Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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 240305
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
905 PM MDT SAT MAY 23 2015

.UPDATE...
ISSUED AT 904 PM MDT SAT MAY 23 2015

ONE LINE OF STORMS STILL MOVING ACROSS SEDGWICK AND PHILLIPS
COUNTIES. SEVERE THREAT SHOULD BE LOW BUT STILL SOME POTENTIAL
HEAVY RAIN. MEANWHILE WHAT SHOULD BE THE LAST LINE OF STORMS FOR
THE NIGHT IS MOVING OUT OF DENVER...WITH ANOTHER PATCH OF DRY AIR
BEHIND IT. WILL NEED TO HANG ON TO SOME LOW POPS THE REST OF THE
NIGHT...BUT MOST OF THE SHOWER ACTIVITY SHOULD REMAIN CLOSER TO
THE LOW OVER THE MOUNTAINS...AND MAINLY WEST OF OUR AREA. AREAS OF
FOG DEVELOPING DUE TO CLEARING LOOKS GOOD. MAY BE ABLE TO END THE
REMAINING PART OF THE FLASH FLOOD WATCH EARLY...BUT WE WILL HOLD
ON TO IT FOR NOW GIVEN THAT THE STORMS IN THE CORNER ARE SLOW
MOVING AND FLARING UP IN INTENSITY AGAIN AT THIS TIME.

TODAYS RAIN RESULTED IN A SLIGHT UPWARD BUMP IN THE SOUTH PLATTE
FLOOD FORECAST...RESULTING IN A FLOOD WARNING DOWNSTREAM AT BALZAC
ON THE MORGAN/WASHINGTON COUNTY LINE. THERE WILL BE SOME RISES ON
THE UPSTREAM TRIBUTARIES...FROM THE POUDRE AROUND TO THE PLATTE
COMING OUT OF DENVER AND EVERYTHING IN BETWEEN...BUT THESE ARE
EXPECTED TO REMAIN BELOW FLOOD STAGE.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 321 PM MDT SAT MAY 23 2015

AREAS OF THUNDERSTORMS HAVE BEEN MOVING OVER THE NORTHEAST
COLORADO PLAINS FOR THE PAST COUPLE HOURS. ANOTHER STORM IS
PRESENTLY MOVING OUT OF DOUGLAS COUNTY AND TRACKING NORTHEASTWARD.
STORMS HAVE BEEN MOVING FAST ENOUGH THAT RAINFALL AMOUNTS HAVE
GENERALLY BEEN HELD TO LESS THAN THREE-QUARTERS OF AN INCH. NO
FLOODING PROBLEMS HAVE BEEN REPORTED YET...BUT WITH SOME MORE
THUNDERSTORMS STILL EXPECTED...WILL LET THE FLASH FLOOD WATCH
CONTINUE. THE LINEAR SHEAR PROFILE IS OVERWHELMING THE BUOYANCY OF
THE AIRMASS...SO TORNADIC STORMS HAVE NOT DEVELOPED. WILL CLEAR
THE WESTERN EDGE OF THE TORNADO WATCH WITH ISSUANCE OF THE
AFTERNOON PACKAGE. REST OF WATCH WILL REMAIN IN PLACE SINCE
THUNDERSTORM ACTIVITY IS ONGOING.

AFTER THE EVENING CONVECTION DIES OFF...THE MOIST AIRMASS AND WEAK
FLOW WILL ALLOW STRATUS AND FOG TO RE-DEVELOP...SIMILAR TO WHAT WE
SAW THIS MORNING. FOR SUNDAY...MODELS SHOW THE UPPER LOW WILL
STILL BE OVER THE CENTRAL PART OF THE STATE. THIS MEANS ANOTHER
DAY OF UNSETTLED WEATHER. HAVE INCREASED THE CHANCES FOR
THUNDERSTORMS TO LIKELY.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 321 PM MDT SAT MAY 23 2015

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE ACROSS
NORTH CENTRAL AND NORTHEASTERN COLORADO SUNDAY EVENING AS THE UPPER
LOW SLOWLY MEANDERS ACROSS THE CENTRAL ROCKIES. THE SHOWERS SHOULD
GRADUALLY DECREASE ACROSS THE PLAINS AFTER MIDNIGHT WITH A CHANCE OF
RAIN AND SNOW CONTINUING IN THE MOUNTAINS. ON MONDAY...THE UPPER LOW
WEAKENS AND BECOMES AN OPEN TROUGH AS IT MOVES INTO THE CENTRAL
PLAINS STATES. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
REDEVELOP ON THE PLAINS BY AFTERNOON AS MOISTURE ON THE BACK SIDE OF
THE TROUGH WRAPS INTO COLORADO FROM THE NORTH.

