Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS65 KBOU 061653
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1053 AM MDT FRI MAY 6 2016

.UPDATE...
ISSUED AT 1053 AM MDT FRI MAY 6 2016

MADE SOME SLIGHT CHANGES TO THE COVERAGE OF SHOWERS THIS AFTERNOON
OER THE MOUNTAINS...FOOTHILLS AND ADJACENT PLAINS BASED ON THE
FORECASTS OF THE PAST SEVERAL RUNS OF THE RAP MODEL. MOST OF THE
SHOWER ACTIVITY IS EXPECTED TO BE OVER THE MOUNTAINS AND
FOOTHILLS...BUT A FEW STORMS MAY ALSO DEVELOP OVER THE I-25 URBAN
CORRIDOR. GUSTY WINDS ARE GOING TO BE THE MAIN THREAT FROM THE
STORMS THAT DEVELOP THIS AFTERNOON...ALTHOUGH MOUNTAIN AREAS COULD
PICK UP A LITTLE RAIN AND SMALL HAIL TOO. THE PRIMARY BAND OF
SHOWERS IS MOVING NORTHWARD OVER PARK COUNTY AT THE PRESENT TIME.
ADDITIONAL SHOWER DEVELOPMENT AFTER PASSAGE OF THE FIRST BAND OF
SHOWERS WILL BE LIMITED DUE TO THE WEAK SUBSIDENCE TRAILING THE
SHORT WAVE THAT IS DRIVING THE SHOWER DEVELOPMENT. HOWEVER...
THERE COULD BE ENOUGH AFTERNOON HEATING OVER THE MOUNTAINS FOR A
FEW WEAK SHOWERS TO DEVELOP. IT LOOKS LIKE SHOWER ACTIVITY ACROSS
THE EASTERN PLAINS IS GOING TO BE QUITE LIMITED EXCEPT NEAR THE
WYOMING BORDER LATER TONIGHT. THIS WILL ALLOW FOR THE TEMPERATURES
TO CLIMB NICELY INTO THE UPPER 70S AND LOWER 80S.

THE OTHER CHANGE TO THE FORECAST WAS TO ADD BACK THE MENTION OF
SEVERE THUNDERSTORMS ON THE PLAINS SATURDAY AFTERNOON. MORNING
MODEL RUNS INDICATE THE FRONTAL BOUNDARY WILL BE SOMEWHERE OVER
NORTHEAST COLORADO SATURDAY MORNING...PROBABLY ACROSS
MORGAN...WELD AND LARIMER COUNTIES. MODEL SOUNDINGS IN THE GREELEY
AREA SHOW MIDDAY CAPE VALUES IN EXCESS OF 2000 J/KG. FAVORABLE
WIND SHEAR PROFILES ALSO LOOK LIKE THEY ARE GOING TO BE IN PLACE
FOR STRONG THUNDERSTORM DEVELOPMENT BY EARLY AFTERNOON.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM MDT FRI MAY 6 2016

