Winter Like Feel This Weekend With Snow Likely Tuesday

Below average temperatures have worked into Southern New England and they will stick around for the foreseeable future.  Today and this weekend look to be mainly dry but temperatures will struggle to get to 40.  A strong high pressure area is developing in Western Canada which will help turn the winds to the North and Northwest.  There appears to be a good chance of plow able snow on Tuesday.

Current Conditions
Temps

4 am Temperature Analysis (image weatherbell)

Winds

5 am 10 m Wind Speed and Direrction

Locally winds are out of the Northwest.  The surface chart

WPC Surface Analysis 330 AM

A cold front is the leading edge of the real cold air and this will pas through New England tonight.  I cannot rule out a snow/rain shower around dinner time.  However the system is moisture starved.   What it will do is briefly raise heights so temperatures today should get in the low 40's.  

Short Term Forecast

Here is what I expect for temperatures today (click to enlarge)

08z RAP 2 m temp 3 PM (image weatherbell)

Skies will feature a mix of sun and clouds.  The window to see some precipitation tonight is 5-9.   After that lows drop to the low to mid 20's.  Saturday is much like today except the wind should be less intense and there will be more sun than clouds.  Sunday is the brightest day of the weekend, though highs will be near 40 with the wind picking up.  An even colder air mass is set to move in Monday.  A lot of areas will struggle to get to 35 and some will not break 32.  

WPC 3 day precipitation forecast

Long Range Discussion

A storm will cut up through the Great Lakes.  This will allow for low pressure to develop along the east coast and track south of New England.  The abnormally cold air mass in place will allow for mostly snow for Northern New England.  In Southern New England it is a bit more tricky as the low will pass close to the Cape if not directly over it.

WPC Tuesday 8 am forecast surface

I like the WPC idea although my sense is the storm is just a bit further off the coast.  The block is still strong in the North Atlantic so I think the main cyclone cutting through the Great Lakes is forced to develop the surface low further south and east.  Here is the 5 day precipitation totals

WPC 5 day precipitation totals

Here is what I think about precipitation type and a first guess at some amounts.

First guess snow/precip Tuesday

Regardless of exact precipitation our rivers are going to cause some problems in the next few weeks.  Chances are growing for a moderate flooding event during the next few weeks.

Pleasant Wednesday, Winter Makes Comeback

There will be one more day of early spring like weather before old man winter makes a return to New England.  We won't be seeing mid January temperatures but highs will struggle to get to 40.  There are several shots at snow, although nothing major in short to medium range.  There were no problems on the rivers as most crested well below the level that was forecast.

Current Conditions

The main cold front that brought all the precipitation has cleared the coast.

WPC surface analysis 331 EST

The cold air is marked by the cold front running through the Great Lakes.

National 2 m temp analysis 4 am (image weatherbell)

Here is the Jet Stream from last night at 8 PM

00z NAM 250 mb wind 

Notice that the cold is found where the jet stream has dipped.  In New England our flow has been out of the South and Southwest.   Look where we will be tomorrow morning

00z NAM 250 mb wind Thursday 5 am 

Winds will be out of the north and northwest.  Quite a ridge is building in the west which will lead to some record high temperatures in the southwest.

Forecast

09z RAP 2 m temps valid 2 PM (image weatherbell)

Today temperatures max out in the upper 40's.  It wouldn't surprise me to see a 50 degree reading or two.  We remain dry through 72 hours 

WPC 72 hour precip forecast 

Temperatures Thursday and Friday are warmest in Downeast Maine and SE MA.  Tomorrow I think even the Cape and Islands struggle to get to 40

00z EURO 2 m max temps Thursday afternoon (image weatherbell)

Temperatures overnight drop into the mid 20's.  Friday is similar, maybe a degree or two warmer

00z EURO 2 m max temps Friday Afternoon (image weatherbell)

On Saturday a disturbance will pass New England to the south.  There is a lot of cold air just to the north so 1-3 inches of snow is not out of the question.  There also looks to be another shot of snow on Monday/Monday night.  Its a far cry from March 2012.

Earth Physical Sciences Division 

So far March 2013

March to date relative to normal (image weatherbell)

The block shows up nice in the temperature anomaly chart which is part of the reason for the stubborn cold.  Here is one forecast for the rest of the month

GFS 8-16 T anomaly (image weatherbell)

The heat wants to build in the southern US which makes sense, the sun is going to be entering the Northern Hemisphere in a week.  However the signs of the block are still there and that is going to be one heck of temperature gradient.  Severe weather, rain, northern snow are all on the table through March 31 (and beyond?).

Burst of Heavy Rain This Afternoon/Evening

A cold front moving east will drop a 0.5"-1" of rain this afternoon and early evening.  Due to its slow passage the cold air behind it will not work into Southern New England until Wednesday night.  The end of the week and the weekend look to be below average for the middle of March.

