C-19 Chat Post – May 21 2020

7:34AM

DAYS 1-5 (MAY 20-24)

On yesterday’s blog post I gave you a long explanation of how wind direction would have an impact on temperature during this stretch of days when high pressure is in control of the weather. I will not repeat that here because it basically has not changed. The idea is high pressure remains in control of the weather and holds a low pressure area to the south at bay. That low will get a little bit closer by the start of the weekend so that there may be a little more wind and cloudiness than we see before that. But as it stands right now, the next 5 days will be generally dry.

TODAY: Mostly sunny. Highs 56-61 coast, 62-67 inland. Wind E 5-15 MPH.

TONIGHT: Mostly clear. Lows 42-49. Wind variable up to 10 MPH.

THURSDAY: Mostly sunny. Highs 65-72 except cooler south-facing coastal areas. Wind S 5-15 MPH.

THURSDAY NIGHT: Mostly clear. Lows 50-57. Wind SW 5-15 MPH.

FRIDAY: Partly cloudy. Highs 75-82 except cooler Cape Cod & Islands as well as a few other coastal locations. Wind W 5-15 MPH.

FRIDAY NIGHT: Partly cloudy. Lows 50-57. Wind variable up to 10 MPH.

SATURDAY: Partly sunny. Highs 58-65 but may turn cooler coastal areas. Wind NE 5-15 MPH.

SATURDAY NIGHT: Variably cloudy. Lows 45-52. Wind E 10-20 MPH.

SUNDAY: Variably cloudy. Highs 58-65. Wind E 5-15 MPH.

DAYS 6-10 (MAY 25-29)

Memorial Day May 25 looks dry. after this a weakening frontal system should get into the area with an increase in humidity and shower chances. Too soon for details.

DAYS 11-15 (MAY 30-JUNE 2)

No change from the thought process of yesterday with little reliability in medium range guidance and just a general feel for the pattern, will continue with the outlook for near to slightly below average for both temperature and precipitation.

C-19 Chat Post – May 20 2020

7:47AM

DAYS 1-5 (MAY 19-23)

Canadian high pressure will be in control the next few days as it sinks southward across the northeastern US. The transition that takes place in this pattern will be mainly with shifts in wind direction. Today, with the center of the high to the north of the area, it’s a cool northeast wind, which may bring in low clouds from the ocean at times. At the same time the decaying storm system to our southwest will still be trying to send some higher level cloudiness in as well, so it won’t be perfectly sunny all day. The wind will be much lighter Wednesday as the high parks itself overhead. This will be a sunnier day and while inland areas warm up, as this warming takes place closer to the coast a natural sea breeze will kick in, cooling those areas back. Thursday, the high center starts to sink a little more to the south and the gradient wind, while light, will be more from the south, allowing further warming. Still, coastal areas where a wind with a southerly component travels over water will be cooler. By Friday, the center of the high will finally be to the south of New England, and a more westerly wind means that most of the region warms up nicely, but still there are exceptions where even a west wind blows over water before reaching the land, but these are quite limited to places such as outer Cape Cod, west-facing shores of Nantucket and Martha’s Vineyard, and a place like Nahant, for example. These will be your coolest areas on Friday. A peek at the beginning of the weekend shows that a new high will be located in eastern Canada and that the high to the south will have weakened and replaced by a weak low pressure area – the remains of the low currently over the east central US. The high to the north may drive a back-door cold front down the from eastern Canada via Maine and cool the entire area down. What about Arthur? Yup. It’s out there, off the US Southeast Coast, and will be moving away and weakening as it tracks east and eventually southeast, possibly bringing some showery weather to Bermuda the next few days. Buh-bye!

TODAY: Partly cloudy. Highs 55-60 coast, 60-65 interior. Wind NE-E 5-15 MPH interior, 10-20 MPH coast, with higher gusts possible.

TONIGHT: Variably cloudy. Lows 35-40 interior, 40-45 coastal areas and Boston. Wind NE 5-15 MPH evening, diminishing overnight.

WEDNESDAY: Mostly sunny. Highs 60-67 except cooling back to the 50s coast. Wind variable up to 10 MPH with coastal sea breezes.

WEDNESDAY NIGHT: Mostly clear. Lows 42-49. Wind variable up to 10 MPH.

THURSDAY: Mostly sunny. Highs 65-72 except cooler south-facing coastal areas. Wind S 5-15 MPH.

THURSDAY NIGHT: Mostly clear. Lows 50-57. Wind SW 5-15 MPH.

FRIDAY: Partly cloudy. Highs 75-82 except cooler Cape Cod & Islands as well as a few other coastal locations. Wind W 5-15 MPH.

FRIDAY NIGHT: Partly cloudy. Lows 50-57. Wind variable up to 10 MPH.

SATURDAY: Partly sunny. Highs 58-65 but may turn cooler coastal areas. Wind NE 5-15 MPH.

DAYS 6-10 (MAY 24-28)

Not a very high confidence forecast on the middle and end of the Memorial Day Weekend Sunday (May 24), which may be cloudy as low pressure to the south, while not strong, tries to press northward while high pressure to the north holds it off. Does rain make it into part of the area? Probably not, but I say that with hesitation because its spring in New England, and model performance, which normally suffers as you go out in time, suffers even more as we continue to lack some data input with fewer planes still in the sky during the pandemic. My current thought-out scenario would allow the high to eventually win out, slide southeastward, and warm the area up somewhat for Memorial Day (May 25). After this, a weakening frontal system from the northwest and a little more south to southwesterly air flow ahead of it would increase the shower chances heading through the middle of next week. I am certain this forecast will need a lot of fine-tuning.

DAYS 11-15 (MAY 29-JUNE 2)

As little confidence as I have for the 6-10 day period, I have even less for this one, so I will say that taking a look at the overall pattern leads me to believe both temperatures and precipitation will be near to slightly below average.

C-19 Chat Post – May 19 2020

7:53AM

DAYS 1-5 (MAY 17-21)

High pressure from Canada is going to be the dominant player the next several days, despite a warm front attempting to get into the region today (producing a few spotty showers early), its parent low to the southwest and tropical storm Arthur off the US Southeast Coast both being held at bay. The coolest part of the week will be the first few days, and then you’ll notice a warm-up underway. Can’t rule out a shower threat by later Friday as the high pressure area from Canada will have slipped to the southeast by then and grabbed some moisture from south of the region, drawing it northward.

TODAY: Mostly cloudy. Spotty light rain until midday. Highs 58-65. Wind E 5-15 MPH, higher gusts mainly coastal areas.

TONIGHT: Mostly cloudy. Lows 48-55. Wind E 10-20 MPH, higher gusts mainly coastal areas.

TUESDAY: Partly sunny. Highs 55-62, coolest coast. Wind E 10-20 MPH, higher gusts coastal areas.

TUESDAY NIGHT: Mostly clear. Lows 38-45. Wind E 5-15 MPH.

WEDNESDAY: Mostly sunny. Highs 58-65, coolest coast. Wind E 5-15 mph.

WEDNESDAY NIGHT: Partly cloudy. Lows 50-57. Wind SE up to 10 MPH.

THURSDAY: Partly cloudy. Highs 58-65 coast, 65-72 interior. Wind SE up to 10 MPH.

THURSDAY NIGHT: Partly cloudy. Lows 52-59. Wind S up to 10 MPH.

FRIDAY: Partly cloudy. Risk of showers late day or night. Highs 73-80, cooler South Coast. Wind S 5-15 MPH.

DAYS 6-10 (MAY 23-27)

A little more optimistic for better weather overall during the May 23-25 Memorial Day Weekend with any unsettled weather holding off until after that, but will monitor for “surprises”

DAYS 11-15 (MAY 28-JUNE 1)

A quiet battle between high pressure in eastern Canada and high pressure in the southeastern US puts New England in the middle with an uncertain forecast, probably held back from very warm weather and facing a few unsettled days. Continued low confidence forecast.

C-19 Chat Post – May 18 2020

8:39AM

DAYS 1-5 (MAY 17-21)

High pressure is going to win. In terms of southeastern New England’s weather, it doesn’t matter so much whether or not the storm to the south gets a name, whether it’s actually tropical, a hybrid, or whatever. That thing is going to be offshore anyway, no major impact to the East Coast except becoming a player in some wave action over the next few days. As far as the weather in the WHW forecast area is concerned, it’s all about high pressure from Canada. What once looked like a cloudy and often wet stretch beginning some time today and lasting 4 or 5 days or even longer doesn’t quite look so imposing now. Yes, we’ll have some cloudiness around today as warmer air arrives in the atmosphere above us, and we may get a spot or 2 of light rain at some point during the first half of Monday, but high pressure will be strengthening in eastern Canada and sinking down across the northeastern US in a slow but steady fashion during the next 5 days, so beyond the initial cloudiness and brief rain threat, we’re talking about fair weather, although it will be on the cooler side especially through Wednesday, because of a dominant easterly wind, and this may also result in some lower ocean cloudiness coming in at times.

TODAY: Mostly cloudy to partly sunny. Highs 55-62 coast, 62-69 interior. Wind SE-S up to 10 MPH.

TONIGHT: Partly to mostly cloudy. Lows 48-55. Wind S-SE up to 10 MPH.

MONDAY: Mostly cloudy. Spotty light rain until midday. Highs 55-62. Wind E 5-15 MPH, higher gusts mainly coastal areas.

MONDAY NIGHT: Mostly cloudy. Lows 48-55. Wind E 10-20 MPH, higher gusts mainly coastal areas.

TUESDAY: Mostly cloudy. Highs 53-60, coolest coast. Wind E 10-20 MPH, higher gusts coastal areas.

TUESDAY NIGHT: Mostly cloudy. Lows 45-52. Wind E 5-15 MPH.

WEDNESDAY: Partly sunny. Highs 57-63, coolest coast. Wind E 5-15 mph.

WEDNESDAY NIGHT: Partly cloudy. Lows 50-57. Wind SE up to 10 MPH.

THURSDAY: Partly cloudy. Highs 58-65, coolest coast. Wind SE up to 10 MPH.

DAYS 6-10 (MAY 22-26)

High pressure east of New England brings more humid conditions and a risk of rain showers later May 22 and May 23 then a new high to the north and a frontal boundary in the region bring cooler and potentially unsettled weather May 24-25 before conditions improve at the end of the period.

DAYS 11-15 (MAY 27-31)

A quiet battle between high pressure in eastern Canada and high pressure in the southeastern US puts New England in the middle with an uncertain forecast, probably held back from very warm weather and facing a few unsettled days. Low confidence forecast.

C-19 Chat Post – May 17 2020

10:02AM

DAYS 1-5 (MAY 16-20)

New air mass today, still mild, but drier than yesterday, and the threat of storms is now gone. Don’t expect full sun though, as there is some cold air aloft and quite a few stratocumulus clouds will be about at times. Also, a few lingering high clouds along the South Coast associated with last night’s system will be moving out. Tomorrow we’ll see an increase in high cloudiness ahead of our next low pressure system, but it will be a nice day. As far as the next round of unsettled weather goes – this outlook on this has undergone quite the evolution over the last several days, although this is nothing new to forecasting weather. Even now, we have 3 models depicting 3 different scenarios for the weather in the next few days. Basically today I am keeping my ideas from yesterday’s update mostly intact, but I warn you this may change before tomorrow’s update is posted. I just don’t want to do all kinds of forecast flip flopping because of uncertainty, so I’m giving more weight to experience with similar set-ups, and we’ll see how that works. Basically I think the semi or pseudo or whatever you want to call it tropical system to the south that isn’t really tropical will become the dominant low pressure area and start to draw energy from the one approaching from the west. A boundary will still be in place across our area, so expect at least a lot of cloudiness and a risk for some rainfall on Monday, but a lot of that potential (and rainfall) may dry up, and we’ll have to wait for the low to the south to push its rainfall northward, but how much will it be able to do that while up against a fairly large high pressure area in eastern Canada, which is now forecast by one of the more reliable models to push even further south? I’ll go with the wet scenario through Tuesday, then a dry out by Wednesday.

TODAY: Sun/cloud mix. Highs 56-63 coast, 64-71 interior. Wind NW 10-20 MPH this morning, diminishing this afternoon when locally onshore winds may develop at the coast.

TONIGHT: Mostly clear. Patchy valley fog. Lows 43-50. Wind S under 10 MPH.

SUNDAY: Increasing clouds. Highs 55-60 coast, 60-65 interior. Wind SE up to 10 MPH.

SUNDAY NIGHT: Cloudy. Chance of rain. Lows 45-52. Wind E 5-15 MPH, higher gusts coastal areas.

MONDAY: Cloudy. Chance of rain. Highs 52-59, coolest coast. Wind E 10-20 MPH.

MONDAY NIGHT: Overcast. Periods of drizzle. Chance of rain evening. Areas of fog. Temperatures steady 45-52. Wind E_NE 10-20 MPH, higher gusts coastal areas.

TUESDAY: Cloudy. Periods of drizzle, especially coastal areas. Highs 50-57. Wind E 5-15 MPH, higher gusts coastal areas.

TUESDAY NIGHT: Breaking clouds. Lows 43-50. Wind N 5-15 MPH.

WEDNESDAY: Partly sunny. Highs 58-65, coolest coast. Wind N 5-15 MPH.

DAYS 6-10 (MAY 21-25)

High pressure brings dry weather May 21, then moves east of New England and a humid southerly flow brings a chance of showers May 22, and expecting unsettled weather to linger into if not through Memorial Day Weekend, but a complex cast of characters make the detailing of this impossible this far in advance.

DAYS 11-15 (MAY 26-30)

Additional high pressure in eastern Canada and building high pressure over the US Southeast may keep a boundary somewhat nearby, making for a tricky temperature and weather forecast heading down the home stretch of May. Leaning toward a few unsettled days and cool winning out over warm, but with contiued low confidence.

C-19 Chat Post – May 16 2020

7:28AM

DAYS 1-5 (MAY 15-19)

This 5 day segment contains a few more adjustments as I fine-tune the evolving situation. First and foremost, today’s thunderstorm threat remains, but it looks like some of the potential may not be realized – not a bad thing. We’ve already gotten the area of rain ahead of the warm front through, and as the front makes its way through the area I still expect it to have difficulty pushing much beyond the Merrimack Valley of Massachusetts, possibly leaving northeastern Massachusetts and much of southern NH, especially the Seacoast, on the cooler side of the boundary. With a little more sun expected, the temperature potential is a little bit higher away from the ocean’s influence and in the warmer air mass, so the contrast in high temperatures across the region today, given my idea of the front’s position is correct, will be quite large. As for the thunderstorms, the way I see it unfolding is just isolated to widely scattered showers / storms forming after 2 p.m. from west to east across the area for the first round. Any of these storms could become severe with hail and damaging wind, and there is even a risk that an isolated severe storm could be a rotating super cell storm in which case there would be a tornado potential. This is the extreme case, and won’t be widespread, but just something to be aware of if / when storms fire up this afternoon. The greatest practice you can have while monitoring weather: no panic, follow trusted sources, react accordingly. After whatever happens from the first round of threat goes by, we will have to wait for at least one, and up to a few segmented lines of showers / storms, but this may not take place until after 6 p.m. from northwest to southeast across the area, finally winding down around midnight or shortly thereafter for South Coast locations. While there is still the possibility of strong to locally severe storms with these, that type of activity may be rather limited as the activity occurring later, while having some dynamic support, will lack daytime heating to feed on. Obviously, this will be monitored closely. On to the weekend… looks like a nice one as a weak area of high pressure dominates Saturday then starts to move away Sunday as clouds increase ahead of a low pressure system approaching from the west. Expecting wet weather to hold off until Sunday evening, at the earliest, and perhaps all the way to Monday morning. Some of this will depend on the evolution of low pressure to the south of New England. As mentioned yesterday, this evolving system will have an impact on our weather here, as such systems tend to during the springtime. The hype has been the possibility of this thing having subtropical characteristics and getting a name, and that’s honestly the least of the concerns, unless anybody wants to get an early jump on trying to verify a seasonal forecast. Truth is, the storm will probably never really deserve a name, by definition, but the point is, the low pressure area will impact the weather as it moves northward and adds moisture to Monday’s wet weather system, and keeping it slowed down to hang around through the day, along with a gusty wind and cool/raw air blowing in off the chilly Atlantic. So a miserable Monday seems in the offing. There have been some differences in the various guidance as to how quickly to move this system out of here. It does look like high pressure drifting down from eastern Canada will be strong enough to push this system back to the south starting Tuesday, but we will still likely be under its cloud canopy and have at least ocean-enhanced drizzle, even if the rain area has already retreated. This is the scenario I’m going with now. Suffice it to say, the early part of next week doesn’t look very good, weather wise.

TODAY: Mostly cloudy to partly sunny. Isolated to scattered showers and thunderstorms from mid afternoon on, some possibly strong to severe, favoring interior southern MA, northern RI, and northeastern CT. Highs 57-64 South Coast, NH Seacoast, northeastern MA, 65-72 interior southeastern NH, Merrimack Valley, southwestern to south central NH, and far eastern MA, 73-80 interior southern MA, northern RI, and northeastern CT. Wind SE 5-15 MPH coastal NH and northeastern MA, SW 10-20 MPH with higher gusts elsewhere.

TONIGHT: Mostly cloudy evening with showers and possible thunderstorms, diminishing from northwest to southeast late evening. Partly cloudy overnight. Lows 48-55. Wind shifting to NW 10-20 MPH, diminishing overnight.

SATURDAY: Mostly sunny. Highs 56-63 coast, 64-71 interior. Wind SE 5-15 MPH.

SATURDAY NIGHT: Mostly clear. Patchy valley fog. Lows 43-50. Wind S under 10 MPH.

SUNDAY: Increasing clouds. Highs 55-60 coast, 60-65 interior. Wind SE up to 10 MPH.

SUNDAY NIGHT: Cloudy. Chance of rain. Lows 45-52. Wind E 5-15 MPH, higher gusts coastal areas.

MONDAY: Overcast. Periods of rain/drizzle. Areas of fog. Temperatures steady 45-52. Wind E-NE 10-20 MPH, higher gusts coastal areas.

MONDAY NIGHT: Overcast. Periods of drizzle. Chance of rain evening. Areas of fog. Temperatures steady 45-52. Wind E_NE 10-20 MPH, higher gusts coastal areas.

TUESDAY: Cloudy. Periods of drizzle, especially coastal areas. Highs 50-57. Wind E 5-15 MPH, higher gusts coastal areas.

DAYS 6-10 (MAY 20-24)

High pressure pressing southward from eastern Canada should push low pressure far enough south for clearing and dry weather May 20-21, but as this high then moves to a position east of New England, some of the lingering moisture from the old system to the south and southwest may come back as scattered showers with more humid conditions May 22-24. Temperatures not too far from normal during this 5-day period.

DAYS 11-15 (MAY 25-29)

Additional high pressure in eastern Canada and building high pressure over the US Southeast may keep a boundary somewhat nearby, making for a tricky temperature and weather forecast heading down the home stretch of May. Leaning toward a few unsettled days and cool winning out over warm, but with low confidence.

C-19 Chat Post – May 15 2020

7:32AM

DAYS 1-5 (MAY 14-18)

And just like that, the outlook is not quite the same. It almost caught me, and somewhat did, but there were suspicions yesterday, and as they day went on and today arrived they became larger, and the classic “spring thing” will be taking place. How big of an impact it has here is still somewhat unknown. What is the “classic spring thing”? If you ask most meteorologists who have more than 1 seasons of forecasting experience in spring in New England, they will think of either the ocean’s influence on temperature (locally), or the atmosphere’s tendency to do things that are not quite west-to-east (regionally). Both will be the case before the end of this 5 day period, and we’ll continue the story in the 6-10 day period below. But before we get there, let’s rewind to today, a nice day overall, definitely less windy and much milder than the last 2 days have been, but you’ll start to see an increase in high and mid level cloudiness as the day goes on, and this is the atmosphere’s response to increasing warmth and humidity aloft. That is a warm front approaching, and the front will get into the area, but may not completely get through it. I’m still concerned that the front may never fully make it beyond northeastern MA and southeastern NH Friday, while a good portion of the region gets into the warm sector between that warm front and an approaching cold front. So that sets up a tricky forecast for Friday, yup, the day-2 forecast, for both temperature and weather, when areas to the northeast, say Hampton Beach NH for example, could be stuck in the 50s while the suburbs southwest of Boston are pushing into the 70s. In addition, after we get through some warm frontal rainfall initially from tonight into the early hours of Friday, we’ll then have to watch for the development of showers and thunderstorms as the cold front approaches. Areas that get into the warm air stand the greatest chance of seeing the strongest storms, with a few possibly becoming severe. The greatest chance of this in the WHW forecast area would be northeastern CT, northwestern RI, and adjacent south central MA. Closer to the South Coast, a wind off the water would limit this chance, and the lack of deeper warm air would do the same in areas to the north and east of the higher risk area. So this will be something to watch – updated again on tomorrow morning’s blog post and of course when any new ideas can be shared in the comments section. Beyond that, it looks like before the “typical spring thing” happens, we’ll have a fairly decent weekend: fair weather Saturday, coolest on the coast, then increasing clouds Sunday ahead of the next low pressure system, but rainfall may hold off at least until Sunday evening, and possibly until Monday. What takes place on Monday is likely to be different than what I had been touting in previous blog posts. I’d been optimistic that what we would have been dealing with is one low pressure system coming along in the jet stream, giving us its wet weather late Sunday to early Monday, then moving along. But it’s not that simple. An area of showers and thunderstorms coming out of the Bahamas is going to enter an area off the US Southeast Coast that is favorable for early tropical development, not really purely tropical, but a hybrid type system, or potential subtropical storm, and just enough of a dip in the jet stream carrying our system in from the west will draw this system northward. When this happens, the upper level steering currents can see a low pressure area that becomes separated from the jet stream, so it doesn’t just move along and depart. It hangs around, maybe moving westward for a while or doing a loop. This process will be just getting underway Monday, which now looks wet, breezy, and chilly.

TODAY: Partly sunny. Highs 63-70 except 55-62 South Coast. Wind SW 5-15 MPH.

TONIGHT: Cloudy. A period of rain likely. Lows 48-55. Wind SE 5-15 MPH.

FRIDAY: Mostly cloudy to partly sunny. Showers and thunderstorms likely from mid afternoon on, some possibly strong, favoring interior southern MA, northern RI, and northeastern CT. Highs 55-62 South Coast, NH Seacoast, northeastern MA, 62-69 interior southeastern NH, Merrimack Valley, and remainder of southern NH and far eastern MA, 70-77 interior southern MA, northern RI, and northeastern CT. Wind SE 5-15 MPH coastal NH and northeastern MA, SW 10-20 MPH with higher gusts elsewhere.

FRIDAY NIGHT: Mostly cloudy evening with showers and possible thunderstorms, especially RI and southeastern MA. Gradual clearing overnight. Lows 48-55. Wind shifting to NW 10-20 MPH, diminishing overnight.

SATURDAY: Mostly sunny. Highs 56-63 coast, 64-71 interior. Wind SE 5-15 MPH

SATURDAY NIGHT: Mostly clear. Patchy valley fog. Lows 43-50. Wind S under 10 MPH.

SUNDAY: Increasing clouds. Highs 55-60 coast, 60-65 interior. Wind SE up to 10 MPH.

SUNDAY NIGHT: Cloudy. Chance of rain. Lows 45-52. Wind E 5-15 MPH, higher gusts coastal areas.

MONDAY: Overcast. Periods of rain/drizzle. Areas of fog. Temperatures steady 45-52. Wind E-NE 10-20 MPH, higher gusts coastal areas.

DAYS 6-10 (MAY 19-23)

This 5-day period’s weather largely depends on the movement and behavior of a broad area of low pressure just to the south of the region. Current idea is for cool/wet/breezy conditions to start, then lots of clouds and occasional drizzle/showers hanging on for a couple more days before low pressure is then replaced by a southerly air flow, warmer temperatures and higher humidity with additional showers as one of the remaining lows approaches as a trough from the west later in the period, with finally some clearing possible by the very end of the period. This complex evolution idea will probably change so monitor future updates.

DAYS 11-15 (MAY 24-28)

Watching for high pressure in eastern Canada which may put a boundary between cool Canadian air and much warmer air to the south nearby. Tricky forecast in here, but leaning toward more unsettled days than fair ones.

C-19 Chat Post – May 14 2020