Radar
3 responses | 0 likes
Started by wglassfo - June 8, 2021, 2:42 p.m.

Yellow and red travelled up the 401 high way and right over top of our farm

Not one drop of rain

Another system supposed to be headed our way

Will we get rain??? Scattered showers at best

Don't believe what the radar shows on a map

Comments
Re: Radar
0 likes
By mcfarm - June 8, 2021, 5:52 p.m.
Like Reply

radars are different from different sources. And it seems this time of year it gets worse. And what is common is for a dry area to be forced to bright red before actual moisture is falling while in a wet area a light green means you are done for the day in the field.

Re: Re: Radar
0 likes
By metmike - June 8, 2021, 7:15 p.m.
Like Reply

There is some truth to that mcfarm.

Radar only tells you what is happening well above the ground. The farther that the location is from the radar source, the higher the beam is because of the curvature of the earth vs the beam being a straight line(the earth curves away from the beam as it gets higher and higher. I thinks its something like 10,000 feet higher for every 90 miles as the crow flies.

So there are 2 things going on here when the ground is really dry.

1. The radar sees those storms coming in at a distance that are lighting up the heavy rain colors because they are wonderful rain producers aloft/in the clouds which is where the beam is....not on the ground.

2. If the ground is bone dry, its likely the low level moisture from evaporation off the surface is non existent, especially when compared to wet soils. The difference, when you have a system that is just barely over the threshold for producing rainfall can make or break production.

On the other hand, if the soils are wet, in some cases with extremely saturated soils and standing water,  it can be almost like having a body of water below and the low level moisture from that is plenty enough to make potential rain makers passing by as much more productive vs the dry soil case.

You've head the expression, drought begets drought and this is part of it.

Also, if a prevailing dry weather pattern has lasted a long time, its often hard to break out of that pattern.

There is a tendency for the same pattern to repeat itself for awhile. So if you are dry, its likely that you got that way from the prevailing pattern of non productive weather systems. 

Though the weather around the world is very progressive in a general sense, certain large scale features try to get entrenched because of the affects of oceanic and land temperature/moisture relationships, along with the suns changing heat as the year progresses. This is why some places have monsoons and extremely seasonal weather swings every year. 

The same thing applies on a way more complicated, random scale to the relationships of these weather driving forces everywhere that can sometimes resemble a monsoonal type affect........last for several months at a time and cause droughts or repeated excessive rainfall events over the same general areas. 

Looky here for a quintessential example of the result of that exact thing happening this year in the US.

My very educated guess is the cooler water in the Eastern Tropical Pacific, associated with the La Nina which has weakened and is historically the cause of droughts in the US (but you never know where the drought will be) has been displacing the jet stream/causing dry flow in order to cause this pattern. This is causing more upper level ridging in the western part of North America. 

The actual southern branch of the jet stream has been very active and is pummeling the southern half of the US repeatedly with too much rain. Weather systems to the south keep getting deflected to the east(without being able to track farther north) by that dominant flow which is westerly across the West to the northern half of the US.

We've seen this pattern persist for months now.

Daily Anomaly Soil Moisture (mm)

By metmike - June 8, 2021, 7:40 p.m.
Like Reply

Wayne,

I can see exactly how dang dry you are up there in southwest Ontario.

Here's the latest weather.

https://www.marketforum.com/forum/topic/70329/


Sadly, it looks like you will be just north of  the best chance for some big rains in the Ohio Valley and Eastern Cornbelt this week as the same pattern continues.

However, there are several chances for a decent rain event this week for you. It would not surprise me at all for that to happen.

With the heat ridge backing up west, it promotes more northerly component to the flow where you are in week 2 which will cool temps down but is notoriously dry.