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
Climo: 5th place

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

16th Annual 'Season-total'
FINAL results here

Saturday, December 22, 2012

Winter '12 / '13 - The Change

A pattern change appears to be finally in the works as a stable...four wave flow regime with an anti-cyclone parked over the Pole sets up by D+10.

Initial state starts with the 'never-say die' blocking ridge over the Bering Sea and a deep trof in the Gulf of Alaska where SSTAs are below normal thanks to the PDO.

These two persistent teleconnection features have kept the PNA underwater for months...wasting the cold air potential of a negative AO and its sister index..the NAO.

All that is forecast to change in 10 days as the Bering Sea HIGH becomes pinched off and shoved to a position directly over the Pole...where its circulation is re-enforced by the flow around four trofs at lower latitudes.

 The Gulf of Alaska LOW is replaced by the PNA ridge....achored by a cut-off LOW offshore of SOCAL.  The ridge delivers cold air and short-wave energy embedded in the Polar jet stream into the Lower 48 where it has opportunities to phase with short-wave energy ejecting from the cut-off LOW and moisture transport y the sub-tropical jet stream.

This scenario was more-or-less forecast by PSD's GFS '8-14 day' ensembles earlier in the month altho the model had the change in place about ten days too soon.

Even the GFS shows large chunks of arctic air reaching the Gulf of Mexico and Miller 'A' storms moving along the east coast.

Images courtesy Plymouth State Wx

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