Model convergence

If you live outside of MA-128, be ready for a plow able snowstorm that will begin overnight Wednesday night.  All the forecast models are beginning to hone on a solution, making this, hopefully, one of the easier storms to forecast for this winter season.

The low pressure system that will bring the snow is currently moving through the Ohio Valley and will begin to have a significant impact on the Mid-Atlantic tonight.  Heavy amounts of snow are expected along the Appalachian Mountains from VA north into NY and then eventually into Southern New England.

Temperatures at the surface is going to relatively warm, so expect to see a wet, heavy snow from this storm.  Though the further inland you go, the drier the snow will be.  It looks like we will see somewhere between 1 and 2" of liquid precipitation from this system.  Snow to liquid ratio should be somewhere between 6 to 1 and 10 to 1.  The highest precipitation total appear that they will be where it is mostly rain or heavy wet snow.  So if you do some quick math, highest snow totals will likely be between 10" and 14".  There is some fudging in there for wiggle room.

Here is another beautiful map that I've created of where I think the snow will occur and who will end up with what:

Credit for the base image to Plymouth State Weather

There is going to be pretty sharp gradient to the snow in Eastern MA and Southern NH.  The rain/snow line will set up near Rt 128 in Massachusetts and waver back and forth through the day on Thursday.  That being said, if the storm track shifts further to the north, the snow totals will be much lower and the higher totals will occur mainly in Southern NH.

So, if you leave in or near that dark blue color, make sure your snow blower is ready and you have done your stretches, you could be moving some cement like snow on Thursday.

Thanks for reading, more tomorrow.

-Jon K.

Storm Threat

Well, we could go more than a week or so without the threat of what could be a significant storm here in New England.  As with EVERY other storm so far this winter, we are dealing with a lot of model disparity.  The two medium range forecast models have been showing different, but consistent outputs for days, the shorter range models are just starting to gather information as the storm develops in the Northern Plains, so they can't be taken too seriously just yet.

Regardless of if New England sees this storm, this one is going to cause some problems from the Northern Plains, through the Ohio Valley and into the Mid-Atlantic.  There are already too many Winter Storm Warnings to count across the Northern Plains.  Heavy snow and wind will cause numerous travel headaches through the middle to end of the this week from Dakotas to the Eastern Seaboard.

The forecast models are differing in one area, the track of the storm.  The intensity is about on par for each, but one model brings the storm up the East Coast after it exits the land near the Delmarva Peninsula while the other pushes it a bit further out to sea.  I expect that we will likely end up meeting somewhere in the middle.

So what does this mean for New England.  Well, rain and snow.  Most places inside of I-95 will predominately rain.  From I-95 north and west in Southern NH and Central MA, snow to a rain/snow mix, possibly to all rain.  North of Manchester, NH, expect to see all snow, but not much in the way of accumulations.  This is just a cursory look at this event right now.  We "hope" to have better information tomorrow as the models begin to hone in on a solution.  All of this fun would begin during the overnight hours of Wednesday night into Thursday morning.

Currently I don't expect a major impact on New England from this event as places that will heavy a good amount of precipitation will mainly see it fall in the form of rain.  Southeastern Massachusetts and Rhode Island will be the target for this.

The one that does have me concerned is how long the models try to keep this storm nearby.  It looks like it has the tendency to spin just off the coast of Cape Cod for a period of time.  If we end up with a more northerly/colder solution, this could result in a heavy amounts of snow across the interior of New England.  For now, let's hope that doesn't happen.

I'm ready for Spring.

Thanks for reading, more tomorrow!

-Jon K.

Feb 27 Storm

Well, it seems we can't for more than a few days without the threat of significant snow here in New England.  We're back at it again tomorrow as another strong low pressure system will push through the region.

The good news for some is that it will be warm enough for all rain or mostly all rain.  The bad news is that where it will be cold, there is going to be quite a bit of snow.  I've outlined my thinking in the graphic below.

Again, credit goes to Plymouth State for the underlying map.  Please excuse my poor drawing skills.

Anyway, the headline of this storm should be "Elevation Snow".  Places that are generally above 1500 ft or so are going to have quite a bit of snow from this one.  Ski resorts throughout New England, Rejoice!

