Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/12/22


Area Forecast Discussion
National Weather Service Binghamton NY
945 PM EDT Mon Jul 11 2022 .SYNOPSIS... Increasing clouds tonight as a cold front approaches from the west. Showers and thunderstorms move into the Finger Lakes late tonight with additional showers and thunderstorms developing area wide Tuesday afternoon. Cooler weather expected wednesday into the end of the week with a few isolated afternoon showers possible. && .NEAR TERM /THROUGH TUESDAY NIGHT/... 930 PM Update... The Lake Ontario lake breeze made it to the Finger Lakes region prior to sunset and quickly brought down temperatures. Most of the region is now in the 70s though there are still some low 80s out there. Hourly temps were adjusted once again, mainly due to forecasted temps being too high compared to latest observations. The rest of the forecast was doing well with only minor changes needed. Looking at the 00z runs of the HRRR and RAP, both are trending a little slower with the morning round of showers/storms, keeping the region mostly dry until around 09 to 10z. The 00z NAM is not in yet but we will have to see if that will trend later as well. For now, left PoPs as is, but future updates may need to slow down the arrival of this first round of showers and storms. Even with what guidance has come in so far, the best chances continue to be across CNY. 600 PM Update... Not much to change in the forecast for this evening. The warm spots this afternoon were in the northern Finger Lakes while conditions were more pleasant from the Twin Tiers and southward. Hourly temps and dewpts were touched up for this update. Winds also needed some minor adjustments to better match obs. 310 PM Update... With mostly sunny skies and dry soils, temperatures have gotten into the mid to upper 80s for most locations this afternoon with a few 90s across the Finger Lakes. Clouds increase tonight as a shortwave moves into the Great Lakes region. An MCS is making its way across Michigan this afternoon though the thunderstorm activity is waning. Even though the complex will likely dissipate before reaching the region, a vort max that is generated by the MCS will be able to spark off some showers and thunderstorms as it gets to the east side of Lake Erie. Forecast soundings indicate that a deep layer of dry air near the surface across most of CNY into NEPA will limit the coverage of the storms tonight with the Finger Lakes having the best chance of seeing the precipitation with a shallower layer of dry air. Tomorrow, a cold front approaches from the west with falling 500 mb heights. The EML that we have been watching the last few days looks like it will be mostly mixed out by the time it gets here. The MCS currently occurring is helping to mix out the EML. Even though most places will be dry tomorrow morning, the few showers and associated clouds limits day time heating with models trending lower with overall instability tomorrow, especially west of I81 and north of I86. More sunshine in NEPA into the Catskill region will still allow for more instability with MLCAPE nearing 1000 J/kg. Strong shear of 45 to 50 knots with strait hodographs indicate that at least a few of the thunderstorms that develop will contain strong to damaging wind gust. SPC has moved the slight risk a little farther to the SE relative to yesterdays update. Once the cold front is through, CAA drops 850 mb temperatures down to about 10C with low level stratus post frontal. A few sprinkles or light rain showers are possible mainly across higher elevations and ridge tops. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... 240 PM Update.. Showers and isolated thunderstorms will linger across the region on Wednesday as upper level trough will be centered over the Northeast U.S. Showers and storms will be mostly diurnally driven and with the loss of heating, shower activity will diminish after sunset Wednesday evening. Although the upper trough remains in our vicinity on Thursday, high pressure starts building into the region. Forecast soundings are showing very dry air aloft, so have taken out shower chances for now. Dry conditions can be expected through the remainder of the period as dry high pressure continues to build in from Canada Thursday night into Friday morning. && .LONG TERM /FRIDAY THROUGH MONDAY/... 350 PM Update... High pressure will dominate the weather through most of the weekend. Models start to diverge in solutions by Sunday with a warm air advection pattern and upper trough pushing in from the west. GFS is most robust with shower and thunderstorm activity on Sunday into Monday, while the Euro keeps the area mostly dry through the weekend with showers arriving on Monday. For now, stuck with the National Blend of Models solution due to the uncertainty, which spreads out shower chances Sunday and through the day Monday. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... VFR conditions will prevail through the night, and into the morning hours, though a few showers and perhaps the odd thunderstorm will be possible as a shortwave trough approaches the region. Showers would most likely be north of the NY/PA line, and between 08-13Z from west to east. There`s a low probability of thunder at ITH and ELM as well, but too low to mention in the TAFs. Additional showers and thunderstorms are expected in the afternoon, with the best chances being after 21Z at AVP. Chances are high enough there to warrant a VCTS, but any restrictions of MVFR or worse would be brief. Outlook... Tuesday Night...Scattered TSRA/SHRA with occasional restrictions possible before 06Z Wed, patchy fog possible through Wed AM. Wednesday and Wednesday Night...Mainly VFR, but brief restrictions in showers and thunderstorms possible in the afternoon and early evening. Thursday through Saturday...VFR expected at this time. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...AJG/HLC NEAR TERM...AJG/BTL/HLC SHORT TERM...MPK LONG TERM...MPK AVIATION...AJG/MPH
Area Forecast Discussion
National Weather Service Burlington VT
