Severe Thunderstorm Warning 59, NWS Denver/Boulder, CO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
240 AM MDT THU JUN 17 2004

.SHORT TERM...AREAS OF FOG AND LOW CLOUDS WILL BE WIDESPREAD THRU
THE MORNING HOURS ACRS NERN CO DUE TO WEAK UPSLOPE FLOW.  SOUNDINGS
SHOW LOW CLOUDS SHOULD BEGIN TO BREAKUP AROUND 16Z OR SO ALONG THE
FRONT RANGE.  COULD SEE SOME LOCAL DENSE FOG IN A FEW SPOTS BUT WILL
NOT ISSUE A DENSE FOG ADVISORY AT THIS TIME.  FOR THIS AFTN SHOULD
SEE SOME TYPE OF DENVER CYCLONE DEVELOP AND LOCATION OF CONVERGENCE
ZONE WILL LIKELY BE A GOOD FOCUS FOR TSTM DEVELOPMENT.  MM5 HAS
CONVERGENCE ZONE ACROSS THE DENVER METRO AREA WHILE MESO-ETA HAS IT
FURTHER EAST ACROSS ERN ADAMS AND ARAPAHOE COUNTIES INTO ELBERT
COUNTY.  OTHER TSTMS MAY ALSO DEVELOP OVER THE HIGHER TERRAIN BY
EARLY AFTN AND MOVE ACROSS THE I-25 CORRIDOR AS WELL.  SFC BASED
CAPES BASED ON MAX TEMPS ARE FORECAST TO RANGE FROM 1000-1700 J/KG
WITH HIGHEST VALUES OVER ERN ELBERT AND LINCOLN COUNTIES.  WITH
FAIRLY DECENT FLOW ALOFT AND FAVORABLE SHEAR PROFILE SHOULD SEE SOME
SEVERE STORMS THIS AFTN ESPECIALLY FROM DENVER SOUTH TO THE PALMER
DIVIDE EXTENDING EASTWARD INTO THE PLAINS.  LARGE HAIL/STRONG WINDS
WOULD BE THE MAIN THREAT ALTHOUGH COULD SEE A BRIEF TORNADO OR TWO
ALONG THE DENVER CONVERGENCE.  FOR TONIGHT CONVECTION WILL PROBABLY
DEVELOP INTO AN MCS AND THEN MOVE EAST SOUTHEAST OUT OF AREA BY
MIDNIGHT.  WITH WEAK UPSLOPE FLOW CONTINUING OVERNIGHT WILL LIKELY
SEE MORE LOW CLOUDS AND FOG REVELOPMENT LATE TONIGHT OVER PORTIONS
OF NERN CO.

.LONG TERM DISCUSSION...FOR FRIDAY...A MODERATE WLY FLOW WILL BE
OVER COLORADO WITH A BROAD BUT FLAT UPPER RIDGE OVER THE SRN U.S.
AND UPPER TROF AXIS STRETCHING W TO E OVR THE PACIFIC NORTHWEST.
THE ETA/GFS BOTH SHOW A WEAK DISTURBANCE EMBEDDED IN THE FLOW
POSSIBLY MOVING THROUGH SRN WY/NRN CO BY FRIDAY AFTERNOON.   THERE
IS SOME WEAK QG ASCENT ASSOCIATED WITH THIS FEATURE.  ANOTHER FAIRLY
DECENT SURGE ASSOCIATED WITH A COOL CANADIEN AIRMASS WILL MOVE INTO
NORTHEASTERN COLORADO FRIDAY AFTERNOON AND EVENING...WITH LOW LEVEL
UPSLOPE DEVELOPING LATE FRIDAY AFTERNOON AND FRIDAY NIGHT.  THE BEST
POTENTIAL COMBINATION FOR MSTR AND INSTBY WILL AGAIN BE IN AND NEAR
THE PALMER DIVIDE AND SRN FRONT RANGE FOOTHILLS WITH POTENTIAL CAPES
OF 2200 J/KG...SO WILL KEEP MOST FVBL POPS RESERVED FOR THOSE
LOCATIONS.  AMS WILL BE SLIGHTLY MORE STABLE ON SATURDAY WITH SFC
HIGH STILL IN PLACE...AND UPPER RIDGE OVER THE SRN U.S. SLIGHTLY
BUILDING...ALLOWING FOR MORE OF A NORTHWESTERLY FLOW OVR NRN CO.
ETA BUFFER SOUNDINGS AGAIN SHOW FAIRLY STABLE AMS IN PLACE OVER THE
NERN PLAINS WITH THE EXCEPTION OF THE SRN AND WRN FRINGES OF THE
CWFA.  BEST POTENTIAL FOR THUNDERSTORMS WILL BE OVER THE PALMER
DIVIDE ON SATURDAY...ASSUMING WE WARM UP ENOUGH.  WILL GO FOR
SLIGHTLY COOLER TEMPERATURES ON SATURDAY WITH SOME MINOR POP
ADJUSTMENTS THROUGH THE WEEKEND.  OTHERWISE WILL LEAVE RMNDR OF THE
FORECAST AS IS.

