Jonas 2016: ♫ People Are Blowing Snow ♫

If you haven’t thought of the Weezer song with regard to this storm, you’ve failed me. It deserves some parody. I tried. Oh well. Onward…

What’s changed since yesterday, Matt?

Not much. Other than bread and milk supplies in the grocery store being dwindled.

  • The storm is still coming.
  • It still appears the metro Washington, DC area is the bullseye for snow.
  • Coastal flooding is still a serious concern.
  • Blizzard Watches have been expanded to include much of Jersey, Philly, and the New York City area and Blizzard Warnings are posted for DC and Baltimore.
  • The northern edge of the storm is still going to drive most meteorologists to their local bar.

So how much snow for me?

Here’s my updated map:

012116_Snow_Forecast
My own personal snow forecast as of 5:30 PM ET Thursday. Again, not official, but my way of expressing it.

Again, I’ve highlighted the two key areas of uncertainty. The northern fringe is going to be a royal pain. There are some models that still bring good snow 8-12″ to NYC, but I don’t personally buy that scenario right now. Based on my experience, these sorts of storms have disappointed on the northern fringe, so I’d rather take a conservative stance there.

From Philly into Baltimore and DC, it gets complicated too. You’ll have a number of factors driving snow totals. I expect there to be issues with mixing in spots. Convection (thunderstorms…yes, thundersnow) will also be likely with this storm. In those cases, sometimes strong bands of snow setup over one place and effectively “rob” another of snowfall. So it’s possible that the final snow totals will not look this uniform. You could easily go from 18″ one place, to 10-12″ a couple towns over, back to 18″ a couple towns over from that. It’s chaotic. Snow forecasts aren’t meant to be simple.

What about the blizzard part?

Yes, Blizzard Watches and Warnings are posted all over. Fun fact: The amount of snow you see has 0 factor in whether or not a storm is defined as a blizzard. Why is that? My honest answer is because we like to make things difficult on ourselves as forecasters and communicators. That aside, it has to do with impacts mostly. A blizzard is supposed to mean wind, which limits how many storms meet the criteria of one…thus making it special and making it stand out.

For a storm to be a blizzard, it has to have 3 hours of winds sustained at or frequently gusting to 35 mph and visibility below 1/4 mile. That’s all. So we’ll see if that gets achieved, but based on model data, yes, it looks like blizzard criteria will be met at many places. For the sake of yourself, stay home Saturday.

How about the coastal flooding?

Here are the very latest tidal forecasts for Cape May, Atlantic City, and Sandy Hook. You can select others from those sites.

I heard this was going to be like Sandy?

Here’s something that agitated me today. I heard from several people somewhat panicked, thinking this was going to be Sandy II. Sandy was a 940 mb monster storm to the south of NJ, that was dragging days of water across the Atlantic Ocean directly into Jersey and New York. This storm will be strong, but it will be moving away from the coast. It won’t have nearly the same characteristics as Sandy did. Meteorologically, it’s like comparing apples to oranges.

But in terms of actual impact what does it mean? It means something worse than what you saw back in October with Joaquin, but short of what you saw in Sandy. It means a lot of water, yes, and major coastal flooding and a top 10 event perhaps. It means problems. The coast is more vulnerable now than it was 5 years ago.

That said, it does not mean mass devastation like was seen in Sandy. So you are right to be preparing and be concerned. But should you panic? No. Make your preparations as you would for any major coastal storm. Remain calm and heed the forecasts of the National Weather Service.

This will likely be my final forecast post on this storm. Thanks for reading and hope you have some time to enjoy the power of nature without being impacted too hard.

Follow me on Twitter @mattlanza.

Jonas 2016: Make Snow Forecasting Great Again

I don’t have any mom texts to run with today, but I do have a map. We’ll get to that shortly. Let’s break things down.

So what’s changed since yesterday, Matt?

Honestly? Not much really. We still have a storm. It’s still early in the game for snow forecast maps, but we can at least make some assumptions. We still have a major coastal flooding issue to deal with. We do have blizzard watches posted, among other NWS watches and warnings. All this means is “prepare for a snowstorm.”

Where are the watches and warnings?

