Strong cold front to usher in a variety of hazardous weather across theHeartland today; briefly disrupt record warm spell......Powerful West Coast storm brings significant snow and wind to thePacific Northwest beginning late Wednesday into Thursday...Much of the nation's weather story through the next 36 hours remains tiedto a strong Polar cold front which continues to sweep across the Lower 48.After a period of widespread all-time record breaking warmth yesterday,temperatures across portions of the Northern Plains have plummeted nearly50-60 degrees behind the front in a stark reminder that meteorologicalWinter is still with us for two more days. A similar scenario will playout further south across the portions of the Southern Plains and Midwesttoday, as widespread record warmth (including some all time records) areforecast ahead of the front before falling off into the 40's and 50'stomorrow. Stark pattern change aside, this strong cold front will alsodrive Critical fire weather conditions (level 2/3) across the SouthernPlains owing to the combination of very dry, warm, and gusty conditions inplace. To the east in the Midwest and Ohio Valley, an Enhanced risk (level3/5) of severe weather is highlighted for thunderstorms expected late thisafternoon into the overnight hours. All modes of severe weather, includinglarge hail, damaging gusts, and tornadoes (some of which could besignificant) are possible with this activity. This thunderstorm activitywill eventually weaken tomorrow, but locally heavy rainfall and a fewsevere thunderstorms are possible ahead of the front stretching from theOhio Valley into the Northeast.  Our attention then turns to the West Coast late Wednesday into Thursday asa significant winter storm focuses impacts atop the Cascades and SierraNevada in California. Extremely heavy snowfall rates exceeding 3 inchesper hour will lead to multiple feet of snow for higher elevations in theseareas (particularly above 5000 feet), including passes in theaforementioned ranges. When combined with strong wind gusts, this snowfallwill lead to difficult to impossible travel conditions in the mountains.Accordingly, a swath of Winter Storm Warnings and Watches extend from theOlympics and Cascades southward into the Shastas and Sierra Nevada. In thelower elevations, localized heavy rainfall can be expected along thePacific Northwest and Northern California coastline.