Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/29/24


Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
113 PM AKDT Fri Jun 28 2024 .SYNOPSIS... Warm weather will continue over much of the Interior through the weekend. Areas of dense smoke from fires burning is reducing visibilities over the Middle Tanana Valley. Smoke will be in and out through the weekend. Scattered thunderstorms are expected north and east of Fairbanks. Isolated storms will persist into the weekend. && .DISCUSSION... Analysis and Model Discussion... A strong ridge of high pressure aloft remains over the eastern half of Alaska, & the center has shifted northward to be over the eastern North Slope. The ridge has weakened slightly today with temperatures remaining warm to downright hot in some areas. A strong vertically stacked low will remain in the central Bering Sea. A number of shortwaves are moving northward between the low and the ridge this afternoon bringing scattered thunderstorms from the western North Slope SE to Fort Yukon this afternoon and evening. Convection on Saturday looks to just be isolated over the eastern Interior but widely scattered right along the Alcan Border and in the SE Brooks Range. Models in good agreement through the short term. The HRRR smoke model showing smoke persisting over the Interior. Interior...Warm weather will continue over much of the Interior through the weekend. Highs in the mid 80s and a few upper 80s over the Yukon Flats. Areas of dense smoke from fires burning is reducing visibilities over the Middle Tanana Valley. Smoke will be in and out through the weekend. Dense smoke advisories have been extended into Saturday. Smoke may thin and visibility may improve in the afternoon around Fairbanks but become dense again early morning on Saturday. High pressure builds back in for the weekend with rising temps back into the 80s, and much lower thunderstorm activity, with that ridge aloft suppressing thunderstorm potential. Isolated thunderstorm threat returns over the southern Interior on Sunday. West Coast and Western Interior... Showers will continue to rotate around the large Bering low along the West Coast. Isolated overnight thunderstorms will continue into this morning today over the W Interior to NW Arctic, with more afternoon thunderstorms mainly over the Upper Kobuk Valley north to the Brooks Range, with just some isolated spotty thunder farther south toward the Alaska Range to the Kuskokwim Mtns. North Slope and Brooks Range... Another warm day today with more very active thunderstorm activity, as a thermal low will remain parked over the Brooks Range. Scattered to numerous thunderstorms will be possible from the W Brooks Range east to Chandalar, with some storms being very strong and capable of producing very heavy downpours, frequent cloud to ground lightning, and hail up to half an inch. Northwest winds will cool temps back down closer to normal values albeit still warmer than average. On Saturday, the thunderstorm threat moves Anatuvak Pass to the AlCan border. For now, widely scattered wet thunderstorms are expected. On Sunday, isolated storms return over the southern Interior. Extended Forecast Days 4-7... By Monday, a narrow Mainland ridge aloft will still be in place, but there will be a series of lows which will move overtop that ridge, gradually weakening it and bringing wetter onshore flow to the NW Arctic and down the West Coast Tuesday and Wednesday, with those fronts moving inland by the latter half of the week. This should allow for some relief from hot temps and may even bring rain into the Interior. Coastal Hazard Potential Days 3 and 4...None. && .FIRE WEATHER... Red Flag Warnings are in effect for lightning for the Yukon Flats and SE Brooks Range where we expect scattered wet thunderstorms, though an isolated dry storm is possible. Temperatures will cool only slightly and RHs will moderate. On Saturday, the thunderstorm threat moves Anatuvak Pass to the AlCan border. For now, widely scattered wet thunderstorms are expected. On Sunday, isolated storms return over the southern Interior. && .HYDROLOGY... Heavy rain showers and thunderstorms over the Brooks Range today may feed into faster moving streams and cause rapid rises, which will remain high into this weekend. Glacial fed rivers including the Tanana are beginning to rise as warming temperatures lead to increased high elevation snowmelt. && .AFG WATCHES/WARNINGS/ADVISORIES... AK...Red Flag Warning for AKZ911-933. PK...Small Craft Advisory for PKZ801-802-850. && $$ JK
AREA FORECAST DISCUSSION
National Weather Service Albany NY
944 PM EDT Fri Jun 28 2024 .SYNOPSIS... High pressure will depart off the coast of New England tonight, allowing for increasing clouds, with temperatures not as cool as last night. It will be mostly cloudy, breezy and more humid on Saturday with an increasing chance for showers and thunderstorms through the day. Showers and thunderstorms, some with heavy downpours, is expected on Saturday night for much of the area. A lingering shower or thunderstorm is expected on Sunday with warmer temperatures, before drier weather returns for the start of the upcoming week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... .UPDATE...Main change with this update was to expand likely PoPs eastward to include the Capital District around or shortly after sunrise, due to a surge of moisture along with warm advection. The past few runs of the HRRR have consistently shown a batch of showers moving E-NE from central overnight. Most of the showers should be light into early Sat morning, although a few embedded brief heavier showers may occur in some spots. .PREV DISCUSSION[0751]...Tranquil/dry conditions in place across the region early this evening. Dewpoints remain low in the 40s to mid 50s range, resulting in lower than usual humidity for late June. Satellite imagery shows high/mid level clouds increasing from the west. Made some minor adjustments based on latest obs, with no significant changes with this update. As high pressure starts to depart off to the east this evening, some mid and high level clouds (currently seen over western New York) will spread towards the area for this evening into tonight. In addition, a southerly flow will start to increase across the region for the overnight hours. With the increasing clouds and the breeze, temps won`t be as cool as last night, with lows in the 50s. A warm front over the Ohio Valley and mid Atlantic will start moving northeast for late tonight. With increasing moisture within the southwest flow aloft, an area of light rain will be developing across western and central New York overnight. This may spread towards the Adirondacks and Mohawk Valley for late in the overnight and towards daybreak on Saturday. Amounts through sunrise on Saturday look fairly light and limited to northwestern parts of the area. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... On Saturday, the warm front will continue lifting northeast towards the area. Our region will be in broad south to southwest flow aloft ahead of an approaching upper level disturbance over the Great Lakes. The low level jet will be around 50 kts, allowing for plenty of moisture advection and warm air advection from the southwest. Our area will remain on the northern side of the surface boundary through much of the day on Saturday, so surface-based instability looks fairly limited. Based on the 12z SPC HREF, our area may finally start to see some minor amounts on instability by Sat night (mainly under 1000 J/kg) and it`s unclear still if this will be surface-based or not, as the timing within the diurnal cycle may allow for this to elevated. 0-6 km bulk shear will be increasing thanks to the strong flow aloft, with values in the 40 kt range. Plenty of moisture will be increasing across the region with PWATs rapidly rising to around 2.00 inches by Sat evening. However, the moist profile will keep lapse rates rather poor across the region. Some light rain or showers will be ongoing for far northern areas early on Sat morning. However, as these continue to track eastward towards New England, they will be weakening and dissipating as they run into a drier air mass. However, the approaching warm front will allow for another batch of showers to spread towards the area from the west for Wed afternoon or early evening. Most of this activity is expected to impact western and northern areas. There may some embedded heavier bursts, but the bulk of this looks fairly light. Otherwise, skies will be mostly cloudy through Saturday with temps only in the 70s. As our area gets into the warm sector and we finally get some instability in place, there will be the potential for some heavier downpours on Sat night, as the pre-frontal trough allows for additional areas of convection to develop. CAMs had different ideas on the exact placement and coverage of this precip, so this is somewhat uncertain. However, there could be some heavier downpours on Sat night for parts of the region, and ponding in urban/poor drainage areas will be possible, especially if repeated rounds occur. Can`t rule out a rogue strong wind gust due to the decent shear and high moisture in place, but limited instability will keep this threat fairly isolated. Temps will remain mild and muggy in the mid 60s to low 70s with much stickier dewpoints than recent nights. On Sunday, the surface cold front will be passing through the region from west to east. It may cross western areas earlier in the day, but will cross southeastern areas in the afternoon. Enough heating should occur ahead of the front to allow temps to reach into the 80s, especially southeastern areas. While the morning should be fairly quiet, some convection may develop ahead of the boundary for the afternoon hours. Exact coverage is still in question, but enough instability and shear could be in place for some stronger storms before activity heads towards the coast for late in the day. SPC has a marginal to slight risk across the region, although the greatest threat may be just southeast of the area, although it will depend on the exact timing of the front. Behind the boundary, cooler and less humid air will return to the region for Sunday night with clearing skies. && .LONG TERM /MONDAY THROUGH FRIDAY/... Mainly quiet weather is expected through the long term period. High pressure will be passing over the area for Monday into Tuesday. This will allow for dry conditions with fairly clear skies. Dewpoints will remain comfortable in the 50s. After highs in the 70s on Monday, they will rise into the 80s on Tuesday. Mon night will likely be another clear and cool night with lows in the 40s and 50s once again. By the middle of the week, temps and humidity levels will be rising as our area gets back into the return flow on the backside of the departing high pressure area. Highs will be well into the 80s for Wed through Fri, with dewpoints into the 60s. At this point, heat index values look just below advisory criteria, but will need to watch closely in case temps/dewpoints look higher. It should continue to be dry most of the time, although some spotty showers (or perhaps an isolated t-storm) will be possible during the late week, mainly in the diurnally favored afternoon or evening hours. At this point, forcing and dynamics look weak, so the potential for strong storms looks low at this time. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... Through 00z Sunday...VFR conditions are expected to prevail through the night with increasing high then mid level clouds ahead of an approaching warm front. The warm front will bring showers Saturday morning from the KGFL-KALB corridor starting around 09z-11z. These showers will likely stay north of KPOU, but could get near KPSF so will mention VCSH there. Cigs will gradually lower to MVFR levels Saturday morning due to increasing moisture, but could remain VFR at KPOU for several more hours. Periods of showers will likely continue Saturday afternoon from KGFL-KALB as the warm front pushes north/east. There will be a better chance of showers developing at KPSF by Saturday evening, while the majority should still remain north of KPOU. Conditions are likely to be MVFR at all sites prior to 00z Sunday. Winds will be variable around 5 kt or less through the evening, becoming south-southeast around 5-10 after 06z Saturday. Winds on Saturday will be southerly and steadily increase to around 10-15 kt with gusts of 20-25 kt. Outlook... Saturday Night: High Operational Impact. Breezy. Definite SHRA...TSRA. Sunday: Moderate Operational Impact. Breezy. Chance of SHRA...TSRA. Sunday Night: No Operational Impact. NO SIG WX. Monday: No Operational Impact. NO SIG WX. Monday Night: No Operational Impact. NO SIG WX. Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: No Operational Impact. NO SIG WX. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...Frugis NEAR TERM...Frugis/JPV SHORT TERM...Frugis LONG TERM...Frugis AVIATION...JPV
Area Forecast Discussion
National Weather Service La Crosse WI
649 PM CDT Fri Jun 28 2024 .KEY MESSAGES... - A few more showers/storms tonight. A conditional severe risk this evening, moreso for northeast IA. - Aside from spotty light showers, mostly north Sat afternoon, dry and cool conditions expected Sat into Mon. - More showers and storms Monday night into Tuesday. Heavy rain threat. Conditional severe threat Tuesday into Tuesday evening. && .DISCUSSION... Issued at 245 PM CDT Fri Jun 28 2024 * REST OF THE AFTERNOON/TONIGHT: storm chances - conditional severe threat for northeast IA into the evening Extensive cloud cover has persisted into the early afternoon while the morning rains have moved east/south of the local forecast area. The clouds are inhibiting daytime heating, thusly working against sfc destabilization. A thin line of showers/storms has developed in southern MN/IA on the western flanks of the cloud, on the edge of the MLCAPE plume (100-250 J/kg), a small region of differential heating plus what looks like a remnant MCV (per watervapor imagery). These should continue to push east, but will quickly run out of instability a loft. CAMS models continue to provide a wealth of potential outcomes, almost by the hour, lowering confidence in how the evening will unfold. A few things to focus on though. The MCV should continue to provide enough lift for shower/storm production into the evening as it shifts across the area. Again, instability is limited. With RAP/HRRR soundings holding the cap in place (thanks clouds), effective wind shear will be mostly above 1 KM...with fairly short hodographs. Not sure there is much there to support whatever CAPE can be realized. To the west a cold front is advancing east and right around the boundary RAP/HRRR soundings show some uptick in instability profiles, although still suggesting the CAP could hold (non sfc based). Showers/storms should develop along the front, but likely more favored along the southern flank - in Iowa. These would have a bit more promise for strong/severe upscaling with a deeper instability pool, moisture axis to work with. In additional to all this is the potential interplay of the low level jet. Currently the RAP has a fairly steady stream of 850 mb moisture transport from IA into central WI, with a gradual shift eastward ahead of the front through the evening. Not much convergence. However, the HRRR refocuses the jet into southwest WI by 00-02z, resulting in blossoming of