Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/15/24


Area Forecast Discussion
National Weather Service La Crosse WI
1008 PM CDT Sun Jul 14 2024 .KEY MESSAGES... - Storm chances persist for this evening into Monday evening. A few storms may be strong to severe with damaging wind gusts and localized flooding being the primary threats primarily on Monday. Large hail is a secondary threat. - Hot and humid conditions continue into Monday with highs in the upper 80s to near 90. Widespread heat indices in the lower to upper 90s with some areas reaching 100 on Sunday. - Cooler and drier conditions beginning Tuesday and into much of the upcoming week with highs in the middle to upper 70s. && .DISCUSSION... Issued at 304 PM CDT Sun Jul 14 2024 Humid With Storm Chances This Evening, Some Strong to Severe: Muggy conditions are the name of the game this afternoon with observed dewpoints across much of the region well into the 70s. Air temperatures maintaining into the lower to mid 80s are maybe a touch cooler than expected with some cloud cover around but still relatively on track to see highs reach into the upper 80s in spots by late afternoon and early evening with heat indices in the middle to upper 90s in some locales. As we head into the evening hours, our convective environment is essentially a powder keg with guidance showing the potential for the cap to erode across southern portions of our area during the evening hours (shown in the KDBQ 14.13z RAP sounding at 6pm). When considering MLCAPE values of 2000-3000 J/kg across our south would expect storms to initiate very quickly with anything that provide any kick in the atmosphere. Looking at GOES-16 water vapor imagery, a remnant MCV can be noted across western and central MN that is slowly trekking southeast accompanied with a subtle shortwave. As a result, many of the CAMs rapidly develop a cluster of storms across portions of northeast IA and southwestern WI later this evening. Currently, the main question with this is the aforementioned cap which tries to erode with this weak forcing. How much the cap erodes will determine convective coverage. Shear profiles appear fairly weak with 0-6km shear in the 14.16z RAP being fairly minimal, around 20-30 kts. As a result, would expecting a more multi-cell configuration with individual cells struggling to maintain. Consequently, would only expect to see hail with more robust updrafts. However, with fairly robust DCAPE values collocated with the MCV, would think that cores could collapse fairly vigorously which could lead to isolated downburst gusts to 60 mph. Storms will quickly exit the region to the southeast with the window for storms being likely a few hours (through about 8-9pm at the latest). Severe Weather Potential Early Monday into Monday Evening: As we head into the overnight, forecast soundings show in the 14.16z RAP has low-level saturation and fairly light winds throughout the low-levels. Consequently, with much of the recent rainfall we have seen over the past few days, could see areas of fog initially during the overnight, with questions remaining as for how long it maintains as an incoming MCV approaches. As this MCV and accompanying 500mb shortwave approaches, expecting to see convection as it approaches the local area during the morning hours. As it then progresses eastward a surface cold front is draped across our region and pushes south with additional convective initiation possible. As a result, with severe regimes in play for Monday several different scenarios may be possible. Starting with the morning MCV, as the shortwave moves through the local area (Which also still maintains some uncertainty in timing amongst deterministic guidance) during the morning hours, modest MLCAPE of 2000-3000 J/kg would certainly provide enough of a boost to get convection going. However, deterministic soundings (14.15z RAP) would suggest a cap is still largely in place during the morning hours which would be a serious hindrance to convection as noted in the 14.12z HRRR which has storms fizzling out as they approach the local area. However, if storms can form an organized cold pool with the higher effective bulk shear in the vicinity of the MCV. This type of convective complex (as illustrated in the 14.12z ARW) would likely pose some damaging wind threat if it can utilize the instability gradient and get through the cap. As we head into afternoon, the aforementioned cold front pushes through the region during the afternoon. The key question as we approach this time of day is how the cap will behave, the CAMs vary considerably on this with the 14.12z HRRR keeping the cap in place throughout the day leading to minimal convective development as the front progresses through. This is contrasted heavily by the most aggressive solution in the 14.12z ARW which would favor an organized MCS along the boundary pushing south with relatively uncapped thermodynamics and plenty of 0-3km shear (roughly 35-50 kts in the 14.15z RAP) for forward propagation and potential bowing structures. As a result, if this scenario were to manifest would expect damaging winds to be the primary threat with heavy rainfall potentially leading to flash flooding concerns where soils are already very saturated. Consequently, the SPC has a slight risk (Threat level 2 of 5) across much of the local area. The last caveat to this whole forecast is an organized MCS across central IA that some of the recent CAMs have been trying to pick up on. While much of the CAMs mainly keep it south of the area through the afternoon and evening hours, fairly favorable 0-3km shear profiles and MLCAPE of 3000-5000 J/kg in the 14.15z RAP would enable a bow echo type structure to push east with the potential for damaging wind gusts (perhaps approaching 70-80 mph). Furthermore, this is highlighted in the 14.12z HRRR neural network probabilities which has modest probabilities (40-50%) for winds over 50 kts across portions of northeastern IA. With some uncertainty in exactly where the MCS positions itself the SPC has put extreme southern portions of our forecast area across northeast Iowa and southwestern WI in an Enhanced risk (Threat level 3 of 5) to address this potential. However, many questions remain such has how any prior convection`s outflow could affect the environment and available instability for this MCS. As a result, will be very important to stay tuned to upcoming forecast updates as mesoscale details become more fine tuned. Regardless, if storms materialize will want to watch the heavy rain potential as well with precipitable waters of around 2" and fairly respectable warm cloud depths (around 3.5 km in the 14.12 NAM) which would lead to some efficient rainfall makers. While the 14.12z EC/GEFS ensemble generally only has medium probabilities (30-60% chance) or over 0.5" through Monday night, the 14.12z HREF ensemble max paints spots of 2-3" over the next 48 hours which would suggest areas that receive repeat rounds of storms could see locally heavy rainfall amounts. As a result, when considering prior rainfall from yesterday of anywhere 2-5" leading to saturated soils, localized flash flooding may be possible. Cooler and Dry Pattern Begins Tuesday: Going into Tuesday, a broad scale synoptic trough pivots its way into our region, aiding in the shove cold air advection further south resulting in a cooling trend through the middle of next week. As a result, the 14.00z grand ensemble (GEFS/EC ensemble/Canadian ensemble) with an inter-quartile range of highs at La Crosse for Wednesday of 71 to 76 with a median of 74. Median temperatures in the grand ensemble generally trend in the middle 70s to lower 80s. Additionally, with increasing subsidence with surface high pressure building in mid-week, would expect minimal precipitation chances through Friday. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1005 PM CDT Sun Jul 14 2024 Much of the showers and storms will remain south and southeast of the TAF sites overnight. On Monday, there will be 2 areas of showers and storms moving southeast through the region. The first will move through the morning. This one looks to be weakening, so did not include precipitation at KLSE. The other one moves in during the afternoon. Still some uncertainty on the strength of these storms, so just went with vicinity showers at the TAF sites. With the light winds overnight, decided to add BCFG between 15.09z and 15.13z for KLSE. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...Naylor AVIATION...Boyne
Area Forecast Discussion
National Weather Service State College PA
1126 PM EDT Sun Jul 14 2024 .SYNOPSIS... High pressure will remain near Bermuda for the first part of this week, resulting in a prolonged heat wave over the region. A cold front will push southeast across Pennsylvania late Wednesday, then high pressure will build in from the Great Lakes late in the week. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... The main feature of interest in the near term forecast is a mid level shortwave entering Western PA, which is progged to track across Central PA late tonight. Modest height falls and surging pwats ahead of the shortwave supports at least a slight chance of an overnight shower over much of the area. Can`t rule out a tsra across the Susq Valley, where RAP indicates higher instability overnight. The entire region will remain very warm and humid overnight with increasing clouds and an overall uptick in humidity ahead of the upstream shortwave aiding in keeping temps up. See no reason to deviate from NBM min temps, which range from the mid 60s in the coolest northern valleys to the mid 70s in the more urbanized spots of the Lower Susq Valley. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... Diurnal heating, combined with the approach of shortwave over the Grt Lks, should result in scattered convection Monday afternoon/early evening. Modest instability/shear profiles could support some multicell storm organization and the threat of isolated severe weather, mainly over Northern PA where progged mid level flow is strongest. Convection should dissipate after sunset, as the shortwave passes east of the area. The more-certain wx trouble is the heat. Have converted the watch to a warning for Mon and Tues. Wed also looks hot, but more like advy numbers for the SE only. To keep confusion to a minimum and play up the danger in the nearer two days, we`ve chosen to make the simple change to a warning for Monday and Tuesday at this point and left Wed out of it. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Heat wave peaks Tuesday afternoon, as a large Bermuda high pumps increasingly hot and very humid air into CPA. 850mb temps rising to around 22C supports highs peaking between 90-100F with max heat indices 100-105F southeast of the Alleghenies. High confidence in excessive heat risk lead to the issuance of a heat advisory for the south central mountains and Middle Susquehanna Valley Mon & Tue and an excessive heat warning for the Lower Susq Valley, where max heat index around 105F appear likely. A round of at least semi-organized/possible severe convection is possible Tuesday PM ahead of cold front pressing southeast through the Great Lakes toward Lake Erie. However, a better chance of more widespread showers/tsra is in the cards for Wed PM with the passage of the front. All medium range guidance supports a return to fair and seasonable weather with much lower humidity late in the week, as high pressure builds southeast from the Grt Lks. Will maintain just a slight chance of convection along the southern tier Thursday to account for some uncertainty regarding how far the dying cold front makes it south of the Mason Dixon Line. The stalled front is likely to return northward next weekend, resulting in the return of diurnal convection, mainly over the southern counties. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... Line of showers/storms moving east across Ohio continues to weaken, but still expecting BFD and possibly JST to see a few showers from this later on this evening. Overnight, BFD stands the best chance (50-60%) of seeing MVFR ceilings while all other sites see much lower probabilities and thus have maintained VFR conditions at all other sites. Given a good deal of cloud cover, have opted to maintain VFR visibilities at this time with fog more confined to deeper valleys. Sub-VFR probabilities for visibility cap out at 30-40%. Monday will bring a better chance of showers and storms in the afternoon and evening. The highest probability of having a storm will be in BFD, UNV and IPT, as there will be a weak trough swing down from the north. Still too early to nail down a specific time for TSRA/CB mention. A real/potent cold front does look like it will finally pass through in mid-week (Tues night or Wed) and bring a drier airmass behind it. Outlook... Tue...Scattered, mainly aftn, SHRA/TSRA possible. Wed...More widespread SHRA/TSRA, with brief restrictions likely. Thu...Lingering -SHRA diminishing. Fri...no sig wx. && .CLIMATE... The duration of warm nights is noteworthy. Here are the longest stretches with temperatures at or above 70F on record at Harrisburg. # OF DAYS DATES YEAR 17 7/19-8/04 2020 13 8/16-8/28 2021 13 7/13-7/25 2010 12 7/18-7/29 2022 12 7/17-7/28 1999 12 7/20-7/31 1940 11 8/04-8/14 1977 10 8/10-8/19 2016 10 7/14-7/23 2013 10 8/01-8/10 1968 10 7/21-7/30 1898 9 12 times, most recently 7/3-7/11/2020 8 7/04-7/12 2024 ................................................. && .CTP WATCHES/WARNINGS/ADVISORIES... Heat Advisory from noon Monday to 8 PM EDT Tuesday for PAZ019- 025>028-034-035-045-046-049>053-058. Heat Advisory until noon EDT Monday for PAZ036-056-057-059- 063>066. Excessive Heat Warning from noon Monday to 8 PM EDT Tuesday for PAZ036-056-057-059-063>066. && $$ SYNOPSIS...Fitzgerald NEAR TERM...Fitzgerald SHORT TERM...Fitzgerald/Dangelo LONG TERM...Fitzgerald/Bowen AVIATION...Guseman/Dangelo CLIMATE...Evans
Area Forecast Discussion
National Weather Service Cheyenne WY
