Tag Archives: winter

NYC Weather Update – Nov 17, 2014

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The main headline for weather this week will be bitterly cold temperatures that are highly abnormal (in fact, possibly record setting) for this time of the year. We’re talking lows on Wednesday morning in the low 20s in the city, teens and even single digits north and west, and wind chill values in the single digits with a stiff west wind. The cold air finally breaks this weekend, though, with the arrival of a storm system that will push warm air in from the southwest.

Tuesday – high temperatures tomorrow will only be in the mid-30s under sunny skies following the passage of a cold front that’s currently right at our doorstep. Behind this front, breezy west winds between 20-25mph will pick up with wind gusts as high as 35mph. That will translate to wind chill values in the 20s for most of the day tomorrow.

Wednesday – we could break some records for lowest maximum and minimum temperatures Wednesday. Lows overnight Tuesday into Wednesday morning may only be in the low 20s, and with a west wind still kicking around 20mph, wind chill values will be in the low teens by daybreak. Temperatures won’t rebound much during the day either, with a high temperature forecast to be barely at the freezing mark.

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Thursday – temperatures should rebound considerably with the passage of a warm front late Wednesday and prior to another cold front passing later Thursday. High temperatures should reach the mid-40s. This front will be moisture-starved, so we’re not anticipating any precipitation.

Friday – temperatures will slide back into the upper 30s and low 40s after the cold front.

Warmup this Weekend

We finally snap this bitter cold spell with an influx of warm air from the Gulf streaming ahead of a storm system that will move in next Monday. This weekend should feature gradually warming temperatures, and by next Monday we could hit 60 briefly.

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NYC Weekend Weather – Nov 14, 2014

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You can feel the chill in the air now. This cold will continue Saturday, but we’ll get a slight warmup Sunday and Monday ahead of a low pressure system moving in from the southwest. Behind that low pressure system, we get a reinforcing blast of arctic air that will be entrenched through the rest of next week. I’m also monitoring the potential for a Nor’easter just in time for the busy travel day Wednesday and through Thanksgiving.

Saturday – a cold day on tap despite ample sunshine. High temperatures will be generally in the lower 40s. There’ll be a noticeable northwest wind making it feel like it’s in the 30s.

Sunday – a milder day with warm air flowing in ahead of a low pressure system, but by warm, I mean highs only around 50. Clouds will increase throughout the day and there could be some rain Sunday night.

Monday – rain will be falling for the majority of the day, with highs in the city in the mid-40s. Monday night gets interesting with the potential for a rain/snow mix in the city, and all snow in interior regions north and west. Depending on the timing of the main slug of precipitation with this system, we could actually get some accumulating snow in the city also (the later in the night the main body of precipitation falls, the colder it will be, and the better the conditions for snow).gfs_namer_075_1000_850_thickTuesday – cold air rushes back in behind this storm on Monday and we drop back into high temperatures hovering in the low 40s.

Potential Thanksgiving Nor’easter?

In looking ahead at the long-term GFS model output, I’m noting the possibility for a possible high-impact Nor’easter that would be timed to coincide with the busiest travel day right before and then during Thanksgiving. Of course, this far out, there’s still considerable uncertainty to the forecast, so this scenario could not pan out, or the storm track could be nowhere close to where it needs to be to produce a high-impact Nor’easter. Still, it’s worth watching, as it could be a major headache for folks if it does materialize.gfs_namer_276_1000_850_thick (1)

NYC Weather Update – Nov 11, 2014

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I hope you all took advantage of this gift of incredibly warm weather that coincided with a federal holiday, because that’s going the be the last gasp of mild weather for at least the next 7-10 days. As you probably heard, we are going to get walloped by an arctic airmass the latter half of the week that will bring an abrupt end to fall temperatures and make it feel like we jumped straight into winter – I’m talking high temperatures that won’t even get out of the low 40s by week’s end. Before you ask, no this is not a polar vortex – it will be damn cold nonetheless.

