####018006452#### FXUS63 KGID 160001 AFDGID Area Forecast Discussion National Weather Service Hastings NE 701 PM CDT Sat Aug 15 2026 .KEY MESSAGES... - Isolated showers/weak storms through early evening. Better chance for at least scattered storms tonight after midnight, esp. for areas along/S of the state line. Some storms may be strong to marginally severe, with wind gusts of 50-60 MPH the primary threat. - Mainly dry on Sunday with pleasant temperatures in the upper 70s-80s. Next chance for showers/storms comes late Sunday night and into Monday morning. - Fairly active pattern continues through at least the first half of the new work week. Some of the storms late Monday and on Tuesday may be strong to severe. - Temperatures next week will oscillate back and forth between the upper 70s to upper 90s - warmest on Tuesday (esp. KS zones), and coolest on Wednesday. && .DISCUSSION... Issued at 415 PM CDT Sat Aug 15 2026 A weak upper disturbance (MCV) left over from last night's convection continues to gradually shear out/weaken as it slides NE into the Siouxland region. There has been just enough lift on the tail end of this wave to spark some isolated to widely scattered showers over N zones. Another area of isolated development has been along/E of a weak convergent zone (subtle mixing boundary?) mainly E of Hwy 281 where atmosphere is quite juicy with temps in upper 80s and dew points in mid 70s. Hard to see either area really taking off next few hours in terms of coverage or intensity given what should be gradually increasing subsidence as what's left of the aforementioned upper wave moves even further away. Upper pattern remains generally unchanged from 24-48 hours ago...so expect at least scattered convection to develop all along the Front Range this afternoon, then move E onto the Plains this evening and overnight. Recent CAMs (including 12Z HREF and 18Z HRRR) have been placing the highest chances and strongest activity across KS - closer to the main baroclinic zone evident in sfc obs - running SW to NE across the state. This boundary, along with overnight LLJ, should help focus one or two MCSs overnight and into early Sunday morning. Similar to past few nights, appears the most robust activity will tend to favor areas W and SW of the local area, but still...lingering MUCAPE and system organization (additional MCVs?) should carry at least a low-end damaging wind threat into mainly our KS zones after midnight tonight. Believe we're seeing the beginning of such MCS development over SE Colorado now. Besides perhaps some lingering showers in SE zones early in the morning, the brunt of the daytime hours Sunday appear dry and pleasant...besides the usual/seasonable humidity. Should see decreasing clouds through the day and highs top out in a very comfortable range in the upper 70s to mid 80s. Very nice way to end the weekend! Upper pattern looks to make a slight transition from mainly SW/zonal as it is weekend to mainly zonal/NW for at least the first half of next week. This will be in response to a deepening upper low around the Hudson Bay in Canada and moderate ridging again asserting itself over the Desert SW. This will favor frequent chances for storms as the Canadian low forces a cold front into the region late Mon/Tue that then stalls out somewhere over the Central Plains through midweek. Frequent weak waves interacting with this front...along with the upslope flow along the Front Range behind the front...should provide the necessary lift for at least scattered storms each afternoon that then roll E during the evening and overnight - perhaps aided at times by a nocturnal low level jet. This is the BROAD idea of what the pattern should look like, but of course, the "devil is in the details". Monday daytime hours should be mainly dry for most, if not all, locations as the primary area for development looks to be over north central Nebraska. Some of this activity could slide SE into the local area during the late evening and overnight and pose a Marginal Risk (level 1 of 5) for strong to severe wind gusts (50-60 MPH). Tuesday looks to be the warmest day of the week, but specifics will depend on timing and placement of the cold front. KS zones have the best chance to remain ahead of the front through peak heating, and the latest forecast there is for very warm highs in the upper 90s. Tuesday looks to feature the best chances for late afternoon and evening development overhead along the boundary, and the latest SPC Day 4 outlook implies Slight Risk level severe probabilities (level 2 of 5). This threat will obviously be refined in the coming days. Wednesday currently looks to be the coolest day of the week behind the front and perhaps in quite a bit of lingering cloud cover. Ensembles generally indicate declining rain chances late next week and gradually recovering temperatures - though confidence on specifics this far out is quite low. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 700 PM CDT Sat Aug 15 2026 For KGRI/KEAR Airports: Light, roughly northerly winds are forecast through the majority of the forecast. Scattered low- level clouds have developed across the area in response to the diurnal heating this afternoon. This cloud cover is expected in coverage this evening as thunderstorms approach the area from the west. Even though these thunderstorms are expected to stay south of the terminals, mid to upper level cloud cover is expected to increase in response to their proximity. The main uncertainty with the forecast is the cloud cover/visibilities late tonight/early tomorrow morning. Depending on the track of these storms, some brief periods of lower cloud cover may be possible, with cloud bases at low end VFR. However, if these clouds move out of the area quicker, some fog development could be possible. Uncertainty remains with its formation or density. Ceilings are expected to improve tomorrow afternoon as storms continue to move off to the East. Winds will become NE around 6-8 kts. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ DISCUSSION...Thies AVIATION...Scott ####018005026#### FXUS65 KTFX 152356 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 556 PM MDT Sat Aug 15 2026 Aviation Section Updated. .KEY MESSAGES... - A few storms may produce localized strong, gusty winds and even some instances instances of brief downpours capable of localized flooding, mostly over central and southwest Montana. - Some patchy fog will develop again by early Sunday morning, mostly for the southwest valleys and the river valleys over the plains. - Daily rounds of showers and thunderstorms will continue through mid- week, most widespread Monday evening through early Tuesday. - Seasonable temperatures will climb back above average towards the end of next week with shower and thunderstorm activity increasing once again next weekend. && .DISCUSSION... /Issued 1250 PM MDT Sat Aug 15 2026/ - Meteorological Overview: A moist southwesterly flow aloft will become more westerly and undergo some drying heading into early next week. This drying will bring increased breeziness and lowering minimum relative humidity values. Daily scattered shower and thunderstorm activity will continue through mid-week, most widespread during a shortwave passage late Monday into Tuesday. Ridging aloft strengthens over the Great Basin with heights rising as high as the 588 to 594 dm range over the Northern Rockies by Friday. This will reduce shower and storm coverage and push afternoon temperatures back to the upper 80s to near 90 while seasonal breeziness continues. A Pacific trough approaches the region sometime next weekend and brings increased shower and thunderstorm activity with the warmest temperatures of week looking to occur just ahead of this system. This will be followed by breezy to windy conditions and slightly cooler temperatures. - RCG - Forecast Confidence & Scenarios: Daily rounds of showers and thunderstorms through Tuesday... Scattered showers and thunderstorms are already developing over S ID with W MT not far behind. This activity will move toward the northeast into central and southwest MT and interact with peak ML CAPE generally running between 500 and 1000 J/kg and effective shear above 20 kts. With surfaces beginning to dry out, localized strong, gusty winds, lightning, and perhaps some small hail will be the primary hazards, but PWATS as high as 0.80 inches may bring some heavier downpours capable of localized flooding, particularly for the more sensitive burn scars. No flood products are planned for today given the isolated nature of the heavier downpours, but conditions will be closely monitored through the evening hours. Showers and storms will weaken in coverage and intensity as they move northward into north-central MT later this evening into the overnight hours. Westerly flow aloft will begin to thin the moisture profile Sunday and Monday, but will maintain at least similar shear and instability for continued scattered shower and thunderstorm activity. Dryer sub- cloud layers will increase instances of strong to severe wind gusts while decreasing the localized flooding threat. All locations will be subjective stronger storms, although southwest MT and areas along the Hi-line will be most susceptible. Showers and storms will be most widespread during a shortwave passage late Monday into Tuesday, although the timing of the trough and attendant cold front will determine whether this activity will be able to take advantage of the peak diurnal instability for stronger storm initiation. - RCG && .AVIATION... 