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.

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.

Historic Early Season Snowstorm

Snowfall forecast for Saturday - click to enlarge!

Sometimes, you just need to call it what it is. This is straight up a bonafide snowstorm, the likes of which not many people have ever seen or probably will ever see again…because of when it’s occurring. If you showed me these maps, I probably would have guessed mid to late November…still early, but more reasonable. If this storm occurred in December, we’d be talking about a blizzard for the Northeast Corridor. It’s remarkable by every stretch of the imagination.

The snow map is above, and here are a few things to note…especially the 3rd one…

1.) Wind: It will be strong, with our models today suggesting we see some 20-30 mph winds in the interior, with perhaps some 40-50 mph gusts on the coast. This will cause havoc inland, as any sort of wind > 10 mph with heavy, wet snow on trees that still have some leaves will lead to trees coming down and likely widespread power outages in the red area, numerous power outages in the purple area, and scattered outages in the dark blue area.

2.) The Northwest Connecticut into Western/Central Massachusetts corridor looks to be absolutely crushed by this storm. It will likely be an extremely severe hit there and could be one of the worst snowstorms in terms of problems and inconvenience for them in recent memory.

3.) Elevation will play a MAJOR role in this storm. While I have opted to unfilter things a bit regarding snow amounts, I can’t help but feel that there may be a wide and sometimes unbelievable disparity in snow totals in some areas…especially in and around Hartford, CT, Morris County, NJ, the area between Reading and Pottstown in PA, north and west of Baltimore…all places where terrain tends to transition from the more flat Coastal Plain to the Appalachian foothills…this may occur elsewhere as well, especially in valleys, like the Lehigh, Susquehanna, and Connecticut Valleys. You may see some areas with 2-3″ of wet snow…travel 5 miles north to slightly higher terrain and see 6-10″ of snow. It will be that kind of storm…the kind where a truly accurate snowfall forecast map is next to impossible.

4.) The Big Cities will likely see flakes…especially Philly-Boston, but mostly at the tail end of the storm and any accumulation should be minor and mostly on grassy surfaces….though Saturday evening could be comical in some places.

So go load up on supplies for Sunday’s football games, enjoy game 7 tonight, and enjoy the snow while you have it, because warmer air will start melting this stuff as fast as Sunday afternoon.

Yes, It Does Snow in October

Snowfall Forecast for Saturday, 10/29 Storm. Click to enlarge!

It has happened before, and it will happen again. Snow in October I mean. This will probably be somewhat overhyped, given that it is October, but still…this is a very, very impressive storm for this time of year. And given that it’s coming on the heels of a storm that’s currently producing snow in parts of Upstate NY and New England, it makes it somewhat more impressive. So with that said, the computer models we look at have come into much better agreement today with a coastal low developing Saturday and bringing absolutely miserable weather to the Northeast and Mid-Atlantic. College games may be more entertaining than usual, with Illinois at Penn State and West Virginia at Rutgers (which has seen snow and/or cold rain occur on several of their past meetings…some of which have occurred in December, not October…so blame the NCAA I guess for this).

Anyway, for most of the Big Cities, this will be a cold, miserable rain. Temps starting the day in the upper 30s or lower 40s will fall into the mid 30s….with rain. At times when the rain is heaviest, there may be some wet snowflakes coming down, but accumulation should be nil. Philly and Baltimore could run the risk of a coating in a few grassy spots. But nothing more than that I don’t think.

That’s the higher confidence part of the forecast. It gets lower as you get outside the cities. This is very sensitive to the final track of the storm. We have one shorter term model that insists this thing is going out to sea and being a waste. Fortunately, it’s one of our most unreliable models, so I’m not putting much stock into that right now. The GFS and Euro models…the two bigger boys…are both suggesting a coastal low and producing some rather impressive snow amounts at rather low elevations. There is some risk that the immediate N & W suburbs of NYC and Philly do better in this storm than we might think. This is very out of season obviously, so my gut is to use slightly more rigorous thresholds for snow to accumulate (especially given that you’ve had nary a freeze this year thus far in most areas). But the further north and west you go, the better you should do. I’m up to 3″ at most right now, but there is some potential if the air mass is a little colder or the storm a little further west that these amounts could be a bit higher.

