It’s all about Blocking!!…….Chilly Weekend better for round the clock snow-making today into Saturday…..Milder Weather the end of the Weekend to be Followed by a Weak System Mid Week…..
Friday November 15, 2013
Posted at 9:29 am by Howard
Yes it’s all about blocking! Where the blocking sets up and how you relate geographically…..Simplistic but true….
It’s mid November and it is getting to be that time of year when forecast model accuracy takes a significant jump to the better. Over the past few weeks, medium and long-range guidance has been awful. It’s not the weathers fault, it’s the time of the year and the transition, to the ocean’s taking over as the thermal heat source with most gradient’s off shore now instead of over land. Over the next few weeks, forecasters will be able to tell what kind of animal we’ll be dealing with this winter. At least from a longer range perspective I think.
Getting back to blocking, for the past week high latitude blocking has been too far west at or beyond the dateline, conducive to storm energy reaching the central west coast. The flow has been split with that persistent Rex Block NNW of Hawaii and the upper cut off trapped underneath. However, mother Nature is going to be putting her peddle to the metal this weekend by blowing out the block and pushing the weakened cut off to the west coast Wednesday. This might bring us some light snowfall. More importantly…..This should open up the wavelength and allow western pacific to reach to the Eastern Pacific and be more consolidated. What happens afterwards is what is most important……
There has been a few ensemble members of late that are redeveloping the block in the long-range “further east” which has wet possibilities for the central west coast. The Dweebs were counting on this over a week ago when it looked like a wet period for at least Northern Ca and heavy wet snow for the Central Sierra. Thus the Comments about the “AR” in many discussions. I think that because of what I have been seeing out over the pacific the past month that she may take another run at this pattern at the end of this month.
If Mother Nature takes another run at that pattern by the end of this month into Early December and if it sets up say another 1000 miles further east…..It would only take a short 3 day AR event to pile up so much snow on the mountain to last months….. I am including the AR type pattern in this sentence because I see the possibility of another REX Block developing again when the pattern resets in a couple of weeks. However, this time hopefully much further east.
Note: If we go back to the ridge and block further west again…. we will just go from one dry pattern to another.
The Dweebs will be watching to see what develops after the Central Pacific “Blow-Out” that will occur this weekend that will push the remains of the mid pacific cut off, though the west coast Wednesday, followed by a major transition in the pattern the end of this month. Chances are good, we will 1st experience the effects of the old Cut-Off low Wednesday followed by a subtropical-ridge that builds strongly the weekend of the 23rd. …….followed by a different WX Pattern the following week. IE. (End of the month)
Keep the faith as Winter is still well over a month away!
Dr Howard and the Dweebs………………………:-)