Note: This is copied from my 9-2 Weather Update below. I thought it was worthy to carry over on its own.
Hi Farmerguy89 - Let's distinguish 'Frost' from 'Freeze'. Remember, a 'Frost' can occur and cause plant damage with air temps as high as 42 degrees F (5.5 degrees C).
It's about the heat flow. There are three fundamental ways of transferring heat: Conduction (direct contact), Convection (contact with a fluid) and radiation (electromagnetic waves).
Crops can experience frost even though the ambient air temperature is above freezing if the heat loss due to radiation (cloudless night) is greater than the convective heat gain from the air.
Crops can experience frost even though the ambient air temperature is above freezing if the heat loss due to radiation (cloudless night) is greater than the convective heat gain from the air.
'Freezing' is when the temp drops below 32 degrees, and the water in the plant expands and destroys the cell walls, which, if severe enough, will kill the plant.
Now, with that said, I'm not in Canada. I'm going by what I'm seeing on the weather maps, that I have no reason to not be accurate. And, actually, the temps have fallen more as of tonight. Here's the latest maps that I am referring to:
As you can see on the map above, this event starts on Sunday night, the 7th. The full moon is the 8th. The map above clearly shows large areas of Alberta to Ontario with cool temps. Freeze here - no, frost, very possible. (actually, the temps start dropping as early as Friday night, the 5th, but gets colder as the 7th approaches). By next Thursday, the 111th, this is what we see:
Everything from Alberta to Ontartio is cold. This WILL BE FROST - some of these areas will see the end of the growing season in a freeze. These temps are getting colder as the days have gone by. One more map:
This is for Friday, the 12th. The cold now dips into the Northern Tier states of MN and ND. Again, probably not a freeae here in the US, but this event is going to slow down crop development.
Anyway, this is what I'm seeing. Coincidence that it is occuring over the full moon? I don't think so, but we've had this argument before on here. The US is going to escape most of this event. I could have been worse....
Jen
Wow - Now this is a Low:
This is the Jet Stream forecast for next Thursday. This is a massive Low, and why the temps have been dropping in the forecasts. If this happens, I see the temps dropping even lower, and farther South...stand by...
Jen
