In a recent webinar, Colorado State University hurricane forecaster Phil Klotzbach remarked that if the “busy” hurricane season is a bust then it would be largely due to the European heat wave. Given that, let me explain, so stick with me.
First, let’s tackle that heat wave which has been ferocious and deadly. Last month, 116.6 F was recorded in Pinho, Portugal, on Thursday, July 14, for the highest July record ever in that country, the Seine river in Paris is at crucially low depths while France is having its hottest summer on record, and England is rationing water usage and suffering with almost all residents having no air conditioning. What has happened?
Very strong high pressure over the Atlantic is keeping the northerly jet stream north of Europe, so any rainy low pressure systems are missing them to the north. In fact, we continue to see low pressure systems off of Portugal and Africa just sitting there -- they are too far away from the jet stream and so are cut-off from it and not moving quickly. Thus, these are known as cut off lows. That low circulates very hot, dry Saharan desert air northward into Europe. Here’s the 500 mb map this past weekend, illustrating this across both the Atlantic Ocean and Europe:
Over this past weekend, high temperatures were forecasted to be in the triple digits, even to southern France with upper 80s to 90° in Britain:
So that is how the European heat wave has been working all summer and will continue to work the rest of the summer.
How does that affect the hurricane season? The cut off lows do finally move slowly across Europe to the east, but that hot, dry air is still sitting there over Europe and the same Atlantic high moves that air southward over the Atlantic. Hurricanes have a problem with dry air! Here are two forecast maps showing just that -- for this coming Wednesday and a week from Wednesday.
In fact, if the American Model is correct, the long-term forecast continues to show almost every system coming off Africa withering in the dry air before getting started. However, we may see something show up the end of the month. Take a look:
Not to say we couldn’t see a spin up of a tropical system in the Gulf or Caribbean-- after all, look how close we came in Corpus over the weekend -- but we just might get to the end of this month with very little happening in the tropics!
Have a great week and stay cool and hydrated!