####018009144#### FXUS62 KRAH 070541 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 140 AM EDT Tue May 7 2024 .SYNOPSIS... A series of mid to upper-level disturbances will interact with an unseasonably moist airmass as they move across NC through Thursday, while sub-tropical high pressure will otherwise extend across the South Atlantic states. A cold front will move across the region on Friday. && .NEAR TERM /THROUGH TONIGHT/... As of 935 PM Monday... An area of showers and isolated thunderstorms that tracked across much of the northern half of the forecast area is currently falling apart around Rocky Mount, while another broken line of showers and thunderstorms extending from Myrtle Beach to Charlotte and eastern Tennessee is now approaching from the west. An increasing low-level temperature inversion should reduce the amount of instability for thunderstorms, but still think that thunderstorms will be a possibility through the night, although severe potential is minimal. The observed precipitable water value from the 00Z GSO sounding was 1.18 inches, just over the 75th percentile for the date, meaning that the showers/thunderstorms could be efficient rain makers as well. Expect another muggy night with overnight temperatures in the low to mid 60s. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... As of 340 PM Monday... Tuesday and Tuesday night: Aloft, as the s/w moves east and off the mid-Atlantic coast, a brief period of omega blocking will set up as the sub-tropical ridge builds northward through the Southeast US, central Appalachians, OH Valley and western Great Lakes. To the east of the block, a low will progress eastward through Quebec and Newfoundland Tue, then out over the northern Atlantic Tue night. To the west, a large low will sit over the northern Plains as several s/w disturbances rotate around it. The eastern low progressing eastward Tue night will weaken the block, allowing a leading s/w moving through the OH Valley around the western low to push the ridge slightly eastward and suppress it southward. At the surface, a warm front will lift newd through the area early Tue, with a Piedmont trough setting up east of the mtns and strengthening through Tue night as a low develops over the southern Great Lakes. Expect continued advection of warm, moist air into the area, with PWATS starting the day around 1.7 inches, decreasing slightly with daytime mixing, but remaining largely in the 1.4-1.6 inch range. The 12Z NAM and 12Z GFS both have MLCAPE values of about 1000-2000 J/Kg (GFS lower than the NAM) across all of central NC Tue aft/eve, with effective shear around 30 kts. The SPC has included just about all of central NC in a marginal risk for Tue. The big question will be the presence of a forcing mechanism to get storms firing. Look for showers/storms to largely form along the developing lee trough and/or differential heating boundaries if they are present. An isolated strong to severe storm is possible, with the primary threat of damaging wind gusts and possibly hail. As for temperatures, highs should top out in the mid to upper 80s, while lows in the mid 60s to around 70 degrees are expected. Wednesday and Wednesday night: Aloft, the leading s/w will continue eastward through the Northeast US toward the eastern low, while the western low finally begins to migrate slowly eastward. A second s/w will swing through the Plains and the MS Valley Wed/Wed night. At the surface, the surface low will move slowly eastward through the Northeast US Wed and offshore Wed night. Another low will develop along the front over the southern Plains early Wed, lifting newd into the upper MS Valley through Wed eve before drifting eastward into the OH Valley Wed night. The trough over central NC will weaken and lift northward out of the area as the low move east and offshore Wed night. The frontal zone between the two lows should generally remain north of the area through Wed night, with continued swly flow over the area. Expect continued advection of warm, moist air into the area, with PWATS largely in the 1.4-1.7 inch range. The 12Z NAM and 12Z GFS both have MLCAPE values of about 1500-2500 J/Kg across all of central NC Tue aft/eve, maximized over the eastern Piedmont and Coastal Plain, with effective shear again around 30 kts. The SPC has included all of central NC in a marginal risk for Wed. The forcing mechanism will likely be the lee trough as it moves eastward through the area. An isolated strong to severe storm will once again be possible. As for temperatures, highs should be about a category higher than Tue, topping out in the upper 80s to low 90s. Lows should be in the upper 60s to low 70s. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 202 PM Monday... Thursday/Friday: There is good consensus amongst models supporting an upper trough moving east from the Great Lakes/Midwest across the eastern seaboard Thursday into Friday. This feature will promote increasingly swly flow and deep moisture advection into the southeast with PWAT rising to 150 to 200 % of normal. At the sfc, a weak low initially over IN/OH Thursday morning, will deepen some as it progresses east into the Mid-Atlantic through Thursday night. An associated cold front will approach the Southern Appalachians Thursday night, before passing through central NC on Friday. Given high humidity and temperatures reaching the upper 80s/lower 90s on Thursday, moderate instability is expected to develop across our area ahead of the approaching front. Aloft, increasing mid-level height falls and associated perturbations will help to generate widespread pre-frontal showers and storms which should grow in coverage/intensity Thursday afternoon. Additionally, severe parameters including bulk-layer shear (30 to 40 kts), 0-1 km shear (15 to 25 kts), mid-level lapse rates (>7 C/km), and even helicity (200 to 300 units) will all be elevated. As such, there still appears to be a good chance for severe weather (potentially widespread) Thursday and Thursday night. Damaging wind gusts, large hail, and isolated tornadoes would all be possible. The SPC has outlined our entire area with a 15% chance for severe storms four days in advance, increasing confidence that Thursday could be a complex severe weather day. Depending on the eventual evolution of the cold front, some guidance does show instability forming ahead of the front as it moves through our area on Friday. As such, maintained thunder in the forecast for those south of Raleigh on Friday. Additionally, the upper trough will swing through on Friday which could generate additional showers/storms into the evening period. Highs on Friday may be a bit tricky given uncertainty wrt to the advancing cold front. For now, highlighting mid to upper 70s north to lower to mid 80s south. Saturday through Monday: The cold front will have pushed east of the area by Saturday morning, behind which considerably drier and cooler air will filter across central NC. An additional weak perturbation aloft will pass over later Saturday which may generate a few showers across our northern areas, but overall the area should stay mostly dry. Similar conditions are expected Sunday through Monday, with dry and cooler temps in the upper 70s. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... As of 140 AM Tuesday... Several small clusters of showers and thunderstorms extend from the NC mtns to the western and central Piedmont. The general model consensus is for the convection to drift east into central and eastern NC overnight and into the early/mid morning hours. While associated MVFR to IFR restrictions will be possible at just about any of the TAF sites, confidence is the exact timing and location is low. Additionally, continued unseasonably moist/humid air will also favor the redevelopment of areas of IFR-MVFR stratus late tonight-Tue morning. Associated ceilings should then lift and scatter and yield to a gusty swly surface wind by ~14-16Z Tue. Some additional convection is possible this afternoon and evening, but should be more isolated/widely scattered in nature and potentially limited INVOF KINT and KGSO. Outlook: There will be a chance of mainly afternoon-evening showers and storms throughout cntl NC through Thu, then ahead of a passing cold front, mainly at FAY, on Fri. && .CLIMATE... Record High Minimum Temperatures: May 8: KGSO: 66/1938 KRDU: 68/1930 KFAY: 70/2003 May 9: KGSO: 68/2002 KRDU: 70/1936 KFAY: 71/2009 && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...MWS NEAR TERM...Green SHORT TERM...KC LONG TERM...Luchetti AVIATION...CBL/MWS CLIMATE...RAH ####018007221#### FXUS61 KPHI 070541 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 141 AM EDT Tue May 7 2024 .SYNOPSIS... A cold front will work its way through the region tonight before becoming nearly stationary south of Delmarva. Low pressure tracks along the front late tonight through Tuesday morning. Another area of low pressure passes through the region on Wednesday followed by a stronger low on Thursday. A cold front passes through on Friday, then several disturbances are possible this weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Forecast is on track this morning. No real changes made. A cold front is slowly sliding through. Some