textproduct: Newport/Morehead City

WHAT HAS CHANGED

Winds continue to trend upwards with Sunday-Monday coastal low. Gale Watches have been hoisted for most area waters.

Area of accumulating snowfall has been expanded to most areas along and north of Highway 264, although forecast totals remain under half an inch.

Fog, possibly dense at times, will linger until front completely clears the coast later this morning.

Marine Dense Fog advisory for coastal waters and sounds S of Ocracoke Inlet has been extended until sunrise. May need to be extended yet again depending on if the front has cleared the area or not.

KEY MESSAGES

1) Light rain expected through today behind a stalled front.

2) Rapidly deepening low pressure off our coast Sunday and Monday will bring a host of impacts to our area including strong winds and minor snowfall accumulations.

Marine...The probability of Gale force winds late Sunday and Monday continues to increase across our waters as a rapidly deepening low pushes off the Mid- Atlantic Coast.

DISCUSSION

KEY MESSAGE 1)...Latest surface analysis depicts a surface cold front stalled roughly along the I-95 corridor early this morning leaving eastern NC in a relatively mild airmass characterized by temps in the 50s to around 60. The frontal boundary is forecast to sag southward later this morning and stall. Combined with a weak embedded shortwave in southwesterly mid-level flow, the front will be a focus for on- and- off isentropically forced light rainfall through much of Saturday. Accumulations will be light, amounting to a few tenths of an inch.

KEY MESSAGE 2)...Guidance continues to converge on a positively tilted shortwave tracking across the central plains today (very well defined on satellite), with the trough taking on a more negative tilt and deepening slightly as it phases with a faster moving mid-level disturbance currently pushing across the southwestern CONUS. At the surface, the aforementioned frontal boundary will serve as the focal point for cyclogenesis, intensifying Sunday as trough takes on an increasing neutral and eventually negative tilt through the day. After some track spread in the guidance the past few forecast cycles, the 00z suite this morning has converged on a solution favoring a stronger low passing quite close to the coast.

After a brief lull from the isentropically driven precipitation, more robust rainfall will return Sunday morning. Eastern NC will remain on the cool side of the low, but temps in the upper 50s to low 60s Sun morning along the Crystal Coast and equivalent Tds may provide just enough instability to support a rumble of thunder or two. Total rainfall on Sunday into Sunday night will amount closer to a half inch, although any convection will boost storm totals.

Precipitation gradually ends from west to east Sunday night into Monday with strong CAA ramping up behind the departing low as it rapidly deepens off the Mid- Atlantic coast allowing temps to fall into the 30s. Global, ensemble and hi-res guidance all agree on a risk of minor snowfall north of Highway 264 as cooler air gets wrapped in with the moisture, although the 00z suite has trended accumulations farther north towards the VA border. Ensembles continue to favor a modest few tenths of an inch, and our forecast reflects this consensus - the only change being the expansion of accumulations west through portions of Pitt and Martin counties. A shortwave rotating through the departing low may keep low clouds and light precip lingering through much of Monday, although we will have dried up a decent amount at that point.

A stronger low now favors a set up of stronger winds Sunday night into Monday, and the forecast now calls for gusts pushing 45-50 mph across portions of the Outer Banks. If this holds, Wind Advisories will likely be needed in the next cycle or two. This has also raised the risk of some minor coastal flood impacts, although this will likely be limited by the brevity of stronger gusts.

AVIATION /06Z SATURDAY THROUGH WEDNESDAY/

Light southwest winds will continue for several more hours this evening in advance of a cold front approaching from the west. Weak moisture advection within that flow, pre-conditioned low- levels from earlier rain, and some radiational cooling effects should support a risk of reduced VIS in BR/FG until the front completely clears any respective location. After that time, drier air is forecast to filter in behind the passing cold front. Despite lack of model support, I am going with prevailing MVFR with TEMPO IFR groups for all TAF sites from 6-10Z. Some sites may absolutely crater with LIFR or VLIFR possible, best chance for this happening will be ISO and PGV, but confidence is not high enough to include that explicitly in the TAF, but worth mentioning here. With OAJ's secluded location and EWN's proximity to water, they're not completely out of the woods for SubIFR flight cats either, but confidence for these two locations is slightly lower.

After an initial drying period in the low levels directly behind the front, moisture will increase aloft which should support the development of widespread light to moderate RA in the early morning hours and through the day SAT. Rainfall rates look to be light, and this should support mostly VFR VIS. There may be enough elevated instability to support a very low- end TSRA risk near the Crystal Coast on Saturday, but not enough confidence to include in TAFs.

Moderate westerly winds above the low-level inversion will support an increased risk of LLWS impacts through around 05z-07z this evening, mainly from KISO east through KFFA.

Outlook: MVFR and IFR flight cats becoming more likely latter half of the weekend with CIGs decreasing through the overnight period SAT night persisting into SUN as an area of low pressure travels through the area along tonight's front that will have stalled to the south, bringing likely rain, lower CIGs/VIS, and stronger NWerly winds into early next week.

MARINE

Marine Dense Fog Advisory has been extended for the waters south of Ocracoke Inlet this morning amid persistent moist southwesterly flow over cooler waters, while cold front remains stalled to the west. This boundary will eventually push southward later this morning and help scour out lower visibilities.

SCA has been dropped as seas fall to 3-5 feet and westerly winds drop to 10-15 kt, but still up to 20 kt at times across outer waters. Boating conditions will be relatively benign for much of today into tomorrow in northeasterly flow before rapidly deepening low pressure zips along the aforementioned frontal boundary and lifts across the waters Sun afternoon into evening. Strong Gales likely to develop in westerly flow behind the low, and Watches have been posted for all offshore waters and inland sounds with peak gusts around 40-45 kt. Some Storm-force gusts are not entirely out of the question, although the probability of this currently remains low (around 10%). Seas will rise in response to around 7-10+ feet, especially beyond 10 nm offshore.

Outlook: Gales last into Monday midday but SCA conditions likely to extend well into Tuesday before westerly winds fall enough to let seas subside. Offshore waters likely to remain poor late next week as southwesterly winds increase ahead of an approaching cold front forecast to cross next weekend.

MHX WATCHES/WARNINGS/ADVISORIES

NC...None. MARINE...Gale Watch from Sunday evening through late Sunday night for AMZ131-230-231. Gale Watch from Sunday evening through Monday morning for AMZ135. Gale Watch from Sunday evening through Monday morning for AMZ150-152. Gale Watch from Sunday evening through Monday morning for AMZ154-156-158. Dense Fog Advisory until 7 AM EST early this morning for AMZ156-158.