Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 260942
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
342 AM MDT TUE MAY 26 2015

.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 309 AM MDT TUE MAY 26 2015

WATER VAPOR IMAGERY SHOWING THE UPPER TROF SLOWLY MOVING EAST OF
COLORADO INTO THE CENTRAL PLAINS. THIS TROF WILL BE REPLACED BY
WEAK RIDGING ALOFT TODAY ACROSS COLORADO. THE TREND OF SLIGHTLY
DRIER AND WARMER WILL CONTINUE TODAY AND SHOULD SEE TEMPS AROUND
70 DEGREES OVER THE PLAINS. THIS WILL BE THE FIRST TIME OF 70S
TEMPERATURES WE`VE SEEN SINCE MAY 14TH AT DENVER. THERE ARE LOW
TEMP/DEWPOINT SPREADS THIS MORNING SO COULD BE SOME PATCHY FOG
WITH THE LIGHT WIND FIELDS. IN FACT...FNL JUST DEVELOPED SOME FOG
SO WILL ADD THIS TO FORECAST.

DESPITE THE RIDGING TODAY...THERE APPEARS TO STILL BE ENOUGH
MOISTURE AND MARGINAL INSTABILITY FOR SCATTERED SHOWERS AND
THUNDERSTORMS ESPECIALLY OVER HIGHER TERRAIN. THERE ARE SOME
SHOWERS AND STORMS OVER UTAH THROUGH THE NIGHT AND THIS WILL WORK
ITS WAY INTO COLORADO BY THIS AFTERNOON. PW VALUES ARE HOLDING
CLOSE TO .60 TENTHS OF AN INCH WHICH IS ACTUALLY A BIT UP FROM
YESTERDAY. QG FIELDS ARE WEAKLY SUBSIDENT THIS MORNING AND THEN
NEUTRAL THIS AFTERNOON/EVENING SO NOT MUCH HELP UPSTAIRS. BACK TO
A MORE TYPICAL PATTERN OF AFTERNOON/EVENING STORMS THEN CLEARING
OVERNIGHT OVER NORTHERN COLORADO. SEVERE STORMS NOT EXPECTED AS
SURFACE BASED CAPES GENERALLY UNDER 800J/KG ALONG WITH MARGINAL
WIND SHEAR. COULD BE HEAVY RAIN AND SMALL HAIL WITH THE STRONGER
STORMS AS WE SAW YESTERDAY.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 309 AM MDT TUE MAY 26 2015

FLOW ALOFT WILL TURN MORE SOUTHWESTERLY WEDNESDAY AS AN UPPER
TROUGH PUSHES INTO THE GREAT BASIN AND SURFACE FLOW WILL TURN
MORE SOUTH- SOUTHEASTERLY AS A SURFACE TROUGH DEEPENS ALONG THE
LEE SIDE OF THE ROCKIES AND INTO THE GREAT PLAINS. THIS WILL ALL
COMBINE TO INCREASE MOISTURE ACROSS THE FORECAST AREA AND IN TURN
CAPE VALUES. NAM SEEMS TOO HIGH WITH MORNING CAPES OF OVER 1000
J/KG OVER THE FAR EASTERN PLAINS. WILL STICK WITH MORE OF THE
DIURNAL TREND OF AFTERNOON AND EVENING STORMS WITH MORE WIDESPREAD
ACTIVITY COMPARED TO TODAY. HIGHER CAPES...WARMER MAXIMUM
TEMPERATURES AND A THETA E RIDGE AXIS MOVING INTO FAR EASTERN CO MAY
ALLOW FOR SOME STRONGER STORMS OUT IN THAT AREA.

