Tuesday, December 11, 2012

Something Interesting Brewing Next Week?


12:45 PM Tuesday Update... I don't want to get into the habit of posting every single model run, but I will today just to show you the consistency between the two major long term models I like to use when forecasting.  Remember though, these always change as we get closer to the actual event.  Sometimes it's for the better and sometimes it dashes the dreams of snow lovers.  

I'm like a kid in a candy store this time of year when the computers start cranking out patterns like the one we're going into, especially at Christmas time.   Remember, we live in Arkansas and snow is hard to come by.  Just stay tuned and hope for the best.  Don't get excited about next Tuesday until we get to the end of this week.  That's when things get clearer.

Here's the new run of the European model valid next Tuesday at noon.

The Tuesday morning run of the Euro valid NEXT Tuesday continues the trend.  DON'T TRUST THE DETAILS, JUST NOTICE THERE'S A CONTINUATION OF THE IDEA HERE.  This shows the upper low digging into the mid south.  The low pressure area at the surface is over MS.  The black lines around it show a northerly flow at the surface pulling the cold air down.  Snow is widespread across the state on this model.  Remember, DON'T TRUST THE SPECIFICS YET!  It should be pointed out the model shows surface temperatures in the 30s and 40s.  Maybe too warm at the surface, but in the long range, it may not see the colder air yet.
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11:10 AM Tuesday Update... The GFS just came in and it continues to show rain changing to snow Tuesday morning next week.  The Euro actually shows the same thing, but it's slower with the upper level energy and the infusion of cold air.  The Euro last night shows that transition to wintry weather Wednesday.  It will be interesting to see what the new Euro shows this afternoon.  Here are a couple of maps from the new GFS...

By midnight Tuesday, the surface low is moving through Arkansas with rain, but look on the back side out in OK and KS. Cold air is pouring in as the upper level dynamics move into AR.  The blue dashed line is usually a good indicator of the rain/snow line.

By 6 AM Tuesday, the surface low is over MS.  That's the closed back line with 1000 on it.  That's 1000 mb.  The cold air pouring into the state with the blue dashed line is well south.  This shows a good swath of snow across the northern half of the state in the greens and yellows.  Ryan Vaughan better book his flight to the Bahamas and he better do it soon!!!!!  Remember, we're still a week away and I have seen these situations change drastically from snow to no!  So just stay tuned and hope!

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 You know I don't like to go into the long term, but there are a couple reasons I'm going to throw this out there:  Both the GFS and Euro show it and there's some consistency.  The details can't be trusted and the timing is in question, but there will be a very interesting system to watch in the Monday through Wednesday time frame of next week.  This is NOT an ideal set up for major wintry weather, but it needs to be watched.  Right now, it appears a surface low will develop near or just east of the state.  As cold air gets infused into the system, rain could change to some sort of wintry weather as the system lifts away.  Again, this has all the makings of a major model flip flop so DON'T get excited just yet.  As we get closer, we can fine tune the details.  At least we have an active pattern now unlike the past few weeks.  This could turn out to be fun, nothing, or just rain.  

Here are the model maps....

This is the GFS valid early next Tuesday morning.  See that black closed circle over Mississippi?  That's the surface low pressure developing.  Upper level energy is strengthening it at this time and precipitation is developing NW of that surface low.  What kind of precip according to this model?   We'll assuming surface temperatures are at or below freezing, this is frozen and probably snow.  The blue dashed line is the "540 thickness" line and it's south of the entire state!  North of this line, atmospheric conditions are favorable for snow production.
This is the European model valid next Tuesday morning.  It has low pressure developing over Louisiana.  This is a cold rain for the entire state.  So you can see the timing and weather is different here, but it has the storm.  Look over Kansas.  This is the upper level energy diving south with snow breaking out over that portion of the plains.  As that upper level energy develops the surface low, watch what happens in the next map.
The surface low shoots northeast and cold air pours in behind it.  Look at that 540 line!!!!  Rain would change to light snow according to this Wednesday morning of next week as moisture wraps around the system.  This would be nothing heavy as it's not an ideal set up for anything significant over Arkansas.  
With that said, all of this will change and flip flop all over the place.  Just like the last system that came through Monday, we didn't call for 4 inches of snow when we saw the NAM because we understood models can be completely wrong.  Turns out our ideas were in touch with reality.  It showed us where it would most likely snow/sleet, but we didn't buy into the amounts due to obvious reasons... warm temps at the surface and ground.

Applying those forecasting principles here, we know there's a storm next week.  The details can't be trusted on either of the major models, but it will be fun to watch!  I'll keep you updated here, on twitter, and on my facebook page.

4 comments:

tboyce1979 said...

Bring it! I miss my weather friends!!

Omarr Wilson said...

Now Todd I don't want to crash any hopes here b/c I'm LOVING the GFS and the EURO right now. Those two models are feeding into my "Snow Ego". But You know how the GFS likes to Overdo stuff. Now these two models have LOTS of credibility, but they love to overdo things sometimes. But I'll tell you what, if these were to verify. We are going to have a Very INTERESTING winter with all these teasers lol.

Todd Yakoubian said...

Stay patient and hope!!!

Todd

jimmylee42 said...

Todd that Dec. 22nd rings 3 bells with me. 1963, 1990 and 2004 most recently. All three of those winter storms hit on that date and all three left snow and ice on the ground for the 25th. Those were among at least 6 white Christmases in those years of 1962-2004. In that time span that comes out to one every 7 years. It has been 8 years, so you could say we are due. Thanks to the NWS for the records of thee events.

Octo-BRRR