1045 PM EDT Mon Jul 11 2022 .SYNOPSIS... Dry weather this evening will give way to increasing rain chances overnight tonight, and then additional chances for showers and thunderstorms Tuesday afternoon ahead of an approaching cold front. A few storms may briefly become strong to severe. An additional front will leave some chances for showers the rest of the midweek, followed by a drying trend with seasonable temperatures expected heading into the weekend. && .NEAR TERM /THROUGH TUESDAY NIGHT/... As of 1040 PM EDT Monday...Everything continues to be on track this evening as cloud cover associated with a warm front overspreads the North Country. A few showers and thunderstorms have been seen on the Canadian side of the St. Lawrence River already but these are expected to pass harmlessly to our north and west. Otherwise, shower and thunderstorm activity will begin to move into the St. Lawrence Valley over the next few hours before spreading eastward. As a heads up to tomorrow`s severe potential, everything continues to look on track. The preliminary data from the latest NAM/NAM3/FV3-HighRes shows all the ingredients we have been advertising. The big question still remains the early afternoon dry-slot but upstream convection may be able to saturate the environment a little quicker like recent runs of the HRRR have shown. Previous Discussion...Weather conditions have been quite pleasant, even if a bit on the warm side, due to low dewpoints and a steady breeze. There are a few holdouts in the upper 70s, but most are in the low to mid 80s at this time, with pockets of high clouds here and there. Anticipate increasing dewpoints tonight and a warm night overall as a warm front approaches and quickly lifts north after midnight. Shortly after its passage, moisture will slide eastwards as the upper ridge and surface high responsible move farther east over the Atlantic Ocean. This should result in a relatively warm night with mainly 60s across the region, and widespread precipitation, primarily over northern New York during the overnight hours. The synoptic forcing associated with this is supportive of some convection, and there`s some elevated instability, again mainly for northern New York. Thus, showers with a few embedded thunderstorms are expected, which will lift southwest to northeast and exit across northern Vermont. A few convective allowing models allow additional convection to fire on the south side of this feature and impact southern Vermont, while others leave southern Vermont dry. Given the south to southwesterly flow, this seems reasonable, but meso-beta elements suggest some right movers may move just south of due east. So, it`s possible with efficient warm, moist advection via a 35 to 45 knot low-level jet that south-central Vermont won`t be completely dry. Late Tuesday morning, we should experience some partial clearing as this activity shifts east. This will be the time frame where we`ll be closely monitoring how well we can warm up and destabilize before convection initiates near or just after noon. Upstream satellite imagery in northern Minnesota and Wisconsin show a narrow dry slot behind the warm front and ahead of the cold front. We should see temperatures climb towards the upper 70s to lower 80s at this time. Morning rains and advection of a subtropical air mass into our region should bring dewpoints in the mid 60s to near 70 over the region, and the relatively dry air in the dry slot will yield good low-level lapse rates. Such will result in CAPE values upwards of 1000-1500 J/kg while there`s still fairly fast flow across the region. Thus, we expect discrete cells to develop and then quickly race northeastwards. While we do have shear and instability present, the low-level jet will be quickly moving east and away, along with little surface convergence or upper level divergence to support updrafts. With dry air as well, it will be difficult to produce organized, long-lasting activity. With the pros listed earlier and these cons the idea of a marginal to slight risk of severe storms from the Storm Prediction Center seems quite reasonable. Activity shifts east of Vermont after 7 PM or so, and then we await the actual wind shift. There should be a few more showers and an isolated rumble of thunder in and around midnight, but trending drier and cooler. Overnight lows should fall into the mid 50s to lower 60s. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... As of 355 PM EDT Monday...Synoptic pattern supports mid/upper lvl trof acrs the Great Lakes into the NE CONUS with weak embedded s/w`s. Overall moisture content of airmass is marginal with pw values btwn 0.70-0.90 as heat/humidity remain to our south. Best forcing with s/w energy and pocket of 700 to 500mb rh arrives around 18z acrs the SLV, but dives southeast and weakens toward 00z Thurs. Have continued with previous fcst idea of schc/chc pops with main focus over northern NY into central/southern VT areas, but overall areal coverage wl be limited. If model trends continue these values could be knocked back into schc range over the next 1 to 2 cycles. Progged 925mb temps near 18C should get most areas into the mid 70s to lower 80s range, with warmest here in the CPV urban areas. Sfc based instability looks marginal acrs our most of our cwa with CAPE values <500 J/kg, but did note slightly higher values over Rutland/Windsor counties around 21z Weds, supporting the potential for a rumble or two. Weds night a relatively quiet night anticipated as energy aloft lingers in mid/upper lvl trof acrs our cwa. A spot shower or two is possible, but expecting most dry conditions to prevail. Clouds and some weak llvl caa/gradient flow wl limit temps from dropping too much, but lows generally upper 40s to mid/upper 50s acrs our fa. Another comfortable sleeping night ahead. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 355 PM EDT Monday...Mid/upper lvl trof prevails thru the rest of the work week, with several embedded 5h vorts traveling acrs our fa. Next in the series of s/w`s arrives on Thurs aftn with limited moisture but some pockets of instability. Have mention chc pops with schc for thunder, given sfc based cape values in the 400-800 J/kg range. By Friday a 1020mb sfc high pres is progged to be directly overhead and continue into Saturday. The only target for opportunity in this time frame was to lower min temps both Thurs and Friday nights, with readings expected in the mid/upper 40s to mid/upper 50s. In addition, did knock down aftn dwpts by 3 to 5 degrees as soundings support drier air aloft mixing toward the sfc. As sfc high pres shifts to our east, a return south/southwest flow wl develop late Sat into early next week. This wl produce warming thermal profiles, along with increasing dwpts with values back into the 60s anticipated. Progged 925mb temps btwn 19C-22C support highs upper 70s to mid 80s for Sat thru Monday with lows falling back into the mid 50s to mid 60s. Warmest in the urban heat islands of the CPV, while coolest in the NEK/SLK regions. Have continued with very low chc pops for Sunday aftn and again on Monday for aftn/evening showers/storms. Guidance begins to diverge on timing details and evolution/track of potential next system for Sunday/Monday of next week. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... Through 00Z Wednesday...VFR conditions and light winds will continue through 06Z. Thereafter, a warm front will begin to lift across the region with winds shifting to the south and becoming increasingly gusty between 06Z and 12Z. A period of rain showers and possible thunder will accompany the warm front during the second half of the overnight period. The best thunderstorm chances remain across northern New York but it`ll be something we will be watching closely should this change. In addition to the increasing surface winds, a strong low level jet between 35 and 40 knots will set up right off the deck leading to period of wind shear during the 09Z to 15Z timeframe. A brief break in showers is expected during the late morning and early afternoon hours before another round of showers and thunderstorms between 18Z and 00Z. Outlook... Tuesday Night: VFR. Chance SHRA, Chance TSRA. Wednesday: VFR. Slight chance SHRA. Wednesday Night: VFR. Slight chance SHRA. Thursday: VFR. Chance SHRA, Slight chance TSRA. Thursday Night: VFR. NO SIG WX. Friday: VFR. NO SIG WX. Friday Night: VFR. NO SIG WX. Saturday: VFR. NO SIG WX. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Haynes NEAR TERM...Clay/Haynes SHORT TERM...Taber LONG TERM...Taber AVIATION...Clay
