wxgeek's weather-Weather Outlook Jan 12-21-Update 1/16

Update Fri Jan 16

Prominent mountain wave cloud across the Front Range this morning is beginning to dissipate, thus with more sunshine this afternoon temps across eastern CO will approach record levels. Upper winds in advance of approaching system over the Great Basin will pick up this afternoon into Saturday morning which will cause winds over the High Country and foothills to increase to 20-45 mph with gusts to 60 mph. Highest winds will be overnight into Saturday morning, then diminish during the day on Saturday. Snow will move into the northern and central mountains this evening into Saturday morning, with some snow moving as far east as the Front Range Crest. Mountains could see 1-3 inches of snow overnight.

Cold front drops into eastern CO Saturday morning, so as winds diminish, temps will remain at or slightly below seasonal norms on Saturday. Snow will also diminish Saturday morning and end by Noon in the mountains.

Sunday, CO will be between systems, so temps will be back above seasonal norms with mostly sunny skies, but westerly winds will begin to pick up Sunday afternoon into Monday morning ahead of next system. Mountains and foothills could see speeds in the 20-45 mph range with gusts to 60 mph. Snow will also move into the northern and central mountains Sunday evening and night with snow level around 6000 ft. Cold front moves through early Monday morning, so winds will diminish but temps on Monday expected to be below seasonal norms. Snow expected to persist much of Monday in the High Country, with an additional 2-5 inches possible from Sunday night into Monday evening.

For the rest of next week, models in better agreement today and have leaned towards the GFS solution, which keeps a broad upper trough over the Great Basin, but provides little additional snow to CO. Temps look to remain below seasonal norms Monday through Wednesday, then return to seasonal norms or above Thursday and Friday. Some light snow may be possible over the High Country Tuesday and Wednesday, but no significant accumulations expected.

Next chance for precip would be next weekend into early the following week if you believe long range models from today. They suggest upper ridge along the West Coast retrogrades west into the eastern Pacific which allows systems to move into the Great Basin and CO. Will have to wait and see if this actually happens.

For NFL championship games on Sunday, Seattle will receive 1-3 inches of rain Saturday into Sunday morning, then turn to showers on Sunday, so intermittent rain likely during the game on Sunday with temps in the low 50's, and southerly winds of 10-20 mph. For New England, system moves up the east coast Sunday, with snow likely in the morning across New England, turning to a cold rain or rain/snow/sleet combination Sunday evening during the game. Southerly winds of 10-20 mph expected with temps in the mid to upper 30's. Lovely night for football.

_________________
"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 Thu Jan 15

Sunny and mild day across the state as upper ridge builds over the Great Basin. Temps running in the low to mid 50's across eastern CO today which is 10-15 degrees above seasonal norms. On Friday, a weak upper level trough will flatten the upper ridge and begin to move towards CO. The impact of this will be to increase westerly winds aloft over CO on Friday. This means breezy to windy conditions over the mountains and foothills, and the down-sloping winds will warm temps in the lee of the Front Range to near records levels Friday, with temps in the low to mid 60's. Westerly winds of 15-35 mph with gusts to 50 mph will increase during the day on Friday and persist overnight into Saturday morning. By Saturday morning, cold front will push into northern and eastern CO dropping temps back near seasonal norms. Some flurries will be possible in the High Country, mostly north of I-70, Friday night into Saturday morning as well with 1-2 inches of accumulation possible. Winds will diminish through the day on Saturday.

Sunday will see temps climb back above seasonal norms with some breezy westerly winds again in the High Country and foothills into Monday morning. A few flurries possible again in the mountains north of I-70 with snow level 7000-8000 ft.

Next week remains a bit uncertain, as models have some differing solutions. Early in the week, cold front will move south into CO Monday night with some light snow possible over the northern and central mountains. Tuesday into Wednesday temps should remain below seasonal norms statewide as upper level trough moves over the Great Basin. Some light snow will be possible each day, mostly over the High Country, but a few flurries may be possible into the foothills and adjacent plains, but no accumulations over 1 inch expected. For Wednesday into Thursday, GFS and Euro models differ. GFS digs an upper trough into AZ which would keep nearly all precip south of CO, while the ECMWF models has the upper trough in the 4 Corners region, which would bring a chance of snow to most of CO. Will need to wait and see how the model evolve. Either way, temps should be below seasonal norms most of next week. Both models then clear things out and warm temps back up next Friday into next weekend. Longer range models bring a chance for precip into CO the following week, but it appears we will end Jan with below average snowfall, a familiar trend this season. We can only hope that the Feb-Apr period brings us average to above average snowfall.

