Posts

Steven Copertino

Public Analysis: Remnants of Cindy Likely to Bring Heavy Rain, Seasonable Conditions Return Next Week

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Good Afternoon and Happy Friday! 

Getting right into things, earlier this week we highlighted the potential for some heavy rain associated with the remnants of Tropical Storm Cindy, which made landfall along the Texas coastline early Thursday morning. At that time, we stated that there were two scenarios that were likely to play out, one being that the remnants of Cindy would not hold up all that well after landfall, and the other being that they would. Over the past twelve to eighteen hours or so, it has become apparent that the remnants of Cindy have remained quite robust as they traveled over the Ozarks and into the Tennessee Valley, at least in the mid levels of the atmosphere. With very deep, tropical moisture streaming north from the Gulf of Mexico, the significance of having a more coherent remnant system means that the leftover energy will spark widespread showers and thunderstorms through this evening and into Saturday. In addition to the remnants of Tropical Storm Cindy, which has been downgraded to a remnant low pressure area, we also have a cold front surging through the Ohio Valley.

This cold front has been working to funnel all of the moisture from the Gulf of Mexico to the north and east, allowing it to pool up over the eastern third of the nation over the past two days. This has made for a very soupy and humid day today across the majority of the Northeast. We saw some very subtle lift manifest itself over Pennsylvania around noon today, which allowed for some showers to move eastward through eastern Pennsylvania, New Jersey, and New York. Occasional breaks in the clouds and very warm temperatures a few thousand feet off the ground allowed temperatures to spike back into the low to middle 80’s across the entire region, despite sudden temperature drops with any gusty showers that passed through some locations.

As of 630pm, a convective complex was evolving over the eastern half of Pennsylvania, and this complex will continue to head eastward through the evening. With adequate amounts of wind shear, instability, and an extremely moist air mass in place, torrential downpours, frequent lightning, and some gusty winds seem quite likely for those in the path of these showers and storms. Synoptic winds (winds not associated with small scale features) have already been quite impressive this afternoon, so we are quite confident that the probability for tropical-like downpours and gusty winds could cause some localized flooding with debris from trees likely clogging sewers. In lieu of this slight risk for severe thunderstorms, the Storm Prediction Center in Norman Oklahoma has issued a severe Thunderstorm Watch until 10pm this evening. The rest of the evening should remain quite unsettled, with the potential for more showers and thunderstorms behind this complex, so make sure to pay attention to your local NWS office for any potential warnings!

Animated regional radar mosaic, showing the evolution of a complex of showers and thunderstorms approaching the area. The main threats appear to be heavy downpours and gusty winds (Courtesy of College of DuPage)

Animated regional radar mosaic, showing the evolution of a complex of showers and thunderstorms approaching the area. The main threats appear to be heavy downpours and gusty winds (Courtesy of College of DuPage)

Saturday Morning to Evening

As we head into tomorrow morning, things look to remain quite unstable as the energy from the remnants of Cindy approaches the area while the cold front to our east compresses all of the rich tropical moisture into a focal point, located right over our area. During the day today, the high resolution models have been keying in on a very heavy band of rain moving over portions of Pennsylvania, New Jersey, New York, and Connecticut by 7-10 am tomorrow. This band of heavy rain is directly associated with a mid level piece of energy currently located over portions of Kentucky, which will likely continue NE throughout the evening hours. A crucial point here is that since the energy already exists and is well sampled, the models likely have a decent grasp on the situation over the next 12-18 hours. Regardless, as this piece of energy nears our area tomorrow morning, we will have to monitor the situation very closely since any rainfall with this system will likely be quite intense, which could produce localized flash-flooding, and exacerbate and potential flooding issues caused by tonight’s storms.

Thankfully, the rain threat looks to quickly diminish later tomorrow morning, into the early afternoon hours. Any residual showers and thunderstorms look to press off to the east and offshore, leaving much drier conditions in their wake. With clearing skies, westerly winds, and warm low to mid level temperatures, temperatures should be able to climb into the middle 80’s with ease by late tomorrow afternoon, making for a nice rebound. Weak high pressure will be over the region Saturday night. Clear to partly cloudy skies are expect with lows in the 60s in many of the suburbs to lower 70s in NYC and urban areas.

