Severe Thunderstorm Warning 174, NWS Denver/Boulder, CO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
330 PM MDT SUN AUG 15 2004

.SHORT TERM DISCUSSION...LOW TOP CONVECTION OVER THE MOUNTAINOUS
TERRAIN...PARK COUNTY AND ALONG A WIND CONVERGENCE BOUNDARY IN
ELBERT AND EASTERN ARAPAHOE/ADAMS COUNTIES HAS BEEN SLOW TO DEVELOP
THIS AFTERNOON DUE IN PART TO A GRADUAL REDUCTION IN MOISTURE AND
SOME STABILIZATION AT MID-LEVELS. ON THE PLAINS...AREAS SHROUDED IN
FOG AND LOW CLOUDS NEARLY ALL MORNING STILL PRETTY MUCH DEVOID OF
CLOUDS AT THIS HOUR. MM5 OMEGA AND SFC THETA-E FIELDS ONLY GRIDS TO
PICK UP ON THE POTENTIAL INSTABILITY AXIS ASSOCIATED WITH THE WIND
CONVERGENCE BOUNDARY EAST OF THE DENVER METRO AREA. BOUNDARY HAS
SHOWN VERY SLOW WESTWARD PROGRESS PAST COUPLE OF HOURS. MAY SEE ONE
OR TWO T-STORMS POP ALONG THIS BOUNDARY NEXT FEW HOURS...BUT SHEAR
AND INSTABILITY NOT LOOKING ALL THAT FAVORABLE FOR DEEP CONVECTION.
SAME GOES FOR THE ISOLATED T-STORMS TRYING TO FORM OVER THE FRONT
RANGE AND CHEYENNE RIDGE. MAY SEE ONE OR TWO OF THESE CELLS ROLL OFF
THE HIGHER TERRAIN AND OVER THE URBAN CORRIDOR LATE THIS AFTERNOON.
GUSTY WINDS AND LIGHTNING THE MAIN THREAT AS SFC DEW POINTS ALONG
THE FOOTHILLS HAVE DROPPED INTO THE 40S IN MANY AREAS EVEN WITH
LIGHT E/SELY LOW-LEVEL FLOW. OVERNIGHT...GRIDS SHOW SLY LOW LEVEL
FLOW ADVECTING HIGHER DEWPT AIR UP INTO LINCOLN CTY AND NERN CORNER
OF THE STATE. SHOULD SEE AT LEAST PATCHY FOG FORMING AGAIN AFTER
MIDNIGHT IN AREAS EAST OF A FORT MORGAN TO KIOWA LINE.

ON MONDAY...COLD FRONT IN NERN WY AND SD ATTM PROGGED TO SLIDE SWRD
DOWN THE I-25 URBAN CORRIDOR BY AROUND 12Z...THEN SEWRD ACRS THE
NERN PLAINS OF COLORADO DURING THE MORNING. INITIALLY NLY POST-
FRONTAL FLOW SHOULD LOWER SFC DEWPTS AND WARM TEMPS DURING THE
MORNING WITH FLOW DOWNSLOPING OFF THE CHEYENNE RIDGE. BUT BY EARLY
AFTERNOON...GRIDS SHOULD WINDS TURNING ELY AND SPEEDS INCREASING AS
A SECOND SURGE OF HIGH PRESSURE AIR PUSHES SWRD THRU NERN CO. SEE A
FAIRLY RESPECTABLE JUMP IN DEWPTS AND THETA-E VALUES WITH ARRIVAL OF
THIS SURGE. SHOULD SEE STORMS FIRING FIRST OVER THE FRONT RANGE
AROUND MIDDAY...BEFORE SPREADING ONTO THE PLAINS. NRN FOOTHILLS AND
LARIMER CTY MAY SEE A FEW HVY RAINERS BY MID-AFTERNOON WITH
FAVORABLE SELY UPSLOPE FLOW. HAVE GONE WITH SCATTERED POPS
EVERYWHERE EXCEPT IN THE NRN MTN VALLEYS AND OUT NEAR NORTHEAST
CORNER OF THE STATE.  FINALLY...TEMPS PROBABLY ABOUT THE SAME AS
TODAY. MAY EVEN SEE A FEW LATE DAY STORMS ON THE PLAINS GOING
SEVERE.

.LONG TERM DISCUSSION...MON NGT-WED...MDLS KEEP NWLY FLO ALF ACRS
CNTRL RCKYS AS UPR RDG REMAINS ENTRENCHED OVER WRN U.S.  THE AIR
MASS ACRS THE FCST AREA WILL REMAIN MOIST AND UNSTABLE WITH LATE
DAY HEATING.  CAPES FM FCST UPR AIR SOUNDINGS ON MON NGT RANGE FM
OVER 200J/KG IN THE HI COUNTRY TO NEARLY 1100J/KG OVR PLAINS ON
MON NGT.  CAPES ARE FCST TO BE LWR ON TUE AFTN AND EVE BUT MDLS
SHW QUITE A BIT OF PCPN.  ON WED A GUD SHT WV WILL ADD LIFT TO
THE AIR MASS IN FORM UPWRD Q-G FORCING AND PVA.  WILL KEEP MOST
POPS SCT DURING AFTNS AND EVES THRU PRD.  TEMPS WILL REMAIN AT
OR BLO SEASONAL NORMS WITH WED THE COOLEST DAY AS SURFACE HI PRES
SPREADS S OVR HI PLAINS.  WILL MAKE ONLY SML ADJUSTMENTS TO GFS
MOS TEMP GUIDANCE.

