cae

Snowing nicely again here. Biggest flakes of the day. About 4.5".

REPS (RGEM ensemble) I added the REPS to this one because I think this was a good example of why a short-range ensemble is useful. At 00z on 1/11, less than 48 hours before snow started falling, the Euro, Ukie, and GFS had DC getting less than 0.3" of precipitation. The wettest global was the GGEM, which showed DC in the 0.4" - 0.6" contour. The RGEM and HRDPS were both out of range, and the NAMs effectively were. This is what the 3k NAM was showing at the time, with precip having moved offshore at the end of the run. But the RGEM ensemble mean put DC in the 0.6" - 0.8" contour, which was even wetter than the GGEM. In retrospect, it was a good sign that this system still had a lot of upside potential. At the time it was an outlier, but it arguably ended up busting low. The below images use the weather.us color scale.

HRDPS The HRDPS was similar to the RGEM on this one.

RGEM The RGEM did better than most of the globals, but like the GGEM it missed the higher precip totals in central MD.

3k NAM The 3k NAM was way off in its early runs, but after it caught on (about 54 hours before the end of the storm) it was arguably the best of the mesoscale models.

NAM The long-range NAM was way off, and in the short range it was overdone, but overall it was a signal that some of the globals were too dry.

FV3 The best global model overall might have been the FV3. Like the ICON, it looked pretty good at the end, but unlike the ICON it had been fairly consistent. I mentioned above that the Euro was arguably the worst model for the first 24 hours of the storm. The FV3 was arguably the best. Below is the actual precip totals from the first 24 hours followed by the FV3's final 24-hour prediction. Looks good to me.

ICON The ICON bounced around a lot but ended up looking pretty good in the end. Arguably the best of the globals at game time.

GGEM From the model discussion thread: "I tell you what too... CMC has consistently pointed at higher totals (little ebb and flow) and better coastal enhancement. The 12z is even better than 0z lol. If it scores a coup on the gfs/euro I’ll build a mini shrine to it on my desk." In some ways this was similar to the last storm, with the GGEM generally showing higher totals around Washington than most of the other globals. It ended up being too dry in the end, but for a while it looked like a wet outlier.

GFS Like the Euro, the GFS also kept the precip too far to our south but started to catch on at the end. It did better than the Euro with the first part of the storm though.

UKMET The Ukie was also too dry near us, even at the end.

Euro Here's the precip analysis. The Euro predictions are below that, using the same color scale. Again the Euro was too dry around us, only catching on near the end. For the first part of the storm (up to 12z on Saturday), it was arguably the worst model. Below is its 24-hour total precip forecast at 12z on Friday. This is what we actually got over those 24 hours. Another global did much better with the first part of the storm. We'll get to that below.

Here's the LWX preliminary snowfall map for this event. I'll go through the major models below, and then I'll write up some extra thoughts at the end. The below gifs show the runs from 12z 1/09 to 18z 1/12. Some snow had fallen in the western areas by 18z 1/12, but I chose 18z instead of 12z so we could get more model runs in. The precip totals are from the start of the run to 12z 1/14. For the RGEM and HRDPS, I include runs that end as early as 00z 1/14 because they only go out to about 48 hours.

Filler post so we don't have too many graphics on one page.

Filler post so we don't have too many graphics on one page.

Filler post so we don't have too many graphics on one page.

Filler post so we don't have too many graphics on one page.

Filler post so we don't have too many graphics on one page.

Filler post so we don't have too many graphics on one page.

Filler post so we don't have too many graphics on one page.

Filler post so we don't have too many graphics on one page.

Filler post so we don't have too many graphics on one page.

Filler post so we don't have too many graphics on one page.

Filler post so we don't have too many graphics on one page.

Filler post so we don't have too many graphics on one page.