Links have been checked(as of December 2018) to see that they work and a few have been added. Be sure to scroll through the thread in order to see the quality links that other folks have added...
Weather Models (**updated Nov 2018**)
Tropical Tidbits (great starter site for folks new to weather model watching)
e-Wall, Electronic Map Wall (Euro Wx Model and more, Penn State University)
Canadian Global Deterministic Prediction System (GDPS)
Canadian Regional Deterministic Prediction System (RDPS)
Plymouth Weather Center (Wx Models)
Twister Wx Data (Clown Maps for Snow)
UQAM Weather Centre (Wx Models, UKMET)
CFSV2 (Long Range Model)
JMA - Japanese Wx Model
College of Dupage Wx Lab
SPC Mesoscale Analysis
Dacula Weather
Regional Weather Offices (**updated Nov 2018**)
Morristown, TN Weather Office (MRX)
Nashville, TN Weather Office (OHX)
Memphis, TN Weather Office (MEG)
Huntsville, AL Weather Office (HUN)
Paducah, KY Weather Office (PAH)
Climate Outlooks/Indices and Weather Discussions (**updated Nov 2018**)
Long Paddock (SOI Values)
NAO, AO, PNA, AAO Indices (CPC)
Climate Prediction Center (CPC)
Earth System Research Laboratory (EPO, NAO, WPO, PNA Indices)
ENSO El Nino - Southern Oscillation (CPC)
Madden Julian Oscillation (MJO)
Storm Prediction Center
National Hurricane Center
Meteogram Generator
Radars (**updated Nov 2018**)
NWS Radar Sites
Glossary Resources (**updated Nov 2018**)
Basic Weather Acronyms (CPC)
Weather Glossary
Space Weather (**updated Nov 2018**)
Solar Wx - Sunspots
Tennessee Valley Weather and Climate Resources (**updated Nov 2018**)
TVA Reservoir Information (River Levels/Flood Stages)
Elevation Reference Points for the TN Valley
Frequented Quality Weather Sites (**updated Nov 2018**)
Dacula Weather (AmWx member w/ Tennessee Valley roots!)
WxSouth (AmWx member and meteorologist!)
Beau's Wx (Facebook Page)
Snowfall Maps - Earl's
Historical Weather/Climate Data (**updated Nov 2018**)
Reanalysis Data NCEP
Iowa State Historical Radar Data
WxUnderground Surface Observations
National Climatic Data Center