WPC
Posted by cypresstx on 9/16/2018, 6:16 am
| https://pbs.twimg.com/media/DnNJAXxW4AAflAf.jpg:large https://twitter.com/NWSWPC/status/1041256546674651136 NWS WPC [5 AM Sunday] Catastrophic, life-threatening flash flooding risk today across much of NC, portions of SC, & southwest VA. Additional rainfall amounts of 5-10" inches are expected, which will produce flash flooding, river flooding and possible landslides in the mountainous areas. and from Met Watch: http://origin.wpc.ncep.noaa.gov/metwatch/metwatch_mpd.php  Mesoscale Precipitation Discussion 0848 NWS Weather Prediction Center College Park MD 540 AM EDT Sun Sep 16 2018 Areas affected... southern/southeastern NC into northern SC Concerning... Heavy rainfall... Flash flooding possible Valid 160935Z - 161535Z Summary... Heavy rain and catastrophic flash flooding will continue to affect the central and eastern NC/SC border with an additional 3-6 inches of rain through 15Z. Heavy rain will also begin to impact portions of the southern Blue Ridge Mountains by late morning. Discussion... KLTX reflectivity loops over the past 3-6 hours showed that a rain band over Brunswick, eastern Columbus and Bladen counties has not shifted significantly east or west since 03Z. While it has not been continuous, bursts of heavier rain embedded within the band have been responsible for at least 6 inches of rain near the Wilmington area since 03Z according to local Wunderground.com stations with rainfall rates fluctuating between 1-3 in/hr. More recently, another rain band has begun to focus in northeastern SC affecting Marion, Dillon and Marlboro counties with KLTX estimated rates of 2-3 in/hr, but without ground truth to confirm actual rates. The 09Z advisory from NHC has downgraded Florence to a tropical depression but the high risk for flash flooding remains. GOES 16 10.3 micron imagery showed an impressive outflow channel on the eastern side of Florence's circulation across the western Atlantic, with a 350 mi long band of colder cloud tops tied to the aforementioned rain band. Strong upper level diffluence continues across the coastal Carolinas owing to an anticyclone located about 100 miles offshore. The latest NHC track for Florence takes the center of the circulation off toward the northwest through 18Z, which when combined with the onset of daytime heating, should allow CAPE to slowly increase toward the west through eastern NC/SC, helping support higher rainfall rates across inland locations (approaching 2-3 in/hr). An additional 3-6 inches of rain is forecast through 15Z for locations generally east of I-85 toward the NC/SC coastal border. The other effect of Florence tracking toward the west will be veering 850 mb flow of 50+ kt in western NC allowing a more perpendicular orientation into the southern Blue Ridge Mountains. 6 hour rainfall into the terrain is expected to range between 1-3 inches through 15Z, but a growing flash flood threat will exist through the afternoon into the mountains. Otto ATTN... WFO... CAE... CHS... GSP... ILM... MHX... RAH... ATTN... RFC... LMRFC... SERFC... |
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