Rapid Precision Models deception of this evening and tomorrow mornings heavy rain threats (Courtesy of WSI)

Rapid Precision Models deception of the possible heavy rain threats this evening, lasting into tomorrow morning (Courtesy of WSI)

Sunday and Beyond 

Sunday looks to be quite beautiful early on, with increasing sunshine during the early morning and afternoon hours and light winds from the west/southwest due to high pressure exiting off the Mid Atlantic coast. With the mid/upper level trough moving over the region during the day, slightly cooler temperatures aloft will limit just how warm temperatures can get, with highs likely reaching into the lower to middle 80s over much of the area. There is some potential for sea-breeze activity to knock temperatures down into the 70’s during the afternoon hours, but this will likely happen on a very small scale. Later in the day, a weak cold front looks to move through the area, and bring at least an increase in cloudiness, with an outside chance at a shower or weak thunderstorm towards the evening hours.

By Monday, troughiness will increase once again over the northern section of the Great Lakes region, which will likely usher in a cooler and much direr air mass compared to what we have been experiencing over the past few days. This area of below normal temperatures looks to continue into at least Tuesday, before we have to watch for the potential of a ridge building over the east, possibly by Wednesday. Mid level ridging may continue to build into the Northeast and Mid-Atlantic through end of the week, with more heat and humidity possible over the east.  As of right now, no significant precipitation or convection is expected, until the trough over Rockies finally shifts east into Northeast/Mid-Atlantic region by next weekend.

This afternoons European Ensembles showing a rather high likelihood of below normal temperatures for the first half of next week.

This afternoons European Ensembles showing a rather high likelihood of below normal temperatures for the first half of next week.

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Have a great evening!

Steve Copertino

 

Steven Copertino

Public Analysis: Oppressive Early Week Heat Wave, Relief Coming?

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Good Evening!

As promised, yesterday and today have been the exact opposite of last week, with highs well into the 90’s for most locations and rather dry conditions. This heat looks to continue for another day or so, but we may have to deal with some strong thunderstorms tomorrow afternoon across portions of the area. Afterwards, a cold front looks to move through and bring in a much cooler Canadian/maritime airmass towards Wed/Thursday. In the longer range there are some indication that we may once again return to warmer weather, with highs at least in the upper 80’s to lower 90’s by next week, but the computer model guidance this afternoon is diverging on whether or not this next bout of heat will be here to stay, or will be a one or two day event.

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This Evening 

The large ridge of high pressure that was forecast to move over the eastern two thirds of the nation has done just that over the past two days, and it has led to quite the temperature surge over our area. With winds out of the southwest this afternoon and abundant sunshine, we saw highs soar into the low to middle 90’s, with some locations getting all the way up to the upper 90’s. Combined with some modest low level moisture, today definitely had a muggy feel to it, making it rather hard to spend prolonged periods of time outside. In fact the NWS in Upton has issued a Heat Advisory, with the new criteria being “A Heat Advisory is issued when the combination of heat and humidity is expected to make it feel like it is at least 95 degrees for two consecutive days…or 100 degrees for any length of time.”

This evening should continue to be rather hot, with more breezy conditions developing later in the day, in addition to some increase in clouds, but really not enough to make all that much of an impact on the temperatures. As stated, with skies being quite clear, light winds after dark, and an area of high pressure located to our south, conditions should be favorable for some radiational cooling to take place. This will allow lows to drop around 20-25 degrees, into the upper 60’s and lower 70’s for most of the area, with coastal locations getting a few degrees lower.

This afternoons latest super high resolution satellite imagery from the GOES-16 Satellite, regional radar mosaic, and surface temperatures showing a rather hot, but start to the work week

This afternoons latest super high resolution satellite imagery from the GOES-16 Satellite, regional radar mosaic, and surface temperatures showing a rather hot, but start to the work week

Tomorrow Into Tomorrow Evening 

Tomorrow will likely be just as warm, or possibly even a degree or two warmer in some locations as very warm temperatures aloft and southerly/southwesterly winds continue to feed into the area. Tomorrow morning will likely start off quite clear across the area, so temperatures should rise very rapidly as the sun angle increases throughout the early morning and into the afternoon hours. As the afternoon continues on, a cold front will be moving southward across the area and moving into a rather unstable airmass juxtaposed over the region. This cold front will act as a “trigger” and should begin to ignite at least scattered thunderstorms over portions of New York, Pennsylvania, and Connecticut.

While there does appear to be adequate instability for some strong to possibly severe thunderstorms, weak wind shear will prevent any widespread severe thunderstorms from developing, at least south of the New York City area. Additionally, the weaker shear will promote very slow storm motions, so the main hazards with any storms tomorrow appear to be gusty winds, frequent lightning, very heavy rainfall, and possibly some isolated large hail in the strongest of storms.

Otherwise, tomorrow looks to be on track for widespread 90 degree readings over much of the area. Heat indices look to also look to be in the middle to upper 90’s for locations removed from the coasts, so make sure to have plenty of water and take breaks if you are spending prolonged periods of time outside tomorrow! As we head into the evening hours, shower and thunderstorm activity should gradually progress east/southeast and weaken over time as the cold front begins to overtake the area. This will provide cooler temps tomorrow evening and increasing winds from the west/northwest.

