Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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000
FXUS65 KBOU 280919
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
319 AM MDT THU MAY 28 2015

.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 216 AM MDT THU MAY 28 2015

A DISTURBANCE AHEAD OF A WK UPPER LEVEL TROUGH WILL MOVE INTO NERN
CO BY EARLY AFTN. MEANWHILE AT THE SFC THERE WILL BE A LOW OVER
THE PLAINS SOMEWHERE BETWEEN AKRON AND LIMON WITH A CONVERGENCE
ZONE OVER THE FAR ERN PLAINS. APPEARS CONVECTION MAY DVLP ALONG
THIS CONVERGENCE ZONE BY LATE MORNING WITH ADDITIONAL ACTIVITY
DEVELOPING ACROSS THE REST OF NERN CO BY EARLY AFTN AS DISTURBANCE
MOVES ACROSS. ALTHOUGH PRECIPITABLE WATER VALUES WILL BE NR AN
INCH OVER THE FAR ERN PLAINS...WITH INCREASING MID LVL FLOW BY
AFTN STORMS WILL BE RATHER FAST MOVING SO WILL NOT ISSUE A FLASH
FLOOD WATCH. THERE WILL BE SOME THREAT FOR A FEW SVR STORMS OVER
PARTS OF THE PLAINS WITH LARGE HAIL AND GUSTY WINDS. OVER THE
HIGHER TERRAIN THERE WILL BE SCT SHOWERS AND TSTMS DUE TO
FAVORABLE LAPSE RATES. AS FOR HIGHS WILL KEEP READINGS IN THE
LOWER TO MID 70S OVER NERN CO.

BY TONIGHT THE DISTURBANCE WILL MOVE EAST OF THE AREA BY EARLY
EVENING AS THE WK UPPER LEVEL TROUGH MOVES INTO WY.  PCPN WILL
GRADUALLY DECREASE THRU THE EARLY EVENING HOURS ACROSS THE PLAINS
WITH SOME LINGERING ACTIVITY OVER THE HIGHER TERRAIN.  AS THE MAIN
UPPER LEVEL TROUGH SLOWLY MOVES SE INTO NRN CO LATE TONIGHT THERE
MAYBE ANOTHER CHC OF SHOWERS TOWARDS MORNING AS A FNT MOVES ACROSS
THE PLAINS.


.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 216 AM MDT THU MAY 28 2015

AN UPPER TROUGH WILL PASS OVER COLORADO FRIDAY...WITH COOLER AIR
PUSHING INTO THE AREA IN UPSLOPE FLOW. ALL MODELS HAVE SHOWN A
BRIEF BREAK IN THE EARLY MORNING FROM PRECIPITATION...BEFORE THE
POST FRONTAL NORTHERLY WINDS TURN MORE NORTHEASTERLY. HAVE ADDED
THIS DETAIL INTO THE FORECAST. MAIN PLUME OF MOISTURE WILL PUSH IN
FOR THE AFTERNOON AND EVENING AS HIGH SURFACE PRESSURE MAKES ITS
MAIN PUSH INTO THE STATE. HAVE NOT ADJUSTED EXPECTED RAINFALL
AMOUNTS MUCH...EXPECT AROUND A QUARTER TO A HALF INCH OF RAIN OVER
THE FRONT RANGE MOUNTAINS...FOOTHILLS AND PALMER DIVIDE...AND ONE
TO TWO TENTHS OF AN INCH OVER THE EASTERN PLAINS AS WELL AS IN THE
HIGH COUNTRY WEST OF THE DIVIDE. WITH CLOUD COVER ALL DAY AND
SCATTERED TO WIDESPREAD RAIN SHOWERS...TEMPERATURES WILL STAY IN
THE MID 60S FOR THE PLAINS. MOUNTAINS WILL LIKELY SEE READINGS IN
THE 50S TO LOW 60S. SNOW LEVELS WILL BE DOWN AROUND 9000 EARLY
FRIDAY MORNING...INCREASE TO NEAR 11,000 FEET IN THE AFTERNOON
THEN BACK DOWN AROUND 10,000 FT AT NIGHT. EXPECT A FEW INCHES OF
WET SNOW AT THE HIGHER ELEVATIONS. COULD SEE MORE CONVECTION AND
THUNDERSTORMS OVER THE HIGH COUNTRY...BUT ALL ARE EXPECTED TO BE
WEAK.  FEEL LIKE CONVECTION WILL BE DONE FRIDAY EVENING

