Severe Thunderstorm Warning 54, NWS Denver/Boulder, CO

NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER COLORADO
243 AM MDT WED JUL 12 2000

MAIN CONCERN TODAY WL BE POTENTIAL FOR FLASH FLOODING IN BOBCAT AND
HI MEADOWS BURN AREAS.  LOW LVL MSTR AND MONSOON MSTR WL BE MORE
ABUNDANT TODAY THAN YESTERDAY.  MEANWHILE DISTURBANCE OVR NRN AZ WL
MOVE AROUND UPR LVL HIGH AND SHOULD MOVE ACRS NRN CO LATER THIS AFTN
AND EVENING.  THIS FEATURE WAS HARD TO FIND IN GRIDDED DATA BUT DID
SHOW UP IN 250 MB POTENTIAL VORTICITY FIELDS.  WND FIELDS TODAY WL
BE RATHER WK AND WITH PRECIPITABLE WATER VALUES AROUND AN INCH AND
STG THETA-E DG IN PLACE SLOW MOVING STORMS PRODUCING UP TO 2" OF
RAIN IN LESS THAN AN HOUR WL BE PSBL.  IF ANY STORM MOVES OVR THE
BURN AREAS THERE COULD BE A SERIOUS FLASH FLOOD PROBLEM.  WITH THIS
IN MIND WL ISSUE A FLASH FLOOD WATCH FOR BURN AREAS FOR THIS AFTN
AS BELIEVE THREAT IS HIGH ENOUGH TO WARRANT A WATCH.  OVR THE REST
OF THE AREA SCT TSRA COULD DVLP JUST ABOUT ANYWHERE LATER THIS AFTN
INTO THE EARLY EVENING HRS WITH HEAVY RAINS PSBL.  ALTHOUGH
SFC BASED CAPES BY AFTN WL BE OVR 2000 J/KG BELIEVE LACK OF VERTICAL
SHEAR AND WRM MID-LVL TEMPS WL LIMIT SVR POTENTIAL.

FOR TONIGHT COULD SEE SOME TYPE OF MCS OVR NERN CO WITH CONCENTRATED
AREA OF VERY HEAVY RAINS SOMEWHERE OVR THE PLAINS AS LOW LVL JET
DVLPS AND TRAINING OF CELLS OCCURS.  WITH RATHER WRM MID-LVL TEMPS
APPEARS PCPN PROCESSES COULD TRANSITION FM COLD TO WRM CORE REGIME.

ON THU UPR LVL HI WL BUILD OVR RGN WITH WARMING TEMPS ALOFT.
ALTHOUGH UPR LVL HI WL BUILD OVR RGN MONSOON MSTR MAY CONT TRAPPED
UNDER RDG.  MODELS WHAT TO DRY OUT LOWER LVLS HOWEVER THIS MAY BE
OVERDONE SO WL MENTION SOME WDLY SCT TSRA IN MOST AREAS.  AT THIS
POINT CAN'T SEE ANY FEATURE TO ENHANCE PCPN SO ACTIVITY WL BE DRIVEN
MAINLY BY HTG.  TEMPS MAY BE A FEW DEGREES COOLER TODAY DUE TO
COOLING AT 700 MB AND MORE CLD COVER.  ON THU 700 MB TEMPS WL RISE
AGAIN AND ALLOW TEMPS TO WRM WELL BACK INTO THE 90S ACRS NERN CO.  KLEYLA

.DEN...FLASH FLOOD WATCH THIS AFTERNOON ZNS 35 AND 36...FOR BOBCAT
    BURN AREA OF LARIMER COUNTY AND HI MEADOWS BURN AREA OF      
    JEFFERSON COUNTY.

COZ030-032>050-121800-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
1010 AM MDT   WEDNESDAY   JULY 12 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

...FLASH FLOOD WATCH FOR HI-MEADOW AND BOBCAT BURN AREAS FROM NOON
   TODAY UNTIL MIDNIGHT TONIGHT...

SYNOPSIS:  MONSOON MOISTURE REMAINS OVER COLORADO AS A STRONG HIGH
PRESSURE CELL BUILDS OVER THE STATE.  THE WINDS ALOFT ARE WEAKENING
WHICH MEANS ANY SHOWERS AND THUNDERSTORMS THAT FORM TODAY OR TONIGHT
WILL BE FAIRLY SLOW MOVING.  THIS WILL ESCALATE THE THREAT OF HEAVY
RAIN OVER THE FRONT RANGE FOOTHILLS...NORTH-CENTRAL MOUNTAINS AND
THE PLAINS OF NORTHEAST COLORADO.  THE AMOUNT OF MOISTURE IN THE
ATMOSPHERE OVER THE AREA COMBINED WITH LIGHT WINDS ALOFT INDICATES
THAT 2-3 INCHES OF RAIN IS POSSIBLE IN SOME LOCATIONS THIS AFTERNOON
AND EVENING.  THE AIRMASS IS WARM ENOUGH THAT THE THREAT OF SEVERE
WEATHER WITH LARGE HAIL AND STRONG DAMAGING WINDS IS VERY LOW.

SCATTERED SHOWERS AND THUNDERSTORMS WILL BE DEVELOPING BY NOONTIME
OVER THE MOUNTAINS AND FOOTHILLS THEN SPREAD INTO THE PLAINS DURING
THE AFTERNOON AND EVENING.  MOST OF THE SHOWERS AND THUNDERSTORMS
WILL PRODUCE LESS THAN ONE INCH OF RAIN...HOWEVER SOME LOCATIONS MAY
GET AS MUCH AS 3 INCHES OF RAIN IN ONE HOUR.  THIS AMOUNT OF RAIN IS
LIKELY TO CAUSE FLOODING OF LOW LYING AREAS...STREETS AND
INTERSECTIONS.  IN ADDITION SOME SMALL CREEKS AND STREAMS MAY REACH
OR EXCEED BANKFUL CONDITIONS.

A FLASH FLOOD WATCH IS IN EFFECT FROM NOON UNTIL MIDNIGHT FOR THE
HIGH MEADOW BURN AREA IN JEFFERSON COUNTY AND THE BOBCAT BURN AREA IN
LARIMER COUNTY.  ANY RAIN EXCEEDING ONE HALF INCH PER HOUR IN THESE
AREAS IS LIKELY TO CAUSE LARGE AND RAPID RUNOFF.  IN ADDITION
SIGNIFICANT EROSION OF SOILS AND BURN DEBRIS IS LIKELY WITH SOME
ROAD WASHOUTS POSSIBLE.  ANYONE IN THE BURN AREAS SHOULD BE PREPARED
TO TAKE ACTION IF MODERATE TO HEAVY RAIN IS OBSERVED OR A FLASH
FLOOD WARNING IS ISSUED.

SPOTTER ACTIVATION IS NOT ANTICIPATED BUT RAINFALL REPORTS WILL BE
VERY MUCH APPRECIATED IF HEAVY RAIN IS DETECTED.

END...GCF...WSFO DENVER

COZ030-032>050-121800-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
115 PM MDT   WEDNESDAY   JULY 12 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

...FLASH FLOOD WATCH UNTIL MIDNIGHT FOR HIGH MEADOW AND BOCAT BURN
   FIRE AREAS...

SYNOPSIS:  VERY MOIST AND UNSTABLE AIRMASS OVER COLORADO TODAY WITH
WEAK WINDS ALOFT.  NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS WILL
DEVELOP TODAY AND TONIGHT AND MOVE VERY SLOWLY.  THIS WILL ENHANCE
THE THREAT OF HEAVY RAIN OVER NORTHEAST COLORADO INCLUDING THE FRONT
RANGE FOOTHILLS AND NORTH-CENTRAL MOUNTAINS.

WHILE MOST RAINFALL AMOUNTS WILL BE IN THE ONE HALF TO ONE INCH
RANGE...SOME PLACES MAY GET 2 OR 3 INCHES OF RAIN THIS AFTERNOON AND
EVENING.  THIS AMOUNT OF RAIN IS LIKELY TO CAUSE FLOODING OF LOW
LYING AREAS...STREETS AND INTERSECTIONS.  IN ADDITION SMALL CREEKS
AND STREAMS MAY REACH OR EXCEED BANKFUL CONDITIONS.

THERE IS ALSO A SMALL THREAT OF SEVERE WEATHER OVER THE PLAINS WITH
A RISK OF TORNADOES AND LARGE HAIL AFTER 3 PM.

A FLASH FLOOD WATCH IS IN EFFECT UNTIL MIDNIGHT FOR THE HIGH MEADOW
BURN AREA IN JEFFERSON COUNTY AND THE BOBCAT BURN AREA IN LARIMER
COUNTY.  ANY RAIN EXCEEDING ONE HALF INCH PER HOUR IN THESE AREAS IS
LIKELY TO CAUSE LARGE AND RAPID RUNOFF.  IN ADDITION SIGNIFICANT
EROSION OF SOILS AND BURN DEBRIS AS WELL AS SOME ROAD WASHOUTS CAN
BE EXPECTED.  ANYONE IN THE BURN AREAS SHOULD BE PREPARED TO TAKE
ACTION IF MODERATE TO HEAVY RAIN IS OBSERVED OR A FLASH FLOOD
WARNING IS ISSUED.

SPOTTER ACTIVATION MAY BE NEEDED AFTER 3 PM FOR PLAINS AREAS EAST OF THE
DENVER METRO AREA.  RAINFwALL REPORTS WILL BE VERY MUCH APPRECIATED
IF HEAVY RAIN IS DETECTED.

END...GCF...WSFO DENVER