Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/16/24


Area Forecast Discussion
National Weather Service La Crosse WI
1025 PM CDT Sat Jun 15 2024 .KEY MESSAGES... - Storms tonight into Sunday. A few strong to severe storms possible tonight into early Sunday and north of I-90 Sunday night. Heavy rain will also accompany the storms. - Highest shower/storm chances shift farther northwest late Sunday through early next week then increase with a cold front Tuesday night. - Hot and humid Sunday through Tuesday. The rain from tonight may hold temperatures down somewhat. 70-95% probability of temperatures above 90 degrees Sunday for most areas. && .DISCUSSION... Issued at 205 PM CDT Sat Jun 15 2024 Today through Tuesday: Heat and Storms The next few days will bring periods of shortwave troughs into the area providing the area with increased chances of precipitation. Strong instability and humid conditions are expected each day. Starting with today, there continues to be an area of showers passing through. These showers will push off to the northeast during the afternoon. There will be a slight break in the action this evening before the next round of precipitation starts up tonight. Looking ahead to tonight, a warm front will lift north this evening ahead of the rain. Strong moisture transport and a strong low level jet, 40 to 50kts, will help to increase instability and PWATs across the area. PWATS are expected to be near 2" and MUCAPE mostly between 1500 and 2000J/kg during the overnight. As the night progresses, both PWAT and MUCAPE will continue to increase. The greatest severe weather threat will be with these storms as they enter a more unstable airmass. Hail looks to be the main threat with the early to mid morning storms. With these high values and moisture transport, there will be a potential for heavy rain to occur. Current forecast has between 0.75" and 1.75" with the higher totals in western portions of the local area and lower totals in southwest Wisconsin. Heading into Sunday, a ridge will strengthen over the eastern CONUS. As this ridge strengthens, strong southwesterly flow will be in place through early next week. This will allow for strong instability and humid conditions over the local area. With our area being on the western fringes of the ridge, cold and warm fronts will pass through each day. On Sunday, a cold front will enter the region from the northwest and bring the next chance of thunderstorms with it. There are still some uncertainties with exactly where this boundary will set up. Some models have it further northwest while the NAM has it centered over our area. Where this boundary sets up will be where storms fire up. This region will already have the available moisture and instability to support storms, all it needs is some shear to work with to maintain the storms. Even though the cold front itself will have some shear, most of the shear will remain off to the northwest where the jet stream is stronger and there are stronger winds aloft. With this in mind, SPC has given a slight risk (level 2 of 5) for severe weather for eastern Minnesota and portions of western Wisconsin. By Monday, the cold front that moved through, stalls out along I-90 through the morning. This will allow for continued chances of precipitation from the overnight period, to linger on through the morning. Eventually the warm air overcomes this boundary and pushes a warm front northward. The highest chances for severe weather and thunderstorms are expected to be where this boundary is as well as a surface low situated over the northern Plains. For Tuesday, most of the local area will be dry through the afternoon, before a cold front pushes through the area late Tuesday evening into the overnight period. This boundary will help to bring rain through the overnight into Wednesday. The severe weather potential remains low as even though there is ample instability and moisture, shear is quite low. There could be some mesoscale processes that help to amplify this severe potential, however the overall potential looks to be low. Something that is more consistent with guidance is the chance for heavy rain to occur. Periods of high moisture transport across the Upper Midwest remain through the week. Current guidance has between 1" and 2" for most places around the local area with potential for higher amounts. Something to note is that this pattern we are in continues to change each day, an example would be that Monday continues to trend drier and so total precipitation through the time period is lower than what it was with previous model runs. In addition to the rain, temperatures will be quite warm early next week. Ensemble and deterministic guidance continues to show strong southwest flow over the area, helping to increase temperatures. Current NBM probabilities have a high chance, between 70% and 95%, of most of the local area having 90F+ degrees occurring on Sunday and Monday. With these temperatures and heat indices