Robert Gilman - Direct/Cross/Redirect

MR. GILMAN: Yes.

MR. GILMAN: Good morning.

MR. GILMAN: Good morning.

MR. GILMAN: Good morning. My name is Robert Gilman. G-I-L-M...

MR. GILMAN: Meteorologist.

MR. GILMAN: Northeastern University and the Pennsylvania State University, Penn State.

MR. GILMAN: I received a bachelor of science in earth science and in meteorology.

MR. GILMAN: I worked at the US Geological Survey. while I was finishing my education. I also worked at the Nuclear Regulatory Commission in Washington. I worked at AccuWeather uh at Penn State. And then I started my own business when I came back to the Boston area uh working both in media writing a column for the Patriot Ledger, radio 95.9 WATD, and also providing information to municipalities about snow and ice in consulting.

MR. GILMAN: I worked in the uh division of site safety and earthquake analysis that was primarily involving siting nuclear power plants.

MR. GILMAN: Meteorology. Uh I worked starting out uh drawing maps. We drew our own maps back in those days um providing observations to meteorologists and helping uh develop forecasts.

MR. GILMAN: New England Weather Science. That's correct.

MR. GILMAN: Over 45 years.

MR. GILMAN: Well, the term is actually a shortened term of hydrometeorology, one who studies falling water things, and it's a study of the atmosphere.

MR. GILMAN: Mostly uh measured data such as temperature, humidity, wind, precipitation, but also uh sensing data with satellites that orbit the Earth and with radar that shoots electronic beams out and comes back and forms images that we can analyze.

MR. GILMAN: Well, the observing stations uh generally are at airports for instance, but they're also at utilities and uh there are private networks and these either automated or um amateur weather observers uh take down data uh such as I just mentioned — temperature, precipitation, visibility — uh at these different locations.

MR. GILMAN: Meteorologist.

MR. GILMAN: I work for Precision Weather Forecasting Incorporated and I also do work to assist requests for uh past weather data both for clients of ours at Precision Weather Forecasting and other requests for weather data.

MR. GILMAN: Yes. Uh thank you. It's it's a company that uh we founded — my partner and I. I've been working with meteorologist Bill Guile for 30 years. Uh we're both local and we found that we had a lot of interest together. Uh I don't stay up 24/7. He stays up overnight a lot of times and we work much better, you know, on that shift kind of work during the day. Um, answering questions of clients about snow and ice especially. Uh, so we formed our own corporation, a Massachusetts corporation in uh, 2016.

MR. GILMAN: Oh, I would say uh over 45 years, going back to uh 1979, 1980.

MR. GILMAN: Precise snow and ice information. I own the website snowyandice.com and our clients depend on very local, precise snow and ice guidance. It's for safety. Um, it's for efficiency, environmental concerns of not putting down a lot of chemicals when snow is going to change to rain, that kind of thing. So we're giving very local, precise weather information to help anyone that has snow and ice management concerns.

MR. GILMAN: Uh mainly precipitation timing — uh when snowfall might begin in a particular place, the intensity of the snow, whether it might be expected to change to ice or rain or go back to snow or ice — to help with those kinds of operations.

MR. GILMAN: As meteorologists, we develop it ourselves. It's all in-house. We take a variety of different data from numerical modeling guidance products and observational information and develop the forecast specifically for the client.

MR. GILMAN: Uh we work for most of the towns and cities in Norfolk County. We work for the largest cities in Massachusetts, uh some of the largest colleges and universities and other facilities, hospitals.

MR. GILMAN: Again, safety, um efficiency, environmental concerns — to give them the best information to do the job they need to do, and it's a difficult job as you can imagine.

MR. GILMAN: Yes.

MR. GILMAN: I was asked to provide a simple report of the days preceding January 29th, 2022, and a more detailed report of the early morning hours of January 29th about estimating snowfall during that time period.

MR. GILMAN: Um, I believe it was January 26 to the 29th.

MR. GILMAN: Oh, yes.

