Significant Nor'easter to impact Northeast...

By: Zachary Labe , 7:35 PM GMT on February 06, 2013

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Zachary Labe
Posted: 6 February 2013

A northern stream influence will phase with another disturbance out of the southern stream and subsequent cyclogenesis along the New England coast is anticipated during the February 8-9 time period. Significant storm impacts will occur from western New York east to Cape Cod. Given the late redevelopment and associated Miller B-type storm formation, many areas south of the 40N will see little impact from this event. Slow movement and impressive mesoscale banding will result in snow accumulations in excess of two feet for some areas just west of Boston. While too early to declare this a KU event, the entire situation is definitely worth monitoring over the next few days with potential NESIS ratings likely on the order of 2-3.

Current Surface Plot...

(Courtesy of HPC)

February 8-9 Nor'easter
A quick hello after a short hiatus from blogging over the past few weeks; I know many of you are still waiting to hear my thoughts on the American Meteorological Society conference. Eventually I will get around to writing up a quick summary for those interested. Nevertheless, it was a necessary to provide an immediate full update on what will be a very significant nor'easter to impact the Northeast. Blizzard conditions will likely occur across much of the densely populated portions of eastern Massachusetts including the Boston metropolitan region.

The complex and impressively large storm system will build itself in a series of critical puzzle pieces that will fit together to east coast cyclogenesis. A northern stream wave, which is already evident on radar across the northern and eastern Midwest will continue tracking south and east. This weak surface low (not even evident on some surface maps) will track across southern Ohio. A weak H85 low will be associated with this wave and will move into Pennsylvania and extreme southern New York. Therefore WAA at the surface will likely occur under southwest winds despite a strong banana high pressure system to the north. As the northern stream begins to interact with the moisture-filled subtropical jet, another low pressure will begin to take shape off the North Carolina coastline. This is a very typical Miller B type storm evolution.

The low pressure will begin to rapidly deepen and expend its precipitation shield inland. Isentropic lift and weak frontogenic forcing ahead of the S/W in Ohio will spread light snows across western and the southern tier counties of New York State by Thursday night. This precipitation will be primarily driven from the northern stream system. Guidance is suggesting a small window of bombogenesis with pressure falls ~3mb/hr as surface pressures drop to 988mb south of Long Island, NY. A track just inside the 40/70 benchmark is then expected.

Precipitation will be falling in two distinctive shields. One across New York State and the other expanding in the Delmarva with the coastal low. Eventually as the phasing occurs (timing remains uncertain), the radar will take on a different graphic with a strong dominant deformation axis from central New York that will slowly move east spreading heavy snow in its path. There will likely be a large dry slot that will form to the south and east of the deformation axis. It is likely this will impact most of the state of Pennsylvania. As will be noted below, there are a few signs on the latest guidance that this dry slot could impact areas as far east and north as New York City and the Connecticut river valley.

The low pressure will continue trekking northeast and develop several impressive mesoscale bands associated with the CCB axis from New York City northeast to Boston. Guidance suggests high Omega values and near-ideal snow growth with a low, moist dendritic layer. H85s will primary focus around -10C providing an additional support for excellent snow rates during the height of this storm especially for areas just inland towards Worcester, Massachusetts. QPF will likely exceed .5" in a small three window for some areas of central and eastern Massachusetts with therefore associated snow rates exceeding 2"/hr. Elevated instability will be possible along the highest frontogensis and PWATs axis again focused in central areas; therefore thunder snows cannot be ruled out. This signal though may grow as we get closer to the event and 4km HIRES models have a better look at the banding impacts of the storm.

A few current models indicate that as the low becomes vertically stacked, that it may stall for a period of time. It is likely this is an over-amplification error. Therefore the QPF amounts >3" are likely irrelevant to this event. In general the jet flow is still relatively progressive and inhibits these classic KU characteristics.

A widespread and uniform moderate snowfall will occur from western New York east and north to the northern Maine with 4-10" of snow. The best forcing will be south and east along with the best snow growth. Closer to the tightly wrapped east coast low will be an axis of very high snow amounts that may approach two feet in some areas. The highest QPF and snow will likely fall near the Worcester region.

A few concerns of mine still exist for this event. Given the progressive flow if the phase capture occurs a bit later, the secondary low will form farther northeast. Therefore the dry slow will approach the tristate region into portions of even eastern Connecticut. This would also limit the higher snowfall amounts across the southern tier of New York allowing for more WAA as 2m temperatures warm into the mid 30s. Also the exact location of the rain/snow primary lines, especially towards New York City, will be highly dependent on the strength of the deformation axis/CCB. Therefore a high bust potential exists in this region. A few days remain before the event, but by Thursday evening WAA snows will already be moving into western New York. Stay tuned!

Regional Radar...
(Courtesy of Intellicast)

Regional Advisories...

