Flash Flood Warning 9, NWS Denver/Boulder, CO

404 
WGUS75 KBOU 182208
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
408 PM MDT THU JUL 18 2013

COC013-190000-
/O.CON.KBOU.FF.W.0009.000000T0000Z-130719T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BOULDER CO-
408 PM MDT THU JUL 18 2013

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 600 PM MDT FOR
THE FOURMILE BURN AREA IN CENTRAL BOULDER COUNTY...

AT 405 PM MDT...AUTOMATED RAIN GAUGES INDICATED THAT 0.3 TO 0.8 INCH 
OF RAIN HAS FALLEN OVER THE FOURMILE BURN AREA. THUNDERSTORMS WITH 
HEAVY RAIN CONTINUE TO MOVE ACROSS THE FOURMILE BURN AREA.

HEAVY RAINFALL OVER THE FOURMILE BURN AREA CAN CAUSE MUD SLIDES NEAR 
STEEP TERRAIN. A MUD SLIDE CAN CONSIST OF ROCK...MUD...VEGETATION 
AND OTHER LOOSE MATERIALS.

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
SUMMERVILLE...SALINA...CRISMAN...GOLD HILL...SUNSHINE AND WALLSTREET.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL WILL CAUSE FLASH FLOODING OF CREEKS...STREAMS...AND
DITCHES IN THE FOURMILE BURN AREA.  SOME DRAINAGE BASINS AFFECTED BY
EXCESSIVE RUNOFF INCLUDE FOURMILE CREEK...GOLD RUN...AND FOURMILE 
CANYON CREEK.  WATER WILL BE FLOWING DOWN ROADWAYS. ROCK SLIDES OR 
DEBRIS FLOWS CAN ALSO BE EXPECTED.

&&

LAT...LON 4008 10533 4006 10529 3999 10533 4002 10542
      4005 10544 4008 10541

$$
TLH

249 
WGUS75 KBOU 182229
FFSBOU

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
429 PM MDT THU JUL 18 2013

COC013-182231-
/O.CAN.KBOU.FF.W.0009.000000T0000Z-130719T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BOULDER CO-
429 PM MDT THU JUL 18 2013

...THE FLASH FLOOD WARNING FOR CENTRAL BOULDER COUNTY IS CANCELLED...

THE HEAVY RAIN IN AND NEAR THE FOURMILE BURN SCAR WEST OF BOULDER HAS ENDED...
AND FLOODING IS NO LONGER EXPECTED TO POSE THREAT.

EARLIER THIS AFTERNOON RAINFALL AMOUNTS OF 0.50 TO 0.75 INCH CAUSED WATER 
TO RUN OVER ROADS AND ALSO CAUSED MINOR RISES ON STREAMS. AT THIS TIME 
THE BOULDER EMERGENCY MANAGER HAS REPORTED NO DAMAGE. 

PORTIONS OF GILPIN AND BOULDER COUNTIES INCLUDING THE FOURMILE BURN AREA 
REMAIN UNDER A SMALL STREAM FLOOD ADVISORY UNTIL 6 PM MDT. STORMS IN THE 
AREA COULD STILL PRODUCE RAINFALL RATES UP TO A QUARTER INCH IN UNDER 
30 MINUTES.        

LAT...LON 4008 10533 4006 10529 3999 10533 4002 10542
      4005 10544 4008 10541

$$
BAKER

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
319 PM MDT THU JUL 18 2013

.SHORT TERM...SLOW MOVING THUNDERSTORMS AN ISSUE OVER LARIMER
COUNTY THIS AFTN. FLASH FLOODING REPORTED IN THE FERN LAKE BURN
SCAR THIS AFTN WHERE RADAR ESTIMATED 1.5 TO 2.5 INCH STORM TOTALS.
SIMILAR ISSUES WILL CONTINUE THE REST THE AFTERNOON AND EVENING
ESPECIALLY IN THE FOOTHILLS OF LARIMER AND BOULDER COUNTIES. STORM
MOTIONS 10 KTS OR LESS THIS AFTN WITH PW VALUES CLOSE TO ONE INCH.
16Z HRRR KEEPS THE BEST CONVERAGE ALONG AND NORTH OF INTERSTATE
70 AND 76 TONIGHT...SO WILL GO WITH THE HIGHEST COVERAGE THERE. ON
FRIDAY IT WILL BE COOLER FOLLOWING THE PASSAGE OF A COLD FRONT
TONIGHT. SPATIAL CROSS SECTIONS SHOW A DEEPER EASTERLY FLOW WITH
SIMILAR PW VALUES FOR FRIDAY AFTN. AS A RESULT...SLOW MOVING
THUNDERSTORMS WITH HEAVY RAIN AND FLASH FLOODING WILL AGAIN BE AN
ISSUE ESPECIALLY IN THE BURN AREAS...BUT IN OTHER POOR DRAINAGE
AREAS AS WELL. NO FLASH FLOOD WATCH AT THIS TIME...BUT ONE MAY
BE NEEDED FOR FRIDAY AT SOME POINT.