MR. GILMAN: Well, the forecast for the first couple of days uh was dry and very cold to bitterly cold. Uh as we got closer to the 28th and 29th, we were looking at a storm coming in from the west and strengthening along the Mid-Atlantic coastline. And we issued warnings again two to three days ahead of time to let our clients know that this was going to be a significant winter storm.

MR. GILMAN: We expected the storm — the snowfall and the increase in wind — to begin very late Friday evening uh the 28th uh with light to very light snow, and then to increase in intensity especially later in the morning and through the late morning and midday of the 29th.

MR. GILMAN: A blizzard uh technically requires a great reduction in visibility. Doesn't even have to be snowing. Either falling or blowing snow, visibility a quarter mile or less, with winds of 35 miles an hour, either sustained or frequent gusts, for 3 hours or more.

MR. GILMAN: The storm did absolutely. Um, for Boston and much of the greater Boston area, including in Canton at the Blue Hill Observatory. Uh however, not every spot had all of those criteria during the entire time period that the snow was falling.

MR. GILMAN: This was the biggest January storm in history uh with 27 inches of snowfall and it snowed heavily for several hours. Uh visibility under a quarter of a mile and the temperature was dropping during that time and the winds were gusting frequently to 40 and 50 miles an hour in this area.

MR. GILMAN: Three locations. Uh the Blue Hill Observatory, which is the oldest continuously operating weather observatory in North America, uh close by. Uh Boston, which is a first order weather station at Logan Airport, and Norwood Airport, which is a mile away. Uh and those were the three locations. Uh I was considering the surface observations uh from those locations. Uh also considered other types of observational data. I mentioned the uh radar data. The uh National Oceanic and Atmospheric Administration maintains a NEXRAD NOAA database. And third was the National Operational Hydrologic Remote Sensing Center, which categorizes snowfall and snow depth. So those three different types of data at those three different locations.

MR. GILMAN: It was established by Abbott Rotch, who left his family home at 5 Commonwealth Avenue in Boston and built this really strange little structure at the top of Great Blue Hill on February 1st of 1885.

MR. GILMAN: Yes, I do. If you don't mind me consulting my notes for a moment.

MR. GILMAN: I'm reading uh notes I took on measurements from Blue Hill to Fairview.

MR. GILMAN: Uh thank you. That would be seven miles.

MR. GILMAN: One mile.

MR. GILMAN: Yes.

MR. GILMAN: Sure. Boston again is a first-order station. It's equipped with automated equipment. It's called ASOS — automated surface observing system — and it takes measurements of temperature, visibility, wind, humidity at very frequent intervals throughout the 24-hour day. It also collects precipitation, which isn't easy if you think of Logan Airport being out in the harbor and trying to collect every raindrop in that environment, but they have a very sophisticated rain gauge system that actually does a fairly good job of collecting precipitation. Moving on to Norwood Airport, very similar — it's not as high a caliber a station as Boston is in terms of the frequency of observations or the complete set of data. Blue Hill Observatory is a special case indeed.

MR. GILMAN: It had been manned for most of the day for many years. The former observer is still alive and well in Hingham, Bob Skilling. For the last several years — 10, 15 years or so — it was an ASOS system that I just mentioned. But in recent years that was cut back. So there are observers that are there and they take observations when they're there, and they take automated observations otherwise and take a record of that, but it's not on the — for instance — the FAA network. Federal Aviation Administration weather data of course is extremely critical to aviation and they have a network of weather data. The Blue Hill Observatory currently is not on that network.

MR. GILMAN: Yes.

MR. GILMAN: Yes, there are standards established. I'm a member of the American Meteorological Society, the professional society of meteorologists, and there are standards that are established on taking weather measurements.

MR. GILMAN: Yes.

MR. GILMAN: Yes, I do.

MR. GILMAN: This is a local climatological data sheet for January 2022 for each day. And I believe there's — as I look through it — hourly reports of weather observations, especially for January 29th, at Norwood Airport. And this is published by the US Department of Commerce — NOAA, the National Environmental Satellite Data and Information Service.