16/00Z TAF Period Scattered thunderstorms and rainshowers are moving through Southwest, Western and Central MT tonight from 16/00z to 16/08Z with isolated showers continuing through North Central MT early morning by 16/12Z. Primary threat from these storms is localized heavy rainfall and some strong gusts up to 35 KT. MFVR conditions for low ceilings and fog will develop over KCTB and KHVR areas with a 50% chance for LIFR at KCTB overnight into the morning from 16/08Z to 16/12Z. For KGTF: Light winds out of the Northeast and VFR conditions will be prevail tonight with a 30% chance for thunderstorms after 16/04Z until 07Z. Tomorrow, winds will shift to the West at 12KT prevailing with another chance for thunderstorms in the afternoon after 23Z. - Akins && .PRELIMINARY POINT TEMPS/POPS... GTF 51 83 52 82 / 20 30 30 0 CTB 46 77 47 75 / 10 20 20 0 HLN 50 82 53 82 / 80 20 30 10 BZN 47 79 48 81 / 60 30 40 0 WYS 34 75 35 76 / 80 20 20 10 DLN 44 77 46 78 / 70 30 30 10 HVR 49 84 50 81 / 30 20 30 10 LWT 48 79 49 78 / 50 30 30 20 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls ####018008391#### FXUS65 KCYS 160001 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 600 PM MDT Sat Aug 15 2026 .KEY MESSAGES... - Another round of thunderstorms will bring the potential for localized flash flooding and isolated strong to severe thunderstorms this afternoon and evening. - A Flood Watch & Severe Thunderstorm Watch are in effect through this evening for much of the High Plains. - Isolated strong to severe storms and localized flash flooding will remain possible Sunday, though overall storm coverage will be lower. - Drier weather and temperatures close to seasonal averages will return early next week. && .SHORT TERM /THROUGH SUNDAY NIGHT/... Issued at 216 PM MDT Sat Aug 15 2026 Another round of slow moving thunderstorms is in store for this afternoon and evening. Looking at Water Vapor, the mid and lower levels show plumes of moisture advecting through Colorado and Arizona and into our region. This will drive our PWAT values into the 1.0-1.25 inch range during the weekend as we are in Southwest flow. 700mb flow will remain rather slow today, with generally westerly to southwesterly flow expected. A messy, surface high pressure system will attempt to develop west of the Rocky Mountains over western Colorado before strengthening into the afternoon hours. With ample moisture available due to continued monsoonal moisture advection, the easterly flow will lead to very moist, upslope flow along and east of the Laramie Range. 700mb and 500mb vorticity maxima will be the major players in the synoptic forcing which is expected to increase into the later afternoon hours. Heavy rainfall is anticipated once again today, with the Weather Prediction Center placing portions of the region in a Slight Risk of excessive rainfall and a larger portion in a Marginal Risk of excessive rainfall. With the sustained rainfall across the lower elevations yesterday, the soils should be moderately saturated to aid in localized areal and urban flooding. A Flood Watch was issued on the overnight shift that is valid from 2PM through 10PM for nearly all locations along and east of the Laramie Range, where Precipitable Water values remain at and above the 90th percentile and moist, upslope flow persists. In addition to the flooding risk today, the Storm Prediction Center has placed far southeast Wyoming and western Nebraska in a Slight Risk (Level 2 of 5) of severe weather this afternoon. Primary hazards look to be isolated, large hail and damaging wind gusts. Isolated pockets of MLCAPE and SBCAPE around 1000 J/kg will provide enough instability for stronger updrafts to develop this afternoon, especially across western Nebraska. The biggest question will be whether or not the early morning cloud cover anticipated across the region puts a damper on the severe potential this afternoon. Pockets of clearing skies occurred across the forecast area to aide in some diurnal heating this morning and strengthening the instability for the showers/thunderstorms later. Forecasting the daily high temperatures and trying to get the hourly trend will be rather difficult as these clouds push into the region potentially cooling areas faster than the models could predict as well. For Sunday, slightly drier condition as the upper-level flow turns a little more westerly, cutting off some of the monsoonal moisture advection into the area. However, with the ample moisture present over the past