Severe Thunderstorm Warning 45, NWS Denver/Boulder, CO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
325 PM MDT THU JUN 7 2012

.SHORT TERM...INITIAL SHORTWAVE KICKED OFF STORMS EARLIER THIS
AFTERNOON FROM THE FOOTHILLS AND MOVED EAST. A BIT OF STABILIZING
SEEMS TO HAVE OCCURRED ON THE BACKSIDE. DENVERS EXTRA 19Z SOUNDING
SHOWS PRECIPITABLE WATER ABOUT A THIRD OF AN INCH HIGHER THAN
YESTERDAY...CAPE OF 2500 J/KG AND A CAP EXISTING 700 MB. THIS
MORNINGS CLOUD COVER AND THE HIGHER DEWPOINTS MAY BE INHIBITING
CONVECTION THIS AFTERNOON. TEMPERATURES WILL NEED TO WARM MORE IN
ORDER TO BREAK THAT CAP...CURRENTLY THINKING WE MAY BARELY REACH
CONVECTIVE TEMPS. HOWEVER CONVECTION IN WYOMING CONTINUES AS THEY
ARE CLOSER TO THE UPPER SHORTWAVE TROUGH. CURRENT OBSERVATIONS
SHOW THIS ACTIVITY STARTING TO PUSH SOUTH AND SEVERAL RUNS OF THE
MESOSCALE MODELS HAVE BEEN SHOWING THIS TREND AS WELL. THIS MAY
MEAN A LATER ROUND OF CONVECTION FOR NORTHEASTERN COLORADO AS
THESE STORMS AND OUTFLOWS MAY HELP KICK STORM OFF TO BREAK THE CAP.
IF AND WHEN THESE STORMS FORM...THEY WILL BE CAPABLE OF PRODUCING
LARGE HAIL UP TO 2 INCHES IN DIAMETER...OUTFLOW WINDS OVER 60 MPH
AND POSSIBLY A FEW TORNADOES.

DRIER AIR WILL BE MOVING IN FROM THE WEST TONIGHT AND INTO
TOMORROW. THERE IS A SLIGHT CHANCE AFTER THE RAIN TONIGHT TO SEE
PATCHY FOG OVER THE EASTERN PLAINS NEAR SUNRISE...EXPECTED TO
DISSIPATE QUICKLY AFTER SUNRISE. SOUTHWEST FLOW ALOFT WILL BRING
IN WARMER TEMPERATURES WITH THE DRIER AIR AND SHOULD SEE MOSTLY
CLEAR SKIES. HOWEVER AIRMASS WILL STILL HAVE SOME INSTABILITY SO
ANY MOISTURE LEFT COULD FIRE OFF ISOLATED SHOWERS OR
THUNDERSTORMS. KEPT IN THE SLIGHT CHANCE POPS FOR TOMORROW.
ANOTHER CONCERN FOR TOMORROW WILL BE FOR CRITICAL FIRE WEATHER
CONDITIONS AS HUMIDITIES LOWER TO BELOW 15 PERCENT IN THE HIGH
COUNTRY. AS THE SOUTHWEST FLOW STRENGTHENS DURING THE
AFTERNOON...THE HIGHER TERRAIN MAY SEE CONDITIONS NEAR RED FLAG
CRITERIA...BUT DO NOT THINK IT WILL LAST LONG OR BE WIDESPREAD.
WILL NOT ISSUE HIGHLIGHTS.

.LONG TERM...DRY AND WARM WEATHER FOR THE FIRST HALF OF THE
WEEKEND WILL BRING A RETURN OF FIRE WEATHER CONCERNS...AT LEAST TO
THE MOUNTAINS. MOUNTAIN AREAS STILL HAVE NOT RECEIVED MUCH
PRECIPITATION SO THAT THE HIGH TEMPERATURES...LOW HUMIDITIES AND
INCREASING WINDS ON SATURDAY WILL PRODUCE VERY HIGH FIRE
CONDITIONS SATURDAY AFTERNOON. THE STATE WILL BE UNDER INCREASING
SOUTHWEST FLOW ALOFT AHEAD OF AN APPROACHING UPPER TROUGH. THE
UPPER TROUGH WILL PASS OVER THE STATE SUNDAY MORNING...BRINGING
COOLER TEMPERATURES TO THE FORECAST AREA SUNDAY. THE UPPER TROUGH
WILL BE LACKING IN MOISTURE...SO THE COOLER TEMPERATURES WILL BE
THE ONLY IMPACT AS IT MOVES BY. TEMPERATURES AROUND NORMAL WILL
CONTINUE INTO EARLY NEXT WEEK AS WESTERLY FLOW ALOFT CONTINUES
ACROSS THE COUNTRY. MOISTURE AND INSTABILITY ARE EXPECTED TO
GRADUALLY RETURN TO THE PLAINS BY THE MIDDLE OF NEXT
WEEK...BRINGING BACK THE CHANCE FOR AFTERNOON AND EVENING
THUNDERSTORMS. LOOKS LIKE SUMMER IS HERE TO STAY.

