Wednesday September 9 2020 Forecast (7:42AM)

49 Comments

DAYS 1-5 (SEPTEMBER 9-13)

High humidity does more than make the air feel sticky. This morning it has a lot of the region enshrouded in fog and low clouds, which will dissipate as the sun climbs higher into the sky. However some of the low cloudiness may hang on longer in some valley and coastal areas as the temperature / dew point stay closer together lower in those locations. Also, a fan of higher cloudiness above will limit the sun’s power so the process may be slower anyway. The bottom line is that today will not be as sunny a day as yesterday was. Also, other than parts of far southern New England under a blanket of clouds late yesterday, some may have noticed a hazier appearance to the sky later yesterday leading to an atypical sky hue at sunset. That was caused by smoke in high altitudes from western US wildfires. This is not highly unusual at all for our region during fire seasons of both Canada and the western US, and we will probably see more of this in the weeks ahead. But getting back to local weather, the high humidity will be hanging around through Thursday. I am going to undercut guidance rainfall coverage and numbers and just go for a few areas of showers during the day Thursday, favoring areas south of I-90, and a broken to scattered band of showers and possible thunderstorms that crosses the region from northwest to southeast at the end of the day and early at night from a cold front passing through the region. This will put an end to the higher humidity for a couple days, along with bringing cooler air into the region for Friday and Saturday. While clouds may linger Friday morning, especially for southern areas, expect plenty of sun to eventually dominate and another mainly sunny day Saturday – great for late summer outdoor activities. By Sunday, the humidity comes back a little bit as we are on the “return-flow” side of high pressure and another frontal system approaches from the west. Once again I believe a lot of our computer guidance may be overdoing the rainfall potential here, and also moving the front in a little too quickly, so my forecast will reflect weaker and slower timing – basically Sunday looks not-too-bad to me at the moment. But I can’t say I have the highest confidence in that forecast so please check for updates.

TODAY: Fog and low clouds for many areas to start, then mostly cloudy to partly sunny. Highs 75-82, coolest South Coast. Dew point lower 60s. Wind SE to S increasing to 5-15 MPH.

TONIGHT: Partly to mostly cloudy. Patchy fog. Lows 61-68. Dew point lower 60s. Wind S up to 10 MPH.

THURSDAY: Partly sunny. Isolated to scattered showers possible favoring areas south of I-90 through early afternoon. A late-day shower or thunderstorm possible mainly northwest of I-95. Highs 77-84. Dew point middle to upper 60s. Wind S 5-15 MPH.

THURSDAY NIGHT: Variably cloudy. A shower or thunderstorm possible through late evening. Lows 57-64. Dew point falling to upper 50s. Wind SW 5-15 MPH shifting to NW.

FRIDAY: Variably cloudy morning with most clouds over southern locations, then mostly sunny. Highs 66-73. Dew point middle to lower 50s. Wind N 5-15 MPH.

FRIDAY NIGHT: Clear. Areas of ground fog lowest elevations. Lows 40-45 interior lower elevations, 45-50 elsewhere. Dew point falling to lower 40s. Wind N under 10 MPH.

SATURDAY: Sunny. Highs 65-72. Dew point 40s. Wind NE to E 5-15 MPH.

SATURDAY NIGHT: Partly cloudy. Patchy fog. Lows 50-57. Dew point upper 40s to lower 40s. Wind E to SE up to 10 MPH.

SUNDAY: Variably cloudy. Chance of a few showers, favoring late day or night. Highs 71-78. Dew point rising to lower 60s. Wind SE to S 5-15 MPH.

DAYS 6-10 (SEPTEMBER 14-18)

High pressure builds in and brings cooler/drier air through mid period followed by a warm up as the high center shifts offshore late period.

DAYS 11-15 (SEPTEMBER 19-23)

Upper pattern generally zonal (west to east) supporting a return to mostly above normal temperatures with very limited chances for any rainfall.

49 thoughts on “Wednesday September 9 2020 Forecast (7:42AM)”

  3. Good morning and thank you TK. I was going to ask you about Thursday, but you answered my question already. Thanks

    1. I slept right through it, looks like where I am near Mount Holly is right at the edge of where any reports of feeling it came in. Flemington may have had a better shot, they’re a little closer. Small quake but the biggest in this area in some time. Been a busy year of weather so might as well add some geologic shenanigans in 🙂

  7. Thank you, TK.

    The cold front sitting near the Canadian border is close, yet far away. It’s kind of stationary and now sweeping through the region. North of it the air is crisp and fall-like. South of it the air is sticky and summer-like.

