Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/01/24


Area Forecast Discussion
National Weather Service Bismarck ND
1009 PM CDT Wed Jul 31 2024 .KEY MESSAGES... - Hot temperatures and drier conditions are expected Thursday and Friday, with highs in southwest North Dakota just above 100 degrees on Friday. - A cooling trend is expected to begin Saturday, with highs decreasing into the 70s and 80s through next week. Daily chances for showers and thunderstorms will return as well. && .UPDATE... Issued at 1002 PM CDT Wed Jul 31 2024 A quiet night continues across western and central North Dakota with lows expected in the upper 50s to the low to mid 60s. Just blended in the latest observations to the going forecast. Aviation discussion also updated below. UPDATE Issued at 620 PM CDT Wed Jul 31 2024 Most of the showers and storms have moved out of the southeast but there is still a slight chance of another isolated storm or two in that area given the circulation evident on satellite imagery, generally centered over the far south central. We will also continue to see an isolated shower (maybe a stray rumble of thunder) across the west over the next hour or two before sunset. After that, we are looking at a dry and mostly clear night. For this update, no major changes were needed other than to back off precipitation chances southeast a bit and to blend in the latest observations to the going forecast. && .DISCUSSION... Issued at 254 PM CDT Wed Jul 31 2024 The convection this morning across the south central has nearly cleared our area completely, with multiple lines of convection entering Minnesota from the west at the moment. A few showers are present to the south of Dickey County, but these storms appear to be in an environment that has been modified by the earlier convection to the point where they are struggling to maintain themselves. As a result, the severe threat for our area has ended, as well as most chances for precipitation, with chances only lingering in the southern James River Valley for the next few hours. Surface high pressure has begun to enter the northwest, along with a gradually weakening surface pressure gradient, which will help calm winds heading into the evening and overnight hours. Some cumulus fields have developed across the west as daytime heating ramps up, with a few tiny cells picking up some radar returns in far northeastern Montana. Given how dry the environment is up there, we`re not too concerned about any storm development. There could be a singular cell or two that strengthens to the point of dropping some rain, but it still remains highly unlikely. The most recent HRRR Smoke model run indicates that there`s a good chance the smoke will finally be exiting the area later today, which will help get rid of the constant hazy and smoky skies. This smoke should clear from northwest to southeast through the evening today. Highs today will mostly top out in the 80s across the area, with overnight lows in the 60s. From Thursday through Saturday, we are expecting to see a generally warmer and drier pattern. Ridging over the western CONUS will begin to nudge east into the Dakotas on Thursday, with the 850mb thermal ridge most prevalent across the area on Friday. High temperatures on Thursday are forecast to be in the mid 80s east to mid 90s west, with temperatures increasing into Friday, where the current forecast highs are exceeding triple digits in the southwest. We could see temperatures around 101 and 102 in this area. While heat headlines are not currently planned, if forecasted temperatures and heat indices climb over the next 48 hours, we may need to evaluate this hazard again. This stretch will generally be quiet weather- wise, with mostly clear skies, light winds, and no chances for precipitation until late Saturday night. While temperatures will begin to cool on Saturday, highs will mostly be in the 80s and lower 90s. The aforementioned ridge will begin to flatten late Saturday night into Sunday, with troughing to the north of it beginning to build south. This will allow for shortwaves to begin digging into North Dakota, bringing about daily chances for showers and thunderstorms. These shortwaves will also help bring some cooler temperatures to the area, as they descend south from Saskatchewan and Manitoba. A cooling trend from Sunday through much of next week has been relatively consistent over the past couple days, with high temperatures decreasing into the 70s across the entire area by Wednesday. This pattern will also be somewhat less conducive for strong thunderstorm development, with the CSU machine learning guidance not really suggesting anything in terms of severe risk across the area. Its still a bit far out to be certain with regards to the mesoscale setup these days, but given the gradually decreasing temperatures and generally weak synoptic lift, showers and thunderstorms will mostly be the typical spotty, short-lived Summer showers. Long range guidance is leaning towards this pattern continuing through the rest of next week and into next weekend. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 1009 PM CDT Wed Jul 31 2024 VFR conditions are expected through the period with dry weather and generally light/variable winds. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...ZH DISCUSSION...Besson AVIATION...ZH
Forecast Discussion at weather.gov/mqt.

&& .DLH WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. MARINE...None. && $$ DISCUSSION...Huyck AVIATION...Britt MARINE...Huyck
Area Forecast Discussion
National Weather Service Des Moines IA
329 PM CDT Wed Jul 31 2024 .KEY MESSAGES... - Thunderstorms likely tonight with an Enhanced Risk of severe weather over much of the forecast area. Although large hail and a few tornadoes are in place, damaging winds are the primary concern. - Lingering chances for showers & a few storms north and east Thursday - Mainly dry this weekend && .DISCUSSION... Issued at 328 PM CDT Wed Jul 31 2024 The primary concern is obviously what is going to transpire over the next 12-18 hours with another round of severe weather and heavy rains anticipated. The airmass is becoming increasingly unstable with MLCAPEs now approaching 4000 J/kg west, however CINH is equally strong and still 100+ J/kg due to a noted warm layer around 2km. This has suppressed even much cumulus development. Forecast temps and heat indices have not reached expected values due to morning convection lingering longer than anticipated, but the sensible weather is still warm and humid with dewpoints into the 70s so will leave the current advisory in place until expiration. This situation is expected to change later this evening however as lift associated with the current Dakotas upper low is expected to cross the MO River into IA. Vertical motion from diffluence aloft and QG forcing is expected to cool the mid levels and erode this warm layer allowing for convection to rapidly develop to our northwest during the late afternoon or evening hours, with a separate cluster likely occurring farther southwest ahead of the current NE MCS. RAP forecast soundings over western IA suggest MLCAPEs may reach 4000-5000 J/kg, mid level lapse rates around ~9 C/km, and DCAPEs as high as 1500 J/kg. This alarming thermodynamic parameter space and very warm airmass is very conducive for damaging winds, and both the 12Z HREF and recent HRRR runs suggest that localized high end gusts are possible (70+ mph). Recent HRRR runs have had good agreement on this magnitude, but not placement, occurring anywhere from the Siouxland area into MO. While the warm airmass and only moderate effective shear ~40kts may temper the large hail potential somewhat, and less than favorable 0-1km shear and SRH aren`t ideal for tornadoes, the magnitude of the instability and stretching/parcel acceleration potential keeps both of those in play. With organized wind/bowing segments favored, the heavy rain potential may be minimized due to the progressive nature of the MCS, and the 12Z HREF reflects that as well with only spotty 1-4" amounts, lesser than noted for previous events. The severe weather potential should be over by Thursday, but the parent upper low is expected to mature over the Upper MS Valley with lingering forcing in eastern IA aiding precip chances in the morning, and the low modifying the environment such that steep low level lapse rates may produce showers and a few storms, and possibly even a funnel cloud or two near the core of the upper low. By Friday and the weekend, although there won`t be a significant change in airmass, surface high pressure should dominate leading to mainly dry conditions and seasonal temperatures and humidity. By early next week, the sprawling Rockies upper high will become progressive enough that increasing return flow and warm advection will return leading to warmer temperatures, especially southwest. The models are in good agreement that a northern stream short wave will bring another frontal passage and chances for showers and storms around Monday night, especially north, and this time leading to a cooler temperatures and a more notable change of airmass. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1255 PM CDT Wed Jul 31 2024 Convection lingers south of KOTM, but VFR conditions can be expected there and elsewhere with mostly clear skies over much of the area this afternoon. However a period of strong to severe thunderstorms is anticipated tonight, with the potential starting at TAF sites around 01Z-04Z west to east. The confidence in occurrence is sufficient to include thunder at this lead time. Generic, VFR conditions have been mentioned, but MVFR/IFR conditions are certainly possible but will not be included until trends become clearer. Confidence in VFR conditions increases again Thursday morning after the frontal passage. && .DMX WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 7 PM CDT this evening for IAZ033>035- 044>048-057>061-070>075-081>086-092>097. && $$ DISCUSSION...Hagenhoff AVIATION...Small
