Tornado Warning 70, NWS Denver/Boulder, CO

000 
WWUS55 KBOU 300000
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
600 PM MDT WED JUL 29 2009

COC039-073-300008-
/O.CAN.KBOU.TO.W.0070.000000T0000Z-090730T0015Z/
LINCOLN CO-ELBERT CO-
600 PM MDT WED JUL 29 2009

...THE TORNADO WARNING FOR EAST CENTRAL ELBERT AND CENTRAL LINCOLN
COUNTIES IS CANCELLED...

ALTHOUGH THE TORNADO WARNING HAS BEEN CANCELLED...A SEVERE 
THUNDERSTORM WARNING REMAINS IN EFFECT FOR CENTRAL LINCOLN COUNTY 
UNTIL 700 PM MDT.

HAIL...INTENSE RAIN AND STRONG DAMAGING WINDS ARE LIKELY WITH THESE 
STORMS. TAKE COVER IN A SUBSTANTIAL SHELTER UNTIL THE STORM PASSES. 
THE THUNDERSTORM.  HEAVY RAIN WILL ALSO CAUSE FLOODING IN LOW LYING 
AREAS.  

LAT...LON 3925 10344 3902 10350 3914 10379 3924 10383
      3935 10378
TIME...MOT...LOC 2358Z 304DEG 26KT 3912 10355

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
328 PM MDT WED JUL 29 2009

.SHORT TERM...FRONT PASSED CWA PLAINS EARLY THIS AFTERNOON...HELPED
TO STABILIZE LOWER LEVELS OF ATMOSPHERE. STILL HAD SCATTERED
ELEVATED CONVECTION IN RESPONSE TO SHORTWAVE MOVING ACROSS NORTHERN
COLORADO. STORMS WERE BELOW SEVERE LIMITS. RADAR AND SATELLITE
SHOWING SHORTWAVE ACROSS MOUNTAINS...BEGINNING TO PUSH ONTO PLAINS.
NICE BATCH OF PRECIPITATION ACROSS WELD AND LARIMER COUNTIES...
ASSOCIATED WITH THE BEST QG ASCENT. AS SHORTWAVE CONTINUES TO HEAD
EAST...WOULD SUSPECT PRECIPITATION TO SPREAD ACROSS REMAINDER OF
AREA. GIVEN CURRENT PRECIPITATION COVERAGE...WILL ADJUST POPS
ACCORDINGLY. NAM AND RUC INDICATE MAIN BATCH OF QPF ACROSS ZONES 36
AND 41 FOR THIS EVENING WHERE THE PRIME UPSLOPE EXPECTED TO RESIDE.
STORMS EXPECTED TO PRODUCE HEAVY RAIN AND PERHAPS SOME SMALL HAIL
GIVEN THE COOLER AIRMASS. MODELS INDICATE CAPE VALUES RANGING FROM
500-1000 J/KG WITH THE HIGHER VALUES ALONG THE ELEVATED REGION OF
THE PALMER DIVIDE. SEVERE POTENTIAL REMAINS LOW...BUT WILL NEED TO
WATCH FOR THE HEAVY RAIN. STORM MOTION 10 TO 15 KTS...WHICH SHOULD
LIMIT FLOOD CONCERNS. MODELS SHOWING ACTIVITY TO LINGER BEYOND
MIDNIGHT DESPITE SUBSIDENCE BEHIND THE SHORTWAVE. POPS ARE ALREADY
LOW...SO WILL NOT CHANGE MUCH. BOUNDARY LAYER WIND AND HUMIDITY
PROGS SUGGEST LOW CLOUDS AND POSSIBLE FOG ACROSS MUCH OF PLAINS
DURING THE EARLY MORNING HOURS THURSDAY. THIS STILL LOOKING ON
TRACK...SINCE CEILINGS ARE CURRENTLY NEARING MVFR VALUES. WEATHER
AND POP GRIDS SEEM REASONABLE. MODELS SHOW A BRIEF LUL IN THE
WEATHER BY LATE MORNING...THEN POSSIBLE SHORTWAVE MOVES ACROSS
REGION DURING AFTERNOON. WITH LOW LEVEL MOISTURE AND UPSLOPE IN
PLACE...SHOULD SEE A CHANCE OF STORMS DURING THE AFTERNOON
PARTICULARLY ALONG AND ADJACENT TO FOOTHILLS. FORECAST SOUNDINGS
SHOW CAPE VALUES GENERALLY LESS THAN 1000 J/KG...SO SEVERE THREAT
WILL AGAIN BE LOW. CONCERN WILL AGAIN BE HEAVY RAIN...AS
PRECIPITABLE WATER VALUES EXPECTED TO BE AROUND NINE TENTHS OF AN
INCH. HIGH TEMPERATURES THURSDAY CHANGE LITTLE FROM TODAYS READINGS.

