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Public Analysis: Much Cooler Today, Multiple Rain Threats Ahead

Good Afternoon!

High pressure off of the Canadian maritimes has set up in the perfect position today to usher in cool winds from the Atlantic, keeping temperatures a good 10-12 degrees below what they were just 24 hours ago. In addition to the cooler winds from the southeast, clouds and even some light showers have been noted across the western portions of the area this afternoon. Back to the east, there have been some breaks in the clouds noted on visible satellite imagery over parts of New Jersey and New York. Even with these breaks in the cloud deck temperatures have not been able to get much higher than the low to mid 50’s, with temperatures in the 40’s being reported over portions of Long Island and Connecticut.

Cloudy skies and cooler temperatures should continue to be the theme for the rest of today as a mid-level warm front begins to approach from the west later this afternoon and into the evening hours. This front will bring increasingly cloudy skies and even the threat of some showers later this evening as available moisture begins to increase in conjunction with the passing of this front.

As the evening progresses onwards, a very weak cold front associated with a disturbance in Canada will pass through the region and bring yet another chance at some more showers as lift with this system is only slightly stronger than the warm front that preceded it. Overall, it should be a rather raw and dreary afternoon and evening as temperatures remain pretty much capped off in the 40’s to low 50’s across the entire area.

Latest visible satellite imagery, surface temperatures, and regional radar mosaic showing a relatively cool Spring day (Courtesy of GREarth)

Latest visible satellite imagery, surface temperatures, and regional radar mosaic showing a relatively cool Spring day (Courtesy of GREarth)

Thursday into Friday Afternoon 

Tomorrow morning should start off with some broken clouds across the metro area as weak upper level energy riding up and over an area of high pressure. At this time it seems that any shower  activity  should remain quite limited, though some areas of drizzle may be possible along the coast early on in the morning. As tomorrow continues on, a surface warm front looks to move north through the region and provide a renewed chance at some more low to mid-level cloudiness as more warm/moist air begins to work its way in.

There are still some questions as to how much warming occurs tomorrow with the combination of some leftover southeasterly winds off of the Atlantic, as well as increasing cloudiness, but it does look like tomorrow will at least be a warmer day than today. Temperature should be able to rise into the mid to upper 60’s for locations away from the coast, but highs may struggle to get out of the 50’s for coastal sections of New Jersey, Long Island, and Connecticut. Some inland locations of New Jersey and Pennsylvania may have a chance at reaching the low 70’s, but this will be highly dependant on the aforementioned variables.

The area of low pressure that we mentioned back in Friday’s discussion will begin to track through the upper Great Lakes region late Thursday afternoon and evening, and this will bring yet another warm front for our area later in the evening. However, confidence decreases significantly as a high pressure system coming down from central Canada and stalling over portions of southeast Canada may work to stall this warm fronts progress. Where this warm front stalls will dictate where cooler temperatures setup Thursday night. Areas north of the front will see lows back into the 40’s and low 50’s. Areas to the south will see temperatures remain in the 50’s to possibly even low 60’s overnight as southerly flow increases.

Unlike the warm front passing through this evening, the front tomorrow night and into Friday morning should have enough moisture and dynamics associated with the area of low pressure passing to our north to provide a decent chance at some showers and even thunderstorms. With limited instability, a strong low level flow, and deep moisture transport, it appears that there will be a chance at some convection possibly developing during the evening hours. The main threat with these storms appears to be locally heavy rainfall and possibly some flooding for areas with poor drainage, so make sure to stay up to date on these possible storms over the next 24 hours.

15z Rapid Precesion Model showing some heavy showers and thunderstorms developing from west to east on Thursday evening and into Friday (Courtesy of WSI)

15z Rapid Precession Model showing some heavy showers and thunderstorms developing from west to east on Thursday evening and into Friday (Courtesy of WSI)

Friday Evening and Beyond

Finally, a cold front, will come through later Friday afternoon and evening. But any more showers will be more widely scattered with less lift and instability along and ahead of this front. Skies will finally clear later Friday night and Saturday, as weak high pressure build into the Northeast, behind this storm system. Sunshine with northwest downslope winds on will help temperatures rise into back into the lower to middle 60s on Saturday afternoon.

