Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/08/24


Area Forecast Discussion
National Weather Service La Crosse WI
1040 PM CDT Fri Jun 7 2024 .KEY MESSAGES... - Rain likely across much of the area (50-90% chance) overnight and into Saturday morning. Rain chances (50-70%) have increased across portions of northeast IA and southwestern WI. - Below normal temperatures expected this weekend and early next week. An isolated shower or two are possible late Saturday and Sunday (10-20% chance). - Warming trend is expected with temperatures trending above normal by the second half of next week. Highs will reach well into the 80s for much of the local area. && .DISCUSSION... Issued at 240 PM CDT Fri Jun 7 2024 Tonight - Saturday: Rain Likely Overnight, Isolated Thunder Possible Current surface analysis shows low pressure centered over the pan handle of Nebraska with southerly flow advecting moisture north in a somewhat narrow ribbon 3/4ers the width of the state. The 60F dewpoint line has rapidly shot north to near I-80 with radar showing elevated /10ft/ showers and storms across SD into nwrn IA early this afternoon. This area is associated with a strong area of 600-700mb frontogenesis within the MuCAPE gradient of 250-750 J/Kg per SPC, with the heart of the MUCAPE pool further southwest over wrn NE/CO. Per latest RAP guidance, this elevated forcing /fgen/ translates east today in swift zonal flow, grazing northeast IA closer to I-35 early this evening, however without the elevated instability /which spreads in late tonight/. With the low-level ridging and dry air mass holding firm across the Upper Miss Valley, would think this will translate into thick clouds at 10kft and scattered very light showers or sprinkles. GOES water vapor showing a well-formed shortwave trough in northwest flow dropping southeast through srn Saska/Alberta at 18Z. Short term model consensus has moderate 300-500mb QVector convergence along and north of I-90 Saturday morning with moderate isentropic lift through the low-levels as well with this wave. As the low-level southwest flow increases late tonight as the ridge axis pushes east, low MUCAPE instability /100-300 J/Kg/ does shift in near and south of I- 90, and is speed convergent, isentropically upgliding. Have a hard time believing showers would not be present south of I-90 with isolated thunder too after about 3 am. At that same time, a cold front with the northwest flow trough is heading through MN, moving through the area Saturday morning into very early Saturday afternoon. This will act to prolong the period of showers Saturday and there is some timing spread among the CAMS. So, forecast will paint a little bit bigger window than may actually occur and hopefully timing can be refined in the next 12 hours. So, continued very high rain chances near and I-90 and north late tonight into Saturday, and increased them southward into northeast IA and southwest WI /60%/...with clearing trying to work in post-frontal in the afternoon from NW->SE. Saturday Night - Monday: Cool, Slight Shower Chances Heading through the rest of the weekend, temperatures will continue to remain on the cooler side of average with highs consistently shown in guidance to remain in the upper 60s and lower 70s areawide, roughly around 5-10 degrees below normal. Monday will likely be the coolest day with the 07.00z grand ensemble (GEFS/EC ens/Canadian ens) showing an inter-quartile range of 66 to 72 degrees for highs at La Crosse with a median of 70 degrees. A few showers and storms are possible late Saturday and Sunday with continued cyclonic flow in place allowing for cooler air aloft enabling some diurnal instability. However, this is fairly inconsistent between different CAMs runs so will hold with lower precipitation chances (10-20%) for now. Tuesday - Friday: Warming Trend, Shower/Storm Chances As we approach the middle of next week, deterministic guidance shows a weak shortwave trough progressing towards our region. While deterministic guidance has come into some more agreement on how this trough will manifest, still lots of questions with available moisture and any instability associated with it. Consequently, confidence still remains not the highest with the 07.06z GEFS showing around 50-70% chance for measurable precipitation with this wave. As a result, have some increase in precipitation chances (20-40% chance) with the recent NBM for Tuesday but will still need to assess, either way would likely be very light amounts and have minimal thunder chances. Otherwise, the other story for next week, mainly into Wednesday is an upper-level ridge will progress east and flatten as it inches its way into our region. While this will help warm temperatures some, northwest flow appears to maintain through the period which should keep temperatures from trending well above normal when also considering the 07.00z EFI shows minimal signal for significantly above normal temperatures. Consequently, expecting highs to get as warm as the middle to upper 80s, perhaps a 90 in a few spots. Thursday currently appears to be the warmest day next work week with the NBM percentiles showing an inter- quartile range of 84 to 91 degrees with a median of 87 degrees. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1023 PM CDT Fri Jun 7 2024 Scattered showers moving west to east at 08.04Z ushering in VFR cloud deck. Widespread precipitation chances will be slow to usher east as low level dry air sustains for a short time locally. Eventually, widespread precipitation chances reach the local area overnight into early Saturday morning, ushering in MVFR clouds. No visibility restrictions expected as intensity expected to remain light. Model guidance is optimistic to lift as the precipitation forcing quickly moves east into central Wisconsin into Saturday afternoon. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...Baumgardt/Naylor AVIATION...JAR
Area Forecast Discussion
National Weather Service Bismarck ND
