Tornado and Hail in Colorado, June 4, 2001

NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER COLORADO
310 PM MDT MON JUN 4 2001

SHORT TERM DISCUSSION:  T-STORMS HAVE ALREADY FIRED UP OVR THE
NRN FRONT RANGE AND JUST NE OF DEN METRO AREA AS OF 20Z.  STORMS
WERE PRODUCING PLENTY OF CG LIGHTNING AND HAIL.  STORMS ON THE
SOUTHERN EDGE OF A MUCH LARGER STORM REGION IN WY WHERE BEST MID-LVL
Q-DIV AND INSTABILITY WAS ON LEFT EXIT QUAD OF 80+ KT JET MAX
PASSING OVR NRN CO ATTM.  STORM ACTVTY EXPECTED TO SHIFT SWRD ACRS
NERN CO THIS EVE WITH THE URBAN CORRIDOR AND ADJACENT CTYS IN BEST
POSITION FOR STG T-STORMS.  AREA LIES ALONG SFC-700 THETA-E RIDGE
AXIS WITH HIGHEST SB CAPES AND INSTABILITY THRU 03Z.  HWVR LATEST
ACARS SOUNDINGS OVR DEN SHOW A PRETTY STG CAP AT ABOUT 650 MBS AS OF
21Z...PSBLY EXPLAINING WHY CNVCTN SLOW TO GET GOING THIS AFTN.  BLV
IT/S ONLY A MATTER OF TIME BEFORE CAP BREAKS AND STORMS REALLY GET
GOING.  0-3KM HELICITIES OF 150-220 M2/S2 ALONG CONVERGENCE BNDRY
STRETCHING W ACRS NRN LINCOLN...SRN WASHINGTON...ELBERT AND DOUGLAS
CTYS...THEN N ALG FACE OF FNT RNG FTHLS.  CAP ALL BUT GONE OVR HIR
TRRN S AND SE OF DEN METRO AREA AND HELICITIES JUST SE OF DEN METRO
AREA ENOUGH TO SUPPORT A FEW SUPERCELLS.  LARGE DAMAGING HAIL AND
HVY RAIN BIGGEST THREAT...BUT AGAIN CAN NOT RULE OUT A TORNADIC
STORM.  STORMS SHOULD RACE NEWRD WITH STG SWLY JET FLOW ALOFT...BUT
STORM INTENSITIES XPCTD TO DROP OFF RAPIDLY E OF A BRIGGSDALE TO
LIMON LINE WHERE ATMOSPHERE REMAINS QUITE COOL AND STABLE.  STILL A
FEW SHWRS AND T-STORMS A PSBLTY IN THIS AREA.  LATER TONIGHT...
BNDRY LYR NOT LOOKING AS WET AS LAST 2 NIGHTS AS BNDRY LYR FLOW
SUPPOSEDLY BECOMES MORE S-SELY TOWARDS DAWN.  WILL KP LOW CLOUDS
FOG IN FCST...BUT MAINLY IN AREAS N AND E OF DEN METRO AREA WHERE WK
UPSLOPE REMAINS IN PLACE.

LONG TERM DISCUSSION:  WARMING TREND STILL IN THE CARDS BEGINNING
TUESDAY AS MEDIUM RANGE MODELS SHOW UPR RIDGE TRANSLATING EWRD OVR
COLORADO BY WEDNESDAY.  MOIST UPSLOPE FLOW E OMTNS FINALLY BREAKS
DOWN WEDNESDAY ALLOWING BNDRY LYR WINDS TO RESUME ITS NORMAL DIURNAL
FLOW PATTERN.  YESTERDAY MRF SHOWED AIRMASS REALLY DRYING OUT LATE
IN THE PERIOD...BUT NOW MRF HINTS AT SOME SUBTROPICAL/MONSOONAL
MOISTURE CREEPING UP INTO COLO UNDER UPR RIDGE BY FRI.  CAN/T IGNORE
THIS AS IT/S NOT OFTEN THE MTNS GO WITHOUT PCPN FOR MORE THAN A FEW
DAYS THIS YEAR.  SO WILL ADD A SLIGHT CHANCE FOR AFTN/EVE T-STORMS
TO MTN ZONES FRI THRU MON.  AS FOR TEMPS...MRF INIDCATES WARMEST
TEMPS SFC AND ALOFT OVR CWFA SAT-MON WITH TEMPS PEAKING UP AROUND
90 ON THE PLAINS.  HWVR THIS MAY BE A BIT OPTIMISTIC IF WE SHOULD
SEE MID-LVL MOISTURE GETTING CAUGHT UP IN THE RIDGE AS DISCUSSED
ABOVE.  BAKER

.DEN...NONE.

COZ030>051-042100-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
1045 AM MDT MON JUN 4 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...A VERY MOIST AIR MASS WILL REMAIN IN PLACE ACROSS THE
NORTHEASTERN PLAINS OF COLORADO DURING THIS AFTERNOON AND EVENING.
LOW LEVEL UPSLOPE FLOW WILL CONTINUE TO PUSH THIS MOISTURE AGAINST
THE EAST FACE OF THE MOUNTAINS.  AN UPPER LEVEL DISTURBANCE
ASSOCIATED WITH A COLD FRONT AND JET STREAM WILL MOVE ACROSS THE
AREA AND PRODUCE GREATER INSTABILTY BY LATE AFTERNOON INTO THE
EARLY EVENING.

SCATTERED SHOWERS AND THUNDERSTORMS WILL FORM OVER THE MOUNTAINS BY
AROUND MIDDAY AND MOVE OVER THE URBAN CORRIDOR DURING THE EARLY
AFTERNOON AND FARTHER EAST ONTO THE PLAINS DURING THE LATE AFTERNOON
AND EARLY EVENING.  ADEQUATE SHEAR ALONG WITH STEEP LAPSE RATES...
STRONG INSTABILITY AND LOW LEVEL MOIST ADVECTION WILL ALLOW THE
FORMATION OF ISOLATED SEVERE THUNDERSTORMS WITH LARGE HAIL...
DAMAGING WINDS AND POSSIBLE TORNADOES OVER ALL THE NORTHEASTERN
PLAINS.

SPOTTER ACTIVATION MAY BE NEEDED OVER THE URBAN CORRIDOR AND
NORTHEASTERN PLAINS DURING THE AFTERNOON AND EVENING.

GARD...WFO BOULDER