Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/30/24


Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
912 PM CDT Sun Sep 29 2024 .KEY MESSAGES... - Critical fire weather conditions expected through Monday due to dry and windy conditions. Winds will gust to 45 mph at times, which will cause any fires that ignite to spread rapidly and be difficult to control. Burning should be avoided. - Cooler air will be in place for Monday and Tuesday with temperatures around average. Warmer air moves in for Wednesday with temps running about 10 to 15 degrees above average. && .UPDATE... Issued at 901 PM CDT Sun Sep 29 2024 Breezy/gusty southerly winds will persist overnight out ahead of an approaching cold front. This front is still on track to move into central SD after 06Z tonight, then makes its way eastward towards the James River by around 12Z or shortly after. Forecast already has this handled fairly well, so no changes expected. With the winds and warm air in place, lows will stay mild and may not fall below 60 degrees for many areas. No changes anticipated to temps for the overnight either. && .SHORT TERM /THIS EVENING THROUGH MONDAY NIGHT/... Issued at 225 PM CDT Sun Sep 29 2024 As of 2pm, there is an upper longwave trough over the Pacific NW and moving eastward. RAP analyzed upper jet streak is rounding the base of the trough and helping to intensify a low from 999mb this morning to 995mb now in central Saskatchewan. Farther east, a surface high is located over southern Ontario and leading to a tight pressure gradient over the Dakotas. This has helped pull in anomalously warm air, with 850mb temps around 21-24C (well above 90th percentile per KABR/KHON soundings back to 1954) and 925mb temps in the mid-upper 20s. Thus, surface temps have warmed up upper 80s and lower 90s thus far across the area. RAP analysis is showing mixing still a little delayed in exceeding the 850mb warm nose, thus winds have been slowly increasing thus far. But they still have been gusting to 30- 35mph and expect that to increase in central SD as the forecast is to mix up to 800-750mb. Expect the highest gusts over north central SD, with brief gusts of 45-50mph where the greatest max momentum transfer values are located in the HREF members. The combination of the winds and the warm temps producing RH values to 15-25% in central SD, the going Red Flag Warning still looks to be in good shape. As the low continues to slowly intensify as it moves northeast through central Canada, it will drag a cold front southeast across the Dakotas after midnight tonight and exit the CWA to the southeast by mid day Monday. Ahead of the cold front, the low level jet will be increasing (40-50kts at 0.5km above the surface), but confidence is low on those strong winds actually reaching the surface with the diurnal inversion developing consistently in the HREF ensemble members. That being said, pressure gradient will keep the sustained winds up in the 15-25mph range, with the gusts of 30-40mph likely confined to higher terrain locations or ones favored by a little bit of downsloping winds with southerly flow. Then as the dry cold front moves through, expect the strongest winds to occur for a few hour period, as strong low level cold air advection helps mix into the stronger winds aloft. The front looks to arrive at Corson/Dewey counties around 8Z, Pierre to Leola around 10Z, and Sisseton/Watertown by 15Z. The question is if a wind advisory is needed for that brief period, around 2-4hr, behind the front and when diurnal mixing increases during the morning hours. HREF does point towards that need (primarily in central SD), with the ensemble max momentum transfer having winds up to or a little above advisory criteria. Thus, opted for a wind advisory starting as the front moves through central SD and kept it to the west of the James River Valley area. Expect the winds to gradually diminish through the late afternoon as diurnal heating is lost. Finally for winds, will need to watch the eastern portion of the Coteau late tonight into tomorrow morning, as winds try to turn to a favorable downslope direction right before the frontal passage. That could lead to advisory level winds there too on Monday morning. Now shifting back to the fire weather side of things. The RH is not expected to have a whole lot of recovery