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Weekend Outlook: Warming Trend & Scattered T-Storms in the Northeast

Happy Friday! Overall a pretty decent summer weekend is on the way for outdoor plans, with just a little more heat and humidity. But there may some isolated or scattered showers and thunderstorm by Saturday night or Sunday, that you may take cover for briefly.

First for today, mostly sunny skies are expected, as high pressure remains in control. But it will begin shifting offshore, winds become more south-southeast. This will allow areas just inland to reach the middle to upper 80s, while areas near the coast remain a little cooler.  A beautiful warm evening is on tap, then partly cloudy skies are expected overnight, as a warm front with some showers passes well to north of the region. Lows overnight will be in the upper 50s over the Interior to upper 60s or around 70 over urban areas. Read more

Beautiful weather today, potential increasing for snow Monday

Happy Saturday!

Weekend Weather Rating | 7/10

Saturday should start off nice and clear, but chilly across the Northeast as and area of high pressure takes control of our weather. Conditions should gradually warm up throughout the day tomorrow with clear skies and southerly winds developing. This should allow temperatures to warm back up into the lower to middle 50’s across much of the New York metro area, with middle to upper 50’s likely over portions of the Mid Atlantic. Clear and dry conditions look to persist throughout the entirety of the day, so tomorrow will likely be an excellent day to go outside and enjoy the day! High pressure will continue to gradually move offshore tomorrow evening, but will still supply the region with enough warm air from the south to keep temperatures from dropping too low. Lows should be in the upper 30’s to lower 40’s for the area, with middle 40’s likely over portions of southern New Jersey.

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

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.

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

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

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

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

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!

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

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

Have a great night! 

Steven Copertino