NOVEMBER 2018 MONTHLY SUMMARY ROCKVILLE 2.8 WNW MARYLAND
By Kevin Shaw, Observer in Charge
November 2018 was colder and wetter than normal, based on new normals for
my station developed out of the PRISM program out of Oregon State Univ. My
max temp (48.9°) was 7.0° below normal, my min temp (37.0°) was 0.2° above
normal, and my mean temperature (43.0°) was 3.4° below normal. My total
precipitation of 7.76″ was 4.18″ above the newly computed normal precipitation
November value for my station of 3.58”. Snowfall was 2.1″ during the month.
Snow normals are not computed by PRISM that I know of but most likely this
amount is a bit above normal for November.
My first sub-freezing minimum temperature of the fall season was 30.8° late
on the 10th which is later than old long-term averages but pretty close to the
dates we have been seeing over the last 5-10 years. Unusual cold around
Thanksgiving was the most notable temperature highlight, with high temps
mostly holding at or below freezing on Turkey Day and the day after.
Minimums were below normal but not as much as the max temps. There were
12 days with measurable precipitation, and 4 days with an inch or more,
highlighted by the monthly maximum of 1.72″ on the 24th, just after our
coldest period of the month when the highest pressure was recorded at 30.64″
on the 23rd. 29.48″ on the 26th was the lowest pressure of the month at the
end of our biggest rainy period of the month of 1.98″ (24th-26th)
The highest temperature reached during the month was 73.2° on the 1st while
the lowest temperature in November was a chilly 25.5° early on the 23rd.
The highest dew point temperature reached during the month was 64° on the
2nd while the lowest dew point temperature value reached during the month
was 3° on the 23rd.
Barometric pressure differences during the month increased more over
October’s readings, with the lowest value found on the 26th when 29.48” was
reached at the end of the wettest storm period of the month (1.98” from the
24th-26th) October’s highest pressure value for the month (30.64”) occurred
just a few days before, on the coldest day of the month on the 23rd. This type
of pattern is quite common during the colder months of the year, when greater
dynamics of pressure systems are more frequent.
November had 14 cloudy days, 13 partly cloudy days, and only 3 clear/sunny days.
There were 660 heating degree days and 0 cooling degree days during the month.
There were 9 foggy days, 6 windy days, and 1 day (each) of snow, sleet, and
freezing rain (the 15th). There was no thunder heard during the month. The
windy day category is subjective with no personal real data values to back it,
just based on my descriptive email daily weather posts that are posted on
Daily max/min temperatures varied more than the previous warmer months.
My maximum temperature frequencies included 2 days between 70° and 79°,
no days between 60° and 69°, 9 days between 50° and 59°, 14 days between
40° and 49° and 5 days between 30° and 39°. On the minimum temperature
frequency side of things, there were 6 days between 20° and 29°, 15 days
between 30° and 39°, 6 days between 40° and 49°, and 3 days between 50°
and 59°. The coolest daily max temperature was 32.6° on the 23rd with
the warmest daily min temp of 53.5° on the 2nd.
The diurnal range daily monthly average was 14.2°. Our greatest daily range
of temperature was only 22.2° on the 25th, formed from a high of 58.1° and
low of 35.9°. We had a total of only 3 days with daily ranges above 20.0°.
Our lowest range of temperature was 4.2° (48.2°-44.0°) on the 9th during
one of several cloudy, cool, and rainy days that occurred this month. There
were a significantly above normal 13 total days with diurnal temperature
ranges of less than 10.0° throughout the month. The more frequent
cloudier and wetter days helped to suppress this month’s daily diurnal
Fortunately I’ve had no more power (battery) problems with my VP2
weather station as I did back in September. I am still constantly
checking on my data quality frequently, along with discussion and data
comparison with several of my Maryland weather cohorts and reliable
online close by observer data. I have prepared the outside components
for the winter, such as removal of the inner cylinder and funnel to aide
in collecting snow and other freezing precipitation types but I have not
deployed my snow board yet.. I continue to occasionally (as time allows)
submit GLOBE Cloud observations, complete with submission of sky
pictures at the time of the observation, usually timed with the passage
of satellites and/or solar noon (about 70 minutes past actual EDT noon).
Please ask me any questions you want at any time about my station setup
and/or my data through any means available to you.
NOVEMBER 2018 – ROCKVILLE 2.8 WNW MD – CLIMATE STATS
Average high temperature 48.9° (- 7.0°)
Average low temperature 37.0° (+ 0.2°)
Mean temperature 43.0° (- 3.4°)
Precipitation 7.76″ (+ 4.18”)
Greatest daily amount (date) 1.72″ (24)
Greatest storm total (dates) 1.98” (24-26)
2018 year-to-date precipitation total 58.81″ (+ 20.00”)
High temperature for the month (date) 73.2° (1)
Low temperature for the month (date) 25.5° (23)
Highest barometric pressure (date) 30.64” (23)
Lowest barometric pressure (date) 29.48” (26)
Peak wind gust (date/direction): N/A
Heating degree days for the month: 660
Cooling degree days for the month: 0
Greatest diurnal range (date): 22.2° (25)
Least diurnal range (date) 4.2° (9)
Number of days:
Partly Cloudy 13
Max temp ≥ 70° = 2
Min temp =< 32° = 10
Precip ≥ 0.01” = 12