Category Archives: Tropical/Hurricanes

NYC Weekend Weather + Hurricane Matthew Update – Oct 6, 2016

The main weather headline for this weekend was going to be about possible impacts from Hurricane Matthew. I’m glad to report it now appears the storm will miss us, but the good news for us translates for doubly bad news for Florida. We went from a possible hurricane/tropical storm impact this weekend to a weekend where we expect to see some decent, fall-like weather.

Rest of today – sunny with a high temperature in the low-70s.

Friday – sunny, slightly warmer with highs in the mid-70s. High pressure remains anchored over the area, blocking the progress of Matthew northward, and also giving us great weather.

Saturday – a cold front will approach from the west, clouds will increase overnight and there is a chance for rain on Saturday. Mostly cloudy otherwise with highs in the low-70s. Part of the reason Matthew is expected to miss the Northeast is because this frontal boundary was faster to approach than was forecast earlier. This means it will have a role in pushing Matthew out to sea, instead of lifting it north towards the coast here.

Sunday – noticeably cooler with below average high temperatures only in the mid-60s and skies clearing.

Hurricane Matthew No Longer a Threat to the Northeast – Could Hit Florida Twice

As of 11AM EDT, the National Hurricane Center‘s advisory showed that Hurricane Matthew had restrengthened into a robust Category 4 storm with maximum sustained winds of 140mph. It had just moved past New Providence island in the Bahamas moving northwest at 14mph, having avoiding a direct landfall on the highly populated island where the capital Nassau sits. However, as we get more information in, it’s becoming clear that some areas of Haiti really got the worst case scenario. This video footage from the small town of Jeremie on the northern side of the western tip of the Tiburon Peninsula shows the catastrophic damage Matthew caused. Jeremie took a direct hit from the storm’s northeastern eyewall, the strongest part of the storm, as Matthew made landfall on Haiti as a Category 4 with 145mph winds. This gives you an idea of the raw power of the storm that’s now headed for Florida.

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Satellite image of Matthew at 11AM EDT October 6th, 2016. Below: radar imagery from Miami shows Matthew’s eye.

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Outlook for Matthew

Luckily for us, long-range forecast models show that Matthew no longer poses a threat to the Northeast. The flip side is that a fairly unprecedented scenario might befall Florida. Some models are suggesting that after Matthew moves offshore of the Carolinas, it may execute a large cyclonic loop, with the possibility of making a second landfall on South Florida later next week, albeit as a much weaker storm. First, Floridians all up and down the east coast, will have to contend with a dangerous Category 4 storm scraping along the shore or maybe making direct landfall. The coast scraper scenario would result in worse outcomes for Georgia and South Carolina, since reduced interaction with land will mean a stronger storm, as well as higher storm surge.

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NYC Weather + Hurricane Matthew Update – Oct 3, 2016

After a gloomy, but appropriately fall-like start October, this week looks like it will bring much improved weather. Temperatures are expected to be just below or at normal for the majority of the week. The big question mark in the long-term for weather in our region is the progress of Hurricane Matthew, which could impact the area this coming weekend.

Tuesday – mostly cloudy to start with gradual clearing and high temperatures in the upper-60s.

Wednesday – mostly sunny with high temperatures in the upper-60s. High pressure anchored over southeastern Canada will give us an extended period of nice weather.

Thursday – sunny, warmer with high temperatures in the low-70s.

Friday – sunny, with high temperatures in the low-70s.

Hurricane Matthew an Increasing Threat to the US East Coast

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Hurricane Matthew as captured by one of NOAA’s geostationary satellites on Monday, Oct 3 at 5PM EDT.

Hurricane Matthew poses an imminent and possibly catastrophic threat to Haiti, and portions of Eastern Cuba. Heavy rains from rain bands associated with the storm have already begun falling over Hispaniola and have hit Jamaica as well. Matthew is a potent Category 4 storm with maximum sustained winds at 140mph. It is expected to bring rainfall of 8-20″ across the region, with some places receive 7-11′ of storm surge.