over central SD this evening and through the overnight hours. RH value look to rise into the 20-30% range, which only puts them slightly over criteria and with the arrival of the front, it keeps the fire weather risk up through the night. Thus, opted to extend the warning through the night and into Monday for the central SD counties (instead of a brief period of no headlines this evening). That area also has the driest fuels in the CWA. Farther east, we start to see an increase in the percent green based on satellite NDVI, but with the dry conditions over the recent week, they may be nearing fuel conditions that would need to have a Red Flag Warning issued. That idea matches the ERC percentiles, which shows that fuels are above the 90th percentile across the CWA. With the drier air that moves in behind the front (dewpoints in the upper 20s and lower 30s) that offsets the colder temperatures (temperatures in the 70s), RH values are expected to be in the 18-24% range across the entire CWA. Thus, converted the existing watch areas to a Red Flag Warning and issued a watch for the rest of the eastern areas. Finally for Monday night, high pressure will slide from central MT and southeast to western NE by 12Z on Tuesday. That will help weaken winds through the night across the area, especially in south central SD. Expect there to be enough of a lingering gradient over northeast SD and west central MN to keep winds in the 5-15mph range. How much those winds will stay up with influence temps. If they diminish to be calm, could see lows dropping to or below freezing, which is shown in northern SD on the MET/MAV guidance. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Issued at 225 PM CDT Sun Sep 29 2024 Clusters are in agreement along with deterministic models on northwest flow continuing Tuesday, on the eastern side of a ridge, over the Northern Plains behind the exiting shortwave. Another shortwave will push west to east over the southern Canadian territories Tuesday into Wednesday, which will break down the ridge, creating zonal flow over the Northern Plains. Wednesday into Thursday, another ridge moves over the western CONUS, moving slightly east and becoming highly amplified into the weekend, as the low in Canada finally starts to weaken as it moves north/northeast. Overall zonal flow looks to continue through the end of the week. We start to see a bit of a difference between the Cluster ensembles Friday into the weekend on exact position and amplitude of the ridge. At the surface, models are in agreement with a high pressure system centered over the central Plains on Tuesday, keeping the weather quiet with light winds. The 850mb to surface trough, associated with the incoming shortwave, will be over MT/southern Canada. As the high shifts southeast, the trough moves in with the axis positioned over the Northern Plains into Manitoba by early Wednesday with its warm front extending southward over the Dakotas. WAA winds increase just above the surface out of the southwest (LLJ) over the eastern CWA during the early morning hours on Wednesday. This may cause for downsloping winds along and east of the Coteau. Latest models show winds will increase around 06-07Z with sustained winds between 15- 25kts with gusts up to 35kts. This will decrease through the morning as the LLJ pushes east. Other than some mid level moisture with the shortwave, dry air continues from 850mb-surface across the CWA with ensembles indicating winds shifting from the south (behind the warm front) to the northwest as the cold front sweeps across the CWA through the day on Wednesday. With CAA behind the front and a steeper pressure gradient between the low and incoming high, winds could get a bit breezy with gusts 25-30 kts, mainly from north central SD and northward into ND Wed afternoon where low level lapse rates are steeper and winds gustier aloft. With forecasted MIN RH values in the upper teens to the mid 20 percentile range midday into the afternoon along with the increased winds across central SD, this could lead to an elevated fire concern. This high moves in and will be out dominant over the area through the end of the week. With the high pressure and a cooler air mass overhead for Tuesday, highs will be back to around normal, ranging in the 60s to around 70 as the model spread between the 25-75th percentile range is only 3 to 5 degrees across the CWA. WAA moves in Wednesday morning and will be over the area behind the warm front with highs back in the upper 70s to the mid 80s, warmest over central SD. Behind the cold front and incoming high, CAA takes over with highs back down in the 60s for Thursday (and lows in the upper 30s to the lower 40s!) and mid to upper 60s/lower 70s for Friday, however, the spread does increase between 5-7 degrees and 7-13 degrees for the weekend due to model variability this far out. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 642 PM CDT Sun Sep 29 2024 Terminals KABR,KATY,KPIR,KMBG VFR conditions will prevail through the TAF period. Gusty southerly winds overnight will switch to the northwest through the TAF period as a cold front moves east across the region. Low-level wind shear (LLWS) will be a concern tonight as well, and have inserted mention of this into the TAFs. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...Fire Weather Watch from Monday morning through Monday evening for SDZ007-008-011-019>023. Red Flag Warning until 8 PM CDT /7 PM MDT/ Monday for SDZ003-004- 009-015-016-033>035-045-048. Wind Advisory from 4 AM CDT /3 AM MDT/ to 4 PM CDT /3 PM MDT/ Monday for SDZ003-015-033-045-048. Wind Advisory from 7 AM to 4 PM CDT Monday for SDZ004-005-009- 010-016-017-034>037-051. Red Flag Warning from 7 AM to 8 PM CDT Monday for SDZ005-010-017- 036-037-051. Red Flag Warning from 11 AM to 8 PM CDT Monday for SDZ006-018. MN...Fire Weather Watch from Monday morning through Monday evening for MNZ039-046. && $$ UPDATE...TMT SHORT TERM...SRF LONG TERM...MMM AVIATION...TMT
Area Forecast Discussion
National Weather Service Amarillo TX
742 PM CDT Sun Sep 29 2024 ...New AVIATION... .KEY MESSAGES... Issued at 226 PM CDT Sun Sep 29 2024 - Heat ramps up tomorrow, more locations see highs in the 90s. - Cold front Monday night into Tuesday brings breezy winds and cooler temperatures. - Above average heat comes right back Wednesday onward. && .SHORT TERM ... (This evening through Monday night) Issued at 226 PM CDT Sun Sep 29 2024 The heat is back on tomorrow thanks to upper level ridging currently spanning from the southwest to midwest CONUS. Even as high pressure weakens with an approaching trough over southern California, warming 850mb temps will push our way. Daytime highs tomorrow will easily climb into the upper 80s to mid 90s area wide as a result. Record highs appear less likely, but that`s of little consequence considering just how unseasonably warm it will be for late September. We finally catch a break as the aforementioned trough allows a cold front to enter the northern Panhandles Mon night - Tue morning. The initial impacts of the front will be seen across the north-northwestern Panhandles, when winds will begin to ramp up out of the northeast. Latest 12z runs of the HRRR and NAM Nest depict gusts up to 30-35 mph possible with the frontal passage as early as midnight, lasting into Tue morning. While the breeze will make it feel cooler, most folks should still wake up to low temps in the 50s just like most mornings as of late. Precipitation is not expected with this front. Harrel && .LONG TERM ... (Tuesday through next Saturday) Issued at 226 PM CDT Sun Sep 29 2024 Still tracking trends on Tuesday, when a cold front is expected to enter the area. Model guidance continues to fluctuate on how much of a temperature difference this front will ultimately make, but they`re finally starting to converge on some middle ground. Latest forecasts show breezier winds with the front Tuesday morning thanks to a tighter pressure gradient. These north- northeast winds of 15-25 mph (gusts up to 35 mph) would allow slightly better advection of cooler air to the Panhandles before the front stalls out through the day. Right now, most of the Panhandles can expect highs in the 70s Tuesday afternoon, with temps in the low 80s more likely along and south of the I-40 corridor. If cooler guidance such as the NAM pans out, highs may even be 5-10 degrees cooler than NBM projections, but this isn`t the most likely outcome. High pressure and heat promptly returns midweek onward, with highs progged to be in the 80s to low 90s each day. Winds will be lighter, but still breezy at times. Overnight lows should stay steady in the 50s. Another weak