Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS65 KBOU 292201
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
401 PM MDT TUE JUL 29 2014

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 333 PM MDT TUE JUL 29 2014

THUNDERSTORMS HAVE BECOME ORGANIZED AS THE FRONT EDGE OF THE
SYNOPTIC SCALE SHOWERS RAN INTO THE EASTERLY WINDS ON THE PLAINS.
EXPECT THIS AREA TO REMAIN THE FOCUS OVER THE NEXT SEVERAL HOURS
SPREADING EAST INTO THE INFLOW. ALSO EXPECT A NEW AREA OF STORMS
TO DEVELOP OVER THE FOOTHILLS IN A COUPLE OF HOURS AS THE
EASTERLIES COMBINED WITH OUTFLOW FROM THE CURRENT CONVECTION
PUSHES UPHILL INTO THE INCOMING SHOWER AREA. THIS MAY RESULT IN
WIDESPREAD RAINFALL THAT IS HEAVIER THAN WAS FORECAST AS THE
SECOND AREA COULD SPREAD BACK EASTWARD OVERNIGHT. THIS WOULD HIT
THE AREA FROM DENVER NORTH TO THE STATE LINE HARD THIS EVENING.
TRENDED FORECAST THIS WAY...THOUGH STILL NOT SURE WE WILL HAVE THE
SUSTAINED LARGE SCALE UPSLOPE BEYOND THE CURRENT TRENDS MENTIONED
ABOVE. FOR THE TIME BEING...RAISED FORECAST RAINFALL A BIT...NOW
SHOWING 1.5 TO 2.5 INCHES INSTEAD OF THE 1 TO 2 THAT WE HAD...AND
RAISED POPS FURTHER.

FOR WEDNESDAY STILL SOME QUESTIONS AS IT WILL BE COOLER AND THERE
WILL BE A BIT LESS OF EVERYTHING TO WORK WITH. SOME OF THE MODELS
GENERATE A SUBSTANTIAL BATCH OF CONVECTION THAT DROPS FROM SE
WYOMING ACROSS THE FRONT RANGE CITIES WEDNESDAY MORNING.
CONDITIONS MAY STILL BE FAVORABLE FOR HEAVY RAIN AT THAT TIME...IT
WILL BE DRYING FURTHER EAST AND LATER IN THE DAY. WE ALREADY HAD
PRETTY HIGH POPS AND QPF FOR WEDNESDAY SO I HAVE LEFT THAT ALONE
AND WILL KEEP THE FLASH FLOOD WATCH RUNNING THROUGH WEDNESDAY. I
SUSPECT THE THREAT MAY BE LOWER IN THE AFTERNOON...BUT WE COULD
HAVE ADDITIONAL PROBLEMS IN THE MORNING ESPECIALLY GIVEN WHAT WILL
BE HAPPENING OVERNIGHT.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 333 PM MDT TUE JUL 29 2014

SOME DECREASE IN THE SHOWER AND THUNDERSTORM ACTIVITY WEDNESDAY
EVENING AS FORCING FROM MID LEVEL SHORTWAVE MOVES EAST OF THE
CFWA AND SLIGHTLY DRIER AIR SPREADS IN FROM THE NORTH. BEST CHANCE
FOR STORMS TO BE ACROSS THE MOUNTAINS AND PALMER DIVIDE. STORMS
WILL STILL BE CAPABLE FOR PRODUCING LOCALLY HEAVY RAIN...BUT
FLASH FLOOD THREAT SHOULD BE DECREASING. THUS WILL NOT EXTEND THE
FLASH FLOOD WATCH INTO THE EVENING HOURS. OVERNIGHT...AIRMASS TO
CONTINUE TO STABILIZE AND BECOME A BIT DRIER WITH ONLY SOME WEAK
CONVECTION POSSIBLE OVER THE HIGHER TERRAIN. ON THURSDAY...UPPER
RIDGE ACROSS GREAT BASIN WITH NORTHWEST FLOW ALOFT OVER COLORADO.
MODELS KEEP SOME MONSOONAL MOISTURE OVER THE AREA...MAINLY OVER
THE MOUNTAINS. BOUNDARY LAYER WIND AND RH PROGS SUGGEST SOME
POTENTIAL FOR LOW CLOUDS AND FOG IN AND NEAR THE FOOTHILLS DURING
THE MORNING...BUT FOG POTENTIAL APPEARS LIMITED AT THIS TIME TO
INCLUDE IN GRIDS. OTHERWISE A FEW STORMS POSSIBLE OVER THE HIGHER
TERRAIN DURING THE MORNING...THEN STORM CHANCES INCREASE ACROSS
THE AREA DURING THE AFTERNOON AND EVENING. BEST CHANCE FOR STORMS
TO BE OVER THE HIGHER TERRAIN. THOUGH AIRMASS TO BE A BIT
DRIER...STORMS WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAIN.
LOOKS TO BE ENOUGH FLOW ALOFT TO KEEP STORMS MOVING...LIMITING
THE FLASH FLOOD THREAT. STILL...BURN AREAS AND LOCATIONS WHICH
RECEIVED DECENT RAIN FROM THE RECENT STORMS WILL NEED TO BE
MONITORED. AIRMASS TO BE A BIT WARMER THOUGH TEMPERATURES WILL
REMAIN BELOW NORMAL.

