Submitted by: Daniel Crawley (@SoApps1979)
Good Sunday morning to everyone across the region, we continue to monitor what is left of Florence as it is finally showing signs of forward movement toward our region. This forecast over the past several days has been very fluid to say the least. Florence has thrown forecasters a few curve balls along the way…
Recent meso-analysis indicates that Florence was located near Orangeburg South Carolina as of 2 am this morning and moving off to the west-northwest at 6 mph, which is the fastest it has moved since late Friday night.
Sateliite and water vapor shows that Florence continues to hold a decent structure considering it has been inland for close to 48 hours at this point. One reason it has held intact is because of high pressure overhead giving the storm good ventilation in the upper levels to the north and east sides of the storm. If this feature was still out over water, we would likely be talking an intensifying storm. Also, Florence continues to have a strong inflow from the Atlantic, today the storm will lose some of that direct moisture inflow but moisture should continue be very plentiful to produce widespread precipitation all day long, heavy at times.
The rainfall which has filled in quite a bit since last Saturday evening will continue to do so on Sunday morning. Rainfall rates (1/2 in per hour) while not very intense right now will get stronger as we go through the day
The peak of intensity in precip may begin around noon and could last for a 3 of 4 hour window where rates could run at 1-2 inches per hour. The exact placement of this feeder band will largely determine the locations to receive the heaviest rainfall. The surface low will be roughly to the west of Newberry South Carolina as this juncture, that will result in easterly surface which will begin to provide upslope in our favored locations in the foothills.
By late afternoon, the low pressure will be located near where the North Carolina, South Carolina and Georgia state lines meet. Surface flow will be veering to southeast at this point keeping the rainfall at a steady rate. Plus our feeder line of moisture from the Atlantic will continue to impact our northern tier.
Right now we continue to forecast the potential of excessive rainfall through early Monday as amounts could range up to six inches (storm total), however any of the feeder bands that develop could result in local higher amounts. Upslope flow into the higher terrain will also provide elevated rainfall amounts. This should result in flash flooding later today in several local areas…
In summary here are the key points for today’s weather as Florence will provide its biggest impacts to the Western Carolinas today…the entire weather team will be monitoring the latest with Florence and will have continuous updates here at our website and on social media.