834 PM CDT Fri Jun 7 2024 .KEY MESSAGES... - Isolated showers (20 percent chance for rain) are forecast for Saturday. High temperatures to remain near to slightly below seasonable normals. There is a 10 percent chance of showers during the day Sunday, increasing to 30 percent at night. - Widespread chances (20 to 50 percent) for showers and thunderstorms to be found Monday. - Cooler temperatures expected Sunday and Monday. How much cooler still remains uncertain. Moderate to high confidence remains for warmer temperatures during the middle of next week with high temperatures into the 80s. && .UPDATE... Issued at 834 PM CDT Fri Jun 7 2024 Showers continue mainly in the center through east central parts of the state. These showers will continue moving east through the evening hours. There are also scattered popcorn showers in southern Canada heading towards northern parts of the state. However, these will likely dissipate as the sun continues to set. No lightning strikes have been observed for about 45 minutes as of this time. A few more lightning strikes aren`t totally out of the question, though no instability is being analyzed on the mesoanalysis page. This suggests less than 250 J/kg of MUCAPE is present, and any limited instability that does remain will continue to decrease as the sun sets. UPDATE Issued at 646 PM CDT Fri Jun 7 2024 Previously quasi-stationary frontal boundary has steadily been sinking south and is presently over the southernmost tier of counties. A couple of weak thunderstorms had developed in eastern Adams and southern Grant counties. The former moved into South Dakota and the latter has weakened. It remains possible that a brief strong thunderstorm could develop in far southern ND, though is looking less and less likely. As the frontal boundary continues into South Dakota, any remaining threat for strong storms will diminish over the next hour or so. Otherwise, scattered showers continue in central North Dakota. Recently, there were a few lightning strikes in southern McLean County. However, with the lack of instability, any embedded thundershowers should be few and far between. These showers will continue working through to the east southeast and exit the forecast area late this evening, or shortly after midnight. && .DISCUSSION... Issued at 255 PM CDT Fri Jun 7 2024 A weak disturbance in northwest flow could still bring showers and thunderstorms through this evening. SPC maintains a Marginal Risk of severe weather in southcentral and portions of southwestern North Dakota through this evening. The threat for severe weather overall looks very isolated today. Some HRRR CAMS are showing an isolated stronger storm later this afternoon into this evening across these marginal risk areas. There is abundant shear in this area during this time period. The bigger concern though is the lack of instability. HREF ensemble data showing MUCAPE up to 500 J/KG. While surface based CAPE is higher in some instances, the elevated nature of today`s convection would be tough to tap into this. A quick change from easterly flow at the surface to westerly flow aloft could be adding some SRH and perhaps promote weak rotation in isolated storms, yet again this would require surface based storms. More looking into the elevated storm environment the hodographs become more straight. This could still help with hail production, especially given the high amounts of shear. The concern still remains the lack of instability. There is a weak warm front boundary setting up as well in these Marginal Risk areas. If a stronger storm can get going along this boundary and pulse up, then perhaps hail up to an inch in diameter and wind gusts up to 60 mph are possible. For now kept messaging sub severe as this is where our highest confidence currently resides given the lack of instability. Precipitation activity should diminish shortly after midnight tonight. Look for overnight lows to be in the 40s, and light winds tonight as they switch back to a westerly direction. A broad upper low then looks to linger in southern Canada for Saturday maintaining the near to slightly below normal temperatures across the CWA. The unsettled northwest flow could result in a few isolated showers Saturday, with the higher confidence areas coming in the north where a weak frontal boundary may help with lift. Instability lacks even more than today, thus left our mention of thunderstorms for Saturday. Northwest winds may increase slightly for Saturday, yet be below advisory criteria. Sunday still remains a day of uncertainty as temperature and precipitation chances will highly depend on how far south this cut off low can progress. Clusters are about 50/50 on the low`s location which brings quite the spread in temperatures. There is somewhat of consensus that below normal temperatures will be found. How cold will depend on this location. NBM may have raised slightly today compared to last night, although this may be the trend until more model consensus can be found. NBM also keeps Sunday mainly dry for the time being, again dependent on the lows placement. A wave moving across the Pacific North West could then lift across the area Sunday night through Monday. This will linger cooler temperatures, yet make the next chance for widespread showers and thunderstorms. There is a high amount of shear during this time period, although instability looks limited. The chance for severe weather perhaps will need to be monitored going forward given the amount of shear available. One last note for the weekend, cooler temperatures could also be found in the morning with perhaps some upper 30s possible Sunday morning. Ridging to flat ridging could then be found through mid next week. This westerly flow could bring some warming temperatures, with NBM placing highs in the mid 70s to mid 80s for much of the CWA. Flat ridging could promote a few weak waves in the flow and possibly bring a shower or thunderstorm at times. Predictability is low for this pattern at this time and left in NBM PoPs for now. Clusters then indicate perhaps a return to a broad trough or at least northwest flow pattern. This may slightly cool the temperatures and bring more chances for showers and thunderstorms. CSU-MLP putting in some slight chances for severe weather mid to late next week. These chances are isolated to scattered and will have to be monitored going forward. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 646 PM CDT Fri Jun 7 2024 Scattered showers are present in central ND. These will continue to gradually work east southeast through the evening. KJMS seems like the terminal most likely to see any shower activity, with KBIS having a chance as well. A few lightning strikes are possible over the next couple hours before the threat ends as the sun sets. In addition to this evening, there is also a slight chance of showers for the western half of the state and in the north Saturday afternoon. Other than during any shower activity, VFR ceilings and visibility will prevail through the period. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Telken DISCUSSION...Anglin AVIATION...Telken
Area Forecast Discussion
National Weather Service State College PA
