Hurricane Isabel and the significant storm surge and flooding it produced had a huge impact on the Chesapeake Bay region, especially near Annapolis, Maryland. Of all the damage and devastation wrought by hurricanes, storm surge is by far the largest contributor to this damage. There are currently several numerical models which are used to predict storm surge in particular areas. Determining the accuracy of these models is vital to understanding which models are most useful in predicting flooding. In turn, this understanding is helpful in preventing or reducing the death and destruction associated with drastic storm surges by providing coastal communities with forewarning. This paper examines the impact Hurricane Isabel had on the Chesapeake Bay region with respect to flooding though the analysis of the observed and predicted CO-OPS water levels along with the water level output of NOAA's SLOSH model for eight locations in the bay area. Through comparing the CO-OPS observed storm surge with the SLOSH model's predicted storm surge, the overall accuracy of the SLOSH model was determined for conditions associated with Isabel in the Chesapeake Bay region. With the exception of three difficult-to-model locations, the SLOSH model analyzed was found to be fairly accurate. Contributing factors to the storm surge such as wind direction and strength, pressure, and location of the hurricane help to explain why the SLOSH program predicted the values it did and why the observed water levels deviated from these predictions.