Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 261110 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 710 AM EDT Wed Apr 26 2017 .SYNOPSIS...
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High pressure centered well offshore from the Southeast U.S. Coast will become the primary feature affecting the area today through Thursday. Expect a nice warm up with plenty of sunshine to help dry things out. Isolated showers or thunderstorms will be possible Friday. High pressure will strengthen across the area late Fri through the upcoming weekend. Daily highs and lows each day through the weekend will run up to 15 degrees above normal. Widespread 80s are expected with 90s well inland. Isolated showers and storms are possible Sunday mainly along the sea breeze, however a better chance will occur late Monday due to a cold frontal passage.
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&& .NEAR TERM /THROUGH TONIGHT/... As of 330 AM Wednesday...The cool advection associated with the recent cutoff upper low will shut down and be reversed today. Southwesterly flow and a building shortwave ridge will allow temperatures to warm into the low to mid 80s. This ridge will poke up between the departing upper low and a large trough over the nation`s midsection and help keep the area rain-free. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 330 AM Wednesday...Low amplitude ridging aloft to affect the FA Thu, complements to the northeast moving upper closed low. The associated ridge axis, overhead at the start of this period, will slide east and off the Carolina coasts by Thu evening. An expansive and rather amplified upper trof will become established across much of the CONUS with it`s trof axis nearly mimicking the continental divide. At the sfc, weak high pressure centered well offshore from Florida, will ridge back across the southern portions of the FA Thu. An eastward moving and weak frontal boundary, well displaced from it`s parent sfc low near Hudson Bay, will approach from the west before stalling across the far western Carolinas and Virginia Friday morning. Moisture accompanying the front remains limited, and will eventually push well ahead of the stalled front by Friday morning. Just enough dynamics and weak instability to aid isolated to widely scattered showers late Thu night thru Midday Friday along with a possible rumble of thunder. Upper level ridging will spring back up across the southeast States and the Atlantic waters. 5H Heights rise to 590+ dam. Strengthening Bermuda high pressure will ridge back to the west and extend inland in the vicinity of Cape Romain by daybreak Sat. Subsidence aloft, ie. NVA, will become more dominant late Fri aftn and night, essentially putting a lid on any convection that tries to develop. The pre-dawn hours of Thu, and Fri and Sat will each feature a SW low level jet. The stronger jets will occur Fri and Sat mornings. This will aid in keeping SW winds active at the sfc and in turn likely preventing any radiational fog development each night. As for daily max and min temps for the 2 days, you may be looking at the warmest temps of the Spring season so far. Model Mos Guidance shows widespread 80s both days with 90 degree readings possible inland locations on Fri. In essence, will be looking at max/min temps running up to 15 degrees above climo. && .LONG TERM /SATURDAY THROUGH TUESDAY/... As of 300 PM Tuesday...Surface and mid level ridging will be the dominant features through the weekend. The 5h ridge axis is just offshore and a slow but steady increase in moisture as flow aloft becomes more southwesterly opens up the possibility of sea breeze/diurnal convection, especially Sun afternoon and evening. Temperatures will be above to well above climo with potential for 90 degree readings inland. Next system winds up over the central CONUS early next week, lifting from the plains on Sun to the Great Lakes on Mon. Warm advection ahead of the front will maintain temps above climo through Mon. Cold front trailing the low moves into the area later Mon preceded by convection. Best dynamics pass well north of the area but there will be a narrow band of deeper moisture along with low level convergence and a strengthening low level jet. Also potential for some PVA depending on timing of any shortwave rotating around the base of the trough. Surface high and broad troughing aloft Tue contribute to deep westerly flow, drying the region out but with a cooler air mass building in temps will be slightly below climo as the period ends. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
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As of 12Z...MVFR and pockets of IFR will occur across the region thru 14Z, either from ceilings 1k-2k feet and/or BR/FG especially areas outside the veil of SC/AC cloudiness. As the stacked low moves further away today, temporary upper level ridging and sfc ridging from off the SE Atlantic will both affect the FA by this aftn thru tonight, ending the cyclonic flow associated with the retreating stacked low off to the northeast. Light NW-W flow this morning will back to the SW this aftn thru tonight. Coastal terminals may see it back to the S due to a the development of an aftn/evening weak sea breeze. A low level SW 20 to 30 kt jet will develop and affect the area terminals between 04Z thru 12Z Thu. This will keep winds active at the sfc and likely prevent any widespread fog. If this jet is weaker than expected or does not quite develop as expected, fog would then become an issue especially with grounds still remaining nearly saturated from the heavy rainfall event of the past 2 days. Extended outlook...VFR expected from Thursday afternoon through Sunday. Isolated MVFR from spotty showers Thu night.
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&& .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 330 AM Wednesday...The system moving into the Northeast will no longer be the main wind- making feature today. In its wake the high over the Atlantic will bring a S to SW flow. An approaching cold front will also slightly contribute. With the coast between the two winds will be quite light. Seas will setting into a general 2 to 3 or 4 ft range. Some larger waves outside of 20nm have swell energy from the departing storm as evidenced by the 10 sec dominant period. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 330 AM Wednesday...Thursday will feature weak ridging from offshore high pressure east of Florida, extending inland just south of the area waters. Thursday will see SSW to SW flow at 10 to 15 kt with an 8 to 9 second period ESE ground swell dominating the significant seas. By late Friday thru Friday night, strengthening ridging sfc and aloft, will affect the area waters. The sfc pg will tighten-some, resulting with SW 10 to 20 kt winds. An ESE ground swell will remain present but increasing short period wind waves will eventually dominate the significant seas. In addition, a SW low level jet will affect the local waters during the pre-dawn hrs of THu, Fri and Sat. The strongest low level jet will occur Fri morning and may just be strong enough to produce SCEC and/or SCA conditions. Will monitor. The aftn/evening sea breeze each day will also provide additional choppiness to the overall seas. LONG TERM /SATURDAY THROUGH SUNDAY/... As of 300 PM Tuesday...High pressure will be the dominant feature through the period with south to southwest flow in place. Speeds will be on the low end of the 10 to 15 kt range early in the period but increase to a solid 15 kt Sun as gradient becomes a little more defined. Seas mostly 2 to 3 ft early in the period will experience an upward trend late in response to increasing southwest flow. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...DCH NEAR TERM...MBB SHORT TERM...DCH LONG TERM...III AVIATION...DCH is the U.S. government's official web portal to all federal, state and local government web resources and services.