Tag Archives: nyc wx

NYC Weather Update – Labor Day Weekend

August 29, 2014NYC, Rain, Thunderstorms, Weather Update, Weekendlabor day, labor day weekend, labor day weekend weather, new york city weather, nyc weather, nyc wx, thunderstorms, weather forecast, weekend weatherLei Zhao

Rejoice! The long awaited Labor Day Weekend is upon us. Although I’d love to say that the weather will be fantastic throughout, but unfortunately there will be a few disturbances traversing the region the second half of this weekend. Thunderstorms accompanying these disturbances may literally rain on the annual West Indian Day Parade in Brooklyn on Monday.

Friday – the remainder of today will be a picture perfect, fall-like day with high temperatures hovering right around 80. A pleasant, dry airmass is in place in association with an area of high pressure that’s currently sitting over us.

Saturday – essentially a repeat of Friday, but with a bit more cloud cover.

Sunday – high temperatures on Sunday will be considerably warmer than Saturday, since the area of high pressure sitting over us now will have moved to the east, building up southwesterly winds and allowing for an influx warm air to penetrate the region. Expect more humid and warm highs between the mid-upper 80s. A weak frontal boundary will be approaching Sunday, and transit the region late Sunday into Monday. This will be our first shot at rain and thunderstorms, some of which may deliver some heavy rain.

Labor Day – the timing of the aforementioned frontal passage will be critical in terms of sensible weather Monday. It currently looks like Monday will be partly cloudy, with highs again in the mid-80s. There will be an increasing chance of scattered thunderstorms later in the day Monday leading into Tuesday as another weakening cold front nears the area.

Tuesday – the return to the work week will continue to feature warm and humid highs in the mid-upper 80s and a continued chance of thunderstorms as that cold front works its way through.

NYC Weather Update – Aug 25, 2014

August 25, 2014NYC, Rain, Thunderstorms, Weather Update, Weekendlabor day, labor day weekend, nyc weather, nyc wx, rain, weather, wxLei Zhao

We have a fairly straightforward weather week ahead of us leading into the Labor Day Weekend. Currently, our region is sitting under an area of high pressure, which will be sliding to the southeast. As it does so, winds will shift to the south and southwest, allowing the entry of a warm and humid airmass that’s been responsible for brutal triple digit heat in the southern tier of the country.

Tuesday – temperatures will continue to climb into the mid-upper 80s under clear skies due to the aforementioned atmospheric dynamics.

Wednesday – this will be the warmest day of the week with temperatures approaching, if not topping 90, in some spots around the region. Some clouds will start to build in ahead of a cold front that is forecast to push through the area late Wednesday or Thursday. There is some discrepancy between different forecast models as to whether there will be a significant chance for precipitation with this frontal passage. Given this set up, it is likely even if there is rain, it won’t be widespread in coverage or long in duration.Thursday – following the passage of the cold front, temperatures will fall back into the low-mid 80s for Thursday. Mostly sunny skies will return with high pressure moving in behind the cold front.

Friday – should be a similar day in most respects to Thursday, with slightly cooler highs around 80.

Labor Day Weekend – currently, Saturday looks like the best day of the long weekend, with high pressure still in control over the region. High temperatures should be around 80 again with mostly sunny skies. Unfortunately, it does appear that there will be an increasing chance of precipitation in the form of showers and thunderstorms Sunday afternoon and Monday. More on this later in the week.

NYC Weather Update – Aug 22, 2014

August 22, 2014NYC, Outside of NYC, Tropical/Hurricanes, Weather Update, Weekend2014 atlantic hurricane season, cristobal, hurricane season, new york city weather, new york city wx, nyc weather, nyc wx, storms, tropical storm, tropical storms, ts cristobal, weather update, weekend weather, weekend wxLei Zhao

We had a solid round of rain from some showers and thunderstorms that passed through the area overnight. Over the weekend, high pressure will start to build into the area, ushering in a period of calm, pleasant, and seasonable weather.

