Severe Thunderstorm Warning 134, NWS Denver/Boulder, CO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
231 PM MDT FRI AUG 6 2004

.SHORT TERM DISCUSSION...DAYTIME HEATING HAS ALLOWED FOR CONVECTION
TO DEVELOP ACROSS THE MOUNTAINS AND FOOTHILLS...WITH SOME STORMS
BEGINNING TO PUSH ACROSS PLAINS. ACARS SOUNDINGS STILL SHOWING A CAP
AROUND 650 MB AND SUGGESTING A TEMPERATURE OF 88 DEGREES F. TO BREAK
THIS CAP.  CURRENTLY...TEMPERATURES HAVE REACHED 90 DEGREES F. ALONG
URBAN CORRIDOR...SO STORMS TO CONTINUE TO TREK ONTO PLAINS.  CAP
SHOULD BE ERODED ACROSS FAR EASTERN PLAINS WITHIN THE NEXT FEW HOURS
AS TEMPERATURES WARM.  MAY ALSO SEE A BOUNDARY OR TWO PUSH ACROSS
THE AREA...AIDING IN BREAKING OF CAP.  COULD STILL SEE A FEW STORMS
BECOMING SEVERE EAST OF A NEW RAYMER TO LIMON LINE WHERE THE BETTER
LOW LEVEL MOISTURE RESIDES. LAPES ANALYSIS SHOWING CAPES REACHING
3000 J/KG OVER LOGAN AND NORTHERN WASHINGTON COUNTIES.  SOUTHEAST
SURFACE FLOW IN THIS AREA ON THE INCREASE WHICH IS IMPROVING THE
SHEAR PROFILE.  HAIL AND GUSTY WINDS WILL BE THE MAIN THREATS.
COULD SEE SOME LOCALLY HEAVY RAIN...BUT FLOODING PROBLEMS APPEAR
LIMITED AS STORM MOVEMENT AROUND 15 KTS. AS FOR MORGAN COUNTY...
LATEST INFORMATION INDICATES CREEKS REMAIN OUT OF BANKS WITH THE
POTENTIAL FOR A FEW STORMS MOVING ACROSS AREA.  WILL PROBABLY NOT
SEE MUCH IMPROVEMENT IN THE NEAR FUTURE AND WILL KEEP FLOOD WARNING
GOING THROUGH 6 PM.  THIS WARNING MAY NEED TO BE EXTENDED.  ALL
ACTIVITY SHOULD BE DONE BY MIDNIGHT AS SUBSIDENCE REDEVELOPS.  ON
SATURDAY... AIRMASS EXPECTED TO BE DRIER SATURDAY AS RIDGE FLATTENS
A BIT IN RESPONSE TO APPROACHING UPPER TROUGH.  THIS SHOULD CONTINUE
TO SHUNT MOISTURE SURGE TO THE EAST.  MODELS INDICATE THETA-E AXIS
ACROSS KANSAS WITH PRECIPITABLE WATER VALUES DROPPING TO TO BELOW
.75 INCH. HOWEVER...THERE SHOULD BE ENOUGH MID LEVEL MOISTURE LEFT
OVER FOR SOME AFTERNOON CONVECTION.  WILL PROBABLY SEE MORE VIRGA
AND WIND GUSTS THAN RAIN DUE TO THE VOID OF LOW LEVEL MOISTURE.
MODELS ALSO INDICATE AN INCREASE IN MOUNTAIN TOP WIND...ENOUGH TO
MENTION IN MOUNTAIN AND FOOTHILL ZONES.  7H TEMPERATURES WARM 2
DEGREES CELSIUS BY 00Z SUNDAY.  TEMPERATURE AND THICKNESS FORECAST
GRIDS AS WELL AS GUIDANCE SUGGEST HIGHS IN THE LOWER AND MID 90S
ACROSS MUCH OF PLAINS.  THIS ALL LOOKS REASONABLE...WILL NOT MAKE
CHANGES TO TEMPERATURE GRIDS.

.LONG TERM DISCUSSION...THE GRIDS ARE SHOWING AN UPPER TROUGH/CLOSED
LOW PUSHING EASTWARD ACROSS THE NORTHERN UNITED STATES SATURDAY
EVENING.  THE FLOW ALOFT BECOMES NORTHWESTERLY SATURDAY EVENING.
THIS CONTINUES THROUGH MONDAY.  THE LOW LEVEL PRESSURE AND WINDS
FIELDS SHOW A COLD FRONT MOVING IN EARLY SUNDAY...WITH UPSLOPE IN
PLACE ALL OF SUNDAY...SUNDAY NIGHT...AND MONDAY.  THE DIV-Q GRIDS
SHOW WEAK SYNOPTIC SCALE ASCENT TO NEUTRAL FORCING FOR THE FORECAST
AREA SATURDAY NIGHT THROUGH MONDAY.  CROSS SECTIONS SHOW SOME MID
LEVEL MOISTURE SATURDAY NIGHT...SAME FOR MOST OF SUNDAY.  SUNDAY
NIGHT...THE PROLONGED UPSLOPE FINALLY GETS SOME MOISTURE DEVELOPING
DOWN LOW...THEN THIS CONTINUE WELL INTO TUESDAY...ESPECIALLY EAST OF
THE DIVIDE. CROSS SECTIONS SHOW GOOD POTENTIAL INSTABILITY LATE
DAY SUNDAY AND MONDAY.  LAPSE RATE GRIDS SHOW A PRETTY STRONG CAP
OVER THE FORECAST AREA SUNDAY AND MONDAY. THE THETA-E AXIS RETURNS
TO THE FORECAST AREA BY SUNDAY EVENING AND CONTINUES INTO TUESDAY
WITH THE BEST WIDESPREAD CAPE VALUES BY LATE DAY MONDAY.  POPS-WISE
...NOT TO EXCITING....BEST CHANCES ARE MONDAY.  QPF GRIDS ARE NOT
VERY EXCITED EITHER.  FOR TEMPERATURES...GRIDS SHOW A 3-5 C COOL OFF
FOR SUNDAYS HIGHS FROM SATURDAYS.  THEN READINGS FOR MONDAY ARE
PROGGED 4-6 C COOLER AGAIN.  SO 70S LOOK GOOD ON MONDAY...TUESDAY
TOO.

