National Weather Service Forecast Discussion

000
FXUS65 KBOU 292106
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
305 PM MDT THU JUL 29 2010

.SHORT TERM...MONSOONAL MOISTURE PERSISTS ACROSS CFWA. CURRENT
INTEGRATED PRECIPITABLE WATER VALUES HAVE INCREASED TO 1.30 INCHES
AT KBOU AND AROUND 6 TENTHS OF AN INCH AT KNWT. SCATTERED
THUNDERSTORMS CONTINUE TO DEVELOP ACROSS MOUNTAINS AND FOOTHILLS. NO
STORMS YET ON THE PLAINS...ALTHOUGH A NICE BOUNDARY EXISTS ACROSS
EASTERN ADAMS AND EASTERN ARAPAHOE COUNTIES EXTENDING SOUTHWEST INTO
DOUGLAS COUNTY. DECENT STORM FORMED OVER THE SOUTHWEST EDGE OF THE
BOUNDARY NEAR THE HAYMAN BURN AREA WHICH WAS DUMPING SOME HEAVY
RAINFALL. CUMULUS CONTINUES TO DEVELOP ALONG THE OTHER SECTIONS OF
THE BOUNDARY. SHOULD SEE STORMS CONTINUE ACROSS MOUNTAINS AND
THROUGH THE EVENING. ACARS SOUNDINGS SHOWING PLAINS STILL A BIT
CAPPED WHICH IS HINDERING STORM FORMATION. HOWEVER...THERE ARE
SEVERAL BOUNDARIES FROM THE FOOTHILLS STORMS MOVING ONTO PLAINS
ALONG WITH THE BOUNDARY SOUTH AND EAST OF DENVER. INTERACTION FROM
THE BOUNDARIES SHOULD BE SUFFICIENT FOR DEVELOPMENT OF STORMS ALONG
URBAN CORRIDOR. HIGHEST POPS FOR THIS EVENING OVER MOUNTAINS AND
FOOTHILLS...WITH CHANCE POPS ADJACENT PLAINS. FURTHER EAST...SLIGHT
CHANCE POPS SHOULD BE SUFFICIENT. WITH DECENT PRECIPITABLE WATER
VALUES STORMS COULD DUMP UP TO 2 INCHES OF RAIN IN A SHORT PERIOD OF
TIME. RADAR INDICATING STORM CELLS ARE MOVING AROUND 10 KTS SO STORM
MOVEMENT MAY KEEP FLOODING CONCERNS TO A MINIMUM. WILL NEED TO WATCH
FOR ANY TRAINING COLLIDING OF STORMS. MODELS SHOW ACTIVITY ENDING BY
MIDNIGHT...THOUGH THE NAM KEEPS SOME LIGHT QPF ACROSS MOUNTAINS
OVERNIGHT. WILL LEAVE THE LOW POPS THERE AFTER MIDNIGHT...BUT MAY BE
OVERDONE AS THERE DOES NOT APPEAR TO BE ANY SHORTWAVE WHICH WILL
KEEP ACTIVITY GOING. ENOUGH CLOUD COVER FOR AT LEAST PARTLY CLOUDY
CONDITIONS WHICH WILL KEEP MINS RATHER MILD MOST AREAS. ON FRIDAY...
LITTLE CHANGE EXPECTED IN OVERALL PATTERN. RIDGE AXIS REMAINS
CENTERED ACROSS EASTERN COLORADO WITH WEAK FLOW ALOFT. STILL QUITE A
BIT OF MOISTURE ACROSS CFWA...MAINLY OVER MOUNTAINS. PRECIPITABLE
WATER VALUES EXPECTED TO RANGE FROM 1 INCH TO 1.4 INCHES ACROSS
PLAINS AND AROUND NINE TENTHS OF AN INCH ACROSS MOUNTAINS. DAYTIME
HEATING WILL AGAIN GET STORMS DEVELOPING ACROSS MOUNTAINS AND
FOOTHILLS. NO REAL DYNAMIC FORCING TO INCREASE STORM COVERAGE...WILL
KEEP THE CHANCE POPS FOR MOUNTAINS AND FOOTHILLS. ACROSS PLAINS...
LATEST NAM  AND GFS SHOW SURFACE FRONT MOVING ACROSS AREA AFTER
18Z. THIS FEATURE WILL ENHANCE UPSLOPE FLOW ALONG FOOTHILLS AND
ADJACENT PLAINS WHICH SHOULD AID IN STORM DEVELOPMENT. BUT FORECAST
SOUNDINGS SHOW A BIT OF A CAP ACROSS PLAINS DURING THE AFTERNOON AND
COULD LIMIT ANY STORM FORMATION. WILL KEEP THE HIGHER POPS IN
UPSLOPE FAVORED AREAS...LOWER POPS FURTHER EAST. STORMS COULD
PRODUCE HEAVY RAIN. MODELS INDICATE STORM MOTION AROUND 10 KTS WHICH
SHOULD KEEP FLOODING CONCERNS LOW. WILL HOLD OFF ON ANY FLASH FLOOD
WATCH AT THIS POINT.  TEMPERATURE AND THICKNESS PROGS SUGGEST HIGHS
IN THE 80S ACROSS PLAINS WITH 60S AND 70S OVER THE MOUNTAINS.
GUIDANCE INDICATES HIGHS CLOSE TO 90 DEGREES FOR PLAINS. THIS
APPEARS REASONABLE. SHAVED A FEW DEGREES OFF THE MAX TEMPERATURE
GRIDS FOR THE PLAINS.