several days, plenty of residual moisture will be present to get another round of showers and storms Sunday afternoon into the evening hours. A few lobes of 500mb vorticity will advect across the region Sunday afternoon, providing some forcing for ascent. Slightly stronger 700mb warm air advection briefly develops Sunday afternoon, adding an additional forcing for ascent for showers and storms. Surface flow turns southerly Sunday afternoon through much of the overnight hours, leading to weak ascent across the Cheyenne Ridge, likely resulting in showers and storms developing in this area once again. Precipitable water values look to return towards more climatologically average values Sunday, decreasing the threat for isolated flooding across the region. However, with monsoonal moisture still in play, flooding potential continues for Sunday with a Marginal Risk of Excessive Rainfall from the Weather Prediction Center. Another round of strong to severe storms will be possible Sunday, with a Slight Risk of severe weather for much of the area and a small portion of the region under a Slight Risk of severe weather once again. && .LONG TERM /MONDAY THROUGH FRIDAY/... Issued at 216 PM MDT Sat Aug 15 2026 Drier air will work into the area on Monday, bringing us a break in the stormy monsoon weather pattern. Expect mostly sunny skies to return to the area with temperatures generally near seasonal averages, in the lower 80s around Laramie and Rawlins, and mid to upper 80s along and east of I-25. While isolated showers and/or thunderstorms will still be possible, coverage will be significantly lower than the preceding days. The boundary layer will be much drier on the Wyoming side, which may lead to a dry microburst, threat, while a few actual rain producing thunderstorms will be possible mainly on the Nebraska side. The monsoon tap recovers somewhat on Tuesday into Wednesday, though the flow will remain largely westerly aloft. Still, some low to mid level southerly flow over the Great Basin will help inject higher PW into our area, pushing values back to around 0.75 and 1.2 inches or so across the area. This will of course be not quite as high as the current monsoon surge, but should be sufficient to kick up coverage of showers and thunderstorms for Tuesday and Wednesday, especially with some help from an upper level shortwave trough riding over the top of the ridge Wednesday. While the boundary layer will still b on the dry side during this period, there looks to be plenty of moisture aloft so rain should still reach the ground even in the drier areas. Tuesday should see temperatures climb just a smidge above seasonal averages, while these values will fall by a few degrees Wednesday with the aforementioned shortwave. The upper level ridge will amplify to our west on Thursday, and Friday, turning the flow aloft to a more dry, northwesterly flow. Expect storm chances to become much more isolated once again as temperatures climb back above seasonal averages. An early look at 700-mb temperatures appears fairly marginal for record highs with this round with NAEFS means hovering around +15 to +18C, or near the climatological 90th percentile. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 600 PM MDT Sat Aug 15 2026 Heavy showers and thunderstorms are ongoing across the eastern plains late this afternoon and should continue into this evening. Activity may linger past 03Z, but confidence is limited at this time due to poor model agreement and very isolated coverage. Low CIGS and fog will be the primary concern between 05z and 12z Sunday before another round of thunderstorms impacts the region Sunday afternoon. HAZARDS/WEATHER TRENDS: Primary concern is thunderstorms with strong gusty winds, very rainfall, and LIFR conditions over the next 3 hours (00z to 03z). Kept TEMPO and prevailing groups for higher confidence or activity already across the terminal, with PROB30 for lower confidence. After 03z, expect patchy coverage of lower CIGS with the possibility of fog for KCYS, KAIA, KBFF, and KSNY between 06z and 12z Sunday. Another round of thunderstorms expected after 20z Sunday, but coverage is expected to be much more isolated, so will keep out of the TAF for now. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Flood Watch until 10 PM MDT this evening for WYZ102-107-108- 117>119. NE...Flood Watch until 10 PM MDT this evening for NEZ002-003- 019>021-054-055-095-096. && $$ SHORT TERM...MM LONG TERM...MN AVIATION...TJT ####018007643#### FXUS62 KCHS 160001 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 801 PM EDT Sat Aug 15 2026 .WHAT HAS CHANGED... The Aviation section was updated for the 00Z TAFs. && .KEY MESSAGES... - 1) Heat will remain a concern into the middle of next week. - 2) Strong to severe thunderstorms are possible this afternoon and Sunday afternoon. && .DISCUSSION... KEY MESSAGE 1: Heat will remain a concern into the middle of next week. A rather long duration heat wave has taken hold across the area and relief from the heat does not look to come until later next week. Large-scale ridging centered across the Deep South extending into the coastal Southeast will remain in place through the foreseeable future leading to continued heat issues through at least Wednesday possibly Thursday of next week. Ample sunshine will promote strong sfc heating each day while a west- northwest downslope flow persists across the region. Guidance continues to support afternoon highs in the mid-upper 90s with a few locations potentially touching 100 degrees mainly on Monday and Tuesday of this week, which could result in record warmth (see Climate Section below). Humid conditions will also persist with sfc dewpts in the mid-upper 70s each day. Although the downslope flow should result in a slightly delayed seabreeze and some mixing out of sfc dewpts inland, moisture should pool near the boundary as it shifts inland as well as bring higher moisture content onshore. Rest of today through Sunday: So far observations across the area are on track with widespread 108 to 113 heat indices across the area. The highest heat indices look to be along the immediate coastline as the seabreeze has begun its slow march inland. Scattered storms have begun to develop this afternoon north of the area across northern SC and this activity is expected to slowly build southward into our area likely bringing temporary relief tonight for some locations. Further south relief may not come; however, confidence across Georgia in higher heat indices is lower thus things should even out across the board tonight. Sunday should have similar results based on the persistent pattern. However, a slight uptick in convective coverage is possible as a subtle shortwave moves across the area and a weak boundary encroaches from the north. Storms may also begin earlier in the day closer to the noon timeframe which will help "limit" how hot we get during the afternoon. Given some uncertainty in convection trends, have opted to go with a Heat Advisories over the area. Early to Middle of Next Week: The resurgence in the hot/humid conditions looks likely on Monday and Tuesday as the upper ridge restrengthens across the area. Record warmth looks possible with latest guidance suggesting several areas of 100+ temps Monday/Tuesday and with little to no shower/thunderstorm activity. Heat indices will likely climb into the 110 to 115 range almost area wide and some isolated coastal areas may approach heat indices of near 120. Conditions still remain hot heading through mid-week as the upper ridge slowly backs off heading into the weekend. Additional heat headlines are likely early into the middle of next week. KEY MESSAGE 2: Strong to severe thunderstorms are possible this afternoon and Sunday afternoon. The heat and humidity (mentioned in Key Message 1) will provide a moderate amount of instability across our area this afternoon and again Sunday afternoon. Depending on the model, SBCAPE values peak in the 2,000-2,500 J/kg range, with DCAPE values upwards of 800 J/kg. There are some minor differences amongst the various near-term CAMS and even the synoptic models. But the general consensus is that there should be isolated to scattered convection both afternoons. The storms are most likely to start along the sea breeze and then shift inland, with outflow and boundary interactions playing a role in storm formation and persistence. Given the aforementioned instability, strong to severe thunderstorms are possible. The main threat would be damaging winds. But heavy rainfall is also a concern due to weak steering flow. Backbuilding and/or training of storms could drop enough rainfall to generate very localized flooding. The convection each afternoon is expected to dissipate each evening. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... 00Z TAF Discussion: A cluster of strong storms are ongoing across Charleston/Dorchester/Colleton Counties. These storms will likely persist for another couple of hours, but they are moving southwest, away from KCHS and KJZI. Showers with minimal impacts could still affect KCHS and KJZI through around 02Z before completely dissipating. TEMPO groups may need to be introduced for that. Otherwise, VFR conditions are expected overnight and into Sunday morning. Another afternoon of scattered showers and thunderstorms are expected Sunday, where PROB30 groups have been introduced at all terminals. Extended Aviation Outlook: Periodic flight restrictions are expected in showers and thunderstorms through next week. && .MARINE... Through Sunday: Surface high pressure over the western Atlantic with weak inland troughing will continue the mostly quiet conditions over the waters. Expect westerly to southerly winds throughout the period, with the breeziest winds occurring both afternoons along the land-sea interface with gusts to 20 knots. Thunderstorms that develop over land this afternoon and Sunday afternoon could shift offshore during the later afternoon into early evening hours. A few thunderstorms could remain strong when shifting across coastal areas. Monday - Wednesday: There will be areas of High pressure in the western Atlantic and the northern Gulf, while surface troughing will be over the Southeast U.S. The interaction between all of these synoptic features will generate a typical summertime wind pattern. Winds will generally be from the SW, backing a bit each day and veering some each night. The strongest winds should be during the day, especially closer to the coast due to the sea breeze. Seas will mainly be in the 2-3 ft range. && .CLIMATE... Record High Temperatures: August 14: KCHS: 102/1995 KSAV: 102/1925 August 15: KCHS: 96/2023 KCXM: 99/1918 KSAV: 100/1918 August 16: KCHS: 99/1954 KSAV: 100/1954 August 17: KCHS: 102/1954 KSAV: 102/1954 August 18: KCHS: 101/1995 KCXM: 97/1995 KSAV: 100/1995 August 19: KCHS: 98/1983 KSAV: 99/1900 August 20: KCHS: 97/2005 KSAV: 102/1900 Record High Minimum Temperatures: August 14: KCHS: 80/2023 KCXM: 83/2023 KSAV: 80/2023 August 15: KCHS: 78/1995 KCXM: 83/2021 KSAV: 80/1995 August 16: KCHS: 78/2019 KCXM: 83/2016 KSAV: 78/2019 August 17: KCHS: 80/2017 KCXM: 83/2017 KSAV: 78/2017 August 18: KCHS: 80/2017 KCXM: 82/2017 KSAV: 78/2010 August 19: KCHS: 79/2010 KCXM: 83/2021 KSAV: 79/1878 August 20: KCHS: 78/2017 KCXM: 82/2017 KSAV: 82/1878 && .CHS WATCHES/WARNINGS/ADVISORIES... GA...Heat Advisory from 11 AM to 8 PM EDT Sunday for GAZ087-088- 099>101-114-115-137-216>219-238>241. SC...Heat Advisory from 11 AM to 8 PM EDT Sunday for SCZ040-042>045- 147>152. MARINE...None. && $$ ####018006048#### FXUS63 KDMX 160001 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 701 PM CDT Sat Aug 15 2026 ...Updated for the 00z Aviation Discussion... .KEY MESSAGES... - Scattered shower and thunderstorm chances this afternoon into the early evening. Severe risk is low, but isolated gusty winds and heavy rainfall are possible, mainly in southern Iowa. - Drier conditions for most on Sunday with low chance (less than 20%) for scattered showers/storms in far southern Iowa. - Dry conditions continue during the day Monday, thunderstorm chances returning northwest on Monday then area-wide on Tuesday. && .SHORT TERM /THROUGH SUNDAY/... Issued at 246 PM CDT Sat Aug 15 2026 Low stratus continues to span much of the forecast area early this afternoon. This cloud deck has limited sunshine over the northern two thirds of the area, keeping temperatures relatively cooler compared to southern Iowa where skies are clearer. As of 2 pm, temperatures are only in the upper 70s over northern Iowa, but nearing 90 in far southern Iowa. The clearing in southern Iowa is notable not only for temperatures, but also for thunderstorm potential as a subtle shortwave and associated boundary tracks through Iowa today. Weak radar returns are already being detected by the KDMX radar, albeit mostly showers at this time. Through the afternoon, mixing of the boundary layer will allow for destabilization and surface-based convection to develop, mainly over southern Iowa. Mixed layer CAPE values are expected to exceed 3000 J/kg, providing plenty of energy for displaced parcels. There will be no shortage of moisture around this afternoon, as indicated by the sultry upper 70 to near 80 surface dewpoints and precipitable water values of 2 to 2.1". This will make for rather efficient rainfall rates with any storm that develops. Isolated flash flooding could occur, but the sporadic storm coverage and progressive storm motions should limit the overall risk, so have therefore opted to hold off on another flash flood watch for this evening. With the efficient rain production, gusty winds could become a concern as updrafts go up and collapse into a well-mixed boundary layer boasting DCAPE values of 1500 to 1900 J/kg. This threat will also be fairly isolated and most likely over the southern portions of the area where sun has been more prevalent today. While there are isolated risks with storms this evening, those mentioned above are generally the only things the storms have going for them. Mid-level lapse