USCAPEWEATHERAF

Yeah it is 36 here too, but our dew point is 26F

12z GEM and 12z RGEM both bring over 1" of QPF to the Cape

Models are leaning towards that secondary low tracking further west, the 12z GFS is off compared to the others

What were the official numbers? Anyone have the archives for this event?

All the short range guidance has come in with over 3" of snow, the 12z 12km NAM is less bullish then the 3km NAM which shows over 6" of snow for CHH. 850mb temps are extremely cold when this norlun like band of heavy snow moves through, could be thundersnow in the heart of the band. We need the H5 upper low to shift about 25 miles southwest.

4"/hour is rare period, but especially on the Cape. Maybe one or two times in my lifetime, Jan 05, and Jan 15

Do you think I am to far southwest for anything meaningful snow wise Thursday night/Friday? 12z NAM went bonkers with QPF over the area.

850mb temperatures will drop to near -30 to -40 C across the SNE region. Cape and Islands could see a nasty band of ocean enhanced snowfall as a large upper low develops a surface low to the east of Maine and drops southeastward. The location of this surface low will determine how close the band can get to the Cape and Islands later Friday. With the massive cold pool aloft, winds will bring a ton of moisture, question becomes how strong will the lift become, and snow growth. Right now, it is a toss up! DAMN!

18z RGEM is quite robust across eastern MA, RI and SE MA.

You know the NAM changed a lot at 18z for the H5 pattern for the 28/29th system. models are leaning towards a more northerly development of the H5 low and subsequent lows to the surface! Stay tuned could trend to a full blown nor'easter phase.

18z NAM trended better for the 28/29th system, even if it means better chances for OES.

Yeah, northwest winds at the surface push the best bands offshore of the Cape National Seashore. One of those events where when I was going to Bishop Stang for high school and rode the bus home to Harwich, there would be these huge ocean effect clouds and every time I get over the bridge I would be excited to see if it was snowing at home, turns out the clouds weren't even close and were far offshore. We need that surface low to move more west. Again the parameters suggest intense instability with delta Ts greater than 22C, strong low-level convergence, and extremely cold air mass. Again we need the surface winds to act properly.

thanks, I know, it is frustrating, it feels like a ten inch plus snowstorm or bust is quite the common theme here, or we get a 3-6" storm that rains.

Man why do I get rain in this scenario?

So it must be the progressive flow that is shunting the upper low southeast to the east of CHH instead of south of LI. Because couldn't the block insist on shunting the upper low to the south of LI? Also couldn't the tug of the southern stream system cause the upper low to move more west and south of LI?

Will, the models bring that H5 low to the south of the region, problem is, the upper low is too transient

I am thinking that an upper level low that intense will deliver some insane snow bands over the coastline. There is room for the storm on Thursday to shift northwest some still. As our first low develops a secondary low off the Delmarva, the blocking pattern slows the storm down offshore, and as the primary weakens and is brought to the coastline and south of LI and ACK it leaves a weakness in the overall surface pattern. The models today compared to 12z yesterday all showed a slower southern stream and a faster movement of the Polar vortex to the southeast. Now a few stronger trends to a closer interaction we could see the monster low develop closer to the benchmark and with such a large upper circulation present snows could develop hundreds of miles northwest of the low. I just think 72 hours is enough time still for changes to occur.

I mean the PV lobe is catching up slowly

12z RGEM is trending towards a full phase of the 29th system. Stay tuned!

Man....

Will I believe here for KBOX CWA its 6: in 12 hours or 8" in 24 hours for winter storm warning criteria to be met. Remember that NYD's event sometime in the past ten or so years that retrograded back in from Nova Scotia, and places along the Outer Cape got 11-12" while parts further west received a lot less? We could see amounts increase further east as we get within the 48 hour period for Friday. So tomorrow's 12z runs!

That is not shredded at H5

Will, that phase is just late on the EURO and most guidance now want to involve the entire PV lobe and the phase is just late. The big news to take away from today's runs, is that the PV is getting involved, now we need it west and then southwest or complete capture and phase with better timing. Man that ridge out west flexes its muscles as the PNA rises.

Every piece of guidance skews the southern stream because they are infusing the PV lobe into the shortwave troughing that becomes a longwave off the coast. Previous runs were trying to figure out where this lobe would locate itself over the next few days, they are not set on one location and therefore the PV lobe will continue to migrate in each direction until the models can determine the puzzle it presents. Honestly, I am beginning to lean towards a bigger phase potential because as Tip mentioned previously, the PNA is rising towards the 30th and the NAO is rising as well, so the block will recede some towards the end of the month in this timeframe. The PNA rising will allow the trough to slow down its progress like the RGEM and NAM have been showing towards Day 3.

Tip, I think we are leaning towards a potential full phase of the PV lobe with the southern stream system. Has there ever been a scenario where the PV phases with the southern stream?