Tag Archives: severe thunderstorms

NYC Weather Update – Apr 26, 2016

April 26, 2016Climate, NYC, Severe Weather, Storms, Thunderstorms, Weather Updateclimate, new york city weather, nyc weather, nyc wx, severe thunderstorms, severe weather, severe wx, thunderstorms, tstormsLei Zhao

There is a potential for strong to severe thunderstorms today, especially for areas south and west of the city today. Stormy weather gives way to calmer, cooler conditions Wednesday before another round of rain moves in late Thursday. Cooler temperatures prevail in the short to medium term.

Rest of today – the Storm Prediction Center has placed portions of the region under a marginal to slight risk of severe weather today. These areas are largely confined to those south and west of the city. A frontal boundary is draped from west to east across the area, such that portions to the east will be in colder air north of the frontal boundary, while those areas to the west will be in a warmer area south of it. Any strong to severe thunderstorms will be confined to areas that see the warmest temperatures today, where the spread in high temperatures could be over 25ºF from eastern Long Island to Central New Jersey.

In the city, expect high temperatures in the upper-60s to low-70s with a potential for thunderstorms, some possibly with damaging winds and small hail. These storms will be coming in two rounds, one around 11AM this morning (radar returns are already showing this batch of weaker showers), and the second, stronger batch coming around 3PM.

Wednesday – temperatures cool off considerably in the wake of these storms. High temperatures will be around 60ºF tomorrow with sunny skies.

Thursday – another cool day with high temperatures in the upper-50s and increasing clouds along with an increasing chance of rain during the day into the overnight hours.

Friday – high temperatures in the upper-50s to around 60ºF with partly sunny skies.

Below Normal Temperature Trend to Continue – Rain Needed

An upcoming series of storm systems moving over the region will lead to colder air being pulled in behind them. This will result in below normal temperatures for this time of year throughout much of the next two weeks.

Due to a long stretch of dry weather, many portions of the NYC region have fallen behind normal precipitation levels for this period of the year by considerable margins. Hopefully, the rounds of rain we are forecast to receive coming up will help to prevent drought conditions from redeveloping in the area before this growing season starts in earnest.

NYC Weather Update – Jun 22, 2015

June 22, 2015NYC, Severe Weather, Thunderstorms, Weather Updatecold front, nyc weather, nyc wx, severe thunderstorms, severe tstorms, severe weather, severe wx, tstorms, weatherLei Zhao

The official start of summer was this weekend, and this week will be accompanied by decidedly summer-like weather. High temperatures for the first half of the week will be quite warm, in the mid-upper 80s, with some areas probably passing the 90º mark on Tuesday. Along with the summer-like temperatures, there will also be a chance for strong thunderstorms.

Rest of today – sunny skies will allow temperatures to rise up into the upper-80s and possibly 90 in the city. However, since humidity and dewpoints are low, it will not feel oppressively hot.

Tuesday – a cold front approaching from the west could serve as the trigger for some strong to potentially severe thunderstorms. Ahead of this cold front, continued southwesterly winds will maintain very warm temperatures in the upper-80s to low-90s in some parts.

Timing of thunderstorms looks to be in the late afternoon, possibly around the PM rush, with a line of storms moving . Warm temperatures and a humid airmass look to yield moderate SBCAPE (surface-based convective available potential energy) values in the 2000-3000 J/Kg range. This environment should support intensification for any storms that form to marginally severe limits. Correspondingly, the Storm Prediction Center has placed most of the area in a slight risk area for severe weather tomorrow, except for eastern Long Island and Connecticut.

North American model high resolution simulated radar for Tuesday, 5PM EDT

Wednesday – behind the cold front, things dry out and temperatures should cool off a bit, with high temperatures in the mid-80s.

Thursday – this will begin a period of unsettled weather that looks poised to persist through the weekend. The front that moves south of us Wednesday then stalls not too far, and remains nearly stationary starting Thursday. Several waves of low pressure are expected to move along this frontal boundary. While at this time, Thursday looks dry, cloud cover will be increasing and temperatures should be cooler, only around 80.

NYC Weekend Weather – Jun 11, 2015

June 11, 2015NYC, Severe Weather, Thunderstorms, Weather Update, Weekendair quality index, aqi, cold front, high pressure, low pressure, nyc weather, nyc weekend weather, nyc weekend wx, nyc wx, pollution, rain, severe thunderstorms, severe wx, thunderstorms, warm front, weather, weekend weatherLei Zhao

We will likely be experiencing one of the hottest days of the year so far, with temperatures expected to top out in the upper-80s and into the low-90s in a few spots this afternoon. The warm weather continues through Saturday, when an area of high pressure over eastern Canada brings us some relief from the heat. In terms of the weekend, Sunday will definitely be the better day, with cooler temperatures, but dry weather.