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1150 PM EDT Mon Jul 11 2022 .AVIATION... Broken line of showers and thunderstorms working across mid-Michigan early tonight will continue to slide across the terminal corridor for the first couple hours of next TAF period. Cold front quickly follows behind this line allowing slightly drier air to work back into SE MI. This likely isn`t sufficient for significant clearing but enough to allow for more breaks in the deck early this morning. Secondary cold front drops south into the this Tuesday afternoon reinforcing/expanding ~5kft cu. A couple showers or storms possible with this second front this evening however confidence in one reaching a terminal isn`t high enough to include mention at this time (best potential would be over the northern sites). For DTW...Broken line of storms vacate the area by the first hour or two of the new forecast period with the associated cold front crossing early this morning setting up W-NW flow for today. Drier air post-front isn`t able to clear clouds out today with SCT to BKN ceilings around 5kft possible throughout the day. .DTW THRESHOLD PROBABILITIES... * Moderate for ceiling at or below 5000 ft tonight and Tuesday. * Moderate for thunderstorms - especially in the vicinity - between 06-08Z tonight. && .PREV DISCUSSION... Issued at 926 PM EDT Mon Jul 11 2022 UPDATE... Small line of deep convection over Western Lower Michigan has developed within a ribbon of advancing deeper instability along a limiting streamline evident in GOES-East Channel 9 imagery. Isolated showers over Central Lower Michigan are along the leading edge of this deeper instability. Deep layer shear is sufficient to support balanced convection into the early mornings hours, with an interesting anti-cyclonic shear character within the inflow layer - suggesting the ability to keep the inflow breathing freely. Given the orientation of the forcing feature, current translation of the convective features, and the aforementioned shear configuration - expect the activity to persist, likely at sub-severe levels. Any propagating cells that migrates more southeast will posses an uptick in intensity worthy of attention. Extrapolation and latest CAM guidance offers a timing after 10pm across the Saginaw Valley, toward midnight for Flint and the Thumb, and an hour or so later for Metro Detroit. Forecast was updated to reflect the refined timing of the shower and storm chances. PREV DISCUSSION... Issued at 412 PM EDT Mon Jul 11 2022 DISCUSSION... An area of showers originating from previous thunderstorm activity over Lake Michigan earlier today is working across the region this afternoon. This elevated convection was initially riding the eastern edge of the inbound moist and unstable air mass, but has clearly outpaced it as radar and satellite trends continue to show its demise as it reaches the still weakly stable and drier environment over the eastern half of the state. Do still expect the shortwave over southern Wisconsin to draw in better low-level moisture and instability tonight, but weak subsidence in the wake of this initial convection will likely act to suppress convection through much of the evening as ascent/low-level convergence is overall lacking until the wave itself and associated cold front move in overnight. Hi-res guidance today has overall had a poor grasp on the early afternoon activity, but recent hourly runs of the RAP and HRRR that at least acknowledge this convection do favor a later arrival of the unstable conditions tonight. Scattered showers/storms will still be possible ahead of and along the cold front that works in late tonight, but with a shorter window for better instability to build in, overall prospects for severe storms tonight look to be lower than earlier data suggested. Won`t be able to rule out a threat for isolated damaging wind gusts with unidirectional bulk 0-6km wind shear profiles on the order of 40+ kt suggesting potential for linear segments to develop. The favored corridor for this better wind shear and the best forcing will be north of I-69, but the best instability may hold off to the south of I-94 tonight. Weak subsidence in the wake of early morning fropa should bring about dry conditions for much of the mid to late morning hours Tuesday. The longwave trough will however remain parked over the Great Lakes with renewed shower/non-severe thunderstorm chances developing during the afternoon tomorrow as the diurnal cycle produces weak instability. A slightly cooler and drier air mass will filter in through the day on a breezy WNW wind. Highs reach mainly into the lower 80s. A more significant shortwave will drop through the longwave troughing late Tuesday night into early Wednesday morning. With little to no instability in place, this feature and the associated cold front should pass through with little fanfare. 850mb temps do take another step downward to around 10C on Wednesday, supportive of highs in the mid 70s to around 80. Weak diurnal instability brings another chance of showers and/or non-severe storms on Wednesday as the troughing lingers overhead. The trough finally makes its departure on Thursday with strong height rises in its wake causing high pressure to expand across the area. This spells a quiet late week period with high temps rebounding into the low to mid 80s by Saturday. MARINE... A cold front is still slated to drop through the region tonight, bringing chances of showers and thunderstorms along with it. A first band of showers is currently passing through southern Lake Huron but will be weakening over the next couple hours. The chance for stronger storms is still there for this evening into tonight along the front. Prefrontal winds are gusting into the low 20 knot range but the lack of 25 knot gusts near the water will warrant allowing the Small Craft Advisories to expire at 4pm today. Winds will veer more westerly tonight after the front and veer further to the northwest on Tuesday behind a secondary front. This second front may cause a few more showers and thunderstorms to develop in the afternoon. A third round of showers may sweep through on Wednesday before quieter weather moves in mid week with an area of high pressure building in. HYDROLOGY... Scattered showers and thunderstorms are forecast tonight ahead of a cold front that will move through early Tuesday morning. A muggier air mass will continue to work into the region this evening which will enable any stronger storms to produce heavy rainfall rates. Storms will be moving west to east at around 40 mph and basin- average rainfall is expected to remain around a quarter to half inch for those areas that do see storms. However, the strongest thunderstorms will be capable of producing over one inch of rain in a short period of time which could result in localized flooding. Overall confidence in the coverage and magnitude of any excessive rainfall remains low. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...NONE. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ AVIATION.....KDK UPDATE.......99 DISCUSSION...TF MARINE.......DRK HYDROLOGY....TF You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Lincoln IL
