Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
686 FXUS65 KPIH 092050 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 150 PM MST Sat Nov 9 2024 .SHORT TERM...Tonight through Sunday Night. Early afternoon satellite imagery shows a H5 ridge axis of high pressure situated directly over ERN Idaho which is continuing to lead to clear skies, light winds, above normal temperatures, and dry conditions. Increasing clouds will move into our region this evening through the overnight hours as a split H5 trough moves onshore from the NE Pacific to the PacNW and NRN Rockies. As this trough splits on Sunday, a closed H5 low will occlude off the California Coast as a now weakened H5 shortwave trough is left over the PacNW. This trough will track east throughout the day on Sunday over the NRN Rockies with widespread cloud cover and isolated rain/snow showers further north with best chances in the CNTRL Mountains and ERN Highlands along the Montana/Wyoming border regions. Any precipitation will remain very light with the latest forecast showing up to around a T-1" of snow above 7000 feet further north with dry conditions favored everywhere else. As this trough departs east Sunday night into early Monday, this will set the stage for a stronger system to move in late Monday into Tuesday with widespread precipitation and gusty winds. Ahead of this system, temperatures through the weekend into Monday will remain above normal with highs in the 40s/50s and lows in the 20s/30s. MacKay .LONG TERM...Monday through next Saturday. Generally expect dry conditions most areas Monday with afternoon snow moving into the central mountains, then overspreading the remainder of the state Monday night into Tuesday. Snow levels start out in the 6 to 7 thousand foot range Monday so only high elevations affected, then drop to near valley floors in the 4 to 5 thousand foot range through the day on Tuesday. There is a high probability of over 2 inches in the Sawtooths and eastern and southeastern mountains in the 60 to 85 percent range, but those diminish to well under 50 percent over 4 inches other than extremely high mountain passes which may affect Galena Summit and also in the Upper Snake Highlands. Well under an inch is expected in the Snake River Plain. It will be very warm ahead of the cold front Monday with highs in the 40s mountains and 50s to near 60 in valleys. Expect some 10 to 15 mph southerly winds Monday. Behind the cold front Tuesday will see highs only in the 30s mountains and 40s valleys with strong west to southwest winds in the 15 to 20 mph range in the Snake Plain and Magic Valley and gusts 20 to 30 mph. Another system Wednesday and Thursday will mainly affect the central mountains with some light snow with general 1 to 4 inch amounts there and little precipitation in grids elsewhere. At least a chance of more widespread precipitation is in the grids Friday and Saturday with low confidence on details. Expect above normal temperatures Wednesday and THursday with highs in the 40s mainly with some 30s mountains and lower 50s valleys as well. Temperatures much colder right now for Saturday with snow levels dropping back to valley floors and highs mainly in the 30s. GK && .AVIATION...18Z TAFS through 18Z Sunday. Not expecting impacts at the TAF sites through Sunday afternoon. Generally nothing more than some increasing high cloud cover tonight but any ceilings should be above 10 thousand feet. May see some lowering clouds late Sunday afternoon to the 6 to 8 thousand foot range at SUN with some vicinity showers but VFR conditions will be in effect for the next 24 hours. GK && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$