Just when we thought winter was on its last legs, and spring was on its way. Unfortunately, as the Climate Prediction Center forecast a couple weeks ago, a cool down is in the cards to end the month of March. In fact, it will get so cold that snow could accumulate Friday into Friday night. After a brief warmup, another shot of colder than normal air will return to grip the area to end off the month.
Thursday – a below normal, but dry day with plenty of sun and high near 40.
Friday – (ironically, first day of astronomical spring) a coastal low moving offshore of the Carolinas will then track north. Enough cold air will be in place Friday, along with a persistent northerly flow with counterclockwise circulation around the low pressure center that snow is looking likely during the course of the day. Current forecast snow accumulations are on the light side, no more than 3-4″. If temperatures are even a few degrees warmer than currently forecast, we could get away with little accumulation.
Friday’s storm
Saturday – things clear up quickly on Saturday with high temperatures back near normal in the mid-upper 40s.
Sunday – a dry cold front moves through Sunday, leading to a drop in temperatures to below normal in the upper 30s.
Cool Off Coming Up
The climate prediction center continues to point to cooler than normal temperatures for the last two weeks of March. One can only hope that the temperatures are not so cold as to allow for more snow, but I wouldn’t rule this possibility entirely out given some of the longer term forecast models.
6-10 temperature outlook8-14 day temperature outlook
Today may be the last major winter storm of the winter for us. It certainly has been an eventful and cold winter for the books. We’ll end the week and start off this weekend and early next week with below normal temperatures, but temperatures will rise steadily throughout next week, such that we should be back to normal temperatures in the mid-upper 40s by the end of next week.
Rest of today – snow is already tapering off over the area, with widespread snowfall totals of between 4-8″ reported (largely in line with forecasts). Any remaining precipitation should completely clear the area within the next couple of hours.
Friday – we endure what we all hope will be the last day of temperatures in the low-mid 20s as cold, dry air filters in behind this storm system.
Saturday – high pressure moves in over the weekend, with temperatures Saturday edging up to around freezing.
Sunday – fair weather continues, but perhaps with more clouds on Sunday as some weak impulses of energy move over areas well to the north of NYC. High temperatures will increase to the low 40s.
Monday – the warming trend continues as spring approaches, high temperatures continue to warm into the mid-40s under partly cloudy skies.
Finally leaving the Arctic air behind?
A large scale warming trend is forecast to take hold over much of the US during the medium term. Temperatures next week should warm progressively such that by next Friday, we’ll be looking at (gasp) high temperatures near 50. The week after, on the cusp of spring, almost the entirety of the Continental US is forecast to experience warmer than normal temperatures, with the exception of Texas, and New York into Southern New England. However, we are forecast to be in normal range of temperatures for this time of year, which means mid-upper 40s. Not quite flip flops and t-shirt weather, but a positive trend nonetheless.
March will start off with quite an active, messy week for us. During the middle of the week, we’ll see snow, rain, and then more snow, before we end off the week with temperatures well below normal once again.
Tuesday – clouds will begin to increase throughout the day with chances for snowfall increasingly steadily as well. Not much in the way of accumulating snow is expected during the day Tuesday. High temperatures around 30.
Wednesday – overnight Tuesday into Wednesday, temperatures will actually rise as a warm front pushes through. This will allow temperatures on Wednesday to top 40. Snow early on will give way to sleet, then eventually transition to all rain. This period of rain should melt some of the existing snowpack, and there could be some minor/nuisance flooding of poor drainage areas as this occurs.
Thursday – once the cold front depicted above pushes through late Wednesday, cold air will rapidly fill in behind it and allow for temperatures to drop back into the mid-20s. As this occurs, a second wave of low pressure is expected to form over the Mid-Atlantic and move over the area. This may lead to enough precipitation to warrant a Winter Storm Warning, with 6″ of snow possible by Thursday afternoon. Highs will be near 30.
Friday – as these storms finally move away, Friday will be a sunny day, but with Arctic air back in place over the area, we’ll be once again welcoming high temperatures in the mid-20s, which at this point is over 15 degrees below normal.
Another cold weekend is on tap for the area, before the start of a week of active weather. It does appear that March will be coming in like a lion this year.
Rest of today – some sun, with a chance for light flurries and a high in the mid-20s.
Friday – diminishing clouds with a high temperature again in the mid-20s. High pressure begins building to our west, yielding northwesterly winds that will allow chilly, Arctic air to filter back into the area. Overnight lows Friday will be in the low teens.
Saturday – with high pressure to our west still firmly in control, it will be a sunny, but cold day, with highs again only in the mid-20s.
Sunday – clouds will be increasing ahead of an approaching storm system and as high pressure exits to the east. There will be a slight warmup ahead of the storm, with temperatures topping out near freezing. Snow likely overnight, although significant accumulations are not expected.
