Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/26/24


Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
652 PM MDT Sat May 25 2024 ...New UPDATE... .UPDATE... Issued at 650 PM MDT Sat May 25 2024 Winds across the highlands of the central mts and eastward have decreased below warning and advisory criteria and will continue diminishing through the evening. The High Wind Warning and Wind Advisory have been allowed to expire. && .SYNOPSIS... Issued at 223 PM MDT Sat May 25 2024 Critical to extreme fire danger is expected through this evening, rapidly spreading any active fires and additional ones that are started. Wildfire smoke will impact areas downwind of the Blue 2 fire, including Ruidoso. Winds trend weaker tomorrow in most areas, but elevated to locally critical fire weather conditions are still likely along and east of the central mountain chain. Pleasant weather is forecast for Memorial Day with slightly above average temperatures and a light breeze. Temperatures will rise early next week as winds continue to drop. Moisture will likely return to eastern NM, potentially generating showers and storms each afternoon Tuesday through the end of the week. && .SHORT TERM... (This evening through Sunday night) Issued at 223 PM MDT Sat May 25 2024 A fast-moving upper level trough moving north of the Four Corners region today has forced a 110 kt speed max and associated dry slot over NM. As of 2pm, winds have increased to between 30 and 40 mph in most areas with localized gusts near 50 mph from Ruidoso to Dunken and isolated spots of eastern NM. The core of 45 to 55 kt 700-500mb winds is still on target to cross southern and eastern NM centered around 6pm. Winds will likely increase further thru late today as the 12Z HREF shows peak gust timing from 4pm to 7pm with a subtle west wind shift. No additional changes are needed to the current Wind Advisories and High Wind Warnings. Blowing dust will increase as well, especially areas that have not received wetting rainfall in the past couple weeks. The area around Roswell will be monitored closely for potential impacts to the Relief Route as winds pick up from the southwest. Significant downwind smoke impacts are possible as well across parts of eastern NM based on surface-concentrations from HRRR and BlueSky. A subtle west wind shift will occur thru sunset as a weak Pacific cold front passes thru the region. Winds will diminish slowly in the wake of the front in most areas. The exception will be along the central mt chain with westerly downslope winds continue thru the entire night. A few locales may still see gusts over 35 mph all night. Winds will then shift from west/northwest Sunday with breezy conditions focused over the high plains of eastern NM, especially around Clines Corners. Overall, a much better day is expected other than lingering smoke impacts from any active fires. Temps will trend slightly cooler with slightly higher humidity as well under sunny skies. Lighter winds will take hold Sunday night under clear skies and seasonably cool temps. && .LONG TERM... (Monday through Friday) Issued at 223 PM MDT Sat May 25 2024 Pleasant late Spring weather is expected for Memorial day with near to slightly above average temperatures, light winds, and partly cloudy skies. Confidence continues to increase that ridging will amplify over the Intermountain West early next week, bringing temps further above average and also helping Gulf moisture sneak into eastern NM. Tuesday looks like it could be the first of several days with dryline convection in eastern NM. A shortwave grazing the area in combination with LIs as low as -10C and steep mid-level lapse rates indicate there is the potential for strong storms on Tuesday afternoon in eastern NM if the dryline pushes far enough west. Depending on the location and intensity of convection, Albuquerque could see an east canyon wind Tuesday morning and again Wednesday morning. Elsewhere, winds should be relatively light through the end of the week. If ridging sticks around, shower and storm chances will continue for eastern NM, but if a trough develops over the central Rockies late week, stronger westerlies could kick the dryline back to the east. As far as temperatures go, highs should hover near to as much as 10 degrees above average throughout the week, with the hottest weather likely Tuesday and Wednesday when Albuquerque could see its first 90F day of the year. Highs in eastern NM will be pushing the mid-90s each day, although these could drop in future days if the dryline is expected to setup further west. Higher dewpoints and increased cloud cover across the east could help to keep overnight lows a few degrees above average as well. && .AVIATION... (00Z TAFS) Issued at 535 PM MDT Sat May 25 2024 Gusty wly and swly winds will persist through the early evening before tapering off aft sunset. BLDU and FU from nearby wildfires may impact vsbys through the evening, particularly at KROW and KCVS. FU may also settle in valley locations overnight, including the upper Rio Grande Valley, creating impacts to vsbys. Winds will remain elevated most terminals overnight, with the potential for LLWS in and around the nrn mts and their adjacent highlands-- including KLVS--btwn 26/08Z and 26/15Z. Breezy wly to nwly winds will prevail tomorrow. HZ and FU may impact vsbys tomorrow aftn, most notably around KROW, KLVS, and KSAF. && .FIRE WEATHER... Issued at 223 PM MDT Sat May 25 2024 ...CRITICAL TO EXTREME FIRE WEATHER CONDITIONS AREAWIDE TODAY, THEN CRITICAL CONDITIONS MAY RETURN TO THE CENTRAL HIGHLANDS SUNDAY... Widespread strong winds over the region today will taper off in most areas between sunset and midnight. Locations along the east slopes of the central mt chain will likely see breezy west winds continue for the entire night. West to northwest winds Sunday will remain breezy along the central mt chain with a focus around the Central Highlands from near Las Vegas to Clines Corners and Vaughn. There is a small area of critical fire weather based on wind and humidity but Haines indices are moderate and RFTI category is subcritical. The Fire Weather Watch will not be upgraded given lower confidence. A break to the fire growing pattern will beginning Sunday night. Low level moisture will begin sloshing over eastern NM next week while a weak ridge of high pressure develops over the region. Temps will be much warmer as well with the hottest readings so far this season over central and western NM. Eastern NM will see increasing chances for showers and storms, especially Tuesday through Thursday. && .PRELIMINARY POINT TEMPS/POPS... Farmington...................... 44 77 45 84 / 5 0 0 0 Dulce........................... 33 75 34 80 / 10 0 0 0 Cuba............................ 39 73 43 79 / 0 0 0 0 Gallup.......................... 35 77 39 83 / 0 0 0 0 El Morro........................ 37 73 43 79 / 0 0 0 0 Grants.......................... 36 78 39 83 / 0 0 0 0 Quemado......................... 38 75 43 81 / 0 0 0 0 Magdalena....................... 46 78 50 82 / 0 0 0 0 Datil........................... 41 74 45 79 / 0 0 0 0 Reserve......................... 33 82 39 86 / 0 0 0 0 Glenwood........................ 48 85 53 90 / 0 0 0 0 Chama........................... 32 68 35 73 / 10 0 0 5 Los Alamos...................... 47 73 50 78 / 0 0 0 0 Pecos........................... 45 74 48 79 / 0 0 0 0 Cerro/Questa.................... 38 68 43 72 / 0 0 0 0 Red River....................... 33 65 35 69 / 0 0 0 5 Angel Fire...................... 32 67 32 71 / 0 0 0 0 Taos............................ 36 75 37 79 / 0 0 0 0 Mora............................ 41 72 42 76 / 0 0 0 0 Espanola........................ 45 81 45 85 / 0 0 0 0 Santa Fe........................ 45 76 50 80 / 0 0 0 0 Santa Fe Airport................ 45 79 48 83 / 0 0 0 0 Albuquerque Foothills........... 52 81 56 86 / 0 0 0 0 Albuquerque Heights............. 48 83 53 87 / 0 0 0 0 Albuquerque Valley.............. 48 85 51 89 / 0 0 0 0 Albuquerque West Mesa........... 50 83 54 87 / 0 0 0 0 Belen........................... 46 85 49 89 / 0 0 0 0 Bernalillo...................... 49 83 52 88 / 0 0 0 0 Bosque Farms.................... 46 85 48 89 / 0 0 0 0 Corrales........................ 48 84 52 89 / 0 0 0 0 Los Lunas....................... 46 85 49 89 / 0 0 0 0 Placitas........................ 51 78 53 84 / 0 0 0 0 Rio Rancho...................... 50 83 53 87 / 0 0 0 0 Socorro......................... 50 88 54 92 / 0 0 0 0 Sandia Park/Cedar Crest......... 47 73 51 78 / 0 0 0 0 Tijeras......................... 45 77 49 82 / 0 0 0 0 Edgewood........................ 44 78 45 83 / 0 0 0 0 Moriarty/Estancia............... 41 78 41 84 / 0 0 0 0 Clines Corners.................. 44 73 46 79 / 0 0 0 0 Mountainair..................... 43 77 47 82 / 0 0 0 0 Gran Quivira.................... 43 77 47 83 / 0 0 0 0 Carrizozo....................... 50 82 53 87 / 0 0 0 0 Ruidoso......................... 49 75 50 81 / 0 0 0 0 Capulin......................... 42 74 43 76 / 0 0 0 0 Raton........................... 42 79 43 81 / 0 0 0 0 Springer........................ 42 80 43 81 / 0 0 0 0 Las Vegas....................... 45 76 44 79 / 0 0 0 0 Clayton......................... 50 81 50 83 / 0 0 0 0 Roy............................. 46 81 48 81 / 0 0 0 0 Conchas......................... 51 88 52 88 / 0 0 0 0 Santa Rosa...................... 51 83 50 86 / 0 0 0 0 Tucumcari....................... 55 88 51 90 / 0 0 0 0 Clovis.......................... 55 89 55 92 / 0 0 0 0 Portales........................ 56 91 54 94 / 0 0 0 0 Fort Sumner..................... 54 88 53 91 / 0 0 0 0 Roswell......................... 58 95 59 97 / 0 0 0 0 Picacho......................... 52 86 55 90 / 0 0 0 0 Elk............................. 49 86 52 90 / 0 0 0 0 && .ABQ WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 9 PM MDT this evening for NMZ101-104>106- 109-120>126. Fire Weather Watch from Sunday afternoon through Sunday evening for NMZ125. && $$ SHORT TERM...42 LONG TERM....16 AVIATION...12
Area Forecast Discussion
National Weather Service Columbia SC