THE DEEPENING TROUGH/CLOSED LOW TRACKING SLOWLY E-SEWRD ACROSS
SOUTHERN CALIF IS BEGINNING TO EXERT ITS DOMINANCE ON FLOW AT ALL
LEVELS AND WX AS FAR EAST AS THE SRN AND CNTRL ROCKIES. DEEP S-SWLY
FLOW ON THE FRONT SIDE OF THIS TROUGH CONTINUES TO DIRECT MID AND
HIGH-LEVEL MOISTURE UP INTO THE AREA AND LATER TODAY A SPOKE OF MID-
LEVEL ENERGY AND SHEAR WHICH THE RAP AND OTHER MODELS INDICATE
PASSING OVER NRN NEW MEXICO AT THIS TIME. EVEN WITH VARYING AMOUNTS
OF HIGH CLOUDINESS THIS MORNING STRONG DIABATIC HEATING SHOULD
MANAGE TO GENERATE 8-9C/KM BNDRY LAYER LAPSE RATES AND SFC BASED 600-
1200 J/KG CAPES ON THE PLAINS BY MIDDAY. WHILE THE WELL MIXED
BOUNDARY LAYER APPEAR LACKING OF MOISTURE...MODELS INDICATE A
GRADUAL INCREASE IN MID-LEVEL MOISTURE WITH INCREASING SELY MID-
LEVEL FLOW IN ADVANCE OF THE SHORTWAVE DISTURBANCE SWINGING UP FROM
SERN COLORADO. WHILE CONVECTIVE CLOUDS WILL BE ON THE INCREASE THIS
AFTERNOON...MODELS DO NOT INDICATE MUCH IN THE WAY OF QPF ON THE
PLAINS TODAY. INVERTED-V MODEL SOUNDINGS INDICATE A FAVORABLE SUB-
CLOUD ENVIRONMENT FOR MICROBURST FORMATION THIS AFTERNOON EVEN AS
MEAN LAYER PW VALUES CREEP UPWARD PRIOR TO PASSAGE OF THE U/A
DISTURBANCE TIMED TO OCCUR AROUND 00Z IN THE DENVER AREA. AFTER
00Z/SAT...THE MICROBURST THREAT SHOULD QUICKLY DIMINISH FROM SOUTH
TO NORTH WITH INFLUX OF DRIER MIX-LEVEL AIR BEHIND THE SHORTWAVE.
THIS DRYING IS FORECAST TO CONTINUE EVEN NEAR THE GROUND OVERNIGHT AS
MODELS SHOW A WELL PRONOUNCED DRY SLOT ROTATING UP FROM NEW MEXICO.

FOR THE HIGH COUNTRY...ODDS LOOK BETTER FOR MEASURABLE PRECIP
TODAY...BEGINNING AS EARLY AS LATE THIS MORNING. GREATER MOISTURE...
BETTER SYNOPTIC SCALE LIFT..INSTABILITY AND OROGRAPHICS SHOULD
PROVE ADEQUATE FOR SHOWER AND T-STORM FORMATION. SHOWERS AND
T-STORM MOTIONS WILL PRIMARILY SOUTH-TO-NORTH TODAY. SO THERE`S LITTLE
CHANCE THAT THE PLAINS WILL SEE MUCH IF ANY OF THIS HIGH COUNTRY
CONVECTION. GUSTY WINDS AND SHORT PERIODS OF LIGHT TO MODERATE
RAINFALL POSSIBLE THIS AFTERNOON THRU EARLY EVENING FROM THE
FRONT RANGE WESTWARD. I PUT THE CHANCE OF MEASURABLE PRECIP IN THE
HIGH COUNTRY AT 30-50 PCT...WITH AS FEW POCKETS OF 60 PCT OVER
THE HIGHER PEAKS AND RIDGES ROUGHLY NORTH OF I-70 LATE. LIKE THE
PLAINS...THE CHANCE OF PRECIP IN THE HIGH COUNTRY SHOULD STEADILY
DECREASE WITH CLOUD COVER OVERNIGHT WITH AN INFLUX OF DRIER AIR
FROM THE SOUTH AHEAD OF THE UPPER TROUGH.

TEMPERATURES TODAY WILL BE QUITE WARM AGAIN BUT NOT QUITE RECORD
TERRITORY. RECORD HIGH AT DENVER IS 86. SHOULD SEE LOW 80S IN THE
METRO AREA AND LOW TO MID 80S ACROSS THE PLAINS. HIGH COUNTRY WILL
ALSO BE UNSEASONABLY WARM TODAY WITH HIGHS IN THE UPPER 50S AND
60S. TONIGHT...TEMPERATURE WILL REMAIN QUITE MILD WITH MID 40S/
LOWER 50S ON THE PLAINS AND MOSTLY 30S IN THE HIGH COUNTRY.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 430 AM MDT FRI MAY 6 2016

