Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
072 FXUS65 KPIH 041941 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 1241 PM MST Mon Nov 4 2024 .SHORT TERM...Tonight through Thu afternoon. Complicated low has a boundary crossing through this afternoon, raising wind speeds, mostly. But a second stronger cold front is still on track to bring snow and low elevation rain and snow as early as late this afternoon in the central Idaho mountains, but most will not see precipitation until after 05/00Z this early evening. The amounts are still light to moderate, with the focus being in eastern Idaho between Interstate 15 and the entire WY-ID border. Moderate snow is staying above 7000ft elevation. So the Winter Weather Advisory still looks appropriate at this time, and have continued the headlines. Snow actually peaks during Tue morning and afternoon for this region. The front is very strong, and wind will be even stronger with the second feature. Expect close to Wind Advisory for the mountains, with gusts above 50 mph, and gusts to 40 mph in the Snake River plain, with the lone exception the Mud Lake to Dubois region which will be sheltered at first. Gusts drop off strongly by Tue afternoon, except for Cassia County. With the kind of wind this storm is bringing, it would be logical to assume a large temperature difference behind this front, and it appears that way, with temperatures in the teens in the mountains and 20s in the Snake River plain, to mostly single digits in the mountains and teens in the Snake River plain for Tue night. Temperatures Tue will struggle to reach 40 deg F at the lower elevations, and same for Wed with the surge of cold air, despite mostly sunny conditions on Wed. The rest of this period is sunny days and clear nights. It will take until the extended period for temperatures to modify to warmer conditions. The sunshine is due to high pressure, which means light wind for the remainder of this period after Tue afternoon. The slow warming is due to a northerly airflow the keeps bringing in cold air from Montana and Canada. Messick .LONG TERM...Fri through next Mon night. Fri and most of Sat appeared to have a strong ridge dominating. This is the point at which the model clusters start showing sharp differences in the handling of the next low. The NBM now brings in slight chance to chance of snow everywhere by Sat night. This is due to the retreating high and more zonal flow with most guidance, but about 40 percent of the solutions indicate another, weak, trough moving into the region. Things are a little more sure for Mon, so would not be surprised to see some wild shifting around for Sat night and Sun the next couple of days. Messick && .AVIATION...Winds will be breezy for the rest of today and will continue to increase in magnitude ahead of and along the front, peaking between Midnight and sunrise tomorrow morning. Sustained winds will generally range 15 to 25 kts with gusts to 35 kts at KPIH, KIDA, and KBYI and remain under 20 kts at KSUN and KDIJ. Precipitation will enter the central mountains near sunset and is expected to be in the vicinity of the remaining terminals between 02z and 04z. Rain/snow mix will be likely below 5,000 feet elevation late tonight before snow levels drop behind the front. Snow will likely then become the sole precipitation type beginning around sunrise Tuesday. Total snow accumulation through Tuesday night will be much lighter further west, with only an inch of snow forecast at KSUN, zero to a few tenths in our valleys, and around 3" at KDIJ. VFR to MVFR CIGs and VIS are forecast with IFR or LIFR VIS possible under more organized/moderate snow at KSUN and KDIJ. Cropp && .PIH WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 5 PM this afternoon to 11 PM MST Tuesday for IDZ060>066. && $$