Severe Thunderstorm Warning 9, NWS Denver/Boulder, CO

NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER COLORADO
305 PM MDT SAT MAY 22 1999

STORMS INCREASING IN COVERAGE ACROSS CWA...ESPECIALLY EASTERN
PLAINS.  SURFACE FRONT ACTING AS TRIGGER FOR DEVELOPMENT.  TORNADO
WATCH ALREADY ISSUED.

AFTER EVENING CONVECTION ACROSS PLAINS...UPSLOPE INTENSIFIES AS LOW
LEVEL MOISTURE INCREASES.  WILL MENTION FOG IN ZONES TONIGHT...SOME
AREAS COULD SEE DENSE FOG...ESPECIALLY EAST OF LIMON TO GREELEY
LINE.  SHOWERS SHOULD LINGER ACROSS MOUNTAINS AND HIGHER FOOTHILLS
AS UPSLOPE PUSHES FURTHER WEST.

ON SUNDAY...MODELS INDICATE A MORE STABLE AIRMASS...WHICH SHOULD
KEEP CONVECTION TO A MINIMUM.  LATE MORNING BREAKS IN CLOUD COVER
SHOULD ALLOW FOR ENOUGH SUN TO WARM THE LOWER LAYERS ENOUGH TO
WARRANT THE MENTION OF AFTERNOON SHOWERS AND THUNDERSTORMS.  EXTREME
NORTHEAST ZONES MAY BE TOO STABLE FOR ANY CONVECTION...BUT WILL
LEAVE SOME CHANCE OF SHOWERS THERE.  GUIDANCE TEMPERATURES SEEM TOO
WARM SUNDAY...BASED ON THICKNESS VALUES.

A BETTER CHANCE FOR DECENT CONVECTION MONDAY AFTERNOON AS SOUTHEAST
FLOW BRINGS A RETURN OF LOW LEVEL MOISTURE.  SHEAR ALSO BECOMES
FAVORABLE...AS UPPER LEVEL WINDS STRENGTHEN IN RESPONSE TO CUTOFF
LOW OVER ARIZONA BEGINNING TO MOVE NORTHEAST.  MODIFIED CAPE VALUES
SHOW READINGS OF 1500 JULES BY 00Z TUESDAY.  THUS...HIGHER POPS THAN
GUIDANCE WARRANTED FOR MOST ZONES.

THE UPPER LOW SHOULD CONTINUE TO GRADUALLY MOVE TOWARD THE AREA
DURING THE WEEK...WITH A BETTER CHANCE FOR CONVECTION EACH DAY.  IN
ADDITION...TEMPERATURES TO SHOW A COOLING TREND.   D-L

.DEN...NONE.

COZ030-032>050-230600-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
1150 AM MDT SAT MAY 22 1999

THIS OUTLOOK PERTAINS TO THE FOLLOWING COLORADO COUNTIES

ADAMS     ARAPAHOE     BOULDER   CLEAR CREEK   DENVER       DOUGLAS
ELBERT    GILPIN       GRAND     JACKSON       JEFFERSON    LARIMER
LINCOLN   LOGAN        MORGAN    PARK          PHILLIPS     SEDGWICK
SUMMIT    WASHINGTON   WELD

SYNOPSIS:  A COLD FRONT LYING ACROSS SOUTHEAST WYOMING LATE THIS
MORNING IS EXPECTED TO PUSH SOUTH THROUGH NORTHEAST COLORADO DURING
THE AFTERNOON.  LOW LEVEL MOISTURE ALONG AND BEHIND THE FRONT WILL
PROVIDE FUEL FOR SHOWERS AND THUNDERSTORMS LATER THIS AFTERNOON.
THUNDERSTORMS ARE EXPECTED TO BEGIN DEVELOPING IN THE NORTHEAST CORNER
OF COLORADO AFTER 2 PM WITH PASSAGE OF THE COLD FRONT THROUGH THE
AREA.

AS THE FRONT SLIDES SOUTH INTO MORE MOIST AND UNSTABLE AIR...
SOME OF THE THUNDERSTORMS DEVELOPING ALONG THE FRONT MAY BECOME
SEVERE.  LARGE DAMAGING HAIL AND STRONG WINDS APPEAR TO BE THE MAIN
SEVERE WEATHER THREAT WITH THUNDERSTORMS ON THE NORTHEAST PLAINS.
HOWEVER ISOLATED TORNADOES CAN NOT BE RULED OUT...PARTICULARLY IN
THE VICINITY OF THE COLD FRONT.

AT THIS TIME...THE MOST FAVORABLE AREA FOR SEVERE WEATHER LOOKS TO
BE ALONG AND EAST OF A LINE FROM GREELEY IN WELD COUNTY TO
BURLINGTON IN KIT CARSON COUNTY.  HOWEVER...A FEW THUNDERSTORMS MAY
APPROACH SEVERE WEATHER CRITERIA IN AREAS WEST OF THIS LINE LATE
THIS AFTERNOON AND EARLY THIS EVENING WITH THE COLD FRONT PUSHING UP
AGAINST THE FOOTHILLS.

SPOTTER ACTIVATION MAY BE REQUIRED AFTER 3 PM MDT THIS AFTERNOON.

BAKER