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 precipitation 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 11^th through the 13^th. This amount was just about 62% of the monthly total amount. There were two 9-day dry periods during the month (2^nd-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 18^th-19^th, when coincidentally I recorded my highest pressure reading of the month (30.65” on the 19^th when I also had my lowest temperature value for the month (29.0°). I managed to drop down to 29.8° late on the 18^th 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 7^th and 10^th, culminating in my highest temperature of the month of 74.1° on the 10^th.  

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 15^th-17^th and 1^st-3^rd 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 27^th (a PWG of only 10 MPH from the NW) with a general calm period also noted between the 6^th and 9^th with daily PWG values below 15 MPH each day.    

The highest dew point temperature value reached during the month was 68° on both the 11^th  and 12^th 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 16^th, 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 30^th 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 11^th. (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 16^th (2.3”) but nothing more since then.

November 2020 Data Spreadsheet (PDF) : 

2020-11 Rockville 2.8 WNW

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