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Saturday, December 25, 2010

Should of asked for a waffle maker this Christmas--- (Threat growing for MORE significant snow)

**Noon Update**
I like the 2-4 inch call after examination of the noon data. Original Call stands.



Wow, I've heard a few forecasters describe this line of work as humbling. Despite being a local guy who does this for fun, after following these models for 10 years and even taking some classes, days like this make me completely understand why this is said. When dealing with Mother Nature, Chaos theory still rules the day.

We've gone from
2-3 days of thinking a BIG snow was possible to
24 hours of thinking an inch was the MAX
to
Currently thinking 2-4 inches is once again possible.

WHY??
 Computer modeling is amazing and addictive. Earlier, we had talked about a "phase" and how the phase had a 6-12 hour window to happen at the right time and at the right place, or the storm will still form, just well to our north and east.

Today, the noon model data came out and some had formed the storm earlier--but the powers that be (Hydrometeorological  Prediction Center) stated that the data had assimilated incorrectly and was wrong. The ECMWF (Again, the proven most statistically correct model) Did not form the storm far enough south and west to change my thinking from **possible** coating to an inch, with only Hampton Roads area getting a decent event.

Late day, the american models that run STILL had the event in our region.

As of 4 am, Christmas day, as Santa is dropping off presents on the west coast, Every model states most of the Central and SW VA region sees a decent snow from this event. All data points towards 2-4 inches ( One could argue for 3-6, but let's start small and stay with it)

Basically, the 2 phasing jets-- the subtropical has remaind a SMIDGE stronger and polar jet has dampened out the first piece of energy in favor of the second piece just behind it and the low begins to explode just to our south and we get a late evening, early Boxing day snow.




Current Radar for Lynchurg and Roanoke.

This should reach the ground towards sunrise. This first batch will slide east with our original coating and a second, stronger area moves in from the SW after 1 PM-- most of the region has snow falling by 4 PM.

General snowfall ideas.

Mt Areas west of 1-81 (Entire event, including upslope snows)
6-12 higher elevations, 3-6 lower, south of the NRV and 2-4 lower elevations north of there.

2-4 Roanoke, Lynchburg--and all the small towns in between.

3-6 Martinsville, Danville, Farmville and Charlottesville.

Hampton Roads 6-12 some mixing issues, 6-12 over most of Delaware with Mixing issues near the coast and 6-12 for my Two favorite nephews in Broomall, PA. (Coastal regions have higher shot both mixing and the highest totals)

Will update later today, as the more intense this storm gets--the better chances we have of getting the higher end of these numbers . This is a "white of the eyes" storm-- won't know the full impact until we see the white of its eyes.  Challenging forecast-- Merry Christmas!

**Quick 7am update before my kids get up to open up presents**
1. It is currently snowing--first wave made it in as expected. Won't be more than a coating, but how awesome is light snow Christmas morning
2. Based on WV loop and some other model data, I'm concerned this becomes a much larger event for our region. The MID runs are spitting out over 6 inches of snow. Let's wait until the on hour model data happens, but this could be a MAJOR event.

Attached is the precip output from the GFS ensemble means--the .75 liquid basically runs right up to highway 29-- the operation runs up to .5 precip. This would yeild 5-8 inches of snow across the region.

1 comment:

  1. NWS has issues Advisorys for most of our area for 2-4 inches and 3-5 Storm WARNINGS for Southside.

    6z data rolling in, looks as good, if not better.

    ReplyDelete