approaching 100F, a heat advisory may be needed either Sunday or Monday. The chances lower for Tuesday, but there is still a decent signal for temperatures to be in the upper 80s to near 90F. Wednesday through the Weekend: More Rain Chances? As the rest of the week unfolds, the ridge begins to flatten out. Multiple shortwaves look to move through the region and the temperatures will cool slightly into the upper 70s to mid 80s. Rain chances will continue to be with us, as will the potential for heavy rainfall. This trend is different from yesterday, as the ridge was forecasted to shift westward and then break apart the following week. This would have meant warmer temperatures and a decrease in precipitation chances into the weekend. With the current ensemble and deterministic guidance, the pattern looks to remain active through the weekend. We will continue to monitor trends in the potential for heavy rainfall and severe weather. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1025 PM CDT Sat Jun 15 2024 CIGS: RAP and NAM still favoring a period of MVFR at the TAF sites moving through the overnight, mostly tied to areas of shra/ts. GFS and HRRR not as suggestive. Not much support from downstream obs, but rain and increasing low saturation favor the low cigs and will trend both TAF sites this way. Expect a scattering of the deck as a warm front pushes north of the TAF sites later Sun afternoon. WX/vsby: widespread shra/ts kicked off a few hours earlier than prev forecast as low level jet worked on various sfc boundaries. The pcpn will persist through the overnight night, with some consensus in the CAMS for clearing the pcpn east between 12-14z Sun. Warm front lifts north of the TAF sites Sunday afternoon, and where it ultimately lays up will be key for where further shra/ts are more likely - namely along/north of it. South of the boundary the atmosphere will be capped. Mixed messages in the models keeping forecast confidence on the low-end for how this plays out. For the moment, will keep the rain north of the TAF sites, adjusting based on later model runs/trends. WINDS: southeast becoming more southerly for Sunday. Expect to stay 10+ kts sustained through the period with gusts mostly in the low/mid 20 kts. Increasing low level jet will bring LLWS into the picture at KLSE for a few hours after 06z tonight. && .HYDROLOGY... Issued at 345 AM CDT Fri Jun 14 2024 At this time, it appears the local area can take the rainfall amounts expected through tonight. That being said, due to the higher rainfall potential over local areas, flood advisories/warnings could occur with repeated storms over the same area. The FFG of 2 to 3 inches for tonight would likely decrease after the rain tonight, so will need to assess for the multiple rounds of rainfall next week. Through Wednesday night, a large portion of MN could see 3-4"+ of rainfall. This would likely keep the Mississippi River elevated for the next couple of weeks. There is a 30% chance that the Mississippi River reaches Minor Flood Stage over the next 10 days through Winona (and 40% chance at Wabasha). && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...Cecava AVIATION.....Rieck HYDROLOGY...Zapotocny
Area Forecast Discussion
National Weather Service Grand Forks ND
1008 PM CDT Sat Jun 15 2024 .KEY MESSAGES... - Storms will arrive in the Devils Lake Basin and northern Red River Valley late tonight. They will be weakening as they move east, but a few isolated storms could still produce hail to quarter sized and 60 mph gusts. - A few isolated storms could develop in northwestern Minnesota Sunday afternoon and produce ping pong ball sized hail and 60 mph winds before quickly moving east. - Additional thunderstorms will move into southeastern North Dakota and west central Minnesota late Sunday night and continue into Monday. A few isolated storms could again bring some quarter sized hail and 60 mph winds gusts, but the main impacts with this system will be heavy rain and flash flooding into Tuesday. && .UPDATE... Issued at 1007 PM CDT Sat Jun 15 2024 Thunderstorm activity has diminished across the area this evening, with a few cells just north of Towner county moving into southern Manitoba. This lull in activity is looking to continue through the evening, with the next round of storms around the 10pm to 2am timeframe. Upstream activity in northwestern ND and also into central ND will be watched to see if it will be able to retain its structure as it heads into eastern ND. Shear will need to increase as well as the LLJ will need to align with the storms to help maintain them into our area. UPDATE Issued at 630 PM CDT Sat Jun 15 2024 Strong to Severe Thunderstorms are affecting areas in Cavalier and Towner counties this evening. This is co located to the location of the warm front, with strong surface vorticity and high instability. Sfc to 6km shear is 25-30kts, while low level sfc to 3km shear is less than 20kts. These storms will continue to build eastward