Posts

Steven Copertino

Public Analysis: More Dreary Weather Likely Thursday, Improvements This Weekend?

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Good Evening!

Most of the area saw a rather damp and dreary start to the work week today as areas of moderate to heavy rainfall moved over portions of the Mid-Atlantic and Northeast. This is due in part to a large upper level system over the central part of the country that will be gradually strengthening and progressing eastward over the rest of the week. This should allow for more damp and unsettled conditions down the line, especially on Thursday and Friday. A break from this pattern may be possible by the time we reach the Memorial Day Weekend, but this will all depend on the evolution of the previous systems this week.

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Today Into Tonight

Most of the tri-state area and portions of southern Pennsylvania saw a rather damp and cool day today with highs only reaching into the mid 50’s to lower 60’s. Though much of the area saw rain today, the heaviest bulk of the rain was concentrated to portions of central and southern New Jersey, where localized amounts over 2″ were seen. Further north totals were more in the trace to half-an-inch mark, especially in northwestern New Jersey, southern New York, as well as Connecticut. The rain has begun to pull away from the area, with only coastal sections of New Jersey and Long Island still stuck under steadier showers. Drizzle is likely to last for some locations until after dark, but overall conditions should begin to improve despite mostly cloudy skies. Some clearing may take place towards the late evening hours, or early tomorrow morning, but the cloud cover should be able to hold overnight lows into the lower to middle 50’s for much of the area, including the coast.

A cold front will pass through the area later this evening and usher in a much drier, but also temporary air-mass from the north and west that will work to end any lingering showers that may exist over the area. An area of weak high pressure just north of the region in addition to the introduction of drier air will decrease cloud cover tomorrow afternoon. A weak wave of low pressure will develop along the cold front that passed over our area and this low pressure will begin to move northeastward by later tomorrow afternoon.

Most of this afternoons model guidance keeps this small area of low pressure to the south and east of the area, but there is the possibility that at the very least this low will lead to an increase in cloudiness, but some rain showers are possible along the coastal sections of New Jersey and Long Island. Highs tomorrow will be just slightly warmer than today as highs are able to reach into the upper 60’s and lower 70’s across the area, and some locations may see slightly warmer highs if they are able to experience prolonged periods of clearing. These highs will be slightly below-normal over much of the region, with departures around 5 degrees below-average. With increased cloudiness and windier conditions possible, lows tomorrow evening will likely remain in the middle to upper 50’s, with the possibility of isolated locations holding in the low 60’s.

Latest regional radar data, stations plots, visible satellite imagery , and temperature plots as of this evening showing cloudy, cool, and damp conditions persisting over portions of the area (Courtesy of College of DuPage)

Latest regional radar data, stations plots, visible satellite imagery , and temperature plots as of this evening showing cloudy, cool, and damp conditions persisting over portions of the area (Courtesy of College of DuPage)

Wednesday and Thursday 

Some light rain showers may linger along the coast on Wednesday morning, but as the weak area of low pressure begins to pull away, any potential impacts will begin to diminish. This will lead to improving skies during the afternoon hours with peaks of sunshine, allowing highs to reach into the upper 60’s to middle 70’s over the entire area.

The large upper level low that we have been talking about for over a week now will likely be rotating into the Great Lakes region and portions of the Northeast by late Wednesday evening or very early Thursday morning. As this large system begins to lumber towards us, it will drag up an impressive amount of moisture from the Gulf of Mexico and southwestern Atlantic and begin to transport it northward towards our area. Once this upper level system begins to mature and strengthen, it will spawn a primary area of low pressure over the Appalachian mountains, and potentially another low that may develop just off the Mid-Atlantic coast.

There are some uncertainties regarding this system, but steady, heavier rain is likely during the day on Thursday, especially if the secondary low develops off the coast. However, if the system turns out to mature quicker and becomes more disorganized once it reaches our area, then the rain may be more sporadic and in the form of convection, but will still have the chance to produce some heavy rain.

