Monday, March 18, 2024

Very wintry week with snowfall expected almost every day through Thursday

Winter-like temps and snow showers have returned to the northern Vermont country and I am expecting a very interesting next 3-4 days of weather. It begins rather immediately as a deep layer of instability, not atypical of early Spring, but impressive regardless, establishes itself over the state. The vertical cross section of the lowest 9,000 feet of the Mad River Glen atmosphere is rather magnificent looking  and is inidcating the potential for very heavy snow showers Monday evening and night. We are lacking just a tad on the flow. Mad River Glen snow squall fans such as myself prefer a northwest flow off Lake Champlain the prevailing west to northwest flow favors Smuggs and Stowe, but I expect this deep layer of instablity to work some magic anyway. Intermittent heavy snow Monday evening and night will bring 3-6 inches to the mountains, 1-3 inches to valley areas and potentially more than 6 to the mountains north of Waterbury.

The ski day on Tuesday appears drier and chilly with temperatures hovering in the 20's on the mountain. An approaching clipper system will help stabilize the lower troposphere and also help lower wind speeds from what was a blustery Monday. Snow from this aforementioned clipper will arrive Tuesday evening and fall sporadically and not too heavily through Wednesday morning. We are not on the right side of this clipper system and this will keep snow accumulations in the 1-3 inch range Tuesday night and during the ski day on Wednesday. Once we turn the flow northwesterly later Wednesday, heavier snow showers are again likely and should persist into early Thursday. The depth of the instability doesn't appear quite as impressive as Monday night but the flow is better aligned for MRG and snow totals are certainly capable of exceeding an additional 4 inches (on top of what falls Tuesday night and Wednesday). The incoming airmass late on Wednesday is also quite cold for late March and will bring temperatures into the 15-25 degree range for most of Thursday. It will be dry by Friday morning with more sunshine and with temperatures as low as 5 degrees in few spots. 

Where have you been arctic pattern ? It's here for this week with cold air in place for the upcoming weekend as southern stream moisture tries to converge with a polar impulse. Models are still at odds with whether this can successfully manifest into a big snow producing event though I think a light accumulation of snow Friday night or Saturday is likely while a bigger event remains possible. 

Jet stream configuration and trough axis along with the cold air is expected to shift west after this weekend lowering our prospects for the continuation of winter weather though not eliminating the chances for snowfall entirely. More spring-like temperatures or at least spring-like days have become more likely beginning Monday the 25th and I expect at least two of those in the week beginning that day.

Thursday, March 14, 2024

A two-dose shot of wet snowfall over the next few days across northern Vermont high country

 It has been an especially warm winter in the Great Lakes region. After recording the warmest February on record, the first 14 days of March in Chicago has been warmer than the same period in the historically warm March of 2012. The state of Vermont has also been very mild during this 6-week period, but has not featured that mid-spring warmth that has persistently impacted locations farther west. It's been pretty close however with excessive temperatures often impacting Burlington and locations in the Champlain Valley while failing to make it passed the Long Trail. All of these regions are poised to have a very different outcome than March of 2012 as a different weather pattern will dominate the eastern two thirds of the country for the back half of the month. A mild day or two appears possible during the last 5 days of the month but both colder weather and snowfall should remain a more prevailing part of the outlook until April with the dominating jet stream feature consisting of a omega-like block near the Yukon/AK border.

There are a few chances for some wet snowfall over the next few days. A wave of low pressure passing to our south will spread an area of rainfall over northern Vermont Thursday night. This rain will turn to snow beginning at higher elevations first, but ultimately everyone in the valley will be seeing snowfall by morning. This appears to be a 2-5 inch wet snowfall for the high country ending by late morning with the near freezing temperatures rising to the high 30's during the afternoon. 

Only a few intervals of blue sky can be expected for the weekend, mostly on Saturday. More elevation sensitive snowfall can be expected for Sunday. This time we are on the wrong and warmer side of the impacting low pressure area and though its cold enough to snow above 2000 feet, precipitation will be fairly disorganized and the moderate, accumulating snow will be intermittent across the mountains or falling as mixed precipitation and/or graupel over valley locations. Another 2-4 inches is my first guess with this 2nd event, though to reiterate, this applies only to the mountains and little accumulation can be expected on the valley floor. 

