The first weekend of meteorological summer is upon us, and it’ll certainly feel like summer around here.
A warm front will move across the region this afternoon, and as an upper-level disturbance swings through tonight, those two will combine to bring in some showers and thunderstorms. While a few of them may produce some heavy rain near the South Coast, most of us shouldn’t see that much rain tonight. Another upper-level disturbance crosses the region on Friday accompanying a dying cold front. This will produce another round of showers and thunderstorms, mainly during the afternoon and evening. A few of these storms could produce downpours and gusty winds.
Once everything moves offshore Friday night, high pressure builds back in for the weekend and Monday. We’ll dry out on Saturday and with developing sunshine, temperatures should get well into the 80s away from the South Coast. For Sunday and Monday (and into the middle of next week), we’ll have a Bermuda High in place, which means southwest winds pumping very warm to hot and humid air into the region. Temperatures will be near or just above 90 for most of us on Sunday, and on Monday, highs will reach the lower to middle 90s, perhaps even some upper 90s, which will be close to the record highs for much of the region. While it won’t be as humid as it normally is deeper into the summer, it’ll be fairly humid by early-June standards, with dewpoints in the 60s, meaning that it will feel like mid to upper 90s during the afternoon.
Thursday night: Cloudy with a few showers or a rumble of thunder, mainly along the South Coast. Low 59-66.
Friday: Plenty of clouds with some showers and thunderstorms possible, mainly during the afternoon. High 74-81, a little cooler along the South Coast. Offshore: Southwest winds 15-20 knots, gusts to 30 knots, seas 3-6 feet, visibility 1-3 miles in showers and fog UV Index: Moderate. Water temperatures are in the upper 50s to near 60.
Friday night: Showers and storms taper off during the evening, some clearing possible late at night. Low 56-63.
Saturday: Becoming partly to mostly sunny. High 83-90, cooler along the South Coast. Offshore: Southwest winds 15-25 knots, gusts to 30 knots, seas 3-5 feet, visibility 1-3 miles in morning fog. UV Index: High.
Saturday night: Partly cloudy. Low 64-71.
Sunday: Sunshine and a few clouds, becoming humid. High 88-95, cooler along the South Coast. Offshore: Southwest winds 10-15 knots, gusts to 25 knots, seas 2-4 feet, visibility 10 miles or better. UV Index: Very High.
Sunday night: Clear skies. Low 64-71.
Monday: Partly to mostly sunny. High 90-97, cooler along the South Coast. Offshore: West to southwest winds 10-15 knots, gusts to 25 knots, seas 2-4 feet, visibility 10 miles or better. UV Index: Very High.
Bond villian Elliot Carver said it in “Tomorrow Never Dies”, but it’s appropriate for the forecast for the next several days – “Let the mayhem begin”
We start off with a developing low pressure system well offshore tonight. The system will continue to strengthen, but also continue to pull away, so it won’t directly impact us. However, it will produce northerly winds around here that will serve two purposes. First, they’ll continue to produce some ocean-effect snow across parts of eastern Massachusetts and the New Hampshire Seacoast, and second, they’ll usher in some of the coldest air thus far this winter.
First, we’ll look at the ocean-effect snow. It’s been ongoing since early this morning, and will continue off and on into this evening. While it won’t amount to much for a good chunk of the region, right along the coast, especially Cape Ann, coastal Plymouth County, and Cape Cod, could see an inch or two in spots. On Friday, a disturbance rotating around the ocean storm will bring some more ocean-effect snowfall back into Cape Cod. This could result in additional accumulations, especially across the Outer Cape, where a few inches is possible.
Back to the cold air. This past week has been rather chilly compared to the rest of January, but temperatures have only been near to a little below normal. That’s going to change tonight and this weekend. Skies will start to clear out tonight (except for Cape Cod), and it’s going to get cold. Temperatures will likely drop into the single numbers for much of the region tonight, but it will remain quite breezy, so we’re looking at wind chills of 10 to 20 below zero Friday morning. Wind Chill Advisories have been posted from Worcester County westward, but even without the advisory, you should know enough to dress warmly if you have to go outside.
Friday looks rather chilly as well. Some clouds may move in from the ocean, but even in places where the sun is out, it’ll still be breezy and cold, with daytime highs only in the teens to lower 20s. Skies clear out again Friday night and winds will start to diminish, so we’re looking at another cold night, with some places possibly dropping below zero. Saturday should feature a lot of sunshine, but it will still be cold, with highs only in the upper teens to lower 20s. After another bitterly cold night Saturday night, temperatures should start to moderate a bit on Sunday, but we’ll also see clouds starting to move back in ahead of another storm system heading this way. This brings us to Monday.
For several days now, most of the forecast models have been showing the potential for a storm system to impact the Northeast early next week. They’ve bounced around with the details on strength, timing, and track, but in general, there’s been a fairly strong signal that something is going to happen around here after we flip the calendar to February. Well, that signal hasn’t gone away, and the Universal Hub website has upgraded to a Level 2 on the French Toast Alert System. In other words, don’t worry just yet. However, knowing how the media can be around here, and knowing what the models are showing, we’re issuing our own Extreme Hype Watch. An Extreme Hype Watch is issued when conditions are favorable for media hype of an event to reach extreme levels within the next 48-72 hours. If conditions warrant, a Hype Advisory or Extreme Hype Warning will be issued as the event draws nearer.
As for the system itself, there are still plenty of questions that need to be answered. We’ll have a large high pressure area in eastern Canada keeping some cold air in place. It’s not quite in the ideal position for a big storm here, but it is there. We’ll have a low pressure system moving through the Midwest that will redevelop over the Mid-Atlantic states, then head northeastward, likely passing south and east of New England, close to the “benchmark”. The benchmark is at 40 degrees North latitude and 70 degrees West longitude, about 90 miles south of Nantucket. Storms that pass over that spot are usually (but not always) in a prime position to deliver heavy snow to much of the region. Storms that pass north and west of there usually end up with a rain/snow line farther inland, and storms that pass south and east of there don’t always deliver snow far inland. This is more of a general rule than an absolute, but it’s something we look for. The other issue we have is that an upper-level low pressure area will be moving in, and the storm may get stuck underneath it, which could stall it out or have it meander around south of us for a day or so, which would result in an extended period of precipitation.
In addition to the models, another tool we use is analogs. You will most often hear about these in relation to a seasonal pattern or a hurricane season, but we can also use them for individual storms. Basically, we compare the pattern to previous setups, and see how it compares, and see what those previous setups produced to give us an idea of what is possible. Now, these analogs are run compared to the forecast of one model, so if that model isn’t the one your using, then the analogs might not be of much help. Based on the midday run of that model, the best analog for the pattern early next week is the storm of January 26-28, 2015. You may recall that storm received an extreme amount of media hype, and did produce very heavy snow around here, but was considered a “bust” in New York City, where the actual amounts fell well short of the forecast. It also was the storm that essentially kick-started our 6-week snow blitz (and also was responsible for the formation of the original StormHQ Facebook page). Using the Top 15 analogs for the forecast pattern, here’s the average of snowfall from those 15 systems:
As you can see, there is a signal for a significant snowstorm, which is why we’re going to be monitoring this closely for the next several days. We’re not going to post any model snow forecasts yet because there’s still too much uncertainty. We’ll let the media and Facebook Forecasters take care of that. If conditions warrant, we’ll issue another blog post either Saturday or Sunday as the details become more clear.
Thursday night: Mostly cloudy along the coast with a few snow showers across the Cape, clearing inland, breezy. Low 1-8.
Friday: Intervals of clouds and sun, more snow showers across Cape Cod, windy. High 13-20.
Friday night: Lingering clouds across Cape Cod, clear elsewhere, still breezy during the evening. Low 2-9.
Saturday: Plenty of sunshine, except for some clouds across the Outer Cape. High 16-23.
Saturday night: Clear skies. Low 0-7.
Sunday: High clouds stream in. High 22-29.
Sunday night: Thickening clouds. Low 12-19.
Monday: Cloudy and breezy with a chance of snow (or possibly rain south of Boston) High 30-37.
September is when we start to transition from Summer to Winter, but this September is starting off with a bang.