MR. GILMAN: It's one element. That's right. And again, I put a lot of strength to this data because it is in such proximity to Canton and to the location we're concerned about.

MR. GILMAN: The snow began to accumulate during this winter storm. And by the way, I think I can use the term nor'easter, blizzard, bombogenesis, bomb cyclone, winter storm — all referring to the storm event of the 28th, mostly the 29th. The first snowfall began late in the evening on the 28th and continued into the 29th.

MR. GILMAN: Very little — enough to track a cat — 2/10 of an inch.

MR. GILMAN: Yes, as the hourly precipitation data, temperature and other information was reported, I was able to analyze it each step of the way as the storm progressed.

MR. GILMAN: Well, as I said in the report, it's estimated that as it began, it was on the order of 3/10 of an inch an hour on the 29th until 1:00, and it stayed in that light range. And anything under an inch an hour of accumulation is termed light snowfall. So that by 3 and 4 a.m. we were looking at 3, 4, 5/10 of an inch an hour. There started to be a more noticeable increase in the intensity by 5:00 a.m. with another inch, and then by 6:00 a.m. with another 1.2 inches.

MR. GILMAN: I believe that was — let me do my arithmetic. 3.9 inches up to 6 a.m.

MR. GILMAN: Then we started getting into more moderate snowfall — and again, that's an inch an hour or more. So that by 7:00 was another inch and a half, by 8:00 another 1.1 inches, and then by 9 and 10:00 it was getting to be moderate to heavy snowfall based on the radar returns and NEXRAD radar information, based on the visibility reduction, based on the amount of precipitation that was melted in the rain gauges, based on other reports from cooperative observers. So that's on the order of an inch and a half an hour of intensity, and that continued through the middle of the day, rapidly accumulating on the ground, and it accumulated at even 2 inches an hour by the early afternoon before it started to wind down in intensity, as these types of storms always do.

MR. GILMAN: By seven or eight o'clock in the evening, it was back down to light snowfall of half an inch to 2/10 of an inch. And the snowfall accumulation had ended by 10:00 at night.

MR. GILMAN: Around 6:00 p.m.?

MR. GILMAN: Well, again, I'm just going to do the arithmetic of subtracting the snowfall after 6 p.m. — which was 1.3 inches — from the total, which was 23.8. Let me do that arithmetic. 23.8 was the total snowfall and 1.3 — 22.5 inches. So that's 22 and a half inches — just short of 22 — excuse me, just short of 22 and a half inches by 6 p.m.

MR. GILMAN: That's correct.

MR. GILMAN: 23.8 inches.

MR. GILMAN: That's correct. The biggest snowstorm in January in our history.

MR. GILMAN: Yes.

MR. GILMAN: Yes, I've seen these.

MR. GILMAN: The first one is a storm warning report that was sent to our clients in this area regarding the upcoming snowfall — winter storm. And we began sending this type of report — as I said, 3 days prior. This was one of the last ones that was sent as the storm was getting underway in this area. So, this was sent by my colleague, my partner Bill Guile, at 8:00 that Friday evening, and it's a detail of when the snow is going to start, when the first inch will be on the ground, the total snowfall, the duration of the storm, and what's going to happen after the storm — which is also critical for our clients to know how to clean it up — and what kind of post-storm conditions as far as temperature and other things to consider. So, that's the heading of the form.

MR. GILMAN: Then we get into this detailed 6-hour time block series. And of course, that begins at 6:00 p.m. to midnight, since this was issued at 8:00 p.m. And we talk about the weather conditions and how much — if any — snowfall.

MR. GILMAN: Yes. Well, our company sent out — my partner, Bill Guile actually sent it.

MR. GILMAN: These are images taken from one of those three sets I talked about — the data set from NOAA, the National Operational Hydrologic Remote Sensing Center — and it's an image of snow depth, or snow on the ground, at two times on January 29th. The first time is 1:00 a.m. and the second time is 7 a.m., and it's a map of greater Boston down to the South Shore into northwestern [unintelligible] Rhode Island.

