Record Breaking Cold Blankets United States -- Coldest November Morning Since 1976

Dr. Ryan Maue -- WeatherBELL November 18, 2014      

Update Wednesday Nov 19: Many more record low temperatures were set this morning -- record low minimums -- as well as record low maximums this afternoon (low high temperatures). Baltimore was once such city that hit a two-fer setting both the record low and high. As records filter in over next few hours, I'll summarize here.

Tuesday morning, America 'as a whole' awoke to the coldest it has been in November since 1976 -- 38 years ago. The Lower-48 or CONUS spatially average temperature plummeted overnight to only 19.4°F typical of mid-winter not November 18th!   Data

An astounding 226-million Americans will experience at or below freezing temperatures (32°F) on Tuesday as well -- if you venture outdoors.

More than 85% of the surface area of the Lower-48 reached or fell below freezing Tuesday morning. All 50-states saw at or below freezing temperatures on Tuesday.

Record lows from Idaho to Nebraska and Iowa south to Texas and east through the Great Lakes, the eastern 2/3 of the US will shatter decades-long and in some cases, century-long records. Temperatures east of the Rockies will be 20-40°F below climate normals.

Compared to normal, temperatures over the past several days have dropped off a cliff -- to 10°C below climate normal -- more anomalous than even during the #polarvortex of early January. Anomaly Chart . November is shaping up to be a colder-than-normal month by a lot.

Brisk northwesterly winds in the Great Lakes will cause heavy lake effect snow which will be measured in feet from Michigan to New York state. Monday, almost half of the Lower-48 was blanketed in snow. Please visit Mashable and Washington Post Capital Weather Gang for daily updates.

Cold air pushes east thru Wednesday with a reinforcing shot of Arctic air with origin from the North Pole & Siberia to arrive on Thursday in the Great Lakes. Any relief is is 5-6 days away as Chicago, Minneapolis, and Detroit will struggle to rise above freezing until Saturday.



Let my Weather Maps tell the story:

Map of near-surface temperatures plotted from the brand new NCEP HRRR 3-kilometer mesoscale weather model


Upper-atmosphere depictions of 500-hPa pressure-level height (left) showing extremely deep trough over Great Lakes and equally impressive ridge over Alaska. Jet-stream winds (right) from NOAA GFS global weather model crossing from Siberia over North Pole into Northern Plains.
Record Low Predictor Selected cities overnight lows (°F) forecast by NOAA GFS model with locations circled indicating potential record-lows for Nov 18th. A total of 29 locations set or break a record low. 40 stations come within 1°F and 80 within 3°F of a record. These cities are from the "Threaded-Extremes" dataset which diligently assembles historical station information often back into the 1900s or even 1870s. The forecast model temperature data is compared from midnight-to-midnight to determine potential record lows.



Snowfall Total accumulations through Thursday morning from the NCEP-NAM mesoscale model (4-km Nest) showing multiple foot amounts in the snowbelts along the Great Lakes.
Temperatures departure from normal °F from NOAA GFS global weather model. Purple colors range from 20-40° below climate normals.
Snow depth in inches estimate from the NOAA GFS global weather model.