Data Library Global Atm Circulation Atm Temp Bulletins Climatologies Forecasts Ocean Temp Overview Precipitation Precipitation Anomaly Monthly OLR Pentad OLR Percentiles Persistence Seasonal Seasonal OLR SPI Station Obs WASP Indices help@iri Printable Page english

Seasonal Outgoing Longwave Radiation

OLR ANOMALY (W/m2): LATEST SEASON

SEASONAL AVERAGE OLR (with shading in tropics): LATEST SEASON   (W/m2)

Data:   Outgoing Longwave Radiation ("OLR") anomaly  and observed (watt/m2) on a 2.5 x 2.5 deg. lat/lon grid Base Period for Climatology:  1974-present Data Source:  NCEP, Climate Prediction Center Description Top Plot:  Departure of seasonal OLR from the long term seasonal mean in units of Watts/m2.  Negative values imply increased cloudiness and enhanced likliehood of precipitation.  Positive anomalies imply decreased cloudiness/precipitation.  These relationships work best in tropical regions. Bottom Plot:  Observed seasonal OLR in units of Watts/m2, contour interval 10.  Green shading in tropical regions indicates areas where the seasonal OLR is less than 240 W/m2, a general indicator of precipitation in the tropics.