Snowsqualls off the Manitoba lakes on November 10, 2004

What happened?

On November 10, 2004, a cold front swept through southern Manitoba. In behind this front snowsqualls set up off of the Manitoba lakes. The forecast challenge of that day was determining how intense the snowsqualls would be.

It turned out that, while impressive on the visible satellite imagery, there was very little snow falling. This is likely due to a couple of reasons.

First, the air coming from the north was very dry--thus, it started off having less potential (aka moisture) for snowsqualls.
Second, the winds from the surface to the top of the cloud layer (700 mb) were not well aligned--unlike severe thunderstorms, wind shear in snowsqualls tends to weaken them by tearing them apart.
Third, the trajectory of the squalls was such that perhaps they **did** produce lots of snow--but if they did, it was in unpopulated areas and thus it will never be known how much did fall.

Tephigrams

The 12Z tephigram from The Pas, MB
The modified 12Z tephigram from The Pas, MB modified for a 4°C lake temperature

Satellite images

The visible satellite animation About 5 mb
The water vapour satellite animation About 6 mb

RADAR images

The RADAR animation About 2.5 mb

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