Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
865 FXUS65 KPIH 301951 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 151 PM MDT Tue Apr 30 2024 .SHORT TERM...Tonight and Wednesday Afternoon satellite imagery shows gradually increasing clouds over the region although there is still a lot of blue skies to be had throughout eastern Idaho. Seeing breezy conditions again this afternoon across the upper Snake and into the Arco Desert where a Wind Advisory continues through 9PM tonight. Hi-res CAMs show the potential for some showers into the evening and overnight, mainly across the Montana Divide and into the eastern highlands. Temperatures will be cold enough for much of this to fall as snow showers. Impacts should be pretty limited however and only light accumulations would be expected across the higher terrain. As the calendar turns to May tomorrow, it won`t feel much like May. Freeze warnings are out once again for the growing region. This isn`t a "slam dunk" warning like yesterday though as there will be more clouds to contend with tonight so it`s a bit more marginal. Nevertheless, chose not to get cute with putting some zones under a Frost Advisory and others with a Freeze Warning. Urban centers around Burley, Pocatello and Idaho Falls may flirt with, or avoid, freezing conditions but the more rural locations will likely get there. Especially if cloud cover isn`t as pronounced as forecast. An upper trough digging into the region tomorrow will bring us some cooler, slightly active weather for Wednesday. After the cold start, temps will only warm into the 40s for most locations, maybe a few places reach 50. Additionally, models show some showers and thunderstorms developing during the afternoon tomorrow. Highest PoPs are forecast across the northern half of the region and into the eastern highlands but everyone may get in on the action. Given the cooler temperatures once again, some of this will be in the form of snow, despite the fact that it is May. This includes the lower valleys. Not expecting any issues with accumulations however given marginal temps and warmer ground temps but don`t be shocked to see some flakes fall tomorrow. Another freeze warning is likely going to be needed into Thu AM before out overnight lows start to trend upwards into the weekend. McKaughan .LONG TERM...Thursday through next Tuesday The next round of rain and snow showers shifts across the state later Thursday into Friday. Clouds and showers will keep temperatures running a few degrees BELOW AVERAGE. Precipitation amounts don`t look too heavy, but heavier showers may produce 0.10-0.20" of moisture. Saturday should be mostly dry until later in the day, as moisture shifts northward across eastern Idaho...for the next round of showers. With the low still to the west, the best chance will across the central mountains south into the Magic Valley. Despite some increasing clouds, southerly flow will drive temperatures up, with lower valley temperatures pushing 70. This is where things get a bit hectic. It will be back on the cool side and showery heading into next week. However, we are seeing some glaring differences on how the models and cluster forecasts are handling the track of that low. The ECMWF wants to drag the low almost on top of us, with a trailing developing on the back side of it. The GFS develops split flow and takes the main low to our south and east. The clusters have a 55(ECMWF)/45(GFS) split in their forecast Saturday, and 60(ECMWF)/40(GFS) split on Sunday into Monday...although the split favoring the GFS is less pronounced vs the operational GFS. Keyes && .AVIATION... Breezy conditions will continue into Wednesday. Gusts of 20-35kts are possible throughout the period. We will see occasional showers especially Wednesday. We did include VCSH for this afternoon at SUN, although the risk may end up being too far north to impact the airport itself. We also included VCSH tonight for IDA and PIH, but that is highly conditional. We may end with virga since the airmass is really dry out there right now. At DIJ, we included a mix of rain and snow showers since probabilities and potential look a lot better there. For tomorrow, we will likely carry VCSH until we get a better idea on timing. We may also have a low risk of thunderstorms with tomorrow`s activity. Keyes && .PIH WATCHES/WARNINGS/ADVISORIES... Freeze Warning from 2 AM to 9 AM MDT Wednesday for IDZ051>055. Wind Advisory until 9 PM MDT this evening for IDZ052-053. && $$