DECEMBER 2020 MONTHLY SUMMARY ROCKVILLE 2.8 WNW MARYLAND

December 2020 was warmer and wetter than normal.

My maximum temperature average (45.7°) was 0.5°

above normal but my minimum temperature average

(32.7°) was much more significantly above normal

(+ 4.5°), resulting in the mean temperature average

of 39.2° to be 2.5° above normal. These are quite

similar to my December 2019 temperature averages

and departures. My total precipitation of 4.93"

was 1.83” above the normal December value for my

station of 3.10”. There were 10 days with

measurable precipitation, roughly 96% of which

occurred in three periods (0.98” on the 4th-5th,

2.04” on the 14th and 16th, and 1.71” on the 24th-

25th). All 2.3“ of the monthly snow occurred on

that wet 16th date, with a trace of snow (flurries)

on Christmas Day . The year-to-date (annual final)

total of precipitation of 53.41” was 10.37” above

the normal average annual total of 43.04”.

There were two short, moderately cold spells

during the month, one around the mid-month snow

event from the 15th-19th and the other right

around Christmas when max temps held in the 30s

and lows were mostly in the low-mid 20s. The

coldest day of the month was the day after

Christmas when the max barely got above the

freezing mark (32.2°) with the lowest min temp

of the month (22.0°) also being reached. No

really notable high temperatures occurred

during the month, with one moderate 3 day

streak from the 11th-13th holding forth with

max values around the 60° mark, the highest

of which was 62.3° on the 12th.

The monthly maximum daily precipitation amount

of 1.38" was measured on Christmas Eve, with

an additional 0.33 falling on Christmas Day.

The two day total of 1.71” was the greatest

rainstorm of the month. The highest barometric

pressure (30.60” on the 29th-30th) occurred

only a few days after the lowest pressure

reading of the month on Christmas Day (29.41”

at the end of the month’s biggest rain event).

The highest dew point temperature reached

during the month was 59° during the Christmas

Eve rainstorm on the 24th. With a strong cold

front following immediately thereafter, the

lowest dew point temperature of the month of

9° was reached the very next day, on Christmas

Day, the 25th. This is a pattern we often see

between the highest and lowest pressures of

the month, but not this time.

December had 9 cloudy, 19 partly cloudy, and

3 clear/sunny days, probably about normal for

this time of year. There were 797 heating

degree days and no cooling degree days during

the month. There were 9 foggy days, 11 windy

days, 2 days with snow and 1 day (each) with

glaze and sleet. The peak wind gust noted

during December was 40 MPH from the NW on

the 2nd.

My maximum temperature frequencies included

3 days between 60° and 69°, 4 days between

50° and 59°, 16 days between 40° and 49°,

and 8 days below 40°. On the minimum

temperature frequency side of things, there

were 10 days below 30°, 16 days between 30°

and 39°, and 5 days between 40° and 49°.

The coldest daily max temperature day was

32.2° on the 19th while the warmest daily

min temp day of 45.0° was reached on the 12th.

The diurnal range daily monthly average was

only 13.0° (- 4.0°). Our greatest daily range

of temperature was 32.5° on the 25th (55.1°-

22.6°). We had a total of only 3 days with

daily ranges above 20°. Our lowest range of

temperature was 4.5° (47.7°-43.2°) on the 4th.

There were 11 days with diurnal temperature

ranges of less than 10° during the month,

spread fairly evenly throughout the month.

December 2020 was a bit wet and exhibited the

usual mild month pattern largely due to warm

minimum temperatures with our first measurable

snow of the season occurring on the 16th.

Amazingly enough once again the monthly minimum

temperature did not reach into the teens at all.

There has been no real ice formation on local

ponds yet. The wet month added to what was

generally a wetter than normal year. Amazingly

enough these characteristics were strangely

similar to last December, and I used much of

the same text with just a little bit of

editing needed.

DECEMBER 2020 – ROCKVILLE 2.8 WNW MARYLAND

SUMMARY STATISTICS

Average high temperature 45.7° (+ 0.5°)

Average low temperature 32.7° (+ 4.5°)

Mean temperature 39.2° (+ 2.5°)

High temperature for the month (date) 62.3° (12)

Low temperature for the month (date) 22.0° (26)

Precipitation 4.93" (+ 1.83“)

Greatest daily amount (date) 1.38" (24)

Greatest storm total (dates) 1.71” (24-25)

2020 year-to-date precipitation total 53.41" (+ 10.37”)

Snow 2.3” (16)

Highest barometric pressure (dates) 30.60” (29,30)

Lowest barometric pressure (date) 29.41” (25)

Peak wind gust (date/direction): 40 (2/NW)

(USG data across the street)

Heating degree days for the month: 797

Cooling degree days for the month: 0

Greatest diurnal range (date): 32.5° (25)

Least diurnal range (date) 4.5° (4)

Number of days:

