Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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721
FXUS65 KBOU 021632
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1032 AM MDT MON MAY 2 2016

.UPDATE...
ISSUED AT 1028 AM MDT MON MAY 2 2016

ADJUSTED SKY COVER FOR THIS MORNING AS MUCH DRIER AIR MOVED IN
THAN FORECAST. ALSO ADJUSTED SKY AND SHOWER COVERAGE LATER THIS
AFTERNOON OVER THE SOUTHERN PLAINS...NOT EXPECTING MANY SHOWERS
TO MOVE OUT OVER THE PALMER DIVIDE AT THIS TIME. REMOVED THE
MENTION.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM MDT MON MAY 2 2016

THE BAND OF MID AND HIGH CLOUDS STRETCHING WEST-TO-EAST ACRS CENTRAL
AND SOUTHERN COLORADO ATTM IS ALIGNED WITH THE TAIL END OF A
SHORTWAVE TROUGH WHICH IS SLOWLY TRANSLATING S-SEWRD. PRECIPITATION
IS NO LONGER DETECTED WITHIN THE CWA AND SKIES HAVE CLEARED FOR THE
MOST PART OVER NERN COLORADO. THIS CLEARING AND THE WET GROUND MAY
STILL RESULT IN PATCHES OF FOG MAINLY AS ALONG RIVER BOTTOMS SUCH AS
ALONG THE SOUTH PLATTE RIVER DOWNSTREAM FROM DENVER. LIGHT DRAINAGE
FLOW SHOULD REDUCE THE RISK OF FOG IN THE DENVER AREA...BUT SHOULD
WINDS BECOME LIGHT AND VARIABLE AS SOME MODELS INDICATE...COULD SEE
PATCHY FOG HERE TOO.

TODAY...CLEARING SHOULD CONTINUE THIS MORNING FROM NORTH TO SOUTH
WITH SINKING AIR AND WARMER TEMPERATURES. LIGHT AND VARIABLE FLOW
ALOFT AT THE PRESENT ACQUIRES A NORTHERLY COMPONENT THIS MORNING
WHICH USHERS IN SLIGHTLY COOLER AIR ALOFT. BUT A RELATIVELY STRONG
MAY SUN SHOULD COUNTERACT THIS COOLING AND HELP PUSH TEMPERATURES TO
LEVELS NOT OBSERVED IN RECENT DAYS. THIS SAME HEATING TOGETHER WITH
AMPLE LOW-LEVEL MOISTURE GENERATE SFC BASE CAPES IN THE 400-1000
J/KG ALONG THE SPINE OF THE MOSQUITO...TEN MILE AND SRN PORTIONS OF
THE FRONT RANGE MTNS THIS AFTERNOON ACCORDING TO THE NAM. CAPE
VALUES ON OTHER MODELS NO WHERE AS IMPRESSIVE...HOWEVER THEY STILL
SHOW THIS AREA PRIMED FOR LOW-TOP/LOW INTENSITY T-STORM FORMATION
AFTER 18Z TODAY. BECAUSE OF NLY STEERING FLOW ALOFT DO NOT EXPECT TO
SEE ANY OF THIS CONVECTION MOVING OVER THE I-25 URBAN CORRIDOR.
TEMPERATURES TODAY WHILE STILL WELL BE AVERAGE...WILL CERTAINLY FEEL
WARMER WITH THE SUNSHINE. HIGHS TODAY WILL RANGE FROM THE MID 30S-
MID 40S IN THE MTNS...MID 40S TO LOWER 50S IN THE MTN VALLEYS...AND
GENERALLY IN THE 50S ON THE PLAINS.

TONIGHT...ATTENTION SHIFTS TO THE CLIPPER SYSTEM RACING SOUTH ACRS
ERN MONTANA AND THE DAKOTAS AT THE MOMENT. BASED ON ITS FORWARD
PROGRESS...THIS SYSTEM WITH ITS CLOUD COVER...GUSTY NORTHERLY
WINDS...COOLER AIR AND SPOTTY LIGHT PRECIP...MAY ARRIVE SOONER THAN
WHAT MODELS INDICATE. MOST OF THEM SHOW THE LEADING EDGE OF THIS
SYSTEM REACHING THE NERN CORNER OF THE CWA BY 00Z TODAY. I BELIEVE
IT`LL ARRIVE SOONER...SAY BY 21Z AS THE NAM INDICATES. MODELS DO NOT
GENERATE ANY CAPE OR STEEP LAPSE RATES OUT THERE. SO WILL REMOVE ANY
MENTION OF THUNDER OUT THERE. SYSTEM APPEARS TO BRUSH THE NERN
QUARTER OF THE CWA OVERNIGHT WITH LOW CLOUDS AND A LOW CHANCE OF
RAIN/SNOW SHOWERS. AT THIS TIME...DO NOT SEE ANY PRECIP EXTENDING AS
FAR WEST AS THE I-25 CORRIDOR...BUT I WOULDN`T RULE IT OUT ENTIRELY.
SHOULD SEE THIS CLIPPER SYSTEM RACE SOUTH AND EAST OF THE FORECAST
AREA BEFORE MORNING WITH QUICK CLEARING IN ITS WAKE. WITH CLOUD
COVER OVERNIGHT...TEMPERATURES NOT AS COLD WITH LOWS ON THE PLAINS
GENERALLY IN THE 30S.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 420 AM MDT MON MAY 2 2016

AN UPPER LEVEL RIDGE WILL BECOME MORE DEFINED FROM TUE INTO WED
WITH WEAK FLOW ALOFT. THERE WILL BE SOME LIMITED MOISTURE
REMAINING OVER THE HIGHER TERRAIN BOTH DAYS TO ALLOW FOR SOME
ISOLD TO WDLY SCT CONVECTION IN THE AFTN. ACROSS THE PLAINS IT
WILL BE DRY WITH A WARMING TREND AS HIGHS REACH THE LOWER TO MID
70S BY WED.

