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FXUS65 KBOU 031826
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1126 AM MST MON MAR 3 2014

.UPDATE...

&&

.SHORT TERM...FORECAST GENERALLY ON TRACK. SCATTERED LIGHT SHOWERS
OVER THE MOUNTAINS...LOOKS LIKE THERE MAY BE SOME INCREASE THE
NEXT COUPLE OF HOURS THEN DRYING BEHIND THAT BUT HEATING MAY
OFFSET THAT. ON THE PLAINS SOME DECREASE IN CLOUDS BUT THEN
ANOTHER BATCH FOR LATER IN THE AFTERNOON. ONLY CHANGES COMING ARE
ADDING A COUPLE DEGREES TO TODAYS HIGHS AND A LITTLE MORE
WIND...MAINLY OVER THE HIGHER MOUNTAINS WHERE THERE ARE 40-50 MPH
GUSTS ON THE CREST OF THE FRONT RANGE.

&&

.AVIATION...VFR THROUGH TONIGHT. NO CHANGES.

&&

.PREV DISCUSSION... /ISSUED 357 AM MST MON MAR 3 2014/

SHORT TERM...TODAY AND TONIGHT..ARCTIC IS RETREATING EAST AT
THIS TIME. TEMPERATURES ARE STAYING STEADY OR SLOWLY RISE ACROSS
THE AREA. PACIFIC AIR WILL RESIDE OVER THE STATE TODAY.
TEMPERATURES WILL BE MUCH WARMER WITH HIGHS IN THE 50S FOR MOST OF
NORTHEAST COLORADO. READINGS TONIGHT WILL ALSO BE MILD WITH LOWS
MAINLY IN THE 20S.

A WEAK SHORT WAVE EMBEDDED IN THE WESTERLY FLOW ALOFT WILL MOVE
ACROSS COLORADO THIS MORNING. THIS WILL BRING SCATTERED SNOW SHOWERS
TO THE MOUNTAINS TODAY. FOR NORTHEAST COLORADO...JUST EXPECT MID AND
HIGH CLOUDS FROM THIS SYSTEM...MAINLY DURING THE MORNING HOURS.
MOISTURE WILL INCREASE AGAIN LATE TONIGHT OVER THE FAR NORTHERN
MOUNTAINS AND LEAD TO A BETTER CHANCE FOR SNOW SHOWERS.

LONG TERM...ZONAL FLOW ALOFT TOPPING A FLAT UPPER RIDGE COUPLED
WITH WEAK SUBSIDENCE AT MID-LEVELS OVER NORTHEAST COLORADO TUE
MORNING WILL BE REPLACED BY WEAK TO MODERATE DEEP LAYER ASCENT
DURING THE AFTERNOON AND EVENING HOURS ON TUE. MODELS ALSO SHOW
A COLD FRONT SLIDING SOUTH OUT OF EASTERN WYOMING MID TO LATE
AFTERNOON. WRF...NAM AND GFS SHOW THIS FRONT REACHING THE DENVER
METRO AREA SOMETIME BETWEEN 19Z-22/TUE WITH NORTH-NORTHEAST
LOW-LEVEL FLOW OF 10-25KTS SPREADING OVER THE PLAINS IN ITS WAKE.
MODELS SHOW THIS UPSLOPE FLOW EAST OF THE FRONT RANGE CONTINUING
THROUGH AT LEAST MID-EVENING...ALTHOUGH THE NAM SHOWS IT LINGERING
THROUGH MIDNIGHT. THEN A LIGHT DRAINAGE FLOW DEVELOPS TOWARDS DAWN
WITH THE FORMATION OF LEE SIDE MTN WAVE. STRONGEST LARGE SCALE
ASCENT INDICATED ON QG VERTICAL VELOCITY FIELDS OVER NORTHEAST
COLORADO AROUND 00Z/WED. FRONTOGENTIC AND OROGRAPHIC FORCING...AND
LIFT PROVIDED BY A PASSING JET SPEED MAX APPEAR TO COME TOGETHER
ABOUT THAT TIME. LIGHT TO MODERATE SNOWFALL RATES IN THE HIGH
COUNTRY DURING THE 12-HOUR PERIOD ENDING AROUND 09Z/WED...WITH A
PATCH WORK OF LIGHT QPF/SNOW ACCUMULATION ON THE PLAINS. EARLIER
MODEL RUNS SHOWED A BAND OF 1-3 INCH SNOW ACCUMULATION BISECTING
THE NORTHEAST CORNER OF THE STATE TUE EVENING. LATEST RUNS NOW
INDICATE A NUMBER OF POSSIBLE SNOW BANDS...ONE UP ALONG THE
COLORADO/WYOMING BORDER... ANOTHER OVER THE PALMER DIVIDE...AND
YET ANOTHER CROSSING THE GREATER DENVER METRO AREA ACCORDING THE
WRF AND EUROPEAN MODELS. SNOW TOTALS ON THE PLAINS BY 06Z/WED
COULD RANGE FROM A TRACE IN MOST AREAS TO UPWARDS OF 3 INCHES
ALONG THE PALMER DIVIDE. IT/S POSSIBLE THAT PARTS OF THE DENVER
METRO AREA COULD SEE AN INCH OR TWO OF SNOW BY MIDNIGHT. ALL
DEPENDS ON WHERE THE JET FINALLY ENDS UP. HIGH COUNTRY SNOW TOTALS
BY LATE TUE NIGHT EXPECTED TO RANGE FROM A COUPLE INCHES ON THE
VALLEY FLOORS TO UPWARDS OF 5 INCHES ON HIGHER WEST FACING MTN
SLOPES. DO NOT SEE MUCH WIND WITH THIS SYSTEM...SO BLOWING SNOW
NOT LIKELY TO BE AN ISSUE. THAT SAID...WILL CONTINUE TO RAISE POPS
EVERYWHERE LATE TUE AFTERNOON AND EVENING WITH THE HIGHEST POPS IN
THE HIGH COUNTRY...ALONG THE SOUTHERN FOOTHILLS AND OVER THE
PALMER DIVIDE.