&&

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

KLEYLA/COOPER

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE DENVER CO
1111 AM MDT THU JUN 17 2004

COZ030>051-181200-
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-
1111 AM MDT THU JUN 17 2004

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

.DAY ONE...TODAY AND TONIGHT

THERE IS A THREAT OF SEVERE THUNDERSTORMS ACROSS NORTHEAST AND NORTH
CENTRAL COLORADO THIS AFTERNOON.

SHOWERS AND THUNDERSTORMS WILL BECOME MORE WIDESPREAD ACROSS THE
AREA THIS AFTERNOON AND EVENING.  ALTHOUGH THE ATMOSPHERE IS QUITE
COOL...THERE IS JUST ENOUGH SUNSHINE OVER THE MOUNTAINS SOUTH OF
INTERSTATE 70 AND ACROSS THE PALMER DIVIDE AREA TO SPARK THE
DEVELOPMENT OF SEVERE THUNDERSTORMS.  THE THREAT OF SEVERE
WEATHER IS HIGHEST FROM PARK AND SOUTHERN JEFFERSON COUNTIES
EASTWARD THROUGH DOUGLAS...ELBERT...LINCOLN...AND WASHINGTON
COUNTIES.  FARTHER NORTH...ONLY AN ISOLATED SEVERE STORM IS
POSSIBLE.  THE MAIN THREAT FROM A SEVERE STORM TODAY WOULD BE LARGE
HAIL. A SHORT LIVED TORNADO IS POSSIBLE ALONG A CONVERGENCE
ZONE EXTENDING FROM DOUGLAS COUNTY THROUGH ELBERT AND EASTERN
ARAPAHOE COUNTIES.  OTHER STORMS TODAY WILL PRODUCE A BRIEF PERIOD
OF MODERATE TO HEAVY RAIN AND ONLY SMALL HAIL.  ENOUGH RAIN MAY FALL
IN THE BURN AREAS OF THE FOOTHILLS TO PRODUCE FLOODING PROBLEMS.

A STRONG UPPER LEVEL DISTURBANCE MOVING ACROSS THE REGION AND
UPSLOPE FLOW EAST OF THE CONTINENTAL DIVIDE WILL PROVIDE THE BETTER
CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

A MOIST AND UNSTABLE AIRMASS WILL REMAIN IN PLACE WHILE ANOTHER COLD
FRONT IS EXPECTED TO MOVE THROUGH THE REGION ON FRIDAY AFTERNOON.
ALTHOUGH THE FAR NORTHEASTERN PLAINS WILL BE TOO COOL AND CLOUDY TO
SUPPORT CONVECTION...SOME STORMS WILL BE POSSIBLE IN THE HIGH
COUNTRY AND ON THE PLAINS FROM I-70 SOUTHWARD.  SOME STORMS MAY BE
SEVERE...PARTICULARLY IN AREAS SUCH AS ELBERT AND LINCOLN COUNTY.
SATURDAY THROUGH WEDNESDAY...THERE WILL BE AT LEAST A SLIGHT CHANCE
OF THUNDERSTORMS EACH DAY AS THE ATMOSPHERE WILL BE UNSTABLE DURING
THE AFTERNOON AND EVENING HOURS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE REQUIRED BY 1 PM.

BARJENBRUCH/046