The same section of high country that is expecting some wet snowfall over the coming few days, can expect a 5 day period of below freezing temperatures beginning on Monday. Instability snow showers will accompany the chill late on Monday through most of Tuesday. By Wednesday there are indications that a more significant clipper type feature capable of bringing more substantial and powdery snow to MRG. The snow could be followed by our coldest weather of the month on the mountain with readings potentially staying below 25 both Thursday and Friday and struggling to bet above freezing over the mountains. The reinforcing area of cold late next week should bring the return of some sunshine for at least a day or two. If the strong southern branch storm stays south of New England for the weekend of March 23 and 24th, sunshine will continue and temperatures will moderate. If the storm comes north, that will be a situation certainly worth discussing.

Tuesday, March 12, 2024

Colder weather pattern supports additional snowfall for the VT high country with some spring-like days sprinkled in

The duration of March will feature some sprint-like days, especially over low lying valley areas. That said, winter 2023-2024 isn't done and the weather pattern for the foreseeable future favors several opportunities for additional snowfall and a few multi-day periods of colder weather capable of keeping temperatures below the freezing mark across the mountains. 

Temperatures will drop into the 20's Wednesday morning before one such spring-like period begins with readings climbing into the 40's during the afternoon followed by near 50-degree temperatures Thursday near base areas. Clouds will be more prevalent Thursday as low pressure approaches from the southwest. It will pretty mild when precipitation from this feature arrives from this feature, mild enough for rain or mixed precipitation in valley locations. We are on the colder side of this system however and this means some additional wet snowfall for the high country early Friday. I wouldn't expect a lot, 2-5 inches of pretty gloppy snow, but it does replace my wetter expectations from a few days ago.

It appears as if we are in between weather systems for Saturday, another more spring-like day in valley areas with temperatures in the 40's though it should remain a bit closer to freezing over the high country. A widespread area of colder air will then be pushing south into the Great Lakes region by early Sunday, bringing with it, along with the colder air, an area of precipitation that should impact northern Vermont Sunday. Again, temperatures might not be cold enough to support snowfall in valley areas, but they should be over the mountains and this means more accumulating wet snow. By Monday, colder air will support more powdery snowfall, probably in the form of snow showers. 

This is probably the most favorable upstream environment we've had for sustained wintry weather in Vermont with favorable conditions both in the Pacific and in the Alaska/Yukon area. Most of the week beginning Monday the 18th through Friday, March 22n appears wintry and I think there's some storm potential for late in the week. The favorable weather pattern has to overwhelm an obscene warm weather feedback stemming from a warm Great Lakes aggregate thanks to the sustained torch impacting that region through much of last month. Another big storm late in March is thus certainly not a guarantee but the weather patterns certainly supports this possibility both late next week and beyond the 22nd when more colder late March weather appears likely.

Sunday, March 10, 2024

Over a foot of mostly powdery additional snow expected over the mountains late Sunday into Monday

Heavy wet snow pummeled much the northern Vermont high country Saturday night and early Sunday and with it came the power outages. The wet snow always brings this risk, but it appears especially bad thanks to the fact that snow fell over largely unfrozen ground, leaving many large trees susceptible to an uprooting. Thirteen thousand customers just in Washington County alone according to power outage US.  Hopefully folks impacted by this get electricity back soon including the ski areas which appear to have been affected Sunday morning. With the surface low pressure center tracking west of Boston and over interior New Hampshire and Maine, much of Vermont experienced the expected lull in the storm early Sunday. A deep layer of northwest flow is poised to establish itself over the entire state Sunday afternoon allowing the wrap-around moist conveyor of the storm to bring snow back to the mountains. Snow should be falling lightly late Sunday afternoon and evening and intensify over the mountains even as it remains more intermittent in valley areas. Most importantly, temperatures above 1500 feet will cool into the 20's changing the consistency of the snow to a drier, more powdery variety. Aside from being nicer to ski in, the drier is also a little easier on power lines. Northwest winds are expected to increase Sunday night into Monday even as the snowfall continues. Expect blustery conditions Monday with 20-40 mph winds, temperatures in the 20's and the additional snowfall which should taper off to flurries Monday afternoon or evening. I expect we receive another 2-4 inches Sunday, 6-12 inches of powdery snow Sunday night and an additional 3-6 during the day Monday. This would bring us to a storm total ranging from 20 to 34 inches.

More sunshine, diminishing winds and milder 35-40 degree temperatures can be expected for Tuesday with readings climbing into the 40's across valley locations. Clouds are expected to return for Wednesday but temperatures are expected to climb well into the 40's 

More weather is expected late in the week as low pressure is expected to emerge in the plains and track eastward and eventually somewhere south of Vermont. Cold air is in short supply but a minimal push of cooler temperatures is expected to push south just ahead of any precipitation which keeps us in play for some wet snowfall. The prospects for snow appear better as we get closer to St Patrick's Day thanks to colder air which as I've mentioned in prior posts, appears to want to stick around for the ensuing week. More on that in the next update.