1100 PM EDT Fri Jun 7 2024 .SYNOPSIS... Persistent Northwest flow aloft with a few embedded upper level troughs will keep it cooler, breezy and pleasant heading into the weekend with low humidity. After another round of showers Sunday morning, we expect a reinforcement of cool air Monday preceding a warming trend towards the middle and end of next week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Plenty of high based stratocu and altocu clouds covered much of Central and Northern PA this evening as a well defined mid level thermal trough with a positive tilt (from Central NY to the Middle Ohio River Valley) slides east across the CWA. Latest RAP guidance shows pockets of 200-300 J/KG SFC-BASED CAPE associated with this trough and some light spotty showers along the I-80 corridor. This area of clouds will gradually spread over the Middle and Lower Susq Valley before decreasing in coverage late tonight. Low temps around daybreak Sat in the 50-60F range are within a few degrees either side of early June climo. Partial clearing could allow patchy fog to form toward daybreak Saturday in the deeper east- central valleys, but the dry air and persistent westerly breeze should maintain good visibility in most places. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/... Vertical mixing up to around 5 KFT AGL by Late Sat morning will be sufficient to mix out most of the lower clouds, leaving some flat cu and higher based Altocu or Cirrus for the afternoon. WNW Wind gusts should be in the 20 to 25 mph range during the late morning and afternoon hours Saturday. With the temporary departure of the cold pocket of air aloft, afternoon max temps will be 4 or 5 deg F warmer than today (Friday) with the NW Mtns seeing a 6-8 deg F rebound. Little day to day temp diff will be seen across the Lower Susq Valley on Saturday. Saturday`s highs will be in the 70-80F range from NW to SE across the CWA. Model consensus continues to indicate the next period of showers from late Saturday night into Sunday morning as another shortwave trough and cold front move through the region. The showers will be most numerous acrs the NW part of the state, and gradually diminish as the move across the Middle and Lower Susq Valley. Continued breezy and relatively cool for this time of year with max/min temps near to below the historical avg. for early June. Temps Sunday will dip just a little compared to those on Saturday. Another moderately breeze day is in store for Sunday with gusts from the WNW in the low to mid 20s (MPH). Monday should be the coolest day of the upcoming 7 days. The approach of a potent shortwave and surface cold front dropping SE from the Glakes will bring more clouds than sun, along with some afternoon and evening showers across primarily the Central and NW 2/3rds of the state. && .LONG TERM /TUESDAY THROUGH FRIDAY/... Upper level troughiness over the northeastern United States will keep temperatures below normal through Tuesday. After that, we should see a moderating trend through the mid to late week. There could be some showers by late week, as cold fronts drop southeastward across the area. Low level moisture appears to be limited at this point. However, past experience is that such a pattern provides the potential for isolated strong storms if moisture gets advected into the area. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... Winds will gradually weaken as we head into the late evening hours. Expect CIGS (consisting mainly of high based stratocu and alto cu) to stay mainly in the VFR range, but a brief period of lower CIGS may be possible at BFD, thus used a TEMPO group at BFD. Winds will pick up again on Saturday just after sunrise. The depth of vertical mixing increases to 5-6 kft AGL in the late morning and afternoon hours with peak gusts in the 20 to 25 mph range). A fast moving cold front will bring a chance of a few showers Sunday (mainly during the morning hours). Outlook... Sun...AM low cigs possible NW Mtns, MVFR cigs linger into midday north and west of the Allegheny Front. A chance of a few showers. Mon-Wed...No sig wx expected. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Lambert/DeVoir NEAR TERM...Lambert/DeVoir SHORT TERM...Lambert/DeVoir LONG TERM...Martin/Evanego AVIATION...Lambert/Martin
Area Forecast Discussion
National Weather Service Dodge City KS
606 PM CDT Fri Jun 7 2024 .KEY MESSAGES... - Slight Risk (Level 2 of 5) Severe thunderstorms this evening with damaging straight line winds 60-70 mph the greatest risk. - Slight Risk (Level 2 of 5) also for Saturday evening, as a larger thunderstorm complex likely to develop with severe wind gusts and a greater probability of 1"+ rainfall across much of southwest Kansas (30 to 50% chance). - Shower and Thunderstorm chances continue, albeit lower, Sunday and Monday, but core of highest rainfall likely just south of southwest Kansas. && .UPDATE... Issued at 414 PM CDT Fri Jun 7 2024 ** MESOSCALE DISCUSSION ** Surface-based thunderstorms were developing along a leeside trough axis where boundary layer convergence was greatest within region of 0-3km AGL lapse rates greater than 9 degC/km. Kansas State mesonet observations of dewpoints out west were higher than HRRR, which has a bias of over-mixing dewpoints after a wet period. For instance, 21Z dewpoints were in the 62-64F range as far west as a Lakin to Sublette line. Initial thunderstorms were forming in the drier airmass, but once storms tap in to the lower to mid 60s dewpoints, we expect the severe weather risk to increase, especially as individual cells begin to interact and a cold pool becomes established with damaging straight line winds being the most likely risk, particularly in the 23Z to 02Z time frame...which is the most likely 3-hour window for severe across our forecast area. The new Severe Thunderstorm Watch #396 includes all 27 counties of the NWS DDC forecast area, which runs through 03Z (10 PM CDT). && .SHORT TERM /THROUGH SATURDAY/... Issued at 237 PM CDT Fri Jun 7 2024 The main forecast challenge will be severity and timing of severe storms along with precipitation amounts for the first mesoscale convective system (MCS) event this evening. Early morning showers and weak thunderstorms moved into central Kansas early in the afternoon with temperatures recovering into the mid 80s as far east as Hays to Dodge City. West toward the Colorado line, afternoon temperatures were warming well into the lower to mid 90s. Dewpoint temperatures were holding on nicely with afternoon boundary layer mixing not having much impact on lowering dewpoints...at least through 1830Z. Surface wind convergence along the leeside trough will continue to strengthen through the afternoon across far southeast Colorado, which is where initial thunderstorm development is expected