Saturday, January 31, 2015

More Snow For Monday

The National Weather Service in Taunton has issued a Winter Storm Watch for much of Southern New England 
NWS Boston Hazards 
The Winter Storm Watch (dark blue) is in effect in all of MA/RI/CT; however the active Wind Advisory (brown) and Wind Chill Advisory (light blue) supersede the future WSW.  The WSW is effective late Sunday PM through late Monday PM.

The wind chill is advisory is up because of bitterly cold AM temperatures today
8 am 2 m temperatures (image Weatherbell)
Strong overnight winds ushered in the Arctic hounds as high pressure to our Northwest and a strengthening storm in the Gulf of Maine tightened the pressure gradient
WPC Surface Analysis 7 am
As to our next storm...it is currently in the Western US.  Two pieces of energy will phase to create a wide swath of snow from Nebraska and South Dakota all the way to New England.  At the surface the lows are in the Southwest and Montana.  At the upper levels we look like this
12z NAM 500 mb vorticity (Image NCEP)
24 hours later (7 am tomorrow) we can see the phase taking place in the Plains (Kansas for the geography illiterate) 
12z NAM 24 hr 500 mb vorticity valid 7 am Sun (image NCEP)
At the surface we see this
7 am Sunday Surface Analysis (image WPC)
A healthy snow storm will greet our friends in the Missouri and Ohio Valleys as warm moist air from the Gulf rides up and over the cold Arctic boundary.  New England is fine throughout Sunday.  There are no worries for the Super Bowl other than the Seahawks.  In Connecticut some snow may break out before midnight but that's okay.  There are too many Jets and Giants fans in that state anyway.  Snowfall begins after 1 am in our Western regions, probably closer to 4 am in Eastern/Central regions.
12z NAM 1000-500 mb thickness, mslp, precip valid 7 am Mon (image Weatherbell)
Temperatures Monday are cold in the interior, a bit warmer towards SE MA/RI.  It should be all snow for most locales with the exception of the Islands.  It may mix on Cape Cod as warmer air is ingested into the system.  
12z NAM 54 hr temp snapshot valid 1 pm Mon (image Weatherbell)
Temperatures like that mean high snowfall ratios for Central and Western New England.  Therefore I am expected a general 1' of snow across SNE with a bit less SE (heavier, wetter snow) and North (less precipitation).  The NWS looks good but I would cut back in SE MA and go 8-12 north of the pike.
NWS Boston snowfall totals
This is gone by Monday evening.  Teachers you will be off Monday but should be back by Tuesday.  We will stay cold throughout the next 10 days so there will be more chances for snow.  I'll update tomorrow, have a good one.

-Zack Green








 

Wednesday, January 28, 2015

Wrapping Up the Blizzard, Looking Ahead

The National Weather Service in Taunton has gone through all the observations and has officially declared Tuesday's Nor'Easter a blizzard.  It sure lived up to the hype in Southern New England.  A widespread 2-3 feet of snow fell in Central and Eastern Massachusetts (also NE CT, N RI).
NWS Boston Snow Total Reports 
The Blizzard dropped 34.5" of snow in Worcester which is good enough for 1st place in recorded history!  CBS Boston's weather team puts the storm in perspective
WBZ Weather team top 5 Worcester snowstorms 
The storm was good for 3rd in Providence and 6th in Boston.  This is the greatest recorded January snow in Boston's history.

Cape Cod and SE MA also dealt with strong damaging winds
NWS Boston Wind Gust Reports
Thanks to light fluffy nature of the snow the widespread power outages that were feared never happened.  That said the entire island of Nantucket was without power for a time thanks to 18+ hours of wind gusts over 60 mph, maxing at 78 MPH.  

