Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
395 FXUS65 KPIH 302024 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 224 PM MDT Thu May 30 2024 .SHORT TERM...TODAY THROUGH FRIDAY NIGHT... Weak troughing today...the wrn fringes of yesterday`s departing storm system...will transition to weak ridging Fri. All of this spells quiet wx with dry, mostly sunny/clear conditions and winds trending lighter each day (still a bit breezy today) as well as a warming trend as today`s 60s turn into tomorrow`s upper 60s to low 70s. Main impacts-based focus of the short-term forecast was looking at low temps Fri AM, and it does indeed appear one more FROST ADVISORY is needed up most of the Shoshone to Snake Plain corridor (although excluding the Ern Magic Valley zone this time). Exact low temps will be very borderline for frost formation...generally 32 to 36 degrees, so frost coverage may be quite patchy and will tend to favor outlying areas west of our I-15 population centers where temps will be coldest. However, did not feel comfortable holding without the advisory and banking on all locales staying above freezing, not to mention a few areas got 1-2 degrees colder than forecast last night. The good news? This MIGHT be the last FROST ADVISORY we need this spring! 01 .LONG TERM...SATURDAY THROUGH NEXT THURSDAY... Overall pattern remains shallow and progressive through the early part of next week, with good ensemble cluster agreement on both depth and timing of upper flow. Weak shortwave drives through late Saturday/Saturday night for potential showers through Sunday, mainly across the north. Precipitation amounts remain low. Breezy/windy conditions expected Sunday as well, along with temperatures dropping to near normal levels after a very warm Saturday. Stronger low shifts into the region Sunday night into Monday, with much better chances of precipitation. NBM means exceed 0.25" for a significant portion of the Central Mountains through Monday night, with 90th percentile (1 in 10 chance of exceedance) around an inch. Current deterministic values put total precipitation for this event in the 0.25-0.75" range for a good portion of the Sawtooth Rec Area/Frank Church regions, along with a sliver of the Yellowstone region north and east of Island Park. Although this is Day 5 of the extended, the clusters and ensembles appear to be in good agreement with a persistent trend, though it is worth noting that the 10th percentile (9 in 10 chance of exceedance) keeps most areas dry. WPC has already preliminarily brushed the central mountains in a marginal risk for excessive rainfall for Monday, so this would be the highest confidence period for the best chance at rainfall. Following this system, the trend for Tuesday and beyond is for dry and turning warmer again, as an amplified ridge slowly builds into the intermountain west. Could lower elevations reach 90 for the first time this season? The 6-10 and 8-14 day outlooks keep highlighting much above normal temperatures, and the NBM spreads continue to point to at least upper 80s. Stay tuned. DMH && .AVIATION... Breezy conditions continue for the Snake Plain terminals KBYI/KPIH/KIDA today with sustained winds 15-20kts and gusts around 25kts. Winds diminish overnight and remain around/below 10kts into Friday. Expect generally clear skies with a few afternoon build ups, with VFR CIGS. DMH && .PIH WATCHES/WARNINGS/ADVISORIES... Frost Advisory from 3 AM to 8 AM MDT Friday for IDZ051>054. && $$