convection. Instability still limited at best and doesn`t have a lot of strong-severe support. Overall, a few more showers and storms this evening. A conditional severe risk continues, but more focused into IA and associated with the cold front. Certainly a scenario to monitor. * SAT NIGHT/MON: cooler, drier Aside from a shortwave trough/cold air advectively driven afternoon shower chances, mostly north of I-94 Sat, the local area is looking at a few dry days for a change. High pressure at the sfc slides across the region Sunday while a shortwave upper level ridge edges over the upper mississippi river Mon morning. EPS/GEFS paint highs for most of the area in the lower 70s - a consistent signal with only a few degree spread in the 25/75 percentiles. Meanwhile, the LREF suggests little chance (0 to 10%) to warm into the upper 70s Sun/Mon. So, expect cooler, but perhaps welcomed conditions to kick off the new week. * MON NIGHT/TUE: more rain, storm chances - heavy rain threat Long range guidance remains in good agreement with driving ripples of upper level energy eastward from the PAC NW, with the progressive zonalish flow tracking them over the upper mississippi river valley Mon night/Tue. Broad low level thermodynamics will precede the upper level forcing while an attendant north-south running sfc cold front currently set to track across the region Tue afternoon/eve. Potential 300 mb jet streak Tue could enhance lift along the front via its right entrance region. Broad area of rain should break out/shift in from the west late Monday afternoon, night in response to the thermodynamics. Not much for instability at this time but couldn`t rule out at least a few storms thanks to the nose of a 50 kt 850 mb jet. Favoring mostly rain though. Moving into Tue, more bits of shortwave energy/MCV will come into play along with the cold front. Questions on how much cloud cover/rain early in the day will be lingering with impacts on atmospheric recovery/destabilization. SBCAPE in the LREF currently progged from 1-1.5+ J/kg in the afternoon with favorable deep layer shear to support strong/severe storm development. VERY conditional with a lot of unknowns - that may not become more clear until the actual day. While the severe threat is murky at this time, the potential for heavy rain is a bit more clear. PWs in the LREF pushing near 2+" while ECMWF and NAEFS PW anomalies creep up to 2.5. EFIs even edging above 0.70. Add in the persistent low level jet and moisture transport with warm cloud depths from 4 to 4.5 kft and the setup is very favorable for heavy rain. Obviously how the system unfolds, where the variety of forcers set up/move, and potential training are all important factors that are much less clear. Still, as it sits, the setup is there and will have to be watched closely - especially given the ongoing flooding and/or high running river systems. More water is not needed. * THU/FRI RAIN CHANCES The GEFS and EPS continue to trend toward rain chances for the end of the new work as the both shift an upper level shortwave from the PAC NW eastward across the region. However, not all their members agree on timing/placement for the resulting QPF - a few even suggest it could be dry, shifting the pcpn away from the area. Less agreement compared to some previous model runs. Given the currently progged upper level dynamics, still looks like a good shot for rain, albeit with potential to shift in location/timing. On the plus side. the heavy rain parameters via the GFS are shifting more south and east of the local area. A trend the area would welcome given the recent heavy rain and expectations as we move into the early part of the new week. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 648 PM CDT Fri Jun 28 2024 A mesoscale convective complex will move east of the forecast area by 29.03z. The showers and storms associated with this system will move east of KLSE within the next hour. Another line of showers and storms is being watched to our northeast, but current thinking is that line will stay north of the TAF sites. While the precipitation will be moving out of the area, ceilings will likely remain IFR and MVFR through the evening. With clearing skies and winds less than 10 knots during the late evening and early overnight, we will have to look out for the potential of fog development. For the time being, went with BCFG at KRST and 1 1/2sm br at KLSE between 29.09z and 29.13z. Skies will clear briefly on Saturday morning and then a 2500 to 500 deck of clouds will move into the area during the evening. && .HYDROLOGY... Issued at 425 AM CDT Fri Jun 28 2024 With three more periods of precipitation ahead - today into tonight, Monday/Tuesday, and Thursday/Friday - area rivers will remain swollen. Both of those first two rounds in particular show the potential for many areas to pick up around another 1-2". Given this and the large amount of water flowing downstream, the Mississippi River is expected remain in minor to moderate flood through at least the next five days. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...Ferguson AVIATION...Boyne/EMS HYDROLOGY...Ferguson
Area Forecast Discussion
National Weather Service Cleveland OH
1017 PM EDT Fri Jun 28 2024 .SYNOPSIS... Low pressure will track from the northern Plains into the northern Great Lakes tonight, lifting a warm front through the region by Saturday morning. A trailing cold front will sweep across the region Saturday night into Sunday morning as the low tracks into Quebec. High pressure will build into the region Sunday and Monday before moving east Tuesday. && .NEAR TERM /THROUGH SATURDAY NIGHT/... 10:15 PM Update... The bulk of the forecast remains on track but did tweak PoPs and QPF to account for latest hi-res guidance. Given better confidence on axis of highest QPF with heavy rainfall expected early Saturday morning through Saturday evening, opted to issue a Flood Watch from Lorain County south to Holmes County and points east. Total rainfall amounts will generally range between 1 and 2 inches with locally higher amounts of 3 inches or more possible. Previous discussion... Very active weather is still expected late tonight and Saturday with areas of heavy rainfall as well as a few severe storms likely. The heavy rain and flooding threat is still higher confidence than the severe weather threat, but there is uncertainty regarding where the heaviest, most persistent thunderstorms may set up. See details below. Water vapor loops this afternoon show a strong mid/upper shortwave trough and associated closed low moving from the northern Rockies into the northern Plains. This shortwave will progress into the northern Great Lakes late tonight and Saturday morning before becoming absorbed into a broader mid/upper trough digging down across the Great Lakes by Sunday. The associated surface low, currently over northern Minnesota, will cross the UP of Michigan tonight before exiting into Quebec Saturday night, dragging a strong cold front through the region Saturday night into Sunday morning. Upstream radar and surface observations show a sign of what`s to come late tonight and Saturday, with strong warm/moist advection bringing dew points into the 70s in the warm sector across a large area of the corn belt, as well as widespread showers and elevated thunderstorms driven by isentropic ascent ahead of the warm front. This warm front will slowly lift east-northeastward across the region tonight into Saturday morning, with strong warm/moist theta e advection tapping into the aforementioned rich low-level moisture to the west and southwest. Expect dew points to rise quickly this evening and tonight, with most dew points touching 70F by 12Z Saturday. There is no doubt that the environment will become juicy in a hurry, but the location of the heaviest, most widespread axis of convection is uncertain. Regarding heavy rain/flooding details, A 40-50 knot west- southwesterly low-level jet will feed high theta e air and elevated instability into the region, with associated isentropic ascent driving elevated convection ahead of the slowly lifting boundary, but CAMS are struggling to pinpoint where the best axis will set up. There is a wide range of possibilities from over Lake Erie to over the southern and eastern tier of counties, so held off on a Flood Watch for now given the uncertainty. What is certain is that any thunderstorms late tonight and Saturday morning will contain highly efficient (torrential) rainfall rates given PWATs rising to 2 to 2.3 inches (maximum daily value of climatology), very deep, saturated warm cloud depths, and low LCL heights of 400-800 m to minimize evaporation. CAMS suggest some training or repeated rounds of convection is possible before the warm frontal boundary lifts NE, and with the aforementioned environment supporting rainfall rates in excess of 3 inches per hour, flash flooding is likely in areas that see training or multiple rounds despite current 3 and 6 hour FFG`s being high. Will wait to see where the axis starts to set up tonight to determine where the greatest flooding threat will be, but heavy rainfall rates are possible anywhere. Regarding the severe weather potential Saturday afternoon and evening, this is far more conditional and uncertain. As the warm frontal boundary lifts ENE across the region Saturday morning, it is likely to slow over NE Ohio and NW PA. NAM and RAP forecast soundings and plan views suggest impressive veering with height near the boundary leading to curved hodographs and 300-400 m2/s2 of low- level (0-1Km) SRH. This along with low-level shear of 30+ knots and deep layer effective shear of 40-50 knots in the morning near the warm front could support an isolated tornado or two, aided by the low LCL heights as well. However, instability and time of day are the biggest limiting factors. Forecast soundings suggest elevated CAPE over 1000 J/Kg but very little SBCAPE available, so it`s possible that we just see some elevated rotation along with heavy rainfall. If severe weather occurs, there is a better chance for the afternoon and evening as the area gets fully into the warm sector behind the warm front. Latest CAMS are suggesting a lull most of the afternoon which could allow for breaks in the overcast and greater heating/instability. If this occurs, then scattered severe thunderstorms will redevelop ahead of the cold front and move across the region from NW to SE during the afternoon and evening. These storms could produce damaging winds, an isolated tornado or two, and additional heavy rainfall given deep layer shear staying marginally favorable (30-35 knots) along with marginally favorable low-level shear of 20+ knots and low-level SRH of 100-200 m2/s2. However, there is uncertainty in how much redevelopment will occur since there could be extensive cloud cover and outflow lingering from the morning convection. Some CAMS show very little redevelopment or redevelop the convection SE of the area. At this time, the SWODY2 slight risk still looks reasonable given the shear that could potentially take advantage of greater heating, but again, very conditional. Any showers and thunderstorms will quickly end from NW to SE Saturday night as the cold front passes through the region and drier air works in behind it thanks to broad surface high pressure over the Upper Midwest. Highs Saturday will range from the low/mid 80s in most areas, but more precip could keep NW PA and NE Ohio in the upper 70s to around 80. It will be oppressively humid with dew points in the low to mid 70s. The cooler air will start to come in Saturday night with lows in the low to mid 60s. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... An upper level trough will be over the Great Lakes region extending into southern Ontario and Quebec during the later part of the weekend. High pressure at the surface will be centered over the Upper Midwest on Sunday slowly building into the region. Cooler air will advect in with a northwesterly flow Sunday. There will be mix of sun and clouds across the area with more cloud cover down downwind of Lake Erie. There also could be a few isolated lake effect rain showers early Sunday morning before the atmosphere dries out. Afternoon temperatures will reach the lower and middle 70s on Sunday. High pressure will continue to build over the region Sunday night into Monday. Skies will clear out Sunday evening and overnight low temperatures will fall into the lower 50 middle 50s away from the immediate lakeshore. Monday will be very nice day with plenty of sunshine and light winds with the center of high pressure nearby. Afternoon temps will be in the lower to middle 70s Monday. && .LONG TERM /TUESDAY THROUGH FRIDAY/... A summertime ridge of high pressure will develop across the Lower Ohio Valley and Mid-Mississippi River Valley regions by the middle of next week. Our area will be on the edge of this ridge. Southerly flow will return on Tuesday with a return to summer like temperatures climbing into the middle and upper 80s. The humidity will also start returning Tuesday into Wednesday. A shortwave trough will move through the Upper Great Lakes region on Wednesday with a trailing cold front. Wednesday will likely be the hottest day of next week with temperatures reaching the upper 80s and lower 90s. A weak cold front will move into the area next Wednesday night with scattered showers and thunderstorms. This frontal boundary may stall out from west to east over Ohio Thursday into Friday with multiple rounds of showers and storms possible towards the end of next week. High temperatures will remain in the middle to upper 80s late next week. && .AVIATION /00Z Saturday THROUGH Wednesday/... VFR conditions will continue across terminals through the rest of this evening and early tonight. Rain showers will begin to approach western terminals early Saturday morning (roughly 06-09Z) and gradually move eastward through the morning and afternoon. Instability will increase by late morning which will allow for instances of isolated to scattered thunderstorms embedded in rain. As heavier rain and thunderstorms move overhead, expect for MVFR cigs/vis with IFR possible in heaviest showers and storms. Kept rain mentions in eastern TAFs through the afternoon to account for the potential for showers to redevelop along and east of I-71. Conditions will gradually improve back to VFR near the end of the TAF window. Generally southerly winds 8-12 knots tonight and early Saturday will turn southwesterly while increasing to 12-15 knots with gusts up to 20-25 knots. By the end of the TAF window, winds become westerly while diminishing below 12 knots. Outlook...Non-VFR possible in showers and thunderstorms Saturday afternoon into Saturday night. Non-VFR possible in showers and thunderstorms Tuesday night and Wednesday. && .MARINE... Southerly, offshore flow will continue at 10 to 15 knots tonight. The flow will become southwesterly on Saturday and increase 15 to 20 knots ahead of an approaching cold front. The front will move across Lake Erie Saturday evening. Winds will shift from the northwest and onshore around 15 knots Saturday night through Sunday afternoon. We could briefly reach SCA conditions for a few hours Saturday night into Sunday behind the front but confidence is uncertain at this time. Waves will be higher along the lakeshore by Saturday evening and overnight. High pressure will build in Sunday night into Monday. Winds will be northerly Sunday night 10 to 15 knots. On Monday, winds will shift from the northwest around 10 knots becoming light and variable by Monday evening. South to southeasterly winds around 10 knots will return on Tuesday and further increase 15 to 20 knots from the southwest by next Wednesday. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...Flood Watch from 4 AM EDT Saturday through Saturday evening for OHZ010>014-020>023-031>033-038-089. PA...Flood Watch from 4 AM EDT Saturday through Saturday evening for PAZ001>003. NY...None. MARINE...None. && $$ SYNOPSIS...Garuckas NEAR TERM...Garuckas/Iverson SHORT TERM...Griffin LONG TERM...Griffin AVIATION...Iverson MARINE...Griffin
