060520 Forecast

Weather Headlines

Some thunderstorms could become strong to locally severe, especially by later Wednesday into early hours of Thursday ahead of a strong front. Locally heavy rains will be possible from Tuesday evening through Wednesday evening.

SPC Risk Regions_8 AM Wednesday to 8 AM Thursday_10-11 June 2020

*Localized, hit-miss activity Tuesday will give way to more widespread action along a cold front trailing from deep low pressure to the north Wednesday.

Interactive Doppler Radar

Cooler And Wetter Trend Upcoming

*Conditions will turn significantly cooler from Thursday into this weekend as upper air troughing develops once again, with coolest air (relative to average) centered over the Great Lakes initially.

European Model_850 MB Temp Anomaly Forecast_11-16 June 2020

This will mark the beginning of a cooler and wetter weather pattern that will become dominant from this weekend through much of next week (*).

*It should be noted that model trends are divided for next week, with some ensemble members showing above average rainfall while others predict below average rainfall.

The track and development of low pressure in upper levels of the atmosphere will help determine rainfall amounts. Either way, until a prolonged dry pattern does develop the flash flood risk will remain higher than average (especially in locations having had the greatest precipitation amounts this year).

An elevated flash flood risk will continue and need to be closely monitored.

Anomalously wet conditions observed during the past 6+ months have created flashy conditions in locations within and near the High Knob Massif, but the entire region will likely need to closely monitor conditions given current forecast trends.

European Model_850 MB Temp Anomaly Forecast_14-19 June 2020

Local flash flooding observed in recent weeks could become more problematic (impacting more people). Stay tuned for later updates into next week.

European Ensemble Mean_500 MB Height Anomaly Forecast_14-19 June 2020

Previous Update

*ALERT For Elevated Stream Levels Along Big Stony Creek (Including Devil Fork) And The South Fork Of Powell River Into Saturday

Observed Stream Levels Since 1 May 2020

Torrential rain producing showers and localized thunderstorms have dropped a general 1.50″ to 3.00″ of rain between Maple Gap and Osborne Gap this afternoon, including the peaks of Eagle Knob, High Knob, Little Mountain Knob, Huff Rock Knob and Thunderstruck Knob of Powell Mountain.

Some of the headwater creeks impacted include: Big Stony Creek, Benges Branch, Chimney Rock Fork, Clear Creek, Cove Creek, Devil Fork, Glady Fork, Lost Creek, Robinette Branch, South Fork of Powell River and Straight Fork.

Reference Early Summer 2020_High Knob Massif

High Knob Lake Recreation Area_High Knob Massif_Summer 2020

Check for updated precipitation totals for 2020, including early June, at the above link during the next couple of days.

Warmer Then Cooler As Cristobal Passes

European Ensemble Mean_500 MB Height Anomaly Forecast_6-11 June 2020

Large-scale sinking air will renew warming as Cristobal moves through a weakness in an upper air ridge pattern across the eastern USA into early next week. This is expected to initially lower rain chances and increase air temperatures across the mountains and adjacent regions.

European Model_850 MB Temperature Anomaly Forecast_6-11 June 2020

Shower & thunderstorm chances will increase along a cold front attached to Cristobal remnants by the middle of next week. Significant cooling will then occur with upper air trough formation by later next week-weekend.

European Ensemble Mean_500 MB Height Anomaly Forecast_10-15 June 2020

A W-WNW flow pattern will need to be monitored for the potential of thunderstorm cluster development heading into the middle of June, which will tend to form around a developing heat dome anchored over the central Plains.

European Model_850 MB Temperature Anomaly Forecast_10-15 June 2020

Some of the wettest and most stormy conditions are expected to develop along a thermal gradient between blazing heat and unseasonably cool air, such that the ultimate position of this horizontal temperature gradient will be a key factor in where clusters of showers and thunderstorms develop. The placement of this thermal gradient, and heat dome core, is yet to be precisely determined.

Stay tuned for updates as details of this new pattern become more clear.