Headlines/Current Conditions
A Flood Watch is posted for most of Southern New England

NWS Boston Flood Watches

There is a lot of moisture to the west/south

NWS Regional Radar 529 AM

Its easy to see the culprit on the surface chart

WPC Surface Analysis Chart 321 AM

Notice how the cold front stretches into the Gulf of Mexico.  On Satellite the storm looks like this

NOAA GOES_East Water Vapor Satellite (445 AM)

The warm front has completely cleared New England.  Here are the latest temperatures

Regional 2 m Temps 5 am (image weatherbell)

All of this is setting the stage for a mild moist afternoon/evening.

Forecast

Rain pushes into Southwestern New England around 11 am.  It will make its way towards Worcester and Providence between 3-4 PM and reach Boston around 5 PM.  Its a quick burst of rain, but we can expect around an inch in most places.

WPC 2 day precipitation totals

The rain clears the coast by midnight.  There is a chance for some strong wind gusts that could take down isolated tree branches and blow around the trash barrels.  The peak threat is 4-11 PM for these with a strong potential between 5-9 PM.

08z RAP 900 mb winds, ,mslp (image weatherbell)

These are 60-70 mph in orange just a few thousand feet up.  A strong line of convection may be able to mix these to the surface.  Temperatures today will be in the low 50's.  For a period between 11 am - 1 pm we will be near 60 from Worcester County east

08z RAP 2 m Temp 11 am (image weatherbell)

Temperatures will drop into the upper 20's overnight.  Check out the gradient at midnight

06z NAM Hires 2 m temp (image weatherbell)

This will lead to a "flash freeze" overnight as the melted snow and wet roads freeze over rapidly.   High temperatures on Wednesday are in the mid to upper 40's.  By Thursday highs drop into the 30's.  Due to the combination of snow melt and the rain some smaller rivers may overflow their banks.  Here are a few rivers around the region.

Blackstone River @ Northbridge

NO FLOODING FORECAST

Assabet River @ Maynard

MINOR FLOODING FORECAST

Merrimack River @ Lowell

NO FLOODING FORECAST

Blackstone River @ Woonsocket

NO FLOODING FORECAST

For more river forecasts click here.

Not a good start to mud and flood season.

Early Spring Feel to The Next Several Days

It might be time to move on from blogspot.  I spent 2 hours on this post (originally) only to have it delete itself.  Here is a shorter version.

Current Conditions

NWS Northeast Regional Radar

On the Water Vapor Loop

GOES_East Water Vapor image 

At 500 mb

00z NAM 500 mb heights

Areas of increasing heights (and temperatures) are shown by the red arrows.  Lowering heights are shown by blue arrows.  These are troughs (blue) and ridges (red).  This will help push temperatures into the low 50's today.

Forecast

00z EURO 2 m Max temps Monday (image weatherbell)

A mix of sun and clouds today, becoming mostly cloudy overnight.  Lows drop only to the low 40's tonight.  Temperatures again approach 50 tomorrow but will be accompanied by heavy rain.  Here is the WPC 3 day rainfall total 

WPC 3 day rainfall totals

This begins Tuesday afternoon.  There will be some decent wind gusts as this front pushes through

06z NAM hires 900 mb winds (image weatherbell)

Due to the stubborn Greenland block the front will take its time to clear the region.  Precipitation will be done by Wednesday morning but the cold air will not work into New England until Wednesday night.  Expect temperatures around 50 on Wednesday.  By Thursday temperatures fall back into the upper 30's/low 40's which is normal for this time of year.  Similar conditions expected for Friday.

Long Range Outlook

Here is the 10 day EURO precipitation totals

00z EURO 10 day precip totals (image weatherbell)

Here is the 9 day MSLP and 850 winds.  This is 8 PM on March 20th.

00z EURO 9 day MSLP 850 winds (image weatherbell)

This would bring considerable snow, wind, rain, and coastal flooding/erosion.   I don't want anymore snow but we can live with it.  Its March afterall it will not stick around long.  I'm concerned for the coast as another major ocean storm would be devastating.   Is it irresponsible to talk about a storm 9-10 days out?  99/100 yes it is.  Today I break the rule.  If you live along the coast be aware there is the potential for another major hit.  When people's homes are in danger of falling into the ocean I want to let them know as soon as possible.  River flooding will need to be watched as well.  There is plenty of time to watch this.  Everyone wins if this blows out to sea.

What Went Wrong With the Storm?

I, like 99 % of meteorologists officially under did the snowfall totals.  I thought I and other smaller meteorological enterprises (ie other blogs, some premium forecasters) did much better than the Day Shift of the NWS, WPC, and yes the hard working TV meteorologists in Boston.  It wasn't a lack of skill; here is the NAM from Tuesday Night out 48 hours...so valid Thursday night at 7 PM

00 3/6/13 Hires NAM snowfall totals thru Thursday (image wxbell)

Two points about this....1) Swing and a Miss in DC, but captured the heavy snow in VA very well.  2) It has the amounts, missed the timing.

Zoomed in NWS Boston snowfall totals

SO what happened?  The main storm center moved way out to sea.  The snow on Thursday was from the ocean storm.  The snow Friday was as complex a situation I have come across in my brief time forecasting full time.  Judging by our more experience meteorologists they haven't either!  An upper level low pressure system was also moving east from Southern Ontario and that dove down into Western PA.  The interaction between the two storms was enhanced by a 1036 mb High Pressure system to the north.  That squeezed the isobars that you see on a weather map and allowed for snow rates to climb to 1-2" per hour.  