Fog 9

Windy 11

Glaze 1

Sleet 1

Snow 2

Cloudy 9

Partly Cloudy 19

Sunny/Clear 3

Max temp = 60° 3

Min temp <= 32° 17

Max temp <= 32° 1

Precip = 0.01” 10

NOVEMBER 2020 MONTHLY SUMMARY ROCKVILLE 2.8 WNW MARYLAND

November 2020 temperatures were, as usual, above normal, still

due to the more frequent trend of recent years of above normal

average minimum temperatures (43.0° or 6.2° above normal) but

not as much different as usual than the mean or max temperature

differences. The average maximum temperature was also above

normal (60.4° or 4.5° above normal). The resulting mean average

temperature of 51.7° was 5.3° above normal. My total precip.

of 3.79" was only 0.21” above my station normal of 3.58”. There

were only 7 days with measurable precipitation, with 2.34”

falling from the 11th through the 13th. This amount was just

about 62% of the monthly total amount. There were two 9-day dry

periods during the month (2nd-10th & 14th-22nd) with no

measurable rain falling. The 2020 tropical season, as active as

it had been earlier, ended with a whimper in our area with no

systems noted during the month. Also, no thunderstorms were

noted during the month. A persistent westerly component to the

daily peak winds totaled 25 days during November, Much of the

month’s rainfall predictably came on days with wind flows from

directions other than that persistent westerly flow.

Persistent mild temperatures lasted most of the month, with only

one brief cold spell around the 18th-19th, when coincidentally I

recorded my highest pressure reading of the month (30.65” on the

19th when I also had my lowest temperature value for the month

(29.0°). I managed to drop down to 29.8° late on the 18th which

marked my first sub-32° temp reading of the season, once again

that statistic occurring later in the season with our warmer

climes of the times. They were the only 2 days during the entire

month to drop below the freezing mark. I don’t have the exact

statistics to back it up, but in the 70s/80s, the average first

freezing temperature in the fall was around October 20. Now over

the past 10 years or so, the average is more like the first week

of November and this year was among the latest I have recorded.

No overwhelming warm spells occurred during October, though a

moderate 4 day streak of maximums above the 70° mark occurred

between the 7th and 10th, culminating in my highest temperature

of the month of 74.1° on the 10th.

The highest daily PWG readings recorded on the University of

Shady Grove anemometer across the street picked up some when

compared with October. The highest reading of 53 MPH occurred

on the 15th from the W. The 15th-17th and 1st-3rd were the

windiest days of the month, with daily values over 40 MPH each

day. A total of 9 days during the month had daily peak wind

gusts of 30 MPH or more. The calmest day of the month was on

the 27th (a PWG of only 10 MPH from the NW) with a general calm

period also noted between the 6th and 9th with daily PWG values

below 15 MPH each day.

The highest dew point temperature value reached during the month

was 68° on both the 11th and 12th during our biggest rain event

of the month (2.32” on those 2 days) The lowest dew point

temperature value of the month of 20° was recorded on the 16th,

when the lowest relative humidity value of 25% was also recorded.

The highest barometric pressure reading during November was 30.65”

on the 19th, when my coldest minimum day of the month (29°) was

recorded. The lowest barometric pressure reading for the month

occurred in the big rainstorm at the very end of the month on the

30th when 29.39” was reached (Interesting to note that that same

value was recorded almost exactly a month before on October 29

during another end of the month rainstorm) This stormy, rainy

pattern on November 30 is also normally reflected in high winds,

but that wasn’t the case this month as only a modest PWG of 27

MPH was recorded.

November had 7 cloudy, 21 partly cloudy and 2 clear/sunny days.

There were 400 heating degree days and 0.4 cooling degree days

during the month. There were 6 foggy and 9 significantly windy

days in November.

My maximum temperature frequencies included 0 days of 80° or

greater, 4 days between 70° and 79°, 11 days between 60° and

69°, 12 days in the 50s, and 3 days in the 40s. On the minimum

temperature frequency side of things, there was 1 day in the 20s,

8 days in the 30s, 17 days in the 40s, 3 days in the 50s, and 1

day in the 60s. The coolest daily maximum temperature day was

41.1° on the 18th while the warmest daily minimum temperature

day of 62.4° was reached on the muggy, rainy 11th. (Interesting

contrast from last month- my warmest min for October of 62.2°

was also recorded on the 11th on another rainy, muggy day)

The diurnal range daily monthly average was 17.4° (- 1.7°).

Our greatest daily range of temperature was 27.4° on the 7th

at the start of our modest 4 day warm day streak (71.9°- 44.5°).

Our lowest range of temperature was 6.0° on the wettest day

(11th) of the month (68.4°- 62.4°). There were a total of 3 days

during the month with single digit daily diurnal ranges and 12

days with ranges greater than 20°.

I continue to get my tipping bucket clogged frequently with tree

and other debris. I still partially rely on the tipping bucket

data from the USG station across the street to give me a good

indication on how much storm event rainfall I have received plus

immediate rainfall rates as it is occurring before I get my final

amount from my daily CoCoRaHS rain gauge reading. We got our first

measurable snowfall on December 16th (2.3”) but nothing more since

then.

