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000
FXUS65 KBOU 240941
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
341 AM MDT FRI MAY 24 2013

.SHORT TERM...SOUTHWEST FLOW ALOFT WILL PREVAIL TODAY AS A RIDGE
RESIDES OVER THE CENTRAL PART OF THE COUNTRY AND A LOW SPINS OVER
THE PACIFIC NORTHWEST. THIS PATTERN WILL USHER IN WARMER AND DRIER
AIR TO PARTS OF THE AREA TODAY.

AT THE SURFACE...A LOW PRESSURE TROUGH WILL MOVE EAST ACROSS WYOMING
AND COLORADO CAUSING SURFACE WINDS TO SHIFT FROM THE SOUTHEAST TO
THE SOUTHWEST. THE SOUTHWEST WINDS WILL BRING DRIER AIR AND CREATE A
DRY LINE OVER EASTERN COLORADO TODAY. EAST OF THE DRY LINE DEW
POINTS WILL CLIMB INTO THE 50S. THIS COMBINED WITH HIGHS AROUND 80
DEGREES WILL CREATE SURFACE BASED CAPES OF UP TO 2500 J/KG. SUPER
CELL THUNDERSTORMS WILL BE POSSIBLE EAST OF THE DRY LINE DUE TO THE
INSTABILITY AND DECENT SHEAR. LARGE HAIL...DAMAGING WINDS AND AN
ISOLATED TORNADO OR TWO WILL BE POSSIBLE. THE SEVERE THREAT WILL BE
EAST OF THE DRY LINE...WHICH LOOKS TO STALL OUT ALONG A LINE FROM
STERLING TO AKRON TO BURLINGTON.

FOR THE REST OF THE FORECAST AREA...IT WILL BE WARM AND DRY. HIGHS
ALONG THE FRONT RANGE WILL REACH THE MID 80S THIS AFTERNOON.
SOUTHWEST WINDS MAY BECOME GUSTY OVER THE HIGHER TERRAIN THIS
AFTERNOON.

TONIGHT...LOW LEVEL MOISTURE WILL SLIDE BACK WEST ACROSS MUCH OF
NORTHEAST COLORADO. THE MOIST LAYER WILL BE VERY SHALLOW...SO NOT
EXPECTING ANY PRECIPITATION WITH THIS. COULD SEE LOW CLOUDS AGAIN
TONIGHT OVER FAR EASTERN COLORADO. BECAUSE OF THE WARM AIRMASS AND
MOISTURE...LOWS WILL BE MILD TONIGHT WITH READINGS AROUND 50 DEGREES
ALONG THE FRONT RANGE.

.LONG TERM...STRONG RIDGING OVER THE CENTRAL CONUS PLACES COLORADO
IN A VERY WARM AND MOSTLY DRY DEEP LAYER SOUTHWESTERLY FLOW THROUGH
MONDAY OF NEXT WEEK. MODEL GUIDANCE INDICATES DAYTIME TEMPERATURES
10-15 DEG F ABOVE AVERAGE ON SATURDAY...SUNDAY AND MONDAY...WITH MID
TO UPPER 80S FOR HIGHS ON THE PLAINS AND 60S-70S IN THE HIGH
COUNTRY. MIN RH VALUES ON SATURDAY ARE EXPECTED TO BE NEAR 10
PERCENT ON THE PLAINS. MAY ALSO SEE WEST-SOUTHWEST WINDS POSSIBLY
GUSTING TO 25 MPH OVER THE HIGH TERRAIN AND THE PALMER DIVIDE. THAT
SAID...CURRENTLY FUELS ARE DEEMED TOO GREEN/MOIST TO CARRY FIRE
EASILY. HOWEVER WILL CONTINUE TO MONITOR THE FUELS SITUATION SHOULD
WINDS ON THE PALMER DIVIDE BECOME STRONGER THAN PREDICTED. ONLY
OTHER GLITCH IN DRY AND VERY WARM FORECAST FOR SATURDAY HAS TO DO
WITH THE SLIGHT CHANCE OF LATE DAY THUNDERSTORMS IN THE FAR
NORTHEAST CORNER OF THE STATE.

LOW-LEVEL SHEAR INCREASES IN THE FAR NORTHEAST THROUGH THE AFTERNOON
AS LOW LEVEL MOISTURE CONVERGENCES ALONG A DRY LINE MEANDERING
ACROSS THE AREA. MAY SEE SUFFICIENT INSTABILITY/BOUYANCY TO GENERATE
ISOLATED T-STORMS IN PHILLIPS AND/OR SEDGWICK COUNTIES BY EVENING.
A BRIEF MODERATE SHOWER AND GUSTY OUTFLOW WINDS MAY BE ALL THAT WE
SEE FROM THEM THOUGH. OTHERWISE REST OF THE FCST AREA WILL REMAIN
DRY.

