Wednesday, January 29, 2014

The Best Way To Bust A Forecast

If you forecast weather for any length of time, you're going to miss some forecasts.  We call it a "bust." It happens. If you do it long enough though, you'll soon learn the BEST practice in limiting the damage from a busted forecast.

Case in point, Atlanta, GA and Birmingham, AL last night and today.  Last I heard, some were STILL stuck in traffic!  How did this happen?  Well for one thing, local TV meteorologists were calling for a "dusting" of snow and they wound up with up to 3 inches.  Sadly, at least one news story called it a "misleading forecast," which is really unfair. The LAST thing reputable meteorologists are trying to do is mislead the public.

In the case of Atlanta and Birmingham, even though these mets are among the best in the nation, they really don't get the chance to forecast snow very often.  The drivers in those cities don't get a lot of practice on how to drive on it.  Street and road departments don't have the equipment to treat it and handle it like those further north.

To be fair, some really good mets whiffed on this one, including one of the best meteorologists in the nation, James Spann.  To his credit, he manned up and took responsibility.  It happens to the best sometimes.

My approach in my 30 plus years of forecasting takes on a little bit of "handicapping." I try to determine what is going to happen, but weigh in the possible ramifications in case of a miss.  This is especially true with snow which is VERY HARD to precisely forecast with amounts, timing, etc.

If you forecast a large amount of snow and we wind up getting just a little or none, people are disappointed and they might point a finger at you, but most of the time, they were prepared for the worst and took precautions.

If you forecast little or none, and you wind up getting several inches, you wind up with a situation like they had in Atlanta and Birmingham, where people were UNPREPARED: traffic jams, wrecks, children stuck at school, etc.  MAJOR PROBLEMS and HARDSHIP for people.

That's why I've always tried to "widen the goal posts" and forecast snow to allow for the upper end of what "could" happen, so that people can take that into consideration and be prepared.  If the data indicates we'll get 2 inches.  I might forecast 1/2" to 4" to allow for banding, bursts and other things which could throw off what the data indicates.  Snow is NOT a precise thing at all.  The more precise one tries to be with a snow forecast, the more likely one is to appear wrong.

I remember a couple of years ago, a younger meteorologist contacted me and and was down on himself for missing a snow forecast.  What had happened was a disturbance caused a "burst" of snow over part of the region and they wound up with 4 or 5 inches instead of the one inch he thought we would get. I passed along my philosophy to him and also told him, "Hey it happens sometimes, to the BEST of us." In that case, EVERYBODY, not just him, missed low.

My advice to meteorologists in forecasting snow is do your best to determine what's going to happen, but also do your best to determine the consequences of what could happen if conditions shift and factor that into how you communicate the forecast to the public.  That way, they might not be caught off guard as much!