Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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 281545
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
945 AM MDT THU AUG 28 2014

.UPDATE...
ISSUED AT 945 AM MDT THU AUG 28 2014

UPPER LEVEL LOW OVER NORTHERN COLORADO WILL SLOWLY SHIFT EAST TODAY.
FLOW ALOFT WILL BECOME NORTHERLY BY THIS AFTERNOON. EXPECT THE
SCATTERED SHOWERS OVER THE MOUNTAINS AND WYOMING TO SPREAD SOUTHEAST
ACROSS THE AREA LATE THIS MORNING AND THIS AFTERNOON. AS THE AIRMASS
WARMS AND DESTABILIZES...THUNDERSTORMS ARE EXPECTED TO FORM LATER
ON. BECAUSE OF THE COOL AIRMASS...SOME SMALL HAIL WILL BE POSSIBLE
WITH THE STRONGER STORMS. WITH ALL THE SHOWERS OVER THE MOUNTAINS
AND IN WYOMING...INCREASED POPS FOR TODAY. OTHERWISE THE FORECAST
APPEARS ON TRACK.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 316 AM MDT THU AUG 28 2014

A MID LVL CIRCULATION IS NR THE CO-WY BORDER EARLY THIS MORNING AND
WILL MOVE EAST ACROSS NE CO THRU THIS AFTN.  CROSS-SECTIONS SHOW
QUITE A BIT OF MOISTURE IN THE MTNS WITH NW FLOW AT 700 MB WHICH
WILL LEAD TO OROGRAPHIC PCPN THRU THE DAY. TEMPS WILL BE COLD
ENOUGH FOR SOME LIGHT ACCUMULATION OF SNOW ABV 11000 FT THRU MID
MORNING. OVER NERN CO WITH COLD POOL ALOFT OVER AREA AND CAPES
FCST TO RANGE FM 500-1000 J/KG SHOULD SEE SCT SHOWERS AND TSTMS
DVLP BY EARLY AFTN. AS FOR HIGHS READINGS SHOULD STAY IN THE 70S
OVER NERN CO.

BY THIS EVENING THE UPPER LEVEL TROUGH WILL MOVE EAST OF THE AREA
WITH MOISTURE DECREASING SO SHOWERS SHOULD GRADUALLY END BY MID
EVENING.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 316 AM MDT THU AUG 28 2014

A DRY AND STABLE NORTHWESTERLY FLOW ALOFT MOVES OVER THE FORECAST
AREA ON FRIDAY AS AN UPPER LEVEL RIDGE MOVES IN FROM THE GREAT
BASIN. A TYPICAL EARLY MORNING SFC WIND DRAINAGE PATTERN IS FCST TO
SHIFT TO NWLY BY LATE MORNING...THEN NELY DURING THE AFTERNOON. THIS
UPSLOPE FLOW WILL COMBINE WITH DAYTIME HEATING IS EXPECTED TO
PRODUCE ISOLATED TO SCATTERED SHOWERS/T-STORMS OVER THE FRONT RANGE
MTNS DURING THE LATE AFTERNOON AND EVENING HOURS. BECAUSE OF THE
DRIER ATMOSPHERE...PRECIP AMOUNTS SHOULD BE ON THE LIGHT SIDE.
TEMPERATURES ON FRIDAY WILL STILL BE BELOW AVERAGE.

OVER THE WEEKEND...TEMPERATURES CONTINUE TO WARM ON SATURDAY AS THE
LOW AMPLITUDE UPPER LEVEL RIDGE PASSES BY. DOWNSLOPE FLOW WILL
GENERATE ADDITIONAL WARMING AND DRYING EAST OF THE FRONT RANGE
PROBABLY MAKING SATURDAY THE WARMEST DAY DURING THE EXTENDED PERIOD.
LOOKING FOR HIGHS IN THE MID TO UPPER 80S ON THE PLAINS AND 60S AND
70S IN THE HIGH COUNTRY. ON SUNDAY...THE UPPER RIDGE MOVES EAST
ALLOWING A BROAD UPPER LEVEL TROUGH TO SWING DOWN FROM THE PACIFIC
NORTHWEST. THROUGH THE DAY SHOULD SEE SYNOPTIC SCALE LIFT INCREASE
WITH DIVERGENT SWLY FLOW ALOFT AND AN INCREASE IN INSTABILITY
RESULTING IN ISOLATED TO SCATTERED T-STORMS OVER THE HIGH TERRAIN
DURING THE AFTERNOON AND EVENING HOURS. THIS SWLY FLOW ALOFT MAY
CARRY A FEW STORMS OVER THE ADJACENT HIGH PLAINS LATE IN THE DAY
WHERE GUSTY WINDS AND LIGHTNING WILL BE MORE OF A CONCERN DUE TO A
RELATIVELY DRY BOUNDARY LAYER. MEANWHILE A WEAK SFC COLD FRONT IS
FORECAST TO SLIDE SOUTH OUT OF SERN WYOMING SUNDAY AFTERNOON AS THE
UPPER TROUGH PASSES OVERHEAD. STORMS MAY BECOME MORE NUMEROUS ACROSS
NORTHERN SECTIONS OF THE CWA IN THE HIGHER HUMIDITY BEHIND THE COLD
FRONT. NOT SURE HOW FAR SOUTH THESE STORMS WILL DEVELOP. LATEST
MODEL RUNS KEEP THIS POST-FRONTAL CONVECTION NORTH OF THE DENVER
METRO AREA. FOR NOW WILL FOLLOW GUIDANCE AND KEEP THINGS DRY ACRS
CENTRAL AND SOUTHERN PORTIONS OF THE I-25 CORRIDOR. TEMPERATURES ON
SUNDAY LOOK TO BE AT LEAST 3-4 DEG C COOLER THAN THE DAY BEFORE.

FOR LABOR DAY...DRIER AND SLIGHTLY WARMER CONDITIONS RETURN TO THE
FCST AREA WITH THE REGION REMAINING UNDER THE INFLUENCE OF A BROAD
UPPER LEVEL TROUGH. SEE LITTLE IN THE WAY OF STORMS WITH THE DRIER
CONDITIONS. WILL GO WITH HIGHS IN THE LOW/MID 80S AT LOWER
ELEVATIONS AND 60S/LOWER 70S IN THE HIGH COUNTRY.

SEE LITTLE CHANGE FOR TUESDAY AND WEDNESDAY AS A STRONG HIGH
PRESSURE RIDGE EXPANDS ACROSS THE WESTERN CONUS. AFTER A SLIGHT
DIP IN TEMPERATURES ON TUESDAY...SHOULD SEE TEMPERATURES NEAR TO
SLIGHTLY ABOVE AVERAGE ON WEDNESDAY.

&&

.AVIATION...(FOR THE TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 945 AM MDT THU AUG 28 2014

LIGHT WINDS THIS MORNING WILL TURN TO THE NORTHWEST AROUND 17Z.
GUSTS TO 30 KNOTS WILL BE POSSIBLE...MAINLY NEAR THE SHOWERS AND
THUNDERSTORMS. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
FORM AROUND 18Z AND LINGER THROUGH ABOUT 00Z. BRIEF HEAVY RAIN WILL
BE POSSIBLE WITH THE STORMS. JUST A SLIGHT CHANCE FOR SMALL HAIL.
SKIES WILL CLEAR THIS EVENING AS THE LOW PRESSURE SYSTEM EXITS THE
REGION.

&&

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

$$

UPDATE...MEIER
SHORT TERM...RPK
LONG TERM...BAKER
AVIATION...MEIER


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