ON SUNDAY...DAY STARTS OUT DRY EVERYWHERE AND QUITE MILD WITH
TEMPERATURES THE NIGHT BEFORE SEVERAL DEGREES ABOVE AVERAGE THANKS
TO A WARM SOUTH-SOUTHWESTERLY FLOW. BY AFTERNOON...THE GFS...
CANADIAN AND TO A LESSER EXTENT...THE NAM MODELS SHOW BOUNDARY LAYER
WINDS TURNING EAST-SOUTHEASTERLY AROUND A WEAK SFC BASED CYCLONE IN
THE VICINITY OF WASHINGTON COUNTY. WHILE ALL THIS IS GOING
ON...MODELS SHOW A WEAK SHORTWAVE TROUGH AT MID-LEVELS LIFTS
NORTHEASTWARD OVER THE AREA. NAM IS FCSTG SFC BASED CAPES IN THE
1000-2000 J/KG RANGE BY AROUND 00Z/MONDAY ACROSS MORGAN...LOGAN...
WASHINGTON...SEDGWICK AND PHILLIPS COUNTIES. CALCULATED CAPE VALUES
EVEN GREATER OFF THE GFS. WHILE THE ECMWF CAPES ARE LOWER THAN
EITHER OF THESE MODELS. HOWEVER ALL 3 MODELS SHOW QUITE A BIT OF CIN
OUT THERE...ESPECIALLY THE GFS. A SFC BOUNDARY LYING ACROSS THE AREA
COULD SERVE AS A FOCUS FOR STORM DEVELOPMENT SHOULD THE CAP BREAK.
FOR NOW WILL KEEP A SLIGHT CHANCE OF LATE AFTERNOON AND EVENING T-
STORMS ROUGHLY EAST OF LINE FROM CHEYENNE TO GREELEY TO LIMON. SMALL
HAIL AND GUSTY OUTFLOW WINDS WILL PROBABLY BE THE MAIN THREAT FROM
THESE ISOLATED STORMS.

MONDAY...LOW LEVEL MOISTURE APPEARS TO FLUSH EAST OF THE AREA WITH A
RESUMPTION OF DRIER WEST-SOUTHWESTERLY LOW LEVEL FLOW. IT NOW
APPEARS THIS THE DEEPER MOISTURE AND THUS GREATER CAPES REMAIN EAST
OF THE FCST AREA ON MONDAY. ALTHOUGH THE GFS DOES INDICATE A NARROW
STRIP OF 2000-3000 J/KG CAPES ACROSS THE EXTREME NORTHEAST CORNER
AROUND 00Z/TUESDAY...BUT STILL QUITE A BIT OF CIN. FOR NOW WILL KEEP
THE SLIGHT CHANCE OF LATE AFTERNOON/EVENING T-STORMS IN THE FAR
NORTHEAST CORNER...AND A SLIGHT CHANCE OF HEAT DRIVEN STORMS OVER
THE FRONT RANGE.

TUESDAY AND BEYOND...MODELS SHOW THE UPPER RIDGE SHIFTING EAST OVER
THE EASTERN GREAT PLAINS AND MISSISSIPPI RIVER VALLEY...PLACING
COLORADO UNDER STRONGER SOUTHWEST FLOW ALOFT. LATE ON TUESDAY...THE
CANADIAN MODEL SHOWS WHAT APPEARS TO BE MOIST OUTFLOW FROM A LARGE
CONVECTIVE COMPLEX TO OUR NORTHEAST. WHILE THE NAM AND GFS SHOW NO
SUCH OUTFLOW AS THEY CONTINUE THE WARM AND RELATIVELY DRY WEST-
SOUTHWEST FLOW OVER THE FCST AREA. THEREFORE WILL BACK OFF ON T-
STORM CHANCES ON TUESDAY/TUESDAY NIGHT AND JUST KEEP A SLIGHT
CHANCE IN THE FAR NORTHEAST COUNTIES. GOING INTO WEDNESDAY...MODELS
BEGIN TO DIVERGE AS THE GFS INDICATES AN OPEN LONGWAVE TROUGH
HEADING FOR COLORADO...WHILE THE ECMWF SHOWS AN ELONGATED TROUGH
OVER THE GREAT BASIN WITH AN UPPER LOW CLOSING OFF OVER ARIZONA.
THIS CREATES A RELATIVELY MOIST SOUTHEASTERLY MID-LEVEL FLOW OVER
THE FCST AREA ON WEDNESDAY. MEANWHILE THE CANADIAN MODEL SHOWS THE
TROUGH ALREADY PAST THE AREA BY WEDNESDAY WITH A DRIER ZONAL FLOW
OVER THE FCST AREA. DIFFERENCES IN THE MODEL GUIDANCE NOT ANY
SMALLER ON THURSDAY. FOR NOW WILL KEEP A SLIGHT CHANCE OF AFTERNOON
AND EVENING T-STORMS FOR PRETTY MUCH ALL OF THE CWFA ON TUESDAY AND
WEDNESDAY...AND DRY THINGS OUT ON THURSDAY...ASSUMING THE TROUGH
PASSES BY THEN. AFTER TUESDAY...WOULD EXPECT TO SEE A GRADUAL
REDUCTION IN TEMPERATURES WITH THE PASSING TROUGH.

&&

.AVIATION...LOW CLOUDS OVER EASTERN COLORADO WILL SLOWLY LIFT AND
SHIFT EAST THIS MORNING. THERE ARE LOW CLOUDS VERY NEAR KDEN AND
KAPA...LESS THAN 5 MILES. THEY COULD MOVE OVER ONE OR BOTH OF THE
AIRPORTS FOR A SHORT TIME BEFORE 12Z. DRIER WILL IS MOVING INTO THE
AREA AND WILL ERODE THE CLOUDS. SOUTHERLY WINDS WILL DECREASE THIS
MORNING. WIND DIRECTION WILL BE TRICKY TODAY AS A DENVER CYCLONE
DEVELOPS. BY 00Z...APPEARS WINDS WILL END UP NORTHWEST AS THE
CYCLONE SHIFTS EAST OF THE DENVER AREA.

&&

.HYDROLOGY...NO CONCERNS FOR THE BURN AREAS.

&&

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

$$

SHORT TERM...MEIER
LONG TERM....BAKER
AVIATION...MEIER