GEMA Weather Outlook for Tuesday December 1, 2009:

Strong to possibly severe thunderstorms possible in western and southwestern Georgia tonight.

Forecast:

A developing weather system currently located over the western Gulf of Mexico off the coast of Texas near Brownsville will intensify and move northeastward today. This weather system, coupled with a strong upper-level weather system, will produce thunderstorms / hazardous weather along the central Gulf Coast this evening and tonight (areas south and west of the brown line above). Thunderstorms that develop as a result of this weather system will be capable of tornadoes and strong winds. The threat to Georgia will occur late tonight and early tomorrow in western and southwestern Georgia (GEMA Areas 2, 4, and 6). Accordingly, the Storm Prediction Center (SPC) has issued a Slight Risk (green line above) for the threat of severe thunderstorms along the central Gulf Coast that abuts southwestern Georgia.

Before the severe weather event for Georgia begins tonight, weather across the state today will include sunny skies this afternoon and afternoon highs reaching the mid 50s north to mid 60s south. Tonight, clouds will begin to build in from the west with chances for rain in the southwest and overnight lows dropping to the lower 40s north to near 60 south.

Extended Weather Outlook:    

A significant severe weather event is possible in Georgia tomorrow ...

Forecast:

The weather system that will produce unsettled weather along the Gulf Coast today and tonight will rapidly move northeastward into the Tennessee Valley tomorrow. As this system moves northward, an attendant warm front will sweep northward across Georgia bringing abundant moisture and heavy rain across the state. Additionally, widespread severe thunderstorms will affect most of the southeastern half of the state tomorrow and will be capable of damaging winds -- possibly in excess of 70 mph -- and tornadoes, potentially a few strong tornadoes.

Severe Thunderstorm Threat:

Severe thunderstorms will begin to affect portions of southwestern Georgia early tomorrow morning and will move northward and eastward as the day progresses. Both the Storm Prediction Center (SPC) and the National Weather Service (NWS) caution that powerful thunderstorms will be possible tomorrow that will be capable of producing damaging winds in excess of 70 mph and isolated tornadoes, some possibly strong. Accordingly, the SPC has issues a Slight Risk (areas south of the green line above) for most of Georgia with the possibility of this categorical risk being upgraded to a Moderate Risk later today or tomorrow. The highest probabilities of severe weather exist in areas south of the red line above (GEMA Areas 2, 3, 5, and 8) and the blue shaded area above (GEMA Areas 2, 3, 5, and 8) depicts areas where significant severe weather are possible (damaging winds in excess of 70 mph and / or strong tornadoes).

The threat for severe weather will include both isolated thunderstorms and a line of thunderstorm that both pose a threat of damaging winds and tornadoes. The threat will shift eastward as the day progresses and will conclude late tomorrow / early Thursday morning.

Rainfall / Flooding Potential:

Widespread heavy rainfall will occur as a result of tomorrow's tumultuous weather. As noted in the graphic above by the rainfall predictions from the Hydrometeorological Prediction Center (HPC), widespread rainfall totals across Georgia tomorrow will range from one to two inches with the possibility of three to four inches (red and orange above) in a northeast-southwest swath from southwest Georgia through central and northeast Georgia. This weather system will move quickly, so no prolonged rainfall is anticipated. The NWS cautions that some minor flooding is possible, but no significant flooding is anticipated.