front could make a push towards the Panhandles by Friday, but long range models are less than thrilled with this potential. Harrel && .AVIATION... (00Z TAFS) Issued at 740 PM CDT Sun Sep 29 2024 Dry weather continues to hold through the overnight leaving all terminals in VFR conditions for the period. Otherwise, expect winds to stay light for the night with all terminals seeing surface winds less than 10 knots. && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 56 93 56 80 / 0 0 0 0 Beaver OK 53 93 53 74 / 0 0 0 0 Boise City OK 52 90 49 72 / 0 0 0 0 Borger TX 57 97 58 81 / 0 0 0 0 Boys Ranch TX 54 93 54 78 / 0 0 0 0 Canyon TX 54 91 55 80 / 0 0 0 0 Clarendon TX 57 91 58 80 / 0 0 0 0 Dalhart TX 50 89 50 74 / 0 0 0 0 Guymon OK 51 92 51 73 / 0 0 0 0 Hereford TX 54 93 54 81 / 0 0 0 0 Lipscomb TX 56 93 57 76 / 0 0 0 0 Pampa TX 57 93 56 78 / 0 0 0 0 Shamrock TX 57 93 59 81 / 0 0 0 0 Wellington TX 57 93 59 84 / 0 0 0 0 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...None. OK...None. && $$ SHORT TERM...38 LONG TERM....38 AVIATION...11
Area Forecast Discussion
National Weather Service Bismarck ND
1030 PM CDT Sun Sep 29 2024 .KEY MESSAGES... - Critical fire weather conditions expected across much of western and south central North Dakota tonight through Monday. - Much cooler with strong northwest winds on Monday. - Increasing potential for areas of frost across western North Dakota Monday night into Tuesday morning. && .UPDATE... Issued at 1014 PM CDT Sun Sep 29 2024 It appears as if the cold front has just entered the northwest corner of the state. Western portions of Divide county are starting to see winds shifting to out of the northwest. Isolated showers and thunderstorms have developed behind the front across eastern Montana and should approach the North Dakota border over the next hour or so. For this reason, we decided to introduce isolated precipitation chances gradually moving through the west and then portions of the central in the 03z to 08z time frame. RAP soundings suggest that we could see a couple hundred J/kg of MUCAPE across portions of the west until around 06z or so, so we did add an isolated mention of thunder until then. Finally, we let the Red Flag Warning expire on time for Ward, McHenry, McLean, Sheridan, Burleigh, and Kidder counties. Humidity values have recovered mainly into the 30 to 40 percent range and the winds are not quite as strong as they were earlier. Winds will increase again late tonight and tomorrow, but cooler temperatures should lead to higher humidity values for the counties mentioned above. Much of the south central and portions of southwest North Dakota remain in a Red Flag Warning through 7 PM CDT Monday and at 1 AM CDT on Monday it will also go into effect for Bowman, Slope, Billings, Golden Valley, Dunn, McKenzie, and Williams counties. The Wind Advisory remains in good shape. UPDATE Issued at 615 PM CDT Sun Sep 29 2024 We have seen well above normal heat for the end of September across western and central North Dakota this afternoon. Hettinger officially hit 100 degrees and as of this evening, we still have several sites still sitting in the mid to upper 90s. Bismarck has shattered the record high today (we hit 97 at the Bismarck airport, breaking the old record of 90) with Minot and Dickinson also breaking records (Williston would have broken the record if the reading was still at the old airport). The Red Flag Warning remains in good shape with widespread dry and windy conditions still going strong. && .DISCUSSION... Issued at 315 PM CDT Sun Sep 29 2024 Currently, upper ridge axis has shifted to the east as a well defined mid level S/WV moves onshore and advances inland across the far Pacific Northwest/Southwestern Canada. Associated sfc/mid level low has resulted in increasing southerly flow into the region, promoting strong WAA and unseasonably warm temperatures across the Dakotas. Boundary layer temperatures are at or above the 99th percentiles of climatology today, with record high temperatures already set at several locations across western and central ND. Coupled with strong moderate to strong mixing, afternoon relative humidity has fallen into the teens and 20s, resulting in critical fire weather conditions central and across parts of southwest ND. The Red Flag warning thus remains valid (See Fire Weather