Winter 2017-2018 Archives - Page 2 of 5 - New York Metro Weather

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Mild and Calm Conditions Take Hold, Watching a Potential Coastal Storm for Friday

February 26, 2018/by Steven Copertino

Good evening!

After the cool and dreary conditions over the past couple of days, today was a slight improvement for much of the Northeast as a cold front gradually passed through the region, signaling a change to the sensible weather pattern. This front was luckily rather tame in nature, as the energy associated with the front was strung-out and not well-organized. This allowed for only moderate changes to gradually take place during the course of the day, with a rather cloudy and cool start to the day. As the day continued on, we saw high to mid level clouds lessen with time, eventually giving way to some peaks of sun. Winds shifted to the northwest behind the front, with more dry and cool air filtering into the Northeast. Modest cloud cover and a renewed airmass from Canada kept temperatures in check, with highs ranging from the lower to upper 40’s, with some locations reaching the 50 degree mark. Dry air from the north and west should continue to mix out any residual low level moisture over the next 6-12 hours, leading to mostly clear skies this evening. Additionally, an area of high pressure will be building in over the Mid Atlantic and Northeast tonight, so expect any winds to gradually diminish over time. These conditions will be quite favorable for radiational cooling to take place overnight, with temperatures likely dropping quite a bit into the lower to middle 30’s over much of the area. Some locations off to the north and west will likely drop into the middle 20’s this evening, causing any residual moisture on roadways to freeze, so please watch out for slick patches if you’re driving tonight.

This evenings latest high resolution water vapor imagery, surface observations, and surface winds, showing a more calm temporarily setting up.

Tuesday through Thursday

Tuesday will likely start off quite chilly, but clear as the area of high pressure continues to build and move eastward with time tomorrow morning. Conditions will be quite dry throughout the majority of the atmosphere, so skies will likely remain mostly sunny for the majority of the day, with a few upper level cirrus clouds passing through. The fresh Canadian airmass in place in combination with the high pressure will work in tandem to keep conditions cool, but not too cool over the entire Northeast. Highs tomorrow afternoon should remain in the middle to upper 40’s, with some inland locations likely hitting the 50 degree mark again. All in all, tomorrow should be a rather nice day, but will likely still require a light jacket to stay comfortable. Tomorrow night looks to be calm and cool as well, but not quite as cool as tonight. Lows will likely dip down into the middle to upper 30’s for the majority of the Northeast, with some locations possibly just getting below freezing.

Wednesday looks to be one of the more mild days of the week as the area of high pressure that has been dominating the east begins to move off the Mid Atlantic coast. This should create more southerly flow in the mid to low levels of the atmosphere, bringing in slightly warmer highs for the afternoon hours. Moisture looks to also increase with the southerly flow as a shortwave trough digs into the desert southwest, sending some residual energy into the east. This energy out ahead of the main system should allow for some clouds and even a few isolated showers to develop in the late afternoon hours, but not significant rain is expected. Highs will likely be able to rise into the lower to middle 50’s across the vast majority of the Northeast. Cloudy conditions will likely continue throughout the overnight hours, with the threat of a couple of showers lasting into the early morning hours. Cloud cover and southerly winds should keep lows from dipping too much, with readings likely staying in the middle to upper 30’s-with some locations seeing lows in the lower 40’s.

Things begin to get a little more interesting on Thursday, as the system that was in the southwest begins to move into the Plains and interacts with another shortwave coming down from Canada. As these systems interact and attempt to phase, a primary surface low pressure system should form over the Great Lakes region, with a large area of rain expected over much of the Southeast. As this low moves closer to the Northeast, cloudiness will likely increase in addition to the threat of some showers as we head into the late afternoon hours. Later in the evening, this area of low pressure should continue to intensify, as the mid level system becomes much more organized. This process should continue into the overnight hours, as a stationary front likely sets up over the Mid Atlantic, which may become the focus for a secondary low pressure system to form. Temperatures on Thursday will likely remain mild, with highs in the lower to middle 50’s over the entire Northeast.