Rest of today – temperatures are expected to top out right around 90 in the city. Increasingly humid air will lead to an uncomfortable feeling day. There is some potential for thunderstorms, some possibly marginally severe, occurring in the afternoon hours as a cold front approaches from the north and west. The orientation of the frontal boundary and primary storm vector will align in such a way that training of storms could occur, leading to the same locations getting hit by multiple storm cells.

In addition, an air quality alert is active today, with PM2.5 particle being the primary driver in pushing the Air Quality Index into the low 100s (unhealthy for sensitive groups).

High Resolution Rapid Refresh model simulated radar composite for 4PM EDT.

Friday – the cold front that pushes through today with some possible thunderstorms will stall just south of the area, then push back north through the area as a warm front Friday. This means we will not get any respite from the heat, with highs again expected to be in the upper-80s to near 90, and another chance at more thunderstorms. There will be more sun Friday than today, but atmospheric dynamics are not expected to be supportive of severe weather.

Saturday – the warm front that passes through Friday comes back yet again as a cold front as it gets dragged along by the low pressure center moving to the northeast. This means yet another chance for thunderstorms, and ahead of that, warm temperatures remaining in the upper-80s.

Sunday – the weather finally settles down and stabilizes as a high pressure center builds to the north in behind the cold front passing on Saturday. This should lead to cooler temperatures and sunny skies for Sunday, when temperatures are expected to be in the low-80s.

Monday – another frontal boundary will be making its approach from the west on Monday, however, the timing of its approach is such that chances for rain will be low on Monday. Temperatures should again be comfortable around 80.

NYC Weather Update – Oct 14, 2014

October 14, 2014Flooding, NYC, Outside of NYC, Rain, Severe Weather, Storms, Thunderstorms, Tropical/Hurricanes, Weather Updatebermuda, cold front, flooding, gonzalo, hurricane fay, hurricane gonzalo, new york city weather, nyc weather, nyc wx, severe thunderstorms, severe weather, severe wx, weather updateLei Zhao

Apologies for the lapse in posts last week. There was plenty to talk about with the formation and dissipation of Hurricane Fay, and with Hurricane Gonzalo developing. Gonzalo won’t be a threat to the U.S. mainland, but may wreak havoc in the vicinity of Bermuda as a low end Category 3 storm with 115-120mph sustained winds. This storm has the potential to hit Category 4.

Back to our region:

Today – we get to enjoy a very warm day for this time of the year with highs in the mid-upper 70s and sunny skies! Unfortunately, clouds will begin spreading over the area in a few hours time ahead of a system described in detail below.

Wednesday – there will be a chance of light rain in the morning, with the chance for more substantial rainfall increasing in the afternoon. Temperatures will remain mild in the mid-70s with persistent southeasterly flow channeling in warm, moist air from the south ahead of the cold front and storm system that was responsible for a severe weather outbreak in parts of the Midwest and Southeast earlier this week.

Thursday – will be the main event. Lucky for us, the storm system coming at us won’t be bringing severe weather, however, a thunderstorm or two is not out of the question. The main issue for us will be the risk of flooding from this slow moving system. Forecast models show training of storm cells, meaning the same areas will get hit repeatedly or continuously with moderate rain showers. Rain will likely be falling throughout the entirety of the day Thursday with little or no breaks. Rainfall totals of nearly 2″+ could lead to some minor flooding. However, the rain is welcome since we are nearly 3″ below average for rainfall. Temperatures should again remain on the warm side with highs in the mid-70s.

NAM high resolution model output for Thursday, Oct 16 @5PM – note the bright blue and purples stretched over the area, indicating bands of heavier rain

Precipitation total forecast for 8PM Wednesday-8PM Thursday. Nearly 2" for the NYC area. — Precipitation total forecast for 8PM Wednesday-8PM Thursday. Nearly 2″ for the NYC area.

Friday – things settle down quickly as a brief window of calm weather enters the picture. Temperatures will be cooler in the wake of the cold front with west winds and highs in the lower 70s.

NYC Weather Update – Jul 21, 2014

July 21, 2014NYC, Storms, Thunderstorms, Weather Updatebermuda high, cold front, new york city, new york city weather, nyc weather, nyc wx, severe thunderstorms, thunderstorms, weather, weather forecastLei Zhao

This will be my last weather update for the next 3 weeks as I will be traveling to Costa Rica during that time.

Tuesday – things will heat up on Tuesday as the high pressure center responsible for the what has been a refreshingly cool and fair stretch of weather moves to the southeast. This will allow warm, tropical air to move back into the area, setting the stage for high temperatures to climb well into the mid-upper 80s under partly cloudy skies.