IN EXTENDED PERIOD...THU-SUN...MDLS MAINTAIN UPR RDG OVR WRN U.S.
WITH CONTD MOIST NWLY FLO ALF ACRS CNTRL RCKYS.  SHT WVS EMBEDDED
IN NWLY FLO ALF WILL ONLY BRUSH STATE AS MAIN JET STREAM FLO WILL
REMAIN WELL TO NE OF AREA.  WILL KEEP CHC OF AFTN AND EVE CONVCTN
EACH DAY THRU PRD.  TEMPS WILL GENERALLY BE BLO SEASONAL NORMS.

&&

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

&&

BAKER/GARD...WFO BOULDER

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE DENVER CO
1242 PM MDT SUN AUG 15 2004

COZ030>051-161200-
JACKSON COUNTY BELOW 9000 FEET-WEST JACKSON AND WEST GRAND
COUNTIES ABOVE 9000 FEET-GRAND AND SUMMIT COUNTIES BELOW 9000
FEET-SOUTH AND EAST JACKSON/LARIMER/NORTH AND NORTHEAST GRAND/
NORTHWEST BOULDER COUNTIES ABOVE 9000 FEET-SOUTH AND SOUTHEAST
GRAND/WEST CENTRAL AND SOUTHWEST BOULDER/GILPIN/CLEAR CREEK/
SUMMIT/NORTH AND WEST PARK COUNTIES ABOVE 9000 FEET-LARIMER AND
BOULDER COUNTIES BETWEEN 6000 AND 9000 FEET-JEFFERSON AND WEST
DOUGLAS COUNTIES ABOVE 6000 FEET/GILPIN/CLEAR CREEK/NORTHEAST PARK
COUNTIES BELOW 9000 FEET-CENTRAL AND SOUTHEAST PARK COUNTY-LARIMER
COUNTY BELOW 6000 FEET/NORTHWEST WELD COUNTY-BOULDER AND JEFFERSON
COUNTIES BELOW 6000 FEET/WEST BROOMFIELD COUNTY-NORTH DOUGLAS
COUNTY BELOW 6000 FEET/DENVER/WEST ADAMS AND ARAPAHOE COUNTIES/
EAST BROOMFIELD COUNTY-ELBERT/CENTRAL AND EAST DOUGLAS COUNTIES
ABOVE 6000 FEET-NORTHEAST WELD COUNTY-CENTRAL AND SOUTH WELD
COUNTY-MORGAN COUNTY-CENTRAL AND EAST ADAMS AND ARAPAHOE COUNTIES-
NORTH AND NORTHEAST ELBERT COUNTY BELOW 6000 FEET/NORTH LINCOLN
COUNTY-SOUTHEAST ELBERT COUNTY BELOW 6000 FEET/SOUTH LINCOLN
COUNTY-LOGAN COUNTY-WASHINGTON COUNTY-SEDGWICK COUNTY-PHILLIPS
COUNTY-
1242 PM MDT SUN AUG 15 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL
COLORADO.

.DAY ONE...TODAY AND TONIGHT

ISOLATED THUNDERSTORMS WILL DEVELOP THIS AFTERNOON OVER THE FRONT
RANGE...PARK COUNTY AND ALONG A WIND CONVERGENCE BOUNDARY SITTING
NEARLY STATIONARY ACROSS ELBERT AND EASTERN ARAPAHOE COUNTIES. ONE
OR TWO STORMS MAY DRIFT OFF THE FOOTHILLS AND OVER THE I-25 URBAN
CORRIDOR LATE THIS AFTERNOON AND EARLY THIS EVENING. FARTHER OUT
ACROSS THE NORTHEAST PLAINS OF COLORADO...THE ATMOSPHERE SHOULD
REMAIN CAPPED FOR MUCH OF THE DAY...WHICH SHOULD DELAY THE FORMATION
OF ISOLATED THUNDERSTORMS UNTIL THIS EVENING. THUNDERSTORMS STORMS
ARE NOT EXPECTED TO BECOME SEVERE...BUT THEY MAY PRODUCE WIND GUSTS
TO AT LEAST 40 MPH...DEADLY CLOUD-TO-GROUND LIGHTNING AND BRIEF
HEAVY RAINFALL.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.

BAKER/GARD...WFO BOULDER