over the next several hours along the theta E gradient. Further development later this evening and into the overnight period as development increases in central North Dakota. && .DISCUSSION... Issued at 316 PM CDT Sat Jun 15 2024 ...Synopsis... Southwesterly flow throughout the period sets up an active pattern for the Northern Plains, with a bit of a break currently. Main upper trough out over MT tonight will lift into Canada and help push a surface trough into the Red River Valley by tomorrow morning. Our western counties currently have some decent ML CAPE developing but the effective shear is around 25 kts or less and there is little forcing until later tonight when the trough approaches. HRRR and other CAMs have been fairly consistent on not bringing storms into our northwestern counties until late tonight, most likely after midnight. There will be a weakening trend, but HREF still has some good updraft helicity tracks still moving into the Devils Lake basin into the northern RRV. Overall, no changes to the messaging for severe weather, but did adjust to highlight later timing. Tomorrow, there is some differences in how far east the trough axis moves before peak heating hits, with a few of the CAMs breaking out strong to severe cells in our far eastern counties. Most of the HREF UH tracks are right along or just east of our CWA border, but cannot rule out a quick hail report up to ping pong ball sized and 60 mph winds before it is DLH`s problem. The bigger issue Sunday night will be with a shortwave lifting from the southwest into the eastern Dakotas, with surface low pressure developing to our southwest. A boundary will push north into our southern counties, and there is some question of how far north it will get. There is a good chance for some elevated instability Sunday night and into Monday as this boundary hangs around the area, with quarter sized hail and 60 mph winds still the main threats. However, with the 850mb jet bringing lots of moisture and PWATs nearly 3 to 3.5 standard deviations above normal, the main issue for Sunday night into early next week will be heavy rain. Set up for storm motion is also parallel along the frontal boundary which will be ideal for training. Probabilities of over 3 inches are over 50 percent in many locations in west central MN, and probs for over 4 inches are over 20 percent, which is high chances for that much rain. WPC has upgraded the excessive rainfall outlook to moderate, and will upgrade messaging. The main surface trough will be moving out on Tuesday, and much will depend on how Monday plays out but with at least some instability and plenty of moisture, heavy rain and severe potential will continue until the system finally pushes out Tuesday night. There should be a bit of a break with surface high pressure on Wednesday, but active pattern continues for the end of the week and into the weekend with southwesterly flow continuing and additional shortwaves coming through. Additional rainfall could cause impacts given how much is expected early in the week, but predictability is low for placement of greatest rain amounts as well as strength of storms at this point. Thus, will focus on the more immediate concerns. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 630 PM CDT Sat Jun 15 2024 Winds are decreasing slowly this evening for all TAF sites, but we continue to see GFK, DVL, TVF, and BJI gust up to 30kts. Around 02-04z winds should diminish as we loose day time heating. A cluster of strong to severe thunderstorms are moving through portions of the Devils Lake Basin this evening, but should remain toward the north of the DVL TAF site. There is a chance for VCTS as the storms move east. Better chances for -TSRA are around 6z-12z as further development of storms are expected out to the west. As the storms move through the region, winds will shift toward the west. This happens mid to late morning tomorrow, with gusts up to 25kts possible for TVF, DVL, and GFK 18z through the end of the TAF period. Ceilings drop to MVFR and isolated IFR 04-06z through 12-15z. Ceilings improve west to east. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Spender DISCUSSION...JR AVIATION...Spender
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1003 PM EDT Sat Jun 15 2024 .SYNOPSIS... Strong high pressure will remain across the region through the weekend. The high will linger over the region through much of next week keeping temperatures above normal. Isolated diurnal ridgetop showers and thunderstorms will be possible each day through Monday. Drier conditions are expected to return Tuesday into Friday. && .NEAR TERM /THROUGH SUNDAY/... As of 955 PM: Large uncapped SBCAPE remains near the southeast-facing Escarpment at 8 PM with weak easterly flow continuing. No surprise then that weak convection continues to bubble over the mountains and foothills. Some capping does eventually appear on prog soundings as ridge moves overhead, but until then little change in profiles, with