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000
FXUS65 KBOU 130215
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
815 PM MDT WED JUN 12 2013

.UPDATE...


&&

.SHORT TERM...WILL LET RED FLAG WARNINGS EXPIRE AT 9 PM. OTHERWISE
NO MAJOR CHANGES.

.AVIATION...WELL DEFINED DENVER CYCLONE WAS LOCATED OVER THE WRN
SUBURBS. LATEST RAP KEEPS IT WEST OF DIA OVERNIGHT WHILE THE NAM
MOVES IT SE OF DIA BY 12Z. WITH DEEPER LOW LVL MOISTURE MOVING IN
FM THE NE IT APPEARS STRATUS WILL DEVELOP LATE TONIGHT OVER THE
NERN PLAINS AND WRAP AROUND THE CYCLONE WHICH COULD AFFECT BJC AND
DIA BY 12Z DEPENDING ON WHERE THE CYCLONE IS. SMOKE PLUME FM FIRE
OVR BLACK FOREST AREA IS NOT AS DEFINED AS EARLIER BUT STILL COULD
SEE SOME LIMITED VISIBILTIES OF 5-6 MILES FOR THE NEXT FEW HOURS
IN SOME SPOTS.


&&

.PREV DISCUSSION... /ISSUED 348 PM MDT WED JUN 12 2013/

SHORT TERM...HAVE UPGRADED TO RED FLAG WARNINGS...SEE FIRE
WEATHER SECTION BELOW. STILL SEE SOME HIGH BASED CONVECTION
DEVELOPING THIS AFTERNOON ALTHOUGH MOSTLY VIRGA EXPECTED WITH VERY
DRY AND DEEP SUB-CLOUD LAYER. THERE IS A LOW RISK OF THUNDER
DEVELOPING ACROSS THE PALMER DIVIDE AREA...BUT MOISTURE SURGE FROM
THE LATEST MESOSCALE MODELS SEEMS A BIT OVERDONE AS DEWPOINTS EVEN
AS FAR EAST OF GOODLAND HAVE MIXED. WILL MENTION SOME SMOKE
SPREADING FROM THE PALMER DIVIDE NORTHWARD INTO THE DENVER METRO
WITH LATEST TRAJECTORY FORECASTS...DEVELOPING DENVER
CYCLONE...AND NOCTURNAL INVERSION.

ON THURSDAY...MOISTURE WILL LIKELY INCREASE ACROSS THE PLAINS
THROUGH EARLY MORNING BUT THEN BEGIN TO MIX AND SCOUR EASTWARD
ONCE AGAIN WITH DAYTIME HEATING/MIXING. THERE IS A WEAK SHORT
WAVE/SPEED MAX MOVING TO OUR NORTH WHICH WILL HELP CONVECTIVE
DEVELOPMENT WITH A SLIGHT INCREASE IN MID/UPPER LEVEL MOISTURE
DURING THE DAY. MAIN THREAT WILL BE LIGHTNING/GUSTY WINDS IN/NEAR
THE MOUNTAINS AND FRONT RANGE URBAN CORRIDOR. BETTER CHANCE OF
STRONGER AND PERHAPS A COUPLE SEVERE STORMS AS WE MOVE EASTWARD
ACROSS THE PLAINS WHERE BETTER LOW LEVEL MOISTURE COULD RESULT IN
CAPES NEAR 2000 J/KG.

LONG TERM...UPPER LEVEL RIDGE TO MOVE INTO CENTRAL PLAINS THURSDAY
EVENING WITH SOUTHWEST FLOW ALOFT ACROSS COLORADO. WEAK MID LEVEL
DISTURBANCE MOVES ACROSS WYOMING DURING THE EVENING WITH MID LEVEL
QG ASCENT SLIDING INTO THE NORTHEAST CORNER. MID LEVEL MOISTURE
MOVES EAST WITH THE WAVE...STILL ENOUGH ACROSS THE AREA TO
MAINTAIN A SLIGHT CHANCE OF STORMS DURING THE EVENING. MAIN THREAT
WILL BE GUSTY OUTFLOW WINDS AND LIGHTNING AS RAINFALL WILL BE
LIMITED. BETTER LOW LEVEL MOISTURE FAR NORTHEAST CORNER WHERE
THERE IS ALSO SOME CONVERGENCE AND SHEAR. POTENTIAL FOR A FEW
SEVERE STORMS IN THE NORTHEAST CORNER WITH CAPES AROUND 1500 J/KG.
STORMS SHOULD END BY MIDNIGHT AS WEAK SUBSIDENCE MOVES ACROSS THE
AREA BEHIND THE EXITING SHORTWAVE. A FEW STORMS COULD LINGER OVER
THE FAR NORTHEAST CORNER OVERNIGHT. ON FRIDAY...SOUTHWEST FLOW
ALOFT CONTINUES AS UPPER TROUGH MOVES INTO THE NORTHERN GREAT
BASIN. CROSS SECTIONS SHOW MID LEVEL MOISTURE OVER THE AREA.
MODELS ALSO INDICATE A SURFACE FRONT MOVING INTO NORTHEAST
COLORADO DURING THE AFTERNOON WITH SOME INCREASE IN LOW LEVEL
MOISTURE. AIRMASS STILL A BIT SUBSIDENT. BUT DAYTIME HEATING
SHOULD BE ENOUGH TO GENERATE A FEW AFTERNOON AND EVENING STORMS
WITH THE BEST CHANCE OVER THE FAR NORTHEAST CORNER IN AREA OF
BETTER LOW LEVEL MOISTURE. TEMPERATURES TO BE SLIGHTLY COOLER WITH
HIGHS AROUND 90 DEGREES ACROSS THE PLAINS. ON SATURDAY...UPPER
LEVEL TROUGH MOVES ACROSS IDAHO AND MONTANA WITH A SLIGHTLY WEAKER
SOUTHWEST FLOW ALOFT OVER THE AREA. MODELS SHOW A SECONDARY SURGE
MOVING INTO NORTHEAST PLAINS DURING THE MORNING ALONG WITH A
SLIGHT INCREASE IN LOW LEVEL MOISTURE. AIRMASS SLIGHTLY COOLER
WHICH MAY BE A BIT TOO STABLE FOR CONVECTION. FORECAST SOUNDINGS
ONLY INDICATE A WEAK CAP...WILL INCLUDE A SLIGHT CHANCE OF
AFTERNOON AND EVENING STORMS. MEASURABLE RAINFALL WILL BE POSSIBLE
WITH THE STORMS ACROSS THE PLAINS. HIGH TEMPERATURES TO BE A FEW
DEGREES COOLER WITH HIGHS IN THE MIDDLE 80S ACROSS THE PLAINS...
STILL ABOVE NORMAL. FOR SUNDAY...UPPER LEVEL RIDGE BUILDS INTO
COLORADO WITH SLIGHTLY WARMER AND DRIER AIR. STILL SOME MOISTURE
FOR A SLIGHT CHANCE OF AFTERNOON AND EVENING STORMS...MAINLY IN
AND NEAR THE FOOTHILLS WHERE LOW LEVEL SOUTHEAST WINDS SHOULD
PROVIDE LOCAL UPSLOPE. TEMPERATURES TO WARM A FEW DEGREES FROM
SATURDAY...WITH HIGHS IN THE MIDDLE AND UPPER 80S ACROSS THE
PLAINS.

