National Weather Service Forecast Discussion

000
FXUS65 KBOU 102229
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
320 PM MST WED MAR 10 2010

.SHORT TERM...THE FORECAST AREA REMAINS UNDER THE GRIPS OF A BROAD
CYCLONIC CIRCULATION PATTERN ROUGHLY CENTERED OVER THE CENTRAL GREAT
PLAINS. MOISTURE ROTATING WESTWARD AROUND THE OUTER EDGE OF THIS
CIRCULATION CENTER HAS CONTINUED TO FEED INTO NORTHEAST COLORADO ON
10-20KT N-NELY BNDRY LAYER WINDS. THIS UPSLOPING FLOW HAS COMBINED
WITH A CONDITIONALLY UNSTABLE LOWER ATMOSPHERE TO PRODUCE SCATTERED
INSTABILITY RAIN AND SNOW SHOWERS OVER AND ALONG THE FRONT RANGE
DURING THE PAST COUPLE OF HOURS. SHOWER FORMATION IS EXPECTED TO
CONTINUE THROUGH THIS EVENING SO LONG AS WEAK SFC-500MB QG ASCENT
REMAINS IN PLACE. WITH COOLING TEMPERATURES SHOULD SEE THE SHOWERY
PRECIPITATION CHANGING OVER TO ALL SNOW...EXCEPT PERHAPS OVER SRN
PORTIONS OF LINCOLN COUNTY...DURING THE EARLY EVENING HOURS.
ISOLATED SHOWERS COULD PRODUCE SNOWFALL RATES UP TO AN INCH OR SO
PER HOUR THIS EVENING...MAINLY ACROSS SRN THIRD OF THE I-25 URBAN
CORRIDOR. OVER THE FRONT RANGE FOOTHILLS AND PALMER DIVIDE...UPSLOPE
FLOW WILL FURTHER ENHANCE SNOWFALL THIS EVENING WITH UPWARDS OF 1 TO
3 INCHES OF SNOW ACCUMULATION BY MIDNIGHT. HIGHER FOOTHILL AREAS IN
JEFFERSON AND WESTERN DOUGLAS COUNTIES MAY SEE UPWARDS OF 5 INCHES
OF ACCUMULATION BEFORE THE SHOWERY PRECIP WINDS DOWN AROUND MIDNIGHT.

BY MORNING...FLOW ALOFT BECOMES PREDOMINANTLY NORTHERLY IN DIRECTION
WITH THE UPPER LOW CONTINUING TO WOBBLE OVER ERN NEBRASKA. THIS WIND
SHIFT WILL CUT OFF THE FLOW OF MOISTURE INTO THE FCST AREA...EXCEPT
PERHAPS ALONG THE ERN BORDER. THEREFORE SHOULD SEE THE CHANCE OF
PRECIPITATION ON THE PLAINS DECREASING THRU THE MORNING HOURS...AND
ALL BUT ENDING ALONG THE FRONT RANGE IN THE AFTERNOON. WILL HANG
ONTO SCATTERED POPS OVER THE FAR ERN ZONES THRU THE DAY BUT EVEN
THERE SHOULD SEE A DROP OFF IN ACTIVITY DURING THE AFTERNOON WITH
THE UPPER LOW CONTINUING TO MOVE AWAY.

SEE LITTLE CHANGE IN TEMPERATURE DURING THE NEXT 24 HOURS WITH THIS
PATTERN. MAX TEMPERATURES ON THE PLAINS ON THURSDAY SOME 6-10F BELOW
AVERAGE.


.LONG TERM...HIGH PRESSURE ALOFT WILL BUILD ACROSS COLORADO THURSDAY
NIGHT AND FRIDAY BEFORE SHIFTING AND WEAKENING OVER THE CENTRAL
PLAINS ON SATURDAY. DRY AND WARMER CONDITIONS ARE EXPECTED DURING
THIS PERIOD.

THE NEXT POTENTIAL STORM SYSTEM IS EXPECTED TO TRACK TO NEAR THE 4
CORNERS REGION BY EARLY SUNDAY BEFORE TRACKING SOUTH TO SOUTHEAST
INTO EASTERN ARIZONA OR NEW MEXICO ON SUNDAY. THE LONG RANGE MODELS
ARE IN GENERAL AGREEMENT BUT ENOUGH VARIABILITY SHOWING UP TO RESULT
IN A CHANCE OF PRECIP OR NO PRECIP AT ALL FOR OUR CWA IF THE TRACK
REMAINS FURTHER WEST AND SOUTH. LAST FEW RUNS OF THE
CANADIAN/EUROPEAN ARE SHOWING THE TRACK FURTHER WEST...AND GIVEN THE
STRONG JET DIVING SOUTH ACROSS THE GREAT BASIN...THIS MAY NOT BE
THAT FAR OFF. BEST INITIAL CHANCES FOR SUNDAY WOULD BE OVER OUR
WESTERN MOUNTAINS.

THERE IS A SURGE OF COLDER AIR THAT MOVES INTO NERN CO ON SUNDAY AS
IT INTERACTS WITH THE LOW TO THE SOUTHWEST AND ALSO A DISTURBANCE
WHICH ROTATES AROUND THE OLD LOW ACROSS THE EASTERN PORTION OF THE
COUNTRY. SOME OF THIS MOISTURE BACKS AROUND ALL THE WAY TO COLORADO.
IF THIS SOLUTION HAPPENS THERE COULD BE A CHANCE OF SHOWERS RIGHT
FROM SUNDAY AFTERNOON THROUGH MONDAY. THERE IS ALREADY A SLIGHT CHC
IN THE GRIDS AND WILL LEAVE THIS ALONE FOR NOW.

DRY AND WARMER AGAIN FOR THE TUE-WED TIME FRAME AS HIGH AMPLITUDE
RIDGING MOVES BACK INTO THE REGION.

&&

.AVIATION...SCATTERED RAIN AND SNOW SHOWERS WILL CONTINUE TO MOVE
SOUTH ALONG THE FRONT RANGE OVER THE DENVER METRO AREA LATE THIS
AFTERNOON...AND REMAIN OVER THE METRO AREA THROUGH 9 OR 10 PM THIS
EVENING. APPEARS THE MIXED PRECIPITATION SHOULD CHANGE OVER TO ALL
SNOW BETWEEN 6 AND 7 PM. EXCEPT FOR SNOW ACCUMULATIONS OF AN INCH OR
SO ALONG THE BASE OF THE FOOTHILLS ON THE SOUTH AND WEST SIDES OF
DENVER...DIA AND MOST OF THE DENVER METRO AREA SHOULD SEE LITTLE OR
NO ACCUMULATION BY THE TIME SHOWERS WIND DOWN LATE THIS EVENING.
CONDITIONS IN THE METRO AREA SHOULD CONTINUE TO IMPROVE AFTER
MIDNIGHT AS DRIER NORTH-NORTHWEST BREEZES. ON THURSDAY...ISOLATED
SNOW SHOWERS IN THE MORNING SHOULD GIVE WAY TO PARTIAL CLEARING
DURING THE AFTERNOON. NO NEW SNOW ACCUMULATION IS ANTICIPATED ON
THURSDAY.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...FLOOD ADVISORY IN EFFECT FOR
SEDGWICK COUNTY...ZONE 50 UNTIL 0630Z TONIGHT.

$$
BAKER/ENTREKIN

NWS BOU Office Area Forecast Discussion