4/15 ,16 and maybe even 17 NOR'Easter

[cpdaman]

hi guys i know don is the man around here with predictions and he is a wealth of knowledge but i would like to make some estimates as well


the upcoming situation as of 1230 am friday early morning appears to have a low coming out of the southeast late saturday and heading up just off the coast rapidly intensifying as it moves steadily northeast. most models seem to have it just off new jersey coast and setting up shop just south of long island late sunday nite and then the interesting part begins.

first there is no impressive high forecast to be north of the region, so strong easterly/NE'ly winds will not be a problem that far ahead of the storm (imo)

wether the storm moves northeast up through eastern new england or slides east south of long island or does some weird loop around and off long island monday and after remains to be seen ( obviously the storm isn't even out of the rockies)

but it appears there is (IMO) a chance of significant spring snow event in the mountain of west virginia, MD, the pocanos of pennsylvania, the berkshires, and also in the elevated areas of south central NY ( as in a couple FEET of snow)

near the coast it appears to mild for snow possibly some sleet especially later on monday if the storm moves east or loops South east, but at this time i don't see the bigger cold pool necessary for a significant changeover below 1000 feet in new england, however Worcester will likely be on the fence.

winds could be pretty fierce and the highest tide of the season is on monday evening/nite so the flood threat must be monitored from NJ up through southern new england. buckle up

p.s severe weather will break out as well

[boca]

I think this might be a rain event for the NE because the NAM and GFS are saying the low will be inland during its entire track. This was out of MT Holly.

.LONG TERM /SUNDAY THROUGH THURSDAY/...
PRECIP IS EXPECTED TO BE ONGOING, AND POSSIBLY HEAVY DURING MOST OF
SUNDAY AND WILL RAISE POPS TO CATEGORICAL. THE MODELS ARE
CONTINUING THEIR TREND OF A MORE INLAND TRACK. BOTH THE NAM AND GFS
KEEP THE LOW OVER LAND DURING ALL OR MOST OF ITS LIFETIME THROUGH
THE CWA. THIS WOULD ALSO BE A WARMER TRACK WHICH WOULD KEEP THE
THREATS OF ANY WINTER PRECIP MINIMIZED, EXCEPT FOR POSSIBLY OVER THE
POCONOS AND EXTREME NORTHERN NJ. THE GFS IS SLOWER ENDING THE
PRECIP AS WELL, BUT STILL HAS MOST OF IT OVER BETWEEN 06Z AND 12Z
MONDAY. HOWEVER, THERE IS STILL QUITE A BIT OF UNCERTAINTY WITH
REGARDS TO THE FINER DETAILS OF THIS SYSTEM, AS THERE WOULD BE WITH
MOST SIMILAR TYPE STORMS. UNTIL THERE IS SOME MORE MODEL
CONSISTENCY, WILL NOT MAKE ANY MAJOR CHANGES TO THE CURRENT TRACK.
TEMPS WILL BE CHILLY AS THE LOW PULLS AWAY, AND THERE COULD BE SOME
SNOW SHOWERS WITH THE INSTABILITY FROM THE UPPER LOW.

[cpdaman]

thank you for the above post

and here's why

there seem to be 2 camps with the models this morning (and some weather service locale's are basing there forecast on the coast hugger track (mount holly fri morn) which btw has switched as of 5 am sat morn to support more of a compromised track is still supported by NAM and GFS and some (taunton ma and albany NY )are basing there's on the slower and coastal track based on the canadian, ecmwf and ukmet

the first set as you mentioned want to track the low inland up the coast and bring it up as far as west central New england

the second bring the storm up just over or south of central/eastern long island and then weaken and drift it offshore ESE monday nite-wednesday

the inland scenario storm like this would not become as strong and also would not produce as much snow

the coatal would be much worse in terms of danger

THE FACT that the NWS is known to play it safe makes me lean toward the inland coast hugger scenario coupled with the fact that the progs across the deep south already have the storm more north than previously forecast (mobile al 9am disc) however the latest trends as of ( the 5 am across NE) call for the storm to be off/over/ central long island sunday nite so to sum it up (THERE is an unusual amount of uncertainty over the strength and track of strom as well as timing.

