Hurricane Isaias

Hope everyone has had a fantastic week! Lot's to talk about in weather today, so we'll get right to it.

You've probably heard of hurricane Isaias, which formed overnight. A big topic in the meteorological community has been the pronunciation of Isaias - so I'll clear it up for you. Luckily, having studied in Spain this fall, I don't have too much difficulty with the Spanish pronunciation. It is pronounced: EEE-SAH-EEE-AAHS. Now that we've cleared that up, let's talk about the storm.

Atlantic Tropical Cyclones and Disturbances (NHC)

As of this morning, Isaias is located in the Caribbean near Cuba, Haiti, and the Dominican Republic. The maximum sustained winds with the storm are 75 mph, it has a minimum central pressure of 992 mb, and it is moving northwest at 16 mph. 

Here is a look at the forecast cone, which includes us here in New England.

Isaias forecast cone (NHC)

I envision initial winds arriving in southern New England by some point on Tuesday in the morning, before losing its tropical characteristics. 

Isaias tropical storm force wind arrival time (NHC)

New models have brought the storm closer to land, which would weaken it a bit. I think that we'll see significant rainfall totals (which are much needed). My big worry, though, is the winds.

Wind Speeds from GFS (Tropical Tidbits)

Right now, the GFS is showing winds approaching 60 mph here in New England, though the storm track brushes just south of us. We'll certainly see impacts. I think the rip currents will be significant near Cape Cod, Nantucket, and Block Island - those areas will see the brunt of Isaias' impacts.

Here is a spaghetti plot showing different potential storm tracks for Isaias.

Isaias spaghetti plots (Cyclocane)

We can see that some models shift the storm further out to sea, while some bring a direct hit here in New England. I think the brush of the coast scenario seems most likely. However, with each new model run that comes out, the storm track can definitely shift. 

While tropical storms don't quite excite me as much as winter weather does, I'll do my best to keep a close eye on this one and to keep you updated.

How humid has it been?

Happy Wednesday! If you have stepped outside so far today, you've probably noticed that it feels MUCH better and more comfortable than it has over the past few days. Temperatures are not much cooler today that they have been, but the humidity as dropped significantly, making it feel much better out.

Dew points as of 11:00 a.m. this morning (Mesonet)

Dew points throughout New England are in the low 60s and 50s in spots, which feels much more comfortable than the 70s that we have seen over the past few days.

How humid has it been so far this year? Here is a bit of analysis.

Daily min/max dew point for 2020 (IEM)

All of the red you see on the above plot are days when the dew point was greater than or equal to 70 °F at Bradley International Airport (BDL) in Windsor Locks, CT. I think 70 °F is a good threshold for determining how humid it has been - anything above 70 °F is truly oppressive. We have hit 70 °F for the dew point at BDL on 13 days so far this year.

Hours at or above 70 °F dewpoint at BDL (IEM)

Another interesting chart to look at is the one above. The upper chart in the image above shows the number of hours that the dew point has been >= 70 °F since 1949 at BDL, for each year. The yellow on the upper chart shows 2020. We still have not spent as many hours with the dewpoint >= 70 °F as last year, but I think that is definitely possible, looking at the data. The most humid year on record, 2018, looks like it'll be difficult to mach this year.

Over the next few days, we stay relatively muggy, though not quite as oppressive as it has been, as evidenced by this GIF.

GFS dew points through Friday (Tropical Tidbits)

I am also tracking Tropical Cyclone NINE (soon to become Isiasis) and will have an update on it later this week or weekend.

Mt. Greylock Adventure

I hope everyone had a great Monday so far and found ways to stay cool.

I had a fantastic 2-day adventure in the Berkshires, which I wanted to recap in this post. Not quite related to weather/climate, but it feels appropriate to document the trip on this blog.

I left my house at around 4:00 p.m. yesterday to drive up to Lanesborough, MA, where I booked a campsite at Mt. Greylock Campsite Park. I absolutely love camping, and it was nice to have a beautiful site at the top of a hill along Route 7, which cuts through the bucolic Berkshires.

Unfortunately, I forgot to bring my book, and when you're camping alone without a book, things can get pretty boring. Luckily, I had my phone and the road atlas in my car to keep me (somewhat) occupied. I was treated with some nice cotton candy skies last night.

I woke up at around 5:45 this morning to the sound of birds chirping and an air temperature of around 65 °F. I quickly packed up my tent and prepped for the day's first adventure, a bike ride to the summit of Mt. Greylock. 

Mt. Greylock is the highest peak in Massachusetts, with a summit elevation of 3,491 feet. The mountain is a part of the Taconic Mountains in Berkshire County. The summit is actually in the town of Adams, but it is accessible from Williamstown, Lanesborough, Cheshire, and North Adams (I may be missing a few). There is a large network of trails weaving around the mountain with the most famous one being the Appalachian Trail, which runs from Georgia to Maine. Additionally, an auto road that runs to the summit is open during the summer months. That was the road that I set out to tackle on my bike this morning.

I was the only one in the visitor center parking lot at 6:45 this morning.

I biked the 8 miles to the top before the temperatures had gotten to hot, and was treated with spectacular, yet hazy, views of the town of North Adams to the north.

There were very few other people at the summit before 8:00 a.m., though I did meet a man that began his hike in Georgia in early March and was planning to end in Maine. I swiftly descended the ~ 2,000 feet to the visitor center parking lot at the mountain's base, and prepared for the second adventure of the day: a Greylock summit hike with my parents.

(State of Massachusetts)

We took the "Summit Hike" trail shown on the map above, which begins part way up the auto road. It was fun to spend some time with my parents, and we made it to the summit much quicker than expected.

After spending about 15 minutes on the summit and fueling and hydrating, we decided to extend our hike a bit, so we traveled north on the Appalachian trail for about 20 minutes. We turned around and hiked back to the Campground parking lot, returning to our cars at about 12:30 p.m. Luckily, we got our hike in early enough to avoid the oppressive heat that was present throughout the region today. 

This was a fantastic adventure for me! Two summits in one day, plus some time spent with my parents in the great outdoors. I capped it off with a dip in Greenwater Pond in West Becket, MA to cool off. This was my third time at Mt. Greylock, and I definitely plan to return!

Heatwave Part II

Happy Sunday. Get ready for a hot one today with temperatures in the 90s throughout the region and upper 90s in spots. My last post contained a discussion of heatwaves and the 6 day heatwave that ended on Thursday. Yesterday, temperatures reached 93 °F, which is almost certain to be the commencement of a heatwave that'll last at least through Monday. I think that Monday will bring in some of the hottest temperatures of the summer so far.

NAM 2-m temperatures for 3 p.m. tomorrow (Tropical Tidbits)

To me, it's felt like heatwaves have become more frequent each year and they've gotten longer. (It's also possible that they are now more overhyped in the media.) Simply put, each year it seems to get more oppressively hot for more sustained periods of time. To see if my speculations are true, I took a look at some historical heatwave data for Bradley International Airport (BDL) in Windsor Locks, CT. The temperature data for BDL date back to 1949.

First, I wanted to see if the length of heatwaves is increasing. Remember, you only need 3 days with the temperature greater than or equal to 90 °F to have a heatwave. I was curious to see if heatwaves are now more frequently 5, 6, or 7 days.

Time-series graph  or heatwave length

The blue regression line of the data for the length of heatwaves at BDL dating back to 1949 has a slope of .000000000121 * 10^-10. With such a small slope for this line, I think we can safely say that heatwaves aren't getting any longer. When first analyzing the data, I figured that this was due to an increase in the number of 3-day heatwaves that we are seeing now. So I decided that I would look to see if we are experiencing more heatwaves each year.

Number of heatwaves each year at BDL

My thoughts that we are seeing more heatwaves each year (including 3-day ones) was somewhat right, since the slope of the blue regression line of the data in the above graph is 0.0148563. This means that each year we are seeing 0.0148563 more heatwaves than the previous year. Curiously, though, the year with the greatest number of heatwaves (7) is actually the first year that data are available for BDL, 1949. I eliminated this datapoint from my analysis to see if there was any change in the above graph.

Number of heatwaves each year at BDL without the 1949 datapoint

Here, we see that the slope of the blue regression line increases to 0.0211603, meaning that there is an average of 0.0211603 more heatwaves each year than the previous year. I found this analysis fun, though I don't think it tells us that we're seeing significantly more heatwaves each year or that they're getting longer. 

Stay cool!

Heatwave

Happy Thursday!

First, be sure to keep your eyes to the sky and radar today, as there will be some potentially severe convective storms. Severe thunderstorm warnings are currently in effect for parts of Connecticut, so be sure to look at those for the latest updates on the weather and stay safe.

I wanted to take a look at the heatwave that we are currently experiencing, which, as of today, has extended to 6 days! Bradley International Airport (BDL) in Windsor Locks, CT officially recorded a temperature of 91 °F today, extending the heatwave an additional day. I think today could be the last day of the heatwave, especially since some of the severe weather today should look to cool things off.

According to data provided by NOAA Regional Climate Centers, there have been 21 heatwaves of 6 or more days here in CT, so this one that we are experiencing now marks number 22 that is 6 days or longer.

As a reminder, to officially have a heatwave, you only need 3 or more days where the temperature is greater than or equal to 90 °F. The longest heatwave we've had here in CT was 10 days, which occurred in 2016 and 1995. We average 2.35 heatwaves each year, and that number looks to be increasing. I would also imagine that the average length of heatwaves is increasing as well. (That would be a fun project for me to tackle).

This was a short post - I simply wanted to update on the long stretch of heat we've been experiencing. Stay safe during today's severe weather!

Your meaningless winter 2020-2021 forecast

Welcome to the point of the summer when we are all simply too hot and we start to think about fall and winter! With that in mind, I wanted to give a meaningless mid-July forecast for winter 2020-2021. Meteorologists often attempt to predict if it will be a snowy or cold winter well in advance of the start of winter, but in my opinion, this is simply too hard to do (especially now, when it starts getting done). That said, I'm going to share some insight anyway. **If you don't feel like reading information that is essentially meaningless, close your webpage now**

To begin, the Climate Prediction Center (CPC) issued a La Niña watch on July 9. According to the CPC, while ENSO-Neutral conditions are favored to remain through the end of the summer, there is a 50-55% chance of La Niña conditions developing in fall 2020 and continuing through winter 2021. Let me unpack all this for you. The El Niño-Southern Oscillation (ENSO) is an oscillating climate pattern that involves changing surface water temperatures in the central and eastern Pacific Ocean near the equator. The 3 stages of ENSO are El Niño, ENSO-Neutral, and La Niña. Meteorologists like to track ENSO because it can have important implications on the jet stream, which can in turn affect temperatures and precipitation. Right now, we are in an ENSO-Neutral phase of the cycle, meaning that Pacific Ocean temperatures are not particularly hot nor cold. The CPC is tracking the possibility of a La Niña developing this fall and continuing into the winter, which would have a setup like this in the pacific ocean:

Sea surface temperatures during La Niña (Wikipedia)

The large swath of blue near the equator in the eastern Pacific Ocean indicates that Pacific sea surface temperatures (SSTs) are lower than average. What does this oceanic configuration mean for our winter weather in New England? Generally during La Niña we see about average temperatures with above average precipitation.

Typical winter pattern (NWS)

So on the basis of La Niña forming (which the CPC says has ~ a 50% chance of happening), we can expect a snowy winter with fairly typical temperatures. Note that this does not always happen during La Niña winters. We certainly can experience a dry and cold winter when there is a La Niña in place. And if you've made it this far, note again that all of this information is practically meaningless, as it's so difficult to forecast for the winter this far out.

Here is what the CPC thinks for temperature probabilities during December 2020 - February 2021.

Three-Month temperature outlook for Dec 2020 - Jan 2021 (CPC)

Probabilistically, the CPC calls for approximately a 55% chance that we'll see above average temperatures during that three month period. And for the same period, the CPC is stating that there is a 50/50 chance that we'll se above normal precipitation.

Three-Month precipitation outlook for Dec 2020 - Jan 2021 (CPC)

The above map shows a typical La Niña pattern: dry in southern areas, and wet in northern areas.

