Saturday, November 26, 2011

Weather History: Great Appalachian Storm of 1950

November 25th-26th, 1950 produced one of the more significant storms in terms of intensity, strength, and contrasts that we've seen on the East Coast in the era of weather observations and significant weather data. This storm system was the result of a phasing of a sharp trough with a southern stream disturbance, which formed a low pressure center in North Carolina that intensified into a deep, powerful low pressure system that moved slowly north and then westward into the Great Lakes. The storm killed 22 and deluged the East Coast with rain and the Midwest and Appalachians with heavy snow.

The storm intensified and stacked itself in the atmosphere and at the surface, capturing warm air off the Atlantic and pulling it inland over the Great Lakes.  The pull of warmth around the storm was such that Detroit was able to see temperatures rise from the teens to the upper 30's with the north-northeast wind pulling the lingering warmth into the low pressure center as it spun into Northern Ohio, while at the same time temperatures in Pittsburgh fell below ten degrees as it was situated to the south of the low pressure center and was getting blasted with cold southerly (yes, you read that right) winds.  Pittsburgh ended up with thirty inches of snow from this storm.   While Pittsburgh was in the teens and single digits, Buffalo was in the 50's with east winds.  The Ohio State-Michigan game that typically ends the season for both teams was played in the midst of a snowstorm in Columbus, OH, with temperatures in the low teens, earning the nickname of "Snow Bowl".

You can sorta 'see' the temperature contrast on the graphic below.  Granted the hard observational data is sparse in making up that map but you can see how warmth and moisture were sucked into the storm's counter-clockwise rotation.  Because the storm was strong at the surface and aloft, the pull of warmth was such that it could be warmer to the north of the storm than to the south (as colder air was able to quickly infiltrate the storm on the south and west sides of it).   The fact that 6 AM temperatures in Washington were over fifty degrees warmer than they were in Atlanta could tell most meteorologists and most casual observers that this storm meant some business...and it really did mean business regardless of location.

In Philly, the impact was over three inches of rain and sustained winds to 50 mph while temperatures flirted with 60 degrees in the morning before falling back into the 30's by evening and 20's by midnight.  Philly picked up a trace of snow from this storm at the very end (but followed this up with 1.8" of snow just two days later from a clipper).   Newark, NJ, had sustained winds to 60 mph and gusts to over 100 from the storm to go with the nearly three inches of rain they received.

In terms of storms, this one doesn't have the same reputation that the '93 Superstorm has but it arguably brought as much bang for buck in terms of impact and arguably makes for one of the more interesting storms to look at from an analysis standpoint because of its ability to pull warm air in around the northern side of the low.