(Courtesy of NOAA)

This is my current rain/snow line...
Pittsburgh, PA - State College, PA - Wilkes-Barre, PA - Mt. Pocono, PA - New York City, NY - New London, CT - Hyannis, MA

***For this event there will not be one defined snow line. Also little to no mixed precipitation is expected given the setup therefore limiting precipitation types to either rain or snow. I chose my line based on a 75/25 split with >75% being snow as the majority precipitation for areas along and north of the line. Therefore while areas will mix with rain to the south, some snow accumulation cannot be ruled out especially for areas in the deformation axis as the system begins to pull northeast into the Gulf of Maine.

Storm Reports...
None.

Storm Impacts...
1. Widespread snow accumulations possible in excess of 10" from Buffalo, NY east to Boston, MA.
2. High, damaging winds anticipated along the immediate coast with gale force gusts in excess of 55mph particularly along Cape Cod.
3. Rain/snow mix can be expected in a narrow corridor along the southern periphery of the deformation axis. This may impact the NYC metro area.
4. High snow rates can be expected with model output suggesting up >6"/hr totals for a 3 hour period in New England during the height of the event.
5. Major impacts along I-95 corridor north of 40N where few winter storms have occurred this year to prepare people for winter driving conditions.

Snow Map...


***Snow map posted 3pm 2/6/2013. This snow map is preliminary due to its early posting, but should give a general idea for most locations where the heavier snow will occur. My favored axis for two feet potential is just west of Boston towards the Worcester corridor where high snow rates and excellent snow growth will occur in correspondence to the impressive CCB band. A more difficult forecast for New York City is likely where they will be very close to a dry slot and warmer temperatures. In the end my forecast does abide by a colder approach give the dense air mass over the region and a bit of snow cover. Therefore I am extending some light snow accumulation as far south as Philadelphia where they may see the tail end of the deformation axis. The dry slot will significantly inhibit snowfall over the Middle Atlantic including Maryland, Washington DC, and central Pennsylvania. Warmer temperatures at the surface will also prevail in this region. Nevertheless it is possible for light snow accumulations as far south as the Mason-Dixon line.

Current Great Lakes Water Temperatures...

(Courtesy of NOAA)

Selected City Accumulations for the Northeast...
Hagerstown, MD- Light to moderate rain
Baltimore, MD- Scattered rain showers
Salisbury, MD- A few rain showers
Pittsburgh, PA- Rain/snow showers. Snow accumulations up to 2-3"
State College PA- Rain/snow showers. Snow accumulations 1-3"
Williamsport, PA- Periods of snow mixing with a little rain. Snow accumulations 2-4"
Altoona, PA- Rain/snow showers. Snow accumulations 1-2"
Harrisburg, PA- Rain/snow showers. Snow accumulations T-2"
Lancaster, PA- Rain/snow showers. Snow accumulations T-2"
Philadelphia, PA- Periods of rain mixed with occasional heavy snow. Snow accumulations 2-4"
Allentown, PA- Periods of heavy rain/snow. Snow accumulations 3-6"
Scranton, PA- Periods of heavy rain/snow. Snow accumulation 3-7"
Washington, DC- A few rain showers
Wilmington, DE- Occasional rain/snow showers. Snow accumulations 1-4"
Dover, DE- Occasional rain showers
Trenton, NJ- Periods of heavy rain/snow. Snow accumulations 2-5"
New York City, NY- Heavy snow occasionally mixed with rain. Snow accumulations 3-7"
Poughkeepsie, NY- Periods of heavy snow. Snow accumulations 4-8"
Binghamton, NY- Periods of heavy snow. Snow accumulations 5-10"
Ithaca, NY- Periods of heavy snow. Snow accumulations 5-10"
Albany, NY- Heavy snow and gusty winds. Snow accumulations 10-14"
Hartford, CT- Heavy snow and strong winds. Snow accumulations 10-15"
Concord, NH- Heavy snow and strong winds. Snow accumulations 14-18"
Providence, RI- Heavy snow occasionally mixed with periods of rain. Snow accumulations 10-14"
Worcester, MA- Blizzard conditions expected. Snow accumulations 15-20" with localized higher amounts
Boston, MA- Blizzard conditions expected. Snow accumulations 12-15" with localized higher amounts
Nantucket, MA- Periods of rain mixed with heavy snow. Snow accumulations 3-7"
Hyannis, MA- Periods of heavy rain/snow. Snow accumulations 4-8"
Burlington, VT- Heavy snow expected. Snow accumulations 8-12"
Portland, ME- Blizzard conditions expected. Snow accumulations 14-18" with localized higher amounts
Bangor, ME- Periods of heavy snow. Snow accumulations 8-12"
"Subject to Change"

Current Northeast Snow Depth and Northeast Wind chills...

(Courtesy of Wunderground)

Model Analysis
A few computer model differences still exist especially in regards to the evolution of the phasing of the northern and southern streams. The extent and timing of this is critical for forecasts. Currently the NAM is the flattest piece of guidance despite the overly excessive QPF progged once the storm moves east of Cape Cod. 3-4" storm totals will not be occurring anywhere for this event; I do not buy into the storm stalling and being captured theory. I also believe the ECMWF is having a few QPF issues in the extent of the western periphery of the 1" range in New York state. Also it is currently running as the coldest model with 2m temps <0C as far south as the Mason-Dixon line during the start of the event. It is likely there will be enough WAA to allow temperatures to rise into the mid 30s as far north as Williamsport for a short period.

