Weekly Outlook: May 30 – June 6

We’ve got a little bit of everything in this week’s forecast. Well, OK, not everything, there’s no snow in the forecast, but just about everything else. We start off with a rather wet Memorial Day, thanks to a cold front and the moisture from “Bonnie”.

Much of the region will receive around an inch of much-needed rain on Memorial Day. Bad for barbecues, good for lawns. Image provided by WeatherBell

Tuesday, we get back into the sunshine and warm temperatures with high pressure building in. Wednesday looks to be dry as well, but a backdoor cold front may bring another cooldown to coastal areas into Thursday. The end of the week looks a bit unsettled and a little cool for early June, with another cold front slowly moving into the region, giving us a chance for more showers and thunderstorms.

Seriously, that’s a tropical depression? Loop provided by NOAA.

Monday: Periods of rain, possibly heavy at times, especially during the morning. High 71-78.

Monday night: Showers taper off in the evening, some clearing towards daybreak. Low 58-65.

Tuesday: Becoming partly to mostly sunny, though clouds and a few showers could linger near the South Coast and Cape Cod for a while. High 78-85.

Tuesday night:Clear to partly cloudy. Low 53-60.

Wednesday: Sunshine and a few clouds.High 70-77, turning cooler along the coast in the afternoon.

Thursday: A mix of sun and clouds.High 64-71.

Friday: More clouds than sunshine, chance for an afternoon shower or thunderstorm.High 65-72.

Saturday: Partly sunny, scattered showers and thunderstorms.High 68-75.

Sunday: Intervals of sun and clouds, more showers and thunderstorms possible.High 68-75.

Tropical Storm Bonnie Forms (Insert Punchline Here)

Earlier today, Tropical Depression Two “strengthened” into Tropical Storm Bonnie off the South Carolina coastline. In related news, Pablo Sandoval was overwhelmingly voted as the fan favorite on the Red Sox. In other words, “Bonnie” is in all likelihood NOT a tropical storm.

See if you can find the “center” of Tropical Storm Bonnie. (Hint: It’s not under the thunderstorms, like you would normally expect). Loop provided by NOAA.

For now, we’ll play along and pass along the details of the storm. As of 8pm EDT, TD 2, er, Tropical Storm Bonnie was centered about 135 miles south-southeast of Charleston, South Carolina and was stationary. Maximum sustained winds (likely found in one thunderstorm somewhere in the vicinity of the storm) are near 40 mph. A Tropical Storm Warning remains in effect for the coast of South Carolina from Savannah River to Little River Inlet. The official forecast from the National Hurricane Center calls for some additional strengthening before the storm makes landfall in South Carolina on Sunday.

On Sunday “Bonnie” moves inland, weakens, and dissipates. End of story, right? Not for those of us in New England. Even though “Bonnie”doesn’t look like much, it will have a big impact on our Memorial Day weather. A backdoor cold front will move across the region early Sunday, bringing an end to the heat we’ve had for the past few days. High temperatures on Sunday will be 15-25 degrees colder than Saturday, with coastal areas staying in the 60s, while inland locations reach the 70s. You’ll need to head to the Connecticut Valley to find readings in the 80s. The cooler conditions will be accompanied by clouds and a few showers.

High temperature forecast for Sunday from the GFS. Image provided by WeatherBell.

For Memorial Day, things aren’t looking pretty. With the jet stream configured in a pattern that basically goes from south to north along the East Coast, the moisture from “Bonnie” will head right up the coastline, and into New England for Monday. That means that we’re in for a good slug of rainfall for Monday, especially during the morning hours. The Spring has been really dry, so we definitely need the rain, but unfortunately, it has to fall on Memorial Day. If you made plans to head to the beach or grill up some burgers and dogs, start looking for alternate ideas. It’s going to be cloudy, wet, and only in the 60s to lower 70s for high temperatures.

Rainfall forecast for Monday. Image provided by WeatherBell.

At least most of next week looks dry and warm with high pressure in control. So, we’ve got that going for us.

Tropical Depression Two Forms – Will it Ruin Memorial Day Plans?

The second tropical depression of the 2016 Hurricane Season has developed in the Western Atlantic Ocean.

As of 8pm EDT Friday, Tropical Depression Two was centered approximately 400 miles southeast of Charleston, South Carolina, and was moving towards the west-northwest at 13 mph. Maximum sustained winds are near 35 mph, and additional strengthening is expected.

Infrared satellite loop of Tropical Depression Two. Loop provided by NOAA.

The storm is expected to continue on a general west-northwest track into Saturday, with some modest strengthening possible. If the system attains maximum sustained winds of 39 mph or more, it would be named Tropical Storm Bonnie. This may occur on Saturday. However, many of the forecast models are indicating that the system may not strengthen much over the next few days, due to a combination of, wind shear aloft, and sea surface temperatures that are only marginally warm enough to sustain a tropical cyclone. Most of these models do show a track towards South Carolina over the next 24-48 hours.

Model forecasts for the strength of Tropical Depression Two. Image provided by tropicaltidbits.com
Model forecasts for the track of Tropical Depression Two. Image provided by tropicaltidbits.com

As the storm nears the coastline it will start to slow down as the upper-level steering currents start to weaken. A turn towards the north is possible, but if the turn occurs too early, it would prevent the storm from making landfall in South Carolina, but would make a landfall in southeastern North Carolina a bit more likely. Residents along the coast from Georgia to North Carolina should keep an eye on the storm’s progress, as it will likely have a significant impact on the holiday weekend forecast.

The storm will also have an indirect impact on the weekend forecast for much of the remainder of the East Coast. As the upper-level flow becomes south-to-north along the East Coast, it will take moisture from the storm and send it northward, ahead of a cold front. This will result in periods of heavy rain for the Mid-Atlantic states later on Sunday, and the Northeast on Monday. Rainfall totals of 1-2 inches or more are expected, and while it will ruin plans for barbecues and beach days, the region has not received much rain this Spring, so any moisture that does fall is needed.

Rainfall forecast from the GFS model for Sunday and Monday Image provided by Pivotal Weather

So, should you cancel your Memorial Day plans? Things can obviously change, but we’d have a backup plan ready. Right now, much of the day looks to be a washout, especially the morning and early afternoon, with temperatures only in the 60s to lower 70s. The rest of the holiday weekend looks great though. Saturday will feature a mix of sunshine and clouds, with a few popup showers and thunderstorms in the afternoon. High temperatures will be in the 80s to lower 90s, with some cooler readings right along the coastline. For Sunday, a backdoor cold front will move in, with more cloud cover, though still some sunny breaks. High temperatures will only be in the 60s to lower 70s along the coast, but inland, temperatures should reach well into the 70s, with some lower 80s well inland.

Weekly Outlook – May 23-30

The upcoming week will feature a wide range in temperatures across the region, as is typical of Spring in New England. However, as we approach Memorial Day, the traditional start of Summer, it looks like some summer-like weather will finally settle in. As always though, there is a fly in the ointment – a backdoor cold front.

We’ll start the week with clouds and cool temperatures, thanks to low pressure moving up the East Coast. It will spread the clouds in today, with showers moving in tonight and Tuesday.

Bring an umbrella if you’re heading out Monday night or leaving for work early Tuesday. Up to half an inch of rain is possible across the area. Image courtesy of WeatherBell

High pressure starts to build in on Wednesday with sunshine and warmer temperatures. Thursday is where things start to get tricky. It should be a warm day with showers and thunderstorms likely in the afternoon as a cold front moves through the region. That front stalls out to our south, so Friday will be likely cooler, especially along the coast, thanks to a wind off the still-cool ocean. The big question is, when does the front head back to the north as a warm front? If it’s late Friday, as some models suggest, then temperatures could spike into the 80s in the afternoon across inland areas while the coast stays cool. If it’s late Saturday, then Friday remains cool in most spots, while Saturday could see the temperatures spike in the after noon. Showers and thunderstorms are likely to accompany the front as well. Regardless of when the front comes through, Sunday and Memorial Day look look to be partly to mostly sunny and quite warm, with temperatures well into the 80s, maybe even low 90s in a few spots. A few showers and thunderstorms may pop up each afternoon, but it looks like the bulk of the activity will stay to the north.

The GFS is forecasting temperatures near 90 for much of the region on Memorial Day. Image provided by WeatherBell.

Monday: A sunny start, then increasing clouds.High 69-76.

Monday night: Cloudy with showers developing, possibly a rumble of thunder. Low 48-55.

Tuesday: Cloudy with scattered showers and a few thunderstorms. High 60-67.

Tuesday night: Gradually clearing skies. Low 50-57.

Wednesday:A mix of sunshine and clouds. High 77-84.

Thursday: Partly sunny, chance for a few showers and thunderstorms.High 77-84.

Friday: More clouds than sunshine, showers and thunderstorms are possible. High 62-62 along the coast, 70-77 inland.

Saturday: A mix of sun and clouds. High 76-83.

