Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
147 FXUS65 KPIH 102022 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 222 PM MDT Mon Jun 10 2024 .SHORT TERM...Tonight through Tuesday Night. Following an active past 72 hours across ERN Idaho, seasonably warm and dry conditions will return for much of this upcoming week under the increasing influence of a H5 ridge of high pressure over the WRN CONUS. While today will feature a nonzero chance of showers and thunderstorms east of I-15 this afternoon and evening associated with lingering moisture behind Sunday`s cold front, conditions will remain predominantly dry and continue into Tuesday as warm, dry, and zonal/SW flow shifts overhead. Highs today will range from the low 70s to low 80s and will warm about 4-8 degrees for Tuesday into the mid 70s to upper 80s with overnight lows in the 40s and 50s both tonight and Tuesday night. Winds will remain elevated primarily during the afternoon and evening hours with sustained winds peaking around 15-25 mph with locally stronger winds across the Snake River Plain. MacKay .LONG TERM...Wednesday through next Monday. Models continue to show a weak trough moving well north of Southeast Idaho on Wednesday causing zonal flow aloft with breezy winds (gusts of 25 to 40 mph) at the surface with the strongest winds over the Arco desert. Right now models are showing 20 mph sustained winds at the American Falls reservoir late Wednesday. A lake wind advisory for the American Falls reservoir may be needed. Late Wednesday into Thursday models still show weak high pressure building back in before bringing a trough/cold front through the area on Friday into Saturday. Expect dry conditions Tuesday through Thursday. Will see an increase in the chance for convection with showers and thunderstorms Friday, mainly along the Montana Divide. Saturday looks mostly dry, but breezy. Look for temperatures 10 to 15 degrees above normal for Wednesday and Thursday.Thursday will likely be the warmest day of the week, with temperatures possibly hitting 90 degrees (30 to 60 percent chance from NBM model) for some lower areas across the Shoshone, Eastern Magic Valley, Southern Snake Plain, Raft river, and the Franklin/Oneida/Cache Valley regions. Temperatures look to drop quite a bit on Saturday, becoming near normal. Sunday and Monday look for temperatures to drop even more, 3 to 6 degrees below normal (50/60s in mountains and low to mid 70s for lower valleys). Wyatt && .AVIATION...For the 18Z TAFS through 18Z Tuesday. High pressure is building in across Southeast Idaho from the west to east this afternoon into tomorrow. Look for mostly clear skies and slightly afternoon breezy winds today and tomorrow. KDIJ has some lingering moisture and mid-level ceilings in the area. Models have backed off on precipitation for this afternoon with the HREF showing less than a 10% chance of precipitation for Driggs. Driggs will become mostly clear by this evening. Wyatt && .FIRE WEATHER... The passage of last night`s cold front will cool off temperatures. Humidity will be much lower in the afternoon as skies clear and the precipitation ends. As upper level high pressure returns, look for warming to resume Tue. By Wed, afternoon humidity below 15 percent should return to lower elevations in the Salmon- Challis and the Arco Desert. Gusty afternoon wind will continue. Messick && .HYDROLOGY... A FLOOD WARNING remains in effect for the Teton River near Driggs as small streams/creeks and the main stem river continue to run high. Minor flooding is being observed on the Teton River and is expected to remain at that level through Tuesday, aided by additional snowmelt from the Tetons and Big Holes. With the latest NWRFC forecast showing this gage dropping below minor stage on Tuesday, have gone ahead and added an expiration time for the warning to be 3 PM Tuesday. This may need to be adjusted dependent on future flows and trends going forward, with warmer temperatures certainly still leading to additional snowmelt. This additional snowmelt is expected to keep the river in action stage through much of this upcoming week. Further downstream along the Teton River near St. Anthony, that gage remains at action stage and is only a couple inches away from minor flood stage. That gage is expected to crest today and come down below action stage by Wednesday. Several other rivers across the CNTRL Mountains are also seeing diurnal increases with the Big Lost River at Howell Ranch currently hovering around action stage. Along the Snake River, increased flows out of Palisades Reservoir have also led to the Snake River near Heise gage climbing up to action stage and it is expected to stay there until further notice. MacKay && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$