Severe Thunderstorm Warning 87, NWS Denver/Boulder, CO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
315 AM MDT MON JUL 5 2004

.SHORT TERM...MAIN FEATURE IN THIS PERIOD IS THE WAVE PASSING FROM
YELLOWSTONE AREA TOWARD THE ESE. IT LOOKS LIKE WE WILL BE UNDER
DOWNWARD QG FORCING THROUGHOUT...AS THERE IS A RIBBON OF LIFT
DROPPING SOUTH OF US NOW AND THE NEXT BATCH STAYS NORTH OF US.
CURRENT CLOUD PATTERNS SEEM TO SUPPORT THIS IDEA. LOW LEVEL DETAILS
ARE RATHER OBSCURE AT THIS POINT. THERE WILL BE A COLD FRONT WITH
THE WAVE PASSING BY...PROBABLY ACCENTUATED BY OUTFLOW FROM AFTERNOON
STORMS IN WYOMING. ETA HINTING AT AN AFTERNOON FRONTAL PASSAGE...BUT
IT THINK IT WILL TAKE THE STORMS UPSTREAM SO PERHAPS MORE LIKE LATE
AFTERNOON. WIND FIELD AHEAD OF THE FRONT IS DEBATABLE...MODELS KEEP
A BLAND W-SW BUT THERE ARE ALREADY HINTS OF IT TURNING MORE SLY. WE
WILL BE FAIRLY DRY AHEAD OF THE FRONT...BUT SLY WINDS WOULD HELP GET
SOME CONVERGENCE ON THE FRONT AND MAYBE BRING BACK SOME MOISTURE IN
THE EAST. IT MAY BE TOO DRY TO GET MUCH CONVECTION ON THE FRONT NEAR
THE MOUNTAINS...BETTER BET ON THE PLAINS WHERE CAPES WILL AGAIN BE
IN THE 1000-2000 J/KG RANGE. ONCE THE WINDS TURN MORE NELY THERE MAY
BE A WINDOW WHERE THE UPSLOPE CAN PRODUCE STORMS ALONG THE FOOTHILLS
BEFORE THE AIR IS TOO COOL. LATE NIGHT SHOWERS ARE LOOKING DOUBTFUL
AS UPPER LEVEL SUPPORT MAY NOT EXIST. ONE MORE THING...IF WE DO GET
ONE WELL DEFINED LINE OF STORMS COMING OUT OF WYOMING IN THE LATE
AFTERNOON...SHEAR INCREASES SUBSTANTIALLY BY THEN AND WOULD SUPPORT
SUPERCELLS WITH GOOD HAIL POTENTIAL. THESE COULD COME ACROSS THE NE
CORNER OF CO. NOT SURE THE TIMING WILL WORK OUT FOR THIS AS AN
EARLIER WIND SHIFT COULD REDUCE THE INSTABILITY AND LOW LEVEL
CONVERGENCE.

.LONG TERM DISCUSSION...SEE NO REASON TO MAKE ANY BIG CHANGES TO THE
LONG TERM PORTIONS OF THE FORECAST PACKAGE.  MODELS CONTINUE SHOWING
A COLD FRONT MOVING OVER EASTERN COLORADO LATER TONIGHT WITH COOLER
AND STABLE CONDITIONS THROUGH TUESDAY.  AGREE WITH PREVIOUS
FORECASTER THAT AIRMASS ON THE PLAINS MAY DE-STABILIZE LATE TUESDAY
AFTERNOON...SO NEED TO HANG ON TO VARYING CHANCES OF THUNDERSTORMS
ACROSS THE FORECAST AREA.  SOME DRYING AND A FAIR AMOUNT WARMING
LOOK TO BE IN STORE FOR COLORADO ON THURSDAY AND FRIDAY AS THE UPPER
LEVEL RIDGE AXIS BUILDS OVER THE STATE.  THIS MAY BRING ENOUGH
SUBSIDENCE TO CAP ANY CONVECTION...BUT THERE MAY ALSO BE A FAIR
AMOUNT OF LOW AND MID LEVEL MOISTURE LINGERING IN THE VICINITY.
THIS JUST MAY HELP TO MAKE THE THUNDERSTORMS THAT DO DEVELOP ALL THE
MORE STRONGER...SO WILL KEEP 10-20 PERCENT CHANCE OF AFTERNOON AND
EVENING THUNDERSTORMS IN THE FORECAST WHILE HIGH TEMPERATURES CLIMB
TO NEAR 90 ON THE PLAINS.  FOR THE END OF THE WEEK...THE RIDGE AXIS
SLIDES EASTWARD AND COLORADO COMES UNDER INCREASING SOUTHWESTERLY
FLOW ALOFT.  IT IS WAY TOO EARLY TO TELL IF IT WILL BE DRY
SOUTHWESTERLY FLOW...OR IF IT WILL BE A PATTERN THAT TAPS INTO GULF
MOISTURE AND BRINGS AN ACTIVE SET UP FOR PLAINS THUNDERSTORMS.
CLIMATALOGY PROBABLY LEANS TOWARDS THE LATTER.

&&

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

&&

GIMMESTAD/DANKERS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DENVER CO
1116 AM MDT MON JUL 05 2004

COZ030>051-061200-
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-
1116 AM MDT MON JUL 05 2004

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

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON
INTO THIS EVENING ACROSS THE FRONT RANGE AND THE PLAINS.  A COLD
FRONT WILL RACE THROUGH THE AREA TOWARD EVENING WHICH COULD PROVIDE
THE FOCUS FOR CONVECTION TOWARD SUNSET.  AT THIS TIME...IT APPEARS
THE FAR NORTHEASTERN CORNER OF THE STATE HAS THE BEST CHANCE FOR
THUNDERSTORMS.  A FEW STORMS COULD BE SEVERE NEAR THE NEBRASKA
BORDER THIS EVENING AS LOW LEVEL SHEAR WILL BE BEST IN THIS AREA.
THE PRIMARY THREAT WILL BE LARGE HAIL TODAY ALONG WITH STRONG
WINDS.  THE THUNDERSTORM ACTIVITY WILL DIE OFF AN HOUR OR TWO AFTER
SUNSET.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

DRIER AND WARMER CONDITIONS ARE EXPECTED WEDNESDAY THROUGH FRIDAY
WITH ONLY A SLIGHT CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS
EXPECTED EACH DAY. THE CHANCE FOR THUNDERSTORMS MAY INCREASE THIS
WEEKEND WITH SUBTROPICAL MOISTURE COMING UP FROM THE DESERT
SOUTHWEST AND GULF OF MEXICO. HOWEVER...AT THIS TIME CONFIDENCE IN
THIS RETURN TO WETTER CONDITIONS REMAINS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.