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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS65 KBOU 150337
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
937 PM MDT TUE MAY 14 2013

.UPDATE...

&&

.SHORT TERM...
-- Changed Discussion --
SHOWERS SLOWLY DIMINISHING AS EXPECTED THIS EVENING.
THIS TREND SHOULD CONTINUE WITH ONLY SLIGHT DECREASE IN THE HIGHER
CLOUD COVER OVERNIGHT. CURRENT FORECAST IS LOOKING GOOD. STILL
SOME THREAT OF SLOW MOVING THUNDERSTORMS OVER THE FOOTHILLS
WEDNESDAY AFTERNOON...THOUGH CLOUD COVER AND LIMITED MOISTURE AND
INSTABILITY DIMINISH THE THREAT. IT ALSO LOOKS LIKE WINDS ALOFT
MAY BE INCREASING IN THE AFTERNOON...AND EARLY CONVECTION MAY
PRODUCE OUTFLOW BOUNDARIES TO MOVE THE SHOWERS AROUND. ON THE
PLAINS THE CLOUD COVER AND COOL LOW LEVELS SHOULD DELAY
CONVECTION UNTIL LATE IN THE DAY.
-- End Changed Discussion --

&&

.AVIATION...
-- Changed Discussion --
VFR CONDITIONS EXPECTED THROUGH WEDNESDAY. SCATTERED
SHOWERS AND THUNDERSTORMS ARE EXPECTED IN THE AFTERNOON AND
EVENING. THERE COULD BE LOCALIZED MVFR CEILINGS/VISIBILITIES BUT
THESE ARE EXPECTED TO BE LIMITED IN TIME AND AREAL COVERAGE. THERE
IS A BETTER CHANCE OF NEEDING INSTRUMENT APPROACHES TO KDEN DUE TO
CEILINGS OF 5-7 THOUSAND FEET AGL.
-- End Changed Discussion --

&&

.PREV DISCUSSION... 
-- Changed Discussion --
/ISSUED 328 PM MDT TUE MAY 14 2013/

SHORT TERM...WEAK FLOW ALOFT WILL CONTINUE OVERNIGHT. LOW LEVEL
MOISTURE WILL GRADUALLY INCREASE FROM THE EAST FOLLOWING THE
PASSAGE OF A COOL FRONT. FOR TONIGHT...WILL CONTINUE WITH SLGT CHC
OF TSTMS THROUGH THE EVENING. THE STORMS WILL BE FAIRLY BASED SO
GUSTY WINDS TO 50 MPH AND LIGHTNING THE MAIN THREAT...RAINFALL
WILL GENERALLY BE AOB ONE TENTH OF AN INCH. ON WEDNESDAY...
PRECIPITABLE WATERS WILL BE BETTER VS TODAY WITH VALUES AROUND
0.75 INCHES. STORM MOTIONS WILL AGAIN BE LESS THAN 10 KTS. A WEAK
SHORT WAVE TROUGH WILL BE OVER CENTRAL UT IN THE AFTERNOON AND IS
PROGGED TO CONTINUE TO SHIFT SLOWLY EASTWARD. TEMPERATURES WILL
BE CLOSER TO SEASONAL NORMALS ON WEDNESDAY. FORECAST CAPES IN THE
AFTN WILL GENERALLY BE IN THE 1000-1400 J/KG RANGE. OVERALL SHEAR
PRETTY WEAK SO THE STORM WILL BE PULSE TYPE PRODUCING WET VS DRY
MICROBURSTS...AND COULD PRODUCE MODERATE TO HEAVY RAINFALL ALONG
WITH GUSTY OUTFLOW WINDS. MAIN CONCERN IN THE AFTN WILL BE OVER
THE FOOTHILLS NEAR THE BURN AREAS SO WL NEED TO MONITOR THIS
SITUATION CLOSELY.