1030 PM EDT Sat May 25 2024 .SYNOPSIS... A frontal boundary is expected to stall near the forecast area resulting in chances for afternoon and evening showers and thunderstorms through tomorrow. Another, more organized system is expected to cross the eastern US Monday and Tuesday with additional chances for thunderstorms. Drier weather is expected to return Wednesday. && .NEAR TERM /UNTIL 7 AM SUNDAY MORNING/... A few showers and thunderstorms continue to move across portions of the Eastern Midlands this evening. They are currently below severe limits and unlikely to develop much further with the loss of daytime heating. The entire forecast area should be dry around midnight. Skies should be generally clear tonight outside of areas of low clouds and patchy fog. Forecast low temperatures will be in the mid-60s to near 70 degrees. && .SHORT TERM /7 AM SUNDAY MORNING THROUGH TUESDAY/... A flat H5 ridge axis is forecast to move across the region on Sunday. Subsidence underneath the ridge axis should be an inhibiting factor for convection initiation, especially for the central and southern Midlands as well as the CSRA. The Northern Midlands could be close enough to disturbances moving into the Mid Atlantic States for a greater chance of convection. The atmosphere remains moist and unstable area wide with afternoon SBCAPE values in excess of 1500 J/KG and PW values around 1.5 inches. The Eastern U.S. undergoes a major pattern changes Memorial Day through Tuesday with an unseasonably strong upper low moving into the Great Lakes region. The Midlands and CSRA will begin to experience H5 height falls on Memorial Day and continue into Tuesday. An unstable and moist airmass will be over the region on Memorial Day with afternoon SBCAPE values around 2000 J/KG and PW values up to 1.75 inches. A cold front approaches the region in the late afternoon or evening time frame. The forcing is not lined up time wise with the best instability. SPC has our region in a Marginal Risk of severe weather on Memorial Day with a Slight Risk over much of North Carolina. The Slight Risk could be extended southward during the next update. Damaging wind gusts are the primary concern. A cold front moves across the region Monday Night before stalling offshore on Tuesday. PW values decrease to below one inch during the day with dew points dropping into the 50s. If this forecast solution verifies, cooler and much drier conditions push into the region. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... Ensembles depict a high probability of much below normal H5 heights across the Eastern U.S. next week. This should allow Canadian surface high pressure to move into the region Tuesday Night through the end of the week. Temperatures and dew points should be below normal with dry weather. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... VFR conditions expected although some early morning fog or stratus is possible late tonight...at AGS. Weak surface trough across the area with ridge offshore. Convection moving well east of the terminals at 00z. Satellite showing mainly mid level clouds in the wake of the convection. winds will become light and variable overnight. Lamp and HRRR guidance is suggesting some MVFR fog near AGS late tonight and early Sunday. Ridge offshore Sunday and expect southwest winds 5 to 10 knots. The air mass will be moderately unstable again. A flat upper ridge will be over the area and overall thunderstorm threat appears lower with Convective models suggesting thunderstorms will focus north of the terminals in the afternoon. However, can`t rule out isolated thunderstorms near the terminals after 18z with scattered cumulus. EXTENDED AVIATION OUTLOOK...Restrictions possible Monday afternoon in scattered thunderstorms as a cold front approaches. Otherwise, significant restrictions not expected. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$
Area Forecast Discussion
National Weather Service Peachtree City GA
1016 PM EDT Sat May 25 2024 ...Late Evening Update... .UPDATE... Issued at 1010 PM EDT Sat May 25 2024 Aside from a few isolated rain showers all is quiet across North and Central Georgia at this hour. Current temperature readings are in the 70s with light and/or variable winds. Patchy fog and low clouds will be possible early Sunday morning as a result of recent rain. Latest hi-res guidance indicates another MCS may clip portions of far North GA on Sunday. Aside from this feature, given that there is no change in the present airmass, diurnally driven convection particularly in the vicinity of remnant outflows will be possible Sunday afternoon. Though chances are on the lower end due to uncertainties. A few tweaks to PoPs, temps and sky grids were made to reflect current trends. && .SHORT TERM... (This afternoon through Sunday) Issued at 222 PM EDT Sat May 25 2024 The line of thunderstorms continues to move to the southeast, into an area which has received plenty of destabilizing sunshine. MUCAPE across the southern CWA hangs around 2000 to 3000 J/KG. However limited forcing outside the cold pool and little to no shear mean thunderstorms will likely continue to pulse up and fall along the cold pool. Conditions behind the line are significantly more stable with MUCAPE values of ~1000 and over 250 CIN. Given the limited time for reheating, have left very low PoPs for the possibility of an isolated thunderstorm or shower later this afternoon across the region. Winds overnight die out with ample surface moisture. This may mean some patchy fog overnight across North and Western GA. Small PoPs return across Northeast GA tomorrow morning into early tomorrow afternoon with several CAMs indicating a potential MCS through Eastern TN into the Carolinas which may clip the area. Impacts for the CWA from this should be low, though some precipitation and some thunder is possible. Our next chance for thunderstorms comes Monday with a more energetic front. This system could have some stronger to severe thunderstorms. GEFs ensemble indicated 60 to 80% probs of CAPE greater than 2000 J/KG and 40 to 50 kts of shear. This currently looks like more of a wind threat than anything although. We will continue to watch this as models initialize with a better solution of our current system. SM && .LONG TERM... (Monday morning through next Friday) Issued at 222 PM EDT Sat May 25 2024 Active weather is still expected for the first part of next week. A cold front is expected to move through the CWA later Monday into Tuesday. The higher res models are producing an MCS out ahead of the main frontal boundary early on Monday. Since the models continue to struggle with the MCS/MCV/shortwave systems, timing and coverage of storms will likely have to be adjusted later forecast cycles. The HRRR has been better lately with trends further out in the forecast cycle than within the first 12 hours. Fairly quiet weather anticipated for the remainder of the week. No major changes needed. NListemaa && .AVIATION... (00Z TAFS) Issued at 725 PM EDT Sat May 25 2024 VFR conditions will continue at all sites over the next several hours. Still observing SCT Cu at 3-5kft across the area though should begin to diminish after 02z. Given rainfall today, patchy fog and lower cigs will be possible as early 09z Sunday. Timing and occurrence of additional shra/tsra is still largely uncertain for Sunday. Given no change in the airmass, tsra may develop near remnant outflows boundaries. At this time do not have the mention of tsra in the TAF given low confidence and uncertainties. This may change in subsequent TAF packages. Winds remain out of the SW 3 to 10kts with some isolated gusts nearing 18kts possible Sunday aftn. //ATL Confidence...00Z Update... Low to medium confidence on tsra potential for Sunday PM and on timing/extent of IFR cigs Sunday AM. High confidence on remaining elements. 07 && .PRELIMINARY POINT TEMPS/POPS... Athens 67 90 69 86 / 20 20 30 60 Atlanta 69 91 71 86 / 20 20 30 60 Blairsville 63 84 64 79 / 20 40 60 70 Cartersville 66 90 68 86 / 20 20 50 70 Columbus 70 93 72 89 / 30 0 10 50 Gainesville 67 88 70 84 / 20 30 40 70 Macon 69 93 71 89 / 20 10 10 50 Rome 67 89 70 86 / 20 20 50 60 Peachtree City 67 91 69 87 / 20 10 20 60 Vidalia 70 93 72 92 / 20 10 0 30 && .FFC WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...SM LONG TERM....NListemaa AVIATION...07
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
900 PM CDT Sat May 25 2024 .KEY MESSAGES... - Severe weather returns tomorrow morning. The line of thunderstorms is expected to move through from 5am to noon. Main hazards with this line is large hail and damaging wind. - There is a second round of severe weather tomorrow afternoon. It will be a mix of discrete supercells that eventually merge into a line. This will be an all hazards possible round: large hail, damaging winds, tornado or two, and flooding. - Flash flooding is most likely to occur where the outflow boundary will set up over the are that was affected yesterday and is very saturated already. A Flood Watch is in effect from 7pm to midnight tomorrow. - After tomorrow the weather will be dry and pretty through most of next week. && .UPDATE... Issued at 900 PM CDT Sat May 25 2024 Low pressure has migrated into western KS, while the high pressure center that was over IL today as moved northeast of the area. The resulting pressure gradient has allowed a light southeast wind to initiate across much of central IL after a mostly calm wind day, and this wind will increase to a breezy 15 mph or so by Sunday morning as the low continues toward IL overnight. Supercell thunderstorms ahead of the low this evening will likely develop into a more organized line or cluster of storms as they head toward central IL by morning. High resolution models bring the first storms into the central IL forecast area around 5 to 6 AM and continue them eastward through the I-57 corridor by 10 AM. These storms continue to have a risk of large hail and severe wind gusts. Timing is a bit earlier than previously forecast, so have updated forecast with storm timing/location an hour or two/county or two earlier/farther east than the afternoon package. Otherwise, lows mainly in the lower 60s look on track for tonight. 