Archive for January, 2011

Melting The Snow ….
January 31, 2011

It’s a popular game that most meteorologists play when it comes to heavy snowstorms. The game is ” figure the snow-to-liquid” ratio. In places like Utah, with the dry desert air and somewhat “salty” composition of the atmosphere, you can easily see storms have a snow-to-liquid ratio of 40:1. That means 40 inches of snow to 1 inch of rain. That is why it’s called “The Greatest Snow on Earth”. You can’t make snowballs out of it cause there is hardly any liquid to compact the snow. So, what kind of ratios do we have here? During the Christmas Eve Blizzard, Oklahoma City received about 14 inches of snow. But, if you melted it all down, it was only about .80 inches of water. That’s right, 8 tenths! So, what is a normal “snow-to-liquid” ratio for Oklahoma? Check out the graphic below:

Most of Oklahoma, during any winter storm will average a snow to liquid ratio of 12:1. That means that a foot of snow will melt down to about an inch of rain. Many different factors go into determining what a snow-to-liquid ratio is. But, if we go off of climatology in forecasting this storm, then we could see some snowfall totals that dwarf The Christmas Eve Blizzard. This is what the models are thinking with amount of liquid:

Only time will tell…

-Damon

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What The Storm Is Doing Now
January 31, 2011

All this talk of what he storm will do to Oklahoma, but we have said very little as to what the storm is doing now. So, here comes a small brief as to what the storm is doing to those in Nevada and California. And the answer is… not really a whole lot. Strong winds in Las Vegas and high surf in San Diego. Flights will be departing to the west coast all day.. hurry up and buy your ticket!

-Damon

Watch Out!
January 31, 2011

It’s tough forecasting a storm that hasn’t “fully developed” yet. But, as it does develop, which will be over Oklahoma, it will dump a lot of snow and bring in a lot of wind to the state. Measuring snow with this storm will be difficult because of the winds blowing the snow against buildings. Snow drifts could approach 3-4 feet in places. If there is any sort of good news with this storm, it’s that the ice threat will be low compared to everything else. Still, expect that many roads will be closed and cars will get stuck. Get ready Oklahoma!

-Damon

Update: Possible Snow Accumulations
January 31, 2011

Not much time to really type a whole lot here. Let the graphic do the talking. The model that we are using here is a “private” weather model known as the RPM 12km model that is available from our weather company here, WSI. If there is anything to take from this graphic, it’s that the snowfall totals continue to be high with higher amounts being reported in the western part of the state. It looks like heavier bands of snow will set up and totals could range from 9-14 inches even across The Metro. This storm has a lot of the same qualities that the blizzard had. But remember, this is just a model. Human expertise will be necessary with forecasting this storm and I honestly think that this storm could go down in the record books and surpass the totals we had on December 24th, 2009.

-Damon

This Is Where It Gets Nerve Racking
January 30, 2011

The forecast has been issued, (large) snow amounts have been forecast, everyone knows that we’re expecting a not-so-run-of-the-mill storm.  Now what?  Well, we keep going over the newest data that will come into the weather center. 

This is where it can get a bit tense.  If a model comes in and suddenly shows something different, it can play with your confidence as a forecaster.  I’ve been there when it looks like a big storm, then all of a sudden, the models back off on the intensity.  Now I’m at that point that this looks like a bad storm, and I’m calling for a bad storm, so I want it to happen.

But I don’t want any loss of life so all of you need to do your part.  Plan ahead and make sure you have all the supplies you will need to get you through at least Wednesday.  Remember your pets.  Bring them inside if you can.  Tuesday through Thursday will be the coldest of the season so far.  Use common sense, and by all means don’t try to travel if you don’t have to, especially late Monday and Tuesday.

For the very latest, go to our Facebook page called Oklahoma Weather Updates.  You can also follow me on Twitter at kocoweather.

Rick

What I Know, And What I Think I Know
January 30, 2011

What I know is that big weather changes are coming.  Gone are the 70s of yesterday and Friday.  Arriving Monday will be highs in the 30s, followed by temperatures mostly in the teens and 20s on Tuesday. 

I also know that north winds on Tuesday will gust to near 40 mph with wind chill values below zero. 

And yes, I know that there’s going to be precipitation.  It will most likely start Monday evening as a mix of freezing rain and sleet, and then change quickly over to snow.  I’m confident that the bulk of the sleet and snow will fall after midnight Monday night, and last through about noon on Tuesday, with blowing and drifting snow continuing through Tuesday night.

I’m feel strongly that travel will be quite messy and there’s no way I would have any family member of mine out on the roads from late Monday through Tuesday.