This afternoons American model showing very impressive upper level jet structure that looks to be quite favorable for heavy rainfall over portions of our area on Thursday (Valid 8am Thursday)

This afternoons American model showing very impressive upper level jet structure that looks to be quite favorable for heavy rainfall over portions of our area on Thursday (Valid 8am Thursday)

Friday and Beyond

This area of low pressure looks to begin to fill-in and stall somewhere over the Northeast on Friday morning due to the high-latitude blocking that has persisted near the Canadian Maritime region and portions of Greenland. This should allow cloudy conditions, cooler temperatures, and  the threat of showers to last throughout the rest of the day as the low lingers around the region during the day.

Some improving weather looks likely for the start of the first big holiday weekend of the Summer,  at least on Saturday and no washouts are anticipated each day. So don’t cancel or change any outdoor plans yet!

However, there may be some left over blocking and some upper level ridging over the West Coast, which may continue to support a somewhat unsettled and potentially active weather pattern into this weekend. At this time, model guidance is beginning to suggest that another storm system tracking northwest of region, that could bring some showers to the region, sometime on Sunday or on Memorial Day. But more forecast details will likely be fined tuned throughout the week.

This afternoons American model showing showing yet another potential system working its way down from Canada around the Memorial Day time frame

This afternoons American model showing showing yet another potential system working its way down from Canada around the Memorial Day time frame

Stay tuned for another for more updates, with discussion on later this week and Memorial Day 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

Steven Copertino

FREE Public Analysis: Damp and Dreary Conditions Gives Way to Above-Normal Temps

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Good Afternoon and Happy Friday!

The low pressure that moved just west of our area yesterday has slowly continued on towards the north and east this afternoon, bringing yet another gloomy and day. This low will gradually lift out into eastern Canada by Saturday, but stout northwesterly winds will keep temperatures somewhat below-normal throughout the day. By Sunday, some relief from this cool and gloomy weather should arrive as an area of high pressure builds in from the southwest. As this high locks itself offshore during the beginning of next week, we may see temperatures well-above average for this time of year. The question is, does this warm period last, or is it just a passing tease?

This Afternoon and Evening 

As mentioned, the very energetic area of low pressure that produced heavy rainfall, intense lightning, and even some damaging wind gusts for portions of the New York metro area has lifted into Canada this afternoon, leaving behind much cooler temperatures in its wake. Temperatures have struggled to get out of the mid-upper 40’s this afternoon, which is a good four to six degrees (c) for this time of year. When coupled with wind gusts in the 20-30 mph range, this makes temperatures feel even worse, dropping down into the upper 30’s and low 40’s. These windy conditions are due to the strong area of low pressure exiting to the north east of our area, producing a tight pressure gradient over the region as it presses against a high pressure system currently located over the Mississippi Valley.

Showers have been relatively persistent this afternoon across the area, providing some light rain or drizzle to really put the icing on the miserable conditions of this afternoon. As the last piece of energy associated with Thursday storm swings through, these showers and a weak cold front may bring some more showers towards sunset, with the possibility of a mix of snow and rain in the more inland/elevated locations. These rain or mix showers are expected to be very light in nature and no significant precipitation is expected to fall from these showers as support for their development gradually wanes this afternoon.

Mostly cloudy conditions should persist throughout the rest of the afternoon as the weak front and associated upper level energy wring out the last bit of moisture available in the atmosphere. Once we head into this evening, the remaining showers should die off and skies should gradually clear, leaving temperatures rather cold for this time of year. Most locations should see lows this evening range from the mid 30’s, to low 40’s closer to the coast.

Current surface temperatures, regional radar mosaic, and visible satellite imagery showing relatively cold and damp conditions this afternoon (Courtesy of GREarth)

Current surface temperatures, regional radar mosaic, and visible satellite imagery showing relatively cold and damp conditions this afternoon (Courtesy of GREarth)

Saturday and Sunday

As we work our way into Saturday morning, temperatures should be relatively cool to start off the day with 30’s and low 40’s being commonplace across the area. As high pressure begins to establish itself on Saturday afternoon, winds from the northwest will keep things dry, but also relatively cool. Temperatures should be in the low to upper 50’s across the area under mostly sunny skies, however the pressure gradient that was mentioned earlier will still be lingering over the region, so winds of 15-20 mph may make things feel a bit more chilly than they actually are. Overall, Saturday should be an improvement from the past few days, but will ultimately be a few degrees below normal in the end. Saturday evening should feature clear skies with temperatures in the mid 40’s, with upper 30’s possible to the north and west of New York City.

As the high pressure system begins to move to our south on Sunday morning, winds will begin to shift to the south/southwest with somewhat chilly conditions to start off with. As the morning progresses,  these southwesterly winds will usher in much warmer conditions by Sunday afternoon. Temperatures should have no problem reaching into the 60’s on Sunday afternoon with clear skies and light southerly winds. This will make Sunday the highlight of the weekend, but this is only the beginning of the above-normal temperature regime!

3km NAM showing temperatures reaching at or around 60 degrees areawide on Sunday afternoon (Valid 2pm)

3km NAM showing temperatures reaching at or around 60 degrees areawide on Sunday afternoon (Valid 2pm)

Extended Range (Monday-Friday)

With the area of high pressure centered off of the Mid-Atlantic coast on Monday, warmer temperatures will continue to build throughout the week with increasing, deep southwesterly flow at the surface. This will allow temperatures to reach all the way up into the mid 70’s and possibly even low 80’s for southern locations on Monday and Tuesday. If such temperatures are realized early on in the work week, these would easily be around 12-15 degrees above normal for this time of year, which would be a remarkable contrast to this week’s dreary deluges.

In addition to this period of much warmer weather, conditions should also be much less active for now, as the storm track across the country leads the low pressure track well off to our west.

Temperatures should remain a good 8-15 degrees above normal each day through Thursday afternoon, before a potential disturbance from Canada drops down and brings in a chance at some more unsettled weather and cooler temperatures.

After this period of more calm and dry conditions, the Pacific looks to become much more active once again, so we will have to watch for more stormy conditions on the horizon as multiple systems line up to impact the western US and possibly travel east.

12z GFS upper level winds at 300mb showing a very active potential pattern shaping up over the Pacific, similar to the one that recently provided the severe weather and heavy rains (Valid 8am Thursday)

12z GFS upper level winds at 300mb showing a very active potential pattern shaping up over the Pacific, similar to the one that recently provided the severe weather and heavy rains (Valid 8am Thursday)

With some impressive warmth and a potentially more active pattern returning in the long-range, make sure to stay tuned for updates!

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 weekend!

Steve Copertino

Miguel Pierre

4/01 All Zones AM Update: Dreary Start to the Weekend, Active Pattern Continues Next Week

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Happy Saturday and welcome to April! Unfortunately this weekend and month is off to another dreary start. Low pressure that has brought over 1″ of rainfall to much of the region since Thursday night, is now moving slowly offshore. A mid-level dry slot has cause steadier rain (and wintry mix well north) overnight to taper off this morning some light rain or drizzle. Some areas of fog have also developed. These cloudy and damp conditions will likely continue for much region into early this afternoon, with perhaps some additional showers from a upper-level trough coming through for northern areas.

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Steven Copertino

Public Analysis: Active Pattern Out West Yields Another Damp and Dreary Week

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Good afternoon!

After the brief warmup that some locations saw on Saturday afternoon, we’re back into the same cool and wet pattern that we have been stuck in for nearly a week now. For now, we expect this to continue for at least the rest of this week as a very active Pacific jet streak allows storm after storm to roll through the Central Plains, and then eastward to the Northeast. While the brunt of the weather will be felt out to our west with multiple severe episodes likely, our area should at the very least should see an abundance of rain. Even though this may seem like a pretty abysmal pattern to be stuck in, most of the Northeast does actually need the rain as most of our area and especially portions of Connecticut remain in a moderate to severe drought. So, the more we can chip away at these precipitation departures before the summer months, the better off we’ll be in the long-run.

Earlier this morning we saw multiple rounds of showers roll through with some locally heavy rainfall noted from some weather observation sites. The last batch of steadier showers moved through the NYC metro area at around 930 am, and has since left behind mostly cloudy and cool conditions. As of 3pm, temperatures were quite variable, with southern New York, portions of Connecticut, and far northern New Jersey stuck in the low to mid 40’s. To the south, the NYC metro area is currently near 50 degrees, with warmer temperatures of about 60 degrees common near central/south New Jersey.