937 PM MDT Sun Jul 14 2024 .KEY MESSAGES... - Red Flag Warning for the majority of southeast Wyoming and portions of the Nebraska Panhandle today. Dry thunderstorms will become scattered to numerous, and possible fire starts from lightning strikes may occur. - Very hot temperatures will continue through Monday. Heat Advisories remain in effect for the High Plains along and east of I-25. - Increased precipitation chances and cooler temperatures are expected late Monday through Wednesday. && .SHORT TERM /THROUGH TUESDAY/... Issued at 145 PM MDT Sun Jul 14 2024 High based thunderstorms beginning to develop across parts of the CWA at 1PM. Seeing lightning strikes across central Laramie County near Cheyenne...and out in Carbon County from Rawlins to Arlington. Beginning to see development across Albany County and southern Platte County as well. Looking at GFS forecast soundings...18Z PWATS range from 0.6 inches out near Rawlins to 0.7 inches in the Panhandle. There is a surface trough analyzed along a line from Pine Bluffs to Casper along the east slopes of the Laramie Range. An upper level vort max moving through the ridge this afternoon providing some upper level lift which will set us up for a pretty significant dry lightning event the remainder of this afternoon into this evening. Looking at HRRR and RAP simulated radar...convection blossoms after 22Z along the Laramie Range with high based storms moving into the Panhandle through 03Z-04Z. Given very dry air in the lower elevations...storms will be high based and mainly dry. Given what we are seeing currently...will keep the Red Flag Warnings going as they are through 10 PM this evening. Local fire customers will need to be on alert for increased fire starts with these dry thunderstorms through mid to late evening. PWATS on the increase for Monday...increasing to an inch across southeast Wyoming and near 1.2 inches in the Panhandle. Better chances for wetting rains. ECMWF/SREF/NAM and GFS all showing fairly widespread QPF across the CWA. Continued high PoPs (50-80 percent) Monday afternoon and evening...that dissipate towards 06Z. These diurnally driven showers and storms will continue Tuesday with good chances for afternoon and evening storms. Long/skinny CAPE profiles suggest storms capable of producing heavy rainfall with these increased PWATS. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Issued at 431 AM MDT Sun Jul 14 2024 For the extended period, weather across SE WY and E NE will be dominated by a persistent ridge of high pressure over the western half of the United States. A broad upper trough centered over Ontario at the beginning of the period will shift east into Quebec by Thursday, allowing the western ridge to expand north and east causing height rises and weakening flow aloft through Saturday. Abundant mid-upper level mositure will continue to round the ridge over WY and W NE. At the surface, persistent southerly/southeasterly flow will keep low-mid-50s dew points in W NE through the weekend. Confidence in the large scale evolution through Saturday is high given ensemble and deterministic model agreement. By Sunday, models begin to diverge on the timing of a trough digging into the northwest US, which may begin to break down the ridge for the end of the weekend and start of next week. For Wednesday, showers and thunderstorms look to be most abundant for this day given the position of the ridge allowing for better flow aloft and embedded disturbances to force development. With PW values ranging from 0.75" to over 1" over much of E WY and W NE, above normal for this time of year, storms that develop could produce heavy rainfall. Flash flooding potential will be enhanced by relatively slow storm movement. Both Instability (adequate moisture beneath steep ll and ml LRs) and borderline deep layer shear (still decent flow aloft) should support a strong-severe storm, especially further east into NE. Temperatures across the region will be the coolest of the forecast, with highs ranging from the low to mid 80s for most. Confidence in the general precip+temp forecast for Wed is moderate-high, with details regarding exact location of storms and severe potential low-moderate. Thursday through Saturday, as the ridge expands and heights rise, flow aloft will weaken, and temperatures will rebound. Although deep layer shear and instability will be slightly weaker, abundant moisture aloft and very deep inverted V profiles will support showers and storms producing gusty winds, along with a dry lightning potential, especially further into WY. The strongest thunderstorm potential will be confined to W NE where ll mositure and shear will be best. High temps each day are expected to rise into the upper 80s to low 90s for the lower elevation areas. Confidence in the forecast during this period is moderate, while that in thunderstorm intensity is low given cross-model and run-run inconsistencies in the degree of ll moisture return and extent during this period. Sunday and beyond, the upper trough digging into the US should dampen the ridge at some point impacting our sensible weather. However, timing and impact differences yield low confidence in when and what that impact will be. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 932 PM MDT Sun Jul 14 2024 West northwest flow aloft will continue, with low and mid level moisture increasing on Monday, producing increasing chances for late day showers and thunderstorms. Wyoming TAFS...Scattered to broken clouds near 10000 feet will continue. Expect thunderstorms in the vicinity after 00Z Tuesday. Winds will gust to 25 knots at Cheyenne from 12Z to 00Z, and to 23 knots at Rawlins and Laramie from 15Z to 00Z. Nebraska TAFS...Scattered to broken clouds from 8000 to 10000 feet will continue. Thunderstorms will be in the vicinity after 00Z Tuesday. Winds will gust to 25 knots at Sidney from 15Z to 20Z. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Red Flag Warning until 10 PM MDT this evening for WYZ417-418- 425-428>433. Heat Advisory until 10 PM MDT this evening for WYZ101-102-107- 108-118-119. NE...Heat Advisory until 8 PM MDT Monday for NEZ002-003-019>021-054- 055-095-096. Red Flag Warning until 10 PM MDT this evening for NEZ435>437. && $$ SHORT TERM...GCC LONG TERM...WFOCYS AVIATION...RUBIN
Area Forecast Discussion
National Weather Service Des Moines IA
644 PM CDT Sun Jul 14 2024 ...Updated for the 00z Aviation Discussion... .KEY MESSAGES... - Enhanced Severe Storm Risk Monday with potential of significant damaging wind gusts over 70 mph - Heat Advisory in place to this Evening and Monday South - Cooler and Mainly Dry Tuesday through Sunday && .DISCUSSION... Issued at 252 PM CDT Sun Jul 14 2024 .Short Term /Tonight through Monday Night/... Confidence Short Term: Low to Medium Several competing factors in the short term forecast again this period with regard to precip chances. Heat remains the constant for now, though debris clouds from leftover convection will modulate highs a bit again today in some areas. Weak synoptic surface features remain over the region. Aloft at H700, the leading edge of the cap of 10C was over eastern Iowa at 12z. This did allow the two MCS to increase in strength around sunrise as they reached the eastern extent of the H700 cap. The approaching wave/MCS from South Dakota has now entered the region of warmer air aloft and correspondingly diminished over northern Iowa as anticipated. By this afternoon, some increase in storm coverage is expected as the H700 wave over the Northern Plains tracks east into Iowa this evening and crosses the state overnight. The synoptic models (EC/GFS) are holding the H700 cap over Iowa through the overnight. CAMS, particularly the HRRR and ARW cores are showing some weakness in the cap again over eastern Iowa by 21-23z this afternoon. Though no solution is heavily favored over the other, we will keep some thunder chances this afternoon over the northeast along the US20 to US30 corridors. Tonight the main areas of convection should hold north of Iowa until late in the period when some storms may cross into northern Iowa prior to sunrise