Tonight: All The Slippery Is In The First Quarter Inch

snow-flies-by-the-engine-on-Southwest-1440

There’s a line I’ve been saying on TV for a generation. When it comes to snow, “All the slippery is in the first quarter inch.” Was that ever true tonight!

Our connecting flight from Baltimore got to Bradley a few minutes before midnight. We were 58 minutes late!

The pilot mentioned the Windsor Locks METAR as we taxied toward takeoff: one mile visibility, light snow. By the time we landed the visibility had dropped to a half mile and the precipitation intensified to moderate snow.

Bumpy descent? A little.

For the last fifteen minutes we flew through snow. It was horizontal snow. I assume all that snow hitting the windshield meant the pilots were solely depending on instruments until we were nearly on-the-ground.

This is the kind of things 737’s do–especially when 9,500 feet of runway is available. It still makes me nervous, especially when braking isn’t optimum.

As we broke free of the clouds, just before landing, the snow’s impact was obvious. Every road we flew over or near was white, as was the runway we landed on.

The drive home was slow.

The roads remained covered as we drove away. The snow wasn’t deep. The stripes marking the lanes were still dimly visible through the accumulation.

It didn’t make any difference. Traction was in short supply. We saw a few cars off the road or on the shoulder after an accident.

I did 40-45 mph most of the way in Helaine’s 4WD SUV. I drove gingerly. That’s the secret to snow. Make no fast moves!

Road crews were out, but there was little they could do. It was falling too fast for plowing to make a difference.

We followed a shoulder-to-shoulder convoy of plows and spreaders who blocked all passing attempts from Middletown to Hamden! Other than their blinding strobes and our significantly reduced speed their labor had no impact I could see.

Roads in Hamden seemed pure and virginal. The snow was untouched.

I climbed the little hill to our neighborhood in 4WD Low. If you have a 4WD vehicle and have never used a low gear, you’re missing an incredible safety feature. We took the hill as if we were wearing spikes.

We’re home now. Enough traveling.

I’ve Seen This Storm Before

An admission. Other meteorologists remember storm details vividly. Not me. Storms are transients. I try not to get too attached.

I used to be astounded by Dr. Mel’s ability in this regard. He remembered individual storms the way Pete Rose remembers individual pitches.

It’s a skill set I don’t have.

There are a few memorable exceptions. Hurricanes and tornadoes, obviously, qualify. So too do major forecast busts. I have a little experience with those too.

The weather tonight reminds me of a particularly painful forecast disaster. My best recollection says this storm’s doppelganger hit in the mid-80s. It was snow. The rudimentary models of that era did a poor job understanding its complex dynamics.

I sat on the air at WTNH and hour-after-hour pointed to the radar, said I could see the storm’s caboose and that it would be gone within the next few hours. I said that through eight or nine inches of additional snow!

It still makes me cringe.

It still makes Helaine cringe. She had to console me.

Viewers were brutal afterward. They wouldn’t forgive easily. For months, no matter where I went I got called on that forecast! It took over a year to for me to remove that one storm’s stench.

As with our current system, this one was obviously moving east into the Atlantic. What wasn’t as obvious was an upper low to the west which sucked moisture back from the ocean.

Sure the low’s center was moving away, but it made no difference. It’s influence was increasing. That more than compensated for its reduced proximity.

It’s a rare scenario you might not see for a decade or more. I still get the heebie jeebies thinking about it.

Glad not to make that mistake again tonight.

The Long Duration Snow Event

The Sun is shining. The birds are chirping. Half my front lawn is snow free. It’s so easy to think spring.

Not so fast, Bucko.

With snow, accumulation = intensity * duration. You can get a significant snow from a brief heavy burst or many hours of light snow. Odds are we’re getting the latter Wednesday morning through Friday morning. 48+ hours of precipitation seems likely!

As has been the case recently, the GFS and Euro disagree on most of the finer points.