MR. GILMAN: As defined, a forecast is your best estimate based on science and data available of how the future is going to play out in terms of weather — the amount of snowfall, the temperature, the observed data. And I often make the distinction between soup and sandwich. Weather and forecast always seem to go together, but there actually is weather, and that's separate from what the forecast is. And there's always some small distinction. Lately, we've been getting pretty good at getting accurate weather forecasting done, but it is the actual weather that's measured. How much snow is on the ground, how much snow fell, uh, what the wind speed was during any given period, temperature, those kind of elements that actually occurred.

MR. GILMAN: Yes.

MR. GILMAN: Sure. So below the heading — I think I defined the heading just before — uh, we have these six-hour time periods. So the columns are: the day, in this case today being Friday in this forecast; the weather; the amount in inches, that would be of snowfall; the temperature — that's the air temperature, and air temperature is taken 5 ft above the ground in a natural surrounding; the road temperature, also in Fahrenheit, and that is the surface ground temperature, which is very important to our clients. And then we have wind, both sustained and gusts. Below that, we have special notes to amplify our message. A lot of times people don't read everything, so we try to highlight what's important or add something that wouldn't be in one of those columns.

MR. GILMAN: A windchill is a calculated uh amount or figure of heat transfer based on how human beings react to temperature. So this is the actual temperature that will be measured on a thermometer.

MR. GILMAN: Certainly. Uh, the same applies to the columns. Now, we're into tomorrow. So, since this was issued at 8:00 p.m. on Friday, tomorrow is Saturday. And we're going through each six-hour period and how much snowfall could be expected. You see it starts with 3 or 4 in and then ramps up as we get later in the morning to as much as 6 to 10 in of snow. And you can calculate what that hourly rate might be based on the six-hour period. We give that type of range because it's scientifically accurate. People really want to know every minute, every hour, and that's just not something that modern science can do. So, we give this period to be as accurate as possible while still being extremely precise.

MR. GILMAN: Uh, seven to nine inches during the afternoon period, and then it winds down to two to three inches toward midnight.

MR. GILMAN: At uh, Blue Hill Observatory, there's often an observer, a trained observer, making measurements. The standard is to use what we call a snowboard. And if any of the members of the jury do weather observing or know weather observers, you might be familiar. It's just like a piece of plywood, something that doesn't radiate like pavement would or a house would. Uh, just something that would allow the snowfall to accumulate in a natural way, and then that's cleaned off every 3 hours and those amounts are added throughout the duration of the snowfall event. So that's the way the observers at Blue Hill Observatory have literally been doing that since 1885. Uh, when you come to Logan Airport, you don't have an observer right there.

MR. GILMAN: There was — back before the '70s, '80s, around that time period, before ASOS came into play — there were people that were in the weather office that would go out and make those measurements. Now they contract with an observer, and I'm not sure of the location right now or during this event in 2022. I believe it may be in Winthrop, but it's very nearby to Logan Airport. And this is a contracted observer that makes these measurements. Uh, at Norwood, there is no snowfall measurement made uh right at that location.

MR. GILMAN: Heavy snow again can be defined in two ways. Uh, either by the reduction in visibility or by the accumulation rate. So it's an intensity of snowfall. And in terms of visibility, it would be less than a quarter of a mile — so something like three-eighths of a mile. That's when you get into the heavy snowfall range. In terms of the way it accumulates — that might be more familiar to most of us since we don't know what that visibility might or might not be — but it's an inch and a half an hour or more. Uh, it's not something that you want to be driving in — very hazardous and big impact on a lot of our activity.

MR. GILMAN: I don't know there's a scientific explanation, but it's a good term that is used quite a bit, and it would be heavy snowfall. Uh, again, snowfall can reduce visibility to near zero, even below three-eighths of a mile. You know, you may be getting 2 in of accumulation, 3 in per hour. When you have a very convective, energetic storm like a thundersnow event — a lot of upward motion in the atmosphere — you could get four, even 5 in of snowfall per hour, and that certainly would be termed white-out.

