Tornado and Hail in Colorado, July 26, 2001

NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER COLORADO
330 AM MDT THU JUL 26 2001

SHORT TERM: STAGE IS SETTING UP FOR AN ACTIVE WEATHER DAY FOR CWA
LATER THIS AFTN AND TONIGHT. MOISTURE PLUME FROM MEXICO CONTINUES
STREAMING INTO CO WITH PW VALUES AROUND AN INCH. MAIN PLAYER FOR OUR
WEATHER WILL BE WEAKENING LOW NOW LIFTING TO THE NORTHEAST ACROSS NW
ARIZONA. THIS TROUGH WILL BE MOVE ACROSS NW CO LATER THIS AFTN AND
WEAKEN AND SHIFT THRU CWA DURING THE NIGHT. DIV-Q FIELDS SHOWING
FAIRLY DECENT UPWARD FORCING ESPECIALLY FOR THE SUMMER TIME. FORCING
IS ALSO AIDED BY 60KT SPEED MAX AS TROF LIFTS ACROSS REGION. AT THE
SURFACE...WEAK SURGE HAS BACKED INTO FAR NERN CO FROM OVERNIGHT
COMPLEX IN NEBRASKA WITH INCREASING LOW LEVEL MOISTURE(SFC DEWPOINTS
IN MID 60S) ON E-SE WINDS. SAT PICS ALSO SHOW STRATUS/FOG MOVING IN
AS WELL. DON'T THINK IT WILL MAKE IT ALL THE WAY BACK TO DEN...BUT
WILL ADD SOME FOG FOR ERN PLAINS ZONES THIS MORNING. WITH THE
INCREASING S-SE FLOW...EXPECT A DENVER CYCLONE OR CONVERGENCE LINE
TO SET UP OVER OR JUST EAST OF THE URBAN COORIDOR DURING THE
AFTERNOON. THIS SHOULD BE THE FOCUS FOR A SEVERE WX SET UP LATER
THIS AFTN/EVENING. 06Z MESOETA SHOWING CAPES AROUND 2000-2500J/KG
EAST OF DENVER OVER THE PLAINS...AND BETWEEN 1000-1500 J/KG FOR
WESTERN PTNS OF CWA. THE DIFFERENCE TODAY IN COMPARISON TO LAST FEW
DAYS IS THE HIGHER CAPES...GREATER LOW LVL MSTR AND STRONGER MID LVL
FLOW. ALSO STORM REL HELICITIES ALSO LOOKING GOOD WITH VALUES
BETWEEN 200-300M2/S2. EXPECT STRONGEST STORMS CAN PRODUCE LARGE HAIL
UP TO 2 INCHES IN DIAMETER AND EVEN AN ISOLATED TORNADO NOT OUT OF
THE QUESTION WITH THIS NICE DIRECTIONAL SHEAR PROFILE SETTING UP.
WILL MENTION POSSILBE SEVERE STORMS IN ZONES FOR TNT OVER THE
PLAINS.

TIMING OF STORMS SHOULD BE ON THE LATE SIDE AGAIN TODAY...WITH
MTNS/HIR TERRAIN GOING FIRST AGAIN BY MID AFTERNOON...URBAN COORIDOR
AND ADJ EAST SECTIONS BTWN 22-00Z...AND EASTERN PLAINS THIS EVENING.
THE LATE FIRING DUE TO MORE CLOUD COVER/FOG EASTERN PTNS THIS
MORNING...AND UPR SUPPORT NOT REALLY IN HERE UNTIL AFT 00Z.

LONG TERM: WEATHER WILL BE CALMING DOWN ON FRIDAY...BUT PIECE OF
TROF LAGGING BEHIND FRI AFTN AND MAY CREATE SOME THUNDERSTORMS OVER
THE FAR EAST PLAINS. WESTERN PTNS OF CWA SHOULD BE DRYING OUT WITH
SUBSIDENCE MOVING IN WITH ISOLD TS COVERAGE AT BEST.  WEEKEND STILL
LOOKING RATHER DRY WITH STRONGER WESTERLY FLOW...BUT CAN'T RULE OUT
AN ISOLD TSRA. UPPER HIGH SHIFTS EAST AGAIN NEXT WEEK AND TS CHANCES
SHOULD INC. THIS COVERED WELL IN ZONES. ENTREKIN

.DEN...NONE.