37 && .DISCUSSION... Issued at 252 PM CDT Sat May 25 2024 With a high pressure in place today, weather has been calm and beautiful. It has provided a nice breather before the next round of active, potentially severe, weather tomorrow morning. Skies have been clear and sunny. Highs today have been around the upper 70s. Lows tonight are expected to drop down to the low 60s. Tomorrow is a different story. POPs increase again late tonight into early tomorrow morning. The models struggled with the previous event that moved through yesterday and once again today, they are not agreeing on timing and evolution of the event. Both the NAM 3km and HRRR show an initial line moving across the CWA tomorrow morning, but the way the afternoon unfolds is uncertain. However, that uncertainty could mostly play into if the environment can recover sufficiently from the morning convection, which could also be playing a factor in how the models are depicting the afternoon "mess". Timing on the HRRR is showing the initial line of storms moving across central and southeastern Illinois from 10z to 18z tomorrow morning. Whereas, the NAM 3km is showing 13z to 18z. So the consensus is that the line of storms should be out of the area by early afternoon, but the start time is still variable by a couple hours. The ARW model shows it entering around 12z. To generally summarize when we think the line will begin to affect our area, it should be around the time everyone is waking up in the morning. Mesoscale Factors....... The morning time has MUCAPE of 2000-2500 J/kg, lapse rates aren`t super impressive (~7.5-8.5 C/km), and bulk shear 30-40 knots. This round of convection appears to be elevated, bringing the primary risk of large hail and damaging winds and limiting the tornado threat. In the afternoon, the risk shifts some. The CAPE becomes more surface based (SBCAPE of 1500-2000 J/kg). The lapse rates are impressive just as the CI begins (LR of 9 C/km) but quickly weaken as we go into the evening hours. Bulk shear increases to 40-60 knots. The initial storm mode in the afternoon could be supercells with a tornado and large hail risk but will transition to a more linear mode as we go into the evening, shifting the hazards to more a flash flooding, large hail, and damaging wind set up. This initial line will arrive well before the front and will be associated with a strong shortwave passage, with the afternoon convection potentially firing along the outflow boundary of the morning line. If the afternoon round sets up along and south of I-72 again, we could have some flooding concerns. Forecast soundings from the GFS and NAM show PWAT values in that area of 1.5 to 2 inches and somewhat long, skinny CAPE. Our storm motion is too quick so the threat will come from training storms over the same areas that have already been saturated to the max over the past week. The cold front should move through tomorrow evening. After tomorrow the next real chance for any rain comes on Friday. Temperatures will slowly rebound this week. The first part of the week the highs will be in the low to mid 70s and by Thursday high will be getting to the low 80s. The skies should be blue and clear for the most part this coming week after Sunday. Copple && .AVIATION... (For the 00z TAFs through 00z Sunday Evening) Issued at 651 PM CDT Sat May 25 2024 A few rounds of strong to severe thunderstorms are possible across the central IL terminals after around 12Z Sunday. The first round looks to sweep across the area from around 12Z-16Z, then there is much higher uncertainty in timing and location with subsequent rounds. MVFR to possible brief IFR conditions are possible with these storms, especially from 12Z-20Z where MVFR cigs will likely be predominant. Winds light and variable, then SE 5-10 kts after 03Z, shifting to S and increasing to 12-16 kts with gusts 20-28 kts by around 16Z. 37 && .ILX WATCHES/WARNINGS/ADVISORIES... Flood Watch from 7 AM CDT Sunday through late Sunday night for ILZ044>046-049>057-061>063-066>068-071>073. && $$
Area Forecast Discussion
National Weather Service Indianapolis IN
1204 AM EDT Sun May 26 2024 .KEY MESSAGES... - Dry and Mild Tonight - Storms arrive on Sunday, mid-morning through mid-afternoon. - Severe Thunderstorms storms will be likely Sunday; Tornadoes possible && .FORECAST UPDATE... Issued at 915 PM EDT Sat May 25 2024 Surface high pressure, over Lake Michigan, along with a flat ridge and dry column has lead to clear skies across central Indiana this evening. Good confidence that it will remain dry overnight as well with only perhaps some increase in high cloud debris from the approaching Plains convection. Would not completely rule out fog toward daybreak but an approaching upper trough will act to veer and increase southeast winds overnight to 10 knots which should discourage fog. && .SHORT TERM (This evening through Sunday)... Issued at 213 PM EDT Sat May 25 2024 Synopsis: Surface analysis early this afternoon shows strong high pressure in place over western IL. Light but cool NW flow was in place across Central Indiana. GOES16 shows some stratocu clouds across central Indiana on the leading edge of the approaching high pressure system. Clearing was building across northwest Indiana, pushing east. Water vapor imagery shows an area of subsidence pushing across Indiana and Illinois. Looking farther west, a moderate trough was found over the inter-mountain west, with southwest flow and lift ahead of this system over CO emerging into the high plains. Temperatures over Central Indiana were in the mid to upper 70s with dew points in the lower 60s, revealing relatively moist lower levels. Tonight - Models suggest the surface high pressure will push across Indiana and reach the eastern Great Lakes overnight. Forecast soundings across Indiana reveal a dry column through the night as weak southerly flow on the backside of the high develops. A strong dry layer looks to remain within the middle levels due to previous subsidence. Thus mostly clear but mild weather will be expected overnight. Look for lows in the upper 50s and lower 60s. Meanwhile the trough to the west is expected to emerge over the plains and generate a strong convective system, an MCS, and an associated area of surface low pressure. These features are these features are expected to propagate toward Central Indiana, but not reach Indiana, setting the stage for storms on Sunday. Sunday - An active weather day will be expected. High confidence for rain on Sunday. Severe storms will be possible with damaging wind gusts, very heavy rain, lightning and even an isolated tornado. At 12Z a strong MCS is expected to be in place over IL, pushing east- northeast within the moderate flow aloft. Models show the trough axis pushing east to the plains with the left front nose of the upper jet poised to push across Central Indiana through the day. This will provide strong lift through the day. Furthermore a favorable air mass will be in place ahead of the arriving MCS as forecast soundings suggest over 1500 J/KG of CAPE by mid day and favorable wind shear. Meanwhile within the lower levels, an associated area of low pressure over the plains is expected to push toward Wisconsin, allowing for a warm front to be pushed across Central Indiana along with a warm and humid southwest flow. Dew points are expected to rise into the mid to upper 60s. The MCS should be arriving across Central Indiana at a time which is typically the diurnal minimum for these type of systems. However as discussed earlier, several elements favorable for continued convection are expected. The HRRR suggests an area of showers and storms from the MCS over the Wabash valley by 15Z, poised to push across our area through 20Z-21Z. Thus will focus highest pops during this time period. The key to precise timing and strength will be development of the system over the plains tonight along with the evolution of the system as it pushes east overnight, so all eyes will be on that this evening. Best forecasts on timing and strength will be more clear overnight. Overall, showers and storms will be expected on Sunday, with more storms expected on Sunday night. Cloud cover should limit heating and highs in the mid to upper 70s should be expected. && .LONG TERM (Sunday night through Saturday)... Issued at 213 PM EDT Sat May 25 2024 Sunday Night. The second and likely more significant round of storms is expected during the evening to early overnight hours Sunday into Sunday night as storms initiate across Missouri during the afternoon and quickly grow upscale into a mature MCS by 6-7PM. Details on the broader system associated with this severe weather is above. Models have come into much closer alignment in the timing and track of this mature MCS with highest confidence in impacts after 6PM towards 12AM. The majority of the impacts with this system will likely be seen south of the I-74 corridor with the highest threat for tornadoes across the far southwestern portions of the forecast area if not further south towards the Ohio River. Any tornado that forms would be of the lower end QLCS variety with little risk of thunderstorms outside of the main complex of storms. Depending on the maturity of the cold pool, significant wind gusts in excess of 70 mph look probable in at least portions of Indiana. This will be a progressive system with storms exiting shortly after midnight and only small chances for scattered light rain on the stratiform portion of the backside of the system. Flooding may be a concern depending on the amount of rain from the initial wave of thunderstorms during the afternoon, but the progressive nature of this system should keep total amounts less than 1.5 inches. Monday Through Thursday. There may be some wrap around light rain showers Monday into Tuesday as the parent upper level low sits across the Great Lakes region and a strong northwesterly jet pivots around the low. Outside of any rain, there should be fairly frequent and widespread cloud cover through early Tuesday with cooler than normal temperatures. A weaker secondary low within the broader upper level jet is expected to move across the northern portions of the forecast area Tuesday night into early Wednesday with a period of light rain likely. High pressure then looks to set in with gradually warming temperatures through Thursday. Friday and Saturday. The pattern will begin to shift Friday into Saturday as the ridge of high pressure begins to break down and the next system exits the Rockies. There is a wide spread in model guidance on the strength of this low pressure system, but there is at least good agreement in a cold frontal passage during the weekend with rain likely and the severe potential being dependent on the more intense low pressure system scenario panning out but even that looks very unlikely at this time. && .AVIATION (06Z TAF Issuance)... Issued at 1203 AM EDT Sun May 26 2024 Impacts: - Low probability of MVFR stratus early-mid morning - First round of storms 15-20z; second round 00-05z - Southwest winds will gust to 25 knots Sunday; higher near storms Discussion: Winds will veer from northeasterly to southeasterly this morning and increase in response to an upstream weather system. There are uncertainties with timing of thunderstorms associated with this system and some adjustments to TAFs via amendments can be expected, but the current thinking is 15-16z onset for most TAF sites for round 1. Round 2 would occur around 00z or after. Both rounds have the capability of producing strong wind gusts higher than the already elevated gradient winds expected. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...MK SHORT TERM...Puma LONG TERM...White AVIATION...BRB
