Kevin Shaw

12:45 AM Wednesday - West Rockville MD 

Thin overcast 

Temp 31.9 Dew Point 22  RH 68%

Barometer steady at 30.34" 

Winds 1-3 MPH from the ESE 

Did KA put out a summer forecast this year? Just wondering if he did and if so, if he concurs with the present thinking about the summer being cooler than normal. I sure would appreciate cooler than normal, like it has generally been so far.  Have not posted here on the BB in quite some time. Will check back soon - I had lost my login but remembered it a few mins ago. Thanks, Kevin Shaw Rockville MD 

           AUGUST 2018 MONTHLY SUMMARY ROCKVILLE 2.8 WNW MARYLAND
                                             By Kevin Shaw, Observer in Charge

August 2018 was similar in many respects to July. Temperature averages were just about the same, 
and both July and August were wet months. In fact, the wettest day of each month both fell on the 
21st of the month (4.02” on 7/21, 3.92” on 8/21). August had 6 days with max temps of 90° or 
greater and July had 8, but August didn’t have the 5 days in a row heat wave at the beginning of 
the month like July did. The biggest difference in temperature issues was minimums of 70° or greater. 
July had 11 and August had 21. With global warming, we have been trending to have warmer minimums, 
not only in summer but most all months Differences in some patterns between July and August were also 
in evidence. The first half of July was very dry, while the first 22 days of August were quite wet. 
13 days of measurable rain was pretty close to the normal amount for August and once again compared 
favorably with the 12 days in July. It was an incredibly diverse month with Mother Nature turning her 
"faucet" on then off.      

Once again, significant pressure differences during the month were muted, even more so than in July. 
The lack of tropical activity didn’t put a crimp on our rainfall, but didn’t give us very low pressure values 
during the month. August’s pressure extremes included the extreme highest pressure for the month 
(30.29”) on the 25th with the extreme lowest (29.78”) on the 22nd on the day after our biggest 
rain of the month. The month had 10 cloudy days, 13 partly cloudy days, and 8 clear/sunny days. 

There were 0 heating degree days and 383 cooling degree days during the month. There were 6 foggy 
days and 7 windy days with thunder (mostly all in thunderstorms during our wet periods the first 22 
days of 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 also posted on weathertogether.net. 

Daily max/min temperatures varied about the same as June.  My maximum temperature frequencies 
included 6 days of 90° or greater, 20 days between 80° and 89°, and 5 days between 70° and 79°. 
On the minimum temperature frequency side of things, there was 1 day between 50° and 59.9°, 
10 days between 60° and 69.9°, and 20 days at or above 70°.  The coolest daily max temperature 
was 77.0° on the 23rd with the warmest daily min temp 76.1° on the 16th.   

The diurnal range daily monthly average was 15.2°. My greatest daily range of temperature was 
21.9° on the 24th, formed from a high of 80.7° and the monthly low of 58.8°. We had only a 
total of 3 days with daily ranges at or above 20°. Our lowest range of temperature was 6.7° 
(77.4°-70.7°) on the wettest day of the month on the 21st. There were only 2 other days with 
diurnal temperature ranges less than 10.0°, on cloudy, but not particularly wet, days.  

Please ask me any questions you want at any time about my station setup and/or my data 
by replying to this message. Thank you. 

AUGUST 2018 - ROCKVILLE 2.8 WNW MARYLAND – SUMMARY STATISTICS

Average high temperature                           85.0°
Average low temperature                            69.8°
Mean temperature                                      77.4° 

Precipitation                                               7.67" 
Greatest daily amount (date)                        3.92"   (21)
Greatest storm total (dates)                         4.06”  (21-22)
2018 year-to-date precipitation total            38.08"

High temperature for the month (date)         91.9°  (29)
Low temperature for the month  (date)         58.8°  (24)

Highest barometric pressure (date)               30.29”   (25)
Lowest barometric pressure (date)                29.78”   (22)

Peak wind gust (date/direction):                     N/A

Heating degree days for the month:                  0
Cooling degree days for the month:                 383

Greatest diurnal range (date):                        21.9°  (24)
Least diurnal range (date)                               6.7°  (21)

Number of days:

Fog                           6                   
Windy                       7 
Thunder                    7      
Cloudy                     10
Partly Cloudy            13
Sunny/Clear               8
Max temp >= 90°       6
Min temp  =<  60°      1         
Precip =>  0.01”        13   

Chris, 

I make the following first freeze predictions for the 2018 fall season. 

DCA : 12/3 BWI : 11/6 IAD: 11/1 RIC : 11/25 Tiebreaker : 2.28" (October 2018 rainfall at IAD)

Kevin Shaw