Glad you asked. Here:

012016_snowwarnings
National Weather Service Watch/Warning Map as of 5:45 ET Wednesday

In the East, the purple are winter weather advisories, the blue winter storm watches, the pink winter storm warnings, and the green near DC is a Blizzard Watch. Consult your local NWS office website for what it all means exactly, but the bottom line is a major winter storm is going impact places from Central Arkansas to New York City.

Has the coastal flooding idea changed?

Not really. There have been some forecast tweaks, but overall you’re still looking at a top 5-10 coastal flooding event along the Jersey and Delaware Shore, and possibly for places south and north of there also. Basically, this should be the worst you’ve seen since Sandy. It should *not* match Sandy in most places (though in Cape May and Delaware it’s going to come close), but I don’t want that to diminish the significance. The coast is far more vulnerable in spots now than it was then, so just because it’s not Sandy II, does not mean it’s going to bust. This is a big deal. Here are the very latest tidal forecasts for Cape May, Atlantic City, and Sandy Hook.

This flooding event will rival some of the great nor’easters in memory. Think Ash Wednesday 1962, Halloween 1991, December 1992. This storm will have elements of those storms and it should be treated seriously if you live on the coast or back bays.

Alright, so talk to me about snow.

Here is *my* snow forecast thinking. This is not an official forecast. It’s subject to change, and you should always consult the official NWS forecast or local TV for the most up to date info. Yes, I’m a native of Jersey and spent 5 winters drawing snow maps in Upstate New York when I worked in Syracuse and Utica, but I live in Texas now. I can only do so much.

012016_Snow_Forecast
My snow forecast as of Wednesday evening. Not an official forecast, just my own opinion.

What do I think? Some key points.

The northern fringe of this storm is an absolute nightmare. If you live north of I-195 in NJ or I-76 in PA, this is going to be an incredibly difficult forecast to peg down. The tight gradient in snowfall that I spoke of yesterday is going to wreak havoc. A 20 mile shift in track of the storm (highly possible) could lead to a 6-12″ difference in snow totals, if not more. This is going to be a big problem for North Jersey, possibly the Harrisburg metro area, New York City and extreme southern Connecticut/Long Island.

The Jersey Shore is oscillating between a total mix scenario and a thumping snow. I don’t think this is like the storms of 2009 and 2010, where coastal South Jersey absolutely raked in snow totals. This will be more complex, and I’ve cautiously gone about 3-6″ there, but I do see risk for higher amounts depending on the exact final track.

The thump zone for this will be Northern/Western Virginia through DC and Baltimore. While I don’t expect a uniform 18-24″ in that zone, I do expect some locations to push 30″, contingent on mixing and thunderstorm potential. Other areas will see less than 18″. That’s the nature of snowstorms like this.

Yes, thunder is going to be likely from VA through NJ with this I think.

Winds of 30-50 mph are likely, and some gusts could be even stronger. This will create blizzard conditions. I would not be shocked to see Blizzard Watches expanded tomorrow.

Anything else I should know?

Snowstorms are fun. This one is going to be big, massive, and historic. While fun, it has a very serious element to it that should be respected. If you have plans on Saturday, I would strongly consider rescheduling them. Heed the warnings from NWS. They’re not just throwing this stuff out there. It’s serious.

And please consider taking pictures of something other than your patio furniture. Seriously. Get creative!

Follow me on Twitter @mattlanza.

Your East Coast Winter Storm Run-Up Survival Guide

As a forecaster and communicator, I try and approach my audience a lot like I would my mother. Would my mom understand what I’m talking about? Sometimes I deviate and get nerdy; we all do. But when it comes to the forecast details, it has to be simple, clear, and easy to understand.

So my mother sent me an interesting text message today. She said:

Ok. I’m getting anxious. Or curious. I’ve heard so many maybe this or maybe that’s. I want the truth. I’m sick of speculation.

That’s such a great mom text.

In the run up to this major East Coast winter storm, blizzard, Winter Storm Jonas, whatever you use to describe it, you’re going to get a ton of this speculation.

So today, you’re all my mother, and consider this my survival guide for you.

What’s going on here?

The weather models have been hooked on this idea of a major winter storm in the Eastern US for awhile now. There is good agreement among all the various models we use that something is going to happen. Someone’s getting a major storm.

So how much snow am I getting?

No one can answer that question today unfortunately. What we know is that a number of factors are going to contribute to this storm being loaded with moisture. In other words, someone is going to get a *lot* of snow. It’s just not possible to say who that is yet.