Wednesday – this will be the last day we get above 60 degrees for quite a while. We are currently in a warm sector in between a warm front that pushed through earlier this week and ahead of a cold front that will be open the door to an arctic airmass swinging down from Canada. High temperatures in the Central Plains and Intermountain West where this airmass has already taken hold are ranging from the teens to the 30s. But Wednesday, we’ll still be in the mid-60s, although it won’t be as pleasant as today with a foggy and cloudy start to the day. Once the cold front below passes, clouds should clear quickly and lead to excellent conditions for radiational cooling, with low temperatures dropping into the low 40s and into the 30s in the interior areas north and west.Screen Shot 2014-11-11 at 5.49.52 PM
Thursday – it won’t be that cold just yet, with high temperatures still expected to hit the low 50s. But clouds will again increase ahead of a second, quick-moving storm system that is expected to pass through Thursday night into Friday. This will be the real arctic sledgehammer that brings seriously cold air into the region. There will be enough energy and moisture in the atmosphere for the possibility of rain/snow mix on Thursday night and even all snow in the city Friday morning.

Friday – skies should clear quickly during the day Friday, but despite all the sun, temperatures will struggle to hit the mid-40s. Arctic air will be firmly entrenched from this point on until as long as Thanksgiving!

Saturday – High pressure will be in control Saturday, high temperatures will have a difficult time hitting 40 though, because the setup of the high will favor northerly winds. gfs_namer_096_1000_850_thickSunday – yet another storm system brings us the chance for some precipitation. Behind that system – you guessed it, more cold air and temperatures that will be two standard deviations below normal for this time of year, as per our local forecast office.

For those of you who are interested in the long-term outlook, based on forecast models and the arctic oscillation index forecast, it looks like this blast of cold air will be sticking around with us for at least the next 7-10 days, and may not break until Thanksgiving. The Arctic Oscillation measures the climate pattern of winds circulating at high latitudes close to the arctic. When it is in it’s negative phase (as is about to be the case, on the right end of all the charts below), higher pressure tends to dominate over the arctic while lower than normal pressure occurs in mid-latitudes (i.e. our area). Air tends to flow from areas of high pressure towards areas of low pressure, so this pattern sets up favorable conditions for the intrusion of bitterly cold air into our region.

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NYC Weather Update – Oct 28, 2014

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Summary

This week will be archetypical of autumn weather, with large temperature swings in store for the region. We’ll start off with highs more characteristic of late summer near 70, though with clouds overhead, we may not top that number. A weak cold front will push through tomorrow with some chance of showers. Behind this front, temperatures will drop to more seasonable highs around 60 with dry conditions. The week ends like winter with an arctic airmass invading the region, leading to the possibility of snow and high temperatures only in the upper 40s.

Wednesday – clouds build in and showers will be possible for most of the day. Most rain should conclude by the evening hours. High temperatures will remain warm ahead of the passage of the cold front with winds from west pushing warm air ahead of the front.

Weak cold front passing through Wednesday, scattered showers possible.
Weak cold front passing through Wednesday, scattered showers possible.

Thursday – clear and sunny skies behind the cold front passing Wednesday, high temperatures cooler near 60. Overnight lows will be quite cool in the lower 40s with good conditions for radiational cooling.

Friday – clouds will increase ahead of the next storm system, and high temperatures will remain near 60.

Saturday – an intrusion of arctic air accompanying a strong, deep trough (cold front) will set the stage for what should be a raw, chilly, winter-like day. With the arctic air pumping in, high temperatures will struggle to even hit 50. In the chart below, you’ll see a height of 540 near us. Without going into too much detail, low heights generally correspond to colder temperatures, as colder air is more dense, it takes up less volume than the same mass of warmer air. A height of 540 is considered by forecasters to be important when determining precipitation type, as it indicates temperatures cold enough to support snow. That’s right – we will probably see some snow north and west of the city, and depending on the track of a secondary low that forms Saturday along the coast, we could even get some of the white stuff in NYC. This is a complex system, so it will bear watching over the next couple days.

 

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Really Cool Graphic – Frozen Great Lakes

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It may be spring now, but it certainly doesn’t look or feel that way for the Great Lakes, most of which are still ice-bound. Superior, Huron, and Erie are still almost entirely covered by ice, while Michigan is less than half covered. The only lake not ice-bound this winter has been Ontario at the far-right. Image from LANCE MODIS taken on March 16th.

