ZSE TCF

Traffic Flow Management Convective Forecast (TCF)

TCF Legend	TCF +4hr Forecast
TCF +6hr Forecast	TCF +8hr Forecast

Product Description:

The TCF is a high confidence graphical representation of forecasted convection meeting specific criteria of coverage, intensity, and echo top height. The TCF graphics are produced every 2 hours and valid at 4-, 6-, and 8-hours after issuance time.

Areas of convection in the TCF include any area of convective cells containing (at a minimum):

1. Composite radar reflectivity of at least 40 dBZ;
2. Echo tops at or above FL250;
3. Coverage (a and b) of at least 25% of the polygon area;
4. Forecaster confidence of at least 50% (High) that criteria (a, b, and c) will be met.

Lines of convection in the TCF include any lines of convective cells:

1. Composite radar reflectivity of at least 40 dBZ having a length of at least 100 nautical miles (NM); and
2. Having a linear coverage of 40% or greater; and
3. Having echo tops at or above FL250.
4. Forecaster confidence of at least 50% (High) that criteria (a, b, and c) will be met.

All four of the threshold criteria listed above for both areas and lines of convection are required for inclusion in the TCF. This is defined as the minimum TCF criteria.

The TCF domain is the Flight Information Regions (FIR) covering the 48 contiguous states and adjacent coastal waters. It also includes the Canadian airspace south of a line from Thunder Bay, Ontario to Quebec City, Quebec.