wxgeek's weather-Weather Outlook Apr 27-May 7-Update 5/1

Update Thu May 1

A mostly sunny day across the state with temps nearly back to seasonal norms. Northwest winds still gusting to 15-35 mph across portions of the state, but winds should continue to die down by this evening and tonight as upper low system continues to move slowly east.

Upper ridge will build over CO Friday through Sunday and provide some beautiful Spring weather across the state. A slight chance for afternoon showers will exist Friday with temps slightly above seasonal norms. Snow level will remain above 12,000 ft. For the weekend, temps 10-15 degrees above seasonal norms, lots of sunshine and little if any chance for precip statewide. Gusty westerly winds will begin to pick up Sunday and persist into Tuesday, so increased fire danger as temps warm, winds pick up and RH values drop below 15%. Fair and warm weather expected to persist into next Tuesday, then looks like a change is in store.

By next Wednesday, an series of upper troughs will move across CO from Wednesday into Friday. This will lead to cooler temps, and good chances for precip across most of the state. First impulse will bring precip from late Tuesday night into Wednesday night, with snow level between 9000 and 10,000 ft. Most areas look to receive 0.10 to 0.50 inches of precip. Next impulse comes in Thursday afternoon into Friday evening. Snow level with this system could drop to 8000 ft overnight on Thursday. Another 0.10 to 0.5 inches of precip possible for most areas, heaviest from the Divide to the foothills. Conditions then look to improve by next weekend into early the following week.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

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Update Wed Apr 30

A small dusting in the foothills last night, enough to make some roads rather slick this morning. Otherwise, less wind and less snow in the mountains today. Upper level low still centered over IA today, so has not moved much past 24 hours, with surface low now in WI. Cold front extends along the east coast into the FL panhandle. Western FL panhandle sections received over 10 inches of rain past 24 hours, so dealing with some flooding issues. Severe weather threat remains for 1 more day from FL north into the mid Atlantic region.

For CO, gradual trend from today into Friday will be warmer temps, less precip and less wind. By Thursday, temps will be close to seasonal norms with no precip expected statewide, and relatively calm winds. By Friday, temps expected above seasonal norms, no precip, but some breezy westerly winds developing along the foothills. For the weekend, temps will be 10-15 degrees above seasonal norms, no precip expected, but gusty southwesterly winds expected to develop Saturday into Monday. Wind speeds could be in the 20-40 mph range at times, and combined with low RH values, this will create higher fire danger in most of the foothills as snow is mostly gone below 9500 ft.

Warm and dry as well as breezy weather expected to persist Monday and Tuesday next week. Models then have suggested for a while that an upper level trough will move into the region. Latest model output brings upper trough across CO next Wednesday into Thursday. This would bring precip chances across CO Wednesday into Friday morning. Depending on how much cold air is associated with the upper trough, snow levels could lower to 8000-9000 ft during this period. Models currently indicate relatively robust precip amounts, up to 2 inches of liquid equivalent for this period. It is likely actual amounts would be lower, but cannot rule out the potential for heavy rain and snow above 8000-9000 ft mid to late next week.

I will do my best to provide updates, but will be on an extended business trip to Alaska and the West Coast Friday through next Thursday, so may not be able to post as often as usual.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

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Update Tue Apr 29

Rather nasty day across the state today. Snow and wind in the High Country, and I'm not sure windy is the appropriate term for eastern CO today with northerly winds of 30-60 mph, with some gusts to 80 mph reported on the eastern plains. Travel across much of CO in the difficult to impossible range today. Upper and surface low currently centered over Iowa today. Decent band of showers on the back side of large upper low will move into CO this afternoon into tonight. Snow level today in the 6000-7000 ft range, but will lower to plains level overnight, so a dusting of snow is possible in many areas of eastern CO this evening and tonight. Very strong northerly winds will persist through this evening, then diminish to just windy to breezy conditions overnight into Wednesday.

Upper low is so large now, that the impacts extend from the Rockies to the Atlantic coast. Some snow across the Great lakes, Northern Plains and Rockies, with another round of violent severe weather on tap across much of the South northward into the Ohio Valley today. Cold front on the east side of upper low moving very slowly eastward, so severe weather impacting much of the same areas affected yesterday. Severe weather area will move into the Southeast and mid Atlantic region on Wednesday.

For CO, continued breezy and cool on Wednesday, although not as windy as today. Showers will persist mostly across the High Country Wednesday with snow level in the 6000-7000 ft range. As upper low moves into the Great Lakes region Wednesday, surface pressure gradient will relax across CO, so less windy. By Thursday, CO will begin to see some much nicer Spring weather. Temps will warm back to seasonal norms and only light breezes with no precip. Friday through Sunday will feature temps back above seasonal norms with dry conditions expected statewide, so beautiful weather to be outside this weekend. Some westerly winds will possibly pick up along the foothills by Sunday into Monday, so fire danger will increase this weekend into early next week. Monday and Tuesday look warm and dry statewide.

Models still figuring out what will transpire later next week. Upper level pattern not quite clear at this time, but GFS persists in producing a fair amount of precip across CO from Wednesday through next weekend. I have big doubts the amounts being predicted will be seen, but could see some periods of precip during this period. Will have to wait and see how this develops. usually, models will define a single feature that produces some precip in a more refined time period, so will have to wait and see where and when in future model runs.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

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Update Mon Apr 28

Blustery day across the state. Upper level low currently centered in central NE, with surface low over eastern NE. Some wrap around showers occurring over the far northeast plains as well as mountain flurries. Shower activity expected to increase this afternoon and evening, mostly over higher terrain, but foothills and plains could see isolated showers. Snow level today in the 6000-7000 ft range, lowering to 5000-6000 ft overnight. Northwest surface winds will remain strong, in the 20-45 mph range with higher gusts especially over the mountains and eastern plains. Tuesday looks quite similar to today, blustery with showers developing in the afternoon and evening and snow level 6000-7000 ft during the day, lowering to plains level Tuesday night. Expect Wednesday to be a three-peat of the past two days. Winds may be slightly less on Wednesday and shower activity may be increased during the afternoon and evening hours.

By Thursday, upper level system will have moved into the Great Lakes, thus warmer temps and less wind expected across CO, with only isolated mountain showers expected with snow level 8000-9000 ft. From Friday through Sunday, expect mostly dry conditions with temps at or above seasonal norms. Only a slight chance for isolated afternoon and evening showers over the High Country.

By next week, Monday and Tuesday also look warm and mostly dry. Models then bring a slow moving upper trough into the Great Basin that slowly moves through CO by next Saturday. Thus, there could be a period of unsettled weather from next Wednesday through Saturday with periods of rain/snow and showers along with thunderstorms. Snow level Wednesday and Thursday expected to remain above 10,000 ft, but as upper trough moves closer to CO, snow level could lower to 8000-9000 ft Friday and Saturday. Still too early for details, but we could see periods of moderate to heavy precip mid to late next week.

Assuming we do not receive any appreciable snowfall this week, we will end April with 25.5 inches of snow, well below the average of 39 inches for April. At my location, that puts the season total at 102.5 inches which is 59% of our average annual snowfall of 173 inches. The report from the Conifer Mountain Almanac site have a higher season total of 120 inches, yet still only 69% of average for the season. Only 1 month this season had above average snowfall, which was January. Since all snow is now gone, this would also be the earliest final melt on record, since 1993. Average final snow melt is May 22 on Conifer Mountain. The bottom line is that we have had one of the driest snowfall seasons on record, and with ground exposed already, ground fuel moisture levels will be very low unless we continue to get regular precipitation. Our fire season will depend on how much precipitation we get in May and June, the two worst fire months of the year. If these two months have below average precip, it could be a difficult fire season for the foothills until Monsoon season begins, which is normally in early July.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

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Sun Apr 27

Rather strange system for CO. Mountains got a fair amount of snow, foothills nothing, and areas just east of Denver have received over 2 inches of rain. Upper low currently over western KS and surface low over central NE. Strong pressure gradient and upper level winds causing strong northwest surface winds across CO with speeds in the 25-50 mph range. This system is also spawning a large amount of severe weather across the Cental Plains and Midwest today.

Models consistent in moving this uppper level system slowly from the central Plains into the Midwest through the week. This will keep a strong surface pressure gradient across CO as well as strong northwest winds aloft. The result will be continued strong west to northwest surface winds through Wednesday. This will also keep a chance for isolated showers across CO through Thursday afternoon, mostly along and west of the Divide, but we could see a brief shower in the foothills and Urban corridor this week. Temps remain well below seasonal norms through Thursday, and snow level remains in the 6000-7000 ft range most of the week.

Temps begin to climb back to sesaonal norms or above by Friday into next weekend, but afternoon and evening showers will remain in the forecast, with snow level above 12,000 ft. The following week looks to keep precip chances across CO as well.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

Bump for 4/28 update

Bump for 4/29 update

Bump for 4/30 update

Bump for 5/1 update