Wednesday September 30 2020 Forecast (7:11AM)

DAYS 1-5 (SEPTEMBER 30 – OCTOBER 4)

Discussion…

A cold front is moving across the region this morning. Ahead of it are numerous showers, some of them heavy, and rather gusty southerly winds. The wind is a bigger story than the rain for many, as some scattered power outages have been occurring. But this is a short-lived event, and while the wind is certainly impressive, the rainfall amounts will be rather modest, and not putting much of a scratch in the still-worsening drought, especially since, despite 2 more rain chances that I can see in the days ahead, the long-term pattern remains dry. What about the next rain chance? Hold on, don’t you want to know about the clearing this afternoon and the nice day tomorrow? There, now you know. Another wave of low pressure brings a rain chance on Friday, but it doesn’t look overly impressive to me. Nevertheless, I think most areas will get wet for a while before high pressure moves in for a dry and seasonable first weekend of October.

Details…

TODAY: Cloudy start with numerous showers, some heavy, and a slight risk of thunder, then breaking clouds but still a chance of passing showers into late morning, followed by mostly sunny with just passing clouds midday and afternoon. Highs 70-77. Dew point starting in 60s then falling to 50s. Wind S 15-25 MPH, but with gusts 35-50 MPH and even higher than that in some open coastal areas and higher elevations early, shifting to W and diminishing slightly to 10-20 MPH with gusts 25-40 MPH by late morning then gradually decreasing further during the afternoon.

TONIGHT: Clear. Lows 53-60. Wind W 5-15 MPH.

THURSDAY: Mostly sunny. Highs 70-77. Wind W 5-15 MPH.

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

FRIDAY: Mostly cloudy. Chance of rain or showers, favoring the afternoon. Highs 62-69. Wind variable 5-15 MPH.

FRIDAY NIGHT: Mostly cloudy with a chance of rain evening. Clearing but patchy fog overnight. Lows 53-60. Wind variable up to 10 MPH.

SATURDAY: Sun and passing clouds. Highs 59-66. Wind NW 5-15 MPH.

SATURDAY NIGHT: Mostly clear. Lows 40-47. Wind NW 5-15 MPH.

SUNDAY: Mostly sunny. Highs 58-65. Wind W 5-15 MPH.

DAYS 6-10 (OCTOBER 5-9)

A wave of low pressure brings a risk of some rain October 5 and a cold front may bring a shower risk about October 7, otherwise it’s mostly dry weather with a more zonal flow pattern. Temperatures variable, with the sharpest contrast possibly coming in the form of a warm spike October 7 then chill-down at the end of the period.

DAYS 11-15 (OCTOBER 10-14)

Minor shower risk early in the period otherwise mostly dry weather with a west-to-east (zonal) flow overall. Temperatures near to above normal.

Tuesday September 29 2020 Forecast (7:48AM)

DAYS 1-5 (SEPTEMBER 29 – OCTOBER 3)

Discussion…

Things are on track, forecast-wise, it seems. We’re in the middle of a 3-day unsettled and humid stretch, and while we did not see a whole lot of shower activity yesterday, and won’t again today, I cannot rule out passing showers at times in a few areas later today. But our main window of opportunities for the most widespread and significant showers will be from about midnight tonight to noon Wednesday, as a wave of low pressure pulls a cold front eastward trough the region. From tonight through Wednesday morning we’ll also have a period of moderate to strong wind gusts which could result in local tree damage with some isolated power outages. While we remain on the eastern side of an upper level trough through the end of this week we will remain vulnerable to additional unsettled weather, and my target date of October 2 for the next round of unsettled weather remains a go, with a chance of some rainfall on Friday, mainly during the afternoon based on current timing. This should be long gone so that the start of the weekend will feature dry weather. The first 3 days of October (Thursday-Saturday) will also feature a cooling trend as the mild and muggy air we have now will be replaced with a Canadian airmass arriving indirectly via the Great Lakes and Midwest.