This evenings NAM model showing the development of a potentially impactful system for the Northeast

Potentially Impactful Coastal System Shaping up for Friday

This afternoons model guidance continues to show the potential for the primary low pressure system that travels over the Ohio Valley to redevelop just off the Mid Atlantic coast early Friday morning, but there are still a large amount of uncertainties with this forecast. Regardless, what we do know is that an area of blocking will be located over Greenland, which will act to slow down the mid level system and allow it to strengthen as it nears the coast. This should lead to the development of a strong low pressure system adjacent to the Mid Atlantic coast during the day on Friday, likely leading to a wide range of impacts. Almost all of the model guidance shows an impressive swath of winds just above the surface with this system due to a tight pressure gradient. Additionally, this system will be capable of tapping moist air from the south, so it will likely have a good amount of moisture to work with, leading to the development of widespread moderate to heavy precipitation. Lastly, winds out over the ocean will likely be directed towards the coast, which will create at least a moderate threat of coastal flooding as we enter a full-moon phase. One of the main things we do not know at this time is exactly when and how much phasing will occur with the two original disturbances over the Ohio Valley. A quicker phase would lead to a stronger coastal low tucked right along the coast, while less/delayed phasing will likely lead to a weaker and more elongated system.

There is also the question of precipitation type, which is something that seems to be highly sensitive at this time. While a stronger system would be able to create enough dynamic cooling for some snow to fall, this solution would also mean that the primary low in the Great Lakes sticks around longer, which creates more warm air for the coastal plain. At this time it does not seem like a widespread significant snowfall is likely from this system, but there could be some locally heavy snow in the higher terrains of the Northeast if conditions line up correctly. We will be keeping a very close eye on this system this week and will continue to provide updates as they become available!

This afternoons European ensemble individual members showing a wide variety of solutions for Friday’s system

Have a great night!

Steve Copertino

Potentially Record-Breaking Warmth and Unsettled Conditions Take Hold Over the East

February 19, 2018/1 Comment/by Steven Copertino

Good evening!

It certainly has been a wild swing of events over the past week or so, with above normal temperatures, a snowstorm, and now the potential for some record breaking warm weather later this week! This will likely be a gradual process, with the first major changes taking place during this afternoon and evening. A very large upper level trough out in the western half of the country is currently digging into southwest, allowing for a very large mid level ridge to build over the east. This large mid level trough has also spawned a weak, but expansive low pressure system over the Plains today, with numerous showers and thunderstorms extending from the deep south, into the Ohio Valley and Northeast. This large low pressure system has sent moisture north into the region which has been collecting along a mid level frontal system. This mid level front has been responsible for areas of steady rain over portions of New England, with more patchy rain to the south over Pennsylvania, New Jersey, New York, and Connecticut. This area of rain should continue to lift north with the frontal system through the overnight hours, leaving spotty drizzle and cloudy conditions behind. Mid level temperatures will be rising quite a bit this evening as high pressure to our south sends a stout southwesterly flow over the East. This will ensure that conditions stay rather cloudy with much above-normal temperatures this evening. In fact, lows may not drop at all for most of the immediate coastal plain, and may actually rise a bit into the middle to upper 40’s. The only real chance for any cooling looks to be well to the north and west of the city, with lows only getting down into the lower 40’s. Due to some locations still having some snow on the ground and increasing surface temperatures, there may be some areas of fog that develop after dark. These areas of fog could be locally dense, so please use caution if you are driving this evening!

This afternoons national radar mosaic, surface temperatures, mid level temperatures, and mid level heights showing a clear southwesterly flow in place already over the East

Tuesday Into Wednesday

Tuesday morning will likely start off rather mild, with patchy fog and mostly cloudy conditions over much of the Northeast. The mid level warm front will be located well to our north over southern Canada by tomorrow morning, so the threat of rain looks rather low for tomorrow-though some patchy drizzle may be possible closer to the coast. Relatively dry air is forecast to punch into the Northeast tomorrow afternoon, which should help to burn away the vast majority of the cloud cover tomorrow afternoon. With mid level temperatures much above normal and sunny conditions in place, highs tomorrow will likely reach well into the 60’s over much of the New York metro area, with a chance at breaking into the 70’s for portions of Northeast New Jersey and locations to the south of New York City. “Cooler” highs in the lower 60’s will be possible off the north and west as well as along coastal locations due to onshore flows bringing in a more maritime airmass. While not as widespread, tomorrow will be the first day the record high temperatures could fall across the interior locations of the Northeast. Clear and mild conditions should last well into the evening and overnight hours, with southwesterly flow continuing to increase mid level temperatures. This should allow lows to be quite warm for this time of year, with many locations seeing readings stay in the lower to middle 50’s-which could potentially set record maximum low temperatures for this time of year.