patchy fog has developed out ahead of it. Some fog could be locally dense, though not expecting it to be as widespread as yesterday morning. Otherwise, a cold front will slowly slide south across the area tonight and with a weak wave of low pressure track along it the best best forcing for ascent and RH is across the southern areas (highest PoPs will be here for the overnight). Overnight lows will be in the lower 50s to lower 60s. Weak low pressure will be just east of Delaware Tuesday morning. This will keep some showers in the forecast through at least the daybreak hours. Some showers and possibly a few thunderstorms are expected to decrease by lunchtime as low pressure moves offshore. PoPs won't be zero for the remainder of the day for all areas, but the most showers should be in the morning. Afternoon highs will be in the 70s for most places. Another area of low pressure will track from the Great Lakes into the Ohio Valley. A warm front extending out from that system will lift towards southwest portions of the area later in the day. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... Another area of low pressure will track from the Great Lakes into the Ohio Valley. A warm front extending out from that system will lift towards southwest portions of the forecast area Tuesday night. Scattered showers and thunderstorms will develop in the evening and then become likely for most of the region after midnight Tuesday night and into Wednesday morning as that warm front lifts through the region. Precipitation tapers off by midday Wednesday, and then a warm and humid airmass will be in place. Highs top off in the mid to upper 80s, except for the low 80s in the southern Poconos and northern New Jersey, and in the 70s along the coasts. Surface dew points will be in the upper 50s to low 60s in the afternoon. Low pressure approaches from the west Wednesday night, and scattered showers and isolated thunderstorms will move into portions of southeast Pennsylvania and Delmarva late Wednesday night. As the main surface low tracks towards western New York and Pennsylvania, a secondary low will develop out ahead of this primary low, resulting in more widespread showers with scattered thunderstorms moving into the region Thursday afternoon and evening as a warm front lifts north of the region. Global guidance has indicated some instability as the warm front lifts north, suggesting the potential for some strong to severe thunderstorms south of the warm front during the afternoon, but exactly how far north the warm front progresses will greatly determine the coverage of any strong to severe storms in our forecast area. At the moment, it remains too uncertain to mention anything more specific at this time. Even the afternoon high temperatures will be highly variant on where the warm front ends up, with low to mid 60s north of the front and mid to upper 70s south. Showers and storms will taper off Thursday night as the storm system shifts offshore. && .LONG TERM /FRIDAY THROUGH MONDAY/... A cold front will push through the region Friday afternoon and evening. Yet another round of scattered showers and isolated thunderstorms will affect the area during that time. Behind the cold front, surface high pressure builds east. Several weak disturbances may touch off some afternoon showers on Saturday and Sunday. Highs will then be in the 60s for southeast Pennsylvania and New Jersey and in the low to mid 70s in Delmarva on Friday. Below normal highs expected for Saturday and Sunday, generally in the low to mid 60s. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Rest of Tonight...MVFR/IFR conditions at the Lehigh Valley and I-95 terminals. Should be more of VSBY restrictions at KABE/KRDG as a cold front slowly slides through, with stratus and patchy fog developing at the I-95 terminals. Conditions drop to LIFR at KACY/KMIV where the fog will be more widespread and some marine stratus moves onshore. Winds generally light and variable, 3 kt or less. Moderate confidence overall. Tuesday...Conditions quickly lift to VFR with fog mixing out and any lingering low ceilings lifting. All terminals outside of KMIV/KACY should be back to VFR by the late morning (12z-14z or so). Lower visibilities and ceilings persist at KMIV/KACY through midday or so, though expecting VFR for the afternoon. Very light flow out of the north/northeast in the morning will shift to a more southwesterly flow in the afternoon. Wind speeds 5 kt or less. Moderate confidence overall. Tuesday Night...MVFR/IFR conditions redeveloping with low clouds and patchy fog. Southerly winds 5 kt or less. Low confidence