to occur. Most of the convection-allowing models (CAMs) have the first storms developing in the 20-21Z time frame (3-4PM CDT) with further development into far southwest and west central Kansas not long after. If the surface dewpoints do not mix out as much as the HRRR model indicates, we will likely see scattered severe storms not long after convective initiation from Elkhart northeast to Garden City up to Scott City. Forecast hodographs do support at least some modest storm organization, including a marginal supercell or two, however temperature-dewpoint spreads of 35+ degrees (F) will strongly favor outflow dominant storms and a transition to quasilinear structure(s) as cold pools become more prevalent. A few wind gusts in the 65 to 70 mph range will be possible, and while a large hail threat will exist with more discrete storms, the high wet-bulb zero heights and large evaporative cooling potential early in the event will likely limit very large hail. If we see storms later in the evening tap upper 60s dewpoints along/east of Highway 283, the probability of severe events will ramp up...at least until boundary layer cools off too much after sunset. Going in to Saturday, cool northeasterly winds will likely prevail across much of western Kansas in the wake of tonight/early Saturday morning`s MCSs, therefore the degree of warmup in the afternoon is at least a little bit in question. The latest NBM 50th percentile temperatures for Saturday afternoon are in the mid to upper 80s along and north of the Arkansas River (89 to 93F south), which is a good forecast for now, because if clouds do clear out, the early June insolation should help temperatures rebound quickly, despite the easterly winds. This will set the stage for what looks to be a fairly impressive MCS later Saturday Night (more on that in the Long Term section). && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... Issued at 237 PM CDT Fri Jun 7 2024 At the onset of this Long Term Period, Saturday evening, strong/severe thunderstorms will likely be underway across eastern Colorado about to move into western Kansas. Nearly every model, both CAM and non-CAM, shows a substantial MCS signal moving across west central/southwest Kansas, and for that reason, POPs have been increased to 70-80% for the Saturday Night period. The Storm Prediction Center has upgraded the severe outlook to a Slight Risk (Level 2 of 5), but there is some support for an even higher risk outlook if models continue to show such strong support, backing up traditional conceptual models of early-mid June western Kansas MCS patterns. Low level moisture will not be a problem, along with low level winds from the east-southeast providing long moisture transport vectors into MCS(s). Much of the DDC CWA is within the latest WPC QPF of 1"+, including Dodge City and Garden City. The west-northwest to east-southeast axis of highest QPF is still likely to shift slightly to the south or north, however any shift will not likely be by much. After Saturday Night`s system, cooler, more stable air will will follow on Sunday which will likely push much of Sunday evening`s MCS to the south of our southwest Kansas region. For that reason, POPs Sunday Night will be highest in the far southwest portion of our area (Morton County). On Monday/Monday Night, global models are showing a mid level disturbance in vicinity of southwest Kansas down into West Texas, which will likely aid in another MCS or two, so POPs will remain in the forecast (mainly 30-40%). This mid level weakness will likely then move east/southeast of our forecast area Tuesday which will result in a drier forecast. Toward the end of this forecast period, temperatures should warm back up as an upper level ridge axis expands across New Mexico into southern Colorado and adjacent West Texas/southwest Kansas && .AVIATION /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 601 PM CDT Fri Jun 7 2024 In general we should have VFR flight category for all terminals during the time period. Isolated to widely scattered thunderstorms will be in the vicinity of the LBL and GCK terminals through 01z, DDC terminal between 01-03Z and the HYS terminal between 01-04Z. Storms will have an environment to produce downburst winds greater than 50 kts. After 04Z storms should exit the region and we will be left with mid level clouds through the morning on Saturday. Skies should clear out by late morning. && .DDC WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Umscheid SHORT TERM...Umscheid LONG TERM...Umscheid AVIATION...Tatro
Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
639 PM CDT Fri Jun 7 2024 .KEY MESSAGES... - A complex of thunderstorms is expected to move through the region from northwest to southeast late tonight into early Saturday morning. Damaging wind gusts up to 70 mph and locally heavy rainfall will be the primary hazards. - Additional rounds of storms are possible tomorrow afternoon and tomorrow night into early Sunday morning. Marginally severe storms and locally moderate to heavy rainfall will be possible. && .DISCUSSION... Issued at 223 PM CDT Fri Jun 7 2024 The current synoptic weather pattern across the CONUS is defined by a mid level low over southern Ontario with associated troughing over the eastern Great Lakes into portions of northern Appalachia with a mid level high over Texas. Mid level flow over western Missouri and eastern Kansas remains out of the WNW between these two features. At the surface, high pressure remains in place overhead, with generally fair skies, temperatures in the mid to upper 80s, and a southerly breeze. A mid level speed max/subtle shortwave trough over western Nebraska will continue to the east southeast today and tonight, with a deepening surface low developing over north central Nebraska. Severe storms have already begun to initiate over north central Nebraska as of 230 pm. Meanwhile, further to the south out over central Kansas, a cluster of showers and thunderstorms has also developed within an area characterized by low to mid 60 dewpoints. This should continue to move to the east through the afternoon hours, but should weaken as it approaches our CWA as it enters into a drier low level environment. However, storms over north central Nebraska should move southeast through the afternoon hours, growing upscale into a mesoscale convective system and moving northwest to southeast through the region late this evening into the early overnight hours. The primary hazard with these storms would be the potential for damaging wind gusts up to 60 to 70 mph and locally heavy rainfall on the order of 1 to 2 inches. Another subtle shortwave/disturbance