Sunday: Partly sunny, chance for afternoon showers and thunderstorms. High 83-90.

Memorial Day: Partly sunny, afternoon showers and thunderstorms possible again. High 83-90.

Hurricane Season is Nearly Here

June is a little more than a week away, and while that marks the start of meteorological summer, it also marks the start of Hurricane season in the Atlantic Basin (North Atlantic Ocean, Caribbean Sea, and Gulf of Mexico).

Hurricane season in the Atlantic runs from June 1 through November 30, but it got off to an extraordinarily early start in 2016 when Hurricane Alex formed back in January. Alex became the first January tropical system in the Atlantic when it acquired subtropical characteristics south of the Azores on January 13. It became a full-fledged hurricane on January 14, the first January hurricane in the Atlantic since Alice in 1955. Alex crossed the Azores as a strong tropical storm on January 15, and eventually headed out in the open Atlantic, transitioning to an extratropical cyclone on January 17. The next storm that forms will be given the name Bonnie.

Name list and pronunciation guide for the 2016 Atlantic Hurricane Season

Is the early start a harbinger for an active hurricane season? Not necessarily. What will be more of a factor is the developing La Nina in the Pacific Ocean. In an El Nino, such as the one we had in 2015, the subtropical jet stream is stronger, which inhibits storm development as the jet stream effectively cuts the tops off of storms before they can develop. In a La Nina, the subtropical jet is weaker, allowing easterly winds to dominate, which allows the storms to develop.

Map showing all tropical systems across the Atlantic Basin from the 2015 Hurricane Season. Image provided by the National Hurricane Center.

The presence of El Nino or La Nina is just one of many factors that go into whether a hurricane season is active or quiet, but most predictions are for a more active season than 2015, and above normal. In a normal season, the Atlantic Basin sees 12 named storms, of which 6 become hurricanes and 3 become major hurricanes (Category 3 or higher on the Saffir-Simpson Scale). While there are plenty of hurricane forecasts out there, these were pioneered by Dr. William Gray, who recently passed away after over 50 years in the field. His research team at Colorado State University continues his work, and for this season is calling for 14 named storms, of which 8 could become hurricanes, and 3 major hurricanes.

An active season doesn’t guarantee that a storm will make landfall in the United States though. In 2010, there were 19 named storms, 12 hurricanes, and 5 major hurricanes. Only 1 storm, Tropical Storm Bonnie, made landfall in the United States. On the flip side, 1992 was a quiet season, with just 7 named storms, 4 hurricanes, and 1 major hurricane, with the first named storm not forming until August 16. Of course, that first storm was Andrew, which slammed into South Florida on August 24 as a Category 5 hurricane, one of just 3 Category 5 storms to ever make landfall in the United States.

The peak of the season usually occurs from mid-August through late September, but an early start isn’t unusual. On average, the first named storm of the season occurs on July 9, with the first hurricane forming around August 10. In 2015, there were two tropical storms during May and June (Ana and Bill), while 2012 saw 4 named systems (Alberto, Beryl, Chris, and Debby) with 1 hurricane (Chris) forming before the end of June.

Here in New England, we should always pay attention when a storm is nearing the Bahamas, as those are the ones that have the potential to impact us. On average, a tropical storm makes landfall in Southern New England or Long Island once every 4 years, while a hurricane makes landfall once every 8 years. The last tropical storm to make landfall was Irene, which passed right over New York City in 2011, so we’re about due for another one. As for hurricanes, while we’ve been threatened several times in the past few years, the last one to make landfall was Hurricane Bob in 1991. That 25-year gap is the 2nd longest on record (dating back to 1851), second only to the 28 year gap between 1896 and 1924. In other words, we are very overdue.

Hurricane Bob approaching Southern New England. Image courtesy of NOAA

So, is anything imminent? No, and even if something were to form soon and head this way, the waters off of New England are too cold to sustain a tropical system, so we’d see something more like a typical nor’easter. Only two tropical storms have ever made landfall in the Northeast before the end of June. The first was an unnamed minimal tropical storm that crossed Long Island and went into southern Connecticut on May 30,1908. The other was Tropical Storm Agnes, which made landfall near New York City on on June 22, 1972, then caused devastating flooding across parts of the Mid-Atlantic states. In terms of hurricanes, the earliest one to ever make landfall up this way was Hurricane Belle, which slammed into Long Island with 90 mph winds on August 9, 1976. Statistically, the most likely time for a hurricane to hit New England is between the middle of August and late September. Of the 23 hurricanes that made landfall in New England or Long Island since 1851, 20 of them have done so between August 19 and September 27.