This will be quick hitting storm, arriving during the pre-dawn hours of Wednesday morning and continuing into the early evening before departing Wednesday night.  It will impact 2 commutes however.  Most places outside of I-495 in MA will start with snow Wednesday morning.  As the morning progresses, temperatures at the surface will begin to warm and the snow will begin to mix with and then change over to rain.  The further north and west you are away from Boston, and the higher you are in elevation, the snow will begin to pile up quickly after 10 AM.  I expect that Central and Northern NH and Western Maine will see the most snowfall, similar to the storm over the weekend.  I wouldn't be surprised to see a few spots have a bit more than 12", but those locations should be isolated and mainly on higher terrain.

This is going to be a wet heavy snow again.  Take care when you do your digging out!

Thanks for reading!

-Jon K.

Storm progress

So that lack of confidence in my forecast is paying off.  Warmer temperatures are hanging in a lot longer than I expected along the coast of Massachusetts.  This is going to result in much lower snow totals inside of I-95/MA-128.  Eventually colder air will take hold and the majority of the rain will transition to snow, but the snow will not live up to my forecast totals.  It looks like along the I-495 corridor into Central and Southern New Hampshire will see the highest snow totals.

Even those numbers will not be impressive.  I don't expect to see many reports of over 6" when this storm is over.  Here in Hudson, we have about 2" of heavy, wet snow.

The location that is going to have the most snow from this system is going to be in Maine.  It's been cold enough there from the beginning.  The snow will continue there for a good portion of the day.  I expect to see a few spots that top off around 10".  I didn't focus on this area too much because I don't have too many readers from this area.

Overnight last night and early this morning, areas around Concord had a prolonged period of moderate to heavy snow.  This put anywhere from 1-6" of snow down, most places received about 3-4".

Expect the rain/snow to continue through at least the early afternoon before gradually tapering off in Eastern MA and Southern NH. Central NH and Maine may continue to receive snow into the first half of the night before the storm begins to weaken and pull away.

I'll share some links tomorrow that show the final snow totals so I can show you how badly I forecasted this event!  :-)  I'm not afraid to admit I blew it.

Thanks for reading!

-Jon

Update for 2/23-2/24 Storm

Feeling a little more confident in my forecast today, though I can say that confidence still isn't very high.  I'm seeing some features develop that is giving me a better idea as to what will happen but there is still a lot of uncertainty.

I've made a rather "crude" map using Google Docs.  My first time using it so excuse the horrible-ness of it.

Base Map is courtesy of Plymouth State Weather.

It looks to me like the majority of the heavier snow is going to be confined to Eastern MA and Southeastern NH.  I think there will be a jackpot to the north of Boston along the North Shore.  Here there could be up to 8" of snow.  South of Boston would probably also be a jackpot, but an extended period of mixing and then temperatures close to or above freezing will keep amounts down slightly.  Outside of the here, this storm is not going to be a big deal.  It will be not much snow over a long period of time, 12-18 hours.  It's looking like the worst of the storm will be after 7 AM Sunday to about 2 PM Sunday.  After that, things will start to wind down as the storm pulls further away.

If I see things changing, I'll update later today or early tomorrow.

Thanks for reading!

-Jon

Tricky forecast

I'm fairly sure I've used this title before, but this storm warrants the use of it again.  As I'm sitting here writing this, I have very little confidence in what will happen and therefore have no idea what to say.  I'm not saying I'm winging it, but it's pretty close to that.  Basically I'm going with my gut.

Let's start with model disparity.  It's been rampant with this storm and for the last few storms in general.  The difference from run to run is making it very difficult to come up with a solid forecast and hard for meteorologists to hold onto their sanity.  Every Met in New England who has been forecasting the last 4 weeks is earning all of their salary.  As it stands this evening, the models are forecasting anywhere from nearly no snow to 8-10".  The location of where this snow is expected to fall has been jumping around as well.

Nearly all the models do agree on one thing.  The storm passing south of New England, moving relatively quickly.  This path keeps most of the precipitation off shore.  The problem lies with a feature meteorologists call a Nor'lun trough.  I believe I have talked about this in previous blogs.  It is VERY difficult to forecast.  We've already had one of these this winter that was miss-forecasted by about 100 miles.  The result was a lot of busted forecasts.  Where there was supposed to be 4-8" of snow...there was NONE.  We are essentially dealing with the same situation now.  Will this Nor'lun trough even develop?  If it does, will be stretch far enough westward to impact New England.  How much moisture will be available?