Right, right, I get that, but give me your best shot.

This storm is big, slow, and it has a number of complex parts to it that will make it difficult to peg down until we are closer in than usual. But, some trends have evolved in the last couple days that lead us to believe a few facts about this storm.

First, it will be a *big* storm. That means even if you don’t get snow, you may get impacts. It will be slow moving. It will have wind…lots of wind. It will have major, major coastal impacts. Depending on track, we could be looking at a top 5-10 coastal flooding event for folks from the Jersey Shore into Virginia perhaps. That is a serious issue.

But what about snow? The storm has slowly trended south on the weather models. Additionally, it has a very, very sharp gradient on the north side. In plain English? If you live on the northern fringe of this storm, there’s going to be a razor thin margin between major snow and conversational snow.

Here now, a map of where I think things stand as of Tuesday afternoon. Remember, this is subject to change.

011916_snowrisk
My Own Tuesday Evening Snow Synopsis for the Weekend

The trouble is in New England, New York City, and Northern NJ. The models show a tremendous cutoff in snowfall here. The next map is a weather model’s output for precipitation (liquid, not snow). I’ve focused on the NYC area.

011916_precip
18z GFS Model Precip for New York City area (Weather Bell)

Why am I showing this? Notice how in the Central Jersey area, the model spits out about 1.5″ liquid. Go 50 miles north from there. So, like Orange County, NY? About 0.5″ liquid. A 1″ liquid is roughly equivalent to about 10″ of snow. So 10″ snow difference over 50 miles, and the reality is likely that it will be even sharper than this. You’re talking about (surprise!) a major difference in snow totals likely over a short distance over a major population center.

Bottom line in all this: I have higher confidence in heavy snow hitting Virginia and probably DC right now than I do for the Northern half of NJ, New York, or New England. I don’t focus on North Carolina much since the majority of my family and friends are between DC and Boston. But this has potential to be a big storm in a good chunk of NC also.

Alright, so when does all this unfold?

Snow should start in Virginia as early as later Friday morning, and it probably won’t end until about Saturday night. In Philly, it’s a Friday afternoon start and late Saturday night finish. Add a couple hours to all this as you go north to NYC. I have lower confidence in anything further north, so I won’t speculate beyond this.

What about this coastal flooding?

Yeah, this one goes unchecked sometimes. Snow is way sexier, but this is way more damaging potentially. The NWS office in Mount Holly has done an excellent job highlighting this risk. If you look at storm surge guidance for Cape May, NJ, you’ll see the first high tide cycle impacted late Friday ends up at a water level of about 8.5-8.7 feet. Sandy saw a tide level of 8.9 feet there, October 29, 2011 was 8.7 feet, the December 1992 nor’easter was 8.6 feet. An 8.5 foot tide level would rank in the top 8 all time at Cape May. This one’s big. It’s like a 90’s throwback nor’easter.

011916_Cape May
Cape May Surge Guidance shows a tidal level over 8.5′ Friday night/Saturday AM. This would be a top 10 event without much trouble. (NOAA)

If you live along the coast or Back Bays of New Jersey, Delmarva, Virginia, you should begin planning for the possibility of 2-3 high tide cycles like this. If the storm track shifts a bit or the intensity changes, we could see these values change. It’s a fluid forecast, but it’s a serious issue along the coast. Follow your local NWS office for info and guidance.

So will it be a blizzard?

Maybe for someone. It’s entirely possible, but specific criteria must be met regarding wind speed and visibility. It’s too soon to say exactly where and who or how long, but it’s a distinct possibility.

That’s all for now. Feel free to ask any questions and follow me on Twitter at @mattlanza.

Cold, Flooding, Snow…Just Another Spring!

Trying to hit a few key issues today. First, the potential for accumulating snow in the Mid-Atlantic over the weekend. It’s snowed, sleeted, thundered, etc. across much of the Mid-Atlantic and Northeast in the last 36 hours…why not add something else to the mix?

