Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/14/21

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
555 PM MDT Mon Sep 13 2021 .AVIATION... 00Z TAF CYCLE Broad high pressure remains over southern NM/AZ with very dry west and northwest flow aloft over NM through Tuesday. A backdoor cold front will result in a wind shift and isold to wdly sct showers and thunderstorms to the northeast quarter Tuesday afternoon. Elsewhere, VFR will be the rule with continued haze mainly south of I-40 and east of I-25. 33 && .PREV DISCUSSION...254 PM MDT Mon Sep 13 2021... .SYNOPSIS... Hot, dry and hazy conditions persist across the region under the influence of strong high pressure. A weak backdoor front will bring chances for storms to northeast and east central New Mexico late Tuesday, some of which may become strong to severe. Isolated storms are possible Wednesday, mainly along the central mountain chain. Hot and dry conditions will persist across most of the area Thursday through Saturday, with above normal temperatures. Breezy conditions will develop late Sunday into Monday ahead of the first notable cold front of the season, forecast to move across our area early next week. && .DISCUSSION... SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)... Another hot, hazy and dry day is underway as high pressure aloft continues to reside over the American Southwest. The high has stretched along a west-east axis, an orientation that has kept mid level moisture intrusions cut off from NM. Any cumulus over northern and western NM have generally stayed flat with little vertical development thus far this afternoon, and temperatures are on their way to near-record or even record values. The remnants of this afternoons cumulus will slowly dwindle overnight, and latest HRRR runs suggest near-surface and vertically integrated smoke concentrations should continue decreasing overnight. A shortwave trough moving through the northern Great Plains today will slide over the Great Lakes area early on Tuesday, and this will send a surface cold front southward down the plains. This front is modeled to make a entrance into northern Colfax and northern Union counties by Tuesday afternoon, introducing increased surface convergence along the boundary while also advecting increased low level moisture and interjecting deep layer directional shear in the lower half of the troposphere. Scattered thunderstorms are expected along and east of the Sangre de Cristos as the front arrives late Tuesday afternoon and into the evening with a few strong to perhaps briefly severe cells. Aside from a modest cooldown in the far northeast, the above average and near-record warmth will continue Tuesday. Most areas outside of the northeast will remain dry, but a stray anemic cell or two cannot be ruled out over the southwestern or south central high terrain. The front will then advance farther south and west Tuesday night, eventually inducing gusty canyon winds in centrally favored locales. LONG TERM...(WEDNESDAY THROUGH MONDAY)... Breezy east canyon/gap winds will persist into Wednesday morning from the middle RGV south to the upper Tularosa valley. The front will introduce sufficient moisture for late day build-ups west of the central mountain chain Wednesday afternoon, but little-to-no measurable rainfall is expected as this round of convection will favor strong/erratic wind gusts. The southern Sangre De Cristos and the south central mountains could see some deeper convection late Wednesday with wetting rainfall due to a deeper moist layer along/east of the central mountain chain. The upper high will pump back up over our area Thursday into Friday, keeping well above normal temperatures going with near-record or new daily record highs possible. Isolated thunderstorms are possible late Thursday from the south central mountains east into Chaves Co., but our entire area should be devoid of storms on Friday due to a lack of moisture. The 12Z model solutions are at odds with the exact timing of an upper level trough and associated cold front moving southeast out of the Pacific NW late in the weekend and into early next week, but at least are in agreement that we`ll be getting our first notable cold front of the season at some point Mon/Tue. Breezy conditions will likely develop Sunday as the westerlies increase across the region in advance of the approaching upper level trough, with windy conditions likely to accompany the fropa. Above to well above normal temperatures will persist until we get some relief from the cold front. 52/11 && .FIRE WEATHER... Fuel moisture will continue to dwindle over the next several days as above normal temperatures and mostly dry conditions persist. Afternoon humidity will commonly drop to or below a 10 to 20 percent range in the days ahead, and many northern and central zones will struggle to recover to 35 to 50 percent in the overnight and early morning periods. The northeastern plains and adjacent highlands will receive scattered footprints of wetting rainfall on Tuesday, but the cold front responsible for the storms will provide only short-lived relief from the hot temperatures. The front will also be responsible for the primary wind concerns (other than thunderstorm outflows) as it is expected to surge through central gaps and canyons with accelerated gusts Tuesday night and Wednesday morning. 52 && .ABQ WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Gaylord MI
1155 PM EDT Mon Sep 13 2021 .UPDATE... Issued at 942 PM EDT Mon Sep 13 2021 Low pressure is lifting across the central plains. Surface front is easing northward toward the IL/WI border, though is still largely stalled along the southern lower MI border. Return flow continues to increase into the western lakes, and this is supporting a skinny band of convection north of the front. This extends from GRB to MBL to far southern Lk Huron. This is also along the MuCape gradient per SPC mesoanalysis, with MuCape values of 1-1.5k j/kg over most of the GRR/DTX forecast areas. Have accelerated the onset of pops a bit in the far sw (MBL/Frankfort/ CAD). Anticipate the existing band of showers to lift northward with time, initially quite slowly, but more quickly overnight. Expect showers/t-storms to also become more common along this band, as theta-e advection increases. Very late overnight, the more widespread area of precip over MN and environs will push into nw sections of this forecast area. Would not preclude a near-svr cell within the band(s) of convection as they develop and lift northward tonight (as we saw earlier in the evening over the Thumb). However, the possible development of MCS(s) ahead of the advancing low in se MN/central WI poses the main svr threat (which is not large). Some HRRR runs do bring an MCS into w central lower MI after 6 am. Have lowered min temps a smidge in many areas, given present opportunity for cooling before clouds thicken and the pressure gradient tightens further. && .NEAR TERM...