Discussion Below for more information). The aforementioned S/WV will continue east along far southern Canada/Northern Plains region tonight into Monday, and will drive a strong cold FROPA through the region later this Sunday evening through early Monday. Resultant weather will be northwest winds increasing west to east, along with much cooler temperatures surging into the region (Highs Monday upper 50s northwest - low 70s southern James Valley), around 20-35 degrees cooler than today. The main concern with the frontal passage remains strong wind and fire weather. Opted to issue a wind advisory across the entire CWA from 03Z this evening through the day Monday. Strongest winds will likely occur along and behind the FROPA tonight-Monday morning, where winds will gust to around 50 mph. BUFKIT soundings and ensemble probabilities are in agreement with warning criteria winds remaining aloft, but wouldn`t be surprised to see a few +58 mph gusts late tonight/early Monday with the front. Very dry air will also accompany the frontal passage, and will result in another period of critical fire weather. Opted to upgrade the Fire Weather Watch for tonight/Monday to a Red Flag based on the projected Min humidity, strong northwest winds, and in collaboration with our neighbors. The Red Flag over western ND will start late tonight, while the Red Flag south central and for parts of the southwest will basically remain valid now through Monday. Again, see Fire Weather discussion below for details. A quasi-zonal flow pattern remains forecast for the remainder of the work week, with mainly dry weather conditions and temperatures more seasonal. The probabilities for morning frost and minimum temperatures dropping to around freezing continue to increase for Tuesday morning west, with another chance next week Friday morning. In addition, can`t rule out more elevated fire weather concerns next week, as fuels cure and we see several dry and breezy days ahead. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 615 PM CDT Sun Sep 29 2024 VFR conditions are expected through the period with dry weather. However, it will remain fairly windy through the period. A cold front will cross the state from northwest to southeast overnight, shifting the winds from out of the south to out of the northwest. The windiest time frame will be in the morning and afternoon hours on Monday. Sustained winds up to 30 mph and gusts to 55 mph will be possible. There also may be some enhanced low level wind shear over KBIS and KJMS overnight. && .BIS WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 7 PM CDT /6 PM MDT/ Monday for NDZ001>005- 009>013-017>023-025-031>037-040>048-050-051. Red Flag Warning until 7 PM CDT /6 PM MDT/ Monday for NDZ009- 017-018-031-032-040-043. Red Flag Warning until 7 PM CDT /6 PM MDT/ Monday for NDZ019- 020-033-034-041-042-044>047-050. && $$ UPDATE...ZH DISCUSSION...NH AVIATION...ZH
Area Forecast Discussion
National Weather Service Dodge City KS
1100 PM CDT Sun Sep 29 2024 ...Updated Aviation/Key Messages... .KEY MESSAGES... - Unseasonably hot Monday afternoon in the lower 90s. - Strong cold front Monday evening will bring northeast wind gusts near 40 mph, followed by refreshingly cooler air Tuesday. - Southwest Kansas will remain dry for the foreseeable future, through at least October 10th. && .DISCUSSION... Issued at 212 PM CDT Sun Sep 29 2024 18z observations and RAP upper air analysis shows a large upper level ridge and surface high across much of the central plains through the desert southwest. Water vapor analysis displaying a large segment of dry air from southwest Kansas through New Mexico leading to no clouds in site across much of the region. Short term highlights will be unseasonably warm temperatures on Monday. An upper level trough that will move into the northern plains will eject a cold front through Nebraska into northwest Kansas during the day on Monday. Ahead of the front with southwest downsloping winds and very little moisture for cloud cover we should see efficient prefrontal compressional heating. 