Area Forecast Discussion...Correction
National Weather Service Northern Indiana
622 PM EDT Sat May 25 2024 .KEY MESSAGES... - Showers and thunderstorms expected Sunday afternoon and night. Damaging wind, hail and flooding will all be possible with tornadoes possible with any evening storms that form. - Lingering showers/embedded thunder may impact activities on Memorial Day through Wednesday. - Dry weather looks to follow for late this week. - Hazardous swimming conditions for Lake Michigan beaches in La Porte County in Indiana and Berrien County in Michigan Memorial Day through Wednesday. && .DISCUSSION... Issued at 253 PM EDT Sat May 25 2024 Saturday starts with a phased Pacific and Subtropical jet across the southwestern US within a Western CONUS trough and a Northern Plains upper low. All this is west of a departing trough in the Northeast CONUS. Pushing play on the model physics causes the Northern Plains upper low to push farther northeast into Canada and opening up an opportunity for coupled jets to form a surface low pressure system across the Central/Southern Plains this evening. Closer to home, a cold front pushed eastward this morning and is in the I-69 corridor this afternoon. With the moisture axis having just departed, the strongest convective ingredients will be in our east and lingering/dissipating instability east of I-69, but minimal shear may allow for a pop shower/storm this afternoon before it departs. Will carry slight PoPs there to cover that possibility. Behind the cold front, expect clearing clouds as dry air temporarily moves in. Moving forward to Sunday`s severe weather chance, the aforementioned Western CONUS trough, shifts eastward carrying the developing aformentioned surface low towards the forecast area Sunday. 8am Sunday morning, the moisture axis is south of the forecast area due to Saturday`s cold FROPA, but lifts northward in conjunction with an arriving 40 kt low level jet just to our west. As a warm front lifts northeastward, the 12z HRRR indicates thunderstorms will be along it, but how strong it will be is in question. Expect 60F degree dew points to begin pushing in with 850 mb dew points also achieving mid teens Celsius readings. Temperatures will begin rising into the 70s tomorrow morning with 80 degrees possible south of US-30. This combination of heat and humidity will allow for 500 to 1000 J/kg of MUCAPE and 900 J/kg of DCAPE. These ingredients lead to more of a marginal severe setup with wind being the primary hazard, but hail also not ruled out. At 2pm Sunday, effective shear of 30 kts have just reached our west, which is just behind the warm front. This begs the question about if we can get clouds to scatter out behind the warm front. Should there be enough insolation, there could be a chance to force a second round of severe weather starting around 8pm and continue until after midnight. Should clouds break, instability approaches 1500-2000 J/kg of CAPE, mid level lapse rates approach 7 C/km along with 8 to 9 C/km low level lapse rates, effective shear reaches 45 to 55 kts by 00z and low level turning in hodographs and effective helicity surpasses 200 m2/s2 allowing for all severe hazards to be on the table. Flooding could also become an issue with training storms in a moist environment. Storm motions appear fast enough to keep things progressive, which could negatively impact QPF totals. An initial guess on when things would dissipate would be between 2 and 4 am. The cold front doesn`t look to move through until Monday morning, but instability drops off Sunday night with mid level lapse rates dropping to 6 C/km by 2am. Of course, another wrinkle in this is that models have been too slow with the arrival of recent thunderstorm events so this could be pushed earlier and that would also affect instability recovery windows. For Monday, subtle ridging and mid level height rises indicate a break in the action will be possible behind the departing cold front. Negative theta-e advection will be drying out the moisture column allowing dew points to fall into the 50s and highs only achieve the upper 60s to low 70s. A Pacific shortwave is directed towards the region for Monday evening with these antecedant conditions. Instability appears to be at or below 500 J/kg for thunderstorms so rain will be the likely outcome, but embedded, non- severe thunderstorms will be possible. Rounding this carousel of shortwaves, the vorticity from the original central Canadian upper low rounds the base of the trough towards the area for Tuesday. Dew points are still relatively dry, in the 50s, but the ECMWF still forms 1500 J/kg of MUCAPE (GFS is more like 500 J/kg) so perhaps a thunderstorm or 2 could be had with that given scattered cloud cover at best, but thunderstorms appear marginally severe, at best. Meanwhile, on Monday, a cold front ejecting off of southeast Asia starts a chain of cyclonic wave breaks later Sunday/Sunday night across the North Pacific that invigorates a strong ridge across the Western CONUS Monday night into Tuesday. Rain is finally out of the area on Wednesday as this ridging arrives and provides a reprieve of dry weather until at least Saturday. Mid 60s to low 70s highs on Wednesday slowly trend warmer, reaching the low 80s across a few of our southern counties on Saturday. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 622 PM EDT Sat May 25 2024 Light winds and mainly clear skies are expected tonight with sfc ridging in control. Strong warm front and associated moist advection looks to send an arcing line of convection east- northeast through northern Indiana during the early-mid afternoon hours on Sunday. Added a tempo TSRA/IFR group in the 18-20z window given relatively high confidence, though refinements in timing will likely be needed in future issuances. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Roller AVIATION...Steinwedel
Area Forecast Discussion
National Weather Service Louisville KY
958 PM EDT Sat May 25 2024 .KEY MESSAGES... * Severe storms possible Sunday into Sunday night. Main hazard is damaging winds with localized hurricane-force gusts possible. Tornadoes, large hail, and flooding cannot be ruled out either. * Unsettled pattern will continue into Monday with additional shower and thunderstorm chances. && .UPDATE... Issued at 958 PM EDT Sat May 25 2024 Overall, a fairly quiet evening was in progress across southern Indiana and central Kentucky. Only convection was a small storm over Bourbon/Nicholas counties which will continue to move off to the east over the next hour. Appears that we had a boundary that dropped southward across northern KY this evening. It was detectable by radar and winds shifted to the north behind the boundary. Dewpoints on either side of the boundary were not all that different, but many sites saw a small drop in temperatures as the boundary slid through. For the overnight period, it looks to be a quiet night as we wait for convection from the Plains and lower MO valley to move in from the west. That looks to occur well after sunrise tomorrow. We`ll see some mid-high level cloudiness spread in from the west as that convection approaches. Lows tonight will be in the mid-upper 60s. Remainder of the forecast remains generally unchanged for Sunday. It appears that we`ll be seeing a couple of lines of storms coming across the region. The first looks to come through mid-late morning tomorrow with a second line coming through Sunday evening. The first line will have some instability to work with and will be capable of producing heavy rainfall, damaging winds, and perhaps some marginal hail. Uncertainty increases after that line goes through as it is not overly clear how much instability will be taken out by the first line and if the atmosphere will recover. Model soundings do show substantial reductions in SBCAPE and MLCAPE. However, we may have a bit of elevated CAPE to deal with in the mid- late afternoon that could support elevated convection ahead of the second line (like the 18Z HRRR suggests). The second line will then surge through here in the mid-late evening with a damaging wind threat. There will likely be continued shifts in the CAM guidance tonight and into early Sunday as they start to better initialize on what the convection across MO does overnight. We`ll continue to monitor and evaluate that data overnight. Folks should continue to stay vigilant and be prepared for an active weather day across the region tomorrow. && .SHORT TERM /THROUGH SUNDAY NIGHT/... Issued at 348 PM EDT Sat May 25 2024 We continue to focus on the severe weather potential for tomorrow which continues to transition as it comes into better focus. A few days ago when global models were the only models to have Sunday in range, hodographs looked ominous. There was a