822 PM CDT Mon Jul 11 2022 .SYNOPSIS... Issued at 200 PM CDT Mon Jul 11 2022 Scattered showers and thunderstorms are possible late this evening along a cold front. Otherwise, dry and seasonably hot weather will persist through late week as a stable air mass settles over the Great Lakes region. && .UPDATE... Issued at 821 PM CDT Mon Jul 11 2022 Continue to closely monitor the potential for storm development this evening in an unstable but capped environment. 00Z KILX sounding continues to show around 40 J/kg MLCIN capping moderately strong instability just in excess of 3000 J/kg. Frontal boundary and cu field is approaching the Illinois River Valley this hour and weak convection was noted just before sunset west of Peoria but the updraft was too weak to sustain itself. 00Z HRRR rolling in now has pushed back convective initiation several hours and now focuses the possibility closer to the I-70 corridor after midnight tonight. While can`t completely rule out isolated storms developing, the threat appears to be diminishing and most of the area will remain dry overnight. Will cap PoPs in the slight chance/isolated range the rest of the evening. Temperatures are on track to fall into the mid to upper 60s north of I-72 and upper 60s to lower 70s south. && .SHORT TERM...(This evening through Tuesday) ISSUED AT 200 PM CDT Mon Jul 11 2022 Two areas of interest stand out right now on visible satellite: (1) a cu field extending along the I-72 corridor which is associated with an outflow boundary from earlier convection, and (2) another cu field along a slow-moving cold front that extends from roughly UGN- to- OTM-to-EVU. Both of these boundaries exist in an environment of impressive MLCINH, which doesn`t bode well for severe convection over the next couple hours. The severe weather potential then for tonight remains limited, although parameter space does improve this evening as deep-layer shear increases with an upper- level speed max digging into the Lower Great Lakes region. This feature, along with a modest LLJ veering in ahead of the weakly forced surface front, should provide enough shear and buoyancy to support the development of scattered showers and thunderstorms tonight. At this point, we believe any storms that do develop along the cold front tonight will not become rooted in the boundary layer to support a damaging wind threat. The more likely solution is a broken line of scattered, elevated thunderstorms where downdrafts struggle to permeate the cap. Pockets of heavy rainfall will accompany any storms that develop and become organized tonight. This idea comes from the 12z HREF guidance where localized amounts between 1-2" are possible east of a Shelbyville-to-Bloomington line. Elsewhere, a few tenths of an inch would be more common. Dry conditions are a more sure bet into Tuesday as surface high pressure settles in behind the departing cold front. Temperatures will be a few degrees cooler as well with afternoon highs in the low-to-mid 80s. .LONG TERM...(Wednesday through Monday) ISSUED AT 200 PM CDT Mon Jul 11 2022 An anomalous upper-level ridge and expansive surface high pressure will squelch precip chances through at least Thursday as conditions remain stable over the Great Lakes region. Temperatures during this stretch will be seasonably hot with NBM output offering daily highs in the low-to-mid 80s and overnight lows near 60 degrees. The forecast begins to exhibit some variability by Friday as a mid-level disturbance rolls atop a robust 594mb ridge. This disturbance could break the stretch of dry weather with a return to wet and unsettled conditions over the weekend. Global models and their envelop of ensemble solutions disagree on the strength of this upper-level disturbance, with more semblance found in timing. As the upper-level disturbance becomes displaced further east Sunday into Monday, its attendant cold front may washout somewhere over central or northern Illinois. This diffuse surface boundary may become the focus for additional shower or thunderstorm development early next week, and this is reflected in the latest NBM output with low chance PoPs (< 30%) both Sunday and Monday. It should be mentioned at this point that it`s more likely for the forecast to stay dry into early next week. Furthermore, even if the aforementioned mid-level disturbance late this week fosters MCS development, it`s unlikely to be a prolific rainmaker. This has more to do with the origins of moisture. And, with a tropical disturbance loitering somewhere along the Gulf Coast through most of this period, any rich low-level moisture will likely be deflected away from central Illinois. Instead, any rainfall that does develop over the Plains late this week and into the weekend will expel moisture with Pacific origins, which tends to be milder and a little drier. Temperatures Friday through Monday will remain in the low-to-mid 80s. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 614 PM CDT Mon Jul 11 2022 A weak cold front is sagging south across central Illinois this evening. W/WSW winds ahead of the front will veer to the NW behind the front and remain there through Tuesday. While couldn`t rule out some tempo MVFR ceilings this evening, outside of any showers and storms conditions will be VFR with skies clearing Tuesday. The chance for storms this evening is diminishing but a few isolated storms couldn`t be ruled out with BMI and possibly PIA having the best chance, but overall this threat is low. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Deubelbeiss SYNOPSIS...MJA SHORT TERM...MJA LONG TERM...MJA AVIATION...Deubelbeiss
Area Forecast Discussion
National Weather Service Louisville KY
953 PM EDT Mon Jul 11 2022 .Forecast Update... Issued at 954 PM EDT Mon Jul 11 2022 Things are quiet across the CWA at this hour with mostly clear skies in place. Keeping an eye on any upstream developments ahead of a frontal boundary currently stretching from central IL/MO, and back toward the southern Plains. So far, haven`t seen any development ahead of this feature, and with the loss of daytime heating, it is going to take a bit more triggering from a shortwave rotating through the parent trough. The recent runs of the HRRR have been on the slower side of the guidance envelope, and given the lack of upstream development to this point, am starting to lean toward a slower arrival of isolated to widely scattered precipitation toward dawn on Tuesday. Will continue to keep a slight chance of a shower, or perhaps a rumble or two of thunder, across our northern CWA in the pre-dawn hours to around sunrise. We`ll see a relative lull in any activity through late morning into the early afternoon before more development is expected ahead of the boundary sagging south and east through our area. Any PM activity is likely to be confined to our far south and east CWA. && .Short Term...(This evening through Tuesday) Issued at 215 PM EDT Mon Jul 11 2022 High pressure continues to dominate the region with mostly sunny skies and light winds. Latest surface analysis shows a string of low pressure systems from Lake Superior to IA to KS pushing a cold front through portions of the MS Valley and toward the OH Valley. Expect quiescent conditions for the rest of today with a benign layer of cirrus adorning crepuscular skies. A northwesterly nocturnal LLJ will rejuvenate convective activity along the aforementioned cold front overnight over central IN. Storms and showers will weaken as they approach the OH River as most of the energy remains well to the NE, but our southern Indiana counties could hear a few cracks of thunder during the pre-dawn hours. Morning showers south of the OH River will be possible, but these will likely dissipate before reaching LEX. Cloud cover will help to temper afternoon highs north of I-64 where we expect to see mid to upper 80s. More insolation south of there will allow temps to rise into the low 90s. This will also help to fire off new convection along the same boundary, which will likely be stretched just SE of a line from BWG-LEX. So expect a chance of showers and possible thunderstorms Tuesday afternoon, especially in the Bluegrass and Lake Cumberland regions. .Long Term...(Tuesday night through Monday) Issued at 310 PM EDT Mon Jul 11 2022 Synopsis...Mean mid-level wave pattern will primarily consist of a West CONUS ridge steaming from a stationary high centered over the Southwest US, troughing from the Midwest to the Northeast reinforced by training shortwaves, and a closed low over the Gulf of Mexico interacting with a front. At the surface, high pressure will dominate the weather by advecting a drier and more stable airmass behind Tuesday`s frontal passage (see Short Term section above). Predictability of the synoptic features remains above-normal until Friday, when models start to show disagreement on the strength and degree of interaction between a shortwave moving along the ridge;s edge and the Gulf of Mexico tropical low. Nonetheless, the trends has been consistent indicating a wetter pattern for the weekend starting Saturday afternoon. Wednesday-Friday...Expect near-normal hot afternoon temperatures as highs will linger in the upper 80s with some brief relief overnight since lows will fall to the mid 60s. Another factor that will help with the heat is the fact that dewpoints will stay in the low 60s and possibly falling below 60 degrees on Friday. Some mid to upper level clouds might move from the west on Wednesday ahead of a vort max shifting through the Great lakes, but no rain is expected thanks to the strong stability in place. Weekend...Greatest change noted with the latest deterministic runs include the GFS depicting a deeper tropical low meandering over the Gulf, aligning more towards the ECMWF and UKMET output. However, it still favors some kind of early interaction with the midlatitude shortwave while its counterparts do not. This can be explained by analyzing the 500-mb vorticity field since the GFS has maintained an stronger and more amplified shortwave. Along the same lines, strong PVA ahead of the wave could promote convection, or even MCS development, that explains Saturday`s rain chances over the northwest portion of the CWA. && .Aviation...(00Z TAF Issuance) Issued at 745 PM EDT Mon Jul 11 2022 VFR conditions will continue through this TAF period. There is a cold front stretching from the Great Lakes southwestward into central Missouri this evening, and is expected to approach the region by the pre-dawn hours tomorrow morning. As this front approaches, expect increased mid-level cloud cover and vicinity showers at HNB/SDF before/near sunrise tomorrow. After the cold front passes through, winds will turn from a SSW component to a NW flow by the late morning or early afternoon. Expect winds to generally remain under 10kts for the period. Storms should redevelop along the front tomorrow afternoon during daytime heating. It`s possible BWG/LEX could see some VCTS tomorrow afternoon towards the end of this TAF period, but not confident enough to include any TS in TAFs at this time. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Update...BJS Short Term...CG Long Term...ALL Aviation...CJP
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
909 PM CDT Mon Jul 11 2022 .UPDATE... Issued at 909 PM CDT Mon Jul 11 2022 Confidence continues to diminish in footprint of convective potential this evening, however ample conditional instability and deep layer shear combo would continue to suggest that any decent storms that manage to develop could present a damaging wind threat. At this time, it would appear the best potential for isolated to scattered thunderstorm development would be with an outflow boundary pushing south-southeastward from storms over southeast WI, or along/ahead of weak cold front roughly along/south of the I-80 corridor. At 845 pm, radar depicted an area of scattered thunderstorms over far southeast WI and parts of southern Lake Michigan, moving to the east over the lake. These storms were producing an outflow boundary, which was pushing to the south-southeast at around 20 kt however, which looks to move into far northeast IL around 930 pm. SPC mesoanalysis data estimates 1000-2000 J/kg of MLCAPE was in place across northeast IL ahead of this boundary, with an aircraft ascent sounding KMDW at 0045Z modified for current surface conditions yielding around 1300 J/kg though with weak capping between 900-800 mb. Convergence along the outflow boundary may be able to initiate isolated convective updrafts as it pushes south into northeast IL after 930 pm, though even this may not be able to overcome the weak low level lapse rates/capping. Thus confidence in convective initiation is low. If isolated storms are able to initiate however, either along the outflow boundary or the weak cold front along/south of the I-80 corridor, MUCAPEs of AOA 2000 J/kg and effective deep shear of 50-55 kts would support the potential for organization (supercell structure earlier with storm which passed across northern Cook county late this afternoon). Largely unidirectional shear and weak low level lapse rates would support mainly a damaging wind risk, though again would expect overall coverage to remain fairly limited. SPC has maintained a slight (level 2 of 5) risk with their 01Z update through the remainder of the evening hours across roughly the southeast half of the cwa for