Matthew has displayed a number of anomalous characteristics that have defied forecasters and experts best efforts at predicting its intensity. Matthew underwent a period of rapid intensification, going from tropical storm to a Category 5 hurricane with 160mph winds in just under 36 hours. This puts Matthew in an exclusive circle of just a handful of storms in recorded history that have accomplished this feat. Even more amazing, Matthew underwent this rapid intensification in the face of strong southwesterly wind shear that would typically stall a storm’s growth or weaken it.

During much of its life, a large area of intense thunderstorms has accompanied Matthew, at times exceeding the actual storm center in size. Scientists are uncertain as yet what role this feature had in Matthew’s unusual intensification. This feature has been impacting Hispaniola.

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Infrared satellite image of Hurricane Matthew as a strong Category 4, note the impressive area of intense thunderstorms east of the storm’s core.

Outlook for Hurricane Matthew

Matthew is expected to either skirt the extreme southwest peninsula of Haiti or make landfall there, then perhaps a secondary landfall on Eastern Cuba. The more interaction Matthew’s circulation has with the high terrain of these regions, the weaker it will get before entering the wide open, and warm waters of the Bahamas. It is expected to maintain major hurricane status (maximum sustained winds greater than 115mph) throughout most of the 4-5 forecast period.

Since even earlier today, major forecast models have come into much better agreement about the path of Matthew in the longer term. The unfortunate news is that the models have settled on solutions that push Matthew further to the west than previous runs. This dramatically increases the chances of a landfall somewhere on the Southeastern US, with Florida also in the range of possible tracks. Should this scenario unfold, we would be spared from a direct landfall here, but would still receive a storm of considerable strength with strong winds and heavy rains possible.

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NYC Weekend Weather: TS Matthew – Sep 29, 2016

We are in an active weather pattern for the entirety of the weekend, with chances for rain nearly every day. This rain is welcome and much needed, as drought persists across much of the area. Friday looks to deliver the heaviest, most persistent rain. We’re also closely monitoring the progress of Tropical Storm Matthew. While Matthew is still only in the Caribbean, it appears increasingly likely it will impact the East Coast next weekend.

Today – high pressure anchored over southern Quebec/southeastern Canada will serve to block the progress of an upper-level low that’s been drenching areas of the Mid-Atlantic. The influence of the high should keep most of the region relatively dry today, with the exception of further west in New Jersey. However, the high pressure to the east and frontal boundary siting just south of us will induce an onshore northeasterly wind, bringing cooler than normal temperatures only in the mid-60s.

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Friday – rain chances ramp up considerably Friday as the front depicted to the south edges slightly northwards. This looks to bring a batch of moderate to heavy rain onshore primarily in the afternoon and evening hours. Temperatures will be even cooler than today in the low-60s with overcast skies and that persistent northeast wind.

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Saturday – temperatures warm up a little into the upper-60s, but rain chances continue throughout the day along with overcast conditions.

Sunday – rain chances begin to diminish as temperatures continue to warm to around 70ºF. Even if rain doesn’t fall, it’ll still be a cloudy day.

Tropical Storm Matthew – Potential East Coast Impact?

Tropical Storm Matthew formed just east of the Lesser Antilles a couple days ago as a vigorous tropical storm and has been steadily progressing west and growing in intensity. Matthew is already a 65mph storm. It is being impacted by moderate southwesterly wind shear that will impede significant strengthening the next couple days. However, this shear is expected to ease as it moves over the warmest waters of the Caribbean. That should allow for more rapid intensification.

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Of course, Matthew is far from being a threat to us now, but for days, it’s been clear from various forecast models that this storm will eventually turn north. The pivotal question for whether Matthew becomes a direct threat to us is when this turn north occurs. It’s not looking particularly good for us now, as the forecast package from the National Hurricane Center continues to suggest Matthew will eventually move up the East Coast next week.