LARGE UPPER LEVEL LOW WILL BE OVER THE GREAT BASIN SATURDAY. A
STRONG WAVE EMBEDDED IN THE SOUTHWEST FLOW ALOFT WILL MOVE ACROSS
EASTERN COLORADO SATURDAY AND EVENTUALLY BECOME THE NEW CENTER OF
THE UPPER LEVEL LOW SOMEWHERE OVER WYOMING OR NORTHEAST COLORADO.
FOR SATURDAY...A SURFACE LOW WILL BE OVER NORTHEAST COLORADO WITH
A BOUNDARY DRAPED ACROSS THE AREA. EASTERLY WINDS NORTH OF IT WILL
PUMP MOISTURE INTO THE AREA. SURFACE BASED CAPES WILL BE UP TO
2000 J/KG. THIS COMBINED WITH GOOD SHEAR IS EXPECTED TO PRODUCE
SEVERE THUNDERSTORMS WITH LARGE HAIL...STRONG WINDS AND POSSIBLY A
FEW TORNADOS. STILL SOME UNCERTAINTY WHERE THIS BOUNDARY WILL SET
UP. LATEST MODEL RUNS ARE LITTLE MORE NORTH AND HAS MOST OF THE
CONVECTION NORTH OF A LINE FROM FORT COLLING TO AKRON. STILL
WOULDN`T BE SURPRISED IF THIS BOUNDARY ENDS UP FARTHER SOUTH THAN
THE MODELS ARE FORECASTING.

ON SUNDAY...THE ECMWF HAS THE CENTER OF THE UPPER LEVEL LOW OVER
NORTHEAST COLORADO WHILE THE GFS SHOWS IT OVER WYOMING. NO STRONG
FEELING WHICH ONE IS RIGHT. IT WILL BE COOL AND IF THE LOW FORMS
OVER COLORADO...EXPECT MORE PRECIPITATION ACROSS THE AREA.

NORTHWEST FLOW WILL PREVAIL MONDAY AS THE UPPER LEVEL LOW WEAKENS
EAST OF COLORADO. STILL SHOULD BE ENOUGH MOISTURE AND INSTABILITY
TO TRIGGER SCATTERED/ISOLATED SHOWERS AND STORMS. ANOTHER UPPER
LEVEL LOW WILL MOVE INTO THE NORTHERN ROCKIES MONDAY. THIS LOW IS
EXPECTED TO DIG SOUTH INTO WYOMING TUESDAY. ISOLATED TO SCATTERED
CONVECTION WILL AGAIN BE POSSIBLE. THIS LOW IS EXPECTED TO MOVE
EAST OF THE AREA WEDNESDAY AND THURSDAY. COULD SEE A FEW SHOWERS
AND STORMS WEDNESDAY...BUT DRIER AND WARMER CONDITIONS SHOULD
PREVAIL THURSDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1053 AM MDT FRI MAY 6 2016

THROUGH THIS AFTERNOON AND TONIGHT...VFR CONDITIONS SHOULD
CONTINUE AT DENVER AREA AIRPORTS. THE DEVELOPMENT OF SOME
AFTERNOON SHOWERS WITH MICROBURST POTENTIAL STILL EXISTS THIS
AFTERNOON. GUSTS UP TO 40-45 MPH MAY ACCOMPANY THE HIGH BASED
SHOWERS. STORM MOTIONS WILL BE FROM SOUTH TO NORTH...GIVEN THE
INCREASING SOUTHERLY FLOW ALOFT IN PLACE OVER EASTERN COLORADO
TODAY. MOST SHOWER ACTIVITY SHOULD BE OVER BY 7 PM TO 8 PM.
SOUTHERLY WINDS ARE EXPECTED TO CONTINUE OVERNIGHT...ALTHOUGH THEY
COULD BE A BIT GUSTY AT TIMES. MORE THUNDERSTORMS ARE EXPECTED
SATURDAY AFTERNOON WHICH MAY BRING SOME HEAVY RAINS AND CEILINGS
DOWN TO MVFR AT TIMES.

&&

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

$$

UPDATE...DANKERS
SHORT TERM...BAKER
LONG TERM...MEIER
AVIATION...DANKERS


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.