ON WED...TROUGH MOVES EAST AS A LARGE UPPER LEVEL HIGH PRESSURE
RIDGE CONTINUES TO BUILD OVER THE GREAT BASIN/DESERT SOUTHWEST.
THIS PLACES THE FCST AREA UNDER A WARMER AND DRIER NORTHWEST FLOW
ALOFT. TEMPERATURES START OUT CHILLY FOLLOWING THE COLD FRONT THE
DAY BEFORE...BUT STEADILY WARM THROUGH THE DAY AS DOWNSLOPE/WEST-
SOUTHWEST/FLOW SPREADS OUT ACROSS THE PLAINS AND SUBSIDENCE ALOFT
ELEVATES TEMPERATURES ALOFT. SHOULD SEE TEMPERATURES RETURN TO ABOVE
AVERAGE FOR MOST AREAS.

THU CONTINUES TO LOOK DRY AND VERY WARM FOR THIS TIME OF YEAR WITH A
STRONG UPPER LEVEL RIDGE ADVANCING ACROSS THE REGION. MODELS
INDICATE A 700MB TEMP IN THE 3.5 TO 4.5C RANGE OVER THE I-25 URBAN
CORRIDOR DURING THE AFTERNOON. MIXED DOWN DRY ADIABATICALLY THIS
WOULD GIVE US MAX TEMPS IN THE MID TO UPPER 60S FOR THIS AREA...WITH
SLIGHTLY COOLER READINGS THE FARTHER EAST YOU GO. HIGH COUNTRY ALSO
LOOKS DRY AND VERY MILD. HOWEVER SHOULD SEE AN INCREASE MID AND HIGH
CLOUDS THROUGH THE DAY WHICH WILL SLOW HEATING...AS WELL AS AN
INCREASE IN WESTERLY WINDS.

THU NIGHT THROUGH FRI NIGHT...RIDGE MOVES EAST ALLOWING A DEEPENING
SHORTWAVE TROUGH TO DROP DOWN OUT OF THE PACIFIC NORTHWEST. MODELS
SHOW THIS TROUGH CONTINUING TO AMPLIFY AS IT PASSES OVER COLORADO ON
FRIDAY. EUROPEAN MODEL IS SLOWER TO MOVE THIS SYSTEM OUT WITH THE
700-500 MB TROUGH AXIS STILL OVER ERN COLO SAT MORNING. TROUGH IS
ACCOMPANIED BY A RATHER STRONG COLD FRONT WHICH MODELS SHOW
SLIDING THROUGH NERN COLO FRI MORNING. COULD SEE A PERIOD OF
FAIRLY INTENSE CONVECTIVE TYPE PCPN...RAIN AND/OR SNOW WITH ITS
PASSAGE. STILL APPEARS A SECOND BATCH OF EVEN GREATER ENERGY AND
MOISTURE SWINGS DOWN FROM WYO LATE IN THE DAY. THIS COULD RESULT
IN AN EVEN BETTER CHANCE OF ACCUMULATING PRECIP ACRS MOST OF THE
CWFA.

FOR THE WEEKEND...TEMPERATURES GRADUALLY WARM AND THE AIRMASS
DRIES OUT AS A LARGE DOME OF HIGH PRESSURE BUILDS IN FROM THE
WEST.

AVIATION...WEST TO SOUTHWEST WINDS WILL PREVAIL ACROSS THE DENVER
AREA TODAY. SPEEDS ARE EXPECTED TO BE LESS THAN 20 KNOTS.
SCATTERED/BROKEN MID AND HIGH CLOUDS WILL STREAM OVER THE AREA
TODAY.

&&

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

$$

SHORT TERM...MEIER
LONG TERM....BAKER
AVIATION/UPDATE...GIMMESTAD