wxgeek's weather-Warm then some snow-Update Oct 22

Update Tue Oct 23

Warm and windy day today, and winds expected to strengthen later this afternoon and tonight. Southwest winds of 20-40 mph likely, with some gusts to 55 mph possible tonight. High fire danger will accompany these winds and low RH values. Red Flag warning in effect for much of eastern and southeast CO today, and conditions at or very close to Red Flag criteria in the foothills as well. Conifer HS has reported southwest winds to 47 mph with 10% RH.

Upper level low still off the WA coast, but models consistent in bringing this upper trough eastward across CO with first impulse on Wednesday. Clouds will increase Wednesday across CO with precip moving into northwest CO Wednesday afternoon. Snow level initially 7000-8000 ft during the day on Wednesday. Cold front will move south through eastern CO on Wednesday bringing northerly winds and cooler temps by afternoon. Precip will move east into the foothills and Urban Corridor by late afternoon/evening with initial snow level 6500-7500 ft. Latest model guidance has done a switch on the two impulses, now forecasting the Wednesday night system to be the stronger of the two. Heaviest precip still looks to remain north of I-70, but precip will move south at least to the Palmer Divide. Snow level should be down to Plains level by midnight Wednesday night. For amounts, northern and central mountains should get 3-6 inches, 1-3 inches for the foothills, with highest amounts north of I-70, and a trace to 1 inch for the Urban Corridor and Plains. Warm temps this week will melt most snow on road surfaces below 7000 ft, but higher elevation roads could have some slick spots Thursday morning.

Thursday will be a mix of clouds and some flurries, especially in the mountains and foothills, although little if any additional accumulation expected during the day. The next impulse still expected Thursday night, but models now forecast this system to be much drier, although still colder. Amounts from this system look like 1-2 inches in the mountains, a trace to 1 inch in the foothills, and a dusting for the Urban Corridor and Plains, again with heaviest amounts north of I-70. Colder temps will cause roads to be more slick on Friday morning, although with such light amounts, should not have any serious issues outside of the usual early winter season accidents. Clouds should dissipate by late Friday morning with mostly sunny skies by afternoon, although temps will remain on the cool side.

After a cool start Saturday, more sun and warming temps this weekend, although afternoon temps likely to remain below seasonal averages. Long range models indicate dry and mild conditions early next week, then a chance for more precip later next week. Models toying with a more significant system Thursday/Friday next week, so will need to keep an eye on this.

Tropical Storm Sandy has formed in the Caribbean, and is expected to move northward over Jamaica on Wednesday, over eastern Cuba on Thursday, and into the Bahamas on Friday. Sandy is expected to become a category 1 hurricane before crossing Jamaica near Kingston. Rainfall of 10-15 inches is expected, so devastating flooding is expected in Jamaica and eastern Cuba along with 4-8 foot storm surges and hurricane force winds. The trend in model guidance is to push the track farther west, so Sandy could impact southeast Florida Friday and Saturday with rain, high winds and heavy surf. Sandy is not expected to make landfall on the U.S. mainland, but remain over the Atlantic and head towards Bermuda later in the weekend.
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"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 Oct 22

A few more warm and mostly sunny days before we get our next taste of Fall/Winter. Warm and dry weather expected today through Wednesday morning, with south to southwest winds increasing causing breezy to windy conditions from Monday night into Tuesday night. Upper level low currently off the WA coast bringing precip to much of the West Coast and northern Inter-Mountain region. Snow levels down to 4000 to 6000 ft along the West Coast, with 12-18 inches of snow above 7000 ft in the Sierras.

The first short wave trough will move across CO on Wednesday. A cold front will push south through CO late Tuesday night into early Wednesday morning, and a surface low is expected to develop over southeast CO by Wednesday evening, with upslope flow developing Wednesday afternoon across the Plains and foothills. Precip will move into northwest CO Wednesday afternoon with snow level 6500-7500 ft, and precip will develop over the foothills and Plains by Wednesday evening and persist into Thursday morning. Highest precip amounts will be north of I-70, but precip should make it south to the Palmer Divide, and possibly south to US 50. Snow level will begin around 6000-7000 ft Wednesday evening but lower to Plains level by 9:00 pm to midnight. Snow amounts currently look like 1-2 inches for the foothills above 7000 ft, with a trace to an inch through the Urban Corridor by Thursday morning, with possibly slightly higher amounts north of I-70. With the warm temps this week, most of the snow will melt on asphalt and concrete surfaces, although some may stick above 7000-8000 ft, so roads could be slick late Wednesday night and Thursday morning, increasing commute times a bit Thursday morning.

Models indicate upslope flow will persist Thursday so low clouds, fog and some light snow is possible to persist during the day on Thursday, although additional accumulation expected to be little if any. A second short wave trough will move across CO Thursday night into Friday, which will push an even colder airmass into CO Thursday night into Friday. This will increase snow chances overnight Thursday into Friday afternoon with snow level down to Plains level, so all snow. Amounts with this system look to be 1-3 inches for the foothills, with 1/2 to 2 inches for the Urban Corridor and Plains. Snow should end by Friday afternoon. This impulse expected to create slick roads throughout the foothills and Plains Thursday night into Friday morning, so this commute could be much slower than the Thursday commute.

Skies should clear Friday night causing cold temps Saturday morning, but temps should warm during the day under sunny skies. Upper level ridge builds back over the western U.S. this weekend into early next week, so dry and warmer conditions Saturday through next Tuesday, although some light showers are possible Monday and Tuesday across the northern mountains. Beyond that, models are struggling with a solution. Could be additional precip later next week, but still too early for anything with confidence.

Lastly, a tropical depression has formed in the Caribbean and is expected to move north northeast over the next several days. The system is expected to become a tropical storm later today and pass over eastern Jamaica on Wednesday, and eastern Cuba on Thursday and into the Bahamas on Friday. Present track keeps the system away from the U.S. mainland, although Florida and the south Atlantic coast states likely to see some heavy surf from the system later this week. System currently expected to remain a tropical storm, although category 1 hurricane status is possible Friday into the weekend.
_________________
"Climatology is what you expect, Weather is what you get".

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

Bump for Oct 23 update