Been busy the past few days…but here's is the discussion to go with my final winter outlook for the DJF time-frame:
- A predominantly negative NAO.
- A variable AO.
- A slightly negative QBO.
- A variable EPO.
- A negative PDO.
- A weakening +AMO.
- A neutral PNA.
- A moderate to strong East/Central based La Nina…
- Stronger Arctic & Pacific Jets, weaker STJ.
- SW & SE Ridging. At time the SE ridge may “flex its muscles” and spread further northward.
- The La Nina should still register as moderate to strong for the winter, however as people on SEVERAL weather forums have pointed out…There appears to be some weakening in western regions. IF the La Nina will transition to a west-bases as the Winter progresses, has yet to be seen.
- Solar activity has been and will remain persistently lower than normal.
- N. Hemisphere snowcover has been doing fair, on average.
- Over the past couple of Winters we've entered into a multi-decadal cycle where the North Atlantic Oscillation tends to average on the negative side most often. This will continue.
- And finally, there is the possible effects of any volcanic ash and whatnot. While effects on the weather this Winter is not likely, anything is possible.
- Temperatures: Temperatures will average on the colder side of things in northern New England. Departures ranging from -2 to -4 degrees fahrenheit. In southern New England, things will be much more normal with temperature departures ranging from -1 to +1. This may even need to be stretched a little more to -1.5 to +1.5.
- Precipitation: Precipitation will average above normal in this region, mostly falling in the form of snow. Departures will range from 100% to as much as 150% above normal!
- Temperatures: Temperatures in this region will average near normal to slightly above normal. This is due to the variable effects of a SE ridge. Departures will range from -1 to +1 in the Northern Mid-Atl to +1 to +2 in the southern Mid-Atl. Conditions will be variable overall here. For example, one day it may be 39, the next day 63.
- Precipitation: Precipitation will average near normal in the northern Mid-Atl to slightly below normal in the southern areas. Most precipitation will most likely fall as sloppy mixes. There will be snow at times. The risk of Ice Storms in this area is HIGH this season. Precipitation departures will range from 85-100% in the north to 75-95% in the south.
- Temperatures: Temperatures will average from slightly above average to much above average. This is thanks to persistent SE Ridging through much of the January and February time-frame. Departures will range from +1 to +2 in the northern areas to +3 to +5 in the Deep South and Gulf Coast.
- Precipitation: Precipitation in this area will average from slightly below normal to much below normal with drought persisting in areas further south. Departures overall will range from 75-95% in the north to 50% of normal or lower the further south you go. The exception will be the mountains where near normal snowfall is possible. Most precipitation would fall as rain or sloppy mixes HOWEVER, snow is possible at times. Along the Gulf Coast snowfall is N/A because their average snowfall is less than 0.5″.
Mid-Western & Central areas coming next…