Major coastal flooding occurred in numerous seaside towns in Eastern MA.  Marshfield was among the hardest hit with over 4 feet of storm surge and 15-20 foot waves.  This constant battering compromised an 80 ft section of sea wall.
Sea Wall breach in Marshfield, MA (image Marshfield Police Twitter)
Safe to say we will talk about the Blizzard of 2015 anytime a major Nor'Easter is forecast to impact Southern New England.  It doesn't compare to 1978 for anyone.  As hard as the Cape and Islands were hit this wasn't as bad as the Blizzard of 2005.  For the interior this was a manageable snowfall unlike the Blizzard of 2005 and the April Fools Day storm.  That said I cannot remember seeing so much snow from one storm.  At the end of the day this was a fun storm to track and observe.  Here's to those in Nantucket and our coastal communities that are dealing with the burden of property damage; we know you will get back on your feet soon.

A few images from Northbridge...
From Brian Paulhus
CBS News requested permission for this photo but I never saw it.  This is from Brian Paulhus as he opened his garage door around 11 AM yesterday.  That's his daughter in front.  Brip you may not have made the Evening News but you made NewEnglandwx.blogspot.com   STATE!
My Parents Back Deck
After the 30th straight hour of snow this is what my parents back deck looked like.  Here were their cars around 11 am
My Parents Front Yard
Finally a cool loop of the storm developing from the GOES13 IR4 satellite thanks to NWS Boston

Friday Snow Chances
It looks like a couple of inches of snow are possible, especially in Northeastern MA on Friday/Saturday AM.  Guidance has been blowing a clipper up in the Gulf of Maine.  It looks like the whole region sees a general 1-3 but totals may be much higher NE Middlesex and Essex counties.  The NWS has a good general idea; but like I said I'm leaning towards higher amounts North and East.  
NWS Boston forecast snow totals Thursday-Saturday 
Maine will really get hammered from this one.  Guidance is suggesting temperatures in the low 30's but I don't really buy it with the deep snow pack and entrenched cold air.  None the less expect two batches of snow.  First is overnight Thursday into Friday with 1-3 inches of snow.  Second would be overnight Friday into Saturday.  Temperatures are going to drop Friday night so the best accumulations would be with the second shot, though that may be too far east for Worcester County.  

I'm off to Long Island for a few days to see Bruins-Islanders so trust the NWS for updates.  weather.gov/box 

There is a threat for Monday PM but its entirely possible this slides Out to Sea.  More on that this weekend.

-Zack Green






Monday, January 26, 2015

Evening Blizzard Thoughts

We are in the toddler stages of our Nor'Easter (blizzard to be).  Here a few of my thoughts/observations.  

General Overview
I don't expected all of you to be as enthralled with this satellite image as I am, but this is just a gorgeous image 
GOES_east Water Vapor Satellite Image through 615 PM (NOAA)
The main precipitation shield is rapidly approaching Southern New England.  Conditions will be deteriorating within the next several hours everywhere.  
NWS Northeast Regional Radar through 708 PM
It is in the teens outside of SE MA/RI which are in the Mid 20's.  
2 m temperatures 6 PM (image Weatherbell)
I am concerned about these temperatures in SE MA/RI.  They are going to get hammered tonight/tomorrow with heavy wet snow and powerful winds.  The snow will certainly pile up in Southern Worcester County/E CT/N RI/North Shore and it will be windy but the power outage threat is less than our friends to the South and East.    We are looking at 1"+ per hour snow in this region starting now (734 PM as I write) and lasting...how long?!?
SPC Mesoscale Snowfall discussion 
These bands will rotate towards Hartford and Worcester through the night.  Here is where the storm is centered right now with the general track.
SPC Mesoscale Analysis 7 pm Surface Pressure/radar overlay
Considering it will continue to deepen and track closer the hype is justified for Southern New England.  I don't know if this ends up as a Top 5 storm but guidance has been CRUSHING Eastern MA.  For example, check out the Short Range Ensemble Forecast (many members with slightly different initial conditions) for Logan Airport 
15z Boston SREF Plume Total Snowfall (SPC)
The mean is 30 inches.  The lowest member is 20 and it is all alone.  Boston needs 25" to crack the top 5 and 27.7" to break its record set back in 2003.  Providence may set its record as well which is 28.6" set in 1978.  I think Providence will finish in 2nd, ahead of the Blizzard of 2005 but shy of 78.  Don't be shocked to hear thundersnow tonight either.  This storm is juiced!

Enjoy it, stay safe.





Sunday, January 25, 2015

Major Winter Storm Monday PM-Wednesday AM UPDATED 422 PM

UPDATE
Blizzard warnings have been posted for all Eastern MA, RI, and CT.  This includes Southern Worcester County.
NWS Hazards 1/25/15 4 PM Update
Totals have updated a bit too.  It now appears likely a large portion of Southern New England will see 2-3 feet.
NWS Boston snow total forecast
Previous discussion below.




Winter 2014-15 has started cold but rather dry.  That all changes tomorrow.  A major winter storm that may end rivaling the all time greats is on tap.  For many 1978 is the top dog and it will be hard for anything to top that storm.  For those of us who aren't AARP members or coming close this should stack up with the April Fools Day storm of 1997, the Presidents Day Storm of 2003, the Blizzard of 2005, and the Blizzard of 2013 (Nemo).   Its also a welcome distraction from deflated football talk.

Overview
The National Weather Service in Taunton has issued a myriad of watches/advisories already
NWS Boston watches and warnings
So far Worcester County/NE CT are not in the blizzard watch (lime green) but they will probably be added later today.  The official definition of a blizzard is falling/blowing snow with sustained winds (or frequent gusts) over 35 mph and visibility less than 1/4 of a mile for at least 3 hours.  The piece of energy that will become our storm is currently in Missouri/Iowa/Illinois
WPC Surface Analysis 12z (7 AM)
The high pressure in Ontario is important to note as well; it will lock in very cold air during the storm and increase the pressure gradient thus increasing wind/blizzard potential.  In terms of upper level steering
NAM 12z 500 mb vorticity 7 am (image NCEP)
Notice the potent dip in the height field traveling down the ridge in the Western US. We can see the players on the water vapor satellite loop
NOAA GOES_East Water Vapor Satellite through 1015 am
Evolution of Storm/Timing
Light snow breaks out by Monday PM say 4-5 PM.  My initial thinking was 10-12 PM but things have changed.  By 7 PM the storm will look like this
NAM 500 mb vorticity 7 PM Monday (image NCEP)
At the upper levels the Eastern trough takes on a negative tilt which will enable the storm to close off near Southern New England.  At the surface
WPC Surface Forecast Monday 7 PM
The projected radar
NAM Hi-res Simulated Radar 7 PM Monday (image Weatherbell)
Temperatures
NAM Hi-Res Temperature Snapshot 7 PM Monday (image Weatherbell)
By 7 am Tuesday we are looking at a raging Nor'Easter
NAM 500 mb Vorticity valid 7 am Tuesday (image NCEP)
The upper levels close off allowing the storm to stall out
WPC Surface Forecast 7 am Tuesday
The simulated radar
NAM Hi-Res Simulated Radar 7 am Tuesday (image Weatherbell)
With sustained winds cranking in Eastern MA, RI, coastal CT and Long Island
NAM Hi-Res 10 m winds 7 am Tuesday (image Weatherbell)
The storm will pull away Tuesday night, though the exact end time is uncertain at this point.  We have time to nail that down tomorrow.

Impacts
No need to make my own snow map- the National Weather Service is on top of this.
NWS Boston forecast Snow totals
There will likely be pockets of snow totals greater than 24 inches.  I'm thinking the Foxboro/Mansfield/Norton area as well as the North Shore.  The Cape/Islands will deal with some mixing issues keeping totals down.  Also someone will end up in the dreaded dry slot (dreaded if you love big storms).  I ended up in one during the Post Christmas Blizzard of 2010 and it sucks.  So some will end up with less than predicted, others will overachieve.

Over the Cape winds will max near Hurricane Force. In SE MA/RI winds will gust upwards of 60 mph Tuesday AM.  South of the Pike should gust to 50, everywhere else 40-45.  There is a chance of power outages.  The snow will be light as temperatures Tuesday will be in the teens.  

Multiple rounds of coastal flooding are likely as well.  Tides are not astronomically high but the storm is strong enough to cause problems.  So in summary hit the stores today and get what you need to deal with the storm.  Make sure to get some booze; there will be no travelling Tuesday!

I'll update as needed.

-Zack
















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