If you are a member of CoCoRaHS there is a form online in which you can enter thunderstorm information in regards to the amount of thunder contained in any storm. The specific guidelines are listed below:
Guide To Measuring Thunder Claps
When you are aware that there is an approaching thunderstorm, listen for the sounds of thunder. Record the time that you hear the first clap of thunder. From this time on, record the time of every clap or rumble you hear until the event’s conclusion. A series of claps or rumbles that all occur within 5 seconds is considered one clap. Moreover, a cluster of rumbles or claps should be counted only once.
Example 1: You hear a clap immediately followed by a series of rumbles. This should be counted only once.
Example 2: You hear a series of claps, and then 30 seconds later you hear another series of claps. This should be counted twice.
Example 3: You hear a series of claps, 3 seconds of silence, and then another rumble. This should be counted once.
Example 4: You hear a series of claps, 7 seconds of silence, and then another rumble. This should be counted twice.
If you have a watch with seconds, record the time of the thunderclaps including seconds since there may be more than one clap in a minute. If you do not have a timing device with seconds in it, simply record the time to the minute. For instance, if you hear a clap at 6:48 PM, and then another clap 40 seconds later when it is still 6:48 PM, make a record that you heard two separate claps at 6:48 PM.
We are not going to separate the thunderclaps from different thunderstorms. So if a morning thunderstorm produces six separate claps and then an evening storm produces 8 separate claps, the claps do not have to be grouped. Simply record what time of day each of the claps occurred. There will be an internet form to record the thunderclap information.
We had expectations of rain yesterday however most dried up before reaching SW Michigan – we received a trace here in Otsego. Once again the temp peaked at 70° with mainly cloudy skies. Today will be much the same though the temps should reach the mid-70s. Rain should approach the area late reaching I-96 after dark.
Forecast Discussion
-- Off and on showers and storms through Tuesday -- The rain that has occurred with this system thus far since Saturday night has been quite underwhelming to say the least. We continue to think that a lot of the forcing that was forecast to bring rain to the area was mitigated by a fairly dry easterly flow. That said, we are looking at multiple additional (and better) chances of showers and/or storms through Tuesday. There is a weak band that is just north of the state line early this morning that is forecast to push north through early this afternoon. This will be mainly just light showers with little rainfall amounts expected. A better chance will develop/push through the area focused on this evening and early overnight hours tonight. This batch will have a better threat of some thunder embedded in it also. There is better direct forcing expected to drive this batch via an increasing low level jet developing ahead of the upper low opening up and approaching the area. The best chance for thunder will be down south where some diurnal heating could add to the existing instability that will be present over the area. The severe threat looks limited as the window for the boost in diurnal instability will be short with the instability becoming mostly elevated toward and after sunset. Also, deep layer shear will be limited to 25 knots or less, keeping the potential organization limited. The final chance of showers/storms through Tuesday will come during the late morning-mid afternoon hours on Tuesday. We should see any shower/storm activity from tonight mostly come to an end as the low level jet axis driving them will move east. However, the upper trough and associated sfc trough will remain to our west until Tuesday afternoon. These will push through the area close to peak heating. If breaks in the clouds can occur, we could see CAPEs increase to over 1,000 J/kg, especially further southeast. Shear is not ideal with values as high as 30 knots. If better instability can build with some sunshine with the better shear, we will have the potential for some strong to locally severe storms. -- Additional storms likely Thursday -- Once the trough moves through later Tuesday afternoon, we should see a break in the rain chances for Tuesday night and most of Wednesday. We will be in between the system from Tuesday, and the next incoming system to our west. The latest trends in the models indicate that the MCS that should develop to our west by Wednesday evening, will likely stay mostly north of our area Wednesday night as the nose of strengthening low level jet will ride across Northern Michigan. Our best chance of rain with this system will come Thursday afternoon and night as the associated cold front presses into the area. It is possible that some kind of outflow boundary may drift down into the area on Thursday from the Wednesday night convection. This possible boundary, and the cold front will be encountering a warm and moist air mass the further southeast you go with less cloud cover and better heating. CAPEs could exceed 2,000 J/kg where better heating would take place. Shear would be a bit more favorable with 0- 6km values of 30-35 knots likely. Details three days out are a bit uncertain yet, but the potential is there for an active afternoon/evening. Showers and storms may linger into Thursday night before the front would finally clear the area. -- Quiet and seasonable next weekend -- Once the front is able to clear the area no later than Friday morning, the large upper ridge axis will build in, and bring a sfc ridge right overhead late Friday. The upper ridge would slowly build toward the area through next weekend, providing mostly dry conditions with warming temperatures.
Currently 70* degrees out in my area with clouds perfect July day …..INDY
Today will be the 5th day in a row (the 6th for the month so far) the 5 days is the most days in a row when it has not reached 80 at Grand Rapids in July since 2014. In 2013 the last 8 days did not reach 80 at Grand Rapids. That cool spell continued into August when the first 6 days did not reach 80. At this time it is cloudy and 73 here at my house.
Slim
There have now been 4 days in a row of highs in the 70’s the last time that July had 4 days in a row of highs in the 70’s was in 2014. There was just a trace of rain fall here yesterday. The overnight low here was 63 and the official low looks to have been 62 at GRR. At this time it is cloudy and 72 here.
Slim
So far this year there have officially been 13 “thunderstorms” at Grand Rapids. Now while that may seem like a lot here at my house I have not counted the thunder events and I am sure there would be some that I miss but personally I feel we have NOT had many events this year so far. While it is true there have been times of some distance lightning there has of yet been a close up storm here that I know of.
Slim
Some of the storms have been pretty hit-or-miss. I live close to the airport and we have had a number of days with nearby claps of thunder that I am sure other parts of the county missed out on. It would be interesting to see how many thunder days Mark has counted… they have had a ton of thunderstorms the past 30 days in the Lansing/Okemos area.
Too many to count, I reckon.
According to the Lansing weather station report there have been 15 in the last 30 days.
Slim