Event Summary

National Weather Service, Raleigh NC   




09 January 2004 Winter Storm

Under development








The 12z run of the ETA model on 8 January 2004 was not very robust in its forecast of  low-level forcing. Comparing the 24-h forecast from the 12Z Eta to the analysis from 12z  9 January 2004, the analysis shows stronger 850 mb warm air advection. Note on the analysis the flow at 850 is directed almost perpendicular to the 850-mb isobars, where the 24-h forecast was weaker with the flow and was parallel to the isobars. There is also a tremendous differences in the 700-mb omega field. The 24-h forecast actually showed a bulls eye of *sinking* motion almost directly over RDU, where upward motion of 3-6 microbars s-1 is seen the analysis. Greater than expected low level forcing may have contributed to snowfall amounts in central North Carolina being more on the order of 2-3 inches than the 1-11/2 inches that were forecast.