The Euro is colder. Often I’ll look at the 850mb 0&#176C line–where the temperature at ~5,000 feet is 32&#176 Fahrenheit. It’s an excellent rain/snow predictor. That line is farther south on the Euro, meaning we’re more likely to see all snow even on the shoreline. The GFS solution leans toward mixed precipitation for the first 12-15 hours.

I’d go whole heartedly with the Euro, except for the addition of the SREF (Short-Range Ensemble Forecast) model. Uh oh, another American model?

The SREF goes out 87 hours and has been optimized to,

address the aspects of winter weather events beyond accumulation – specifically duration, timing, and intensity.

The SREF is actually 21 slightly different models run simultaneously to produce an ensemble. Like its American cousin, the GFS, it’s leaning toward mixed precipitation for the first half day.

Truth is in both the Euro or American models, Wednesday’s precipitation looks light. Even as all snow we’ll get no more than a few inches by nightfall Wednesday.

By Thursday all the models come into agreement on Ptype (precipitation type)–Snow!

By this time the forward progress of this storm has been slowed to a crawl. The GFS shows the central low pinwheeling in place most of the day!

Here’s the bottom line: Mainly light snow inland, with light mixed precipitation on the shoreline beginning Wednesday morning. Accumulations by Wednesday sunset just a few inches inland. Travel Wednesday will be a little slippery, not terribly bad. However, the storm continues.

Light snow overnight Wednesday/Thursday with light to moderate snow continuing through late morning Friday (a little longer toward I-395). Thursday will be a more difficult travel day. Friday morning too!

Final accumulations 6-12″ inland, with highest amounts north of Hartford, in the hillier terrain Northeastern and Northwestern Connecticut and inland near the Rhode Island border. On the shoreline, 4-8″ with lowest amounts in the New London/Groton/Stonington area.

Remember, in this case ‘final’ isn’t until Friday!

More updates to come.

This Weekend’s No Storm

Earlier this week my ears perked up. Friends on Facebook were asking about an upcoming weekend snow storm. I’m not as bothered by snow now that my commute to work is primarily over carpet, but I still enjoy running the forecast numbers.

It didn’t take long for the forecast of snow turn to a forecast of rain. It makes no difference. Once a day has been associated with snow it’s tough to convince people otherwise.

I just looked at the Euro and GFS models and they’re both showing mainly rain. Run-by-run the models have been warmer over Connecticut.

As the storm pulls away and cold air rushes in there will be a turn to snow late Saturday night into Sunday morning. It’s possible a few communities might get an inch or two, but if the ground is wet (and I expect it will be), much of that snow will be eaten by puddles!

A nasty weekend? Yes.

Net snow effect on Connecticut: not much!

Extremely Brief Weekend Weather Update

The afternoon run of the European model is even warmer than the late night run. That means more rain, less snow. In fact most of the state well get no snow at all.

Saturday will be a crappy day. Wet, not white.

The Euro Gets Schizo

My forecast last weekend will not get me into the Meteorologists’ Hall of Fame. Another weekend. Another storm. Another chance.

For the past few years nearly every meteorologist in the United States has been bad mouthing the American models and applauding the multi-nation European model. I am in that crowd. It has been rock solid.

Diane Smith wrote me earlier today. It’s cool to be Diane Smith’s friend. She is the Ambassador from Gracious Living.

I told her a foot in Hartford, probably rain at the coast.

Anyway, Diane’s got the rock solid Euro forecast… and then… the 00Z.

Consistency be damned! This run has a different solution.

The forecast in a minute. First the proviso.

This major shift implies there’s something in the current state of the atmosphere that’s not being modeled correctly. All the dynamic atmospheric models take massive shortcuts, otherwise they wouldn’t be finished calculating before the actual weather arrived!

Don’t change plans yet.

The Euro brings the low much farther south. It’s a warmer solution.

The Euro maps don’t have the detail I like, but 10:00 PM Saturday night to 1:00 AM Sunday morning shows between 1/4 and 3/8″ of moisture, but only a spotty inch of snow from the airport north. The rest is being modeled as rain.