TEMPERATURES WILL WARM INTO THE LOWER 70S ON THE PLAINS ON TUESDAY
AS UPPER LEVEL HIGH PRESSURE BUILDS OVER THE ROCKY MOUNTAIN REGION.
THERE WILL STILL BE ENOUGH RESIDUAL MOISTURE AROUND...COMBINED WITH
DAYTIME HEATING TO PRODUCE ISOLATED TO SCATTERED AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS...MOST NUMEROUS IN THE MOUNTAINS.
THE UPPER FLOW BECOMES SOUTHWESTERLY ON WEDNESDAY AHEAD OF AN UPPER
TROUGH OVER THE WESTERN UNITED STATES. THE SOUTHWEST FLOW WILL
RESULT IN HIGH TEMPERATURES IN THE LOW 70S ON THE PLAINS WEDNESDAY
AND THURSDAY. SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS WILL ALSO BE POSSIBLE EACH DAY AS WEAK UPPER LEVEL
DISTURBANCES INTERACT WITH RESIDUAL MOISTURE AND DAYTIME HEATING.

COOLER UNSETTLED WEATHER COULD RETURN BY FRIDAY AFTERNOON AS UPSLOPE
FLOW DEVELOPS BEHIND THE PASSAGE OF A COLD FRONT. THE GFS SHOWS
QUITE A BIT OF QPF FROM THE CONTINENTAL DIVIDE EASTWARD INTO THE
URBAN CORRIDOR SATURDAY AFTERNOON AND EVENING...WHILE THE ECMWF
SHOWS VERY LITTLE. WARMER AND DRIER WEATHER IS EXPECTED BY SATURDAY
AS UPPER LEVEL HIGH PRESSURE BUILDS INTO COLORADO FROM THE WEST.

&&

.AVIATION...(FOR THE TAFS THROUGH 06Z SUNDAY EVENING)
ISSUED AT 904 PM MDT SAT MAY 23 2015

THUNDERSTORMS WILL MOVE OUT OF THE DENVER AREA BY 04Z WITH
CLEARING FOLLOWING. AREAS OF FOG WITH IFR CONDITIONS WILL DEVELOP
BY 09Z. THERE MAY BE SOME LOCALIZED LIFR. THE FOG SHOULD BREAK UP
BY 16Z. MORE THUNDERSTORMS ARE EXPECTED LATE SUNDAY AFTERNOON WITH
PERIODS OF MVFR CONDITIONS AND VARIABLE GUSTY WINDS LIKELY.

&&

.HYDROLOGY...
ISSUED AT 321 PM MDT SAT MAY 23 2015

AFTERNOON THUNDERSTORMS HAVE BEEN MOVING ALONG NICELY AND ONLY
PRODUCING ABOUT ONE-THIRD TO THREE-QUARTERS OF AN INCH OF
RAINFALL. THE HRRR MODEL SHOWS ANOTHER ROUND OF SHOWERS OVER THE
DENVER METRO AREA DURING THE EVENING...BUT WITH GENERALLY LIGHT
AMOUNTS. THE THREAT OF ADDITIONAL ROUNDS OF THUNDERSTORMS ON THE
NORTHEAST PLAINS CONTINUES...SO WILL LET THE FLASH FLOOD WATCH
CONTINUE.

THE CACHE LA POUDRE AND SOUTH PLATTE RIVERS REMAIN ABOVE FLOOD
STAGE ACROSS WELD COUNTY WITH MINOR IMPACTS. THESE FLOOD WARNINGS
WILL CONTINUE FOR ANOTHER COUPLE DAYS AS THE RIVERS WILL BE SLOW
TO RECEDE.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR COZ048-050-051.

&&

$$

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



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