As we continue onwards, the active pattern looks to continue as the computer models are keying in on the potential for a storm system to approach from the southwest on Saturday evening, however they diverge significantly on the strength and timing of this system. As of this afternoon it appears that at least moderate rain appears likely as this system tracks to our south, and then stalls off the Mid Atlantic coast on Sunday.

It is worth noting that this system will be moving across the southern Plains and will have time to take in a considerable amount of water vapor before it reaches our area and it is also important to mention that with a considerable amount of time left in this forecast, there is the potential that this system could trend stronger when it passes to our south as well as potentially stall closer to the coast than what some of the models currently have. This would possibly bring a more significant system for our area on Sunday and possibly into Monday, with heavy rain and even some strong winds possible for the coast.

12z European model showing an area of low pressure over the Southeast US states potentially bringing the threat of moderate rains later this weekend (Courtesy of Accuweather Pro)

12z European model showing an area of low pressure over the Southeast US states potentially bringing the threat of moderate rains later this weekend (Courtesy of Accuweather Pro)

Make sure to stay tuned over the next few days for updates on the potential storms tomorrow evening, and our next storm chance this 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

Public Analysis: Cooler and More Unsettled Pattern Taking Shape

Good Afternoon!

The work week has had a rather dreary start today as cloudy skies and even some rain showers pushed through the area this morning and afternoon. Most of these showers were relatively light in nature, but most of the metro area remained at least under rather thick low level clouds. This area of cloudiness and showers was caused by a weak disturbance in the mid levels of the atmosphere just ahead of a larger system that is still located back in southern Canada.

As of 3pm this afternoon, the clouds and showers associated with this weak system have begun to dissipate and move to the east/southeast, giving way to clearing skies over northeast NJ and portions of Connecticut. Despite the cloudy conditions and the mixed in showers, temperatures have been able to rise into the mid to upper 60’s this afternoon. In fact. the locations that are beginning to see more sun poke through the clouds this afternoon have actually made it back into the low to mid 70’s. Even though these temperatures are still slightly above normal for this time of year, they are still a good 15-20 degrees cooler than the highs this time yesterday afternoon. Temperatures may continue to warm for portions of central and southern New Jersey as gradual clearing takes over, but overall highs should remain in the mid to upper 60’s with some locations able to break into the low 70’s.

As we work our way into later this afternoon and evening, more gradual clearing will begin to overspread the entire area behind the weak disturbance and antecedent cold front.  Some breezy winds of around 25-30 mph may linger into the evening hours, but as we progress towards sunset, winds should begin to subside, eventually giving way to clearer and more calm conditions. These conditions should allow for all locations to see some rather cool conditions once again this evening, as lows drop into the 40’s for coastal locations and possibly down into the upper 30’s for farther inland locations.

Latest surface temperatures, regional radar imagery, and visible satellite imagery showing improving conditions across much of the area this afternoon (Courtesy of GREarth)

Latest surface temperatures, regional radar imagery, and visible satellite imagery showing improving conditions across much of the area this afternoon (Courtesy of GREarth)

Tuesday Into Wednesday

As we move into tomorrow, generally cooler weather is expected once again as offshore flow brings in a cool maritime air mass from the Atlantic. Winds out of the northwest will also usher in drier conditions as well, so expect mainly clear skies during the day tomorrow with rather pleasant conditions. High pressure located to the northeast will also help to keep things relatively calm and seasonable for this time of year as highs stay in the mid to upper 50’s across much of the area, with a few locations seeing temperatures creep into the lower 60’s tomorrow afternoon.  Tomorrow should feel quite pleasant with frequent sun and light winds, but tomorrow should be right around normal for this time of year. 

Tuesday evening should see a gradual increase in clouds as moisture from the offshore winds bring in some low level moisture. Depending on how much cloudiness winds up manifesting tomorrow night will ultimately determine just how cool the low temperatures can get, but right now it seems that most of, if not all of the area will be seeing lows tomorrow evening in the 40’s. There is a small chance that inland locations that are further away from the coast, and therefore have less chance of marine influence, could possible see lows dip in the upper 30’s, but this will have to be monitored.

