Wednesday was a partly sunny, dry day, with afternoon high clouds streaming in ahead of our upcoming storm on Thursday and Friday.  – see featured image of the day for an example of the cirrus and cirrostratus I saw along with a spreading contrail – showing the moisture coming in at high altitudes for our Thursday/Friday storm)
High temps reached the upper-mid 40s in the mid-afternoon, after early AM  temps in the upper-mid 20s. Evening temps dropped through the 30s then held during much of the overnight. The contrail featured better in the embedded image shown below. 

The maximum temperature was 47.3° at 1520.

The minimum temperature was 27.0° at 0553.

Dew point temperatures ranged from a low of 24° @ 0000 up to a high of 33° @ 1347.

Relative humidity values ranged from a high of 89% @ 0747 down to a low of 57% @ 1513.

Barometric pressure ranged from a high of 30.23″ @ 0251 down to a low of 30.09″ @ 1511.

No rain or snow fell on Wednesday. December 2018 still has a total of 4.18″ of precipitation (liquid water equivalent). The year-to-date precipitation is still 62.99″. These amounts should remain stable till Thursday when yet another potentially very wet system moves in. Unfortunately snow is not in future forecasts for the foreseeable future through Christmas, so a White Christmas looks rather unlikely for our immediate area.

My current online data (except for rainfall/snowfall – use cocorahs link shown below for that dataset) is showing regularly on Weather Underground. My data is posted there every 5 minutes. My ID is KMDROCKV200 and my station is called “Gardens of Traville.” Data is online, normally just about in real-time now as it is being updated on a 5 minute interval. The web address for my data on weather underground is:
https://www.wunderground.com/personal-weather-station/dashboard?ID=KMDROCKV200

I contribute my precipitation data daily to CoCoRaHS as Rockville 2.8 WNW, Station ID MD-MG-115 on https://www.cocorahs.org/

Please remember that Weather Underground precipitation data reflects what is recorded automatically through the tipping bucket VP2 gauge, just as it does on WxLink 2.0. The tipping bucket is producing erratic values so should not be used save for general precipitation timing. For example last Saturday it recorded 5.62″ for the day, clearly a significantly higher amount when compared to my 4 inch gauge total that day (3.24″). I actually use the data I post to CoCoRaHS from my 4 inch CoCoRaHS gauge I read manually as my “official” precipitation total each day.

Thursday has turned cloudy with a 100 POP for PM rain, temperatures remaining steady in the mid-upper 40s most of the day before a late evening warmup to near 60° with the heavier rain. There is an Area Flood Watch out for most of the region from Thursday evening through sometime on Saturday – but stay tuned for updates on that. 

Friday should stay mild during the overnight with highs around 60° through the afternoon then cooling off in the evening/overnight into the upper 30s under cloudy, rain showery (70 POP – heavy at times – perhaps even a rumble of thunder) skies. There is another chance for flooding rains with
this system. (Current forecasted QPF values in the 1-2 inch range.)

Saturday will dry out and cool off with partly cloudy skies, highs in the mid 40s, lows around freezing.

Sunday will be mostly sunny with highs in the upper 40s and lows in the mid 30s.

Wednesday’s midnight observations included a temperature of 37.9°, relative humidity 75%, barometric pressure 30.11″ and falling, with a dew point of 30.7° under cloudy (mid-high type) skies.

Currently at 0939 the temperature is 39.9°, dew point temperature 35°, relative humidity 81%, and barometric pressure at 30.09″ and steady under cloudy skies. During the overnight, temperatures held in the 30s and after sunrise headed up towards the 40° mark. 

Good morning from the Walrus on this cloudy Thursday.