I'm not all that disapointed in my forecast except I wish I updated my snow map Thursday night.  I knew it was going to over perform by then everything was in place.  I missed the dry slot- I thought the Pioneer Valley saw it when it was more the Hope Valley region of RI.

IN MY OPINION...the bust in DC made forecasters up here nervous.  The storm track was so far out to sea us meteorologists thought "Well there is no way...".  The models have not been much of a help since the blizzard with wild swings from forecast to forecast.  So all of this snowballed in a 4-8, 6-10 type storm into a 1-2 feet.

Current Weather

The sun is shining nice and bright.  A fresh foot of snow lays in the yard (I measured 16- not sure who sends in there reports to NWS from town).  Temperatures

Regional 2 m temps 5 am (image weatherbell)

Today we improve, but due to the deep snowpack South Central and Eastern New England will not get into the 50's today.

10z RAP 2 m temps 3 PM (image weatherbell)

Western New England warms into the 40's and 50's.  Central/ Eastern will struggle to break 40.  Providence or Fall River could do it, no one else.  Good news is we are dry.  Still a bit windy in SE MA and the Cape

06z NAM 10 m Winds valid Sat 1 PM (image weatherbell)

Tonight the major headline is we lose an hour of sleep.  Will update tomorrow's forecast later but pretty much a repeat of today just slightly warmer and less wind.

Snow Increases With Intensity Throughout Day

Light snow has broken out across Southern New England and so far the storm is on schedule

NWS Boston local radar (512 AM)

The Cape and Islands are Rain (denoted by the red line) while everything west is falling as snow.  The regional radar shows plenty of storm to go

NWS Northeast Regional Radar 458 AM

The water vapor satellite shows a healthy storm off the Mid Atlantic coast

415 am Water Vapor Satellite (NOAA)

So far the dreaded dry slot has worked into Worcester County and Northern RI.  Lets call it the Cantore effect, since the Weather Channels Jim Cantore has moved from DC (where a lot of meteorologists busted) to Worcester to cover the storm.  This morning the NWS has expanded Winter Storm Warnings to the east

NWS Boston Watches/Warnings

I've enjoyed the back and forth between the midday NWS shift and the overnight crew.  The overnight crew is more bullish that the region sees over 6 inches of snow.  The midday has high doubts about the storm!  I noticed the same thing with the Weather Prediction Center (formerly HPC).  Here is the 3 day precipitation totals from the WPC

WPC 3 day precipitation totals

That's over an inch of precipitation from Worcester east, with more in SE MA.  So we know there will be a good slug of precipitation...how much falls as snow?  We'll have to look at the temperatures at several levels.

Current temps

5 am Regional  2 m Temps (image weatherbell)

At 5000 feet

850 mb temps, heights, wind

This image shows temperatures are -4 C to -5 across a lot of MA or 23-25 F.  One can also see the piece of energy moving through Northern Michigan which will really energize our ocean storm this afternoon.  These temperatures at 850 not only support snow, but during the day if surface temperatures are not to warm and precipitation is heavy enough it will accumulate.  According to the latest RAP (a super short range model) we will not see anything accumulate in MA today

10z RAP 2 m T 1 PM (image weatherbell)

Surface temperatures of 37 across much of SE New England will allow for slushy accumulation on the grass but will keep pavement wet, not white.  Interesting enough there is plenty of cold air in Northern New England.  As soon as the wind turns to the north (which may not happen until early evening) everyone will turn to accumulating snow.  The Cape will likely see little to no snow, but the coast has a MAJOR flooding event underway.  This is, has been, and will be the major story from this storm.  Here is a look at winds

10z RAP 900 mb winds 7 am (image weatherbell)

Those winds are at 3000 feet or so.  At the surface they will be howling at 60-70 over the water.  High tide is around 7 so you can see the issue.  High winds, large fetch, slow moving storm will mean several cycles of flooding.  Inland once the snow starts to accumulate on trees the winds will be gusting 30-40 mph inland, 45-55 along the coast.  I can't rule out 60+ because Nantucket has already reported one.

I like my snowfall map from yesterday and I do not like to flip/flop.  

Snow forecast

Can I see more in the Connecticut Valley? I sure can, especially in Southern CT.  Can I see more in Fall River and New Bedford? I can definitively see that.  The jackpot may well extend towards Norfolk and Foxboro.  In my hometown of Northbridge I like around 9 or 10.  I think Logan Airport measures 3.5 inches   The 6-10 may be pushing it in Providence.  I like the lower end of 5 or 6 there.  

So to recap it will snow today but will struggle to accumulate unless it is heavy.  It really picks up overnight as a system in the Great Lakes interacts with the storm and enhances precipitation rates.  Temperatures aloft look plenty cold enough so tonight we will see a good thump of snow.  It pulls away by early afternoon Friday.  The weekend has a warm up!  I don't see this as a flip to spring unfortunately; its just a tease.  More this afternoon if needed.  Watch out for falling branches it only takes two inches of heavy wet snow and 40 mph winds to cause problems.