lot of synoptic forcing, tons of instability, and high levels of shear at all levels. Tornadoes looked favorable. Then, as the NAM picked up on Sunday, it showed one or two line segments extending south out of central Indiana into southern Indiana and north central Kentucky, but it wasn`t too impressive. Now that the CAMs have had multiple runs that have captured tomorrow`s events, the forecast continues to get fine tuned. Every model doesn`t agree on the exact timing, but the general idea is pretty strong among the models. Tonight, upper flow is mostly zonal. There is a little bit of a trough over the Southern Rockies and a little ridging over New England. Extending south from near Chicago, surface high pressure extends through Kentucky while a surface low sits over western Kansas, and as upper flow begins to push the surface low east to east-northeast, the system is expected to send a line of convection over the Plains. By Sunrise, the line is expected to be crossing the Ozarks and Midwest as it surges towards the Lower Ohio Valley. Around 15-16z Sunday morning, the line is expected to begin impacting the western edge of the CWA. As it will be late morning, there could still be some low level stability. Low level lapse rates are marginal in the 7.5 C/km range, but the main driving force at this time will be the system`s cold pool. After the line has traveled all night, the cold pool is expected to be ahead of the main line. This could help to decay the line as it moves west to east over the CWA, but as it begins to enter areas on the the eastern side of the CWA, including the Bluegrass and Lake Cumberland regions, some afternoon heating could help increase lapse rates to 8.5 C/km or more. This could help to intensify the line into the later afternoon. The line is expected to be near Louisville around 17-18z and east of the CWA by around 20-21z. The main thing this line has working for it is instability. MLCAPE values ahead of the line will begin in the 2,000 J/kg range and increase to around 2,500 J/kg over southern Indiana and up to 2,700 J/kg over southern Kentucky. MUCAPE values will begin around 2,500 J/kg and increase to near 3,300 J/kg. Low level shear is only marginal with 0-1km SRH around 90. A tornado can`t be ruled out, but chances are fairly low. The main threat will be gusty winds from the storms downdrafts. With the high levels of instability, the strongest cores could also produce hail. Another concern will be flash flooding. With all the rain we have had lately, mainly over southern Kentucky, flash flood guidance is low. Don`t believe the north to south oriented line will cause too many flooding issues as the dwell time over any one spot will be limited. There is a chance, mainly over southern Kentucky. That some storms could develop behind the line and drop to the south, so if any location gets multiple rounds or sees training storms over the same area, flash flooding will likely occur. With the first line of convection outrunning the surface low, a second line is expected to develop early tomorrow night just ahead of the low. It could begin to enter our Indiana counties by around 4z Monday, and Kentucky counties an hour or two later. This second line won`t be as mature as the first line, so the convection should stay on the leading edge of the convection which could help overcome the near surface inversion given the time of day. It also looks like instability could be more limited, but low level shear will be much higher with this second wave. 0-1km SRH will approach 400 under a 50 knot low level jet. The high LCLs above 1km and stable low levels are reasons against tornado development, but strong low level shear in a convective environment could help to produce a spin-up. Believe the chances for a tornado will be greater in this second line compared to the first line, but gusty winds will be the main threat. The threat of hail will be less in the second line given the much lower instability. The line will likely begin to dissipate before the line exits the CWA by at least 9z. && .LONG TERM /MONDAY THROUGH SATURDAY/... Issued at 348 PM EDT Sat May 25 2024 Monday through Tuesday Night... Surface cold front is still forecast to push through the region during the day on Monday which will bring an end to the severe threat locally. Now the upper level trough axis will remain across the region, so some convective redevelopment is likely during the afternoon across the region. Some stronger storms can`t be ruled out across our east during the afternoon. Highs on the day will range from the upper 70s to the lower 80s. Breezy conditions will be seen as well on Monday with sustained winds of 10-15 mph with occasional gusts to 20-25 mph at times. Drier air will filter into the region by Monday night and dry/tranquil weather is expected through the remainder of this forecast period. Lows Monday night will be upper 50s to around 60. Highs on Tuesday will be in the upper 70s to the lower 80s with overnight lows in the mid-upper 50s. Wednesday through Saturday... Upper trough axis will push east of the region by Wednesday and heights will gradually build into the day on Thursday. Toward the end of the week, the pattern looks to become a bit more blocked as the east coast trough closes off and becomes a closed low just south of Maine. Another shortwave trough axis will be pushing through the Plains, while the Ohio Valley remains in a sharp but narrow ridge axis. Overall, the pattern for Wednesday through Friday supports dry weather conditions. Within the southwest flow by Saturday, we could see some isolated/scattered storms fire, though the best potential for rainfall looks to hold off until late Saturday night and early Sunday. Highs Wednesday and Thursday will be in the upper 70s to near 80, with overnight lows in the low-mid 50s. A few of our valley locations could see temps dip into the upper 40s each night. Temperatures will warm a bit by Friday as readings rise into the upper 70s to the lower 80s. Mainly lower 80s are expected by Saturday. && .AVIATION /00Z TAFS THROUGH 06Z TUESDAY/... Issued at 747 PM EDT Sat May 25 2024 Impacts/Confidence: - Medium to high confidence in MVFR VIS at LEX/RGA tonight - Medium confidence in timing and impacts of heavy rain and storms late tomorrow morning into the afternoon - Medium to high confidence in gusty southerly winds tomorrow Discussion...Surface cold front has stalled across northern Kentucky this evening with surface high pressure moving eastward along the Great Lakes. Radar shows isolated, weak showers moving towards LEX and RGA in the coming hours, but the loss of daytime heating and sporadic coverage results in very low confidence to mention any impacts. For tonight, winds will change to the south as the a surface low pressure ejects from the Central Plains to the Midwest and the stalled front lifts to the north. In addition, model guidance still indicates MVFR VIS and few/sct low ceilings for the Bluegrass region around 8Z which goes in line with the lifting frontal boundary pattern. For tomorrow, two waves of heavy rain and potentially strong storms are anticipated related related to the aforementioned surface low and attendant cold front. The first wave will arrive from west to east late in the morning and continue through the early to mid afternoon hours. Although confidence in CAM models have increased, there is still some timing uncertainties, so expect the onset of strong storms to suffer slight modifications in future updates. Nonetheless, MVFR to IFR visibilities will be common as well as strong wind gusts (30+ kts) and a non-zero chance of severe weather. Gusty southerly winds around 15 to 20 knots will continue after the first round of unsettled weather. Extended Outlook...The second wave of heavy rain and strong storms will arrive probably after 27/0Z as the cold front races thorugh the region. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ UPDATE.......MJ SHORT TERM...KDW LONG TERM....MJ AVIATION.....ALL
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1054 PM CDT Sat May 25 2024 .KEY MESSAGES... -Severe thunderstorms are expected late tonight through Sunday morning, primary threat is damaging winds. -Severe thunderstorms are expected again during Sunday afternoon and evening, with damaging winds, tornadoes, and large hail possible. -Locally heavy rainfall, up to 2-5 inches, is possible with both rounds of thunderstorms on Sunday. -Next week will usher in a pattern change toward drier, more seasonal weather. && .SHORT TERM... (Through Late Sunday Night) Issued at 334 PM CDT Sat May 25 2024 Surface ridge will continue to slide off to the east this evening. Otherwise, the upper level trough over the Rockies has begun to lift out towards the Great Lakes region. The majority of the latest deterministic as well as ensemble models have good agreement with the timing, strength and placement of the system as it moves through the area late tonight through Sunday. As a surface low deepens in the lee of the Rockies, the accompanying warm front will lift northward across the forecast area late tonight. Still expect convection will initiate on the nose of a strong southerly low level jet (40-60kts) over central Kansas, advecting in plenty of low level moisture and instability as it congeals into an MCS. As the low level jet veers, the MCS will slide east across the region. Still some uncertainty on the exact track of the complex, with some guidance solutions pushing it along the I-70 corridor, while others push it across southern Missouri and Illinois. As for the threat for severe storms late tonight through midday Sunday, strong deep layer shear (0 to 6km bulk shear of 40-50kts) as well as 3000+ J/kg MU CAPE combined with cold pool support from the MCS will allow portions of the MCS to become strong to severe. The main threat will be damaging winds and a low threat of tornadoes. The first round of storms will weaken and exit the region by midday Sunday. Then there is the matter of a second round which will be conditional depending on where the atmosphere can recover from the morning activity. So where ever the outflow from the morning activity ends up, thunderstorms are expected