BY THU AN UPPER LEVEL STORM SYSTEM WILL BE OVER CALIFORNIA WITH SSW
FLOW ALOFT ACROSS THE AREA.  THERE WILL BE SOME INCREASE IN MID
LEVEL MOISTURE OVER THE HIGHER TERRAIN BY AFTN WHICH MAY LEAD TO A
LITTLE BETTER COVERAGE OF AFTN CONVECTION.  ACROSS THE PLAINS IT
WILL BE DRY THRU THE AFTN WITH HIGHS IN THE 75-80 DEGREE RANGE.

FOR FRI THE UPPER LEVEL STORM SYSTEM WILL BE OVER SRN CALIFORNIA
WITH SSW FLOW ALOFT REMAINING OVER THE AREA.  AT THE SFC LOW PRES
WILL INTENSIFY NR THE FOOTHILLS WITH INCREASING SSE FLOW ACROSS THE
PLAINS WHICH WILL ALLOW FOR DEEPER LOW LVL MOISTURE TO ADVECT IN.
AFTN CAPES ARE FCST IN THE 1000-1500 J/KG RANGE SO COULD SEE A FEW
STRONGER STORMS DVLP ALONG A CONVERGENCE ZN ASSOCIATED WITH A DENVER
CYCLONE.  IN THE MTNS THERE WILL BE DECENT LAPSE RATES AND COMBINED
WITH AFTN HEATING WILL SEE A CHC OF SHOWERS AND A FEW STORMS.
HIGHS ONCE AGAIN ACROSS THE PLAINS WILL BE IN THE 75 TO 80 DEGREE
RANGE.

LOOKING AHEAD TO THE WEEKEND HAVE LITTLE CONFIDENCE IN BOTH THE
ECMWF AND GFS SOLUTIONS WITH REGARDS TO MOVEMENT OF THE UPPER LEVEL
LOW OVER SRN CALIFORNIA.  WITH THE FLOW RATHER BLOCKED UP OVER THE
US AND NOTHING BEHIND IT TO KICK IT OUT SUSPECT BOTH MODELS MAY BE
EJECTING THIS LOW ENE TOO FAST HOWEVER TIME WILL TELL.

AT THIS POINT STILL LOOKS LIKE A POTENTIAL ACTIVE TSTM DAY ACROSS
NERN CO SAT AFTN AS MAIN SFC LOW WILL LIKELY STAY CLOSER TO THE
FOOTHILLS MUCH LIKE THE ECMWF SHOWS WITH A TRIPLE POINT SOMEWHERE NR
OR JUST EAST OF DENVER WHERE CAPES OF 1500-2000 J/KG WILL RESIDE
ALONG WITH FAVORABLE SHEAR PROFILE.  OVER THE HIGHER TERRAIN THE
ECMWF DOES SHOW A DISTURBANCE MOVING NE ACROSS THE MTNS BY AFTN SO
WILL KEEP IN A CHC OF SHOWERS AND A FEW TSTMS.

ON SUN THE ECMWF HAS THE MAIN UPPER LEVEL LOW NR THE FOUR CORNERS AT
12Z AND THEN HAS IT OVER CNTRL WYOMING BY LATE IN THE AFTN.  THIS
PATTERN WOULD BASICALLY DRY SLOT THE ENTIRE AREA WITH THE ONLY CHC
FOR PCPN POSSIBLY OVER THE FAR NERN PLAINS.  MEANWHILE THE GFS HAS
THE UPPER LEVEL LOW OVER ECNTRL CO ON SUN WITH ABUNDANT PCPN ACROSS
MUCH OF THE AREA WITH MUCH COOLER TEMPS.  AS STATED ABV CONFIDENCE
IN EITHER OF THESE SOLUTION IS VERY LOW SO WILL JUST KEEP IN 20-30
POPS OVER THE RGN WITH COOLER TEMPS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1028 AM MDT MON MAY 2 2016

VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS. LIGHT AND VARIABLE
WINDS ARE EXPECTED TODAY...WITH A TENDENCY FOR NORTHERLY WINDS
LATE THIS MORNING AND AFTERNOON. TONIGHT SKIES WILL GO PARTLY TO
MOSTLY CLOUDY WITH A WEAK WEATHER DISTURBANCE BRUSHING THE
NORTHEAST CORNER OF THE STATE. CLOUD BASES IN THE DENVER AREA
SHOULD REMAIN AT OR ABOVE 8000 FT AGL WITH NO PRECIPITATION ANTICIPATED.

&&

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

$$

UPDATE...KRIEDERMAN
SHORT TERM...BAKER
LONG TERM...RPK
AVIATION...KRIEDERMAN



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