Category Archives: Tropical/Hurricanes

NYC Weather Update – Aug 23, 2015

August 23, 2015NYC, Outside of NYC, Tropical/Hurricanes, Weather Updatecape verde, cold front, high pressure, new york city weather, nyc weather, nyc wx, satellite images, tropical cyclones, tropical storm danny, tropical storm erika, tropical wave, tropical weather, weatherLei Zhao

A slow moving cold front brings an unsettled start to the week. Ahead of this cold front, temperatures will rise along with humidity, leading to a late-summer feel. Once this frontal boundary passes, high pressure to the west will allow for a cooler, drier Canadian airmass to enter the region, leading to more seasonable temperatures along with sunny skies.

Rest of today – a mix of sun and clouds continues with a small chance of some rain, with temperatures topping out around average in the low-80s.

Monday – as a cold front approaches from the west, humidity and temperatures will rise along with a south wind. There is some small chance for thunderstorms, especially west of the Hudson. Otherwise, expect a mix of sun and clouds with temperatures in the mid-80s.

Tuesday – with the cold front lingering in our vicinity, a small chance for showers and thunderstorms continues, along with warm and humid temperatures in the mid-upper 80s.

Wednesday – the cold front finally pushes through Tuesday, and gives way to high pressure building in from the west on Wednesday. This will lead to comfortable temperatures in the low-80s with sunny skies.

Thursday – similar conditions to Wednesday, with sunny skies and a pleasant, comfortable high in the low-80s.

A Note on the Tropics

We’re about to enter the most active period of the Atlantic hurricane season, and things have definitely picked up in the tropics. A series of monsoonal tropical waves are moving off of the cost of West Africa, giving rise to the potential for a couple of Cape Verde type tropical cyclones. This conveyor belt of tropical waves has already spawned this season’s first hurricane, Danny, which peaked as a major hurricane with winds of 115mph (Category 3) at the end of last week. Danny has weakened considerably, but could still bring some much needed rain to Hispaniola and Puerto Rico in the next couple days. Meanwhile, another tropical wave following on Danny’s footsteps could become Tropical Storm Erika in the coming days. Neither of these storms poses any immediate threat to the United States for the time being.

NYC Weekend Weather – Jun 19, 2015

June 19, 2015Drought, NYC, Rain, Storms, Thunderstorms, Tropical/Hurricanes, Weather Update, Weekendhigh pressure, nyc weather, nyc weekend weather, nyc weekend wx, tropical depression bill, tropical weather, tropical wx, weather, weekend weatherLei Zhao

In contrast to last weekend, where Sunday was the better half, the reverse will be true this weekend. Remnants of Tropical Depression Bill will be moving over us on Sunday, bringing the potential for extended periods of showers and heavy rain. It is hoped that this much needed rain will put a dent in the persistent moderate drought conditions in the region.

Rest of today – there is a small chance for thunderstorms up until around lunchtime today, after which skies should gradually clear. High temperatures are expected to top out in the upper-80s to near 90.

Saturday – high pressure will be shifting to the east, bringing in an onshore flow, keeping temperatures cooler in the upper-70s under partly sunny skies. Chances for rain will be increasing steadily through the evening such that by the overnight hours, periods of steady rain should be the norm.

Sunday – As referenced above, remnants of Tropical Depression Bill, still carrying tropical moisture, will be moving over the region. There is still some uncertainty as to whether the areas of heaviest rain will move further south and over the ocean, however, at this point it seems likely that Sunday will feature periods of steady rain, heavy at times. Rainfall probability and rainfall totals will drop precipitously from south to north, since the storm center is expected to track to our south. We could pick up as much as 1″-1.5″ of rain over Long Island, which would be a blessing since this area is still in the grip of moderate drought conditions. With clouds and rain, high temperatures should top out around 80.

Quantitative Precipitation Forecast for Sunday

North American Model high resolution output for Sunday at 11AM EDT

Drought coverage in New York as of this week

Monday – conditions improve following the passage of the storm on Sunday, with high temperatures rebounding into the mid-upper 80s under mostly sunny skies.