This afternoons Rapid Precision Model showing strong to possibly severe thunderstorms developing tomorrow afternoon due to moderate instability and weak wind shear (Courtesy of WSI)

This afternoons Rapid Precision Model showing strong to possibly severe thunderstorms developing tomorrow afternoon due to moderate instability and weak wind shear (Courtesy of WSI)

Wednesday and Beyond

As the cold front begins to push offshore early Wednesday morning, anticyclonic flow will become established over portions of New England that should begin to send winds in from the east over our area. These easterly winds in conjunction with a more moderate Canadian airmass will make for a much more bearable day on Wednesday, with highs likely reaching into the low to mid 80, with broken clouds with some sun peaking through at times.

Thursday should be even cooler than Wednesday as the anticyclone/high pressure area off of Cape Cod really digs in during the day. This will enhance easterly winds over the area, which likely be running into more moist low level air that should promote increased cloudiness and even some patchy shower development during the late morning and into the afternoon hours.

Friday looks to feature the only real threat of rain this week as a weak upper level disturbance moves to the north of the area, and surface trough to our south may try to trigger some showers over the area, with seasonable temperatures expected during the day. As of right now, the heavy rainfall threat is low, though we will continue to provide updates during the week!

This afternoons European Ensembles Model blend showing the potential for warmer temperatures to once again return, though they may be rather brief this time around

This afternoons European Ensembles Model blend showing the potential for warmer temperatures to once again return, though they may be rather brief this time around

For more information and posts like this one, make sure you sign up for Zone Forecasts — where multiple detailed articles, videos, and interactives are posted each day. Also, come interact with our staff and many other weather enthusiasts at 33andrain.com!

Have a great evening!

Steve Copertino

Steven Copertino

Public Analysis: Brief Taste of Summer, Cooler Conditions Likely This Weekend

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Good Afternoon! 

Earlier this week we mentioned that there was a strong likelihood that much of the area would be seeing temperatures rising into the mid to upper 80’s, and possibly 90’s starting today. This has indeed turned out to be true, with many stations this afternoon reporting highs in the lower 90’s across Pennsylvania, New Jersey, New York, and Connecticut. Tomorrow looks to be even warmer, with highs possibly reaching the mid 90’s by lunchtime tomorrow. However, this heat looks to be short-lived as another cool shot from Canada will likely bring temperatures back down to seasonable levels by this weekend!

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Due to the rather clear and calm conditions over the area last evening, most locations were able to drop down into the lower 50’s and upper 40’s during the early morning hours today, which made for a cool start to the day for anyone who was active before today’s sunrise. After sunrise, the clear and calm condition’s allowed temperatures to shoot up into the upper 80’s and lower 90’s across the entire region, with locations in Long Islands and coastal Connecticut seeing lower temps due to southerly winds coming off the of the cooler Atlantic ocean. This was quite the impressive rebound, and the 40+ degree rise in temperatures this afternoon actually helped a few record highs get surpassed, with LaGuardia Airport(NY), Monticello (NY), Danbury (CT), Hartford (CT), and Belmar (NJ) all beating their daily high temperatures. The rest of the afternoon should continue to be quite warm and pleasant, with the sea-breeze likely working its way deeper into portions of New Jersey, Southeastern New York, and Connecticut.

Later this evening, temperatures should stay relatively mild as the humidity begins to increase as a subtropical high pressure system off of the southeast coast continues to move eastward and pump up moisture from the Gulf and Atlantic. Clouds may begin to increase during the evening, as increasing high-level clouds were noted on the latest visible satellite imagery. Overnight lows should remain in the upper 50’s to upper 60’s across much of the area, with the exceptions of coastal communities, which may see lows in the middle 50’s due to continued southerly winds blowing in from the cooler Atlantic.

Latest visible satellite, surface temperatures, offshore buoy data, and regional radar mosaic showing very warm temperatures over the area this afternoon. Also note the cooler temperatures over Long Island and Connecticut due to the southerly winds from the Atlantic

Latest visible satellite, surface temperatures, offshore buoy data, and regional radar mosaic showing very warm temperatures over the area this afternoon. Also note the cooler temperatures over Long Island and Connecticut due to the southerly winds from the Atlantic