You may be wondering why Lake Ontario is the exception to the frosty rule here. Ontario’s average depth is about 283 feet, only Superior has a greater average depth (Erie is the shallowest, so even though it’s further south than Ontario, it’s often the first to freeze). Furthermore, Ontario is located at a lower latitude than Superior and Huron, and it’s relatively smaller surface area maximizes its heat retention.

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Weather Update – Midweek Storm, Mar 11, 2014

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Wednesday is shaping up to be a stormy, rainy day. Low pressure center currently located over Nebraska and Oklahoma will slide to the northeast into the Ohio valley while continuing to strengthen.

Current forecasts point to the storm center tracking just north of the NYC area. This should ensure that most of the region receives all rain for this storm. As the storm center draws closer, a nearly stationary frontal boundary will slowly push through to just north of the NYC area. This will allow the area to be entrenched in the warm sector, this means temperatures will stay relatively mild with highs in the mid-50s. It also raises the possibility for some weak thunderstorms in the afternoon hours as the cold front trailing the storm center pushes through.

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In fact, the Storm Prediction Center has placed the DC-PHL metro areas as well as parts of southern Pennsylvania, northern Virginia, Maryland (see diagram below) under a slight risk for severe thunderstorms. The same cold front could trigger stronger storms down to the south due to the likelihood of warmer temperatures, more unstable air, and favorable conditions for thunderstorm initiation.

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Behind the cold front, temperatures will plummet during the evening and overnight hours. The departing low will continue to strengthen into Thursday, with increasing northwest winds ushering in this colder air as well as a chance for snow showers (negligible accumulation expected). Highs will only barely hit the mid-20s.

Conditions will improve later in Thursday and Friday as an area of high pressure moves over the region. Temps will climb back into the low 40s Friday just below average, and rise to near 50 Saturday. Next chance of significant precipitation looks to be Sunday into Sunday night – with the potential for a snow storm!

 

NYC Weather Update – Mar 10, 2014

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After a quiet weather weekend, the NYC area will be experiencing a mid-week storm.

Tuesday – a mild day with partly sunny skies and highs in the mid-upper 50s across the area ahead of the frontal system that will impact the region on Wednesday. The cold front will be draping west-east and positioned through Pennsylvania, allowing a westerly flow of warm air into the area.

Wednesday –  the surface low pressure responsible for the mid-week storm will be over the central Ohio valley. Precipitation will extend eastward from the low pressure center along the frontal boundary referenced above. The center of the storm is forecast to pass right over the NYC region. Coastal areas should see all rain from this storm with a warming onshore flow developing (east winds). Areas in the interior could see a mix of rain/snow and possibly freezing rain. Heavy rain could develop during the afternoon hours.

Thursday – the low pressure center will strengthen as it passes over NYC and eventually pushes offshore. Cold air will wrap around the low pressure center and winds will shift to the north and northwest. There’s a possibility that the city could see a transition from rain to snow during this period of cooling temps. Temps on Thursday will struggle to only reach the low 30s.

Friday – high pressure will build in briefly Friday allowing a return to mostly clear conditions and warmer temps in the low 40s before the next storm system moves in with a clipper type system moving in from Canada. Dry conditions should lower chances for precipitation on Saturday.

Below: NAVGEM forecast map for 7PM EST Wednesday night. Notice an area of surface low pressure forming off the coast of Southeast NJ.

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NYC Midweek Weather Update – Mar 5, 2014

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Just a quick update on the weather for NYC for the rest of the work week into the weekend. It’s finally going to be a quiet weather week for us after what’s been an cold and snowy February.

Tonight, a slight chance of flurries, and a cold night with fairly good conditions for radiational cooling, lows dropping into the low 20s in the city and teens in the interior. Wind chills in the single digits for Thursday morning.

Thursday – high pressure will prevail and bring sunny skies, but still a cold day with highs in the low 30s. Clouds will increase during the day with another slight chance for snow during the night into Friday morning.

Friday – cloudy with temps warming to the low 40s. As the high pressure center moves offshore, winds will shift to the west.

Saturday – increasingly warm with temps near 50 especially in coastal areas due to a northeast wind off of the relatively warmer ocean waters. A storm system will pass well to our south and east, so no precipitation is expected.