Friday, March 8, 2024

Biggest storm of the season set to hammer MRG with 21-42 inches Saturday night through Monday

Got a real solid update on our powerful winter storm storm incoming. Just a beautiful elevation event for the northern Green Mountains and it really just comes down to sorting through all the particulars which we will try to do in this update. 

Meanwhile, sunshine finally made an appearance and another round of sub-freezing temperatures Friday night should give us a short break from the mud. We've managed to eradicate the excessive warmth for the time being but temperatures are still running above normal and are more typical of the back half of March than the first half. All that said, even the limited amounts of cold appears to be enough to keep this upcoming event snow above 2,000 feet and mostly snow between 1000 - 2000 feet. Clouds from this approaching weather system should arrive just after sunrise Saturday and continue to thicken throughout the ski day. 

I was really encouraged to see data from higher resolution Euro and NAM indicate very robust strengthening of low pressure near the Jersey coast Saturday night. This feature will quickly become the dominant component of this system, consolidating the storm as it tracks just west of Boston on Sunday. With temperatures rising into the 40's across valley areas Saturday and near 40 across the high country, precipitation is likely to start as a mix or rain depending on elevation Saturday evening. Wet bulb readings suggests a quick turn to snow above 2000 feet and a gradual turn to snow above 1000 feet. Very heavy snowfall is indicated on a few simulations early Sunday morning before a potential lull in the storm during the middle part of the day.

Snow consistency appears pretty wet below 3000 feet during the first part of this event. There is a substantial column of boundary level air indicated to be in the 28-33 degree range on model cross sections through midday Sunday. Keep in mind that heavy wet thump snow can both make travel conditions very treacherous and cause power outages, especially when combined with wind.  Conditions begin to change late Sunday as colder air begins to settle across the high country as the flow becomes northwesterly. This is ultimately what will separate this storm from the pack this year as the setup appears outstanding for a continuation of colder snow across the mountains Sunday evening, night and Monday. The flow looks great and the storm will be slow enough to depart to allow lingering moisture to just hammer the northern Greens with continuous cold snow. Here are my expectations on snow totals period by period. Please keep in mind that this is a very elevation sensitive event and if you're reading from the Champlain Valley, your outcome will be very different and considerably less snowy than the one forecasted for the mountains. 

Saturday Night: Mixed precip changing to snow - thump potential toward dawn. 6-12 inches mostly wet snow 

Sunday Day: Heavy snow early, possible lull midday or afternoon. 3-6 inches mostly wet snow 

Sunday Night: Snow occasionally heavy. 6-12 inches of powder 

Monday: Snow or snow showers. Another 6-12 inches ! 

Total storm accumulations by Monday evening: 21-42 inches 

Snow will be out the door by Tuesday and temperatures will moderate approaching 40 degrees at base areas with the help of some sunshine. Stronger doses of sun on Wednesday will boost readings even further. Clouds are expected to return later in the week and there is a risk of light rain or mixed precipitation before cooler conditions return for St Patrick's Day weekend. 

I still like the idea of a colder regime settling that could begin with some snow on St Patrick's Day. More generally however, it looks like we have a return of more wintry conditions by Monday and that should bring the potential for additional snowfall in some form during the week beginning Monday March 18.

Wednesday, March 6, 2024

Powerful storm has the potential to bring a foot or more of snow to the northern high country Sunday into Monday

 Cloudy, damp and rainy weather continue plague the MRV and rainy part of this picture is expected to be with us through Wednesday night. The rain is expected to fall heavy enough Wednesday evening to total upwards of an inch though temperatures will stay cold enough to slow the continued melting of snow where it continues to exist across the high country. Boundary layer conditions would support a changeover to snow during the day Thursday if precipitation were to continue. Though models have teased such an outcome sporadically, there's been a pretty clear consensus that it dries out Thursday with the sun even making an appearance later in the day. The decrease in cloudiness will allow the mud to freeze Friday morning before another round of 40-50 degree temperatures and a welcomed full day of sunshine brings the mud right back. 

Sunshine is now expected to return for the first part of Saturday which appears to be an excellent and very typical early spring day in Vermont (much like Friday appears to be) with lots of 20's in the morning and 40's in the afternoon. Clouds from our incoming storm system arrive for the back half of the day but winds should stay tame and precipitation won't arrive until sometime Saturday evening or at night. 

