Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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000
FXUS65 KBOU 282134
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
334 PM MDT THU MAY 28 2015

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 252 PM MDT THU MAY 28 2015

THERE IS PRETTY GOOD CONVECTION GOING OVER THE PLAINS RIGHT NOW.
HAIL OVER AN INCH HAS BEEN REPORTED WITH SOME OF THE CELLS. THERE
ARE BOUNDARIES ALL OVER THE PLACE. THE WATER VAPOR PICTURES ARE
SHOWING ANOTHER DECENT BATCH OF CONVECTION UPSTREAM IN EASTERN
UTAH AND WESTERN COLORADO...AGAIN ASSOCIATED WITH THE APPROACHING
TROUGH AXIS. MODELS SHOW THE WEAK UPPER TROUGH AXIS TO PUSH ACROSS
THE CWA THIS EVENING AND TONIGHT. BY FRIDAY AFTERNOON...A WEAK
UPPER RIDGE IS MOVING ACROSS COLORADO. THE FLOW ALOFT IS PRETTY
WEAK TONIGHT AND WEAK NORTHERLY ON FRIDAY. MODELS HAVE A TAD OF
WEAK UPWARD QG VERTICAL VELOCITY FOR THE NORTHEAST QUARTER OF THE
CWA TONIGHT INTO FRIDAY MORNING...THEN ALL DOWNWARD FOR ALL THE
CWA FOR THE FIRST TWO PERIODS. THE BOUNDARY LAYER FLOW IS MAINLY
NORTH AND NORTHEASTERLY TONIGHT AND FRIDAY FOR MUCH OF THE CWA.
CONCERNING MOISTURE...THERE IS A LOT TONIGHT AND FRIDAY. THE DEW
POINTS ARE IN THE MID 40S TO MID 50S F THIS EVENING...THEN MOSTLY
THE 40S F OVERNIGHT AND FRIDAY. THERE IS SOME CAPE AROUND THIS
EVENING...MOSTLY OVER THE EASTERN HALF OF THE CWA. VALUES ARE OVER
1000 J/KG OVER THE FAR EASTERN BORDER AREAS. THERE IS CAPE FOR
ALL THE CWA ON FRIDAY...BUT NOTHING OVER 1000 J/KG. IT WILL LIKELY
NOT GET VERY WARM ON FRIDAY WITH ALL THE CLOUDINESS EXPECTED.
THERE IS SOME MEASURABLE PRECIPITATION OVER ALL THE CWA MOST OF
TONIGHT AND FRIDAY TOO. THE GREATEST AMOUNTS ARE PROGGED THIS
EVENING OVER THE EASTERN CWA. WILL KEEP POPS GOING OVERNIGHT...BUT
LOW AFTER 06Z. BY LATE MORNING FRIDAY WILL GO WITH "LIKELY"S FOR
MUCH OF THE CWA. FOR TEMPERATURES...FRIDAY`S HIGHS LOOK TO BE 3-7
C COOLER THAN TODAY`S.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 252 PM MDT THU MAY 28 2015

TROUGH WILL MOVE EAST OF COLORADO FRIDAY NIGHT. SOME DISAGREEMENT
ABOUT HOW FAST THE CLEARING/DRYING WILL COME. NAM CONTINUES TO BE
FASTER SUGGESTING LOTS OF CLEARING EARLY MONDAY MORNING...WHILE
THE OPERATIONAL GFS REMAINS SLOWEST/WETTEST AND STILL HAS
SIGNIFICANT RAIN IN THE FOOTHILLS FRIDAY EVENING. WILL STICK WITH
THE IDEA OF A COMPROMISE SHADED TOWARD THE DRIER SOLUTIONS...I
LEFT THE EVENING POPS AS THEY WERE BUT SPED UP THE DEPARTURE OF
THE WEATHER BY A FEW HOURS. THIS HAS ONLY MINIMAL POPS ON THE
SOUTHERN BORDER AND IN THE MOUNTAINS EARLY SATURDAY MORNING. AFTER
THAT IT WILL BE WARMING AND DRYING ALOFT AND SHOULD BE TOO STABLE
FOR MUCH AFTERNOON CONVECTION...THOUGH I DID LEAVE SOME LOW
AFTERNOON POPS IN THE MOUNTAINS. MODELS HAVE TRENDED WARMER FOR
SATURDAY WHICH FITS THE SLIGHTLY EARLIER TIMING AND MORE SUNSHINE.