A warm front has been lifting to the north through southern NJ this afternoon, which is why we are seeing another stark contrast with temperatures today. Just like this past weekend, this warm front will only be allowed to lift so far north before stalling out. This will cause temperatures to remain generally steady as thicker cloud cover to the north prevents any more significant warming. With moist southwesterly flow overspreading the region, mostly cloudy conditions are expected for the entire region, but some southern locations in NJ and PA may see some less-dense cloud cover, or even a few late peaks of sun.

Latest visible satellite, surface temperatures, and regional radar imagery (Valid 2:20pm)

Latest visible satellite, surface temperatures, and regional radar imagery of the Northeast (Valid 2:20pm)

As we head into the evening, clouds may begin to clear a bit more to partly cloudy conditions with time due to some very brief dry air. This dry air will be located just ahead of another disturbance that will move in during the overnight hours and work to once again enhance the mid to low-level moisture air in the atmosphere just enough so that we may have to worry about some showers. Patchy fog may develop later tonight into tomorrow morning with increasing moisture and very light winds. This fog seems like it will be localized in nature, but motorists may need to exercise caution when proceeding into the morning commute tomorrow.

With the aforementioned warm front stalled to the south of NYC tomorrow morning, another cool and dreary start to the day is expected with another tight temperature gradient likely setting up. Where this gradient sets up will be dependant on where the frontal boundary decides to rest. This will lead to another situation where temperatures to the north of the boundary will be in the 40’s to mid 50’s, and temperatures to the south of the front may rise into the 60’s and even low 70’s in some locations.

This will be a difficult feature to nail down, as yesterday’s models did a poor job with just how much the warm front would lift to the north for today. Regardless, as we go throughout the day tomorrow, an area of low pressure will develop along the stalled frontal system and provide a good chance of some showers, and possibly even a few rumbles of thunder across the area tomorrow afternoon. These showers should continue throughout the afternoon and into Tuesday night just ahead of a cold front. Temperatures should remain relatively mild, with lows in the mid-upper 40’s, to low 50’s for the southernmost locations.

This afternoons 3km NAM showing showers and possibly even a thunderstorm in the southern zones tomorrow evening as an area of low pressure moves through (Courtesy of WxCharts.eu)

This afternoons 3km NAM showing showers and possibly even a thunderstorm in the southern zones tomorrow evening as an area of low pressure moves through (Courtesy of WxCharts.eu)

Finally on Wednesday things seem to calm down for the moment as a cold front associated with the weak area of low pressure moves through the Northeast. This cold front will provide some fresh, cool air for the entire region, so expect highs mainly to be in the mid 50’s to around 60 degrees on Wednesday afternoon with clear skies also likely. As we move into Wednesday night, a large area of high pressure passing to our north in Canada will briefly reinforce this cold air, which will work to drop temperatures into the upper 20’s to mid 30’s across the region—with some frost possible for inland locations.

As the high pressure system up in Canada continues to move quickly to the east on Thursday, another sunny, but below normal day looks to be on tap. Northwesterly flow will limit temperatures to the upper 40’s and low 50’s, and these temperatures will certainly feel below-normal when coupled with some light, but gusty northwest winds.

12z NAM showing a much cooler air mass on Thursday morning with temperatures below freezing for some northern locations (Valid 8am Thursday)

12z NAM showing a much cooler air mass on Thursday morning with temperatures below freezing for some northern locations (Valid 8am Thursday)

Unfortunately, this calmer period seems to be short-lived as a cut-off mid level system works its way east by Friday evening and into Saturday morning. This system will be somewhat slow-moving in nature and will have a hefty moisture feed from the Gulf of Mexico, which may allow for some heavy rainfall across much of the Northeast this weekend. We may have to monitor this system for some potential flooding issues, as warm air and heavy rainfall will quickly erode any residual snowpack in northern New England.

With the extremely active Pacific jet lining up disturbances all the way back to Japan, it seems likely that we should remain in this stormy pattern for at least the next week to ten days, so make sure to stay tuned for the latest updates on any upcoming systems!

12z GFS showing multiple disturbances lined up all the way back to Japan courtesy of a very active upper level jet

12z GFS showing multiple disturbances lined up all the way back to Japan courtesy of a very active upper level jet (Valid Saturday at 2am)

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 day!

Steve Copertino