Area Forecast Discussion
National Weather Service Grand Rapids MI
948 PM EDT Wed Jul 31 2024 .KEY MESSAGES... - Thunderstorms Chances Exist This Evening Through Thursday Night - Showers and Storms Possible Friday - Dry Saturday, Chance of Storms Late Sunday, Larger System Potentially Next Week && .UPDATE... Issued at 945 PM EDT Wed Jul 31 2024 The convection over MI continues to weaken as the atmosphere stabilizes. The HRRR continues to show fog developing overnight and some of it could be dense. No headlines at this time. Based on the latest model runs, it looks like any convection later tonight will likely hold off until after 12z Thu. We will feature only very low POPs for the far southwest parts of the CWA including the South Haven area. && .DISCUSSION... Issued at 329 PM EDT Wed Jul 31 2024 - Thunderstorms Chances Exist This Evening Through Thursday Night Isolated to Scattered thunderstorms will be possible late this afternoon and evening. The area that storms may occur looks to be fairly limited though given a divergent lake breeze off of Lake Michigan. This can be seen in both satellite imagery with a clearing over Western Lower Michigan and in the obs along the lakeshore that have diverging winds Muskegon and South Haven. The best chance for storms will be in the late afternoon through mid evening in the northeast CWA up towards Clare, Mt Pleasant and areas nearby. Plenty of instability exists with limited shear. So any storms will be of the pulse variety and likely non severe. Cannot rule out an isolated severe report of wind given DCAPE over 1,000 and surface based CAPE values of 2500-3000 j/kg. Convection will fade diurnally during the late evening hours. Areas of fog are possible tonight given the high dew points and light winds. Likely more of a general haze or light fog. A wave diving southeast in the upper flow will bring the next round of showers and storms Thursday afternoon into Thursday night. Cloud cover with the approaching shortwave trough may inhibit good heating and therefore instability on Thursday. The trusted HREF is showing most unstable CAPE values topping out in the 1000-2000 j/kg range which is modest by August standards and deep layer shear of only 20 knots. We are still expecting showers and storms but it may be muted a bit by the cloud cover and possible activity moving in early in the day. The HREF is not overly bullish on convection as the neighborhood probabilities never really exceed 50 percent across our forecast area. The most concentrated convection looks to be just south and southwest of our CWA which can be seen in the day 2 (Thu/Thu night) SPC outlook which has a slight risk southwest of us. - Showers and Storms Possible Friday Friday will begin the day with a strong upper level shortwave moving through the midwest with warm air advection and anomalous PWATS of 1.5 to 2 inches. Warm, humid air along with daytime heating should provide another good opportunity for storm formation. The question that will be, and has been all week, is whether or not the system will provide enough shear. There remain some questions of timing and movement of the low. It could trend to the south with the best shear through Indiana and Ohio. Given the current passage and timing of the low, the best area for convection will be in the far SW corner. If any showers or storms do form, expect them to have locally heavy rainfall. - Dry Saturday, Chance of Storms Late Sunday, Larger System Potentially Next Week The before mentioned upper level shortwave will exit the region Saturday with a positively tilted upper level ridge that will coincide with warm dry air through the first half of the weekend. The trend for a pattern change Sunday remains in place, as a large upper level low over eastern Canada will dominate the weather pattern into next week. That low will bring successive waves and moisture boundaries across the region. Previous discussions talked about a cold front moving through the region and latest runs stall that front and bring it through closer to Sunday night. Showers and storms will be possible along the front through that timeframe. Cooler and drier air will begin the weekend with another chance for showers and storms Tuesday. Models diverge on timing but there is a decent signal for a another storm event around mid next week. There seems to be solid warm air advection out ahead of the approaching system. Definitely a system that bares watching. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 746 PM EDT Wed Jul 31 2024 A moisture rich near surface environment with light winds will support fog development late tonight into early Thursday morning. Fog may drop down to less than one mile at times. Fog will mix out after sunrise quickly turning back to VFR for the rest of the day. Afternoon showers and storms will be possible after 20z Thursday. && .MARINE... Issued at 329 PM EDT Wed Jul 31 2024 Limited concerns for high winds and large waves over the course of the remainder of the week and upcoming weekend. It is not out of the question that we could see our advancing high setup over the weekend during the afternoon hours. Overall however, we are do not have any major synoptic scale systems that will be generating wind. Our main marine concerns over the next couple of days will be some fog/haze and the chance for thunderstorms. The moisture advecting over cooler water (surface dew points higher than the water temperature) is producing some light fog and haze over the water this afternoon. Nothing too significant at this point, but some areas of fog are possible tonight. These conditions will continue into Thursday. Chances for thunderstorms will exist over Lake Michigan from Thursday into Friday. The stronger storms may contain locally heavy rain, lightning strikes, small hail and gusty winds to 35 knots. Winds and waves will be higher in and near storms the next couple of days. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ UPDATE...MJS DISCUSSION...Duke/Ceru AVIATION...Thielke MARINE...Duke
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
907 PM CDT Wed Jul 31 2024 .KEY MESSAGES... - Another round of storms will move across the region late tonight into Thursday morning. There is a slight risk (level 2 of 5) for severe storms with this system with damaging wind gusts the primary concern. - Heat and humidity may result in heat indices in excess of 100 degrees Thursday, especially south of I-72. Confidence is too low for a Heat Advisory at this time due to uncertainty in storm track/timing and possible lingering cloud cover. && .UPDATE... Issued at 906 PM CDT Wed Jul 31 2024 Have updated timing of thunderstorm chances through Thursday morning as a bowing line of thunderstorms over southern IA/northern MO heads eastward around 50 mph, and additional clusters of thunderstorms over eastern KS shift eastward as well. Severe wind gusts to 65 mph and wind damage continue to be reported with the IA feature as it moves into an axis of 3500-5000 J/KG MLCAPE that extends from east central MO into NW IA, however RAP based mesoanalysis indicates it will be moving into an area of under 1000 J/kg in central IL struggling to recover from being worked over from today`s convection. The 00Z HRRR run begins to weaken the convective line dramatically in eastern IA, however convection currently over KS then intensifies as it crosses the instability axis and arrives in central IL a little later than previous runs that expected the IA convection to dominate. Despite the variety of model runs coming in lately, it would appear chances for thunderstorms arrive in west central IL around midnight to a few hours after midnight and spread eastward through the early morning, and should be fueled by up to 2000 J/kg MUCAPE, a low level jet nosing into the area, and a convectively induced shortwave creating 30-40 kt bulk shear and lift. A Slight Risk for severe thunderstorms continues to be designated by SPC, mainly for severe wind gust potential. Otherwise, changes this evening are minimal, with warm lows in the mid 70s maintained by southerly winds as the warm front located just south of the area this evening lifts northward in the overnight. 