Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 301714
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1114 AM MDT WED JUL 30 2014

.UPDATE...
ISSUED AT 1104 AM MDT WED JUL 30 2014

WEAK LIFT WILL GRADUALLY FADE OVER THE FRONT RANGE THIS AFTERNOON.
MEANWHILE DRIER AIR IS CREEPING IN FROM THE NORTHEAST. CURRENT
TRENDS ARE A SUBTLE INCREASE IN THE RAINFALL FROM DENVER NORTH TO
GREELEY AND FORT COLLINS AS THE BETTER LIFT MOVES OVER THIS
AREA...SO WE WILL SEE CONTINUED MODERATE RAINFALL FOR A FEW MORE
HOURS AND WILL CONTINUE TO MONITOR FOR ANY AREAS OF ENHANCEMENT OR
PERSISTENCE THAT MIGHT NEED ADVISORIES OR WARNINGS. AT THIS POINT
EXPECT ANY FURTHER FLOODING TO BE LIMITED TO A FEW SMALL AREAS. I
WILL BE DROPPING THE WATCH ON ITS EASTERN FRINGE OVER MORGAN AND
WASHINGTON COUNTIES WHERE THE DRIER AIR IS MOVING IN. THERE COULD
BE SOME CONVECTION THERE LATER THIS AFTERNOON BUT THE INTENSITY
SHOULD NOT PRODUCE ENOUGH RAIN FOR FLOODING.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 408 AM MDT WED JUL 30 2014

A WK UPPER LEVEL TROUGH WILL MOVE SLOWLY ACROSS THE AREA TODAY THRU
EARLY THIS EVENING.  THERE WILL BE SOME MINOR MID LVL QG ASCENT WITH
THIS FEATURE THRU THE AFTN HOURS.  MEANWHILE THERE WILL STILL BE
ABUNDANT MOISTURE WITH PRECIPITABLE WATER VALUES AROUND 1.25".
OVERALL THERE MAY BE A DECREASE IN PCPN COVERAGE THRU THE MID
MORNING HOURS HOWEVER COVERAGE MAY INCREASE AGAIN BY LATE MORNING
THRU THE AFTN.  WITH ABUNDANT CLOUD COVER EXPECTED OVER MUCH OF THE
AREA WILL NOT SEE MUCH HEATING THIS AFTN WHICH WILL REDUCE THE
THREAT FOR WIDESPREAD STG STORMS THAT WOULD PRODUCE HEAVIER
RAINFALL. HOWEVER WITH SATURATED GROUND AND TROPICAL REGIME STILL IN
PLACE COULD SEE SOME LOCALIZED HEAVY RAIN IN A FEW PLACES DUE TO
WRM CORE LOW TOPPED CONVECTION. THUS WILL LEAVE FLASH FLOOD WATCH
IN PLACE THRU THE AFTN FOR NOW. AS FOR HIGHS READINGS OVER NERN CO
MAY ONLY REACH THE MID 60S TO NEAR 70 EXCEPT FOR THE FAR NERN
CORNER WHERE SOME CLEARING IN THE AFTN MAY ALLOW FOR READINGS IN
THE MID 70S.

FOR TONIGHT RAIN CHANCES SHOULD GRADUALLY DECREASE THRU THE EARLY
EVENING HOURS FM NORTH TO SOUTH WITH SHOWER THREAT ENDING BY
MIDNIGHT IN MOST AREAS.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 408 AM MDT WED JUL 30 2014

