I am back from a long haul flight and Toronto is being inundated with freezing precipitation: FZRA, PL with FZDZ to come. The YYZ METAR below states there is ice on the indicator one millimeter thick (piece of aluminum to replicate an aircraft's skin) and about 2 cm of snow (probably ice pellets) have accumulated. Hundreds of flights have been cancelled. The winds are easterly (ugly wind) and the temperature is -2C with an IFR ceiling.
CYYZ 061800Z 08009KT 2SM -FZRA -PL OVC007 M02/M04 A2995 RMK SC8 1MM ICE ON INDICATOR /S02/
Last evening while flying in from Tel Aviv, Israel during my annual route check, I noticed the temperature on approach to be +3C whereas the surface temperature hovered at -2C. I immediately thought it to be a subsidence inversion as the stratocumulus cloud top was compact and level. However, some middle to high cloud lurked foreshadowing a frontal inversion. I tried to point this inversion out to my flying mates, but I remembered I was getting a route check and below 10,000 feet supposed to be a sterile environment. Oops.
So how does Buffalo, New York aid a Canadian forecaster? For an area with millions of people in the Greater Toronto Area we get our upper air data from the balloon launched twice a day in Buffalo.
Below is the upper air data called a Skew-T Log-P diagram, I wanted to point out the nice frontal inversion associated with a winter warm front. I tried to find a diagram that depicted heights in feet. One can get the data in text, and the above freezing started at 750m (2400 feet) to 2450 (8000 feet). Thick!
Here in Canada we call it a tephigram ) T for temperature and Phi for entropy (thermodynamic entity).