Locally dense fog developed (especially over South Georgia and the lower Suwannee Valley) early this morning, where visibilities were near zero. The morning balloon launch from Tallahassee indicates that the moist layer is very shallow near the ground and that the air is quite dry in the remainder of the atmosphere. As a result, the fog will rapidly dissipate and skies will become mostly sunny today. Upper air data and water vapor imagery depict a weak shortwave near the Red River of Texas and Oklahoma. It's expected to quickly whisk through our area tonight, but there is simply not enough deep-layer moisture available to produce rain as the upper disturbance moves by. Instead, it will push a poorly-defined cold front through the area. Under nearly calm winds and clear skies, temperatures should bottom out in the upper 30s on Sunday morning. Low-lying, outlying areas could even see a light frost. Full sunshine is expected on Sunday and this should permit temperatures to reach near 70 degrees just about everywhere with a moderate northwesterly breeze behind the weak cold front. A similar pattern should repeat itself Monday night and Tuesday; that is, a chilly start with areas of frost followed by sunshine mixed with perhaps a few more clouds. Highs may end up a couple of degrees cooler yet on Tuesday, but we should get near average as the mercury gets into the mid and upper 60s.
We are once again faced with an interesting midweek forecast. The next in a series of Pacific systems is showing up on satellite imagery this morning over the Gulf of Alaska. For their part, the models have done a fine job so far this winter giving us a heads up on the approach of these systems. The latest runs of the GFS, UKMET and ECMWF models are in very good agreement in taking the Pacific energy to the northern U.S. Rockies on Monday, to the central and southern Plains Tuesday, and then just about on top of us on Wednesday. The Canadian model is less amplified with this upper air disturbance and its solution is similar to yesterday's GFS runs. However, the GFS clearly has trended toward the very reliable ECMWF and UKMET (as noted above) and I suspect the Canadian model will follow suit. There is also strong agreement that a lead shortwave will kick out of South Texas and toward our area on Tuesday. So even though the main upper tropospheric wave will not arrive until Wednesday, the lead wave should give us a good threat of rain and thunderstorms Tuesday and/or Tuesday night. The wind fields will be relatively strong (like this past Wednesday), but the big question is whether sufficient warmth and high dewpoints can return from the Gulf of Mexico to give us with a severe weather threat. The Storm Prediction Center in Norman, OK, has outlooked the entire state of Florida, Southern Alabama, Central/Southern Georgia and into the coastal Carolinas for what it says is a "considerable severe potential". We will be monitoring this situation very carefully, but I want to see more concrete evidence of instability before sounding the alarm on a severe threat. Should sufficient low-level destablization occur, the threat of supercells and tornadoes would be high.