    My question for you, TK, is why some cold fronts like this one stall, and others (most of them in fact) push through. By the way, answer this only if you have time. My folk meteorological `explanation’ is that something is preventing the cold front from sweeping through, and that’s the stationary high pressure area sitting offshore. But, I’m probably wrong about this.

    2. The high offshore is part of the reason. The real reason is that the front is parallel to the steering winds. In this amplified pattern with a Rockies trough and flatish ridge near or off the East Coast, the upper winds between them are southwest for a few days and there’s nothing to dig a trough to swing that front eastward. It will finally happen by early Friday.

  8. Denver had a high of 93 on Monday and a low of 31 on Tuesday. The 62-degree drop from high to low is the 3rd largest change in the city’s history, and the biggest in 132 years. The only larger ones:

    January 25, 1872, high of 46 the previous day to a low of -20 that morning.

    January 21, 1888, Morning low of -2, afternoon high of 62.

  9. As I just mentioned to TK, I agree with him that Sunday’s rain will likely underperform. Tomorrow, however, I don’t have the same feeling. I do think there will be a swath of decent rain along the South Coast and into parts of SE Massachusetts. The area that could end up with more than forecast is the rest of eastern Mass and Rhode Island. We’ve got tropical moisture streaming up from the south and a cold front approaching from the northwest. This is a setup that could bring in heavier rain farther north than what the models are currently showing. Add to that the fact that the operational models have done rather poorly with many short-term events lately, and I’m even more skeptical. Many members of the GFS Ensemble do show a swath of heavier rain across E MA/RI, with a mean of 0.75-1.25″ across the region. The ECMWF Ensemble has a mean of 0.75-1.25 across all of southern New England through Friday morning. Don’t be surprised if tomorrow is a lot wetter than what is currently being advertised.

        1. This tends to be a strength of Pete’s. Similar to your uncanny strength when it comes to rotation. He isn’t always right but then no one is. But I always take him seriously.

    1. today the CFTC released a report that Warns of Financial Havoc From Climate Change. This has already been well known in science but for a government based group to release such a strong statement is progress. https://www.cftc.gov/PressRoom/PressReleases/8234-20

      There have been entire cities and towns being evacuated. Large swaths of land being burned out west, it looks extremely apocalyptical. Yes there has always been wildfires but the amount that are occurring is unprecedented and is due to anthropological climate change. This is just one way that Anthropogenic climate change is going to hurt our pockets.

      2. Despite the media headlines, wildfires across the nation are BELOW normal to date.

        Total Fires through 9/9: 41,427
        10-Year Average through 9/9: 43,915

        Acreage burned through 9/9: 4,696,162
        10-Year Average through 9/9: 5,752,922

        Data from the National Interagency Fire Center (https://www.nifc.gov/fireInfo/nfn.htm)

        Just as with weather, media hype far exceeds reality. This is not “unprecedented”, not even remotely close.

        1. Sak, there are many professional environmental scientists, climate scientists, ecologists, wildfire ecologists I can keep on going that will strongly disagree with you.

          1. You can give me all the opinions you want. I quoted cold hard data. Data doesn’t lie. Fires have been below normal this season. I’ll take actual data over anyone’s opinion on any subject at any time.

            1. Do you think that these scientists are just making this up? Environmental scientists, fire ecologists, forestry scientists and several other disciplines do not just make this up. I suggest you start reading up on the scientific literature. I know some people personally that are also helping to fight these fires the past several years. They themselves been told by older members of the fire teams that these fires are getting worst and this is not normal.

              1. Thank you for the photo, JPD. My BIL has said the same and it is chilling. Matt. I know of course your information is fact and not media based nor is it politically influenced. It just is. You are telling me the same that I am hearing from other qualified individuals. This may explain the confusion as to why some believe the fires are not increasing. It will help that the quotes are from the source listed by SAK. There is a lot to read and absorb but this quote by NIFC seems to be key. “The US National Interagency Fire Center (NIFC), which maintains the database in question, tells Carbon Brief that people should not “put any stock” in numbers prior to 1960 and that comparing the modern fire area to earlier estimates is “not accurate or appropriate”.

                https://www.carbonbrief.org/factcheck-how-global-warming-has-increased-us-wildfires

                1. Once again, I quoted actual hard data (and included the link) that shows that by the number of fires and by the acreage burned, 2020 is BELOW normal compared to the last 10 years.

