The prototype Mesoscale Precipitation Discussions (MPDs) provide enhanced situational awareness of heavy rainfall and potential flash flooding events to National Weather Service (NWS) Weather Forecast Offices (WFOs), the media, and emergency managers. MPDs are an on-demand forecast product focused on heavy rainfall events occurring in the 1-6 hr period over an area approximately the size of two County Warning Areas (CWAs). Each MPD consists of a graphic indicating the area of concern and any pertinent meteorological features as well as a brief text discussion focused on the mesoscale features supporting the anticipated heavy rainfall. The potential for flash flooding within the area of concern will be highlighted by one of three headlines:

FLASH FLOODING LIKELY Environmental conditions are favorable for heavy rainfall that is expected to result in flash flooding.

FLASH FLOODING POSSIBLE Environmental conditions are generally favorable for heavy rainfall, but there are questions about how the event will evolve and/or whether flash flooding will occur.

FLASH FLOODING UNLIKELY Environmental conditions are becoming less favorable for heavy rainfall and flash flooding is not expected.

The Flash Flooding Unlikely headline may also be used for cases in which conditions are generally favorable for heavy rainfall, but flash flooding is not expected.

The prototype period began on May 16, 2012 and will extend through September 14, 2012. While in prototype mode, the desk is typically staffed on weekdays only between 9:00am 6:00pm. Once fully operational, the desk will be staffed at all times. This product will continue to evolve based on customer feedback throughout the prototype period. Please use the feedback link to provide any comments or suggestions.