National Weather Service United States Department of Commerce

High-Impact and Far-Reaching Winter Storm Continues; Cold Expands and Persists

A major winter storm will shift its impacts into the Northeast U.S. with heavy snow through tonight while over the Mid-Atlantic, sleet and freezing rain will diminish. Extremely cold air behind the storm will prolong dangerous travel and infrastructure impacts. Sub-zero low temperatures are expected nearly every morning from the Northern Plains through the Ohio Valley and into the Northeast. Read More >

Fire Weather Watch/Red Flag Warning Criteria
Specific conditions must be met for a Fire Weather Watch and/or a Red Flag Warning to be issued. These conditions are as follows:
1. KBDI greater that or equal to 600, and
2. Two minute ASOS winds greater than or equal to 17 kts (20 mph), or 20 foot winds greater than or equal to 14 kts (16 mph), and
3. Minimum relative humidity of less than 60% in one or more observations, and
4. Low 10-hr fuel moisture, typical less than 13.
5. Monthly precipitation less than two inches with a decrease and/or cessations of percolation (dew)can signal the onset of the fire season. Forecaster judgment must be used in the watch/warning decision making process.