We published a news story yesterday entitled "November Arctic Cold Blast Forecast", where we explained our concern for a cold, stormy latter half of November, possibly disrupting travel during Thanksgiving week. Today I want to take a look at some of the computer forecast models and try to quantify just how cold they think it will be.
There are really only two forecast models that go far enough into the future to glimpse this cold snap. The GFS goes out two weeks, and its last low temperature prediction is shown above. That's right, below zero in the Plains and single digits into Pittsburgh. As a result of that extremely-cold forecast, the model is estimating that this is what the Snow Cover map will look like on Black Friday:
But before you get too excited, checking the GFS ensembles (multiple runs of the same model), the average temperature in Pittsburgh is near 0 C (32 F) that night, not single digits. Why the disagreement? Apparently the "real" GFS is an outlier when you take all the different perturbations into account -- although that average (mean) prediction is +/- 5 C at Pittsburgh and +/- 15 degrees (based on the other runs) in the Plains because the model gets less accurate as it forecasts out into time.
The ECMWF model only goes out 10 days, but shows single digits on the central Canadian border on November 20th. If both models continue to be in agreement about a major cold outbreak, it will likely happen, though it's also likely it won't be as bad as the Operational GFS says above.
There was a blizzard warning in effect for Hawaii on Dec. 25. What sorcery is this?
There are a number of holiday (Black Friday, Cyber Monday, Holiday) sales happening this season with gadgets that can help you observe the weather.
Tragedy struck on the day before Christmas Eve this year when four people were killed by a tornado in Mississippi. Tornadoes also struck Georgia, Louisiana and (on Christmas Eve day) the Carolinas.
Siberia has fallen to -66 degrees as the cold air pool grows and throws off a storm to soak Japan with 2 feet of rain and even more snow.
This week's powerful California storm has now brought a report of a tornado in southern L.A. this morning, and additional reports of waterspouts this afternoon
A very deep storm in the North Atlantic, not far from a strong high pressure system, will cause incredible wave heights midweek.