As we talked about last week, we are headed into what looks to be a more active pattern later this week that is quite reminiscent of late March as multiple storm systems and potential backdoor cold fronts have the possibility to impact our area. As of right now, Wednesday looks to be a rather seasonable day with broken clouds likely throughout the day just ahead of a gathering storm system in the central part of the county. This storm system will continue to head east towards the area throughout the day, and at least bring some enhanced cloudiness towards the evening hours. 

12z GFS 13km model showing a gathering storm system on Wednesday over the central US on Wednesday evening (Image courtesy of GREarth)

12z GFS 13km model showing a gathering storm system on Wednesday over the central US on Wednesday evening (Image courtesy of GREarth)

Thursday and Beyond 

Thursday should be a rather unsettled day as a frontal boundary ahead of the main area of low pressure in the Ohio Valley begins to sink to the south of the region. This should provide a chance at some showers and possibly a thunderstorm or two before the main low pressure approaches on Thursday evening. As of right now, there seems to be two main options for the late week storm, with the first option looking somewhat more likely as of this afternoon’s model guidance.

This option would mean that the main area of low pressure in the Ohio Valley would be able to lift the frontal boundary that was previously to our south, back up to our north. This would bring more warm/moist air into the area Thursday evening and into Friday afternoon. In this scenario, the low pressure would then track along the frontal boundary to our north during the day on Friday, and this would in turn bring the potential for heavier rain, with some thunderstorms also possible if enough instability is able to work its way in.

The other scenario would be that the low pressure system and frontal boundary remains to the south of the region late Thursday and into Friday, thus a cooler and steadier rain would be more likely. While both scenarios have the potential for heavy rain, the first option would be more intense, but also more localized. The second option would obviously be much more widespread and could even have a wind threat associated with it if the system remains far enough to the south.

12z European model showing the main area of low pressure tracking well to our north on Friday morning, bringing in a more moist/unstable airmass with the potential for heavy showers and even thunderstorms (Valid 2am Friday)

12z European model showing the main area of low pressure tracking well to our north on Friday morning, bringing in a more moist/unstable airmass with the potential for heavy showers and even thunderstorms (Valid 2am Friday)

As we head into the weekend, there is a chance things may briefly calm down, but overall temperatures are likely to remain slightly above or near normal through the weekend. Afterwards, there is a chance that a more substantial rain event could take place. This afternoons guidance has been hinting at the potential for a coastal system to impact the region, but this is of course in the long range and there is a great amount of uncertainty right now.

Regardless, it seems that things are going to become active once again with multiple rain chances over the next 7-10 days, so make sure to stay tuned for future updates on the upcoming pattern!

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 afternoon!

Steve Copertino

All Zones Mid-AM Update: Cooler Early Week, More Unsettled, Wetter Weather Late Week

Happy Monday! Today will begin a cooling trend after a summer-like day on Easter Sunday! More clouds than sunshine are likely through at least the early afternoon hours, as cold front approaches. A weak mid-level disturbance moving through the Mid-Atlantic region, is also producing some showers over Southeast PA and Southern NJ this morning. A few scattered showers or sprinkles are possible further north into Northern NJ, NYC and Long Island. But most of these showers should stay to south.

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Midday Zones: Summer warmth today, unsettled late week

Happy Easter to this who celebrate! We hope you’re able to enjoy the day with the family, friends, and loved ones who are most important to you. Regardless of whether you celebrate or not, we’re all being treated to summer-like warmth today. A deep west/southwesterly flow became rooted at the low levels of the atmosphere this morning and will continue through the afternoon. This has helped to advect a very warm airmass into the area and this air will remain over the region.

The west/southwesterly wind component to the airmass is probably the most critical (and meteorologically fascinating) aspect to the airmass which settles into the area. You may remember last week, much of the interior experienced warmth very similar to today. Temperatures rose into the lower and middle 80’s on those days as well. But near the coast, the cold ocean waters had their say — marine air shifted inland by 25 miles or so and kept coastal locations (and much of Long Island) very cool compared to their surroundings.

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