SPOT WEATHER FORECAST

11/13/2009 Weather Discussion: Snow will turn showers today and taper off overnight. A ridge of high pressure will dry things out tomorrow before a large trough of warm and wet weather approach the PNW on Sunday. Long-term models show Sunday’s system initially starting out as snow but then turning to rain as the trough develops a southwest fetch. Cool air, with more moisture is expected to fill in behind this system on Monday/Tuesday. Too early to be confident in the effect or timing of these features. 24 hour forecast starting at noon on Friday Precipitation “ Water: .25 “ of Snow: 2-4” Base area temperature: Low 20 High 24 Trend: down Winds speed: Pass level 0-5 SW shifting WNW Ridge top: 5-15 SW shifting WNW -gusty TRENDS AND TIMING Precipitation: The snow will begin to taper off after 4pm today. Showers will linger to about midnight. Tomorrow expect dry weather with some sun breaks. Clouds will move in tomorrow evening in preparation for Sunday’s system. Currently, on Sunday, the precip will start out as snow and then turn to rain after noon. Not sure when it will turn back to snow – stay tuned for those details later. Freezing levels: Freezing levels will hover near 2500-3000’ through the day and then drop overnight. Freezing levels could dip below 1000’ during the early morning hours. (watch for freezing rain on the roads down valley) Freezing levels will then begin to rise, reaching pass level by noon on Sunday. Freezing levels will then continue to climb above ridge top elevations into Monday. Winds: Winds will be gusty at times as these front come and go. Winds will swing to W and the NW through the next 24 hours. SW flow will accompany Sunday’s frontal system. jdm