850 mb temperatures are forecast to range from 22-28 (C) by 21Z and we should see highs for much of southwest Kansas reach at least 90 degrees. HREF probabilities of 60-70% of hourly temperatures > 90F in the afternoon and NBM MaxT probabilities of 50-70% of > 90F shows good confidence we should have high temperatures in the low 90s. Short term deterministic models has the leading edge of the front reaching our northwest zones by 21-22Z Monday and then quickly moving through the rest of the CWA by 06Z Tuesday. Models are probably lo w with the wind speeds as with the sharp baroclinic zone and pressure gradient we should see wind speeds at 20-30 mph with gusts over 30 with the post frontal winds through at least late morning Tuesday. Loaded NBM90th percentile winds for sustained and gusts as a result. With little moisture every model has virtually no chance of rain. Tuesday should bring cooler temperatures at around 20 degrees cooler than Monday. 25-75 percentile spreads for MaxT on Tuesday range at 3-4 degrees so high confidence that the post frontal cooldown will be in the lower to mid 70s. Long range ensemble clusters keep an upper level weather pattern of a large ridge over the western CONUS with the main upper jet staying across Canada and northern plains. This could be the first signs of the upper level pattern being affected by the upcoming La Nina pattern as the climate prediction center`s latest update have 71% chance of a La Nina emerging in the fall and continuing through the winter. Ensemble clusters also have virtually 0% chance of any measurable precipitation through the next week. Despite the fact long range outlooks for MaxT temperatures continues to have a wide spread of 13-16 degrees...this pattern will continue to favor a warmer regime. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1100 PM CDT Sun Sep 29 2024 Excellent flying weather will continue through 00z Tue, with more VFR/SKC and light winds. A dry cold front will race through the airports 00-03z Tue, with strong northeast winds gusting 30-35 kts. && .DDC WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Tatro AVIATION...Turner
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
713 PM CDT Sun Sep 29 2024 .KEY MESSAGES... - Aside for patchy fog each of the next two nights, no other weather-related impacts are forecast for central Illinois through Saturday. && .UPDATE... Issued at 713 PM CDT Sun Sep 29 2024 Regional radar mosaics show isolated showers continuing from southwest Illinois into western Ohio. Water vapor imagery shows drier air building southward with time, so the lingering rain should diminish from north to south this evening. Have extended some 20% rain chances over the southeast third of the forecast area for another 2-3 hours. A fairly large clear area has emerged across locations northwest of I-55, but additional clouds continue to stream southwest from Indiana. Some adjustments have been made to the sky trends for this evening as a result. Getting past midnight, low stratus is expected to become more predominant over eastern Illinois, though skies become partly cloudy once again west of I-55. Geelhart && .DISCUSSION... Issued at 157 PM CDT Sun Sep 29 2024 Residual low-level moisture and forcing associated with the remnants of Helene will result in isolated showers this afternoon and again Monday afternoon in areas south of a Paris to Shelbyville line. Any diurnal showers that do develop will be light and transient, with 48-hr QPF totals only offering a few hundredths of precip. Perhaps the greater nuisance will be forecasting clouds and fog the next couple nights. While the fog probabilities offered by both the hi-res ensemble (HREF) and blended guidance (NBM) are low for tonight and Monday night (currently a 10-30% chance for visibility < 3 miles), there are a select few deterministic, hi-res solutions such as the HRRR that paint areas of dense fog (< 0.5 mile) throughout southeast Illinois Monday night. Any coverage of fog tonight will be confined west of I-55, where some partial clearing occurs, while any fog that develops Monday night could be confined to areas east of I-55 where soils remained damp from residual daytime cloudiness. Of these next two nights, the synoptic set-up for fog looks more favorable Monday night, and we will continue to monitor trends in guidance. The Tuesday - Saturday Night time frame continues to look mostly dry despite a pair of shortwave troughs and attendant cold fronts pushing through our region. Simply put, we will lack the moisture return ahead of these fronts, with low-level flow mostly from the north along the Gulf coast through next Saturday. Additionally, strong mid-level ridging to our west throughout the week should mitigate any recycled Pacific moisture from reaching central Illinois as well. These trends are well-depicted by both WPC`s 7-day QPF and CPC`s 6-10 day precip outlook, which signal very little precip. Otherwise, temperatures are trending a hint above normal through the next week as temperatures surge into the low 80s on Monday and Thursday ahead of the cold fronts but then slump into mid-to-low 40s behind the fronts. MJA && .AVIATION... (For the 00z TAFs through 00z Monday Evening) Issued at 613 PM CDT Sun Sep 29 2024 Main aviation concerns will be with ceilings late night into Monday morning. Latest model guidance has trended toward higher risk of MVFR or even IFR conditions, with 18Z HREF highlighting about a 60-70% chance of ceilings below 1,000 feet at KBMI/KCMI. Areas further west may stay partly cloudy longer, though brief IFR ceilings can`t be ruled out toward 12Z around KSPI/KPIA. Ceilings should improve through the day, though it may take until early afternoon to get back to VFR in east central Illinois. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion...UPDATED
National Weather Service Memphis TN
919 PM CDT Sun Sep 29 2024 ...New UPDATE... .UPDATE... Issued at 919 PM CDT Sun Sep 29 2024 Skies were partly cloudy to mostly cloudy across the Midsouth at 9 PM, with winds generally calm. Greatest cloud cover was evident along and west of the MS River. KNQA radar sensed isolated light returns in this region, consistent with showers. Patchy drizzle was reported via mPING over north MS, outside of the stronger radar returns. Latest runs of the HRRR continue to indicate dense fog developing east of the MS River after midnight. Dewpoint depressions in this region were running a 0-2 degrees F at 9 PM. With calm winds, fog development will be likely where skies partially clear overnight. Current forecast remains on track. PWB && .SYNOPSIS... Issued at 230 PM CDT Sun Sep 29 2024 Cloudy, drizzly, and cool conditions will continue on Monday as an upper level low pressure system slowly pulls away. Dry and seasonably warm conditions will return Tuesday and persist through next weekend as high pressure remains over the region. High temperatures will range from the upper 70s to lower 80s with lows in the 50s and 60s. && .DISCUSSION... (This evening through next Saturday) Issued at 230 PM CDT Sun Sep 29 2024 Scattered light rain showers continue this afternoon as a stubborn and expansive upper level low pressure system remains over the Ohio and Lower Mississippi Valleys. This system will slowly fill and break apart over the next 24 hours or so. As it does, cloud cover will thin and fog will develop overnight across much of the region. Light winds and a saturated boundary layer will result in some dense fog development along and east of the Mississippi River. HREF probabilities are quite high ranging from 40 to 80 percent for visibilities of less than one quarter of a mile across west Tennessee and north Mississippi. Went with widespread fog for now, but there is increasing confidence that that fog could become dense. Cool, cloudy, and drizzly conditions will continue on Monday as the system slowly pushes south and east of the region. Temperatures will be a tad warmer with highs in the upper 70s and lower 80s. Fog is possible again Tuesday morning as winds go calm and skies clear. A weak and dry cold front will move through the Mid-South Tuesday. A few light showers are possible, mainly south of I-40. Thereafter, dry and seasonable temperatures will persist through next weekend. Highs will be in the upper 70s to lower 80s with lows in the 50s and 60s. Dry and warm conditions look to persist through the long term forecast as the polar jet remains displaced to the north and east of the region. AC3 && .AVIATION... (00Z TAFS) Issued at 620 PM CDT Sun Sep 29 2024 Main aviation concerns pertain to the development of widespread fog and low stratus across the airspace overnight. LIFR conditions are expected at most sites, with the potential for IFR conditions at JBR. Gradual improvement to MVFR is expected by the mid morning tomorrow, with VFR conditions prevailing by the afternoon. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...AC3 AVIATION...JPR