March 25-26, 2014 Storm Graphics

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Forecast Thoughts For Potential Major Nor'easter Tues-Weds 3/25-26

   Highs today were near 60° for portions of the area but all eyes continue to be on what now appears to be a significant early Spring Nor'easter for much of the region later on Tuesday into Wednesday morning with the brunt of the effects expected over the eastern sections of Southern New England.

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   OVERVIEW: Arctic air looks to settle in Sunday eve and especially Monday where we could see record low maximum temps and begin to set the stage for a decent snowstorm  and what looks to be the first significant one since Feb 18th I believe. Northern energy for the pending storm is now entering the Pacific Northwest and will dive SE towards the Southeastern US states and merge with a southern based sub-tropical jet and form a storm off the Carolina's early in the day on Tuesday as the upper levels of the atmosphere dig a deep amplified trough over the East Coast Tuesday eve sending a phased storm off to the north/northeast that will undergo meteorological bombgenesis in response to rich Atlantic Ocean moisture and a clash of above normal sea surface temperatures and below normal SST's along its track and an assist from the Gulf Stream. Low pressure will pass just outside the 40/70 benchmark early Wednesday somewhere around 970 millibars, perhaps even lower  before heading towards Nova Scotia late Wednesday.

   TIMING : Flurries and light snow could break out as early as Tuesday am as upper level energy over the Ohio River Valley starts to interact with building moisture off to the south as the main storm takes shape near or off the Outer Banks of North Carolina. Flurries, perhaps a period of light snow should continue through the daylight hours before intensity will pick up south to north through the evening hours with the peak of the storm occurring overnight Tuesday into early Wednesday before  it pulls off to the northeast.
   IMPACTS & EFFECTS: Very strong signals continue to indicate the most significant effects and impacts will be felt near coastal locations. The heaviest snow and strongest winds are likely near the coastal plain. Banding of heavy snow is likely for eastern SNE especially near and inside interstate 495 in eastern Massachusetts as this area will be closest to the storm center and in the area of greatest signaled vertical motion. Unlike previous storms where there had been a sharp cutoff due to incredibly dry air contrast to the north and northwest of the storm, this one will have decent mid level moisture at least at the get go to spread light accumulating snow to the entire region before the storm really blows up and pulls the heaviest snow and banding closer to the coast and especially over the Cape and Islands. It will be very hard to see thermal profiles rise to the point where any mix would be involved so this is a predominantly snow event. Winter Storm warning headlines are very possible and even a Blizzard Watch could be warranted near the eastern Shores. The other issue and it could be a BIG one is the potential for powerful sustained  winds, again affecting the coast the most. There are strong signals of potentially damaging wind gusts along the immediate shore to Cape Cod and the Islands as the storm continues to intensify passing by.  There is a big difference between a weakening storm system and an intensifying one  like this will be . Enough signals have been there that I feel  *High Wind Warnings* are likely near the shores with even  *Wind Advisories* possibly further inland. Images below show the sustained and gust potentials during the brunt of the storm overnight Tuesday into Wednesday morning.

Wave heights are expected to grow to 15-20 feet near or just off our coastlines. The Wednesday high tide cycle will have to be closely monitored for likely splash over and potential for moderate coastal flooding. This aspect is very dependent on exactly how close that low center comes. There is great agreement as of now but slight shifts are still likely.
   So now to answer the big question I am sure many of you are asking. How much snow?  Its still a bit early to tag numbers for certain locations, however,  I believe I will be able to estimate further by this time tomorrow. In the map below it shows the best probability of seeing and exceeding 6" of snow. Confidence is quite high here, and if it  all comes together, as it has the potential to do so, someone will come away with a foot, perhaps a bit more when all is said and done Wednesday ino mid-day over eastern SNE.

