Severe Thunderstorm Warning 57, NWS Denver/Boulder, CO

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

SO FAR THE DIRTY RIDGE HAS NOT BEEN ABLE TO STOP THE STRING OF 90
DEGREE DAYS AT KDEN.  TODAY WAS THE 14TH.  FOR THE NEXT COUPLE DAYS
THE UPPER RIDGE WL REMAIN IN PLACE AND IT LOOKS LIKE MSTR WL CONT TO
BE TRAPPED UNDER THE RIDGE.  FLOW ALOFT IS WEAK AND WATER VAPOR
PICTURES SHOW THE MSTR ALOFT CIRCULATING UNDER THE RIDGE WITH
ADDITIONAL MSTR BEING INTERMITTENTLY FED INTO THE RIDGE FROM NW MEX.
EACH OF THE MODELS CONT TO SHOW HIGH THETA-E VALUES OVER CENTRAL AND
ERN CO FOR THE NEXT COUPLE DAYS WITH 700 SPEC HUMIDITY VALUES ALSO
ARND 8 G/KG.  EACH OF THE MODELS IS HAVING A HARD TIME WITH THE MSLP
FIELDS MAKING IT DIFFICULT TO TELL WHETHER BOUNDARIES OR DEN
CYCLONES WILL BE IN PLACE TO SUPPORT CONVECTIVE DEVELOPMENT.  MSTR
LVLS APPEAR TO BE HIGH ENOUGH THAT SCATTERED POPS ARE JUSTIFIED FOR
JUST ABOUT EACH PERIOD.  THE AVN AND MRF CONT HOLDING ON TO THE UPR
RIDGE WHICH MEANS THE AMS WL UNDERGO LTL CHANGE.  TEMPS ON THE
PLAINS SHOULD CONT REACHING AFTN HIGHS IN THE LOW 90S BEFORE AFTN
AND EVENING SHOWER ACTIVITY GETS STARTED.

CONCERNING THE FLASH FLOOD WATCH...SHOWER ACTIVITY HAS BEGUN OVER
THE FTHLS.  AS EXPECTED THE STORMS ARE SLOW MOVING...SO WILL CONT
THE WATCH UNTIL MIDNIGHT WHEN SHOWER ACTIVITY SHOULD HAVE COME TO AN
END.

.DEN...FLASH FLOOD WATCH UNTIL MIDNIGHT...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