NOVEMBER 2020 – ROCKVILLE 2.8 WNW MARYLAND

SUMMARY STATISTICS

Average high temperature 60.4° (+ 4.5°)

Average low temperature 43.0° (+ 6.2°)

Mean temperature 51.7° (+ 5.3°)

Precipitation 3.79" (+ 0.21“)

Greatest daily amount (date) 1.68" (11)

Greatest storm total (dates) 2.34” (11-13)

2020 year-to-date precipitation total 48.48" (+ 10.37”)

High temperature for the month (date) 74.1° (10)

Low temperature for the month (date) 29.0° (19)

Highest barometric pressure (date) 30.65” (19)

Lowest barometric pressure (date) 29.39” (30)

Peak wind gust (direction/date(s)): 53 NW (15)

(USG data across the street)

Heating degree days for the month: 400

Cooling degree days for the month: 0.4

Greatest diurnal range (date): 27.4° (7)

Least diurnal range (date) 6.0° (11)

Number of days:

Fog 6

Windy 9 (PWG => 30 MPH)

Snow 0

Thunder 0

Cloudy 7

Partly Cloudy 21

Sunny/Clear 2

Max temp = 70° 4

Min temp <= 32° 2

Precip = 0.01” 7

NJWO December Zoom Meeting Thursday, December 10th

Join us this Thursday at 7 pm for our monthly Zoom meeting and virtual holiday party!

http://zoom.njwo.org. the password is in The Weather Shelter. Call/email with any questions!

Jim sells his calendar to raise money for charity at: https://hfyf.org/calendars/ They are available at a few stores in northern areas or southern NY state but you can also order online!

OCTOBER 2020 MONTHLY SUMMARY ROCKVILLE 2.8 WNW MARYLAND

October 2020 temperatures were above normal, mostly due

to the increasingly more frequent trend of recent years

of well above normal average minimum temperatures (51.4°

or 5.9° above normal). Essentially the average maximum

temperature was normal (66.5° or 0.2° above normal).

The resulting mean average temperature of 58.9° was 3.0°

above normal. My total precipitation of 3.27" was only

0.16” below the Prism-derived normal value for my station

of 3.43”. I am still studying these normal monthly

precipitation amounts as they still appear to be lower

than I would suspect. There were 9 days with measurable

precipitation, with 2.04” falling on the 29th-30th. This

amount was just about 62% of the monthly total amount.

There were 2 dry periods during the month (6-10 with 0

and 13-24 with a few trace (drizzle) amounts). No real

tropical systems affected my local area during the month,

even though elsewhere in the Atlantic Basin activity

remained quite active. Also, there were no thunderstorms

falling during the month. A split flow of both easterly

and westerly component winds fought it out for dominance

during the month. A notable early morning foggy period

driven by a persistent easterly marine flow set up in our

area during several days of the mid-month period (19th-23rd).

Persistent mild temperatures lasted most of the month, with

a downward shift right at the end, when my only sub 40°

minimum occurred on the 31st when the monthly lowest min

temperature of 36.3° was recorded. No overwhelming warm

spells occurred during October. My highest temperature of

the month (and only max above 80°) occurred on the 7th when

81.6° was reached. Once again this October failed to reach

the freezing mark for the monthly low temperature. I don’t

have the exact statistics to back it up, but in the 70s/80s

the average first freezing temperature in the fall was

around October 20. Now over the past 10 years or so, the

average is more like the first week of November.

The highest daily PWG readings recorded on the University

of Shady Grove anemometer across the street were relatively

low during October. The highest reading of 34 MPH occurred

on the 7th from the W, which also was the warmest day of

the month, A total of only 7 days during the month had

daily peak wind gusts of 25 MPH or more. 15 of the last

17 days of the month had PWG values less than 20 MPH.

The highest dew point temperature reached during the month

was 69° on the 22nd. 12 out of the 15 days between the 10th

and 24th had dew point values over 60°. The lowest dew point

temperature value was 29°, recorded on the 17th, when the

lowest relative humidity value of 33% was also recorded.

The highest barometric pressure reading during October was

a fairly respectable 30.56” on the 31st, on our coolest day

of the month. The lowest barometric pressure reading for

the month occurred just 2 days before on the 29th when

29.39” was reached. That day was the rainiest/stormiest

day of the month. More often than you might think the

monthly pressure value extremes occur within a few days

of each other. This pattern normally is also reflected

in high winds, but that wasn’t the case this month as a

PWG of only 20 MPH was reached on the 30th.

October had 11 cloudy, 19 partly cloudy, and 1 clear/sunny

days. There were 199 heating degree days and 11 cooling

degree days during the month. There were 8 foggy and 1

significantly windy days in October.

My maximum temperature frequencies included 0 days of 90°

or greater, 1 day between 80° and 89°, 11 days between 70°

and 79°, 15 days between 60° and 69° and 4 days below 60°.

On the minimum temperature frequency side of things, there

was 1 day in the 30s, 10 days in the 40s, 16 days in the

50s, and 4 days between 60° and 69°, The coolest daily

maximum temperature day was 49.9° on the 31st while the

warmest daily minimum temperature day of 62.2° was reached

on the muggy, rainy 11th.

The diurnal range daily monthly average was 15.1° (- 5.7°).

Our greatest daily range of temperature was 28.4° on the

7th on the warmest day of the month (81.6°- 53.2°). Our

lowest range of temperature was 5.5° on the cloudy, cool,

rainy 30th (51.0°- 45.5°). There were a total of 6 days

during the month with single digit daily diurnal ranges

and 6 days with ranges greater than 20°.

