As we enter the Christmas thaw, the US is heading for a record-breaking onset of winter!
A significant reduction, including a partly stormy westerly wind and heavy rain, is in store for the Christmas holidays. The prognosis is different in the USA: There, a marked onset of winter is in the starting blocks, which will ensure icy conditions on the Christmas weekend of all days – even as far as the coast of the Gulf of Mexico!
Snow is of course also in sight, although by American standards the amounts will usually be limited. By Christmas, however, the north-east of the United States in particular (apart from the Atlantic coast) will be wrapped in wintry white. Larger amounts of 30-60 cm are only found in exposed locations on the Great Lakes and regionally in Canada.
The cold is coming
The drop in temperature, on the other hand, is much more striking. Light to moderate freezes are in sight for the Christmas weekend even along the south coast of Texas to Florida. For comparison: New Orleans, in the state of Louisiana, lies on the Gulf of Mexico at regarding the same latitude as Cairo. Lows and highs between -20 and -30 degrees are common in the central and northern United States. A quite striking event for this extreme region of the world, but the records are still a bit away and are usually -30 to -50 degrees.
Icy wind
The cold snap will also be accompanied by a stormy north wind. The perceived temperature will therefore be significantly lower due to the icy wind. The so-called “wind chill index” is now the standard measure to determine such a perceived temperature in degrees Celsius. In the north of the USA, wind chill values between -40 and -45 degrees are even in sight, but even from Texas to the Atlantic coast it will not be exactly comfortable at Christmas with values well below 0 degrees.
Last but not least: The graphics below give a good estimate of the drop in temperature in selected major cities in the USA. Temperatures will drop between 20 and 30 degrees in just 24 hours. For Chicago and Denver, such values are still a long way from winter records (Chicago -33 degrees, Denver -32 degrees), only New Orleans might set a new cold record on Christmas Day (previous absolute cold record is -6 degrees).