NYC Weather Update & TS Bill – Jun 16, 2015

June 16, 2015Cool Images, Flooding, NYC, Outside of NYC, Rain, Thunderstorms, Tropical/Hurricanes, Weather Update2015 atlantic hurricane season, atlantic hurricane season, bill, flash flooding, flooding, high pressure, nyc weather, nyc wx, tropical storm bill, ts bill, warm front, weatherLei Zhao

We’ve certainly seen plenty of rain during the month of June, yet the NYC region remains in an area of moderate drought as of last Thursday. However, this does not reflect the rain that fell overnight Sunday into Monday. After a gloomy start to the week, we get a break of decent weather tomorrow, before another possible round of rain Thursday. The week ends with some drying out and improving conditions.

Rest of today – highs should top out in the upper-70s to around 80 today, with the potential for showers and thunderstorms later this afternoon. Storms have already formed to our west over northeastern Pennsylvania, but there is a stabilizing marine air layer over NYC and points east, so these storms may yet break apart before reaching us.

High Resolution Rapid Refresh model simulated radar for 1PM today.

Wednesday – skies will clear rapidly overnight and lead to a sunny, dry, and pleasant day on Wednesday. Highs should be near 80. The high pressure creating these pleasant conditions will not stay around long, as another warm front approaches from the west.

Thursday – will look a lot like today, with mostly cloudy skies, and a potential for showers and thunderstorms in the afternoon as a warm front nears the region. Highs will be a bit cooler in the mid-70s with the influence of clouds and a southeasterly flow off the ocean ahead of the warm front.

Friday – the warm front from Thursday is followed quickly by a cold front passing Friday morning. Behind this, high pressure takes control and brings decent weather for the first half of the weekend. Highs Friday should be in the low-80s with clouds and sun.

Tropical Storm Bill

Over the weekend, a disturbance organized over the western Gulf of Mexico, and by last night it had consolidated and intensified enough to be designated the 2015 Atlantic Hurricane Season’s second named tropical cyclone – Tropical Storm Bill. Bill will be making landfall imminently in Texas as a moderate strength tropical storm with maximum sustained winds of 60mph.

However, for people living in the path of Bill, it is not the wind but rather the potential for dangerous flash flooding that is the primary concern with this storm. Bill is forecast to bring as much as 10″ of rain over the next few days to parts of Texas, and upwards of 6″ for a wide swath of Oklahoma and Missouri. As you may recall, some of these areas were the scene of deadly flooding just a few weeks back, and the arrival of a rainmaker like Bill is most unwelcome for these areas that are still in the midst of recovering. Moisture from Bill will eventually work its way into our region, but in a much less intense way.

NYC Weekend Weather & 2015 Hurricane Season Forecast – May 28, 2015

May 28, 2015Climate, NYC, Tropical/Hurricanes, Weather Update, Weekend2015 atlantic hurricane season, atlantic hurricane season, cold front, hurricanes, national hurricane center, nyc weather, nyc weekend weather, nyc weekend wx, nyc wx, thunderstormsLei Zhao

Yesterday, portions of our area got some much needed rain from a round of thunderstorms associated with a prefrontal trough. Today, we get another shot at rain and thunderstorms as the primary cold front actually pushes through. Behind that front, things cool off and dry out for Friday, before the humidity returns on Saturday. Things should stay dry Saturday, but we will see a more substantial chance at widespread rainfall Sunday with the passage of another cold front. Also of note, the National Hurricane Center released its outlook for this year’s Atlantic hurricane season, calling for a below normal season.

Rest of today – clouds give way to sun with warm temperatures in the mid-80s. Showers and thunderstorms are expected to form later this afternoon. The atmospheric setup today is a bit more favorable to showers and thunderstorms being able to persist into NYC and western Long Island, unlike yesterday when these showers essentially died out as they hit the stable marine air layer near the coast. The exact location of where storms form and move into will still be tricky to pinpoint even at this time.

High Resolution Rapid Refresh model output simulated radar for 3PM EST today.

Friday – once the frontal boundary passes through later today, it will usher in a much cooler and drier airmass for Friday. Temperatures should top out in the mid-upper 70s (still 5-10ºF above normal) under sunny skies.

Saturday – temperatures will be slightly warmer in the low-80s on Saturday with an increase in humidity as well. There could be a slight chance for scattered thunderstorms later in the day as well.

Sunday – another cold front passes through the region Sunday, bringing with it the chance for more substantial and widespread showers. Temperatures will also cool off to around normal, in the low-mid 70s.

2015 Atlantic Hurricane Season Outlook

The National Hurricane Center released its initial outlook for the 2015 Atlantic Hurricane Season that officially starts on June 1st. As you’ll see from the graphic below, forecasters are calling for a below normal season with 6-11 named storms (tropical storms with sustained winds greater than 39mph). Of these named storms, forecasters think 3-6 have a chance to intensify into hurricanes (maximum sustained winds greater than 74mph), and of those hurricanes 0-2 could become major hurricanes (Category 3 or higher, maximum sustained winds greater than 111mph).

The primary reason for the 70% probability of a below normal season is the disruptive effect of El Niño in the Eastern Pacific, which is known to alter the pressure and air currents over the tropical Atlantic, dampening the formation of hurricanes. On the other hand, the above average sea surface temperatures in the Pacific associated with El Niño are expected to induce an above average Pacific Hurricane/Typhoon season. Read the full statement from the NHC here: http://www.noaanews.noaa.gov/stories2015/20150527-noaa-hurricane-outlook-below-normal-atlantic-hurricane-season-is-likely-this-year.html

NYC Weekend Weather – May 8, 2015

May 8, 2015NYC, Outside of NYC, Thunderstorms, Tropical/Hurricanes, Weather Update, Weekendana, high pressure, nyc weather, nyc weekend weather, subtropical storm, subtropical storm ana, tropical storm, tropical weather, weather, weekend weatherLei Zhao

Another splendid weekend is in store for us with warm temperatures in the upper-70s and near 80. Subtropical Storm Ana marks the first named storm of the 2015 Atlantic Hurricane Season. It is not expected to bring us any direct impacts, however, it could bring moisture our way that could supplement a storm system forecast to pass through early next week.

Rest of today – early fog has burned off, skies have cleared, and temperatures should top out near 80. We have been under the persistent influence of a high pressure center that has been responsible for pumping in this warm, moist air from the south.

Saturday – clouds and sun, with sunny breaks more likely to appear near the coast in the afternoon. High temperatures should be a bit cooler in the mid-70s with the influence of clouds, however, any sunny breaks could easily shoot temperatures up a few degrees.

Sunday – once again, Sunday comes through as the best day of the weekend, with mostly sunny skies and highs in the low-80s.

Monday – clouds for the most part as a frontal boundary approaches from our north and west. High temperatures will still be quite mild with the influence of high pressure bringing southerly winds, expecting a high again near 80. Some chance for afternoon thunderstorms to develop as that frontal boundary nears.

Tuesday – probably our best shot at getting measurable rainfall as the aforementioned front passes through. Some left over moisture from Ana could work its way into this setup. Ahead of the front, temperatures should still rise into the upper-70s. It’ll be noticeably cooler for the second half of the week.

Subtropical Storm Ana

We have our first named storm of the 2015 Atlantic Hurricane Season which doesn’t officially begin until June 1st. Subtropical Storm Ana developed out of a weak tropical disturbance off of Florida. This just goes to show, a tropical cyclone can form under the right conditions at any time of the year.

Subtropical Storm Ana fortunately does not have much time to organize and intensify before it makes landfall on the coast of the Carolinas. This should limit any serious damage, however, these areas will likely experience prolonged high winds, torrential rain, and coastal flooding.

Global Forecast System ensemble forecast tracks for Ana

NYC Weather Update – May 6, 2015

May 6, 2015Climate, NYC, Outside of NYC, Rain, Tropical/Hurricanes, Weather Updateatlantic hurricane, atlantic hurricane season, atlantic tropical weather, nyc weather, nyc wx, rain, tropical depression, tropical weather, weather, wxLei Zhao

A downright summer-like stretch of weather that started this week will get mirrored again towards the end of this week and going into next week. After clearing out clouds today, the remainder of this week should see dry and sunnier weather with highs in the mid-upper 70s. This weekend, we are looking at the possibility of temperatures near 80, nearly 15º above normal. We also have what could turn into the 2015 season’s first tropical depression/storm churning up off the coast of Florida now.