Wednesday looks to be the warmest day of the week as deep southwesterly flow is maximized over the region, bringing in highly abnormal temperatures across much of the East. The day may start off with some low clouds and fog, but dry mid levels will likely aid in the vast majority of this cloud cover burning off by the early afternoon hours. After that, temperatures will be off to the races across the entire Northeast. Widespread records may fall during the afternoon, as readings soar into the middle to upper 70’s across the Northeast. Lower readings are guaranteed over portions of coastal NJ, CT, and Long Island due to onshore flow that will bring in that maritime airmass once again. Cloud cover will then begin to increase later in the afternoon as a cold front approaches from the west, with scattered showers along it. As this front approaches, shower activity will likely be on the steady decline, so only expect broken showers through the area during the evening and overnight hours. Temperatures should fall during the overnight hours as the front passes through the region, with lows still staying 5-10 degrees above normal.

NWS forecasted highs on Wednesday with the circles representing potential records being broken

Unsettled and Mild Into the Weekend

The very impressive mid level ridging over the Western Atlantic will remain in place throughout the remainder of the week, keeping conditions rather mild, with chances at light to moderate rain events. The first potential rain event looks to occur on Thursday evening as Gulf moisture streams up and around the mid level ridging and into the Northeast. A very impressive upper level jet streak also looks to be just to the north of the area, so this will likely promote the development of at least light to moderate rain over the Mid Atlantic and Northeast. The chance for rain looks to continue through the overnight hours on Thursday and into Friday, as another upper level system digs into the West. This will create yet another plume of moisture streaming north into East, with moderate rain likely over at least western portions of the Northeast. The models begin to divergence on the last rain threat over the weekend, but this afternoons European model shows a rather expansive area of rain developing over the Ohio Valley and Northeast Saturday night and lasting into Sunday. Despite the run-to-run uncertainty, the overall upper level pattern looks to be one that could support some rather widespread moderate rain over the area, with some potentially heavy showers embedded into the mix due to a favorable/peaking jet structure. Temperatures during this period look to be above-normal, but not as warm as Tuesday or Wednesday, with highs in the 40’s and 50’s. In the longer range, we may have to watch for a potential shift in the overall pattern, but we will dive into this more later in the week.

This afternoons European Ensembles showing a very wet and active pattern in the central and eastern US over the next week

Have a great night!

Steve Copertino

Quick-Hitting Snowstorm Likely for Portions of the Northeast Saturday Night

February 16, 2018/by Steven Copertino

Good evening!

Today has been yet another in a string of warmer and unsettled days across the Northeast, with light to moderate rainfall training over portions of the Mid Atlantic and Northeast. Today’s rain was part of the same strung-out and progressive upper level energy that was responsible for the heavy rain and flash flooding that occurred over portions of the Ohio Valley and Mid Atlantic states last evening. The heavy rains last evenings moved quickly along a frontal boundary that remained stationary over the same areas, causing showers and even some embedded thunderstorms to train over the same locations. While the vast majority of these showers and thunderstorms very quite weak in nature, there were some stronger storms over the Ohio Valley and Northeast that produced some damaging wind gusts, along with an EF-1 tornado just to the south and east of Pittsburgh. Regardless, today was a rather dreary day across the entire region as the mid level energy over the Ohio Valley quickly moved east and caused numerous showers to break out once again. The showers have since moved offshore as the majority of the mid level energy moves off to our east, leaving behind mostly cloudy conditions. Despite the mostly cloudy and rainy conditions today, temperatures were able to rise to above-normal levels once again across the Northeast. Readings varied from the lower to middle 50’s over the New York metro area, to middle 50’s to lower 60’s across portions of southern New Jersey. These mild conditions should last until the late evening hours as a cold front begins to approach the area from the west, bringing in cooler temperatures overnight along with Northwesterly winds. High pressure will begin to build in over the Northeast tonight, with lows likely falling quite a bit into the middle to upper 20’s over the majority of the area, with lower 20’s expected to the North and West of the city. Calm conditions will likely prevail through the overnight hours as the high pressure expands over the Northeast.

This evenings latest high restitution water vapor satellite imagery along with regional radar mosaic and surface temperatures from across the area. Note the clearer and more dry air over portions of northern PA and NY.

Quick-Hitting Snowstorm Likely Tomorrow Across Portions of the Northeast

Well, with the way this week has went the last thing you would expect is a snowstorm for this weekend, but that is exactly what looks to be shaping up for portions of the Mid Atlantic and Northeast tomorrow night into Sunday morning. A weak a relatively disorganized area of mid level energy will become trapped in the fast-moving west-to-east flow over the CONUS tomorrow morning and begin to race towards the East. As it reaches the Great Lakes region tomorrow afternoon, it will begin to meet up with some energy from the sub-tropical jet over the Southern Plains states, and this will likely cause numerous showers and some localized thunderstorms to develop over portions of the Tennessee valley. At the same time, the area of high pressure that will be over the region this evening will be moving off of the coast, leaving some stale cold air over the region. Winds will begin to shift to the south over the Mid Atlantic and Northeast, bringing in a slightly warmer low level airmass for tomorrows highs, but overall temperatures look to stay in the middle to upper 30’s. As we get deeper into the evening hours tomorrow, we should see the shortwave trough associated with tomorrows potential storm begin to amplify or strengthen a bit as the ridging over the southeast and western Atlantic causes the system to buckle.

This afternoons NAM model showing the potential evolution of tomorrows snowstorm

As the mid level energy begins to strengthen tomorrow evening, we will also see the upper level jet streak associated with this system begin to expand, allowing precipitation to break out farther north into portions of the Mid Atlantic by sunset. Surface low pressure should then begin to develop over the Mid Atlantic coast tomorrow night, with snow quickly expanding from southwest to northeast over the Northeast. This afternoons model guidance still shows a reasonable amount of uncertainty with the strength of this system, which will be crucial to this forecast. Depending on how deep this low gets will determine how much dynamic cooling will take place as the precipitation is falling. A weaker storm will be warmer at the surface with less precip, and therefore less snow. A stronger system will be able to overcome marginal surface temperatures and have increased snowfall rates, yielding higher snow totals. At this time, a healthy compromise of the two seems plausible. Precipitation may start off as a mix of snow and rain over southern portions of the Northeast, but should turn to all snow by 8-10pm or so with the exception of immediate coastal areas. The snow will quickly become moderate to heavy over portions of Pennsylvania, New Jersey and New York, with an enhanced chance at mixing over Long Island due to easterly winds. Moderate to heavy snow should continue through the overnight hours, likely until 3-5am as the system quickly accelerates to the north and east and moves offshore. Totals will likely vary by location and elevation over the region, but right now we expect a general 3-6″ from southeastern PA through northern NJ, and into SNY and CT. Portions of Long Island may see less than shown here due to prolonged periods of mixing. Travel conditions will likely be quite hazardous if you plan on driving tomorrow evening, so please stay up to the date with your local NWS for any watches or warnings in your area!

Our latest storm total snowfall map

We will have updates tomorrow on this system including a new snowfall map!

Have a great weekend!

Steve Copertino

Mild and Unsettled Pattern Begins to Take Shape

February 12, 2018/by Steven Copertino

Good evening!

The dreary and wet conditions that took over back on Saturday afternoon have finally begun to break as a cold front pushed through the Northeast this morning and early afternoon. Rainfall amounts were in the moderate range for most of the Mid Atlantic and Northeast, with locations closer to the immediate coast seeing totals in the 2-4″ range. Widespread was not recorded due to most of the Mid Atlantic and sections of the Northeast actually being in a drought do to a lack of any substantial precipitation over the past few months. Luckily, this recent rainfall was very beneficial to the area, and may have been able to knock some locations back to around normal precipitation departures. Regardless, most of the area saw their Monday start off rather mild, with highs being recorded in the morning hours over a large portion of the Northeast. This was due to a cold front that has been lagging begin the main system which actually pushed offshore last night with the remaining bulk of the heavy rain. As this cold front moved through portions of the Northeast, the cold air was quick enough on the backside to catch up to the remaining precipitation and cause a very brief mix of rain/snow/grauple. These spotty areas of mixing were quite light and brief in nature, so no accumulations were recorded. Conditions became rather calm, with even some patchy sun showing up for the middle and later afternoon hours, as temperatures over the region leveled off in the upper 30’s to lower 40’s. Conditions should remain quite dry, but occasionally a bit gusty as drier Canadian air filters into the region tonight. A strong area of high pressure will also be gradually building in over the Northeast from west to east, so this will ease winds overnight and cause clouds to gradually subside. Lows should be rather cold, with location around the NY metro area likely seeing temperatures in the lower to middle 20’s, with locations off to the north and west likely getting down into the teens with good radiational cooling.

This evenings latest surface temperatures from the HRRR with surface observations and the regional radar mosaic showing a rather calm, but cooler night taking shape

Tuesday Into Thursday

Tomorrow should start off rather clear and cold, as the aforementioned strong high pressure system continues to move over the Northeast. A fast zonal (west to east) jet streak will still be dominating the pattern across the entire country. This mean that any system over the next couple of days will be moving very quickly across the United States, with no time to amplify or strengthen. This will be the case throughout the entire day on Tuesday as some shredded-off energy from a decaying system over the west moves into the Mid Atlantic and Northeast. This energy is too insignificant to cause anything other than some high-level cirrus clouds during the afternoon hours tomorrow as the jet stream roars overhead. Highs tomorrow should be rather seasonable, with temperatures likely staying in the middle to upper 30’s, with some locations off to the south of the city possibly getting into the lower 40’s. Tranquil conditions will last well into the evening and overnight hours, as radiational cooling allows lows to drop once more into the middle to upper 20’s, with locations off to the north and west in the lower 20’s.

Mid level ridging will begin to build over the Plains during the day on Wednesday, leading to southwesterly flow increasing quite a bit over the Mid Atlantic and Northeastern states. This will begin to cause the classic response of mid level temperatures rising as well as moisture beginning to stream northward from the Gulf of Mexico. Showers and thunderstorms will likely begin to develop over the Southeast Wednesday afternoon, with some of that moisture possibly making it into the central parts of the Mid Atlantic before dark. Conditions will likely turn at least mostly cloudy during the day as increased moisture leads to the development of mid level clouds over much of the Northeast. Despite the clouds, temperatures should be quite mild, with highs likely getting into the middle to upper 40’s, with some locations likely hitting the lower 50’s. The threat for some showers will gradually increase as the night goes on, with showers likely moving in around 10pm or so for the New York metro area. Lows will be much more tame on Wednesday night, with readings likely staying in the upper 30’s to lower 40’s.

Thursday will be the first much above normal day in the period as a trough over the Western US states continues to cause the downstream strengthening of ridging over the East. Moisture from the Gulf will continue to move northward over the entire Northeast, likely leading to a wet start to the day on Thursday. As mentioned earlier, the mid level disturbance responsible for this rain will be so disorganized and moving so quickly that only light rainfall amounts are expected. The exact temperature forecast is a little complicated at this time and will depend on just how quickly the rain showers will be able to move out, but it certainly looks like highs should be able to rise well into the upper 50’s and lower 60’s across much of the Mid Atlantic and southern portions of the Northeast. Conditions will likely remain unsettled with spotty showers possible throughout the rest of the evening and overnight hours, as another in a series of weak disturbances pass through the Ohio Valley

This afternoon European ensembles showing a high probability of temperature anomalies reaching 20 degrees above normal on Thursday!

Mixed and Mild Weekend Ahead

The same pattern looks to almost certainly continue through this weekend as the southerly flow increases once more on Friday ahead of a large area of disorganized energy out over the Plains . A more moderate rain event may be in the cards starting on Friday as more Gulf moisture becomes available over the South. A cold front behind this system looks to temporarily cool things down a bit late in the day on Friday, but Saturday looks to still be a slightly above normal day across the East as mid level ridging starts to buil over the Plains once more. This area of ridging looks to strengthen quite a bit over the east on Sunday, allowing high pressure to get pushed off of the east coast and provide strong southerly flow once more for the entire area. This looks to set the stage for an even larger warm-up next week as some models are depicting a very deep trough to set up in the west, which would be strongly supportive of much above average temperatures lasting through the week next week. In fact, this afternoons European model had many locations across the Northeast well into the 70’s by next Thursday! This can very easily change over the next couple of days, but we will continue to monitor this period of prolonged above normal temperatures!

This afternoons European ensembles showing a very warm pattern shaping up in the medium range across the East

Have a great night!

Steven Copertino

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