Thats the skinny on the system as I see it right now. I do not expect many drastic changes but do stay tuned to me on twitter and facebook if they should arise between now and then. The good news is we could hit 60° by Friday with a better chance Saturday and we may finally be able to put the snow behind us and move forward to enjoy 'Spring'. Thank you for reading     ~Anthony

A Few Forecast Thoughts

 Though we do have a couple weather ‘systems’ approaching before , my eyes continue to be fixed on the March 25-27th timeframe. I have shared a few images on twitter in recent days, but the fact is they are only one run of one operational model. Take note though that there have been signals of this in guidance for almost 5 days now ! Regardless if they have been strong signals (some very intense) or weak, the fact remains that it looks to be an upper level pattern that is prone to producing right into earl April and continued strong signals of anonymously cold air as well. That has not changed. And when you have cold in late winter and early Spring, some pretty dramatic occurrences can occur whether it be a severe weather outbreak or even a major winter storm.  There are many past events of such and some in New England need no introduction. Its just the nature of the pattern , temperature gradients across the CONUS during this time of year. It is more volatile than any other part of the calendar year. Always need to be on your toes this time of year even though most seasons the transition from Winter to Spring does goes fairly smooth.
  Its important to note that it is ok to share model images of potential and I would not do it out of just the fantasy of wanting a storm or because it is the most dramatic solution on the table. I am not lazy like that and have been observing (30yrs) and forecasting weather for quite some time and know better and have a great , deep respect of weather. When I see signals I mention potential whether it is 10 days out or a sneak attack in a much shorter timeframe. Aside from just many operation model runs and signals of such through global ensemble guidance signals for the 3/25-27 timeframe there have been signals of a potentially brief but importantly timed pattern change in the upper levels of our atmosphere. Two of importance. A building of a western US ridge with indication of a building positive PNA (Pacific/North American Pattern) . This in turn sends/keeps a deep trough over the eastern US. Yes this has occurred  recently and we have escaped potentials but when there are also signals of the North Atlantic Oscillation (NAO) at least trending towards a negative phase (downstream Greenland blocking) or potentially going slightly negative near the time frame it is certainly a potential to keep an eye on . It is a formula/combination that has not  occurred much this year despite the above normal snowfall for most.  In fact the last time such occurred was mid January . Could I be dead wrong? Of course I could and have been quite a few times this year but it will not stop me from moving forward.
  There really are no details set in stone being still a week or so out but feel it would be best to surely keep at least an eye on this due to the time of year and certain plans, some vital that many people and businesses make as we transition from Winter to Spring. Thank You for reading and stay tuned.    ~Anthony

OVERVIEW: Big winter storm approaching the Northeast. Anomalously strong March low pressure currently located over Missouri will track east/north east and pass over Southern New England early Thursday am around 978mb ! This storm will bring a major snowfall to northern New England. With the storm track expected to track over/just south of Long Island this brings mild temperatures both at the surface and aloft to begin with rain changing to a period of wintry precipitation with crashing temperatures on the back side of strengthening low pressure moving over and northeast of Southern New England early Thursday am. This a a huge snowstorm and great news for ski country. Have a look at the 6 hr snowfall animation I put together for Weds-Thurs

SNE IMPACTS & TIMING: Heaviest snowfall expected to remain north of SNE. That does not mean we will escape impacts from this storm. It appears as though 1-2" of rainfall is likely across the region. The potential is there for a gusty thunderstorm as well Wednesday evening . South winds ahead of the storm may gust 35-45mph along south coastal locations Weds eve/early Thurs.  Light rain showers break out Wednesday morning from SW-NE and become steadier as the day goes on as low pressure approaches from the WSW. With low pressure moving over and eventually starting to pull off the the north east, rain will start to turn into a wintry mix over western SNE Weds eve into pre-dawn Thursday as colder air rushes in behind the departing storm. This creates an issue with a potential flash freeze. Even a small amount of snow or mix with temperatures crashing can create big problems. The Thursday morning commute looks rough. Light snow/mix showers could continue right into the early afternoon Thursday near the coast. Not much accumulation expected anywhere across SNE, but it wont take much with the expected crash in temperatures. Below is a graphic showing general precipitation types and timing potential with the upcoming storm.

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EXPECTED SOUTHERN NEW ENGLAND SNOWFALL THROUGH  THURSDAY MIDDAY 

More Snow Tuesday, possible wintry mix Wednesday, then changes !