.LONG TERM...THE MAIN UPPER LEVEL HIGH PRESSURE AREA WILL GRADUALLY
SHIFT TO THE SOUTHEAST INTO TEXAS AND OKLAHOMA THROUGH THE MIDDLE OF
NEXT WEEK. THIS WILL KEEP THE MONSOONAL MOISTURE FLOWING INTO
COLORADO THROUGH THE PERIOD. VERY HARD TO PICK OUT ANY INDIVIDUAL
WAVES IN THE FLOW BUT PW VALUES EXPECTED TO REMAIN A BIT OVER AN
INCH. GIVEN THE WEAK FLOW ALOFT...THE MAIN THREAT WILL CONTINUE TO
BE HEAVY RAIN. TEMPERATURES WILL BE AT OR SLIGHTLY ABOVE NORMAL
SEASONAL HIGHS WITH READING INTO THE LOWER 90S ACROSS LOWER
ELEVATIONS. HIGHEST POPS WILL REMAIN IN THE MOUNTAINS AND HIGHER
TERRAIN WITH LOWER CHANCES OVER THE FAR EASTERN PLAINS.

&&

.AVIATION...A COUPLE OF BOUNDARIES HEADING TOWARD DENVER AREA WHICH
COULD GENERATE A FEW STORMS THROUGH AROUND 03Z. IF STORMS
DEVELOP...THEY COULD PRODUCE HEAVY RAIN AND MVFR CONDITION FOR A
BRIEF PERIOD. OTHERWISE...CEILINGS AROUND 5000-6000 FEET AGL
POSSIBLE THROUGH 04Z WHICH WILL AFFECT ILS APPROACHES. WINDS WILL BE
VARIABLE THROUGH 03Z WITH SPEEDS LESS THAN 10 KTS. EXPECT DRAINAGE
PATTERN BY 06Z WHICH SHOULD KEEP FOG AND STRATUS FROM FORMING. ON
FRIDAY...CHANCE FOR STORMS AFTER 18Z...MAINLY ALONG FOOTHILLS WEST
AND SOUTH OF DENVER. A FEW STORMS COULD AFFECT THE AREA AIRPORTS
WITH BRIEF HEAVY RAIN AND MVFR CONDITIONS. OTHERWISE...VFR
CONDITIONS SHOULD PREVAIL...THOUGH CEILINGS OF 5000-6000 FEET AGL
COULD DEVELOP WEST OF THE AREA AFFECT ILS APPROACHES. SURFACE FRONT
TO MOVE ACROSS AREA AFTER 18Z WHICH WILL SHIFT WINDS TO AN EASTERLY
DIRECTION. SPEEDS SHOULD STAY BELOW 12 KTS.

&&

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

$$
D-L/SWE

NWS BOU Office Area Forecast Discussion