rates overhead are quite poor (around 6 to 7 C/km) and will actually be diminishing to under 6 C/km through the afternoon. The kinematics will also be fairly poor and storms will struggle to organize with deep layer shear values mostly under 30 kts. The low level kinematics are also unimpressive given the weak low level flow. Therefore, the risk for severe hail or tornadoes is low, leaving isolated gusty winds and heavy rainfall as the main concerns this evening. The storm prediction center's (SPC) marginal risk for severe weather (level 1 of 5) over southern Iowa seems appropriate for this afternoon. If any gusty wind risk exists, it will be with storms in this area with diminishing threat farther north. On the rainfall side of things, the weather prediction center has trimmed up the slight risk (level 1 of 4) for excessive rainfall to only include eastern and southeastern Iowa and a marginal risk (level 1 of 4) of excessive rainfall for the rest of the area. Most of guidance pushes the boundary south of Iowa this afternoon, taking most of the remaining instability and overnight shower or thunderstorm potential with it. There is still a chance (~20% or less) for some showers or storms to scrape along the Iowa/Missouri border tonight into early Sunday, but most solutions keep this south of Iowa and over northern Missouri. For most, if not all of the area, Sunday looks like it will be a nice reprieve from the onslaught of shower and thunderstorm chances we've seen over the last week. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... Issued at 246 PM CDT Sat Aug 15 2026 Our lull in precipitation chances will continue into the day Monday but our break is short-lived as shower and thunderstorm potential returns to northwest Iowa Monday night, and area-wide again Tuesday into Wednesday. Given this will be another northwest flow regime, it's tough to get too involved in the details. That said, the Tuesday storms do seem to have a rather healthy environment with increasing instability and modest deep layer shear supportive of more organized convection. SPC does have a day 4 15% risk for most of Iowa and WPC has put out a slight risk for excessive rainfall for Tuesday. The pattern remains relatively active through mid-week and then ridging begins to build through the second half of this week. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 648 PM CDT Sat Aug 15 2026 Showers and thunderstorms remain the primary focus across south central and southeastern Iowa this evening. KDSM and KOTM could see terminal impacts through 04Z. Light showers may affect KFOD, KMCW and KALO over the next few hours, though confidence remains high in no thunder with the northern activity. Showers and storms will taper off tonight, giving way to lower ceilings overnight. MVFR ceilings are expected across much of the area, with IFR to localized LIFR restrictions favored near KALO and KMCW in northeast Iowa. Patchy fog is also possible across northern Iowa late tonight. VFR conditions are expected to return tomorrow afternoon. && .DMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Dodson LONG TERM...Dodson AVIATION...TDR ####018006617#### FXUS63 KIWX 160004 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 804 PM EDT Sat Aug 15 2026 .KEY MESSAGES... - An isolated strong to severe storm or two possible between 6 and 9 PM EDT today, mainly east of I-69 and the US 30 corridor. Main threats will be damaging winds and an isolated tornado. - Additional round of rain and sub-severe storms likely between 4 AM and Noon EDT. - Flood Watch continues along and south of US 30 where heavy rain will continue to exacerbate ongoing flooding through Sunday. - Dry conditions return Monday and Tuesday. && .DISCUSSION... Issued at 1230 PM EDT Sat Aug 15 2026 Stratiform rain continues to diminish as of midday, although there are still some areas of light rain ongoing south of US 24. Visible satellite shows a few pockets of clearing as an MCV approaches the IL/IN border, but more widespread breaks in the clouds will be needed to recharge the atmosphere for potential storms this afternoon and evening. It is worth noting that isolated strong to severe storms are still possible despite the downgrade from SPC to a Marginal Risk (level 1 of 5) for severe weather today. The aforementioned MCV is expected to move across northern Indiana this afternoon and evening. Storm development is possible between 4-8 PM EDT today. Coverage will likely be spatially limited as the better environment is off to our southwest, however, I think the best chances for isolated severe weather today will be mainly east of I- 69 and along/south of US 30. This would include Grant, Blackford, Jay, Wabash, Adams, and Allen counties in Indiana and Defiance, Henry, Putnam, Paulding, Putnam, and Van Wert in Ohio. Models vary widely on a solution, with some showing no storms and some showing discrete cells capable of producing severe weather. 