37 && .DISCUSSION... Issued at 153 PM CDT Wed Jul 31 2024 THROUGH TOMORROW MORNING... This afternoon, a couple boundaries from earlier storms are noted on satellite imagery, the closest stretching from near Quincy to near Lawrenceville. To the north, temps have been suppressed by convective debris and are generally running in the 70s to lower 80s. Further south upper 80s and 90s are noted. A sharp instability gradient is the result with the warm side of the boundary characterized by 3000+ J/kg MLCAPE values. This will likely be the focus for additional storms this afternoon, mainly impacting our far southern counties in the CWA adjacent to the St Louis and Paducah forecast areas. Most of central Illinois north of I-72 should be dry through the afternoon. This evening, low level jet is progged to strengthen to our west with storms redeveloping on the nose of the LLJ over NW MO/SW IA. These storms will grow upscale and track east into central Illinois on the veering LLJ late tonight into Thursday morning. Moderately strong MUCAPE in excess of 2000 J/kg is progged to be in place ahead of the advancing line of storms and will support its maintenance overnight as they track east towards the local area similar to the past couple nights. A severe threat will accompany the line but should gradually wane with time and eastward extent. THURSDAY... A closed H5 low will track slowly southeast from southern MN Thursday morning to central IN Friday evening. Ongoing storms Thursday morning will leave outflow boundaries across central Illinois that will interact with the approaching upper level disturbance and serve as the foci for the next round of storms across portions of central Illinois. There is some uncertainty on location of these boundaries. Moderately strong instability is expected to develop Thursday afternoon with MLCAPE in excess of 3000 J/kg while sufficient deep layer shear of around 30 kt will be in place supporting strong to severe storms. Heat and humidity continue to be a concern Thursday afternoon with potential for heat indices to exceed 100 degrees. As has been the case the past couple days, morning storms, convective debris and cloud cover add considerable uncertainty to the temp forecast and will hold off on issuing any heat headlines. If clouds hold on longer than expected or storms form earlier, temps may hold in the 80s. If full sunshine breaks out for several hours, temps should be able to warm into the 90s and a heat advisory may eventually be needed. Surface cold front will sag south across central Illinois Thursday evening and overnight and will support a chance for additional showers and storms. Unfavorable diurnal timing resulting in diminishing instability and gradually weakening deep layer shear should limit the severe threat Thursday night, but wouldn`t rule out a few stronger storms. FRIDAY... Main H5 low will pass across central Illinois Friday with scattered showers and storms expected with its passage. Northwest winds behind the front will help usher in less warm temps with highs in the lower to mid 80s Friday afternoon. This will keep instability modest and help limit the chance for severe storms Friday. SATURDAY THROUGH WEDNESDAY... High pressure will build across the region this weekend and linger into early next week favoring a stretch of mainly dry weather across central Illinois. Temperatures will be more seasonable over the weekend with highs in the mid to upper 80s, though a few 90s will creep back in early next week as upper ridging builds over the west and Great Plains and inches eastward. While temps will be slightly more subdued, humidity levels will remain high with dew points generally running in the upper 60s to lower 70s. Deubelbeiss && .AVIATION... (For the 00z TAFs through 00z Thursday Evening) Issued at 639 PM CDT Wed Jul 31 2024 A line of thunderstorms, potentially remaining severe, is likely to affect the central IL terminals overnight. While timing is still not certain, latest blend of model and observations of the developing line suggests the first impacts in the KSPI-KPIA area by 07Z, sweeping eastward to KCMI by around 09Z. Trailing showers and thunderstorms could last until around 14Z. Expect MVFR or worse vsbys and perhaps cigs as well, with strong gusty winds that could briefly exceed 40 kts in thunderstorms. Until then, VFR conditions are expected. Another round of thunderstorms is possible Thursday afternoon. Winds light and variable to SSE around 8 kts tonight, becoming SW 6-10 kts by 14Z. 37 && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Indianapolis IN
951 PM EDT Wed Jul 31 2024 .KEY MESSAGES... - Uncertainty remains high on thunderstorm coverage and timing through tomorrow night - Heavy rain/flooding and some severe storm potential exists - Heat indices near or above 100 degrees possible Thursday afternoon - Drier conditions this weekend into early next week with a warming from near normal to above normal once again && .FORECAST UPDATE... Issued at 950 PM EDT Wed Jul 31 2024 The main issue with the update will be timing and paths of upstream MCS activity, currently over the upper Midwest south to Kansas. Earlier convection today over central Indiana stabilized the atmosphere for a but, but instability has since rebounded north of I- 70 and the highest CAPEs continue to be across the lower Wabash Valley and into southern Illinois. An upper trough, seen on H20 vapor imagery, over the northern Plains is expected to move into the upper Midwest by daybreak. This feature will supply synoptic forcing to the convective complexes and deep shear vectors will be mostly from west to east with a near perpendicular component to any linear convective systems. Meanwhile, a modest nocturnal jet will feed into the systems. Currently, the CAMS have a line of storms associated with merging convection into the upper Wabash Valley around 12z. That said, CAMS are usually a bit slow as the do not handle cold pools well. In addition, the stronger storms may tend to move further southwest toward the greatest instability. With the uncertainty, keeps PoPs low until after 10z at which time PoPs increase to likely over the Wabash Valley. Isolated storms remain possible through the remainder of the evening and overnight associated with warm advection, an unstable atmosphere, a moist boundary layer and remnant boundary, across far southwestern Indiana. && .MESOSCALE UPDATE... Issued at 452 PM EDT Wed Jul 31 2024 The bow echo accompanied by a rear inflow jet has moved south and east of Jennings county. This prompted an earlier severe thunderstorm warning as the line moved into better shear balance and low level lapse rates increased as a 60+ knot base velocity signature popped up along the northern edge of the line. However, the activity has moved off to the east which will result in the cancellation of the Severe Thunderstorm Watch. Areas near and north of I-70 have been worked over and should not longer be a big concern tonight but would not completely ruled out additional isolated to scattered convection, in warm advection, south of the I-70 corridor, where the atmosphere is much more unstable with LAPS data indicating SB CAPEs to 2500 J/kg. HRRR reflectivity progs are going along with this potential scenario. && .SHORT TERM (This evening through Thursday)... Issued at 251 PM EDT Wed Jul 31 2024 The most intense convection today has reformed south of residual cold pool in reservoir of stronger instability across roughly the southern third of central Indiana. This convection should continue to overturn the low-level thermodynamic environment and perpetuate further southward expansion of effective cold pool, limiting further thunderstorm development into the evening. Midlevel overcast will be present in the wake of remnant MCS. With complicating factors of today`s convection and weak flow to replenish the low-level moisture, convective development late tonight is in question. As is potential MCS maintenance tomorrow morning. We think modest west-southwesterly 850-mb flow helping advect deeper moisture in and increasing