Globals will struggle with the exact positioning and cut-off of the dry slot. I would expect this region to be larger than anticipated on guidance and pose a significantly wrench in forecasting efforts for portions of the Middle Atlantic. In general not many other model contrasts exist at this point as it is a bit too early for HIRES 4km runs.

After the Storm
Quieter weather and little in the way of lake effect snow is likely for the period after this event. We will begin to see the ridge axis slide east across the central United States allowing for milder air to slide in across the east coast. Nevertheless, the air mass only remains marginally above normal so a torch period is not expected. A low pressure will track up through the Great Lakes for the beginning of next week. Some cold air immediately at the surface will allow any rain to fall as freezing rain especially for areas along and north of I-80. Eventually the precipitation will change to all rain north to the Canadian border. QPF amounts will generally be light and less than 0.5" for all areas. The next storm system of interest impacts the region on Valentine's Day. This event poses a bit more of a threat for wintry precipitation. Current wavelengths suggest though that precipitation type will be a problem for some areas at the minimum. At this point a significant east coast snow storm is not likely, but some areas of moderate to heavy snow accumulations are possible. February continues to look farely active with a top heavy northern stream. In response periods of dry, cold air such as that which occurred in January will not affect the Northeast this month. Snowfall accumulations may average near normal for many areas along and north of 40N this month. Again the general circulation is fairly similar to an -ENSO despite the conflicting teleconnections. I will post a new blog as soon as I can towards this coming weekend.

Please post storm reports in this blog from across the Northeast during the winter storm and please post location of observation in each report...

This blog is in progress. Check back soon...

Follow my 24hr forecasts on Twitter... Link and Facebook... Link.

Lower Susquehanna Valley Doppler...

(Courtesy of WGAL)

"10mi northeast of Harrisburg 2012-2013 Winter Statistics"
(Snow Stats)
Monthly Total (October)- 0.0"
Monthly Total (November)- 0.8"
Monthly Total (December)- 9.5"
Monthly Total (January)- 5.8"
Monthly Total (February)- 1.8"
Seasonal Total- 18.1"
Winter Weather Advisories- 6
Winter Storm Warnings- 0
Ice Storm Warnings- 0
Blizzard Warnings- 0
Freezing Rain Advisories- 1
Winter Storm Watches- 0

(Temperature Stats)
Lowest High Temperature- 32.1F
Lowest Low Temperature- 18.2F
Wind Chill Advisories- 0
Wind Chill Warnings- 0

(Snow Storms Stats)
First Trace of Snow - November 24 - Lake Effect Snow Showers
First Measurable Snow - November 27 - 0.8" - Overrunning event
Enhanced Clipper - December 24 - 2.1" - Christmas Eve Snow!
Miller B - December 26 - 3.3" - 0.15" of freezing rain also
Miller B - December 29 - 4.1" - Moderate all snow event
SWFE - January 15-16 - 1.0" - Snow/sleet/freezing rain/rain
Arctic Cold Front - January 21 - 0.5" - fluffy snow
Weak southern disturbance - January 25 - 3.3" - snow ratios above 20:1
Great Lakes Cutter - January 28 - 1.0" - snow/sleet/freezing rain/rain
Alberta Clipper - February 2 - 1.0" - very light snow

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This is not good news:

COASTAL FLOOD WATCH

* SEAS...WAVE HEIGHTS OFF THE COASTS OF NEW JERSEY AND DELAWARE
ARE FORECAST TO BUILD AT LEAST INTO THE 8 TO 12 FOOT RANGE FOR
FRIDAY AFTERNOON THROUGH SATURDAY MORNING.

* IMPACTS...NUMEROUS ROADWAYS WILL FLOOD AND MINOR TO MODERATE
PROPERTY DAMAGE IS POSSIBLE. THE TIDES AND WAVE ACTION WILL
RESULT IN MODERATE TO SEVERE BEACH EROSION.
Member Since: September 26, 2011 Posts: 105 Comments: 24566
In my experience i have noted when offices hold off on updating that they are considering significant forecasting upgrades - and before doing that - they want to be, got to be, convinced they are doing the right thing.

If you like big storms, the delays are usually an indication they see something, are really pouring over the data, and will upgrade.



Yes, the latest ECMWF tends to indicate virtually no changeover from central NJ northward... we need continuity on that but EVERYTHING seems to have trended colder and stronger this afternoon.

Flip flop? Significant pattern of change? I don't know. It's been so wishy washy...
Member Since: September 26, 2011 Posts: 105 Comments: 24566
ECMWF wowzers! Is this indicating no changeover to rain at all? I mean given the totals with a secondary bullseye over NYC Metro and LI I would be inclined to think so. I am surprised as P indicated that there has been no update whatsoever from Upton. It aint 630 anymore dudes its 3 PM, lets go.
Member Since: October 29, 2011 Posts: 0 Comments: 96
12Z ECMWF looks stronger and colder.


