Good Saturday morning to one and all.
Thank you very much for considering this weather blog as a place to go for the information you need, and the deeper look at the forecast you crave ;-)
Let's go back over the forecast for this past event, using this blog post as a reference.
...And here's what happened...
|National Snow Analysis - Satellite Based Snow Depth (pre-storm)||National Snow Analysis - Satellite Based Snow Depth (Today)|
Satellite-based analysis is obviously looking at things from a distance, we can supplement it with surface observations, both from you all and from the official measuring stations.
|Location||Total Snowfall (as of 12/31/12)|
|Coal Run Village||2.0"|
It's clear that the verification of the forecast found that the final numbers came in lower than what was anticipated, however the actual forecast itself was at least better than the consensus values from what else was out there. I had mentioned in the write-up the other day that I did want to have the 1" possibility in there regardless if the conventional wisdom going was that 3" was closer to the median value.
The biggest surprise for me was the low snowfall totals east of Charleston. The post-frontal upslope snowfall never really materialized (perhaps because of how quick-moving the developed coastal low high-tailed it out of here). Even Snowshoe mountain had only 2" of new snow (though it was still snowing this morning). Only the higher terrain in the Northeast WV mountains are getting close to those upper totals. The numbers being low north of Charleston and I-79 did not surprise me as much because I knew that was going to be a possibility. I actually took a stab at the higher totals there specifically because of the light and fluffy totals from the day before. They actually got a similar amount of liquid water out of this event, but it did not fluff up this time despite similarly cold temperatures (more on that soon). It's one of those things about snowfall forecasting that's such an interesting challenge. Even if you get the amount of water that falls out of the cloud right, you still need to further refine it to divine how fluffy or dense the resultant snow will be.
One thing I learned...
I talked about this yesterday in an update to the blog post in the morning. When evaluating the vertical temperature profile of the atmosphere (critical for assessing precipitation type), it became clear to me that a rain/snow mix was not going to come up to the I-64 corridor because the soundings (vertical temperature profile) was entirely below freezing. However, what I failed to see was that there was enough dry air at one particular level of the atmosphere to essentially slice the cloud layer in two-- creating a problem. This problem was that the clouds creating the snow could not get cold enough to sustain proper flake (dendrite) growth. This threshold is -10°C as far as the physics tells us. A cloud warmer than this, even though entirely below freezing, instead of spitting out flakes we got freezing drizzle (in this case super-cooled water falling to the surface). Had we been able to maintain the proper cloud physics that the vertical temperature profile engendered, we definitely would have had more snow. Indeed, if you recall that switch to freezing drizzle came at a critical time where the precipitation was going good.
(The above is a note-to-self for not missing this in a future forecast) ;-)
Our next storm system is going to be a rain maker, so enjoy whatever you've got for snow while you still have it.
|NAM - Monday AM||NAM - Precip Type - Monday AM|
The first finger of moisture scrapes through Monday morning and will be rain. There is a threat of freezing rain in the eastern sections of the Mountain State, but they will be located on the opposite side of the higher peaks, well outside our area.
This is just the beginning of a run of warmer temperatures sure to melt a ton of snowpack. But, off in the distance is another storm system that will serve to turn the tables and channel winter air back into the tri-state. Snowflakes also look to be a role-player.
|GFS - Early Thursday|
This event is advertising another post-frontal wrap around of cold air and lake-effect snow showers. It would be wise to remember the track record this type of scenario has in bringing accumulating snow to the river-cities area compared to the Kanawha Valley hills and up the moutains along/east of I-79: Not that great ;-)
|Regional Radar/Satellite with Warnings Tracking||
From the Storm Prediction Center (below): Click For a Larger Image
|Activity Overview||Storm Outlook||Watches||Potential Watches||Storm Reports|
|Temperatures||HD Doppler Radar||Estimated Rainfall||Active Warnings|
|Click For Larger||Click For Interactive Radar||Click For Larger||Click For Larger|
Have a great day everyone!