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This is my final map for this snowstorm. Not as widespread with the snowfall amounts, 12:1 ratios make sense as it will get colder throughout the storm. Ocean enhancement/effect snows will add to the amounts over mid and outer Cape Cod. Not buying latest NAM run as the hires NAM shows significant accumulations for the south shore, Cape and Islands. Winds might be a problem with the fluffy snowfall. Blizzard like conditions will hamper travel tomorrow night into the morning hours on Tuesday. I will get video of the heavy snow as 1"/hour snowfall rates are possible for a time Tuesday morning.

Rain will start off our Sunday morning and will either stop entirely on Sunday night and then start as Snowfall on Monday afternoon. It will fall heavily for a few hours as there is decent lift in the Dendrite Snow Growth zone over the Cape and Islands, if the west trend continues into the 12z runs tomorrow afternoon hours then we could see more than 8" on the Outer Cape and Nantucket. This is my final snow map as this is the most likely amounts.

12z and 18z models beginning to indicate a secondary shortwave riding up the coastline forming a coastal storm on the frontal boundary and could become quite potent -winter storm threat is increasing as models gain confidence in what disturbance will do what on Sunday through Tuesday -Snow threat remains high, models increasing precipitation into the region as a frontal boundary plows offshore and the coastal low develops into a powerful nor'easter -as Nor'easter develops a potentcy wind threat increases out of the northeast - as nor'easter strengthens coastal flooding becomes a threat -Please stay tuned to the latest updates from the Taunton NWS WFO

**Winter Storm Alert** - development of a coastal nor'easter is becoming possible in the day 5-7 time frame - cold air looks to reenter the region as a cold front passes through sometime between the 27th and 28th of January followed by a nor'easter threat around the 29th - Region in most danger is Southern and Northern New England -danger level is low at this time, due to uncertainty, stay tuned!

I could see how Cape Cod could end up with more snow from both systems than say Springfield MA if the coastal storm on Wednesday takes a more southeasterly path

This map is the combined storm threats the next four days, I included the Thursday storm because I believe that the models will come northwest with the coastal storm on Thursday enough to add a few inches to the forecast for Cape Cod. I believe 12"+ will occur on the Cape, south and north shores of Boston, MA as this is combining all three events which it looks like all three will contribute 3-6" of snow to this part of the region. Most of the rest of the region will be 6-9 or 9-12" from the Wednesday event alone. Coastline gets their snow Wednesday into Thursday from two likely different events

Three snow threats this week, all pointed out in the two graphics below the second one to the right is the dual coastal storm threat combined snow fall totals expected

As of 1215am EST clouds are building over the Outer Cape Cod area, the next 24 hours should bring some accumulating snows to the area east of Hyannis, MA

My next post is about the potential snows from Saturday evening through Thursday morning. Models are in general agreement that the potentials for Ocean Effect Snow from Sunday through Tuesday and then storm produced snows from Wednesday through Thursday due to a coastal storm is on the table. However, this post will solely focus on the Ocean Effect Snow potentials. First is the event Sunday through Monday. Mesoscale WRF-NMM and WRF-ARW both support a single band of ocean effect snowfall impacting the region of Cape Cod from Hyannis to Chatham and Provincetown on Northerly winds from 900mb to the surface, which means a single convergence band is more likely than multiple bands of snow which are less intense. These two models keep the band over this region from about 12z Sunday to 00z Monday or later, that is at least 12 hours or more of heavy snowfall over this area of the outer cape, this could produce more than 6" of snow, we will have to see the next few runs until the event starts and then diagnose the real short range models and what they produce. For now the potential exists of a few inches to as much as 6" or more over the Outer Cape Cod area. Stay tuned!

Latest NAM run 00z shows a strong potential for ocean effect snow event from the Cape Cod Canal eastward to Provincetown on northerly winds, also unidirectional wind flow from 900mb to the surface indicates a single band event is probable along with a strong instability burst from 850mb to surface ocean temperature differential (Delta Ts) of 18-20C which is sufficient enough to produce heavy snows over the Cape and Islands. Also the flow is stronger than 10mph which should be sufficient enough for consistent band developing as we transition into a clipper low for the next few days. Big storm potential if the clipper low slows down its movement like the latest 12z guidance suggests at H5 with the low developing and closing off the H5 flow over the Northeast US. This will prolong the snow chances from Sunday morning to Wednesday afternoon for overall snow chances. Stay tuned!