Saturday & Sunday – clouds will diminish later Saturday, and by Sunday we’ll see mostly clear skies. Both days will feature high temperatures around 80.

Monday – as you see below, by Monday an area of high pressure will be firmly entrenched over our region. This high pressure area will persist through the middle of the week, giving us fair conditions and pleasant highs in the low 80s.

Screen Shot 2014-08-22 at 12.38.19 PM — High pressure firmly entrenched in the Northeast for the beginning of next week.

Tuesday & Wednesday will look and feel essentially the same with highs in the low 80s and mostly sunny skies.

Our next chance of rain will be later in the week, perhaps Thursday into Friday with the arrival of a cold front from the west.

In the Tropics

There’s a tropical disturbance currently positioned offshore of Puerto Rico that will very likely become the 2014 Atlantic Hurricane Season’s third named storm, Cristobal. You can already begin to see the storm organizing, as over the last day or so, a circulation has become evident, and strong thunderstorms are forming in the northern semicircle are also apparent (see the classic cauliflower tops). Outflow bands are also forming up (thin wispy clouds north and northeast of the center).

Screen Shot 2014-08-22 at 12.49.40 PM — High resolution satellite image of the tropical disturbance

This storm will fell some negative impacts from the high terrain of Hispaniola and Puerto Rico. As you can see, the southern semicircle is considerably less organized than the northern.

As for the track of the storm, you can see the rather large spread between the different forecast models, which is not surprising given that the storm is still in its early stages. Note that there is an outlier model solution showing landfall on the Mid-Atlantic. This is unlikely at this point, but worth noting. It seems, given the conditions ahead of the storm, that this will become Tropical Storm Cristobal in the next couple days, and may become Hurricane Cristobal shortly thereafter.

NYC Weather Update – Aug 18, 2014

August 18, 2014NYC, Rain, Weather Updatenyc weather, nyc wx, weather, weather record, wxLei Zhao

This week will feature mostly calm and tame conditions for the most part, which is excellent news in comparison to last week when a record-breaking storm dropped 13″+ of rain on Islip.

Today-Wednesday will feature essentially the same weather, sunny to mostly clear skies with pleasant high temperatures in the upper 70s and low 80s.

Our first and only real chance at precipitation this week will be on Thursday, and it’s a low chance at that with the passing of a weak impulse of energy through the area.

Friday – high temperatures will continue to drop into the mid-70s as winds coming from the east will allow for a cooler marine air layer to park over the area.

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 15, 2014

July 15, 2014NYC, Rain, Severe Weather, Storms, Thunderstormsflash flooding, flooding, new york city, new york city weather, nyc, nyc weather, nyc wx, rain, severe weather, severe wx, thunderstormsLei Zhao

A correction from yesterday – I had said today may see less potential for severe weather. In fact, the Storm Prediction Center once again has most of the NYC metro area under a slight risk for severe thunderstorms later today.

Based on current satellite trends, it does appear there will be some breaks in the clouds this morning and afternoon. This will allow sufficient sunshine and daytime warming to fuel strong to severe storms across our region again later today. In the upper atmosphere, largely unidirectional winds from the south-southwest, a favorable jet stream set up, and approaching cold front suggest the potential for storms with damaging wind gusts and even some hail. Flash flooding is again a distinct possibility.

As you see below, portions of our area saw up to 1-1.5″ rain yesterday, and these same areas are in the target zone for severe storms today as well. With the upper level winds lining up from the south-southwest, training (where multiple storms hit the same location over a period of time) of storms is likely. This will enhance the risk for flash flooding.

A note about the term unidirectional winds: Unlike a hurricane, severe thunderstorms thrive on upper atmospheric energy, and unidirectional winds at all levels are more conducive to imparting a rotation on a rising parcel of air (rotating thunderstorms can produce tornadoes).

