####018005614#### FXUS62 KCHS 031608 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 1208 PM EDT Fri May 3 2024 .SYNOPSIS... Atlantic high pressure will remain across the Southeast through much of next week. && .NEAR TERM /THROUGH TONIGHT/... This forecast is in good shape and captures trends well. No major changes were made for the noon update. Today: It will be another warm one across Southeast South Carolina and Southeast Georgia. Morning GOES-E multi-layer water vapor analysis and RAP initialization progs show subtropical ridging remains in place across the Southeast U.S. this morning with the ridge axis centered just offshore the South Carolina and Georgia coast. This ridge will slowly propagate farther out in the Atlantic today as weak impulses move across the Deep South into the western Southeast States. Conditions will favor the genesis of another progressive pure sea breeze with the boundary propagating steadily inland through the local area through the afternoon and evening. 850 hPa theta-e pooling coupled across the far interior with some mixed-layer instability (MLCAPE ~1200 J/kg) per modified RAP soundings at KSBO and KMHP would suggest some convection that develops over the CSRA and east-central Georgia could meander into roughly the Reidsville-Millen corridor late this afternoon and evening. Slight chance pops were maintained in this area to account for this possibility. The fog/stratus will lift into another healthy cumulus field this afternoon which will scour out with the passage of the sea breeze. Some high clouds will pass through aloft as well. The net result will be mostly sunny to partly cloudy skies for most areas. Highs from the upper 80s/near 90 inland to the mid-upper 70s at the beaches look on track. Tonight: A better looking short wave trough moves through the Tennessee Valley and northern Gulf coast. This along with any outflow boundaries from prior convection in and near the area, will allow for isolated or scattered showers and a few t-storms to occur. This is mainly far inland sections. There will be at least some form of fog again after midnight given the southeast and south flow in the boundary layer. However, there is likely too much mid and high level clouds from the nearby convection for dense fog to occur. We currently have mention of the "patchy" fog qualifier, and we will monitor for any dense fog potential. Low temperatures will be several degrees above climo. && .SHORT TERM /SATURDAY THROUGH MONDAY/... A mid-level ridge axis will push off the Southeast coast Saturday with passing waves of shortwave energy across the region through the short term forecast period. High pressure will remain the primary feature at the surface. Convection should be a bit more active over the weekend and into Monday with the presence of deeper moisture as PWATs increase to 1.5+ inches. Coverage of showers/thunderstorms will be highest in the daytime when instability is maximized, but with some upper forcing in play activity could linger into the overnight period. The greatest chances are focused away from the immediate coast owing to a progressive sea breeze. High temperatures will generally peak in the low to mid 80s over the weekend, warming into the mid to upper 80s Monday. Overnight lows are only expected to drop to the mid to upper 60s, with locations right along the beaches and Downtown Charleston near 70 degrees. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... Atlantic high pressure will persist through the middle of next week. Chances for showers/thunderstorms are limited Tuesday as weak forcing/remnant shortwave energy passes offshore the Mid Atlantic coast. Beyond Tuesday, rainfall chances are little to none as a ridge rebuilds overhead. This will allow max temperatures to rise into the low/mid 90s by mid next week, possibly approaching record levels by Wednesday/Thursday. && .AVIATION /16Z FRIDAY THROUGH TUESDAY/... 04/18z TAF Discussion: KCHS/KJZI/KSAV: No major issues are expected. VFR conditions will prevail. There are signals that some shallow fog and/or status could impact KSAV early Saturday morning, but with increasing mid-level clouds expected, conditions do not look overly favorable for fog/stratus development at this time. This will be monitored carefully, however. Any risk for isolated/scattered shower/tstm impacts look to hold to the west for all terminals this afternoon into tonight. Extended Aviation Outlook: Scattered showers and thunderstorms are possible through Monday. && .MARINE... Today: High pressure from the Atlantic will be the main feature, and even with sea breeze influences this afternoon, SE winds will be no more than about 10 kt (10-15 kt with gusts 20 kt in the Charleston Harbor). Seas will be only around 2 feet. Tonight: Weak high pressure continues across the maritime community. Once again the SE winds are no more than about 10 kt with seas just 2 feet. Saturday through Wednesday: Atlantic high pressure will maintain benign conditions over the local waters. Southerly winds in the morning will back out of the southeast during the afternoon and evening hours nearly each day as the sea breeze develops. Winds will average 10-15 kt with seas 2-3 ft. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ ####018006838#### FXUS62 KILM 031609 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 1209 PM EDT Fri May 3 2024 .SYNOPSIS... Dry and warm weather will continue today. Scattered showers and thunderstorms will develop this weekend as a front approaches from the west. High pressure will build overhead by Tuesday with well above normal temperatures likely during the middle and late portions of next week. && .UPDATE... Quiet, warm day currently underway with scattered diurnal cumulus and intermittent high clouds. Temps will reach upper 80s away from the coast this afternoon. && .NEAR TERM /THROUGH TONIGHT/... Still expecting fog development this morning, although confidence in how much and how dense is lacking. Based on dewpoints, boundary layer moisture is a little lower than last night and boundary layer winds are a kt or 2 stronger. There are also cirrus clouds moving in from the northwest. Overall the environment seems less favorable for widespread dense fog, but still expect to see fog development in the pre-dawn hours, especially closer to the coast. Fog that does develop will be quick to dissipate, likely doing so before 8AM. Bermuda High off the coast and weak shortwave ridge aloft will offer a glimpse of summer today. Very dry air aloft remains over the area with precipitable water struggling to hit 1". While these values aren't far off climatological values for early May, the bulk of the moisture is in the lowest 1k ft and above 25k ft. The RH between 700- 500mb drops into the single digits and a weak subsidence inversion is evident in forecast soundings. Once fog and low clouds from this morning dissipate, skies will be mostly sunny with patches of high cloud moving across the area at times. Some flat cue is possible along the afternoon sea breeze, but the region will remain dry. Late tonight a weak shortwave, bursting with moisture, rides up the west side of the shortwave ridge. This feature will spread cloud cover over the forecast area in the evening/overnight and may have weak, scattered convection just west of the area by 12Z Sat. Given the abundance of dry air and the relatively weak nature of this feature think measurable rain before 12Z Sat is unlikely. Temperatures will run well above climo today and tonight. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... Low level thicknesses depict a weak cold front stalled across the NC/SC Piedmont on Saturday. This weak boundary will be the focus for unsettled weather on Saturday and Sunday. As ridging pushes offshore, weak vorticity will advect northward along the western extent of the ridge. This energy, while not robust, should help to develop showers and storms across the area on Saturday in conjunction with the existing surface front. Mid and high level moisture advection across the region will result in thick cloud cover early in the day. Early cloud cover will impact instability, which model soundings continue to keep rather weak. There is some uncertainty in the position of the front and resulting coverage of showers and storms. Low level thicknesses are having a hard time depicting the front, even west of the mountains, therefore there is a question as to how far east the front will move. For now, I have kept PoPs fairly high with multiple potential forcing mechanisms and increasing moisture depth, even in weak instability. Developing sea breeze along the coast and poor low level saturation on the western edge of a ridge should keep coastal areas mostly dry on Saturday. With a potential surface front near the I-95 corridor, PoPs increase rapidly as you head inland. Temperatures generally in the lower 80s due to the increased cloud cover. Shortwaves on the western extent of the ridge will start to push eastward overnight with showers and a few remnant storms approaching the coast. Overnight lows in the mid 60s. A similar day on Sunday, albeit with better saturation and resulting instability, particularly along the coast. High temperatures should still reach the lower 80s. Developing sea breeze will increase shower chances. Less cloud cover overnight with similar morning lows; mid 60s. && .LONG TERM /MONDAY THROUGH THURSDAY/... Maintaining shower and storm chances for Monday. This is especially true along the sea breeze which will be bolstered by increasing southerly flow. An approaching shortwave Monday night into Tuesday will keep showers and storms in the forecast overnight. Weak ridging builds behind the shortwave on Tuesday, but warmer temperatures will produce better instability. A few afternoon storms are possible, typical of a diurnal warm-season pattern. High temperatures in the mid and upper 80s will be the start of a warming trend through Thursday. Southeastern US ridge amplifies on Wednesday and Thursday, bringing high temperatures well above normal. Lower 90s are expected each day. SW winds will pin the sea breeze near the coast, keeping coastal sites above normal as well. && .AVIATION /16Z FRIDAY THROUGH TUESDAY/... Range of VFR to IFR visibility and ceiling across the region this morning. Majority of the area will be VFR by 12Z. A few sites may hold onto IFR beyond 12Z, but by 13Z all sites should be VFR. Light winds continue today with another round of fog and low stratus possible tonight, although looking more like it may be an MVFR event vs IFR, will depend on cloud cover overnight. Extended Outlook...Scattered mainly diurnal convection will bring brief visibility restrictions in heavy rain Saturday through Monday, especially inland affecting KFLO and KLBT. Lightning is also possible. && .MARINE... Through Tonight... Light southerly flow continues today as Bermuda High remains the dominant feature. Weak sea breeze will develop in the afternoon which may bump winds near shore to around 10 kt. Seas 2 ft or less continue to be a mix of a dominant southeast wind wave and a weak easterly swell. Saturday through Tuesday Night... Bermuda high will maintain SE flow this weekend, becoming southerly on Sunday around 10 knots. Winds increase early next week as winds turn S and SW. SW flow by Tuesday will increase to 10-15 knots. Seas 1-2 feet this weekend, increasing to 2-3 early next week. Low impact easterly swell will continue through the period. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...None. SC...None. MARINE...None. && $$ SYNOPSIS...ILM UPDATE...VAO NEAR TERM...III SHORT TERM...21 LONG TERM...21 AVIATION...III MARINE...III/21