moves across the Plains tomorrow afternoon/evening. Scattered storms may develop by mid to late afternoon toward central Missouri, quickly moving eastward out of our region. Severe convection is likely to develop across eastern Colorado and western Kansas by tomorrow afternoon, moving eastward through the evening hours and growing upscale into another MCS, moving through our region late tomorrow night into early Sunday morning. Marginal severe weather may be possible (60 mph winds and up to quarter sized hail), but the bigger concern will be the threat for an additional round of locally moderate to heavy rainfall on top of what falls tonight, which could create some flooding concerns. Convective allowing models disagree a bit with the exact placement of the MCS tomorrow night, with the NAM Nest taking the heavier rain south of the KC metro, but the 18z HRRR dropping another 1-2 inches over the KC metro. Other than slight chance PoPs on Tuesday afternoon, the region should remain generally dry for Sunday afternoon through Thursday. Temperatures should be cooler, closer to seasonal normals, for Sunday through Tuesday with warmer temperatures returning for Wednesday and Thursday. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 638 PM CDT Fri Jun 7 2024 VFR conditions are expected to last for the next few hours. As showers and thunderstorms from the east begin to move over the area, expect conditions to worsen. Showers are anticipated to last until around 10Z. Winds will shift from the south to the north by Saturday morning and remain around 10 knots or less. VFR conditions are expected to return by tomorrow afternoon. && .EAX WATCHES/WARNINGS/ADVISORIES... MO...None. KS...None. && $$ DISCUSSION...Williams AVIATION...Collier
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
944 PM CDT Fri Jun 7 2024 .KEY MESSAGES... - A decaying thunderstorm complex will arrive late tonight into early Saturday morning...with the highest rain chances (60-90%) focused along/south of a Macomb to Mattoon line. - Near to slightly below normal temperatures will continue for the next several days before the return of summertime warmth with temperatures in the middle to upper 80s by the end of next week. && .UPDATE... Issued at 926 PM CDT Fri Jun 7 2024 The only change to the forecast this evening was a slight northward pull of PoPs tomorrow (Saturday) evening, as recent iterations of various 00z HREF members show thunderstorms developing along the southward-moving cold front. The HRRR remains the most bullish of the bunch, having pockets of 60+ dBZ simulated reflectivities (indicating perhaps some hail) in the feistiest cells between 7 and 10 pm, so we`ll have to have one eye on mesoscale trends tomorrow evening. Though the HREF mean would suggest 35-40+ kt of 0-6km bulk shear near the front, storms to our southwest will get the first drink from the faucet of warm and moisture advection from the LLJ, theoretically robbing our area from the more appreciable instability necessary to sustain strong- severe storms. The HRRR`s 2000-3000 J/kg of SBCAPE ahead of the front remains the outlier pulling up the HREF mean (nearer 1000 J/kg), but it still bears consideration; we`ll keep an eye on things tomorrow evening, but at this time feel severe chances are quite low (less than 5%) at any given location. Bumgardner && .SHORT TERM...(Tonight through Saturday) Issued at 248 PM CDT Fri Jun 7 2024 A short-wave trough dropping southeastward across Saskatchewan and Montana is providing the necessary synoptic lift for thunderstorm development across Nebraska this afternoon. 19z/2pm satellite mosaic shows cells blossoming over far southern South Dakota into central Nebraska and these are expected to become more numerous and spread southeastward this evening...eventually aided by a 50-60kt 850mb jet oriented northeastward from the Texas panhandle. The storms will push into Missouri later this evening, then will spill into parts of central Illinois overnight. Most CAMs keep the bulk of the convection just S/SW of the KILX CWA, but bring showers into parts of the area before dawn Saturday. Based on current satellite trends and the 18z HRRR, have focused highest PoPs along/south of a Macomb to Mattoon line from 09z/4am to 15z/10am. Instability will be meager as NAM MUCAPE values remain below 100J/kg. Nevertheless have included slight chance for thunder due to strong LLJ curving northeastward toward central Illinois toward dawn. Once the early morning showers depart into Indiana, mostly dry weather is anticipated for the remainder of Saturday. A weak cold front will push into the area from the northwest, so cannot rule out widely scattered showers/thunder during the afternoon/evening, but think most locations will remain dry. Have held on to chance PoPs south of I-70 into Saturday night as the front settles southward into the Ohio River Valley, but it appears the bulk of the convection associated with the nocturnal jet will occur well S/SW across Missouri into western Kentucky. Barnes .LONG TERM...(Sunday through Next Friday) Issued at 248 PM CDT Fri Jun 7 2024 Cool and predominantly dry weather is expected early next week with highs in the 70s and lows in the 50s Sunday through Tuesday. Coolest night will be Monday night when lows perhaps dip into the upper 40s along/north of the I-74 corridor. After that, upper heights will rise and temperatures will climb back above normal into the middle and upper 80s by next Thursday/Friday. Barnes && .AVIATION... (For the 00z TAFs through 00z Saturday Evening) Issued at 650 PM CDT Fri Jun 7 2024 Mid-level cloud deck at around 15000ft will continue to stream across the sky through the evening before a decaying convective complex approaches from the west overnight. Given the initially very dry airmass and the fact that that convection currently developing in Nebraska will drop southeastward into Missouri and mainly stay S/SW of central Illinois, have limited precip mention in the 00z TAFs. Opted to include predominant showers for a few hours at KSPI after 10z and at KDEC after 14z, but have only carried VCSH at the other terminals. Ceilings will lower Saturday morning, but perhaps not as much as the CONSShort guidance would suggest. Based on NAM forecast soundings, have lowered ceilings to MVFR after the 14z-16z time period and kept them there through 00z. Winds will become light/variable this evening, then will become S at 10-15kt Saturday morning. Winds will then veer to SW and decrease to 10kt or less after 21z as a cold front settles southward into central Illinois. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service North Platte NE