On my computer/hardware weather station front, I continue

to get my tipping bucket clogged frequently with tree and

other debris. I still partially rely on the tipping bucket

data from the USG station across the street to give me a

good indication on how much storm event rainfall I have

received plus immediate rainfall rates as it is occurring

before I get my final amount from my daily CoCoRaHS rain

gauge reading. The display for this station is now through

a Vantage Vue model. The record breaking hurricane season

remained active through October, though not in my area but

rather in other regions of the Atlantic East and Gulf Coast.

OCTOBER 2020 – ROCKVILLE 2.8 WNW MARYLAND

SUMMARY STATISTICS

Average high temperature 66.5° (+ 0.2°)

Average low temperature 51.4° (+ 5.9°)

Mean temperature 58.9° (+ 3.0°)

Precipitation 3.27" (- 0.16“)

Greatest daily amount (date) 1.86" (29)

Greatest storm total (dates) 2.04” (29-30)

2020 year-to-date precipitation total 44.69" (+ 9.46”)

High temperature for the month (date) 81.6° (7)

Low temperature for the month (date) 36.3° (31)

Highest barometric pressure (date) 30.56” (31)

Lowest barometric pressure (date) 29.39” (29)

Peak wind gust (direction/date(s)): 34 W (7)

(USG data across the street)

Heating degree days for the month: 199

Cooling degree days for the month: 11

Greatest diurnal range (date): 28.4° (7)

Least diurnal range (date) 5.5° (30)

Number of days:

Fog 8

Windy 1 (PWG => 30 MPH)

Hail 0

Thunder 0

Cloudy 11

Partly Cloudy 19

Sunny/Clear 1

Max temp = 80° 1

Min temp < 40° 1

Precip = 0.01” 9

SEPTEMBER 2020 MONTHLY WEATHER SUMMARY AND STATISTICS FOR WEST ROCKVILLE MARYLAND FOR THE NJWO BLOG

SEPTEMBER 2020 MONTHLY SUMMARY ROCKVILLE 2.8 WNW MARYLAND

By Kevin Shaw, Observer

September 2020 was actually a tad cooler but a bit drier than normal.
My maximum temperature average (74.5°) was actually 2.6° below normal
which was enough to overcome my minimum temperature average of 59.4°
which was only 2.3° above normal, resulting in the mean temperature
average of 67.0° to be 0.1° below normal. My total precipitation of
3.49″ was 0.54” below the Prism-derived normal value for my station of
4.03”. I still am having reasonable doubts about that average being too
low and will be checking into the records further in the coming weeks
ahead. There were 12 days with measurable precipitation, with 2.64”
falling on the first 10 days of the month. This amount was just about
80% of the monthly total amount. There were 2 six day completely dry
periods (11-16 and 19-24) that were separated by the amazingly light
2 day total on the 17th and 18th of 0.08” that fell from the remains
of tropical storm Sally that passed very weakly through our area during
that time. Sally was the only tropical system that came close enough to
have any measurable effects on my location during the month. There
were only two notable thunderstorms that fell during the month on the
2nd and 3rd. More details to follow on these noteworthy stormy days
which fed off a sub-tropical moist SW flow that followed late August
Hurricane Laura activity.

There was a significant 4 day cool period from the 19th-22nd when
max temps stayed in the 60s and mins bottomed out in the 40s (My
lowest monthly value was 42.8° on the 22nd). More rural, favorable
locations mostly to my N and W actually had mins in the 30s with
pockets of frost on their lawns and fields during this period, helping
to usher in astronomical fall appropriately. Conversely the modest
streak of 6 days of 80 of more during that first 10 days of the
month was not significant except to note that I did not reach 90
for a monthly max temperature. My high for the month was 88°
(87.5° actually) on the 3rd.

On the two thunderstorm days during the month, the two highest
daily PWG readings recorded on the University of Shady Grove
anemometer across the street included the highest reading of 50
MPH on the 3rd and 33 MPH on the 2nd. . After a 29 MPH gust
on the 4th winds really calmed down most of the remaining days
of the month, with 17 days having PWG less than 20 MPH, The
predominant general direction was from a W component (also 17 days).

The highest dew point temperature reached during the month was
79° on the 3rd, reached just prior to our biggest thunderstorm of
the month. The dew point remained at or above 70° all day on 3
days during the month, and reached the 70° mark (at least) on 10
days. The lowest dew point temperature value was 32° recorded on
September 19. Five days in a row (18-22) featured comfortably low
dew point values in the 30s.

The highest barometric pressure reading during September was a
respectable 30.62” on the 21st, during our previously described
most significant cool spell of the month. The lowest barometric
pressure reading for the month was a modest 29.61” on the 30th
during our month ending light rainy pattern featuring 5 of the last
6 days of the month with measurable rainfall amounts.

September had 10 cloudy days, 15 partly cloudy days, and 5
clear/sunny days. There were 61 heating degree days and 119
cooling degree days during the month. There were 3 foggy days,
3 windy days, and 2 days with thunder.

