Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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000 FXUS65 KBOU 301528 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 928 AM MDT Fri Sep 30 2016 .UPDATE...
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Issued at 912 AM MDT Fri Sep 30 2016 showers this morning have moved further east on the plains than indicated on the hrrr model...these showers will continue moving slowly northeast...but will likely not drop much east of Sterling. Hrrr suggests the activity will transition from the northern plains today...to the palmer divide this evening with some stronger convection also developing. this reflected in the grids...will adjust pops a bit based on radar trends this morning.
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&& .SHORT TERM...(Today and tonight) Issued at 424 AM MDT Fri Sep 30 2016 A stream of moist air is moving over the state this morning, mainly over the mountains. Shower activity over the mountains early this morning should increase through today as diurnal warming helps the airmass become slightly unstable. Light radar echoes have developed over the north central mountain counties, but the heavier echoes so far have been over the west slope. The moisture is moving over the state on deep south to southwesterly flow as an upper ridge axis holds its position over western Kansas. The southerly fetch will make it difficult for much precipitation to move over northeast Colorado until later this afternoon and evening. And even then, areas along the I-25 corridor may be the only ones to see any rainfall. The forecast will have the highest chances of precipitation over the mountains. By afternoon, the atmosphere may become unstable enough to support thunderstorm activity, but only moderate rainfall is expected. Temperatures today will be held back by the increasing cloud cover, but still a couple degrees warmer than normal. Later tonight, temperatures in the mountains will cool enough for snow to fall at elevations above 8000 feet. Shower activity will be winding down at that time, so no significant accumulations are expected. .LONG TERM...(Saturday through Thursday) Issued at 424 AM MDT Fri Sep 30 2016 A flat upper level ridge will be over the area on Sat and will become more swly on Sun as an upper level trough deepens over the Pacific NW. There will be some mid lvl moisture over the rgn on Sat with not as much on Sun. Over instability is not that great either day with capes aob blo 500 j/kg. Overall the best chc of convection looks to be on Sat over the higher terrain with only isold activity over the plains. Temps will remain abv normal both days with readings in the upper 70s to lower 80s across nern CO. On Mon swly flow aloft will increase as an upper level low moves into the Great Basin. Surface low pres will intensify east of the mtns with gusty ssw winds expected over the plains with increasing fire danger. Moisture will increase in the mtns by aftn mainly west of the divide which will lead to a chc of showers and storms as some mid lvl qg ascent moves in. As for highs temps will remain above normal especially across nern CO as highs reach the lower to mid 80s. For Mon Night into Tue the upper level low will move ene across WY with the flow aloft becoming more wnw across nrn CO. Cross-sections show best moisture will stay to the north of the area with downward forcing in place. Will keep in a chc of showers mainly north of I- 70 across the higher terrain. Temps will be cold enough for some snow in the mtns with a mix across the higher valleys. Over nern CO will keep in a slight chc of rain showers. Winds will increase in the foothills and across the plains as a bora type fnt moves across late Mon Night into Tue morning. As for highs readings will drop into the 60s across the plains. By Tue Night into Wed the upper level low will move into the wrn Dakota`s with wnw flow aloft remaining over the area. There are some differences between the ECMWF and GFS with handling of moisture. The GFS shows an increase in moisture Tue night into early Wed morning while the ECMWF has this moisture increase late Tue night thru the day on Wed. Overall should see a better chc of snow in the mtns Tue night possibly into Wed depending on the timing of this moisture as orographics will be favorable. Over the nern CO will see a slight chc of showers. Winds will remain gusty across the area as well. Highs over nern CO will remain in the 60s. For Wed Night into Thu the flow aloft will continue wnw as drier air spreads across the area. This should lead to a dry pattern with temps warming back to nr seasonal levels. && .AVIATION...
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(For the 06Z TAFS through 06Z Friday night) Issued at 424 AM MDT Fri Sep 30 2016 Showers today will stay mostly north of the Metro area and over the mountains...metro area aiports will have a slight chance of showers after 21z. Will put vcts at kapa and kbjc vcsh at Kden. Aviation impacts should be minimal...with mostly vfr ceilings and spotty mvfr ceilings. Winds in the metro area will be light.
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&& .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...RTG SHORT TERM...Dankers LONG TERM...RPK AVIATION...Dankers

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