Sounds like they were waiting for it's support before upgrading some forecasts in the borderline areas.

Well, it's in, and it's a doozy.


What will the forecasting approach be now?

Member Since: September 26, 2011 Posts: 105 Comments: 24566
Got to say Mt Holly is handling their discussions well for this event. If only they did this all the time.



WE`VE LOWERED MAX TEMPS TOMORROW AND ADDED MORE SNOW DURING THE
DAY I78 NORTH. WE HAVE SEEN THE RGEM THROUGH 48 HRS AND IT BASICALLY
CONCURS WITH A COLDER SNOWIER APPROACH...CERTAINLY I80 NORTH IN
OUR CWA AND POSSIBLY I78 NORTH. THE 12Z GFS AND 09Z SREF SUPPORTS
HEAVIER SNOW AMTS NNJ AND NE PA. THE 12Z UK IS MUCH FURTHER EAST
AND BOTHERSOME WHEN ITS NOT PART OF THE REMAINING CONSENSUS.

THE EVENT THEN DEPENDS ON PHASING OF THE GTLKS SHORT WAVE WITH
THE FEEDER WARMER SHORT WAVE MOVING OFF THE MID ATLC COAST. ALL
DELICATE AND SUBJECT TO CHANGE BUT ITS SLOWLY LEANING...COLDER
AND SNOWIER...TALKING """"POTENTIAL"""" FOR MORE THAN A FOOT AND
DRIFTS TO 3 FT FAR NNJ ALONG AND N OF RTE 80. WE HAVEN`T ISSUED
THESE KIND OF FCSTS YET AND ASK THAT YOU WAIT BEFORE GOING FORWARD
WITH THIS AS MORE LIKELY DETERMINISTIC SCENARIO. WE NOW HAVE THE
12Z RGEM/NAM IN CONCURRENCE WITH THE 00Z EC AND 09Z SREF AND THE
THE 12Z GFS TO A LESSER DEGREE BUT STILL IN THE BALLPARK.

THIS LOOKS TO BECOME A MAJOR SNOWSTORM FOR FAR NNJ...WITH 1 TO 2
INCH PER HOUR ACCUMULATIONS LATE FRI AFTN THROUGH 07Z SATURDAY...
GUSTY N WINDS 30 TO 35 MPH AND NEAR BLIZZARD CONDITIONS.

WE ARE CONSIDERING A BLIZZARD WARNING FOR MONMOUTH COUNTY FRIDAY
NIGHT BUT WILL NOT ISSUE IF THE ECMWF DOES NOT SUPPORT.



===========================


....that would be me. We'll see. They haven't released anything since 1230PM/111PM --- still waiting to see what they comment on regarding their "details coming 230PM" bit.

Member Since: September 26, 2011 Posts: 105 Comments: 24566
looking at the radar does it seem that the storm in the Midwest is moving slow? will the two phase on time?
Member Since: January 26, 2007 Posts: 72 Comments: 6285
Mt Holly updated at 111PM to this: (this will change, again)

* ACCUMULATIONS...GENERAL SNOW ACCUMULATIONS WILL PROBABLY RANGE
FROM 10 TO 15 INCHES ALONG AND NORTH OF INTERSTATE 80 TO BETWEEN
5 AND 10 INCHES ELSEWHERE IN THE WATCH AREA.



Upton is waiting...holding their 627AM of this: (this will change)

* ACCUMULATIONS...SNOW ACCUMULATION OF 6 TO 10 INCHES.
Member Since: September 26, 2011 Posts: 105 Comments: 24566
They see something.....


Mt Holly:


.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
**IMPOSING WINTER STORM TO PRODUCE HAZARDOUS ACCUMULATIONS OF
SNOW FRIDAY AND ESPECIALLY FRIDAY NIGHT OVER MOST OF OUR AREA...

ALL LEGACY AND POINT-CLICK FORECASTS UPDATED WITH MORE SNOW AND I
LIKE THE WORDING.

WE`VE HAD AN EASTERN REGION CONFERENCE CALL WITH NCEP AT NOON AND
UNLESS THE ECMWF BACKS OFF CONSIDERABLY TO THE SE IN THE 12Z
RUN...WE WILL WARN AND ADVISE. DETAILS TO BE FORTHCOMING AROUND
230 PM.
Member Since: September 26, 2011 Posts: 105 Comments: 24566
WWA just posted for LSV.
Member Since: Posts: Comments:
Gee, I wonder if VA will even get hit??
Member Since: Posts: Comments:
Same old PP, I mean "Colortheworld", hasn't lost a beat!
Member Since: January 31, 2009 Posts: 0 Comments: 8011
Quoting zotty:
Oh- and where is the color the PP? I haven't seen him in a bit. I expect him to be raring to go for this event... I seem to remember another Friday night snowstorm when he was the star of the show...