12z models trending towards a major coastal redeveloping nor'easter come next Tuesday into Wednesday. NWS Taunton WFO has a 50% of snow in the forecast for Tuesday and 40% chance of snow for Wednesday, depending upon whether or not the trough closes off at H5 into a low will determine the duration of this winter storm, could be anywhere between 18-36 hours of snow

I added lollis of 24"+ to the map because I seriously think the storm hits the benchmark and pushes the snowfall further west, Hartford, CT to Boston, MA gets 12-24" of snow overall with less on the Cape and Nantucket due to more rain forecasted, this storm came west congrats people along and west of I95 corridor

Good evening folks, This is my latest blog entry and the first official entry on the potential Blizzard of 2018, or Storm of the Century potential on January 3-5th 2018. The first image is water vapor imagery taken as of this hour, it represents the different ebs and flows in our country. Also it currently has three disturbances that will impact our storm potential this week. The arctic disturbance is circled over NW Canada in a pink dot, the second disturbance is in red, the Pacific shortwave and then the third is in green the sub-tropical jet which is already providing moisture and rains in TX and LA this evening and will enter the Gulf of Mexico in the overnight into the early morning hours. This green dot disturbance will be the southern stream disturbance that gets carried northward as our storm develops by the next disturbance in the polar jet and the arctic jet. These will be our catalysts towards a destructive nor'easter, perhaps with the intensity we have never witnessed south of the benchmark in history. I believe the only way this system hits the benchmark head on as it tracks up the coastline is if the trough is more centered over or west of James Bay, Canada and recent runs have adjusted this direction. So I am now saying the track officially of the storm should be between 25-75 miles east of the 40/70 benchmark location as a sub 960mb low, stronger than the Superstorm of 93, stronger than the Blizzard of 2017, stronger than the Blizzard of 2016. 2015 and more. My second image is my snow map of impacts to the East Coast and potential snow accumulations of light. moderate and heavy. And I highlighted in red where on the coast can expect blizzard conditions.

What I am thinking preliminarily right now for this weekend as ocean effect snow gives way to a northern stream (arctic jet stream) disturbance running through the flow amps a bit as it reaches the East Coast of the US and perhaps tries to tilt negatively for a time this Friday and Saturday. There are many different disturbances in the flow this weekend that could turn something meager into a beast of a storm. The runs this weekend of showing a monster hit are no longer showing this due to the presence of a strong upper level low over the NE pacific Ocean influencing the departure of the positive values in the PNA region. If this disturbance were to weaken or split into two groups, one moving westward into the northern Pacific and the other piece of the low moving into the US, then the ridge would be able to build itself upwards once again and positively influence our troughing in a more positive way this weekend. However, there is poor sampling in this part of the Pacific Ocean, and there is no way in knowing how the PNA ridge will react to a split in the disturbance energy field. Some models collapse the ridge temporarily while others recharge it later on into Monday through the rest of the New Year first week. therefore, models are now signaling there will not be a full phase between the Arctic jet and the Pacific jet so there will be no bombogenesis present this weekend, however, models are keying in on a potential one jet bombing low pressure center as it takes off, off the NJ coastline sometime Sunday and produce its own snow shield, this could put down a 1-2" swath of snow from western VT to eastern and southern ME and north of the MA Pike, while areas south of the MA Pike see 2-4" generally, while the South Coast of MA, Ri and SW CT see about 4-8" due to the high snow ratios and then the cape cod area east of Barnstable and Hyannis could see upwards of 8-12" or more of snow as ocean effect adds to the fluff factor and a very little of moisture can lead to high amounts of snow. I am expecting models to back more precip onto the SNE coastline than currently projected first because of the OES processes and also because I expect the storm to be further northwest in the end and strengthen a little faster in earlier developmental phase. I will have another map after the 00z runs tonight if I need to change anything.

Today all options remain on the proverbial table. Anything from an epic blizzard to a weak coastal is in store for this weekend. NWS Taunton has a 1in10 chance snow map for 4" in my neighborhood, and a 1% chance at seeing 8"+ this weekend. Let's discuss this major potential?

During the next 48 hours, the Tug Hill Plateau could receive up to 5 feet of new snow. This is the BUF snowfall map with the legend showing >48" of snow likely in the forecast map

Here is the more detailed snow map for the final call, I added an 8-12" amount region and a special 12" amounts region for the mountains of NW ME and N NH. I think some of the mountains in northern ME could see 12-18" of snow considering nearby arctic air mass and ratios. Also I added a blizzard conditions possible area and a high wind 60mph+ gusts area, mostly the ocean northeast of CHH, but includes CHH and the Outer Cape Cod area. This storm will bomb out as it develops over the Cape Cod Canal, Boston is a tricky spot for the forecast, could be as little as an inch and as much as 6" possible, NE MA is most certain location for 6" in SNE.

Here is the second updated map version for our storm on Monday (Christmas Day) has everyone done their Christmas shopping, I am doing mine last minute today.

This is my snow map I will update it come after the 12z runs tomorrow

As of the 12z and 18z runs this morning and this afternoon suggest that we have three storm potentials this holiday week coming up. With the NAO in flux, the PNA positive and the AO in flux, this is the best time to get snowstorms across the Northeastern US. With the AO going negative long term and the PNA staying above neutral, we have a chance at transient ridges and shortwave amplification potential. The first system is for Christmas Day, where an inverted trough/norlun trough bring accumulating snows for interior SE MA and RI into NE MA and S NH Christmas morning into the afternoon. The second storm is a weak coastal storm on the GFS and the EURO is out to sea with the low, but as long as the potential threat exists I will mention it, seems like this storm is for Wednesday the 27th. The third and final storm is potentially a long duration miller B coastal storm, with such a large high in Ontario, and Quebec, Canada banana high as in its shape and orientation favors an East Coast snowstorm impacting all of the Northeastern US. Stay tuned, this one could be our first 2' potential since the Blizzard of 2015.

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