Area Forecast Discussion
National Weather Service Cheyenne WY
541 PM MDT Fri Jun 28 2024 .KEY MESSAGES... - Active weather pattern ahead, with a cooling trend possible next week due to several passing cold fronts. && .SHORT TERM /THROUGH SUNDAY NIGHT/... Issued at 159 PM MDT Fri Jun 28 2024 Radar continues to be quiet, only showing a few lonely blobs across the southern Nebraska panhandle. Hi-Res guidance continues to trend precipitation downwards, however, severe weather still cannot be ruled out with the RAP showing a bubble of 2000 J/kg of CAPE later this afternoon in Kimball and Cheyenne Counties. Being in the right entrance region of a 250 mb jet streak and and forcing from an incoming secondary cold front should provide the necessary lift, however, the better environment looks south of the Nebraska/Colorado border. If storms do develop, they should dissipate by this evening. Quiet weather is expected on Saturday as brief ridging passes over the Rockies. For the most part, this should keep storms at bay, however, a weak disturbance aloft could spark some convection along the high terrain. Temperatures behind the cold front will be about 10 degrees cooler compared to Friday, so mainly looking at highs in the mid 70s to low 80s. More severe weather is possible on Sunday as the ridge slides eastwards and a trough begins to enter western CONUS. Southwest flow aloft will usher in a plume of moisture east of the Laramie Range. Combined with more southerly surface flow into the panhandle, PWs will be over an inch, which is roughly the 90th percentile for this time of year. This will likely lead to heavy rain in storms Sunday afternoon. As mentioned, severe weather could be possible with a weak shortwave passing overhead. Currently, it appears more like a wind threat on Sunday with DCAPE values exceeding 1200 J/kg. Can`t rule out some large hail with MUCAPE values approaching 1500 J/kg. Hi-Res guidance shows wide scattered storms throughout the day, so we`ll have to monitor most of the CWA. && .LONG TERM /MONDAY THROUGH FRIDAY/... Issued at 315 PM MDT Fri Jun 28 2024 Medium range models in good agreement with the overall weather pattern through Wednesday, but then models diverge significantly late this week...including Independence Day. Starting on Monday, models indicate another Pacific upper level trough and associated cold front pushing southeast across Wyoming and western Nebraska late in the day after the brief warm up on Sunday. Another round of windy conditions are possible, especially west of I-25, as the cold front slides east across the area. Not expecting High Wind criteria (40+ mph sustained/58+ mph gusts) at this time, but a few recent events have overperformed, so will have to keep an eye on this one for mainly Monday morning through mid Monday afternoon. Thunderstorm probabilities actually look lower on Monday due to dry westerly winds and substantial mid to high cloud cover shown by most deterministic models and also the majority of ensembles as the cold front moves into the area. Kept POP between 15 to 25 percent for most areas with higher coverage/chances in the mountains and east central Wyoming/northern Nebraska Panhandle. Slightly cooler weather is expected for Tuesday and Wednesday as most models show northwest flow aloft and east to southeast winds at the surface. However, afternoon temperatures should still be seasonable for this time of the year with highs in upper 70s to middle 80s. Models and ensemble are hinting at a lower coverage of showers and thunderstorms across the area, even with the natural convergence zone along the Laramie Range. Further analysis indicates relatively low PWAT for this time of the year across southeast Wyoming with values around 0.40 to 0.60 inches. Granted, this is enough for thunderstorm initiation but strong to severe storms look unlikely at this time and limited to gusty outflow winds. Lower PWATs are likely due to the progressive west to northwest flow across the Pac NW and northern/central plains, with poor moisture transport from the Gulf of Mexico. Will continue to keep an eye on this since northwest flow in July can lead to some pretty big severe weather events, but without the moisture, kept POP below 25 percent for now. For later in the week, large ensemble spreads exist for both precipitation and especially temperatures. Deterministic models show a pretty strong upper level shortwave trough digging south into the northern high plains on Independence Day/Thursday. Models all show 700mb temperatures as low as 0c to 4c as the cold front pushes south into northern Wyoming Thursday morning. Will need to monitor this front due to the possibility of late night/early morning convection possible across the plains, and much cooler temperatures for July 4th celebrations. With significant timing differences and ensemble spreads, not very confident in either of these scenarios, so kept highs in the 80s with a mention of thunderstorms north of Interstate 80 for now. Further out, all long range models seem to come into better agreement after day 7...showing a strong 600dm upper level high forming over the western Great Basin Region. Hot temperatures are possible across the whole forecast area next weekend. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 532 PM MDT Fri Jun 28 2024 VFR conditions currently at area terminals with isolated thunderstorms along a line from KLAR to KSNY late this afternoon. These storms will continue over the next few hours into early this evening, but any terminal impacts should be brief and limited, therefore kept any mention to VCTS through 02z. Winds should begin to turn northerly later this evening through Saturday morning with the expected frontal passage. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...SF LONG TERM...TJT AVIATION...MB
Area Forecast Discussion
National Weather Service Quad Cities IA IL
656 PM CDT Fri Jun 28 2024 .KEY MESSAGES... - Isolated showers and storms are possible overnight into early Saturday morning. SPC has a Slight Risk for severe storms west of a line from Manchester to Cedar Rapids to Kahoka, Missouri, and a Marginal Risk to the east. - Another round of active weather will occur Monday through Wednesday with several chances for showers and thunderstorms. Heavy rain is possible each day. - Moderate to Major flooding is expected on several area rivers. && .SHORT TERM /THROUGH SATURDAY/... Issued at 152 PM CDT Fri Jun 28 2024 At 2 PM, showers continue across eastern Iowa, northwest Illinois and far northeast Missouri with thunderstorms over Iowa, Keokuk, Jefferson, Washington and Henry Counties. Clouds and rain have limited temperatures through the afternoon. At 2 PM, temperatures range from 67 degrees at Freeport to 75 degrees at Keokuk. The heaviest rainfall amounts have been along and north of the Highway 30 corridor where rainfall amounts over 1 inch have been reported. The wave currently moving across the area is forecast to exit into Illinois by bringing a break in the rain across the area. Farther to the west along the Nebraska and Iowa border, instability has increased where skies have been clear through the day but is limited the farther east that you go. Models continue to limit instability to near the cold front which is forecast to move across the area from overnight into Saturday morning. This instability will be tapped as a weak wave moving to our north during the 9 PM to 4 AM timeframe. There has been little change in the Storm Prediction Center Day 1 Outlook through the day with a Slight Risk west of a Manchester Iowa to Kahoka line and a Marginal Risk to the east. Little instability is needed with 0 to 6 km shear near 45 knots. The HRRR continues to be aggressive in the development of storms to our northwest Illinois that moves across the area after 9 PM while other models are more limited in the convective coverage and intensity overnight. There remains low confidence in this forecast but the potential remains in place for severe storms. Based on current instability and model forecast and the timing of the front during the overnight hours, think that ant storms that develop this evening will be in a decaying as they move across the area overnight. Think that the main threats will be lightning, hail, and damaging wind gusts. Heavy rain remains a possible given precipitable water values over 2.00 inches. Probability match mean for rainfall shows a large spread among the models in rainfall potential tonight with models having anywhere between 0.40 to 1.50 inches. The cold front is forecast to be in the vicinity of the Mississippi River by 12 UTC Saturday with a continued threat for showers and storms ahead of the front. Severe storms are not anticipated. Dry air is slow to advect in behind the front but dewpoints will be falling into the 60s through the afternoon. High temperatures on Saturday are forecast to range from the lower 80s along the Highway 20 corridor to the upper 80s in far northwest Illinois. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... Issued at 152 PM CDT Fri Jun 28 2024 This weekend, we return to zonal flow aloft, becoming northwest flow on Sunday, as a ridge builds over the Central US. Surface high pressure will slowly traverse through the area during this time period, exiting through the day on Monday. This timeframe will be relatively quiet, weather-wise, which is welcomed. Saturday, we are expecting temperatures to increase into the mid-upper 80s in our southeastern half of the forecast area, with temperatures trending near to slightly below normal Sunday and Monday. The warmer temperatures Saturday will result from the slow-moving cold front passing through the area that morning, allowing temperatures to warm ahead of it. There will be a chance for showers and storms earlier in the day, but as we approach the afternoon hours, we will see chances drop off. From there, we will remain dry through Sunday and much of Monday. Monday night and into Tuesday, we see our first wave that is set to impact the area this coming week. Much of the action with this seems to be late Monday night, moreso during Tuesday morning, as the LLJ takes much of the night to shift east over our area. Although, if this system speeds up, we may see showers and storms earlier in the night on Monday. This action will be associated with the leading shortwave trough, with the bulk of the energy in our northern forecast area. Thus, this will be the focus for higher precipitation amounts and thunderstorm potential. It is too soon to discuss deterministic amounts of rainfall, but we will see the potential for heavier rainfall. Guidance is highlighting the potential for high moisture content once again, with PWATs near 2.00- 2.50". Ensemble guidance remains quite low on probabilities for rainfall, while deterministic guidance comes in quite aggressive with precipitation. Thus, we will refrain from more details. Rather, just be mindful that this can be a wet period, especially for those in our northwest. The parent wave comes through Tuesday into Wednesday, which will bring the chance for more heavy rain and thunderstorms. As the cold front approaches that afternoon/evening, moisture will pool along the boundary, with guidance highlighting this being the timeframe with the highest PWATs. Thus, an increased risk for higher rainfall rates. Beyond that, guidance starts to diverge on the next system, with large differences in timing and placement. While guidance seems to favor the Thursday night into Friday timeframe for more precipitation, will opt to refrain from any more details, as there is plenty of time for this to change. In either case, it would seem that we will approach the end of the work week with another round of showers and storms for the area. All guidance highlights much of the end of the week and into the weekend as an active period for rainfall. Unfortunately, all of this rainfall will lead to further fluctuations on the projected flooding along area rivers. Be sure to stay up to date on local flood headlines! && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 645 PM CDT Fri Jun 28 2024 Periods of MVFR/IFR are forecast tonight into early Saturday morning, with the lowest ceilings at CID and DBQ. Isolated showers and storms will remain possible into Saturday AM, but confidence on direct impacts to the terminals is low. BRL may have a slightly higher chance for scattered storms late tonight into early Saturday AM, but with low confidence on where (or if) this round of convection develops, left thunder mention out of the TAFs for now. && .HYDROLOGY... Issued at 1213 PM CDT Fri Jun 28 2024 Headline Changes: Issued a flood watch for the Wapsipinicon River near De Witt due to recent rainfall and QPF in the next 24 hrs. Upgraded Illinois City LD 16 on the Mississippi from Moderate to Major flood category. Discussion: Higher rainfall fell in the Wapsipinicon River basin than initially forecast. As a result, the new forecast for the De Witt gage has the river reaching flood stage in a little over 24 hrs. However, confidence in the placement of QPF tonight remains too low to issue a warning at this time. Later shifts will monitor trends and can issue if needed. The Cedar River forecasts remain on track, with crests likely in the next 24 hours at Palo and Cedar Rapids. A secondary rise with a lower crest than the 1st one, is now forecast on the Cedar due to the 1-2 inches that fell near the headwaters in the past 24 hours. On the mainstem Mississippi, rises will continue at all sites over the next 7 days. Higher rainfall amounts in southern MN and northern IA in the past 24 hours has resulted in a quicker forecast to Major flooding for many sites by approx. 36 to 48 hrs earlier, including Rock Island LD 15. Crests along the river should begin to show up in upcoming forecasts this weekend beginning with Dubuque LD 11. Barring any more heavy rainfall, crests are anticipated in the July 4th-10th timeframe. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Cousins LONG TERM...Cousins AVIATION...Uttech HYDROLOGY...Gross
Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
