We’re going to take a glance at the data and forecast for August 2017. It’s the last full month of summer and the days are getting ever so slowly shorter. Still we’re going into what some like to call the dog days of summer. To start August it isn’t going to feel very much like mid summer in a lot of areas east of the Rockies (west of there, the west coast the heat is on) First let’s take a look at the Canadian weekly forecast model.
In the first week of August another trough (quite deep for this time of year) will be swinging through the Great Lakes into the North east bringing with it another cooler more dry air mass. We see in the image above, the mid level flow in the atmosphere. See how this reflects at the surface in the next image (temp anomalies)
As cold fronts slide south they will likely get hung up in in the south or perhaps the Gulf coast (watch out for fronts that do stall in the Gulf of Mexico as that can be a focus for tropical system development)
We start to see a turn around in the pattern by mid month as the Atlantic ridge tries to move westward bringing humid warm air back into the south east.
Week 3 above shows heights aloft rising with the temps also on the rebound in areas where they are or below normal.
Week 3 temps in the above image. The CFS (Climate Forecast System) is also quite cool for the first half of August but as seen in the image below over the course of the month the weather starts to do a flip from cool and wet to warm and a bit more dry
Overall for August things will likely end up just below to near average in places where it’s cool now (though the Great Lakes and New England I can see ending up just below normal by months end)
Canadian monthly forecast model of the mid level flow.
The Climate Prediction Center is going with this for August.
Probability of above, below or near average temps in the image above, below is the rain fall probability.