textproduct: Newport/Morehead City

WHAT HAS CHANGED

Rain chances have decreased even more for Sunday, while remaining the same for Saturday.

The threat for thunderstorms, some potentially severe, has increased a bit for Monday.

Marine: North winds have been increased behind the front Monday night into Tuesday, with poor boating conditions likely.

KEY MESSAGES

1) It appears the bulk of heaviest showers or storms will remain mostly to the south of Eastern NC or offshore for most of this weekend.

3) A strong cold front will move through late Monday. Widespread rain showers are expected (80-90%). Depending on the timing of the front, scattered severe thunderstorms and heavy rain may accompany the frontal passage.

4) A warm front lifts through the Carolinas followed by a cold front midweek representing the next wave of precip.

DISCUSSION

KEY MESSAGE 1...Several low amplitude and weakly sheared shortwaves sweep across the Mid Atlantic and Southeast this weekend. GOM is cutoff from moisture with sfc low pressure(s) expected to remain south of the region, and thus precip looks to be much more spotty in nature.

For Saturday, overrunning light rain (up to 40% chance) with perhaps a few embedded storms (20% chance) are still in the forecast, with best chances of seeing rain acrs the srn CWA. It will not be an all-day washout, but periods of showers or light rain with an iso storm will be present as a warm front lifts through and weak lift transits the area.

Sunday, forecast has trended even drier, with subsidence in wake of aforementioned light overrunning event, and the FA in broad srly flow. Can't rule out a shower or two across the wrn FA (Coastal Plain counties), but bulk of guidance on the dry side, including the AIFS, which as been quite consistent.

KEY MESSAGE 2...Decent agreement on next stronger shortwave and attendant cold front moving through the region by late Monday. This system will have decently strong dynamics with fairly sharp troughing aloft pivoting over ECONUS to become more negatively tilted and potentially steeper lapse rates. Depending on diurnal timing, a severe thunderstorm threat is possible with this system, with the main threats appearing to be severe wind gusts and large hail, along with heavy downpours. MLCAPE vals approaching 1K J/KG per latest 08/12Z ECMWF. Still outside of HiRes guidance resolution window, but global guidance suggest another quick half inch of rain or more is possible with this FROPA. The ECMWF, UKMET, and ICON favor a late afternoon or evening fropa, which would be an ideal window for a greater severe t'storm threat. Stay tuned to later forecast updates.

KEY MESSAGE 3...After a brief cooldown amid northerly dry flow on Tuesday, a stacked low cutting across the Sern extent of the Great Lakes and high pressure migrating offshore brings warm and moist air across the Carolinas mid week ahead of the next front set to cross the area around the Thursday time frame. Will need to watch this system for severe potential as well.

AVIATION /06Z SATURDAY THROUGH WEDNESDAY/

A weak area of low pressure is forecast to develop overnight within a more broad surface trough in the vicinity of KMRH. It appears likely that SCT SHRA and TSRA will develop in the vicinity of this developing low, but should move quickly ENE within the fast westerly flow aloft. This should keep the greatest risk of low CIGs and TSRA east of the TAF sites, but this activity could skirt runways along the OBX. In the wake of the morning activity, a fast moving upper level wave is forecast to move through Saturday afternoon and could be accompanied by another risk of SCT SHRA and TSRA. Guidance shows less confidence in the placement and coverage of the afternoon activity, therefore I have opted to keep SHRA/TSRA out of the TAFs for now. In the wake of the afternoon wave, guidance shows the potential for sub-VFR conditions in either low stratus or BR/FG, and this potential will continue to be monitored.

Outlook: The next opportunity for sub-VFR conditions looks to be focused Sunday night into Monday as a cold front sags south towards, and eventually through, ENC with an increased risk of SHRA and TSRA. Reduced VIS and lowered CIGs are expected as well.

MARINE

Light N to Nerly flow today becomes serly and then south tonight as high pres migrates offshore. Winds remain in the 5-15 kt range, with gusts upwards of around 20 kt as gradient inc on Sat. Winds on the Gulf waters esp south of Hatteras will ocnl gust to 25 kt, but will not issue any SCA's attm due to marginal nature of these stronger wind gusts and seas remaining below 6 ft. Showers and a few storms will sweep across the waters on Saturday as weak low pressure moves through the region. Best chance for thunder is over the Gulf waters where greater instability will reside.

Outlook (Sunday through Wednesday): Winds and seas diminish on Sunday, with next fropa expected Monday with SCA conditions becoming more likely with post frontal northerly flow of 25+ kt Monday night into Tuesday. Winds diminish later Tuesday into Wednesday as high pres reestablishes itself.

MHX WATCHES/WARNINGS/ADVISORIES

NC...None. MARINE...None.