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NYC Weather Update – Post-Tropical Storm Hermine – Sep 4, 2016

Although tropical storm warnings are still up for the five boroughs, coastal Connecticut, Long Island, and New Jersey, it appears at this time that the threat from Hermine is diminishing. The center of Hermine is now located well out into the Atlantic Ocean, and even if it does make its eventual turn to the north and northwest, it will be far enough east of us that most impacts should be on the moderate side.

Rest of today – over the last few days, Hermine has continuously trended east of the official National Hurricane Center forecast track, and has still not made a turn to the north or northwest. It is still forecast to make that turn today, bringing it closer to shore, and increasing clouds in the area. Winds should pick up as well, with high temperatures around 80ºF.

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Post-tropical cyclone Hermine this afternoon

Labor Day (Monday) – assuming that Hermine does make its projected turn towards the coast, Monday would entail a chance for rain, as well as strong winds, possibly approaching tropical storm force. High temperatures are only expected to reach into the upper-70s in this scenario. Could be a tough day for the Caribbean Day Parade.

Personally, I do not believe Hermine will produce tropical storm conditions (sustained wind greater than 39mph, less than 74mph). during this time, the confidence in this track forecast has been low, and any turn towards the coast has yet to verify. That said, nothing about this complex storm would be surprising, and a shift in storm track 50-60 miles west could dramatically increase the likelihood of the city receiving tropical storm conditions. Primary impacts will still be moderate to major coastal flooding with multiple tide cycles of storm surge and large waves leading to serious beach erosion in some places.

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Based on latest track forecasts and current position of Hermine, NYC rests in a zone of 30% chance of experiencing tropical storm force winds, with the probability increasing sharply further east.

Tuesday – could end up being a pretty decent day if Hermine is further off to the east at this point. If that happens, we’ll probably see decreasing clouds and improving conditions with high temperatures in the mid-upper 80s. If Hermine sticks around, then we could see another day of wind and rain.

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Will be posting another update tomorrow.

 

 

NYC Labor Day Weekend Weather – TS Hermine – Sep 2, 2016

I wrote that I would not be posting any updates while on vacation unless there were to be a special event that warranted it. Well, the likely approach of the remnants of Tropical Storm Hermine into the offshore waters in our region certainly warrants this special update. As of now, it appears that Labor Day itself will be the only day when we could see significant impacts from this storm, but this could change. I will likely have another update Sunday.

Rest of today – sunny, and pleasant with a high in the low-80s. This will be by far the best day of the long weekend.

Saturday – increasing clouds, high temperature around 80ºF.

Sunday – mostly cloudy, with chances for rain increasing in the afternoon. Cool, with highs only in the mid-upper 70s.

Labor Day (Monday) – tropical storm conditions possible, strong and gusty winds, and possible periods of heavy rain, especially in coastal areas. Dangerous rip currents at the beaches, as well as moderate to major coastal flooding. Mostly cloudy otherwise with high temperatures in the upper-70s.

Tropical Storm Hermine this morning
Tropical Storm Hermine this morning

Tuesday – with the remnants of Hermine currently forecast to linger off of the coast of the Northeast, we could see another day of possible tropical storm conditions. Warmer, with high temperatures in the low-80s.

Tropical Storm Hermine’s Forecast

Since the inception of Hermine as a tropical wave off the coast of West Africa, forecasters have had difficulty in accurately capturing the track and intensity of this storm. Its approach towards our region is no different. The forecast is complicated by the fact that Hermine will be completing a process of extratropical transition. A complex set of interactions between it and a frontal boundary adds a high degree of uncertainty towards the late period of this forecast.

Forecast Track

As of this morning, the National Hurricane Center’s official 5 day forecast called for Hermine to continue tracking rapidly northeast just inland of the Southeast coast as it initially interacts with a frontal boundary in its vicinity. During this period, it is expected to weaken, but by Saturday evening, it is expected to re-emerge over open water off the North Carolina Coast. At this point, Hermine is expected to have completed extratropical transition. It will begin another interaction with a baroclinic frontal zone, which is expected to significantly slow its forward progress down. This slowing will likely also lead to the storm erratically meandering off the Northeast coast, possibly doing a loop.

