Friday, January 18, 2008

0z NAM: A painful betrayal

The NAM has been our friend in the leadup this storm. It's the one that first latched on to the storm and it's the model that has kept the highest precip totals over the past few days.

Tonight, after all that flirting, it dumped us.

The 0z NAM lurched south taking most of its precip with it. Instead of a 4-6 inch snow, it leaves us with a paltry .25 inches of precip -- barely enough for an inch, maybe 2 of snow. This puts it squarely in the GFS camp and means the chances of a big snow -- as I have feared all day -- have greatly diminished.

Here is the 0z NAM precip map for the storm.
Here's the same map, but from the 18z NAM.

While from afar the differences may seem subtle, if you zoom in, you see that the dark blue area of precip (.5 or higher) that brushed the southeast corner of Cleveland County has retreated 80 miles to the southeast (we were hoping for an 80 mile move THE OTHER WAY).

Now, there is model agreement that this is a very minor event for us. Worse yet, any type of further move east could result in just a dusting of snow or no snow at all.

Is there hope?
A glimmer or two. First, temps are great. There may be a quick initial period of rain, but it will quickly and permanently be cold enough for snow. Second, radar trends from the Gulf Coast still aren't matching up with the models' short term forecasts. It could be simply a complex system that the models are not and will not correctly forecast -- it has happened before. But that's hoping, not forecasting.

I would now place heavy emphasis on a marginal to minor event from a dusting to 1 inch, possibly 2.

Maybe the 0z GFS will do the same flip flop the other way, but this one is looking like a very near and very frustrating miss.


Snowman said...

I'm afraid to comment since I was told I was a Skip wannabe. But, I have said it would be too far south from the very beginning. It rarely pans out with these types of storms.

If we could just get an upper level disturbance closer to us then the possibility is still there. Anything is possible.

For the record, I enjoy Skips blogs but we do have differing opinions.

chad said...

i agree skip... the model shows like it would be direct hit so im hoping that your right on the storm being to difficult to track by the models. from the radar it looks like it is growing in size also... but maybe the models will be wrong :)

Snowman said...

Skip check . I think there is enough expanded precip to where we may get a little more than expected. The radar shows a wide band of precip but the dry air over Tennessee may drain much of that precip.

Skip Foster said...

Honestly Snowman, neither you nor I nor anybody else knows what's going to happen -- an hour ago you were all over the WBTV bandwagon, then nothing, then "not 3 inches" I can't keep it straight.

And truthfully, I haven't been any better -- it's simply a very unique, confounding pattern. On the message boards I frequent, the professional mets are scratching their heads.

I'm sure some of you noticed that the GSP office of the National Weather Service put their ENTIRE FORECAST AREA under the same advisory -- a snow advisory for 1-3 inches -- they basically admitted they did this because of the major uncertainty in what's going to happen.

Radar trends are reason for optimism, but when all the models say one thing maybe an inch or 2, it's time to raise the white flag.

Bottom line -- very, very unusual setup with overrunning over an arctic boundary racing in from the northwest -- hasn't happened in my weather memory.

Models and mets (much less amateur bozos like me) have been flummoxed by the entire storm.

Only when tomorrow morning rolls around will we really know the deal.

I might update after the 0z GFS (especially if it's good news!!!)

snow blog said...

I was just watching news 14 weather and their in-house models are showing us getting 2-6 inches in the Shelby area. Crum says that their in-house models are usually very reliable so I hope he is right.

Snowman said...

Never been on the WBTV bandwagon. I said I didn't understand why they weren't backing down their snowfall totals.

I was wrong about the cold air though. It is currently 35.8 degrees by my 2 tthermometers. A little cooler than what they said on TV.

This is exactly what I said about 3" of snow: "From what I see on the radar at this moment, I just don't see enough precip for anything big. By big I mean more than 3' of snow". I didn't predict 3.

I checked all of todays blogs and I never predicted anything more than an inch.

The width of the precip does give me hope and before I turn I will put exactly what will happen in black and white for all to see. Then I will be right or I will be wrong.

Anonymous said...

Skip, for what it is worth... I think we are going to get hammered tomorrow. I can just feel it in my bones and smell it in the air. As far as everyone can tell something is coming...So get to bed early. It is going to be a long day tomorrow and we need you on your toes. Keep up the good work. One Who Smells Snow.

snow blog said...

I hope anonymous is right and I hope an upper-level low develops and sits on us for a while. Goodnight.

P.S Also I see that there might be a couple more opportunities into next week for winter weather.

Anonymous said...

According to meteorologists they are saying that we should get 3 to 4 inches of snow! Hope so! They also say that roads will be very, very icy on Sunday with low 20's tomorrow night. I sure hope their right!