634 PM CDT Fri Jun 7 2024 .KEY MESSAGES... - There is an enhanced risk (level 3 of 5) for severe thunderstorms mainly through mid evening across portions of north central into central Nebraska. Large hail and damaging winds are expected with an isolated tornado or two possible. - Cooler highs in the upper 60s to 70s Saturday through Monday, with chances for showers and a few thunderstorms. The greatest threat is over the western half of the forecast area. - Drier weather with much warmer temperatures developing Tuesday into Wednesday and persisting through Friday. && .SYNOPSIS... Issued at 210 PM CDT Fri Jun 7 2024 H5 analysis this morning had an upper level high over western Texas/southeastern New Mexico. An elongated area of low pressure extended from central Saskatchewan east southeast into southeastern Ontario. For the northern half of the CONUS, from the pacific NW into the Dakotas, broad east to west flow was noted. Within this flow, a shortwave was noted over southwestern Wyoming this morning with a second shortwave noted over northern portions of the central valley of California. Other disturbances were noted on the southern periphery of the Saskatchewan low and extended from southeastern British Columbia into southern portions of Saskatchewan. At the surface this afternoon, a warm front extended from just north of Thedford, ease southeast to just south of Ord Nebraska. Skies were partly to mostly cloudy across the area and 2 pm CDT temperatures ranged from 73 at Valentine, to 93 at Ogallala. && .SHORT TERM /THROUGH SATURDAY NIGHT/... Issued at 210 PM CDT Fri Jun 7 2024 Severe potential this evening will be the main forecast concern in the short term period. Thunderstorm initiation is expected to take place around 20z this afternoon. As for location of initiation, looking at the latest NAM Nest, 13z HRRR and 12z WRF-ARW storm initiation ranges from Keya Paha County (NAM Nest), to Brown and Rock counties (HRRR and WRF). The model solns this morning lift the warm front up to as far north as the SD/NE border by mid afternoon. This may be over done given the ongoing convection over northern Nebraska and will need to be ascertained near forecast issuance time. Believe initiation will take place along this frontal boundary and this lies the highest potential for tornadoes. As we progress into the latter afternoon and early evening hours, super cell thunderstorms will track to the southeast, eventually exiting the area by mid evening. Support for supercell thunderstorms lie with deep layer shear on the order of 40 to 55 KTS this afternoon early evening. Low level moisture has streamed into southwestern and western Nebraska this afternoon and coupled with readings in the 80s/Lower 90s, has led to SB capes > 3000J/KG, which will be ample enough to overcome the 40+ kts of shear. Very steep mid level lapse rates and 25+KTS of shear are noted generally east of a Valentine to North Platte line which would favor very large hail as the storms migrate southeast away from the warm front. Eventually based on forecast DCAPE, supercells will congeal into a line/bowing segment. By that point, the convection should be exiting the area around the 01-02z time frame. Additional convection may develop over the Cheyenne Ridge late this afternoon, early evening. This activity may eventually make it into the southwestern forecast area later this evening. ATTM, this activity is not expected to be severe. Regardless, will introduce some low pops in the SW to account for this threat overnight. Overnight, surface high pressure will build into South Dakota forcing a pseudo- backdoor cold front through the forecast area. By Saturday, this feature will be oriented along the front ranges of southeastern Wyoming/Colorado, south into the Oklahoma Panhandle and east along the OK/KS border. Low level easterlies, anticipated cloud cover and h85 temps in the lower teens are noted across the area on Saturday and highs will struggle to get out of the lower 70s. There will be a continued threat for precipitation Saturday, as showers and thunderstorms develop off to the west and gradually lift east into western portions of the forecast area. As for the severe threat, it appears to be well off to the west and south of the forecast area INVOF the backdoor cold front. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Issued at 210 PM CDT Fri Jun 7 2024 Surface high pressure will remain anchored over the Missouri Valley Sunday into Monday. This will lead to a continuation of easterly/southeasterly winds with a frontal boundary anchored off to the west of the forecast area. Precipitation chances will remain highest in the western forecast area as convection drifts east off the higher terrain of eastern Wyoming/NE Colorado. Highs Sunday and Monday will struggle to get out of the lower 70s both days which is 10 to 15 degrees below normal for this time of year. A second cold front will push through the area Monday night into early Tuesday with a decent threat for showers and thunderstorms. This will be followed by a general warming trend for Wednesday through Friday with a more limited threat for precipitation. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 634 PM CDT Fri Jun 7 2024 A line of thunderstorms passed through western and north central Nebraska this afternoon along a strong low pressure system and associated boundaries. Winds will remain gusty through the evening hours, before boundary layer decoupling settles in and calms surface winds. A stratus deck is expected overnight, which will lower ceilings. The main challenge for the TAF period will be the ceilings, as there may be brief drops to MVFR and IFR conditions. There may be some brief showers through the TAF period, though confidence is low in timing and placement, so will omit from TAFs at this time. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Buttler SHORT TERM...Buttler LONG TERM...Buttler AVIATION...Richie
Area Forecast Discussion
National Weather Service Louisville KY