this possibility, though expect that any such threat would be very isolated. It`s entirely possible no storms develop at all. Isolated thunderstorm threat should end after midnight, as the weak cold front sags southeast of the forecast area. Ratzer && .SHORT TERM... Issued at 1209 PM CDT Mon Jul 11 2022 Through Tonight... Looking forward to this afternoon and evening, our main forcing mechanisms will approach from the north and west. A fairly anomalous upper trough over the upper Midwest will spread southeastward and steer a cold front toward the upper Mississippi valley. Height falls ahead of the trough, right entrance of the jet core ahead of the trough and the front will all work to weaken a the cap -- and near term guidance suggest the first attempt at this will be closer to this forcing in northern/northeast Illinois and maybe more so into Wisconsin. The cap will take more time to erode in our south. Current uncertainty centers on this mid level cloud cover, but IR satellite indicates some decent warming aloft, and we have low level moisture increasing from the south and west, so there still appears to be a window over northeast Illinois for severe storms. We expect there will be convective attempts this afternoon, but the window may be fairly narrow. Both the RAP and HRRR suggests the cap erodes but differ as to the degree of instability at that point, and the HRRR window of weak capping is quite narrow, and even the RAP which was more aggressive in its earlier runs has backed away, likely a result of some latching on to the worked over environment. We may have to watch for some decaying storms that form in Wisconsin that drift southeast this evening. The instability axis gets shifted south of the I-80 corridor pretty quickly late this afternoon and evening ahead of the remnant boundary form this morning and any lingering differential heating boundary. With this in mind, the SPC Slight Risk (Level 2/5) area has been focused out ahead of these boundaries. This is the area that stands the best chance of a few scattered severe storms mainly in the evening hours once the upper forcing makes further southeastward progress. Damaging winds would be main hazard with a 2,000+ J/Kg of MLCAPE and some 40-50 kt of deep layer shear, but there still remains some uncertainty as to the best corridor of storm development. Drier air will filter in behind the front/trough later tonight and end of the storm threat. KMD && .LONG TERM... Issued at 258 PM CDT Mon Jul 11 2022 Tuesday through Monday... Following this evenings cold frontal passage and potential period of active weather breezy northwesterly winds on Tuesday will transport a drier and cooler air mass into the area. This cooler and drier airmass is likely to persist across the area through later in the week as as upper level troughing (cyclonic upper flow) sets up over the Great Lakes. This will generally result in pleasant weather continues each day, with inland highs generally in the lower 80s and lakeside highs in the 70s. Precipitation chances through the Friday looks rather low. However, a couple of minor weather disturbances, along with rather cool mid-level temperatures will support diurnal cumulus development both Tuesday and Wednesday afternoon, and possibly a few light widely scattered showers. The slightly better chance for these showers looks to be over far northern IL Tuesday afternoon and over inland areas of northern IL Wednesday afternoon. Surface high pressure is expected to settle over the Great Lakes on Thursday, before shifting to the east late Friday and on Saturday. While this will support pleasant and dry weather both days, temperature and humidity values will begin to increase into the weekend as the low level flow turns southerly following the eastward departure of the surface high. The weather pattern also may turn a bit more active and supportive for some clusters of thunderstorms for at least a portion of weekend. This as an upper level ridge over the west begins to build eastward into the Plains and accordingly places our area right within an active belt of northwesterly mid/upper level flow. Given the inherent uncertainties with timing and placement at this timescale, we continue to mention only low end chance POPs in the forecast through the weekend. KJB && .AVIATION... For the 00Z TAFs... The primary aviation weather concerns through the 00Z TAF period are as follows: - Isolated showers and thunderstorms across the Chicago metro through ~01Z Isolated showers and potentially an additional thunderstorm or two remain possible in the vicinity of the Chicagoland terminals through roughly 01Z this evening. There exists a small potential for additional rainfall moving over the area through as late as 03Z, though confidence and expected coverage is far too low to include in the TAF. Following the rain potential, skies should be mostly clear and gusty westerly winds will begin steadily subsiding. Through the night, winds should average at around or just over 10 kts. Another breezy day on Tuesday will feature gusts near 20 kts from the late morning through mid-evening while winds blow in from the WNW. Winds will then subside to under 10 kts for the last few hours of the extended TAF period. VFR conditions can be expected through the entirety of the period. Doom && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at weather.gov/chicago Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/NWSChicago www.twitter.com/NWSChicago www.youtube.com/NWSChicago
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1055 PM CDT Mon Jul 11 2022 .SHORT TERM...(This evening through Tuesday night) Issued at 213 PM CDT Mon Jul 11 2022 KEY MESSAGES: - Isolated to scattered thunderstorms north of I-94 into early this evening and again Tuesday afternoon-evening, a few of which may be severe. - Still warm but a little less humid on Tuesday. A fairly nondescript surface pattern will remain in place tonight through Tuesday night with NW-SE oriented high pressure centered over the Northern Plains keeping NW flow in place atop MN/WI. Aloft, deep cyclonic flow from eastern Canada extends into the north-central CONUS, with one main shortwave trough axis driving southeast this afternoon-evening over MN/WI with a second shortwave axis expected to swing through Tuesday afternoon-evening. Peak heating, leading to best instability within a surface environment of dewpoints into the low 60s, will aid in allowing scattered showers/thunderstorms to develop in the vicinity of the shortwave trough. Showers/thunderstorms to continue mainly north of I-94 through early evening, with a small potential for a few storms to be strong to severe. MUCAPE will reach 2000 j/kg in that portion of the WFO MPX coverage area and steep low-level lapse rates (better than 7- 8 deg C/km) will make for sufficiently colder temps aloft. Coverage will be quite limited, thus making for a limited severe threat, but still non-zero. Convective activity this evening will cease with the loss of daytime heating, but a similar scenario can be expected for Tuesday with another shortwave trough arriving with no change in the surface synoptic pattern. So, again, will look for isolated-scattered showers and thunderstorms north of I-94 for Tuesday afternoon. A weak cold front will slide southeast through the region Tuesday evening, helping bring an end to any convective threat to the area. Temperatures will run very similar tomorrow as what is experienced this afternoon. Highs will again range from the upper 70s to mid 80s. Lows will also be very similar, running in the upper 50s to mid 60s. However, with the aforementioned cold front swinging through Tuesday evening, lows in interior western WI will be a little cooler, down to the mid 50s. .LONG TERM...