October 2014 Weather in Review Friday Weather Discussion 31 October 2014

Global View Left: 1-27 October mean 500 hPa geopotential height (m) Right: Departure of 1-27 October mean from climatology Data obtained from NOAA/ESRL/PSD, derived from NCEP-NCAR Reanalysis

Global View Left: 1-27 October mean 850 hPa temperature (K) Right: Departure of 1-27 October mean from climatology Data obtained from NOAA/ESRL/PSD, derived from NCEP-NCAR Reanalysis

Up North Left: Arctic sea ice extent, 1 July to 29 October Right: Northern Hemisphere snow and ice cover as of 29 October Sources: Natl. Snow and Ice Data Center (left), National Ice Center (right)

Regional View Left: Average 2-m temperature (°F), 1-29 October Right: Departure of avg. 2-m temperature from mean Data obtained from Midwestern Regional Climate Center.

Regional View Left: Accumulated precipitation (in), 1-29 October Right: Percent of mean for 1-29 October accum. precip. Data obtained from Midwestern Regional Climate Center.

Local View Data obtained from the National Weather Service. High Low Departure from normal

Outline Midwestern US precipitation episodes – October 1-2, 9-10, 13 Amplified pattern across Eurasia Notable tropical cyclone events and their possible influences upon the mid-latitudes

Midwestern US: 1-2 October

Midwestern US: 1-2 October Top: 500 hPa height (every 6 dam), temperature (every 2°C), and observations Bottom: 850 hPa height (every 3 dam), temperature (every 2°C), dew point temperature (every 1°C), and observations Valid: 0000 UTC 2 October 2014 Source: Storm Prediction Center

Midwestern US: 1-2 October

Midwestern US: 9-10 October

Midwestern US: 9-10 October Top: 500 hPa height (every 6 dam), temperature (every 2°C), and observations Bottom: 850 hPa height (every 3 dam), temperature (every 2°C), dew point temperature (every 1°C), and observations Valid: 0000 UTC 10 October 2014 Source: Storm Prediction Center

Midwestern US: 9-10 October

Midwestern US: 13 October

Midwestern US: 13 October Top: 500 hPa height (every 6 dam), temperature (every 2°C), and observations Bottom: 850 hPa height (every 3 dam), temperature (every 2°C), dew point temperature (every 1°C), and observations Valid: 0000 UTC 14 October 2014 Source: Storm Prediction Center

Midwestern US: 13 October

Eurasia: 1-31 October Early: higher latitude blocking, vortex merger and subsequent southward displacement Middle: ejection, but with reinforcement of longwave trough-dominated pattern Late: more progressive pattern taking hold

Hurricane Gonzalo Image obtained from

Hurricane Gonzalo Image obtained from NOAA/Environmental Visualization Laboratory.

Hurricane Gonzalo Loop credit: Brian McNoldy/RSMAS-UMiami. Radar credit: Bermuda Weather Service.

Hurricane Gonzalo Image credit: University of Wyoming.

Hurricane Gonzalo

Image credit: NASA/TRMM (