Deconstructing Goliath; Bonus January Outlook

One of the benefits of being a hobby/amateur forecaster is that I really have no "skin" in the game.  While I really do want to give you good insight and accurate forecasts, my career doesn't depend on doing so.  So, unlike the pros, I'm happy to admit when I made a miscalculation in the spirit of learning and doing better next time.

While I realize I'm grading my own homework here, I thought it might be fun to deconstruct yesterday's storm against my own forecast.

What I Got Wrong:

1. The biggest thing I got wrong was the high temperature, and that impacted other parts of the forecast.  I predicted a high of 33, thinking that the warm air wrapping around the low would drive up the temperature as the system approached in the late afternoon.  Instead, I recorded a high of 28 in New Glarus -- also the official high at the Madison airport.
2. Because of the colder temperatures, we saw more snow accumulation than I expected.  I predicted 2-4".  Madison's official snowfall was 5.9", and here in New Glarus, I measured 4.5".  Still within the meteorological margin of error, I suppose, but I was low nonetheless.

Here's what the early snow totals look like around the region (click to enlarge).

What I Got Right:

1. First and foremost, I was ahead of this storm by 6 days.  While it's risky to start talking about a December 28th storm on December 22nd (as I did on Facebook), I felt that with the holidays and folks traveling, the reward outweighed the risk.
2. I got the "pre-slopitation" right.  Here in New Glarus (and nearly all other locations I was tracking), we had sleet, freezing rain and snow.  In fact, the sleet was steady for almost a 5-hour period between 2pm and 7pm, when precipitation changed back to snow.
3. The wind forecast was also correct.  The highest speed I recorded was 34 MPH, but other reports were as high as 60 MPH (which I accurately predicted would occur in the far southeast corner of the state).  
4. I mostly got the timing right.  I said the storm would start mid-morning.  Here in New Glarus, it started at 8am.
5. Finally, and this might actually be the most important thing, I said in a Saturday Facebook post that driving would be a really bad idea on Monday.  Safety is important to me in winter forecasts.  As you probably heard, emergency services responded to hundreds of crashes, rollovers and slide-offs in southern Wisconsin alone.

With that, let's look ahead to what January may have in store.

All models are currently showing a southern jet stream through at least the third week of the month.  This allows colder Canadian air to infiltrate the Midwest, setting us up for seasonably cold temperatures.  I don't see any polar vortices on the horizon; in fact, there's a chance we could get through January without even seeing subzero temperatures.  I don't know if that's ever happened before in January, but I'm looking into it with the State Climatology Office.  I'll keep you posted.

At the same time, major storm systems for the first couple weeks of January seem like they'll be relegated to both the east and west coasts (a trademark of El Nino winters), with very little action here in the Midwest.  The GFS model is showing a weaker disturbance next Thursday, January 7th, so I'll keep on eye on that.  Otherwise, there's not much out there.  Of course, that can change.

Finally, I want to say "thanks" to those of you who are genuinely interested in Rippeology.  Obviously, I enjoy it, but it is a bit of work.  Since Saturday, the blog has had over 250 visitors, which is pretty cool.  I appreciate your interest!

As always, let me know if I can answer any questions for you, either here or on Facebook.

~Scott