ZCZC SPCSWOMCD ALL ACUS11 KWNS 171949 SPC MCD 171949 MTZ000-IDZ000-ORZ000-WAZ000-172345- Mesoscale Discussion 0078 NWS Storm Prediction Center Norman OK 0149 PM CST Wed Jan 17 2024 Areas affected...Washington...northeast Oregon...northern Idaho...and western Montana Concerning...Heavy snow Valid 171949Z - 172345Z SUMMARY...Heavy snowfall rates between 1-2 inches per hour are probable - especially at higher elevations - through the afternoon and early evening. DISCUSSION...Surface observations over the past hour have reported an uptick in snowfall intensity across portions of OR and northern ID. This comes as a swath of precipitation becomes more widespread ahead of a compact, progressive upper disturbance moving into the Pacific Northwest. Lift will likely be focused/maximized along a mid-level baroclinic zone between 850-700 mb, which should overlap to some degree with a DGZ between 700-600 mb (based on recent forecast soundings). The combination of more focused ascent within a portion of the DGZ should support moderate to heavy snowfall rates up to 1 inch/hour. More localized orographic ascent will likely enhance snowfall rates within the higher elevations, and could support snowfall rates up to (and possibly exceeding) 2 inches/hour. A minimum in snowfall rates is anticipated across central WA where orographic ascent contribution will be considerably smaller. ..Moore.. 01/17/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TFX...PIH...MSO...BOI...OTX...PDT...SEW...PQR... LAT...LON 43741612 44651774 44931811 45281833 45861883 46051943 46172017 46232081 46132148 46802166 47772154 48162145 48712115 48912075 48981908 48941667 48921651 48961360 48821298 47921283 44061289 43751324 43471384 43451480 43481542 43741612 NNNN