Monday – temperatures will warm potentially into the low 40s on Monday as warm air from the southwest gets pulled into the storm system. There may be some mixed precipitation along the coastal plain, with all snow elsewhere, mostly early in the day.Tuesday – following the passage of the storm on Monday, temperatures dip back to around freezing, ahead of another storm system that will be impacting the area Tuesday into Wednesday. This storm has a greater potential significant precipitation.
After that brief “warmup” during the weekend, we’re once again mired in Arctic cold air. This cold trend continues with a reinforcing shot of cold air as a cold front sweeps through Wednesday. Behind that, high pressure builds in over the area for the end of the week and into the weekend, ensuring another prolonged stretch of chilly, much below normal temperatures.
Wednesday – ahead of what will a dry cold front passing through, high temperatures may be able to climb to just about the freezing mark under mostly sunny skies.
Thursday – once the cold front moves offshore, an area of low pressure will strengthen, but remain well offshore of the area. However, precipitation may still make its way over the region, especially the far eastern areas. There’ll be a chance for snow flurries further west in the city. Temperatures will be back in the mid-20s again in the wake of that cold front.
Friday – clearing skies will be accompanied by stagnant cold temperatures with highs again in the mid-20s.
Saturday – as you’ll se below, a strong 1040mb area of high pressure will be parked over the Ohio Valley will be responsible for the sunny, but cold temperatures through at least Saturday night. Highs Saturday may approach 30ºF. Normal highs for this time of the year are closer to 40ºF.Looking Ahead
Climate Prediction Center’s 8-14 day temperature outlook for March 4th to March 10th, with our region in an area expected to experience below normal temperatures.
The beginning of next week looks to feature a fairly active pattern, with two storm systems passing through, one on Monday, and another on Wednesday. With the current track of the second storm, it looks like we are going to be on the south side of the low pressure center. This would allow for warmer air to wrap into the area. We could top 40ºF again, but the tradeoff will be a slushy, wet day maybe with some mixed precipitation to start. Once this second storm passes through, we return to cold temperatures once again.
Sunday night’s lows were the coldest of the year thus far, indicative of the coldest airmass to hit the area in recent memory. Again, according to climatology, the last time New York City itself hit a low of zero was in January 1994. Unfortunately, the cold snap does not show any signs of abating during the week, although the first half of the week will see daytime high temperatures in the mid-upper 20s as opposed to the teens. We’ll finish the week off back into the teens before a warmup to above freezing with an approaching storm system this weekend. Behind that – you guessed it, another round of arctic air and abnormally cold temperatures.
Rest of today – cold and overcast, with high temperatures not even getting to 20 in the city. Snow should begin falling overnight, with generally light accumulations by daybreak.
Tuesday – slightly warmer with high temperatures in the mid 20s, but also with a chance for snow as a storm system now dumping snow across a vast swath of the South passes well to the south of us. We could still end up picking up 2-5″ of snow in the city, with higher amounts along the south facing shores of Long Island and minimal accumulation north of I-84.
Snowfall total forecast for Tuesday
Wednesday – a weak cold front will pass through Wednesday, and may give us a small chance for light snow, otherwise, expecting cloudy skies with high temperatures in the mid-upper 20s.
Thursday – behind that cold front, we get our next shot of Arctic air, with overnight lows into Thursday struggling to hit 10 in the city, and zero and below in outlying inland areas. Daytime highs will only be in the mid-teens despite ample sun. Thursday night, we might get another shot at low temperatures hitting zero in the city, with lows below zero across most inland locations.
Friday – basically a repeat of Thursday, sunny but with brutally cold temperatures in the mid-teens.
Over the weekend – watching for the development of a storm system that could bring some wintry mix/freezing rain to the area, but finally give us a break from below freezing temperatures.
More Cold on Tap to End February
After the weekend storm, we get yet another reinforcing blast of Arctic air to end the month of February. Below, you’ll see the Climate Prediction Center‘s 8-14 day outlook spanning February 23 – March 1. We’re in a region with a greater than 60% probability of experiencing below average temperatures for this period.
Climate Prediction Center 8-14 day outlook for Feb 23 – Mar 1
The main headline for the upcoming weekend and into next week will be the very cold airmass that will be spreading over the region, bringing with it what will likely be the coldest temperatures we’ve seen thus far this year. The coldest period over this stretch will be overnight Sunday into Monday, when low temperatures in the city could touch zero. If that does happen, it would be the first time the city has hit zero or below since January of 1994, according to National Weather Service records!
Friday – there will be a noticeable difference in daytime temperatures versus today. High temperatures are going to struggle to even hit the upper teens in the city, once the cold front responsible for the off and on flurries today passes through tonight. Overnight lows will again be in the low teens in the city, and colder in outlying suburbs.