645 PM CDT Fri Jun 28 2024 .KEY MESSAGES... - Strong to severe storms expected overnight, with damaging winds, large hail, and heavy rainfall being the main hazards. - Temperatures cool temporarily going into the weekend. - Very hot and humid conditions expected to return next Tuesday. && .DISCUSSION... Issued at 106 PM CDT Fri Jun 28 2024 Early day storms and showers have mostly moved out of the region at this point, leaving behind a cooler, moist airmass. Cloud cover has persisted over much of eastern KS and MO throughout the day, with some pockets evident on satellite. With these conditions in place, the risk of severe weather tonight has become more uncertain. This is in addition to the presence of a strong capping inversion over the region. If cloudier conditions continue, then the lack of warming to this airmass may not destabilize it enough to create energetic storm modes. However. with some clearing evident within the cloud shield, there is a non-zero chance of severe development going into the overnight hours. With a cold frontal boundary forcing from a surface low and its coincident upper level trough, a line of precipitation is set to develop across NW MO and NE KS starting around the evening. Models such as the NAM Nest and HRRR keep a line of storms tracking over north-central MO, with the HREF keeping them organized throughout the night. The likeliest period of impact will begin at 7pm, with storms tracking southeast into midnight tonight. Taking a look at forecast soundings before the line of precipitation moves through, primary threats will be damaging wind and large hail, with a layer of dry air aloft and a lower freezing level. Lapse rates are forecast to remain lower around 6.5 degC/km, and forecasted shear values of 40-50 kts could maintain stronger updrafts in any severe storms that form. Irregardless of the severe threat, this line of storms will be efficient precip producers (PWAT values ~2 inches across the line), and will bring a threat of heavy rainfall to much of central MO overnight. This will serve to exacerbate hydrologic headlines in the region. By tomorrow morning, conditions should become mostly clear as the complex exits towards the southeast in full. With the passage of this storm system, temperatures are expected to fall in the upcoming days with the establishment of a surface high bringing northerly winds and slightly cooler air to the area. Afterwards, though, the propagation of this surface high towards the east alongside its upper level ridge over the southern CONUS will provide persistent southerly winds. With these winds, temperatures are expected to rise once more to the low 90s by early next week. Sporadic shortwave troughs embedded within the upper level ridge`s flow will bring more opportunities for scattered precipitation moving into next week. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 631 PM CDT Fri Jun 28 2024 Currently VFR at all terminals with southerly winds around 10 knots. Convection has initiated along the cold front over eastern Kansas. These storms should progress eastward this evening, likely impacting the terminals in the 2z to 7z time frame tonight. There could be periods of heavy rain with VSBYs dropping as low as IFR, along with a chance for hail and strong wind gusts up to 55 knots. Winds should turn easterly and eventually northerly by tomorrow morning, remaining at 10 knots or less, with VFR conditions likely. && .EAX WATCHES/WARNINGS/ADVISORIES... MO...None. KS...None. && $$ DISCUSSION...CDB AVIATION...BMW
Area Forecast Discussion
National Weather Service Hastings NE
734 PM CDT Fri Jun 28 2024 ...Short Term and Aviation Update... .KEY MESSAGES... - There is a Marginal (1/5) to Slight (2/5) Risk for severe thunderstorms this evening for the area, with wind being the main threat with any storms that are able to develop. A Marginal Risk for Excessive Rainfall has also been put out for the area. - The weekend is looking pleasant with cooler temperatures and periodic chances (20-50%) for showers and thunderstorms mainly Saturday night through Sunday. - The weekend is looking pleasant with cooler temperatures and periodic chances (20-50%) for showers and thunderstorms mainly Saturday night through Sunday. - Areas north of Interstate 80 have been outlooked in a Day 4 risk area for severe weather by the Storm Prediction Center. This will be something to keep an eye on as we get closer to the event. - Independence Day will be hot with highs ranging from the mid-80s to low 90s. There is a 20-30% chance of showers and thunderstorms. && .UPDATE... Issued at 734 PM CDT Fri Jun 28 2024 -- Various thoughts on thunderstorm/severe potential through the rest of the evening-overnight: - As largely expected, we have remained storm-free SO FAR this evening, with robust severe storms along the very leading edges of the synoptic cold front firing up "safely" southeast of our coverage area (CWA) over northeast KS. Meanwhile, any (so far weak) storms developing off the High Plains of the NE/CO/KS border area have remained well to our west. -- Between now and roughly 2 AM: - Obviously the MILLION DOLLAR QUESTION is whether (and to what degree) storms and possible severe weather will impact our CWA? - Unlike last evening (when by now it was becoming quite clear that we were not going to see much mainly due to stronger capping), tonight`s capping situation is perhaps a LITTLE weaker (but with 700 millibar temps still a good 12-13C). Otherwise, the environment is certainly supportive of at least isolated severe, with mixed-layer CAPE solidly 1500-2500 J/kg and deep-layer/effective shear 40+KT (these parameters would support east-southeast tracking supercells. - Leaning on the last few HRRR runs as much as anything (usually a reasonable bet in the very short-term), it has trended a bit more aggressive with its depiction of isolated to perhaps scattered storms (a few severe?) invading our western counties 9-11 PM, and then gradually weakening as they slide farther east into our CWA between 11 PM-2 AM. Interestingly, the HRRR focuses on two separate areas for greatest storm potential: 1) one near/south of the KS border (which seems most reasonable based on upstream radar trends)...2) another mainly north of I-80, which seems a bit more questionable but also plausible, as RAP forecast soundings suggest our northern zones will be most prone to realizing elevated instability release around 1000 J/kg with storms based up around 750 millibars (these would likely be more of a hail threat with perhaps penny to quarter size potential). The former area near/south of the KS border would (in theory) pose more of a damaging wind threat...particularly if they organize a surging cold pool. - PLEASE NOTE: because of residual capping/weak forcing aloft, it is also quite possible that storm coverage/intensity again "underachieves" this evening, which is why chances/PoPs have been intentionally held UNDER 50% at this time. -- After roughly 2 AM: - In one change from previous forecast, have lingered/added at least slight PoPs (20%) to the entire CWA through the late night/early-AM hours, as both HRRR/NAMNest are now more suggestive that at least isolated storms (possibly marginally- severe?) could persist especially within counties along/north of I-80 even through around sunrise. - It is possible that small shower/thunderstorm chances may even need lingered into the official Saturday daytime forecast period (which starts at 7 AM) mainly in our northern zones, but with higher-res models suggesting that even elevated instability should be on a downward trend by then, will likely defer to overnight forecaster to decide whether this is warranted. && .DISCUSSION... Issued at 401 PM CDT Fri Jun 28 2024 The heat continues this afternoon across portions of south central Nebraska and north central Kansas. Current temperatures are primarily in the 80s to low 90s, with a cold front pushing through the state. The front has moved through the Tri-Cities, with winds mainly out of the north to northwest. A few showers moved through the area earlier today, with additional chances mainly after 7PM. Thunderstorms will start across the western portions of the area, expanding in coverage to the east as the evening progresses. SBCAPE of 2000+ J/kg, and MLCAPE of 1000+ J/kg are expected along with DCAPE values of 1100+ J/kg, ML lapse rates around 7 C/km, and steep low-level lapse rates in the west. The main concern for any severe weather this evening will be wind. Some hail, an isolated tornado, and localized flooding may also be a concern. The Storm Prediction Center has outlooked portions of the area for either a Marginal Risk (1 of 5) or Slight Risk (2 of 5) for tonight. The main areas of concern for severe weather will be along and ahead of the front (which includes the southern and western portions of the area. Additionally, the Weather Prediction Center has outlooked us in a Marginal Risk for Excessive Rainfall for this evening. Heading into the overnight hours, thunderstorm chances (20-30%) persist, with strong to severe storms not expected. The cold front will bring in some cooler air for the weekend, making conditions very pleasant. Expected high temperatures will range from the mid- 70s to low 80s for Nebraska and the upper 70s to low 80s for Kansas. Lows will be primarily in the 50s and 60s on Sunday morning, and the 60s on Monday morning. As far as precipitation chances are concerned for the weekend, a few showers and thunderstorms may linger into the morning on Saturday. The rest of the day is looking dry, with additional showers and thunderstorms late. Showers and thunderstorms will be possible again on Sunday. Monday, an upper ridge moves to the east, with southwest flow in place over the High Plains. Temperatures are expected to climb with warm air advecting into the region. The current forecast as most areas in Nebraska in the 90s and north central Kansas in the 90s to around 100 degrees. Heat index values may approach or exceed 105 degrees, which may result in heat headlines needing to be considered. The heat is expected to continue into Tuesday, although, slightly cooler temperatures are expected. Periodic shower and thunderstorm activity is expected through mid- week. Any one area may not see shower and thunderstorm activity each day. The Storm Prediction Center has put out a Day 4 Outlook for severe weather for areas along and north of Interstate 80. The Weather Prediction Center has outlook the northeastern portion of the Hastings CWA with a Marginal Risk for Excessive Rainfall. For those planning on outdoor activities for Independence Day, there is a 20-30% chance of showers and thunderstorms through the day. Daytime highs are currently forecast for the mid-80s (north) to low 90s (south). Continue to monitor the forecast for the latest updates. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 734 PM CDT Fri Jun 28 2024 For KGRI/KEAR Airports: - General overview: Odds strongly favor VFR ceiling/visibility and rain/thunderstorm-free conditions through the vast majority of the period. That being said, there will be at least a 3-4 hour "window of opportunity" for thunderstorms later this evening (perhaps strong to severe?), and there is also a low chance for at least a brief MVFR ceiling late tonight behind a passing cold front. Wind-wise, aside from any possible thunderstorm-induced outflow, the overall-strongest breezes with gusts 20-25KT will occur out of the north during the day Saturday. - Ceiling/visibility/rain/thunderstorm details: Although far from a "sure thing", there is just enough support for the possibility of a broken line or cluster of thunderstorms to pass through from west-to-east this evening, that have opted to introduce a generic "vicinity thunderstorm" (VCTS) 02-06Z KEAR/03-06Z KGRI. IF storms occur, there is a low probability that they could be strong to marginally-severe, with the main issue being strong outflow winds 40-50KT. Will closely monitor this possibility and amend for possible TEMPO and/or prevailing thunderstorm inclusion as needed. Beyond 06Z, there is still a very low (around 10%) chance of spotty shower/weaker thunderstorm activity through around 12Z, but this chance is low enough to omit from TAFs at this time. The other possible "wrench" in things are at least minor hints of at least 1-2 hours of possible MVFR ceiling late tonight in some (but not all) model data. Have "hinted" at this with a SCT015 group 06-12Z, but far from enough confidence to go prevailing MVFR at this time. - Wind details: Aside from any possible much stronger thunderstorm-related outflow this evening, winds during these first 12-hours will be fairly light (under 10KT out and mainly northerly). However, the latter half of the period will be a bit breezy out of the north, with the majority of Saturday daytime featuring sustained speeds around 15KT/gusts 20-25KT. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ UPDATE...Pfannkuch DISCUSSION...Wekesser AVIATION...Pfannkuch
Area Forecast Discussion
National Weather Service Grand Junction CO
555 PM MDT Fri Jun 28 2024 .KEY MESSAGES... - Afternoon/evening showers and storms expected again today though coverage and intensity will be less than seen over the last few days. - Drier air moves in Saturday for a brief downturn in shower and storm activity though some convection is expected along the Continental Divide. Temperatures will run around 5 degrees above normal. - Deep subtropical moisture returns Sunday onward, with a return to widespread convection and increased chances for flash flooding. && .SHORT TERM /THROUGH SATURDAY/... Issued at 204 PM MDT Fri Jun 28 2024 This mornings sounding reported 1.01 inches of PWAT here at the Grand Junction airport. This matches up fairly well with forecast amounts so subtropical moisture does continue to linger across eastern Utah and the Western Slope. Much drier air can be found to our north and west and has started advecting into the area, however. Despite this intrusion of drier air, we can still expect some afternoon showers and storms. Speaking of, cells have just started popping across the CWA as forecast by CAM models. Upper level support is lacking though there is some weak divergence aloft that will help with lift outside of daytime heating. SPC`s Mesoanalysis Analysis page is highlighting widespread values of 500 to 1000 J/kg of CAPE, down from 1500 J/kg that was showing up in earlier model runs. This is good news as storms shouldn`t be as strong as what we`ve seen over the past few days. The highest shear is found across the northern half of the CWA and also across much of eastern Utah. The 18Z HRRR run continues to show the best coverage to be north of the I-70 corridor though some cells do fire over eastern Utah and SW CO. In this environment, we will continue to see some hail, gusty outflow winds and heavy rainers though not as intense as what we experienced yesterday. The convection will continue into the early evening hours before starting to weaken. Thus, the Marginal Risk (5% chance for wind >= 58 mph and/or hail >= 1 inch) for severe thunderstorms issued by SPC for the northern half of our forecast area. Showers and a few storms will likely persist for an hour or two after midnight before dying off completely. PWATs finally drop down to 0.6 to 0.8 inches across the area for Saturday and CAM guidance is picking up on this downturn with less convective coverage. Having said that, the higher terrain will be favored for convective initiation with the San Juans and areas along and around the spine of the Continental Divide also being favored for showers and storms. The NBM agrees with slight chance to chance there (20 to 50%) along the Divide but little elsewhere. Probably underdone and may need to bring in the HRRR or NAMNEST to bump PoPs for the remaining higher terrain. Will change as needed. As the atmosphere will be drier than seen today, gusty surface winds will be probable along with some hail. Heavy rain will be possible as well, under and near the strongest convection, but widespread heavy rain appears less likely. Enjoy this reprieve, brief as it is, because the next surge of moisture starts Sunday. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... Issued at 204 PM MDT Fri Jun 28 2024 The persistent monsoonal regime stays put Sunday and Monday, along with the oblong high pressure anchored over the southern states. The pending arrival of a PACNW trough nudges the subtropical moisture plume eastward enough to keep some of our northern counties out of the crosshairs. This doesn`t mean a dry forecast, because fringe moisture interacting with a strong southwesterly jet max Sunday afternoon should get things going on the terrain of the Tavaputs, Flat Tops, Elkheads, etc. up there. Meanwhile down south, where the moisture is best, there should be no problem with another round of robust convection around the Four Corners, Central Mountains and the San Juans. The trough axis works across the Great Basin Sunday night and should keep some active weather going during the overnight hours into Monday morning. Leftover cloud cover on Monday leaves some forecast uncertainty to the level of convective instability we might see. Moisture will remain abundant, as well as the presence of the dynamic forcing under the now broadened open wave working across the northern Rockies on Monday afternoon. For now, it`s best to expect more monsoonal showers and thunderstorms for the forecast Monday and likely Tuesday too. Shower activity Tuesday looks to turn down as the upper trough moves eastward, kicking the subtropical return on the high back onto the Plains and thereby dries us back out under northwesterly flow spilling in from the PACNW. Another trailing wave ripples through Wednesday with little new moisture to work with. Remnant moisture will get worked on and likely spark a shower or two down in our southern counties and along the southern Divide again. A break in the unsettled weather pattern finally arrives in time for Fourth of July festivities as the trough on the Plains suppresses the high enough to shut off the monsoonal feed and introduce some dry air from the northwest. This trend holds for Friday and perhaps beyond as high pressure amplifies over the West. Temperatures surge upward Sunday before cloud cover and precipitation bring them down some Monday and Tuesday. The late week dry pattern should see the return of warmer conditions as well. The big wheel of the monsoon keeps turning. Stay tuned. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 555 PM MDT Fri Jun 28 2024 Scattered showers and thunderstorms continued to move eastward north of the Roan Plateau into the Flat Tops with another area of activity in the vicinity of KHDN. It appears likely that in addition to storms in the vicinity, KHDN will likely see a brief shower, though VFR conditions will persist. In fact, VFR conditions are expected for all TAF sites during the next 24 hours and it`s unlikely that any of the other TAF sites will see a thunderstorm threat. Gusty outflow winds with today`s storms have been far less intense than yesterday with the highest observed 45 mph. Storms will dissipate this evening with clearing occurring overnight. The region will see fewer showers and thunderstorms on Saturday afternoon. Winds will shift to a light drainage flow toward late evening, switching to normal upslope flow on Saturday afternoon. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...TGR LONG TERM...LTB AVIATION...NL
Area Forecast Discussion
National Weather Service Grand Rapids MI
942 PM EDT Fri Jun 28 2024 .KEY MESSAGES... - Showers and storms tonight into Saturday - Dry and comfortable Sunday through Monday - Unsettled and warmer much of the holiday week && .UPDATE... Issued at 942 PM EDT Fri Jun 28 2024 The 00Z run of the HRRR is quite startling in that it paints a narrow swath of 4+ inches of rain overnight along the I-94 corridor between Kalamazoo and Jackson. There is a decent theta-e surge and a low-level wind confluence axis that makes localized heavy rain seem plausible. The 00Z SPC HREF Prob Matched Mean (PMM) and Local PMM guidance should lend a bit more insight once it becomes available in the next hour or two. Not going to completely bite on a single deterministic run at this point, but certainly there is some concern since this could cause pronounced localized flooding should this come to pass. Otherwise, no changes to the forecast planned in terms of overall coverage and timing of anticipated thunderstorms. && .DISCUSSION... Issued at 337 PM EDT Fri Jun 28 2024 - Showers and storms tonight into Saturday Some light rain is falling in places this afternoon across Southwest Michigan. This rain is falling from high cloud bases that from the most part are above 5,000 feet. This precipitation is associated with a weak shortwave moving through the area as well as the initial surge of moisture advection. The most substantial rainfall will occur tonight into Saturday as an upper trough digs into the northern Great Lakes driving a cold front through the area on Saturday. Instability tonight is not all that substantial, but on the order of 500-1000 j/kg. The HREF would suggest some embedded storms within a broader area of rain showers. Not expecting anything close to severe tonight given the limited instability. We are likely looking at 0.25 to 0.50 inch rainfall amounts in many areas tonight with local amounts towards an inch in the heavier swaths. On Saturday the cold front will bisect the area at daybreak with storms mainly expected southeast of a Holland to Clare line. As we work through the day, the best chance for storms in the afternoon and early evening will be near and south of I-96. Showers and storms on Saturday will be a bit more transient so rainfall totals will be lower, ranging from trace amounts to 0.30 to 0.40. We are in a SPC marginal risk for severe weather, but we expect instability to be muted by clouds and morning precipitation. Chance for any severe weather look low. HREF tries to indicate some scattered showers and storms moving back into Central Lower Michigan during the late afternoon and evening ahead of the main upper shortwave. This activity will be scattered and given the drier air moving in we have a lower confidence in this occurring. There are hints at some lower clouds developing Saturday night in the wake of the precipitation. We have brought some of these clouds into Central Lower Michigan at this time. - Dry and comfortable Sunday through Monday After the unsettled weather in the first couple of periods of the forecast, the area will see dry weather and cooler temperatures make their way over the area for Sunday and Monday. This will be the result of a fairly decent upper ridge and Canadian sfc high moving over the area. This will provide for strong subsidence to cap any clouds that try to grow at all in the vertical. 850 mb temperatures on Sunday around 7 to 9C will support max temperatures in the low to mid 70s. Return flow setting up on Monday will support highs in the upper 70s. - Unsettled and warmer much of the holiday week The upper ridge responsible for the dry weather Sunday and monday will slip east of the area by Tuesday. This will allow a long wave trough over the Pacific NW to move over the upper midwest. Deeper flow from the SW will bring warmer and more moist air to the state. Embedded short waves in the flow will bring multiple chances of showers and a few storms to the area for Tuesday and Wednesday. Details at this point are obviously a bit up in the air, but we can expect temperatures to warm back into the 80s with more humid air, and occasional chances for rain. There has been some decent agreement that much of the wet weather may settle just south of the area on the Holiday. The short waves moving through Tuesday and Wednesday flatten out the upper jet a bit. They will also lay out a front that looks to stall out over the southern portion of our area, or just south of the state. This will take the better chances of rain further south. However, this could end up being a scenario where waves ride along the front, and MCS activity just north of the front could be found. For this reason, small rain chances will be maintained for the holiday. The uncertainty by next Friday with respect to frontal and wave positions will obviously be fairly high due to the sequence events that takes place leading up to then. There is some hint that maybe a short wave ridge may build in on Friday in the wake of the early week trough, and the next trough reloading over the western portion of the country. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 756 PM EDT Fri Jun 28 2024 Regional radar shows thunderstorm development across central Wisconsin where MUCAPE values of around 1000 J/kg are present. We do not achieve those values until mainly after 06z and especially after 09z. As such, there is no mention of VCTS until then for the terminals. A consensus of high resolution models indicates good confidence for lowering ceilings into the IFR category ahead of a frontal boundary, namely in the 12z to 18z window across the region, when ceilings were trended down below 1000 ft. Afternoon thunderstorm redevelopment may occur ahead of and along the cold front mainly late, but confidence is not high yet on timing or coverage. && .MARINE... Issued at 337 PM EDT Fri Jun 28 2024 We have extended the current Small Craft Advisory (SCA) through 800am on Saturday from Grand Haven northwards. South winds of 15 to 25 knots will produce marginal SCA conditions of 3-5 feet tonight. The highest waves per the WaveWatch3 model look to remain offshore which is why we do not have a corresponding Beach Hazards Statement (BHS) out. After tonight, the focus will shift to our next wave event which develops behind a cold front Saturday night and Sunday. 4 footers develop just after midnight Saturday night and will continue through the day on Sunday. Waves will peak on Sunday morning in the 4 to 6 foot range. A SCA and BHS will be likely on Sunday. That said, weather conditions will not be ideal for a beach day with water temperatures in the 60s (and falling). Air temperatures on the beach will likely hold in the 60s as well, so we are not expecting a high beach population and even less so in the water. A north wind is the direction that are biggest upwelling occurs with. As a north wind commences, each layer below the surface turns a bit to the right due to Coriolis. Therefore the general flow below the water surface (in a north flow above the water) is offshore and upwelling occurs. So, with air temps in the 60s and falling water temperatures we are not expecting lots of people in the water. We will message it with full force on Saturday a day ahead of the actual event. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory until 8 AM EDT Saturday for LMZ847>849. && $$ UPDATE...TJT DISCUSSION...Duke/NJJ AVIATION...Hoving MARINE...Duke
Area Forecast Discussion
National Weather Service Gray ME
1108 PM EDT Fri Jun 28 2024 .SYNOPSIS... High pressure over the region tonight will push south and east of New England on Saturday with a warm front lifting through the area by late in the day. This will result in increasing chances for showers by late Saturday with rain and embedded thunderstorms Saturday night. Rain will taper off early Sunday ahead of an approaching cold front with the potential for additional showers and thunderstorms Sunday afternoon. High pressure arrives early next week bringing a period of quiet weather and seasonable temperatures. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... 1100 PM Update... Minor changes to reflect latest observational trends. Cirrus will continue to increase overnight with lows into the 40s and 50s. Previously... 715 PM Update... A rather pleasant Summer evening continues across the region with mainly clear skies and warm temperatures. Latest satellite imagery indicates the cirrus shield is still rather far away in VT and Quebec and therefore given the low dew points and weakening winds, temperatures will likely fall rather abruptly over the next few hours. Will continue to monitor these cloud trends and the associated impacts to overnight lows. Previously... High Impact Weather Potential: None. Pattern: The shortwave trough responsible for ushering in a much cooler and drier airmass is now moving east of the region as seen on early afternoon GOES 16 water vapor imagery. Surface high pressure now over southern New England will slowly sag south and east offshore with the flow aloft slowly backing ahead of the next shortwave arriving into the Great Lakes region. Overall this spells a quiet night weather-wise with the focus of the forecast being on cloud cover and overnight lows. Through this evening: Temperatures should quickly drop in the dry airmass with some high clouds overhead. 8pm temperatures will dip below 60 in the mountains while remaining in the 60s to the south. Tonight: High pressure settles south and east of the area overnight as warm advection pattern sets up in the return flow as the H8 ridge axis passes to our east. The result will be top-down saturation with mid and upper level cloudiness increasing. The result will be somewhat warmer temperatures with lows generally in the 50s across the area under light winds. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/... High Impact Weather Potential: Locally heavy rain possible Saturday night. Pattern: Low pressure north of the western Great Lakes early Saturday will move north and east through the short term forecast period remaining well north of New England through Saturday night. Saturday: Southwesterly flow continues to strengthen during the day as surface warm front approaches the region from the southwest. Top down saturation will continue through the morning with ample dry air remaining below H85. By late in the day...there is good short term mesoscale ensemble agreement that some showers will work into the northern zones given continued isentropic ascent in the area of deepest moisture. No convection expected with no instability to work with through evening. Despite warm advection...the southerly marine-influenced flow along with increasing clouds will not yield any significant warming of surface temperatures with highs again around 70 in the mountains and in the lower 70s to the south. Some of the mesoscale guidance is hinting at the midcoast through the Capitol region also struggling to reach 70. Saturday Night: Robust...broad LLJ at H8 crosses the New England Saturday night with MUCAPE plume overspreading the region as the warm front finally drives through northern New England. This occurs in the presence of significant deep moisture...with PWATs around 2" pushing above the 30 year climatology values. Deep forcing is a bit more questionable. There is a weak mid level vort max in the presence of weak height falls with modest right entrance region jet forcing moving overhead overnight in advance of the surface cold front. Thus...despite increasing warm cloud depths in the presence of significant moisture...the overall ensemble signals for heavy rainfall have decreased over the past 24 hours...favoring areas across northern New York. A consensus forecast approach favors basin- wide average QPF of 0.5 to 1"...which also lines up well with the most recent runs of the HRRR and NAM Nest. Certainly some potential for locally heavy downpours given the environment focused over the mountains matching well with the day 2 marginal excessive rainfall outlook from WPC. Temperatures will be much warmer than the night previous as the warm front lifts through the region with southern NH likely to remain in the upper 60s...with upper 60s to lower 60s elsewhere across northern New Hampshire and western Maine. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... I suppose its safe to say we have worked our way into a typical summer pattern as 500 MB ridging take residence S of the Mason- Dixon line, and troughs in north-shifted jet stream. Are generally flatter and more mobile. We start off a little on the cool side but the trend will be fore warming to near and above normal 850 MB temps by mid to late week. The tricky part is what becomes of the closed low that shifts to our SE late in the week and whether it acts as a block to allow S_SW flow to settle, making for another round of hot/humid weather or keep flow more zonal which will lead to more typical summer wx. As for chances of shra/tsra, beyond Sunday, we do see some of wave move to our N around Wed-Thu. On Sunday will see a cold front, trailing fro low pressure moving just N of the St. Lawrence valley cross the CWA. 12Z Euro shows a generally less dynamic system aloft associated with the front, but there should be a surge in low level moisture and instability ahead of it Sunday morning, so cannot rule out SHRA/TSRA, although less certainty about the potential for severe that day. Behind the front, we do a surge of cooler air, and very dry air at least for Mon-Tue, with highs a little below normal on Monday, but nice otherwise, and warming back to near normal on Tuesday. Wed will be warmer still with a bit of increase in humidity, but should stay dry most of the day. Wednesday night and Thursday are the next chance of precip, but theres still a lot of uncertainty with this weaker system. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... Short Term... Summary: High pressure builds south and east of the region tonight with southerly winds strengthening on Saturday as clouds slowly lower. A warm front crosses Saturday evening with deteriorating conditions in rain and embedded thunderstorms. Restrictions: VFR conditions expected to dominate through the day Saturday. Showers with embedded thunderstorms arrive Saturday night with conditions deteriorating to MVFR/IFR CIGS and MVFR VSBYS. Winds: Northwest winds 10g18kts will diminish through this evening before going calm/light-variable for the overnight. For the day on Saturday winds turns southerly and strengthen to 10g18kts for the day. Winds remain southerly around 10kts for Saturday night. LLWS: LLWS is not expected through Saturday. Saturday night...a strengthening low level jet will result in LLWS throughout the region. Lightning: No lightning is expected through Saturday. Showers with embedded thunderstorms are expected across the terminals Saturday night. Long Term...Mainly VFR Sun-Wed, although some restrictions possible in SHRA/TSRA Sunday. Also valley fog possible at KHIE/KLEB Sun and Mon night. && .MARINE... Short Term...Quiet conditions over the waters through early Saturday as high pressure crests over the waters. Southerly winds strengthen Saturday afternoon and Saturday night with SCAs likely necessary for this period. Long Term...SW flow ahead of cold front will allow for SCA conds on Sunday, but these4 drop off Sun night, and stay below SCA levels through mid-week. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory from noon Saturday to 4 PM EDT Sunday for ANZ150>154. && $$ NEAR TERM...Tubbs
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
904 PM CDT Fri Jun 28 2024 .KEY MESSAGES... - Thunderstorms will bring beneficial rain to most of central Illinois late tonight. The risk for severe weather remains low (only around 5%). - There is only a 20-30% chance for thunderstorms Saturday. Once again, the severe risk is low (around 5%). - Drier, cooler, and less humid conditions evolve Saturday night through Monday; ideal for outdoor activities. - The relief from the heat and humidity will be brief as it makes a return by the middle of next week along with daily chances for rain starting Wednesday lasting into the holiday weekend. && .UPDATE... Issued at 904 PM CDT Fri Jun 28 2024 Updates this evening to decrease PoPs as an outgoing shortwave drifts off to the northeast with light showers tapering off behind the feature. Also, lowered overnight PoPs. A couple of bands of showers have been organizing closer to a cold front from the upper Midwest to the southern Plains, with the stronger activity taking place west of I-35 nearest the surface cold front. Mesoanlysis products based on the RAP model depict an axis of strong instability around 4000 J/kg just ahead of the cold front, trailing off to a couple hundred or less along the Mississippi River. A couple of 00Z high resolution model runs just coming in are following a trend of weakening pre-frontal convective bands shifting into central IL overnight, as well as keeping activity more scattered and disorganized. May need additional updates later to delay onset of higher PoPs, which currently shift into the area around midnight. 37 && .SHORT TERM... (Through Late Saturday Night) Issued at 258 PM CDT Fri Jun 28 2024 At 230pm, day cloud phase distinction satellite shows scattered mid (mostly supercooled water, as the freezing level is >14,000 ft!) and high-level (ice) clouds across central Illinois, with scattered convection upstream across southeast Iowa where low level moisture transport is strong ahead of a shortwave trough. Current suite of CAMs suggests this wave of thunderstorm activity will gradually weaken as it becomes displaced from better instability and shear in west central/northwest Illinois, though this forecaster wasn`t confident enough to completely eradicate all mention from the forecast this evening; hence, 25-50% PoPs remain northwest of I-55 this evening. The better chance (60-80%) for precip will arrive later tonight, as storms developing closer to the upper-level forcing drift into our area while simultaneously weakening. It`s uncertain whether we`ll wind up with any hydrological or convective (wind, hail) issues tonight, but the CAMs continue to advertise the greatest thermodynamics to our southwest where storms developing along the northern periphery of the instability axis/LLJ across central/east Missouri may rob our region of any appreciable CAPE. Nonetheless, our morning sounding revealed a PWAT of 1.62 (near the climatological 90th percentile), and given continued warm/moist advection those values may surge to nearly 2 inches overnight - more than enough for efficient rain producers (especially given the depth of the warm cloud layer). NBM suggests the greatest chance (20-35%) for rain amounts surpassing 1 inch will be generally west of a Galesburg to Taylorville line, where some guidance even depicts some highly- localized 2+ inch totals. Precip loading could also contribute to downward momentum transport fostering gusty winds in the heaviest cells, especially if we struggle to decouple given continued mixing via the LLJ. In general, the severe risk appears low, with SPC maintaining just a level 1 of 5, marginal (5%), risk for severe weather. That holds for tomorrow as well, though tomorrow the reason for the marginal risk is slightly different. Recovery of instability (HREF mean is 1500-2500 for SBCAPE) in our area is well forecast by the 12z CAMs, though none of them are particularly aggressive in redevelopment of storms along/ahead of the cold front. If storms should develop, the unstable airmass would favor severe wind/hail with them, though at this point only about 20-30% of guidance shows redevelopment during the afternoon. We`ll be keeping a close eye on model trends for this activity. Tomorrow evening, quite the impressive cold front for this time of year will sink southward across central Illinois, bringing a quick drop in humidity (dewpoints are forecast to drop 15+ degrees, from mid 70s to upper 50s, in the span of 1-2 hours) and increase in wind (northwest gusts are forecast to reach 30+ mph). By Sunday morning, our northwest counties are likely to drop into the mid-upper 50s, while south of I-70 some spots might still be hovering around 70. Bumgardner .LONG TERM... (Sunday through Next Friday) Issued at 258 PM CDT Fri Jun 28 2024 A brief stretch of unseasonably cool and dry weather is on tap for Sunday and Monday as a strong mid to upper level ridge will be building to our west over the Great Plains. Unfortunately, the pleasant stretch of weather will be short lived as the ridge axis passes through by Monday evening, placing us back under a southerly flow regime once again by Tuesday. A weak mid level shortwave, that is expected to traverse across the Upper Midwest Tuesday night into Wednesday, may provide enough forcing aloft to support some rain. With the depth of moisture still in question, especially east of I- 55 in Illinois, only chance PoPs remain for most of the area on Wednesday. The 00z LREF members are in good consensus that the same upper level ridge that will bring us our cool down Sunday and Monday will setup over the SE CONUS, with 500mb heights of 594dm. The current placement of this 594dm heat dome puts us under the "ring of fire", giving us 30-50% PoPs daily from Wednesday through the end of the extended. With deep northwesterly flow aloft, along with rising heights, Sunday and Monday will be dry and unseasonably cool with widespread highs in the 70s. The coolest night in the next 7 days will be on Sunday night when lows are expected to drop into the 50s, bringing a springtime like chill back to the area. With southerly flow returning by Tuesday, temps will be on the rise with highs reaching the upper 80s to lower 90s on Tuesday and Wednesday along with dewpoints reaching the lower 70s. The combination of heat and humidity will result in heat indices nearing or exceeding 100 degrees in some locations on Tuesday and Wednesday, especially south of I-70 in Illinois on Wednesday. Confidence in temps Thursday and Friday is lower due to the uncertainty in the strength and position of the nearby heat dome by the end of next week. Peine && .AVIATION... (For the 00z TAFs through 00z Saturday Evening) Issued at 642 PM CDT Fri Jun 28 2024 Scattered showers will continue for an hour or two to start the TAF forecast period, but there is little chance of significant impact in terms of low cigs, vsbys, or thunderstorms. After a few hours, a line of thunderstorms is expected to organize to the west and sweep into the area by 05Z-07Z, and exit the central IL terminals by 09Z-12Z. This will likely be accompanied by brief MVFR cigs and vsbys. Following the departure of these thunderstorms, a period of MVFR cigs is expected from around 15Z-21Z before low cloud cover lifts and scatters out. Winds S around 10 kts, shifting to W after 15Z. 37 && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Indianapolis IN
814 PM EDT Fri Jun 28 2024 .KEY MESSAGES... - Rain showers/isolated thunderstorms overnight and early Saturday - Becoming partly sunny on Saturday afternoon. - Cooler Sunday and Monday, heat returns on Tuesday and Wednesday. - Rain/storm chances return Wednesday onward. && .FORECAST UPDATE... Good confidence in forecast trends regarding incoming convection, mainly overnight into Saturday. Warm and moist advection ahead of a weak upper wave in zonal flow along with sufficient instability will result in convection moving in from the northwest overnight as Hi-R es soundings show the low levels moistening. CAMs in good agreement on convection becoming widespread after 08z. Currently, some weak echoes in westerly flow will necessitate chance PoPs from around a Clinton to Fishers to Muncie line before Midnight. Lightning detection equipment was not detecting any lightning over the region despite some very weak instability. The southerly winds and overcast conditions and dew points rising into the lower to middle 70s suggest that will be the bottom of overnight lows. && .SHORT TERM (This evening through Saturday)... Issued at 258 PM EDT Fri Jun 28 2024 Surface analysis early this afternoon shows strong high pressure centered over eastern NY and NJ. This high was influencing the weather across the eastern third of the country, including Indiana. The high was providing southeasterly to southerly flow across Central Indiana. Surface low pressure was found over NB. Warm and moist southerly flow was found streaming northward through the Mississippi river valley, where abundant cloud cover was found. This cloud cover was advecting east toward central Indiana. A large area of showers with a few thunderstorms were found over IA/Northern IL and MO. Water vapor imagery showed a mainly zonal flow in place across the CONUS, with a wave of moisture in place from the southern plains to middle Mississippi valley to the western Great Lakes. A short wave within this flow was found over SW MO. Dew points across central Indiana were mainly in the lower 60s. Tonight... Models suggest that within the upper flow several weak upper disturbances will pass across Indiana tonight and on early Saturday. Meanwhile within the lower levels the low pressure system over NB pushing toward the Great Lakes tonight dragging an elongated cold front across the Mississippi Valley toward Central Indiana. Forecast soundings this evening remain dry as these features approach. However the forecast soundings show deeper saturation arriving after 09Z with pwats near 2.25 inches. Instability appears quite limited as CAPE remains mainly below 500 J/KG. HRRR shows showers mainly arriving after 08Z, then passing into the forecast area by 12Z. Thus will have a dry forecast this evening, but begin ramping up pops overnight as the forcing and moisture begin to arrive in the area. Confidence for rain is high. Given the expected clouds and precipitation and the cold front not passing until after 12Z expect lows in the lower 70s, with some middle 70s south. Saturday... Models suggest that at 12Z forcing and the associated cold front will be over Central Indiana. This should then continue to exit to the east through the morning hours on Saturday, with the focus mainly along and south of an I-70 line. By 18Z, forecast soundings lose their deep saturation and winds become westerly in the wake of the cold front. Aloft forcing is lost as it pushes east by the afternoon. Again, instability appears limited as little CAPE is available, however a stray thunderstorm cannot be ruled out. Thus will continue high pops through the morning hours, mainly across the southern half of the forecast area and trend toward a dry forecast by afternoon. Minimal overall temperature advection is expected until Saturday night. This will lead to a quick recovery of high temperatures on Saturday afternoon to the middle 80s. && .LONG TERM (Saturday night through Friday)... Issued at 258 PM EDT Fri Jun 28 2024 Generally quiet weather through much of the long range as broad ridging takes hold early next week. Rain chances return late in the period. Saturday Night and Sunday Any lingering showers from Saturday`s cold front / shortwave will be slowly exiting the area by Sunday morning. Much cooler conditions will follow, as surface high pressure builds in from the north. Model temperatures in the 850mb level drop to around 11C in most guidance, with some members showing as low as 8C by Sunday night. Around the same time, the surface high moves