Flash Flood in Colorado, August 6, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
320 PM MDT MON AUG 06 2007

.SHORT TERM...A VERY MOIST AND SOMEWHAT UNSTABLE AIRMASS REMAINS IN
PLACE OF NORTHERN AND EASTERN COLORADO TODAY WITH MODEL FORECAST
SOUNDINGS INDICATING PRECIPITABLE WATER VALUES AROUND 1.25 INCHES.
A SURFACE LOW OVER SOUTHEAST COLORADO HAS PRODUCED A RATHER
INNOCUOUS WIND FIELD.  BUT ALOFT...SOUTHWESTERLY FLOW OF 30-40 KNOTS
AT 500 MB IS PROVIDING SOME SYNOPTIC SCALE FORCING TO ORGANIZE
SHOWER ACTIVITY.  RADAR DEPICTS SHOWERS OVER THE CENTRAL
MOUNTAINS...MOVING ALONG A NORTHEASTERLY TRACK.  EXPECT SCATTERED
SHOWER ACTIVITY TO CONTINUE INTO THE EVENING AND THEN DISSIPATE.
THE WATER VAPOR SATELLITE LOOP DOES NOT REVEAL ANY SHORT WAVE AXIS
OVER COLORADO...SO IT IS DIFFICULT TO PINPOINT ANY BACK EDGE TO THIS
AFTERNOONS DEVELOPING ACTIVITY.  BY LATE EVENING...MOST OF THE
AIRMASS ACROSS COLORADO SHOULD BE OVERTURNED AND SHOWERS SHOULD
BEGIN DECREASING.

FOR TUESDAY...SOUTHWESTERLY FLOW ALOFT WILL CONTINUE...AND IT
APPEARS THERE WILL BE A BIT MORE SOUTHEASTERLY FLOW ACROSS THE
NORTHEAST PLAINS.  THIS MAY PRODUCE A DENVER CYCLONE WHICH COULD
POOL MOISTURE ALONG THE FRONT RANGE CORRIDOR.  DAYTIME HEATING
SHOULD DESTABILIZE THE AIRMASS...AND ANOTHER ROUND OF AFTERNOON AND
EVENING SHOWERS SHOULD RESULT.  MODEL SOUNDINGS SHOW PRECIPITABLE
WATER VALUES COMPARABLE TO TODAYS VALUES.  MODERATE WINDS ALOFT
SHOULD KEEP STORMS MOVING...BOTH THIS EVENING AND TOMORROW...BUT
INTENSE RAINFALL RATES MAY STILL CAUSE LOCAL FLOODING.

.LONG TERM...KEPT POPS GOING OVERNIGHT TUES AS DISTURBANCE MOVG THRU
NEBR AND WY SHOULD KEEP PRECIP GOING PAST MIDNIGHT ON THE PLAINS.
PRECIP SHOULD DCRS BY DAYBREAK WED.  UPR RDG WL REMAIN STATIONARY
OVER THE SOUTHEASTERN STATES THROUGH MIDWEEK.  AS A TROUGH MOVES
INTO THE PACIFIC NORTHWEST...THE FLOW ALF WL BCM MORE SWLY.  FOR THE
REST OF THE WEEKM...MOST OF THE MONSOONAL MSTR WL BE STEERED EAST OF
THE WEEK.  THIS WILL LEAD TO DRIER AND WARMER WEATHER RETURNING TO
THE FORECAST AREA FOR WED THRU FRIDAY.  ISOLD HIGH BASED TSTMS WL BE
PSBL ON THE MTNS...BUT THE PLAINS WILL REMAIN DRY FOR THE MOST PART.
TEMPS WL BE VRY WARM THIS WEEK...WITH FEWER CLDS EACH AFTN...TEMPS
WL BE WELL INTO THE 90S ON THE PLAINS.

RDG WL GRADUALLY EXPAND BACK WWD INTO THE SOUTHWEST FOR THE WKND.
AS ANTICYCLONIC CIRCULATION DVLPS OVER THE FOUR CORNERS REGION THIS
WEEKEND...THE PLUME OF MONSOONAL MSTR LOOKS TO REDEVELOP OVR THE
MTNS.  FEW CHANGES MADE TO CURRENT FCST.

&&

.AVIATION...LITTLE CHANGE FROM PAST COUPLE DAYS WITH CONVECTION
AFFECTING THE ARRIVAL/DEPARTURE GATES DURING THE AFTERNOONS AND
EVENINGS. HEAVY THUNDERSTORM RAINS WILL LIKELY BRING AT LEAST BRIEF
MVFR CONDITIONS.

&&

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

&&

KDRBY/046

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DENVER CO
1100 AM MDT MON AUG 06 2007

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-
1100 AM MDT MON AUG 06 2007

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

.DAY ONE...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS ARE POSSIBLE AGAIN THIS AFTERNOON AND
EVENING AS A MOIST AIRMASS REMAINS OVER THE FORECAST AREA.  SOME OF
THE THUNDERSTORMS WILL BE CAPABLE OF PRODUCING HEAVY RAINS...WITH
RAINFALL RATES OF AN INCH OR MORE PER HOUR.  WINDS ALOFT ARE A BIT
STRONGER TODAY THAN IN THE PAST WEEK...SO STORMS WILL MOVE A LITTLE
FASTER THAN THE PAST FEW DAYS.  HOWEVER...RAINFALL RATES WILL STILL
BE HIGH ENOUGH TO PRODUCE AT LEAST MINOR FLOODING.

SEVERAL LOCATIONS ON THE EASTERN PLAINS AND IN PARTS OF THE DENVER
METRO AREA SAW PRETTY SUBSTANTIAL RAINFALL LAST EVENING AND
OVERNIGHT AND CONSEQUENTLY THE THREAT OF FLOODING WILL BE INCREASED
IN THOSE AREAS IF THEY HAPPEN TO EXPERIENCE MORE RAINFALL THIS
AFTERNOON OR TONIGHT.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THE BEST CHANCE OF THUNDERSTORMS WILL BE ON TUESDAY AS THE DEEP
MOISTURE WILL REMAIN OVER COLORADO.  SOME LOCALLY HEAVY RAIN IS
LIKELY...HOWEVER WINDS ALOFT WILL BE STRONG ENOUGH TO HELP MOVE
STORMS ALONG... MINIMIZING THE THREAT OF FLASH FLOODING.  FOR
WEDNESDAY THROUGH FRIDAY A DRIER AIRMASS WILL DEVELOP OVER THE AREA
WITH ONLY A SLIGHT CHANCE OF THUNDERSTORM ALONG WITH WARMER
TEMPERATURES.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.

DANKERS/046