Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri May 19 2023 13:38:09 AWUS01 KWNH 191338 FFGMPD NCZ000-191815- Mesoscale Precipitation Discussion 0314 NWS Weather Prediction Center College Park MD 936 AM EDT Fri May 19 2023 Areas affected...Southern North Carolina Coast... Concerning...Heavy rainfall...Flash flooding likely Valid 191335Z - 191815Z SUMMARY...Significant flash flooding ongoing, likely to continue for a few more hours. Further expansion up the coast possible, but not as severe in magnitude. DISCUSSION...Local observations in the western Wilmington suburbs suggest rainfall rates/totals are underestimated from the KLTX radar with numerous 7-9" totals in the last 3hrs. A surface boundary has been attached to the coast and very strong orthogonal 925-850mb unstable air has converged at Wilmington but slowly is shifting northward up the coast. Deep layer moisture flux convergence values are as high as seen in landfalling tropical systems supporting these 3+/hr rates. A weak surface inflection appears to have developed based on the winds, but the latent heat release has developed an MCV that appears to be retrograding west in the near term. With its strength, flanking features are starting to manifest with warm frontal and cold frontal bands located across the northern suburbs of ILM and south toward Oak Island. Visible imagery denotes cumuliform/overshooting tops still remain strong continueing maintenance of the MCV and moisture flux convergence setup for the next 2+ hours. As such, an additional 3-6" (localized maxima up to 10-12") is possible in the areas already affected, but further expansion north and northeastward is becoming more likely increasing the areal coverage for risk of rapid inundation flooding with 4-6" areal coverage into southern Pender over the next few hours.=20 While gradient of instability is very stark toward Cape Hatteras/Newport area, the deeper shortwave and inverted surface inflection/convergence area is lifting north as well, the sharpness of the inverted trough suggests a new focus will develop further up the coast by early afternoon, with similar potential at or very near the coastline itself. Heavy rain should not surge onshore too far from instability source/tight gradient over the near coastal waters.=20=20=20 Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7SEAeQTEsyZ3Pn5ZKXLHWkD-yxjUFnQHzO6RVarSJ-UOyU_2srBNFEk2eQ94COXOHLYX= Y7mNyOrHt1q2d5YI5rgxnLw$ for graphic product... ATTN...WFO...ILM...MHX... ATTN...RFC...SERFC...NWC... LAT...LON 35007681 35007640 34897621 34567652 34607683=20 34507728 34207768 33977781 33837791 33797805=20 33867820 33987839 34307834 34677789 34927740=20 =20=20=20=20=20=20=20=20=20=20=20=20 =3D =3D =3D To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .