CONTEST STATUS - Updated: SAT ... 14-APR-18 @ 9 PM EDT

Winter '17 / '18 - Snowfall Forecast Contests

19th Annual 'Regular Season' Snowfall Forecast Contest
- FINAL Results here
1st Place: Brad Yehl
2nd Place: Don Sutherland
3rd Place: NWS ER WFOs
HM: Herb @MAWS

17th Annual 'Season-total' Snowfall Forecast Contest
- FINAL Results here
1st Place: Don Sutherland
2nd Place: Mitchel Volk
3rd Place: Brad Yehl
HM: TQ
Climo: 5th place

----------------------------------------------------
Winter '16 / '17 - Snowfall Forecast Contests
----------------------------------------------------
18th Annual 'Regular Season'
FINAL results here

---
16th Annual 'Season-total'
FINAL results here

Friday, December 26, 2014

Winter '14 / '15 - Weakening Polar Vortex ==> Sudden Stratospheric Warming: UPDATE 2

The 12z / 25-DEC-14 run of the ECMWF continued its current campaign for a sudden stratospheric warming (SSW) event come JAN.


Progs suggest the birthing of daughter vortices around 04-JAN-15 induced by the upward propagation of a large tropospheric Rossby wave in a QBO-east environment.  A 'major' SSW event is indicated.
 
"A major SSW occurs when the 10 mb 60°N zonal mean zonal wind reverses from westerly to easterly and the 10 mb zonal mean temperature gradient increases poleward of 60°N." (.pdf)
 
Another view of the impeding split at the 475K level from a potential vorticity (NASA) perspective ... 
 
 
The downward propagation of the stratospheric easterly circulation (or a significant weakening of west wind) and the establishment of the Arctic Oscillation (AO) in its negative phase usually follows major SSW events.


No comments: