AR Forecasts

AR Forecasts

The graphics below are designed to forecast the presence and strength of Atmospheric Rivers using data from the NCEP Global Forecast System (GFS), North American Mesoscale Forecast System (NAM), and Global Ensemble Forecast System (GEFS) models. The GFS products are produced at the Center for Western Weather and Water Extremes (CW3E). The GEFS products are produced by Dr. Jason Cordeira at Plymouth State University as a cooperative effort with CW3E. More information on these products and other AR forecasting tools can be found on the CW3E page.

NCEP Global Forecast System (GFS) and North American Mesoscale Forecast System (NAM)

Integrated Water Vapor (IWV)

Click an image to see forecasts out to 180 hours from the GFS and NAM

North Pacific
(GFS only)

North Pacific GFS IWV

Northeast Pacific

Northeast Pacific GFS IWV

U.S. West Coast

U.S. West Coast GFS IWV

North America

North America GFS IWV

North Atlantic
(GFS only)

North Atlantic GFS IWV

Integrated Water Vapor Transport (IVT)

Click an image to see forecasts out to 180 hours from the GFS and NAM

North Pacific
(GFS only)

North Pacific GFS IVT

Northeast Pacific

Northeast Pacific GFS IVT

U.S. West Coast

U.S. West Coast GFS IVT

North America

North America GFS IVT

North Atlantic
(GFS only)

North Atlantic GFS IVT

Time-Integrated IVT

Click an image to see 24-, 48-, and 72-hour time-integrated forecasts out to 180 hours from the GFS

North Pacific

North Pacific GFS TIVT

Northeast Pacific

Northeast Pacific GFS TIVT

U.S. West Coast

U.S. West Coast GFS TIVT

NCEP Global Ensemble Forecast System (GEFS)

U.S. West Coast AR Landfall Tool

Courtesy Jason Cordeira, Plymouth State University.

Hover mouse cursor over an image type or click to open in new tab.


Control IVT
Probability IVT >250 kg m-1 s-1
Probability IVT >500 kg m-1 s-1

The above images display the magnitude, probability, and timing of AR conditions along the U.S. West Coast and inland from the GEFS model. Hover mouse over an image name to see the graphic, or click to get more information on the plot. To see how each forecast type has changed over the previous seven days click on the dProp/dT under the image title. These plots are created by Jason Cordeira, Plymouth State Univeristy.

IVT Thumbnail and Probability Ensemble Plots

Courtesy Jason Cordeira, Plymouth State University

Hover mouse cursor over a forecast lead time to see both images or click to open.

The above images display the 30 members of the GFS Ensemble; each thumbnail shows IVT (kg m-1 s-1) magnitude shaded according to scale and IVT vectors.


Day-0 (F-00)
Day-1 (F-24)
Day-2 (F-48)
Day-3 (F-72)
Day-4 (F-96)
Day-5 (F-120)
Day-6 (F-144)
Day-7 (F-168)
Day-8 (F-192)
Day-9 (F-216)
Day-10 (F-240)
Day-11 (F-264)
Day-12 (F-288)
Day-13 (F-312)
Day-14 (F-336)
Day-15 (F-360)
Day-16 (F-384)

The above images display the probability of IVT exceeding 250 kg m-1 s-1 based on the 30 members of the GFS ensemble and the IVT vectors from the control forecast.

NOAA ESRL PSL Automated AR Detection Click image to see seven day forecast

Integrated Water Vapor (IWV)

integrated water vapor

Integrated Water Vapor Transport (IVT)

integrated water vapor transport