May 12: Forecast update - Model roller coaster

We went to Busch Gardens a couple weekends ago, but I feel like I'm still riding Apollo's Chariot. Forecasting for our Plains storm photography expedition has been as difficult as ever this week. Today's blog post has two parts, since I'm posting an update this evening.

I posted this early this morning: The long-range models have continued to indicate the east coast trough locking itself in place for an extended time, shutting the Plains severe weather maker down indefinately. Indications now are that the inactive pattern might persist through at least the end of the month. Our departure date now looks to be as late as around the 27th of May or beyond. There are some indications of a western trough taking shape earlier, but most models do not agree on this feature - and the ones that do have not been consistent in maintaining it from day to day. Unfortunately we might be looking at the possibility of not having an extended trip this year if the model forecasts verify, but we won't look at making that type of decision until it's apparent we absolutely have to. If we cancel our main trip, we will likely just plan to take a short-fuse 3 to 5 day trip when and if the patterns do change back to favoring supercells and tornadoes.

8:09PM: Now, the latest model runs look much better for late May, giving the 21st-27th period another chance. So, we'll make another dramatic adjustment to our probability table.

Based on the current outlook, this probability table charts the chance of our trip starting on a particular date:

2006 Storm Photography Expedition - Departure Date Probability as of May 12 (PM)

May 12-16

May 17-20

May 21-27

47%

May 28-June 4

47%

No trip