large scale ascent from the approaching trough should be enough for some isolated convection later tonight, though spatial details on this development remain uncertain. This modest moisture advection may help maintain any MCS that evolves from convection upstream as well, though this may preferentially propagate further south than most CAMs currently anticipate along residual cold pool periphery. At least the more intense part. Tonight/tomorrow`s scenario will continue to influence the mesoscale environment which will drive convective coverage and intensity late tomorrow. However, forcing for ascent with the trough and strengthening warm advection coupled with diabatic surface heating should lead to an uptick in convection late tomorrow somewhere across the area. Modest effective shear and sufficient instability will support some severe threat, with damaging winds being the primary concern, especially if a more organized cold pool-driven forward propagating system can evolve. Anomalous moisture will continue to support some heavy rain/localized flooding threat, especially if training happens. Bottom line, mesoscale details that cannot yet be resolved will drive the important details of the forecast, with regards to storm timing and associated hazards. Thus, confidence is lower than typical given the pattern and frequent forecast updates will be needed through the short term period. && .LONG TERM (Thursday night through Wednesday)... Issued at 251 PM EDT Wed Jul 31 2024 A couple of notes based on the latest model cycles. Please see the previous discussion below. 1. Broadening deep low over our area Friday will shunt the stronger IVT and deepest moisture southeast by early Friday. Remnant low- level moisture and convergent flow pattern will support extensive clouds and numerous showers with locally heavy rainfall/flooding potential. Organized heavy rain and flooding will decrease during the day. Have trended temperatures down slightly with clouds/showers. 2. With aforementioned low detached from main polar jet, we won`t see an intrusion of dry continental air, and will thus remain moist/humid. Weak perturbations within west-northwesterly flow aloft may be enough for periodic chances of convection through the long term period, but it remains difficult to identify a period of stronger forcing and greater coverage at this time. --previous discussion-- Friday and Saturday... An upper low will move south into the area and a surface cold front will move through on Friday. This forcing will interact with the still plentiful moisture to produce widespread showers and some thunderstorms across the area. Will go at least likely category PoPs all areas. Heavy rain and flooding will remain threats. Clouds and rain will keep temperatures in the 80s. As the upper system moves east on Saturday, enough forcing will remain for chance PoPs most areas. Highs will be in the mid to upper 80s. Sunday and beyond... High pressure will keep the area dry Sunday into Tuesday for most areas. The upper ridge will try to sneak back in from the southwest, bringing some 90s back into the area, especially south. A cold front may be able to get into the area on Wednesday, depending on how strong the upper ridge is. This may spark a few showers or storms. Hot temperatures will continue south ahead of the front. && .AVIATION (00Z TAF Issuance)... Issued at 719 PM EDT Wed Jul 31 2024 Impacts: - Thunderstorms with MVFR and briefly worse conditions are possible mainly after 11z Thursday Discussion: Isolated thunderstorms are possible this evening. Better chances for storms will be Thursday, however coverage and timing is too uncertain to throw in the TAFs at any one given time. A lot of the uncertainly hinges on whether or not the atmosphere can recover from convection earlier today. MVFR and briefly worse visibilities and ceilings are possible in convection. Winds away from convection will be SSW mostly 10 knots or less and very light tonight. Higher gusts are possible in thunderstorms. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...MK SHORT TERM...BRB LONG TERM...BRB/50 AVIATION...MK
Area Forecast Discussion
National Weather Service Medford OR
830 PM PDT Wed Jul 31 2024 .DISCUSSION...A "front" of smoke has traveled from the north and is beginning to affect portions of the Umpqua and Rogue Valleys. The Illinois Valley may not be far behind. Have updated the forecast to account for this in the next couple of hours, but it is worth noting that the HRRR smoke model is not seeming to initialize very well. That being said, we may get a little relief from the smoke tomorrow afternoon and evening. Otherwise, will continue to monitor for any additional updates. For more information on the forecast, please see the previous discussion below. -Schaaf && .PREV DISCUSSION... /Issued 458 PM PDT Wed Jul 31 2024/ DISCUSSION...Current satellite shows the smoke from the fires in Lane County has moved into Douglas County including Roseburg with less than a mile visibility. This smoke will continue moving south this evening, so parts of Jackson and Josephine counties, including Medford, could see smoke impacts from this string. Stratus is still present at the coast and offshore, but there is some sunlight coming through. This afternoon has a jump in heat with highs from the mid-70s at the coast to near triple digits for west side valleys. Temperatures will not recover much overnight, and there is only a 10-20% probability for Medford to fall below 65 degrees, and a 30-40% probability for Roseburg. This heat will only increase for inland locations Thursday with highs in the 100-105 degree range for west side valleys (including the Klamath River and Shasta valleys). With this in mind, a Heat Advisory will be in effect tomorrow afternoon through tomorrow afternoon for west side valleys. Friday morning`s temperatures will be similar to Thursday. Checking back into cloud cover, there will be stratus once again at the coast that will likely reach parts of the Coquille Basin. Being in between the high pressure to the east and low pressure to the west gives northern California and Southern Oregon the position to gain southerly winds back tomorrow. There will be an increase in high clouds that come from the south through the day tomorrow. However, this southerly flow will bring smoke from the Park Fire in Northern California to Siskiyou and Modoc counties tonight and it will continue moving into southern Oregon through the day tomorrow. Tomorrow afternoon and evening will be the worst for the Rogue Valley and east into Klamath Falls. With the continued issue of worsening air quality, an Air Quality Alert has been issued through Friday for Klamath and Lake counties. Intermittent smoke is possible in Jackson, Josephine and Eastern Douglas counties. By the end of the work week, thunderstorms are in the forecast. Starting Friday afternoon, the main area will be the Cascades, northern Klamath County and parts of Siskiyou County. This trend continues with more confidence on seeing thunderstorms in northern Lake and Klamath counties Saturday afternoon with SPC guidance showing a 40-50% probability of thunderstorms in the area. Ensembles are showing that areas east of the Cascades could see a few hundreths for rainfall, and overall less than a tenth of an inch is in the forecast, although locally higher amounts are possible. -Hermansen AVIATION...01/00Z TAFS...IFR/LIFR marine stratus is affecting the immediate coast near Cape Arago, just offshore of Bandon, near Cape Blanco, and also south of Pistol River to Brookings. These ceilings will press inland about 10 miles tonight (to include North Bend), but a little farther than that into Coquille/Myrtle Point over interior Coos County. These last until 16-18Z Thursday before clearing to VFR. VFR will prevail inland for the next 24 hours, except wildfire smoke will become much more widespread overnight into Thursday. Earlier today, the smoke briefly lowered visibility to IFR at Roseburg (along with an MVFR ceiling), before vertical mixing pushed the smoke out to the south and east. All of Roseburg, Medford and Klamath Falls will likely see at least some visibility reductions due to wildfire smoke/haze on Thursday, generally in the 3-5 mile range. Closer to the eastern Lane/Douglas fires and the Park fire, visibility due to smoke could even be IFR or lower at times. -Spilde MARINE...Updated 230 PM Wednesday, July 31, 2024...North winds and steep seas around 6 to 7 feet briefly return to an area between Cape Blanco and Brookings through tonight. More low clouds and lower visibilities are anticipated along the coast. Improved conditions follow Thursday and Friday. North winds over the weekend are likely to remain below advisory levels, although seas