- A Short-cut to Cryogenic Death

Should freezing rain be encountered, your best escape route is usually UP.  If you are crossing a warm front, continue on your current heading, but add full power and CLIMB.   You should find warmer air above.  Freezing rain tends to be altitude specific.  Left or right turns to escape it are not likely to solve the problem.  

Freezing rain can be encountered in VFR conditions, but it is rare.  If you are not IFR rated, don't proliferate your problems by climbing into the clouds.  Instead, consider initiating a steep descent into colder (VFR) air below.

WARNING:  Do not delay taking evasive action.  Contact ATC and issue an URGENT Pilot Report (UUA) for freezing rain.  If you are on an IFR plan, advise them that you need an immediate clearance for a higher altitude.  ATC should be responsive, but if they are not, declare an emergency and begin a full power climb anywayDon't wait.    Freezing rain can render your aircraft uncontrollable in a matter of minutes!

The absolute safest way to avoid a freezing rain encounter is to remain on the ground any time the weather is less than sunny, warm, calm, and clear!  From a practical perspective, however, your best defense against a freezing rain encounter is to obtain a comprehensive weather briefing prior to every flight.  Know where any warm and cold fronts are relative to your planned route of flight.  Plan on crossing the warm fronts in a perpendicular fashion.  Do not fly close to and parallel to the front, particularly ahead of a warm front that is passing over freezing weather below.

  1. Types of Precipitation

Supercooled Water: Common in atmosphere between -15oC and 0oC
Rain: Liquid Drops
Drizzle: Small Liquid Drops
Snow: Aggregates of Ice Crystals
Sleet or Ice Pellets: Raindrops which have frozen in the atmosphere
Freezing Rain: Raindrops which freeze on contact with the ground or solid objects
Freezing Drizzle: Small supercooled droplets which freeze on contact

2. Causes of Freezing Rain: Vertical Structure

Precipitation Types & Warm Fronts
See also Fig. 11.1 and Fig. 11.2
Denver Freezing Drizzle #1 #2

3. Ice Storm Climatology 1982-1990 (from Robbins and Cortinas, 1996)

National summation of freezing rain observations by month
Number of freezing rain observations September through April
Hourly distribution (LST) of freezing rain observations
See also Figs. 11.6 and 11.7

4. Weather Patterns w/ Freezing Precipitation

A. Warm air "Overrunning" cold surface air
B. Shallow pools of cold air in valleys
C. Cold air damming


see also:

The Thermic Lance