6/29/10 FCST: ID / MT

[Matt Gingery]

SPC has put up a slight risk for severe weather in areas of the Snake River Valley and areas both east and west of the Bitter Root range. Lee cyclogenisis is progged across the E. half of Montana, but the focal point for initiation is in and close to the approaching cold front. Upper level trough is progged to push into the PAC NW and model progs for 50-60kt swly mid level jet. Winds are progged to vear with height with backing at the sfc and be supportive of a few supercells. Isolated tornadoes are possible in Western and Eastern Montana and maybe portions of SE Idaho near the Sun Valley to Arco areas including Pocatello. Modest variables are forecast to be present across the area. Modest CAPE values as well as EHI values will provide the necessary instability. SFC Td's will be in the 50's for the most part, but according to some models there are areas of moisture pooling in the 60F range. Not a chaser hot spot, however I decided to post the discussion for the few that are chasing. Any input on this situation would be greatly appreciated. I felt it necessary to help out and post this discussion for the few I know that are chasing this event the next several days.

 

[AndyGabrielson]

Looking at the models this morning I don't see anything too exciting but if there was to be a tornado threat I would see it confined to parts of wc ID... or maybe SW MT. Here there is a little more instability, LI is best it appears over wc ID, highest DP pool is also in that same area it seems... Matt mentioned the mid level jet already, I guess the mountains the valleys out there probably really mix things up too, I am by no means a great forecaster or claim to know ANYTHING about this area weather wise, but if I was chasing...
Target: Cambridge, ID

 

[Matt Gingery]

You are absolutely right in what you say Andy. It is very difficult to forecast with the mountain terrain throwing mesoscale effects in on the play. We are targeting SW Montana today near Great Falls. Visibility is better and less terrain and trees to compound the problems. Cape Bulleseye of 1500-2000 forecast in this area today. For those chasing it is closer to them than us. This area to them is like Oklahoma to us.