Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 181607
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1007 AM MDT MON AUG 18 2014

.UPDATE...
ISSUED AT 1002 AM MDT MON AUG 18 2014

BAND OF MOISTURE ON THE SOUTH SIDE OF A JET STREAK WILL BE ACROSS
NORTHERN COLORADO TODAY...LIKELY REMAINING JUST NORTH OF DENVER.
NOT MUCH IN THE WAY OF LOW LEVEL WINDS...WE WILL HAVE NNW WINDS
MIXING DOWN AT MIDDAY WITH SOME COMBINATION OF THE DIURNAL
UPSLOPE AND A BIT OF ANTICYCLONIC TURNING...ALSO NORTHEAST...LIKELY
DOMINATING THIS AFTERNOON NEAR THE MOUNTAINS. MODELS ARE INSISTENT
ON CHEYENNE RIDGE CONVECTION DOMINATING AND THIS DOES APPEAR TO BE
WHERE THE MAXIMUM ENERGY WILL BE...SO STUCK WITH THIS IDEA. RAISED
POPS AND CLOUD COVER A LITTLE FOCUSED ON THESE FEATURES. MAX TEMPS
MAY BE A BIT AMBITIOUS IF THE CLOUD COVER FILLS IN...BUT WE WILL
PROBABLY GET THAT WARM FIRST...THEN COOL A LITTLE LATER IN THE
DAY.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 214 AM MDT MON AUG 18 2014

THE BROAD HIGH PRESSURE RIDGE ALOFT WILL GRADUALLY SHIFT EASTWARD
AND WEAKEN A BIT INTO NORTHERN NEW MEXICO THROUGH TONIGHT. WITH
TIME TODAY...IT APPEARS THERE WILL BE MORE MOISTURE AVAILABLE FOR
STORMS THAN PREVIOUS DAYS. THERE IS ALREADY SOME SCATTERED SHOWERS
DEVELOPING OVER EASTERN UTAH AND FAR WESTERN COLORADO EARLY THIS
MORNING.

AT THE SURFACE...WEAK UPSLOPE WILL DEVELOP BY AFTERNOON OVER THE
NORTHEAST PLAINS AS SURFACE HIGH PRESSURE BUILDS IN FROM THE NORTH
AND EAST. THIS WILL USHER IN HIGHER DEWPOINT AIR WITH READINGS IN
THE 50S FOR LOCATIONS NORTH AND EAST OF DENVER. TEMPERATURES WILL
BE SLIGHTLY COOLER TODAY BEHIND THE WEAK FRONTAL BOUNDARY. GIVEN
THE HIGHER DEWPOINTS...SURFACE BASED CAPES INCREASE TO 1000-2000J/KG.
SHORT RANGE MODELS STILL IFFY ON LOCATION AND COVERAGE OF
STORMS...STILL MAINLY ISOLATED IN COVERAGE. BOTH NAM/HRRR SEE TO
DEVELOP AND FOCUS STRONGEST STORMS OVER THE CYS RIDGE AND THEN
MOVING INTO THE FAR NORTHEAST PLAINS. AIRMASS WILL BE INITIALLY
CAPPED OVER THE PLAINS BUT SHOULD BE ABLE TO GET GOING FROM OTHER
ACTIVITY FROM HIGHER TERRAIN. GIVEN HIGH CAPES...COULD BE AN
ISOLATED SEVERE STORM OVER THE PLAINS WITH HAIL AND DAMAGING
WINDS. VERY LITTLE SUPPORT ALOFT SO EXPECT STORMS TO MAINLY
DIMINISH BY MIDNIGHT.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 214 AM MDT MON AUG 18 2014

ON TUE AN UPPER LEVEL DISTURBANCE IN SW FLOW ALOFT STILL LOOKS LIKE
IT WILL AFFECT THE AREA IN THE AFTN AND EVENING HOURS.  IN ADDITION
MONSOON MOISTURE WILL INCREASE AS WELL SO SHOULD SEE A BETTER CHC
TSTMS IN MOST AREAS.  CAPES OVER THE NERN PLAINS WILL BE IN THE 1500-
2000 J/KG RANGE SO AS STORMS MOVE INTO BETTER INSTABILITY AND HIGHER
THETA E MAY SEE SOME HEAVIER RAINFALL.  AS FOR TEMPS WILL KEEP HIGHS
IN THE MID 80S TO LOWER 90S OVER NERN CO.

FOR WED SW FLOW ALOFT WILL REMAIN OVER THE AREA HOWEVER THERE
WILL BE A DECREASE IN MONSOON MOISTURE WITH LOWER INSTABILITY SO
WILL KEEP BEST CHC OF STORMS IN THE MTNS WITH ISOLD TO WDLY SCT
ACTIVITY ELSEWHERE. HIGHS ON WED WILL BE IN THE UPPER 80S TO LOWER
90S OVER NERN CO. BY THU THE FLOW ALOFT IS STILL FCST TO BE SWLY.
THE GFS SHOWS ANOTHER DISTURBANCE ALONG WITH AN INCREASE IN
MONSOON MOISTURE WHILE THE ECMWF DOES NOT SHOW THIS DISTURBANCE
AND HAS CONSIDERABLY LESS MOISTURE. FOR NOW WILL KEEP BEST CHC OF
STORMS IN THE MTNS WITH A SLIGHT CHANCE ELSEWHERE UNTIL IT BECOMES
MORE CLEAR AS TO WHICH WAY TO TREND POPS. HIGHS ON THU LOOK
SIMILAR TO WED IN MOST AREAS.

BY FRI SWLY MID LVL FLOW IS STILL SUPPOSED TO BE OVER THE AREA AS
THE GFS SHOWS ANOTHER DISTURBANCE MOVING ACROSS WHILE THE ECMWF DOES
NOT SHOW THIS FEATURE.  HOWEVER BOTH MODELS DO SHOW MONSOON MOISTURE
INCREASING ALONG WITH BETTER INSTABILITY SO THERE MAY END UP BEING A
BETTER CHC OF STORMS REGARDLESS IF THERE IS A DISTURBANCE OR NOT.
AS FOR HIGHS THE GFS ONLY HAS HIGHS IN THE LOWER TO MID 80S FOR NERN
CO WHILE THE ECMWF IS IN THE UPPER 80S TO LOWER 90S.  FOR NOW WILL
KEEP READINGS IN THE 85 TO 90 DEGREE RANGE.

FOR NEXT SAT THE GFS HAS WLY FLOW ALOFT DEVELOPING WITH DRIER AIR
SPREADING ACROSS THE AREA WITH A DECREASING CHC OF TSTMS WHILE THE
ECMWF HAS A DISTURBANCE MOVING ACROSS IN SW FLOW ALOFT AS A COLD
FRNT MOVES INTO NERN CO BY SAT AFTN OR EVENING.  AS A RESULT IT HAS
A BETTER CHC OF PCPN.  FOR NOW WILL JUST MENTION A SLIGHT CHC OF
TSTMS WITH HIGHS IN THE 80S OVER NERN CO.  BY SUN THE ECMWF SHOWS
COOLER AND DRIER AIR ACROSS THE AREA WHILE THE GFS SHOWS AN INCREASE
IN MOISTURE WITH BETTER INSTABILITY AND A CHC OF TSTMS.  ONCE AGAIN
WILL JUST MENTION LOW POPS AREA WIDE AND KEEP HIGHS IN THE LOWER TO
MID 80S OVER NERN CO.

&&

.AVIATION...(FOR THE TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1002 AM MDT MON AUG 18 2014

ISOLATED THUNDERSTORMS EXPECTED AROUND DENVER THIS
AFTERNOON...POSSIBLY MORE OVER THE MOUNTAINS AND IN NORTHEASTERN
COLORADO. A CHANCE OF AN OUTFLOW BOUNDARY OR TWO WITH WINDS
GUSTING TO 30 KNOTS...OTHERWISE LITTLE OR NO IMPACT EXPECTED AT
THE DENVER AREA TERMINALS.

&&

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

$$

UPDATE...GIMMESTAD
SHORT TERM...ENTREKIN
LONG TERM...RPK
AVIATION...GIMMESTAD


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