Area Forecast Discussion
Issued by NWS Newport/Morehead, NC
Issued by NWS Newport/Morehead, NC
245 FXUS62 KMHX 052314 AFDMHX Area Forecast Discussion National Weather Service Newport/Morehead City NC 714 PM EDT Sat Jul 5 2025 .SYNOPSIS... Newly named Tropical Storm Chantal will drift towards the Carolinas this weekend, bringing an increased chance of showers and thunderstorms, including the risk of locally heavy rainfall, through early next week. && .NEAR TERM /TONIGHT/... As of 7 PM Saturday... Key Messages: - Waves of showers and thunderstorms expected to continue through the night, with the potential for locally heavy rain and an isolated tornado or two, as Tropical Storm Chantal drifts towards the Carolinas. No significant changes in forecast thinking, but did add in a HYDRO section to the discussion as several bands of showers and thunderstorms are forecast to impact ENC through Monday. See (HYDRO Section) for more info. Latest analysis depicts a closed low over the Gulf Coast underneath ridging over the Midwest and Mid-Atlantic. At the surface, Tropical Storm Chantal (named this morning) is drifting slowly northward roughly 150 miles south-southeast of Charleston, SC. The slow progression of Chantal will allow for multiple days of moderate to heavy rainfall potential. A band of scattered showers and thunderstorms is currently pushing through the northern tier of the forecast area, and latest high-res guidance shows the potential for additional bands of showers and thunderstorms to push onshore and through ENC tonight into tomorrow morning, with the best chances along and south of a Hatteras-to-Kinston line and especially along the Crystal Coast. Latest high-res guidance forecasts low-level wind fields to gradually become more favorable overnight, with CAMs supporting an increase in 0-1 km SRH to 100-200 m2/s2. Coupled MLCAPE of around 500-1000 J/kg, this will yield the risk for transient supercell structures and an isolated tornado or two. SPC currently has the far southwestern coastline in a Marginal Risk (level 1/5) for severe weather tonight. In addition, PWATs of 2.00-2.25"+ will yield a risk for locally heavy rainfall and isolated flash flooding. WPC has maintained a Marginal Risk of excessive rainfall for most of the region today. Outside of showers and thunderstorm chances, expansive cloud cover is forecast to keep temps slightly warmer than last night, with lows forecast in the low-to-mid 70s. && .SHORT TERM /SUNDAY AND SUNDAY NIGHT/... Key Messages: - Waves of showers and thunderstorms expected to continue through Sunday night/early Monday morning as Tropical Storm Chantal continues to drift north/northwestward. Locally heavy rainfall is possible with thunderstorms, and an isolated tornado or two cannot be ruled out. - Chantal is forecast to transition northeastward across ENC while progressively weakening Sunday night/Monday morning. The highest wind impacts for our area are expected during this time, with the potential for wind gusts to 40 mph for some locations. As of 2 PM Saturday...Heaviest rainfall of the day is expected late tonight and into tomorrow morning as Chantal and associated deep tropical moisture (PWATs of 2"+) continue to lift north and west, with the current expectation for landfall along the northern SC coast late morning or early afternoon on Sunday. Following landfall, Chantal is expected to turn northeastward as it moves across eastern NC through Sunday and into Monday. Like today, most likely area for heavy to torrential rainfall will be focused along the Crystal Coast and the Outer Banks south of Cape Hatteras where convergence will be enhanced along the stalled frontal boundary, but the potential for heavy rainfall will be present across all of ENC, with WPC maintaining a Marginal ERO for the forecast area tomorrow. Storm total rainfall through Monday morning will likely range from 1-3", but HREF LPMM guidance continues to suggest local maxima of up to 4". After increasing tonight, CAMs show low-level shear profiles becoming marginally less supportive of any tornado risk during the day tomorrow as modest boundary layer mixing increases. Despite this, CAM forecasts indicate 0-1 km SRH values of up to 100 m2/s2 will remain present during the day tomorrow amidst modest instability of 1000-1500 J/kg. Thus, an isolated tornado or two cannot be ruled out within the thunderstorm activity in the rainbands associated with Chantal tomorrow. SPC currently has the southwestern portions of the forecast area in a Marginal (level 1/5) risk for Sunday. Given expansive cloud cover and precipitation chances, highs are forecast to be lower tomorrow, topping out in the mid-80s. Easterly winds will veer southeasterly throughout the day, becoming gustier towards the afternoon/evening. The center of Chantal will approach the southwestern portions of the CWA tomorrow evening and is expected to transition eastward across the forecast area through Sunday evening and into Monday as it progressively weakens. While precipitation is currently to be more isolated Sunday evening, PWATs are expected to remain elevated above 2", allowing the threat for isolated heavy rainfall and localized flash flooding to persist into Monday night. Low-level shear profiles are again forecast to strengthen during the overnight hours as mixing subsides, with CAMs depicting 0-1 km SRH increasing to 100-150 m2/s2. With MLCAPE of 500-1000 J/kg, the threat for an isolated tornado or two will linger through the overnight hours on Sunday. With the center of the Tropical Storm passing through the area, the greatest wind impacts for our area are expected during this time (Sunday night into Monday morning). Winds will turn southeasterly ahead of Chantal, increasing to 20-30 mph as the storm passes. Locations closest to the storm (and coastal marine areas) are likely to see locally higher gusts to 40 mph. In response, SCA`s have been expanded to now include the waters from Cape Hatteras to Oregon Inlet and the Pamlico Sound. Will continue to monitor the potential for additional SCAs for the northern waters and the remaining inland rivers/sounds. && .LONG TERM /MONDAY THROUGH SATURDAY/... As of 400 PM Saturday... Key Messages - Multiple rounds of moderate to heavy rainfall possible this week TS Chantal will weaken across the NC coastal plain Monday and slowly lift northward Monday night and Tuesday. Periods of heavy rainfall will continue to be possible on Monday with PW values around 2" or greater. Weak ridging builds across the area Monday night and Tuesday but could see isolated to scattered showers bringing locally heavy rainfall. A series of shortwave trough will push across the region mid to late week continuing to bring an unsettled weather across the region. With high PW values, the greatest threat from the storms will be heavy rainfall. At this time, instability and shear parameters do not look overly impressive for severe storms to develop but could see a few storms producing strong wind gusts. The warmest temps of the long term look to be Tuesday and Wednesday with highs in the low 90s inland from the coast and heat index values around 100-105, otherwise temps expected to be near or a couple of degrees below climo. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... SHORT TERM /through Sunday/... As of 715 PM Saturday...Tough aviation forecast this evening with TS Chantal slowly tracking to the north and eventually making its closest point of approach to ENC by Sun evening. Currently have VFR ceilings and vis across just about all of ENC, though with another band of showers and isolated tstms making their way onshore as of this update, a brief period of sub-VFR (likely MVFR) conditions may impact the Crystal coast and EWN/OAJ terminals. While guidance does show the entire area being under MVFR ceilings currently, this has been overly aggressive the past day or so and as such I have pushed back the start of more permanent MVFR ceilings compared to the previous update. Though even this may need to be pushed back some depending on when the lower clouds from the outer edges of TS Chantal finally enter into the region. Either way now expect MVFR ceilings to build into ENC from south to north between 03-09Z tonight and then remain over the area into Sun afternoon. Several rounds of showers and storms will also be possible through the entire period and have added in periods of categorical showers, as well as tempo and PROB30 groups for tstms to capture the current trends. As we get into Sun afternoon some slightly better mixing may allow for VFR ceilings to return after about 18Z outside of any shower and thunderstorm activity. LONG TERM /Sunday night through Thursday/... As of 315 PM Saturday...TS Chantal will lift into the coastal plain Sunday night and gradually dissipate as it slowly lifts northward bringing periods of showers and thunderstorms bringing sub-VFR flight cats. A series of mid-level systems will push across the region mid to late week continuing to bring the threat of showers and storms with reduced flight cats. Late night and early morning fog and stratus will also be possible most mornings. && .MARINE... As of 4 PM Saturday... SHORT TERM /through Monday/... - Tropical Storm Chantal will bring hazardous marine conditions through Monday Tropical Storm Chantal is currently located approx 185 mi south of Wilmington, NC this afternoon and will slowly lift NNW toward the SC coast, making landfall early Sunday morning, and then slowly dissipate wile lifting across the Carolina coastal plain Sunday into Monday. Currently seeing E to SE winds around 5-15 kt across much of the waters with 15-20 and gusts up to 25 kt across northern Onslow Bay. Seas have built to around 3-6 ft today as well, highest across Onslow Bay. Similar conditions expected tonight, then will deteriorate further Sunday into Monday as Chantal passes to the west of the waters bringing S to SE winds around 15-25 kt and gust to around 30 kt, and could see occasional gusts to around 35 kt. Seas will also build to 4-7 ft tonight and continue into early Monday before gradually subsiding late Monday. Have expanded the SCA north to Oregon Inlet and to include the Pamlico Sound with the afternoon package and could see expansion to other waters depending on the eventual strength and track of Chantal. At this time thinking is that TS force winds will remain south of the waters outside of occasional gusts but again any unexpected strengthening or track shift could change that. LONG TERM /Tuesday through Thursday/... As of 4 PM Saturday...High pressure remains centered over the western Atlantic next week with a series of systems pushing across the area. This will keep gradients somewhat pinched with SW winds around 10-20 kt and seas around 2-4 ft currently forecast during the long term period. However, some guidance is suggesting low end SCA could occur at times during the middle of next week, especially in gusts. && .HYDROLOGY... As of 7 PM Saturday...Bands of heavy rain and thunderstorms have already brought 2-3 inches of rainfall to portions of ENC today as the outer bands of TS Chantal have begun to track across the region. Latest forecast calls for additional rounds of heavy rain and thunderstorm activity through at least Sunday as TS Chantal makes it closest point of approach to ENC on Sun evening. Latest guidance suggests and additional 1-2 inches of rain with localized amounts in excess of 3 inches will be possible across portions of ENC bringing at least a low end flash flooding threat which would be maximized in our more urban areas and across the areas that saw 2-3 inches of rainfall today. Expect the rainfall and flooding threat to gradually lower on Monday through the day as the last of the tropical moisture from Chantal makes its way to the north and east away from ENC. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...Beach Hazards Statement until 8 PM EDT this evening for NCZ195- 199. Beach Hazards Statement from Sunday morning through Sunday evening for NCZ195-196-199-203>205. MARINE...Small Craft Advisory from 8 AM Sunday to 6 PM EDT Monday for AMZ135. Small Craft Advisory from noon Sunday to 6 PM EDT Monday for AMZ152. Small Craft Advisory from 2 AM Sunday to 6 PM EDT Monday for AMZ154. Small Craft Advisory until noon EDT Monday for AMZ156-158. && $$ SYNOPSIS...MHX NEAR TERM...RCF/ZC SHORT TERM...ZC LONG TERM...SK AVIATION...SK/RCF MARINE...SK HYDROLOGY...MHX