I'm working on some stuff. Perhaps a blawg dedicated to "A blizzard in Baustin". We'll see if I can find enough Massachusetts-related items to crap on in what will likely get me thrown off this site for a day or two...
Member Since: Posts: Comments:
Quoting bwi:


:) These days, with so much moisture and potential energy available for storms, it doesn't pay to write off any guidance as necessarily crazy! Anything can happen. I remember reading LWX discussions about 24hrs before Snowmageddon saying stuff like "I can't believe I'm forecasting, this, but 18-36 inches for central MD..." And it was accurate!


For me what was even more amazing wasn't just the single event...but the fact that it was one of four paralyzing storms - all of which were well hit on by GFS and NAM.

Remember posting here "GFS with another clown map!" about four different times...

Referring to another snow output forecast loaded with the entire color scale.

Member Since: September 26, 2011 Posts: 105 Comments: 24566
For the heck of it, since we're all in watching mode...

GFS also coming in much better at 12Z.

Not sure what to make of these two models (NAM and GFS) flopping all around like fish - but hey...its all in fun.



12Z GFS Link to map below:


Member Since: September 26, 2011 Posts: 105 Comments: 24566
Quoting PattyNorthShoreLI:
To summarize for those who do not want to go through the entire blog... Boston and surrounding area will get slammed with wind and snow, who knows on everything else. Haha


A couple of kitchen sinks...and locusts, definitely locusts.
Member Since: September 26, 2011 Posts: 105 Comments: 24566
School closings are starting to come in,suspect by evening everyone will be closed.
Member Since: September 6, 2007 Posts: 896 Comments: 16202
Quoting toph:
12Z NAM is indeed "crazy". Has the entire NYC metro area (and all of NE) as 18+. I think they need more colors for the output overlay:

http://wxcaster.com/gis-snow-overlays.php3?STATIO NID=OKX

So much for delaying the phasing...


That's quite a flip for certain. To what end do we take it? Outlier crazy? Finally figured it out? Latest model is always right? Hehe. I dunno. I'm sticking with Friday morning for confidence.

As nice as that map is, and its very nice... well. Ya know.


Want more colors? The Regional outputs have more colors.

Link to Below, 10 to 1 ratio nam

Member Since: September 26, 2011 Posts: 105 Comments: 24566
I'm still hoping...
:(
Member Since: July 7, 2004 Posts: 18 Comments: 2998
To summarize for those who do not want to go through the entire blog... Boston and surrounding area will get slammed with wind and snow, who knows on everything else. Haha
Member Since: October 29, 2011 Posts: 0 Comments: 96
Hi everyone, and thanks for your detailed musings on this storm!

We've got a chance at snow or, even if the storm pans out, we could get mostly rain. So back to work; waiting to see what happens tomorrow. (Although I'll still compulsively read everything today and tonight!)
Member Since: December 18, 2009 Posts: 0 Comments: 1485
74. bwi
Quoting toph:
12Z NAM is indeed "crazy". Has the entire NYC metro area (and all of NE) as 18+. I think they need more colors for the output overlay:

http://wxcaster.com/gis-snow-overlays.php3?STATIO NID=OKX

So much for delaying the phasing...


:) These days, with so much moisture and potential energy available for storms, it doesn't pay to write off any guidance as necessarily crazy! Anything can happen. I remember reading LWX discussions about 24hrs before Snowmageddon saying stuff like "I can't believe I'm forecasting, this, but 18-36 inches for central MD..." And it was accurate!
Member Since: September 4, 2007 Posts: 0 Comments: 1636
73. bwi
Tracking the gulf low will be fun tonight. I'll say 1002mb at Cape Hatteras at 12z Friday and 985mg off Atlantic city at 0z Saturday, per GFS roughly. And now we'll see!
Member Since: September 4, 2007 Posts: 0 Comments: 1636
72. toph
12Z NAM is indeed "crazy". Has the entire NYC metro area (and all of NE) as 18+. I think they need more colors for the output overlay:

http://wxcaster.com/gis-snow-overlays.php3?STATIO NID=OKX

So much for delaying the phasing...
Member Since: Posts: Comments:
Great analogy Pc,as with all coastal storms,but this type of scenario especially,will the flame get close enough to the gas.
Member Since: September 6, 2007 Posts: 896 Comments: 16202
Quoting testbenchdude:
That southern component sure looks like it's whipping right out to sea... I'm wondering if/when it will start slowing down/turning north...

Also, your posts are awesome, Pc. Thanks for the insights.



thanks.

Member Since: September 26, 2011 Posts: 105 Comments: 24566
NEWX, Cantore also has a bit of a history of being a big bust-bringer to some events!


Zotty: If you look at the radar again, focus only on northern most Georgia, SW North Carolina, and the very light echoes through central NC.. and put your hand over the rest of the beast along the coast.