The main area of concern is the northern Lehigh Valley into the Poconos and Northwest Jersey, then into the Catskills and Berkshires, as well as parts of northern Connecticut and central Massachusetts. Provided the storm track stays near where it is now, I think 3-6″ is likely in these areas, with higher amounts a very good possibility as you go up in elevation. This sort of snow is somewhat unimpressive, but given it’s October and many trees are still leafed, a little bit of gusty wind could cause a lot of problems with a very heavy, wet snow coating trees/power lines. So this is why this storm is somewhat of a concern and of interest.

A couple things to keep in the back of your mind: It’s October and it is not easy to accumulate snow this time of year. There are many factors working against it. But this may be the rare instance where it works really well. Secondly, the final storm track will obviously be what determines who gets what. The models have been…for lack of a better word…awful the last few weeks. So there is some risk that they may be flat out wrong. But, given past experience, typical biases, and recent trends, this is where we stand 48 hours before it occurs.

So stay tuned…I may not draw up another snow map for this event, but this is a good jumping off point. Enjoy this first taste of winter!

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April’s Not Foolin’ for New England & Update on Opening Day

Here’s just an updated forecast on Thursday and Friday’s home openers.

Opening Day Thursday

Detroit at NY Yankees
Atlanta at Washington
Still looking at clouds, chilly temps, and scattered showers. I think NY is safe right now, but there are some signs that rain will envelope DC before game’s end, so keep an eye on that.

Milwaukee at Cincinnati
Still looks: Partly cloudy to mostly sunny and generally in the 40s.

LA Angels at Kansas City
San Diego at St. Louis
Still tracking a shower threat in KC. But those look more hit/miss, so I’m not anticipating any major disruption. Saint Louis looks pretty solid with sun and clouds. I’d take mention of showers out.

San Francisco at LA Dodgers
5 PM local time for first pitch at Chavez Ravine, and it will be postcard LA weather. Sunny, with temperatures probably 85-90 for first pitch, slipping into the upper 70s by the end of the game. Second place “Pick of the Weekend.”

Friday’s Home Openers

Minnesota at Toronto
Baltimore at Tampa
Dry and 70s…dome sweet dome.

Houston at Philly
It still looks like the worst of the weather will be in the morning in Philly. The snow/rain will lift into New England during the afternoon. It will be cold, breezy, raw, damp, gross. Should be some flurries around. Despite the fact that the worst will be long gone by game time, I would label this game as a risk to be rained or snowed out though, just because of how miserable the weather will be.

Pittsburgh at Chicago
Mostly cloudy here with some rain showers likely. I doubt it’s delay inducing stuff, but it may make Wrigley an unpleasant experience…sort of a raw, damp day.

Chicago at Cleveland
Still looks partly cloudy here. Looks like low 40s…a pleasant day for baseball, but still a bit chilly.

Boston at Texas
No changes in the ideas here either, except it could be a couple degrees warmer…low to maybe mid 80s in Arlington Friday. The Red Sox will be happy they’re opening there and not in Boston.

Arizona at Colorado
Not what you’d expect in Denver for baseball this early. Sunny, mild, and temps in the low 70s. This is the State of Occlusion “Pick of the Weekend!”

NY Mets at Florida
Taking out any mention of t’storms here. Looks good for the Mets/Fish. Temps upper 70s/low 80s at first pitch.

Seattle at Oakland
Partly cloudy after a nice day when highs should push into the 70s. We’ll see temps around first pitch in the 60s, easing back into the low 60s or upper 50s at game’s end.

Northeast Snow

The map to the left is this morning’s GFS model forecast for snow in the Northeast from Earl Barker’s model website. This is a pretty significant storm, for any time of winter, let alone early April. The GFS forecast is reasonable. Here’s how it breaks down.

NYC-Philly-DC: AM Rain, perhaps ending as some steady snow north and west, with a little coating possible there, and maybe some flurries into the cities.