A rain/snow mix is awful, but as long as temperatures are above freezing it’s normally not a major threat. It’s sort of hellish to be out in.

The show starts Saturday morning and lasts the day.

There’s a chance for some snow Sunday as the colder air following the system is dragged in. Alas, this ‘after the low’ snow is modeled more often than it happens.

Bottom line: Unpleasant weekend and a forecast that’s crying to be updated later on Thursday. Will do.

This Saturday’s Snow And Steven Segal

Saturday we get a normal New England snowfall–and not a big one.

The snow starts around midnight and continues through Saturday. If duration alone counted this would be a monster. Luckily, this storm will be many hours of mainly light snow.

In the movie “Under Seige 2: Dark Territory” terrorists grab a transcontinental passenger train. On board, Casey Ryback (Steven Segal). Of course Ryack is not rounded up by the terrorists, but his niece (played by a young Katherine Heigl) is.

As the terrorist leader discovers her connection to their nemesis, she pulls a cannister of mace from her pocket and sprays it in his face.

Penn: Not mace, sweetheart. Pepper spray. Sold to civilians.
[snatches canister from Sarah]
Penn: But once you get used to it…
[sprays some into his mouth]
Penn: …it just clears the sinuses!

We are pretty much at the same point with snow. After last week’s blizzard, a normal snowfall just clears the sinuses.

Saturday we get a normal New England snowfall–and not a big one.

The snow starts around midnight Friday night and continues through Saturday. If duration alone counted this would be a monster. Luckily, this storm will be many hours of mainly light snow.

The European model data available to me has three hour resolution and one inch threshold for snow. In none of these three hour windows does Connecticut reach an inch of snow. But, as I said, this is a long duration event. The snow exits after dark. We could see twenty hours of the white stuff!

As the storm moves into the Atlantic it will ‘bomb’. By then it will be far east of us. We’ll get little of that fury, though snowfall numbers toward the Rhode Island border will be enhanced.

Most of Connecticut will get 2-4″ of snow, with a little less in Fairfield County and a few inches more near I-395.

I’ll keep watching the HRRR, the high resolution, short time frame model Our storm encounter is starting to move into its domain. The HRRR does show some heavier snow just west of us late Friday evening. If that trend continues I’ll update this entry.

Right about now there are lots of Connecticut residents suffering cabin fever. When they bolt the house on their day off they’ll face slippery roads and slow traffic. We shouldn’t have road closures or massive power outages this weekend.

Remember, all the slippery is in the first &#188 inch. Stay safe. Milk and bread will still be available Sunday.

Don’t Be Scared Of Wednesday Night

Everyone wants to know about Connecticut’s next snowstorm. No problem.

No, I’m not saying making the forecast will be no problem, I’m saying the teeny bit of snow falling Wednesday night will be no problem. It will whiten what we’ve already got. Not much more.

That’s it. Relax.

My Blizzard Of 2013 Timelapse

Helaine got me a GoPro Hero for my birthday. It’s a very small, nearly indestructible, video camera. They have been dropped by sky and scuba divers and survived.

This time lapse starts just after 6:00 AM and goes past 11:00 PM. It stops because there’s nothing left to see!

There are a bunch of web postings saying the GoPro’s battery is only good for 2.5 hours of timeslapse. That’s why I plugged it into an AC adapter and propped it up against a glass paneled door to the deck.

It’s Pouring Snow – The Video

Take a look at the snow as it pours off my roof. By this time we had about a foot of blowing, featureless snow! There are drifts against doors, windows and walls.

Taken inside during the Blizzard of 2013.

The Truth About Bombogenesis

7pm weather observations

I just heard a loud clap of thunder here in Hamden. Thundersnow! This low is bombing out. Bombogenesis!

Bombogenesis really is a word! It describes the explosive growth of a low pressure system. We’re seeing it right now, especially in Eastern Connecticut.