Now for the things I think I know.  Let’s start with snow amounts.  I believe the OKC metro area will end up with around 4 inches of sleet and snow.  The computer models are in great disagreement on how much snow will fall in central Oklahoma.  Take a look at this:

This is a snowfall forecast by the GFS ( a computer model) up through 6 pm Tuesday.  Look at Oklahoma and you can see green colors through the state.  The green represents snowfall of 1 to 5 inches.  There is yellow and orange in the northeast part of the state.  That would be snow in excess of 6 inches there.  So based on this model, OKC would have about 2-4 inches.  Combine that with near 40 mph gusts and below zero wind chills, you still have a nasty storm.

Now look at the NAM model valid for the same time:

Can you see the difference?  Look at the huge area of yellow and red colors representing over a foot of snow for much of the state!   If this model verifies it would be worse than the 2009 Christmas Eve blizzard.

My feeling is that we will end up in between these models, but probably closer to the GFS totals of around 4 inches.  The NAM just seems overdone with its amount of moisture.  I still believe this will be a powerful storm in terms of its effect on Oklahoma, so be prepared.

By the way, we now have a weather page on Facebook called Oklahoma Weather Updates.  Also look for kocoweather on Twitter.  We’re doing all that we can to bring you the information you need to keep you safe and informed.  And don’t forget to watch Eyewitness News 5 tonight at 5:30 and 10:00 pm as I will have the very latest on what to expect.

Rick

Models Hinting at Colder Quicker, More Snow
January 29, 2011

New model data keeps coming in. And it keeps looking colder, with the potential for significant snow. The latest run of the NAM model brings a 6″ swath of snow from the metro to Northeast OK on Tuesday, with a 12″ swath from Ada into Central Arkansas. This model shouldn’t be taken literally, but it’s another sign that a major winter storm is possible. Combined with what I saw on the GFS model today, here’s the part of the state I think may see significant snow…more than 6″.


If the colder air does move in faster, it will be a quicker transition to snow, but of course that means the possibility of higher snowfall totals. I think we will still see all types of winter weather including sleet and freezing rain, but hopefully no significant ice. Here’s the timeline for the metro as I see it now:

This means you have all of Sunday and most of Monday to prepare for Monday Night and Tuesday. Travel may be dicey or impossible on Tuesday. Look for frequent updates on koco.com and our new facebook page…just search “Oklahoma Weather Updates” on FB.

Rusty

Winter Storm Still Far Away
January 28, 2011

Perhaps not that far away in time…about three days….but, certainly far away in distance. The storm we believe will bring us a good chance of winter weather is still hundreds of miles off the West Coast. It’s approximately 2,100 miles from OKC. It’s quite impressive looking on IR satellite imagery.

Of course, when a storm is this far away, the track is uncertain. And the track may be the ultimate factor in what type of winter precip we see and how much we would get. As you can see, our jobs of forecasting a storm 2,000+ miles away ain’t a rodeo. As we get closer to Monday night, we can narrow that window of uncertainly down.

For now, we believe the storm will slip in right behind an arctic cold front that will dive through the Southern Plains on Monday. One model has the cold front well south of us by Monday night, and establishes sub-freezing air through the state earlier. This is depicted by the graphic above and would mean a quicker transition to a winter mix and snow for central and northern Oklahoma.

A second model brings a warm front over central Oklahoma as a “warm nose” of air extends northeast from the storm. This would keep the metro liquid Monday night into Tuesday morning, reducing ice and snowfall potential.

I think the chance for winter weather is very high, but the amount and type we will see is still certainly in question. I think northwest Oklahoma should prepare for significant snow, enough to slow travel or even make it impossible for a time on Tuesday. The metro may have to contend with enough of a snow/ice combination that travel may also be greatly affected.

Rusty

 

 

How Are You Enjoying The Mild Weather?
January 28, 2011

How are you taking advantage of this nice Oklahoma weather?  Here’s a video of what I’m doing in the 70+ degree warmth, plus some thoughts on Tuesday’s possible winter storm.

http://www.youtube.com/watch?v=ljVV5-bj9EI&feature=feedu

Rick

Tuesday Winter Storm–Rough Draft
January 28, 2011

So the next few days will be pretty awesome, so let us just jump right into next week.  Looks colder Sunday with a slight chance for showers.  Monday we could see some freezing drizzle but only light precipitation amounts are expected.

Tuesday is the day that travel and plans will likely be interrupted.  Highs will stay below freezing, with a good chance of Ice accumulation and snow accumulation.

The question is, how much?  Right now, with what the computer models ar saying, I would be prepared for about 1/4 inch of ice and 4 inches of snow…but this will likely change before Tuesday.  The weather computer models have not been very consistent with this system, and we are still 4 days out. One thing I can speculate on, is who will see the most snow, that will be Northwest Oklahoma.  I can also say that most of central Oklahoma will see some ice accumulation before the transition to snow.  A shift in the timing of the transition is what will change the ice and snow totals.  It is simply too early to be exact.

Sarah