Weather is a part of our day. We are aware of it. We plan for it. We are affected by it. Many people take weather information for granted. Its on our phones, television screens, Internet pages, or radios. The "weather fairy" does not produce those forecast numbers, emojis, and warnings. Meteorologists, using various tools, do. I often say we are living in a golden age of weather forecasts. The public often gets stuck in the "inertia of perception." I find that there is a lack of understanding of the accuracy of weather forecasting and personal misconceptions about how good forecasts are supposed to be. A previous piece that I wrote in Forbes explores why people think weather forecasts are bad when they are actually pretty good. Meteorologists work under very stressful and high-pressure conditions, especially when dealing with situations like Hurricane Michael or potential tornado outbreak. It is why a weather forecast discussion issued by a forecaster at the National Weather Service Office in Juneau, Alaska this week was so refreshing.
To understand what I am talking about, I present to you the long-term analysis in the Southeast Alaska Forecast Discussion by the National Weather Service, Alaska. This Forecast Discussion was issued at 5:43 am AKDT on October 30th and brilliantly captures, in an accessible way, the challenges of making snow forecasts.
"I have done the deed," as Macbeth once nervously proclaimed. As is customarily the case when one first reads "snow" in the forecast, one can imagine the trepidation felt by a forecaster at the first instance where said forecaster is presented with this high profile conundrum. It is truly the stuff of Shakespearean tragedy. Someone has to do it; it is Alaska and the calendar doth say, "Consider it not so deeply." But even after it is done, there is always thoughts of doubt, as Lady Macbeth states, "I am afraid they have awaked and tis not done." It may not be done, because the low on Thursday night comes hither on a path more southerly than we originally thought, so
slaying each outlier model run as one bidst "God bless us," and the other "Amen," has become a challenge indeed in such a difficult pattern to get right. While earlier we speculated the low to follow a northerly course across the north central Panhandle, suggesting a warmer system, we are looking at possibly a much more southerly track with areas north of Petersburg under the influence of a cooler air mass. So while we have decreased pop (probability of precipitation), yet not erased it, and lowered expected precipitation amounts across the north, we have also cooled temperatures a bit more boldly, therefore adding a chance of rain and, yes obligatorily,
snow for much of the northern Panhandle Thursday night through the weekend. "This is a sorry sight," rings the wisdom of Lady Macbeth. So while we feel as if we needed to get the deed done, we also acknowledge that much of this forecast averages solutions that will likely span two bookended likelihoods of either a drier and colder atmosphere whereby nothing falls from the sky, or else, a more northerly track with a wetter and warmer atmosphere whereby the only thing that does fall is in liquid form. And thus we risk our messaging going haywire with our forecasts marked with magical four-letter words beginning in `s.` Only we should stress the
preceding words--"chance of."
By the way, what is the Forecast Discussion anyhow? The National Weather Service (NWS) offices issue Forecast Discussions to provide a summary of the meteorological logic and thinking behind weather forecasts that are issued. They are often found on NWS webpages or occasionally in their social media feeds. As a meteorologist, I typically go right to the Forecast Discussions, but they can have quite a bit of meteorological jargon. In reality, the target audience for these products may be a bit different than the more publicly-facing advisories issued by the NWS.
In the case of the "Macbethian" discussion, the forecaster is cleverly providing insight into the challenges of assessing the track of a low pressure system and its eventual impact on the possibility of snow. If you live in the South or Northeast, these same challenges are often at play. The position and track of a low can mean the difference in a location receiving a lot of snow or rain. The infamous "rain-snow" line drives meteorologists crazy. I loved it and so did Twitter. Curtis Marshall tweeted "Promote that guy," and Will Weaver said "Bahaha, I love it when forecasters do things like this!"
