WARMER TEMPERATURES...ABOUT 10 DEGREES
ABOVE NORMAL...TO MOST AREAS. UNCERTAIN HOW MUCH MOISTURE AND
INSTABILITY IS AVAILABLE BUT LONGER DAYS AND STRONGER HEATING DOES
SUPPORT A LOW THREAT OF AFTERNOON SHOWERS/STORMS. THE AIRMASS
SHOULD DRY ENOUGH BY TUESDAY WITH STRONGER SOUTHWEST FLOW ALOFT
FOR MAINLY DRY WEATHER...AND TEMPS WILL CONTINUE TO WARM. A FEW
SPOTS ON THE PLAINS COULD REACH 80F FOR HIGHS. FIRE DANGER WILL
INCREASE BUT THERE WILL BE ADDITIONAL GREENUP OF GRASSES THROUGH
THAT TIME.

FOR WEDNESDAY AND THURSDAY...AN UPPER LEVEL TROUGH WILL MOVE
ACROSS THE NORTHERN ROCKIES. ANOTHER HIGHER FIRE DANGER DAY COULD
OCCUR WEDNESDAY WITH STRONGER WEST WINDS AND LOW HUMIDITIES IN
ADVANCE OF TROUGH...BUT THEN COOLER WEATHER IS EXPECTED BY
THURSDAY. COLD ADVECTION ALOFT WILL ALSO LIKELY BRING SNOW SHOWERS
TO THE MOUNTAINS WITH SOME ACCUMULATION POSSIBLE DEPENDING ON
AMOUNT OF AVAILABLE MOISTURE AND TRACK OF UPPER TROUGH.

&&

.AVIATION...(FOR THE TAFS THROUGH 06Z FRIDAY EVENING)
ISSUED AT 840 PM MDT THU APR 17 2014

DRAINAGE WINDS ARE ALREADY GOING. THEY MAY BE A BIT STRONGER THAN
THE NORM DUE TO LOW LEVEL TROUGHING DEVELOPING EAST OF THE
MOUNTAINS OVERNIGHT. THERE SHOULD BE NO CEILING ISSUES.

&&

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

$$

UPDATE...RJK
SHORT TERM...D-L
LONG TERM...BARJENBRUCH
AVIATION...RJK