My maximum temperature frequencies included 0 days of 90° or
greater, 7 days between 80° and 89°, 16 days between 70°
and 79°, and 7 days less than 70°. On the minimum temperature
frequency side of things, there were 4 days in the 40s, 11 days
in the 50s, 10 days between 60° and 69°, and 5 days 70° and
above, The coolest daily maximum temperature day was 62.4°
on the 19th while the warmest daily minimum temperature day
of 73.4° was reached on the muggy, rainy 10th.

The diurnal range daily monthly average was 15.1° (- 4.9°).
Our greatest daily range of temperature was 29.3° on the
23rd at the end of the month’s major cool snap (79.8°- 50.5°).
Our lowest range of temperature was 5.7° on the cloudy, rainy
10th (79.1°- 73.4°). There were a total of 5 days during the
month with single digit daily diurnal ranges, 4 of which occurred
during this period (9-12) that featured mostly cloudy, muggy,
rainy conditions.

On my computer/hardware weather station front, I continue to
get my tipping bucket clogged frequently with tree and other
debris but was very recently cleaned up and a new ISS battery
installed by Marty. I still partially rely on the tipping bucket
data from the USG station across the street to give me a good
indication on how much storm event rainfall I have received plus
immediate rainfall rates as it is occurring before I get my final
amount from my daily CoCoRaHS rain gauge reading. Also during
Marty’s visit I got the display for the data from across the
street changed over to a Vantage Vue model, which I am enjoying
reading daily. I look forward greatly to the coming cooler autumn
days with the usual fall foliage changes. Tropical storm activity
and intensity records continued to fall in parts of the Eastern
and Gulf Coast states during this 2020 hurricane season, though
our immediate area was spared any heavy activity during September.

SEPTEMBER 2020 – ROCKVILLE 2.8 WNW MARYLAND
SUMMARY STATISTICS

Average high temperature 74.5° (- 2.6°)
Average low temperature 59.4° (+ 2.3°)
Mean temperature 67.0° (- 0.1°)

Precipitation 3.49″ (- 0.54“)
Greatest daily amount (date) 1.00″ (3)
Greatest storm total (dates) 1.78” (1-3)
2020 year-to-date precipitation total 41.42″ (+ 10.69”)

High temperature for the month (date) 87.5° (3)
Low temperature for the month (date) 42.8° (22)

Highest barometric pressure (date) 30.62” (21)
Lowest barometric pressure (date) 29.61” (30)

Peak wind gust (direction/date(s)): 50 W (3)
(USG data across the street)

Heating degree days for the month: 61
Cooling degree days for the month: 119

Greatest diurnal range (date): 29.3° (23)
Least diurnal range (date) 5.7° (10)

Number of days:

Fog 6
Windy 3 (PWG => 30 MPH)
Hail 0
Thunder 2
Cloudy 10
Partly Cloudy 15
Sunny/Clear 5
Max temp ≥ 90° 0
Min temp < 50° 4
Precip ≥ 0.01” 12

AUGUST 2020 MONTHLY WEATHER SUMMARY AND STATISTICS FOR WEST ROCKVILLE MARYLAND FOR THE NJWO BLOG

AUGUST 2020 MONTHLY SUMMARY ROCKVILLE 2.8 WNW MARYLAND

By Kevin Shaw, Observer

August 2020 was warmer and wetter than normal. My maximum temperature
average (84.0°) was actually 0.2° below normal but my minimum temperature
average (69.6°) more than balanced that out with that value well above
normal (+5.4°), resulting in the mean temperature average of 76.8° to be
2.6° above normal. My total precipitation of 8.67″ was 5.48” above the
Prism-derived normal value for my station of 3.19”. I have reasonable doubt
about that average being too low and will be checking into the records further
in the coming days ahead. There were 17 days with measurable precipitation,
distributed fairly evenly throughout the month save for a 5 day dry period
between the 7th and 11th. There were three wet periods (2.66” from the
1st through the 6th, 5.06” from the 12th – 19th and 0.95” from the 22nd – the 31st) that were punctuated by 6 thunderstorm and 2 tropical storm
days, the heaviest of which occurred during the passage of TS Isaias on the
4th (1.91”). These three periods accounted for all of July’s monthly
precipitation.

There were four “sort of” chilly days during the month with max values
holding in the 70s. during 2 days mid-month and during 2 other days at
the end of the month. Rain fell on three of these four days, including
the 2nd wettest day of the month on the 16th (1.47”) The coolest min
temp day of the month occurred on the 17th with a very modest low of
62.6°. There were twelve total days with minimum temperatures below
70°, doubling July’s total amount. Conversely, there were only four days
with max temps of 90 or greater, only topping out at 90.8 on the 10th.
Three of these four days occurred during a mini-streak from the 10th-
12th.

There were six thunderstorm days during the month, all occurring
between the 12th-28th, No really high PWG was recorded across
the street, only peaking out at 35 MPH on the 28th. The windiest
days of the month were concentrated towards the end of the month.
Like July, August was generally a light wind month, with 15 days having
a daily PWG under 20 MPH. The predominant general direction was from
the west (19 total days).

The highest dew point temperature reached during the month was 79° on
the 25th. The dew point remained at or above 70° all day on 8 days
during the month, and reached the 70° mark (at least) on 24 of the
31 days of the month. The lowest dew point temperature value was 57°
recorded on August 30.

The highest barometric pressure reading during August was only 30.20”
on the 8th, during our longest dry spell of the month. The lowest
barometric pressure reading for the month was 29.56” on the 29th
during the passage of tropical remnant LOW Laura. Rainfall amounts
(0.28”) and the PWG (29 MPH) were rather unimpressive with this storm.
TS Isaias yielded the greatest daily rainfall amount during the month
(1.91” on the 4th) but had a modest PWG of 29 MPH and a modest
barometric pressure low value of 29.69”

August had 12 cloudy days, 15 partly cloudy days, and 4 clear/sunny days.
There were no heating degree days and 366 cooling degree days during the
month. There were 5 foggy days, 3 windy days, and 6 days with thunder.

My maximum temperature frequencies included 4 days of 90° or greater,
23 days between 80° and 89°, and 4 days under 80°. On the minimum
temperature frequency side of things, there were 12 days between 60°
and 69° and 19 days in the 70s, The coolest daily maximum temperature
day was 74.1° on the 16th while the warmest daily minimum temperature
day of 77.2° was reached on the 2nd.

The diurnal range daily monthly average was 14.4° (- 5.6°). Our greatest
daily range of temperature was only 20.1° on the 17th when the min temp
of the month was reached (82.7°- 62.6°). Our lowest range of temperature
was 8.6° on the cloudy, rainy 31st (74.4°- 65.8°). There were a total of
5 days during the month with single digit daily diurnal ranges.

On my computer/hardware weather station front, there are no new updates.
I continue to get my tipping bucket clogged frequently with tree and other
debris, and still rely on the tipping bucket data from the USG station across
the street to give me a good indication on how much storm event rainfall I
have received plus immediate rainfall rates as it is occurring before I get my
final amount from my daily CoCoRaHS rain gauge reading. I am still actively
sheltering in place these days as I am sure you all are doing also when
necessary. I look forward greatly to the coming cooler autumn days with
the usual fall foliage changes. Tropical storm activity and intensity records
continue to fall during this 2020 hurricane season.

AUGUST 2020 – ROCKVILLE 2.8 WNW MARYLAND

SUMMARY STATISTICS

Average high temperature 84.0° (- 0.2°)
Average low temperature 69.6° (+ 5.4°)
Mean temperature 76.8° (+ 2.6°)

Precipitation 8.67″ (+ 5.48“)
Greatest daily amount (date) 1.91″ (4)
Greatest storm total (dates) 4.91” (12-17)
2020 year-to-date precipitation total 37.93″ (+ 11.23”)

High temperature for the month (date) 90.8° (10)
Low temperature for the month (date) 62.6° (17)

Highest barometric pressure (date) 30.20” (8)
Lowest barometric pressure (date) 29.56” (29)

Peak wind gust (direction/date(s)): 35 NE (28)
(USG data across the street)

Heating degree days for the month: 0
Cooling degree days for the month: 366

Greatest diurnal range (date): 20.1° (17)
Least diurnal range (date) 8.6° (31)

Number of days:

Fog 5
Windy 3 (PWG => 30 MPH)
Hail 0
Thunder 6
Cloudy 12
Partly Cloudy 15
Sunny/Clear 4
Max temp ≥ 90° 4
Min temp < 70° 12
Precip ≥ 0.01” 17

JULY 2020 MONTHLY WEATHER SUMMARY AND STATISTICS FOR WEST ROCKVILLE MARYLAND FOR THE NJWO BLOG (small patial editorial correction to earlier transmission)

I would like to make a small one word correction to my

JULY 2020 MONTHLY SUMMARY ROCKVILLE 2.8 WNW MARYLAND

sent earlier today

The word minimum has been changed to maximum

(shown in larger bold text) in the paragraph below. Thanks so much

to my friend Ray Muller who alerted me to this error in a phone

call a few minutes ago. So sorry for this error and the possible

confusion it may have caused.

If you have any questions please let me know.

My maximum temperature frequencies included 18 days of 90° or

greater, 12 days between 80° and 89°, and 1 day under 80°. On the

minimum temperature frequency side of things, there were 6 days

between 60° and 69° and 25 days in the 70s, The coolest daily

maximum temperature day was 76.6° on the 31st while the warmest

daily maximum temperature day of 96.3° was reached on the 19th.

JULY 2020 MONTHLY WEATHER SUMMARY AND STATISTICS FOR WEST ROCKVILLE MARYLAND FOR THE NJWO BLOG

JULY 2020 MONTHLY SUMMARY ROCKVILLE 2.8 WNW MARYLAND
By Kevin Shaw, Observer

July 2020 was warmer and wetter than normal. My maximum temperature
average (90.3°) was 4.0° above normal while my minimum temperature
average (72.1°) was a bit more significantly above normal (+6.4°),
resulting in the mean temperature average of 81.2° to be 5.2° above
normal. My total precipitation of 4.69″ was 0 86” above the normal July
value for my station of 3.83”. There were 14 days with measurable
precipitation, distributed fairly evenly throughout the month. There
were three wet periods (1.09” from July 1-12, 2.61” from July 20-24
and 0.99” from July 30-31) that were punctuated by 10 thunderstorm
days, the heaviest of which occurred on July 22 (1.23”). Those three
periods accounted for all of July’s monthly precipitation.