MR. GILMAN: I think it has a lot to do with the fact that we drive a lot these days, that people are familiar with limitations to being able to drive a car, and, you know, if you're driving along, the windshield wipers are going at maximum speed and you just can't make out anything on the horizon or the car in front of you — you say it's white-out conditions. You know, that's the way it's reported.

MR. GILMAN: Heavy snow definitely occurred in this storm. Uh, I've heard it referred to as white-out conditions, and it's somewhat in the eye of the beholder. Uh, but I would say yes, white-out conditions did occur.

MR. GILMAN: Well, visibility is just the reduction of how far you can see based on some weather element, as long as we're talking about weather. So, haze can reduce visibility, fog, different types of precipitation, smoke can reduce visibility in the atmosphere. Uh, but in terms of snowfall, the heavier the intensity of the snowfall, the lower the visibility.

MR. GILMAN: Well, it's measured in miles, uh, or quarters of a mile, which is the standard here in the United States. Um, and you sometimes see it in eighths of a mile, but generally with these automated systems, it would be 3/4 of a mile or half a mile. Or, as the snow intensity lightened up quite a bit, it may go up to 7 miles. I've seen snow falling at 10, even 11-mile visibility, which you'd hardly notice if you were out. Uh, that's not much of a reduction in visibility, but it can come all the way down to near zero.

MR. GILMAN: I would base that on Norwood Airport, uh, because it was especially in this immediate area and they do a good job of measuring visibility, and that came down to a quarter of a mile at the airport. It certainly may have been lower than that at times, but it was on the order of a quarter to perhaps as low as three-eighths of a mile or an eighth of a mile between observations.

MR. GILMAN: Uh, temperature is measured with a thermometer, and there are different types. Uh, we depend heavily on electronic thermometers now that uh measure the amount of heat in the air, and we get a reading, and we generally use that reading as the air temperature.

MR. GILMAN: Again, air temperature — the standard is the temperature of the atmosphere 5 ft above the ground in a well-ventilated natural surroundings. Road temperature or ground temperature is actually at the surface. So it's out beyond the atmosphere, right at the surface uh of the ground.

MR. GILMAN: There are basically two ways. Uh, one way would be to put some kind of sensing device, a probe, in the surface — uh, just below the surface — and the other way would be to use uh infrared uh radiation. And so you'd mount a sensor on a pole, and that infrared wavelength measurement would give you — I'm sorry — a road temperature, a surface temperature.

MR. GILMAN: And I've heard this so many times from our clients. You know, you can forecast or expect an inch of snowfall or 3 in of snowfall. If it's going to melt because the road temperature is 34° or 35° F, they don't really want to do anything. You know, they don't want to put a lot of chemical down. They don't want to hire private contractors with plows. Whereas if it's going to accumulate, especially on the road surface, they need to be prepared. And there's so much demand now on having black pavement during winter storm events. There are so many automobiles on the roadways in this area that each of these municipalities is constantly under demand to make sure they do the best job they can.

MR. GILMAN: And in order to do that, they need to know what the road temperature is going to be — or the ground temperature is going to be — in order to best have snow and ice operations to meet those demands.

MR. GILMAN: They're different substances. So they have a different pattern of temperature change. Air temperature changes much more quickly. And of course when we're talking about temperature, we're talking about energy, or the way the molecules in the atmosphere are moving. The faster they're moving, the higher the temperature, the more energy. So depending on what is causing that change in temperature, the atmosphere is going to react more slowly. The ground — I mean, the ground will react more slowly to the change. The atmosphere will react pretty quickly and much faster.

MR. GILMAN: Correct.