All important questions that I don't have an answer to right now.  Anyone who says they are confident about their forecast is lying.  That is a fact.  I'm basically going to give you the most likely scenario and then update the forecast again tomorrow based on trends.

Here it goes:

As the storm passes to our south, there will be some light snow south of I-90 in RI, CT and MA.  This should generally be less than 2".  This snow will start falling midday on Saturday.  North of I-90, snow showers and flurries will likely develop mid afternoon and continue off and on through Saturday night.  A dusting to 1" possible.  Early Sunday morning is when the action could happen.  The nor'lun trough is expected to develop after midnight on Sunday morning and potentially persist through midday.  The range of affected areas will likely fall between the Outer Cape to Plymouth, MA northward to Portland ME.  Or it could not reach that far back and stay completely off shore.  I believe this one will actually make its was onto land, but it will be limited in its reach.  I think areas around Cape Ann north to Portsmouth, NH are likely to take the brunt of this storm.  It may reach as far inland as Manchester, NH, but I think that is a stretch at this point.

So look for a band of snow, oriented southeast to northwest from Cape Ann to Portsmouth, affecting Northeastern MA and Southeastern NH.  Here is where snow totals could top off around 8".  My official range is 4-8 for this area as a storm total.  Boston will be in the 1-3".  Worcester and surrounding areas, 2-4".  South central and Southwestern NH along with Concord northward to Plymouth, NH 2-4".  Southwestern Maine, 3-6".

There ya have it.  The hype that this storm got early in the week is essentially gone.  A lot of meteorologists are starting to get giddy about what the forecast models are showing for next weekend, but I'm not going to start talking about that just yet.

Thanks for reading!

-Jon

Another weekend storm?

That's right folks, our winter isn't over yet.  As I expected, the frequency of storms has increased.  Each storm is becoming "warmer" than the last.  I'll explain this shortly.

I don't want to get into a vast amount of detail, but confidence is increasing for a strong storm to impact New England Saturday afternoon into Sunday.  Computer forecast models began to pick up on this late on Monday and have been consistently showing the storm moving just offshore of Cape Cod.  The good news for some folks is that there will be some rain with this and some places will see nearly ALL rain.  Others won't be lucky and will be stuck with heavy wet snow, and potentially a lot of it.  Right now it looks like 12" is a good maximum to put on this and just about every weather outlet is thinking along those lines.

So I did mention that the storms would be getting "warmer" as we head toward the end of winter.  Most of this is the natural progression of the season.  The sun angle is higher and we are gradually getting more daylight.  On top of this, the upper level troughs are developing further to the West and this is forcing the storm path just a bit closer to the coast, allowing warmer air to move a bit further inland.  This looks like it will happen this weekend as there will be some places that see mainly rain, as I stated earlier.

If you have travel plans this weekend, pay attention to this storm, it's almost guaranteed to cause travel headaches.

More to come....

-Jon K.

Late Winter/Early Sping Outlook

Aside from the chance of a strong storm affecting New England this weekend, not too much to talk about in the short term.  Forecast models still vary on the outlook for the weekend, so stay tuned.

I wanted to address what I see happening over the next 2 months in terms of the weather pattern.

With the passing of a storm as powerful as we saw this past weekend, you tend to see a pattern change following it.  It may not be immediate, but it will set that stage for things to change.  Leading up to this storm, we've had a relatively cold winter so far.  Not steadily, but much colder than the last couple of winters.  Compared to last winter in New England, every other winter is cold!

You probably noticed the warmer temperatures at the beginning of this week.  Early indication of a pattern change.  Granted some of the added warmth comes from the sun getting higher in the sky, but it's not the only reason.  All this week temperatures will be somewhat mild.  It won't be until this weekend that they drop back closer to the freezing mark for daytime highs.

Over the past month, we've been dealing with an upper level trough across the Eastern United States.  Its been rather persistent, hence the longer stretches of cold weather.  After the passing of the blizzard, I'm starting to see a shift in the location of the trough in the mid levels of the atmosphere.  The medium range forecast models are indicating this, showing the trough shifting to the west toward the Central and Western United States.  What this means for New England is generally 2 things.  Warmer temperatures and an increased risk of storms.