12Z NAM Snowfall Forecast (From Earl Barker's Site: http://wxcaster4.com)

Map to the left is the NAM model depiction of snowfall for the next 72 hours. It shows you snow stretching from Omaha to Kansas City to St. Louis to Louisville to Cincinnati to just south of Washington, DC. This has been shown off and on throughout the week on all the models. It looks like we’re game on for a snow event. The problem is (of course) the exact storm track. The GFS forecast is *slightly* further north, which would bring more snow into DC and much less around Richmond. I would side in between the two right now…with light snows south of Baltimore to south of Richmond, with an axis of heavier snow, probably in the middle, through, say Fredricksburg, VA. Could be a decent event for the  northern part of the Blue Ridge. This will not be a *major* event, but given that it’s almost April, every snow event is extra painful.

So if you have weekend plans, specifically Sunday, keep this in mind. It is the time of year where it’s tougher to get snow to stick on the roads, but given that we’re leading into this event with several cold days, we could see more sticking than we normally would in late March.

In other news, spring may be delayed somewhat in the East. Just got a look at the latest weekly forecast from the European model…and, yeah, it looks cold if you live anywhere north of about Florida. Not guaranteed to verify, but this is certainly not what you want to see if you live in the Northeast, Plains, Great Lakes, or Mid-Atlantic.

However, this may help slow snow melt some over the northern tier…which is good because the latest river forecasts show major flooding likely on the Mississippi near St. Paul. Could be another painful Upper Midwest flooding season.

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Facebook Us…Oh, And Snow.

It’s been a disruptive month for State of Occlusion! Transitioning my life offline from the West Coast to the East Coast, so haven’t had time to blog. I’ve discovered Facebook to be an extremely useful tool to communicate short bursts of information and post maps quickly. I will occasionally use this blog to elaborate on various significant events, but in the meantime, for the latest thoughts and information from me, like the Facebook page and tell your friends. We’ve already got 100 fans…let’s go for 200!

Follow State of Occlusion on Facebook for the latest!

In the meantime, while many in the Northeast enjoyed record warmth this Friday, winter is around the corner ready to take its season back. It will be cooler and extremely windy Saturday, followed by a leveling off of temps Sun and Mon. One storm will swing through Monday, potentially dropping heavy snow on Upstate NY, far N PA, into Connecticut and Southern/Central New England. Round two will affect areas south of I-80, somewhere between DC and New York, bringing the potential for very heavy snow on Tuesday as colder, Arctic air pours in. Right now the best odds for this appear to me to be between Baltimore and Allentown, back west across all of PA into Ohio and east into NJ. Potential does exist for 6″ or more with this storm, so this may cause significant travel issues in the Mid-Atlantic on Tuesday. Cold Wednesday followed by another semi-thaw (though not to the extent you saw this week).

I will post updates on Facebook through the holiday weekend.

Here We Snow Again!

Snowfall Forecast for Tues/Wed.

There’s the snow map at the left. Here’s some ideas by region.

– Boston area could see some very high snow amounts of 16-20″, depending on the exact track of the storm. If the storm tracks just right, they could get slammed, as some models suggest. Interior Southern New England right now would appear to be the jackpot, but I wanted to emphasize the risk to the Boston area. Parts of CT and MA may see some 20″+ amounts, with generic 8-16″ amounts as you approach the coast (some coastal areas and the CT River Valley may see lesser amounts). Cape Cod will likely be close enough to the storm to mix or change to rain. This will cut down on snow amounts a bit there. Additionally, wind will crank on Wednesday, leading to blizzard conditions in parts of New England.

– Metro NYC area/NE NJ won’t be the jackpot this time around. However, this still appears to be a respectable, business hampering snow. Think of the last system that went through, think of post-Christmas, and expect this storm to end up somewhere in between the two. There will yet again be a very sharp cutoff to significant snows, somewhere within the I-287 corridor. Blowing and drifting snow will occur in this region Tuesday night and Wednesday.

– Southern NJ will be close to the center of the storm, so I do expect the possibility of a mix. It also appears the storm will really explode a little too far away from this area this time. I still expect a respectable 4-8″, with the potential for higher amounts in mainland Cape May, Atlantic, Burlington, and Ocean Counties (6-10 perhaps?). Coastal sections may even see less, primarily in Cape May County. If mixing for some reason does not occur, tack on an additional 2-4″ to these forecast amounts. Blowing snow will cause a few problems Wednesday.