to redevelop during the afternoon and into the evening as the mid level trough moves through and erodes inhibition. Latest RAP soundings have MU CAPEs back around 3000+ J/kg with 45 to 50 knots of effective shear, which will support supercells with primary threats of very large hail (2"+) and damaging winds (up to 80 mph). Even though confidence is highest that the best location for severe storms will be in the warm sector south of the outflow boundary, could see enough recovery north of the outflow where the environment would be quite favorable for tornadoes, so a few significant tornadoes (EF2 or stronger) are possible. Another issue to deal with will be locally heavy rainfall as each round of storms move through. Yesterday portions of west central and southwest Illinois received up wards of 3 to 5 inches of rain, with few locations in excess of 6 inches. If thunderstorms train over this area, the threat for flash flooding will be greater. If the storms either don`t train or they move over areas that have not gotten as much rain, the threat for flash flooding will be lower. With the possibility of 2 to 5 inches of rain, have issued a flood watch for areas along and south of a Pittsfield, IL to Monroe City, MO line from 06z Sunday until 06z Monday. Byrd && .LONG TERM... (Monday through Next Saturday) Issued at 334 PM CDT Sat May 25 2024 Even though dry and mild weather is expected through most of the work week, another shortwave will rotate around the surface low over the Great Lakes region. This could bring another round of showers Monday afternoon, but for now confidence is low. Beyond that, pattern begins to change late in the work week with next chances for rain by next weekend. Byrd && .AVIATION... (For the 06z TAFs through 06z Sunday Night) Issued at 1033 PM CDT Sat May 25 2024 Two rounds of severe weather are still expected within the TAF period. The first round of severe weather will enter central and northeast Missouri near sunrise. This will be a line of thunderstorms capable of damaging winds of up to 60 kts and brief tornadoes. When this line impacts a terminal, expect ceiling and visibility drops. Added IFR tempo groups at each terminal for this, but heavy rain may reduce flight conditions even further. We expect a short break in the late morning/early afternoon before convection develops in southeast Missouri this afternoon and evening ahead of a cold front. During this round, very large hail (2+ inches), damaging winds up to 70 kts, and significant tornadoes are possible. Confidence in exactly where these thunderstorms will be is low given the dependence on tonight`s round. As of 04z, the St. Louis metropolitan terminals have the highest chance of impact by this round. Again, expect stark drops in flight conditions in the case of a direct hit. The wind speed and direction over the period will be highly influenced by convection through the period. Generally, winds will be southerly and will continue to increase, becoming gusty later tonight. They will veer to northwesterly behind the front Sunday evening and subside thereafter. Jaja && .LSX WATCHES/WARNINGS/ADVISORIES... MO...Flood Watch through late Sunday night for Audrain MO-Boone MO- Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO- Iron MO-Jefferson MO-Lincoln MO-Madison MO-Moniteau MO- Monroe MO-Montgomery MO-Osage MO-Pike MO-Ralls MO-Reynolds MO-Saint Charles MO-Saint Francois MO-Saint Louis City MO- Saint Louis MO-Sainte Genevieve MO-Warren MO-Washington MO. IL...Flood Watch through late Sunday night for Bond IL-Calhoun IL- Clinton IL-Fayette IL-Greene IL-Jersey IL-Macoupin IL- Madison IL-Marion IL-Monroe IL-Montgomery IL-Pike IL- Randolph IL-Saint Clair IL-Washington IL. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Memphis TN
1001 PM CDT Sat May 25 2024 ...New UPDATE... .UPDATE... Issued at 924 PM CDT Sat May 25 2024 Fairly quiet across the Mid-South with a few showers that are slowly dissipating. Overnight a shortwave rotating through the Mid MS Valley will kick off a cluster of storms that will track along the northern border of the Mid-South. A few severe storms are possible across mainly the northern tier of counties with this complex as SBCAPES of nearly 3000 J/kg continue and 0-6km shear values climb above 50 kts with the approach of the shortwave. There is a tornado threat with this round along the MO/AR and KY/TN borders. This first round will push east of the area in the morning. The interesting thing will be to see where the outflow boundaries from this cluster end up during the afternoon. Expect at least isolated convection to develop along the outflow boundary wherever it ends up by Sunday afternoon. The latest CAMs are less aggressive with Sunday afternoon development but it still bears monitoring. HRRR model soundings across much of the area are impressive by 21z. For example at Memphis expect SBCAPES around 3500 J/kg, 0-6km shear values greater than 50 kts and 0-1km helicity values of 175 m2/s2. If convection can get going Sunday afternoon it will likely be severe with damaging winds, large hail and perhaps a tornado. There does seem to be a cap around 750mb that may be a result of some shortwave ridging between the departing morning shortwave and the next one approaching Sunday evening. This may inhibit convection Sunday afternoon until it breaks, if it does. As the next shortwave rotates into the area and lift ramps up expect coverage to quickly increase resulting in a few broken line segments that eventually form a line of strong to severe storms Sunday evening trekking SE across the Mid-South. The line will exit into central MS and northern AL by 10z or so. Expect damaging winds, large hail and a perhaps some quick spin up tornadoes. && .SYNOPSIS... Issued at 342 PM CDT Sat May 25 2024 Enhanced severe weather chances return Sunday with multiple rounds of storms possible through early Monday morning. The main concern at this time remains potential for afternoon supercells to develop and produce all hazards of severe weather. In addition, flooding chances remain elevated as efficient rainfall rates accompany storms. Unsettled weather should come to an end on Monday, when dry conditions return to the Mid-South. && .DISCUSSION... (This evening through next Friday) Issued at 342 PM CDT Sat May 25 2024 Shortwave ridging aloft has precluded shower and thunderstorm chances this afternoon, with only a few pop-up storms present on radar as of 3PM. Isolated storms may continue to develop over the next few hours, with a few possibly reaching severe limits. If storms do form, the main concerns will be damaging winds and large hail. Greater severe weather chances will materialize on Sunday, with multiple rounds of storms possible. The first round will be driven by a shortwave trough pushing into the Midwest late tonight. Several CAMs depict an MCS developing over Missouri, pushing eastward into Kentucky by 7AM. The main question regarding this round of storms lies in the southern extent of the MCS. The 18Z HRRR keeps storms along the Kentucky / Tennessee border. However, all other CAMs support storms pushing well into northeast Arkansas and the Missouri Bootheel. Regardless of which scenario materializes, severe weather chances will be possible as dewpoints surge to the low 70s by 7AM. The main threats with this batch of storms will be damaging winds and large hail. A secondary round of convection may materialize in the mid afternoon hours along a remnant outflow boundary from the aforementioned MCS. At this time, hodographs become more favorable for tornadic development with 0-3 km SRH increasing to 250 m2/s2 in portions of northwest Tennessee. In addition, mid-level lapse rates on the order of 7.5 C/km will support strong updrafts capable of producing large hail. Any storms that develop at this time will likely be discrete and pose the greatest tornadic threat, with a few significant tornadoes possible. As such, the Storm Prediction Center has extended portions of the Enhanced Risk to areas of northwest Tennessee. Important note: confidence for this round of storms remains low due to uncertainties in exact track of Sunday morning`s MCS. The bottom line: if storms do form in the afternoon, they will be capable of all hazards. A third, and final round of storms will occur late Sunday evening into the overnight hours. Convection is expected to form along a cold front that pushes southeast across Missouri in the evening hours. By the time this line impacts the Mid-South, a QLCS structure will be evident with damaging winds the primary concern. A few CAMs decrease lapse rates to around 5.5 - 6.0 C/km overnight, which should hamper large hail development. However, brief spin-up tornadoes will remain possible as the LLJ strengthens and SRH values remain around 150 - 200 m2/s2. The main areas of concern for this round of storms will be northeast Arkansas and west Tennessee. By 4AM Sunday, the severe weather threat will wane with dry conditions returning Monday. In addition to severe weather concerns, flooding potential remains elevated as precipitable water values approach the 99th percentile. Any storms that do develop will likely be prolific rainfall producers, resulting in rises of rivers and streams. The Flood Watch has been adjusted to include areas north of the Tennessee / Mississippi state border now through 7AM Monday. Additional rainfall totals of 1-2 inches with locally higher amounts are possible. ANS && .AVIATION... (00Z TAFS) Issued at 650 PM CDT Sat May 25 2024 Main story this TAF issuance is the timing and intensity of TSRA across each terminal tomorrow afternoon and into the overnight hours. Latest CAMs have two lines of convection: the first looks to form along a few shortwaves out ahead of the second main line associated with a cold front. TSRA is expected to begin impacting JBR/MEM/MKL beginning around 21Z tomorrow afternoon through the TAF period as these lines of convection move across the Mid-South. South/southwest look to gust up to 30 kts tomorrow morning through the TAF period as this cold front passes. VFR conditions are expected to prevail, though each terminal could see a brief lowering to MVFR with onset convection. AEH && .MEG WATCHES/WARNINGS/ADVISORIES... AR...Flood Watch through Monday morning for ARZ009-018-026>028-035- 036-048. MO...Flood Watch through Monday morning for MOZ113-115. MS...None. TN...Flood Watch through Monday morning for TNZ001>004-019>022- 048>055-088>092. && $$ PUBLIC FORECAST...SJM AVIATION...AEH