954 PM EDT Fri Jun 7 2024 .KEY MESSAGES... * Showers and a few thunderstorms this weekend. Locally heavy downpours possible late Saturday night into early Sunday morning across western and southern Kentucky. && .UPDATE... Issued at 954 PM EDT Fri Jun 7 2024 Sun has just set over central Kentucky and southern Indiana, allowing gusty southwesterly winds to relax and temperatures to cool. Clear skies and light winds will lead to efficient cooling. Low temperatures in the morning are expected to be in the upper 50s and low 60s. In the early morning, dissipating convection currently over the central Plains will move over the Ohio Valley bringing broken to overcast clouds and scattered light showers by mid- morning. Current forecast remains on track. && .SHORT TERM /THROUGH SATURDAY/... Issued at 312 PM EDT Fri Jun 7 2024 Tonight, the surface high will be focused just south of us moving toward eastern Tennessee. As a result, there will be mostly clear skies and dry conditions. After a breezy afternoon, the winds will become more light and variable overnight as the high pressure shifts eastward. Temperatures will lower into the mid to upper 50s. Close to sunrise, convective cloud debris from the decaying MCS over Missouri will filter over our area. By sunrise tomorrow, expect increasing mid- and high-level cloud cover. For tomorrow, low rain chances will spread eastward as the remnants of the overnight MCS continue to dissipate. NBM is very bullish on precip chances tomorrow, but given high res model soundings showing very dry air in the lowest 3km, have decided to back off on PoPs slightly. Decided to lower PoPs to 20-30% with the highest chances north of I-64. We can expect some scattered showers tomorrow afternoon over southern IN, and isolated showers for the rest of KY. With increasing cloud cover throughout the day, little to no instability is expected, so thunderstorm chances remain low. Temperatures for tomorrow will range from mid to upper 70s for southern IN, and upper 70s to low 80s elsewhere. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... Issued at 312 PM EDT Fri Jun 7 2024 Saturday Night through Monday Night... Saturday night will feature a cold front slipping in from the northwest and then slowing down in southern KY by dawn Sunday. Nocturnal low-level jet will be in play, but not anywhere as strong as what we saw Friday night. PWATs will be in the 1.75-1.9 inch range along that front so primo juice will be available for convection. Overall convective evolution here is still a bit muddled as the HRRR has some sort of MCS rolling through the central part of our CWA while the 3KNAM, Euro and GFS have an MCS rolling through mainly southwest and far western KY. For now, will keep higher end chance PoPs going for the overnight until we get a bit more forecast convergence within the next few model cycles. Overall severe threat looks pretty low here, but if we get a forward propagating MCS, then gusty winds and torrential rainfall would be the main threats. PoPs should continue into Sunday morning with drier conditions likely in the wake for the afternoon/evening. Overnight lows will be in the mid-upper 60s. Highs Sunday will likely be in the upper 70s to around 80. Sunday night lows will be cooler behind the front with lows in the upper 50s. Dry and less humid conditions are expected for Monday and Monday night with highs in the upper 70s to around 80 and overnight lows in the low-mid 50s. Tuesday through Friday... Moving into next week, the pattern will start off with a trough axis along the east coast with some upper ridging over the Ohio Valley. This trough axis will move east and the flow over the Ohio Valley will remain in a west-northwest type pattern. Earlier forecasts showed a mid-level perturbation working through around midweek. However, latest ensembles and deterministic runs have shifted this feature more to the south and west here. Additionally the GFS and its ensembles have reversed course here and are now much more dry through the period, which matches the Euro. Perhaps the next chance of precipitation may arrive in the Thu/Fri time frame as a stronger wave in the northern stream pushes through the Great Lakes which may bring at least some iso-sct showers/storms to the region. Temps will remain below normal for Tuesday with highs in the upper 70s to near 80. Lower 80s look likely for Wednesday. An uptick in temps looks likely for Thursday as highs will warm into the middle 80s. Latest blend is suggesting upper 80s and lower 90s by Friday. That seems a bit aggressive given the relative moist soil conditions and lush vegetation across the region. More than likely, highs will top out in the mid-upper 80s by late week and into next weekend. && .AVIATION /00Z TAFS THROUGH 06Z MONDAY/... Issued at 726 PM EDT Fri Jun 7 2024 High pressure over the region will keep VFR conditions through the overnight hours. Gusty SW winds are beginning to relax as the day ends. In the overnight hours, showers and storms over the central Plains will move SE dissipating as it enters the region, however bringing some VCSH conditions to the terminals. Clouds will increase in coverage and lower in the morning. Winds will be SSW-SW around 5- 10kts in the afternoon. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ UPDATE...SRM SHORT TERM...CJP LONG TERM...MJ AVIATION...SRM
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1044 PM CDT Fri Jun 7 2024 .KEY MESSAGES... - Rain showers likely tonight into Saturday morning. - Warming trend through mid-week with high temperatures in the 80s likely. && .DISCUSSION... Issued at 247 PM CDT Fri Jun 7 2024 TONIGHT THROUGH SATURDAY NIGHT... Temperatures have climbed into the low to mid 70s so far this afternoon. Winds have remained breezy 10- 15 mph range with gusts 25-30 mph. Much more tolerable versus yesterday`s winds. Our clear skies will slowly fade under a lay of mid level cloud cover. Cloud cover will build in from SW to NE and will set the table for rain showers tonight into Saturday morning. RH values have dropped into the 30 percent range this afternoon, but fire weather concerns have been limited due to the recent wet pattern. A shortwave trough will move through tonight, providing support for rain showers across Minnesota and western Wisconsin. Most of us should see showers overnight, but rainfall totals will be light with values between a few hundredths to a quarter inch on the high end. CAMs and Ensemble guidance give support to this solution as well. There has been a downward trend in QPF amounts with this system in the HRRR and global guidance as low level dry air saps much of the moisture before it reaches the surface. PWATs aren`t too impressive either. An thunderstorm or two is possible to our SW, but 12z CAMs didn`t feature anything noteworthy, likely due to the limited moisture and instability in place. Saturday and Saturday night will be pleasant after the system exits. Clearing skies will support high temperatures into the low to mid 70s. Winds will be out of the northwest at 10 to 15 mph. An increasingly rare forecast as we head into Summer. SUNDAY THROUGH THURSDAY NIGHT... This week ahead will see these pleasant late Spring-like days fade away as a more Summer-like pattern builds in aloft. Temperatures start out pleasant with highs in the 70s and lows in the 50s before the warmer weather ramps up by late next week. Ensemble guidance has continued to advertise a warmer look as an upper level ridge builds east into the central CONUS. High temperatures in the 80s with a few spots in the 90s appears likely by Thursday. It`s important to note that model spread increases to a significant level by this point and what evolves after is far from certain. ECMWF highlights two windows of opportunity for potential rain and thunderstorms next week. The first comes Tuesday with a shortwave system that`ll bring a swath of moisture into Upper Midwest and likely some thunderstorm potential. As this potential system exits, our ridge will build into the Upper Midwest and WAA will ramp up. Temperatures will peak Thursday afternoon in the 80s, possibly some 90s across SW MN, before a stronger shortwave moves through Thursday PM into Thursday night. Temperatures aren`t the only thing that`ll heat up mid-week. An impressive surge of moisture will settle in with dew points in the upper 60s and lower 70s likely. This will likely mark the end of the late-spring weather we`ve enjoyed. PWAT values around 2.0" are reflected in the ECMWF... very humid airmass coupled with temperatures in the 80s... Summertime. This system should produce thunderstorms across the region as a sfc cold front moves across the state Thursday PM. We`ll have to monitor guidance to see what exactly shakes out being over a week away though. If you have any yard work or outdoor activities you`ve been putting off, it may be beneficial to get to them before the end of next week! && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1044 PM CDT Fri Jun 7 2024 VFR with mid level clouds increasing late this evening. Showers will move in overnight and will remain light with VFR likely continuing. As the showers exit early Saturday morning, FEW-SCT MVFR level clouds could follow for a few hours before clearing. Light and variable winds tonight will become northwest again Saturday. KMSP...Light showers should move in between 07-08Z tonight. However, VFR conditions are likely throughout the period. /OUTLOOK FOR KMSP/ SUN...VFR. Wind NW 10-15 kts. MON...VFR. Wind NE 5-10 kts. TUE...Mainly VFR. Chc MVFR/-SHRA. Wind SE 10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...BPH AVIATION...Borghoff
Area Forecast Discussion
National Weather Service Topeka KS
635 PM CDT Fri Jun 7 2024 .KEY MESSAGES... - Severe storms with damaging winds around 70 mph and very heavy rainfall are expected mainly across northern KS tonight. - Another round of storms with heavy rain are likely (60 to 70 percent) across east central Kansas Saturday night. && .DISCUSSION... Issued at 240 PM CDT Fri Jun 7 2024 19Z water vapor imagery showed a weak disturbance moving through central KS with a line of elevated convection. A shortwave was moving out into the northern plains as well. Surface obs have shown a strengthening trough of low pressure in the lee of the central rockies. This has allowed good moisture advection through western KS with dewpoints increasing into the middle and upper 60s. Don`t see what would cause the band of elevated showers to fall apart at this point, except that they may lose some of the better moisture advection as they continue east. Additionally there is higher levels of surface based CIN over eastern KS which may cause the line to weaken as they move east. So have bumped up POPs with coverage wording for the rest of this afternoon. Still looks like the main threat for thunderstorms will impact the forecast area overnight. The shortwave moving into the northern plains is sparking convection across northern NEB. This is expected to be the beginnings of an MCS later tonight and most guidance shows the nose of the low level jet and strongest theta-e advection focused over far northeast KS. There may still be some storms develop within the warm air advection pattern ahead of the MCS, so have POPs ranging from chance across the southern counties to categorical over northeast KS. Forecast soundings show elevated CAPE values increasing up to around 2000 J/kg thanks to the strong moisture advection and there 18Z HRRR is projecting to potential for wind gusts over 70 MPH with the MCS as it moves into northern KS. And deep layer shear will be strong enough that some supercell structure could allow for some large hail for a discrete storm or end of a line segment. PWs increase to over 2 inches so the storms will likely have heavy rain. The MCS is expected to remain progressive enough that rain totals should still be manageable with respect to flash flooding. This activity should exit east of the forecast area by daybreak Saturday with some residual cloud cover hanging around. Outflow from the MCS is progged to stall out across southern KS with an 850MB boundary setting up across east central KS. It still appears this will be a focus for renewed thunderstorms development Saturday evening. However the low level jet is not nearly as strong and veered more to the southwest. Still there is very high moisture pooling along the boundary and convection that does form will be capable of heavy rainfall. Fortunately this looks to mainly fall south of tonight`s heavy rain. Models show strong instability along this boundary and 0-6km shear is forecast to be 40KT to 50KT. So there will be a risk for severe storms. If the low level jet was stronger, there would be better confidence in severe storms. This activity could linger into Sunday morning. For Monday weak surface ridging and some dryer air look to give a break from the convection with afternoon temps in the middle 70s to around 80. Another shortwave within the northwest flow may spark some showers and storms on Tuesday, but the weak surface ridge is progged to still be over the area so moisture quality is instability are questionable at this point. Models show mid level ridging amplifying over the southern Rockies through the second half of next week. This would favor hotter temperatures with POPs generally less than 30 percent. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 622 PM CDT Fri Jun 7 2024 The primary concern this period continues to focus on the arrival time of an overnight storms complex impacting the terminals. Have made slight adjustments to the going forecast and the eventual improving conditions after the storms move through. Still uncertain how fast storms move through the terminals so have left a tempo group for now. As storms become more organized and track toward the area, updates will be made to arrival time frames. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Wolters AVIATION...Drake