Wednesday – the hot weather will intensify Wednesday as temperatures near or top 90 with a noticeable increase in humidity as well. Warm, humid air will be sandwiched between the Bermuda high and an approaching cold front. Scattered showers and thunderstorms are possible later in the day Wednesday. Inland areas to the west of NYC are most likely to see precipitation Wednesday.

Thursday – the aforementioned cold front will move further east, giving the city itself its best chance of a soaking rain on Thursday. Given the humidity and amount of water available for storms Thursday, flash flooding is possible within the heaviest downpours, otherwise mostly cloudy with temperatures in the mid 80s. I wouldn’t be surprised if a few strong to severe thunderstorms popped up Thursday.

Friday – the cold front will clear our area and exit to the east, while cooler air filters down from Canada. High temperatures will return to the low 80s with mostly clear skies.

The Weekend – looks like the weekend itself will be another nice one, with high temperatures in the low 80s both Saturday and Sunday. There is a chance of showers and thunderstorms Sunday leading into what appears to be a fairly active weather pattern for the beginning of next week.

NYC Weather Update – Jul 14, 2014

July 14, 2014Flooding, NYC, Rain, Storms, Thunderstorms, Weather Updateflash flooding, flooding, nyc weather, nyc wx, severe thunderstorms, severe wx, storm prediction center, weather, wxLei Zhao

The Storm Prediction Center has placed the entire NYC metro area in an area for a slight risk of severe weather today. A strong low pressure center over the Great Lakes and its associated cold front are slowly making their way towards the Eastern Seaboard. Despite the cloudiness today, forecasters are still fairly confident that atmospheric conditions will be favorable for the formation of severe thunderstorms in the region. Based on current radar trends, these storms would most likely not be arriving in the NYC area until later this afternoon. The primary threat to our area will be damaging winds and torrential rain capable of triggering flash floods.

Tuesday will feature a similar set up for weather over the region, though there is less risk for severe weather tomorrow. However, strong storms are possible throughout the day and the risk of flash flooding is a distinct possibility. High temperatures will be in the mid 80s despite cloud cover, due to the influence of warm, humid air rushing in between the cold front and high pressure offshore over the Atlantic. This same warm, humid air mass is what will feed the storms for today and tomorrow. As you see below, the forecast rainfall total for today and tomorrow is as high as 3.6″ over Northeastern New Jersey, and ranges between 2.5-3″ for most parts of the Tri-State area.

Wednesday – we get a reprieve from the stormy weather as the cold front and storm system finally move east of NYC. Expect a cloudy start to the day with gradual clearing and conditions improving markedly. The next weather story for Wednesday through the end of the week is the cool, polar air mass that will be a dominant feature. High pressure will build in behind this storm system and usher in much cooler temperatures, with highs in the low 80s Wednesday-Friday, and overnight lows in the low-mid 60s in the city, and in the 50s north and west!

Thursday & Friday – expecting these two days to be essentially the same weather-wise, with high temperatures in the low 80s in the city (and upper 70s further north). Sunny to mostly clear skies for both days.

NYC Nowcast – Strong to Severe Thunderstorms Approaching

July 8, 2014Nowcast, NYC, Severe Weather, Thunderstorms, Tornadoesnew york, new york city, nowcast, nyc, nyc weather, nyc wx, pennsylvania, radar, severe thunderstorms, thunderstorms, tornado, tornadoes, weatherLei Zhao

Severe thunderstorms are approaching the area from our west. Several distinct bowing segments of severe thunderstorms have been making their way steadily towards our area from Central Pennsylvania since earlier this afternoon.

These storms have a history of producing damaging wind gusts and even a few tornadoes. Sundown over some of the areas under the current Severe Thunderstorm Watch areas in our region may weaken these storms, however, overall atmospheric conditions are quite favorable to the forward propagation of this line.

NYC Afternoon Weather Update – Severe Tstorms in Vicinty – Jul 2, 2014

July 2, 2014Cool Images, Nowcast, NYC, Severe Weather, Weather Updatenew york city, nyc, nyc weather, nyc wx, severe thunderstorms, severe weather, storms tstorms, thunderstormsLei Zhao

You may have already experienced it, but if you haven’t you’re probably seeing some huge clouds forming on the horizon. We’re in for some stormy weather this evening, as the Storm Prediction Center and our local forecast office have us under a Severe Thunderstorm Watch. The hot, humid atmosphere, along with ample sunshine earlier today, has made the atmosphere moderately unstable, with CAPE values in the 2000-3000 J/Kg. This, along with mid-upper unidirectional shear will supply ample energy for strong to severe storms, with the greatest threat being frequent cloud to ground lightning and damaging winds.