are anticipated to be steep in the southern waters at times. Then, a stronger thermal trough is possible early next week. -Smith FIRE...Issued 200 PM Wednesday July 31, 2024...High pressure builds over the region resumes control today. This will bring the return of hot temperatures and low daytime humidities, with triple digits for West Side Valleys, and mid-upper 90s for East Side likely lingering through the weekend and into early next week. The peak of the heat is expected Thursday, and this is also when we expect daytime humidities to bottom out. The flow turns southerly on Thursday, and this will allow for an uptick in afternoon breezes on Thursday, especially east of the Cascades and in the Shasta Valley. Guidance has trended slightly stronger with southerly winds, and this was enough to push conditions into the critical category for portions of Siskiyou County and the southern Oregon Cascades. This will mainly affect the Shasta and Scott Valleys, but will include the eastern periphery of the Shelly fire as well as the southern most portion of FWZ 623, south of Highway 140. Near critical conditions are possible for much of the East Side and the rest of northern California on Thursday, but winds won`t quite reach criteria there. Recoveries will trend lower Thursday and Friday mornings, with the poorest recoveries (moderate to poor) expected Friday morning east of the Cascades and across northern California. Recoveries improve Saturday and Sunday mornings with the influx of monsoonal moisture. This brings us to the thunderstorm potential for the weekend as southerly flow pumps moist, unstable air into the region. Thunderstorm chances enter the forecast first on Friday afternoon. Moisture will just be entering the region, so chances (15-20%) are limited to the higher terrain of western Siskiyou County, across the Siskiyous and Cascades. Moisture and instability will be marginal and there really isn`t a clear trigger, but where the elements line up best, which leads to the best chance for thunderstorms, is along the Cascades from Crater Lake northward to areas eastward around Chemult/Crescent. Saturday and Sunday, however, moisture will be more widespread and there is a more well defined trigger (moreso Saturday than Sunday). These are the days we expect thunderstorm activity to peak, including west of the Cascades, with slightly higher confidence for Saturday being the more active day. Current guidance is increasing confidence for scattered thunderstorms on Saturday, especially east of the Cascades. The nocturnal thunderstorm threat is not out of the question for Friday night, it`s just a matter of when the moisture arrives and whether that lines up with any elevated instability and a trigger. Instability looks muted on Friday night, but there is a fairly decent trigger coming through late Friday night into early Saturday morning and this raises the concern for nocturnal storms. In addition, any lingering cloud cover Saturday morning could impact thunderstorm potential for Saturday afternoon. Subtle changes in these elements could lead to big changes in the forecast, and at this point in the forecast, it`s challenging to be confident in any of the details. Stay tuned for updates, with changes to the forecast likely over the coming days. /BR-y && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Red Flag Warning from 2 PM to 8 PM PDT Thursday for ORZ623. Heat Advisory from 2 PM Thursday to 8 PM PDT Friday for ORZ023- 024-026. CA...Red Flag Warning from 2 PM to 8 PM PDT Thursday for CAZ280>282. Heat Advisory from 2 PM Thursday to 8 PM PDT Friday for CAZ080- 081. PACIFIC COASTAL WATERS...Small Craft Advisory until 2 AM PDT Thursday for PZZ356-376. && $$
Area Forecast Discussion
National Weather Service Morristown TN
1010 PM EDT Wed Jul 31 2024 ...New UPDATE... .UPDATE... Issued at 1000 PM EDT Wed Jul 31 2024 Another update to keep a chance of showers and storms going for most of the night with the line that moved through the northern sections of the CWA between 7 PM EDT and the current time. Some storms could be strong still late this evening south and produce heavy rainfall at times so flooding risk continues overnight but should lower late tonight as showers and storms move out. However, some short range models develop more convection between 06Z and 12z across the northern half of the region. && .UPDATE... Issued at 730 PM EDT Wed Jul 31 2024 Updated forecast to increase rain chances along the northern TN border and into Southwest Virginia for the rest of the evening. Line of showers and storms are moving east southeast into northern areas. DCAPE values are around 1200 to 1400 J/KG. Also with the wet soils from earlier heavy rainfall today expect a renewed threat for flooding with FFG values around 0.5 inches or less northern plateau counties. Expect activity to slowly diminish later this evening but new activity is possible in northern areas late tonight. Updated forecast already sent. && .SHORT TERM... (This evening through Thursday) Issued at 301 PM EDT Wed Jul 31 2024 Key Messages: 1. Our chances for severe weather and flooding are now lower through the rest of the afternoon and evening. 2. Still a chance for an overnight MCS to move down out of KY but low confidence. 3. Additional chances for showers and storms tomorrow. Discussion: The severe weather and flooding threat have decreased through the rest of this afternoon and evening. The showers and storms from this morning continue to linger across the central TN valley and points northward. Rain cooled air and clouds have allowed a relatively stable airmass to remain in place through the day. Showers and a few storms will continue through early evening but will then dissipate. If we were to see any stronger storms it would mostly likely be across the central and southern Cumberland Plateau and southern TN Valley, where instability is much higher. However forcing and shear is weak for these locations. So overall, a very low severe threat. If it weren`t for the possibility of an overnight MCS still moving through, I would drop the flood watch. However, there is still a chance, albeit low. The models have been all over the place with the overnight MCS: some runs it`s there then it`s gone. The latest HRRR (17Z) shows an MCS that will drop down into our area from out of KY around 08Z and then progress south into the central TN Valley around daybreak. If this scenario occurs, another round of moderate to heavy rain may be in store for some areas. For this reason, will leave the flood watch as is. The main threat with this MCS, if it occurs, would be localized flooding. A few strong wind gusts are possible but not expected to be widespread. Overall, there is a chance of showers and storms through the day tomorrow as well. The higher chances will be across northeast TN and southwest VA due to high pressure shifting east. How tomorrow`s rain and storms play out are very uncertain though because it all hinges on what the overnight MCS does, if it even occurs. Lingering showers and storms tomorrow morning would likely prevent much afternoon activity. If the MCS doesn`t happen then look for better chances of showers and storms during peak heating. Speaking of heating. There is a chance that the southern TN Valley may need a Heat Advisory for tomorrow. Due to uncertainty with the overnight MCS though (lingering cloud cover into tomorrow), will hold off on the advisory for now and future shifts will reassess. && .LONG TERM... (Thursday night through next Wednesday) Issued at 301 PM EDT Wed Jul 31 2024 Key Messages: 1. Ridging begins to build in mid to late week with heat index values near 107F possible between Chattanooga and Knoxville Friday afternoon. 2. Continued MCS thunderstorm chances Friday into Saturday. Damaging wind gusts and heavy rain rates are main threats. Discussion: Shortwave ridging will occur on Thursday night which give the soil a break from all the rain. Unfortunately, it won`t be long enough. Another trough will translate across the Great Lakes and Ohio River Valley on Friday. Apparent temperatures (i.e. heat index) Friday afternoon will be over 100 degrees to as high as 107 degrees in the Tennessee Valley. A heat advisory will be needed mainly across the southern Valley on Friday. Additionally, scattered showers and thunderstorms will be possible in the afternoon. Locally heavy rain will be possible and damaging winds. The trough will be slow to drift east on Saturday. Therefore temperatures might be slightly cooler than Friday but lingering rainfall will persist into Saturday afternoon. Saturated ground could become a problem with additional heavy showers. Turn around, don`t drown! By Sunday, conditions begin to dry out through early next week and temperatures return to near normal. && .AVIATION... (00Z TAFS) Issued at 730 PM EDT Wed Jul 31 2024 Mostly VFR conditions CHA and TYS expected through the period. At TRI a line of showers and storms may affect the site this evening. Expecting the line to decrease in next couple hours so just have vicinity showers for now. May have to amend if activity changes, strengthens. Then expect MVFR fog late tonight at TRI. Thursday there is much uncertainty with how showers and storms will develop across NE TN so have 2 prob30 groups at TRI for morning and afternoon. At TYS and CHA expect mostly fair skies and light winds and lower chances of showers and storms. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 76 95 76 97 / 10 20 0 40 Knoxville McGhee Tyson Airport, TN 73 92 75 95 / 30 30 10 50 Oak Ridge, TN 73 92 74 94 / 40 30 10 50 Tri Cities Airport, TN 69 85 72 91 / 30 40 30 50 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...Flood Watch until 5 AM EDT Thursday for Cherokee-Clay. TN...Flood Watch until 5 AM EDT /4 AM CDT/ Thursday for Anderson- Bledsoe-Blount Smoky Mountains-Bradley-Campbell-Claiborne- Cocke Smoky Mountains-East Polk-Grainger-Hamblen-Hamilton- Hancock-Hawkins-Jefferson-Johnson-Knox-Loudon-Marion-McMinn- Meigs-Morgan-North Sevier-Northwest Blount-Northwest Carter- Northwest Cocke-Northwest Greene-Northwest Monroe-Rhea- Roane-Scott TN-Sequatchie-Sevier Smoky Mountains-Southeast Carter-Southeast Greene-Southeast Monroe-Sullivan-Unicoi- Union-Washington TN-West Polk. VA...Flood Watch until 5 AM EDT Thursday for Lee-Russell-Scott VA- Washington VA-Wise. && $$ SHORT TERM...TD LONG TERM....AC AVIATION...TD
Area Forecast Discussion
National Weather Service Pocatello ID
205 PM MDT Wed Jul 31 2024 .SHORT TERM...Tonight through Thursday Night. Early afternoon satellite imagery shows clear skies over SE Idaho outside of some fair weather CU building over the higher terrain as a H5 ridge of high pressure continues its progression north. As a result, quiet and dry conditions have returned as temperatures will a warming trend through Saturday. Highs today will be in the 70s and 80s, climbing around 5-10 degrees for Thursday into the 80s and 90s. Winds will remain light and variable given weak 700 mb winds aloft. Have added the mention of patchy smoke to the forecast through tomorrow which while concentrations will remain very light in some places, the HRRR smoke model does show increasing concentrations lifting NE out of the Great Basin tomorrow given predominant SW flow back overhead. MacKay .LONG TERM...Friday through next Wednesday. We will be in the worst of the heat this Friday and Saturday thanks to a ridge of high pressure almost directly on top of Eastern Idaho. This heat will be the biggest weather impact as highs reach the mid to upper 90s and even a few triple digits both afternoons through the eastern Magic Valley, Snake Plain, and valley locations in the South Hills. Around Pocatello, there is a 10 to 30 percent chance of exceeding 100 degrees on Saturday. That chance increases farther west near Shoshone with a 60 to 70 percent chance on Friday and a 40 to 60 percent chance on Saturday. Morning temperatures will range from 50s to low 70s in the valleys on Saturday morning, so debated on an Excessive Heat Watch, but have decided to hold off for now as this heat looks like a Heat Advisory at best, and even that is borderline. Either way, with or without heat products out, the heat will be rough on Friday and Saturday. The second half of the weekend will be slightly cooler thanks to a weak shortwave moving through to loosen the grip of the high pressure. This will allow monsoonal moisture to also return for the afternoons once we get to Sunday through Wednesday. As for our highs, this will mean we cool all the way down to...low and mid 90s by Sunday afternoon. Highs will remain steady for Monday and Tuesday, but we will drop a few degrees for Wednesday with highs mostly in the upper 80s to low 90s, closer to our climate normals for early August. AMM && .AVIATION...For the 18Z TAFS through 18Z Thursday. High pressure begins to build in over the area today which will lead to hot and dry weather with VFR conditions. Winds will be light today and tomorrow with limited clouds aside from afternoon CU off of the mountains. No rain or storms are expected today or tomorrow. Smoke from wildfires has cleared a bit behind yesterday`s system leading to little to no impacts. Some light smoke will return overnight, though 6SM VIS may be too pessimistic. AMM && .FIRE WEATHER... Under the increasing influence of high pressure, conditions will remain very dry with light winds as temperatures see a warming trend through the weekend. Highs will peak on Friday and Saturday in the 90s to low 100s with RHs bottoming out in the single digits and teens. As an approaching H5 trough in the NE Pacific allows the ridge axis of high pressure to shift east, monsoon moisture will be allowed to advect north this weekend with showers and thunderstorms then possible into early next week. While coverage will remain more isolated in nature on Saturday, scattered coverage on Sunday may necessitate a RFW issuance of which those chances will continue each day through Wednesday. Coverage of showers and storms will peak during the afternoon and early evening hours each day as temperatures slightly cool with highs returning to the 80s to mid 90s. MacKay && .AIR QUALITY... Air quality alerts have been lifted for Eastern Idaho as the overall air quality has improved behind the trough that moved through yesterday. Wildfire smoke is forecast to remain light for the rest of today and most of tonight, though we will see an uptick again tomorrow. At this point, Idaho DEQ is forecasting air quality to remain in the "Moderate" category through Friday and we`ve kept a mention of patchy smoke in the forecast. AMM && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Reno NV
1204 PM PDT Wed Jul 31 2024 .SYNOPSIS... * Above average temperatures through the middle of next week. * Smoke from nearby wildfires will continue to impact portions of northeast CA and western NV through the weekend. * Increasing thunderstorm chances late this week through the weekend. && .DISCUSSION... Smoke: The Park Fire in northern California has continued to spew out a considerable amount of smoke overnight. The winds have gone light-northwesterly overnight causing smoke to settle over western NV including the Reno area. This smoke and haze will likely linger through Friday as per the HRRR smoke output. To reiterate, we still recommend everyone to be air quality conscious the next few days. For a very good way to view the AQI in your area we recommend going to fire.airnow.gov. Temperatures: Starting today, temperatures will be back on the rise into the upper 90`s across lower valleys and upper 80`s in the Sierra. By tomorrow, lower NV valleys will crack the 100 degree mark yet again. That heat will carry into next week as we`ll get a Four Corners High that`ll take charge over the southwest US. Extended: With that high pressure system in place late-week, we`ll have a stream of moisture come up from the south. Models have been consistently showing PWATs of around 1" on Friday through this weekend. Daytime heating combined with this increased moisture will create the chance for afternoon/evening thunderstorms across western NV then extending further north into northeast CA Friday night and Saturday. Based on current soundings, Friday`s storms will be fast moving and will likely have lightning, but also have the high potential for localized heavy rain. Current QPF ranges from 0.10- 0.30", so nothing terribly heavy but if storms start to train there could be a flash flood threat. -Justin && .AVIATION... We`re going to see lingering smoke and haze at most terminals today and tomorrow from the Park Fire in northern California. There will be periods of visibilities 3-6 SM and CIGs BKN030-040 in the evening and overnight hours. Due to the winds being light and northerly overnight, smoke will continue to impact western NV and especially northeast CA through Friday morning. Looking ahead to Friday, as it stands right now there will likely be the chance for a combination of smoke and thunderstorms across the entire region. It will also be heating up again this week with temperatures approaching 100 degrees lower valleys and 90 degrees in the Sierra which may result in some density altitude impacts. -Justin && .REV Watches/Warnings/Advisories... NV...Dense Smoke Advisory until 5 PM PDT Thursday NVZ003>005. CA...Dense Smoke Advisory until 5 PM PDT Thursday CAZ071. && $$
Area Forecast Discussion...UPDATED
National Weather Service Springfield MO