Deb Drake @debirlfan @geofffox FYI, thundersnow in Quaker Hill. Scared the dog. 🙂

Thundersnow, a product of bombogenesis, was reported at Bridgeport, New Haven and New London between 6:30 and 7:30 PM EST. Yes, that’s very unusual. It’s also been reported at Marshfield, MA, Providence and Westerly, RI and on the Cape at Otis AFB.

Bombogenesis is an extreme example of cyclogenesis. I know, little help.

Cyclogenesis is the development or rapid intensification of a low pressure system. In New England we see this as winter lows hit the relatively mild waters of the Atlantic. If the cyclogenesis really goes nuts it’s bombogenesis!

This explosive development is seen as a rapid drop of the central barometric pressure.

Wind is reflective of a change in barometer over a given distance. The bigger the change over a given distance the stronger the wind. If the central pressure drops and everything else stay the same the pressure difference between two distant points (we call it pressure gradient or delta) will increase. So does the wind!

Over the rest of tonight, as the storm continues to ‘bomb’ we’ll see the pressure gradient increase. Even as the storm moves away from us this gradient will continue to deliver very strong winds. East of us, like the Massachusetts coast, the wind will be even stronger!

The rest of the forecast looks on target. We’ll be in-and-out of blizzard conditions throughout the overnight hours. Finally accumulations will be measured in feet across New England.

If you’re looking at weather observations and notice snow no longer being reported, sensors at a few airports have iced over and are out of service. This wasn’t a problem when humans did the observing.

Stay put and you should be OK. There will be power outages, but you’re better staying where you are than venturing out.

Just A Little… So Far

photo courtesy: Abby Ferriucci

The snow is clinging precariously to the first thing that’s stopped its fall. That’s a sign. Little wind so far. That is about to change as our nor’easter ramps up over the next few hours.

The last official count came an hour ago. It looks like the highest accumulations in Connecticut are only in the 3-5″ range. That will change too.

Meriden Markham Airport’s 2:53 PM observation was the first in the state with a “+.”

SPECI KMMK 081953Z AUTO 02011G18KT 1/4SM +SN FG VV006 00/M01 A2987 RMK AO2 SLP115 P0007 T00001011 TSNO

That’s 1/4 mile visibility in heavy snow!

That’s not the last “+” we’ll see.

The HRRR (High Resolution Rapid Refresh) model shows heavier snow moving in around 5:00 PM and then with us for the remainder of the night. Many areas will see 2-3″ per hour snowfall!

There’s actually the hint of 5-6″ per hour snows just to our east in Rhode Island. That’s the kind of rate the areas east of Lake Ontario sometimes get–areas that get hundreds of inches of snow every winter!

The wind begins to ramp up around the same time. As with the snow, strong winds will be with us all night.

Power outages: yes

Trees and limbs down: yes

Blizzard conditions with whiteouts: oh yeah!

The storm surge forecast still has the highest surge out-of-sync with high tide, but at Bridgeport it’s somewhat more aligned than earlier projections. There will be a little flooding at high tide, but not at Sandy levels.

By now you should be where you’re going to spend the next 24 hours.

Let me rephrase that. You’re not going anywhere.

I’ll update later (power willing)

My Deck’s White

Good morning. This is an unusual time for me to blog, but I was up and on-the-air with Al Gardner and Lionel on IQ106.9 in Philly. Using Skype audio and a high quality microphone it sounded like I was in the studio, not in my kitchen… and in pajamas.

As the title says, my deck is white! I can still see blades of grass poking through the snow on the lawn. They’ll be gone soon, not to return for a while.

I have a GoPro Hero camera pointing outside so I can have a time lapse of the storm. That comes tomorrow or Sunday. I will post it.

The forecast remains intact from yesterday. Everything you’ve heard from me (and probably from others) still looks to be in the ballpark.

