Severe Thunderstorm Warning 20, NWS Denver/Boulder, CO

NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER COLORADO
230 PM MDT MON MAY 28 2001

SHORT TERM DISCUSSION:  WEAK SHORT WAVE AHEAD OF MAIN H5 TROUGH
LOCATED IN THE GREAT BASIN WILL MAKE ITS WAY ACROSS COLORADO LATE
THIS AFTERNOON AND TONIGHT.  MOVEMENT MAY BE SLOW ENOUGH TO KEEP THE
MENTION OF SHOWERS OVERNIGHT...THIS IS SUPPORTED BY THE ETA MODEL.
FCST SOUNDINGS INDICATE CAPES FROM 1200-1600 J/KG LATE THIS AFTN...
WITH TEMPERATURES IN THE LOWER 70S AND DEWPOINTS IN THE MID 40S...
BOTH OF WHICH HAVE BEEN MET THIS AFTERNOON.  SHEAR HOWEVER NOT THAT
IMPRESSIVE ALOFT...BUT FAIRLY STRONG SOUTHEASTERLY FLOW IS PROGGED
AT THE SURFACE ACROSS THE NORTHEASTERN PLAINS THIS EVENING.  THIS
MAY BE SUFFICIENT ENOUGH TO FIRE OFF A FEW SEVERE STORMS ACROSS THE
PLAINS LATE THIS AFTERNOON AND EVENING.  LARGE HAIL WOULD LIKELY BE
THE PRIMARY THREAT.

LONG TERM DISCUSSION:  MAIN H5 TROUGH SLOWLY TRACKS ACROSS
NORTHEASTERN COLORADO TUESDAY AND TUESDAY NIGHT.  COLD FRONT MOVES
IN FROM THE NORTH DURING THE EVENING HOURS...WITH STRONG INSTABILITY
ACROSS THE NORTHEASTERN PLAINS DURING THE AFTERNOON.  AVN THE
STRONGEST WITH THIS PUSH WITH SHOWERS AND EVEN A LITTLE UPSLOPE FOR
THE URBAN CORRIDOR FROM 00-06Z.  THE ETA ON THE OTHER HAND
INDICATES THE BEST RAINFALL WILL BE ACROSS EASTERN BORDER WITH
LITTLE IF ANY UPSLOPE DEVELOPING.  ETA FCST SOUNDINGS YIELD CAPES
RANGING FROM 1700 J/KG NEAR DENVER TUESDAY AFTN TO A WHOPPING 3000
J/KG IN THE VICINITY OF LIMON...ASSUMING TEMPERATURES REACH THE LOW
70S WITH DEWPOINTS IN THE 45-55 RANGE.  FLOW ALOFT IS WEAK...SO
SHEAR PROFILE MAY NOT BE THAT GREAT ALOFT...THE LOW LEVEL SHEAR
HOWEVER WILL BECOME MORE FAVORABLE IF EAST-SOUTHEASTERLY FLOW
REDEVELOPS AS AVN HAS ADVERTISED.

BY WEDNESDAY...NWLY FLOW ALF RETURNS WITH TROF WELL EAST OF COLORADO
AND BROAD RIDGE BUILDING OVER THE WEST.  SCT POPS LOOK GOOD FOR
THIS TIME FRAME AS MOISTURE LINGERS ACROSS THE CWA AT LEAST THROUGH
WEDNESDAY.  ENOUGH MOISTURE FOR A FEW STORMS IN THE MOUNTAINS
THURSDAY...WITH DRYING TREND EXPECTED FRIDAY THROUGH MONDAY.  RIDGE
DOES SHIFT EAST BY THE EARLY PART OF NEXT WEEK...WITH A DRY
SOUTHWESTERLY FLOW OVER CO AS NEXT TROUGH MOVES INTO THE PACIFIC
NORTHWEST.  COOPER

.DEN...NONE.

COZ030>051-282200-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
200 PM MDT MON MAY 28 2001

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:  SCATTERED THUNDERSTORMS HAVE DEVELOPED OVER THE MOUNTAINS
THIS AFTERNOON...AND WILL SPREAD ONTO THE PLAINS BY LATE AFTERNOON.
A WIND CONVERGENCE LINE HAS DEVELOPED FROM NORTH OF CASTLE ROCK TO
DENVER INTERNATIONAL AIRPORT.  TO THE EAST OF THIS LINE SOUTH TO
SOUTHEAST WINDS WERE INCREASING AND RICHER MOISTURE WAS MOVING NORTH
INTO ELBERT AND LINCOLN COUNTIES.  IN ADDITION...AN UPPER LEVEL
DISTURBANCE IS STILL ON TRACK TO MOVE FROM THE MOUNTAINS ONTO THE
PLAINS THIS EVENING.

THE WIND SHIFT LINE IS EXPECTED TO START MOVING EAST...WITH STRONG
THUNDERSTORMS DEVELOPING AS THE BETTER MOISTURE ARRIVES.  THE BEST
THREAT OF SEVERE WEATHER WILL BE SOUTH OF A LINE FROM CASTLE ROCK TO
BYERS TO YUMA.  THE PRIMARY THREAT WILL BE HAIL TO AROUND ONE INCH
IN DIAMETER...THOUGH WIND GUSTS TO AROUND 60 MPH ARE ALSO POSSIBLE.
A FEW TORNADOES ARE ALSO POSSIBLE IN EASTERN ELBERT OR LINCOLN
COUNTIES THIS EVENING AS THE STORMS MOVE INTO MORE FAVORABLE WIND
AND MOISTURE FIELDS.

SPOTTER ACTIVATION MAY BE NEEDED LATE THIS AFTERNOON.

GIMMESTAD