After a dry Tuesday, a coastal low will bring cooler weather and widespread rainfall across parts of the state Wednesday.
WHAT: An area of low pressure will develop off the North Carolina coast tonight, bringing scattered to numerous showers and thunderstorms to Central and Eastern NC with scattered showers to the mountains. A high pressure system to the north will create for a Cold air damming situation across Central and Western NC, the set up will be just like a winter storm just without the winter part. Along the coast are the areas of most concern heavy rainfall is expected 2-4" of rain will lead to minor flooding. Additionally, a high shear environment is expected and areas, where instability is greater, will lead to the potential of weak Tornadoes.
RAINFALL: The main axis of heavy rainfall will be along and east of I95 to the coast, areas along the coast in red above will see 2-4" of rain with locally higher amounts to 5"+ where thunderstorms train. Orange area or Central NC (Fayetteville, Raleigh, Durham, Goldsboro) scattered thunderstorms will drop generally 1" with locally higher amounts to 2". Western NC areas that don't need rainfall will generally see about a haft of an inch. Flash Flooding is possible along the coast, generally areas that flood first will be the main concern.
SEVERE WEATHER: Due to warmer temperatures and dew points in the 70s along the coast, The Storm Prediction Center has issued a marginal risk of Severe Weather Wednesday for the coast. Wind profiles show low-level veering with height, which when combined with the late-day increase in lift may support a few weakly rotating storms capable of localized wind damage or perhaps a brief/weak tornado.
TEMPERATURES: Due to extremely low dew points in the 40s and 50s with the falling of rain through the atmosphere, When water evaporates, the evaporation process requires taking heat from the environment in order for the evaporation to occur. With the removal of heat from the air, the air cools. The amount of water that is able to evaporate into a volume of air impacts the cooling. Evaporative cooling can occur until the relative humidity reaches 100% (saturated air). Thus, initially dry and warm air will produce the greatest amount of evaporate cooling when this air is saturated through the evaporation process. The combination of these and a high-pressure system to north will create for a Cold air damming event (when cold air gets trapped east of the mountains) well below temperatures are expected. Highs will be in the upper 60s in the mountains, low and mid-70s to the east. The highest temperatures will be along the coast where a warm front will be.
Wednesday will be a good day to stay inside in bed if you can, stay tuned for updates should any Flash Flooding or Severe Warnings are issued along the coast. I'll keep you posted like normal.