Tomas

Tomas will almost certainly adversely affect the weather in Haiti later thisweek and, in a worst-case scenario, could wreak devastation.Through Wednesday, the storm's path will be fairly straight forward as it takesessentially a westward track over the open Caribbean Sea.

Beginning Thursday, a dip in the jet stream over the Gulf together with aneastward shift in Atlantic high pressure will bring a change in tack for Tomas.

It will likely slow then veer towards the north.

For the quake-stricken city of Port-au-Prince and the nation as a whole, theworst scenario would be for the center of Tomas to track northward into Haitislightly east of the city as a powerful hurricane.

Such a track would inevitably lead to extreme flooding rainfall on hillsidesand mountains, including those rising about the capital city.

Runoff from deforested slopes has a history of triggering deadly flooding andmud flows in Haiti, and this could happen in the thickly settled lowlandsreaching eastward and northward from the city center of Port-au-Prince.

A storm tide would funnel into the head of the Gulf of Gonave, on which thecity is located, potentially causing flooding.

It is this writer's hope that Thomas's outcome in Haiti is not at all like thisworst-case scenario.

Story by AccuWeather.com Senior Meteorologist Jim Andrews