Area Forecast Discussion
Issued by NWS Newport/Morehead, NC
Issued by NWS Newport/Morehead, NC
714 FXUS62 KMHX 131809 AFDMHX Area Forecast Discussion National Weather Service Newport/Morehead City NC 209 PM EDT Sun Sep 13 2026 .WHAT HAS CHANGED... Small Craft Advisories have been issued for portions of the ENC waters. && .KEY MESSAGES... 1) Unsettled pattern continues through Monday 2) Warm and mostly dry conditions expected for much of the upcoming week && .DISCUSSION... KEY MESSAGE 1...A surface trough over central NC will push east across ENC this afternoon, and will interact with the seabreeze and a moderately unstable airmass. Despite some drier air moving in aloft, there should be sufficient low-level convergence to support isolated to scattered convection through early this evening. The deepest convection should be focused east of HWY 17 where low-level forcing will be strongest. Deep layer shear will be weak (~20kt) and this should help to minimize the risk of strong to severe thunderstorms. Additionally, weak low-level lapse rates and low DCAPE should limit the magnitude of gusts with any of the taller cores. With notable PWATs in place, moderate to high rainfall rates will be possible in the strongest thunderstorms. Westerly flow in opposition of the seabreeze may allow thunderstorms in that area to have more residence time due to a net motion that is very slow. Should this occur, a localized flood risk may develop. However, with drier air trying to work in aloft, confidence in sustained deep convection is lower, and the overall flood risk appears low for the area at large. On Monday, a cold front will move south along the coast of NC during peak heating. West to northwest low-level flow should tend to limit the strength of convergence along the front. However, as the front encounters the developing seabreeze, there should be a local enhancement to low-level forcing, especially along and south of HWY 70. This is the area where the best chance for sustained, deep convection exists. The risk is conditional on sufficient low-level forcing, but should this occur, a short-lived risk of strong to marginally severe thunderstorms may develop thanks to elevated deep layer shear (~30kt) and moderate instability (MLCAPE up to 1500j/kg). Machine learning guidance isn`t all that excited about this potential, and this likely speaks to the conditionality of the threat. This risk will quickly end from north to south as the front shifts off the Crystal Coast by sunset. KEY MESSAGE 2...Guidance continue to trend stronger with an upper level ridge that will be expanding across the Southern U.S. this week. In fact, ensemble guidance is now forecasting 500mb heights around 600dm with this ridge, the strength of which is very unusual for this time of year. Normally, this would spell anomalous heat for ENC. However, a pocket of "cooler" thicknesses is forecast to be over the Carolinas associated with the post-frontal northeasterly flow regime, especially Tuesday and Wednesday. While it will be dry, those cooler thicknesses may shield ENC from the anomalous heat that other parts of the South will experience. That pocket of lower thicknesses may begin to erode by the end of the week, with temperatures warming by then. However, guidance differ on when/if this will occur. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... Forecast confidence is moderate over the next 24 hours. A surface trough will move through ENC this afternoon and, in tandem with the seabreeze, will support a risk of SCT SHRA and TSRA. The greatest overlap of lift and instability is expected the further east you go, and for this reason, I`ve limited the TSRA mention to KEWN for now. Elsewhere, the risk of TSRA looks to be lower. All SHRA and TSRA will be capable of brief reductions to VIS, but the TSRA will have the greatest potential to see a longer period of sub- VFR conditions compared to the areas that see quick-moving, and weaker, SHRA. A slightly drier westerly flow tonight may limit the risk of low CIGs and VIS. However, light winds, recent rainfall (for some), and residual low-level moisture may still allow periods of reduced VIS in MIFG. Another risk of SCT TSRA is expected on Monday afternoon along a cold front that will be moving south through ENC. There is the potential for some of the thunderstorms to become strong, capable of gusty winds of 40kt+. This risk is contingent on sufficient instability and lift developing along the front. A northerly wind shift, and a bump up in winds, is expected behind the front. Wind gusts as high as 20-25kt will be possible for a few hours behind the front. Outlook: High pressure builds in through the middle of the week with mostly VFR conditions expected. The high should also keep a lid on the TSRA potential. && .MARINE... Southerly winds of 10-15kt will continue into this evening ahead of a surface trough that is approaching from the west. That trough will move through area waters this evening and tonight with the winds becoming westerly, and laying down to 5-10kt. Northerly winds then quickly build from north to south on Monday as a cold front moves through. Deterministic and ensemble guidance continue to show a strong signal for 25kt winds within the post-frontal northerly surge of wind, and marine headlines have been issued to account for this. Thunderstorms will be a risk for all waters through this evening. By tonight, that risk is expected to shift to the outer coastal waters along the Gulf Stream. On Monday, scattered thunderstorms are likely to develop along the southward- advancing cold front, but this risk should quickly end by sunset. Outlook: An extended period of northeasterly flow is expected through at least Wednesday or Thursday. Winds are forecast to lay down below 25kt, but elevated seas may linger for much of the week, especially with the contra flow against the Gulf Stream waters. For the near-shore coastal waters, the Small Craft Advisories may need to be extended into mid-week depending on how long the elevated seas last. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...None. && $$ DISCUSSION...RM AVIATION...RM MARINE...RM