_________________
"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 Jan 14

Sunny day statewide with temps returning to near seasonal norms. Upper low in NM and will move farther east today. Upper ridge that has been along the West Coast will shift east into the Great Basin which will warm temps above seasonal norms Thursday and Friday and keep the state dry.

Some Pacific systems will move through the upper ridge to our north this weekend and next week. The primary impact will be stronger westerly winds in advance of these systems, and a slight cooling in temps after they pass. First system will pass to our north Saturday. Westerly winds will pick up in advance of this from Thursday night into Saturday morning. Temps will cool back to near seasonal norms on Saturday in wake of system. Only a slight chance for some flurries Friday night into Saturday morning over the northern mountains. Sunday looks dry with temps back above seasonal norms.

For next week, models still shifting the forecast around a bit. In general, upper ridge will re-build along the West Coast which will allow systems that move through the ridge to drop southeast across CO. First such system moves through Monday night into Tuesday morning. Latest models keep this system fairly dry, a few flurries over the High Country and a cool down in temps Tuesday. Next system drops down Wednesday into Thursday. Latest models keep most precip from this system across southern CO, but given the range of solutions the past week, precip could be anywhere over CO from this system and temps will remain below seasonal norms. Slight warmup next Friday before another system next weekend that could bring more precip to CO. With the dominant upper ridge forecast to remain along the West Coast through the end of January, it will be the slight fluctuations in movement farther west or east that determines if storms will impact CO. The farther east the ridge moves, the warmer and drier CO will be. The farther west it moves into the eastern Pacific, systems have the ability to dig to our west and produce more significant snow across CO. This is not an unusual pattern for January.

January tends to be a relatively dry month for CO. Average snowfall on Conifer Mountain is 15.5 inches, one of our lower snowfall months with current monthly snowfall at 6 inches. Average snowfall through the end of January is around 70 inches on Conifer Mountain. So far this season, we have received 38.5 inches of snow, so about 55% of normal through the end of January. Some of our highest snowfall months are coming up, February through April, which is when we typically receive close to 50% of our seasonal snowfall (about 83 inches). In past seasons with snowfall near what we have received so far this season (2000-2001, 2002-2003, 2010-2011) we have been saved by a snowy Feb-Apr. Hopefully this season will be no different and we will receive abundant snowfall in the Feb-Apr time frame. If not, we all know the trouble that could spell, but I will remain optimistic and see what the atmosphere delivers. Mountain areas are now running below average snow pack, statewide we are at 91%, with southwest mountains far below normal, and central and northern mountains slightly below to near normal.

For Sunday NFL games, Seattle will receive some heavy rain Saturday, then mostly showery Sunday with temps in the low 50's. For New England, latest models suggest the possibility of a Nor'easter moving up the coast Sunday afternoon and night, thus Boston could see northeast winds and snow developing by Sunday evening during the game.

_________________
"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 Jan 13

Upper level circulation currently near the central UT/AZ border area with an elongated tough extending into northeast CO. At the surface, low pressure centered over southwest CO with snow covering much of southwest CO. Models forecast upper level circulation to continue southeast into AZ and then into central NM. This track will have snow persist across southwest CO through this evening, then begin to diminish tonight. Winter Storm Warning is in effect through 6 pm today for much of southwest CO for 10-16 inches of snow, with a Winter Weather Advisory in effect through 6 pm also for 2-8 inches of snow for surrounding areas and the central mountains south of I-70. Foothill areas may see some light snow this afternoon and evening, but any accumulation now expected to be less than 1 inch, with many areas not seeing much if any snow.

On Wednesday, warming and clearing trend begins as upper ridge builds along the West Coast. Temps should climb above seasonal norms by Thursday into Friday. As systems ride up and over upper ridge into the Pacific Northwest, then dive southeast into the Midwest, CO will see some fluctuations in temps and clouds. First such system will skirt to our north Saturday, which will bring increased clouds and westerly winds Friday afternoon and night, but no precip is expected. Temps will be cooler on Saturday in wake of passing cold front. As upper ridge builds back up, temps will increase Sunday and Monday under mostly sunny skies statewide.

