Severe Thunderstorm Warning 128, NWS Denver/Boulder, CO

NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER COLORADO
325 PM MDT TUE SEP 5 2000

SUBTROPICAL MOISTURE CONTINUES TO STREAM NEWRD OVR CO THIS AFTN
AROUND UPR LVL RIDGE CENTERED OVR THE SRN PLNS.  LATEST RGL NEXRAD
LTG PLOTS SHOW SCTD T-STORMS POPPING ACRS WRN CO AND IN THE MTNS W
OF DEN/BOUY AND FNL DIRECTLY UNDER THIS STREAM OF MOISTURE.
DIFFICULT TO PICK OUT ANY ONE FEATURE REPONSIBLE FOR THE CONVECTION.
HWVR VORT MAX LIFTING NEWRD OVR SWRN CO ATTM CALCULATED TO BE
SOMEWHERE NR SUMMIT CTY BY MIDNIGHT...TOO LATE TO HV MUCH IMPACT ON
CWA.  NEVERTHELESS WITH SWLY TRANSPORT WNDS...SHOULD SEE SCT STORMS
ROLLING OFF THE FNT RNG NXT COUPLE OF HRS.  CONVECTION MORE
WIDESPREAD THAN YESTERDAY AT THIS TIME...SO EVE POPS WILL REFLECT
THIS.  AGAIN MAIN THREAT WITH STORMS APRS TO BE STG MICROBURST WNDS
AS BNDRY LYR MOISTURE ON THE LOW SIDE.  EVEN WITH MID/UPR LVL
MOISTURE CHANNEL STAYING IN PLACE OVRNGT...SHOULD SEE SKIES CLRG A
FEW HRS AFT EVE STORMS EXIT THE AREA.

ON WEDNESDAY...ETA AND AVN SHOW LEE TROFG WITH W-SWLY SFC-7H WINDS
THROUGH 18Z.  DURING THE AFTN...MID/UPR LVL MOISTURE XPCTD TO
INCREASE WITH MOISTURE CHANNEL SHIFTING EWRD.  WK DISTURBANCES
MOVING UP FM THE FOUR CORNERS AREA WILL PROVIDE THE ADDED LIFT FOR
SCT STORMS.  SHOULD SEE SHWRS AND TSTMS BREAKING OUT OVR THE MTNS
AND HIGH VLYS BY THE NOON HR AND OVR THE PLNS DURING THE AFTN.  WITH
RISING PRECIPITABLE WATERS...SEE A BETTER CHANCE FOR MEASURABLE
PCPN...PARTICULARLY BY LATE AFTN.

WEDNESDAY NGT/THURSDAY...HEIGHTS FALL WITH COOL UPR LVL TROF PASSING
OVRHEAD DURING THE PD.  THE NEW 18Z/ETA ALSO SHOWS BNDRY LYR WNDS
BECOMING NLY ACRS NERN CO WITH PASSAGE OF A COLD FNT BY WED EVE.
MDL SHOWS COOL AIR AND MOISTURE LAGGING BEHIND FRONT SOME 6-9 HRS
UNTIL ERLY THURSDAY MRNG.  ANTICYCLONIC UPSLOPE FLOW THEN DEEPENS
ACRS THE PLNS DURING THE DAY THURSDAY.  COLD SFC HIGH DROPS SEWRD
OVR S DAK AND A SFC LOW DEEPENS IN SWRN KS.  MOS GUIDANCE IS GIVING
A MAX TEMP AT DEN SOME 8-12 DEGS BELOW THAT PROGD FOR WED.  THIS
LOOKS REASONABLE WITH THE EXPECTED ELY WNDS...CAA AND INCREASED
CLOUD COVER.  WILL GO WITH SCATTERED POPS ON THU/THU NGT WITH
EMPHASIS ON UPSLOPE SHOWERS AND LESS ON T-STORMS SINCE SYNOPTIC
FORCING AND LAPSE RATES NOT THAT IMPRESSIVE.

IN THE LONG TERM...WILL MAKE ONLY SLIGHT CHANGES TO CURRENiT FCST...
MAINLY TO MAX TEMPS SINCE MRF KEEPS CWA UNDER MID-UPR LVL MSTR THRU
MOST OF THE PD.  BAKER

DEN...NONE.

COZ030-032>050-052200-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
130 PM MDT   MONDAY   SEPTEMBER 5 2000

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:  THE AIRMASS HAS BECOME UNSTABLE FROM SOLAR HEATING.
SHOWERS AND THUNDERSTORMS HAVE BEGUN TO DEVELOP OVER THE MOUNTAINS
AND HIGHER FOOTHILLS.  BY 5 PM SOME OF THE SHOWERS AND THUNDERSTORMS
WILL MOVE OFF THE FOOTHILLS INTO THE NEARBY PLAINS.  IN ADDITION...
OUTFLOW BOUNDARIES FROM THE THUNDERSTORMS IN AND NEAR THE FOOTHILLS
ARE EXPECTED TO INTERACT AND PROVIDE THE FINAL INGREDIENT BY LIFTING
THE LOW LEVEL MOISTURE OVER THE PLAINS ENOUGH TO SPURE ADDITIONAL
CONVECTION.

WHILE NONE OF THE THUNDERSTORMS ARE EXPECTED TO BECOME SEVERE...THEY
MAY PRODUCE ONE QUARTER TO ONE HALF INCH OF RAIN...SMALL HAIL AND
WIND GUSTS TO 45 MPH.  AS USUAL...DEADLY CLOUD TO GROUND LIGHTNING
BOLTS CAN BE EXPECTED WITH THE THUNDERSTORMS.

RAINFALL FROM MOST OF THE SHOWERS AND THUNDERSTORMS WILL BE ONE
TENTH INCH OR LESS.

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR THIS EVENING.

BOODA