Now that I’m looking shorter term I’ve switched to the High Resolution Rapid Refresh model. The HRRR has a 1km resolution and time increments as short as 15 minutes.

I love this model. Made in the USA!

Because it is crunching at such a fine level it only goes out 15 hours. It’s more nowcasting than forecasting.

What’s available as I type only goes out to 8:00 PM EST, but shows over 18″ accumulating over portions of the Naugatuck Valley and along I-395 in Eastern Connecticut.

At that point we’re far from finished!

Before I go on, a little about accumulations. With the numbers I’m expecting there will be plenty of settling. That means 18″ could fall, but the pile might be only 13 or 14″.

Don’t fixate on exact accumulation numbers. There will be more than we can handle. The state will slide to a halt, as will most of the Northeast.

The HRRR is also showing a little mixed precipitation right along I-95 on-and-off from 1:00 PM to around 4:00 PM. I’ve been seeing signs of this for a few days. Snow will still accumulate on the immediate shoreline, but sleet or rain always brings down the pile a little.

Tonight this storm will also have very strong wind. We usually don’t seeing blowing and drifting in Connecticut. We will this time.

Blizzard conditions are likely. Whiteout conditions are likely. Trees and power lines will fall. Shelter in place this afternoon and night.

I used to say I get paid by the viewer, but I still care about you. Conditions will deteriorate quickly.

The strongest winds will be along the shore and higher elevations. If you live near a road with the word “Hill,” “Ridge,” “Mountain” or “View” be prepared!

Power outages and road closures from trees down will be scattered across the state tonight.

Wave action in Long Island Sound will be very strong. The good news is, the peak surge from this storm is not in sync with high tide.

Some flooding on the coast is possible, but we’re not talking a Sandy scenario. Things could be much worse on the Massachusetts coast and Eastern Long Island. I am not an expert on Long Island’s weather, but it would seem Gardiners Bay and Little and Great Peconic Bay are poised for flooding.

We’ll stay snowy into Saturday. Final accumulations will be mind boggling!

Not only will we get a lot of snow, but we will get it statewide. Sometimes there are huge ratios between our highest and lowest snowfall totals. Not this time.

I’ll be back and update later this afternoon.

Looking At The Snowy Models

I have to be up early Friday. Two brief appearances on IQ106.9 in Philadelphia. I’ll be nice, but they aren’t getting anywhere near the storm we’re getting in Connecticut!

The 00Z models are all in and there’s really no reason to make changes. What I said Thursday afternoon should cover things.

At the moment we look to be lucky with the timing of the highest storm surge in Long Island Sound. It isn’t in sync with high tide. If that changes coastal flooding would be moderate to severe, but it’s remained fairly constant during Thursday.

If you’re leaving the house Friday, please understand the logistics of this kind of snow. Conditions will deteriorate quickly in the late afternoon and evening.

Don’t get caught. Be conservative in your decisions. Blizzard Warnings are up and justified by the guidance. That’s not a guarantee, but a likelihood.

I’ve driven in whiteouts a few times back in Buffalo. I remember sticking my head out the window trying to find the center divider on Elmwood Avenue. Never again, please.

The European model continues to bring us a huge snowfall. Someone in Connecticut, maybe lots of someones, will see over two feet of snow with blowing and drifting–much more of that than we usually see too. Don’t expect much personal outdoor mobility until Saturday night or Sunday.

On the other hand, the Euro now backs off the snow (not the wind) for Eastern Massachusetts, including Boston. I didn’t expect to see that.

I’ll be doing shorter, but more frequent updates on Friday and Saturday.

Friday/Saturday’s Storm Looks Awful

Just before bedtime I wrote about how the GFS’s 00Z run had backed off on precipitation for Friday’s major event. I added, “The GFS is seldom my first choice.” The difference between the 00Z and 12Z runs is a prime example why!

The Euro is in and its solution for Friday/Saturday is sobering. Feet of snow and scattered blizzard conditions seem the most likely scenario. A storm like this can quickly turn a below average winter into something you’ll long remember.