FOR FRIDAY AND SATURDAY...UPPER LEVEL RIDGE BEGINS SHIFTING EAST
INTO COLORADO WITH WEAKENING NORTHWEST FLOW ALOFT. MODELS SHOW AN
INCREASE IN MONSOONAL MOISTURE WHICH MAY LEAD TO A BETTER CHANCE
FOR AFTERNOON AND EVENING THUNDERSTORMS. BEST CHANCE FOR STORMS TO
BE ACROSS THE MOUNTAINS AND ALONG THE FOOTHILLS. LOCALLY HEAVY
RAIN WILL CONTINUE TO BE A CONCERN...WITH AN INCREASING CHANCE FOR
SOME SLOW MOVING STORMS. TEMPERATURES TO BE SLIGHTLY WARMER...BUT
REMAINING BELOW NORMAL.

LOOKING AHEAD TO SUNDAY THROUGH TUESDAY. UPPER RIDGE SHIFTS
ACROSS COLORADO SUNDAY WITH FAIRLY LIGHT NORTHWEST FLOW ALOFT.
MONSOONAL MOISTURE WILL CONTINUE TO ADVECT INTO THE AREA...WITH
DECENT CHANCE FOR THUNDERSTORMS. LOCALLY HEAVY RAIN TO REMAIN A
THREAT. FLOW ALOFT BECOMES SOUTHWEST MONDAY AND TUESDAY AS MODELS
SHIFT THE RIDGE EAST AND BRING AN UPPER TROUGH INTO THE GREAT
BASIN. SOME DECREASE IN THE MONSOONAL MOISTURE...STILL ENOUGH FOR
A CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS. TEMPERATURES LOOK
TO BE SLIGHTLY BELOW NORMAL.

&&

.AVIATION...(FOR THE TAFS THROUGH 00Z WEDNESDAY LATE AFTERNOON)
ISSUED AT 333 PM MDT TUE JUL 29 2014

THUNDERSTORMS WILL BE NUMEROUS AROUND THE DENVER AREA THIS
EVENING...LIKELY GIVING WAY TO A STEADIER RAIN LATER TONIGHT.
AREAS OF MVFR CONDITIONS AND LOCALIZED IFR CAN BE EXPECTED THROUGH
THE NIGHT...AND POSSIBLY THROUGH WEDNESDAY MORNING. SOME
IMPROVEMENT IS LIKELY WEDNESDAY AFTERNOON THOUGH INSTRUMENT
APPROACHES WILL LIKELY STILL BE NEEDED AT KDEN DUE TO CEILINGS.

&&

.HYDROLOGY...
ISSUED AT 333 PM MDT TUE JUL 29 2014

IT APPEARS THERE WILL BE ONE OR MORE LARGE AREAS OF THUNDERSTORMS
WITH MODERATE TO HEAVY RAIN THIS EVENING...AND POSSIBLY ALL NIGHT.
FOCUS WILL BE MAINLY ALONG THE FRONT RANGE DURING THE EARLY
EVENING...LIKELY SPREADING EASTWARD OVERNIGHT. EXPECT MOST OF THE
STORMS TO PRODUCE 1-2 INCH PER HOUR RAINFALL RATES...BUT THEY
COULD BE SUSTAINED FOR A LONG TIME. END RESULT SHOULD BE MINOR
FLOODING IN MANY AREAS AND SEVERAL LOCATIONS THAT EXPERIENCE
SIGNIFICANT FLASH FLOODING.

WIDESPREAD RAINFALL MAY BE ENOUGH TO PRODUCE FLOODING ON THE
LARGER RIVERS INCLUDING THE SOUTH PLATTE. RIVER FORECASTERS ARE
EVALUATING THE SITUATION. IF THE AREA CURRENTLY EXPERIENCING
STRONG THUNDERSTORMS REMAINS THIS WAY THROUGH THE EVENING...THEN
RIVER FLOODING WILL BE LIKELY WEDNESDAY MORNING.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH WEDNESDAY AFTERNOON FOR COZ033>047-049.

&&

$$

SHORT TERM...GIMMESTAD
LONG TERM...D-L
AVIATION...GIMMESTAD
HYDROLOGY...D-L/GIMMESTAD



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.