debor046

The snow that everyone graved finally came to the Midlands.   The same storm system that affected Birmingham and Atlanta also affected Columbia, SC.   Rain and sleet began to fall before noon on Tuesday, but it wasn’t enough to measure and didn’t cause any problems.   The lower atmosphere was quite dry so that it would take hours of light precipitation to moisten the atmosphere enough to allow for any significant precipitation. Finally a band of rain/freezing rain moved across the southern half of the Midlands just before dark.   This was followed by snow in the northern part of the Midlands.   It eventually reached Columbia in the form of freezing rain.   At WLTX we pick up an ice accumulation of 1/10 of an inch before the precipitation changed over to snow.   The southern third of the Midlands saw ice accumulations of a ¼ to ½ inch. The air was chilled by the rain/sleet/snow mix and temperatures fell below freezing over all of the Midlands shortly a...

The National Weather Service issued a Winter Storm Warning for all of the Midlands of South Carolina beginning at 11 a.m. Tuesday and ending at 9 a.m. Wednesday.   The warning was issued for significant accumulations of winter precipitation.   While the warning covers all of the Midlands the effects of the winter storm will be quite nuanced. First, the jet stream in the upper atmosphere is diving far to the south from the Arctic region.   The term polar vortex was used earlier in January to describe to cold weather seen at that time.   Well, it’s baaaaack!   This time a piece of the polar vortex is centered just east of James Bay in Canada.   Cold Arctic air is plunging south to the Gulf coast and covering much of the Southeast. The 500 mb pattern for 00z Tuesday, January 28, 2014.  Click on the image for a larger view.  Image Credit: WLTX-TV. All of the computer models have been signaling this for the past few days.   However, their solutio...

The National Weather Service issued a Winter Storm Watch for the midlands of South Carolina Sunday afternoon.   It is for the time period from Tuesday morning to Wednesday afternoon.   Immediately everyone was jumping up and down for joy over the prospect for snow.   Not so fast bucko!   Everything is not as it seems. It took quite a bit of careful analysis to decipher what the scenario would be.   The computer models have been all over the place with this system; from no snow to more than 15” of snow.   Even our own in-house model has seen big run-to-run swings with 2 to 4 inches of snow in one run to no snow the next.   So what to do? I have decided that the American model (GFS) seems to be preforming the best for now.   The NAM model has been showing wild swings run-to-run and the European model (ECMWF) seems too cold.   None of the models are perfect, but the GFS seems to be closest to actual observations in the forecast. Thus, here is t...

A weather pattern we have seen many times since late October, 2013, has reappeared in its amplified form.   The ridge of high pressure in the upper atmosphere has been building since late last week along the Pacific Coast, stretching from northwest Mexico to Alaska.   This has pushed the jet stream far to the north into Alaska and the Yukon.   The 500 mb pattern for North American at 00z January 21, 2014.  Click on the image for a larger view.  Image Credit: WLTX-TV. The result has been unseasonably warm temperatures for this time of year.   It is still cold, but in Fairbanks the temperature averaged 24° F above normal on Monday.   There have been wild swings in Fairbanks, AK, this month with its coldest temperature of -41° F on January 12 th & 13 th , and its warmest temperature at 34° F on January 17 th .   On that day the temperature averaged 32° F above normal. Alaskan temperatures at midnight January 21, 2014.  These are warm readin...