Details…

TODAY: Low clouds break for sun into midday then more clouds at times during the afternoon with a risk of a passing shower, but mainly rain-free. Highs 73-80. Dew point above 60. Wind increasing to S 10-20 MPH.

TONIGHT: Mostly cloudy. Areas of fog evening. Isolated showers evening. Numerous showers overnight, including a slight risk of thunderstorms. Lows 61-68. Dew point 60+. Wind S 10-20 MPH, gusts 25-40 MPH.

WEDNESDAY: Cloudy with widespread showers and a slight chance of thunderstorms morning, maybe lingering to early afternoon eastern coastal areas. Clearing follows and the day ends sunny. Highs 70-77. Dew point starts above 60 but falls to the 50s by day’s end. Wind S 15-25 MPH with gusts 30-45 MPH morning. SW 10-20 MPH with a few higher gusts afternoon.

WEDNESDAY NIGHT: Clear. Lows 56-63. Wind SW to W 5-15 MPH.

THURSDAY: Partly sunny. Highs 67-74. Wind W 5-15 MPH.

THURSDAY NIGHT: Variably cloudy. Lows 50-57. Wind variable up to 10 MPH.

FRIDAY: Mostly cloudy. Chance of rain or showers, favoring the afternoon. Highs 62-69. Wind variable 5-15 MPH.

FRIDAY NIGHT: Mostly cloudy with a chance of rain evening. Clearing but patchy fog overnight. Lows 53-60. Wind variable up to 10 MPH.

SATURDAY: Sun and passing clouds. Highs 59-66. Wind NW 5-15 MPH.

DAYS 6-10 (OCTOBER 4-8)

A wave of low pressure may bring some additional unsettled weather with a rain or shower chance later October 4 to early October 5. A cold front from passing low pressure to the north brings a shower risk October 7. Temperatures variable, but a sharper cool shot is possible by October 8.

DAYS 11-15 (OCTOBER 9-13)

A shot of cooler air to start this period followed by a warming trend again. Generally dry weather with just minor shower risk around October 10-11.

Monday September 28 2020 Forecast (7:43AM)

DAYS 1-5 (SEPTEMBER 28 – OCTOBER 2)

Discussion…

High humidity and above normal temperatures through Wednesday. However, the 2 days that feel most like late summer instead of early fall will be today and Tuesday, as there will be a threat of showers but much of the time will be rain free and there will also be intervals of sunshine with all the cloudiness we have. It’s Tuesday night into Wednesday when a more solid shower threat occurs with the approach and passage of a cold front. The clouds, showers, and frontal passage will keep temperatures down a little on Wednesday over what they will be during the next two days. Many model forecasts have been bringing an additional wave of low pressure with significant rain up through the region Wednesday night into early Thursday, but I am somewhat skeptical of this. I think a wave of low pressure will occur, but as we go along I’m thinking this may be less potent and further offshore, and the details forecast will reflect that. Models have a lot of trouble sorting out disturbances and timing during transitions, and I think we will see a disturbance move through the region Friday with a chance of additional showers, although with cooler air instead of the warm and muggy weather we have for the start of this week.

Details…

TODAY: Variably cloudy. Chance of a few passing showers. Highs 72-79. Dew point 60s. Wind S 10-20 MPH.

TONIGHT: Mostly cloudy. Areas of fog. Chance of showers. Lows 60-67. Dew point in 60s. Wind S 5-15 MPH.

TUESDAY: Variably cloudy. Chance of showers. Highs 73-80. Dew point 60s. Wind S 10-20 MPH.

TUESDAY NIGHT: Cloudy. Showers likely. Areas of fog. Lows 60-67. Dew point 60s. Wind S 5-15 MPH, higher gusts.

WEDNESDAY: Cloudy with showers likely and areas of fog. Highs 70-77. Dew point 60s. Wind SW 5-15 MPH becoming variable.

WEDNESDAY NIGHT: Mostly cloudy with a chance of showers. Areas of fog evening. Lows 60-67. Dew point 60s falling to 50s. Wind variable 5-15 MPH becoming W 10-20 MPH.

THURSDAY: Partly sunny. Highs 65-72. Wind W 10-20 MPH, higher gusts.

THURSDAY NIGHT: Variably cloudy. Lows 50-57. Wind variable 5-15 MPH.

FRIDAY: Mostly cloudy. Chance of rain or showers. Highs 60-67. Wind variable 5-15 MPH.

DAYS 6-10 (OCTOBER 3-7)

Watch for a wave of low pressure that may bring some wet weather to the region at some point October 4-5, otherwise mostly dry weather is expected until the end of the period when an approaching disturbance or front brings the next risk of showers. Temperatures variable, coolest early in the period then milder late period.

DAYS 11-15 (OCTOBER 8-12)

A shot of cooler air to start this period followed by a warming trend again. Generally dry weather with just minor shower risk around mid period.

Sunday September 27 2020 Forecast (8:02AM)

DAYS 1-5 (SEPTEMBER 27 – OCTOBER 1)

Discussion…

No big changes in this outlook, just a series of expected forecast tweaks. Cloudiness will be more dominant today as a humid southerly air flow becomes more established. This still occurs without any rainfall today, but that changes as we get into the first 3 days of the new week which are also the final 3 days of September, and the shower threat appears in the pre-dawn hours of Monday and continues off and on through Wednesday. Tuesday night through Wednesday still appears to be the most likely time period for the most widespread shower activity. Any rainfall we get will be helpful for our drought situation, which still won’t be breaking any time soon. Immediate help will come for quelling our currently high fire danger. A final wave of low pressure that moves through Wednesday evening, based on current timing, should pull a cold front through the region and open the door for a cooler air mass, indirectly from Canada, via the Great Lakes and Midwest, as October arrives on Thursday.

Details…

TODAY: Areas of fog early, otherwise mostly cloudy to partly sunny. Highs 72-79. Dew point 60s. Wind S 5-15 MPH.

TONIGHT: Mostly cloudy. Areas of fog. Chance of showers after midnight. Lows 62-69. Dew point 60s. Wind S 5-15 MPH.

MONDAY: Variably cloudy. Occasional showers. Highs 70-77. Dew point in 60s. Wind S 10-20 MPH.

MONDAY NIGHT: Mostly cloudy. Areas of fog. Chance of showers. Lows 60-67. Dew point in 60s. Wind S 5-15 MPH.

TUESDAY: Variably cloudy. Chance of showers. Highs 70-77. Dew point in 60s. Wind S 10-20 MPH.

TUESDAY NIGHT: Cloudy. Showers likely. Areas of fog. Lows 60-67. Dew point lower 60s. Wind S 5-15 MPH, higher gusts.

WEDNESDAY: Cloudy with showers likely and areas of fog. Highs 70-77. Dew point 60s. Wind SW 5-15 MPH becoming variable.

WEDNESDAY NIGHT: Mostly cloudy with showers likely. Chance of a thunderstorm. Areas of fog. Lows 60-67. Dew point 60s falling to 50s. Wind SW 5-15 MPH with higher gusts shifting to W.

THURSDAY: Partly sunny. Chance of a shower. Highs 65-72. Wind W 10-20 MPH, higher gusts.

DAYS 6-10 (OCTOBER 2-6)

With a trough axis still to the west of our region, we can expect a couple opportunities for unsettled weather. Continuing to lean toward October 2 & 4 as the most likely wetter days. Temperatures variable, trending cooler. For those unfamiliar, a trough of low pressure is basically a dip in the jet stream and where your unsettled weather usually occurs and the axis of it is basically its mid point. The unsettled weather will often be more likely to the east of the axis. So the set-up described above leaves us vulnerable to additional wet weather, which would be welcomed if it occurs.

DAYS 11-15 (OCTOBER 7-11)

Generally zonal (west to east) flow is expected with overall drier weather, but a couple minor unsettled weather threats. Cooler air probably dominates the first part of the period followed by a warming trend.

Saturday September 26 2020 Forecast (8:01AM)

DAYS 1-5 (SEPTEMBER 26-30)

Discussion…

We’ll have a warmer than normal but more humid weekend, however it will remain rain-free. It won’t, however, remain fog-free for a large portion of the region, especially this morning and again later tonight into Sunday morning. This is one of the results of an increase in humidity. With a mostly clear sky above, the warmth from the day radiates out to space and as the air temperature drops to match the dew point temperature, fog forms, and can be rather dense as it is in some places to start the day today. But the same clear sky that played a role in helping the fog form will also play a role in its dissipation, as the sun rises higher into the sky and shines into the foggy areas, warming the air up, and eventually evaporating the fog. A generally sunny midday and afternoon will be the result today over southern NH and a good portion of MA, but there are already some clouds moving into the South Coast region and those will limit sunshine there today. These clouds make some advance tonight and we also see more fog patches forming which will burn off to a partly sunny to mostly cloudy sky on Sunday. But even with that, still not really a bad weekend for this area. Things change as we start the new week and go through the last 3 days of September. As previously mentioned, high pressure will have shifted offshore and a larger scale upper level trough will be forming west to New England, gradually moving to the east. A slow-moving cold front will approach and eventually enter the region, finally pulling through during Wednesday. While at days 3, 4, and 5 I still can’t time showery periods and drier periods, I can say that the best highest risk for the most widespread shower activity, based on current timing, looks like Tuesday night to early Wednesday.

Details…

TODAY: Large areas of fog and low clouds to start, burning off by late morning to a mostly sunny sky except partly to mostly cloudy South Coast. Highs 74-81.Dew point rising to around 60. Wind S increasing to 5-15 MPH.

TONIGHT: Partly to mostly cloudy. Areas of fog. Lows 57-64. Dew point near 60. Wind S under 10 MPH.

SUNDAY: Areas of fog early. Mostly cloudy to partly sunny. Highs 75-82. Dew point above 60. Wind S 5-15 MPH.

SUNDAY NIGHT: Mostly cloudy. Areas of fog. Lows 58-65 Dew point upper 50s to lower 60s. Wind S 5-15 MPH.

MONDAY: Variably cloudy. Chance of showers. Highs 70-77. Dew point in 60s. Wind S 10-20 MPH.

MONDAY NIGHT: Mostly cloudy. Areas of fog. Chance of showers. Lows 60-67. Dew point in 60s. Wind S 5-15 MPH.

TUESDAY: Variably cloudy. Chance of showers. Highs 70-77. Dew point in 60s. Wind S 10-20 MPH.

TUESDAY NIGHT: Cloudy. Showers likely. Areas of fog. Lows 60-67. Dew point lower 60s. Wind S 5-15 MPH, higher gusts.

WEDNESDAY: Cloudy start with showers likely and areas of fog, then partly sunny with scattered showers. Highs 70-77. Dew point starting in 60s then falling to 50s. Wind SW 10-20 MPH shifting to W with higher gusts possible.

DAYS 6-10 (OCTOBER 1-5)

Model guidance will struggle with development of additional low pressure near the East Coast. While some guidance has additional rain October 1 other guidance is dry. Varying guidance has varying solutions for the first several days of October. With this in mind, the best bet is to leave this portion of the forecast very general in that we’ll turn somewhat cooler and there may be additional opportunities for unsettled weather, still leaning toward October 2 & 4.

DAYS 11-15 (OCTOBER 6-10)

Zonal flow expected but mean trough may hang in the Great Lakes region. This would be a drier trend but not absent of at least brief rainfall threats. Temperatures would be variable but average fairly close to normal.