UPDATE: From Grandfather Mountain, NC's newsletter: "Equipment mounted at the Mile High Swinging Bridge, which records temperatures every minute and on the hour, recorded air temperatures of -17 degrees at 5 a.m. and 7 a.m. that morning. The bridge is located at an elevation of 5,280 feet. The lowest recorded wind chill was -58 degrees at 5 a.m. Jan. 7, according to the data."
The cold outbreak is easing off today, and there's so much information that I'm overwhelmed. I'll hit a few highlights here. Please follow my Facebook WeatherMatrix page or my Accu_Jesse Twitter account for additional breaking information (or see my RebelMouse for both). And of course, follow AccuWeather.com for official information.
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The newspapers went wild with this cold wave. A few of the most impressive examples are shown above. The media adopted a new buzz word - "Polar Vortex" - and the hashtag was tweeted over 100,000 times in a two-day period (illustration below by Tristina Gelinas).
NOTES: In this blog, WC stands for "Wind Chill" and RF stands for the AccuWeather RealFeel. All temperatures are in Fahrenheit. Lowest readings provided by these files from AccuWeather.com Professional & CoolWx.com.
First, I'd like to do a quick summary of what happened at the typical East Coast cold spots during this "Polar Vortex" visit:
- Mount Mitchell, N.C. : Low -24*
- Mount Leconte, Tenn.: Low -17 (WC -55)
- Grandfather Mtn., N.C.: Low -17 (WC -56) Wind gust of 82 mph
- Mount Washington, N.H.: Low -19 (WC -62, RF -71) Wind gust of 98 mph
*The -24 at Mount Mitchell was the second lowest ever, exceeded only by the state record set in 1985 of -34. You can find more information on Southeast lows broken here.
Generally, the lowest temperatures nationwide during this cold wave were around -38 in Minnesota (which had previously dipped to at least -44 on Jan. 2). At one point, 90.1% of the nation was below 32 degrees, with 33.8% of the nation below zero!
The average temperature of the nation even fell to 11.7 degrees, tying the lowest ever measured on CoolWx.com (which has been in business for 20 years), previously achieved on Jan. 9, 2010.
As the polar front moved eastward, it pushed the warm air out of its way; at one point, temperatures ranged from 69 @ Virginia Beach to 0 @ Louisville, Ky. (~500 miles)!
There's no easy way to find the lowest RealFeel temperature in the nation or Canada, and wind chill records are hard to come by too. This is what I saw on the AccuWeather.com Professional maps, where wind chills were literally off the charts:
The lowest RealFeel temperatures and wind chills were in North Dakota, just shy of the forecast which was "only" for -70s). The lowest RealFeel temperature I could find was -68 at Minot, N.D., and the lowest wind chills were -85 from Rugby and Rolla, N.D. However... the -85 reading (which is backed up by the maps on AccuWeather.com Professional but NOT the text obs on the same website) is calculated with the old wind chill formula which was abandoned in 2001. The minimum wind chill calculated with the 2002 formula equals -59 at Rolla. This agrees with the NWS graphic below (by one degree; rounding sometimes causes small errors). Regardless, these are the lowest "feels like" temperatures I have ever witnessed in my 20+ years of meteorology.
Farther east, RealFeels dropped to -55 in Illinois and wind chills of -69 (-49 new algorithm) were observed in Illinois, with only a few degrees more in Indiana.
We have a list of the noteable record low temperatures; the NWS hasn't released how many daily records were set yet, but there were dozens and I'll add more info to this blog soon. All-time record lows were not threatened, as they range from -60 in Minnesota to -36 in Illinois and Indiana.
As far as actual temperatures, the eight-day European (ECMWF) model was actually quite impressive, when compared with this morning's lows (above). Yes, it was too strong in and around Kentucky, Tennessee and the southern Appalachians (that could have been simply due to higher winds than expected not allowing cold air draining). It was, however, spot on in the Midwest and Northeast, if anything actually too high: 15 for New York City vs. this morning's low of 6.
The temperatures in New England, here in central Pennsylvania, central North Carolina, and most other places were within a few degrees of actual. The point is: The ECWMF model has again (as during Hurricane Sandy) proven itself a great one-week-out predictor over the U.S. (GFS) model (which was predicting 50s for most of the area a week before). (Of course, both of those are extreme examples created by a restrictive flow in the atmosphere; the Euro may not do so well in a zonal flow).
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In this week's gadget haul, I review the following NAPA products, including one that fits in your purse but can jump start your car!
The Dimmitt, TX, supercell thunderstorm was on the ground for over 10 hours spawning multiple tornadoes.