Before I get into specifics, allow me to give you some advice. A storm like this can quickly get ahead of anyone who tries to challenge it. People will attempt to travel in marginal conditions only to find those conditions rapidly deteriorate stranding the traveler. A storm like this can kill.

Machismo will not serve you well! Plan on sheltering in place Friday evening into the weekend.

There’s been a lot of talk about two systems combining. Sort of, though that’s misleading.

The majority of what we’ll get comes from the coastal low in the map at the top of this entry. It and an inland low will phase, allowing the western storm to shape the path of the coastal storm.

The second low is why this Nor’easter bends slightly north instead of steaming directly out to sea. Bending the path keeps it closer to us for a longer period of time.

Mo snow. Mo problems.

Friday AM – Friday afternoon

The storm’s first moisture reaches us around daybreak. The latest GFS and ECMWF runs are cold enough to wonder if any rain will be mixed in–even on the shore! Certainly the beginning of the storm looks like light snow everywhere.

By early afternoon you’ll be saying, “Where’s this blizzard they’re talking about?” The midday snow shouldn’t be too bad.

Schools could open–but they probably won’t. They probably shouldn’t. Most school districts have plenty of banked snow days to play with&#185. Be generous. Err on the side of caution.

At cloud level the warmest air arrives early afternoon. That’s the most likely time for any rain or mixed precipitation near the shore. If you’re all snow through 2:00 PM, you’re all snow for the storm!

Afternoon drive will be a mess. 3-6″ already on the coast, a little less inland. All the slippery is in the first quarter inch!

Friday evening

The intensity of the snow begins to ramp up. The temperature drops.

As a rule of thumb, road crews can keep up with 1/4-1/2″ of new snow per hour. By evening we’ll be seeing 2-3″ per hour. Secondary roads will become impassable. Interstates will be treacherous.

As the Sun goes down, the wind picks up. First the shore, then inland (especially the I-395 corridor) will feel gale to tropical storm force gusts. There are Blizzard Watches/Warnings up already. This is why.

By midnight some areas will be approaching a foot on-the-ground with blowing, drifting snow and near zero visibility. The storm center will be east of Atlantic City, south of Narragansett Bay–in the Atlantic, but likely its closest approach to us.

Overnight Friday/Saturday

Heavy snow. Strong winds. Very cold. Blizzard conditions (or nearly so). Coastal flooding at high tide.

I can’t overemphasize how dangerous it will be to leave your home during this time. If you’re walking the dog, stay within sight of your house/apartment–seriously.

Another foot (or more) will fall over portions of the state through the night. By this time accumulation numbers will be meaningless. Too much snow for sure.

There will be enough snow weight to weaken/damage/collapse a few roofs!

In spots, blowing and drifting could trap people in their homes!

Saturday morning

By dawn the wind will begin to diminish in intensity. The snow too. Another few inches are possible before all is said and done around noon.

Earlier I had an IM chat with my meteo prof friend, Bob in Florida. I’ll let you eavesdrop.

1:26 PM
Bob: wow, looks like euro targets CT
lots of banding on back side
through 48hr dry slots groton to providence, but pounds new haven to white plains, no totals, but i’d guess over 2″ liquid

1:28 PM
me: yes
this is all a product of the phasing with the second, western, low.

1:29 PM
Bob: ideal phasing, which the euro has been hinting at all the time

me: look how it bends hard left as we approach 48h

Bob: yeah
nws will issue blizzard warnings state wide if they buy euro

me: and they will. I think we’ve all come to the conclusion it is vastly superior to any US model
It must be a sad time to work at NCEP or MDL

Bob: i don’t see any 850 > 0C air
on euro in CT
i think -2C at shoreline is warmest

It’s been a while since we’ve had weather like this, thankfully.

&#185 – Correction – Because of Sandy many districts used their spare days long before winter arrived. I apologize for the error. H/T Jim McGuire.