MR. GILMAN: I was asked to start the 26th and I said that that's a good way to go because it establishes a period of seasonal freezing ground. It typically happens in this climate in the midwinter that our ground freezes. So if you look a few days before, you get a good sense if that was the case. I mean, there have been winters — there have been months of January in recent years that we've reached 60, even 70°, and nothing is going to be frozen during that time. This was not the case in late January of 2022. It was an unusually cold period and it was important to record that.

MR. GILMAN: Yes. I'll start with the 26th and just go — without going through more than just a day high and low. A high of 28, a low of 12. On the 27th, the high was 27 and the low is just 9° F. On the 28th, Friday, the high temperature reached 36 and the low was 22. And then on Saturday the 29th, the high temperature was 29 and the low is down to 15.

MR. GILMAN: Yes, please. On the 29th — all right. I'll consult this data from Norwood airport if that's the way we should look at this.

MR. GILMAN: And at 1:30 the temperature was 31. By 5:30 in the morning it was down to 24°.

MR. GILMAN: And again, this is right at Norwood airport. It might have been a little bit colder in Canton. It certainly was colder at the Blue Hill Observatory. But I don't have a lot of that. So I'm using this.

MR. GILMAN: So based on this, it was pretty steady through around 2 in the morning. And then because of the nature of this type of storm — it's deepening rapidly, it's low pressure offshore — so the wind tends to back from the northeast to the north-northeast to the north. And that backing wind starts to draw air rather than from the Gulf of Maine, the Atlantic Ocean, the harbor, more from northern New England and Quebec. So that's a tendency of all of these winter storms to tend to get colder as the storm intensifies. And that's what we see starting to happen as you get toward 2:30 in the morning, and especially 4:30 — it's down to 28, 26, and then down to 24° just before 6:00 in the morning.

MR. GILMAN: It's exactly what I would expect. And this is a classic winter nor'easter, and that temperature drop is part of that.

MR. GILMAN: As I said, it's the coldest time of the year anyway in late January here in the Boston area around Canton — midwinter. And this particular year of 2022, it was colder than normal. So road temperatures were dropping much of the time. They may have come up a little bit during the course of the day thanks to sunshine during the 26th and 27th. A little moderation in the temperature on the 28th, but for the most part there was a frost in the ground. The soil was frozen and the temperature was unusually cold at the middle of winter.

MR. GILMAN: Well, again, the ground was frozen, the soil was frozen, and the surface of the ground was frozen. And it would have made the ground impenetrable — that hard — you know, as hard as — too difficult. We wouldn't be able to dig in the ground.

MR. GILMAN: Thank you.

MR. GILMAN: Correct.

MR. GILMAN: Correct.

MR. GILMAN: Correct.

MR. GILMAN: Yes.

MR. GILMAN: Not — New York. This is — we're in Massachusetts.

MR. GILMAN: Yes. I've been in many parts of Canton. I don't believe I've ever been to 34 Fairview.

MR. GILMAN: Yes.

MR. GILMAN: Yes.

MR. GILMAN: I mentioned it's a mile away, right? So it's fairly close. A mile.

MR. GILMAN: Yes, of relevance. Yes.

MR. GILMAN: Thank you.

MR. GILMAN: Yes.

MR. GILMAN: If you want to get the total for the snowfall event. Yes.

MR. GILMAN: Yes.

MR. GILMAN: I believe I said there was very little snow on the ground.

MR. GILMAN: Enough to track a cat.

MR. GILMAN: I don't know how to define it any better than enough to track a cat.

MR. GILMAN: Right.

MR. GILMAN: Oh, a lot of factors would come into play. Most importantly, since this was a forecasted storm event, the town may have pre-treated the road. That lowers the freezing point of the precipitation. So even if it was 25 degrees, it might be melting on the road.

MR. GILMAN: Definitely correct.

MR. GILMAN: Well, there are places — especially with this kind of wind and dry fluffy snow — that you would have drifting, right?

MR. GILMAN: No. Absolutely not. Unless I was a very small animal.

MR. GILMAN: I thought you were asking about the larger numbers.

MR. GILMAN: Okay.

MR. GILMAN: Correct.