Sunday – slightly cooler with highs in the low 40s and a increasing wind from the north.

Our local NWS forecast office put together a great graphic that shows how this past February stacks up climatologically. Check it out:

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NYC Weather Update, Monday Storm – Mar 1, 2014

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Summary

March is coming in like a lion this year (let’s hope it leaves like a lamb), with yet another snow storm to add to our misery here in the NYC area Sunday night into Monday night.

Background

A strong coastal storm that’s currently pummeling California with heavy rain and snow will be transferring its energy and moisture to the aforementioned storm. For California, the rain and snow is a mixed blessing: with a hundred-year drought gripping the region, moisture is welcome; however, so much rain in such a short time window is leading to flash flooding, mudslides, and other headaches. See the video below:

Forecast

Our local NWS forecast office has issued a winter storm watch for Long Island, NYC, and central NJ on south. The latest snow maker will be two waves of low pressure that will travel along the length of an arctic cold front Sunday and Monday. This cold front will across our area during this period, ensuring that the air will be cold enough for all snow during the strongest part of the storm, although precipitation may start off as a rain/snow mix during the day Sunday with highs expected to be in the mid 30s.

The forecast graphic below depicts probabilities of snowfall accumulations at least 6″ or more across the region from 8PM Sunday through 8PM Monday. As you can see, we are right on the cusp of a high confidence zone for more than 6″. As it stands, 6″ seems to be the going number for the areas under the winter storm watch. A slight northward adjustment of the storm track would increase the chances we get more than 8″.

This will be a prolonged weather event – so, moderate snow for a longer time, but less of the heavy snow that we saw with the last storm.

Screen shot 2014-03-01 at 1.50.16 PMOvernight lows on Sunday will be around 20 in the city, and highs Monday will be in the mid 20s, with the cold air flowing in behind the cold front.

Extended Forecast

Things settle down after the storm passes Monday, with mostly clear and dry conditions Tuesday through Thursday. High pressure will dominate, bringing these clear conditions, but also extending the cold snap well into next week as it continues to pump Canadian air into the area. Highs will continue struggling to reach the mid-upper 20s, with overnight lows in the teens at the coast and single digits in the interior.

Interesting note: some of the GFS (Global Forecast System) models are showing the potential development of a strong coastal storm next weekend. Of course, it’s far too early to talk specifics about precipitation type and amounts as this storm may not materialize. The models are fairly consistent in developing a low over the northern Gulf of Mexico, however, a frontal system also develop to be strong enough to push this storm well offshore as it approaches the region.

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NYC Weather: It’s gonna get cold – Feb 25, 2014

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The big weather story for the NYC region this week is going to be the return of bitterly cold temperatures across the region, thanks in part to our least favorite visitor, the polar vortex. By the end of the week, we’re looking at high temperatures in the mid to low 20s in the city, with lows in the teens to single digits. To put that into perspective, highs in the low 20s are 20 degrees below normal for this time of year, and just over two standard deviations from the mean.

There is one shot at precipitation during the work week, which is coming Wednesday. Fortunately for us, this storm will be taking a more southerly track, meaning that we’ll likely see under 1″ in the city, with slightly higher amounts out in eastern Long Island. Areas north and west should see trace to no accumulation from this system.

Today – increasing clouds with a high near freezing.

Wednesday – high near freezing, snow flurries likely, especially from the city east. Light accumulation under 1″ in the city – slightly higher east.

Thursday – the polar vortex returns along with a reinforcing dry arctic cold front. Mostly sunny with temps near freezing, but dropping rapidly during the evening hours with an overnight low in the teens.

Friday – clear skies but a high temp only in the mid 20s, overnight low in the teens.

Next shot of precipitation comes Saturday, associated with another arctic cold front. An area of strong high pressure will build in behind the front, pumping in frigid air from Canada for the end of the week.

Interesting to note that the ensemble forecast for the Arctic Oscillation is unanimous at this point that we’ll see a negative phase. As I noted in the earlier post linked above, these negative phases of the AO are often associated with the abnormally cold temperatures, and that certainly looks to be the case again this time around.

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