The giant upper level ridge that has been giving the Twin Cities its extended summer temps has begun to shift east, giving way to an equally large trough coming in from the west. As a result, we now have what is known as a trough/ridge pattern over the contiguous United States (CONUS as we weather types refer to it). This large-scale pattern, otherwise known as a “long wave” pattern, is quite pronounced and will serve to bring Minneapolis some very windy conditions indeed. This is because the boundary between these two large air masses is approaching the Twin Cities. This boundary represents where the changes in pressure between the trough and ridge are the most drastic. This creates what is called a “tight pressure gradient.” It is this tightening in the pressure gradient over a relatively small area that creates very windy conditions as air flows from areas of high to low pressure. So, with the approaching boundary between these two “long-wave” features, and its associated “tight pressure gradient”, we are in for some very windy conditions. The Twin Cities can expect these winds to pick up in earnest on Friday morning and last throughout the day and into the evening hours.
There does appear to be an indication of some rain beginning late Friday night . However, the National Weather Service has issued a Fire Weather Watch as well as a Wind Advisory for southern and central Minnesota as a result of the dry and windy conditions that currently persist. These advisories are in effect until Friday evening. So, be very careful with any campfire, bonfire, or any other fire type of activities.
Friday will be a very gusty day with winds out of the south at 20 to 30 mph and gusting up to 40 mph. There is a slight chance of some rain late Friday night, but this will more likely come on Saturday morning. Temps will remain warm due to this southerly flow with a high temp of 82 expected. The overnight low will be 65.
Saturday begins with our best chance of precipitation in quite a while. Rain totals will remain less than a half inch, but any rain at this point is very welcome. Winds will begin to die down during the morning hours and will flatten out by midday. The daytime high will be in the lower 70’s and the overnight low will be near 55 degrees.
Sunday will be cooler and cloudier as the long wave trough and associated surface low move toward the area. Conditions will be mostly cloudy with a high in the upper 60’s. The expected low will be near 55 degrees.
So, there it is. Dry and windy until Friday night, then some quick rain Saturday morning followed by a cloudy Sunday. Here’s hoping you have a great weekend!