enough low level wind to keep PBL mixed. Thus, kept PoPs as-is after earlier updates, as they appear more in line with observations than recent HRRR runs which have trended drier overnight. Outflow from Midlands convection has made it to southern Anderson and Greenville counties and that still could serve as a focus for new development in the next few hours. Still anticipate the sea breeze may reach the I-77 corridor by dawn, although that may be more of interest as a route low cloud cover could develop, so retained increasing sky cover at the end of the night in that area. Looks to become more convectively active across the mtns Sunday as se/ly BL flow develops and upslope enhancement helps produce pulse type storms. Dont anticipate severe level storms as the environ remain neg forced, but a couple cells could reach SPS strength as sbCAPE increases to arnd 1200 J/kg. Lows tonight will remain abv normal with increasing in cloud cover late, while highs Sun return to near normal levels. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... As of 110 PM EDT Saturday: An upper level anticyclone will be in place across the region through the short range period. On Sunday night and Monday, there will enough moisture and upslope flow to create showers and thunderstorms in the mountains. However, as the anticyclone strengthens, a strong drying trend is expected with Tuesday being an entirely dry day. Highs each day will be 2-3 degrees above climo, generally upper 80s in the Piedmont and mid 80s in the mountain valleys. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As of 145 PM EDT Saturday: The strong upper anticyclone will settle over the mid-Atlantic region for the middle to end of next week. This will lead to dry conditions and temperatures just a few degrees above climo. There may be an increase in moisture toward the week of the week leading to a return to a normal diurnal chance of showers and storms. Overall, it will be a pretty quiet period. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... At KCLT and elsewhere: Isolated SHRA over the NC mtns or adjacent foothills should gradually diminish diurnally this evening. However, sfc winds are expected to keep the PBL mixed and new development is not entirely out of the question overnight. Winds above the PBL are already SE, which should allow outflows from storms in the SC Midlands to push into the Upstate, and the sea breeze also may reach KCLT before dawn. Any new development should be isolated enough to omit from TAFs. CCLs may lower with an uptick in humidity behind either boundary, so lower VFR to MVFR level clouds remain possible in the predawn hours. Not confident enough to go with restrictive cigs. Still likely too mixed for any fog. SE flow will persist thru Sunday, and with lower LCLs/CCLs chance of diurnal SHRA/TSRA will be a bit better than it was today. Confidence supports VCSH at KAVL in the aftn. Outlook: More moist and generally southerly flow continues into Monday supporting another round of diurnal SHRA/TSRA. Upper anticyclone is likely to result in dry/VFR daytime conditions Tue-Thu, but nocturnal fog/stratus could develop in the early mornings. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...SCW NEAR TERM...SBK/Wimberley SHORT TERM...SCW LONG TERM...SCW AVIATION...Wimberley
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
743 PM CDT Sat Jun 15 2024 .KEY MESSAGES... - Seasonably hot and humid weather is on tap for next week. Heat index values will peak at or above 100 degrees from Sunday afternoon through Monday afternoon before readings settle back into the middle to upper 90s for the remainder of the week. && .UPDATE... Issued at 743 PM CDT Sat Jun 15 2024 Thicker high clouds have been moving past the I-74 corridor and will be out of the area soon. However, skies generally remain partly cloudy west of I-55 overnight, ahead of a shortwave currently across eastern parts of South Dakota and Nebraska. A couple small MCS`s are ongoing in this area and will lift northeast overnight. Latest HRRR runs have been suggesting a glancing blow early Sunday morning northwest of the Illinois River, though general CAM solutions have been tracking it more into northwest Illinois. Went ahead and added some 20% PoP`s early morning north of a Galesburg-Pontiac line to address this possibility. Otherwise, only minor edits made to the forecast grids at this time. Geelhart && .SHORT TERM...(Tonight through Sunday Night) Issued at 228 PM CDT Sat Jun 15 2024 A 1025mb high centered over southern Ontario continues to dominate the weather across central Illinois this afternoon. 19z/2pm temperatures are in the middle to upper 80s: however, dewpoints have diurnally mixed into the lower to middle 50s...resulting in comfortable conditions. Plenty of high cloudiness from a pair of short-wave troughs over the Plains is drifting eastward, leading to a high/thin overcast everywhere north of I-70. These clouds will persist through the night as the wave currently over western Kansas lifts northeastward toward the Great Lakes. CAMs keep any associated convection along/west of the Mississippi River late tonight into early Sunday morning, but will still need to keep an eye out for an isolated shower along/north of a Rushville to Bloomington line. Lows tonight will range from the lower 60s near the Indiana border to the upper 60s to around 70 degrees in the Illinois River Valley where cloud cover will be more prevalent. As the wave lifts into the Great Lakes, boundary layer winds will veer to the SW and increase behind a departing warm front. This will bring hotter and more humid air into the region, pushing afternoon highs into the lower to middle 90s. Thanks to dewpoints climbing well into the 60s to around 70 degrees, Sunday afternoon heat index values will peak around 100 degrees. Barnes .LONG TERM...(Monday through Next Saturday) Issued at 228 PM CDT Sat Jun 15 2024 The hottest day of the forecast period will be Monday when air temperatures reach the middle 90s and heat index values climb into the 100-105 degree range. The one mitigating factor for the heat will be southwesterly winds gusting 20-25mph. As has been seen by the past several model runs, increasing deep-layer moist advection from the western Gulf of Mexico will lead to an increase in cloud cover and the development of widely scattered convection Monday afternoon. The same scenario will unfold on Tuesday, with the increase in cloud cover leading to less hot high temperatures in the upper 80s and lower 90s and heat index readings below 100 degrees. After that, seasonably hot and humid summer-like weather will prevail for the remainder of the extended...with periodic very low chance PoPs. It does not appear any significant frontal boundaries will push into the region, so any convection that occurs will remain widely scattered and disorganized Wednesday through Saturday. Barnes && .AVIATION... (For the 00z TAFs through 00z Sunday Evening) Issued at 606 PM CDT Sat Jun 15 2024 VFR conditions to continue the next 24 hours, with periods of high level clouds, though scattered clouds near 5000 feet will develop Sunday morning. Southeast winds around 10 knots will trend more southerly by morning. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Lubbock TX
641 PM CDT Sat Jun 15 2024 ...New AVIATION... .SHORT TERM... (This evening through Sunday) Issued at 220 PM CDT Sat Jun 15 2024 Mid-level subsidence was noted over the entire forecast area this afternoon on the heels of a shortwave trough shifting east of Highway 83 in westerly flow. Despite this less than stellar theme aloft, the low levels remain rather moist ahead of a surface trough in eastern NM. West Texas mesonets have been sampling a corridor of consistently breezier S-SE winds over the SW South Plains in response to a mesolow near the Guadalupe Mountains. This locally backed and breezier flow should aid with speed convergence and eventually some storms late this afternoon and evening near the TX- NM border provided convective temps in the mid 90s are realized. Most recent HRRR runs have dialed back CI and overall coverage this evening across our western zones, yet this is suspect in light of ample heating, deeper mixing, modest CIN, and expanding cu field. Unlike last evening, storms this evening will exhibit a better E-SE push thanks to 30-35 knots of 0-6km shear. Inverted-V soundings with around 1500 J/kg of MLCAPE and similar amounts of DCAPE favor severe winds before activity declines overnight. Opted to keep NBM`s 20-30 PoPs largely intact on the Caprock as pros for CI outweigh the cons at this time. Moist southerlies stay with us on Father`s Day, yet chances for more storms trend toward zero under weak anticyclonic flow and rising thicknesses. && .LONG TERM... (Sunday night through next Friday) Issued at 220 PM CDT Sat Jun 15 2024 The mid/upper-level pattern will feature the amplification of a large-scale, positively-tilted trough over the western U.S. as a well-defined vorticity lobe rotates into the northern Great Basin early Monday, effectively shunting the subtropical ridge over the northeastern Pacific Basin southward. Farther east, a 596 dam, mid/upper-level ridge will continue to wobble over the eastern tranche of the U.S. as the belt of 250 mb flow between 90-100 kt becomes increasingly meridional over the central and northern Rocky Mountains, resulting in the CWA being positioned within the inflection point of these features. A secondary, more-zonal 250 mb jet streak is forecast to become coupled to the amplified flow over the Great Basin, with the nose of the former 250 mb jet streak emerging into western Texas and becoming increasingly difluent along the apex of the flattening ridge over Mexico. At the surface, lee cyclogenesis of a sub-990 mb low is expected to occur across eastern Colorado in response to the geopotential height falls and related DPVA, with a sharpened dryline extending southward along the TX/NM