Area Forecast Discussion
National Weather Service Raleigh NC
938 PM EDT Sat May 25 2024 .SYNOPSIS... High pressure ridging will build into the area Sunday. A cold front will approach Sunday night and move through the region Monday night. Dry high pressure will settle into the region toward the middle of next week. && .NEAR TERM /THROUGH TONIGHT/... As of 902 PM Saturday... Isolated to scattered showers and storms continue to pop up across portions of the central Piedmont, Sandhills and southern Coastal Plain. At one point this evening, there were numerous outflow boundaries across the Triangle, Sandhills, and Coastal Plain. Little if any storms developed over the northwest Piedmont/Triad and northern Coastal Plain. Satellite imagery reveals a weak mid-level circulation over the southern Piedmont to Charlotte area. This shortwave trough should continue to progress south and east overnight. As this happens, convection should start to collapse south and east into late tonight, dissipating overnight. The latest HRRR suggests this may be the case, though the southern Piedmont has not really been worked over in the sense of there still being some SBCAPE present. As such, lingering/new outflows may spawn new isolated/scattered storm cells across our southern areas for the next 2-4 hours. Activity should largely be sub-severe, though a few stronger cells could produce heavy rain and strong wind gusts. Convection should wane after midnight as the shortwave moves east and subsidence ensues. Lows should hover in the low to mid/upper 60s. Patchy fog could develop almost anywhere in central NC, though may be more prone in areas of Raleigh and the eastern Sandhills, where rainfall amounts were higher. && .SHORT TERM /SUNDAY AND SUNDAY NIGHT/... As of 250 PM Saturday... Sunday will start off dry across the area, some might see patchy fog early morning but will clear shortly after sunrise. By the afternoon an increase of showers and thunderstorms is expected. As the enhanced shortwave trough progresses east from the IL/IN area during the day, by the afternoon it is expected to be on the door step of the Appalachian Mountains by late evening. Isolated to scattered storms are expected to begin to evolve across the region late afternoon. With loss of heating the severe threat is expected to diminish through the overnight hours Sunday. HiRes CAMs are showing a bit more consistency with timing of the first round of storms moving across the region late Sunday night through early Monday morning. While this round of storms are expected to move across the region swiftly, PW values are expected to be above normal (1.5- 2.0inches), thus some heavy rain could cause some minor flooding in poor drainage areas. Drivers should be be extra cautious driving in these storms at night. CAPE values will be lower than what is expected with Mondays storms, but some storms could be strong. Kept PoPs higher across the Northern Piedmont region, but chance PoPs are generally across the region. Sunday will be warm, 5-7 degrees above normal. Highs will be in the mid/upper 80s some areas reaching 90, lows will range from upper 60s to low 70s. && .LONG TERM /MONDAY THROUGH SATURDAY/... As of 345 PM Saturday... There is the potential for Sunday night`s showers/storms to still remain across eastern counties on Monday morning, but the primary chance for rain will come Monday afternoon and evening, driven by a surface cold front and upper level trough. Considering the hot and humid air mass in place, even if there are showers lingering into Monday, there should be time for instability to recover and for strong to severe thunderstorms to occur. The severe weather threat remains highly conditional based on the previously mentioned showers, but also on whatever upstream MCS moves into the region, which will have limited predictability. Hopefully tonight`s 00Z high- resolution model runs will have a better handle on how the system will evolve through Monday afternoon. The only high-resolution model that currently goes out through Monday afternoon is the 12Z NAM Nest, which shows a small cluster of thunderstorms approaching the Triad late Monday afternoon. Forecast CAPE values appear to be slightly higher than they were forecast 24 hours ago, with values up to 2500 J/kg. Shear remains generally unidirectional at around 30 kt. The bulk of the precipitation should move east of the area by midnight Tuesday, although a slight chance of thunderstorms will linger along the I-95 corridor Tuesday afternoon. The region will be in a bit of a low-level synoptic lull on Wednesday before high pressure builds in from the Great Lakes on Thursday and remains the primary surface feature through Saturday. While the GEFS suggests there could be an isolated thunderstorm across western counties late Saturday afternoon, this is not supported by the deterministic GFS/ECMWF and have kept the forecast dry. Monday is likely to be the warmest of the next 7 days, with highs ranging from the mid 80s to the low 90s. After the cold front passes Monday night, highs should be in the 80s everywhere Tuesday with highs eventually being in the upper 70s for most locations Thursday. Normal high temperatures for June 1 range from 82 at Greensboro to 86 in Fayetteville, and forecast values for Saturday appear to be seasonable. There will be several days with lows in the 50s, but it`s a little early to forecast the potential for any locations to drop into the upper 40s overnight late in the week (normal low temperatures are in the low to mid 60s). && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... As of 800 PM Saturday... 24-hour TAF period: Isolated thunderstorms will be possible in mainly southern and eastern portions of central NC (including FAY and RWI) through this evening. Brief gusty winds and sub-VFR conditions may occur with any storm. Otherwise VFR conditions will prevail through 06z. Then as skies become mostly clear and winds very light to calm, patchy fog may develop overnight into early Sunday morning, resulting in MVFR or IFR visibility restrictions. The best chance for this looks to be in the east (including RDU, FAY and RWI) where locally heavy rain fell today. More isolated to widely scattered showers and storms are possible tomorrow afternoon. A more organized line of showers and storms may begin to move into the Triad (including INT and GSO) around 21z-00z. Outlook: Showers and storms may continue on Sunday evening into Sunday night, then again on Monday afternoon and evening. The most widespread coverage looks to be on Monday. Category restrictions will be possible with any thunderstorm, and Monday`s storms could bring especially gusty winds. By Tuesday, VFR conditions are expected under high pressure, which will last into Thursday. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Kren NEAR TERM...Kren SHORT TERM...CA LONG TERM...Green AVIATION...Danco/Green
Area Forecast Discussion...UPDATED
National Weather Service Springfield MO
802 PM CDT Sat May 25 2024 .KEY MESSAGES... - Slight (2 of 5) to Moderate (4 of 5) Risk for severe thunderstorms late tonight into Sunday morning (between 11 pm - 7 am). Damaging winds up to 80 mph and hail up to baseballs are the primary potential severe weather hazards. There is also a conditional risk for a few tornadoes. - Flood Watch in effect tonight for the entire area. Repeating thunderstorms could produce 1-3 inches of rainfall. - Slight (2 of 5) to Enhanced (3 of 5) Risk for severe thunderstorms on Sunday afternoon and evening. Primary hazards are damaging winds up to 70 mph and large hail up to golf balls. && .MESOSCALE... Issued at 800 PM CDT Sat May 25 2024 Severe thunderstorms are ongoing as planned across Kansas and Oklahoma with the most significant concentration south of Wichita into northern Oklahoma. These storms have already produced baseball size hail, damaging winds and at least one tornado. The 00z KSGF sounding data revealed a vastly different airmass than 12 hours ago with significant destabilization having occurred. Surface temps in the 80s and dewpoints in the upper 60s have returned to the area with ML CAPE values being measured at 2300j/kg with very little cap remaining (21j/kg CIN). MU CAPE values were an impressive 3900j/kg therefore the airmass is primed. 0-6km wind shear was 50kts however the low level shear was weak. This will change overnight as the llj increases. Mid level lapse rates were also steep with a max of 8.6C/km measured in between 700-500mb. Latest high res guidance continues to indicate that these supercell storms will continue moving east this evening towards southeast Kansas with additional storms developing further north in Kansas. A low level jet is currently in the process of increasing across Oklahoma and this will nose into Kansas as well. This will increase the low level helicity therefore the tornado threat may begin to increase across Kansas/Oklahoma over the next few hours. An additional cluster of storms also looks to form further north, across north central to northeast Kansas. As storms move into our southeast Kansas counties (generally after 11pm), storms may begin to congeal into a cluster(s) of storms (either line segments or supercells). These cluster(s) still look to produce large hail up to the size of baseballs, damaging winds of 60-80mph and even a strong tornado. These supercell storms then look to move into western Missouri however a few trends are noted in most recent high res models. One being that the storms that eventually form further north (between Wichita and Kansas City) may actually congeal into a strong enough cold pool to begin pushing southeast into the area after 2-3am. With a 50kt llj this could create a northwest to southeast oriented backbuilding line of storms. It is hard to pinpoint where this may occur but if it does then this would increase the flash flooding threat substantially. Last few