Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
547 FXUS65 KPIH 130753 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 153 AM MDT Mon May 13 2024 .SHORT TERM...Today through Tuesday. A pair of shortwave troughs will work through this afternoon and Tuesday afternoon. This will help fire off scattered thunderstorms. The first shortwave is a bit deeper and the consensus of high res models shows two main west-east areas for storms developing this afternoon. The first area is from Custer County east across the lower and upper snake Plain into the upper Snake highlands. The second area is roughly across the southern and southeastern highlands. So the Magic Valley up into Blaine County looks like an isolated threat this afternoon. Storms are not expected to be severe, although there looks like there could be enough instability that a few wind gusts over 40 mph could be possible along with some small hail. In addition to storms, we are expecting breezy conditions today. Winds look marginal for a lake wind advisory with about a 40 percent chance of reaching 20 mph sustained for 2 or more hours on American Falls Reservoir. So will probably hold off on a lake wind advisory at this time. Temps look mild once again with most highs in the Snake Plain and Magic Valley in the mid 70s with 60s common in the valley locations of the mountains and highlands. On Tuesday, the second shortwave trough arrives. This one is a little more shallow with better chances across the upper Snake Plain and Upper Snake highlands. Coverage looks more isolated elsewhere. Once again, not expecting severe weather but some gusts over 40 mph and small hail are possible with the stronger storms. Winds on Tuesday look a little lighter and the probability of reaching lake wind thresholds falls to 20 to 30 percent. Temps on Tuesday with cooler air filtering in behind the first shortwave are about 5 degrees cooler with highs around 70 in the Snake Plain and Magic Valley and generally lower to mid 60s for most of the valleys in the mountains and highlands. Although there are some indications that the highs around Challis could overachieve somewhat. 13 .LONG TERM...Wednesday through next Monday. We should be mostly dry for the middle and end part of the week. A few showers or storms are certainly possible along the Divide and Wyoming border. Temperatures will be right back to near 80 across portions of the Snake Plain, Magic Valley and southern valleys. Just as quick, we switch back into another deepening area of low pressure across the West. While there are differences in where this low sets up, the general idea is supported by around 75% of the cluster forecasts. The weekend looks 5-15 degrees cooler, breezy, with showers and thunderstorms around. Keyes && .AVIATION...Main problem today is thunderstorm coverage this afternoon. Looks like best chances for storms is around IDA and DIJ, but storms may be around at the other sites as well. BYI looks less likely to see storms although they may see convective outflows from storms trekking through the south hills. Erratic wind gusts to 40 kts are possible near storms. Outside of storms, expect breezy conditions with sustained winds of 15 kts and gusts to 25 kts likely at many locations. Most likely looking at a crosswind developing at KSUN this afternoon with gust potential to 20 kts although confidence in the gusts is less and not sure if will include in 12z tafs or not. 13 && .HYDROLOGY...The Portneuf and Blackfoot rivers remain the water ways of concern, though forecasts continue to trend down with water levels throughout the upcoming week. McKaughan/13 && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$