Monday, January 21, 2013

Localized Snowstorm

FINAL CALL (MON 8AM) - Norlun/inverted troughs can be extremely finicky when it comes to where the heaviest band(s) of snow situate.  This one will be no exception.  I fine tuned yesterday's map to include two max zones.  The first max zone will be over the Cape and extreme southeastern MA.  The second max zone will be over extreme NE coastal MA - SE NH - SW coastal ME.  In these max zones I am going for a general 4-8", but please remember that some could get more than that if the placement of the heaviest snow band is just right.  Norluns are known to drop 12"+ in one town and then just an inch or two a few miles away.  So you can see why I labeled this post 'localized snowstorm.'  I  can only give you my best estimate where the heaviest bands will set up.  However, these events are difficult to forecast, so that band could set up further north into Portland, ME or further SW and affect the Boston metro area in a much bigger way.

Regardless, snows break out in western New England by early afternoon and overspread the area during the overnight.  The heaviest snow for eastern sections will occur between midnight and 3AM.  Snow tapers for all by sunrise.  My guess is for school for 95 percent of communities tomorrow.  Updates throughout the day as needed.  

Sunday, January 20, 2013

FIRST CALL for Tuesday AM

FIRST CALL (SUN. 1PM) --- Here is my first call for this complex inverted trough scenario.  We won't know exactly where the heaviest of snows are until this event is underway basically, so expect a wide range of forecasts for this one.  Some TV outlets may be calling for 6"+ in Boston and E MA, while others merely forecast an inch or two.  This is my call right now.  I think somebody in E MA does very well, while others (some who are even in the 4-8" shading!) only get a couple inches.

And guess what?  More snow is in the forecast for Friday.  But before that we will have to deal with sub zero mornings in the 'burbs Wednesday and Thursday morning.  Wind chills could be -10F to -15F in SNE!  Get ready.  It's coming.

Prepare for 4 Day Weekend Inside Route 495

UPDATE (SUN 8AM) -- The NWS just issued its preliminary snowfall forecast for the area tomorrow night into Tuesday.  As you can see, they are going for a general few inches across the region with more along the immediate coast and southeast into Cape Cod and the islands. This seems like a good first call to me, but there is certainly the potential to pull some of those high numbers into the Boston metro area, perhaps even all the way back to Route 495 or even Worcester.  We'll be watching the models come in this afternoon with bated anticipation.  If you live inside of 495, please at least prepare to have the kids home from school on Tuesday.  I'd give widespread school closings about a 50 percent chance of verifying at this point.  Next important update later this afternoon before the Pats.

Saturday, January 19, 2013

Disaster Tuesday AM Commute?

I am waiting on a few more runs of the models before providing more details, but guidance is trending toward a potentially significant snowstorm (esp. for eastern SNE) Monday night into Tuesday.  Our snow would come from a developing low pressure system off of Nantucket that throws snow back into SNE from a 'Norlun' front.  Norlun fronts can be difficult to forecast.  They often have a narrow band of heavy snow with much lighter snows on either side of it.  Wherever that front stalls, the potential exists for over 6 inches of snow.  Some models have that feature over the ocean, while others give the Boston metro area over a foot of fluffy snow.  We'll have to watch this one closely.  Expect it to come into clearer focus by tomorrow afternoon.  Maybe by then I will be confident enough to put up a map with my first thoughts.  Lastly, GO PATS!

Wednesday, January 16, 2013

A Southeastern Mass Snowy Surprise Thursday Night?

It looks like my forecast for this past storm worked out pretty well.  Most of SNE (away from the Cape and islands) saw a general 2-5" of snow with this system.  The accumulating snow has tapered and we will be left with drizzle and snizzle for the rest of the afternoon.  Clearing by tonight.

Then we turn our eyes down into the southeastern states where our next storm is taking shape.  This storm looked to develop off the Carolina coast and then meander offshore, leaving SNE high and dry.  However, recent trends (most notably the GFS and NAM) are bringing this closer to our shoreline on Saturday.  Recent model runs even bring measurable snow all the way to the northwest suburbs of Boston!  I am not saying that it is going to make it that far NW (yet), but the potential is there especially for southeastern zones.  Anyone from Plymouth-points south and east should prepare for at least a couple of inches out of this one.  We will watch the trends closely to see if this threat gets any closer to Boston.  For now, I would lean towards mostly dry in the city and nearby suburbs.  Lots to figure out though.  I may do an update later this afternoon or tonight if this becomes more of a threat.  Also, if it holds, I will be issuing my first call snowfall accumulation map by tomorrow afternoon too.

This is going to be a tricky forecast to say the least.

Monday, January 14, 2013

Snow Map for Tomorrow Night

UPDATE (1-15-13) - 3PM:  I'm making that map my final call for tomorrow.  There may be a couple 6" totals in Worcester County or S NH, but not enough to warrant a new map.  The city of Boston will likely finish with about an inch before changing to a wet non-accumulating snow or even light rain.  Once you get to Route 128, then you will quickly see totals increase to a couple inches and more.  The Cape sits this one out again, but we may have a few more significant winter storm threats next week and beyond.  For now, enjoy the snow tomorrow morning.  It will be gone by late morning in western zones and the early afternoon in eastern areas.

FIRST CALL - I'm not tremendously bold with this one for being a significant snow maker for the area, but we should see advisories hoisted for interior zones.  I'm calling for a general 2-4" of snow with perhaps a town or two (esp. a hill town) to finish with a 5" amount.  Closer to the city, we will have to battle with the warm Atlantic Ocean.  SST's are still in the low 40s, so that will do its best to keep the surface warm near the coast.  The biggest wildcard on this map would have to be inside of 495.  As depicted, I have this area shaded in with 1-3".  However, if the winds remain mostly calm, then the ocean will have less of an effect and therefore snow accumulations would be more like interior zones right to the coast.  Boston will likely have trouble regardless, but as close by as Cambridge or Somerville would be able to pick up a few pasty inches of snow.  Further SE over the Cape and islands - I am expecting mostly rain with this one.  Perhaps they can get some wet, non-accumulating snow, but it would be tough to get anything more than that.  If anything changes tonight, I will touch up the map as needed.  For now though, I think this is a fair depiction of what will take place.  

Warmth Departing, Snow Incoming?

Lots to talk about, but I am going to wait until early this afternoon before posting about snow possibilities - likely Tuesday night into Wednesday.  I hope you enjoyed the springtime warmth too.  As I am typing this just before 9AM, it is 54 degrees outside. It may be a while before we see a morning this warm again.
5PM UPDATE - Everything seems to be coming together for plowable snows for much of SNE tomorrow night and early Wednesday morning.  This will not be a blockbuster, but some spots could pick up a few inches that would make the Wednesday morning commute a bit of a headache.  All of the computer models are hitting the Mass Pike corridor for heaviest precipitation, but the question remains what type will it be?  The European model is the coldest and the American GFS was the warmest at noon, pushing the rain/snow line up to the Pike, including Boston and the immediate coast.

I think those away from the immediate coast and away from the south coast, Cape, and islands will likely stay mostly snow with this one.  I am working on a snow map now, but waiting for the GFS to come out over the next hour before putting numbers up.  I am feeling a general few inches for most of the area.  Nothing we can't handle.  Still, it will be a shock to the system after many towns soared into the low 60s this afternoon.

Next update with the snowfall accumulation map (first call) around 6PM.

Wednesday, January 09, 2013

2012 = Warmest Ever

Nope, your senses weren't fooling you the past 12 months.  The lower 48 just experienced its warmest year on record (EVER)!  Here is an excerpt from NOAA that provides a good summary:

NOAA Press Release on Jan. 8, 2012:

According to NOAA scientists, 2012 marked the warmest year on record for the contiguous United States with the year consisting of a record warm spring, second warmest summer, fourth warmest winter and a warmer-than-average autumn. The average temperature for 2012 was 55.3°F, 3.2°F above the 20th century average, and 1.0°F above 1998, the previous warmest year.

The warmth will continue as we are now in the middle of our January thaw.  Highs soared into the middle 40s in eastern Mass late this afternoon after a slow warmup.  Tomorrow will be slightly cooler with highs in the lower 40s, but then we really go to town.  Saturday starts the torch in earnest, approaching 50 degrees or slightly higher.  Then we are still pushing 60 degrees by Sunday afternoon.  Any sunshine we see will boost the temperatures even higher.  If we get a few hours of sun in the late morning and early afternoon, lower 60s is not out of the question.  Sayonara snow pack in southern New England!

Wintertime cold returns midweek, next week.  Enjoy the spring warmth for now.

Sunday, January 06, 2013

Early Look at Kickoff Next Sunday...

We are a week away from kickoff at Gillette of the AFC Divisional playoff game.  If you're lucky enough to have a ticket, you may ask what is the weather going to be like at Foxboro.  Normally in mid January, you would expect bitter temperatures or maybe even a snow bowl like in 2001 against the Oakland Raiders.  Well, neither look to be in the cards for this year.  After sustaining a solid snow pack for about 1-2 weeks across much of SNE, a massive January thaw arrives by Tuesday and likely peaks right around the end of next weekend, just in time for the Texans to arrive at the Gillette.  In fact, the Houston players may think that they never actually left Texas in the first place because we could easily be talking middle 50s if not slightly over 60 degrees by Sunday afternoon!

4:35PM - Sunday, January 13th
Kickoff:  Mid-Upper 50s Dry
Halftime:  Lower 50s Dry
End:  Upper 40s Dry, Slight Risk Shower

Take a look at the 18z GFS depiction of the warmth for next Sunday.  All you have to know is that there will be a broad push from the southwest into SNE that really warms us up.  High pressure just west of Bermuda, coupled with low pressure pushing northeast through the Great Lakes will push the warmest of the air right into SNE on SW winds, likely pretty gusty.  Showers should hold off until after the game with the cold front to the west.  It may take a while for that front to actually get east of us too because that push of warm air is so pronounced.

I do not have time to post later images from the GFS, but I want to drive home the point that this warmth will NOT last.  It is in here for a 6-8 day stint.  Tomorrow will likely be in the middle 30s and then we are in the 40s through Friday before pushing 50 on Saturday and then 60 on Sunday.  Thereafter we really start to cool down and by the middle of next week after the warmup, we will likely be back to 20s/30s for high temperatures.  It still remains to be seen how much snowfall we will see in the new pattern, but we should be able to increase the chances somewhat just with having cold air around.  Most importantly, nearly every computer model (GFS, EURO, GGEM, etc.) agree that this warmup will be short-lived and that winter is far from over.  In other words, enjoy the warmth while you can this week.