so in effect as of now (and this could change) i don't see this as a (once ever 5 year storm and more a run of the mill nor'easter)

as a result i think the heaviest snow will fall over the east slopes of the northern vermont mountains (2 feet good bet) as well as NW maine north NH as well as the syracuse to binghamton corridor, (the pocano's are a toss up to me) (right now i don't see berkshires doing well on what i feel will be a coast hugger that goes further north and generally a weaker storm and slightly west track (like over NYC).

p.s 11 am the lack of gulf moisture entraining into this system now and further north track makes me rather unimpressed with this storm especially compared to yesterday)

[cpdaman]

well the forecast centers have read the 12z model runs and NOW the taunton/albany centers have SWITCHED and went with guidance of the GFS/NAM which brings the low up on the INLAND track and up to albany monday

thus snow fall over pocano's if any will go over to rain berkshires snow if any will go to rain main snow should go to rain except NW portions

so Northern vermonts eastern slopes should still get slammed

and since storm is track further north across the tennessee valley and is also forecast to take a more inland track i wonder how brief a period and where this thing will reach the coast

haven't seen any discussion calling for parent low to transfer energy off to secondary low / but instead they call for parent low to strengthen on account of two things

1. reaching a more moisture rich enviornment (the ocean)
2. and more interesting a closed upper low that is over northern new england is supposedly splitting with one piece going north east of maritimes (out of the way) and the other developing over eastern ontario especially as it interacts with short wave diving across candadian praries. ok now it is when this developing closed low over SE ontarion is supposed to dive south east and meet up with the "mid atlantic low" and begin phasing that the explosive development is supposed to take place

based on this scenario i think the possibility exists for the storm to A/ never really get out over the water before exiting tuesday and B/ be a major flooding threat for parts of central newengland that have a good snow pack especially over west central NH and east central vermont AS THERE SHOULD BE MORE PRECIP in western newengland than eastern new england based on a low stationary over NYC-to ALBANY if not even further west)

north vermonts eastern slopes above 3500 feet should get blasted by this storm but other mountainous areas of new england could go over to rain monday as storm shoves midlevel warming up thru central newengland

i think coastal flooding will be a big concern around NYC and long island thru the SOUTH COAST of new england like eastern CT and especially RI as opposed to the eastern mass area

but again this is based on the phasing of the new developing closed low over se ontatio combining with a storm that will or will not ever make it to the east coast (could stay just west of NJ COAST) if it hits the coast and combines with SE ontario low then we will have a problem

[cpdaman]

there has been a large elongated area of low pressure today that built northward while it has slid eastward presently stretching from southern indiana thru extreme SE louisian

pressures are running generally 29.60-29.70 on a line from new orleans N thru evansville indiana

during mid afternoon (per NOAA wakefield, VA discussion) a new low was initialized across the deep south around JACKSON MISSISSIPPI

this appears to be the main low that will track across the gulf this evening and through the south east overnite and then enjoy some "BOMB-O-GENESIS" as it hits the coast as some energy (shortwave) from the northern branch is supposed to slide down and phase with the system about 30 miles off the new jersey coast (new model updates at midnite will be critical for snow forecasts)

still calling for northern vermonts east facing slopes to get dumped on 2-4 feet while the rest of new england mountains except for extreme N. new hampshire and NW maine start as snow but change to a prolonged period of rain before transitioning back to snow from NW to SE if the low does a loop as it feels the block out ahead of it.

snow estimates are very difficult because of the time of year and very marginal temperature profiles but it appears that snow fall will be over north central new york up thru nw vermont (with the bullseye) being the east facing slopes

[cpdaman]

2 am update

current trends snow is breaking out over the western half of southern new york state on a line from binghamton west tp elmira up to syracuse and back east to the nw of albany especially in elevated areas above 800 feet. there is a big slug of moisture to pass tonite before the warm air off the atlantic has a chance to encroach upon the mid levels so over the next 6-7 hours there could be snow rates close to an inch or two an hour in those elevated areas. tomorrow it may go to rain in the central portions of southern newyork due to heating of the day while western and northern new york enjoy snow as a tad bit cooler air works in.