LONG TERM...CHANCE OF STORMS WEDNESDAY EVENING WITH CAPES AROUND
500-1000 J/KG. BEST CHANCE FOR STORMS LOOKS TO BE ACROSS
MOUNTAINS AND ALONG THE PALMER DIVIDE AS WELL AS ALONG A WEAK
SURFACE CONVERGENCE AREA OVER CENTRAL ADAMS AND CENTRAL ARAPAHOE
COUNTIES. PRECIPITABLE WATER VALUES HOVERING AROUND THREE QUARTERS
OF AN INCH. SHEAR STILL FAIRLY WEAK SO STORMS TO PRODUCE GUSTY
WINDS AND BRIEF HEAVY RAIN. FLOW ALOFT INCREASES A BIT SO STORMS
TO BE MOVING A BIT QUICKER THAT WEDNESDAY AFTERNOON. STORMS TO END
AROUND MIDNIGHT AS AIRMASS STABILIZES. ON THURSDAY...FLOW ALOFT
BECOME SOUTHWEST AS UPPER TROUGH BUILDS INTO THE GREAT BASIN.
MODELS SHOW SHORTWAVE MOVING ACROSS COLORADO DURING THE DAY ALONG
WITH MID LEVEL QG ASCENT. SHOULD BE ENOUGH TO GENERATE A FEW
THUNDERSTORMS DURING THE AFTERNOON. NAM SHOWS PRECIPITABLE WATER
VALUES LOWERING TO AROUND SIX TENTHS OF AN INCH ACROSS THE PLAINS WHILE
THE GFS KEEPS VALUES CLOSE TO THREE QUARTERS OF AN INCH. LOW
LEVELS FAIRLY DRY WITH SURFACE DEWPOINTS IN THE 30S ACROSS MUCH OF
THE PLAINS. STORMS THAT DO DEVELOP WILL PRODUCE GUSTY WINDS AND
LIGHT TO BRIEF MODERATE RAINFALL. MODELS DO SUGGEST THE DEVELOPMENT
OF A DRY LINE ACROSS EASTERN WASHINGTON COUNTY SOUTH INTO
NORTHEAST LINCOLN COUNTY WITH SURFACE DEWPOINTS IN THE 40S EAST OF
THIS LINE. THERE APPEARS TO BE SOME LOW LEVEL CONVERGENCE IN THIS
AREA AS WELL...SO THERE MAY BE A BIT MORE CONVERAGE OF STORMS
THERE WHICH COULD PRODUCE HEAVY RAINFALL. FOR NOW WILL GO WITH
SLIGHT CHANCE POPS. WAVE EXITS THE AREA DURING THE EVENING WITH
SUBSIDENCE MOVING OVER THE AREA. ANY STORMS SHOULD END BY MIDNIGHT
WITH CLEARING SKIES. ON FRIDAY...SOUTHWEST FLOW ALOFT INCREASES AS
UPPER TROUGH MOVES INTO THE GREAT BASIN. DRIER AND WARMER AIR
SPREADS OVER THE AREA...WITH TEMPERATURES WARMING INTO THE MID 80S
ACROSS THE PLAINS. AIRMASS LOOKS A BIT TOO DRY FOR STORMS...THOUGH
A FEW STORMS COULD DEVELOP OVER THE FAR EASTERN PLAINS DURING THE
AFTERNOON WITH SOME LINGERING MOISTURE AND DAYTIME HEATING. ON
SATURDAY TROUGH MOVES CLOSER TO COLORADO WITH SOME INFLUX OF
MOISTURE. DAYTIME HEATING ALONG WITH AN INCREASE IN MID LEVEL QG
ASCENT SHOULD BE SUFFICIENT TO GENERATE SOME AFTERNOON AND EVENING
THUNDERSTORMS ACROSS THE AREA. TEMPERATURES TO COOL INTO THE
MIDDLE 70S ACROSS THE PLAINS. MODELS SHOW THE TROUGH MOVING ACROSS
THE STATE SATURDAY NIGHT AND SUNDAY WITH COOLER AIR AND MID LEVEL
ASCENT. IN ADDITION A SURGE MOVES ACROSS THE PLAINS SATURDAY NIGHT
AIDING IN FURTHER COOLING. ASCENT SHOULD HELP WITH THE DEVELOPMENT
OF THUNDERSTORMS DURING THE AFTERNOON HOURS...WITH SHOWERS
OVERNIGHT SATURDAY. COULD BE COLD ENOUGH FOR SOME SNOW ABOVE 11000
FEET EARLY SUNDAY MORNING. ON SUNDAY...TEMPERATURES LOOK TO COOL
TO AROUND 70 DEGREES ACROSS THE PLAINS.

ON MONDAY...MODELS SHOW UPPER TROUGH STILL OVER THE STATE WITH
COOL CONDITIONS AND WEAK ASCENT. WILL CONTINUE A SLIGHT CHANCE OF
SHOWERS AND AFTERNOON STORMS. BY TUESDAY...THE TROUGH MOVES INTO
THE CENTRAL PLAINS WITH NORTHWEST FLOW ALOFT OVER COLORADO. THIS
WILL RESULT IN DRIER AND SLIGHTLY WARMER CONDITIONS...BUT ENOUGH
MOISTURE OVER THE MOUNTAINS FOR A SLIGHT CHANCE OF AFTERNOON
STORMS.

AVIATION...VFR CONDITIONS OVER THE NEXT 24 HRS. NE-ELY WINDS THIS
EVENING THEN SWLY OVERNIGHT. TSTMS THIS AFTN AND EARLY EVENING
COULD PRODUCE OUTFLOW WINDS 35-45 KTS. ON WEDNESDAY...THE CLOUD
BASES WILL BE LOWER AND COULD SEE BKN CIGS OF 050-060 AGL IN THE
AFTN WITH THE STORMS.

HYDROLOGY...JUST LIGHT RAINFALL EXPECTED THIS AFTN AND EVENING.
INCREASED LOW LEVEL MOISTURE AND STORM MOTIONS UNDER 10 KTS COULD
POSE A PROBLEMS FOR THE BURN AREAS WEDNESDAY AFTN WITH GREATER
POTENTIAL FOR BRIEF HEAVY RAINFALL...0.50 INCHES IN 30 MINUTES. AS
A RESULT...WILL NEED TO MONITOR THE DEVELOPING STORMS OVER THE
FOOTHILLS MORE CLOSELY.
-- End Changed Discussion --

&&

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

$$

SHORT TERM...COOPER
LONG TERM....D-L
AVIATION/UPDATE...GIMMESTAD