I won't go into too much detail about why this result in more storms.  It has to do with the Rocky Mountains, wind direction on the east side of the mountains, and in flow of warm, moist air into the Southern Plains.  Essentially this is a Spring like pattern.  It just appears to be happening a bit earlier this year.  Maybe Punxsutawney Phil was right, early Spring this year!

The bad news is that with the snow pack, a cool ocean to our East and storms passing to our west, we run the risk of more mixed precipitation events.  This means an increased risk of freezing rain and sleet.  Whether this actually happens, time will tell, just laying out what I envision happening.  We'll also likely see a few severe weather outbreaks across the Southern Plains into the Lower Mississippi and Ohio Valleys.

Remember, if this actually happens, you heard it here first!  :-)

Thanks for reading!

-Jon K.

Post Mortem

Just a quick little blog today.  We had a lot of snow, we're dealing with it.  Here is a look at a contour map of snow totals.  At the bottom was my forecast.  Aside from not focusing enough on Connecticut, my forecast map was pretty close.

 

 

 

So yeah, tooting my own horn a little bit.  I'll say that was one of the most impressive winter storms I've ever seen.  Not just because of the snow amounts, but the wind and how long the wind lasted.

 

I'll be back later this week, there is the possibility of another storm this coming weekend.

 

-Jon

 

(first image is courtesy of NWS Raleigh)

 

 

 

February Nor'easter Update

Forecast from yesterday is generally in tact.  Most places are currently seeing snow or have seen some snow already today.  The model runs from this morning are indicating a slight southward shift of the heavy snow bands, though this is captured in the image that I posted yesterday.  I was a little suspicious of this so I made the 18-24" area a bit larger to account for any slight shift.

Places north of Manchester, NH may see a bit less than I expected yesterday, but it likely will only be off by a couple of inches.  For example, 15" instead of 18".  When it's that much snow, it really doesn't matter that much, does it?  :-)

Blizzard Warnings and Winter Storm Warnings are posted all over the region.  Driving bans will be going into effect later this evening.  I can't stress enough that people should obey these bans.  In general, if you aren't ready, it's too late to prepare any further.  The good news is that the snow will be over or winding down by 2-3 PM tomorrow and I would imagine most stores will be open in the afternoon.  Road crews and utility companies knew this was coming days in advance, they are prepared and will clear up everything as quickly as they can.

Lastly, I'd love to hear reports or see pictures of snow in your area.  You can either post comments on this blog or post them on my facebook fan page, which you probably have to "Like" first.  I'd love to hear from you!

https://www.facebook.com/Jontheweatherman

Thanks for checking in!

-Jon K.

Projected snow totals

Alright, here it is.  I was having fun with polygons at work today and put together what I think New England, focusing on Southern and Central areas, will see from this storm.  I believe The Weather Channel is dubbing this storm "Nemo".

Anyway, look for the snow to begin lightly tomorrow morning in most places.  Little accumulation is expected, generally less than 2" during the daylight hours tomorrow.  Once the sun goes down, the intensity will pick up dramatically, producing periods of 2-3" of snow per hour.  Heavy wet snow is expected closer to the coast, generally inside of 128/I-95, with fluffier snow outside of that.  Snow will continue overnight before tapering off West to East during the day on Saturday.  We should be clear of the snow by 5 PM Saturday afternoon.  Then let the clean up begin.

Her is the map:



This image was created using WSI software.

If you have to be out and about tomorrow, you will probably want to be home by 4 or 5 PM.  After that, it's going to be rather unsafe on the roads.

I'll have another update tomorrow morning.

Thanks for reading!

-Jon K.

Update on Friday's storm potential

The title is a bit mis-leading.  Potential is not the right word.  I have all the confidence that it is going to snow here in New England beginning during the middle of the day on Friday, lasting into at least the morning hours on Saturday.

You've probably heard a lot of different stories or forecasts over the last 24 hours.  You might have seen some people post pictures of one forecast model that was forecasting as much as 84 inches of snow in Northern MA, that's 7 feet of snow for those who don't care to do the math.  Is this likely or even possible in a 24 hour period, no, not really.  That was the result of an errant math equation gone haywire.  Not uncommon from computer guidance models.

