Forecasting Woes

2012-02-13 23:58:49.000 – Mike Carmon,  Weather Observer/Meteorologist

Oh, well hello there. Is it time for me to talk with you again already? Since my shift-mates haven’t stepped into this role today, I suppose I will.

Let me fill you in on a struggle I’ve been having throughout the entire shift week. I’ve been doing even more forecasting this week than I normally do, and this has resulted in a total immersion in the goings-on with the weather. We’ve mentioned countless times before that we rely heavily on computer models to craft reliable forecasts to distribute to the general public. With experience forecasting on Mt. Washington, one learns the patterns that models often display in certain weather scenarios, and stores them in their forecasting memory for future occasions where similar weather setups present themselves.

This week, my faith in the models has gone completely out the window, with extreme doubt rushing in to take its place. There have been times in the past when the models would give us numbers that ended up a bit off when verification time came around, but normally, they correct themselves within a day or two. That has been anything but the case this week, and nothing was more telling than this latest high wind event (accompanied by the arctic blast), when we reached a peak gust of 118 mph. If you were up on my forecasting, you would know that it called for 70-90 mph winds on Monday morning, decreasing to 55-75 mph later in the day. However, winds ended up ranging in the 85-105 mph range for the first half of the day, decreasing to about 70-90 mph later.

I’ve been off a bit like this before, but the fact was, I added quite a bit already to what the models were advertising, which apparently was still not enough. Model numbers were forecasting winds on the summit at about 60-80 mph in the morning, decreasing to about 50-70 mph by evening–quite a discrepancy from what actually occurred.

My theory for this and other similar model failures ties into the mild winter we’re currently experiencing–that the wintertime models cannot handle the more warm-season type weather scenarios that have been embracing the region for most of the winter. Due to differences in atmospheric dynamics and thermodynamics between winter and summer, computer models utilize a different set of equations during these two opposing seasons. However, the surprisingly mild winter has thrown a giant monkey wrench into this principle, and is manifesting itself, among other ways, in decreased computer model output accuracy.

So for the sake of my forecasting accuracy for the remainder of the winter, I am hoping more winter-like setups will come to fruition in the coming weeks.

Mike Carmon,  Weather Observer/Meteorologist