You can begin to see the northward tug. Whether or not it ends up a sharp sweeping turn up the coast - or a flatter turn resulting in further off the NC coast? I don't know. Not sure if anyone really is confident yet.



As to ECMWF vs GFS vs NAM. The great run of 2010-2011 both the NAM and GFS were constantly hitting blizzard after blizzard --- whereas the Euro was frequently out to lunch.

It's a give and take. Remember, the Euro hit Sandy and the subsequent snow storm dead on weeks in advance on both counts --- and then since then has been an epic outlying bust of a model.

Certain models' coding just seems to endear them to specific patterns.

This could be a specific pattern that the Euro handles well (and so far, it has) whereas the GFS and NAM get "confused" with how to handle certain features thus leading to poor solutions.



We have to remember that models aren't forecasts. They're guidance. The storm is going to do it's own thing.

What that is, I still firmly believe, is a much bigger toss up than is what has been discussed --- sans again that great comment Mt Holly had on early Tuesday morning.



Friday morning we have good answers. Until then at any moment any one of us, any model, and any forecaster might think they have an ah-ha moment (such as me seeing a potential miss of the connection, as has goofy, and others now) and suddenly hours later? Oh, look at that, we didn't.

So..I'd just wait.


=================

As to the coupling of systems and why 1+1=11 and not 2? Everything is dynamic and geometric, not linear.

Think CUBED, not SQUARED.

Why does it work that way? Each disturbance has something the other does not have. Each disturbance is the light for the fuse of the other.

In this case, the southern system has deep tropical moisture and strong surface signatures and features. The northern stream has cold air and upper level features that are vital to energize and vent surface features.

When the two combine, you get geometric jumps in energy levels.


Linear thinking is both disturbance are a cup of gas each, and combined, are two cups of gas.

Gotta think in the other way. One is a cup of gas, one is a flame. BOOM.


Best....I can describe.

Member Since: September 26, 2011 Posts: 105 Comments: 24566
That southern component sure looks like it's whipping right out to sea... I'm wondering if/when it will start slowing down/turning north...

Also, your posts are awesome, Pc. Thanks for the insights.
Member Since: Posts: Comments:
Hey,and just to seal the deal on us getting nailed?
Jim Cantore is arriving in Boston today.What more indication do we need.
Member Since: September 6, 2007 Posts: 896 Comments: 16202
Oh- and where is the color the PP? I haven't seen him in a bit. I expect him to be raring to go for this event... I seem to remember another Friday night snowstorm when he was the star of the show...
Member Since: Posts: Comments:
P- like Mt. Holly, Upton has become a bit more bullish on the storm, leaning towards more cold air. They are even tossing around the old "bombogenesis." Frankly, the phasing of the two jet streams is a mystery to me- it is like some atmospheric energy coupler, where 1 + 1 = 11. I am not steeped enough in the science to say why it happens, forget why it may or may not happen this time. :)

P, or Blizz- do you recall which model have handled prior nor'easters better, GFS or Euro? I know the NAM is like the crazy uncle who has been put out to pasture- he sometimes has something interesting to say but for the most part you just ignore him- but didn't the NAM do a pretty good job in handling the 2009-2010 train of storms that came up the coast? I don't recall exactly...
Member Since: Posts: Comments:
Man this thing looks incredible on Radar now in the south...just incredible. It has that "LOOK".




Of note, as we wait and wonder if the steadfast ECMWF pans out, this is pretty much what the ECMWF saw, exceptions being, and they are good ones, that the southern disturbance AND the blocking Canadian high are both much stronger than anticipated.


That said, Thursday is just an agonizing day folks. I honestly don't believe that at any time today we're going to get the "ah-ha!" moment and have a viable solution.

By Friday morning we will know if the ECMWF modeled early phasing around NC/VA occured overnight and then know if Philly to Boston gets it..... OR .... we will wake up to a disastrously delayed phasing, and rush to reference what the NAM and/or GFS have in store - since they have both since trended that way.


I don't know folks. Stick to the patient timeline...and keep on remembering the early call by Mt Holly on Tuesday morning: Won't have a solution for Friday UNTIL Friday.

Until then..it's all fun guessing games...except for the professionals who have to be peeling their skin off at this point wondering about their forecasts and if they went too far or not enough in locations.



For what it's worth, someone who is VERY VERY Good, Steve DiMartino from NYNJPAWeather, has been on board with the ECMWF, and has detailed quite well how so far day after day what that model modeled has come true - and he continues with it... and is quite bold on a Philly inclusion and a central NJ northward 6"+ event.

He has a nice video out this morning, short one, with the promise of a long detailed one later this afternoon.

If you got 8 minutes to burn, go give it a look see.
Member Since: September 26, 2011 Posts: 105 Comments: 24566
I hear ya NEWX....on all counts.

I can say with certainty that something historic is going to occur for the upper middle atlantic and the whole of New England.

I only have one question?

What exactly will prove historic?

The storm itself?
Or the forecasting bust?