Rest of today – a very slow-moving, largely stationary front pushed through last night, but is still sitting in our vicinity. Along this front, remnants of more organized convective activity will be able to slide east during this afternoon and evening. While the chances are not high, there could still be an occasional shower during the latter half of today, high temperatures will be somewhat subdued around 70 with the clouds in place.

Thursday – clouds will clear out tomorrow and we should have a sunny day with temperatures in the mid-70s.

Friday – a repeat of Thursday, with mostly sunny skies and highs again in the mid-70s.

Saturday – increasing cloud cover, but should still be a pleasant day with temperatures in the upper 70s.

Sandwiched between rain to our south and to our west, but our weather should still remain dry this weekend.

Sunday – warm and pleasant with a high near 80.

610temp.new — Climate Prediction Center temperature outlook for next week – still looks like we’ll be getting warmer than normal temps

First Tropical System of the 2015 Atlantic Hurricane Season?

As I write this, a low pressure system is building up steadily off the east coast of Florida. The National Hurricane Center puts the odds of this system organizing sufficiently to become the first named tropical depression, subtropical, or tropical storm of the 2015 Atlantic Hurricane Season. Even if this storm does become the first named tropical system, it is unlikely to do much damage as it will have very little time over open water to gain strength before it is forecast to make landfall over the Carolinas later. The most noticeable impact from this storm would be the rain it generates.

Tropical Weather Update | Typhoon Hagupit – Dec 5, 2014

December 5, 2014Outside of NYC, Tropical/Hurricaneshagupit, joint typhoon warning center, legazpi city, leyte gulf, leyte island, luzon, pacific tropical weather, pacific typhoons, philippines, philippines weather, samar, samar island, super typhoon, super typhoon hagupit, tacloban, tropical cyclones, tropical storms, tropical weather, tropical wx, typhoon hagupit, typhoon haiyanLei Zhao

A potent and massive typhoon is taking aim at the northern Philippines, in particular, Samar Island. Some of these areas were devastated by Category 5 Super Typhoon Haiyan less than one year ago, which broke the record for strongest landfalling tropical cyclone with wind speeds measured in Tacloban of 190mph. If you have friends or family in the Northern Philippines, Hagupit certainly bears keeping an eye on. Luckily for Tacloban, the current forecast track should take the center and northern semicircle (the stronger portion) of the storm north of the area, which should spare the area worst hit by Haiyan from another direct hit and the worst effects of a typhoon.

wp201422_sat — Infrared satellite imagery of Typhoon Hagupit – note the symmetrical appearance of the inner portion of the storm, along with a well-defined eye (classic signs of a very strong storm).

Forecast Track

From the image below, you’ll see that Hagupit is currently forecast to move slowly west-northwestwards over the next 48 hours. Due to the strength of the storm, and the uncertainty surrounding the steering mechanisms in place (a subtropical ridge – high pressure area to the north weakening, and a frontal boundary), there is a low degree of confidence over the overall track forecast. However, it does appear, even with the uncertainty factored in that the storm center will pass to the north of Leyte Island and Tacloban, which was devastated by Super Typhoon Haiyan. That’s good news, since this would mean the weaker, southern semicircle of Hagupit would pass over the Leyte Gulf area. This would significantly reduce the effect of a devastating storm surge, since the winds from the storm would not have the best fetch (distance over open water) to build up a storm surge. In effect, with the current track, the strongest winds would be deflected by the terrain of Samar Island, sparing Leyte Island.

It is worth noting, based on this current track, that Legazpi City in extreme southeastern Luzon Island would bear the worst of the storm, including what could be a devastating storm surge. The bay east of Legazpi could serve to funnel storm surge westward under the right conditions, amplifying the effect of the surge in a similar (though less intense) manner as Leyte Gulf and San Pedro and San Pablo Bay did for Tacloban in Haiyan.

Haiyan_2013_track — For comparison, the track of Super Typhoon Haiyan in November 2013. Dots indicate position of the center of the storm every 6 hours, the colors indicate strength, with red indicating Category 5.