state line by the afternoon hours Monday. The CWA will be enveloped within the moist sector, where leeward pressure falls associated with the deepening cyclone to the north generate an isallobaric response that will cause winds to accelerate to 20+ mph with gusts near the 30-35 mph range amidst intense heating. Temperatures are forecast to reach the upper 90s across most of the CWA amidst a plume of dewpoints potentially in excess of 60 degrees extending to the west of the I-27/HWY-87 corridors. A conditionally-unstable airmass is expected to develop as the geopotential height falls and westerly, mid/upper-level flow facilitate maintenance of the elevated mixed layer (EML) atop the southerly low-level flow. The majority of the CWA will be capped, especially in the Rolling Plains, and the dry and hot forecast has been maintained across those locales as 700 mb flow remains veered to the southwest. Intense, diabatic heating; confluent flow nearest the dryline; and the advection of high theta-e air will act to enhance localized areas of convergence along the dryline and erode the strong MLCINH, which should allow parcels to maintain enough residence time to overcome the deleterious effects of entrainment and reach the LFC and result in the initiation of thunderstorms. Low, mentionable PoPs (<15 percent) have been introduced for Monday afternoon and evening across most locations west of the I-27/HWY-87 corridors. Coverage of storms should be widely-scattered at best, with the thinking of cells remaining isolated given the potential for multi-cellular splits early on in the convective stage and weak forcing for ascent aloft. The magnitude of the storm-relative inflow developing by the late-afternoon hours, in addition to the moist boundary-layer (e.g., lower 100 mb mean mixing ratios near 14-15 g/kg), should also support updrafts wide enough to become sustained for a few hours with supercell wind profiles present. The sizable EML indicated on point and area-averaged soundings leads towards the potential for rapid development; however, warm-cloud depths approaching 13 kft AGL should temper the threat for large hail with a focus towards damaging downdrafts and torrential rainfall. The potential for severe-caliber convection will wane after dark as diabatic stabilization occurs despite southerly winds remaining near 20 mph heading into the overnight hours. Broadly cyclonic flow will continue to eclipse the CWA on Tuesday; however, the primary cyclone associated with the mid/upper-level troughing to the west is forecast to rotate into north-central Canada, governing a poleward response to the ridging over the Gulf of Mexico with a slight increase in geopotential heights occurring. Hot and dry weather is expected area-wide on Tuesday as the airmass will be strongly capped beneath the large EML aloft; however, the presence of the EML remaining over the CWA will have implications for the remainder of the forecast period. Thunderstorm chances are forecast to improve across the entire CWA as southwesterly flow aloft remains intact atop the reservoir of subtropical moisture originating from the Gulf of Mexico. There are some differences among the global NWP guidance on the position of the stalling front to the north of the CWA on Wednesday as the aforementioned cyclone in north-central Canada rotates into the Hudson Bay, but there exists a consensus that the front will stall in the vicinity of the OK/TX PH; and the thinking leans towards this scenario given the proximity of the barotropic airmass spread across the region. NAEFS and ENS guidance are indicating precipitable water (PWAT) content rising to nearly two standard deviations above normal Wednesday night into Thursday. Interpolation of the 20-21/00Z sounding climatology from WFO MAF indicates that the forecast PWAT content will be near or exceeding the 99th percentile across the CWA during this time. This points towards the potential for heavy rain across portions of the Caprock and Rolling Plains by the middle and end of next week; however, specificity of where heavy rainfall occurs remains nebulous owing to the limited predictability in the potential placement of thunderstorms. The blended PoPs have been maintained, and it is possible that PoPs may be increased in forthcoming cycles. Cooler temperatures are also forecast by Wednesday onward as southeasterly low-level flow remains intact beneath thickening cloud debris from the daily rounds convection. Sincavage && .AVIATION... (00Z TAFS) Issued at 632 PM CDT Sat Jun 15 2024 There is a window for ISO-SCT TS to pass in the vicinity of KLBB between 01 and 05 UTC, with a lower potential for the same at KPVW. Included a VCTS at KLBB but not at KPVW where confidence is low. There is also a small potential for low CIGS around KLBB Sunday morning, but confidence is too low to add to the TAF. Outside of any low stratus and thunderstorm activity, VFR conditions will prevail with modest S to SE breezes, which will increase late in the day Sunday. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...93 LONG TERM....09 AVIATION...33
