Tag: Connecticut

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.

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)

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.

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.

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.