Intense heat has been common across much of the West for the past few days. Temperatures well over 100 degrees were widespread during Labor Day Weekend, especially across California, with numerous records set. One location, Richmond, on the eastern side of San Francisco Bay, reached 107 degrees Monday afternoon, tying their all-time record, originally set on September 15, 1971. Several other locations set monthly records for September as well. The worst of the heat has passed, but it will remain hot on Tuesday, with highs likely topping 100 across much of interior California and the Desert Southwest, possibly setting a few more records. Temperatures should gradually cool down a little more as we get toward the middle and latter portion of the week.
Heat was also common across the Plains and Rocky Mountains over the weekend, but big changes are developing thanks to a strong cold front. Denver set a record high of 97 on Sunday, then reached 93 on Monday. On Tuesday, that 93 will get reversed, with a daytime high closer to 39 (The high for the calendar day will be the 46-degree reading at midnight). On top of that, accumulating snow is likely. Even by Denver standards, this is quite early in the year for snow. Their all-time record for earliest snow is September 3, 1961, but on average Denver doesn’t see its first flakes until October 18. This won’t be the 1st time that Denver hit 90 one day and then had measurable snow the next. On September 12, 1993, Denver recorded a high of 92 degrees, and on September 13, they had 5.4″ of snow.
While a few inches of snow are likely in Denver and onto the adjacent High Plains of eastern Colorado and western Nebraska, heavier snow is likely across the mountains on Colorado and Wyoming. Across the higher elevations, snowfall totals in excess of a foot are likely. While the snow will likely last a while in the mountains, at the “lower” elevations on the Plains, it will disappear quickly. High temperatures in Denver will be back into the 60s by Friday, and near 80 by the end of the weekend.
While the snow will get a lot of the headlines, the cold air behind the front will be making headlines of its own. The first frost and freeze of the season is likely across parts of the Dakotas, Montana, and northern Minnesota Tuesday and/or Wednesday morning, with lows in the upper 20s and 30s. The cold air will continue to push southward across the Great Plains during the day on Tuesday, with numerous record lows expected Wednesday morning as far south as the Texas Panhandle. The cold air will eventually spread eastward, but will be modified significantly before it reaches the Eastern United States.
While plenty of (frozen) precipitation is expected across the Rockies, the lack of precipitation is causing problems across the Northeast, specifically New England. Aside from a few showers with a cold front on Thursday, generally dry weather is expected across much of New England this week, and things don’t look that promising for much of next week either. This shouldn’t be a surprise, as precipitation has been generally below to well below normal across the region since the Spring. In some areas, the amount of rain has only been around 50-60% of normal since April 1. Drought conditions have developed across nearly all of New England, and for a good portion of the region, it is now considered a severe drought. What the region needs is a series of systems that can produce moderate rainfall to help alleviate the drought (too much at once won’t help that much), but prospects for that aren’t promising at this time. In fact, rainfall looks to remain below normal for much of the remainder of September.
Meanwhile, as we approach the climatological peak of hurricane season, the Atlantic is once again getting more active. Tropical Storms Paulette and Rene both developed on Monday in the central and eastern Atlantic respectively. Paulette is expected to remain a tropical storm for the next several days while remaining over open water. It is not expected to be a threat to land. Meanwhile, Tropical Storm Rene moved into the Cabo Verde Islands Monday night and early Tuesday, producing heavy rain and gusty winds. It will likely strengthen over the next couple of days, possibly becoming a hurricane later this week. Once it pulls away from the Cabo Verde Islands, it is also expected to remain over open water for much of this week, presenting no additional threat to land.
Those systems aren’t the only ones in the Atlantic that are being watched. An area of low pressure a couple of hundred miles west-southwest of Bermuda is expected to drift westward or northwestward over the next day or two. Some development of the system is possible. It may bring some rainfall into parts of the Carolinas and Southeast later this week. The other area that is being watched isn’t immediately apparent right now, as it is still over western Africa. A tropical wave is expected to emerge from the west coast of Africa later this week. Forecast models show the potential for this wave to develop rather quickly once it moves into the Atlantic. It could threaten the Cabo Verde Islands over the weekend.
The peak of hurricane season is during the middle to latter half of September. Given how active this season has been so far, there will likely be more systems developing. There are only 4 names left on this list for this season – Sally, Teddy, Vicky, and Wilfred. Once the list is exhausted, the Greek alphabet is used. This has only happened once before – in 2005. During that season, there were 28 named storms of which 15 became hurricanes.
Heat and humidity continue across the region for a couple more days before relief arrives on Wednesday.
A ridge of high pressure remains in control, so stifling heat and humidity will remain in place until Tuesday. Today looks to be the hottest day, with temperatures well into the 90s. A few places could reach 100, but triple-digit heat shouldn’t be widespread. It will be very humid as well, sending the heat index well above 100 across the region, but dewpoints may actually drop a bit during the afternoon. Tonight will be downright uncomfortable without air conditioning, as low temperatures will only drop into the middle to upper 70s in many areas, and some urban areas, especially Boston, may not drop below 80.
Tuesday will start off very warm and humid, so it won’t take much to send temperatures above 90 once again, but clouds will also start to increase in the afternoon as a cold front approaches the region. This front may produce a few showers and thunderstorms late in the day and at night. Some of these storms may produce some heavy downpours and gusty winds, but we’re not expecting widespread severe weather.
The front slides offshore early Wednesday, then high pressure builds in for the rest of the week and into the weekend. It be a bit cooler, but still near to a little above normal for the end of July, but the more noticeable effect will be that it is drier, with dewpoints only in the 50s to lower 60s.
Monday: Sunshine and some high clouds around, hot and humid. High 92-99.
Monday night: Clear to partly cloudy. Low 72-79.
Tuesday: Sunny early, then clouds move in with some showers and thunderstorms possible late in the day. High 90-97.
Tuesday night: Showers ending during the evening, though possibly lingering for much of the night near the South Coast. Low 67-74.
Wednesday: Lingering clouds along the South Coast early, otherwise becoming partly to mostly sunny and not as humid. High 85-92.
Thursday: Sunshine and some afternoon clouds. High 83-90.
Friday: A mix of sun and clouds. High 81-88.
Saturday: Partly to mostly sunny. High 81-88.
Sunday: Partly sunny. High 82-89.
Finally, we’ll mention the tropical disturbance in the Central Atlantic, since the hype train is already getting set to leave the station. Yes, there are a few models that show a potential threat to the East Coast in about 7-10 days. These should be treated the same as model forecasts in January that show a raging blizzard 7-10 days out. The probability of it happening is still fairly low. The system itself hasn’t even become a tropical depression yet. That may occur later Monday or Tuesday. If (when?) it does, we’ll write a blog post about the storm and it’s future. For now, it has our attention, but that’s it.
By now, you’ve heard the TV meteorologists talking about how it’s going to snow, or you’ve read the headlines about an “historic May snowstorm” that’s coming. As usual, we at Storm HQ will avoid the hype and just give you the facts. Yes, there will be some snowflakes around here and no, it won’t be a big deal at all.
A cold front is moving across the Great Lakes this afternoon, and it move across our area tonight, with plenty of clouds and possibly a few showers. Behind that front, much colder air will start to move into the region. This is an anomalously cold airmass for early May, and in fact, is more representative of early March. That front is expected to stall out near the South Coast, and then a wave of low pressure will develop along the front and ride along it, crossing southern New England Friday night and early Saturday.
We’ll have some rain moving in Friday afternoon and evening, but as the sun sets and temperatures drop, some wet snow will start to mix in. The most likely spots for snow are in the hilly terrain from northern Rhode Island across Worcester County and into the Monadnocks of southwestern New Hampshire, as well as out in the Berkshires. However, we wouldn’t be surprised if there was some wet snow mixed in with the rain even into the suburbs of Boston.
As we mentioned with the last few storms, it’s awfully tough to get accumulating snow into early May for a variety of reasons. For one, the ground is fairly mild. Any accumulations will be mainly on grassy surfaces, as pavement temperatures are much too warm now. Secondly, temperatures may not even drop to freezing, but could stay in the middle to upper 30s. Third, the intensity of the precipitation will be key. Heavier precipitation will bring down colder air from aloft, resulting in the change to snow, whereas light precipitation will tend towards more rain.
As far as accumulations, as we said, we’re not expecting this to be a big deal for most of us. You may wake up Saturday morning, if you’re up early enough, to see a little bit of a coating on grassy surfaces, decks, and car roofs/windshields. As we mentioned, most of the accumulations will be confined to the hilly terrain, where a few inches could fall.
Snow is fairly rare once you get into May. Using data for Lowell, snow has been recorded 5 times during the month of May over the past 92 years, and measurable snow only twice.
The snow is only part of the story though, and in fact, a minor part. As the storm intensifies while pulling away on Saturday, gusty winds are expected across the area. West winds of 15-25 mph with gusts of 40-50 mph are expected, especially along the coast. At the same time, an upper-level low pressure area will be moving into the region, bringing in very cold weather. That upper low may trigger a few rain or snow showers in the afternoon, but the cold temperatures will be the story. High temperatures likely will stay in the 40s, which may set records for the lowest high temperatures for the date in many locations.
The really cold weather will be short-lived, as we will start to moderate on Mother’s Day as high pressure builds in. However, if you’re hoping for some sustained warmth, it’s not coming anytime soon. There are some hints that we may get out of the pattern that’s kept us quite chilly for most of April and early May in another 10 days or so, but a “warm” pattern is still a ways off.
The image above is the high and low temperature forecast for Bedford for the next 45 days, based on the ECMWF Ensemble, which has 51 separate members. The solid red and blue lines in the middle of each graph are the “normal” highs/lows for each day. The green dot is the average of the 51 members for each day (which is also represented numerically in the middle of the 2 charts), and the shaded gray area is the area that between 1/4 and 3/4 of the members fall. The horizontal blue lines above and below that are the extreme on each day. As you can see, this model is forecasting temperatures to remain well below normal through May 14-15. After that, temperatures generally average near or a little below normal until June 9. Granted, “normal” for those dates is upper 60s to near 70 for high temperatures, so it’ll be milder, but still a little cooler than we should be. Finally, we get to near or a little above normal for a sustained period around June 10. Now this is just one model, so take it with a grain of salt, but it’s done fairly well diagnosing the general details of our weather pattern for several weeks now. There is hope that you can finally take your summer clothes out of storage, perhaps as early as next weekend.
The Winter Solstice is Saturday, but winter will certainly make it’s presence felt over the next few days.
The low pressure system that produced severe weather across the South on Monday will head northeastward, impacting our area on Tuesday. The storm will be moving fairly quickly, and it doesn’t have a lot of cold air to work with, so we’re not expecting a big snowstorm. That doesn’t mean it won’t cause any problems.
Snow will develop around midnight across parts of Connecticut and Southern Rhode Island, gradually spreading northward across the rest of the region before daybreak. The snow should quickly change to rain after daybreak across the South Coast and Cape Cod. As warmer air moves in aloft, a change to sleet and freezing rain will start to take place across the interior, with plain rain along the coast as milder air moves in off the still relatively mild ocean. Right now, it looks like the mixing may get as far north as the Merrimack Valley during the afternoon. North of there, precipitation should stay all snow. The precipitation will lighten up during the afternoon, but won’t completely end until the evening or first part of the overnight.
The morning and evening commute will both be impacted by this storm, but the greater impacts will certainly be during the morning commute. Not only could icing be a problem, especially in parts of Connecticut and Rhode Island, we could be looking at a band of moderate to heavy snow along and south of the Mass Pike. With temperatures expected to drop below freezing at night, many roads could ice back up, so untreated surfaces could become slick, especially in areas that changed over to rain during the afternoon.
As for how much snow to expect, we haven’t changed our thinking much from our earlier forecast.
South Coast/Cape Cod: Less than 1″ Southeastern Massachusetts (including the I-95 corridor): 1-2″ MetroWest/North Shore: 1-3″ Merrimack Valley: 2-4″ Central + Southern New Hampshire/NH Seacoast: 3-6″
Behind this system, we’ve got to pay attention to an arctic cold front that will move across the region late Wednesday. It could produce some snow showers or squalls as it moves through. These won’t impact everyone, but in places they do, visibility could rapidly drop, and a quick half an inch to an inch of snow could fall.
Behind that front, some of the coldest air so far this season will settle in for Thursday. Wind chills will be below zero during the morning hours, and actual temperatures may not make it out of the teens during the afternoon. Friday will see temperatures start to moderate a bit, but it will still remain quite chilly, even by December standards.
Given a choice, would you prefer cold weather or warm weather? What about a choice between rain, snow, or dry weather? Well, you’re going to get ALL of these this week!
We start the week with low pressure moving into the Great Lakes and then eventually up the St. Lawrence Valley. With low pressure passing to our north and west, we’ll be on the warm side, with rain expected, mainly in two waves. The first one will come in today, with rain developing this morning, and continuing into tonight, when it cold be locally heavy. The warm air should move in south of Boston fairly quickly, but it may take until tonight to get into the Merrimack Valley and southern New Hampshire.
We’ll have a bit of a lull tomorrow morning, but a cold front will approach later in the day, with rain coming back ahead of that front. We’ll still be on the mild side, that is until the front comes through. Temperatures will quickly drop behind the front late Tuesday and Tuesday night but the precipitation may linger, so we will likely see rain changing to snow Tuesday night.
On Wednesday, a little disturbance will move across the region, bringing us some additional light snow, mainly in the morning. There’s still a bit of uncertainty with this, but plan on the morning commute being impacted. We’re probably only looking at a few inches, but all it really takes to screw up the morning commute is a few flakes at all. High pressure builds in late in the day and into Thursday with drier and much colder weather.
By Friday, temperatures start to moderate again as the high slides offshore. It’ll still be chilly (it is December after all), but not quite as cold as Thursday. The weekend looks even milder once again, but that’s because we’ll have another storm system passing to our north and west, so we’re looking at another round of rain, possibly heavy once again.
Monday: Cloudy and becoming breezy with periods of rain and showers. High 49-56.
Monday night: Cloudy and breezy with rain likely, possibly heavy at times, tapering off late at night. Temperatures hold steady or possibly rise a few degrees.
Tuesday: Cloudy and breezy with showers redeveloping late in the day. High 53-60, but temperatures start to quickly drop from northwest to southeast during the afternoon.
Tuesday night: Cloudy with rain changing to snow during the evening. Low 26-33.
Wednesday: Cloudy with light snow ending around midday. Skies clear out at night. Temperatures hold steady or drop a few degrees during the day.
Thursday: Plenty of sunshine, but cold. High 24-31.
Friday: Becoming mostly cloudy. High 32-39.
Saturday: Cloudy, breezy, and milder with rain likely. High 46-53.
Sunday: Partly to mostly cloudy and breezy, chance for a few showers. High 42-49.
Are you ready? Ready for Winter? It’s coming, and quickly. Better enjoy today, because after that, it’s going to get cold.
We start the week off with high pressure in control, but we’ll have plenty of clouds as a cold front begins to approach the region. That front will move through on Tuesday, with some rain likely ahead of it. Low pressure will develop along this front and move right across the region on Tuesday. Ahead of the low and the front, it will be somewhat mild, but once the front moves through in the afternoon, that’s when things start to happen.
Colder air comes surging in behind the front, and temperatures will quickly drop Tuesday afternoon. Rain will likely change over to sleet and snow from northwest to southeast. Now we’re not talking about a lot of snow, probably an inch or less in most spots, and mainly on grassy surfaces, but snow will be the least of the concerns. Gusty winds will help to dry out the roads, and ground temperatures remain fairly mild, but with temperatures dropping into the 20s by late Tuesday, we could see some ice developing, especially on elevated surfaces like bridges and overpasses. So, if you’re going to be out and about Tuesday evening or night, use caution.
We’ve covered the snow potential, and the potential for slick roads, but here’s the biggest issue we’ll be dealing with – it’s going to be cold. When we say “cold”, we mean “COLD”. As in, record low temperatures Wednesday morning across most of the region. As in wind chills (another phrase most of you don’t like) in the single numbers (Fahrenheit, not Celsius). Yeah, it’s going to feel like January Tuesday night into Wednesday. Oh yeah, we forgot to mention that Wednesday may see highs in the 20s to lower 30s.
Winds will diminish for Thursday, but it will remain chilly. Temperatures should start to moderate a little on Friday as high pressure slides offshore. Of course, another cold front comes through Friday night and then we get cold again next weekend, but probably not quite as cold as Tuesday night and Wednesday. Temperatures will still be well below normal.
