textproduct: Newport/Morehead City

WHAT HAS CHANGED

Marginal (Level 1/5) risk of severe thunderstorms in effect tomorrow for all of eastern NC.

Gale Watch and Small Craft Advisory issued for area waters for Thursday into Friday.

KEY MESSAGES

1) Lower risk of showers and thunderstorms expected across eastern NC Wednesday and Thursday with next higher-end threat Thursday night and Fri ahead of strong front.

2) Increasing heat risk tomorrow along with marginal fire weather concerns. Heat makes a return next week.

DISCUSSION

KEY MESSAGE 1...Cloudy and increasingly soggy morning unfolding across eastern NC this hour. Surface analysis depicts a surface low over southern Virginia lifting northward and pulling a warm front north of Highway 264, with a few stubbornly persistent showers and thunderstorms riding the boundary northward. Farther south, embedded shortwave migrating across an axis of deep moisture streaming off of PTC 1 in the western Gulf of America is aiding in shower development over SC, expected to migrate across our area through this morning and exiting this afternoon. This will add a couple tenths of precipitation to yesterday's totals.

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 PTC 1 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 PTC 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 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 approach 105 in many areas and a Heat Advisory may need to be considered for tomorrow. Additionally, with a noticeable uptick in winds ahead of the approaching front (gusts 25-30 mph) and RHs 35-40% there is a marginal risk of some fire weather concerns, primarily over the inner coastal plain where less rain has been present.

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+.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

Pred VFR conditions across rtes early this morning as warm front slowly lifts northward towards the VA border. Ongoing isolated showers and thunderstorms continue on the north side of this boundary but northeast of the TAF sites and will continue to lift offshore through the next few hours. An embedded shortwave will move through the cyclonic flow aloft through this morning bringing another round of showers and isolated thunderstorms with sub-VFR conditions, highest probabilities for rain and sub- VFR conditions will be across southern and eastern rtes. Winds will generally be SW around 5-10 kt and could see gusts around 15 kt Wednesday afternoon. Improving conditions through tonight with clearing skies and southwest winds remaining elevated at around 5 kt inland, 5-10 kt OBX terminals.

Outlook: More widespread TSRA threat returns Thursday night and especially Friday with a stronger front. Overnight fog and stratus threat possible each morning. Weekend is trending drier and more quiet with predominant VFR expected.

MARINE

Seeing an uptick in westerly winds early this morning ahead of an approaching shortwave from the west, with a few infrequent gusts to 25 kt for the waters from Cape Hatteras south. This is expected to ease later this afternoon as the disturbance passes offshore. Focus then turns to tomorrow into Friday with an uptick in southwesterly winds across all waters ahead of an approaching cold front. Confidence has increased towards Gales this morning, showing probabilities of up to 70%+ for the outer waters east of Duck south to central waters north of Ocracoke Inlet. It should be noted that probabilities 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. For now, Gale Watches have been hoisted where confidence is highest with SCA elsewhere extending to inland rivers and sounds. However, Gale headlines may be expanded further in future forecasts.

Outlook (Thu 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.

MHX WATCHES/WARNINGS/ADVISORIES

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 2 PM EDT Friday for AMZ135. Small Craft Advisory from 10 AM Thursday to 8 AM EDT Friday for AMZ150. Gale Watch from Thursday afternoon through late Thursday night for AMZ152-154-180-182-184. Small Craft Advisory from 2 AM Thursday to 8 PM EDT Friday for AMZ156-158.