Moderating temps over the weekend……Continued dry through the middle of next week….Pattern Change Still Looks Good
Thursday February 3, 2011
Posted at 9:26 am by Howard
The cold pool of Arctic air that flushed through the CONUS’ west and mid sections yesterday was centered over New Mexico. This is expected to spin up an upper low today over northern MX and is expected to give the SE quite a drenching with another ice storm possible over the next 5 days.
Back west…were still looking for our next big dump. One thing is for sure, it won’t happen this week and most likely won’t happen through the middle of next! Sounding forecasts show warming at 700mb the next two days with highs in Mammoth at 8000 ft in the low 50s Saturday, Sunday and Monday. There is still a strong surface gradient as well as upper level support the next couple of days, so it will remain windy over the crest.
Another inside slider seems probable as the eastern pacific high amps along 135W and another 1046mb surface high slips south from western Canada into Montana. So far the 540Dm thickness isohyet remains over east central NV so this should not be as cold as the system last Monday. However, the gradient’s will tighten up again and no doubt it will blow over the crest again by Tuesday/Wednesday.
Beyond Wednesday is the big question. The Dweebs have been touting a pattern change for quite a while now for the middle of February. The models have been playing hide and seek with the prospects of another wet pattern setting up. We are approaching the end of another 21 day cycle of 42 days since the first few day of January which the Dweebs have counted as the end of the Wet pattern of December. The Dweebs also indicated in one of the December discussions that patterns often times repeat themselves over the course of a particular wet season. Will the next pattern to wet be a repeat of the December loader busters with record heavy wet snows for the Sierra? Time will tell…
What I am watching:
1. Looking at this mornings ensembles SEE: http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/ensloopnew.html
You can see that for the 240 hour period only 3 out of the 12 ensembles offer any hope of a significant pattern change. However by the 288 hour it increases to 5 out of 12. Not great but encouraging….
2. Next week begins a period of a series of deepening cyclones coming off Asia….with their track shifting south later in the week to eventually coming off Japan. There is one pertictular surface cyclone that spins up off Japan and becomes a super bomb about the 11th of February. This should enhance the process of retrogression as the cyclone builds an 500mb high back between the dateline and Kauai. This is sort of the pattern that developed last December. The scenario included a REX Block with a tropical fetch that became confluent with the polar jet south AK. See the new 12z February 3rd, GFS North pacific 500MB. http://ggweather.com/loops/gfs_12z_500npac.shtml
Additionally, it is curious that the Wheeler-Hedon Phase Space is forecasted to move into the same phase space as last December. See: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml
With all of the above said, this time the AO Arctic Oscillation is in the positive phase and so the downstream High Lat blocking is not supportive. Will that make a difference? The Dweebs do not know……
Time will tell……
Next week will be quite interesting as to what kind of a wet pattern change will develop…..
Dr Howard and the Dweebs……………………………..:-)
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