Long Range Pattern Discussion And Looking Back At Most Of Meteorological Winter.

March 1st officially begins the unofficial start of Spring, Meteorological Spring. You know, that time of year when we all emerge from the hidden hibernation caves that we cleaned out early this year. Meteorological Spring is earlier than Astronomical Spring, yes, but there is a reason. Without getting into too much detail it is because the astronomical seasons are based on the position of Earth in relation to the sun. Meteorological Winter is based on the annual temperature cycle. So December, January, and February are Meteorological Winter. March, April, and May are Meteorological Spring. June, July, and August are Meteorological Summer. Last but not leas September, October, and November are Meteorological Fall. If you would like to read up on it some here is a great article from NOAA.


Looking Back

There is no doubt that this Winter has been a roller coaster ride. We started out with a pre season ice storm and a perfect setup that delivered and early Winter Season snow. It would turn out that December would end up 1.5 degrees warmer than average for the month with a overall average temperature of 41.2°. January started off mild and in fact we never had one day that the high temperature remained below freezing. The overall average temperature for the month was 39.5° which is a departure of 1.3° above normal. It may come as no shock to you that February is running warmer than normal. Again the month didn't have one day that the temperature remained below freezing. The overall average temperature for February is currently at 45.9°, a whopping 5.2° above average. That means Meteorological Winter is averaging 2.6° above the normal 39.53°. (All data taken from our NWS CO-OP site in Marion.)


Many of you have asked what happened to Winter and we look no further than the evolution of the Northern and Southern Jet Stream. First off the Northern Jet. The Northern Jet Stream didn't come as far South as we had predicted in our Winter Outlook. The Northern Jet took a dive East of the Rockies but became flat and zonal (west to east). When the pattern would shift the Northern Jet would shift North of us due to a Bermuda High ruling the roost per se. That Bermuda High became strong and locked into place after the first couple of weeks of Meteorological Winter. We needed that high to move North and provide some blocking over Greenland, and so far it has only become marginally positioned at times. The ridge pumped warm air North and kept that Northern Jet forced up to the North taking the main storm track from Texas to Indiana. The Southern Jet provided ample water vapor into the systems though. The problem was that the low tracking from Texas to the Ohio Valley provides us with one outcome, rain. Counter clockwise flow around the low pressure systems that passed to the West and clockwise flow around high pressure over the Atlantic pumped warm air in here. Just like with this system we are dealing with currently, the low is tracking through the Tennessee Valley up into the Northeast. The high to the North is transient. We would have been talking a big time winter weather event has we had a high pressure block over Greenland instead of Bermuda. Instead, the pattern is progressive and not bottled up. Therefore that high to the North didn't have enough time to force sufficient sub freezing air south that is needed to get snow here. We have been on the wet side of things but I don't have to tell you that. So far this calendar year we have received 10.32 inches of rain already with is 3.46 inches above normal, and that does NOT include precipitation that fell Tuesday Evening and this morning.


SO WHERE TO FROM HERE

As far as precipitation goes there isn't any change in site. 2019 taking off exactly where 2018 left off and it is showing no signs of slowing down. The pattern would be to have a nice trough over the Eastern United States in about 15 days again. So far that trough has been locked in our west since late January. The models do have us cooling back down to below average after the next 10 days. That pattern really starts to take shape after day 8. High pressure tries to build over the pole and then sling a period of colder than average temperatures South. At the same time though the models indicate zonal flow across the Southern US whereas looking at the overall setup, I believe there will be another storm show up on the models in the 10 - 18 day timeframe (a few ensembles are starting to pick up on it). Does it mean Winter weather though, too soon to know but it is something we will watch. Seth and myself are supposed to fly out to Oklahoma City on March 2nd for a conference and training so that is likely about the time when something will pile drive us, leaving us sitting on the taxi way. LOL! Lets hope not. You all have a good day!


Chris White

Chief Meteorologist


Euro 500mb (Red/Pink Higher Pressure, Blue/Green Lower Pressure) Can that high pressure block over the pole to Greenland?



GFS 500mb (Red/Pink Higher Pressures, Blue/Green Lower Pressures) Slightly different timing on the different longterm models but same question, does that block connect over the Pole?

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