Here we go again Southern New England ! Yes there is a brief and much needed warm-up approaching us Thursday through Sunday but before then we must grind through another period of accumulating snow for much of the region on Tuesday and likely a bit more later on Wednesday. It has been relentless this season.

  WARNINGS & ADVISORIES:  In advance of the storm system all of Connecticut (except the extreme SE part of the state) , central and northern Rhode Island and much of Massachusetts  (away from areas S&E of RT 24)  are under a Winter Weather Advisory for much of Tuesday. Winter Storm Warnings are up for parts of Worcester County north and east into Southern New Hampshire away from the Seacoast.            

  THE SETUP: The System we are watching has brought some heavy snowfall rates to the Chicago area today and reports of thundersnow. This is all associated with a energetic northern stream pool of upper level energy. This energy will be over the eastern Great Lakes by early Tuesday and will form a new low just off the Southern New England coastlines into the Gulf of Maine Tuesday evening and bring us our snowfall. Enough mild air will flow in to make for a mix with rain over southeast portions and likely be mostly rain over Cape Cod and the Islands, so not much if any snowfall is expected 

  TIMING: Snow appears to break out over southwest Connecticut between 7-10am and progress off to the northeast thereafter reaching far northeastern Massachusetts between 11am-2pm give or take. With impressive indications of vertical upward velocity at 700 mb (10,000 ft above) there is the potential for brief snowfall rates to reach or exceed 1" per hour with even the possibility of thunder. This will have impacts on the afternoon and evening commute east of Worcester, Ma up and down Southern New England. Below I have put together a animated simulated radar loop giving a general idea of how precipitation should develop and progress through the day on Tuesday.

   SNOWFALL: Away from the immediate shores and parts of southeast CT, RI & Ma we are looking at a general 2-5" snowfall with this. There will be a couple areas that have a chance to exceed 5" of snowfall though and this will be northern Worcester county into northeast Mass into SE New Hampshire. The reason for less snowfall near the coast this go around is mainly due to low pressure tucked close to our coastlines Tuesday and the projections of a south/southeast onshore wind direction during heaviest period of precipitation.

   OTHER IMPACTS: This is not a typical 'snowstorm' or coastal storm so I am not expected too many other  impacts of significance though we could see some sustained SE winds between 20-30 mph developing over coastal Massachusetts and especially Cape Cod and the Islands as these locations will be nearest to developing and likely  intensifying low pressure off the coast.  Much of Southern New England will see some gusts at times 25-35 mph with  perhaps a few near/over 40mph on the Cape & the Islands Tuesday afternoon and evening.

   WHATS AHEAD ?: Milder weather !  Before we get there though we have a transition day shaping up for wednesday with another potential event with weak low pressure trying to form off of the New Jersey coast Wednesday afternoon which looks to bring  a mix of wet snow and rain to portions of the area. It currently favors central and east the most. I will surely have more details on that potential after Tuesday's event passes and I can get a quick glance at exactly how the upper level pattern appears at that point.  Beyond Wednesday  a south/southwest flow develops along with warming at the mid levels which will bring surface temperatures into the upper 30's to low 40's for much of the area Thursday with a few rain showers possibly brief icing transitioning to rain at night into much of Friday with a storm well off to our northwest and trailing cold front passage slated. Highs on Friday look to soar into the 40's and 50's to near 60 for some ! It looks a bit cooler but mild again Saturday and early Sunday with colder air arriving late with a few rain or snow showers possible.  All indications continue to bring us into a  much colder and potentially stormy pattern once again thereafter.  Thank you for reading.   ~Anthony 

Light Snow Approaching. Watching Potential Storm Mid Next Week

Clouds are increasing this evening ahead of a northern branch disturbance (shortwave) moving east over the lower Great Lakes. It has produced a general Coating-4" to our west. There will be no big storm as I once thought was possible as that has now sped up and is missing off to our south and east this eve but there is enough energy with this shortwave to produce periods of light snow Sunday into Monday across Southern New England. Snow showers and periods of light snow will move in from west to east during Sunday. Before its arrival there could be some ocean effect snow showers as winds shift from west to northwest and to north that may affect parts of Cape Ann and Provincetown. Overall this is a minor event and looks to drop a coating to 2" with just a small chance at this time of a few locations seeing over 2"

This favors the south and east coasts. The storm simply is moving too quickly to produce more with no real moisture source and it being under a fast moving zonal jet stream. It will be all snow though and a bit of a fluff factor too so thats where we see a high end potential. It appears we remain cold for the foreseeable future and need to watch for another storm during the middle of next week. This would include the southern moist jet so the potential is there for a coastal storm but in the wake of the Sunday into Monday disturbance a large, cold dome of high pressure settles in and exactly how quick it releases or how long it decides to hold will make all the difference in the forecast for a potential snowstorm, a mix storm or even a suppressed storm missing out to sea. It is simply where we are at this point with that one and until we figure out how and where the upper levels will steer this thing there will be more questions than answers. I will surely be monitoring its every move and will keep you up to date on that.

January Ends On A Quiet Note. February Starts Active

   January has come to an end with monthly temperatures averaging near or slightly below normal for much of Southern New England while many saw snowfall well above avg. Now its onto February, by far my favorite month to forecast in SNE and with signals of a very active pattern in the first week at least there are plenty opportunities to do such. February is know for some monster storms in this region (a few of which need no introduction) and actually 6 out of 10 of Boston’s top 10 snowfalls have occurred in the month of February and with the signals of an active pattern and a few snow chances for many in the near future, I think its safe to say that winter is far from over regardless of what that little rodent says on Sunday.
   The first system we are watching and quickly approaching is slated for Monday. Right now the energy for that is diving south/southeast from the Pacific Northwest towards Texas. It picks up some Gulf of Mexico moisture and heads off the northeast late tomorrow and early Monday. It’s a quick mover due to lack of blocking to our north but it packs a bit of a punch especially to our south once again.  Low Pressure forms over Mississippi/Alabama Late Sun eve, early Mon and cuts through the southern Appalachians before curving off the coast of the Mid-Atlantic northeast of the Outer banks of North Carolina Monday afternoon. This points to areas of Virginia to New Jersey in the meat of the precipitation through Monday afternoon, though SNE will be on the northern edge of this storm. With a 1028MB high off to the west pushing this and 1024MB high influence along the Ma & VT/NH borders, once again the precipitation favors areas to the south of the Mass Pike. Light snow should break out Monday morning along the south coast of SNE and slowly creep northeast to the Mass Pike by midday before coming to a halt and slipping off to the east by the evening. 

   As far as precip type goes, it is mostly snow as temperatures aloft support such but surface temps will be marginal for many so it does not appear to be a “fluff factor; event to which we have become quite accustomed to this year. It will be a wetter type snow and even a few raindrops mixing in for SE Mass. and Cape Cod & the Islands. As far as amounts go it looks like a general slushy coating-2” with a few locations seeing near or over 3” of snow favoring near the extreme south coast. Not much if any wind expected with this so impacts are minor with this event.

   We get a brief break in the action Tuesday , but then all eyes turn off to our southwest again with building Gulf of Mexico moisture being driven by a very energetic upper level disturbance which will steer all that moisture northeast towards SNE Late Tuesday night and Wednesday. A surface low will work up to the Ohio River Valley , begin to transfer its energy to a secondary low near the Delmarva Peninsula. With this secondary low offshore, it keeps SNE on the cold side of this storm for the most part and with anonymously cold ocean temperatures makes any wind flow off the ocean help retain cold to keep this mostly a snow storm and quite potentially a sizable one (over 6").  The air above will be marginal though, so periods of freezing rain also possible for some. There will be a mix line for a time and that should become much more clear hopefully by later Sunday as the main energy for that storm enters the West coast and more data gets fed into guidance. There is no doubt of the storm occurring though. Another storm looks likely next weekend too ! Busy Pattern. Thank you for reading  ~Anthony