####018008040#### FXUS62 KILM 170610 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 210 AM EDT Sat May 17 2025 .SYNOPSIS... Above normal temperatures near record highs are expected again on Saturday. A weak cold front accompanied by isolated showers and storms will track across the area Saturday night. Mainly dry weather with above normal temps are then expected early next week until a storm system likely affects the area toward the middle of next week, bringing better rain chances and cooler weather for the latter half of the week. && .NEAR TERM /THROUGH TONIGHT/... Key Messages/Highlights: *Above normal temps w/ record high temps possible Saturday *Isolated damaging wind gusts/large hail possible Saturday aftn/eve Confidence: *Moderate to High Details: The mid-level ridge over the area will flatten as shortwave energy moves through ahead of a surface cold front. Rain chances overall look to remain limited given the overall limited moisture but an isolated shower/storm is possible this evening, mainly in NC, and again Saturday across all of SE NC and NE SC. There looks to be quite a bit of instability/shear for any storms to tap into so can't rule out a few damaging wind gusts and/or some large hail. Temps should be the big story though as they will be well above normal, only falling into the mid 70s tonight for most locales, and then likely into the lower 90s away from the beaches Saturday when record highs could be reached (see Climate section below for details on the record temps). && .SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/... A cold front is expected to settle southeastward through the are over Saturday night as a closed mid-upper low and its associated surface low track across New England. This far south, forcing for ascent will be meager, but surface convergence along the front may be enough to develop isolated strong convection. Prior to midnight, environmental parameters will support severe weather for any storm which manages to develop and grow tall enough to take advantage of 45-55 kts of effective shear amidst waning instability during the evening and early overnight. The Storm Prediction Center has maintained a Marginal risk (threat level 1 out of 5) for severe hail and wind as the anticipated coverage is very low. Otherwise, expect fairly rapid cooling during the evening after another hot day with west- southwesterly winds veering to westerly by the end of the night behind the cold front. Morning lows on Sunday should end up in the upper 60s to low 70s, coolest north, as somewhat drier air nudges in. On Sunday, the front should stall just south of the area as it becomes aligned parallel to the flow aloft. Building ridging west of the forecast area will reinstate northwesterly flow aloft which could bring a cluster of showers or storms to far southern portions of the forecast area nearest to the front, but PoPs remain no higher than slight chance (20%) to account for this threat. Otherwise, mid-level dry air and subsidence should keep the region dry and very warm with highs in the upper 80s to around 90F with passing high cloudiness. The continued increase in ridging west of the forecast area will result in greater subsidence developing through the atmospheric column, allowing for a drier and more capped atmosphere to develop on Sunday night. Thus, outside of a decaying shower scraping our southern areas, the region should stay dry overnight with lows in the mid-upper 60s. && .LONG TERM /MONDAY THROUGH FRIDAY/... Confidence in the long-term forecast is rather low as a substantial western US trough with multiple vort maxes evolves and tracks eastward. This will drag the stalled front back northeastward as a warm front during the first half of the week, along which we may see a round or two of convection tracking southeastward into the forecast area. Otherwise, guidance generally agrees that higher rain chances can be expected around midweek as low pressure drags another cold front towards and through the area from the west. Atmospheric parameters become more supportive of severe thunderstorms on Tuesday and Wednesday, but the outcome of whether severe storms actually develop will depend on finer-scale details related to the mid- upper pattern. Furthermore, whether the cold front clears the area with dry weather in its wake will also depend on the outcome of this pattern, but overall, it appears a solid push of cooler and drier air will be in store at some point by the end of the week. However, until the front arrives, continued very warm weather is expected with highs in the upper 80s to around 90, although lower dew points away from the coast should allow low temps to fall to or below 70F in many locations on Monday night and Tuesday night, and potentially much cooler than that behind the front late in the week. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... VFR conditions expected through the period. Convective coverage associated with the system moving across later today/overnight continues to look paltry at best so no significant impacts expected. Low level jetting did warrant LLWS for a few hours this morning. Extended Outlook...Mainly VFR conditions are expected through the period. && .MARINE... Through Saturday... Moderate to high confidence this period. The area will remain between an inland trough and approaching weak cold front and offshore high pressure. Thus, southerly winds will prevail. The combination of the low-level jet and pressure gradient could push winds to near Small Craft Advisory levels Saturday when gusts to near 25 kt are likely, although we don't feel an Advisory is warranted at this time, especially since seas should stay 4 ft or less. Saturday night through Wednesday... Southwesterly winds on Saturday evening of 15-20 kts veer to westerly and subside as a cold front slides through the waters. Winds become light and variable around or below 10 kts for Sunday and Monday as the front stalls just south of the area and wavers (although the sea breeze circulation should yield enhanced nearshore winds around 10-15 kts). The front should lift back northward at some point on Tuesday with winds becoming southerly behind it. Strengthening low pressure northwest of the waters will tighten the pressure gradient and lead to increasing flow on Wednesday ahead of a cold front, with chances