COZ030>051-262000-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
1030 AM MDT THU JUL 26 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:  AN UPPER LEVEL TROUGH...LOCATED OVER NORTHWESTERN ARIZONA
WILL SLOWLY MAKE ITS WAY ACROSS WESTERN AND NORTHERN COLORADO LATE
THIS AFTERNOON AND TONIGHT.  IN ADDITION...SOUTHEASTERLY SURFACE
WINDS ARE EXPECTED TO INCREASE AHEAD OF THIS SYSTEM...ALLOWING THE
LOW LEVEL MOISTURE TO REMAIN IN PLACE ACROSS THE NORTHEASTERN PLAINS
AND URBAN CORRIDOR.

SUFFICIENT SHEAR WILL BE PRESENT FOR THE DEVELOPMENT OF LARGE HAIL
...DAMAGING WINDS AND POSSIBLY AN ISOLATED TORNADO.  HEAVY RAINFALL
...UP TO 2 INCHES PER HOUR...AND FREQUENT CLOUD TO GROUND LIGHTNING
WILL ALSO OCCUR WITH THE STORMS.   THE GREATEST POTENTIAL FOR SEVERE
THUNDERSTORMS APPEARS TO BE EAST OF INTERSTATE 25.

THE MAIN LIMITATION MAY BE THE EXTENSIVE CLOUD COVER PRESENTLY OVER
NORTHEASTERN COLORADO.  THIS MAY DELAY THE ONSET OF THE STRONGER
THUNDERSTORMS UNTIL LATE THIS AFTERNOON.

SCATTERED THUNDERSTORMS WILL DEVELOP IN THE MOUNTAINS AND FOOTHILLS
AFTER 1200 PM...MOVING INTO THE URBAN CORRIDOR AFTER 3 PM.  SPOTTER
ACTIVATION MAY BE NEEDED AT THAT TIME.

COOPER

COZ030>051-262100-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
115 PM MDT THU JUL 26 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 WEAK UPPER LEVEL DISTURBANCE WILL EXIT NORTHERN
COLORADO EARLY THIS AFTERNOON...WITH THE MAIN UPPER LEVEL TROUGH
EXPECTED TO SLOWLY MAKE ITS WAY ACROSS WESTERN AND NORTHERN COLORADO
TONIGHT.

ENOUGH VERTICAL WIND SHEAR MAY BE PRESENT THROUGH EARLY THIS EVENING
FOR THE DEVELOPMENT OF A FEW SEVERE THUNDERSTORMS.  THESE STORMS
COULD PRODUCE LARGE HAIL...DAMAGING WINDS AND EVEN AN ISOLATED
TORNADO.

HEAVY RAINFALL...UP TO 2 INCHES IN LESS THAN AN HOUR...AND FREQUENT
CLOUD TO GROUND LIGHTNING WILL ALSO OCCUR.  SHOULD THE STORMS REMAIN
STATIONARY OR TRAIN OVER THE SAME LOCATION...THEN POTENTIAL FLOODING
OR FLASH FLOODING PROBLEMS MAY ALSO DEVELOP.

AT 1 PM MDT...SATELLITE DATA INDICATED DRIER AIR IN THE MID LEVELS
WAS MOVING IN FROM THE SOUTH.  IF AFTERNOON TEMPERATURES CAN WARM
INTO THE MID 80S...THEN THE POTENTIAL FOR STRONG TO SEVERE
THUNDERSTORMS WILL INCREASE SIGNIFICANTLY.

THE GREATEST POTENTIAL FOR SEVERE WEATHER APPEARS TO BE ALONG
AND EAST OF A BOUNDARY THAT EXTENDED FROM NEW RAYMER TO BYERS TO
CASTLE ROCK.  SPOTTER ACTIVATION MAY BE NEEDED AFTER 3 PM.

COOPER