Northwest NJ/Sussex County: Snow to rain to snow. Ending as a slushy 1-3″ accumulation I think. Higher elevations there could see snow continue longer, and there is definitely a risk that higher snowfall totals occur here. Still model disagreement in this area.

Boston: Mainly a mix in the city, but they could get 3-6″+ just north and west.

Interior CT/MA/Albany: 6-12″ easily, with higher amounts in the higher elevations. Some of those higher terrain areas may see 12-18″ of heavy, wet snow.

Interior NY west of I-87 to I-81 (Albany-Syracuse): Gradually diminishing snowfall gradient of 6-12″ near ALB to 1-3″ near SYR…. 5-10″ for Binghamton/Scranton.

This is just based on a cursory glance, so expect some changes, and refer to the NWS for the most local info. Either way, we’re looking at a large storm, with strong winds possible in New England as well, that could lead to power outages and downed trees/power lines. Just brutal for April.

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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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Winter Doesn’t Give Up That Easily…

If you’ve lived in the Northeast for any length of time (in years), you know full well that spring almost never comes without a price. Temps in the 60s, 70s, and even 80s over the last week are going to give way to the harsh reality that winter can still rule in March and even April.

Latest plot of recent and forecasted NAO from CPC

To the left you’ll notice a plot of the NAO..the North Atlantic Oscillation. You’ve probably heard of it before, but in layman’s terms, it’s a measure of atmospheric blocking (high pressure) in the vicinity of Greenland. Traditionally in winter, a negative phase of the NAO spells more troughing and thus colder conditions in the Eastern US. You’ll notice from the graph that since the beginning of February, the NAO has been almost locked in a neutral or positive phase. As such, you haven’t seen quite the harsh conditions you all experienced earlier in the winter. But the red lines indicate the forecast, and that, my friends, is what we call a tanking NAO.

Latest Plot of Recent and Forecasted PNA from CPC

Off to the right, you’ll see another, similar chart…this for the PNA, or Pacific-North American Oscillation. This measures blocking near the West Coast. When this is positive, there is traditionally a ridge present out west, which usually can translate to a downstream trough. When you have the NAO in a negative phase and the PNA in a positive phase, that’s a usual rock solid combination to generate warmth out West and cold in the East. It appears, we have these factors ready to lock in for a good 10+ days, with the +PNA holding on a little longer perhaps than the -NAO.

What’s this mean? With them both in concert, it spells strong cold conditions for the Eastern US and a developing warm pattern and end to storminess out West. As the NAO starts to fade, but the PNA stays relatively positive, it means the cold in the East will ease some, but there’s absolutely no sign of a return to the 60s and 70s you’ve seen recently. Expect some 30s, 40s and maybe occasional 50s if you live in the Northeast Corridor through at least next weekend.

How about snow?

A few snow chances exist over the next week or so. I won’t go into many details about the one on Sunday and the one next Wednesday, but suffice to say, the conditions do exist for potential snow.

3/22 12Z GFS Snow Forecast from Earl Barker's Model Site: http://wxcaster.com/regional_snowfall.htm

In the immediate term, we’ve got a situation tomorrow. The map to the left is this morning’s projection of accumulated snowfall from the GFS model. If you live in NYC, you can ignore this for the most part (think the model is a little too aggressive with snow there). This is mainly west of I-287 and north of I-80…but you can clearly see the risk. For Northwest NJ and the Scranton area, despite what this model is showing, I’d be shifting those bands south a bit, and a solid 6-10″ thumping seems likely…very elevation sensitive this time of year, so the higher up you are, the better your odds for snow. The highest amounts seem banded in an area east of I-81, north of I-80, west of I-87, and south of US Route 20. There is some model debate as to how far south the snow will get (one model brings heavy snow as far south as Central NJ). I am going against that model for now due to a poor track record this winter. But you will want to keep an eye on this situation. And if you live in Northwest Jersey/Northeast PA, tomorrow and tomorrow night look very unkind.

Wish I had better news, but enjoy this last gasp of winter if that’s your thing.

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