Area Forecast Discussion
National Weather Service Memphis TN
917 PM CDT Sat Jun 15 2024 ...New UPDATE... .UPDATE... Issued at 905 PM CDT Sat Jun 15 2024 Skies are mostly clear across the Mid-South this evening with temperatures ranging from the mid 70s to mid 80s. Some isolated showers and thunderstorms developed late this afternoon across portions of the Mid-South, but all of this activity has gone away. This will leave a dry and warm night across the region with lows Sunday morning in the low to mid 70s. Current forecast looks good with no update needed. && .SYNOPSIS... Issued at 215 PM CDT Sat Jun 15 2024 Hot and humid conditions will persist through Sunday with heat indices reaching the triple degree mark areawide. Cooler temperatures along with chances for showers and thunderstorms will return for Monday and Tuesday as Gulf moisture streams into the region. Dry and hot conditions will return late week with temperatures approaching the mid 90s. && .DISCUSSION... (This evening through next Friday) Issued at 215 PM CDT Sat Jun 15 2024 Our first bout of summer heat is well underway across the Mid- South at this hour. Temperatures are in the low to mid 90s with heat indices around 100F areawide. The latest GOES-East Water Vapor Imagery reveals strong subsidence and abundantly dry air aloft across the Lower Mississippi Valley. The latest RAP analysis depicts a 590dam ridge centered over west and middle Tennessee with a shortwave trough over the Central Plains. Sunday will be nearly a carbon copy of today, albeit a degree or two hotter. A heat advisory may be needed for our extreme southwest counties Sunday, but current guidance suggests that heat indices will only peak around 103 or 104 F. The aforementioned ridge is expected to slowly drift east through early next week. As it does, deep Gulf moisture will advect into the Lower Mississippi Valley. Weak perturbations will rotate clockwise around the ridge and into the Mid-South Sunday night through Tuesday night. Although, it will not be a total washout, model consensus suggests isolated to scattered showers and thunderstorms will be possible each day. Tuesday will be the coolest day of the period, with highs peaking only in the mid 80s due to heavy cloud cover and scattered showers and storms. The ridge of high pressure will strengthen and retrograde back west into the Lower Mississippi Valley by midweek. This will bring the return of hot and dry conditions to the region. Temperatures will remain 4 to 6 degrees above normal with highs in the mid 90s and lows in the low to mid 70s. The positive news is that reduced humidity will keep heat indices below 100F through late week. Long term guidance suggests that the ridge may weaken by next weekend and allow a cold front to drop down into the Mississippi Valley. AC3 && .AVIATION... (00Z TAFS) Issued at 654 PM CDT Sat Jun 15 2024 A quiet evening and overnight period is expected. TMEM radar shows a shower near downtown Memphis, moving northwest away from MEM and weakening. Expect a bit tighter low level pressure gradient on Sunday, resulting in surface winds near 10KT at most TAF locations. LAMP and NBM guidance have a 10-15% chance of measurable rainfall Sunday afternoon. NAM soundings depict a warm layer near FL100 limiting TSRA potential below PROB30 thresholds at this time. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...AC3 AVIATION...PWB
Area Forecast Discussion
National Weather Service Raleigh NC
900 PM EDT Sat Jun 15 2024 .SYNOPSIS... A stationary front will remain pinned south of central North Carolina through tonight then pivot up across western North Carolina through Sunday. High pressure will extend into the region from the Atlantic through much of the upcoming week. && .NEAR TERM /THROUGH TONIGHT/... As of 900 PM Saturday... A 1022mb surface high pressure located over the Great Lakes this evening will continue shifting eastward toward New England tonight behind a cold front that has settled and stalled south of our area. Behind the front dewpoints have fallen into the lower 60s and upper 50s, especially across the north. The seabreeze has been penetrating inland aggressively this evening and allowing some elevated dewpoints to also penetrate back inland. There is relatively good model agreement that moisture confined to a shallow layer below a strong subsidence inversion at 700mb, will shift westward into the western Piedmont overnight with increasing easterly low-level flow flow around the high to our north. The NAM even suggest a tongue of up to 1000 MUCAPE nosing toward the Triad by 09Z, and while that amount of CAPE may be overdone, the HRRR has been consistent in developing some showers in the western Piedmont by daybreak. There is some evidence of the shower activity in the southern NC mountains already this evening. If the showers do not develop prior to sunrise, the moisture