WunderBlog Archive » Category 6™

Category 6 has moved! See the latest from Dr. Jeff Masters and Bob Henson here.

Invest 98L or a nor'easter?

By: Dr. Jeff Masters, 1:52 AM GMT on July 24, 2009

Hi, it's Dr. Rob Carver, filling in for Dr. Masters today.

Take a look at the satellite image below:

Fig. 1 GOES IR composite at 2120 EDT, July 23 2009

What do you see? (This is like a Rorschach test for meteorologists) Well, it's got a comma head with what looks like a front extending southward. It must be a nor'easter with some pretty good precipitation bands from NY into New England. There are also plenty of coastal flood advisories out to make it seem like fall/winter. Right?

Fig. 1 Plot of severe weather advisories made at 2120 EDT, July 23 2009

Well, that's not quite the right answer. For 4 hours earlier today, this low was known as INVEST98L. I have to admit that this designation caught me by surprise. Looking at the QUIKSCAT passes and SSMI data in the dark hours of the morning (I work in the SF office), I saw an elongated cyclone that looked it had a front extending southward. That meant the feature was maybe subtropical at best, and more than likely extratropical given the model analyses available. So, color me surprised when I found out about INVEST98L and even more surprised about it's short lifespan.

Moving on and taking at look at the tropical Atlantic, there's not much in the way of tropical waves to look at on satellite except for the fresh cluster that just moved off the coast. We'll have to wait and see how that wave will develop.



The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.