Tuesday put a sudden halt to our short dry spell, through a heavy mid-afternoon thunderstorm (1.01″ total for the day, about 80% of that from the thunderstorm, the other was from a light shower in the late morning) that was spread throughout the region. Skies were building by late morning/early afternoon. Temperatures remained relatively cool but muggy, only reaching the mid 70s just prior to the thunderstorm arrival with lows in the mid 60s. The Tuesday maximum temperature reached 76.0° @ 1534, while the Monday minimum temperature was 64.4° @ 0847. The dew point temperatures rose, ranging from a low of 59° @ 0458 up to a high of 71° @ 1416. The barometric pressure lowered from Monday – highest being 30.15″ @ 0000 down to a low of 29.96″ @ 2351. The relative humidity rose significantly, ranging from a low of 79% at 0108 up to a high of 98% at 2216. Fog formed late in the evening as the dew point and air temperature reached very close to each other.

Remember now you can get the VP2 data on Weatherlink. You can access the data through http://www.weatherlink.com/user/walrusman444 I am posting daily to weather underground. My ID is KMDROCKV200 and my station is called “Gardens of Traville.” Data is online, normally just about in real-time. The web address for my data on weather underground is: https://www.wunderground.com/personal-weather-station/dashboard?ID=KMDrockv200#history/ I contribute 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, which is currently not functioning. I actually use the data I post to cocorahs from my 4″ cocorahs gauge I read manually as my “official” precipitation total each day.

I had a doctor/lab appointment at 1400 so Mike picked me up around 1330. I was done by about 1530 so headed back to the apartment with Mike driving. On the way, the heavens opened up. Very heavy rain accumulated quickly on the roads, temporarily flooding the roadways especially along the curbsides. When I got out, it was still raining very heavily, so despite cover only a few feet away, when getting out of the car it took no time at all for me to get totally soaked. I had to change my clothes and dry my hair once I got safely in the apartment. Naturally by the time I got settled the storm had moved on. Peak rain was about 1545 to 1600 approximately. No more rain fell the rest of the day. The storms tracked through the entire metro area, causing numerous flood and severe storm warnings during its journey. 

Tuesday was partly to mostly cloudy with the aforementioned thunderstorm in the mid-afternoon the highlight. Temperatures remained moderate, only reaching the mid 70s with lows in the mid 60s. It was still muggy, and in the evening cooler temperatures helped to form some late evening/overnight fog. As I write this on Wednesday early afternoon we have scattered cumulus dotting the sky, with milder temps in the mid 70s and dew points in the low 60s. Wednesday should be partly cloudy with highs in the upper 70s and lows in the upper 50s with no chance of rain. Thursday should be sunny with highs in the low 80s and lows around 60°. Friday should be mostly sunny and a bit warmer, with highs in the mid 80s and lows in the mid 60s. At the start of the Memorial Day weekend on Saturday we should see partly cloudy skies with highs up in the mid 80s and lows in the upper 60s and a 40 POP for PM thunderstorms. Sunday increases our PM thunderstorm chances to an 80 POP, temps maxing out in the low 80s, lows in the mid-upper 60s under partly cloudy skies.

On the Channel 4 radar at 1240 is showing no precipitation in the 4-state mid-Atlantic region. The closest rain is well south over parts of GA and SC, to the west well out in the Midwest around IA and MN, and some leftover storms/showers over northern New England.

As of 1240, the data from the VP2 (coming from the ground radiation shield about 4 feet off the ground just under and out from the balcony) and the Lakewood WX Bug station are as follows:

Partly cloudy, mild, dry with scattered cumulus covering a good part of the sky.

Station Relative Location Temp  RH    DP    BP     Wind High/Low temp on Tuesday
VP2            Ground         77.2° 61%  63° 30.04″R NA   76.0°/64.4°

The total precipitation in the cocorahs gauge was 1.01″ from midnight Monday to midnight Tuesday.

Tuesday’s precipitation was 1.01″
May precipitation is 5.91″
Year-to-date precipitation total is 17.65″

WX Bug Lakewood 4500 ft, 76° 55% 58° 30.07″R S 2 G S 8
                            140° from station                  (est) 77°/63°

The Lakewood rain gauge reported 0.04″ of precipitation on Tuesday. May is showing 6.61″ for the month with the 2018 year-to-date (YTD) amount at 21.41″. I still believe at times the great disparity between the Lakewood WX Bug station precipitation amount total for the month and year and my cocorahs gauge based data is that the Lakewood precip values are estimated/adjusted from radar.

At 2400 obs Tuesday night the temperature from the VP2 was 67.2° RH 98% BP 29.96″F DP 66.6°
Light fog, partly cloudy, dry otherwise at 2400 Tuesday

Good afternoon from the partly cloudy, mild, and dry home of the walrus on this Wednesday.