Tracking next weather maker

The moisture from yesterday's weak trough of low pressure tallied up to a quarter inch in spots. Temperatures remaining above the freezing point should mean wet roadways for the ost part. But watch for refreeze in favored low areas.

We are tracking the system for this weekend. And as Paul has pointed out the models have difficulty during this transition into early spring. We are still looking at the potential for accumulating snow in northern Minnesota.

NWS Chanhassen forecast graphic.

Most likely area to total snowfall of greater than eight inches as forecast by NOAA.

This next system promises to produce a wide swath of precipitation. Heavy rainfall and strong storms are likely in the Ohio Valley.

This is a graphic of the best consensus forecast from NOAA of liquid precipitation the next five days.

Rivers in central and southern Minnesota have mostly crested, but this next wave of precipitation wil prolong the high water levels. The drainage into the Red River Valley remains a work in progress.

A couple weeks ago I visited the North Central River Forecast Center in Chanhassen. I chatted with one of the hydrologists about the disappearing snowpack and the lack of runoff moving down the curbsides. Together we surmised that perhaps as much as one inch of water equivalent from the seasonal snowfall sublimated directly into water vapor.

The quantative measurement of sublimation is not possible, so this is merely old school speculation. But it certainly could have contributed to keeping the river crests down. That along with the cooler than normal March temperatures was fortuitous for those concerned about flooding

In the Twin Cities this March had an average temperature of 29.4 degrees, compare that to the very mild March of 2010 when the average temperature was 41.0 degrees.

An usettled weather pattern looks to continue into next weekend.

CE