HRRR runs show this with a few pockets of 3-5 inches of rainfall wherever storms move over the same areas. We will need to monitor this threat closely overnight. This back building line of storms would still pose a risk for large hail, damaging winds and tornadoes. This cluster or line of storms could persist through the 5-7am timeframe. Therefore a messy convective mode looks likely overnight and given the amount of people outdoors it will be imperative people have multiple ways of receiving warnings and having a way to get indoors. We are planning a special balloon launch in the 4-6z timeframe to get another look at the local atmosphere ahead of the storms. && .SHORT TERM /THROUGH MONDAY/... Issued at 255 PM CDT Sat May 25 2024 This Afternoon-Evening: A warm front is lifting north through the area this afternoon ahead of the next approaching shortwave trough. Ahead of this next system late tonight into Sunday, a rather dry and warm afternoon is unfolding. Highs will range from lower to middle 80s across the area, with dewpoints climbing into the middle to upper 60s, near 70 as the front warm front lifts into central Missouri. Expectations are for the area to remain capped through the afternoon and evening. This has been well captured by the guidance. Supercell thunderstorms will develop west of the area across the Southern/Central Plains, with a Moderate Risk (4 of 5) draped across this area. Tonight: By tonight, the atmosphere becomes primed for development of severe thunderstorms. A brief overview of the environment, depicts instability around 2000 to 4000 J/kg in the vicinity of 0-6 km deep layer shear of 35 to 40 knots. Both deep layer and low-level shear will be on the increase into tonight. Additionally, a low-level jet around 45 to 50 knots builds into the area tonight, which will further amplify low- level flow into the region. This will correspond to strong mid- level flow around 500 mb. SPC highlights a Moderate Risk (4 of 5) into southeast Kansas and southwest Missouri. Further east, Enhanced (3 of 5) to Slight (2 of 5) risk exists into Missouri. Ongoing supercell thunderstorms to the west will slowly slide into the area, generally after midnight for portions of far southeast Kansas and along the Missouri/Arkansas border. Supercell coverage may not be widespread, though the activity that is present will likely be intense. Initial thought is that activity will remain semi- discrete in nature for areas along and west of Interstate 49. Hazards in this area include destructive damaging wind gusts up to 80 mph, large hail up baseballs, and a strong tornado or two. The tornado environment is characterized by sufficient 0-1 km shear around 25 to 30 knots and SRH values around 250 to 300 m2/s2. With winds slightly backed out of southeast and low LCLs, mature supercells may be able to tap into a favorable low-level environment. However, a tornado outbreak is not expected at this time as the window for tornadic development in short-lived before the activity grows upscale. Additionally, steep mid-level lapse rates and ample instability through the hail growth zone supports large hail. Large Hail Parameter paints a picture of values greater 20. As thunderstorms push further east towards Highway 65 in the early morning hours, the transition from supercells into line segments is expected. The primary hazard will become damaging wind gusts up to 80 mph, with less focus on large hail. As for tornadoes, 0-3 km shear around 25 knots from the west- southwest, would support a few brief and weaker tornadoes where the segments are able to become balanced along the UDCZ and bowing structures exist. CAMs suggest this line of thunderstorms to persist into central and south central Missouri, towards sunrise Sunday morning. Damaging wind gusts of 60 to 70 mph will be the primary risk with a gradual "weakening" trend east of Highway 65, though some guidance suggests otherwise. This will need to be monitored closely with radar and mesoscale trends. There is an additional concern for localized heavy rainfall and flooding across the area. HREF highlights a few corridors, particularly across west central into central Missouri of 1 to 3 inches or more in short periods of time where thunderstorms train over the same areas. Pinning down these exact locations in subjective in nature, but the general consensus is that the conditions are favorable for heavy rainfall with efficient rainfall rates to produce flash flooding. Additionally, there may be some backbuilding in the vicinity of the warm front and nose of the low-level jet into this area. A Flood Watch has been issued for late tonight (1 AM Sunday) through Sunday evening (7 PM) to account for this increasing potential. Sunday: The overnight MCS complex will be ongoing Sunday morning across portions of central and south central MO. How the overnight MCS evolves through Sunday morning will play a key role in the potential for additional strong to severe thunderstorms Sunday afternoon and evening along the trailing cold front. If thunderstorms are able to redevelop, the atmosphere will be supportive of large hail up to golf balls and damaging wind gusts up to 70 mph. The area of greatest risk extends from central into south central Missouri where an Enhanced (3 of 5) Risk exists. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Issued at 255 PM CDT Sat May 25 2024 (From Previous AFD) Upper level wave will push through on Sunday night with a drier air mass moving into the area. This should clear the convection to the southeast of the area with temperatures dipping into the upper 50s to low 60s. An upper low in Canada will drop southeast into the Great Lakes region early in the week bringing more of a northwesterly flow aloft to the area. The best moisture axis should remain over the deep south into the southern plains with precipitation chances fairly low for the first half of the work week. An upper level ridge will begin to push into the area on Thursday with moisture beginning to increase over the western CWA by late in the week. Temperatures in the long term period look to remain seasonal for this time of year. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 609 PM CDT Sat May 25 2024 Confidence is high that thunderstorms, some severe, will move into the TAF sites closer to 06z. These storms may linger for several hours at SGF, perhaps into 12z. Damaging winds are likely if these storms move through the sites. Winds outside of storms will be out of the south to southeast with increasing gusts overnight. A brief period of MVFR ceilings may prevail in the morning with VFR then expected for the rest of Sunday. There is a 30 percent chance of thunderstorms in the afternoon at SGF and BBG however confidence is too low to include at this time. Winds will gradually turn southwesterly during the day with increasing gusts. Low level wind shear is likely overnight at the sites. && .SGF WATCHES/WARNINGS/ADVISORIES... KS...Flood Watch from 1 AM CDT Sunday through Sunday evening for KSZ073-097-101. MO...Flood Watch from 1 AM CDT Sunday through Sunday evening for MOZ055>058-066>071-077>083-088>098-101>106. && $$ MESOSCALE...Burchfield SHORT TERM...Perez LONG TERM...Perez AVIATION...Burchfield
Area Forecast Discussion
National Weather Service Tulsa OK
930 PM CDT Sat May 25 2024 ...New SHORT TERM... .SHORT TERM... (The rest of tonight) Issued at 920 PM CDT Sat May 25 2024 Update mainly is for adding tornado watch 311 which will include most of NE OK and far NW AR. Bulk of storm coverage is expected to stay north of I 40 tonight, though isolated to widely scattered storms that develop across SE OK and WC AR will still have severe potential. Made some adjustments to PoPs through 06 based on expected coverage, and just a few minor tweaks to PoPs in the 06-12z time frame. Overnight temperatures look reasonable at this time. Updated ZFP/AFM/PFM already sent && .LONG TERM... (Tomorrow through Saturday) Issued at 230 PM CDT Sat May 25 2024 Thunderstorms are expected to have waned and / or focused more east of the local region by early Sunday. However, the cold front associated with the passing wave will not clear western AR and SE OK until late afternoon and conditions will become increasingly unstable ahead of the boundary. Veered low level winds will limit frontal convergence and overall storm coverage is likely to be low, however at least isolated storms are possible along the boundary by mid to late afternoon before the front clears the forecast area to the east and south. Otherwise, dry weather and warm weather will prevail west of the front. Sfc high pressure builds across the region Monday providing a pleasant day area wide. The pattern transitions toward more northwesterly flow through the southern Plains by Tuesday with daily thunderstorm complexes likely to develop and track in or near the forecast area from Tuesday night through Thursday. Locally heavy rainfall and at least a limited risk of severe weather would accompany these events. By late week into next weekend the pattern reverts to more southwesterly flow aloft and likely remains unsettled with daily thunderstorm chances continuing. && .AVIATION... (00Z TAFS) Issued at 631 PM CDT Sat May 25 2024 The main focus this TAF period is to time potential for storm impacts at the TAF sites this evening and overnight. Per latest HRRR and WoFS, TEMPO groups were used where probs were greater for storm impacts near the KS/MO borders. This would include the KBVO, KXNA and KROG TAF sites. Storm potential was also higher at KMLC per model data, so a TEMPO was used there also. There may also be a period of MVFR cigs as well during the overnight. A front will push thru on Sunday, with conditions at all sites returning to VFR with gusty winds veering to the W/SW. Lacy && .PRELIMINARY POINT TEMPS/POPS... TUL 71 89 62 87 / 50 0 0 0 FSM 73 91 66 89 / 40 20 20 0 MLC 72 91 64 89 / 30 0 10 0 BVO 67 88 58 86 / 60 10 0 0 FYV 69 87 61 85 / 50 20 10 0 BYV 68 88 61 84 / 50 30 10 0 MKO 71 90 62 85 / 30 0 0 0 MIO 67 86 59 83 / 60 10 10 0 F10 71 91 61 86 / 30 0 0 0 HHW 71 89 65 89 / 50 10 10 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ SHORT TERM...23 LONG TERM....07 AVIATION...30