MODEL ANALYSES

The first plot shows the Eta 250 wind speed analysis valid at 12Z on 1/24 with the observed wind speed values from rawinsonde data printed in blue characters. All values are m/s.

12Z 1/24/00 ETA ANALYSIS at 250 mb

The observations colored in purple were rejected by the 3DVAR initialization of the Eta. The Peachtree City, GA wind speed (62 m/s) is valid, but the Eta model rejected it. As a result, the Eta analysis is much too weak with its analyzed wind speed there. It is also too weak around the observation at Greensboro, NC even though it did draw for that observation.

The next plot shows the same information for the 12Z analysis from the AVN.

12Z 1/24/00 AVN ANALYSIS at 250 mb

The AVN also rejected the Georgia 250 mb wind observation, and while it analyzes a slightly stronger wind there than the Eta, it is still underdone. It is weaker than the Eta in the vicinity of the Greensboro, NC and Blacksburg, VA data.

It is obvious that the southwest extent of the mid-Atlantic jet core was underanalyzed by both models. The question is what impact a different jet structure over the southeast would have had on the model forecasts. It is also worth noting that no 250 mb wind data was available at Tampa, Birmingham, or Slidell.

DATA FITS TO RAOBS

PEACHTREE CITY, GEORGIA (72215) ETA WINDS ETA HEIGHTS ETA TEMPERATURES
GREENSBORO, NORTH CAROLINA (72317) ETA WINDS ETA HEIGHTS ETA TEMPERATURES
CHARLESTON, SOUTH CAROLINA (72208) ETA WINDS ETA HEIGHTS ETA TEMPERATURES
JACKSONVILLE, FLORIDA (72206) ETA WINDS ETA HEIGHTS ETA TEMPERATURES
WALLOPS ISLAND, VIRGINIA (72402) ETA WINDS ETA HEIGHTS ETA TEMPERATURES
LAKE CHARLES, LOUISIANA (72240) ETA WINDS ETA HEIGHTS ETA TEMPERATURES
SHREVEPORT, LOUISIANA (72240) ETA WINDS ETA HEIGHTS ETA TEMPERATURES