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Some major forecast model’s current output for Hermine
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GFS ensemble models (spaghetti models), white denotes the consensus track

Intensity Forecast

During the period that the storm is over land, it will weaken continuously. However, by Saturday evening, when it is expected to re-emerge over open water, and complete extratropical transition, it will gain in strength. The extratropical transition will impart energy from baroclinic forces (interactions between airmasses of differing pressures), and the storm is expected to re-intensify into a strong extratropical storm with sustained winds of 60-65mph.

Impacts

The intensity and location of these impacts will depend greatly on the eventual track for this storm.

Tropical storm watches are in effect for the entire New Jersey coast. Heavy rain in coastal areas. Strong sustained winds, winds gusting in excess of 50mph in some coastal areas. Beach erosion along with coastal flooding, possibly for an extended period of time. High surf and dangerous rip currents.

 

NYC Memorial Day Weekend Weather – May 27, 2016

It’s been a week of hot, summer-like temperatures in the city, and this will continue into the Memorial Day weekend as the official kickoff of the summer season gets underway. It’s going to be an excellent weekend for hitting the beach as a pleasant, cooling sea breeze will be present. Memorial Day itself looks increasingly like a rainy day, with precipitation enhanced by an influx of tropical moisture from what could very shortly become the second named tropical storm (Bonnie) of the 2016 Atlantic Hurricane Season.

Rest of today – warm and humid with high temperatures in the upper-80s to near 90ºF. Cloud cover increases this afternoon, and scattered thunderstorms are possible along a sea breeze front, mostly confined to upper elevations in the Lower Hudson Valley.

Saturday – sunny, hot and humid again with high temperatures around 90ºF – a persistent Bermuda High will be the driver of these hot temperatures.

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Sunday – another very warm day with high temperatures in the mid-upper 80s. A backdoor cold front is expected to near the area, but not push through and this frontal boundary could serve as a trigger for thunderstorms, but these will be limited to areas north of the city.

Monday (Memorial Day) – significantly cooler, mostly cloudy, with periods of rain likely as a cold front approaches slowly from the west. High temperatures in the mid-70s. Rainfall may be enhanced by tropical moisture associated with what will likely become Tropical Storm Bonnie.

Tropical Storm Bonnie

An area of showers associated with a low pressure center off the coast of Florida has been steadily becoming better organized over the last couple days. The National Hurricane Center is giving this disturbance a 90% chance of becoming Tropical Storm Bonnie. Though there won’t be a direct impact on this region, the moisture from this storm could drive heavy rain on Monday.

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Satellite imagery of the low pressure area that is likely to become TS Bonnie

A Hot Summer Coming?

The Climate Prediction Center continues to call for a hot summer for almost the entirety of the United States in its latest 3 month temperature outlook.

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NYC Halloween/Marathon/World Series Weekend Weather, Sandy Retrospective – Oct 30, 2015

After a brief warmup mid-week, we return to more seasonable fall weather for the weekend. Luckily, it appears that this weekend should be rain free, providing excellent conditions for Halloween revelers, Mets fans, and NYC Marathon runners alike. It was quite a different story 3 years ago this weekend, when the city and indeed the entire region was just beginning to comprehend the scope and magnitude of the destruction wrought by a once in 500 year storm: Hurricane Sandy.

Rest of today – sunny, with a high right around average at 60ºF. It will be a chilly evening with lows in the 40s. Temperatures during game time at Citi Field should be in the low-50s.

Saturday – cooler, with highs in the mid-50s, but again with plenty of sun with high pressure in the vicinity. Temperatures for trick-or-treaters out there should again be in the low-50s range tomorrow afternoon and early evening. Weather for World Series game 4 should also be in that low-50s range.

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Sunday – AM temperatures should at race time for the marathon should be hovering right around the 50ºF mark with only a light wind. High temperatures warm up into the low-60s later in the day with a warm front moving through. Temperatures won’t cool off that much during the early evening hours, so if the Mets do make it to game 5, conditions should be good for viewing the game. There is only a slight chance for showers overnight into Sunday.