(Through Tonight) Issued at 355 PM EDT Mon Sep 13 2021 High impact weather potential: Marginal risk for severe thunderstorms tonight. Pattern synopsis/forecast: Fairly zonal upper-level flow across the Great Lakes this afternoon will quickly be shunted eastward as mid- upper level ridging encroaches on the region from the west. Our well- advertised nearly stationary boundary remains downstate attm, but will begin its northward shift this evening into the overnight hours as a warm front, in response to strengthening low pressure lifting northeast out of the central plains into the upper Mississippi Valley. Increasing moisture/forcing/instability through tonight will yield increasing scattered shower/storm chances. Primary forecast concerns/challenges: PoPs and severe chances through tonight. Little in the way of sensible weather ongoing this afternoon as the focus remains downstate tied closer to the aforementioned stationary boundary. As was alluded to, this boundary begins its northward progression as a warm front this evening, and especially tonight. Increasing south-southeasterly return flow/warm air advection will aid in increasing deep layer moisture evident by PWs climbing to more than 1.5" by sunrise Tuesday. Better forcing will accompany this boundary, ultimately yielding increasing shower and storm chances from southwest (as early as mid-evening) to northeast (by late tonight). Not incredibly impressed by instability parameters during this overnight period, but none the less, do expect at least some elevated instability (~500-1,000 J/kg) to advect into the area. Combined with increasing wind fields (bulk shear values increasing to greater than 50 kts), still can`t rule out an isolated strong to severe storm, especially across the southwestern half of the forecast area. By no means expecting widespread organized severe weather through tonight as the gut feeling is shower/storm development will largely remain isolated-scattered in nature. Worth watching very late tonight toward sunrise Tuesday for the potential for a MCS to be approaching parts of northern Michigan, especially across the tip of the mitt and eastern upper given the aforementioned unidirectional shear already in place by this point and better dynamics across far northern areas. Overnight lows a bit warmer than last night...generally ranging from && .SHORT TERM...(Tuesday through Thursday) Issued at 355 PM EDT Mon Sep 13 2021 High Impact Weather Potential: Severe thunderstorms Tuesday. Pattern Synopsis/Forecast: Low amplitude jet stream pattern exists across North America and across the northern Pacific though jet level winds speeds much faster across the Pacific. Short wave trough was crossing the Canadian Prairies/northern Plains...with an upper low over southwest Alaska. Zonal flow across the Great Lakes region ahead of upstream troughing. At the surface...stationary front has settled along the Michigan/Indiana/Ohio border stretching back into northern Illinois/Iowa/Nebraska. 1022mb surface high over northwest Ontario ridging south into the Great Lakes on the cool side of the boundary. Definite moisture contrast along the boundary with 1.50 inch precipitable water values pooled along this front with things drying out quick as you go north (0.71 inch PWAT off 12z APX sounding). Lead piece of short wave energy coming out of the western Dakotas this afternoon will spin up a weak surface low that will track northeast across Wisconsin/Upper Michigan Tuesday. Stationary front to the south will lift northward as a warm front Tuesday across Lower Michigan...with a cold/occluded front pushing east across the Lower Peninsula Tuesday afternoon/evening. This will be followed by a second short wave trough Wednesday but very little surface reflection of that across the Great Lakes with weak high pressure crossing the region. This high moves into New England Thursday with rising heights as upper level flow backs a bit with a stronger short wave trough and associated cold front front reaching the upper Midwest by Thursday evening. Primary Forecast Concerns: Thunderstorms on Tuesday will be the main forecast focus...and it is likely that convection will already be ongoing as part of an overnight MCS rolls into northern Michigan along a 30-40kt southwesterly low level jet. Strong mostly unidirectional shear in place already to start the day (45 to 65kts 0-6km bulk shear) at the very least the potential for severe storms will be there to start the day. Mostly unidirectional vertical wind profiles will support bowing segments...whether we can see stronger wind gusts reach the ground is another issue that will depend on boundary layer stability. But severe hail is also a threat early on...and with the surface warm front lurking across northern Lower could see some funkiness if storms can interact with that. Cold/occluded front then crosses Lower Michigan during the afternoon...with perhaps a second round of convection if things can destabilize again and will mention potential for two rounds of strong storms in the afternoon Hazardous Weather Outlook. Locally heavy downpours a good bet as well given precipitable water values in the 1.50 to 1.75 inch range...though think convection will be progressive enough to keep total rainfall amounts from getting out of hand. Looking like a gusty day tomorrow especially assuming some mixing during the day with southwesterly low level jet crossing the forecast area. Non-convective wind gusts to 35mph appear to be a good bet...with winds remaining gusty post-cold front into the evening from the west/northwest before subsiding overnight as pressure gradient flattens out. Beyond Tuesday however the midweek period is looking dry...with seasonable temperatures Wednesday and warmer on Thursday. .LONG TERM...(Thursday night through Monday) Issued at 355 PM EDT Mon Sep 13 2021 High Impact Weather Potential: Minimal as of now. Pattern Forecast: Short wave trough moving into central Canada and the northern Plains Thursday will clip the upper Lakes with some height falls Friday...but the majority of the dynamics as of now are getting pulled well north into Ontario. Associated cold it parallels the upper level flow...may also slow/stall in the vicinity of Wisconsin/Michigan for Friday/Saturday. Rising heights will then be the predominant feature to start next week as overall pattern becomes more amplified with troughing in the west and ridging in the east. Uncertainty with the position/strength of the western trough which will ultimately have downstream impacts on strength of the ridge over the eastern third of North America and position of baroclinic zone which will set up across the nation`s midsection. Forecast Trends: Definitely warm especially this weekend with highs in the 80s which could threaten a few records on Sunday. Rain chances increase Friday and may linger into Saturday depending upon && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 1154 PM EDT Mon Sep 13 2021 SHRA/TSRA chances increasing tonight and Tuesday. IFR at times Tue morning PLN/APN. A front along the southern lower MI border will return northward, with low pressure eventually lifting into the northern Great Lakes on Tuesday. Sct SHRA/TSRA are expanding into nw lower MI, and these will lift across the area tonight. Brief cig/vsby restrictions possible, but at least for tonight VFR will be more common. Toward morning, cigs should lower toward IFR conditions at MBL/APN, before improving later in the day. Cold front passage from w to e Tuesday afternoon will end the precip threat and improve cigs. Increasing se winds tonight will veer s and sw Tuesday. LLWS MBL/TVC late overnight. && .MARINE... Issued at 355 PM EDT Mon Sep 13 2021 Winds and waves will strengthen to SCA criteria late tonight thru Tuesday evening ahead of strong low pressure lifting northeast out of the central plains into Lake Superior. Scattered showers and storms are also possible in associated with this system as early as this evening, but more so late tonight into Tuesday with a low chance of a few severe storms. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY from 5 AM Tuesday to midnight EDT Tuesday night for LHZ345>348. SMALL CRAFT ADVISORY from noon Tuesday to midnight EDT Tuesday night for LHZ349. LM...SMALL CRAFT ADVISORY from 5 AM Tuesday to midnight EDT Tuesday night for LMZ323-341-342-344>346. LS...SMALL CRAFT ADVISORY from 5 AM Tuesday to midnight EDT Tuesday night for LSZ321-322. && $$ UPDATE...JZ NEAR TERM...MG SHORT TERM...JPB LONG TERM...JPB AVIATION...JZ MARINE...MG