Everyone needs to remember that meteorology is NOT an exact science and likely will never be.  It relies too heavily on physics, which has some aspects that are just estimations.

Anyway, enough of the science lesson.  Let's get to it!

Here is what I see happening:

Clouds will start to thicken up overnight Thursday night into Friday morning.  During this time, the storm will have begun its transition to a coastal low.  At the upper level of the atmosphere, conditions will be setting up for this low pressure to develop very rapidly.  You may hear the term "bombogenesis" thrown around by TV Meteorologists.  This essentially means quickly dropping surface pressure over a short period of time.  A sign of a strong storm.

As the storm gets closer, the atmosphere will start to moisten across all levels.  How quickly this happens will impact how early the snow starts.  One proprietary model made by the company I work for, WSI, has this happening quite early.  Not sure I believe this just yet, as it has light, ocean effect snow start around 8 AM across Northeastern Massachusetts.  This will be very similar to the snow that Southern New England had on Super Bowl Sunday.  It basically snowed for what seemed like forever, but never amounted to much.  This will merely be a nuisance for several hours before the real action gets going.

By late afternoon, for the sake of giving a time, say 4 PM, much of Massachusetts will be underneath the northern fringe of the snow bands from this storm.  This will quickly spread northward over the next few hours so that by 8 PM it will be snowing in much of New England, with a few inches already on the ground in MA.  The storm really starts to ramp up from here.  If you watch the late evening news and see reports from the NYC area that nearly a foot of snow is already on the ground, you know for sure it's coming.

After midnight, snowfall rates across Central MA, Northeastern MA into Southern New Hampshire could be on the order of 3-4 inches PER HOUR.  The biggest question will be, where does the band of very heavy snow set up and how long does it stay there?  Right now, nearly all the forecast models are expecting the low pressure center to "pause" off the coast of Cape Cod for 6-12 hours.  During this time, it will just be spinning Easterly winds into New England off the ocean, enhancing the snow band by feeding more moisture into.  A great scenario for a lot of snow.  Personally, I expect this band will set up across Southeastern to South central NH, from Rochester, westward to Manchester-Nashua, then southwestward through Northeastern and North central MA down to Northeastern CT.  Basically just outside of I-495.  I believe this is where the highest snow totals will occur.

Alright, I don't want to get into too much more detail, especially since a slight shift in track or that the storm doesn't pause for several hours will greatly impact storm totals.  Since you are probably thinking, OK, so what are we going to see, here it goes.  Look for a general 15-30 inches of snow with isolated spots possibly getting up to 36".  I'm trying to span nearly all of Southern and Central New England when I give this range.

The snow should start to taper off on Saturday afternoon and then the clean up can begin.  The good news is that it will likely be in the mid to upper 40s by Monday.  :-)

I'll have more tomorrow.  Thanks for reading!

-Jon K.

Major Winter Storm on the Way?

Well folks, it's been a while since I've posted.  Life and lack of significant weather in the Northeastern United States has kept my fingers quiet.  I apologize for my absence.  But anyway, let's get to why you are really here!

So as you may have heard by now, there is the threat for a powerful storm here in New England on Friday.  I know you all just can't wait to hear my opinion either!  I caught wind of this yesterday when I peeked at a couple of long range models.  Only one of several forecasted the storm to develop, the others kept the system disorganized with very little moisture.  Based on how this winter has played out, I was inclined to believe the group of models that was showing the weaker storm.

HOWEVER!

A couple of forecast models have come in line and are now leaning more toward a strong storm.  So here's essentially what would happen if this all comes together.  There are two areas of low pressure in the upper atmosphere, us Meteorologists refer to them as troughs.  One is in the polar flow and the other is in the subtropical flow.  These two troughs will merge together, and with the help of some jet stream support, will rapidly develop a strong low pressure system at the surface.  Remember this is the ideal situation, if all of this "stuff" doesn't happen, the storm will not be as powerful.

So you're probably asking, how much are we going to get?

Answer is, it's way too early to tell.  All we know is that there is a real threat of this happening and the possibility of eclipsing our snow totals for last two winter(not combined), exists.  To put that in perspective, most locations in Southern New England have had roughly 20" of snow each of the last 2 winters.

In conclusion, this storm definitely bears watching.  We should know more over the next 36 hours.

Stay tuned!

-Jon K