FOR SUNDAY THROUGH TUESDAY A WARM DRY RIDGE WILL MOVE OVER. THERE
HAS BEEN A TREND TOWARD WARMER TEMPERATURES WHICH LOOKS ALRIGHT
THOUGH I DID HOLD BACK A FEW DEGREES DUE TO THE MOIST GROUND.
WE WILL BE NEAR 80 ON SUNDAY WHICH COULD BE THE FIRST 80 IN
MAY...THEN LOW TO MID 80S FOR MONDAY AND TUESDAY LOOK GOOD. MODELS
HAVE FLIPPED FOR THE MID TO LATE WEEK TROUGH...BUT THE CONSENSUS
IS THE SAME. SOME MODELS SHOW A WEAK LEAD TROUGH MOVING THROUGH
ABOUT WEDNESDAY WHICH WOULD BRING A LITTLE COOLING AND PERHAPS A
BIT MORE LOW LEVEL MOISTURE FOR SOME INCREASE IN THUNDERSTORM
ACTIVITY. OTHERS LACK THIS AND WOULD HAVE LITTLE CHANGE THROUGH
THE END OF THE WEEK. MAIN FEATURE IS THE UPSTREAM TROUGH WHICH
WILL KEEP A WARM AND MAINLY DRY SOUTHWEST FLOW ALOFT OVER US.
CONSENSUS FORECAST IS FINE WHICH SHOWS A LITTLE COOLING AND SLIGHT
INCREASE IN POPS STARTING WEDNESDAY...BUT PROBABLY NOT A BIG
CHANGE.

&&

.AVIATION...(FOR THE TAFS THROUGH 00Z FRIDAY LATE AFTERNOON)
ISSUED AT 252 PM MDT THU MAY 28 2015

DIA MAY NOT HAVE NORMAL DRAINAGE WINDS BY LATE EVENING TONIGHT
...OR MAYBE JUST A WEAK VERSION OF THEM. NORTH-NORTHEASTERLIES
ARE PROGGED ON FRIDAY. THERE MAY NOT BE ANY CEILING ISSUES THIS
EVENING OR OVERNIGHT...BUT THEY COULD GET DOWN TO BKN040 FROM LATE
FRIDAY MORNING THROUGH THE REST OF THE DAY.

&&

.HYDROLOGY...
ISSUED AT 252 PM MDT THU MAY 28 2015

SOME OF TODAYS THUNDERSTORMS WILL PRODUCE LOCALLY HEAVY RAIN...BUT
ANY FLOODING SHOULD BE LOCALIZED. MORE WIDESPREAD RAINFALL IS
EXPECTED FRIDAY...BUT AGAIN IT SHOULD MAINLY BE LIGHT WITH A LOW
RISK OF LOCALIZED FLOODING AND LITTLE EFFECT ON THE LARGER
RIVERS. THE CACHE LA POUDRE RIVER IN GREELEY WILL REMAIN NEAR
FLOOD STAGE THIS WEEKEND...WHILE THE SOUTH PLATTE DOWNSTREAM WILL
BE SLOWLY FALLING.

BY EARLY NEXT WEEK WARM TEMPERATURES WILL LEAD TO INCREASING
SNOWMELT...LEADING TO HIGH FLOWS ON RIVERS AND STREAMS IN THE
MOUNTAINS. THIS WATER WILL PROGRESS DOWNSTREAM DURING THE NEXT
WEEK SO HIGH FLOWS WILL CONTINUE ON THE SOUTH PLATTE.

&&

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

$$

SHORT TERM...RJK
LONG TERM...GIMMESTAD
AVIATION...RJK
HYDROLOGY...GIMMESTAD/RJK



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