MR. GILMAN: Correct.

MR. GILMAN: Correct.

MR. GILMAN: Yes.

MR. GILMAN: That's a possibility. That's one factor. Another factor would just be the road may be warmer for a number of reasons. That could be another reason why it might be less.

MR. GILMAN: Absolutely.

MR. GILMAN: Yes.

MR. GILMAN: Yes.

MR. GILMAN: Right.

MR. GILMAN: Correct.

MR. GILMAN: If it was still snowing in those 15 minutes, right?

MR. GILMAN: Correct.

MR. GILMAN: Yes.

MR. GILMAN: 0.8 is 8/10 of an inch.

MR. GILMAN: I'm not sure what I follow in that sentence. Did you ask me how much snow fell between 1:00 a.m. and 2 a.m.?

MR. GILMAN: Okay. Between 1:00 a.m. and 2 a.m., 3/10 of an inch is the estimated snowfall.

MR. GILMAN: It would be 1 inch, right?

MR. GILMAN: Yeah, I actually use the knuckle on my thumb to the end of my thumb — that's an inch.

MR. GILMAN: Right.

MR. GILMAN: It definitely would require a comparison. One inch of snow has caused tremendous problems for people. So I would not call — just by the fact of one inch of snowfall — I would never say it's very little.

MR. GILMAN: We'd be out of the track a cat stage.

MR. GILMAN: Well, we're going to have that inch we just talked about at length, and we're going to add the 2/10 from the previous day, the last few hours of the 28th. So we have 1.2. Now we're going to add another half an inch by 4:00 a.m. So somewhere less than — less than or equal to — 1.7 in total.

MR. GILMAN: Yes.

MR. GILMAN: As I said, it's 1.2 in up to 3:00 a.m., and then we're adding some amount before 4:00 a.m. Unknown how that was distributed within that hour. But something like 1.7, equal or less than, total.

MR. GILMAN: Between 1:00 a.m. and 3:00 a.m. — so we have 3/10 of an inch up to 2 a.m., and another 4/10 of an inch — or a total of 0.7. So between 1 and 3:00 a.m. there's only an accumulation of 0.7.

MR. GILMAN: Correct.

MR. GILMAN: Correct.

MR. GILMAN: I can do the arithmetic. It sounds about right. 8.6 in fell up until noon starting at 6 — in that time period — which is about the amount we forecast. And did you ask about the total going back to the night before, or —

MR. GILMAN: Starting at midnight, going until noon. So it's a 12-hour period.

MR. GILMAN: My quick calculation is 12.3 in, right?

MR. GILMAN: Yes.

MR. GILMAN: Correct. Exactly. Yeah.

MR. GILMAN: Correct. I believe so.

MR. GILMAN: Yes. Yeah. I'm sorry — I wasn't sure if you wanted me to do all the arithmetic again, but I did do that. And yes.

MR. GILMAN: The intensity of the snowfall — the amount over time — and visibility, right.

MR. GILMAN: I really don't know exactly. I can look at the report from Norwood Airport. They measure the visibility.

MR. GILMAN: If we're going to do more than one, I would — but let's see if I can.

MR. GILMAN: And we were asked about 1:00 a.m. Is that — yes.

MR. GILMAN: Okay. Visibility reported at 1:00 a.m. was 1.25 miles in light snow.

MR. GILMAN: That means that anything that was more than 1 and a quarter miles away from the observer would be hidden by the snowfall. You wouldn't be able to see it.

MR. GILMAN: As the visibility lowers, your ability to see objects in the distance is reduced.

MR. GILMAN: All other things being equal, yes.

MR. GILMAN: Um, can I further explain to the jury about visibility?

MR. GILMAN: Atmospheric phenomenon, but once you get below 3 miles, we call it fog or dense fog. So anything below that — when you reduce visibility by fog, haze, snow below 3 miles, it's hard to call it good visibility. But if something is at 1.25 miles, there's visibility.