THE ABNORMALLY MOIST AND COOL WEATHER PATTERN FOR THIS TIME OF THE
YEAR IS EXPECTED TO CONTINUE INTO NEXT WEEK. A PERSISTENT UPPER
LEVEL TROUGH-RIDGE-TROUGH PATTERN ACROSS NORTH AMERICA LASTING
THROUGH THE WEEKEND IS GOING TO LEAVE COLORADO UNDER THE UPPER
RIDGE WITH WEAK FLOW ALONG WITH THE CONTINUATION OF A STRONG
NORTH AMERICAN MONSOON. MOISTURE STREAMING OVER THE STATE FROM THE
SOUTHWEST WILL KEEP THE PATTERN OF AFTERNOON AND EVENING SHOWER
DEVELOPMENT EACH DAY IN FULL FORCE. THE GFS AND ECMWF
PRECIPITATION FORECASTS WANT TO KEEP MOST OF THE RAINFALL OVER THE
MOUNTAINS...BUT WITH PERSISTENT SOUTHERLY LOW LEVEL FLOW ACROSS
THE EASTERN PLAINS OF COLORADO. NOW THAT MODERATE AND HEAVY RAIN
HAS FALLEN OVER EASTERN COLORADO...WESTERN KANSAS AND
OKLAHOMA...OVER THE NEXT FEW DAYS...ANY SOUTHERLY WINDS WILL
CONTAIN SIGNIFICANT AMOUNTS OF LOW LEVEL MOISTURE. FOR THIS
REASON...THE MODELS ARE PROBABLY TOO DRY ON THE PLAINS. DAYTIME
HEATING EACH DAY ALONG WITH ANY EMBEDDED SHORT WAVE DISTURBANCES
ROTATING UNDER THE UPPER RIDGE AXIS ARE GOING TO BE SUFFICIENT TO
PRODUCE ROUNDS OF SHOWERS THAT DEVELOP OVER THE MOUNTAINS AND
FOOTHILLS AND DRIFT OUT ONTO THE PLAINS. IT WILL ALSO BE POSSIBLE
FOR SOME SHOWER ACTIVITY TO INITIATE OVER THE PLAINS...INDEPENDENT
OF SHOWERS OVER THE MOUNTAINS. IN ANY CASE...SHOWERS THAT DEVELOP
ARE GOING TO BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL. SOIL
MOISTURE CONTENT OVER THE NEXT COUPLE DAYS WILL BE CRITICAL AS
AREAS OF HEAVY RAINFALL WILL BE QUICK TO CAUSE FLOODING PROBLEMS.

TEMPERATURES WILL BE COOLER THAN NORMAL FOR THE FIRST WEEK OF
AUGUST...BUT HUMIDITY LEVELS WILL BE HIGHER THAN COLORADANS ARE
GENERALLY ACCUSTOMED TO. IT IS DIFFICULT TO TELL IF ANY SINGLE DAY
WILL FEATURE MORE SHOWERS THAN ANY OTHER...BUT THE GFS AND ECMWF
BOTH INDICATE MORE RAIN MOVING OUT ONTO THE PLAINS TUESDAY
AFTERNOON. THIS IS A LONG WAYS OFF...BUT WILL BE SOMETHING TO KEEP
AN EYE ON.

&&

.AVIATION...(FOR THE TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1104 AM MDT WED JUL 30 2014

LIGHT TO MODERATE RAIN WILL CONTINUE IN THE DENVER AREA THROUGH
MID AFTERNOON WITH AREAS OF MVFR CONDITIONS. THE SHOWERS WILL
DIMINISH WITH IMPROVING CONDITIONS THROUGH MID EVENING...THOUGH
INSTRUMENT APPROACHES TO KDEN MAY BE NEEDED THROUGH 04Z. AREAS OF
FOG/LOW CLOUDS WILL DEVELOP LATER TONIGHT AND THERE IS A CHANCE
THAT IFR/LIFR CONDITIONS MAY DEVELOP AT THE DENVER TERMINALS
BETWEEN 09Z AND 15Z.

&&

.HYDROLOGY...
ISSUED AT 1104 AM MDT WED JUL 30 2014

EXPECT QUARTER INCH PER HOUR RAIN RATES OVER THE FRONT RANGE
FOOTHILLS AND ADJACENT PLAINS FOR THE NEXT 2-4 HOURS...A FEW SPOTS
COULD GET UP TO HALF AN INCH PER HOUR. AFTER THAT EXPECT THE
INTENSITY WILL DECREASE...THOUGH THERE COULD BE SOME SHOWERS
PRODUCING SIMILAR RAIN RATES THAT REDEVELOP IN AREAS THAT WARM
UP...MAINLY OVER THE MOUNTAINS. THESE RAINFALL AMOUNTS MAY BE
ENOUGH TO PRODUCE MINOR FLOODING...BUT THE FLASH FLOOD THREAT IS
LIKELY LIMITED TO BURN AREAS AND THE PLACES THAT HAD VERY HEAVY
RAINS YESTERDAY.

A FLOOD ADVISORY HAS BEEN ISSUED FOR THE CACHE LA POUDRE AND SOUTH
PLATTE RIVERS AT GREELEY AND KERSEY BASED ON EXPECTED RISES FROM
THE RAINFALL. THE RIVERS ARE EXPECTED TO REMAIN BELOW FLOOD STAGE
BUT SOME MINOR FLOODING OF SUSCEPTIBLE LOW LYING AREAS IS
POSSIBLE.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 6 PM MDT THIS EVENING FOR
COZ033>043-045>047.

&&

$$

UPDATE...GIMMESTAD
SHORT TERM...RPK
LONG TERM...DANKERS
AVIATION...GIMMESTAD
HYDROLOGY...GIMMESTAD



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