Florence produces record rainfall in North Carolina and South Carolina
After Hurricane Florence made landfall in North Carolina during the morning hours on 14 September, it moved very slowly (at times only 2-3 mph) southwestward into South Carolina during 15-16 September (surface analyses). Prolonged heavy rainfall resulted (WPC summary), with new state records (see below) for precipitation from a tropical cyclone being set in North Carolina (35.93 inches) and South Carolina (23.63 inches). GOES-16 (GOES-East) “Clean” Infrared Window (10.3 µm) images every 5 minutes during the 4-day period of 13-16 September (above) showed the evolution of banding and the development of new convection that produced the heavy rainfall — widespread flooding along with strong winds caused power outages across portions of the 2 states (NC | SC), and closed sections of Interstates 95 and 40. Note that the power outages caused extended dropouts of the plotted surface reports — especially in eastern North Carolina; reports were missing when the gray 4-letter station identifiers disappeared — even though many of those sites were likely experiencing heavy rainfall during those dropout times.Florence also spawned a few tornadoes on 14, 15 and 16 September — SPC storm reports are plotted in cyan on the GOES-16 Infrared images.
Hourly images of the MIMIC Total Precipitable Water product (below) showed tropical moisture associated with Florence as it moved inland during the 13-17 September period.
Animations of plots of rawinsonde data from the coastal sites of Newport/Morehead City, North Carolina and Charleston, South Carolina (below) revealed the increase in deep tropical moisture from 13-16 September — Total Precipitable Water values were as high as 68.6 mm (2.70 inches) at Newport and 67.8 mm (2.67 inches) at Charleston. As the remnants of Florence moved from Kentucky to West Virginia during the daylight hours of 17 September, numerous tornadoes occurred in central Virginia (SPC storm reports | NWS Wakefield summary). 1-minute GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (below) showed the development of thunderstorms which produced these tornadoes.Today, it’s two updates. After some chatter with the @CoCoRaHS observer, we’ve accepted the reading. There was uncertainty in house about the reading. Just trying to be careful. pic.twitter.com/7bF76eeGLQ
— David Roth (@DRmetwatch) September 17, 2018
Radar loops have been finalized for #Florence, and include a 24-hour loop for landfall and a 104-hour loop to cover its slow trek through #NorthCarolina and #SouthCarolina. Please visit https://t.co/vWICHS7kHl @UMiamiRSMAS pic.twitter.com/8jixg0mR1C
— Brian McNoldy (@BMcNoldy) September 17, 2018
===== 18 September Update =====
A comparison of before/after (26 August/18 September) Terra MODIS False Color Red-Green-Blue (RGB) images from the MODIS Today site (above) showed areas of inland flooding (increasing water coverage appears as darker shades of blue) in the wake of Florence across far southeastern North Carolina and far northeastern South Carolina.Looking slightly to the south, a similar before/after comparison of Terra MODIS True Color RGB images (below) revealed areas of sediment runoff into the Atlantic Ocean.