directly overhead with large-scale subsidence. Clear skies, light winds, and a cold air mass should promote temperatures well-below normal Sunday night into Monday morning. Lows should drop well into the 50s with perhaps some rural areas dropping into the 40s. Normal lows are around 65 for this time of the year. Monday Onward Cooler than average temperatures linger into Monday with highs climbing into the 70s for the most part. A few locations may reach 80, especially further south away from the core of the now-departing cold air mass. As high pressure slides eastward, low-level flow turns southerly and a warming trend looks to commence. By Tuesday, 850mb temps rise by about 5-10 degrees, which under full sun and efficient mixing corresponds to highs in the mid to upper 80s. The primary axis of warm air advection remains to our west, however. This warm air advection enables a ridge to build over the Plains which then drifts eastward through the week. As such, generally above-normal temps in the upper 80s / low 90s should persist through the remainder of the week. Low temps should also be a bit above normal, reading in the high 60s to low 70s for most locations. Turning our attention to precipitation chances, we`ll see quiet weather associated with high pressure persisting through Tuesday. Most guidance shows a cold front attempting to infiltrate the aforementioned ridge by Wednesday night or Thursday. This front combined with increasing humidity from the south could allow for repeated shower/storm chances. Ensemble guidance shows the ridge axis moving eastward a bit allowing flow to be south/southwesterly through the column across Indiana. Since the front is diving down from the northwest and encountering largely boundary-parallel flow...most guidance stalls the front somewhere nearby (most show central or southern Indiana). Shower and storm chances could then linger through the rest of the week if this is the case. Ensemble guidance is in fairly good agreement through Wednesday but diverges thereafter. And this is probably due to how individual members handle the front impinging on the departing ridge. Therefore, confidence in forecast temperatures and precipitation decreases by late Thursday and Friday. && .AVIATION (00Z TAF Issuance)... Issued at 543 PM EDT Fri Jun 28 2024 Impacts: - VFR expected for the bulk of the TAF period. - Showers with isolated TSRA after 07Z. Discussion: A cold front will drop southeast across the terminals Saturday afternoon. The front will interact with a deepening column per Hi- Res soundings and an upper wave and result in widespread showers overnight and into Saturday morning. A few lightning strikes are also possible. The showers will be dissipating and ending late in the day. Winds will be SSW 10 knots or less. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...MK SHORT TERM...Puma LONG TERM...Eckhoff AVIATION...MK
Area Forecast Discussion
National Weather Service Northern Indiana
728 PM EDT Fri Jun 28 2024 .KEY MESSAGES... - Heavy rain and thunderstorms are expected overnight, with isolated flooding/ponding possible in fields and on roads. A few storms late morning/early afternoon on Saturday could be strong to severe, with damaging winds and a brief tornado or two. The best severe chances will be in NW Ohio. (Medium confidence) - A second round of storms could develop later in the afternoon/evening Saturday, with damaging winds as the main threat (Low confidence, depends on if recovery happens behind the morning round of storms). - Hazardous swimming conditions are expected on Lake Michigan on Sunday. Waves 4 to 7 feet and dangerous rip and structural currents are likely. Stay out of the water and stay off of the pier! - Dry with near normal temperatures Sunday through Tuesday morning. && .DISCUSSION... Issued at 215 PM EDT Fri Jun 28 2024 Stay weather aware overnight and into the day tomorrow as strong to severe thunderstorms are possible within two rounds of storms. SPC has maintained a Slight Risk (level 2 of 5) for much of our area. GOES visible satellite shows increasing cloud cover moving in from the west as a warm front advances across our forecast area. Dense cloud cover persists through tonight along with a chance of showers this afternoon and evening. Overnight and into Saturday morning, a line of heavy rain and embedded thunderstorms is likely to develop after midnight along a pre-frontal trough. As convection moves eastward into far NE Indiana and NW Ohio, it is likely to intensify, with a few strong to severe storms possible in the morning and early afternoon. Hi-res model guidance varies in coverage and intensity of storms, with the NAM and HRRR showing the best severe potential. Southwesterly winds behind the warm front will advect moisture into the area overnight, which will yield an unstable environment for storms to form. 1500-2000 J/kg MLCAPE is possible coinciding with 30 kts of 0-6 km shear orthogonal to the pre-frontal trough. Low to mid level lapse rates throughout the day Tuesday will be around 6C/km. In addition, there is favorable 0-1 km SRH of 150-200 m2/s2. Damaging winds 40 to 60+ mph and a brief tornado or two will be possible. The best severe chances in the morning will be where the Slight Risk is in NW Ohio, although I wouldn`t surprised if a strong to severe storms develops along or just east of the I-69 corridor. There is increasing confidence in heavy rainfall and localized flooding around midday Tuesday as record PWATs around 2 inches, a deep warm cloud layer, and saturated low to mid levels of the atmosphere will yield very efficient rainfall rates of 1-2 inches per hour in any storms. A cold front will come through Saturday evening and there is low confidence in a second round of storms developing along the front. Should a second round of storms materialize, damaging winds 40 to 60+ mph will be the main threat. Hazardous swimming conditions are expected on Lake Michigan Sunday thanks to gusty northerly winds behind the cold front. Waves will build to 4 to 7 feet and wave periods look to stay in the 6-8 second range (relatively high for Lake Michigan) thanks to a long fetch down the lake. This will increase the probability of dangerous currents, including rip and structural currents. Will hold on any headlines for now but subsequent shifts will likely need to issue a Beach Hazards Statement for Sunday into early Monday, as longer wave periods and high waves may lead to current activity that persists even once wave heights diminish. Those planning to visit the beaches this weekend should stay out of the water and stay off of the pier! It will be mostly dry and cooler with highs in the upper 70s to mid 80s Sunday through Tuesday morning as high pressure builds in at the surface beneath a brief upper level ridge. Clouds move out of the area bringing clear skies for Sunday and Monday. The next chance for rain/storms will arrive on Tuesday afternoon/evening. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 727 PM EDT Fri Jun 28 2024 A warm front moves northward tonight bringing increased moisture to the area. With a few shortwaves moving through overnight tonight expect times of rain tonight mainly through mid to late morning Saturday. An initial dry layer will cut into rain intensities and keep conditions VFR until later in the TAF period. Have MVFR conditions at the TAF sites starting around 13 or 14z. If VISBY reductions occur, it would likely be with the rain in the mid to late morning time period and at SBN, but chances with that are small so will leave that out of the TAFs for now. As we head to the afternoon, we begin to lose forcing and the precipitation coverage and intensity should drop as a result. However, expect winds gusts to increase to 20 to 25 kts as dry advection ensues. TAF shear is very marginal, but there is a period between 7 and 12z that may become conducive to LLWS. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Johnson AVIATION...Roller
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1046 PM CDT Fri Jun 28 2024 .KEY MESSAGES... - Showers and storms end this evening over/near southeast MN with a dry and seasonably cool weekend to follow. - Unsettled weather expected Monday into Tuesday, with heavy rain and some severe storms possible. - Next potential active weather period is the 4th into the 5th, though model spread remains high (and forecast confidence low) during this timeframe. && .DISCUSSION... Issued at 335 PM CDT Fri Jun 28 2024 Surface analysis this afternoon shows a surface low up between Bemidji and International Falls, with a cold front trailing to the south from the low down to about Fairmont at 230pm. We`ve seen extensive cloud cover through the day, which has held down temperatures, but a plume of 70+ degree dewpoints has managed to crawl its way along the front up to just west of the metro. This moisture has allowed mlCAPE values to build to over 1000 j/kg along the front from about Litchfield on south into Iowa. Along this instability axis, we`ve see a weak line of storms develop along the I-90 corridor down into Iowa. Over the next few hours, this line of storms will continue to slide east toward La Crosse, with limited expansion to the north expected. The strongest h85 winds are off to the east of our area, so we have limited low level shear. Still, mid- upper level winds will be strong enough to support 40-50 kts of deep layer shear, so enough deep shear is present to support a low end severe risk. From the 1630z Day 1 outlook, where the SPC has a 2% tornado probability up into southeast MN captures where the greatest likelihood of seeing some stronger storms will be through the evening. As we go through tonight, the cold front will push off to our east, but that does not end our precipitation chances. This afternoon, there`s an h5 low moving into wrn NoDak and as this moves east through the night, we`ll see the threat for scattered showers and maybe an isolated thunderstorms across central Minnesota. For the rest of the weekend it should be mainly dry, but you can`t completely rule out some isolated showers on Saturday as the last piece of upper level energy moves through. Surface temperatures will be cool and the atmo drying out, so we continue to keep PoPs below 15% (which keeps a precip mention out of our point-and-click forecasts), but if things end up as robust as the 18z HRRR shows, we may need to add in some -SHRA mention to the forecast for Saturday. Big thing for Sunday is with the high overhead and the cooler highs on Saturday, lows Sunday morning will fall into the 40s for all but the urban core of the Twin Cities metro. Next up on the weather system merry-go-round comes Monday into Tuesday. Meso scale difference remain, but on the large scale, we see the models bringing two shortwaves across the area. The first goes from the Dakotas into northwest Ontario Monday/Monday night, with the main trough swinging through the upper MS Valley on Tuesday. It`s the first one that will likely pose the greatest issues hazardous weather wise as it will send a 50-60 kt LLJ across the area Monday night. Upstream of this LLJ, we`ll see 1000-1500 j/kg of MUCAPE feeding into this LLJ, which will result in another heavy rain threat Monday night. The severe threat Monday is a little more questionable given the threat for extensive cloud cover and WAA rain to limit surface based instability, but if we see surface features progress as far east as the ECMWF has them Monday afternoon, then a severe risk extending a little farther east than what the SPC Day 4 outlook has will be possible. Going ahead to Tuesday, another round of showers and storms looks likely ahead of the main trough, but where surface features are at that point will determine where the greatest severe/heavy rain risk will be, but we are seeing the potential for one more round of showers Tuesday afternoon before this system departs to the east. Where the second round of precip ends up will help determine what final rainfall amounts look like, but the EPS mean QPF does have near 2" of rain over southeast MN. When looking at the individual members at RST, you do see a handful of EPS members with over 3" of rain early next week, so the heavy rain threat will have to be watched. As has been the case, the break in the weather looks to be short- lived (Wednesday), but we are seeing signs for more unsettled weather from the 4th into the 5th. Model spread during this period remains quite large, so PoPs in the 30s and 40s from the NBM makes sense, but we`re still a couple of days out before we can have much confidence in saying whether or not your holiday festivities will be impacted by weather. Beyond this system, there is some hope that things may start to settle down a little bit as upper ridge starts building farther north and the upper jet begins to nudge north and weaken some, but we`ll see if this hyper-active pattern can actually settle down. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1045 PM CDT Fri Jun 28 2024 Mostly VFR conditions are expected the rest of tonight, though IFR will linger at KEAU. A cold front will drop southward, reaching west central MN around daybreak. It will bring MVFR ceilings that will spread toward the southeast, reaching western WI by mid morning. Northwest winds are expected to increase to 15-20 kts with gusts in the 20s by late Saturday morning. KMSP...Timing of the increase in northwest winds is the main item for this forecast. Have targeted 15Z for gusts around 25 knots but that may vary by an hour or so. Few other concerns. /OUTLOOK FOR KMSP/ SUN...VFR. Wind N bcmg E 5-10 kts. MON...VFR/MVFR, RA likely, chc -TSRA. Wind SE 10-15G25 kts. TUE...VFR/MVFR, chc RA. Wind W 5-10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...MPG AVIATION...TDK
Area Forecast Discussion
National Weather Service Marquette MI
