Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
050 FXUS65 KPIH 050902 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 302 AM MDT Sun May 5 2024 .SHORT TERM...Today and Monday Hopefully you were able to get out and enjoy the sunshine and warmth on Saturday because there won`t be any of that for awhile. A potent storm system has already begun to impact the region this morning and these impacts will be felt throughout the days ahead. Early morning satellite imagery shows a potent low in place across south-central Oregon and the center of this feature will move along the 42nd parallel over the next 24-36 hours. Winds remain gusty ahead of a frontal boundary and a Wind Advisory will expire at 4AM across the South Hills this morning. The temperature gradient along the aforementioned boundary is quite apparent with temps in the 60s at PIH and IDA with Boise and Twin Falls sitting in the 40s. Rain will continue to overspread the region with snow expected above 5500 to 6000 feet. Winter Weather Advisories continue for a handful of mountain zones across the region with a Winter Storm Warning in place across the Bear River Range. As we get into late tonight and into Monday morning, expecting snow levels to drop even further to the valley floors of the Snake Plain. Could see some very light snow accumulations here. As far as temperatures are concerned today, they will run 15-25 degrees colder than Saturday. Highs will generally be in the 40s this afternoon with clouds, rain/snow and wind. Not a pleasant day by any means. Monday looks very similar to Sunday with continued clouds, rain and wind. McKaughan .LONG TERM...Tue through Sat Tue appears once again rainy and snowy, but by Tue night the precipitation threat starts to life from southwest to northeast. By late night Wed the threat is nearly gone. After this time, there is limited showery activity limited to afternoon and early evening hours in the eastern highlands for every afternoon through the period. But it`s all slight chance, and actual locations will be hit or miss. On Tue/Tue night/Wed, the upper level trough and associated cold front is still driving through all of eastern Idaho, which triggers the instability for thunderstorms and continued very windy conditions in the eastern Magic Valley and southern hills, with windy conditions elsewhere. By Thu, the upper level low has shown a retrograde motion to south of the forecast area and a high building to the north in a Rex block pattern. At the beginning the airflow is northerly and cold with freeze conditions possible in the Agricultural areas for Tue night, and possible Wed night. Strong sunshine will modify temperatures strongly, with a return to near to above normal temperatures on Thu night/Fri. Windy conditions at least appear to continue, but it has upper level support with easterly airflow, so it may be very localized. The clusters are fairly similar in timing and only slight variations in the depth of this low. And there is high confidence in the return of warming high pressure, though varying degrees of northerly airflow that would bring the cold air and freezing conditions. The winds are confidently expected to be in the 90th percentile range for both Tue and Wed afternoon. Welcome to a tempestuous mid-Spring. Messick && .AVIATION... Expecting conditions to continue to deteriorate around the region over the next few hours. MVFR conditions likely to prevail through much of the period with occasional IFR possible. Winds, rain and snow will impact all eastern Idaho terminals. Breezy SW winds expected throughout the day at KPIH, KIDA and KBYI. Winds will be a touch lighter at KSUN and KDIJ but still occasionally breezy. McKaughan && .HYDROLOGY... Flooding has dropped to minor flood stage at the Portneuf River at Pocatello with rising levels back to moderate on Sunday and forecast to continue to be at moderate stage through next weekend. Peak is forecast to reach very near major flood stage on Tuesday. Minor flooding continues for the Portneuf River at Topaz where the gauge remains above flood stage and will remain so for several days with only a slight rise expected late this weekend into early next week. Flood warnings also remain in effect for the Blackfoot River near Shelley at Wolverine Canyon with the river remaining at flood stage and also near Blackfoot where the river remains in flood stage. With the potential for significant precipitation Sunday and Monday, rivers will need to be monitored closely. GK && .PIH WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 4 AM MDT early this morning for IDZ056-057. Winter Weather Advisory from 6 AM this morning to 6 AM MDT Monday for IDZ056-057. Winter Storm Warning from noon today to 6 AM MDT Tuesday for IDZ060. Winter Weather Advisory from 9 PM this evening to 6 AM MDT Tuesday for IDZ062>066. && $$