30-40 kts of 0- 6km shear, 100-200 m2/s2 of 0-1 SRH, and a narrow corridor of moderate instability may develop along the I-69 corridor depending on how much clearing we can get this afternoon. This would be a favorable environment for damaging winds and an isolated, brief tornado. With a low end severe threat, this is a highly conditional setup depending on clearing and how much the atmosphere has been depleted by this morning's rain. Despite favorable shear and instability, poor lapse low and mid level rates can be seen in forecast soundings from most of the CAMs, which will likely be a limiting factor. WPC does have a Moderate Risk (level 3 of 4) for excessive rainfall along and south of US 30 today, where a Flood Watch is in effect. Strong moisture transport is expected and precipitable water values will once again be at or above 2 inches today. With such high moisture content in the airmass overhead (99th percentile PWATs and dewpoints well into the 70s), any storm could be a very efficient rainfall producer with rain rates between 1-2" per hour. Given that the ground is so saturated south of US 30, where 6-12"+ of rain has fallen since this past Tuesday, renewed flash flooding in areas that have already been hard hit is becoming an increasing concern. On the very very low chance that an isolated tornado occurs in east-central Indiana somewhere in Wells, Adams, Grant, Blackford, and Jay counties where areal and river flooding is ongoing, the best recommendation is to safely shelter in the lowest level away from windows and doors but to stay away from flooding. One last round of scattered rain and storms is likely Sunday morning, becoming more isolated into the afternoon hours. We will have to monitor convection in eastern Iowa and northern Illinois overnight that will move eastward. Unfortunately, the axis of heaviest rain looks to be south of the US 30 corridor before daybreak Sunday as the LLJ ramps up with the stationary front in the vicinity. High PWATs and dewpoints will contribute to efficient, heavy rainfall late overnight into Sunday morning. The primary timeframe for rain and storms looks to be between 4 AM to Noon EDT. An isolated strong storm is possible south of US 24, but once again, flooding is expected to pose a higher threat spatially than severe weather. Due to this potential, the current Flood Watch has been extended to last until 8 AM EDT Sunday. A welcome break from daily rain and storm chances is ahead! We finally see a reprieve in the 'Ring of Fire' pattern Monday and Tuesday as high pressure builds across the Great Lakes. This will allow for the area to dry out, floodwater to recede, and for river levels to fall. Temperatures will be seasonable with highs in the upper 70s to near 80 degrees with lots of sun. Another chance for rain and storms comes Wednesday with a cold front, although it may be short lived as high pressure looks to return over the Great Lakes once again. After a very active first half of August and a Top 10 wettest August on record for some locations already, we would happily welcome a stretch of dry weather by the end of the week into next weekend. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 756 PM EDT Sat Aug 15 2026 An MCV tracking across far northeast Indiana and northwest Ohio is combining with a weak instability axis for some convective development this afternoon. This focus is expected to remain east of KFWA this evening. Additional showers and isolated storms are expected to develop overnight in a broad low level theta advective regime. Some mid level support via a weak mid level trough is expected to approach from the Corn Belt, but overall organization is expected to be limited with these showers and storms. Did include PROB30 to cover this potential, although confidence in timing is on the lower side. A lull in showers is expected later Sunday morning, but lower coverage convection is possible with the actual cold frontal boundary toward end of this period. Confidence remains too low for inclusion at this time. Otherwise, cigs should deteriorate to MVFR again tonight, and possibly IFR for a time before improving through the morning on Sunday. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...Flood Watch through Sunday morning for INZ012-013-015-020- 022>027-032>034. OH...Flood Watch through Sunday morning for OHZ024-025. MI...None. MARINE...None. && $$ DISCUSSION...Johnson AVIATION...Marsili