THE CICADA SINGS ITS FROSTY SONG...
I started hearing the cicada's singing outside my house a few days ago. My expert source on such things, Steve Gottschalk, says he heard his first song at 9:00 p.m. July 10th. That's about a week later than usual. (He keeps detailed records on this stuff). So why would you care? Well, according to folklore the initial shrill melody of the cicada is an indicator of when the first frost will occur. My mom passed that along to me many years ago and I always think of her when the cicada are in chorus as they are now.
The sound that I'm talking about is not so much a song as it is a high pitched buzz. It's much like ringing in your ears only 10 times louder. When you get a swarm going at one time it can be downright deafening.
The high-pitched song is actually a mating call belted out by males. Each species has its own distinctive song that only attracts females of its own kind. This allows several different species to coexist.
There is a weather folklore saying that you can determine the first frost after hearing the first dog day cicada sing. I mentioned earlier that Steve heard his in Lowden, Iowa on July 10th, which he claims is 5 to 6 days later than usual. There are 3 variations of the folklore saying: the frost will occur 12 weeks after, 90 days after and 3 months after the first song. Based on the 10th of July, the first frost would occur as follows under one of those guidelines:
12 weeks - September 20th
90 days - October 8th
3 months - October 10th
On most any hazy lazy day of summer now you can hear the male "dog day" cicada's calling for females high in the trees. The love song is created by vibrating membranes on their abdomen. Dog day cicada's as their name implies are found during the long hot summer days of July and August.
Cicadas are the only insects capable of producing such a unique, loud, and at times irritating sound. Some larger species can produce a call in excess of 120 decibels at close range. That's about the threshold where pain occurs in the human ear!
Another cool thing about cicada's is that as they turn into adults they leave a shell or nymph casing behind. It looks just like the cicada but its nothing more than a hard brown shell. We would find them as kids on the bark of trees or just laying in the grass below them. We would light the shells on fire or crush them with shoes or hammers. I remember blowing up a shell with a lady finger firecracker! Harmless fun, or so we thought. Here's what a shell/casing looks like.
Anyway, if our singing artist the Cicada is correct, we can expect our first visit from good old Jack Frost between September 20th and October 10th. I prefer the 3 month adage so I like the October 10th time frame.
THE WEEKEND AHEAD
Now to the all important weekend weather ahead. Overnight, the low level jet has kicked in and along with increased moisture and low level convergence has allowed showers and thunderstorms to fire. It's likely that an MCS (or its remnants) will be in the area Friday. Mesoscale details, which are difficult to detect, even at short distances, will play a critical role in where the heaviest rains fall. As it stands now, the northeast half of my area is most at risk, at least with this initial MCS.
Water vapor is shown reaching close to 2 inches. That is a moisture rich environment that is likely to generate a swath of heavy rains that in spots could measure 1-2 inches where the stronger cores travel.
Here's what models are suggesting for rain totals though Sunday.
The GFS
The 12k NAM
The 3K NAM
The EURO
The NBM national blend of models.
The Weather Prediction Center analysis.
While the storms may kick up some gusty winds, severe weather does not appear to be much of an issue with shear indicated to be weak through Saturday.
A tight temperature gradient is likely Friday with upper 70s possible in clouds and rain cooled air, mainly over the northeast. Otherwise, readings in southeast Iowa could easily reach the upper 80s with the aid of any sunshine.
Saturday through Sunday the frontal boundary is still in close enough proximity that there is at least a chance of additional showers and storms. I don't look for much Saturday but the GFS is adamant that a surface wave will form on the boundary enhancing rain chances Saturday night and Sunday. Guidance is quite varied on if or when any rain would occur. I certainly want to stress that the weekend won't be a washout as there will be plenty of dry hours. However things play out over this period, the best chances of significant rain looks to be over my southern counties. Temperature will be highly dependent on how much sunshine can break through both days. Right now highs should generally be in the range of 80 north to 85 south.
With the synoptic set-up not changing much over the coming week, warm muggy conditions are likely. The pattern gets more challenging in terms of temperatures July 21st-28th. Some of that western heat tries to make a push into the Midwest. The question is whether the eastern trough can remain amplified enough to keep any heat intrusion minimal. Additionally, if the heat does make it into my area, how long will it stick around. The Climate Prediction Center is convinced enough that is has issued a moderate risk of excessive heat in my area July 22-28th.
With that, I will call it a post and get serenaded by a cicada. Thank God it's Friday! Roll weather...TS
