Area Forecast Discussion
Issued by NWS Wilmington, NC

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688 FXUS62 KILM 191712 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 1212 PM EST Thu Jan 19 2017 .SYNOPSIS... Weak high pressure today will move offshore tonight. A series of mid level systems will bring unsettled conditions Friday through Monday. The strongest system will move across Sunday and into early Monday. High pressure will build back in toward the middle of next week. && .NEAR TERM /THROUGH TONIGHT/... As of 930 AM Thursday...Though the mid 70s of yesterday are a thing of the past today`s highs in the low to mid 60s are still a good 6-8 degrees above climatology. The low level cool advection has already shut down and the mid level ridge overhead is building in amplitude. The surface gradient is poorly defined making for very light winds today. Some late day cirrus will spill in from the west possibly making for a nice sunset. Forecast soundings from the WRF show that low levels will begin to moisten towards 03Z. The 12Z WRF is also slower with rain advecting in from the west late tonight, generally keeping it all west of here. Will likely adjust the forecast accordingly should other guidance come in supportive of this idea. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 300 AM Thursday...The main area of low pressure will be moving across the Midwest on Fri. Its trailing frontal system will advance into the Carolinas. A mid-level shortwave trough is expected to spawn weak low pressure offshore along the front Fri. The low is expected to then move away, but the front should stay in fairly close proximity. Thus, the forecast remains unsettled and is trending wetter than this time Wed. The initial surge of showers should become more diffuse as they travel from SW to NE. The highest risk for measurable rainfall will be across the I-95 corridor. Will show POPs trending lower as the shortwave energy lifts out with offshore showers becoming dominate. There is a potential for one to possibly two tenths of an inch of rainfall late tonight into Fri. We may catch 12 hours or so where POPs are below threshold as the front gets knocked back by the departing coastal low Fri night. However, by Sat, isentropic lift and a series of upper level troughs will bring showers back into the forecast well ahead of a strong area of low pressure across the Southern Plains. This time the rainfall will be more significant. Given mixed layer CAPE values rise to around 500 J/kg Sat afternoon, will introduce a slight chance for thunderstorms which may persist into Sat night. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 300 AM Thursday...Deep cyclone with complex frontal structure will affect the area Sunday and into the day Monday. Initially mid level low pressure will be moving across the Tennessee Valley with a cold front extending southward into the Gulf of Mexico and a warm front extending eastward bisecting the Carolinas. Sunday will see warm sector showers and thunderstorms somewhat disorganized in nature. The more organized convective line moves across late Sunday night into Monday morning. The last few cycles of the operational GFS show a kind of split in the line as the warm conveyer belt shunts the best moisture off to the east and northwest via a strong dry slot. This could reduce QPF amounts and severe potential, but good coverage of showers and isolated thunderstorms is expected nonetheless. Beyond this, a zonal pattern develops at the mid levels which turns more southwesterly in time with another front approaching very late. No changes to the temperature forecast which are of course warm early on dropping back just a little Tuesday and Wednesday. && .AVIATION /18Z THURSDAY THROUGH MONDAY/... As of 1712Z...VFR through much of the TAF cycle, until a warm front approaches the inland terminals Friday morning. This will likely lead to MVFR CIGS/VSBYS around daybreak, persisting into late morning at inland terminals. Primarily VFR at coastal terminals through the TAF cycle, with BKN-OVC-025-050 at KILM, KCRE, and KMYR aft 14Z Friday. Extended Outlook...IFR ceilings and vsbys are possible inland Fri night into Sat morning as a warm front and rainfall event develops. IFR conditions will again be possible late Sunday into Monday as a strong low pressure system impacts the area. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 930 AM Thursday...High pressure today will move offshore tonight. NE winds 10 to 15 kt today will veer to easterly this eve and then SE overnight. Wind speeds tonight will be 10 kt or less. Seas of 2 to 3 ft this morning will subside to 2 ft or less this afternoon and tonight. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 300 AM Thursday...A warm front will move into the area from the SW on Fri. A mid-level shortwave should spawn a weak area of low pressure along this front offshore. The weak low will move away, but the front should stall/waver in close proximity Sat and Sat night as strong low pressure begins to advance east from the Southern Plains. Expect southerly winds to hold on across the waters through the period. At this time, they are not expected to exceed 10 to 15 kt. Seas will be 2 to 3 ft. Much higher winds and seas are expected late in the weekend when Small Craft Advisory conditions are expected. As dewpoints approach a critical window Sat, there may be an opportunity for sea fog to develop. LONG TERM /SUNDAY THROUGH MONDAY/... As of 300 AM Thursday...Southerly winds will pick up steam during the day Sunday as a potent storm system moves closer to the area. Speeds increase from 10-15 knots early to a healthy 15-20 knots late in the evening. The strongest winds move across early Monday morning reaching a maximum of 20-25 knots. A southwesterly flow develops later Monday behind the front which is essentially a slight wind direction shift. Speeds decrease to 15-20 knots. Significant seas will build as well with small craft conditions developing by midday Sunday and persisting through the remainder of the period. Could see some 8-10 footers at maximum height across the outer waters early Monday. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ NEAR TERM...MBB SHORT TERM...RJD LONG TERM...SHK AVIATION...8 is the U.S. government's official web portal to all federal, state and local government web resources and services.