FORECASTCONTEXT.COM · THE LARGE-SCALE STATE BEHIND THE FORECAST BRIEFINGMOTIONOUTLOOKMETHODSAPI☀ AUTO

FORECAST CONTEXT

DATA THROUGH 2026-10-12 · UPDATED 2026-10-13 11:02 UTC

ERA5 + GFS2.5°DAILY
BriefingStratospherePolar vortex
vT100

Heat flux 100 hPa

Eddy heat flux [v*T*] averaged 45–75°N at 100 hPa: upward planetary-wave activity entering the stratosphere. Large pulses precede SSWs. — Newman et al. 2001