Tornadoes and Hail in Colorado, August 29, 2002

NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER COLORADO
330 AM MDT THU AUG 29 2002

REASONABLE AGREEMENT BETWEEN MODELS AND THE CURRENT FORECAST THIS
MORNING.  THERE ARE TWO JET MAXES IN THE APPROACHING DISTURBANCE.
THE FIRST ONE IS FAIRLY WEAK BUT IS HELPING SPREAD CLOUDS OVER THE
MOUNTAINS ALREADY.  THERE ARE SHOWERS COMING INTO WESTERN COLORADO
AND A GOOD CLUMP OF CONVECTION PROBABLY ASSOCIATED WITH A LITTLE
COOLING AT THE REAR.  THIS FEATURE IS HEADED FOR SERN WY AND WILL BE
AFFECTING THE MOUNTAINS THIS MORNING...BUT MAY NOT BRING CLOUDS ALL
THE WAY ONTO THE PLAINS.  THE SECOND AND STRONGER SPEED MAX WILL RUN
ACROSS THE STATE FROM SW TO NE DURING THE AFTERNOON AND EVENING.
THIS WILL BE WELL TIMED FOR A GOOD BATCH OF CONVECTION...THOUGH
CLOUD COVER WILL LIMIT THE INTENSITY.  WITH THE LEAD FEATURE GOING
NORTH OF US...THERE MAY ALSO BE SOME BACKING OF THE WIND ON THE
PLAINS AHEAD OF THE MAIN WAVE.  THE ETA HINTS AT SOME DRYING...BUT
DENVER CYCLONE MAY INTERFERE WITH THIS AND KEEP THE MOISTURE INTO
AREAS NORTH OF DENVER.  ALL THESE DETAILS SEEM TO POINT AT A LESSER
CHANCE OF STORMS SOUTHEAST OF THE DENVER CYCLONE BOUNDARY SINCE
THERE SHOULD BE LESS QG FORCING AND STORMS THAT FORM AROUND DENVER
OR MONUMENT RIDGE WILL HEAD NORTHEAST.  STILL ENOUGH CAPE FOR A
SEVERE HAIL THREAT ESPECIALLY THIS EVENING WHEN LOW LEVEL
CONVERGENCE AND BOUNDARY COLLISIONS WILL PRODUCE SOME STRONG PULSES
IN THE CONVECTION.  PROBABLY ALSO ENOUGH SE WIND ON THE PLAINS FOR A
SMALL TORNADO THREAT IN THE EVENING.

THE SHORTWAVE PASSES BY MORNING WITH CLEARING AND SUBSIDENCE.  THERE
COULD STILL BE SOME SHALLOW LOW LEVEL MOISTURE AND THE ETA DOES
DEVELOP SOME CLOUD COVER...BUT SOUNDINGS SHOW A MID LEVEL CAP OVER
THE SHALLOW CONVECTION.  LOW LEVELS SHOULD CONTINUE TO DRY ON SAT.

FOR SUN THROUGH WED...NO CHANGES NEEDED.  LATEST AVN HEADED TOWARD
THE ECMWF SOLUTION OF MORE AMPLIFIED PATTERN WITH A BIT MORE OF A
FRONT SUN BUT THEN FAIRLY STRONG RIDGING BY THE MIDDLE OF NEXT WEEK.
GIMMESTAD

.DEN...NONE.

COZ030>051-292000-

HAZARDOUS WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER COLORADO
1000 AM MDT THU AUG 29 2002

THIS OUTLOOK PERTAINS TO THE FOLLOWING COLORADO COUNTIES

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

SYNOPSIS: A MOIST AND UNSTABLE AIRMASS WILL CONTINUE ACROSS NORTH
CENTRAL AND NORTHEASTERN COLORADO TODAY.  AN UPPER LEVEL TROUGH IS
EXPECTED TO BRUSH ACROSS NORTHERN COLORADO LATE THIS AFTERNOON AND
TONIGHT.  THE LIFT FROM THIS SYSTEM...COUPLED WITH AFTERNOON HEATING
...WILL ALLOW FOR SCATTERED THUNDERSTORMS TO DEVELOP ACROSS MUCH OF
THE AREA THIS AFTERNOON AND EVENING.

SUFFICIENT SHEAR WILL BE PRESENT FOR A FEW SEVERE THUNDERSTORMS
...SIMILAR TO WHAT HAS OCCURRED OVER THE PAST FEW DAYS.  CLOUD COVER
MAY AGAIN DELAY THE ONSET OF THE STRONGER STORMS UNTIL THE UPPER
TROUGH MOVES INTO THE REGION LATE THIS AFTERNOON.

THE BEST POTENTIAL FOR SEVERE WEATHER WILL OCCUR JUST TO THE EAST OF
THE URBAN CORRIDOR...WHERE THE BEST POOL OF LOW LEVEL MOISTURE
RESIDES.  LARGE HAIL...DAMAGING WINDS AND LOCALLY HEAVY RAIN WILL BE
THE MAIN THREATS.  A FEW WEAK TORNADOES MAY ALSO OCCUR ALONG ANY
COLLIDING OUTFLOW BOUNDARIES.

SPOTTER ACTIVATION MAY BE NECESSARY AFTER 3 PM.

OUTLOOK FOR FRIDAY...WARMER AND MUCH DRIER.

COOPER