Key MESSAGE 1, The outflow from last night's storms well to our north and west are approaching the region, with showers and thunderstorms along it. Models have handled this very poorly today, with essentially all guidance dry at 12Z. Since then though, current radar data and the 15Z RRFS run have suggested showers and thunderstorms entering the region this afternoon and lingering through the evening. Meanwhile, a weak wave moves in from the south, bringing shower and thunderstorm chances in the evening from the south. Outside of the RRFS, guidance is still not showing this, so with decreased confidence on how long the showers will stick around, elected to cap PoPs at 30%. Plenty of instability, DCAPEs over 700 J/kg, and modest deep shear could bring gusty winds in the strongest of storms.
KEY MESSAGE 2, A frontal system approaches from the northwest, expected to cross the region Friday afternoon/evening. Ahead of the front moving through, rain chances will increase Friday early morning onwards as a closed low pressure system from the remnants of Post Tropical Storm Arthur move through the Carolinas. The tropical nature of moisture advecting into the region brings PWATs near 2.2", which is well above average for eastern NC. In addition, we have modest deep layer shear of 30-40 knots and low level turning of the winds along and to the east of the path of the low. All this results in a severe weather threat for eastern NC Friday morning into the early afternoon. The hazards of note are brief tornadoes, waterspouts, and gusty winds. In addition, tropical downpours with high rain rates can be expected. The quick moving nature of the low precludes any substantial flash flooding concern. Spc has the area in a marginal risk for severe weather for both tonight and Friday.
The cold front moves through Friday PM, from NW to SE. With the low moving through earlier in the day, we will be in a NW flow regime and have some dry air advecting in ahead of this front aloft. With that in mind, should any showers and tstorms form along the front the coverage is expected to be isolated to scattered at best. If the updrafts are able to overcome this dry layer, we will have decent low level lapse rates, deep shear, and some DCAPE to play with and gusty winds would become a concern. For now though, given the dry layer capped PoPs at around 25% along this front.
KEY MESSAGE 3, High temperature this afternoon are expected to be in the mid to upper 90s. With Tds in the low 70s, heat index values will hover plus or minus 105F in many areas. Therefore have decided to keep this heat advisory until 8 PM for all counties outside of the Outer Banks. As far as fire weather is concerned, winds ahead of the approaching front will pick up (gusts 25-30 mph) and RHs 35-45% paired with dry fuels will present fire weather concerns today. An Increased Fire Danger statement is in effect for all of ENC except for Onslow and Carteret counties for today.
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 degrees+.
18z Thursday through Tuesday Pred VFR conditions expected through today. There are some showers and thunderstorms expected to enter the region later this afternoon and the evening, so brief drops to sub-VFR VIS/CIGs and lighting can accompany them. Outside of the precip potential, gusty SW winds are observed across the entirety of eastern NC as strong mixing is in place. After the Sun sets, this mixing will decrease and gusts won't be as potent inland. The current gusts bring crosswind component for KEWN runway 14r/32l.
Tonight, low approaches from the SW, crossing through the region in the late morning and afternoon hours Friday. This will bring low ceilings and vis with heavy rainfall. Despite the more warm nature of the rain processes, thunder can't be discounted but weak mid- level lapse rates will make it difficult for any robust lightning producing storms to exist. Given the lower thunder probs, went from a prob30 to VCTS for thunderstorms Friday. Conditions improve late Friday afternoon into the evening as the low moves away and dry air moves in.
Outlook: 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.
Increasing southwesterly winds this afternoon and Friday across all waters ahead of an approaching low from the remnants of Arthur in addition to a cold front. Gale Warnings remain in effect with this update, with an expansion for coastal waters from Cape Lookout to Surf City for Friday as the low moves through. At this time winds inside the sounds may stay just below Gale criteria but will have to watch the observations for a potential expansion of Gale Warnings or a MWS for the Pamlico Sound.
With the remnants of Post Tropical Storm 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. Boating conditions improve over the weekend behind the passing front, with next threat window for mariners early next week ahead of another front.
Nc, heat advisory until 8 pm EDT this evening for ncz029-044>047- 079>081-090>092-094-193>196-198-199. Beach hazards statement until 8 pm EDT this evening for ncz195- 196-199-204-205. Marine, small craft advisory until 11 pm EDT this evening for amz131- 136-137-230-231. Small craft advisory until 8 pm EDT Friday for amz135. Small craft advisory until 5 am EDT Friday for amz150. Gale warning until 8 pm EDT Friday for amz152-154-156-180-182- 184-186-188. Small craft advisory until 10 am EDT Friday for amz158. Gale warning from 10 am to 6 pm EDT Friday for amz158.
