Key MESSAGE 1, Primary focus this forecast remains a threat for stronger storms, focused on Thursday night into Friday as deepening low pressure and associated cold front pushes across the eastern CONUS. Additionally, the remnants of now TS Arthur are forecast to slowly lift across the Gulf States tomorrow and into Friday. Daytime hours tomorrow are likely to be dry with thunderstorm threat increasing overnight as deeper moisture approaches. Expecting a modest uptick in effective shear Thurs PM into Fri associated with the TS remnants, as well as an increase in low- level shear with a healthy LLJ of 35-40 kt. This, combined with plenty of MLCAPE in excess of 1500-2000 J/kg, will provide a marginally favorable environment for some organized storms capable primarily of damaging wind gusts. Some model soundings do depict some modest low-level wind veering, however, which points to a non-zero brief tornado and waterspout threat as well. Spc has our entire area in a Marginal (Level 1/5) risk of severe thunderstorms for Thursday into Friday morning.
KEY MESSAGE 2, With warm front lifting back northward heat and humidity begin their return today with highs in the upper 80s to low 90s today and mid to upper 90s tomorrow. With Tds in the upper 60s to low 70s, heat index values will be 100-105F in many areas. Given the short duration and extent of forecast heat indices 105F or greater, elected to hold off on a heat advisory with this update. With a noticeable uptick in winds ahead of the approaching front (gusts 25-30 mph) and RHs 35-45% paired with dry fuels there are fire weather concerns Thursday. An Increased Fire Danger statement is in effect for all of ENC except for Onslow and Carteret counties for Thursday.
The passing front will cool the region down briefly for the weekend, but medium range guidance suggests excessive heat will remain a concern early next week with heat index values once again reaching 100+.
18z Wednesday through Monday Generally VFR this afternoon with typical diurnal cu with SW winds today gusting to 15 kt at times. Mainly clear conditions expected tonight with a low end chance of some low stratus forming. Confidence is low but added a few020 to TAFs with this update. More notably, there will be a steady increase in southwest winds as strong cold front approaches from the west. Gusty conditions are likely to begin around dawn and peak Thurs aftn with gusts 25+ kt likely. This will result in a crosswind component for KEWN runway 14R/32L.
Outlook: More widespread TSRA threat and lower ceilings returns Thursday night and especially Friday with a stronger front. Overnight fog and stratus threat possible each morning late this week into the weekend. Weekend is trending drier and more quiet with predominant VFR expected.
Sw winds 10-15 knots for most this afternoon with seas 2-4 ft. Winds along the Gulf Stream will steadily increasing this evening. Focus then turns to tomorrow into Friday with an uptick in southwesterly winds across all waters ahead of an approaching cold front. Previous Gale Watches have been converted to Gale Warnings with this update, with Coastal waters from Ocracoke Inlet to Cape Lookout, previously in a SCA, now in a Gale Warning as well. It should be noted that probabilities for gale force gusts are lower but not zero for a larger swath of waters extending into outer Onslow Bay as well as the Pamlico Sound, and this is particularly true when assessing hi- res guidance. With this in mind, gale headlines may be expanded further in future forecasts.
With the remnants of TS Arthur moving through the area Friday, the track of the remnant low will be worth monitoring. An inland track, which is the current expectation, could bring a waterspout threat to waters Friday in addition to thunderstorms.
Outlook (Thu night through Sun): Periodic nocturnal and early morning risk of showers and thunderstorms is possible each weeknight, although most likely odds will be tomorrow night into Friday. Boating conditions improve over the weekend behind the passing front, with next threat window for mariners early next week ahead of another front.
Nc, none. Marine, small craft advisory from 10 am to 11 pm EDT Thursday for amz131-136-137-230-231. Small craft advisory from 8 am Thursday to 8 pm EDT Friday for amz135. Small craft advisory from 10 am Thursday to 5 am EDT Friday for amz150. Gale warning from 2 pm Thursday to 2 am EDT Friday for amz152- 154-156. Small craft advisory from 8 pm this evening to 8 pm EDT Friday for amz158. Gale warning from 5 pm Thursday to 5 am EDT Friday for amz180- 182. Gale warning from 2 pm Thursday to 5 am EDT Friday for amz184- 186.
