Model Disagreement Continues

There is still considerable disagreement among computer models with the upcoming storm system and associated cold front.

This strong wave which is forecasted to track along the Canadian border will cause a jet streak to form over the Midwest. As I have said before, a jet streak is an area in the jet stream of higher wind speeds. The first thing that this causes is considerably higher vertical sh

ear. Since the jet streak will likely not be located over the area until after the cold front moves through, I would expect that this stronger vertical shear will only have an effect on storms that develop over Wisconsin and Iowa on Saturday afternoon. Second, since jet streaks are associated with winds that are not in geostrophic or gradient wind balance, they will have associated areas of diverging winds, which will destabilize the atmosphere over which the jet is located. An effect that it will have on our area is the fact that it could cause a strengthening of the low level jet, which transports heat and momentum into storms at low levels. If this jet is enhanced, severe storms will be more likely, given stronger low level shear, and continued destabilization of the atmosphere through the overnight hours.

Because of these factors, I have still determined that the main severe weather threat will be damaging winds, due to the fact that MCS development is likely ahead of the cold front in the form of a squall line, with embedded bow echoes.

This will be posted on the blog and I should have an update by afternoon.

Have a great day!