Models indicate a stronger system will move through the upper ridge early next week and will move southeast farther west which will impact CO weather. Cold front will move through Monday night and bring cooler temps on Tuesday. Under northwest flow aloft, northern and central mountains likely to see some snow Monday night into Tuesday evening. Some light snow may be possible into the foothills Tuesday, but amounts would be very light if any accumulation at all. Temps will remain below seasonal norms most of next week under cool northwest flow aloft. Second disturbance is forecast to move into CO next Wednesday and bring a chance for snow to most of the state Wednesday into Thursday morning. A few to several inches expected in the mountains, with light amounts possible for the foothills and plains. Yet another system may bring chances for snow Friday into Saturday next week. Models are just beginning to get better consistency for next week, so details are likely to get fine tuned in the next few days, but at this point looks like a mostly cool and unsettled week next week with snow possible. Longer range models keep a dominant upper ridge along the West Coast which is not good news for CA rainfall, but depending on how system move through the ridge, CO may see regular systems moving down from the northwest. This type of pattern favors snow for the northern and central mountains, with mostly breezy and dry conditions for the foothills and plains. However, if a system digs to our west, then eastern CO would have a chance for a nice upslope system. Too early to tell if or when this might occur.

Latest ENSO discussion has been posted by the Climate Prediction Center. The good news is that the last 3 month average SST anomaly shows a weak El Nino has emerged, with the ONI in the Nino 3.4 region at +0.7. The bad news is that SST anomalies have been trending downward since December, which favors more ENSO Neutral conditions into the Spring and Summer. The other important climatic feature is the Madden-Julian Oscillation (MJO) was in a positive phase over the western U.S. in December, and now in a negative phase in January. This implies drier weather for much of the western U.S. in January. It appears a positive phase may be returning in February which would indicate snowier conditions for CO. The other interesting note is that climatic models suggest that a stronger El Nino may build back this Fall and next Winter. Too early to tell how likely this is so will have to wait and see how things transpire. For anyone interested, a link to the latest ENSO discussion is here: www.cpc.ncep.noaa.gov/products/a ... sodisc.pdf

Lastly, for the NFL championship games this Sunday, looks cool and rainy in Seattle with temps in the upper 40's to low 50's. Sunday evening in New England looks cloudy with temps in the 30's and westerly winds of 10-20 mph.

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

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

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Cloudy day across most of CO today with temps below seasonal norms. Most snow amounts overnight were less than 2 inches, with a few areas along the Palmer Divide in the 3-4 inch range. Some light snow diminishing across eastern CO as well as over the High Country today.

Models have changed the forecast for Tuesday. Upper level trough in the Great Basin is now expected to move into southern UT Tuesday morning then continue to dig due south into AZ Tuesday evening into Wednesday. The implication from this is very little snow across eastern CO on Tuesday. Mountain areas west of the Divide and south of I-70 still expected to get snow, with 4-9 inches possible over the southwest and south central mountains, but little snow now expected in the foothills and plains. Snow will move into western CO this evening and tonight, with snow becoming heavy at times south of I-70. Some light snow may push east during the day on Tuesday to the Front Range Crest and foothills south of I-70, but amounts will be on the light side from a dusting to perhaps 2 inches. Heaviest amounts expected to be south of the Palmer Divide. Best chance for snow in the foothills will be from 3 pm to 9 pm Tuesday. Snow will move out of the area late Tuesday night with clearing by Wednesday morning.

Temps will rebound to near seasonal norms on Wednesday under mostly sunny skies statewide. Upper ridge will build over the Great Basin late this week which will raise temps above seasonal norms and keep the state dry through the weekend. Some gusty westerly winds will be possible Friday into Saturday across the foothills.

Models have been in serious vacillation regarding the forecast for next week. Runs over the weekend had a potentially snowy period over CO early next week, but latest runs have much less precip under a dirty ridge scenario, which may bring some snow to the mountains next Tuesday and again Friday into Saturday. Precip chances for the foothills look pretty low with any snow amounts being rather light next week. However, confidence in any forecast is rather low until models become more consistent.

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

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

Bump for 1/13 update

Bump for 1/14 update

Bump for 1/15 update

Bump for 1/16 update