If we are to inject a little logic and note that the ECMWF has been steadfast while all other guidance and opinion flops around like dying fish on a tainted river bank....and note that it has been a winters' long bust since the early November snowstorm, and muse that it's just a matter of time before it gets one right and gets back on track: Perhaps this is it? The model who saw it first and held continuity throughout?

Yet I can't help but wonder why all the other models failed to see it, then saw it briefly to an eerily identical degree yesterday morning, then swayed far away once again....

...and at the same time look at the radars and satellite imagery and wonder "Is this going to be a lost connection???" (between the upper stream and gulf disturbance).

I mean, what I see right now (which is irrelevant in such a tricky evolving situation), I want to say it's going to be an epic bust, except for perhaps eastern most New England, where the southern low may wind up quickly as a lone entity (much how our last clipper did heading into Newfoundland with that amazing satellite appearance).



Just thoughts... to add to the wholesale confusion that the rest of Thursday will bring to this storm's ultimate solution.
Member Since: September 26, 2011 Posts: 105 Comments: 24566
I do favor the scenario being put out there of light snow beginning in the early morning hours of Friday, turning to a mix or rain by mid day on Friday, then back to a heavy snow by late in the afternoon Friday and snowing all night till about 9am or so Sat. This of course for the NYC metro area. With the northern suburbs getting over a foot by Sat. noon, the City itself 6-9". Very interesting and fun to speculate on. I guess it will be very windy too, no matter what falls. Just picking a final # for my house in Stamford CT., a "lucky" 13" !
Member Since: January 31, 2009 Posts: 0 Comments: 8011
Yep,just sitting back and waiting.Im prepared no matter what happens,and which ever model hits,it appears we here in eastern Mass are in for a lot of snow.Im tending to stick with the ECMWF,simply because I look for consistency when following models,and this has certainly been consistent.
Member Since: September 6, 2007 Posts: 896 Comments: 16202
For what it's worth, and all things considered I'd really say not much value at this time:

00Z GFS and 06Z GFS both are a bit colder earlier for DE/NJ/NYC...with the 06 keeping appreciable QPF over the region for an extended period. GFS also forgoes the Gulf of Maine and just rips off eastward well south of Cape Cod...snow totals greatly reduced on both runs entire regions wide mind you. One Foot Plus totals now confined to eastern Mass, SE NH, and Maine gets in on 20"+ with these two scenarios.

00Z NAM and 06Z NAM delays phasing signifcantly until the Gulf of Maine. Snow totals almost non-existant in NJ/NYC/Western LI. Then the storm bombs out near Cape Cod and goes due northward hugging just offshore of northern New England giving all of MA, Eastern half of CT/Long Island, RI, NH, ME all 20"+.


The ECMWF for what it's worth? I swear if someone told me I've been watching the same runs from 8 days ago every day all day I'd accept that. It has stuck to it's guns like none other. Cold East Coast Blizzard region wide.



...I find it very interesting that early yesterday the NAM and GFS were dead on identical in their tracks and nearly identical in strength.

Since then they've swung wildly not just from each other but from themselves run to run.


I don't know if any conclusion can be drawn other than a not very helpful one of : Very complex system, models have no real handle on it, forecasting is highly suspect, and these errors won't be fixed until the onset of the event.



I just figured I'd share since this storm from the very beginning had a wide range of anywhere from extreme busts to extreme surprise boon potential region wide.


Stay tuned?

Patience is all we have with this type of problem...and it could easily turn you into Patients of a medical facility if you let it really get to ya. (trying to be detailed in forecasting).




Member Since: September 26, 2011 Posts: 105 Comments: 24566
Phasing is a huge questionmark goofy. No doubt about it.

Last nights 18Z models....definitely showed some failed phasing of this event, doing just like you suggest, and the southern low simply bombing on it's own east of Cape Cod...and any phasing occuring generally in the Gulf of Maine.


This wouldn't just out our region of anything significant but it would completely wipe out the majority of the widespread 18-24" totals in CT, VT, NY, Western MA, etc---


High bust potential? Sure.

Some folks with 2 foot forecasts might get rain or little of anything (no phasing means CT goes from blizzard warnings and 2 feet -- to like, well, snow showers LOL!). Some folks with rain forecasts might get 2 feet. The whole thing might even wind up confined to eastern MA, SE NH, and Maine in the end.


An awful lot still has yet to occur or work it's way out.

As Mount Holly said early Tuesday morning? We won't know about Friday UNTIL Friday.

Seems truer words have yet to be spoken on this whole event.


Half of me wants everyone to be wrong and we get a MD-ME 2'+ blast. Half of me wants everyone to be wrong and we wake up Saturday to a couple of inches in eastern most MA/NH/ME.

LOL.