As you see above, there are already strong storms in our vicinity. The storms north of the city have met severe thunderstorm criteria (wind gusts in excess of 58mph, hail greater than 1/4″ in diameter, or a tornado). More storms are forming to our southwest, so NYC itself should not be immune to the threat later on. Check out this image of a classic towering cumulonimbus (thundercloud) below!

NYC Nowcast – Jun 13, 2014

June 13, 2014Nowcast, NYC, Rain, Severe Weather, Thunderstormscape, friday, nowcast, nyc, severe thunderstorms, severe weather, severe wx, thunderstorms, weather, wxLei Zhao

You’ve felt the air warm up and become more humid as the warm front that brought our first round of rain passed through earlier today. Now, we’re getting set for a second round of heavy showers and thunderstorms associated with a pre-frontal trough that’s slowly progressing east towards the area from Eastern Pennsylvania.

Ahead of this line of showers and thunderstorms, the air has destabilized readily with the ample sunshine earlier this afternoon. CAPE (Convective Available Potential Energy – a measure of how much fuel there is for thunderstorms to feed off of) is between 1000-1500 J/Kg over Northeastern New Jersey and NYC. This should allow for this line of storms to hold up and perhaps strengthen before hitting NYC. In fact, a couple sever thunderstorm warnings have already been posted for cells over Northeastern New Jersey.

NYC Weather Update – May 27, 2014

May 27, 2014NYC, Rain, Storms, Thunderstorms, Weather Update, Weekendbackdoor front, cold front, noaa, nws, nyc, saturday, severe thunderstorms, spc, storm prediction center, thunderstorms, tornadoes, weather, weekend, wxLei Zhao

What fantastic weather for the Memorial Day weekend! We topped off in the mid-80s across the area yesterday, and we’re likely to see another day with temperatures in the mid-upper 80s across the region (esp in interior portions of New Jersey).

Sadly, our stretch of summer-like temperatures is about to come to an end as a backdoor cold front (a front that does not approach from the west like most fronts do over this area) approaches the area from the north. Ahead of this cold front, temperatures are in the mid-80s and there is robust moisture in the atmosphere. This will provide the right ingredients for the possibility of severe thunderstorms later this afternoon and evening.

Possibility of Severe Thunderstorms This Afternoon

Current thinking is that these storms approach the NYC metro around 4-7PM during the evening rush hour. The Storm Prediction Center has placed NYC, western Long Island, Northern New Jersey, and much of the Hudson Valley under a slight risk area for severe weather this afternoon. By the way, slight risk in this context does not indicate that storms which occur will not be that severe, rather, it is denoting that the probability for severe storms is on the low side, and that coverage is not expected to be widespread. Just so you all are clear, the National Weather Service defines a severe thunderstorm as producing one or more of the following:

Wind gusts greater than 58mph
Hail greater than 3/4″ in diameter
A funnel cloud or tornado

A severe thunderstorm or tornado watch means that conditions are favorable over an area for the development of these types of weather hazards, however, no immediate threat has yet been identified. A warning means that a severe thunderstorm or tornado is imminent or already ongoing, which is understandably a much more dangerous situation. Anyway, the most likely threat for our immediate area are damaging wind gusts and hail, although a few isolated tornadic supercells cannot be ruled out.

Storm Prediction Center Day 1 Convective Outlook – we are in the slight risk area highlighted in yellow

Wednesday – by tomorrow, the cold front responsible for the possible thunderstorms later today will have moved through our area, however, there is still a chance for lingering showers on the backside of this frontal boundary. Also, since this is a backdoor cold front, temperatures will be significantly cooler tomorrow than today with an onshore easterly wind keeping high temperatures only in the mid 60s (about 20 degrees cooler than today).

Thursday – an area of high pressure will build into the area, but due to its position to our northeast, it will also continue to usher in onshore easterly/northeasterly winds that will keep our high temperatures below normal in the upper 60s. Otherwise, it will be a nice, sunny day.

Friday – another cold front will approach the region from the west and bring in the possibility for afternoon showers and thunderstorms. Slightly warmer with cloudy conditions and a high temperature near 70.

Saturday – high pressure will once again build in across the region and remain in place through the weekend. Therefore, am expecting pleasant, sunny conditions with about average temperatures in the mid-70s.

About that meteor shower… so as it turned out, the Camelopardalis meteor showers were a dud. Astronomers may have miscalculated the timing and/or amount of debris accumulated. Hey, it was the first time this particular shower was supposed to go down, so I guess you can’t blame them for not getting it right.

LZ | Weather

Weather updates & posts for NYC region