Monday: Mostly cloudy with a few showers possible, mainly north of the Mass Pike. High 41-48 north and west of Boston, 49-56 south of Boston.
Monday night: Cloudy with showers developing late at night. Evening low 34-41 north and west of Boston, 42-49 south of Boston. Temperatures may rise after midnight
Tuesday: Cloudy and breezy with showers likely, changing to sleet and snow during the afternoon. Morning high 42-49 north and west of Boston, 50-57 south of Boston, then temperatures quickly drop in the afternoon.
Tuesday night: Any lingering snow showers end in the evening, then clearing, breezy, and colder. Low 13-20.
Wednesday: Sunny, breezy, and cold. High 25-32.
Thursday: Intervals of clouds and sun, a few flurries are possible at night. High 34-41.
Friday: Sunshine to start, then clouds move in during the afternoon. High 43-50.
Saturday: Sunshine and some afternoon clouds. High 31-38.
Two developing storm systems – one off the East Coast and one in Plains, will both wreak havoc in the next few days, but for very different reasons.
Two low pressure areas are developing off the East Coast early this morning. The northern system is the stronger of the two, but the southern one is being monitored by the National Hurricane Center. It has the potential to develop into a tropical depression or subtropical storm later today. Whether it does or not, these two low pressure areas will eventually merge and become a rather strong non-tropical system over the next 24 hours. There is very little in the way of steering currents right now, so the system will just meander around off the coast until Saturday.
As the system drifts northward, it will produce gusty winds along the coast, especially in New England. Tides are astronomically low at the moment, but will be rising later this week, so coastal flooding, while not a major concern, will still be possible in some locations. A coastal flood watch has been issued for parts of Plymouth County, Cape Cod, and Martha’s Vineyard. Rough seas will also be a large concern for marine interests, with Storm Warnings now in effect offshore. However, the biggest concern and also the biggest question mark right now is heavy rainfall.
While the storm will likely spread some heavy rainfall into New England, there is still plenty of uncertainty as to how far north the heavy rain gets, as well as how much rain actually falls. Some of the models are producing extremely heavy rainfall, with totals in excess of 10″ in southeastern Massachusetts! While we aren’t buying the extreme totals, the fact that most of the models are showing this potential means that some very heavy rain is likely, especially south of Boston, where a Flood Watch has been issued.
Thanks to some dry weather over the past couple of months, we shouldn’t have to worry about any flash flooding, though downpours will result in ponding of water on roadways, and some locations normally prone to flooding in heavy rain will also have problems. However, since we’re expecting a prolonged period of heavy rain, flooding is still a possibility in some locations, other than the ones we just mentioned, especially some of the smaller streams and rivers. Strong winds will also start to take some of the leaves off of trees, which may clog up storm drains, resulting in some flooding as well.
While all this is taking place off the East Coast, some very cold air will settle into the Rockies and Plains states as low pressure starts to develop across the Central Plains. Record lows are likely to be set in numerous locations over the next few mornings across the region. This system will head north-northeastward while strengthening. The system isn’t expected to become that strong, but with a large high pressure area building in behind it, it will produce some strong winds. It will also draw warm and moist air northward from the Gulf of Mexico. As this air runs into the much colder air on the backside of the storm, the first significant snowstorm of the season is expected to develop across the Northern Plains.
Winter Storm Watches and warnings have been posted from parts of Idaho Montana, and Wyoming into parts of northern Nebraska and the Dakotas as well as northwestern Minnesota. across Idaho, Montana, and Wyoming, snowfall totals of 6-12 inches are possible, with some heavier amounts in the higher elevations. The biggest issues are expected across the Dakotas and northwestern Minnesota.
The precipitation will start as rain across this area later today, but strong northerly winds will usher much colder weather in, changing the rain to snow from west to east on Thursday. Like its East Coast counterpart, this storm won’t move at a rapid pace, so snow, possibly heavy at times will continue across this area into early Saturday, with snow showers lingering into Sunday.