To recap, it looks like there is a chance that La Niña will develop as we head into the winter. Historically, this would mean that we'd expect average temperatures and slightly above normal precipitation, but this is certainly not always the case. As I've maintained throughout this post, all of this information is more or less meaningless - it's simply too hard to forecast for the winter in the middle of July. We'll simply need to wait until December to know what winter will be like. Until then, it's more heat and humidity for us.

Record Roundup

As I mentioned on Saturday (link here), we are currently experiencing some of the hottest conditions of the summer so far. I wanted to do a quick roundup of some of the temperature records that have been broken over this mid-July stretch. Note that I'd imagine some additional records will still be broken. Here's a nice graphic from the National Weather Service showing some high temperature records that were broken yesterday.

High temperature records set or tied on 7/19 (NWS)

In Vermont, records were tied in Morrisville (91 °F) and Springfield (92 °F), while St. Johnsbury in the Northeast Kingdom set an all-time July 19th temperature record of 95 °F. Here in Connecticut, the official high at Bradley International Airport (BDL) in Windsor Locks was 99 °F, just shy of the all-time July 19th high of 100 °F.

I often find record high low temperatures as more telling for a few reasons. First, the low temperature is what you feel when you're sleeping, and an overnight temperature that only drops to 70 °F can be quite difficult to sleep in. Secondly, overnight lows that are unusually high can take a huge toll on your heating bills. At BDL, the low temperature this morning was 77 °F, exceeding the previous July 20th record high low by 4 °F. That made sleeping last night uncomfortable for many here in Southern New England, especially if you don't have air conditioning. After tomorrow, temperatures will look to drop slightly, though they'll still be in the 90s, extending our heat wave. I wouldn't surprise me if this ends up as the hottest summer on record here in New England.

HOT

Get ready for the hottest weather of the summer this weekend!

Temperatures at 11:30 a.m. (Weather Central)

As I write, it is 11:30 on Saturday morning, and temperatures have already soared into the upper 80s in spots, and they won't look back. We can expect high temperatures to reach the 90s here in New England today, but I think Sunday will be the hottest day of the summer so far. Heres a look at 5 p.m. temperatures tomorrow from the NAM.

NAM forecasted temperatures at 5 p.m. (Tropical Tidbits)

Now what is the reason it is so hot right now? The answer lies in the jet stream, which has shifted far to the north.

GFS 500 mb Geopotential Height, Cyclonic Vorticity, and Wind (Tropical Tidbits)

In the above map, you can see the are area of red, which shows where in the U.S. the jet stream is dipping towards. Right now, it has only dropped down to areas near Southern Canada, causing the impressive heat in our area. What is the jet stream? It is an area of westerly winds in the tropopause that encircles Earth. The jet stream aids meteorologists in forecasting, because its path has important implications on the weather we receive. Often, when we get intense wintertime polar vortices, it is due to a dip in the jet stream into North America. And when the jet stream is at a more northerly latitude, we can expect warmer weather.

It'll be very hot this weekend, so be sure to hydrate sufficiently and stay in the shade when possible. Enjoy the weekend!

Climate Updates

I recently read the National Centers for Environmental Information (NCEI) Global Climate Report for June 2020, and to sum it up, I'd say that June was a very hot month globally (as it was here in New England) and 2020 has also been one of the warmest years on record. You can the report at this link.

As a whole, the June 2020 global land and ocean temperatures were 1.66 °F above the 20th century average for the month, tying June 2015 for the 3rd warmest June on record.

Land & ocean temperature departure from average for June 2020 (NCEI)

The above map shows temperature anomalies from normal for June 2020. Notice the dark red spot in Siberia. You may have heard that Siberia had a temperature above 100 °F, and that record high temperature contributed to the warm temperature anomaly in that region this June. Specifically, the town of Verkhoyansk, Russia recorded a temperature of 100.4 °F on June 20th, which (pending approval from the world Meteorological Organization (WMO)) is the first time temperatures north of the Arctic Circle have risen above 100 °F. Northern Europe was also quite hot during the month, while the Northwest North America and Eastern Europe were on the cooler side. The following graph demonstrates how June temperatures have changed over the past ~ 140 years.

June temperature land and ocean temperature anomalies (NCEI)

Clearly, Junes have been getting much warmer, and June 2020 was one of the hottest on record.