Monday – clouds and sun on Monday with temperatures climbing into the low-mid 60s.

 

Hurricane Sandy Retrospective

Yesterday marked the 3-year anniversary of Hurricane Sandy’s landfall on the central New Jersey coast. Sandy was in many ways a uniquely devastating force of nature: as it matured, it’s size ballooned, allowing for it to push up a significant storm surge ahead of it. Unlike most mature tropical cyclones that reach the mid-latitudes, Sandy did not recurve out to sea and spare the East Coast. At these latitudes, the predominant wind patterns are from the west (the westerlies), and there’s usually a cold front that pushes tropical cyclones to the east. In Sandy’s case, a low pressure system to its northwest actually produced the opposite effect: Sandy was pulled to the northwest along the counterclockwise cyclonic flow around that low pressure system. This resulted in a historic landfall on costal New Jersey. As the forecast models came into consensus on this result, I began to fear for the worst. Because Hurricane Irene had passed the previous year with great hype, but minimal damage, I had a bad feeling that many New Yorkers would not heed the warnings about this monster storm, even though there was high confidence in an historic event about to unfold.

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A monster storm

Sandy’s landfall also coincided with a supermoon high-tide, which meant that its already significant storm surge was augmented that much more by the pull of the moon. This resulted in catastrophic storm surge inundation along a vast expanse of the Northeast. The geology and bathymetry of New York Harbor made it all the more susceptible to storm surge, as its funnel shape served to channel and amplify Sandy’s storm surge. The fact that Sandy made its land fall to the south of New York meant that its most damaging northeast quadrant (Northern Hemisphere cyclones get a boost in the northeast quadrant because the direction of winds in that quadrant coincide with the direction of the Earth’s Coriolis force) hit the city dead on. A record-breaking storm tied of 14 feet was recorded at The Battery in Manhattan, smashing the previous record of 10 feet.

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Scenes of utter destruction like the one below were commonplace. Over 100 deaths were recorded, with areas like Staten Island’s east coast and the Rockaways particularly badly hit. The costs of the damage ran over $60 billion dollars. To this day, many people’s lives still have not returned to normal, many are still not able to move back into their homes.

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On a personal level, I was very fortunate to be in a neighborhood that was left high and dry, and crucially with power. Along with thousands of other New Yorkers, I felt an urgent and compelling need to get out on the ground and help our neighbors who were hardest hit and who had lost so much. My wife, who had just started working at a new school, found out that week that one of her coworkers had been killed – crushed by a fallen tree – during the storm. My volunteer work after the storm took me to many areas of New York City that I had not explored before. I saw witnessed scenes that I will never forget. For me, this day will always entail with it a sense of grieving, and will alway serve as a reminder to remain vigilant, because the storm that we never thought would happen here did – and could again.

Hurricane Joaquin Update – Oct 2, 2015

Good news to report regarding Hurricane Joaquin – since yesterday, forecast models have arrived at a much clearer consensus regarding the track of Joaquin once it leaves the Bahamas – and the resulting forecast track takes it well east of the US East Coast.

This means we will luckily miss any severe impacts from a landfalling tropical cyclone. However, with Joaquin to the south and a ridge of high pressure to the north, continuous onshore northeasterly winds will still present moderate coastal flooding issues. Temperatures will likewise remain cool under the clouds and onshore flow, with rain expected to continue from today until Saturday. Lingering showers may persists on Sunday.

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NYC Weather Update – Hurricane Joaquin in the Picture? – Oct 1, 2015

This week of damp, grey weather is leading up to a weekend when the uncertain future of Hurricane Joaquin may have an enormous impact on our weather. Since its formation earlier this week, Hurricane Joaquin has intensified steadily into a Category 3 storm currently spinning around the Bahamas. Joaquin’s future is still highly uncertain, and there’s been considerable spread between major forecast models as to where the storm will be at the end of the weekend. At this point, a landfall in the NYC region late this weekend is not out of the question.