as a stronger MCS moves through southern Minnesota and Wisconsin. Lows tonight will fall to the upper 60s to lower 70s in the north while the central to south will remain in the mid 70s. Tomorrow lingering debris clouds north and the sagging surface boundary will hold temperatures in the 80s north while the south again will be in the 90s with heat indices in the 100s. Tomorrow will be similar to today with regard to timing out convection. We will still be battling the H700 cap for a portion of the day into the afternoon hours. The main difference tomorrow is the added surface moisture convergence along the boundary moving through the region, plus increasing shear during the day and afternoon. CAMS are now showing some earlier initiation with late morning into early/mid afternoon firing of convection along the sagging boundary into central Iowa. Upper level wind fields are looking more favorable for a potential severe bowing system with more significant damaging thunderstorm winds into the afternoon hours. Still a fair amount of uncertainty with initiation and placement, but a corridor between US20/I80 and around or slightly east of I35 is more favored at this time. SPC is upgrading SWODY2 to enhanced over central to eastern Iowa with this potential in mind. Will need to monitor trends overnight into early Monday morning with regard to outflow, approaching upper level system and model convective trends. After the main area of early afternoon convection exits the region, we will still see trailing convection along the boundary in the evening into overnight hours south as the front sags into northern Missouri. With upper level return flow over the boundary, more storms will be possible through Tuesday 12z in this area. Lows Monday night will fall to the lower 60s north to the lower 70s in the south. .Long Term /Tuesday through Sunday/... Confidence: Medium to High After tomorrow`s potential significant convection, we will get a welcomed break from storms, heat and humidity through the end of the period. Still looking on track for highs to cool to the 70s to lower 80s with lows in the 50s to lower 60s for much of next week. There is some uncertainty late in the period with regard to return moisture, but some showers may advance back into western section around next Sunday. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 644 PM CDT Sun Jul 14 2024 A cluster of thunderstorms this evening is impacting KALO. While precipitation will pass near to just south of the terminal, lighting will be a threat for the next hour. Activity this evening should remain clear of other TAF sites. Confidence decreases on Monday morning as there is the potential for convection across northern and eastern terminals. Timing and location have been difficult to pin down and will depend greatly on how the current storms in Iowa and overnight convection across the midwest play out. Therefore have kept to VCTS mentions and will need to update later as confidence increases in the details. && .DMX WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 8 PM CDT this evening for IAZ004-015-023- 024-033>035-044>048-057>062-070>075-081>086-092>097. Heat Advisory from 1 PM to 8 PM CDT Monday for IAZ057>062- 070>075-081>086-092>097. && $$ DISCUSSION...REV AVIATION...Hagenhoff
Area Forecast Discussion
National Weather Service Sioux Falls SD
1053 PM CDT Sun Jul 14 2024 .KEY MESSAGES... - High humidity with temperatures in the 80s and 90s will lead to heat index values of 95 to 105 degrees. Heat Advisory remains in effect for areas along and south of I-90 until 8 PM. - An area of thicker wildfire smoke can be seen on satellite advecting into south central SD. This moves east through the evening along the southern MO River Valley and northwestern IA; however, no surface impacts are currently expected. - Showers and storms are possible tonight through late Monday morning, although confidence is very low in coverage and timing. Strong to severe storms are possible if storms develop, with all hazards possible. - Unsettled pattern continues into mid/late next week with periodic low shower and storm chances. Starting Tuesday, temperatures will be near to below normal for this time of year. && .DISCUSSION... Issued at 236 PM CDT Sun Jul 14 2024 CURRENTS THROUGH MONDAY: Morning cloud cover has diminished/moved east, although diurnal cumulus is developing across the region. Also noting an area of thicker wildfire smoke over south central SD; however, no surface impacts are expected at this time as it moves to the southeast through the evening hours. Temperatures continue to climb into the 80s and lower 90s. Despite being a bit cooler than yesterday, dew points in the mid 60s to mid 70s raise heat indices into the mid 90s to 105 degrees F. Maintained the on-going Heat Advisory for areas along/south of I-90. Now, attention turns to chances for showers and storms overnight through Monday. Models continue to struggle this run in resolving short wave trajectories over the area during this time, including source region (ND v.s. western SD), timing (tonight v.s. mid day Monday), strength, and number of waves. This leads to very low confidence in convective chances through Monday afternoon. In one camp of models, the main short wave ejects out of ND late tonight bringing a complex of storms into portions of southwestern/central MN as it collides with a surface boundary. This scenario is mostly evident in the NAMNest, ARW, and some runs of the HRRR today. The FV3 is in a similar camp, although is much further to the west (bringing the storms to areas west of I-29). Some of the guidance (a couple of HRRR runs and the RAP) either don`t have this feature or shift it much further east in MN. Another short wave is progged to move into the area later Monday morning, and depending on where the boundary ends up after any overnight convection, this may be a catalyst for additional storm development in the late morning tomorrow along/south of I-90. The NAMNest is the most aggressive with this development in northeastern NE, quickly growing upscale along the front into northwestern IA. Given all the uncertainty, generally tried to use an average of the hi-res models and previous forecast for pops. If storms are able to advect into or develop over our area into late Monday morning, they could quickly become strong to severe. MUCAPE is generally 1500 J/kg or higher (at times approaching 3000+ J/kg), bulk shear of 35+ knots, and steep mid level lapse rates of over 8 deg C/km support wind gusts to 70 mph and golf ball sized hail. Based on last night/early this morning`s storms, would not be entirely surprised if a stronger complex of storms produces wind gusts to 80 mph. Can`t rule out a tornado or two with the surface boundary hanging around, low LCLs, and 0-1 bulk shear around 20 knots. Locally heavy rain is possible as PWATs sit between 1.5 and 2 inches. Not anticipating widespread flooding issues as convection is expected to be fairly progressive. Lows tonight in the upper 60s to lower 70s. Highs tomorrow will be highly dependent on morning convection, cloud cover, and how far south the boundary is. Seasonal temps expected with highs in the 80s to lower 90s. High dew points push heat index values into the upper 90s to near 100 in the southern MO River Valley into northwestern IA. MONDAY NIGHT AND TUESDAY: As the boundary moves south Monday night, CAA begins to filter in, bringing cooler temperatures. A couple of weak waves bring some occasional precip chances to the area, but severe weather is not expected. Lows in the upper 50s to mid 60s. Highs Tuesday will be slightly below average thanks to the CAA and cooler surface high pressure moving in. We`ll only warm into the mid/upper 70s to lower 80s. MID WEEK ONWARD: Surface high pressure meanders south around the northern/central Plains mid week, sliding east into the Great Lakes late week. Northwesterly flow regime and CAA to neutral advection keep temperatures cooler than average. Highs in the 70s to mid 80s and lows in the 50s to lower 60s. A few weak waves could bring some shower and storm chances to the region, but probability is low (< 30%). Synoptic pattern becomes more amplified later in the period as troughing digs in over the eastern US and high pressure deepens over the Southwest. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1053 PM CDT Sun Jul 14 2024 VFR conditions begin the TAF period. Showers and storms have developed across North Dakota late this evening and look to grow into a complex as they progress southeastwards through the night. The storms look to remain along and northeast of a De Smet, SD to Luverne, MN to Spencer, IA line. While away from all TAF sites, have included VCSH in KFSD`s TAF as some trailing showers could impact the terminal. Should see the complex of storms push east/southeast of the area by mid morning tomorrow. A second round of lighter showers is possible during the afternoon hours but confidence is only high enough to include in KHON and KFSD`s TAFs as of now. A cold front will push through the area during the morning hours which will turn surface winds to out of the north. More storms could develop during the afternoon hours on the cold front but confidence is low in where storms could develop at this time. Any chance for showers and storms will push east/southeast of the area by the evening hours, leaving light northerly winds to finish out the TAF period. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ DISCUSSION...SG AVIATION...Meyers
Area Forecast Discussion
National Weather Service Hastings NE
622 PM CDT Sun Jul 14 2024 .KEY MESSAGES... - A Heat Advisory remains in effect through 8PM this evening for Valley, Greeley, Sherman, Howard, and Nance counties in Nebraska. Heat index values as high as 105 degrees are expected. - A Heat Advisory is also in effect for all counties along and south of Interstate 80 as well as Merrick and Polk counties in Nebraska, and for the entirety of north central Kansas, through 8PM Monday. Heat index values as high as 110 degrees are expected. - Cooler temperatures are expected Tuesday through the end of the week, with high temperatures in the 80s Nebraska to around 90 over northern Kansas on Tuesday and then in the 70s and 80s Wednesday into next weekend. - Several small 20% chances for precipitation most evenings/overnights, with the best chance Tuesday evening into Tuesday night (30-60%). && .DISCUSSION... Issued at 304 PM CDT Sun Jul 14 2024 This Evening into Tonight... It will be another warm muggy night with a slight chance (20%) that a few thunderstorms that develop west of our area could possibly slip into our western forecast zones mainly after 10 PM. Severe weather is not expected and the marginal risk area for today has been removed from the forecast. Any thunderstorms that can make it into our western forecast area should be dieing out as they move in or shortly after. Monday (Last Hot Day For Now)... Our Kansas zones will most likely still be baking with over 105 heat index values. However, northern zones will start to see some relief from the heat as a cold front slides southeast through the day. The NBM does indicate a pretty good spread in possible temperatures for this time of year leading towards more uncertainty in the Tri-Cities area due to frontal timing and cloud cover. However, heat index values in the Tri-Cities should still get over 100 for at least a little while and may still briefly hit 105 in some spots. The 18Z HRRR is one of the more aggressive models when it comes to evening thunderstorms moving in from the west and a little more aggressive than recent runs. Therefore, have increased POPs a bit above 20% NBM values, and closer to 30 percent favoring areas south and southwest of I-80. There is a marginal risk and we could see some isolated severe weather along and behind the cold front mainly during the later evening hours. Tuesday (Cooler and Best Chance for Rain)... The NBM temperature spread tightens up a bit in the 80s across Nebraska, while Kansas zones may still hit 90. Agree with NBM guidance that this is probably our best chance for a more widespread appreciable rainfall across the area. However, the most favored zones will be from about the Tri-Cities and points to the southwest and south (40-60%). Locations northeast of the Tri-Cities will see lower rainfall chances 30-40%. Again can not rule out a few isolated marginally severe storms. Wednesday through next Weekend... We will remain under the influence of a cooler northwesterly upper level flow pattern that will result in highs only in the upper 70s and 80s. Rainfall chances are not great, but within this flow pattern there will be weak shortwaves passing through resulting in several mainly small (20-30%) rain chances that tend to favor evening and overnight periods. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 615 PM CDT Sun Jul 14 2024 For KGRI/KEAR Airports: High confidence VFR conditions through the period with some elevated haze and scattered passing high clouds. East southeasterly winds near 10 KTS this evening will gradually subside overnight while becoming more southerly, eventually shifting and becoming northwest behind a cold front Monday afternoon. While an increase in mid/high level clouds will likely be observed with this front Monday afternoon, no precipitation is anticipated through the valid TAF period. && .GID WATCHES/WARNINGS/ADVISORIES... NE...Heat Advisory until 8 PM CDT Monday for NEZ048-049-060>064- 072>077-082>087. Heat Advisory until 8 PM CDT this evening for NEZ039>041-046- 047. KS...Heat Advisory until 8 PM CDT Monday for KSZ005>007-017>019. && $$ DISCUSSION...Wesely AVIATION...Rossi
Area Forecast Discussion
National Weather Service Goodland KS
1000 PM MDT Sun Jul 14 2024 .KEY MESSAGES... - Potentially damaging wind gusts this evening. - Heat Advisory remains in effect for all but far eastern Colorado Monday. - Cooler (less hot) temperatures and a bit better chance for rainfall for much of next week. && .SHORT TERM /THROUGH MONDAY NIGHT/... Issued at 500 PM MDT Sun Jul 14 2024 Tonight...isolated to scattered showers/thunderstorms are anticipated to move from west to east through about 12 AM MDT (1 AM CDT), impacting those generally west of a line from near McCook to Colby and Oakley. The primary hazard will be wind gusts up to 65 mph. HRRR is showing a potential for heat bursts after about 10 PM MDT as shower/thunderstorm activity dissipates. Low temperatures are forecast to be in the middle 60s to middle 70s. Monday-Monday night...we`ll have another chance for showers and thunderstorms from late afternoon through the overnight hours as a better organized weather system moves through from the northwest. A few severe thunderstorms will be possible. High temperatures are forecast to be in the middle 90s to around 107 with low temperatures in the lower 60s to lower 70s. Heat indices as high as 107 are forecast (Norton/Graham counties). Tuesday-Tuesday night...We`ll have a lull in precipitation chances until late afternoon when another weather system moves through from the west-northwest. Presently we have likely pops (60%) for overnight thunderstorm chances. High temperatures return closer to normal for early July with upper 80s to lower 90s forecast. Low temperatures also near normal in the upper 50s to middle 60s. Wednesday-Wednesday night...lingering moisture in the 850-500mb layer in the northwest flow aloft will continue to support daily and overnight chances for rainfall. Presently we have 20%-70% chances during the day with 20%-50% chances overnight. With cooler temperatures aloft and quite a bit of cloud cover, high temperatures look to be below normal with 80 to 85 degrees forecast. Low temperatures are forecast to be in the upper 50s to lower 60s. && .LONG TERM /THURSDAY THROUGH SUNDAY/... Issued at 500 PM MDT Sun Jul 14 2024 Slightly below normal daytime highs in the 85 to 90 degree range are forecast with low temperatures a few degrees either side of 60. Daily rainfall chances are in the 20% to 30% range in general as weather systems move through from the northwest. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1000 PM MDT Sun Jul 14 2024 KGLD...VFR conditions are expected through the period. A southerly wind up to 10kts is expected at taf issuance, veering to the west at similar speeds through 12z. Winds continue to veer to the north through the day Monday at speeds up to 11kts or so. For Monday evening, winds remain generally from the north around 11kts. Showers and thunderstorms could be near or over the terminal after about 22z Monday with a bit better chance after about 03z as the next weather system moves through. The primary hazard would be strong gusty winds. Given overall coverage and timing, I will not be including any mention in the forecast at this time. KMCK...VFR conditions are expected through the period. A light and variable wind is forecast from taf issuance through 14z. From 15z-01z, west winds veer to the north then northeast, gusting up to 20kts or so after 23z. After 02z, winds remain from the northeast around 11kts. Regarding shower and thunderstorm chances, presently the best chance for any to be near or over the terminal is after about 03z. Similar to KGLD, the primary hazard will be strong gusty winds. There wont be a mention of thunderstorms in this taf forecast. && .CLIMATE... Issued at 423 AM MDT Sun Jul 14 2024 Sunday high temperature records Record Year Yuma 105 2010 Burlington 105 1925 Goodland 107 1934 Tribune 107 1934 Colby 109 1934 McCook 109 1954 Hill City 113 1934 Monday high temperature records Record Year Yuma 102 2006 Burlington 103 2000 Goodland 106 1925 Tribune 108 2000 Colby 108 1925 McCook 112 1925 Hill City 113 1934 && .GLD WATCHES/WARNINGS/ADVISORIES... KS...Heat Advisory from 9 AM MDT /10 AM CDT/ to 8 PM MDT /9 PM CDT/ Monday for KSZ001>004-013>016-027>029-041-042. CO...None. NE...Heat Advisory from 9 AM MDT /10 AM CDT/ to 8 PM MDT /9 PM CDT/ Monday for NEZ079>081. && $$ SHORT TERM...99 LONG TERM...99 AVIATION...99 CLIMATE...
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
747 PM CDT Sun Jul 14 2024 .KEY MESSAGES... - Intense heat continues tomorrow, with heat indices of 100-110 degrees during the day. Not much relief is given overnight with lows in the mid to upper 70s. - Some relief from the heat comes Wednesday as a cold front pushes through central and southeastern Illinois over night Tuesday. The CPC shows a below normal trend on temperatures for the next 14 days. - Multiple MCS passages are forecast for the coming days before a brief break starting Wednesday. Some of these storms have the potential to be severe with damaging winds as the main risk. && .UPDATE... Issued at 746 PM CDT Sun Jul 14 2024 This evening, a broken line of thunderstorms has developed from near Rockford SW across the Quad Cities. Strong instability in excess of 3000 J/kg is in place ahead of this line of storms. 00Z ILX sounding showed a "loaded gun" setup with around 3000 J/kg MLCAPE and -68 J/kg MLCIN. Deep layer shear in the region is marginally sufficient (around 25-30kt) to support organized convection this evening and do anticipate storms to congeal into a more organized line over the next few hours. Cloud bearing flow and forward propagating corfidi vectors will generally steer these storms west-to-east across northern Illinois with some potential of clipping our far northern CWA where a severe thunderstorm watch is currently in effect. Damaging wind gusts will be the primary hazard with these storms. That said, veering LLJ this evening will help the southwestern end of the line back-build with upshear Corfidi vectors suggesting storms will propagate S/SW late this evening into portions of the area. Where this occurs, a heavy rain threat is possible due to the slow moving nature and training of storms. Latest HRRR suggests a few pockets of around or just in excess of 2 inches of rain is possible north of I-72. Deubelbeiss && .DISCUSSION... Issued at 214 PM CDT Sun Jul 14 2024 The MCS this morning skirted by the northern periphery of the CWA without incident. This won`t be the only round that threatens central Illinois. Currently, we are keeping a close eye on the MCV that is propagating through north-central Iowa. The HRRR and NAMNest depict the MCV and it`s reignited convection taking a southerly dip once it gets to Illinois, with the NAMNest being the most dramatic in its southern pull. The environment will have had time to recover from the morning convection, as surface heating occurs with the mostly clear skies, the moisture is far from gone (as we can feel the soupy airmass outside), and the MCV (and rebounding CAPE values) provides the needed lifting mechanism. By mid afternoon, SBCAPE values rise to ~3000 J/kg ahead of the CI, with very little to no cap. The main hazard as the next round moves through will be damaging, gusty winds. Tomorrow, the severe threat continues, but this time bigger and better than before. Another complex is expected to develop over Iowa by late morning and move eastward. Its track has it entering the northern CWA by late afternoon between 22-00z. As it does, the environment is primed. The cap is very little (~-20 J/kg), allowing the line to become surface based. SBCAPE values ahead of the line as it enters are 4000-5000 J/kg. The 0-6km bulk shear looks to be around 40-50 knots. SPC has areas along and north of I-74 outlooked for an Enhanced Risk (level 3 out 5). There is a 30% damaging wind risk with a 10% chance of wind gusts greater than 65 knots for areas along and north of I-72. Localized flash flooding is also in play for tomorrow as the area is already quite saturated and PWATs are 1.8-2 inches at the time of the passage. The heat won`t be taking a break tomorrow neither. Today the heat indices are expected to top out between 100 and 105 degrees. The dew points today and tomorrow will be in the upper 70s, getting very close to 80. The 12z.14 HREF shows a 60% chance of dewpoint exceeding 78 degrees tomorrow afternoon, ahead of the storm complex. Heat indices are forecast to top out near 110 degrees