for showers and thunderstorms peaking ahead of this front. Seas will relax from their 3-4 ft state Saturday evening into the 2-3 ft range on Sunday as winds ease up behind the front. Seas are expected to hold in the 1-3 ft range for Monday and Tuesday as the flow remains generally light. Seas increase in tandem with the increasing winds on Wednesday, although how high waves reach will depend on the strength of the low pressure system northwest of the waters. Outside of diurnally-driven wind waves, a persistent 1-2 ft southeasterly swell with a period around 9 sec will continue. && .CLIMATE... A new record high was set at Florence, SC today (95F, the old record was 93F set in 2022). High temperature records may be challenged again Saturday as anomalously warm air overspreads the region ahead of a cold front. Record highs for our four climate sites are as follows: Saturday, May 17th... Wilmington, NC: 92F (1960, 1990) Lumberton, NC: 96F (1941) Florence, SC: 93F (1977) N. Myrtle Beach, SC: 92F (1941) && .ILM WATCHES/WARNINGS/ADVISORIES... NC...None. SC...None. MARINE...None. && $$ SYNOPSIS...ILM NEAR TERM...RJB SHORT TERM...ABW LONG TERM...ABW AVIATION...SHK MARINE...RJB/ABW CLIMATE... ####018005503#### FXUS61 KGYX 170611 AFDGYX Area Forecast Discussion National Weather Service Gray ME 211 AM EDT Sat May 17 2025 .SYNOPSIS... A slow moving low pressure system will bring rounds of showers and thunderstorms through the weekend. Today, there is a low severe thunderstorm risk across New Hampshire as strong winds and hail will be possible in the afternoon near and south of a warm front. More showery weather is expected on Sunday with unsettled weather possibly extending into Monday. Unfortunately, the outlook for the rest of the week is unsettled and colder than normal. && .NEAR TERM /THROUGH TODAY/... As of 06z most of the region is dry except for a weakening small line of thunderstorms in northern NH along with a few showers and isold thunderstorms east of there into central ME. Otherwise, there's areas of fog and drizzle. The bulk of this morning into the early afternoon looks to be mainly dry as a warm front begins to sharpen up over southern NH. However, north of the warm front, which includes most of Maine, the weather will be cool with low clouds, some fog and occasional drizzle. By late afternoon, significant height falls will take place ahead of an approaching short wave trough. Thunderstorms ongoing across Upstate NY and VT will move into western NH. The areas encompassed by the CT Valley as well as southern NH will be near a warm front and most susceptible to surface based destabilization this afternoon. Therefore, storms that move into those areas or develop in those areas will have the chance of being strong to severe with hail and strong winds through the evening hours. Heavy rainfall is likely as well in thunderstorms which could pose a local flooding risk. Showers and thunderstorms will likely move eastward late this afternoon and evening across the warm front into Maine where the air mass will be much less unstable. However, some elevated instability will be present so thunder is not out of the question even here late in the day and into the evening. && .SHORT TERM /TONIGHT THROUGH 6 PM SUNDAY/... Upper level low pressure will continue to approach tonight. The result will be rounds of showers and perhaps a few thunderstorms, some which may contain heavy rainfall. The upper low moves overhead on Sunday which will portend to showery weather with a thunderstorm or two, but mainly just cool showery weather with highs near or a bit below normal. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... 1045 PM Update... Little change in the latest NBM suite of guidance. The main story of next week will be for below normal temperatures for mid to late May. The upper low shifts east of the area early next week to around Nova Scotia, but broad troughing across the NE and enough residual moisture will still be sufficient enough for isolated to scattered showers to develop (lower coverage than Sunday), mainly during the daytime hours. Temperatures will be in the mid 50s to lower 60s for the most part on Monday and then a touch cooler on Tuesday. Another slow-moving, upper low then enters the picture for the second half of next week with models in good agreement a 500-mb low closing off near the Great Lakes that will slowly head toward New England. Shower chances will ramp back up as a result with cloudier conditions and temperatures staying on the cooler side. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... Short Term...IFR conditions are expected today north of a warm front in central NH and ME. Conditions will be MVFR or better across southern NH by early afternoon but showers and thunderstorms are expected to fill in this afternoon with some possibly bringing heavy rainfall, gusty winds, and perhaps some small hail. Long Term...LIFR to IFR fog and/or stratus may stick around 12-15Z Sunday, mainly in the RKD-AUG corridor...otherwise showers will again be likely during the day Sunday into Sunday and could produce IFR to MVFR conditions. For Monday and Tuesday...MVFR ceilings possible during the first part of Monday, but coverage of showers will be lower and mostly during the daytime hours these days. Chances for showers and and flight restrictions then increase toward the middle of next week. && .MARINE... Short Term...Other than fog, no other marine hazards are expected today through tonight. Long Term...Winds become westerly Sunday and then northwesterly Monday into Tuesday as surface low pressure moves east of the waters. Gusts to 20-25 kt may occur from time to time during this period, but in general things look to remain under SCA levels through Wednesday. Winds become east to northeast toward the second half of next week with developing low pressure to the south. It's uncertain what track the low will take, but SCA conditions are possible toward late week. && .HYDROLOGY... Multiple rounds of showers and storms are likely during the afternoon and evening today and could pose another threat of flash flooding. The threat is highest from the foothills and points north on Saturday where WPC has highlighted a Slight Risk of Excessive Rainfall. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Ekster SHORT TERM...Ekster LONG TERM...Combs