FOR THE LONGER RANGE PERIOD...TUESDAY THROUGH FRIDAY...MODELS SHOW
NORTHWESTERLY FLOW ALOFT TO CONTINUE OVER THE FORECAST AREA.  THIS
FLOW IS PROGGED TO WEAKEN AS THE UPPER RIDGE AXIS MOVES INTO WESTERN
COLORADO BY LATE WEEK.  MODELS SHOW AN UPSLOPE SURGE AND A COOLER
AIRMASS IN HERE ON TUESDAY AND WEDNESDAY.  IT WARMS UP ON THURSDAY
AND WITH ANOTHER SURGE ON FRIDAY. ENOUGH MOISTURE IS AROUND TO KEEP
SOME POPS GOING THROUGH THE PERIOD.

&&
.BOU...WATCHES/WARNINGS/ADVISORIES...NONE.
&&

DL/KOOPMEINERS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DENVER CO
1103 AM MDT FRI AUG 06 2004

COZ030>051-071200-
JACKSON COUNTY BELOW 9000 FEET-WEST JACKSON AND WEST GRAND
COUNTIES ABOVE 9000 FEET-GRAND AND SUMMIT COUNTIES BELOW 9000
FEET-SOUTH AND EAST JACKSON/LARIMER/NORTH AND NORTHEAST GRAND/
NORTHWEST BOULDER COUNTIES ABOVE 9000 FEET-SOUTH AND SOUTHEAST
GRAND/WEST CENTRAL AND SOUTHWEST BOULDER/GILPIN/CLEAR CREEK/
SUMMIT/NORTH AND WEST PARK COUNTIES ABOVE 9000 FEET-LARIMER AND
BOULDER COUNTIES BETWEEN 6000 AND 9000 FEET-JEFFERSON AND WEST
DOUGLAS COUNTIES ABOVE 6000 FEET/GILPIN/CLEAR CREEK/NORTHEAST PARK
COUNTIES BELOW 9000 FEET-CENTRAL AND SOUTHEAST PARK COUNTY-LARIMER
COUNTY BELOW 6000 FEET/NORTHWEST WELD COUNTY-BOULDER AND JEFFERSON
COUNTIES BELOW 6000 FEET/WEST BROOMFIELD COUNTY-NORTH DOUGLAS
COUNTY BELOW 6000 FEET/DENVER/WEST ADAMS AND ARAPAHOE COUNTIES/
EAST BROOMFIELD COUNTY-ELBERT/CENTRAL AND EAST DOUGLAS COUNTIES
ABOVE 6000 FEET-NORTHEAST WELD COUNTY-CENTRAL AND SOUTH WELD
COUNTY-MORGAN COUNTY-CENTRAL AND EAST ADAMS AND ARAPAHOE COUNTIES-
NORTH AND NORTHEAST ELBERT COUNTY BELOW 6000 FEET/NORTH LINCOLN
COUNTY-SOUTHEAST ELBERT COUNTY BELOW 6000 FEET/SOUTH LINCOLN
COUNTY-LOGAN COUNTY-WASHINGTON COUNTY-SEDGWICK COUNTY-PHILLIPS
COUNTY-
1103 AM MDT FRI AUG 06 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL
COLORADO.

.DAY ONE...TODAY AND TONIGHT

ISOLATED THUNDERSTORMS WILL DEVELOP ACROSS THE MOUNTAINS EARLY THIS
AFTERNOON AND GRADUALLY SPREAD ONTO THE PLAINS OF EASTERN COLORADO
LATE IN THE AFTERNOON AND EVENING.

THE AIRMASS IS SLIGHTLY DRIER OVER THE MOUNTAINS AND ADJACENT PLAINS
WHICH WILL RESULT IN LESS ACTIVITY THAN YESTERDAY. FURTHER EAST ON
THE PLAINS...LOW LEVEL MOISTURE IS MORE PLENTIFUL AND THERE IS
ADEQUATE SHEAR IN THE ATMOSPHERE.  A FEW STORMS COULD BECOME
SEVERE...MAINLY BE EAST OF A STERLING TO LIMON LINE. LARGE HAIL AND
GUSTY WINDS WILL BE THE MAIN THREAT.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

A COOLER AIRMASS IS EXPECTED TO COVER THE FORECAST AREA FOR MUCH OF
NEXT WEEK.  A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS CAN BE
EXPECTED EVERY DAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED ACROSS THE FAR EASTERN PLAINS AFTER
4 PM TODAY.

D-L/RJK