The update on our late weekend storm goes as follows. Snowfall prospects really hinge on the familiar question of how quickly and efficiently this storm can transfer its energy to the coastline early on Sunday. The low pressure center in question is a formidable one but is tracking right at us with minimal amounts of antecedent cold air support. If we can make an ideal coastal transaction we will be snowing quite heavily across the high country early on Sunday and the snow would continue throughout the day, through Sunday night with snow showers continuing into Monday. Accumulations could total our best of the season by Monday evening and yes that means upwards of 2 feet. I continue to feel as if this is a very viable scenario. That said, models moved somewhat away from the "ideal" coastal transfer and it would allow for a longer period of wet weather Saturday night and early Sunday. This is a dynamic enough storm however to produce for us even with a less than ideal scenario. Midday models on Wednesday are struggling to produce a well defined coastal low near Cape Cod midday Sunday, but a coastal low ultimately does form, strengthen and slow in speed. Not only would a change to snow occur across the high country, snow consistency would become ideal with temperatures dropping into the 20's Sunday night into early Monday. Right now, I would put my snowfall spectrum in the 10-30 inch category. 

The long range also continues to show promise. The outlook for the early part of next week consists of the snow showers I spoke of Monday, mostly sub-freezing weather Tuesday and a more gradual moderation in temperatures for the end of the week. It still appears more spring-like Wednesday to Friday, but more recent simulations have kept temperatures a little closer to climatology. 

Teleconnections also continue to favor a turn toward colder weather after St Patrick's Day thanks to the combined influence of a more favorable Pacific and a jet stream in western North America that will push polar air in our direction. Snowfall during the March 18-22 period appears likely in some form.

Monday, March 4, 2024

Mild and damp for a few more days and then winter reemerges from the dead with snow potential Sunday/Monday and colder weather in the long range

 If you're holding out hope of extending the ski season and even procuring ourselves one more really good storm, I offer some good news today. It continues to be very mild in the Mad River Valley and snow continues to melt, but we are most of the way through this very warm regime and are on the verge of heading back into a more typical March temperature range late this week and perhaps a colder than normal weather picture in the week beginning March 18th. There's snow to talk about as well. I am not especially bullish on snowfall Thursday but there is an excellent chance for some significant snow in the mountains late this weekend and into Monday, March 11. At the very least, it appears we've found a footing and won't go quietly into the night like 2016 and especially 2012. 

I really don't want to spend inordinate amounts of time talking about rain and mild weather so I'll try to be fast with the short term outlook. We've got a wave of low pressure pushing moisture into New England on Tuesday. The clouds will keep temperatures into the 40's and most of the rain will fall south and east of northern Vermont, yet rain is expected during the ski day and for a few hours during the evening.  Models are not showing rain for the Wednesday ski day and are instead insisting that clouds linger through another very mild early March day. A push of cooler weather is expected to arrive to accompany some steadier rainfall Wednesday evening into early Thursday. We are just a few degrees away from snow event with this batch of precipitation and if we are to somehow keep it going through the middle of the day, some wet snow could fall across the high country. Like I mentioned in the above paragraph however, I would not hold your breath.  

Generally mild conditions are expected to continue into Friday before we finally get ourselves a sub-freezing night just ahead of the weekend. At that point, we will be watching a storm system in the Ohio Valley crank up and head in our direction. Our cold air will continue to be in short supply as precipitation arrives sometime Saturday night, so some initial wet weather is certainly possible. By early Sunday however, we've got some hard evidence that this storm will make a very nice transition to the New England coastline while cold air is entrained into back flank of this deepening coastal cyclone. This is not an uncommon New England weather map though I can't remember seeing anything closely resembling it since November which is ridiculous. Models continue to provide us with varying solutions on how the final details play out on Sunday, but I like the idea of mixed precipitation changing to snow and some decent accumulations late in the day Sunday and into the Sunday night and Monday. I certainly hope we can score a foot or more out of this and its possible, though for now I think a 6-plus inch event is the most probable. Hopefully I can upgrade our prognosis in a few days. 

A changeable March scenario appears on tap between March 11-15 consisting of some cooler weather at the start of the week and some milder at the end of the week. The risk of more heavy rain appears minimal even as it warms up late next week but i wouldn't rule out some before it begins to get colder for St Patrick's Day weekend. Meanwhile conditions in the Pacific will be changing dramatically and this sets us up for a very favorable late March jet stream beginning around St Patrick's Day and extending through the following week. Both cold weather and snowfall are favored with the EPO cratering and providing support for a nice looking jet stream ridge in western North America.