FOR THE LATER DAYS...MONDAY THROUGH WEDNESDAY...UPPER LEVEL RIDGE
CONTINUES ACROSS THE AREA MONDAY AND TUESDAY. SOME LINGERING
MOISTURE WILL COMBINE WITH DAYTIME HEATING FOR A SLIGHT CHANCE OF
AFTERNOON AND EVENING THUNDERSTORMS. ON WEDNESDAY...MODELS SHOW
THE FLOW ALOFT BECOMING SOUTHWEST AS AN UPPER TROUGH MOVES INTO
THE GREAT BASIN. AIRMASS LOOKS DRIER AND WARMER WITH POTENTIAL FOR
INCREASING WINDS ACROSS THE MOUNTAINS AND ALONG FOOTHILLS. GFS AND
ECMWF HINT AT A SURFACE FRONT MOVING INTO THE NORTHEAST PLAINS
WITH INCREASING LOW LEVEL MOISTURE AND A CHANCE FOR THUNDERSTORMS.
FOR NOW WILL KEEP WEDNESDAY DRY. TEMPERATURES TO GRADUALLY WARM TO
AROUND 90 DEGREES ACROSS THE PLAINS BY WEDNESDAY.

AVIATION...WE WILL HAVE TO WATCH SMOKE FROM BLACK FOREST FIRE
PUSHING NORTHWARD...ALREADY REACHING SOUTHEAST SIDE OF TOWN AND
TRAJECTORIES DUE TO WEAK CYCLONE AND DEVELOPING INVERSIONS
OVERNIGHT WOULD BE FAVORABLE FOR AT LEAST SOME VSBY RESTRICTION
DOWN TO 3-5SM...BUT CANT RULE OUT SOMEWHAT LOWER VSBY OF 1-3SM IN
THICKER SMOKE AREAS. WILL MONITOR THROUGH THE NIGHT.
OTHERWISE...STILL SEE SOME HIGH BASED CONVECTION DEVELOPING IN THE
FRONT RANGE WHICH COULD PRODUCE GUSTY OUTFLOW WINDS THIS EVENING
IF AIRMASS WARMS A COUPLE MORE DEGREES ON THE PLAINS RESULTING IN
A DEEP DRY ADIABATIC SUB-CLOUD LAYER. CONVECTION THURSDAY
AFTERNOON SHOULD HAVE A BETTER CHANCE OF PRODUCING GUSTY OUTFLOW
WINDS BUT ONLY LIGHT RAIN FOR THE FRONT RANGE AIRPORTS. EVEN THEN
STORM COVERAGE WILL BE 10-20 PERCENT.

FIRE WEATHER...EXPANDED RED FLAG WARNINGS TO COVER THE PALMER
DIVIDE THIS AFTERNOON DUE TO STRENGTHENING WINDS...VERY LOW
RH...AND POSSIBLE SPOTTING FROM THE BLACK FOREST FIRE. ALSO ISSUED
A RED FLAG WARNING FOR THURSDAY AFTERNOON AND EVENING FOR THE HIGH
MOUNTAIN VALLEYS...SOUTHERN FRONT RANGE FOOTHILLS...AND PALMER
DIVIDE AREA FOR GUSTY WINDS...CONTINUED LOW RH...POSSIBLE DRY
LIGHTNING...AND MORE CRITICAL FUEL CONDITIONS DEVELOPING WITH
CONTINUATION OF HEAT AND DRYNESS.

HYDROLOGY...NO ISSUES EXPECTED THROUGH THURSDAY.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ241.

RED FLAG WARNING FROM NOON TO 9 PM MDT THURSDAY FOR COZ211-213-
214-216-241.

&&

$$

SHORT TERM...RPK
LONG TERM....D-L
AVIATION...RPK