902 PM CDT Wed Jul 31 2024 .KEY MESSAGES... - A Heat Advisory is in effect for the area through Thursday at 7 PM. Widespread heat index values of 100-110+. - A weakening cluster of thunderstorms may move into the area overnight (20-50% chance). A few storms could be severe with damaging winds. Many areas will remain dry. Additional thunderstorm chances exist Thursday afternoon (20-40%). - Heat headlines may need to be extended into the weekend for portions of southeast Kansas into southern Missouri. && .MESOSCALE... Issued at 843 PM CDT Wed Jul 31 2024 An area of thunderstorms continued this evening from Iowa down into northern and central Kansas. This area was on the southern periphery of a passing shortwave trough across Nebraska. These storms were beginning to run out of the higher wind fields as evident by the outflow boundaries beginning to surge out ahead of the complex. A 30kt low level jet was now in the begnning phases of organization across western Oklahoma, nosing into the southwest edge of the thunderstorm complex. Therefore, the big question is what happens with this activity as it moves southeast towards the area tonight. The 00z KSGF sounding measured a very unstable atmosphere with 3390k/kg of mixed layer CAPE however it was capped around 750-800mb with 52j/kg of CIN (700mb temps were measured at 14C). Also of note was the ThetaE differential measured at 41C. This is a pretty high number and indicative of the potential for damaging winds with any thunderstorms. The warm mid levels/capping inversion is the main limiting factor for more robust and widespread storm potential. Given the presence of a low level jet feeding into the system, there will remain the potential that this complex survives but slowly weakens as it approaches the area as it moves into a stronger capped environment. The last few runs of the HRRR (including the 00z) have strongly suggested this complex will begin to weaken as it moves into southeast Kansas and western Missouri by midnight however often times there remains wind potential even as the complex is in the weakening phase. Therefore we have increased precip chances overnight for areas north of Highway 60. Damaging winds up to 60mph will be possible with any thunderstorm, otherwise a mostly dry outflow boundary passage may also contain 40-50mph winds as it moves into the area. Overall not a highly confident forecast overnight however areas especially northwest of Springfield will need to monitor this complex as it moves in overnight. && .SHORT TERM /THROUGH FRIDAY/... Issued at 239 PM CDT Wed Jul 31 2024 Current Conditions and Synoptic Overview: Upper-air analysis reveals a strong short-wave trough centered over the Dakotas digging into the central U.S. At the surface, a cold front attached to a surface low by the Nebraska-South Dakota border drapes south across central Kansas and Nebraska. Southwesterly surface winds of 10-15 mph continue to advect warm most air over our area, as the hot and humid airmass expands to the north as a warm front. As such, temperatures have climbed into the low to mid 90s under mostly clear skies. Heat to continue into Thursday: As has been the focus for the past few days, the primary short-term hazard continues to be heat. 850mb temperatures this morning were around the 90th percentile for this time of year, supporting high temperatures today in the mid to upper 90s. Combined with continued surface moisture, with dewpoints in the low to mid 70s, heat indices continue to range between 105 to 110 degrees. Little relief is offered overnight, as lows only fall to the mid to upper 70s. Thursday decided to copy today`s homework and pass it off as its own, with very similar highs in the mid to upper 90s. Continued surface moisture supports the continuation of muggy conditions, and heat indices from 105 to 110. An Excessive Heat Warning is in effect for counties north of I-44, expiring today at 7 pm. A Heat Advisory goes into effect for these northern counties upon the Excessive Heat Warning`s expiration, and is currently in effect for all other counties in our CWA until 7 pm Thursday. As the trough aloft continues to move east, the cold-front across Nebraska and Kansas will begin to drift southeast, arriving over southern Missouri Thursday evening. While this should lower heat indices below heat headline criteria, some heat may linger into Friday and Saturday in southwestern Missouri and southeastern Kansas. Thus, some heat headlines may need to be extended in this region. Low Precipitation Chances Thursday: Thermodynamic conditions are favorable for convection in front of the cold front as it moves to the southeast. Any storms that make it this far south could take advantage of CAPE values of 2000-2500 J/kg across southwestern Missouri. However, given the lack of any mesoscale forcing, most storms are expected to die out before reaching our CWA, which most CAMS support. Any storms that do reach this area would do so early Thursday morning, and likely be weakening. As such, we`ve opted to keep PoPs for our northeastern CWA below 20%. Moving into Thursday afternoon, thunderstorm potential is dependent on convection earlier in the day. The most substantial convective development is expected to our east, in Illinois and far southeastern Missouri along outflow from morning convection. Some CAMs break out isolated development across our north-central CWA, but confidence in this forecast is low. The Storm Prediction Center has our eastern CWA in a Marginal Risk for severe weather. Hazards from these storms include strong wind gusts, locally heavy rainfall, and lightning. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Issued at 239 PM CDT Wed Jul 31 2024 As the shortwave trough moves to the east, our area will sit on the eastern periphery of a trough over the western U.S. As mentioned before, the passage of the weak cold front will lead to slightly cooler temperatures Friday, more so to the north and east (highs in the low 90s versus the upper 80s). Moving into the weekend, temperatures warm up a bit, closer to where they were this week in the mid to upper 90s. Heat headlines may need to be extended into the weekend into early next week, as heat indices may exceed 105, although confidence in this forecast is too low at this time. A signal for cooler temperatures doesn`t occur until midweek next week, as some shortwave energy moves into the area. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 618 PM CDT Wed Jul 31 2024 VFR conditions should prevail through the TAF period however we will be watching to the north overnight to see if an area of showers and thunderstorms can move towards the area. This would be after 06z. JLN and SGF may see a brief wind shift to the north with this if it makes it however chances are currently less than 30 percent. Winds will then turn back southerly for Thursday with a 30 percent chance for thunderstorms by the end of the TAF period. Low level wind shear is possible at the sites overnight however it looks to marginal to include at this time. && .CLIMATE... Issued at 325 AM CDT Wed Jul 31 2024 Record High Temperatures: July 31: KJLN: 104/1980 August 1: KUNO: 100/2012 August 5: KSGF: 101/1982 August 6: KSGF: 102/1956 KJLN: 105/1956 Record High Minimum Temperatures: July 31: KSGF: 78/2012 && .SGF WATCHES/WARNINGS/ADVISORIES... KS...Heat Advisory until 7 PM CDT Thursday for KSZ073-097-101. MO...Heat Advisory until 7 PM CDT Thursday for MOZ055>058-066>071- 077>083-088>098-101>106. && $$ MESOSCALE...Burchfield/Schaumann SHORT TERM...Kenny LONG TERM...Kenny AVIATION...Burchfield CLIMATE...Camden
Area Forecast Discussion
National Weather Service Tulsa OK