Area Forecast Discussion
National Weather Service La Crosse WI
1057 PM CDT Mon Sep 13 2021 .SHORT TERM...(Tonight through Tuesday) Issued at 250 PM CDT Mon Sep 13 2021 Main forecast concern rests on the strong/severe storm question tonight. Where various elements lay up/track will have a large bearing on whether severe weather is realized, and what kind. SETUP: Warm front currently lays out west to east across central IA and northern IL with a band of low clouds just north of it. Gradual progression northward today, with general consensus of making the IA/MN border by 00z. Warm front should get a push northeast this evening as upper level shortwave trough pushes into MN with strengthening sfc low lifting through MN into northern WI overnight. Low level jet/moisture transport kicks in before 00z, focusing northward across the sfc front in NE IA/SE MN, also making steady progress into northern WI as the evening wears on. In addition, 900-800 layer of frontogenetic lift helping spark a west-east narrow band of convection north of the sfc boundary, progged to advance to I-94 by 00z. INSTABILITY/SHEAR: steady, but limited advancement of instability northward of the sfc front. RAP MUCAPES roughly 500-1250 J/kg, but rather skinny profiles per RAP bufkit soundings (not great for updrafts). 0-1 km shear pretty stout along front and to the south, but CIN quickly increases this evening around and northward of the front - limiting/inhibiting surface based convection (and tapping into that shear and/or near sfc instability). 1-3 km shear roughly 20-25kts and upwards of 35 kts of 1-6km. All mostly due east. So some storm organization possible. SEVERE? Elements not syncing up well for severe storms. Surface inhibition, timing, location of front, and CAPE profiles all working against widespread severe storms. Certainly some strong, and potentially a few severe - so need to keep a close eye on the radar through the night. Main threats are hail and wind, although wind will have to compete with the near sfc stability. With good turning and strong shear in the 0-1km layer, cannot rule out an isolated tornado around the warm front. Short window/location for that - looking like the I-90 corridor at this time, .LONG TERM...(Wednesday through Monday) Issued at 250 PM CDT Mon Sep 13 2021 An upper-level ridge builds across the region on Wednesday, providing sunny and seasonable weather. Calm winds from this high pressure will likely result in valley fog development Wednesday morning. An upstream trough axis associated with lower heights in Canada digs eastward across the northern plains on Thursday. Associated surface boundaries begin to interact with our forecast area late Thursday into Friday. Severe threat continues to look minimal with the primary MLCAPE & shear axes focused along the cold front north and west of our forecast area. Due to the ostracized nature of the primary upper-level forcing, models hint at the surface cold frontal boundary becoming stranded for the weekend into early next week leaving our forecast area in the warm sector. The previous few EPS runs have been alluding to high temperatures in the mid to high 80s for Sunday and Monday as well as the potential for unseasonably warm low temperatures. It will be important to continue monitoring for unseasonably warm temperatures. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 1057 PM CDT Mon Sep 13 2021 The initial convection this evening has primarily stayed to the north of both sites other than a few sprinkles. Watching a second line farther west ahead of a developing area of low pressure and cold front. This activity is expected to push through overnight with the bulk once again going north of both sites. However, there should be a broken line along the cold front that could bring a couple hours of showers and maybe a storm to the area. IFR/MVFR ceilings already in place behind the area of low pressure and these will likely spread over both sites late tonight or early Tuesday morning as the winds swing around to the west with the passage of the front. Ceilings should go up to MVFR by late morning with these clouds then scattering out around sunset. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...Rieck LONG TERM....JAR AVIATION...04
Area Forecast Discussion
National Weather Service Cheyenne WY
531 PM MDT Mon Sep 13 2021 .SHORT TERM...(This evening through Tuesday) Issued at 225 PM MDT Mon Sep 13 2021 Showers and thunderstorms associated with the vort max passing over the region this morning have moved off to the east into north- central Nebraska this afternoon. A few collapsing showers produced wind gusts around 55 MPH near and west of Cheyenne right around 18z. Skies have mostly cleared across SE WY and the NE Panhandle, but scattered cumulus development has begun across Carbon Co and the North Laramie Range. Additional showers and thunderstorms are possible late this afternoon into tonight. Main focus for late this afternoon will be along the CO/WY border where additional shortwave energy will pass over the area with marginal instability around 500 J/kg MLCAPE and 40 kts of 0-6 km shear. Main hazards will be strong outflow winds with dry downbursts as LCLs look to sit well above the freezing level, especially west of I-25. Storms currently located north of Vernal, UT could continue to approach southwest Carbon Co in the next few hours around 23z so will need to keep watch. Hi-Res guidance continues to hint at storms mainly along the I-80 corridor from Laramie to Sidney after 6 PM MDT to around midnight. Lastly, a secondary cold front north of the CWA will continue to slide south providing the potential for showers and thunderstorms overnight into early Tuesday morning along the Pine Ridge area from Niobrara Co over to Chadron. NAMNest is much farther south compared to the HRRR with the location of these storms (~50 mi) so will all depend on placement of best forcing after midnight. Clouds will continue to linger around the NE Panhandle through much of the morning while most areas east of the Laramie Range will see cooler temperatures (5- 10F) compared to today. .LONG TERM...(Tuesday night through Monday) Issued at 225 PM MDT Mon Sep 13 2021 Key Messages: 1) Well-above normal temperatures Wednesday through Sunday with near- critical to critical fire weather conditions for portions of the area each day. 2) A colder period looks to be possible early next week with increasing precipitation chances but details on pattern and sensible weather remain for just how cold and what type of precipitation could be possible, especially for higher terrain locations. Weather Details: Global model and ensemble consensus indicate a broad flat H5 ridge to zonal flow across the Central Rockies to the SW CONUS in place. H7 Temperatures will be above normal in the +13C to +16C range over WY/NE. This will lead to above normal to almost record temperatures mid to late week and towards the weekend. Ridge slowly breaks down across the SW CONUS and SW flow develops across central Rockies by the weekend with deeper Pacific NW trouging. Embedded shortwave impulses are likely but overall precipitation chances will be minimal with the dry air mass and weak forcing. Elevated to critical fire weather conditions will be likely across the region with red flag warnings probable. A larger pattern change is advertised for Monday and Tuesday of next week with deterministic GFS showing a deeper trough across the Central Rockies with a solid cold tap from Canada with H7 temperatures falling below 0C to -3C. Latest deterministic ECMWF is a little slower but coming on board with a deeper trough similar to the GFS. Ensemble guidance in long term also hints at a cooler trend with increasing preci[itation chances with the approach of the trough signal. Too far out to go into sensible weather details but snow levels looks to drop near 8/9KFT and while low at this time, there is a hint of wintry possibilities for at least higher terrain locations early next week. Stay tuned through the week as model and ensemble solutions narrow in early next week. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 523 PM MDT Mon Sep 13 2021 Southeast WY (KCYS, KLAR, KRWL): Showers and thunderstorms possible this evening and into the early overnight hours in southeast Wyoming. Winds will diminish and gusts should subside as the evening progresses. Expect skies to clear overnight in southeast Wyoming as this system moves out of the region. Nebraska Panhandle (KCDR, KBFF, KAIA, KSNY): Isolated showers and thunderstorms are possible at KSNY this evening likely after 3Z. Gusty and erratic winds are possible with these. Another line of showers are expected to move through in the early morning hours from the northwest, moving south/southeast. Ceilings and visibilities may temporarily be lowered to MVFR or even IFR levels. More confidence with these impacts will come with the 6Z TAFs. After those showers move through, skies should begin clearing by mid-afternoon. && .FIRE WEATHER... Issued at 225 PM MDT Mon Sep 13 2021 Scattered showers and thunderstorms are possible this afternoon and overnight with a few storms lingering around the northern Nebraska Panhandle through Tuesday morning. Afterwards, elevated to near critical fire weather conditions are possible the rest of the week into this weekend with drier weather expected. Afternoon RHs will drop to into the teens for most areas Wed-Sun with near to above normal temperatures. Gusty winds along and west of the Laramie Range are expected during this period so may need to monitor for potential issuance of RFW products in future updates. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...MB LONG TERM...JSA AVIATION...LK/SF FIRE WEATHER...MB
Area Forecast Discussion
National Weather Service Des Moines IA
643 PM CDT Mon Sep 13 2021 ...Updated 00z Aviation... .DISCUSSION.../Tonight through Monday/ Issued at 241 PM CDT Mon Sep 13 2021 Forecast Highlights: -- A few strong to severe storms northern Iowa tonight - main risk is hail, but conditional, brief tornado cannot be ruled out -- Perhaps a few strong storms far southern Iowa later Tuesday afternoon -- Pleasant Wednesday with seasonable temperatures/humidity -- Return to warm, humid conditions late this week into this weekend with a few opportunities for storms over northern Iowa Details: Early afternoon surface analysis shows the warm front has lifted to around Highway 20 and expect it to continue to lift to near the Minnesota border by 0z Tuesday. Main shortwave trough is moving east of the central Rockies and it is expected that as surface low pressure traverses the front into Wisconsin this evening, the low will be deepening. The risk for storms will likely be delayed until better forcing arrives with the shortwave and surface low toward and likely after 0z over north central Iowa. Upstream 12z RAOBs from ABR/OAX/UNR/LBF show a warm environmental mixed layer centered around 850mb. This warm EML is above northern Iowa and early morning and midday initialized forecast soundings from the NAM, GFS, HRRR, and RAP at MCW and EST show that this will persist over northern Iowa likely limiting any surface based convection. Shortly after sunset, model soundings all indicate the EML remains and is enhanced/aided in strength as the boundary layer decouples from the surface. With increasing inhibition/CIN through this evening, storms over northern Iowa will at least not fully be rooted at the surface with parcels being accelerated from an elevated surface. This should limit the tornado potential, but more on that in a moment. Elevated rotating storms will be possible with deep layer shear over 40 if not closer to 50 knots, though the effective inflow layer shear will be closer to 30 knots. While the main threat will be large hail and perhaps gusty winds if the winds can make it to the surface, a conditional tornado risk could briefly evolve this evening. With linear segments expected to move across northern Iowa and possibly favorable 30+ knot 0-3km shear orientation to the line, if a storm can become or stay surface based, then a brief tornado is possible. Latest runs of the 12z HREF members show only the HRRR with updraft helicity tracks over far northern Iowa and given the expected location of the warm front this evening, risk for any tornadoes would be over our most far northern counties into southern Minnesota. So, while the current forecast thinking is that large hail will be the main concern, cannot rule out a brief tornado and have coordinated with SPC to maintain the 2% tornado at the 1630z update near/at the border. These storms should be largely east of the forecast area around or shortly after midnight. Another shortwave trough moving east of the Cascade Mountains this afternoon will be the impetus for additional storms across the region later Tuesday. Scattered storms will develop along and perhaps behind the front over far southern into far eastern Iowa Tuesday afternoon and evening. For our forecast area, the 9z RAP/12z NAM both have most of the storms developing near the Missouri border if not over northern Missouri. Most of the latest convective allowing model guidance agree that the more robust convection will be close to exiting the forecast area with perhaps some elevated showers or storms post frontal over southern Iowa. Thus, any window for severe storms will be short-lived as the front moves into Missouri. As this shortwave trough moves eastward, surface high pressure will move over the region Tuesday night through Wednesday. This will provide a comfortable September day with low humidity and highs a few degrees below normal ranging from the middle 70s over northern Iowa to near 80 degrees over southern Iowa on Wednesday. The high pressure exits into the Northeastern US Wednesday afternoon with return flow from the south and later southwest allowing for increasing heights/temperatures and moisture. This flow change will also be aided by a longwave trough that will move primarily across Canada and the far northern states. This may allow for a few opportunities for storms Thursday night through early Saturday as temperatures rise well into the 80s over central and southern Iowa with dewpoints into the 60s statewide. 00z WPC cluster analysis of the GFS, CMC, and ECMWF and their ensembles show the most likely place for any QPF over northern Iowa and then northward into the eastern Dakotas, Minnesota, and Wisconsin. Thus, PoPs from initial guidance are highest in our forecast area over northern Iowa with southern Iowa likley missing out on much if not all of the rainfall. Instability and shear are favorable during this period so will need to monitor trends for any severe potential late this week. The next chance for rain and storms would be late in the weekend into early next week as a more amplified longwave trough pushes equatorward and through the central Rockies. Given the robustness of the trough and amplified flow, this should yield widespread rainfall and possible stronger storms early next week as the front moves through the region. && .AVIATION.../For the 00Z TAFS through 00Z Tuesday evening/ Issued at 636 PM CDT Mon Sep 13 2021 There is a warm front across north-central Iowa that will be the focus for rain shower and thunderstorm development later this evening and maybe overnight. This will present at least vicinity impacts to FOD and MCW, and maybe ALO. Conditions across northern and central Iowa will drop to low-end MVFR, and there may be an hour or two of IFR ceilings across northern Iowa. By late Tuesday afternoon, skies may remain overcast but will begin to improve to MVFR. There will also be low-level wind shear concerns this evening as the low-level jet strengthens. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...Ansorge AVIATION...Krull
Area Forecast Discussion
National Weather Service Quad Cities IA IL
919 PM CDT Mon Sep 13 2021 .UPDATE... Issued at 901 PM CDT Mon Sep 13 2021 Have updated forecast to bump up storm chances tonight mainly near and north of Hwy 30 corridor. Storms have developed over the past 60 mins between Sioux City and Omaha ahead of a cold front, and approaching shortwave with additional lift from left exit region of an upper level jet streak. Latest guidance is showing more favorable forcing between the jet streak and wave overnight especially across our northern counties, and last few runs of HRRR appear to be latching onto this and baring out an uptick in convection after 06z-07z N/NW counties. Small hail, gusty winds and heavy downpours possible with a low risk for an isolated severe storm. && .SYNOPSIS... Issued at 242 PM CDT Mon Sep 13 2021 Another beautiful day out there for much of the forecast area, with some high clouds moving through and temperatures in the mid 80s. Dewpoints are a little higher today, making it a little bit stuffy, but far from oppressive. Areas in our northern tier of counties continue to see some scattered showers moving through. Winds are generally light and from the south, as the cold front that stalled over our area overnight developed warm frontal characteristics and has since pushed to the north. On the northern end of this boundary, showers and thunderstorms continue, but mostly sunny and dry conditions will be seen south of it. Through the remainder of the evening, most of the area should stay dry, with some clouds filtering through the area. && .SHORT TERM...(This Evening through Tuesday) ISSUED AT 242 PM CDT Mon Sep 13 2021 Tonight, warm front has since lifted to our north and we sit within the warm sector of the surface low out west. The weak wave in our west will slowly makes its approach, with a cold front progged to move through early tomorrow. The warm front in our north will set the stage for another night of potential showers and storms north of Highway 20. Most of the activity should stay to the north of our forecast area, but a stray shower or storm cannot be ruled out once the strengthening LLJ kicks in after dark. With strong warm advection taking place over the area and clouds moving in ahead of an approaching cold front, temperatures will stick in the upper 60s and low 70s in the area. Breezy southerly winds are expected to continue through the night, as short term guidance indicates a strengthening pressure gradient ahead of the front. This can lead to gusts upwards to 20-25 mph at times. This will generally be late in the night and closer to tomorrow morning. Tomorrow, we will see a bit of a change. The cold front is progged to start its push through our area mid-morning and be out by mid afternoon. Given the timing of frontal passage, not much moisture return, and relatively weak forcing, most of the area is likely to stay dry tomorrow. Thus, I have cut back on PoPs for much of tomorrow, generally keeping most in a slight chance, with the best chances in our far southeast. The severe risk has also been pushed out of our area, leaving us in a general thunderstorm outlook. Some of the short term guidance hints at some showers developing mid day, but this will generally be seen in our southern half of our forecast area, where the moisture return is greatest and we can get some daytime heating. Otherwise, there will be scattered clouds as the front pushes through and some gusty winds out ahead of it. While a slight temperature change will be felt tomorrow, the biggest change will be felt tomorrow night and the following day. .LONG TERM...(Tuesday Night through Monday) ISSUED AT 242 PM CDT Mon Sep 13 2021 Key Messages: 1. Confidence increasing on cold front being well south of the area Tuesday evening and dry forecast 2. Increasing heat and humidity the rest of the period. 3. Low end pops to end the week Discussion: Zonal changing to SW flow is expected through the long term period as the main message is hot and humid to continue. To start the period a cold front will bring in a short reprieve to the heat and humidity Wednesday into Thursday, then the heat returns. A cold front is still forecast to glance the area later in the week and continues to have low chc/schc pops associated with it. When it comes down to it we will likely see dry conditions through most of the long term period. With the exception of the FV3 models, it appears that all of the cams have us dry after 00z Wednesday as the front is well south of the area. This is looking even more likely as festering convection today has only resulted in the warm front mixing 60 miles north from this morning. The FV3 brings an east to west moving MCS system along the sfc cold front. Overspreading north of this boundary leads to some pops across our area. Since only the FV3 model has this, I don`t think it is likely. It will be one of those mental models where if you see it occurring out west, then may need to increase pops after 00z Wednesday. This system appears to be tied to the upper wave and could lead to organized convection/updrafts and strong storms if it happens. This would represent a low end chance forecast. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening) ISSUED AT 708 PM CDT Mon Sep 13 2021 A cold front is slated to push through the terminals Tuesday AM 12z-17z. Ahead of the front tonight expect S/SW winds occasionally gusty, especially prior to sunset then again by late evening into the overnight with a strengthening low level jet. The stronger winds aloft of around 40-45+ kts descending to 1500-2500 ft agl warrants a continuation of LLWS at all terminals roughly 06z-12z. Can`t rule a few showers or storms ahead of the front, especially at KCID and KDBQ with a warm advection wing attendant to low pressure passing north of the region. However, chances look to be lower than PROB30 at this time and therefore no mention was included. Winds will veer to W/NW with the frontal passage Tuesday AM and gust for a period to around 20-25+ kts, especially at KCID and KDBQ before generally settling into 10-15 kt range. MVFR to local IFR ceilings are likely to develop behind the front especially upstream of the terminals. There is the potential for a period of MVFR ceilings at KDBQ and KCID by mid AM through midday as hinted by some guidance, but there`s a lot of guidance keeping these lower clouds just north of the terminals. Also, frontal timing during the daytime lends to potential for some mix out of the moisture. As a result, confidence is not high enough to mention MVFR ceilings yet at KCID and KDBQ. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...McClure SYNOPSIS...Gunkel SHORT TERM...Gunkel LONG TERM...Gibbs AVIATION...McClure
Area Forecast Discussion
National Weather Service Goodland KS
945 PM MDT Mon Sep 13 2021 .SHORT TERM...(This evening through Wednesday) Issued at 244 PM MDT Mon Sep 13 2021 This afternoon, weak shortwaves are traveling along zonal flow across the High Plains. These shortwaves are helping to push a weak cold front east across the area while a lee trough sits along the Rockies. As of 2 PM MT, the front is pushing across NW Kansas, causing some breezy conditions with winds gusting up to 35 mph along/ahead of the front. Today`s environment is more of a high shear-low CAPE setup. CAPE values are less than 1000 J/kg over eastern CO where this afternoon and evening`s storms are expected to develop over the next several hours. CAPE does increase as you move east into NW KS and S NE this evening. Shear isn`t much of an issue with 20-40 kts across the area for locations west of US-83. Model soundings and other convective parameters are favoring more of a strong to damaging wind hazard with any convection that develops; however, given a decent amount of moisture in the mid-levels large hail can`t be ruled out during the early evening hours. The storms are expected to move east through the overnight hours, with a few more showers/storms possibly developing along and east of US-83 after sunrise. It`s possible these storms remain elevated as they ride along the back of today`s front. A moist airmass is expected to remain over the area on Tuesday while another cold front moves south from the Northern Plains. As the front moves down, the lee trough will push off the rockies during the afternoon aiding with the development of storms during the afternoon hours. Despite being cooler, the environment seems more favorable for storms tomorrow afternoon. The CAMs are still disagreeing on how storms move across the area, with the HRRR being the most aggressive with a small line of storms developing off the Front Range and moving across the area south of I-70. The 3km NAM keeps us capped, despite an otherwise favorable environment. Damaging winds and hail are also a threat tomorrow afternoon. If these storms develop, they are expected to move out of the Tri-State area by midnight. Dry conditions will return on Wednesday as a surface high pushes south behind the front and the ridge builds over the Western CONUS. .LONG TERM...(Thursday through Monday) Issued at 132 PM MDT Mon Sep 13 2021 The long term period looks to be warm and dry for the time being. Upper ridging builds into the southern and central Plains on Thursday from the Desert Southwest, leading to southwest flow aloft by Friday. Meanwhile, an upper trough comes ashore over the Pacific Northwest. This disturbance helps to amplify the ridge and gradually shift it eastward through the weekend. On Monday, southwest flow strengthens above the region between the incoming trough and departing ridge. Fire weather conditions will be the main concern during this timeframe. While it is still a bit early to get too specific, elevated to near critical conditions are possible each day of the period. The area of most concern looks to be eastern Colorado on Thursday, Friday, and perhaps Monday. However, the two days that stand out the most are Saturday and Sunday, when relative humidities fall as low as 10 to 20 percent for locations along and west of Highway 25. Will continue to monitor in the coming days as winds appear to be marginal at this time. High temperatures range in the upper 80s to mid 90s for Thursday through Sunday. Low temperatures are mainly in the low 50s to mid 60s through the period. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 945 PM MDT Mon Sep 13 2021 For the 06Z TAF time period scattered showers and thunderstorm potential exists for KGLD through 09Z per recent runs of CAMS however seems to have overdone reflectivity thus far this evening. Shower and storm potential for KMCK still appears to be on track with convection entering the radius of the terminal around 06Z. Guidance indicates the potential for the threat of storms through sunrise with additional chances lingering through the majority of the day Tuesday. I opted to mention VCSH through at least mid afternoon as numerous runs of CAMS have shown this solution. Tuesday afternoon KGLD may see storms, perhaps severe with large hail and damaging winds the main threat during the late afternoon. This threat for KMCK looks to remain to the SW of the terminal so opted not to mention the threat in the TAFS at this time. Winds during the afternoon will gradually shift from from northerly to more ENE during the afternoon and persisting through the end of the TAF period. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...KMK LONG TERM...JBH AVIATION...TT
Area Forecast Discussion
National Weather Service Green Bay WI
547 PM CDT Mon Sep 13 2021 Updated aviation portion for 00Z TAF issuance .SHORT TERM...Tonight and Tuesday Issued at 159 PM CDT Mon Sep 13 2021 The latest RAP analysis and satellite/radar imagery show a stalled front positioned east to west across northern Illinois. Areas of showers and storms have been developing north of the boundary at times today. Farther north, southeast winds have contributed to a field of broken convective clouds over northeast WI early this afternoon. These clouds are relatively shallow and should mix out later this afternoon. The next storm system is tracking east across the northern Plains with widespread showers and storms. As this system moves across the region tonight, details surrounding storm chances and potential for severe weather is the focus of this forecast. Tonight...Shortwave energy will be moving across the northern Mississippi Valley this evening and across northern WI overnight. Ahead of the wave, a developing surface low and strengthening south to southwest flow will push the stalled front northward across Wisconsin this evening. Models, in general, are unenthusiastic about thunderstorm development along this front as it shifts north. But with elevated instability up to 1000 j/kg and thunderstorm activity ongoing along it for much of the morning, maintained chances in the forecast. The main swath of showers/storms will sweep across the area after midnight. Strong dynamics thanks to a 40-50 kt low level jet will advect elevated instability of 1000-1500 j/kg across central to northeast WI ahead of the surface low. This could lead to thunderstorm clusters with bowing segments. The severe potential is relatively unclear, however, due to the rather skinny nature of the instability (limits hail potential) and an inversion centered around 900mb which will make it difficult to get downburst winds to the surface. But given the strong dynamics at play, think an isolated severe threat could develop overnight. The heaviest rainfall will likely occur over northern WI where amounts upwards of 1 inch may fall. Lows ranging from the middle 50s to lower 60s. Tuesday...The surface low will exit early in the morning, while the trailing cold front will take until midday to exit the region. Widespread low clouds will likely hang around northern WI for a good chunk of the morning, and could be accompanied by drizzle at times. Partial clearing is expected in the afternoon, with more sunshine across the south than the north. Highs ranging from the mid 60s north to mid 70s south. .LONG TERM...Tuesday Night Through Monday Issued at 159 PM CDT Mon Sep 13 2021 High pressure should bring mainly dry conditions Tuesday night through Wednesday night, along with near normal temperatures. Patchy/areas of fog are possible over north central and central WI late Tuesday night into early Wednesday morning. Precipitation chances for the extended forecast will occur in association with a couple frontal passages. The first front is expected to slowly move through the forecast area Thursday night into Friday, then linger nearby into Saturday morning. This front, combined with jet and short-wave energy, should bring a chance of storms through the period. Another front is progged to approach the region on Monday, and may bring another chance of storms. Precise details are uncertain, given lingering timing issues with the models. Temperatures are expected to trend well above normal for the weekend and early next week. && .AVIATION...for 00Z TAF Issuance Issued at 547 PM CDT Mon Sep 13 2021 A stalled frontal boundary is expected to lift northward tonight as a warm front. A few showers and isolated thunderstorms have develop to the north of this front along with some brief MVFR ceilings. As a stronger low pressure system and associated cold front approach from the west toward midnight, expect widespread showers and thunderstorms to slide through each of the TAF sites from west to east. Made minor adjustments to shower/thunderstorm timing. Otherwise, lower ceilings are anticipated with the increasing low-level moisture and precipitation. MVFR and a few IFR observations have been noted with this system across Minnesota and the Dakotas. Flight conditions will be slow to improve on Tuesday morning, but its possible conditions will improve to VFR by midday or early afternoon Tuesday as the cold front exits the area. && .GRB WATCHES/WARNINGS/ADVISORIES... Beach Hazards Statement from 4 AM CDT Tuesday through Tuesday afternoon for WIZ022-040-050. && $$ SHORT TERM.....MPC LONG TERM......Kieckbusch AVIATION.......Cooley
Area Forecast Discussion
National Weather Service Lincoln IL
913 PM CDT Mon Sep 13 2021 .SYNOPSIS... Issued at 251 PM CDT Mon Sep 13 2021 Hot and humid conditions will continue into the day Tuesday ahead of an approaching cold front. Scattered showers and storms are expected across portions of central Illinois Tuesday afternoon and evening as the front moves across the region. Precipitation chances linger into the day Wednesday, then expect dry conditions through the remainder of the week. && .UPDATE... Issued at 829 PM CDT Mon Sep 13 2021 A surface warm front, which has been hung up along the IL/WI border this evening, will begin to lift northward overnight as a robust mid- level shortwave trough lifts into the Upper- Mississippi Valley. This disturbance will help drive the surface cold front into the Illinois River Valley by Tuesday morning. The boundary layer will become moist and unstable by afternoon as a plume of low 70s surface dewpoints advect into the region and pool ahead of the cold front. MLCAPE values from the RAP exhibit 2000-2500 J/kg by late afternoon. Meanwhile, deep layer shear is progged between 30-40 kts thanks to an upper-level speed max nosing into the region from the west. This all adds up to a period of deep, organized convection tomorrow evening, mainly for locations east of I-55. Damaging wind gusts remain the prime severe weather threat, with hail and tornado looking less likely due to a skinny distribution of CAPE and straight-hodograph. && .SHORT TERM...(This evening through Tuesday) ISSUED AT 251 PM CDT Mon Sep 13 2021 This afternoon, a warm front is draped roughly along the IL/WI state line with thunderstorm chances mainly north of the front this evening and tonight. Across central Illinois, fair weather will persist with a modest south breeze expected through the night helping to prop up temps with overnight lows in the lower to mid 70s. Low pressure over the central Great Plains this afternoon will track across the Great Lakes Tuesday pushing a trailing cold front across central Illinois. Ahead of the front, temperatures warming into the upper 80s with dew points in the lower to mid 70s will contribute to moderate diurnal instability with MLCAPE values increasing to around 1500-2000 J/kg. Meanwhile, deep layer shear will be marginal, but increases through the day to around 25-30 kt in the vicinity of the front during the afternoon. Guidance is in reasonably good agreement that thunderstorms will initialize along the front mid afternoon between the Illinois River Valley and the I-57 corridor. Steep 0-3 km lapse rates of 7.5-8.5 C/km will support efficient mixing down of winds and support a damaging wind threat with stronger storms. If shear is able to be strong enough to support a few supercells, an isolated hail/tornado threat will also be present. .LONG TERM...(Tuesday night through Monday) ISSUED AT 251 PM CDT Mon Sep 13 2021 By Wednesday morning, the slow moving front is expected to stall near or just south of the I-70 corridor. A broad 500mb trough will move across the region Wednesday providing additional chances for showers and storms in the vicinity of the front, mainly south of the I-72 corridor. Guidance suggests modest instability up to around 1000 J/kg MLCAPE will be in place near the front Wednesday afternoon, but deep layer shear will be diminishing through the day as the upper jet pulls away across the Great Lakes. 0-6km shear values of 15-25 kt during the afternoon hours will be a limiting factor in terms of any organized severe threat Wednesday. After a brief moderation of temperatures Wednesday with passage of the cold front, upper ridge builds back across the region while the h85 thermal ridge builds just to our west and northwest through the weekend. Veering low level flow and building heights will push afternoon highs back into the mid to upper 80s Friday though Monday. While couldn`t completely rule out some isolated diurnal thunderstorm development, most of this time frame will be dry. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 611 PM CDT Mon Sep 13 2021 VFR conditions will continue through much of this TAF period ahead of an incoming cold front that will impact the regional terminals Tuesday evening. Breezy south to southwest winds will gradually veer westerly beyond 21z/4pm Tuesday as the cold front pushes through the region. Confidence and coverage are high enough to include vicinity thunder mention in the TAFs with the arrival of the front. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MJA SYNOPSIS...Deubelbeiss SHORT TERM...Deubelbeiss LONG TERM...Deubelbeiss AVIATION...MJA
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
838 PM EDT Mon Sep 13 2021 .SYNOPSIS... High pressure will remain anchored offshore through much of the week. A backdoor cold front will approach from Pennsylvania tonight, then retreat northward as a warm front Tuesday. Low pressure may develop near the Carolina coast Thursday into Friday as a weakening cold front approaches from the Great Lakes. This boundary eventually stalls and remains well to the west of the region over the weekend. && .NEAR TERM /THROUGH TUESDAY/... Clear skies and calm winds will be the story tonight, along with warm and humid conditions. Low temperatures will be 10-15 degrees above normal for early to mid September. Given the humidity, paired with calm winds and clear skies, could see some valley fog west of the Blue Ridge. Otherwise a dry night, as the convective activity mentioned in the previous forecast is expected to stay well to our north. The MCS is currently over east-central PA moving into northern NJ, and should pose no threat to northeast MD. Given the continued unbreakable cap present in the 00z IAD sounding, no amount of outflow is going to get anything going tonight in our region. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... On Tuesday, a flat upstream trough is forecast to be crossing through the Upper Great Lakes while what is Tropical Storm Nicholas tracks toward east-central Texas. Over the course of the following 24 to 36 hours, the former trough will accelerate toward the northeastern U.S. with weak to neutral height falls grazing the Mid-Atlantic states. While the more discernible severe weather threat is more focused over New England, some strong to severe convection may fire in advance of the cold front over western Maryland and the eastern West Virginia panhandle. There are some hints that mid-level vorticity centers from the circulation of Nicholas may become ingested into this trough by late Wednesday. This could easily augment some of the lift along the advancing trough/frontal zone. Thus, the best chance for showers and thunderstorms will be Wednesday afternoon into the early overnight hours. While some non-zero convective threat exists the prior day, robust instability will again be offset by capping issues. Have maintained convective chances along the Alleghenies with conditions more uncertain downstream. The 12Z HRRR maintains the mid/upper plume of smoke into Tuesday which could again offset high temperatures by a degree or two. The current forecast calls from highs in the low 90s which is around 8 to 12 degrees above average. A few additional clouds the following day could trim numbers off a tad leading to more widespread upper 80s, locally into the low 90s. The persistence of modified tropical air over the region will keep mild overnight lows. Expect low 70s inside I-95 with 60s elsewhere. && .LONG TERM /THURSDAY THROUGH MONDAY/... A mid-level trough of low pressure across the region will be the focal zone of possible shower and thunderstorm development on Thursday. Shower and thunderstorm coverage will be mainly isolated and occur during the afternoon hours. Severe potential is low at this time. High temperatures in the lower to middle 80s. As we get into Thursday night through Friday night and as the trough of low pressure breaks down some, a tropical disturbance could move northward and offshore of the Outer Banks. Models have some agreement that this tropical disturbance, whether develops or not, stays offshore of the Outer Banks before slowly moving out to sea offshore of the lower Delmarva Peninsula and Tidewater of Virginia. It is still early to rule out any impacts to our region from this disturbance, but until it reaches the offshore, we need to monitor it for any further development. Temperatures Friday will top out in the middle 80s. By the weekend of Saturday into Sunday, considering tropical impacts could be lessened or nil, high pressure will make an attempt to build into the region and bring drier air and tranquil temperatures our way. Highs in the middle 80s. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... VFR conditions are anticipated through tonight across most of the terminals. The only exceptions may be over KMRB with some reduced visibility due to patchy fog. Given the anomalous low- level moisture, calm winds, and mostly clear skies, fog could become a bit more widespread than advertised. Otherwise, not expecting any restrictions on Tuesday before sub-VFR conditions are possible at times on Wednesday afternoon and evening due to showers and thunderstorms. Regarding winds, they should gradually shift to southerly for Tuesday and Wednesday. Should the terminals encounter a Thursday or Friday afternoon heavy shower or thunderstorm, then conditions may be temporarily MVFR. Otherwise, expect VFR conditions with winds generally southeast becoming northeast 5 to 10 knots throughout the period. && .MARINE... Increasing southerly flow on Tuesday evening and into Wednesday should lead to channeling of the winds. Thus, SCAs will likely be needed for that time period. Additionally, the threat for convection on Wednesday may warrant Special Marine Warnings with any of the stronger storms. No marine hazards expected at this time Thursday through Friday night. Should there be a close influence from a tropical disturbance moving north offshore the mid-Atlantic region Friday into Friday night, then we could see Small Craft Advisories. It is a little early to make this confidence concrete. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...BRO/DHOF NEAR TERM...BRO/CJL SHORT TERM...BRO LONG TERM...KLW AVIATION...BRO/KLW/CJL MARINE...BRO/KLW/CJL
Area Forecast Discussion
National Weather Service Las Vegas NV
816 PM PDT Mon Sep 13 2021 .SYNOPSIS...Dry conditions and temperatures several degrees above seasonal averages continue through the week as afternoon breezes pick up in the afternoons. The second half of the week will be characterized by gradually decreasing temperatures and elevated southwest winds each afternoon. && .UPDATE...Allowed the Excessive Heat Warning and Red Flag Warning to expire at the top of the hour. Noticed visibility and air quality deteriorating in the Owens Valley due to smoke from the Walkers and KNP Complex wildfires along the western slopes of the southern Sierra in Tulare County. Great Basin Unified Air Pollution Control District currently indicates moderate AQI at Bishop while further south Lone Pine and Keeler are unhealthy for sensitive groups and unhealthy for all. With not much wind forecast the next two days 00Z HRRR Smoke indicates it will remain an issue through Wednesday. && .DISCUSSION...Today through next Monday. Gusty southwest winds have picked up across the region this afternoon with speeds between 20 and 25 mph observed across southern Nevada due to a weak 250 mb jet streak passing aloft. These winds will peak through the afternoon before subsiding around sunset. As such, the Red Flag Warning that is in effect through 8pm PDT remains in good shape, as elevated wildfire danger existing in the Spring Mountains and lower elevations of Clark County. Additionally, temperatures this afternoon are forecast to reach between 5 and 8 degrees above seasonal averages, with portions of the Colorado River Valley experiencing "High" to "Very High" HeatRisk values this afternoon. An Excessive Heat Warning for Lake Mead, Lake Mohave, and Lake Havasu persist through 8pm PDT tonight. Those recreating on area lakes are encouraged to continue to hydrate today, even if they`re not thirsty, and especially if they`re consuming caffeine, alcohol, or drugs. Reminder that heat events that occur at the end of the season like this one are likely to result in an increased number of heat-related emergencies, as bodies are exhausted from regulating internal temperatures during extreme conditions all summer. Windy conditions today will subside for Tuesday and Wednesday as temperatures gradually decrease through the week as a dry, southwest flow sets up over the region. Models continue to differ regarding the weekend. The NBM continues to remain dry, with breezy afternoon winds and afternoon temperatures dropping into the 90s for the lower deserts, to all of which I made no changes. An area of low pressure and associated vorticity maximum may push inland across southern California next weekend, with the GEFS Ensemble moving the vorticity maximum directly across Las Vegas, and with the ECMWF Ensemble pushing it out to sea. Additionally, as mentioned in the previous discussion, the larger model disagreement persists regarding a trough pushing inland across the Pacific Northwest. The strength and depth of this trough will determine regional temperatures, wind speeds, and precipitation chances, with increased fire danger likely. && .FIRE WEATHER...A Red Flag Warning is in effect for much of Clark County, Nevada, including zones NV-464 and NV-465, encompassing the Spring Mountains until 8pm PDT this evening. Relative humidity values in the single-digits will combine with sustained wind speeds of 20-25 mph and critically dry fuels to create very high to extreme wildfire danger. && .AVIATION...For McCarran...Southwest gusts to 25 kts will persist through the afternoon before waning around sunset. Winds for the remainder of the TAF period will be light with diurnal trends. No operationally significant cloud cover expected. For the rest of southern Nevada, northwest Arizona and southeast California...Southwest gusts to 25 kts will persist through the afternoon for the Mojave Desert and Colorado River Valley before waning around sunset. Winds along the Owens Valley and for the remainder of the TAF period will be light with diurnal trends. No operationally significant cloud cover expected. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ UPDATE...Pierce DISCUSSION/AVIATION...Varian For more forecast information...see us on our webpage: or follow us on Facebook and Twitter