– Philly/Trenton will be solidly in the 4-8″ range, with potential for higher amounts (8-12) as you get closer to Trenton/New Brunswick and slightly lesser amounts as you slide south and west of Philly. Blowing snow will be a problem on Wednesday.

– DC/Baltimore appear to be in the 1-4″ range, with again potential for higher amounts in the northeast corner of the map. Much of the interior back through OH/MI will average 1-4″ as well, with potential for a few 4-6″ amounts in spots, depending on how things shake out.

And that’s that! After this storm, it appears we’ll head into a relative period of calm in the Northeast. So enjoy this if you like big storms and snow. Winter is certainly not over though, so stay tuned.

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Just a reminder… State of Occlusion is on Facebook. I’ve posted some additional cool links, quick model updates, and snow maps early on that page. “Like” the blog by clicking here!

A Sierra Special!

Map of NWS Watches/Warnings/Advisories as of 5 PM Pacific, 11/19/10

Wanted to discuss what’s about to unfold in the Sierra-Nevada Mountains of California over the next couple of days. Now, the Sierra get rocked every winter…and sometimes they get mind boggling snow amounts. But for some reason, every time it happens, I’m always floored by the numbers and the forecast. The map at the left shows the mess in the West…winter storm warnings for the entire Sierra Crest, mountains around Los Angeles, as well as northern California, Lake Tahoe, Carson City, and Reno. I’d classify this storm as “fun.” Let’s discuss how some of this will unfold.

Here’s one of the best forecasts ever…for the High Sierra (~ 12,000′) , just northwest of Mammoth. That’s 64-88″ of snow. The NAM model has been especially aggressive with this system, bringing extremely high amounts of precip to the Sierra Crest during this event. Here are a few maps..

Saturday Morning

Sunday Morning

Monday Morning

The first wave/cold front pushes through tonight and Saturday morning, dropping a fairly heavy amount of precip (liquid) on the Sierra. The second wave/front swings through Sunday morning, with probably an equal or greater punch. Wave #3 moves through Monday morning and should just be the “insult to injury” system. You have to remember how California is geographically set up. You basically have an 11-13,000′ wall sitting in the middle of the state and this soaks up any moisture on  a westerly wind component, which just allows them to wring everything out in those mountains.

The NAM model is admittedly ridiculously aggressive with QPF totals over 6″ on the northern crest by Monday evening. Using a standard 10:1 ratio of liquid to snow, that’s 60″ or 5 feet. But you would assume the ratios would be much higher so…yeah, you do the math. The GFS is a little more tepid, spitting out 4″ at max over the northern crest and “only” about 2.5-3.5″ liquid in the rest of the Sierra. That still comes out to close to 60″ when you factor in higher ratios. So the Sierra, Tahoe, etc. will get pummeled in this one, with 2-4 feet of snow on average above 8,000′ or so and lesser amounts in the lower high terrain.

We’re not quite done yet, as that Monday storm may be a sneaky one for the Northwest and deliver snow to Seattle or the area around it…and with cold air locked it, snow levels will get awfully low! Then that storm will move into the Rockies and places like Salt Lake City may get pummeled on Tuesday. An interesting start to holiday travel week!

Hitting the Links

Today is the one year anniversary of the debacle known as “Climategate.” Dr. Judith Curry examines if the climate science community has learned anything from it. There are a few good links to some other articles on the issue. Andy Revkin of the New York Times has a recap of what the last year has been like. While I don’t necessarily agree with how this was done, I think Climategate has done more good than bad for the long-term state of the science. It’s put things in perspective and helped curb the “science is settled” crowd to allow us to look at this with a wider focus before making economically destructive decisions. It’s re-opened a two sided debate and brought skeptics to the table. And that’s important for science.

Related: A departing Republican congressman from South Carolina fires a warning shot about dismissing climate change.

Eyjafjallajökull, the Icelandic volcano that messed up travel this summer, is the focus of a new paper in Nature that examines more about what was known about the volcano and what happened.

Today’s edition of the CIMSS Satellite blog shows ice and cold around Hudson Bay.

The Capital Weather Gang examines if the flood control plan being developed for a Flood Wall in Washington, DC is enough to do its job.

And from the photography side, time lapser Tom Lowe is putting together some truly beautiful and amazing scenes from the Southwest into a movie. Check out the site and some previews here. It really is some incredibly beautiful work.