in timing and extent of restrictions. Outlook... Wednesday through Saturday...Sub-VFR conditions at night in fog and stratus, while VFR conditions overall during the day. Chances for SHRA/TSRA throughout the period with sub-VFR conditions. More widespread SHRA with scattered TSRA Thursday afternoon and evening. && .MARINE... Tonight through Tuesday...The conditions are expected to remain below Small Craft Advisory criteria. Some fog, possibly dense, improving during Tuesday. Outlook... Tuesday night through Saturday...Overall, sub-SCA conditions through the period. Scattered showers and thunderstorms will result in locally higher wind gusts and seas, with biggest impacts coming on Thursday afternoon and evening. && .TIDES/COASTAL FLOODING... Tidal ranges increasing this week as the new moon arrives Tuesday evening. Limited onshore flow means that there won't be much in the way of serious flooding concerns, but still minor tidal flooding is possible beginning tomorrow evening and perhaps Wed/Thu evening as well. A Coastal Flood Advisory may be issued overnight if trends remain. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...None. && $$ SYNOPSIS...MJL NEAR TERM...Gorse/Hoeflich/Kruzdlo SHORT TERM...MJL/MPS LONG TERM...MJL/MPS AVIATION...Gorse/Hoeflich/Kruzdlo/MJL MARINE...Gorse/Hoeflich/Kruzdlo/MJL TIDES/COASTAL FLOODING...NWS PHI ####018006188#### FXUS63 KDVN 070542 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 1242 AM CDT Tue May 7 2024 .KEY MESSAGES... - An organized line of storms is expected to move through the outlook area late tonight between 1 AM to 7 AM (west to east through the area). This system will pose a risk for damaging winds and isolated tornadoes. - For Tonight: The Storm Prediction Center has a Slight Risk for severe storms to the south and west of the Quad Cities with a Marginal Risk covering the rest of the area. - Isolated storms may redevelop Tuesday afternoon and evening, a few of which could be strong. - Scattered showers and storms remain possible on Wednesday before temperatures cool off late in the week. There is a Slight Risk for severe storms across the south on Wednesday with a Marginal Risk to the north. && .SHORT TERM /THROUGH TONIGHT/... Issued at 245 PM CDT Mon May 6 2024 Tonight into Tuesday Morning The forecast remains on track with a squall line expected to track through eastern Iowa, northeast Missouri, and northwest Illinois late tonight into early Tuesday AM. This complex of storms will cover a large spatial area so rain chances are high at 90-100% across the outlook area. The convection will initially develop across Kansas this afternoon/evening before growing upscale and tracking to the ENE into Missouri, Iowa, and Illinois tonight. Confidence has increased on the line of storms still packing a punch as it reaches the western to even central counties of the outlook area. While forecast MLCAPE is on the low side (250-1000 J/kg), low-level shear is high with 25+ kts in the lowest 1 km and 30-35 kts for 0-3 km. The strong environmental shear will help to balance the gust front on the leading edge of the convection, creating more concentrated lift and enhancing the potential for stronger storms. As for timing, the QLCS should reach the western counties between roughly 1 to 2 AM, central areas (near the Quad Cities) between 2 - 4 AM, and far eastern counties between 5 - 7 AM. SPC has expanded the Slight Risk for severe storms to the NE, now encompassing areas to the south and west of the Quad Cities, with a Marginal Risk for the rest of the forecast area. The primary threats are scattered damaging wind gusts around 60 mph, with a low potential for a few higher gusts over the far southwest counties. There is also an isolated QLCS tornado risk (5% within 25 miles of a point), highest in the aforementioned Slight Risk area. PWAT values near 1.25" are forecast with strong WAA forcing. Thus, rainfall on the order of 0.50" to 1" is likely for much of the area. Scattered showers and isolated storms could develop mid to late morning on Tuesday behind the departing QLCS, but these are not anticipated to pose a severe risk at this time. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Issued at 245 PM CDT Mon May 6 2024 The Upper Midwest is forecast to remain under general troughing or cyclonic flow aloft through the period. Flow aloft will be southwesterly a 500 MB through Wed/Thurs it becomes more northwesterly as the current storm system departs. This will allow a series of troughs and ridges in the northwest to move across the area into early next week. The trend for chances of showers and storms continues about every 24 to 36 hours. There will be periods of quiet weather in between. Timing on rain chances will likely vary over the next few days. Temperatures are trending below normal Friday through Sunday. The long term period begins Tuesday/Tuesday night with a closed 500 MB low over the northern PLains. At the surface, a cold front wiil move eastward across Iowa and Illinois through 00 UTC on Wednesday. A decaying MCS will likely be moving across our northwest Illinois counties at 12 UTC on Tuesday and exiting the area. Models show skies clearing quickly and do show some instability across the area ahead of or right behind the front which will lead to the risk of showers and storms during the afternoon. There could be some isolated severe storms with CAPE of 500 to 1000 J/KG and about 20 knots of 0 to 6 km shear. The main threats will be hail and damaging wind gusts. The amount of instability will depend on how quickly skies clear. On Wednesday, the closed 500 mb low will transition to an open wave with a positive tilt as it moves across the area. At the surface, a low is forecast to lift east northeastward from northwest Missouri into northeast Illinois or northern Indiana by 12 UTC Wednesday. This would bring the surface low and warm and cold fronts across the area during peak heating on Wednesday. SPC has a slight or level 2 out of 5 risk of severe storms on Wednesday for the area along and south of a Keosauqua to Iowa to Princeton Illinois with a Marginal or level 1 out of 5 risk for severe storms north of that line. Current model guidance shows the potentail for a high shear low CAPE event but it will depend on the track of the surface low and how much instability moves this far north. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1240 AM CDT Tue May 7 2024 A large complex of showers and thunderstorms remains on track to impact the terminals late tonight, with timing favored between around 08Z to 12Z. This will lead to periods of MVFR/IFR due to lower ceilings and reduced visibilities in heavier rain. The strongest cells could produce wind gusts near 50 kts from the WSW. There remains a low chance (20-30%) of a shower or storm developing Tuesday afternoon ahead of a front across eastern Iowa. However, latest CAMs are not in agreement on location of development or timing so have left a mention out of the TAF at this time. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Uttech LONG TERM...Cousins AVIATION...Haase ####018007232#### FXUS61 KCLE 070543 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 143 AM EDT Tue May 7 2024 .SYNOPSIS... High pressure drifts northeast of the area overnight as low pressure occludes over the Dakotas. A warm front moves into northern Ohio on Tuesday. A cold front will cross the region Tuesday night into Wednesday with multiple disturbances crossing the region Thursday through the weekend. && .NEAR TERM /THROUGH TODAY/... Other than a passing sprinkle across Stark County through 1030PM it looks to be dry through the overnight. Cloud cover will persist inland from the lake with some patchy fog possible where it rained today, mainly south of US 30. Previous Discussion... The near term forecast will begin with a stationary front to the south/southeast of the CWA and weak surface high pressure over the northern half of the area. Showers over the far southern border of the CWA may continue through the rest of this afternoon, but the high will suppress the vast majority of the showers to the south of the CWA. Showers should dissipate by tonight and a brief period of dry weather is expected through Tuesday morning. On Tuesday, an upper low will track northeast across the northern Plains with a shortwave lifting northeast across the region as surface low pressure occludes over the Dakotas. The enhanced lift will allow the aforementioned stationary front to push north as a warm front during the day Tuesday and the front should lift into the area by late Tuesday afternoon/Tuesday evening as a shortwave trough advances east towards the CWA. Showers and thunderstorms will develop ahead of this feature; latest CAMs suggest storms will develop at some point during the late afternoon/early evening and progress east across the area into Tuesday night. Within the warm sector, there should be a nose of enhanced instability and moisture with MLCAPE values as high as 1500 J/kg, primarily in the southwestern part of the CWA which will have the longest residence time in the warm sector. In addition to unstable environment, the robust wind field aloft will result in high wind shear values, including effective bulk shear values