THURSDAY WILL BE QUITE SIMILAR AS THE LOW MOVES CLOSER TO THE
STATE. LOOK FOR TEMPERATURES A COUPLE DEGREES WARMER AND SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE SURFACE LOW
WILL DEEPEN OVER THE CO/NE/KS BORDERS...THEN PUSH SOUTHEAST AS
HIGH PRESSURE PUSHES IN FROM CANADA WITH COOLER AIR AND UPSLOPE
FLOW TO FOLLOW A COLD FRONT EARLY FRIDAY MORNING. THIS WILL
PRODUCE MORE WIDESPREAD RAIN WITH SOME ISOLATED EMBEDDED
THUNDERSTORMS EXPECTED. GFS AND EC BOTH SHOWING 0.5-1.0" OF QPF
THROUGH THE DAY...MOSTLY UP NEAR THE FOOTHILLS IN THE UPSLOPE
REGIME. SNOW LEVELS LOOK TO STAY QUITE HIGH STILL...NEAR 9-10KFT.

HIGH SURFACE PRESSURE OVER THE GREAT PLAINS SHOULD KEEP UPSLOPE
FLOW GOING SATURDAY...WITH RAIN TAPERING OFF THOUGH WITH THE MAIN
MOISTURE PLUME MOVING OUT. THUNDERSTORMS WILL STILL BE POSSIBLE
OVER THE HIGHER TERRAIN ABOVE THE STABLE AIRMASS OVER THE PLAINS.

A MORE SUBSTANTIAL UPPER RIDGE SHOULD BUILD OVER THE REGION FOR
SUNDAY AND MONDAY TO BRING MOSTLY DRY CONDITIONS AND MUCH WARMER
TEMPERATURES. HAVE INCREASED MAX TEMPERATURES INTO THE UPPER 70S
BY MONDAY BASED ON FORECASTED 700 MB TEMPERATURES AND ENSEMBLE MOS
GUIDANCE.

&&

.AVIATION...(FOR THE TAFS THROUGH 12Z WEDNESDAY MORNING) I
ISSUED AT 309 AM MDT TUE MAY 26 2015

VFR CONDITIONS THIS MORNING WITH SOME LINGERING MID/HI LEVEL
MOISTURE IN THE W-NW FLOW. APPEARS STORM COVERAGE WILL BE MORE
ISOLATED TODAY WITH MUCH OF THE ACTIVITY EXPECTED TO REMAIN OVER
MOUNTAINS AND HIGHER TERRAIN. SURFACE WINDS WILL BECOME LIGHT AND
VARIABLE THIS MORNING BEFORE SHIFTING TO A LIGHT EASTERLY
COMPONENT THIS AFTERNOON.

&&

.HYDROLOGY...
ISSUED AT 309 AM MDT TUE MAY 26 2015

RIVER LEVELS REMAINING FAIRLY STEADY OVERNIGHT WITH FLOOD
WARNINGS REMAIN ACROSS THE CACHE LA POUDRE AT GREELEY AND THE
SOUTH PLATTE RIVER AT KERSEY AND WELDONA. FLOOD WARNING WAS
CANCELLED LAST NIGHT AT BALZAC AS LEVELS DROPPED JUST BELOW FLOOD
STAGE AND ARE REMAINING STEADY OVERNIGHT. THE SOUTH PLATTE AT
DENVER AND HENDERSON TOOK A SPIKE UPWARDS LAST EVENING FROM
YESTERDAYS STORMS BUT NOW TRENDING DOWNWARD AGAIN. SCATTERED
SHOWERS AND STORMS TODAY ESPECIALLY OVER MOUNTAINS. FLASH FLOOD
THREAT LOW WITH AS STORMS SHOULD BE MOVING AT 10-15KT AND
INSTABILITY NOT ALL THAT STRONG.

ANOTHER SYSTEM WITH UPSLOPE FLOW ASSOCIATED WITH IT WILL BRING A
CHANCE FOR HEAVIER RAIN/THUNDERSTORMS FRIDAY INTO FRIDAY NIGHT.

&&

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

$$

SHORT TERM...ENTREKIN
LONG TERM...KRIEDERMAN
AVIATION...ENTREKIN
HYDROLOGY...ENTREKIN/KRIEDERMAN



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