On medium-range model guidance and the 3-5 day extended forecast

The medium-range forecast model (MRF) provides the basic guidance for the 3-5-day extended forecast issued by individual Weather Service Forecast Offices. The ability of the MRF to forecast shorter synoptic, subsynoptic, and mesoscale phenomena is examined through the use of the anomaly correlation coefficient and illustrated with several case studies. The operational implications of putting detail in the extended forecast are reviewed. Finally, several suggestions are presented to help operational forecasts determine consistency and accuracy in the extended guidance.