of 50 to 60 knots. If this pans out, all severe weather hazards will be on the table including damaging wind gusts, large hail, and tornadoes (best chance in the SPC Day 2 Enhanced Risk area). It will be quite humid with precipitable water values of about 1.5 inches and can't rule out heavy rainfall rates and potential for localized flooding. There's still a bit to iron out with the mesoscale environment and the resulting severe weather risk, primarily across the eastern half of the area. While there's quite a bit of confidence that severe weather will occur somewhere in the warm sector/Enhanced Risk area, there is still uncertainty in how quickly and how far north/east the warm front lifts before the better upper forcing begins to move east into the local area. There's also potential for an initial round of convection with the warm front Tuesday afternoon with another round arriving with the best forcing Tuesday evening. CAMs aren't quite on the same page with how well this activity holds together before dissipating. Any weakened convection could serve as a boundary for redevelopment/intensification when the main activity moves in Tuesday evening. Storms should begin to lose steam as they move into a slightly more stable environment in the eastern parts of the area Tuesday evening into Tuesday night, as outlined in the Slight and Marginal risks for severe weather across the remainder of the area. Convection should largely exit to the east towards the end of the period, but can't rule out scattered showers through the early morning hours Wednesday. Temperatures will be in the upper 40s into the 50s tonight before warming into the mid to upper 70s Wednesday. Expect overnight lows in the upper 50s to lower 60s Tuesday night. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... High pressure briefly resides over the area, with mostly sunny skies and highs in 70s to areawide (although some spots hitting 80 especially in the central to northwest Ohio region). By Wednesday night, low pressure out of the northern Great Plains moves east to IN/OH region by Thursday morning. Precipitation chances increase Wednesday night and Thursday morning as the warm front associated with low moves into the area. Instability will be low but high shear could result in a very low severe weather threat for our southern counties Wednesday night. Additional convection could develop Thursday afternoon with a low severe weather threat as well. Precipitation chances continue into Thursday night, mainly with isolated to scattered rain showers. && .LONG TERM /FRIDAY THROUGH MONDAY/... On the backside of the departing low, isolated to scattered rain showers persist during the day Friday as the upper-level trough swings through. Cooler temperatures ensue through the weekend following the departure of the low with highs down into the 60s. A weak low and upper-level trough cross the Great Lakes region on Saturday. Low precipitation chances continue through the rest of the weekend, though low confidence in these precipitation chances. && .AVIATION /06Z Tuesday THROUGH Saturday/... Some MVFR ceiling 2-3kft for the rest of the overnight will lift to VFR generally after 12Z. Winds out of the south into the afternoon increasing to 10-12kts, gusting 15-20kts. Expecting thunderstorm activity with an organized system moving through the region after 20Z today. Given the storm mode and it being driven by a low pressure system, used TSRA in TEMPOs for a few hours in the TAF, and timed it as best as possible with the rapid updating convective models. Expect the timing to fluctuate slightly, as well as the gusts in the TEMPO groups. Outlook...Non-VFR likely with periodic showers and thunderstorms through Saturday. && .MARINE... A relatively low impact forecast from a wind/waves perspective as there is a low chance of headlines. High pressure over the Great Lakes departed to the east as a warm front lifts north towards the lake tonight and Tuesday moving north across the lake Tuesday evening. Easterly flow will probably result in some choppiness (2-4 ft waves) in the western basin before the front crosses. High pressure briefly builds in Wednesday before another low moves eastward just south of Lake Erie Wednesday night and Thursday. Behind this low, northwest flow of around 15 knots could result in some 4 ft waves, with a small chance for the need of a small craft advisory Thursday night and Friday. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. NY...None. MARINE...None. && $$ SYNOPSIS...Maines/MM NEAR TERM...Maines/MM SHORT TERM...Saunders LONG TERM...Saunders AVIATION...26 MARINE...Saunders