.LONG TERM...THE UNSETTLED WEATHER OF THE PAST FEW DAYS LOOKS LIKE
IT WILL HOLD ON FOR A FEW MORE DAYS AS THE UPPER AIR PATTERN OVER
THE WESTERN U.S. UNDERGOES ONLY GRADUAL CHANGES THROUGH EARLY NEXT
WEEK.  THE AMPIFIED RIDGE OVER THE WEST IS LEAVING COLORADO UNDER
BRISK NORTHWESTERLY FLOW ALOFT...OPENING THE DOOR FOR CANADIAN
SURGES OF COOLER AIR AT LOW LEVELS.  THE RIDGE IS ANCHORED IN PLACE
WHILE A DEEP UPPER TROUGH REMAINS IN PLACE OVER EASTERN CANADA AND
THE NORTHEASTERN U.S.  A CUTOFF LOW OFF THE NORTHERN CALIFORNIA
COAST WILL ALSO HELP TO MAINTAIN THE AMPLIFICATION OF THE PACIFIC
NORTHWEST RIDGE.  THE ECMWF AND GFS SHOW THE RIDGE EVENTUALLY
SPREADING EASTWARD BY LATE IN THE WEEKEND WHICH WOULD BRING COLORADO
UNDER DRIER AND WARMER WESTERLY FLOW ALOFT.  BUT I DOUBT THAT THE
RIDGE WILL FLATTEN LIKE THE GFS ADVERTISES AS LONG AS THAT UPPER LOW
IS HANGING OFF THE PACFIC COAST.  IN THE MEANTIME...ANOTHER COLD
FRONT SHOULD MOVE INTO THE AREA ON SATURDAY AFTER SOME MODERATION IN
TEMPERATURES ON FRIDAY.  MOS TEMPERATURE GUIDANCE FROM THE GFS
CONTINUES TO WAY OVERPLAY ANY WARMING...SO HAVE LEANED TOWARD THE
NAM GUIDANCE.  AS LONG AS WE REMAIN UNDER THE NORTHWESTERLY FLOW...
THE POSSIBILITY OF AFTERNOON AND EVENING SHOWERS GENERATED BY SHORT
WAVES EMBEDDED IN THE FLOW PATTERN WILL PERSIST.  FOR THE TIME BEING
WILL CONTINUE WITH THE 10-30 PERCENT POPS ACROSS MOST OF THE
FORECAST AREA EACH DAY.  TEMPERATURES WILL ALSO BE 5-10 DEGREES
COOLER THAN NORMAL.

&&

.AVIATION...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TO MOVE
ACROSS AREA THROUGH ABOUT 03Z. EXPECT MVFR CEILINGS WITH THE SHOWERS
AND STORMS MOVE ACROSS AREA. SOME LINGERING SHOWERS POSSIBLE
OVERNIGHT...BUT MAIN CONCERN WILL BE POSSIBLE DEVELOPMENT OF LOW
CLOUDS AND FOG DURING THE 06Z TO 15Z TIME FRAME....WITH PERIODS OF
IFR CEILINGS AND VISIBILITY. VFR CEILINGS SHOULD PREVAIL BY 18Z
THURSDAY...WITH ANOTHER ROUND OF SHOWERS AND STORMS DURING
AFTERNOON. COULD SEE MVFR CEILINGS AS STORMS PASS OVERHEAD.

&&

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

D-L/KDRBY

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DENVER CO
1050 AM MDT WED JUL 29 2009

COZ030>051-301200-
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-
1050 AM MDT WED JUL 29 2009

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

.DAY ONE...TODAY AND TONIGHT

SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED ACROSS THE AREA
THIS AFTERNOON...CONTINUING THROUGH TONIGHT. THE STORMS WILL BE MOST
NUMEROUS ACROSS THE SOUTHERN FOOTHILLS AND ALONG THE PALMER DIVIDE.
THE STORMS WILL BE CAPABLE OF PRODUCING HEAVY RAIN AND SMALL HAIL
ALONG WITH WIND GUSTS TO 45 MPH. A FEW OF THE STORMS ACROSS THE
PLAINS COULD BECOME SEVERE WITH HAIL UP TO AN INCH IN DIAMETER AND
WIND GUSTS TO 60 MPH. THE GREATEST THREAT FOR SEVERE STORMS WILL BE
ACROSS THE PALMER DIVIDE OF DOUGLAS AND WESTERN ELBERT COUNTIES.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THE COOL AND UNSETTLED WEATHER PATTERN WHICH HAS BEEN OVER NORTHEAST
COLORADO THE PAST FEW DAYS IS EXPECTED TO GRADUALLY MODERATE THROUGH
THE WEEKEND AND EARLY NEXT WEEK.  EACH AFTERNOON AND EVENING WILL
HAVE A CHANCE OF SHOWERS AND THUNDERSTORMS WITH THE MAIN THREAT FROM
STORMS BEING BRIEF HEAVY RAINS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT.

D-L/TCD