tomorrow (Monday). A cool down is expected starting Tuesday as a cold front is set to move through, wiping out the moisture. Beyond Tuesday, temperatures become slightly below normal for this time of year, giving us the well needed break from the soupy heat. Highs will be around the upper 70s to mid 80s from Wednesday into the end of the forecast period. There are some additional rain chances through early Thursday morning, then will be dry through Sunday. This break should give the area a chance to breathe after the multiple rounds of heavy rain recently. Copple && .AVIATION... (For the 00z TAFs through 00z Monday Evening) Issued at 631 PM CDT Sun Jul 14 2024 Scattered storms upstream over eastern Iowa will be the focus for any activity spreading south into central Illinois later tonight. Confidence remains low in timing and placement, but the better chances for any storms will be at our northern 3 TAF sites (PIA, BMI, CMI). PROB30 groups are noted at each of these airfields between 04-10Z. South-southwest winds will become light overnight then turn breezy tomorrow afternoon. Mostly VFR conditions will be seen outside of storms, with another round of convection possible Monday evening. NMA && .ILX WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 8 PM CDT Monday for ILZ027>031-036>038- 040>057-061>063-066>068-071>073. && $$
Area Forecast Discussion
National Weather Service Northern Indiana
920 PM EDT Sun Jul 14 2024 .KEY MESSAGES... - There are periodic chances for showers and storms (20 to 60%) tonight through Tuesday night, with one or more rounds of strong to severe storms possible during this timeframe. - Best chances for severe weather will be on Monday late afternoon into the evening, when there is an Enhanced Risk (level 3 of 5) for severe weather. Damaging winds 60-75+ mph and a few tornadoes possible. - Alongside the severe threat, flooding is also possible in any storms, especially in areas that remain saturated from the remnants of Beryl. - Hot and humid Monday, depending on storm coverage, timing, and cloud cover. Afternoon heat indices mid 90s to near 100 degrees. - Cooler, drier weather is anticipated midweek through next weekend. && .UPDATE... Issued at 919 PM EDT Sun Jul 14 2024 Previous forecast trends were maintained, with only small update item of note to slightly increase PoPs across northwest half of the area late evening into the overnight. Compact convectively enhanced vortex continues to track east across northwest/north central Illinois this evening with ring of convection initiating over the past few hours from eastern Iowa into southern Wisconsin and northern Illinois. Background synoptic shear remains marginal, but RAP analysis suggests a small pocket of 35-40 knot effective shear associated with this small scale vort max. Despite this, convection has been rather loosely organized up to this point with several storm mergers/interactions across NW Illinois and some periodic signs of some mid level rotation due to these mergers. Still expecting these storms to congeal into a more linear feature late this evening/early overnight as they track east. Upstream 00Z RAOBs from KILX/KDVN indicates very strong instability with 3000-3500 MLCAPEs. Earlier stabilizing effects from northern Indiana early day MCS will be eroded by westerly advection of this better upstream instability axis along with eastward progression of some better mid level lapse rates. Some low level CIN is expected to develop this evening locally for mixed layer parcels however, so some question as to the vigor of this convection as it tracks east into a slightly less unstable environment locally. There could be some tendency for more vigorous storms to develop upwind across central/east central IL as northern portion of the storms across southern Great Lakes become more outflow dominant. Some isolated severe threat still appears to be intact west of US 31 locally in the 05Z-08Z period with a period of potential gusts into the 40 to 60 mph range. Hail threat should be tempered with eastward extent as storms congeal later this evening. Locally heavy rainfall will be some concern across the west tonight, especially considering recent heavy rainfall over the past week. && .DISCUSSION... Issued at 231 PM EDT Sun Jul 14 2024 Multiple rounds of storms are expected over the next 48 hours, with one or more rounds being strong to severe. Our CWA is on the periphery of a building ridge in the Plains, and with northwest steering flow, this puts the Upper Midwest and Great Lakes regions in a very favorable zone for storms. Several strong shortwaves that drop into the Midwest in the coming days may help to sustain several rounds of MCSs. SPC has us in a Day 1 Slight Risk (level 2 of 5), a Day 2 Enhanced Risk (level 3 of 5), and a Day 3 Marginal Risk (level 1 of 5). The next 48 hours come with a lot of uncertainty in the coverage, timing, and number of rounds of storms. Alongside the severe threat, flooding is also possible with any of the MCSs. Many locations, especially in the Wabash and St Joseph river basins, have had 5 to 8 inches of rain this week. With saturated ground and elevated rivers, it won`t take much for these areas to experience more flooding. High PWATS of and the potential for storms to backbuild along outflow boundaries has me concerned about flooding potential in addition to the multi-day severe threat. As the initial round of storms today has now exited the area, dry conditions will return for the next several hours before yet another chance for storms. Hi-res models have yet to come to a strong consensus, but it is looking more plausible (medium confidence) that an MCS will develop over eastern IA/northwest IL late this evening and move eastward into our CWA between 10 PM to 12 AM EDT tonight. With ample MLCAPE 2000-3000 J/kg and DCAPE 1000+ J/kg, damaging winds would be the main hazard overnight. The greatest confidence in severe weather is along and west of US 31, as the MCS should weaken as it pushes eastward overnight. There is increasing confidence in severe weather Monday late afternoon and into the evening. SPC has introduced 30% hatched wind probabilities into the Day 2 Outlook, prompting the need for a Enhanced Risk (level 3 of 5) upgrade across northern Indiana. Another progressive MCS/bow-echo could develop upstream of a much more favorable environment and ride along the highest theta-e axis through southern WI, northern IL, and into northern IN. Strong buoyancy, increasing vertical shear, and favorable thermodynamics (dewpoints low 70s, highs upper 80s to low 90s, MLCAPE of 4000 to 5000 J/kg) could certainly yield a high-end impact damaging wind event. A derecho is possible with organized damaging winds 60-75+ mph and a few tornadoes possible. Heat and humidity build on Monday, with highs in the low 90s and heat indices potentially in the upper 90s to low 100s. Heat Advisory headline could be needed. Uncertainty in storm coverage, timing, and lingering cloud cover could all result in temperatures being lower than what is currently forecasted. An upper level trough will pivot through the Great Lakes on Tuesday, resulting in chances for storms ahead of and along the front. A continental, cooler airmass from Canada will sink south midweek, resulting in seasonable highs in the 70s, a stark decrease in humidity, and dry conditions. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 755 PM EDT Sun Jul 14 2024 Temporary stabilizing effects from earlier convective complex have allowed for mainly dry conditions through early this evening. However, stronger westerly upstream flow will overspread northern Indiana over the next several hours in advance of next upstream mesoscale convective vortex across NW Illinois. This will allow for recovery in instability via advection. Convection has already initiated with this feature with moderate to strong instability across these areas. This showers and storms should encounter some instability gradient as they reach into northwest Indiana, but localized stronger shear/forcing with the small scale vort max should allow for another round of thunderstorms at the terminals in the 04Z-08Z timeframe. Strongest gusts to around 40 knots expected at KSBN with these potential storms with brief IFR vsbys possible. These showers and storms should wane late tonight, with next upstream possible convectively enhanced short wave arriving toward end of this valid period with more thunderstorm chances. Given a good deal of uncertainty at that forecast distance in this pattern, will omit mention in TAFs for now. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...Flood Watch through late Monday night for INZ012>015-020-022- 103-104-203-204. OH...None. MI...Flood Watch through late Monday night for MIZ078-177-277. Air Quality Alert until midnight EDT tonight for MIZ177-277. MARINE...None. && $$ UPDATE...Marsili DISCUSSION...Johnson AVIATION...Marsili
Area Forecast Discussion
National Weather Service Morristown TN
1031 PM EDT Sun Jul 14 2024 ...New UPDATE... .UPDATE... Issued at 1008 PM EDT Sun Jul 14 2024 Though they appear to be fading from radar since making changes, did populate some showers for parts of the central plateau for the next couple of hours. From about central plateau, to Knoxville, to GSMNP and southward, mostly under two tenths of an inch was recorded today from showers, that is if measuring equipment captured it accurately. Highs today from mid-day climate verified well against forecast. Everything else in the nearest term checks fine besides some most recent obs being blended into the future hourlies. KS && .SHORT TERM... (This evening through Monday) Issued at 306 PM EDT Sun Jul 14 2024 Key Messages: 1. Hot again on Monday with increasing moisture across the southern valley and plateau. 2. Higher risk of diurnal convection on Monday afternoon, mainly across the plateau and southern valley. Discussion: General persistence pattern continues with synoptic conditions potentially resulting in slightly higher chances for diurnal convection on Monday afternoon. Temperatures will be within a degree or two of the past couple days with increasing moisture resulting in higher heat index values between 100 and 105F for the southern valley near Chattanooga. While the 850mb ridge remains across the Southeast CONUS, a weakness or col at 500mb will shift slightly eastward and will be across Middle and West TN. These slightly lower heights aloft, and increased moisture to our west, will result in some higher convective coverage across the Midsouth and portions of the Lower Tennessee River Valley. This is evident in RAP soundings which show increasing moisture across the Cumberland Plateau and portions of the southern valley near Chattanooga on Monday afternoon. While LFC heights are around 3km this afternoon, they lower to around 2km on Monday afternoon due to increased moisture. Instability is also forecast to go from around 500 J/Kg this afternoon to 1500 to 2500 J/Kg on Monday afternoon. This thermodynamic environment will increase DCAPE to around 1000 J/Kg across the plateau and southern valley on Monday afternoon with a low risk for stronger, potentially severe thunderstorms capable of damaging downburst wind gusts. Further north across the central valley through northeast TN and southwest VA, drier air remains with more limited rain and thunderstorm chances. Daily Record High Maximum Temperatures Date Chattanooga Knoxville Tri-Cities Oak Ridge 07-14 103(1954) 101(1954) 98(1954) 101(1954) && .LONG TERM... (Monday night through next Sunday) Issued at 306 PM EDT Sun Jul 14 2024 .LONG TERM... Key Messages: 1. Extreme heat will continue on Tuesday with highs in the mid to upper 90s and heat index values into the 100s across much of the area. 2. Scattered storms are expected on Tuesday with more numerous coverage Wednesday and Thursday. Lower chances continue into this weekend with temperatures dropping to below normal. Monday Night through Thursday At the start of the period, quasi-zonal flow will be in place aloft with weak embedded shortwaves and surface high pressure receding to the south. During this time, 500mb heights will still be above 5,900m with near record 850mb temperatures reaching to 21 Celsius by the day on Tuesday. A shift to weak southerly flow will advect some moisture into the area, which will increase humidity in comparison to recent days. Accordingly, temperatures will not reach quite as high as the days prior, but heat index values will still rise into the 100s. The increase in moisture will also bring chances for more scattered convection, mainly along the higher terrain due to weak forcing overall. On Wednesday, troughing from the north will deepen, leading to height falls and further suppression of high pressure. A frontal boundary will be noted north of the Ohio River Valley. As this front approaches from the north, additional, more widespread chances of convection exist on top of terrain-based development. By Thursday, the front will likely reach near the area, providing additional lift and further reduction in temperatures. It is still unclear how much coverage there will be because of the significant drought and recent trends. But the pattern does look promising for more substantial rain chances, which are very much needed due to worsening drought. Friday through Sunday Late in the week and into the weekend, the main question will be how far south the frontal boundary reaches, which will affect the available moisture and overall forcing. Much of this timeframe will see more of a troughing pattern, keeping temperatures more moderated and even slightly below normal. Based on these indications, daily rain chances were maintained, but confidence is still limited based on the persistent dryness recent model biases. Daily Record High Maximum Temperatures Date Chattanooga Knoxville Tri-Cities Oak Ridge 07-15 103(1977) 98(1995) 96(1995) 100(1980) 07-16 105(1980) 100(1980) 100(1988) 103(1980) 07-17 103(1980) 101(1980) 94(1980) 103(1980) && .AVIATION... (00Z TAFS) Issued at 739 PM EDT Sun Jul 14 2024 VFR expected for most of the period at all sites except an increasing chance of showers and thunderstorms Monday afternoon at CHA. PROB30 added to reflect that chance. Cloud cover expected to increase at all levels into Monday afternoon as moisture is advected into southern parts of the CWA. Otherwise, winds expected to be light from the south to westerly direction. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 75 98 74 96 / 10 30 20 50 Knoxville McGhee Tyson Airport, TN 73 97 74 95 / 0 20 10 40 Oak Ridge, TN 72 98 73 95 / 0 20 10 40 Tri Cities Airport, TN 68 95 69 93 / 0 10 10 40 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...JB LONG TERM....BW AVIATION...KS