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.

CLICK ON IMAGES FOR LARGER VIEW                                                     

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

Deep Winter Cold and Snow threats Roll on

An energetic disturbance from central Canada rotating around James Bay upper level low will dive into the northern US and form a strong broad low pressure center over the Great Lakes early Saturday morning. A strong cold front trailing from low pressure will bring with it periods of light snow and snow squalls into Southern New England midday to late afternoon and evening from west to east during Saturday. Behind the front is a renewal of arctic air along with gusty northwest winds. Ahead of the front a south/southwest flow will develop and bring potential for wind gusts over 30 mph to perhaps as high as 45 mph for east and southeast shores. This will temporarily bring some *milder* air into extreme southeast SNE and would mean a mix of rain and perhaps wet flakes at the tail end late Saturday. 

 There are good signals that many areas in SNE could pick up a coating to 1" of snow from these snow showers/squalls with the potential of 1-4" over northwest Mass, the Berkshires and northwest CT. Not a huge amount of snow but will become a bit hazardous for travelers caught out in it in combination with the wind. This will create low visibility at times. Keep this in mind if you have traveling plans Saturday. Temperatures are certainly looking a bit milder during the day Saturday than it has been in recent days with highs in the upper 20's to low 30's but crashing quickly with the projected frontal passage approaching.  Weak high pressure builds in Sunday with the cold front offshore and high temperatures back into the teens for many ! Winds will still be a bit gusty on Sunday but this time from the west in the wake of the frontage passage. Wind chills will be below zero for much of the region. Yet another disturbance will dive southeast out of central Canada early Sunday rounding the upper level low that will shift close to Hudson Bay at that time. This disturbance has a shot to bring some more snow showers and gusty winds into the region very late Sunday into Monday morning, but confidence a bit lower with this shortwave feature. Beyond this, the deep arctic winter cold chugs on with temperatures remaining well below normal and we make make a run at some record cold as well mid to late next week. There will be the potential to watch for a close brush with a large ocean storm late Tuesday into Wednesday but at this time I feel as though this is a near miss. The upper level pattern seems to not dig enough and go negative in time to take building southeast moisture up the coast, therefore appears to take the bulk out to sea. Its certainly is something keep an eye on at least though.   ~Anthony 

Below is a snow map for Saturday. Click on the image for a larger view

Temperatures Moderate Ahead of a Wet & Windy Period Sat-Sun

   After what appears to be the coldest start to January for much of Southern New England since 1996, the jetstream is now retreating off to the north and temperatures are slowing moderating at both the surface and aloft as we approach the weekend. Much needed relief from the cold for many for many reasons.
   The next weather system will approach us from the Ohio River Valley. It is a weak clipper like disturbance and moisture starved but with cold enough air in place at the surface and aloft briefly, we could see a period of wintry precipitation early on Friday which is more and more looking like some light snow which could coat the ground for a few locations at best. Not a huge deal. After that temperatures will continue rise both aloft and at that surface ahead of our next weather system which will be a developing storm low pressure system over the Great Lakes. Ahead of that storm off to our northwest the jet stream winds (fast flowing river of air about 30,000 ft above our heads) will be screaming from the south/southwest. With the absence of a cold high pressure t the north this will bring in a surge of moist and mild air up into SNE and boost temperatures into the 40's to near 55° for many Saturday .

Showers will be on the increase Saturday morning from WSW-NNE across the area with heavier showers & downpours arriving during the afternoon and especially the evening.
   The other issue is the potential for damaging wind gusts Saturday evening and overnight into Sunday. Upon its approach and ahead of the storm system, winds about 5,000 ft above our heads (850mb) will increase to between 60-80 kts. Its is not always the case that these strong winds aloft are brought to the surface without sufficient mixing like sunshine, but this go around looks to coincide with convective like showers and possibly even some thunder Saturday evening. This would pull some very health wind gusts to the surface and that becomes a problem as of course we have the Patriots at home for their Playoff Game Saturday eve and also brings the potential for scattered tree & power line damage especially east of the Worcester area up and down SNE and favored higher elevations and Cape Cod and The Islands. Given all these factors its safe to say wind gusts could be 40-50 mph with isolated gusts to 55 mph.  We will surely have to keep close tabs on this as we approach. As far as rainfall goes, anonymously high precipitable water values will lead to heavy downpours at times into Sunday morning and it appears as though we are looking at a widespread 1-2" rainfall from this event. With frozen rivers from the recent cold this may bring some flooding issues.  One other concern is large swells building along south shorelines Saturday eve to 10-15 feet and looks to last right through all of Sunday too. Will have to watch for a bit of splash over, minor coastal flooding at times of high tide for those south facing shorelines of Southern New England . Colder air comes rushing in here for Sunday, then things become a bit complex as to whether we stay mild through next week or the jetstream dips back south again. This should become much clearer after Saturday. Thank you for taking the time to read this, I appreciate it !   ~Anthony