Saturday – another clipper-type system will move quickly through the area on Saturday, setting off a period of snow showers that could end up dropping 1-2″ across the region. High temperatures will warm up slightly – if you can call a high near 30 a warm up! Overnight, winds will begin to pick up, with wind chills between -5ºF to -15ºF.
Sunday – a stiff northwest wind will pick up. The clipper system that passes Saturday will rapidly intensify as it moves over the Atlantic. This will set up an increasingly tight pressure gradient with a high pressure center over the Great Lakes. This setup will swing the door wide open for Arctic air to blast into the region. High temperatures Sunday will be in the mid-teens in the city, and overnight lows may be as cold as zero or just below zero. Regardless, the sustained northwest winds will yield wind chill values between -15ºF to -25ºF.
Monday, President’s Day – sunny skies, but that Arctic airmass will still be very much in control, with temperatures struggling to hit 20.
Tuesday – a return to temperatures near freezing again with an approaching low pressure system that will deliver our next chance at precipitation late Tuesday into Wednesday.
Another messy start to the work week is in store for us tonight and into Monday night as we endure a long duration, though relatively light intensity winter storm. Luckily for us, the storm track means we’ll avoid the worst impacts of heavy snow (New England will get the worst of it again). There’s some concern for icing again, although the impact should be slightly less serious than last Monday. The rest of the week will be precipitation free, with the exception of some snow showers possible Thursday. Following these snow showers, another shot of brutally cold Arctic air is expected by week’s end, such that highs will only be in the low 20s and even upper teens.
Monday – as you can see from below, the snowfall totals for the southern portion of the NYC area are on the very low end, only 1-2″ expected in NYC and in Long Island. The higher snowfall totals will be north of I-84 and into Connecticut, with the far northern suburbs getting a chance at over 6″. Bear in mind, the snow is expected over an extended period starting tonight through Monday night.
Storm total snow forecast
Ice is a bigger concern for the immediate coastal areas that will see less snow. High temperatures during the day Monday be below freezing, so freezing rain is expected and could deposit between 0.15″-0.25″ of ice when all is said and done. The majority of this is expected to fall Monday morning before temperatures cool off at the coast and precipitation switches back to all snow.
Storm total ice forecast
Tuesday – high temperatures should be right around freezing with clouds diminishing through the day as the storm system from Monday pulls to the east.
Wednesday – a sunny day expected with highs again near freezing.
Thursday – we get our next chance at snow, on the light side, with a passing low pressure system forming over the Great Lakes and moving east towards us high temperatures will be again around freezing.
Friday – a sunny, but frigid day with highs expected to only be in the upper teens and low 20s. As you can see from the chart above, to the west of the low affecting our area on Thursday, there is an area of high pressure which will usher in that reinforcing blast of Arctic air.
The low overall snowfall totals for NYC yesterday wasn’t so much a problem as the significant icing that resulted from an extended period of freezing rain. Ironically, a week the city government took criticism for shutting down the transit system for blockbuster blizzard that did not come to pass here, it was 1/4″ coating of ice that wreaked havoc on the entire transit system (the hours long complete suspension of the 7 train was an extreme example of this). We do get a couple more shots at snow, once tomorrow night into Thursday, and then again during the weekend, but at this time neither event looks to be nearly as high impact as what we’ve experienced the last two weeks.
Wednesday – will be comparatively mild in the context of the rest of the week and the weather we’ve had recently. High temperatures may actually even hit 40 (slightly above normal). However, as a cold front approaches from the west, we’ll have an increasing chance for snow showers, which maybe mixed with rain at the coast during the earlier part of the evening.
Thursday – chance for snow showers continues along the vicinity of the frontal boundary as it passes over us. Following the passage of that cold front, temperatures take a serious drop as northwest winds allow for Arctic air to make a comeback into the area. Lows overnight Thursday could be as low as the single digits for the city and below zero for outlying suburbs. Coupled with a northwest wind of 15-20mph, this would produce dangerously cold wind chill values.
Generally low snowfall totals expected across the region from this event
Friday – high pressure builds in briefly for Friday, giving us the only guaranteed dry day through the forecast period. It will still be cold with highs only in the low 20s.
Saturday – an arctic front will be approaching during the day Saturday, and ahead of the front, we’ll actually about normal temperatures in the upper 30s due to southwest flow. Clouds build in and the chance for snow showers builds during the later part of the day into the overnight.
Sunday – the arctic front mentioned above moves over us but then it looks like it will stall in our vicinity for an extended period from Sunday into Monday. High temperatures will cool to around freezing in the wake of that frontal passage.