Rest of today – cloudy and cool with high temperatures only in the mid-60s.

Friday – rain at times, windy and raw, with northeast winds in the 20-25mph range. It will feel like November with highs only in the mid-50s.

Saturday – similar to Friday in terms of sensible weather, with highs only in the upper-50s.

Sunday – this is where things get interesting depending on the track of Hurricane Joaquin. Depending on how closely Joaquin comes to hitting us, we could be looking at tropical storm conditions building through the day. If, on the other hand, it recurves out to sea, Sunday could be the best day of the weekend.

The Big Question: Where’s Joaquin Going?

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Currently, Joaquin is a Category 3 storm over the Bahamas, with noticeable central eye, and symmetrical outflow in satellite images. Joaquin has been moving southwest along the edge of a subtropical ridge. Joaquin is an environment favorable for continued intensification, sitting over some very warm water with moderate wind shear.

Forecast Track

Over the last couple of days, forecast models have been set in basically two camps, one curving Joaquin northwest into North Carolina or Virginia. The other camp continues to point to a recurvature of Joaquin. Given the large spread between the models, National Hurricane Center forecasters have been emphatic about the degree of uncertainty with the track forecast up to this point.

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Some major forecast models’ track forecasts for Joaquin
Official NHC track forecast
Official NHC track forecast

Potential Impacts

Regardless of the landfall point for Joaquin, it will be contributing to a plume of tropical moisture leading to widespread heavy rainfall over a large portion of the east coast.

With the persistent northeast winds ahead of the northward advancing Joaquin, coastal flooding is also likely to take place in flood prone areas.

5 day rainfall totals
5 day rainfall totals

 

NYC Weekend Weather – Aug 27, 2015

We have a simply splendid weekend on tap. Temperatures will be on the upward trend through the end of this week and into the weekend. The warm trend will continue into the beginning of next week, along with a return of more humid, dog days of summer type weather. Keeping an eye on the tropics, a great deal of uncertainty surrounds the future of Tropical Storm Erika, which could effect the U.S. East Coast in the long term.

Rest of today – beautiful, sunny skies with high temperatures in the low-80s. High pressure to the west is firmly in control, delivering this pleasant, seasonable weather.

Friday – almost a carbon copy of today, high temperatures in the low-80s with even fewer clouds as the high pressure center will be parked right over us.

Saturday – as the high pressure from the end of the week moves offshore and weakens, a subtropical high pressure center begins to take to control. This setup favors a warmer, more humid regime. Winds will shift to the southwest and temperatures will begin to climb into the mid-upper 80s.

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Sunday – a longer term trend of warm and humid weather, typical of late summer, will continue Sunday. Temperatures will again be in the upper-80s. This trend looks to continue well into next week.

Tropical Storm Erika

A tropical wave that moved offshore of West Africa late last week has tracked across the Atlantic, strengthening along the way to become the fifth named storm of the 2015 Atlantic Hurricane season. Tropical Storm Erika, like its predecessor Danny, is having trouble maintaining its strength due to the influence of dry air and hostile northwesterly wind shear. Due to this shear, Erika’s center of circulation is actually still somewhat exposed (see below), and displaced away from its area of heaviest thunderstorms, which is concentrated in the southeastern quadrant of the storm.

The long term prospects for the storm are highly uncertain due to a number of factors. Erika looks to be tracking over Puerto Rico and may interact with Hispaniola (bringing much needed rain), which would significantly weaken the already feeble storm. This could lead to it dissipating entirely. However, should the storm make it past this area of high wind shear and possible land interaction, it’ll end up in the very warm waters around the Bahamas. This would provide the fuel for it to intensify quickly into a hurricane which could then threaten Florida and the East Coast. Definitely worth keeping an eye on.

Satellite image of Erika, with exposed center of circulation circled in red
Satellite image of Erika, with exposed center of circulation circled in red