Friday, January 16, 2009

Our friends to the East.

It was mentioned in an earlier post that the cold coming into the East this week could be the coldest in years. Well it ended up being the coldest in over a 100 years for some places and an all time record for others. The last 3 nights some extremely cold air has been pouring from the Arctic into the middle and Eastern half of the country. Part of the reason why we have had a ridge. I wanted to take a minute in this post to recognize some of the record breaking cold. The following are some of the records set and the old record & the year the old record was set.

- Aberdeen, SD: -42 [-35 in 1972]
- Sioux City, IA: -20 [-18 in 1972]
- Cedar Rapids, IA: -26 [-23 in 1994]
- Dubuque, IA: -25 [-25 in 1888]
- Burlington, IA: -18 [-18 in 1994]
- Spencer, IA: -27 [-27 in 1972]
- Mobridge, SD: -33 [-30 in 1972]
- Sisseton, SD: -31 [-29 in 1972]

Bismarck, ND was top winner yesterday at -44 which is only one degree off the record of -45 set in 1916. Today's top winner was amazing!!! Big Black River, Maine reported -50 this morning. If this is verified it will be the all time lowest temperature in the state's recorded history! Just about every state in the interior Northeast hit -20 to -40 last night.

Helping these temperatures may be the record pace of accumulating sea ice in the Arctic. Last week a report had the sea ice back to 1979 levels. Also helping is back to back years of La Nina and cold ocean temps, as well as two years of falling global annual temp averages. Bismarck, ND is also on pace for their snowiest year on record. To date it is the snowiest year on record with 61" so far. I thought such an extreme event needed to be talked about. It is affecting our weather here by blocking progression of the ridge from hell we have had the past few weeks.

Update on Our Weather:

I have been talking about the pattern change that is going to occur next week for a couple of weeks now. I need to emphasize that this is a significant event because it will begin the removal of the big strong ridge that has dominated our weather. It will not be significant because of a big snowstorm. Ridges as strong as what we have right now need to be beaten down and storms will get stronger with time. There will however be a big pattern change with a progressive flow and much cooler air.

Of note is that the snow pack here in the Sierra has survived much better than I thought it would have. With light winds at night the temps have been so cold in the valley's, near 10 in Truckee almost every night, that it takes a lont time for the temps to hit their high during the day. The temps only get into the 50's for a few hours before the sun goes down and temps drop. This time of year is also a very low sun angle which limits snowmelt. After3 weeks of no snow there is still snow on the ground everywhere including Martis Valley. So we have done very well and now we have a good base build on.

Models now in concensus that the ridge will reform out at 140w. A storm will try to dive down the West coast with cold air but the ridge will expand north towards Alaska and pinch off the storm from the jet stream. This cut-off low will then slowly come on shore over CA trying to bring moisture under the ridge but there won't be much to work with. Temps will cool down starting Tuesday and should only be in the 30's by Wed. with a chance for snow showers on the mountains with snow levels above 6000 ft. This will not be a big snow event but big in the fact that the ridge is gone and storms are starting to arrive with cooler air.

Latest models show the ridge then retrograding out to 150w and surging toward Alaksa once again the weekend of the 24th, pinching off another cut-off low that possibly gets some subtropical moisture and hits CA on Tuesday the 27th. Ridge then flattens at 150w allowing bigger storms, associated with the jet stream this time, to start striking CA later in the week. I really think the big storms finally get going right at the very end of the month going into the first week of Feb.

Tomorrow Ed Berry's discussion comes out, so I will definitely be discussing the long range in more detail tomorrow night. BA


2 comments:

JimCA said...

I had posted from memory (mea culpa), so better figures are in this revised post:

Arctic sea ice is still about 0.5 million km^2 below the minimum 1979 levels, and about 1.3 million km^2 below the same date in 1979.

The article you seem to be referring to was talking about GLOBAL sea ice, including Antarctica. And the numbers it picked are now almost obsolete, as total sea ice is now just barely above the lowest 1979 levels. (A recent brief peak rose just barely above a brief low point reached in 1979, which just barely made the comparison to 1979 levels plausible, if you're willing to cherry-pick data points.)

You can see good overviews of the data at http://arctic.atmos.uiuc.edu/cryosphere/

BA said...

Thanks for the numbers. I dabble in studying all the global cooling going on, but I don't watch exact figures. I try not to get into it in my weather blog because as of recently some weather and climate issues have become more political than actual science. I was just mentioning all of the cold articles I've read the past week because it has an affect on our weather.