Thursday, February 19, 2015

Brrrutal Cold

Surface temperatures at 6:00 a.m. CST on February 19.
Low temperature records were falling from the upper Midwest to Florida this morning as the leading edge of a Arctic cold air mass surged as far south as the Gulf Coast and central Florida. Watertown, NY plunged to -36°F this morning, shattering the previous record of -24°F set in 1963. The temperature at Chicago's O'Hare International Airport dropped to -8°F this morning, beating the previous record of -7°F set in 1936. In addition, today's high temperature only made it 4°F, a record low maximum high for this date. The previous record was 9°F degrees in 1936. A record low (-24°F) and record low high (-4°F) were also set in Marquette, MI today. Record low maximum temperatures were set in Binghamton, NY (10°F), tied in Syracuse (11°F), broken at Bridgeport, CT (24°F), broken at Islip, NY (24°F), and on and on. A number of these locations in New York broke records on several days this week. Record low temperatures and record low maximum temperatures were set as far south as Alabama, Georgia, South Carolina, and northern Florida. Daytona Beach reached only 50°F today, a record low maximum temperature for today, breaking the previous record of 53°F set in 1958 and 1972.

The lowest temperature this morning in the lower 48 states was -42°F in Cotton, MN, about 36 miles north of Duluth. Duluth's high temperature of -5°F today tied the record low maximum first set in 1941.

Minimum temperatures for the 12 hr period ending at 6:00 a.m. CST February 19.

Surface temperatures at 3:00 p.m. CST February 19.

The wide extent of the cold air is due to a huge upper level trough over the eastern two-thirds of the country. As can be seen on the chart below, the air, which flows parallel to the lines on the map, is coming straight over the Arctic and into Canada and the U.S.

500 millibar map for 6:00 p.m. CST February 19.

More records are likely Friday morning especially across the eastern U.S. where clear skies and snow cover will allow the temperature to plummet. Clouds spreading across the Midwest will slow the temperature drop there. Hard freeze warnings are in effect from southern Alabama through the northern half of Florida.

Forecast minimum temperatures for Friday, February 20.

While the intensity of the cold air is bad enough, the persistence of the cold air is a real problem for an area from the Ohio Valley southeast into Tennessee, Georgia, and western North Carolina where freezing rain from the storm earlier this week caused power outages. Unfortunately, it appears that more icing could occur this weekend from Ozarks east through Tennessee into North Carolina and Virginia.

Forecast for the period from 6:00 p.m. CST February 19 to 6:00 p.m. CST February 22.
It's likely that colder than normal weather will continue through the rest of the month for the eastern half of the U.S. The weather will moderate some next week, but temperatures will still be well below normal.

Minimum temperature forecast for Thursday, February 26.

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