Where’s my snow?: What happened to the forecast this week
With several storms forecasted this week that failed to meet stated expectations, what was there that caused meteorologists to take the heavy hand?
RAPID CITY, S.D. – Where’s the snow? The forecast for this last week 3/6-3/9 called for appreciable snow throughout the Black Hills Region. Many areas fell short – with some areas included in winter storm bulletins having received just a few flakes of snow by Tuesday evening. What happened? How could this happen?
As meteorologists and residents it’s easy to pass off the shortfall as “oh well that’s just the Black Hills” – but that would be disingenuous to the science. Something was missed, or perhaps something was overstated.
Lets break it down. Let’s start with implicit human bias – 3/5 Sunday evening forecast called for maybe an inch or so of snow for Rapid City – a snow squall scooped up appreciable moisture with a close-knit compact low pressure system and strafed the area with several inches of snow.
Forecast called for less than an inch of snow
We got whiteout conditions and several inches of snow.
This puts meteorologists in a position of changing their implicit bias towards future forecasts in the short term. That is to say – conditions are more volatile than they appear.
In the world of “persistence forecasting”, you want to recognize the overall pattern that favors this activity, and inject that into future forecasts. Models were aggressive with Tuesdays system by Monday morning…. which reinforced suspicions that another squall was likely on the way. This is despite that fact that model resolution was inconsistent with low pressure location and strength…. which is important in tipping the scales.
Because of implicit bias from Sunday evenings snowfall, and low level moisture looking favorable. I directed our team to take the stance that models may be under-reporting potential impacts and we should be ready for more snow.
This happened twice, both for Tuesday’s system and for Wednesday-Thursday’s system.
Although we had good easterly winds at the lower levels, we missed the upper level support that a nearby low pressure system would provide. If Sunday’s system was able to produce whiteout conditions with very little support, then Tuesday and Wednesday certainly could given that those days had even more forecasted favorable conditions.
However, most of the energy ended up traveling to our north, and our south. We got split right down the middle.
The good news is I believe we’ll have plenty more chances for moisture over the next few months – we’re in an unstable pattern synoptically, which means even if our local conditions this week didn’t pan out we’re still in a pattern that will likely give us more chances to step up to the plate.
This weeks storm goes into the little black book of weather events – The lesson is that the mother nature will always have the final word – meteorology still has a long way to go.
Appreciate everyone that sent in their storm reports, here are some pictures from across the area.