textproduct: NWS Wilmington

WHAT HAS CHANGED

Extreme Heat Warning issued for the coastal areas of Southeast NC and Northeast SC, with heat indices over 110. Heat Advisory issued for the remainder of the forecast area with heat indices between 105 and 109.

Added key message for upcoming high rip current risk for south- facing beaches. Updated aviation discussion with the issuance of the 12Z TAFS.

KEY MESSAGES

1)The heatwave with just isolated convection to dominate during the near term.

2)Relief from the heat is in sight with increasing coverage of showers and thunderstorms Sat night through Sunday night as a cold frontal system drops south across the area.

3)High risk of rip currents at south-facing beaches Friday and Saturday.

DISCUSSION

KEY MESSAGE 1...The heatwave with just isolated convection to dominate during the near term.

KEY MESSAGE 1 DESCRIPTION... The upper ridge axis across the area will keep a lid on the majority of any convection that tries to develop today. Isolated tstorms remain possible along the pinned sea breeze across coastal Northeast SC. Mid to upper 90s will dominate todays highs with 100+ degree readings still possible. Even the coastal locations will observe low to mid 90 degree readings. Some mixing of drier air aloft will result in upper 60s sfc dewpoints inland which will keep Heat indices within the advisory criteria. However mid to upper 70s dewpoints will remain across the coastal counties which will result in HIs breaching Extreme Heat Warning thresholds. This same scenario will play out Fri and Sat with a noted flattening of the upper ridge. Will still observe Heat Adv thresholds both Fri and Sat but max temps should remain below 100 degrees. This in part to an evolving increasing threat of convection Fri and especially Sat with debris cloudiness likely helping to hold down max temps.

KEY MESSAGE 2...Relief from the heat is in sight with increasing coverage of showers and thunderstorms Sat night through Sunday night as a cold frontal system drops south across the area.

KEY MESSAGE 2 DESCRIPTION... An upper pattern change starting Sun will help aid in dropping a cold front southward, crossing the area Sun with high pressure slow to fill in from the north thru mid-week next week. The result will be the threat for numerous showers and tstorms late Sat night thru Sun night, even after the cold front drops south of the area. This pattern change involves the upper ridge that has plagued the east for quite some time, that will be shifting to the west-central part of the nation and progged to amplify considerably. With plenty of antecedent heat and moisture, the setup should be quite stormy Sunday and Monday, with some storms possibly on the strong/severe side. Temps will also drop considerably with residual low 90s Sun for highs followed by potentially 80s for highs early next week.

KEY MESSAGE 3...High risk of rip currents at south-facing beaches Friday and Saturday.

KEY MESSAGE 3 DESCRIPTION... Building southerly swell will lead to a high risk of rip currents for south-facing beaches Friday and Saturday. Continued hot weather and weekend timing will contribute to increased beach attendance - beachgoers should stay out of the water where a high risk of rip currents is in effect. Conditions improve on Sunday as the swell weakens, and currently a moderate rip risk is forecasted for Sunday for south-facing beaches.

AVIATION /12Z THURSDAY THROUGH MONDAY/

VFR. Scattered diurnal cumulus around 6-8 kft this afternoon. Southwest winds around 10 kts during the day, with gusts near 20 kts. Winds slightly more southerly at MYR/CRE due to sea breeze after 16z. Isolated thunderstorms possible late this afternoon, mainly over NE SC. Mostly clear skies tonight with SW winds around 5-10 kts.

Extended Forecast...Generally VFR. Low potential for flight restrictions from fog or low ceilings each morning. Threat for periodic flight restrictions from daily afternoon and evening showers/thunderstorms through Sat. More numerous thunderstorms possible Sat night into Mon as a frontal system drops south across the region.

MARINE

Piedmont trof to strengthen across the Carolinas today thru Sat. At the same time, the High over the Atlantic Waters centered well offshore from the Carolinas gets suppressed southward. As a result, looking at increasing SW-WSW winds today thru Sat. Winds speeds increase to around 20 kt with possible frequent 25+ kt gusts across the ILM NC Coastal and Offshore waters Fri thru early Sat. In addition, looking at the threat for 6+ ft short period waves, again across the ILM NC Coastal and especially both ILM NC and SC Offshore waters. With this said, SCA remains possible for the ILM NC Coastal waters Fri thru early Sat. A cold front dropping southward, will cross the local waters Sun. Look for widespread showers and tstorms Sun into early Mon. Winds after FROPA will veer to the NE resulting in temporary victory at sea conditions until the NE wind has time to work on the local waters. NE winds will have an initial surge but then taper back some.

ILM WATCHES/WARNINGS/ADVISORIES

NC...Heat Advisory from 11 AM this morning to 8 PM EDT this evening for NCZ087-096-099. Extreme Heat Warning from 11 AM this morning to 8 PM EDT this evening for NCZ105>110. Beach Hazards Statement through this evening for NCZ106-108. SC...Heat Advisory from 11 AM this morning to 8 PM EDT this evening for SCZ017-023-024-032-033-039-059. Extreme Heat Warning from 11 AM this morning to 8 PM EDT this evening for SCZ054>056-058. Beach Hazards Statement through this evening for SCZ054-056. MARINE...None.