textproduct: NWS Wilmington

SYNOPSIS

High pressure offshore will bring warming conditions. A midweek cold front will bring no chance for rain and only flatten the warmup through Thursday. A cold front will arrive late this weekend, only bringing minor rain chances.

NEAR TERM /THROUGH TONIGHT/

Flat flow aloft as weak 5h ridge to the south tries to bump its way north. The fast moving flow helps shift elongated high along the east coast this morning offshore during the afternoon. The resulting return flow/warm advection and abundant sunshine will lead to afternoon temperatures 5 to 10 degrees above normal. Warming will also result in a weak afternoon sea breeze, but will be hard pressed to see more than a cloud or two with the boundary given the strength of the mid-level subsidence. Light return flow continues tonight, helping increase boundary layer moisture. Would not be shocked to see fog/low cloud development, but no signals for dense fog. Continued warm advection overnight and low level moisture help keep lows 5-10 degrees above normal.

SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/

West Atlantic high pressure paired with broad circulation around a low in the Great Lakes will bring a S to SW surface flow locally. Mid level flow will be perfectly zonal and thus out of the west. An upper level jet streak will be in the OH valley putting the Carolinas in the right exit of the ageostrophic quadrant of downward vertical motion. According to forecast soundings this jet will still be close enough paired with a few flat cu beneath a 4kft inversion for a sky cover forecast of 30 percent. Otherwise quiet with light winds and mild temperatures.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

The position of a frontal boundary Wednesday and Thursday is a bit muddled though since it won't bring any rain it's only (potential) impacts to sensible weather will be wind direction and some possible additional cloud cover. Current thinking is that low amplitude ridging to our south keeps the front north of the area Wednesday while a weakly cutoff upper low in the NE has enough energy to drive it through on Thursday. Again, no forcing and no rain and barely baroclinicity so no major impacts. Friday as the boundary lifts back northward in response to the strengthening of the MidAtlantic high guidance shows some very light QPF but mid level heights appear unsupportive of this idea. The weekend pattern change of the mid level ridge moving offshore and the approach of a healthy trough and front from the west now appears slower. Low end POPs will remain from Friday night onwards until the uncertainty gets ironed out. None of the aforementioned situations will deviate the forecast from much above normal temperatures until the late weekend front arrives.

AVIATION /06Z MONDAY THROUGH FRIDAY/

Concern for the valid TAF period continues to be potential for IFR/LIFR fog across inland SC between 11Z and 14Z. Guidance has been going back and forth about the potential, but sites to the west and northwest are starting to report IFR/LIFR visibilities and ceilings. The low level moisture should slowly advect in and, once thin cirrus moves out, the moisture will work in concert with the light to calm winds to produce fog. Confidence is not particularly high given the guidance trends, but the presence of clear skies, low level moisture, and light to calm boundary layer winds are hard to ignore. Fog will only affect FLO, with post sunrise mixing at MYR/CRE setting up before the low level moisture/fog/stratus can arrive. Cannot rule out some MVFR fog reported at CRE from mist off the ICW.

VFR will dominate today with light and variable winds becoming light onshore along the coast with development of weak sea breeze in the afternoon. Light return flow develops today as elongated ridge axis shifts offshore. Setup is often one that leads to fog development as low level moisture increases. Do not have any fog in TAFs between 00Z and 06Z, but something to keep an eye on.

Extended Outlook...Mainly VFR except for possible MVFR Tuesday morning.

MARINE

Through Tonight...

Northerly winds 5-10 kt this morning will become light and variable once surface ridge axis slips offshore. Weak gradient in place today and tonight with development of light southerly flow later in the day as the ridge axis continues to drift east. Speeds remain under 10 kt into Tue with weak landbreeze development possible after midnight. Seas 2 ft or less will be a mix of swells, easterly and southeasterly.

Tuesday through Friday... Tuesday's winds may start light and variable but a southwesterly component should come to dominate as the gradient develops between offshore high pressure and a storm system in the Great Lakes. Wednesday and Thursday will bring more benign conditions with relatively light winds though the wind direction is uncertain due to the position of a frontal boundary that may or may not push weakly through. Best forecast at time is that it moves through Wed night for a wind shift to N followed by veering the onshore as the parent high to our north moves eastward. High pressure becomes more firmly established off the MidAtlantic coast on Friday bringing a return of southerly flow of light intensity. No major swell energy will be present allowing the shorter period wind waves to dominate. The only minor swell will be out of the east as high pressure struggles to consolidate, especially before Friday.

ILM WATCHES/WARNINGS/ADVISORIES

NC...Coastal Flood Advisory from 10 AM this morning to 1 PM EST this afternoon for NCZ107. SC...None. MARINE...None.