092517 Weather Trend

Updated Trend – September 25

While a significant pattern change into chilly conditions will occur by the end of September and beginning of the new month of October, the most recent trend now finds a majority of the European Ensemble members warming temperatures back to above average by race weekend.

European Model 850 MB Temp-Streamline Forecast at 8 AM Saturday ( Sept 30 )

Although I highlight the operational European Model, the mean of the 51-Member Ensemble Group continues to show a shift to unseasonably cool conditions that will impact the 11th Annual High Knob Naturalist Rally.

High Knob Naturalist Rally – September 30, 2017

This will create chilly conditions for the rally, as well as for any racers who may be in the region to practice.

Early Autumn at High Knob Lake Recreation Area – September 23, 2017

Eagle Knob of High Knob Massif
Elevation 4188 feet

Average Daily MAX: 62.1 degrees
Average Daily MIN: 51.4 degrees
September 1-23 MEAN: 56.8 degrees
Highest Temperature: 73 degrees
Lowest Temperature: 41 degrees
Total Precipitation: 3.50″ to 4.00″

Conditions observed during September 1-23

High Knob Lake
Elevation 3527 feet

Average Daily MAX: 64.8 degrees
Average Daily MIN: 50.4 degrees
September 1-23 MEAN: 57.6 degrees
Highest Temperature: 76 degrees
*Lowest Temperature: 41 degrees

*Middle 30s occurred in the colder valleys, with average nightly lows for the September 1-23 period being in middle-upper 40s.

The new development is beyond this time, with a shift back toward eastern-central USA ridging and troughing over the Pacific Northwest leading up to the weekend of the races.

European Model 500 MB Height Anomalies – Valid At 8 AM October 5, 2017

The operational European Model ( above ) has support of all but approximately 14 members of the 51-member ensemble group ( mean of the group below ).

European 51-Member Ensemble Mean 500 MB Height Anomalies: Days 6-10

If this new trend is accurate, it would lead to above average temperatures returning in time for race weekend ( Oct 7-8 ).  Positioning of height centers, above, would also suggest a continuation of mainly dry conditions.

Stay tuned for updates as race weekend gets closer in time and details become more clear.  The first detailed forecast for these races will be made by the middle of next week.