As a whole, 2020 has also been one of the warmest years on record. This map shows the January-June temperature anomalies from normal for the world.

Land & ocean temperature departure from average for January-June 2020 (NCEI)

Siberia has clearly been the warmest area compared to average so far this year, while British Columbia and Alaska have been cooler than normal. I think this is a result of the Polar Amplification effect, where polar locations undergo more extreme changes than more temperate areas of the globe. Interestingly, there have also been some large swaths of cooler than normal temperatures in the Southern Hemisphere.

Jan-June temperature land and ocean temperature anomalies (NCEI)

The above graph shows how January-June temperatures have increased over the past ~140 years. Evidently, we've gotten warmer, and the first half of 2020 has been one of the warmest 1st halves of the year on record. What are some implications of this impressive warmth we've had so far this year? One place we can look is the Arctic. June Arctic sea ice extent, as shown by this image, was 10.1% below average, the 3rd smallest ever for the month.

June sea ice extent (National Snow and Ice Data Center)

Fay Recap + Back into the Muggies

Tropical storm Fay has dissipated and we are back into the typical summertime pattern of hot and muggy weather. I'd say Fay was a bit of an underperformer here in New England, though we did see some impressive wind gusts. Here's a look at rainfall totals from the storm.

24 hour observed Northeast precipitation (NWS)

48 hour observed Mid-Atlantic precipitation (NWS)

As you can see from the above maps (sorry they follow a slightly different color scheme and scale), highest precipitation totals were observed right in the center of the storm track in Delaware, New Jersey, Southeast New York, and Eastern Pennsylvania. Highest totals were in the 5 to 6 inch range, and I saw images and videos of significant flooding at New Jersey beach towns. Stepping outside my house, I definitely noticed the strong winds, which caused some small tree branches to break. Here's a look at peak wind gusts from the storm. Similar to rainfall, the highest winds were observed in NJ and DE.

Fay peak wind gusts (NWS)

With the storm having passed through, it's time to look ahead to next week, and the big story is the heat and humidity. Here's a GIF showing the GFS forecasted temperatures throughout the week.

GFS temperatures for this week through Thursday (Tropical Tidbits)

I think we'll get into the 80s just about every day. Notice some of the purplish colors in mid-Atlantic areas. Those are temperatures that are well in the 90s, making it feel brutal at times. Here is the same GIF but for dew points. Just about every day this week dew points will be in the upper 60s or low 70s, making it feel oppressive.

GFS temperatures for this week through Thursday (Tropical Tidbits)

It isn't until Wednesday that we start to see drier, more comfortable air enter our region. Enjoy the rest of your weekend!

Tropical Storm Fay

Fay, the 6th named tropical storm of the year, is set to impact us in New England this weekend. Here's a nice satellite view of the storm preceding north along the Atlantic coast.

GOES satellite imagery showing Fay preceding northward (NOAA)

Right now, the storm is located near Delaware, and it is moving north at around 10 mph.

Current Atlantic tropical cyclones and disturbances (NHC)

First let's talk timing of the storm. The following image shows the National Hurricane Center (NHC) storm cone, showing Fay's progression.

Fay forecast cone (NHC)

The S that you see in the black dots on the map indicates that sustained winds will be between 39 and 73 mph, making Fay a true tropical storm, and it'll become a tropical depression by Saturday afternoon. As previously mentioned, the storm is currently located around Delaware and it is moving northward. I expect some initial rain to begin in Southern New England this afternoon, picking up in intensity as the storm moves northward. The center of the storm will reach Southern New York overnight tonight, and that's when I'd expect the strongest rain and winds. As Saturday progresses, Fay will continue to penetrate New England, though it should lose it's tropical storm characteristics (39-73 mph winds) by Saturday afternoon.

Let's talk about potential impacts of the storm, the biggest one being rain. I think New Jersey and New York will receive the brunt of the rain, with areas of Southwest Connecticut and Eastern Pennsylvania seeing significant rainfall totals as well. I'd expect widespread rainfall totals of 2 to 4 inches, and the NHC is even forecasting up to 7 inches of rain at isolated maxima along the storm track.

U.S. rainfall QPF (NHC)

This rainfall will be much needed when it comes to lessening the abnormally dry conditions that we're seeing throughout New England, though when we see rainfall totals this significant, flash flooding becomes a threat. Any areas that see a quick burst of rainfall or urban areas are especially susceptible to flash flooding.

The next big impact is the wind. This image shows the probability that areas will see tropical-storm- force winds. Here in New England, CT looks to have the greatest chance of winds greater than or equal to 39 mph.

Tropical-storm-force wind speed probabilities (NHC)

As Fay progresses northwards and we have a better sense of the characteristics of the storm, I'd expect these probabilities released by the NHC to increase. Due to the heavy sustained winds, power outages and downed trees are possible. Overall, I think winds and rain are the biggest threats associated with Fay, but minor coastal flooding and isolated tornadoes near coastal areas of New Jersey, New York, Connecticut cannot be ruled out.

To sum, we can expect rain and heavy winds this afternoon, with the brunt of the storm coming overnight tonight. Flash flooding and potential damage due to winds are possible. 

I plan to make this my only post today, but if there are any drastic changes in the forecast, I'll be sure to update.

Possible Tropical System

First of all, today will feel absolutely oppressive. With high temperatures in the upper 80s to low 90s and due points in the upper 60s or low 70s, it'll simply feel like the hottest day of the summer. The following two images so forecasted air temperatures and due points from the HRRR model for 2 p.m. today. There is no way to sugarcoat it. Today will feel oppressive.

HRRR 2 p.m. temperatures (Tropical Tidbits)

HRRR 2 p.m. due points (Tropical Tidbits)

If you do have any outdoor activities planned, I recommend you do them in the morning to avoid the brunt of the heat and humidity. And on these days, it's essential to hydrate sufficiently.

Moving ahead to the weekend, there are increasing chances that we could see a tropical system affect us here in New England. Here's a look at where the storm is right now, near the Carolinas.

GOES-East Satellite Imagery (NOAA)

And here's a GIF showing the trend of the system approaching our region from the GFS model.

GFS from 8 a.m. Thursday to 2 p.m. Sunday (Tropical Tidbits)

The low looks to track up the Atlantic coast, reaching Southern New Jersey at around 8 a.m. Friday morning. The GFS has the storm tracking particularly far to the west compared to other models, and if that is the case, we could miss out on the brunt of the rain/wind. Particularly, the European model (EURO) has the storm track a little further to the east, leaving us with some more impressive rainfall totals. Either way, I'd expect us to see rain Friday into Saturday. Here's a look at the total accumulated rainfall from the GFS through Sunday morning.

GFS Accumulated Rainfall through Sunday a.m. (Tropical Tidbits)

That large swath of purple in Central New York is an area that could see over 3 inches of rain. And if the EURO storm track verifies, we could see some of that heavier rain and be in for a soaker this weekend!

Thursday afternoon update: The storm has officially been named Tropical Storm Fay, making this one the 6th named storm of the year.

Wednesday Forecast

I haven't done a simple one-day weather forecast in a while, so I figured I'd do one for tomorrow, which looks to potentially have some severe weather.

First, here's a look at the NWS Storm Prediction Center (SPC) day 2 outlook.

SPC day 2 outlook (NWS)

A large swath of New England is in the marginal risk category, meaning we could see some strong to severe storms. The atmosphere is looking pretty unstable tomorrow afternoon with CAPE values > 1000 J/kg, meaning we could certainly see some storms. There is also modest shear in the upper atmosphere, which, coupled with a high CAPE value, can produce strong storms. Any storms that do fire up tomorrow could cause some strong surface wind gusts or hail in spots.

As you can see with the image of the NAM 3 km model below, storms look to be quite isolated, although heavy in spots. This is for 5 p.m. tomorrow

NAM at 5 p.m. EST tomorrow (Tropical Tidbits)

If you do have outdoor activities planned for tomorrow, you should be fine in the morning, although I'd caution against going out in the afternoon. Any storms that do pop up will likely be short-lived.

NAM 2 m temperatures at 5 p.m. EST tomorrow (Tropical Tidbits)

Like today, temperatures will not be unbearable, with highs in the upper 70s to low 80s. Have a nice day, and share any storm info/damage if you have it!