1615 PM EST DEC 30
1300 EST DEC 28
Now that this major nor’easter is over and I have had a chance to get some rest and catch my breath it is time to move on to more things and get NEW things rolling. When you are the private weather business it have to strike when the weather is hot and then once folks see what you can do you end up getting some loyal clients and fans.
Of the the explosive growth over the past 10 days here at WXRISK.COM again caught me by surprise. I thought last winter was a season of significant growth but this one? Holy cow.
FIRST when you to get the chance take a look at this letter which was email to me by Matt Dinardo the Morning and Midday met at TV 8 WRIC here and Central Virginia Richmond. He asked me to place it on the facebook.com/ wxrisk page
You can find the letter over at the discussion section over the facebook.com/wxrisk. I am going to make a few comments about the letter — from MY point of view— since it is a very well written and worth talking about.
The next major event is going to be a the impressive winter storm which comes a roating out of the central Rockies DEC 30 and into the Upper Plains DEC 31. The large cold High pressure area now over the Delta will move off the SE Coast on DEC 29… So winds will naturally turn around to a West or Southwest direction for all areas east of the Mississippi River. So by itself we are in for warming pattern but the development of the big Low over Minnesota and the western Great Lakes DEC 31 is going to cause temperatures to really warm east of the Mississippi River for two or three days. The big MN Low will send a cold front that sweeps into the Midwest and into the East Coast DEC 31-JAN 2. The interaction between this cold front and the High off the SE coast will cause temperatures to really warm even over the snow laden areas of the Nnortheast US. 60 degree is possible over the Ohio valley as well as WVA NC VA on JAN 1.
CLICK ON IMAGES
The front should come through fairly dry as it reaches the East coast on January 2. There will be some cooling behind the front but not a big deal.
The cold front will stall across the Deep south and there may be some overrunning precipitation along the front across the Deep south but this will be mostly the rain.
The general consensus from a lot of private weather services and energy meteorologists for January 2011 is that is going to be a significantly milder month than normal especially from the Rockies over to the East coast. This is the reason that Natural gas prices (and to a lessor degree heating oil) have been going down over the last few months. But there is a lot of data which has come out which is showing that those who have been forecasting a very mild January 2011 are in some trouble… from a forecasting perspective .
One of the leaders in the mild or very mild January 2011 idea has been Accuweather. Unfortunately over the last two weeks the change the January forecast three times! So at this point it is a little difficult to figure out exactly what their January 2011 forecast is. Clearly if you make a forecast for particular a month ….a few months ahead of time …then the given the state of the science ….you SHOULD have the right to updated as you get closer to the month in question. But three updates in the last 14 days is a little much.
The premise for the mild January 2011 forecast from the Rockies to the East coast is based on the proven idea that moderate La Nina events have a strong correlation to Above Normal temperatures in the months of January and February. Of course that being said…. that idea is…itself premised on the idea that the moderate strength La Nina does NOT weaken. However that is Just general guideline about Moderate/ strong La Nina events and it doesn’t always work out .
One of the reasons why the La Nina pattern often turns mild in January and February is that in Moderate & strong La Nina event… the Pacific jet becomes very strong as it approaches the West coast of North America. Because the Pacific jet becomes stronger than normal it is resistant to any sort of pattern shift or ” Buckling”. In other words the jet stream cannot be deflected so that it comes out of Canada. Instead the Pacific Jet brings in stormy and mild Pacific Air from Washington State down to California.
This brings a lot of precipitation to the entire West Coast and heavy snows into the the mountains of the Western CONUS but east of Rockies… this is pattern means mild Pacific air overruns the nation all away to the East coast and there is no path for cold air masses to enter the central and / or eastern CONUS.
One of the basic rules in the weather business whether its 2 days or 10 days… is that for every TROUGH in the jet stream there is a RIDGE and for every RIDGE there is a TROUGH. All this La Nina energy means we get a trough on the West coast that helps bring in that storminess. BUT to counter that there must be a RIDGE in the Jet stream over se states.
That it is the typical Jan and FEB La Nina weather Pattern. Of course when you are dealing with the real world there are a lot of things that can change that. One of them is the -NAO/ Greenland Block which has been in existence for over 30 days. The Greenland block is one several manifestations of the -NAO (there are several other different types of -NAO patterns as well). Having a block in the jet stream over Greenland is very favorable for East Coast major snowstorms and the the event over the holiday weekend clearly supports that assertion. But it also keeps the pattern colder than otherwise it would be .
For January and February to stay mild the block over Greenland which is currently weakening …has to stay nonexistent. Unfortunately the new data is showing that is not going to be the case as all the data shows the block over Greenland will begin to expanded into eastern Canada in the 11-15 day.
This image shows the day 10 European ensemble Model pattern over the northern hemisphere valid for January 7. This is not just one model but 51 versions or individual members of the European model all “averaged” together. I have highlighted a couple features on this map. First is the the black oval shape which I have drawn in over Greenland. We can see the ‘ BEND” or ” BUMP” in those white lines which represent the jet stream beginning to develop over Greenland again. We can also see the two very deep areas of Low pressure in the jet stream: one located over northern Siberia and the other one over Hudson’s Bay Canada. The model also shows a disturbance in the jet stream over the lower Mississippi Valley which is why I placed a short thin black line there. This show the potential for some sort of significant precipitation event around January 7 for some portion of the eastern US…. possibly including the TN th and OH valleys and the Middle Atlantic states.
We can see this enlarged imaged on this next image – which is the euro ensemble (the LEFT side) and the operational or regualr European model (on the RIGHT side). This is not a severely cold pattern because there is no ridge on the West coast and we are still getting to a significant Pacific jet crashing into the West coast but it certainly not a MILD pattern by the any stretch of imagination. Again note the the same black line over the Mississippi Valley and the QUESTION MARK near the East coast.
Here is the GFS ensemble at 300 hrs VALID JAN 9. It shows more of the same pattern with a Ridge or bulge in the jet stream over Greenland building into northeastern Canada. (Note the bright red shading over Northern Canada and Greenland and the white squiggly line that I have drawn over it). There is also another bright red area in the northern Pacific pushing into Alaska which represents another Ridge or bulge in the jet stream. And the BLUE shaded areas –one on the West coast and one right along the East coast represents the mean trough positions .
If we can get the ridge over the northern Pacific to build into Western Canada the pattern could turn severely cold and stormy around the middle the month over the eastern half of the nation. But there is no guarantee that this is goning happen and it is possible the ridge can stay out there by Alaska for several weeks .
Eventually IF the Model data is correct and the Greenland Block really does come back in force and moves into eastern Canada by Jan 10-14 then the idea of a Mild January 2011 is not going to work out. That does not mean it has to be a COLD January either.