&&

.AVIATION...EXPECT TO SEE CONVECTION TO INCREASE AGAIN AFTER 22Z
AS HEATING BEGINS TO MAX. OTHERWISE...CONVECTION FROM WYOMING
SEEMS TO BE MAKING A PUSH SOUTH TOWARD THE STATE. EITHER
WAY...EXPECTING A CHANCE TO SEE MORE TS THIS EVENING. WITH MORE
MOISTURE IN THE AIR...CEILINGS UNDER TS WILL BE AROUND 5K AGL.
STILL A CHANCE FOR STRONG ERRATIC OUTFLOW WINDS AND HAIL.
EXPECTING THIS ACTIVITY TO DECREASE IF NOT DIMINISH BY MIDNIGHT.
WARMER AND DRIER AIR TOMORROW WILL ALLOW FOR VFR CONDITIONS ALL
DAY.

&&

.HYDROLOGY...THUNDERSTORMS ARE EXPECTED TO REDEVELOP LATE THIS
AFTERNOON INTO THE EVENING. HIGHER MOISTURE LEVELS WILL MAKE THESE
STORMS CAPABLE OF HIGHER RAINRATES. MOST OF THE STORMS WILL BE
PRODUCING UP TO TWO TENTHS OF RAIN IN AN HOUR...THOUGH IF A
STRONGER STORM FORMS...COULD SEE A COUPLE INCHES IN LESS THAN AN
HOUR. THESE STORMS WILL BE MOVING EAST AT NEAR 20 MPH.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR COZ040-041.

FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
EVENING FOR COZ211>214-217-218.

&&

SHORT TERM...KRIEDERMAN
LONG TERM....DANKERS
AVIATION...KRIEDERMAN

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DENVER CO
1122 AM MDT THU JUN 07 2012

COZ030>051-081200-
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-
1122 AM MDT THU JUN 07 2012

...FLASH FLOOD WATCH THIS AFTERNOON AND EVENING FOR THE SOUTHERN
DENVER SUBURBS AND NORTHERN DOUGLAS COUNTY...

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

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS WILL DEVELOP AGAIN THIS AFTERNOON AND
CONTINUE THROUGH THE EVENING.  THUNDERSTORMS WILL LINGER AFTER
MIDNIGHT ACROSS PARTS OF EASTERN COLORADO.  SOME OF THE
THUNDERSTORMS WILL LIKELY BECOME SEVERE TODAY WITH LARGE HAIL UP TO
2 INCHES IN DIAMETER AND DAMAGING WINDS TO 70 MPH.  A COUPLE OF WEAK
TORNADOES WILL ALSO BE POSSIBLE.  INITIAL STORM DEVELOPMENT WILL BE
OVER THE FOOTHILLS...BUT MOST OF THE THUNDERSTORM ACTIVITY IS
EXPECTED TO OCCUR OVER THE PLAINS.  HIGH LEVELS OF MOISTURE ARE
PRESENT ACROSS THE NORTHEAST PLAINS TODAY WHICH MEANS THAT HEAVY
RAIN WILL ACCOMPANY THE THUNDERSTORMS AND MAY PRODUCE FLASH
FLOODING.  THE FLASH FLOOD WATCH FOR SOUTHERN PARTS OF DENVER AND
NORTHERN DOUGLAS COUNTY IS DUE TO WET SOILS FROM LAST NIGHTS HEAVY
RAIN.  IF THUNDERSTORMS DEVELOP OVER THESE AREAS...RUNOFF WILL
DEVELOP QUICKLY.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

WARMER AND DRIER CONDITIONS WILL DEVELOP FRIDAY AND SATURDAY...WITH
AN INCREASING WESTERLY FLOW ALOFT OVERHEAD.  THERE WILL STILL BE
ENOUGH LOW LEVEL MOISTURE PRESENT TO PRODUCE A SLIGHT CHANCE OF
THUNDERSTORMS FRIDAY AFTERNOON AND EVENING...MAINLY OVER THE
NORTHEAST PLAINS.  A FEW STORMS COULD AGAIN BE SEVERE.  IT WILL BE
BREEZY...HOT AND DRY ON SATURDAY AHEAD OF AN APPROACHING COLD FRONT.
FIRE DANGERS WILL INCREASE OVER THE FOOTHILLS BECAUSE OF THE DRY
WINDS.  IT WILL BE COOLER SUNDAY THROUGH WEDNESDAY WITH A SLIGHT
CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS POSSIBLE EACH DAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED THIS AFTERNOON AND
EVENING.

KRIEDERMAN/DANKERS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
438 PM MDT THU JUN 07 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0431 PM     HAIL             1 W LEADER              39.90N 104.08W
06/07/2012  M1.50 INCH       ADAMS              CO   TRAINED SPOTTER

&&

JK

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE DENVER CO
457 PM MDT THU JUN 07 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0454 PM     HAIL             4 ESE BYERS             39.69N 104.16W
06/07/2012  M1.00 INCH       ARAPAHOE           CO   TRAINED SPOTTER

0431 PM     HAIL             1 W LEADER              39.90N 104.08W
06/07/2012  M1.50 INCH       ADAMS              CO   TRAINED SPOTTER

0425 PM     HAIL             3 S HOYT                39.98N 104.07W
06/07/2012  M1.00 INCH       ADAMS              CO   TRAINED SPOTTER

&&

JK