HIGH SURFACE PRESSURE OVER THE PLAINS SATURDAY WILL KEEP STABLE
UPSLOPE FLOW OVER THE PLAINS WHILE SOME WARMING WILL OCCUR AT
MIDLEVELS AND AFFECT THE HIGH COUNTRY. EXPECT WARMER CONDITIONS
OVER THE MOUNTAINS WITH AFTERNOON AND EVENING STORMS...WHICH MAY
DRIFT EAST OVER THE WESTERN PLAINS ...BUT STABLE AIR WILL INHIBIT
THEM MAKING IT TOO FAR.

SUNDAY THROUGH TUESDAY WILL FEATURE WARMING AS AN UPPER RIDGE
MOVES OVERHEAD AND A SURFACE TROUGH DEEPENS ALONG THE LEE OF THE
ROCKIES....HELPING TO WARM MORE QUICKLY WITH DOWNSLOPE EFFECTS.
LOOKING AT EXTENDED MOS GUIDANCE...HAVE INCREASED TEMPERATURES FOR
SUNDAY THROUGH TUESDAY TO BE MORE IN LINE WITH THIS GUIDANCE.
THIS EARLY JUNE WARM UP MAY BE SHORT LIVED HOWEVER AS BOTH GFS AND
EC MODELS HAVE ANOTHER WEATHER SYSTEM MOVING OVER THE PACNW WITH
TRENDS OF COOLER AND WETTER WEATHER APPROACHING THE STATE AGAIN.
HOWEVER THE JET SEEMS TO STAY FURTHER NORTH THAN WE`VE BEEN
EXPERIENCING THIS MONTH...SO NOT AS WET AND COLD.

&&

.AVIATION...(FOR THE TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 216 AM MDT THU MAY 28 2015

A SFC LOW WAS JUST EAST OF DIA EARLY THIS MORNING WITH WNW WINDS.  A
NARROW STRATUS DECK HAS FORMED JUST BEHIND THE LOW WITH CEILINGS
DOWN TO 800 FEET AT DIA. THE LATEST HRRR SHOW THESE LOW CLOUDS
MAY LINGER UNTIL 12Z BEFORE BREAKING UP. AS FOR TSTM CHANCES IT
APPEARS BEST CHC WOULD BE IN THE 19Z-22Z RANGE. WINDS WILL BECOME
LIGHT AND VARIABLE AROND 15Z AND THEN LIGHT ESE BY MIDDAY. BY 20Z
THEY WILL BECOME MORE NWLY AND THEN TREND BACK TO MORE SSW BY
EARLY EVENING. OVERNIGHT WILL KEEP WINDS DRAINAGE.

&&

.HYDROLOGY...
ISSUED AT 216 AM MDT THU MAY 28 2015

A FEW THUNDERSTORMS OVER THE PLAINS COULD PRODUCE UP TO AN INCH
OF RAIN THIS AFTERNOON. OTHERWISE RAIN AMOUNTS WILL BE IN THE
QUARTER INCH TO HALF INCH RANGE ACROSS THE REST OF THE AREA.

FRIDAY`S UPSLOPE EVENT WILL STILL LIKELY HAVE WIDESPREAD RAIN
SHOWERS...BUT PRECIPITATION AMOUNTS ARE TRENDING SLIGHTLY
DOWNWARD. EXPECT 0.25-0.5" OVER THE FRONT RANGE
MOUNTAINS...FOOTHILLS AND ADJACENT WESTER PLAINS. AMOUNTS OF LESS
THAN TWO TENTHS ARE EXPECTED OVER THE EASTERN PLAINS. SOME HEAVIER
SHOWERS ARE POSSIBLE IN THE AFTERNOON AGAINST THE HIGHER
TERRAIN...WHICH MAY ADD MORE WATER TO THE AREA RIVERS...BUT AT
THIS TIME THE FLOODING THREAT IS NOT THAT GREAT.

FLOOD WARNINGS CONTINUE FOR THE SOUTH PLATTE RIVER AT KERSEY AS
WELL AS THE CACHE LA POUDRE AT GREELEY.

&&

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

$$

SHORT TERM...RPK
LONG TERM...KRIEDERMAN
AVIATION...RPK
HYDROLOGY...RPK



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