A shortwave trough is moving through central Washington and Oregon with scattered coverage of storms initiating over northeast Oregon and the Idaho panhandle this afternoon.

CIMSS Nearcast Product is depicting a weakly unstable environment averaging 500 to 1000 J/KG along a corridor stretching from eastern Oregon through northern Montana with storms initiating off the higher terrain and continuing to track along the axis of instability within this corridor. RAP analysis is indicating roughly 60 to 70 kts of 0-6km shear collocated with axis of instability…which is likely inhibiting deep growth and organization at this time due to the imbalance of high shear and weak instability.

  Initial look at synthetic WRF IR and WV show relatively good agreement with GOES IR/WV…albeit slightly more progressive by about 50 to 100 mi. Strongest storm so far was analyzed quite well by the WRF in northeast Oregon with only a slight southern displacement from real time location. In general though…the model captured the initiation and future trend of this storm with relatively high accuracy. Additionally…the model is showing future intensification further east off the higher terrain through the evening…although the slightly more progressive system in the model may mean a later initiation and intensification of this activity by an hour or two.

However…once the convection does initiate…slightly less shear collocated with an area of 1000J/kg could allow the storms to become better organized than current trends. The synthetic imagery portrays this situation across western and central Montana 23Z through 01Z. Current surface observations show a relatively dry boundary layer in this area with dew points averaging in the low 40s and downslope winds.  Main threat from any storms in this region will be mainly downbursts but better storm organization will allow for a continued severe hail threat as well.

Mazur/Picca