If today wasn’t a good enough taste of summer for you, then tomorrow will likely deliver what you desire. While we may see some overcast and broken clouds over coastal areas tomorrow morning due to the southerly winds and enhanced moisture in the lower-levels, these clouds will likely break up quite quickly during the early afternoon hours. With low-level temperatures already quite warm, clear skies, and great southerly flow, tomorrow looks to be on track to hit the upper 80’s to low 90’s across much of the area tomorrow. Some portions of Northeastern New Jersey and Connecticut may even see highs in the mid 90’s, while coastal areas of NJ, NY, and CT see cooler temperatures overall, especially once the sea-breezes begin to set in. With temps in the lower to mid 90’s, tomorrow has a high chance of breaking quite a few daily high temperature records, even more so than today did. These warm and humid conditions will likely remain well into Thursday evening, as the model guidance over the past few days has really delayed the timing of the next cold front. Expect lows to range from the upper 60’s to lower 70’s across much of the area (excluding coastal locations)

With the increasingly humid and hot conditions expected to persist into tomorrow afternoon, the National Weather Service has issued an Air Quality Alert for the entire region. Sensitive individuals including the very young, the elderly, and persons with respiratory diseases such as asthma, should avoid strenuous outdoor activities during the afternoon and early evening hours.

High resolution North American Model showing highs in the upper 80's to mid 90's tomorrow afternoon (Courtesy of Tomer Burg)

High resolution North American Model showing highs in the upper 80’s to mid 90’s tomorrow afternoon (Courtesy of Tomer Burg)

Friday Into This Weekend 

Friday will likely be warm, but not quite as warm as Wednesday (today) or Thursday were. Winds should begin to shift to more of a westerly direction during the day on Friday ahead of an approaching cold front located in Northern New York. However, it is likely that this cold front may take its time reaching the area, and with clear skies and southwesterly/westerly winds temperatures should easily reach into the mid 80’s across most of the region. Even though temperatures will remain rather warm, we should begin to see the humidity really drop off as the front ushers in drier Canadian air. Temperatures will gradually begin to fall off as the front should move through the area by late Friday afternoon or early evening. As this front drops southward through the area, temperature will drop into the more seasonable levels, with a more pronounced northwesterly wind developing.

It is worth noting that there is a potential that they delayed timing of the frontal system on Friday may allow instability to build up enough to the point that we may see isolated showers and thunderstorms develop. However, due to the dynamics that would allow the shower and thunderstorms to grow and become more widespread remaining concentrated to the northwest, it seems unlikely that any organized activity will be likely during the day on Friday.

High pressure coming from Canada will begin to move in during the evening hours on Friday, bringing a rather substantial change in air-masses. As the high pressure moves to our north on Saturday afternoon, cooler and drier conditions are likely to persist throughout the day as a more moderate maritime air-mass replaces the warm tropical air-mass that has been over our area. Highs will likely remain in the upper 60’s to lower 70’s across the entire are, with the exception of coastal locations on both Saturday and Sunday. Lows for both days will likely be quite cooler, reaching down into the mid to low 50’s once again. These temperatures will be quite a change, with highs being 12-15 degrees below-normal. Overall, it looks like a much more pleasant and seasonable weekend is on tap, so make sure to enjoy it!

This afternoons European model showing the potential for a pretty large-scale pattern change, with a deep trough located in the east for the middle half of next week and beyond

This afternoons European model showing the potential for a pretty large-scale pattern change, with a deep trough located in the east for the middle half of next week and beyond

The next rain threat looks to be on Monday as some showers and potentially a thunderstorm or two will be possible as another cold front associated with an area of low pressure will be moving through the Northeast.

This afternoons model guidance suggests that the negative NAO will once again flex its muscles, allowing for a large trough to dig into the central portion of the country and gradually progress eastward next week. This will help to once again create a stronger chance at below-normal temperatures and even the threat for a significant precipitation in the long-range as blocking continues to take shape over Atlantic Canada.

Some pleasant, warmer or drier weather could still return at times, as synoptic features in pattern still shuffle around somewhat. But no prolonged heat is expected.  Make sure to stay tuned as we get closer to Memorial Day and begin to get a grasp of what may be on the table for the holiday weekend!

For more information and posts like this one, make sure you sign up for Zone Forecasts — where multiple detailed articles, videos, and interactives are posted each day. Also, come interact with our staff and many other weather enthusiasts at 33andrain.com!

Have a great evening!

Steve Copertino

 

Miguel Pierre

5.15 Midday Zones Update: Summer Warmth Midweek, Cooler Weekend

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Happy Monday! Hope you had a lovely weekend! A coastal storm that impacted the region over the weekend, is still east of New England today. Clouds from this low are moving through parts of the region. As the storm slowly moves out further into the Atlantic, clouds will gradually clear for more sunshine. High temperatures this afternoon will be in mid-upper 60s. Overall it will a pretty decent day. But a tight pressure gradient behind this low will cause northwest winds to gust over 30-40mph, through this afternoon.

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