convergence should be available for isolated showers through mid morning, with a fair amount of stratus or stratocu. Lows tonight in the upper 50s to mid 60s. && .SHORT TERM /SUNDAY AND SUNDAY NIGHT/... As of 225 PM Sunday... A strong ~593dm upper level anticyclone will shift eastward and will become centered over NC. Underneath the associated 30 meter H5 rises, surface high centered over New England will ridge south down the mid-Atlantic and Carolina seaboard. Differential heating and terrain-induced lift via low-level SELY flow along the eastern slopes of the southern Appalachians will support scattered showers and storms across the NC mtns and foothills during the afternoon and evening. Given proximity to this weak forcing and/or associated outflow, cannot rule out a stray shower across the far western counties. Otherwise, dry conditions will persist. The low-level easterly maritime flow into the area will also result in slightly cooler daytime highs. Highs ranging from mid 80s north to lower 90s south, with noticeably less humid air, especially across the eastern half of the forecast area near the low-level ridge axis where dewpoints will lower into the 50s. Lows Sunday night 63-68 with some patchy fog/stratus possible. && .LONG TERM /MONDAY THROUGH SATURDAY/... As of 233 PM Saturday... ...Hot and dry next week with increasing temperatures and minimal rain chances... The forecast for much of the upcoming week will feature dry weather with increasingly warm temperatures. An anomalously strong H5 ridge (with heights around 592-594dm) will center itself over NC on Monday and remain virtually stationary through the middle of the week. At the surface, high pressure off the coast will promote a prolonged period of southeasterly winds through Wednesday. While there will be some moisture on the periphery of the ridge, it`s likely to pool against the mountains to our west with any potential for showers or storms confined to areas of the far western Piedmont. Elsewhere, it`ll be a challenge to get much more than high clouds across the area given strong subsidence throughout the column. Temperatures for the first half of the week should range from the low to mid 90s, with overnight lows generally in the upper 60s to lower 70s. On Thursday the ridge will strengthen further and begin to shift northward. By late week, 500mb heights are forecast to approach 596- 597dm which would be near record values at KGSO for mid June. At the surface, this will translate to even warmer temperatures with late week highs ranging from the mid to upper 90s. Return flow from the ridge will serve to advect additional moisture into the area and precip chances will increase, but only slightly. Strong subsidence aloft will likely limit the potential for any widespread/beneficial precipitation across the area but afternoon pulse-type showers could potentially become more common by next weekend. Grand ensemble still only suggesting 10-15 percent PoPs late in the week which is certainly higher than earlier in the week, but still below climo. Of note: there are some 12Z ensemble members that suggest a subtropical plume of moisture and troughing will enter the area late in the week but exactly how that evolves and what (if any) forcing mechanism comes into play is still very uncertain. In terms of sensible weather impacts next week, increasing temperatures could be problematic for individuals that are sensitive to heat. While Heat Index values will generally stay out of the triple digits through next Saturday (thanks in large part to dewpoints in the 60s vs the 70s), other heat tools such as Wet Bulb Globe Temperature (which takes into account full exposure to the sun along with wind speeds and humidity) and HeatRisk (which examines temperatures relative to climatology along with CDC data) suggest next weekend`s conditions could warrant the first heat-related headlines of the year for portions of central NC. However, the chance of showers and storms and associated cloud cover could keep conditions below dangerous values, adding to the uncertainty of next weekend`s forecast. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... As of 750 PM Saturday... There is a low probability of a brief MVFR to IFR cig may develop near the Triad terminals within a tongue of increased moisture as it advects E to W across central NC after midnight. Confidence remains low on the development of low MVFR cigs after daybreak at GSO/INT, but latest NWP continues to hint at this possibility especially among the more pessimistic guidance. Elsewhere, VFR conditions are expected through the 24 hour TAF period. Surface winds will remain stirred overnight veering to E to SE through the afternoon/evening. Outlook: Some early morning stratus is possible at KINT/KGSO Mon morning. Otherwise, VFR conditions are expected through the period. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Swiggett/Kren NEAR TERM...BLS SHORT TERM...CBL LONG TERM...Leins AVIATION...Swiggett/Kren