.LONG TERM...ONLY MINOR CHANGES TODAY. UPPER RIDGE REMAINS OVER
MOST OF THE COUNTRY. DRIER AIR WORKS IN FROM THE NORTHWEST ON
SUNDAY FOR WARMER AND NEARLY DRY WEATHER...THEN BY LATE IN THE
WEEK MOISTURE COMES UP FROM THE SOUTH AGAIN. THIS IS ALREADY
COVERED WELL...MINOR CHANGES IN MODEL CONSENSUS LOOK FINE.

&&

.AVIATION...16Z HRRR MDL WANT TO KEEP THE HIGHEST TSTM COVERAGE
TO THE NORTH AND WEST OF DENVER THIS EVENING SO IT MAY BE BEST TO
GO WITH VCTS THIS AFTN SO HOLD OFF ON THE TEMPO GROUP FOR TSTMS
FOR THE 00Z TAFS. WILL WATCH THE NEXT COUPLE OF HRRR RUNS AND SEE
HOW THEY HANDLE OUTFLOW BOUNDARIES AND THE CONSEQUENT CONVECTION
OFF THE FOOTHILLS BEFORE MAKING A DECISION. A COOLER AMS WILL BE
OVER THE AREA ON FRIDAY FOLLOWING THE COLD FRONT TONIGHT. FLOW AT
THE SFC AND ALOFT WILL BE EASTERLY FOR FRIDAY AFTN...WITH A BETTER
CHANCE OF TSTMS WEST OF INTERSTATE 25.

&&

.HYDROLOGY...THREAT FOR FLASH FLOODING WILL BE AN ISSUE IN THROUGH
04Z THIS EVENING...WITH ANOTHER POSSIBILITY FOR FLASH FLOODING IN
THE BURN AREAS FRIDAY AFTN. STORM MOTIONS A LITTLE ERRATIC THIS
AFTN WITH SPEEDS OF 6-10KTS...WITH SLOW MOVEMENT AGAIN EXPECTED
FRIDAY AFTN WITH STORM MOTION EXPECTED TO BE NE TO SW.

&&

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

SHORT TERM...COOPER
LONG TERM....GIMMESTAD
AVIATION...COOPER

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1057 AM MDT THU JUL 18 2013

COZ030>051-191700-
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-
1057 AM MDT THU JUL 18 2013

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

.DAY ONE...TODAY AND TONIGHT

HIGHER STORM COVERAGE CAN BE EXPECTED AS MOISTURE INCREASES FROM
WEST TO EAST ACROSS THE AREA. THE STORMS ARE FIRST EXPECTED TO
DEVELOP IN THE MOUNTAINS BY NOON...SPREADING AND DEVELOPING
EASTWARD ACROSS THE PLAINS BY MID TO LATE AFTERNOON. THE STRONGER
STORMS WILL BE CAPABLE OF PRODUCING AROUND 1 INCH OF RAIN IN 20
TO 30 MINUTES...ALONG WITH GUSTY OUTFLOW WINDS UP TO 50 MPH. THE
BRIEF BUT HEAVY RAIN MAY PRODUCE FLOODING IN THE FRONT RANGE BURN
SCARS. STORMS WILL GRADUALLY DECREASE BY OR SHORTLY AFTER MIDNIGHT
TONIGHT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

SCATTERED TO NUMEROUS THUNDERSTORMS ARE EXPECTED FRIDAY WITH
CONCERN OF HEAVY RAIN OVER THE EASTERN FRONT RANGE MOUNTAINS AND
FOOTHILLS. TEMPERATURES WILL BE ABOUT 5-10 DEGREES COOLER FROM
TODAY.

SATURDAY WILL HAVE SCATTERED STORM ACTIVITY BUT WITH LESS
AVAILABLE MOISTURE...SO HEAVY RAIN CONCERNS ARE LOWER. SUNDAY AND
MONDAY WILL BE WARM AND DRY BEFORE MORE MOISTURE MOVES IN FOR
TUESDAY AND WEDNESDAY TO PRODUCE DAILY SHOWERS AND THUNDERSTORMS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.
HOWEVER...ANY REPORTS OF HEAVY RAINFALL WOULD BE APPRECIATED.

COOPER/GIMMESTAD