823 PM EDT Fri Jun 28 2024 .KEY MESSAGES... - Rounds of showers are expected into Saturday and then Monday night into Tuesday night with quiet weather following each round. && .SHORT TERM /THROUGH TONIGHT/... Issued at 416 PM EDT Fri Jun 28 2024 Water vapor imagery and RAP analysis show a well-defined mid-level low over eastern MT with wsw flow downstream into the Great Lakes. In this wsw flow, a shortwave moving across Upper MI is responsible for the shra that have been spreading w to e today. Most of the rainfall has been on the light side. The clouds and shra have resulted in a cool day with current temps mostly in the upper 50s and lwr 60s F. The cool conditions and resulting lack of instability, including for parcels lifted from anywhere above the sfc, have prevented any tsra from developing. To the w, sfc low pres is located in n central MN with a cold front extending ssw thru far nw IA. Within 850mb theta-e ridge ahead of the front, shra/tsra are developing from western IA into se MN. Shra associated with aforementioned shortwave will be exiting the eastern fcst area over the next few hrs. Attention then turns to the convection developing to the sw. Under 850mb theta-e advection as 850mb theta-e ridge advects ne ahead of approaching cold front, there should be additional shra/some tsra development ne thru WI into mainly the se half of Upper MI. Additional shra/tsra, lower coverage, will be possible along the cold front as it moves into Upper MI during the night. With the instability that does build ne into Upper MI limited, svr storms not expected. Temps tonight won`t fall much from current readings. Min temps should be mostly in the upper 50s and lwr 60s F. && .LONG TERM /SATURDAY THROUGH FRIDAY/... Issued at 510 PM EDT Fri Jun 28 2024 Starting Saturday morning, the broad trough will be centered over northern MN with two embedded shortwaves to focus on through the day as the trough shifts east through northern Ontario and the Upper Great Lakes. The first shortwave on the forefront of the trough is situated over western Lake Superior, lifting northeast toward James Bay. The second shortwave trough over the ND/MN state line pivots over the Upper Great Lakes into Saturday night. The associated sfc low around 1004 mb follows the first shortwave northeast into Quebec, dragging a cold front from eastward across the UP through the later part of the day. PVA ahead of the passing cold front supports isolated showers and possibly some rumbles of thunder through the morning, but better chances for thunderstorms hold on until the afternoon with the passing cold front. The NAM and HRRR are the stronger solutions, kicking off storms in the east and south central along Lake Michigan with the higher instability (SBCAPE up to 2000-2500 J/kg). However lingering clouds from previous showers will be a limiting factor for instability, the 6/28 12Z mean SBCAPE only builds up to around 750-1000 J/kg in the afternoon with bulk shear to 45-50 kts. Another limiting factor will be the timing and location of the cold front. While an isolated strong storm bringing some gusty winds and some small hail is possible, severe weather seems unlikely. Forecasted highs were bumped up from the previous forecast into the 70s, warmest south central where MOS guidance points to highs reaching near 80. The exception to this is in the Keweenaw where temps may struggle to reach low 60s under the stronger northwest flow off Lake Michigan. With northwest winds increasing through the day, a high swim risk is expected for the Alger county beaches starting in the afternoon. Moving into Saturday night, high pressure begins building in from the west at the sfc, but one last shortwave digs south across the UP. With the north-northwest upslope flow and low level moisture noted in model soundings, this may support some light showers in areas nearer to Lake Superior. Dry weather is expected to return from west to east overnight as a drier airmass works its way into the area. Stronger mixing is also expected Saturday night, resulting in some gusts up to 20-30 mph over the east. Lows are expected in the 40s, however with clearing and radiative cooling in the west, some interior spots may dip into the upper 30s. The dry period continues through Monday with high pressure overhead and mid level ridging building in from the west. Highs on Sunday are expected to be cooler under northerly flow, generally in the 60s. An And with another night of mostly clear skies and radiative cooling, lows Sunday night dip into the 40s. Mid level ridging becomes centered over the UP on Monday with southerly flow at the lower levels bringing temps near or just below normal with highs in the 70s. Dry dry period ends Monday night in the west ahead of a deepening low moving northeast off the northern Rockies. Confidence is growing in the sfc low track, bringing it through far northern Ontario on Tuesday, reaching Hudson Bay by around Wednesday morning as it deepens to around 995mb. While the details with this system are still a bit murky, general consensus is that it brings two rounds of showers and thunderstorms. The first round touches off Monday night with WAA and isentropic ascent in the west, later supported by a shortwave traversing east over the Upper Great Lakes, then dries out around mid day Tuesday. The second round is driven by the low pressure system`s trailing cold front Tuesday afternoon into Wednesday. After this system, model guidance really begins to diverge. A dry period is expected to follow, but how long that period lasts is still uncertain. Generally a wetter pattern continues into through the first half of July. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 822 PM EDT Fri Jun 28 2024 Flight restrictions to persist for duration of TAF period as a cold front enters Upper Michigan in the wake of an exiting shortwave. MVFR conditions will continue for a few more hours at IWD/CMX before deterioriating further to IFR and even LIFR at CMX tonight. Elsewhere, upsloping southerly winds are keeping SAW at LIFR levels already this evening and will persist into early Saturday morning. Some improvement is possible Saturday morning after frontal passage. In addition, an uptick in showers is expected over the next few hours with a few rumbles of thunder, especially at SAW. And, southerly winds will continue to gust up to 20 kts at IWD and SAW into tonight. Wind shift to the northwest in wake of front is progged for Saturday morning. && .MARINE... Issued at 510 PM EDT Fri Jun 28 2024 Southeast winds up to 20-30 kts, strongest over the east, are expected to diminish this evening from west to east with winds falling below 20 kts by around midnight. Behind the cold front, winds veer northwest on Saturday with increased mixing and a tighter pressure gradient allowing for gusts up to 25-30 kts over the eastern half of the lake. North to northeast winds Saturday night gradually fall back below 20 kts late Saturday night as high pressure builds in from the west. Winds are then expected to remain below 20 kts through much of the day Monday as this high pressure moves east over the lake. With the next passing system early next week, southeast winds increase Monday night to 20-25 kts, veering south to southeast on Tuesday as the low pressure system passes well to the north of Lake Superior. Winds Tuesday night onward look to remain below 20 kts through the remainder of the forecast period. Stronger northwest winds behind the cold front on Saturday will result in waves building up to 5-8 ft waves over the eastern half of the lake Saturday night. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Beach Hazards Statement until 10 PM EDT this evening for MIZ014. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Rolfson LONG TERM...Jablonski AVIATION...TDUD MARINE...Jablonski
Area Forecast Discussion
National Weather Service Raleigh NC
753 PM EDT Fri Jun 28 2024 .SYNOPSIS... High pressure will move off the New England coast tonight. A hotter and more humid airmass will become established across the area this weekend. A cold front will approach the area Sunday bringing the next chance of storms. && .NEAR TERM /THROUGH TONIGHT/... As of 753 PM Friday... Evening analysis shows a stalled boundary across northern sections of SC and arcing into eastern TN. High pressure was situated off the New England coast. The high will shift off into the north Atlantic, resulting in a developing southerly flow toward sunrise Sat. With the more moist flow off the southwest Atlantic, dewpoints will likely rise overnight after mixing out earlier this afternoon. Daytime convection along the sea-breeze brought isolated storms across Sampson Co and the Sandhills. The convection has produced a well pronounced outflow evident on radar, currently pushing into Moore, Lee, and Chatham counties. As this outflow continues to track WNW through the late evening, high-res CAMs such as the HRRR show spotty isolated activity developing over the western/southern Piedmont and perhaps over the Triad. Any storm activity should weaken after midnight with loss of heating and forcing, though cannot rule out a stray shower over the Triad near daybreak. Overnight lows should be in the upper 60s to low/mid 70s. Guidance is hinting at some widespread low stratus and possibly patchy fog with the onshore flow taking shape overnight into daybreak Sat. This should lift and dissipate by mid-morning. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... As of 415 PM Friday... Hot, seasonably humid, with a small chance of showers/storms on the wrn and ern flanks of cntl NC. Cntl NC will remain tucked between a couple of sub-tropical to lower mid-latitude mid-level highs/ridges centered over the srn Plains and w-cntl Atlantic, respectively. Poleward of this expansive zone of ridging, a compact mid-level cyclone now over nern MT will become an open wave trough while pivoting across the nrn Plains and upr MS Valley through 12Z Sat, then accelerate newd and across the Great lakes and QC through 12Z Sun. A trailing shortwave perturbation now over the cntl Canadian Prairies will dig sewd into the upr MS Valley and upr Great Lakes Sat and then follow a similar path as the first shortwave trough through Sun. In the intervening swly flow between these shortwave perturbations and the aforementioned ridges, a convectively-amplified mid-level trough will move across the OH Valley and cntl Appalachians Sat and the Middle Atlantic Sat night, the latter when weak mid-level height falls (10-20 m/12hr) will glance the srn Middle Atlantic. Weak mid-level lapse rates of less than 5 C/km will exist over cntl NC on Sat, with a slight increase to between 5-5.5 C/km, amid the aforementioned weakly falling heights, Sat night. At the surface, the remnants of a couple of fronts that have settled across the South Atlantic states during the past 24 hours will retreat nwd across the Middle Atlantic, on the wrn periphery of high pressure over the Atlantic basin. Broad sly flow will result throughout the South and Middle Atlantic states, while a lee trough will develop with diurnal heating over the srn Middle Atlantic and Carolina Foothills/wrn Piedmont. Weak confluence between the Atlantic high and lee trough will result over the Foothills and wrn Piedmont. A sea breeze will also retreat inland and across ern and e- cntl NC through the evening. While both temperatures and humidity levels will be on the increase as a result of the return to sly flow and the influence of the ridging aloft, afternoon/mixed surface dewpoints are likely to decrease into the upr 60s to around 70 F. Resultant heat index values, when factoring in high temperatures mostly 92-98 F, are likely to peak in the 100-105 F range over all but the nrn and nwrn Piedmont, where upr 90s will be common. Those mixed dewpoints will also result in a minimum of MLCAPE generally between 500-1000 J/KG over cntl NC, with slightly higher dewpoints in the lwr 70s, and MLCAPE between 1000-1500 J/KG, along and west of the Yadkin Valley and from the the far ern Coastal Plain to the coast. A 20-30 percent chance of showers/storms will consequently exist along the wrn/ern flanks of cntl NC. Overall coverage and strength of convection will be limited by the relative lack of buoyancy and forcing for ascent, aside from low-level convergence along the sea breeze and into the lee trough. After a lingering small chance of showers/storms over the srn/wrn Piedmont during the evening, it will otherwise be warm and muggy overnight, with lows 75-80 F. && .LONG TERM /SUNDAY THROUGH FRIDAY/... As of 255 PM Friday... Hot and stormy Sun/Sun night, then generally quiet and mostly dry through the work week. Near normal temps Mon-Tue will once again give way to intensifying heat for July 4th and into the weekend. Sun-Sun night: Expect hot and muggy conditions with high rain chances as a potent mid level trough deepens with a positively tilt as it shifts through far SE Canada/St Lawrence Valley into the Northeast states. Just ahead of this trough axis and its associated surface front, anomalously high PWs near 2.5" will spread in areawide, with mid level moistening and cooling resulting in an erosion of mid level stability, as steepening lapse rates through the column and prefrontal afternoon heating push SBCAPE to 1000-2500 J/kg, according to the latest LREF. Mid level flow and deep layer bulk shear will remain somewhat muted much of the day, however, peaking at just 15-25 kts, highest near the border Sun evening/night as the stronger cyclonic flow aloft dips into our latitude with trough axis passage. This will also result in the better upper divergence holding off until after dark, and this lack of temporal juxtapositioning of buoyancy and dynamic forcing for ascent could limit our severe threat. But given the forecast SBCAPE and deep mixing with elevated DCAPE, the threat of a few strong wet microbursts seems realistic. Will continue with high pops, peaking at likely at some point over the entire CWA. Sun is likely to be another day of dangerous heat, with very warm morning temps and highs mostly in the mid 90s, giving heat indices again around 100- 105 over most of the area. The surface front should drop slowly SE through the area (more likely, jumping into a prefrontal trough or convective outflow) Sun night, with some lower dewpoints expected to start arriving into the north sections overnight. Lows in the upper 60s to mid 70s. Mon-Fri: The front and deep moisture may still be lingering across southern sections Mon morning, so will maintain good chance to low likely pops there early. But as the front settles to our S and drier air works in from the N amid briefly gusty NE winds Mon, and within ridging both at the surface and aloft, expect a trend to no pops late Mon, lasting through mid week as high pressure noses in from the N. Expect temps to be near to even slightly below normal Mon/Tue, with dewpoints in the 50s and 60s, making it feel quite pleasant. Then, as the mid level trough extending down through the Mid Atlantic early Mon shifts offshore and ridging builds further from the S Plains/Lower Miss Valley into the Carolinas, with the surface ridge pushing out over the open NW Atlantic, rising humidity and thicknesses will bring a return to oppressive heat. Highs should be in the low to mid 90s Wed and mid 90s to near 100 on July 4th and Fri, as thicknesses climb to nearly 20 m above normal. With mid level warm/stable air beneath the strong ridge aloft and limited deep moisture flux into the area, rain chances will remain low Wed, then will have a trend toward climo pops for Thu/Fri, just 25-35% chance at most with those higher values focused on the extreme NW where mountain convection could drift late each day. -GIH && .AVIATION /23Z FRIDAY THROUGH WEDNESDAY/... As of 703 PM Friday... VFR conditions will prevail to start the TAF period. However, MVFR to IFR stratus is likely to develop at all terminals late tonight/early Saturday morning. Otherwise, a few isolated showers could reach KINT/KGSO this evening, but overall the forecast appears mostly dry tonight. Any lingering stratus should lift to VFR by late morning/early afternoon. After which, a few isolated showers/storms could impact KINT/KGSO tomorrow afternoon. However, coverage looks limited and mostly confined to the mountains. Outlook: Sub VFR conditions will be possible area wide Sun morning with IFR stratus, followed by a good chance of mainly afternoon- evening showers/storms Sunday. VFR conditions are expected early to mid week next week. && .CLIMATE... Record High Temperatures: June 30: KFAY: 102/2012 July 4: KGSO: 98/1970 KRDU: 101/2012 KFAY: 98/2019 Record High Minimum Temperatures: June 28: KRDU: 76/1952 KFAY: 78/1914 June 29: KGSO: 74/2010 KRDU: 78/1914 KFAY: 76/1969 June 30: KGSO: 74/1936 KRDU: 80/1936 KFAY: 79/1936 July 1: KRDU: 75/2012 KFAY: 76/1990 July 4: KGSO: 73/2018 KRDU: 79/1902 KFAY: 78/1913 && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...CA NEAR TERM...Kren SHORT TERM...MWS LONG TERM...Hartfield AVIATION...Luchetti/CA CLIMATE...RAH