Please send us an email if you have any questions or comments on these new freezing level graphics. The older graphics are still available here.
The maps represent Freezing Levels from two perspectives. One, the red dashed line represents the 32F isotherm at the surface and is derived from the temperature grids from the three forecast offices, Anchorage, Fairbanks, and Juneau. Two, the blue-filled contours represent 32F isotherms above the surface at Flight Levels above Mean Sea Level from the Alaska Aviation Weather Unit. Together, a red dashed line underneath blue-filled contours represent areas with multiple freezing levels.
The purpose of these charts is to determine river basin snow/rain delineation and snow melt for river forecasting purposes These charts are not intended for flight planning purposes. Please refer to the Alaska Aviation Weather Unit (https://www.weather.gov/aawu/) for official aviation weather forecasts.