JETSTREAK FOCUS

The picture with the dark blue and violet wind arrows shows how air behaves when it passes through a jetstreak. Breaking up the jetstreak into four quadrants, the following air- flow characteristics develop.

Right entrance region: upper level divergence
Left entrance region: upper level convergance

Right exit region: upper level convergence
Left exit region: upper level divergence

This is assumed for a linear jetstreak, though often jetstreaks occur within curved flow.

The black and white picture above shows a jetstreak within the base of a trough and one at the crest of a ridge. The one on the left is referred to as a cyclonically curved jetstreak. It can be shown mathematically that flow within the exit region which is the area to the right of the trough base, that upper divergence develops with air converging at the surface.

Now lastly, look at the 300mb map with the blue shadings, marking the regions of fastest wind speed. The red dashed line marks the center of the upper level trough. Take note of the position of the jetstreak within the base. Much of eastern OK and western AR are in the within the area of dashed yellow which is where we will have enhanced surface convergance and upper level divergence due to this cyclonically curved jetstreak. There will be a lot of jet enrgy at hand and this positioning will likely coincide with the period within in which we receive our biggest storms. Right now, this appears to be within the early morning to early afternoon window of Saturday.

Keep it tuned to 40/29! We've got you covered on-air as well as on the web!

Posted by Ted Zarras at 5:06 PM