A low pressure system and associated cold front will slowly sag southward across the region today through Tuesday morning. This storm system will bring periods of showers and isolated thunderstorms to the northern Colorado mountains/valleys, with a minimal chance of showers elsewhere. Moderate snow amounts are expected for the northern CO mountains with winter weather advisories in effect. Across far southwest Colorado, a Red Flag Warning is in effect this afternoon/evening due to expected low relative humidity, gusty winds and dry fuels. It will be much cooler on Tuesday behind the cold front, with showers diminishing in the afternoon. A gradual warm up begins Wednesday with above seasonal temperatures by Friday, it will also generally be dry the latter part of the week aside from a few mountain showers.   (Please visit http://weather.gov/gjt for more information.)