Intensity Forecast

Typhoon Hagupit has well-established outflow in the northern quadrant, as you can see from the satellite image above (white streaks fanning out from the center of the storm). It is being affected by easterly vertical wind shear, hence the absence of the same outflow bands in that sector of the storm. Hagupit has already weakened from a Category 5 Super Typhoon, but is still forecast to approach the Philippines as either a strong Category 3 or weak Category 4 storm, which would mean wind speeds likely in the range of 110-120mph. After landfall, Hagupit should weaken dramatically as interaction with the mountainous terrain of the Philippines disrupts the typhoon’s dynamics.

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 Weekend Weather – Sept 12, 2014

September 12, 2014NYC, Rain, Storms, Tropical/Hurricanes, Weather Update, Weekendcanadian air, cool temperatures, nyc, nyc weather, nyc wx, rain, weather, weekend weatherLei Zhao

Although the passage of a cold front yesterday didn’t bring any precipitation with it, you can definitely feel its impact in the form of much cooler and drier air today. Temperatures will be in the low 70s today with crisp, clear skies above.

Saturday – cloud cover will build tonight as an area of low pressure originating from the Tennessee Valley area slides along the frontal boundary that’s now located offshore to our east. This low pressure system will bring a solid chance at rain tomorrow especially later in the day into the evening hours. High temperatures will be cool, around 70, under cloudy skies.

NAM high resolution model output for Saturday evening at 8PM

Sunday – luckily, this storm system will exit rather quickly to our east, making Sunday an excellent day for outdoor activity of all varieties. Temperatures will be on the cool side, with highs in the low 70s under partly cloudy skies.

Monday – this week begins a trend towards cooler, fall-like temperatures as an upper air pattern favoring the intrusion of a cool, Canadian airmass takes hold. Highs on Monday will again only be in the low-70s, about 5 degrees cooler than average for this time of the year.

Tuesday – brings us our next shot at rain, as a weak impulse of energy passes through. The rest of the week after Tuesday looks like it will be uneventful, albeit on the cool side with the aforementioned arrival of a Canadian airmass and high pressure.

GFS 500mb vorticity and height model output. Note the two areas of very strong vorticity and closed heights in the Atlantic and Eastern Pacific corresponding to two tropical systems.

NYC Weather Update – Sept 9, 2014

September 9, 2014NYC, Outside of NYC, Rain, Thunderstorms, Tropical/Hurricanes, Weather Updatecold front, new york weather, nyc weather, nyc wx, rain, thunderstorms, tropical cyclones, tropical storm, tropical storm edouard, tropical storms, tropical weather, ts edouard, weather, weather updateLei Zhao

This week features a rather active pattern, with several chances for precipitation starting with today.

Tuesday – there is some small chance for scattered rain showers today associated with an area of low pressure that is currently located over North Carolina. However, this chance of rain will be primarily confined to areas south of the city. As the area of low pressure slowly moves offshore of the Mid-Atlantic states, the pressure gradient will strengthen, allowing for a persistent easterly wind to continue transporting cool, maritime air into the region. Temperatures will remain on the cool side, with highs similar to yesterday in the mid-70s.

Wednesday – conditions will improve somewhat as the aforementioned area of low pressure exits east over the Atlantic. We will still not be able to escape a cool, onshore wind from the northeast, so even though clouds will diminish, high temperatures will again struggle to reach 80.

Screen Shot 2014-09-09 at 8.50.45 AM — Cold front approaches on Thursday

Thursday – the most substantial chance for rain this week will arrive with the passage of a cold front late in the day Thursday into the overnight hours. Warmer air from the southwest ahead of the cold front will translate to about average high temperatures in the low 80s under cloudy skies. As the cold front nears, showers and some thunderstorms will be possible. Current timing of the forecast models suggest that the bulk of the rain will not arrive until the evening hours.

Friday – conditions will improve Friday as high pressure builds in again in the wake of the cold front passing Thursday. Temperatures will drop back into the mid-70s with cooler, Canadian air filtering in from the north behind the front.

Tropical Storm Edouard?

Tropical wave off the coast of Western Africa

A vigorous tropical wave moved offshore of Western Africa earlier this week, and is being monitored for possibility of tropical storm formation later this week. Environmental conditions are forecast to remain favorable for development with low wind shear and warm sea surface temperatures. This storm may bring some impacts to the East Coast of the United States, but it is too early at this point to know the scope of that impact.

LZ | Weather

Weather updates & posts for NYC region