Member Since: September 26, 2011 Posts: 105 Comments: 24566
SL on the Old NJ Shore: So there you have it then. So far the lower levels are still warm here. Question is does this become a coastal hugger or move offshore sufficiently to bring N. winds and combine with moisture to chill warm zones and make snow. Is this the ghost of the Lindsey storm of '69 ? This system started in Texas Monday and has moved along the Gulf Coast and is following models fairly well. I don't see any connection where one would see energy transfer from the Lake runner to the formation of a secondary offshore. In fact at the 700 hpa level moisture is feeding the Lakes storm from the Gulf system. The southern system will emerge off Hatteras and either head east of 40 N, 70W or up to Maine. Think the Lakes storm stays north. So we will be south of the main event to our north. Like Maryland Girl and Heavy no or little snow in sight for us out this one. Maybe next time.
Member Since: February 27, 2009 Posts: 0 Comments: 3345
Quoting doom22015:
Would somebody please spell out for me:
KU?
WAA?

WAA = Warm Air Advection. KU = Kocin/Uccellini. They are two authors of the book "Northeast Snowstorms" and whom derived the NESIS scale. Therefore a KU storm stands for an east coast snowstorm that is representative of in historic magnitude. e.g. January of 1996, February 2003, February 9 2010, etc.
Member Since: December 14, 2007 Posts: 285 Comments: 15145
Quoting MarylandGirl:
So down in SO MD we will just sit and watch the pictures...I have family in Worceter County, MA and on the coast in NH, Cambridge, MA and Maine....will be calling all over the weekend. Should get some good reports. All in the path...take care!


Yeah, MG, we just sit and watch --- and envy.
And as if that isn't bad enough, we have to put up with tiresome people talking about how lucky we are.
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Quoting MarylandGirl:


http://www.srh.noaa.gov/mrx/glossary.php This should give you what you need


Thx, MGirl, that had WAA. Still looking for KU -- not in that glossary. The only place I have heard of Ku (radar freq bands) doesn't fit here at all.
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Well, Listener...in an attempt to "Now-Cast" and to try to be as precise and detailed as possible the NWS clearly changes their forecasts following each new model run.

So if the new one shows 1" less...they'll tweak the forecast to match. I think it's a poor practice given that the tools are anything but precise. The day the tools ARE precise is the day that now-casting off of them would be the proper thing to do.


---
My forecast here in Tinton Falls has dropped to 4-6. 6-8 last night. Inconsequential in the big picture which is that the borderline areas could see wild swings in both forecasting and results. I still maintain that I could see as little as a few inches of slushy mess, to the 4-6 or 6-8, all the way to a foot or more.

New York city is pushing 8-10" now. Taunton actually expanded it's 18-24 right through it's coastlines sans outer Cape Cod.


----

It is still only early Thursday morning, for an event whose larger accumulating snows are about 24-36 hours away... given the complexity of the situation, and the admittance by forecasting offices all the way back to Monday that they wouldn't have a handle on this system until it's actual onset, I am going to continue to suggest that forecasting confidence is still low, particularly in borderline areas... NJ, NYC, Long Island. We can swing either way really.

As far as the gigantic 18"+ regions - I really am shocked at the scope of them for a coastal event. We're still waiting for precise phasing of the two disturbances to get these kinds of totals - and even them I am shocked at how far inland 18"+ goes. Honestly never seen an event where the whole of New England + New York state are 18"+ in any single event.


On the bold side forecasting wise for those regions? Absolutely.

On the timid side for the border regions? Not necessarily...more of a forecasting caution due to the continued admitted uncertainty in the rain/snow lines. We just don't know what to expect in those regions.



...with that, today is yet another day of fumbling over the model runs and forecast tweaks. Since this storm is anything but straight forward, and since it's apparent it won't be until tomorrow morning....I honestly don't know if there is any value in tracking things hour to hour. We're still just tracking...GUESSWORK.

Nonetheless everyone should be prepared for it. Prepare like you're getting 2 feet of snow and 75mph winds. In the case of folks like myself who may only see a few slushy inches...no harm no foul....but if it were to shift and we too suddenly get 2 feet? You'd feel awfully stupid for not being stocked. It's not like you're not gunna eat it.



Have a good morning all. Off to stare at the guesswork models.
Member Since: September 26, 2011 Posts: 105 Comments: 24566
Wow! Thank-you, Blizz!
I'm in your 10-14" area. Here they had been saying we'd get 8-14" of snow, but they've changed that to 7-15". Ha! What, does the storm have a wobble? ;-)
Family visit rescheduled by a couple of weeks rather than drive on Saturday.
It must be February!
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Quoting doom22015:
Would somebody please spell out for me:
KU?
WAA?


http://www.srh.noaa.gov/mrx/glossary.php This should give you what you need
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for doom22015. Here is a link with all
http://www.srh.noaa.gov/mrx/glossary.php Let me try again to quote.
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So down in SO MD we will just sit and watch the pictures...I have family in Worceter County, MA and on the coast in NH, Cambridge, MA and Maine....will be calling all over the weekend. Should get some good reports. All in the path...take care!
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XX/XX/XX
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Would somebody please spell out for me:
KU?
WAA?
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I didn't think it was possible, but I think the 00Z NAM is even more crazy than the past 12Z!



12Z



The new 00Z
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