MR. GILMAN: Yes, there is. And again, I'll just — again, if I could explain for the jury, a lot of this is developed for aviation, right? And if you're a pilot, or you think about what a pilot needs to go through, that's where these terms come from.

MR. GILMAN: I sure am. Yes. And you and weathercasters — we all see on TV — talk about visibility on their forecast. Correct.

MR. GILMAN: Correct.

MR. GILMAN: And it is a challenge to communicate that. Yes.

MR. GILMAN: I don't know. But I would never expect — and I do broadcast meteorology — a broadcast meteorologist to say visibility was good if it was less than a mile and a half.

MR. GILMAN: Absolutely. And I'm trying to answer your question about whether the visibility was good.

MR. GILMAN: I only know what you ask me.

MR. GILMAN: Yes.

MR. GILMAN: I was asked about it. Yes.

MR. GILMAN: It does have a relationship to temperature. It's a complex function that was developed by the U.S. Air Force in the 50s to help produce cold weather gear. And it was determined that wind had a major impact on our military in terms of what type of gear they needed, in addition to how low the temperature was. So it's a measurement of temperature to begin with, and then there's a complex function applied based on the wind speed to come up with how that air temperature — how that air is going to impact the human body.

MR. GILMAN: Yes, that was my report based on all those three locations. Yes.

MR. GILMAN: Sure. It was in the report. Yep. And — 23 mph with frequent gusts of 47 mph.

MR. GILMAN: It makes that air feel much colder. So that air — that — did you say 20 and 29, sir, and 15 were the numbers you had given — that range for that day.

MR. GILMAN: So it makes that air temperature feel colder, and it allows that air to take heat out of your body more efficiently and more rapidly. So it feels much colder, and we can calculate roughly how it would feel if there was no wind at all.

MR. GILMAN: I wasn't asked to calculate that. No.

MR. GILMAN: Based on the 29? No. I don't believe so.

MR. GILMAN: Yes.

MR. GILMAN: Again, depending on the wind — if you looked at 5 miles an hour, it wasn't that wind all day — and that 15 degrees might not have been corresponding to any wind at all.

MR. GILMAN: The — yeah, the average wind again made it feel much colder, uh, bitterly cold, extremely cold when you were out in the highest wind at the lowest temperature. So it may have felt like zero to even 10 below zero at the lowest temperature and the highest wind gusts.

MR. GILMAN: Again, I'm just guessing. I don't have — I didn't do the calculation. I wasn't asked to do the calculation. But based on my experience of reporting in this area for 45 years, I basically get the idea of what it's like when the temperature is that low and the wind is that high.

MR. GILMAN: Yes.

MR. GILMAN: Correct. Exactly.

MR. GILMAN: You're welcome.

MR. GILMAN: During that time frame, about 3/10 of an inch.

MR. GILMAN: Correct. During — yeah, that hour or two previous. Yeah, there's — really, in fact I have this chart — I showed the graph, the map. It just showed a trace of zero there, that was less than an inch on the ground. And we measure snow on the ground in whole numbers. So it would either be one inch or zero.

MR. GILMAN: Yes.

MR. GILMAN: Correct. Yes.

MR. GILMAN: A car in front of you, a building in front of you, a person — you know, anything other than weather. And there are other types of weather that can lower visibility besides snowfall, including fog.

MR. GILMAN: Yeah, I really can't say that lighting — obviously you need some light to see anything. That's really all I could say.

MR. GILMAN: Again, it was developed for the military in the 50s to help design — it was actually done here at the Natick labs here in Massachusetts, to help design cold weather gear, because prior to that time — during World War II, the Korean War — unfortunately, especially air force aviators were suffering. They had clothing that might have been adequate for the temperature, but because of the wind, they suffered frostbite and other ill effects. And so research was done, and the result of that was a windchill temperature — the way it would feel to the human body based on the wind on a certain temperature.

MR. GILMAN: Correct.

MR. GILMAN: Exactly.

MR. GILMAN: Thank you.

MR. GILMAN: I have relinquished them to this nice young lady.