This storm also has some questions with it’s precipitation shield. While heavy snow is likely across a large area, how much falls and where the heaviest snow will fall is still a question. Right now, it looks like the heaviest snow will fall from central South Dakota into central and eastern North Dakota, but that still could change. As for amounts, many areas could see more than a foot, with totals in excess of 2 feet possible in some areas. The snow will be accompanied by winds gusting to 40-50 mph, resulting in blizzard conditions, especially late Thursday into Friday.
While snow in October is not unusual across this region, snowfall amounts of this magnitude this early in the year are extraordinarily rare. In Grand Forks, ND, the largest October snowstorm on record occurred October 24-26, 2001, and it dropped 10.9″ on the city. In Fargo, ND, the largest October snowstorm on record is only 8.1″ on October 30-31, 1951. For Pierre, SD, the October snowstorm of record occurred October 30-31, 1943, and it only produce 7.2″ of snow. Current model forecasts are forecasting amounts that are 3-4 times the records. These model forecasts are likely too high, but it seems likely that many of these October records are going to be obliterated in the next few days. Hopefully, this is not a sign of what’s to come this winter.
We warned you in our Weekly Outlook that it was coming, and it’s just about here – some brutal heat and humidity is expected for the next few days.
Friday will start out with some lingering clouds and a little fog, but the sun will return and as winds shift into the southwest, so will the heat and humidity. Many locations will reach 90 on Friday, but not everyone. Dewpoints will get into the lower 70s, sending the heat index well into the 90s across the region. At night, with plenty of humidity around, temperatures likely won’t drop below the middle 70s across the region, making for an uncomfortable sleeping night if you don’t have air conditioning. This sets the stage for Saturday.
Saturday will likely be the hottest day we’ve had around here in several years. Add in the high humidity (dewpoints again in the lower to middle 70s), and well, it’ll be downright brutal outside. Since it will already be warm to start, with plenty of sunshine, temperatures will quickly jump in the morning, with many locations likely reaching 90 by lunchtime, but it won’t stop there. Temperatures will likely get into the upper 90s, with some spots, especially in the Merrimack Valley, possibly topping 100 degrees.
How rare is a 100-degree reading? Since the Merrimack Valley is the likeliest spot, here is some data for Lowell. In the 131 years of temperature records for Lowell, the city has topped 100 degrees just 35 times, or about once every four years. However, it’s actually been 8 years since Lowell hit 100, with a high of 102 on July 22, 2011. Before that, you have to go back to 2002, when it hit 101 on August 14, and 100 on July 3. So that’s just 3 times in the past 17 years. Skewing that average of once every 4 years is the fact that Lowell reached 100 5 times in 1911, 4 times in 1949, and 5 times in 1952. That’s 14 among those 3 years alone. July 22, 2011 was also the last time it reached 100 at Logan Airport in Boston, where they’ve only hit 100 25 times in 147 years of records.
With temperatures in the upper 90s (or higher), and dewpoints in the lower to middle 70s, that means that the heat index will be in the range of 105 to 110 degrees or higher during the hottest part of the day. If you have any plans to be outside, whether it be by the pool, at the beach, at the NASCAR activities in Loudon, or anywhere else, make sure you try to stay hydrated, and take plenty of breaks in the shade if you can.
Saturday night will be another uncomfortable night, with low temperatures only dropping into the middle to upper 70s. Some of the urban locations, like Boston, may not drop below 80. This leads in to another brutally hot and humid day on Sunday. Once again, most places will likely reach 90 by lunchtime and keep going. High temperatures will again get into the upper 90s across the area, with some 100-degree readings possible. Dewpoints will remain in the upper 60s to lower 70s, so we’re looking at heat indices in the 105 to 110 degree range once again.
By late Sunday, a cold front will start to approach, and it may produce some showers and thunderstorms during the evening and overnight. Behind it, much more seasonable air and lower humidity settles in for Monday. There may be a little relief in spots before that as well. Thunderstorm complexes in the Midwest will ride along the top of the upper-level ridge, as it typical in the summer. Right now, it looks like this may happen both late Friday and late Saturday. Unfortunately, it looks like these may fizzle before reaching the Northeast, and if they don’t, they will likely pass southwest of our area. So, we’re not holding out hope for these to help cool us off.
Long range forecasts show that some heat may return late next week into next weekend, but not nearly to the extent of what we’ll be dealing with for the next few days.