Models always seem to underestimate a melt down

[bladeguy]

Hi John!

I have noticed a trend over many years that when a short duration modest warm up is predicted in the north woods during the winter the models will more often than not underestimate the temperature and what we thought would be not too bad a meltdown is ten degrees warmer than expected and a disaster to us snowmobilers. This weekend is just one example (although not calling it a disaster this early in the season but it was warmer than the models predicted). I have a few questions for you:
1. Do you also notice this trend?
2. Is there any data that backs me up? I imagine it is hard to measure this - ie what defines a short duration modest warm up?
3. Do the people who create/run these models look for trends such as this - predicted temperatures in certain situations vs. actual.
3a. If so do they ever adjust the models to try to correct situations that are trending incorrectly? - such as underestimating short duration modest warmups in the north woods during winter.

I am thinking that the powers that be might not think it is such a bad thing to be a little warmer in the winter - most people are pleasantly surprised. But wrong is wrong and for snow lovers it is dissapointing, and causes problems with trip planning. I never believe that the warm up is not going to be too bad - and I sure seem to be right a lot of the time!

Thanks and keep up the great work!

 

[bladeguy]

... I had said ten degrees warmer than expected. Even 5 can be a disaster. 2-3 days of 40 vs 35 degress predicted can have quite a different effect on the snow pack and trails.

 

[jd]

Funny you ask this, as I have found for my particular neck of the woods that this thaw is going about as expected. Temps have stayed within around 2-3 degrees of the forecast and even the snow loss is about what was expected. I have not paid close attention to other areas, so cannot say that it is true for them.

I will say that in many cases, there does seem to be an underestimation of max temps during the warm ups. It would appear that the models do have a bit of a problem trying to nail down temps during a cold season warm up. Problem is, sometimes they do get it right and so the trick as a forecaster becomes trying to figure out when they seem to have it right and not.

-John