Are the next 3 months likely to be exceptionally wet or dry?

The map shows where it is likely to be extremely wet or dry over the next three months. Extreme refers to the lowest or highest 15% of the historical record.

What do I do next?

If you see a colour over your region, possible responses include:

• Contact your local/regional meterological department and monitor their forecasts during the next 3 months.
• Consider who may be most affected by heavy or low rainfall.
• Review your contingency plans and update as necessary.

See the "More Information" tab for details.

Explanation

Blue areas show where there is an enhanced likelihood of extremely wet conditions over the next three months. Darker blue indicates a higher likelihood of extremely wet conditions. Orange and brown areas show where there is an enhanced likelihood of extremely dry conditions over the next three months. The darker brown indicates a higher likelihood of extremely dry conditions.

This forecast shows only the likelihood of 3-month accumulated rainfall (or snow) being unusually high or low, and does not indicate chances of individual heavy rainfall events. The forecasts apply over large areas only, and should not be used to forecast local conditions, or as a flood forecast.

How to use this interactive map

Switch to another map: Select the dropdown menu at the top of the page, to the right of the blue “Forecasts in Context” heading.

Return to the menu page: Click the blue link called “Forecasts in Context” at the top left corner of the page.

Zoom in to a region:
Method 1: Pick a region from the list:

1. Select the dropdown menu at the top of the page, titled “Region”
2. Click on the region of interest, and the map will automatically refresh.

Method 2: Click-and-drag:

1. Click the left mouse button at the upper-left corner of the region to which you would like to zoom.
2. While holding down the button, drag the mouse to the lower-right corner of the region to which you would like to zoom.
3. Release the left mouse button. The map will redraw automatically.

Zoom out to the global map:

1. Move your mouse over the map, until you see three icons appear in the upper left corner.
2. Click the icon of the magnifying glass.
3. The map will redraw automatically. Note that the map cannot display areas outside of the latitudes initially shown on the interface (about 66.25S – 76.25N).

Change the date of the forecast: Forecasts are labeled by the month they were issued. You can find this label by moving your mouse over the map until you see a text box appear at the top with the date inside.

1. To step forward or back by one month, click the corresponding buttons to the left or right of the text box, and the map will automatically refresh.
2. To manually change the forecast issue date, type your date of interest into the text box. This must follow the format: “Jan 2008”. Then, press “enter” or click the “refresh” icon in the top left corner of the map.
3. To produce an animation of these maps over a series of dates, type the date range into the text box. This must follow the format: “start date” followed by “to” followed by “end date”. For example “Jan 2008 to Dec 2008”.

Dataset Documentation

IRI Extreme Seasonal Precipitation Forecast
Data Probabilities that seasonal (3-month) precipitation will be within the upper 15% or lower 15% of the historical (30-year) distribution for the first lead time from the IRI Net Assessment Forecast, issued every month at 2.5° lat/lon resolution
Data Source International Research Institute for Climate and Society, Net Assessment Forecasts, Data Library entry

Helpdesks

Contact ifrc@iri.columbia.edu if you are a humanitarian-decision maker with questions about information in this Map Room, or other weather and climate related questions. We usually respond within one business day.

Contact help@iri.columbia.edu with any technical questions or problems with this Map Room, for example, the forecasts not displaying or updating properly.