There was one “sort of” chilly day during the month on the 31st caused
by an all day rain and clouds, when the lowest max temp of the month
was recorded (76.6°). Coincidentally it also had the lightest daily winds
for the month (8 MPH PWG). The coolest min temp day of the month
occurred on the 15th with a very modest low of 66.6°. There were only
six total days with minimum temperatures below 70°. Conversely, there
were eighteen days with max temps of 90 or greater, I had two modest
streaks of 90 or greater (7 days between July 17-23 and 5 days
between July 26-30).

There were several thunderstorm days during the month, some of which
were severe but not damaging locally. The 3 windiest days were on the
11th, 22nd, and 30th during strong thunderstorms with the highest
monthly peak wind gust (PWG) recorded across the street of 42 MPH
on the 22nd. It was generally a light wind month, with 16 days having
daily PWG of under 20 MPH. The predominant direction was from the
west.

The highest dew point temperature reached during the month was 81°
on the 20th. That is so far the highest reading for the year. One
other day had an oppressive dew point of 80° on the 6th. The dew
point remained at or above 70° on 8 days during the month, and
reached the 70° mark at least on 30 of the 31 days of the month.
The lowest dew point temperature value was barely below the 60°
mark with 59° recorded on July 14. The lowest min temp of the
month (66.6°) followed this relatively low dew point value on the
morning of the 15th.

July had 4 cloudy days, 25 partly cloudy days, and 2 clear/sunny days.
There were no heating degree days of course and 501 cooling degree
days during the month. There were 6 foggy days, 3 windy days, and
10 days with thunder.

My maximum temperature frequencies included 18 days of 90° or
greater, 12 days between 80° and 89°, and 1 day under 80°.
On the minimum temperature frequency side of things, there were
6 days between 60° and 69° and 25 days in the 70s, The coolest
daily maximum temperature day was 76.6° on the 31st while the
warmest daily minimum temperature day of 96.3° was reached on
the 19th.

The diurnal range daily monthly average was 18.2° (- 2.4°). Our
greatest daily range of temperature was 24.0° on the 15th when
the min temp of the month was reached (90.6°- 66.6°). We had
a total of 12 days with daily ranges above 20°. Our lowest range
of temperature was 5.4° on the cloudy, rainy 31st (76.6°- 71.2°).
This marked the lowest min temp day of the month and the only
day of the month with a single digit daily diurnal range.

On my computer/hardware weather station front, no new updates
save for the computer conversion to my new CPU that still has not
been completed. I continue to get my tipping bucket clogged
frequently with tree and other debris, and still rely on the tipping
bucket data from the USG station across the street to give me a
good indication on how much storm event rainfall I have received
plus immediate rainfall rates as it is occurring before I get my
final amount from my daily CoCoRaHS rain gauge reading. I am
still actively sheltering in place these days as I am sure you all
are doing also when necessary. I turned 70 years young at the
end of the month (the 29th). Celebrations were minimal due to
COVID 19 restrictions but I did get to go out to lunch on my
birthday with 2 great friends locally here in Rockville.

JULY 2020 – ROCKVILLE 2.8 WNW MARYLAND
SUMMARY STATISTICS

Average high temperature 90.3° (+ 4.0°)
Average low temperature 72.1° (+ 6.4°)
Mean temperature 81.2° (+ 5.2°)

Precipitation 4.69″ (+ 0.86“)
Greatest daily amount (date) 1.23″ (22)
Greatest storm total (dates) 2.61” (20-24)
2020 year-to-date precipitation total 29.26″ (+ 4.69”)

High temperature for the month (date) 96.3° (19)
Low temperature for the month (date) 66.6° (15)

Highest barometric pressure (date) 30.20” (16)
Lowest barometric pressure (date) 29.66” (11)

Peak wind gust (direction/date(s)): 42 W (22)
(USG data across the street)

Heating degree days for the month: 0
Cooling degree days for the month: 501

Greatest diurnal range (date): 24.0° (15)
Least diurnal range (date) 5.4° (31)

Number of days:
Fog 3
Windy 3 (PWG => 30 MPH)
Snow 0
Thunder 10
Cloudy 4
Partly Cloudy 25
Sunny/Clear 2
Max temp ≥ 90° 18
Min temp < 70° 6
Precip ≥ 0.01” 14

September 2020 Monthly Meeting Thursday September 10th at 7 pm

Meteorologist Joe Martucci will be joining us!

Go to http://zoom.njwo.org

Enter password: the password is in the club newsletter: The Weather Shelter. Please contact me or Bob if you have questions

That will reveal the complete Zoom meeting invitation with a clickable link

Members are encouraged to start joining the meeting 10 minutes early in case the Zoom software needs to be upgraded and/or to work out any technical issues.

JUNE 2020 MONTHLY WEATHER SUMMARY AND STATISTICS FOR WEST ROCKVILLE MARYLAND FOR THE NJWO BLOG

JUNE 2020 MONTHLY SUMMARY ROCKVILLE 2.8 WNW MARYLAND
by Kevin Shaw, Observer

June 2020 was a bit warmer and wetter than normal. My maximum
temperature average (82.9°) was 0.6° above normal but my minimum
temperature average (64.9°) was more significantly above normal
(+3.8°), resulting in the mean temperature average of 73.9° to be
2.2° above normal. My total precipitation of 6.66″ was 2 88” above
the normal June value for my station of 3.78”. There were 11 days
with measurable precipitation, distributed fairly evenly throughout
the month from June 4-26. Somewhat reversing that pattern from
May with dry beginnings and ends during the month. There were
three wet periods (2.98” on June 4-5, 0.95” on June 10-11 and
2.73” from June 17-26 punctuated by numerous thunderstorms,
the heaviest of which occurred on June 5 (1.79”). Those three
periods accounted for all of June’s monthly precipitation.

There were two minor chilly periods during the month on the 1st and
2nd and from the 13th-20th, when all days but one had max
temperatures in the 70s. The coolest min temp day of the month
occurred on the 1st with a low of 49.4°. There were only three total
days with minimum temperatures below 60°. Conversely, there were
three days with max temps of 90 or greater (3rd, 4th, and 22nd).
The rest of the days of the month had max values in the 80s. The
highest max temp reading of the month of 92.6° was on the 3rd.

There were several severe thunderstorm days during the month.
The windiest days were on the 4th and 10th during strong
thunderstorms with peak wind gusts (PWG) recorded across the
street of 53 MPH. There were only 2 other days with PWG over
30 MPH in thunderstorms on the 22nd and 25th. There was another
smaller predominantly eastern PWG direction to the wind between
the 13th-17th; all other days had mostly a mostly westerly
component,

The highest dew point temperature reached during the month was
78° on the 10th. The dew point remained at or above 70° on that
entire muggy, stormy, steamy day. There were 18 days during the
month with dew points in the 70, including 11 days from June 18
forward. The lowest dew point temperature value was reached on
that chilly day on the 1st with a 40° reading. There were 4 other
days during the month with dew points recorded in the 40s.

June had 10 cloudy days, 19 partly cloudy days, and only 1 really
clear/sunny day. There were only 9 heating degree days and 271
cooling degree days during the month. There were 6 foggy days,
4 windy days, and 7 days with thunder.

My maximum temperature frequencies included 3 days of 90° or
greater, 18 days between 80° and 89°, and 9 days between 70°
and 79°. On the minimum temperature frequency side of things,
there was 1 day in the 40s, 2 days between 50° and 59°, 21
days between 60° and 69°, and 6 days in the 70s, The coolest
daily maximum temperature day was 71.7° on the 17th while the
warmest daily minimum temperature day of 73.3° was reached on
the 10th.

The diurnal range daily monthly average was 18.0° (- 3.2°).
Our greatest daily range of temperature was 29.1° on the 3rd
when the max temp of the month was reached (92.6°- 63.5°).
We had a total of 10 days with daily ranges above 20°. Our
lowest range of temperature was 10.2° on the cloudy 17th
(71.7°- 61.5°). This marked the end of a relatively short-lived
cool, cloudy easterly flow off the Atlantic Ocean period. (13th-
17th).

On my computer/hardware weather station front, no new updates
save for the computer conversion to my new CPU that still has not
been completed. I recently got my tipping bucket unclogged but
now I am getting unwanted sprinkler input around 0300 most days
to the tune of about 0.05”. I am relying on the tipping bucket
data from the USG station across the street to give me a good
indication on how much storm event rainfall I have received plus
immediate rainfall rates as it is occurring before I get my final
amount from my daily CoCoRaHS rain gauge reading. I am still
actively sheltering in place these days as I am sure you all are
doing also when necessary. I turn 70 years young next
Wednesday (the 29th). I got a much needed overdue haircut
and pedicure earlier this week. All else is fine.

JUNE 2020 – ROCKVILLE 2.8 WNW MARYLAND –
SUMMARY STATISTICS

Average high temperature 82.9° (+ 0.6°)
Average low temperature 64.9° (+ 3.8°)
Mean temperature 73.9° (+ 2.2°)

Precipitation 6.66″ (+ 2.88“)
Greatest daily amount (date) 1.79″ (5)
Greatest storm total (dates) 2.98” (4-5)
2020 year-to-date precipitation total 24.57″ (+ 3.83”)

High temperature for the month (date) 92.6° (3)
Low temperature for the month (date) 49.4° (1)

Highest barometric pressure (date) 30.37” (15)
Lowest barometric pressure (date) 29.62” (23)

Peak wind gust (direction/date(s)): 53 W (4, 10)
(USG data across the street)

Heating degree days for the month: 9
Cooling degree days for the month: 271

Greatest diurnal range (date): 29.1° (3)
Least diurnal range (date) 10.2° (17)

Number of days:

Fog 6
Windy 4 (PWG => 30 MPH)
Snow 0
Thunder 7
Cloudy 10
Partly Cloudy 19
Sunny/Clear 1
Max temp ≥ 90° 3
Min temp < 60° 3
Precip ≥ 0.01” 11