LARGEST & STRONGEST NOREASTER IN SEVERAL YEARS TO HIT THE EAST COAST SUNDAY- MONDAY

I have been so busy today with so many different things, I haven’t had a chance to actually check the recent records but it seems to me that the developing Coastal Nor’easter that which is going to slam the East Coast on Sunday and Monday from Georgia to Maine is probably the strongest and largest Nor’easter in several years. Perhaps in over a decade. I can qualify that even more by looking at recemt Decembers — he last time I saw a storm this strong on the East Coast in December was the December 18th and 20th historic snow storm that hit the Mid-Atlantic back in 2009.

As I stated on the Facebook page and on the Twitter page (@wxrisksnowstorm) the track of the system is absolutely perfect and ideal if you wanted to deliver a major snowstorm from Western / central North Carolina to New England. except in our case there is no cold air anywhere east of the Rockies across the CONUS

The overall jet stream pattern across North America is one typical of strong El Nino in December pattern. There is very little substantial cold air across the CONUS or southern Canada. But the pattern remains rather active. The map BELOW Is valid early 12/17. It shows two distinct pieces called “Short Waves” S/W). One will be in the Dakotas and the other in MO. The map on the LEFT is valid early 12/17. It shows two distinct pieces called “Short Waves “ (S/W). One will be in the Dakotas and the other in MO. The Map of the RIGHT, valid early12/18 shows the northern S/W located in ILL and the southern S/W in the Gulf Of Mexico. The two S/W are going to merge or phase and produce the severe Noreaster / East Coast rainstorm.

The surface maps valid 12/17 show the initial LOW pressure area intensifying as it moves out of the northeast Gulf of Mexico across northern FL, and along the GA/ SC coasts. Strong SE winds will feed moisture from the Bahamas and the southwest Atlantic into the Southeastern states, the Mid-Atlantic , and New England as the intensifying LOW pressure area moves up the coast .

By late Sunday night or Monday morning, the complete phasing of the two different pieces of energy or Short Waves will be underway. Whenever this kind of event happens on the East Coast in the upper levels of the atmosphere, it always indicates a major East Coast winter storm.

The image on the LEFT is valid early Monday morning. The initial LOW in eastern NC is beginning to transform its energy into a new LOW in New jersey. By the middle of 12/18 both LOW pressure areas have merged into a large system off a New Jersey coast.

If this was the middle of winter AND and if … IF… there was adequate cold air around, this system would result in a historic East Coast snowstorm with possibly blizzard conditions from VA to ME.

By the afternoon of 12/18 this very strong large LOW- pressure area will be located in central and northern NH for Maine. Often when there is a large LOW like this which brings rain to the East Coast, the precipitation will change to snow in the mountains of the Middle Atlantic, NY and New England. But in this instance that does not appear to be the case as the cold air does not make it into the circulation of the coastal LOW in time. The only the moderate to heavy snow showers will fall across the Great Lakes into western PA., western NY and WV.

RAINFALL AMOUNTS — Note the THICK BLACK lines on the GFS and the ECMWF — it represents the 1.5 inch rainfall line. Rainfall amounts drop off precipitously to the west of the line. his is connected to the track of the coastal LOW. If the coastal LOW were to further inland, heavy Rain amounts would push deeper into the Appalachians.

Taking these models verbatim we can see large areas of 1–4 Inch rain amounts in eastern GA, most of the Carolinas, most of VA, much of MD, central and eastern PA and northern NJ / NYC in the eastern half of NY.

WINDS
when the LOW is “bombing” out and reaches Max intensity wit will have Mx winds GUSTS to 70mph — near Hurricane force. But the issue is whether these winds will be on the coast — as the GFS model says OR just offshore — as the ECMWF says.