Otherwise, expecting a warm, humid day, with highs in the mid 80s and some sun before storms arrive later in the afternoon. It will be cooler and more comfortable tomorrow with this stormy cold front having passed us!

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 Weekend Weather – Return of the Polar Vortex? – Jul 11, 2014

July 11, 2014NYC, Outside of NYC, Rain, Weather Update, Weekend500mb analysis, atmosphere, meteorology, new york city, new york weather, nyc, nyc wx, polar vortex, upper air, vortex, weather, weekend weather, wxLei Zhao

You may have heard from media reports that the dreaded polar vortex is set to make a return to the Eastern US during the middle of the coming week. I’ll discuss that in detail below. First, for the weekend forecast:

Today & Saturday – a very pleasant couple of days in the wake of the cold front that finally pushed through our area yesterday. You can feel a marked drop in humidity, and temperatures are much more comfortable. Saturday, high temperatures should top out in the mid 80s in NYC.

Sunday – a chance for afternoon thunderstorms and a high in the mid 80s, chance of rain increasing through out the day into the overnight hours.

Polar Vortex?

Forecast models are in good agreement that beginning Tuesday into most of the rest of next week, an upper air vortex (see below, the trough with an inclosed region surrounded by the blue arrows) will drop into the Midwest and Northeast from the northern regions of Canada. This vortex can be technically referred to as a polar vortex, a term that instantly revives media hype about how cold it will be. But keep in mind, during the summer, polar regions heat up as well, so even the coldest polar airmass and vortexes are much milder than their winter counterparts. Furthermore, the influence of the sun is quite strong as we just passed the summer solstice, so the sun is sitting at a very high angle each day and is highly effective at heating the air quickly. Hence, temperatures are expected to be much below normal for some areas, but we’re not talking about snow or ice.

Screen Shot 2014-07-11 at 1.13.53 PM — Upper air forecast from GFS for Monday, 8PM EDT, 500mb absolute vorticity.

Screen Shot 2014-07-11 at 1.25.37 PM

Next Week

There will be a good deal of energy traveling with the polar vortex, so we’re expecting a somewhat disturbed pattern of weather for the beginning of next week. Tuesday & Wednesday will see the best chances for rain and thunderstorms with a cold front approaching us from the west. Before the cold front, we’ll still see temperatures in the mid to upper 80s with a chance for thunderstorms Monday. Once the cold front passes, we’ll be right in the mix with the “polar” air mass, so our high temperatures will drop into the low 80s, and overnight lows will drop into the upper 60s for the latter part of the week.

NYC Afternoon Weather Update – Jul 9, 2014

July 9, 2014NYC, Severe Weather, Thunderstorms, Weather Updatenyc weather, nyc wx, severe weather, severe wx, spc, storm prediction center, thunderstorms, weather, wxLei Zhao

The Storm Prediction Center has again placed western and interior portions of the NYC region under a slight risk for severe weather today. The atmospheric setup this afternoon is similar to yesterday, with plenty of solar heating and humid air leading to moderate instability. At this hour, CAPE values (a measure of instability) are already hitting 1500-2500 J/Kg across the area, with greater instability further south.

There are already a few scattered thunderstorms forming over Eastern Pennsylvania. These storms are not yet hitting severe limits, but conditions are favorable for further development and increase in areal coverage. With winds aloft mostly unidirectional from the southwest, damaging wind gusts would be the primary threat. Storms that form to the southwest of NYC near the Philadelphia metro area and Central New Jersey would be the ones to watch for immediate impacts in the city.

These storms are still several hours away, and it remains to be seen whether they will hold up upon encountering the cooler and stabilizing influence of marine air infiltrating along south-facing shores with the southwest winds and a sea breeze. Last night, the line of severe thunderstorms weakened just before it hit NYC, sparing us from some wicked weather for the night. The same case may unfold again today, but the situation bears monitoring.

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.

LZ | Weather

Weather updates & posts for NYC region