At this time, it’s too early to know exactly how much snow we would pick up. It does appear that the precipitation with this system will be generally on the lighter side, except as the low pressure center depicted over southern Illinois in the graphic below approaches the coast. Once it arrives just west of the coast, it could draw in some moisture off the ocean as the counterclockwise cyclonic flow around the eastern periphery of the low induces an extended period of onshore flow (like a sea breeze, except in this case, the air over the water is actually warmer than it is over the snowpack on the land). If this onshore flow is robust enough, it could warm coastal areas up enough to get some rain out of the storm.
Stationary arctic frontYou can see the distinct separation between warm and cold airmasses demarcated by the stationary front depicted in the image above – the front separates the areas with the blue dotted lines from the areas of the warm dotted lines.
We got a bit of a (cold) respite during the weekend from any precipitation, but all that is about to change in a big way tonight and into tomorrow. A complex storm system that is set to bring snow across a wide swath of the Midwest will be approaching the area tonight and into tomorrow. Various factors make this storm even harder to forecast than the Nor’easter last week, including a still uncertain storm track and a very tight temperature gradient leading to the potential for a mixed bag of all precipitation types in the NYC region.
Impacts
This storm is set to make Monday a downright nasty day to be out. Snow is forecast to begin falling tonight, with areas to the north of the city expected to pick up the most snow through this storm. During the AM rush, temperatures are expected to rise just enough in the lower atmosphere to allow for the possibility of sleet, ice pellets, and a period of freezing rain along the coast near the city, with rain possible further east in Long Island. Then, to close out the day, temperatures will drop rapidly below freezing, such that any slush or melted snow or wet surfaces could flash freeze. Because the temperature gradient is so tightly packed, it will again literally be a matter of miles between a spot that picks up mostly snow and perhaps 8″+, and another location that picks up almost no snow, but gets a significant coating of ice.
Ice accumulation forecast – anything over 0.10″ can cause serious problems.Snowfall total forecast – note the similarity with the last storm as to how dramatically snow totals range across a very small geographic area.
Below are some probabilistic forecast graphics that will give you a good sense of the degree of uncertainty within this storm forecast. First, with respect to snowfall totals over the next 48 hours.
Probabilities of greater than 2″ of snowProbabilities of snow accumulation greater than 4″Probabilities of greater than 8″ of snow
Here’s the same time window, but with probabilities for ice accumulation.
Probability of ice accumulation greater than .10″Probability of greater than .25″ of ice accumulation
In the snowfall probability maps, you can see just how tightly packed the different bands of probability for snowfall are. A matter of 50 miles means the difference between being in an area of 40%-50% probability of receiving more than 4″ of snow, and an area with a greater than 80% chance of receiving the same total.
Timing
Snow will begin to fall later this evening and pick up in intensity overnight. Depending on the area you’re living in, you could see between 3″-8″ overnight, with the highest totals most likely north of the city, and the lowest totals along the coast and in eastern Long Island. Around the morning rush, areas along the coast and eastern Long Island should begin to see a transition from snow to freezing rain, or some type of wintry mix of ice pellets and sleet. Some parts along the coast may even see a changeover from rain/snow to plain rain. In the afternoon, temperatures will drop quickly below freezing, allowing for flash freezing of slush and other wet surfaces. Winds will begin from the east initially before turning northeast and then north through the day.
Why the Uncertainty?
The reason behind the complexity of this storm with respect to precipitation types, uncertainty of total snowfall amounts, rests with storm’s track and the dynamics in the lower atmosphere accompanying this storm. This storm, unlike a Nor’easter, has its genesis over the Central Plains. However, as it approaches the coast, it will still be able to pick up a good amount of moisture off the ocean and from points south.
Recalling that air around a low pressure center in the northern hemisphere in a flows in a counterclockwise motion, you can better understand what is going on here. The low pressure center is forecast to pass just to our south. To the north of the storm center, colder air will dominate, since the cyclonic flow would be pulling air from north to south. Meanwhile, on the south side of the storm center, warmer air is being wrapped into the storm from the south and east. This onshore flow bringing relatively warmer air in close proximity to colder (sub-freezing) air is the reason why there is such a dramatic range in forecast snowfall totals across the area, and also the reason why there is a possibility for a range of different precipitation types.
Above is a forecast map that shows the forecast position and track of the storm. The colored points represent the individual forecast ensemble members (different forecast models with slightly different inputs) predictions for the storm. Notice that there is still a nontrivial spread between these ensemble members. You may also observe that they seem to cluster to the north of the official forecast track (the black line). Indeed, forecasters have been making slight northward adjustments in response to this trend. Should this bear out, and the low pressure center does move a bit further north, we would end up with less snow, more chance for mixed precipitation and even rain. On the opposite end, if the storm track deviates south, we would get more snow, and less chance for mixed precipitation. A very tricky forecast indeed!
