USCAPEWEATHERAF

Oh all we have now is rain, which is expected. We will see things dramatically change as the upper level low hits the ocean off of HSE or VA Beach and the surface low goes through bombogenesis.

The south trend favors the Cape and Islands, Long Island, Block Island areas. This is where I expect the heaviest snows to occur. The storm bombs either south of the benchmark and travels northward from there to a fifty miles east of CHH.

Could this be a repeat of the December 20th, 2010 Event?

Latest update on the 00z UKMET?

Ray, the QPF max is just north of Provincetown, MA

Ray, there is still enough uncertainty for this round 2 event that you shouldn't expect anything one way or another.

GFS was better for Cape Cod

very true

18z EURO looked better for the Cape and Islands, potential blizzard conditions and 6-12"

Yeah I just figured it out, thanks for the correction, the energy over MO is the one that slows the precip down and actually enhances convection, but the short wave over ERIE is the one that is the catalyst for the secondary bombogenesis tomorrow night.

It is over ERIE?

Right now, the disturbance in question for round 2 is the area of energy over eastern NE and western IA at this hour. Clearly seen on WV imagery. Where the upper level energy catches the surface low will determine where it blows up rapidly and where the best most intense snow rates occur. If it is captured southeast of ACK, Cape and Islands will see a lot of snow and blizzard conditions, but if the capture is later more like south of Nova Scotia and Boston region gets the most snows. When the storm explodes as the upper level disturbance catches the surface low bombogenesis occurs and turns any remaining rain over to a heavy wind blown snow.

I would say the coastal front is the on the west side of downtown Boston right now, northwest winds in the western suburbs, while there is northeasterly winds on the east side of the city.

It started raining about a half hour ago, around 3pm. We have SSE winds, temp at 39F. Ocean temps are near 9-10C. expecting mainly rain tonight into tomorrow afternoon. Not sold on the snow potential with the HIRES NAM 3km showing it off shore and not as close like the 12z EURO had. Our secondary low is developing over Ocean City, MD region, down to 997mb, the parent surface low over the OH Valley is weakening at 1mb/hour pace.

I am really concerned for travelers on Monday night into the overnight and into the Tuesday afternoon period, snow could be heavy with strong winds.

The latest cycle of the 12z model set has led to a high and very large uncertainty for forecasting SE MA and RI weather for Monday night into Tuesday afternoon. The cycle was spilt down the middle, one side shows a potential major impact of snow and wind for the area then, but the other set as the secondary low taking off to far east and southeast and has a very little impact on the area for snow. Right now, there is a less than 40% forecast confidence in any direction. This is very poor for this range. Update on the 18z model cycle.

Final Snow Map issued. Round 2 has a lot of evolution questions right now and is not smart to try and determine what happens there. long duration Nor'easter. Dangerous weather impacts likely ahead.

18z GFS was colder for the Cape on the front end thump, still lack of a backend flip over. The afternoon SREFs were getting bullish on the back end like the EURO.

Yeah the last time it materialized was Feb 8-9th 2013 Nemo.

I am really concerned for Cape Cod and the comma head precipitation that could turn to an all out 6-12 hour blizzard as the mid-level low passes to the east of CHH.

Tonight's update shows that a cold rain looks likely for most of the Cape and Islands for Sunday night into Monday night and Tuesday. I am sorry for those snow lovers on Cape Cod, this is not our storm. There are still plenty of questions on the second part of the nor'easter, it seems like it could bring accumulating snows to the area later Monday night into Tuesday if the air mass is cold enough.

thanks Hoth

I'm convinced this a huge rain event for the Cape.

Will need to watch the ice precipitation and mixing that occurs inland, as the cold air damning situation looks quite strong in the area. Northerly wind drainage with 850mb or higher flow out of the southwest will warm the low to mid level elevated levels, while the immediate surface could be quite cold.

The key for this evolution of the storm for the NYC metro region is the H5 energy that hangs back along the trough axis closer to the NJ coastline. The trough elongates as the primary low reorganizes off the NJ coastline and gets ejected northeastward quickly, then as the energy hangs back to the southwest the low develops southwestward towards DE and NJ and then prolongs the event so it cools down enough for snow on the second low.