the elongated area of low pressure seems to have the low across the deep south (the previous jackson miss low) around central georgia NOW with the lowest pressure on the east coast i can find of 29.48 at lawrenceville, GA as well as a developing line of t'storms east of panama city stretching 150-200 miles south into gulf with a couple storms also popping ahead of this line as far south as tampa

wonder if models have initialized the southern part of the elongated low pressure area (the shield of precip over GA, SC, NC) as well because this is a long tracker moving NE thru sc nc and va tonite and then up the coast while there is a HUGE shield of precip out running this low over PA, MD, NJ, NY could be some surprise snow over the berkshires tonite into 10 am tomorrow esp over 1500 feet

[cpdaman]

7 pm SUN

ok first this storm has not reached it's peak and we have pressure falls down to 28.90 just off the SE coast of VA we have a large area of elongated low pressure off of se NJ, DE, outer banks and SE VA.


ok before i get to the rest of the story for this potent storm which has yet to reach it's potential but i beleive it will just after midnite tonite

to recap today

NYC has seen over 5 inches of RAIN SE PA and parts of NJ have seen 3-4 inches of rain as well with isolated 5 inch RAIN amounts

Ashland, MA has seen 8 inches of heavy wet snow and they are raining/sleeting now with a temp about 34 degrees, ashland has a very complex forecast ahead

BOONE, NC had temperatures fall from the 50's this morning to 32 this afternoon and i saw on there web cam white out snow blanket the area from 3-6 pm VERY cool

the short wave pivoting around the southern periphery of this trough (that gave boone and sw virginia mountains snow ) is sliding nearly due eastward centered along the north carolina and virginia border and is interacting with the broad but powerful low that runs mostly N-S from outer banks NC north to just east of central NJ)

over the next few hours it will be interesting to see how the storm becomes energized by this intense short wave sliding east phases with the low

HOWEVER alot of DRY AIR Is being entrained into the storm and i think this trend will continue and expand coupled with the fact the storm is supposed to stall over NYC (and i have doubts that it gets that far north anyway although it may be further west)

it appears this dry air will cut down on the snowfall amounts over pennsylvania and sw newyork BUT the dry slot over NJ may fill in as the low consolidates and there is more of a easterly component off the water there. time will tell. and oh by the way northern vermonts getting killed and so are the adirondacks of north and north central new york it appers to me some where in the adirondacks they will see 40 inches maybe more

[cpdaman]

830 IMPORTANT OBSERVATION

THE models seem to have been initializing the closed low over ontario as sliding se and meeting up with storm over nyc

THIS aint gonna happen closed low slid ssw and into northern lower michigan

dominant short wave over northern north carolina southern virginia is running the show NOT The closed low over ontario. I am not a pro met and i can't use the lingo to say exactly what the implications of this are exactly but i can take an obvious guess

i can't see the storm heading north to NYC tonite i think the low will be elongated but consolidate from southern NJ to offshore SE virginia and drift north north east so that the northern edge of this elongated low reaches just off the northeast jersey coast down to se delaware late tonite.

which means watch radars for snow/rain to fill in over central and eastern pennsylvania respecitvely over nite. snow will turn to rain in eastern maine but places like central and east central pennsylvania could be in for a surprise blizzard also central parts of western new england may go back to snow with the northern berkshires also an interesting forecast

there is however a lack of cold air to work with an as time moves on warmer mid level air will work around system which will consolidate in the early morning hours and bomb out just east of atlantic city NJ / 150 miles south of long island

THIS southern adjustment is NOT ETCHED in stone yet and it may as well be further west ;=sw

[boca]

I think the low now is South of Long Island. When was the last time you saw a pressure this low other than a tropical system.

http://www.erh.noaa.gov/forecast/MapCli ... &map.y=209

[btangy]

When was the last time you saw a pressure this low other than a tropical system.

There was a 928mb extratropical storm over the N Atlantic in early December I believe. That was the strongest extratropical storm I've ever seen. Don't know if I saved the OPC analysis of it, but it was quite incredible.