Plainly said, the forecast models performed quite poorly with this morning's rain. It became apparent last night that a much stronger-than-anticipated upper air disturbance was going to move out of the Gulf of Mexico into our viewing area. Since some of the lift associated with this disturbance was used to remove the dry air in place, most of the rain totals were less than a tenth of an inch. Tallahassee airport had one of the highest amounts (0.15 inches). Slightly drier air in the middle and upper troposphere will move overhead this afternoon, so we should see a fairly sizable break in the showers that will last through tonight. Perhaps the biggest question today concerns the northward movement of the warm front. It is still south of Apalachicola, but the NAM and GFS insist on bringing the warm front through Tallahassee during the mid or late afternoon and finally reaching Georgia early this evening. Interestingly enough, our locally-run workstation WRF model maintains a narrow cool wedge from the Tallahassee to Valdosta areas, with much warmer air arriving closer to the Apalachicola River. Diabatic cooling from this morning's showers might have enhanced the cool wedge and could delay the warm front from lifting northward. The very fact that the warm front has not yet reached Apalachicola concerns me. I have backed off on the high temperatures a few degrees this afternoon, but I still think we'll take a shot at 70 or better from I-10 southward late this afternoon with any luck. Temperatures in Georgia will probably hold in the 60s, especially along and east of U.S. Highway 319. Skies will be mostly cloudy, but sunny breaks are possible in areas that see the warm front pass before dusk.
Monday's forecast still appears to be on track. The center of low pressure near the coastal Texas and Louisiana border this morning is forecast to reach the Tennessee and Ohio Valleys during Monday afternoon. The cold front will stretch southward from the low into the Florida Panhandle by lunch time. It will cross our area from west to east between mid afternoon and mid evening. The models remain in remarkable agreement in maintaining a squall line across Alabama and the Florida Panhandle, then weakening the line as soon as it reaches the U.S. Highway 319 corridor. The vertical wind shear and instability will be the most favorable in our western and northern viewing area (i.e. Western Big Bend and Southwest Georgia), and could support damaging winds and perhaps a brief/weak tornado. Areas farther east could still see rain showers late Monday, but the severe threat and the amount of rain will be much lower in the Suwannee River Valley.
The cold front will clear our area Monday night, so gradual clearing is anticipated on Tuesday. The airmass behind the front is only expected to be a couple of degrees cooler (at most). That means highs on Tuesday could still eclipse 70 degrees in many locations (especially on the Florida side).
Another front is expected to move eastward from the Plains Wednesday and Thursday. The U.S. Government GFS model forecasts the front to slide through on Thursday, with somewhat cooler temperatures following the front at the end of the week. Meanwhile, the European and U.K. Met Office model hang the front up to our west. So far this fall, the European model anomaly correlations are superior to the GFS model. With this in mind, I'll lean toward the idea of holding up the frontal passage and forecast warmer-than-average temperatures Wednesday and Thursday. The UKMET and European models also have support from the Canadian Global model.