USCAPEWEATHERAF

Why? I have seen a grand total of 7.45" this winter to date. If I can add a few inches to reach last year's total of 11" I will want to do it as soon as possible.

That suggests the 00z EURO came west some.

How can you guys quit on something not even happening yet. We are still 54 hours from initial precipitation beginning. It will likely start off as rain. We get that, but the amounts could be significant especially if the NAM goes another 25-50 miles west the next 3 cycles. That 2-3' range could be over the Cape and Islands, instead of over ACK and 20 miles east of CHH. We still need to pay attention, and the 00z Euro ensembles showed a mean slanted towards the northwest.

6z GFS came west about 50 miles from the 00z run with the track and the precipitation shield. 12z runs are important if they show a more pronounced trend to the west, or stronger with the surface low. Storm mode still in progress, threat is still present.

Latest 6z NAM run comes in hot with over a foot of snow for Chatham in about a 12 t0 18 hour period from 10z Saturday, February 1st to around 00 FEB 2nd or 7pm EST Saturday night. The latest run of the NAM intensifies the shortwave, as a stronger negative tilt occurs as it approaches the NC coastline, around 35N: 75W. This run also brings the surface low from the central GOM to the interior of SC and NC before it reaches the location of 35N: 75W. Then the low tracks Northeastward towards the 40N:70W benchmark location which favors a heavy snow threat for Cape Cod and the Islands. Even the HIRES NAM or 3KM Resolution NAM brings the surface low closer and throws over .3" of Liquid over CHH as the run does not go beyond 60 hours. However, the storm will start within 48 hours of the 12z runs this late morning into the early afternoon. Also water vapor imagery suggests that the northern stream is digging more southward in last few frames than what the recent 00z and 06z guidance even suggests. We could see a sea/saw effect continue for the next day and then trends could be west towards 24 hours and closer to the onset of the precipitation. For a bigger and more severe event, like talking blizzard potential, we need a stronger phase, a colder scenario and a much stronger surface low passing at the benchmark or just about 24 miles west of it.

The 6z NAM hits Cape Cod with the exact moment the 700mb low closes off around the BM and then east of CHH allowing the bands to move more westward than the 00z run.

The 6z run came in stronger with the southern stream system, a better negative tilt towards the shortwave trough and a stronger and a little further northwest track of the surface to 700mb lows, the intensification happens at the right moment to hit Cape Cod and ACK with a foot plus of snow.

6z NAM and 6z 3km NAM both come in hot for the weekend storm threat, now within 60 hours of the onset. Trends could be happening all the way inside 12 hours from the event. Also the water vapor imagery shows the northern stream is really digging southward across Montana.

It seems like the northern stream is trying to phase with multiple shortwaves and the models are having a hard time which one is the one. The puzzle pieces are starting to show their cards and now the next 2 days will need to decide their results. Just a patient game of cat and mouse. It is very comical and very complicated. Two major shortwaves over the southern US and the pattern needs to decide which one phases. The GFS shows a colder scenario, now we just need the earlier phase for our storm to tap that cold and explode closer to the benchmark.

The ridging out west is getting better on the models. 00z CMC/GFS combo were much better at H5 then previous runs, the northern stream really dives in, but is still six hours too late for SNE, while Nova Scotia gets blasted. The 00z CMC deepens rapidly once it reaches the Coast of North Carolina. I believe the track becomes defined within 25 miles west or east of 35N/75W to 40N/70W to 42N/68W

Of course, the statement was using the benchmark track as a guide. As long as the low stays about 20 mile east-southeast of CHH, I am golden for a mostly snow event, with mixing as it makes the closest approach.

00z GFS wants to develop a -EPO in the medium range. Again that would be off topic.

Also if the northern stream becomes the dominant stream for storm development, we will have cold air available for an all snow event.

This morning, I am going to share with you why a snow event is possible and not yet certain.... Why it is possible... NAO is in transition still positive but diving towards neutral slowing duration of the precipitation and storm's movement based upon phasing and capture potential at H5 PNA/EPO coupled ridging over the western CONUS could lead to an earlier phase potential as the northern stream disturbance is shoved southward across the Midwest and OH Valley regions allowing a cold infusion of air before the storm reaches our latitude. -AO transition, as the EPO/PNA ridge builds poleward and allows the northern stream to dig southward across the central US, this also builds into the western Arctic Circle and disrupts the Polar Vortex and the +AO domain and turns towards a -AO domain allowing the arctic jet to become involved in the weather next week producing another chance at a storm or two Again questions remain in the details and eventual A)/NAO domains, we will get help with that in the next 24 hours.

Trends are showing an elongating Alaskan vortex followed by a poleward building PNA/EPO coupled ridge that produces a -Arctic Oscillation and this transition period will continue to freak out the model solutions in the next 24-36 hours and once the northern stream energy gets better sampled we will have a better idea of the kind of phasing that is real. AS a building WEST CONUS ridge continues eastward, this should push the storm track towards the BM or just east of it. I don't think an inland runner is going to be the final track, again not certain, but the way it appears right now that is what it seems like. Oh I wasn't saying the NAVGEM was right last night. My point was that if the storm deepens below 975mb before reaching the 40N latitude, the cold air will be present unless the track is west like over CHH. However, if the storm tracks over the BM instead below 975mb than cold air should be abundant. Also for those worried about the amount of QPF, this should continue to trend towards a bigger QPF event. Originating in the Gulf of Mexico, plenty of moisture should be present and the models should slow the movement of the low down as we head towards closing in on the weekend period. The 12z GFS was only 13 hours of duration for the precip, while the 00z GFS was 18 hours in duration, this should trend towards a longer duration in my opinion.

It is now within 5 days, precip starts on Saturday.

Sub 975 millibar low south of the benchmark or at the benchmark location suggests an early phase and a much colder storm solution overall. This means that whatever precipitation falls on the coastline will likely be snow unless the low tracks over Cape Cod.

Our storm starts to develop within 84 hours over the western Gulf of Mexico and eastern Texas.

Or maybe just an arctic front that stalls and the surface to 850mb flow aligns to northerly or NNW flow.

Yeah perhaps a norlun trough is better.

Signal is growing stronger for an inch at least of snow accumulations on Tuesday afternoon and evening.

When they happen they need a focus for low-level convergence like a front or an inverted trough or they occur as winds align with an offshore clipper.

I remember one six inch event when I was in middle school.

I just want one big bad OES event in my lifetime. Like the one's that hit the Tug Hill Plateau, but I know the likelihood is very low given that the low-level convergence doesn't exist like it does in Buffalo, NY.

any accumulations?