(Wednesday through Monday) Issued at 213 PM CDT Mon Jul 11 2022 KEY MESSAGES: - A few chances for showers and storms with the best chance arriving Thursday night into Friday morning. - Hot temperatures arrive over the weekend with low to mid 90s by the start of next week. The period begins quietly as weak surface high pressure and northwesterly flow aloft bring weak subsidence across the region, with only some fair weather cumulus clouds on Wednesday. Thursday will see increasing clouds we the weak high pressure moves eastwards and a developing surface low moves eastwards over the central Rockies, resulting in low to mid level WAA in addition to an upper level shortwave by late Thursday. The NBM remains fairly conservative at 30-40 PoPs Thursday evening into Friday morning, but expect this to increase as even now there is decent deterministic and ensemble model agreement on precipitation in the area. The main question will be how the atmosphere looks as it pertains to thunderstorms, with forecast soundings from the GFS currently showing modest 500-1000 J/KG MUCAPE alongside 40kts of bulk shear, which typically would be more than enough to produce a few isolated stronger storms. The current timing of the shortwave will play a large role in what happens, as right now it moves into western MN by 03z on Friday and doesn`t reach eastern MN until 06-09z, which would allow for a bit of cooling and stability which could hamper thunderstorm development. For now, the expectation is a broken line of weak showers with a few thunderstorms producing locally heavy rainfall, but not a significant severe weather threat. Other than the chance for showers and storms, the big concern will be increasing temperatures and heat concerns during the last few days of the period beginning Sunday and lasting through most of next week. Current NBM temperatures in the low to mid 90s on Sunday and Monday could still be rather conservative with GEFS and EPS ensemble members showing potential for mid to upper 90s and even some triple digit values next week. An upper level ridge and blocking surface high pressure will not be directly over the area, but centered over the eastern Rockies which does give us some potential to miss the worst of the hot temperatures, as well as gives us a chance for showers and thunderstorms to further cool us down given more prevalent cloud cover. Climatologically speaking our temperatures range from mid 60s at night to mid 80s during the day, and with lows struggling to get below 70 and highs in the 90s, we could be looking at a stretch of 5+ degrees above normal temperatures for several days next week. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 1051 PM CDT Mon Jul 11 2022 A near repeat of Monday is expected for Tuesday, with a diurnal increase in winds and cloud cover. By the afternoon, those clouds will likely have built up into isolated-scattered storms. Most CAMs are like the HRRR in showing that pretty much every MPX terminal will be susceptible to seeing diurnal showers, but the greatest coverage is expected over WI, where a PROB30 for TSRA was added to RNH to go along with the one already in place for EAU. KMSP...MSP could see shra/tsra in the region between roughly 21z and 2z, but expected coverage is still not expected to be enough to warrant a mention in the TAF with a prob30, but that`s the one thing that could happen that is not conveyed in the current TAF. /OUTLOOK FOR KMSP/ Wed...VFR. Wind NE 5 kts. Thu...VFR. Wind SE 10-15 kts. Fri...Chc A.M. SHRA/TSRA/MVFR. P.M. VFR. Wind S 5-10 kts becoming SW. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ SHORT TERM...JPC LONG TERM...TDH AVIATION...MPG
Area Forecast Discussion
National Weather Service Reno NV
135 PM PDT Mon Jul 11 2022 .SYNOPSIS... Thunderstorms are possible Tuesday into Tuesday night with limited rainfall, gusty outflow winds, and new fire starts possible. Wednesday through the upcoming weekend, southwest flow will prevail with near to above normal temperatures. Areas of haze are possible from fires on the Sierra west slope. A few thunderstorms may creep back into the Eastern Sierra and far Western Nevada Friday onward. && .SHORT TERM (through Tuesday Night)... Hot temperatures will stick around through Tuesday, with highs 100+ possible for the lower valleys of western NV and 5-10 degrees above average elsewhere. The Heat Risk category for west central NV is listed as Medium to High on Monday and Tuesday. Sensitive populations and those spending prolonged periods outside should exercise caution during this time. Smoke from the Washburn Fire on the southern edge of Yosemite National Park is currently contained to the western side of the Sierra crest thanks to light easterly flow over the region today. However, a deepening trough off the coast of the Pacific NW will generate southwesterly flow tonight. This will advect smoke eastward over the crest and lead to decreased air quality through Tuesday, most notably over the Tahoe Basin and Carson Valley according to HRRR smoke guidance. Some cumulus buildups along and east of the Sierra crest are possible this afternoon due to intense surface heating, though thunderstorm chances remain low (less than 5%). Thunderstorm chances increase Tuesday evening to as a weak shortwave generates mid-level instability and elevated convection. Highest chances (10-20%) for thunderstorm development include the eastern Sierra into western Nevada. Confidence on wet vs. dry storms is currently low. However, dry thunderstorms are possible under current model guidance and could produce new fire starts Tuesday afternoon and evening. See the Fire Weather section below for more detailed information on fire concerns. For preparedness tips and additional precautions for heat, smoke, and thunderstorms, please refer to the Special Weather Statement. -Whitlam .LONG TERM (Wednesday onward)... * Southwest flow is projected over the region through the upcoming weekend, with us being located in between a Four Corners high and trough off-shore of the Pacific Northwest. * Typical zephyr west-southwest winds are forecast each afternoon- evening, on the order of 20-30 mph. The one day where we could see a slight enhancement is Wednesday with NBM showing closer to 30 mph in valley areas. With a rather dry airmass, this could result in concerns for holdover fires from any lightning we get Tuesday. * Thunderstorm risks are quite low Wednesday-Thursday with dry, stable airmass in place. Starting Friday, looks like we get a little moisture sneak around the west periphery of the Four Corners high such that a few t-storms are possible each afternoon into the weekend. Best chances as usual are in the Eastern Sierra into Lyon and Mineral Counties. Roughly half of the ECMWF ensemble members do show enough moisture for storms to sneak up into the Tahoe basin and western Nevada near I-80. About 20% show enough moisture for storms as far north as Lassen/Susanville. Still way too early to tell what character of storms, wet vs dry. * Temperatures are leaning near to just above normal for the period with no remarkable atmospheric features to prompt either significant heatwaves or cool-downs. NBM guidance showing solid 90s for W Nevada each day with 80s for mountain communities. Nothing unusual for mid July. -Chris && .AVIATION... VFR conditions continue today as light winds with 10-15 kt afternoon gusts persist. Easterly winds will keep smoke from the Washburn Fire in Yosemite west of the Sierra crest through this afternoon. Given fire activity continues through the day, smoke is expected to advect back east of the crest as southwest flow develops over the region. According to current HRRR smoke guidance, thicker smoke will be present along Sierra crest, while hazy conditions will impact the Tahoe Basin and Carson Valley. This haze may reduce slantwise visibility, especially for KTVL- KMEV-KCXP. Thunderstorms are possible Tuesday afternoon, with chances 10-20% for KRNO-KCXP-KMEV-KMMH, and less than 10% chance for KTRK- KTVL. Potential impacts include gusty and erratic outflow winds from any cell that do develop. Afternoon westerly Zephyr winds persist Tuesday onward, with gusts 20-25 kts likely. Higher gusts up to 30 kts are possible Wednesday. -Whitlam && .FIRE WEATHER... Some fire weather concerns exist Tuesday afternoon and evening as convection looks to ramp up across the region. NAM model soundings currently exhibit the most significant mid-level instability, with CAPE values greater than 700 J/kg for locations across the eastern Sierra and western Nevada. These soundings also show the classic inverted-V profile, with drier lower levels, a high-based LCL, and moist upper levels. Thunderstorms under this atmospheric profile could lead to increased fire concerns as cells would remain mostly dry, create gusty and erratic outflow winds, and produce lightning strikes that could ignite new fires. Another fire weather concern includes the return of afternoon westerly Zephyr winds on Wednesday, with gusts up to 30 mph possible. This raises a concern for holdover fires from any lightning strikes on Tuesday night. Mixed confidence on storm type and varying fuel moisture content across affected areas hinders the issuance of any watches or warnings on this event. -Whitlam && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$ For more information from the National Weather Service visit... http://weather.gov/reno
Area Forecast Discussion
National Weather Service Topeka KS
916 PM CDT Mon Jul 11 2022 .UPDATE... Issued at 916 PM CDT Mon Jul 11 2022 The 00Z models are starting to come in line showing the development of elevated showers and storms across east central KS tonight. And the last several runs of the HRRR have been consistent in showing this as well. It appears that some moisture advection along the 700MB front allows for some elevated CAPE between 1500 and 2000 J/kg per the 00Z RAP forecast soundings across east central KS. Bulk shear is rather marginal for severe storms, but forecast soundings still show downdraft CAPE values close to 1000 J/kg so it is not out of the question there could be some isolated downbursts with damaging winds. Will update the forecast to increase POPs to around 50 percent. && .DISCUSSION... Issued at 216 PM CDT Mon Jul 11 2022 Forecast Highlights: - A few storms may be possible into this evening mainly along a weak frontal boundary extended across east central into central KS. - Warming up into the latter part of the week with another ridge building in from the west. A typical summer summer weather pattern appears to be in place over the next several days across the forecast area. The upper flow and mean Westerlies remains generally north of the area with current shortwave trough and DCVA translating into the Western Great Lakes region. Meanwhile, a shortwave ridge is building over the Pacific Northwest region. Monsoonal moisture is over the Desert Southwest with a surface high pressure cell building into the central Plains and Mid MS Valley region. This is helping to push a modified cold front through the area this afternoon. This front will be the focus for any potential storms to develop into this evening as deep enough mixing allows for only a weak cap to remain in place. Weak forcing and fairly weak convergence and somewhat limited depth of moisture along the boundary should make it difficult for storms to develop this evening. Would only expect isolated to possibly scattered storms if they do form. Wind would be the main hazard with some small hail as a secondary hazard but with freezing levels over 16kft the hail threat would be low as storms likely will have trouble becoming very organized. Shear remains boundary parallel at around 30-35kts with not all of that through the depth of any potential storm. However, plenty of instability is in place with surface based CAPE up to around 4000-4500 J/kg. So, if an updraft does develop it would be quick to do so but mixed mode would likely result. Inverted V type profiles would likely allow for some intense isolated damaging winds to take place near the surface. All of this is low probability but something to be aware of generally along a line from Emporia through Ottawa into this evening. Some lingering post frontal elevated showers could linger into early tomorrow morning. This would be welcome moisture if it can be squeezed out of the atmosphere. After this, a dry pattern with a couple of cooler days with lower humidity set up before weak return flow develops into Wednesday/Thursday. A ridge builds in from the west and will help to warm temperatures once again into the weekend but unfortunately outside of some possible isentropic induced showers mainly Thursday morning time frame, precipitation looks to be overall limited. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday) Issued at 536 PM CDT Mon Jul 11 2022 Some of the models including the HRRR continue to show elevated showers and storms developing overnight generally along the 850MB frontal zone. At this time models keep convection mainly south of the terminals, so may just include a VCSH for a few hours when the HRRR shows precip developing. Otherwise a VFR conditions are expected to persist as mid level clouds give way to sunny skies for Tuesday. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Wolters DISCUSSION...Drake AVIATION...Wolters