                  If you have anything beyond anecdotal evidence to refute the data, then please provide it. Otherwise, the data speaks for itself – this fire season, while worse than 2019, is not worse than any of the preceding 4 years, or the 10-year average.

                2. Yea but the link I shared specifically states …by your source….states, once again,

                  “The US National Interagency Fire Center (NIFC), which maintains the database in question, tells Carbon Brief that people should not “put any stock” in numbers prior to 1960 and that comparing the modern fire area to earlier estimates is “not accurate or appropriate”.

                  And according to your source…..(where data is sourced)….” According to data from the NIFC, there has been a clear trend in increased area burned by wildfires in the US since the 1980s, when reliable US-wide estimates based on fire situation reports from federal and state agencies became available.

                  Today, wildfires are burning more than twice the area than in the 1980s and 1990s. These figures include all wildland fires in both forested and non-forested areas. Most of the area burned today is in the western US, where dryer conditions tend to allow for large, quickly-spreading wildfires.”

                  The problem is that you assumed (remember Felix) Matt bases anything on media which immediately belittles his knowledge. I would think And certainly Hope that by now we would all know that is far from accurate.

        1. Not happening. Even if the situation tomorrow produces more rain than I have forecast, we’re not losing the long-term dry pattern any time soon.

  12. I was just talking with my friend in San Jose area who also sent me some “orange sky” pics. It’s interesting to note that despite some early fires this season, and some in not-so-great locations, the fire activity is actually running below average this season to date.

    1. That drought peaked in 2016, but it’s too early to tell.

      What I can tell you is that the level of the local pond I walk around weekly is getting closer and closer to the min of 2016, but not quite there yet. Maybe another foot to go. It remains to be seen whether or not we meet or surpass that drought. But regionally, it will probably vary somewhat. For example, if the South Coast gets 1 to 2 inches of rain tomorrow, and another event happens to perform similarly, we could see their drought get chewed away at much more rapidly. Just a semi-real life speculative example of what may happen. It’s just something we have to monitor and take event-by-event. Everything about the long term to me still says drier than average though.

  14. FWIW, the last HRRR that I saw that went out through most of tomorrow (through 00z Friday) is not nearly as wet as some of the other guidance, although it still has the heaviest amounts generally for the South Coast region.

  15. I again want to thank TK for his amazing skill. It’s not worth the effort to send the picture that my brother sent me. Maybe 1/2 inch on the grass. Even the official reading at the airport was only 2 inches.
    The models were correct about the temps and the snow, but as TK said yesterday, they don’t consider ground temperature.

    So, my question is…..why didn’t the Mets in Denver add that very important info. Is it possible that they suffer from the same “hype train mentality” that we see here in the winter…made so much worse by media management so that ratings can be higher? I am thinking that this is a national problem, not just our area.

  16. Its been moderately humid that last couple days, until a couple hours ago, when it really cranked up. Its oppressive out now.

  19. TK, I am trying to figure out why my sump pump container isn’t dry. I would expect it to be with the drought but it still has water in it just not pumping. Wonder why the water table isn’t lower here.

    1. Has there been any construction in your area recently? Someone I know suffered the consequences of poor planning when heavy rain that used to run into a brook now passes through his back yard, due to really bad decisions.

      Wondering if something wasn’t altered to divert water over the top of underground bedrock. My brother has this issue even when it’s been dry for a long time. His sump pump works even during these dry spells.

  20. A red flag to me: Every run of short range guidance has the max rain swath in a different place for Thursday. The mets here on the page have pointed out many times how poorly even 24 hour forecasts on short range guidance have been lately. Eh. I don’t trust any damn guidance right now.

    1. On the forecasts I’m writing tonight, I’m keeping the heaviest rain south of the Pike, but for all of our clients into southern NH mentioning the possibility that the heavier rain does end up farther north.

      The Ensembles (GFS/ECMWF/SREF), all have a general 0.50-1.00 from southern NH southward, though the GFS keeps it out of northern Worcester County (but does have it for E MA/NH Seacoast).

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