For the next six weeks, my attention is fully dedicated to severe weather and storm chasing.
Yesterday, the SPC showed two tornado reports in eastern Texas. Unfortunately, two people were inured in one of these storms. It goes to show that just because I decide not to chase a system doesn’t mean that it is not a threat.
The Storm Prediction Center (SPC) has issued an Enhanced Risk for parts of the Deep South.
Associated with the Enhanced Risk is a 10% tornado threat ring.
To summarize the SPC: A surface low pressure system will slowly drift through the Ohio Valley. It will drag a cold front across the south arriving in the Carolinas late this afternoon. Also, a warm front will drift northward through the eastern seaboard, warm, humid air in its wake.
The visible satellite imagery shows clouds scattered throughout the warm sector. There are some bubbling cumulus over southern Mississippi.
The surface observations show a mix of sun and clouds over the threat area. There are a few morning showers at the GA/AL line. Winds are largely out of the south.
The frontal boundaries are very hard to see on this chart. I drew the warm front based on the wind shift in South Carolina and Georgia. The cold front is still difficult to see, but will be more visible as the day progresses.
The surface pressure chart shows a surface low over the boot heel of Missouri. The RAP shows this low will amble east over the next six hours.
The Nested NAM simulated reflectivity shows cells will merge into a lightly packed squall line by 17 Z ad move through the region by this afternoon.
High temperatures will rise into the upper 70s, with a little cooling in the wake of the squall line.
The Nested NAM shows dewpoints will remain quite damp, reaching into the 70s F. The dryline is out of play for the day, located much farther west.
The Nested NAM CAPE/CINH plot is showing CAPE is running anywhere from 2000-3000 J/kg ahead of the squall line.
The Nested NAM shows that the supercell parameter will be highest in western Georgia, southwest of Atlanta in the afternoon (17 Z or so).
The 3 km helicity shows a maxima at the AL/GA border southwest of Atlanta.
The Nested NAM shows that the SigTor parameter will peak around 17 Z southwest of Atlanta.
If I were targeting and chasing today, I wouldn’t bite on any of this. I would stay where I was, rather than chase a morning squall line.
Meteorologically speaking, the morning convection will morph into a squall line with a few embedded supercells. The system will leave slightly cooler air in its wake. Compared to yesterday, the squall line will be less densely packed, even though it is in a more humid environment. I think the tornado threat is justified, given the humid air,
Today would likely be a down day for chasing. It’s a bit of a lull in the pattern once this system moves through. Tomorrow, I’ll probably write about what still needs to be accomplished before I leave for chasing on Monday!