833 PM CDT Wed Jul 31 2024 ...New SHORT TERM... .SHORT TERM... (The rest of tonight) Issued at 832 PM CDT Wed Jul 31 2024 The expected thunderstorm complex in central Kansas is tracking well with the latest HRRR run timing- wise, with the intensity of the complex still expected to decrease as it approaches the Oklahoma border. The existing low POPs northwest of I-44 after 06Z appear appropriate to cover the area and extent of whatever remnants hold together this far south, as do the Sky cover grids. Above normal low temperatures should still be expected in most spots, but with temperatures likely to be cooler behind the outflow boundary from the Kansas complex, will drop lows a couple of degrees in parts of northeast Oklahoma and into northwest Arkansas, in line with the HRRR trends. Will also tweak winds to account for the boundary. Other than those two changes, the rest of the forecast looks good. Updated forecast will come after 9 pm to incorporate the expiring heat headlines. && .LONG TERM... (Tomorrow through Wednesday) Issued at 219 PM CDT Wed Jul 31 2024 There is a fair amount of spread in short range guidance regarding the placement of any aforementioned outflow boundary tomorrow afternoon and resultant maximum heat indices. While drier/ slightly cooler air behind the boundary will act to reduce heat indices, dew point pooling just ahead of the boundary may lead to locally enhanced heat indices. This makes for a more complicated and less confident forecast considering implications for heat headlines. That being said, confidence is still high that heat indices will at least warrant an advisory across the entire area, but a warning is less certain across northern counties where the boundary would have the most influence. For now, have kept the northern row of OK counties capped at advisory level with a cluster of warnings around/ SE of the Tulsa metro area and advisories elsewhere. If storms & associated outflow are less aggressive tonight and remain in Kansas, then these northern counties may need to be upgraded to warnings on future forecasts. Additionally, as has been the case the past few days, the river valley in AR may climb very close to warning criteria and this will need to be monitored closely. The front should push through the FA Thursday night and during the day Friday... aided by the passage of an upper level trough across the N Plains into the Great Lakes region. As ridging shifts west Friday into the weekend, flow aloft becomes more north/northwesterly with east winds at the surface. This will allow for a subtle decrease in temperatures over the weekend with highs generally in the mid-upper 90s and heat indices below advisory levels. However, southerly winds and upper level ridging are forecast to return to the region by next week, bringing high temps back into the low 100s with potential for another round of heat concerns. Regarding precipitation chances through the period... there will be a couple opportunities for some rain/ storms through the extended period, yet the overall forecast remains mostly dry. Did introduce low PoPs late Thursday evening into Friday in association with the frontal boundary and an increasing LLJ. This is supported by several CAMs and HREF probs... generally north of I-40. While isolated precip cannot be ruled out Friday afternoon near the boundary in SE OK/ W-Central AR, have opted to keep PoPs below mentionable values for now until better short-range guidance becomes available. Additionally, while chances looks slim for our area as of now, a subtle shortwave embedded in the N/NW flow is projected to move south through W KS & W OK Saturday into Sunday. Currently believe any precip will remain restricted to locations west of the CWA, but it is worth watching. Otherwise, widespread meaningful rainfall remains elusive. && .AVIATION... (00Z TAFS) Issued at 605 PM CDT Wed Jul 31 2024 VFR conditions are expected through the period. Skies will be mostly clear tonight with southerly wind gusts dying down this evening. An outflow boundary could approach far northeast Oklahoma early tomorrow morning with a very low chance (<20%) for some showers or storms to affect KBVO and provide a brief change in wind direction. Otherwise, a weak frontal boundary will slowly drift in NE OK tomorrow afternoon bringing a wind shift to westerly and then northerly across NE OK and NW AR sites with low rain chances (~20%) again near the boundary toward the end of this TAF period. Bowlan && .PRELIMINARY POINT TEMPS/POPS... TUL 81 101 77 100 / 10 10 20 10 FSM 78 101 78 101 / 0 0 0 10 MLC 78 99 77 101 / 0 0 0 10 BVO 75 100 72 99 / 20 10 20 10 FYV 76 98 71 96 / 0 0 20 10 BYV 75 98 72 95 / 0 10 20 10 MKO 78 100 74 100 / 0 0 20 10 MIO 75 98 72 96 / 10 10 20 10 F10 78 101 72 102 / 0 0 10 10 HHW 74 99 75 102 / 0 0 0 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...Heat Advisory until 9 PM CDT this evening for OKZ049-053-068-069- 071>076. Heat Advisory from noon to 9 PM CDT Thursday for OKZ049-053>059- 063>065-068-069-072>076. Excessive Heat Warning until 9 PM CDT this evening for OKZ054>067-070. Excessive Heat Warning from noon to 9 PM CDT Thursday for OKZ060>062-066-067-070-071. AR...Heat Advisory until 9 PM CDT this evening for ARZ001-002-010-011- 019-020-029. Heat Advisory from noon to 9 PM CDT Thursday for ARZ001-002-010- 011-019-020-029. && $$ SHORT TERM...22 LONG TERM....43 AVIATION...04
Area Forecast Discussion
National Weather Service Las Vegas NV
1251 PM PDT Wed Jul 31 2024 .SYNOPSIS...Monsoonal moisture will increase across the area during the second half of the week as a ridge of high pressure builds over the four corners region. This increase in moisture will result in scattered showers and thunderstorms developing on Thursday, which will then continue each day through the weekend. With the ridge building, temperatures will also increase through the weekend and remain hot into early next week. && .SHORT TERM...through Friday. The quiet weather the region has experienced over the past several days will come to an end on Thursday as the combination of a building ridge over the four corners region, along with a disturbance moving across Baja California, will work together to push monsoonal moisture into the area. Thunderstorm activity on Thursday will mainly be confined to Mohave, southern Clark, and San Bernardino counties. However, as the disturbance over the Baja moves north into southern California, shower and thunderstorm activity will spread into Inyo County Thursday night and Friday. WPC has highlighted this area with a marginal risk ERO for Friday. While most areas will not have issues, the increased dynamics associated with the disturbance will result in localized areas of heavy rainfall. Temperatures tomorrow and Friday will depend on the amount of cloud cover and ongoing showers/thunderstorm activity. However, a general increase in readings is expected as the ridge builds over the area. Smoke from the Nixon Fire near Palm Springs, CA, and the Boreal Fire in southern Kern County, CA, has decreased. However, conditions remain favorable, and additional smoke will likely be generated. The latest HRRR shows that any smoke that is generated should remain mainly over San Bernardino, Inyo, Nye, and Esmeralda counties. .LONG TERM...Saturday through Wednesday. By Saturday, the better dynamics shift north into the central Sierra. Scattered showers and thunderstorms will still be possible over the Sierra and in the Owens Valley, but the threat of heavier rainfall has diminished. Sunday through Tuesday look more like our typical monsoon days, with thunderstorms developing over areas of higher terrain before moving into the valleys later in the afternoon and evening. Most of the moisture will remain over Arizona, so the better precipitation chances will remain over Mohave county. With the ridge remaining in place, temperatures will remain hot, with daily maximum readings staying a few degrees above normal. Heat Risk stays mostly in the `Moderate` category with some spotty areas of Major and Extreme Heat Risk in Clark, Mohave, Nye, Inyo, and San Bernardino Counties. However, given the spotty nature of the high impacts, no heat-related products are expected to be issued at this time. && .AVIATION...For Harry Reid... Winds will follow typical diurnal trends today into Thursday, with east to southeast winds developing by early afternoon and persisting into the evening before turning southwest after sunset. Speeds will be light, generally 8kts or less through the TAF period. Smoke from wildfires burning in Kern County, CA, will move across the valley through the evening. No reduction in surface visibilities is expected at the field, but slantwise visibilities may be reduced to less than 7SM at times, with the most significant impacts expected along the Baker and Beatty corridors. Otherwise, an increase in clouds is expected overnight and Thursday morning, but bases should remain 12kft AGL or higher. For the rest of southern Nevada, northwest Arizona and southeast California...Light, diurnally driven winds will continue across most of the region today and tonight. The exception will be in the central and northern Owens Valley, including KBIH, where south to southeast winds gusting to 20 knots can be expected this afternoon and early evening before decreasing overnight. Smoke from wildfires burning in Kern County, CA, will continue to affect Inyo County, with a reduction in slantwise visibilities being the main impact. Convection in southern Arizona may generate outflow winds and mid and high-level clouds that could move into the lower Colorado River Valley (KEED and KIFP) overnight. Otherwise, no operationally significant cloud cover is expected through the TAF period.&& .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM...Planz LONG TERM...Pierce/Planz AVIATION...Planz For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter