Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/26/23


Area Forecast Discussion
National Weather Service Amarillo TX
655 PM CDT Thu May 25 2023 ...New AVIATION... .SHORT TERM... (This evening through Friday night) Issued at 250 PM CDT Thu May 25 2023 Two additional rounds of severe thunderstorm and localized flood potential are ahead during the evening and early overnight hours both Thursday and Friday. Large hail and damaging winds are the primary concerns both days with flooding concerns focused on developed areas and locations that have already received multiple rounds of rainfall. 19z WV satellite readily shows two shortwaves of interest - one over W OK and the other over the Sangre de Cristos. Visible satellite shows and expanding field of flat cumulus. Surface observations show temperatures mainly in the 70s with dewpoints in the upper 50s and lower 60s. This afternoon into tonight, expect another round of convection. Due to the aforementioned cumulus field remaining flat thus far, suppressed ascent in the eastern Panhandles due to the influence of the W OK shortwave, and the later arrival of the shortwave to our west, expect convection to largely hold off until after 7pm, when thunderstorms look to spread northwest to southeast across the CWA. This outcome is in line with many consecutive runs of the HRRR, latest NSSL WoFS convective allowing ensemble, and 12z NAM. Have moved away from NBM PoPs toward the HRRR as NBM PoPs seem to be heavily contaminated by GFS/RAP which suggest light showers and/or drizzle have been occurring all day in the eastern Panhandles, an outcome which has almost totally failed to be borne out. As for potential hazards, with MLCAPE approaching 2000 J/kg and 0-6km bulk shear values of around 30 knots, severe thunderstorms could occur. That said, the low end supportive shear should limit the overall top end severe potential to around golf ball size hail and 70 mph wind gusts. Due to the late arrival of convection, while cold pool dynamics could still force down a severe wind gust, surface stabilization should lead to a very slim tornado risk. Finally, given PWAT values of 1"+ and slow expected storm motions, localized flooding could occur in cities and town and in locations that have received heavier rain on previous days. Tomorrow, with a weak upper ridge reducing in prominence, expect an uptick in wind speeds aloft. Thus, while the pattern looks to be similar to today in which a later arriving shortwave leads to thunderstorms generally occurring after 7pm, increase in shear may lead to a bit higher top end severe potential compared to Thursday, with hailstones greater than 2" in diameter possible and a small risk for tornadoes, particularly if convection arrives closer to 7pm rather than later for optimal timing with respect to surface stabilization and the increase in the LLJ. While storm motions should also be a bit quicker, rich moisture and antecedent conditions suggest a continued risk for localized flooding. Ferguson && .LONG TERM ... (Saturday through next Wednesday) Issued at 250 PM CDT Thu May 25 2023 Showers and thunderstorms look like a pretty good bet on Saturday as the flow aloft strengthens and another short wave trough moves over the region in the southwest flow aloft. Rain chances may actually decrease some Sunday through Tuesday as an upper level ridge builds over the area. Any short waves will be weaker and the shear will be weaker, so coverage of storms are expected to go down during these days. Not to say that we will not have any rain at all. We just are not expecting a large complex of storms to move across the area without the upper level support. Showers and storms may become more widespread again by next Wednesday as the upper level southwest flow increase again. Another stronger short wave trough may also move over on Wednesday. Highs will generally remain slightly below normal in the 70`s and lower 80`s Saturday through next Wednesday. && .AVIATION... (00Z TAFS) Issued at 642 PM CDT Thu May 25 2023 Overall, VFR conditions expected for the early part of the TAF period, but will drop to MVFR/IFR with storms approaching the TAF sites from 02-07z tonight. Have done the best with prevailing 3 hours of TSRA, but will likely be amending at the timing gets a bit more certain. But slower storm motion certainly could have at least 2 to 3 hours of TSRA as the storms expand in coverage. Overnight cigs may still hold MVFR to IFR under back side stratiform rain with isolated thunderstorms embedded. Will not not thunder after the main push of storms as confidence is too low. Weber && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 58 71 58 74 / 90 60 50 60 Beaver OK 59 74 58 76 / 60 60 50 60 Boise City OK 54 72 55 74 / 50 40 50 40 Borger TX 61 73 60 78 / 90 60 60 50 Boys Ranch TX 59 75 59 77 / 90 50 70 50 Canyon TX 58 72 58 75 / 80 60 50 60 Clarendon TX 59 74 59 73 / 70 60 50 50 Dalhart TX 54 71 55 74 / 80 50 70 50 Guymon OK 57 72 57 75 / 60 30 60 50 Hereford TX 58 73 57 76 / 60 50 60 60 Lipscomb TX 58 75 57 75 / 60 60 50 50 Pampa TX 59 71 58 74 / 80 60 50 60 Shamrock TX 60 74 59 75 / 60 60 40 50 Wellington TX 60 77 59 77 / 50 50 40 40 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...None. OK...None. && $$ SHORT TERM...77 LONG TERM....15 AVIATION...89
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
956 PM CDT Thu May 25 2023 .UPDATE... Issued at 954 PM CDT Thu May 25 2023 It appears that diurnally increasing MLCIN is greatly reducing the threat for severe weather across western North Dakota. Chances for thunderstorms remain in the forecast into the night, with a main threat of locally heavy rain. MRMS has estimated a very narrow corridor of 3-4 inches of rain over and just to the south of White Earth Bay Recreation Area. Any additional rainfall over that area would be problematic, but observed trends currently favor a very low chance of a heavier storm there. The wind forecast has been decreased through Saturday night, especially during the overnight periods when the NBM has been exhibiting a significant high bias. It will still be windy across central and eastern North Dakota during the daytime hours on Friday and Saturday, but the probability of widespread advisory criteria is lower than the deterministic NBM guidance would imply. This thinking is supported by observational comparisons to NBM over the past 24 hours, a mostly stagnant synoptic pattern, and ensemble tools such as the ECMWF EFI showing no signal for anomalous winds. UPDATE Issued at 704 PM CDT Thu May 25 2023 Scattered thunderstorms have developed along a surface trough that extends from near Baker, MT to New Town to Portal. The placement of the trough and storms is slightly farther east than consensus guidance had previously indicated, but recent runs of the HRRR seem to be capturing this shift. The 1800 UTC NAMnest correctly had the trough and storms farther east, but also included a cluster of storms along the ND/MT border north of the Missouri River that never materialized. A couple of storms have briefly pulsed to near severe levels, but the lack of strong effective shear and a messy, multicellular mode should continue to inhibit a longer duration severe threat with any given storm. Stronger mid to upper level forcing ejecting north off the Black Hills is producing more robust convection over southeast Montana and northeast Wyoming. As this forcing moves north, it will likely help sustain convective activity across western North Dakota through the evening, and possibly shift it slightly back to the west as it takes over as the primary forcing mechanism. The environment is expected to remain supportive of only marginally severe storms at worst. The greatest hazard could be heavy rain, especially with the increased risk for training convection given storm motions parallel to the surface boundary. MRMS has already estimated as high as 2 inches of rain east of Watford City. && .SHORT TERM...(This Evening through Friday) Issued at 326 PM CDT Thu May 25 2023 Showers and thunderstorms, mainly across western North Dakota, highlight the short term period. This afternoon, an upper high was centered over northern Minnesota, with ridging extending up into the Canadian Prairies. Upstream troughing was centered over the western CONUS, with a closed low over eastern Oregon, and sharp south-southwest flow aloft over the forecast area. At the surface, a cold front was analyzed north- south over far western North Dakota, with a trough extending north into eastern Saskatchewan. Windy southeast winds continue this afternoon from strong southerly low-level flow and a modest pressure gradient with a broad surface high centered well to our east. As a shortwave moves across the surface trough and frontal boundary, convection is expected to continue developing in eastern Montana and western North Dakota through the rest of the afternoon and the evening. With strong southerly flow aloft, storms will be moving almost straight north. The environment is most supportive of a strong to severe storm right along the state line, with SPC mesoanalysis advertising 1000-1500 J/kg of MLCAPE and up to 30 knots of 0-6km shear right in this corridor, before shear quickly decreases to the east further into North Dakota. CAMs have been moderately consistent in developing convection more vigorously in the upcoming couple of hours, with satellite showing towers building in far western North Dakota. Given the environment, main concerns with any strong to severe storm would be hail to the size of quarters and wind gusts up to 60 mph, but with abnormally high PWATs, heavy rain is also a hazard. Storm motions are expected to be a bit higher than they have been the past few days, but will still have to keep an eye out for training storms and potentially locally high rainfall amounts. Precipitation chances are expected to stay limited to western and maybe into far north central North Dakota this evening through the night. Breezy southeast winds will continue through the night and help keep lows mild, in the upper 50s to lower 60s. A similar day is expected on Friday as the upper air pattern stays consistent and there is not much movement on surface features. The expectation is for a break in shower/thunderstorm activity through the morning and into the afternoon before chances increase again late afternoon and through the evening, expanding west to east, although chances stay very low in our eastern counties. The environment is similar as well, with generally 1000 J/kg of instability and weak shear. The area at risk of a few strong to severe storms is again across western North Dakota. Highs will be in the upper 70s to lower 80s. .LONG TERM...(Friday Night through Thursday) Issued at 326 PM CDT Thu May 25 2023 Warm and unsettled weather is expected through the holiday weekend and into next work week. The general expectation from ensemble members is for the upper high to slide east over the Great Lakes region on Saturday, while troughing continues to extend south to be based over the Nevada/Utah region. Southwest flow aloft over the Dakotas supports an active pattern. Slightly more substantial waves are expected on Saturday and Sunday, with blended guidance producing widespread 60 to 70% chances of showers and thunderstorms across much of western and parts of central North Dakota during the afternoon and evening hours both days. CSU machine learning probabilities continue to highlight Saturday with the highest potential for severe thunderstorms, with the focus on southwest North Dakota for severe hail. There are some differences among deterministic guidance, but the consensus is for 1000-2000 J/kg of MLCAPE, with 0-6 km shear forecast around 20-30 knots. Highest PoPs are consistently in the west and north central, decreasing to the east. The upper air pattern looks to become more diffuse later in the weekend and into next week, as some ensemble members tilt the trough positive and even close off a low over California, leading to flow aloft over the Dakotas becoming weaker and a bit more zonal upstream of persisting ridging over the eastern CONUS. More confidence exists in a general active pattern and warmer than normal temperatures, with low predictability in precipitation chances next week. The general expectation is for chances for showers and thunderstorms to be highest in the afternoon and evening, decreasing late at night and through the morning before increasing again the next day. && .AVIATION...(For the 00Z TAFS through 00Z Friday Evening) Issued at 954 PM CDT Thu May 25 2023 Scattered thunderstorms will continue across far western North Dakota this evening. The storms are likely to remain west of KDIK, but could move over KXWA between 03Z and 06Z. Ceilings are likely to remain VFR under any storm, but visibility could drop as low as IFR. The strongest storms may produce gusty, erratic winds, and small hail. Most terminals will see southerly winds continue around 10-15 kts through the forecast period, becoming slightly higher and gusty Friday afternoon. Another round of thunderstorms could begin developing across western North Dakota Friday afternoon. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Hollan SHORT TERM...Jones LONG TERM...Jones AVIATION...Hollan
Area Forecast Discussion
National Weather Service Cheyenne WY
841 PM MDT Thu May 25 2023 .UPDATE... Issued at 833 PM MDT Thu May 25 2023 Not much to change with the forecast update this evening as very slow moving thundershowers continue to push to the east in southeast Wyoming. Heavy rainfall amounts of 1-2 inches per hour have been estimated by radar, and we have been highlighted by the Weather Prediction Center across portions of our cwa to see continued thundershowers with moderate to heavy rainfall at times. The severe weather threat is gone, but instability combined with outflow boundaries and high levels of moisture will continue to provide ample opportunities for rainfall where it occurs. Hi-res models (HRRR) have pinpointed the convection lasting through approximately 9Z as it propagates to the east into the NE Panhandle overnight. && .SHORT TERM...(Tonight - Saturday Night) Issued at 236 PM MDT Thu May 25 2023 Showers are thunderstorms are expected to increase in coverage and intensity across southeast Wyoming through the late afternoon into the early evening hours, aided by strong low-level convergence and dynamic support associated with multiple weak disturbances and PVA aloft. High-res guidance is in good agreement with the majority of this activity staying in southeast Wyoming through 00z. Increasing low-level WAA after 06z on the nose of a 35 knot southeasterly low level jet may contribute to elevated convective development across the western Nebraska Panhandle overnight, mainly focused invof the Platte River Valley. The overall severe threat this evening should be quite low w/ limited shear suggesting pulse-type storms, but w/ MLCAPE approaching 1500 J/kg some storms may briefly produce small to marginally severe hail. Gusty winds may also accompany decaying storms in particular. SPC Mesoscale Analysis & future RAP suggests increasing surface relative vorticity along numerous boundaries in southeast Wyoming over the next few hours, along w/ upwards of 150 J/kg of 0-3 km CAPE and good stretching potential. This is similar to last evening, although the Non-Supercell Tornado Parameter will not be nearly as high. Nonetheless, environmental conditions could lead to landspout development w/ a few updrafts, especially across Platte/Goshen/Laramie counties through early evening. The overall potential for widespread strong to severe storms could increase markedly on Friday w/ continued moisture return resulting in surface dew points climbing into the mid/upper 50s to near 60 F over the western Nebraska Panhandle w/ lower 50s extending west to the I-25 corridor. Steepening mid-level lapse rates in response to cooling aloft associated with multiple disturbances should support CAPEs up to 2000 J/kg. Deep layer vertical shear is not progged to be particularly strong. However, veering low-level wind profiles & deep southwesterly mid & upper-level flow oriented parallel to the surface front should support storm organization. Expect convective activity to initially develop over western reaches of the CWA over Carbon County by early afternoon, intensifying and also increasing in coverage as it moves eastward into the moderately unstable air- mass present to the east of the Laramie Range after 3 PM. Profiles appear to support upscale growth into one or more convective storm complexes likely capable of severe hail and/or wind. Multiple high resolution model cycles have suggested bowing line segments, so do think high winds may be the primary concern with a multicell storm mode. Deep layer shear profiles do not appear to support supercell structures at this time. Confidence is low regarding the potential severity of this event, but no doubt it will be quite busy through the mid/late afternoon and early evening. Status quo for Saturday w/ the same general weather pattern likely to remain in place. .LONG TERM...(Sunday - Thursday) Issued at 400 AM MDT Thu May 25 2023 Heading into the second half of the weekend, the shortwave will eject out of the longwave trough over the west coast, and the retrograding position is expected to lead to more westerly flow aloft. This will result in decreased moisture both at the surface and in the column integrated sense for Sunday, Monday, and possibly Tuesday. GEFS and ECMWF ensemble mean PW values drop to near or slightly below climatological norms for Sunday and Monday. Thus, expect lesser storm coverage and lower precipitation amounts these days, with a little more sunshine likely. That being said, isolated to scattered showers and thunderstorms are still likely, but coverage and strength should be less than what we see in the next few days. Still will have to watch for locally gusty winds and small hail as always. While 700-mb temperatures are expected to remain nearly constant for much of the forecast period, did increase the diurnal range by nudging highs up a degree or two, and lows down a degree or two on Sunday and Monday to account for the drier atmosphere and clearer skies. Models have come into better agreement on showing the west coast trough developing into a closed low aloft by midweek next week, and as this slowly meanders eastward, we should see the flow aloft turn more southerly once again and boost moisture again. Ensemble PW values climb again Tuesday through Thursday. NAEFS mean PW exceeds the 90th percentile of climatology once again by late Wednesday across portions of the area. Thus, have PoPs increasing again above 50% for the midweek period. Temperatures are still expected to hold fairly steady through this period, about 5 degrees above climatological norms. A few models show cooler temperatures (but still not anywhere near freezing) on Thursday as the cutoff low ejects over the area, but a forecast of a cutoff low on day 7 has considerable uncertainty, so won`t put too much stock in this yet. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 528 PM MDT Thu May 25 2023 Wyoming Terminals... VFR conditions currently at all terminals and is expected to remain through the 00Z TAF period. Isolated showers and thunderstorms are ongoing across portions of southeast Wyoming. Included VCTS for KCYS and KLAR through around 03Z as the storms move out of the area by then. KRWL has VCSH, as thunderstorm activity looks to remain further east. Winds are gusty across the terminals, but will begin to decrease over the next few hours and remain low through the night. Gusty and erratic winds are possible in and around any thunderstorms. Nebraska Terminals... VFR conditions at all terminals expected to remain over the next several hours. Isolated showers and thunderstorms are possible across the Panhandle late this evening, so included VCTS at KBFF and KSNY with VCSH at KCDR. During the early morning hours, ceilings will drop to IFR at KBFF, KSNY, and KAIA with MVFR conditions at KCDR. KSNY and KAIA may approach LIFR conditions. Additionally, some fog is possible across all terminals in the morning hours. && .FIRE WEATHER... Issued at 330 AM MDT Thu May 25 2023 Minimal fire weather concerns continue for the next several days due to higher humidity and daily chances for wetting rains. Humidity below 20% is possible in the lower elevations of Carbon county for the next several days, but fuels remain in green-up status. Otherwise, expect very high RH east of the Laramie range for the next few mornings and scattered to numerous afternoon showers and thunderstorms through Saturday. Storms could produce locally heavy rainfall and gusty or erratic winds. Slightly drier air is expected Sunday through Tuesday, so will see lower afternoon RH (but still mostly over 20 to 25%), and less widespread precipitation for those days. && .HYDROLOGY... Issued at 330 AM MDT Thu May 25 2023 Warm temperatures will continue to lead to snowmelt in areas above about 9000 where significant snowpack still lingers. Minor flood stage continues to be reached each morning along the Little Snake River near Dixon and Baggs and this is expected to continue for the next several days. A Flood Warning remains in effect until further notice. A Flood Watch remains in effect for the North Platte River at Saratoga and Sinclair. The river remains in action stage at Saratoga, but is no longer forecast to reach minor flood stage as of the latest forecast from the RFC. Will let the Flood Watch continue for now due to uncertainty regarding rainfall over the next few days, but may be able to let this go by the weekend if rainfall ends up on the low end. Action stage has also been reached on the Encampment river, and this is forecast to continue through the weekend. The Laramie river at Laramie is also forecast to reach action stage this weekend. There are also concerns for burn scar flash flooding through Saturday with daily chances for afternoon showers and thunderstorms that could produce locally heavy rainfall. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ UPDATE...BW SHORT TERM...CLH LONG TERM...MN AVIATION...AM FIRE WEATHER...MN HYDROLOGY...MN
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
743 PM CDT Thu May 25 2023 .SYNOPSIS... Issued at 740 PM CDT Thu May 25 2023 A gradual warming trend will kick of the holiday weekend, with dry conditions continuing through the first part of next week. Chances for isolated showers will return by late Wednesday, though organized thunderstorms appear unlikely anytime soon. && .UPDATE... Issued at 743 PM CDT Thu May 25 2023 Forecast is generally on track this evening. Northeast wind gusts have been easing up a bit as we get close to sunset. Air mass remains quite dry this hour with many locations still seeing humidity values of 20-25%, though winds remain elevated enough (likely around 10 mph) to keep temperatures from completely cratering overnight. However, lows in the mid to upper 40s will prevail. Geelhart && .SHORT TERM... (Through Late Friday Night) Issued at 146 PM CDT Thu May 25 2023 <<<<<<< Key Messages >>>>>>> 1. The air mass remains dry leading to vast diurnal temperature swings the next couple days. 2. Highs remain near to slightly below normal tomorrow. With dry (dewpoint depressions on the order of 35 degrees) northeast flow continuing this evening, temps at 130 PM remain near to slightly sub seasonable in the low 70s. The mid and high level clouds streaming southward from northern Illinois continue to dissipate as they approach the central portion of the state, which implies we`ll get a little more warming before the afternoon`s over. Nonetheless, the cold advection in the wake of the front which moved through last night will keep most of the area (except possible the far southwest) from exceeding 75-77 degF for highs. Given dewpoints remain in the mid to upper 30s, and the absence of any clouds, the only thing standing in the way of an efficient night of radiational cooling would be winds which are currently forecast to stay around 4-7 kt. If those drop off, we`ll have no problem cooling into the mid to perhaps even lower 40s by sunrise. Guidance is suggesting tomorrow will be slightly warmer, with the mean of both the EPS and GEFS ensembles near 80 for highs area-wide. NBM suggests a ~75% probability for highs greater than 75 and even a ~40% chance for reaching 80 degF. As with today, temps may overperform slightly given the dry (and hence susceptible to rapid thermodynamic changes) air mass and lack of clouds. HREF suggests tomorrow afternoon we`ll be a bit drier than today as well with 55- 60% of the ensemble forecasting RHs less than 30% at KAAA; the HRRR even suggests RHs briefly as low as the mid teens. We`ll need to monitor this closely to assess fire weather danger, but at this time with 10h fuel moisture > 10% and winds expected to remain sub 20mph we should be able to do without any headlines. Bumgardner .LONG TERM... (Saturday through Next Thursday) Issued at 146 PM CDT Thu May 25 2023 <<<<<<< Forecast Highlights >>>>>>> 1. Warming temperature trend expected, with 90 degree temps possible (60% chance) by Wednesday. 2. 30% chance for showers/thunderstorms by Wednesday evening. The rex blocking pattern with a trough in the southeast states and an upper high in the northeast and Great Lakes is forecast to be ongoing at the start of the extended forecast period...and, aside from the upper features becoming increasingly washed out with time (as is typically the case), cluster analysis suggests little change throughout the extended. The mean of the ensemble forecast for 500hPa heights has everything shifting ever-so-gradually east, though, which would favor increasing temps as mid level flow switches from east-southeast to south-southwest over central Illinois. Each deterministic model, along with its respective ensemble, thus depicts increasing 850mb temps - especially to our west across the High Plains where multiple rounds of thunderstorms are expected next week. NBM`s 75th percentile increases from the mid 80s Saturday to upper 90s by next Wednesday and Thursday - implying some potential for an early season heatwave across the region. However, (1) there is a bias in which the high end of NBM`s probability distribution tends to run a bit hot this time of year, (2) if there is any convective debris or elevated wildfire smoke that drifts overhead from the west temps would be several degrees cooler than forecast, and (3) the deterministic GFS and CMC each show splotchy QPF across the area by Wednesday evening, likely from diurnally-driven "pop-up" convection which could also hold o19ur highs at or below the forecast which for now brings highs, possibly conservatively, into the lower 90s by Wednesday. The GFS even shows some light QPF dotting a portion of the area Tuesday, so we may not be entirely dry, though if garden variety air mass thunderstorms are the culprit for the QPF signal in guidance the distribution of precipitation amounts will be uneven and hence many folks who could benefit the rain are likely to go without it. Bumgardner && .AVIATION... (For the 00z TAFs through 00z Friday Evening) Issued at 620 PM CDT Thu May 25 2023 VFR conditions expected next 24 hours, as remaining high clouds fade away and mostly clear skies prevail. Northeast winds have been a bit gusty this afternoon, but will fade soon with sunset. However, sustained speeds around 10 knots or so will continue through Friday afternoon. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Lubbock TX
646 PM CDT Thu May 25 2023 ...New AVIATION... .SHORT TERM... (This evening through Friday) Issued at 215 PM CDT Thu May 25 2023 The atmosphere is still fairly worked over from last night`s convection. This is evident by current visible satellite imagery with widespread popcorn cu. Surface temps at 130 PM are in the mid 70s area wide. They should continue to slowly climb through the afternoon. Convection has already begun to develop across the Rotan Ridge in New Mexico. This convection is expected to push slowly to the east-southeastward through the late afternoon before pushing into the Texas Panhandle. Models have been somewhat scattered with their portrayal in tonight`s convection, including the CAMs. Most develop an MCS across northeastern New Mexico and move it into the Texas Panhandle. Beyond that, solutions vary from keeping precip across the Texas Panhandle, pushing the MCS southeastward into the Rolling Plains, pushing the MCS into both the South Plains and Rolling Plains, and developing a line across eastern New Mexico and pushing it eastward across the Texas Panhandle and the South Plains (the least likely outcome). Much of the issue is centered on the upper ridge and where the models initiate the upper ridge. Current observations have the upper ridge slightly more westward than what was initialized in most models. This would result in northwesterly upper flow and would allow for the MCS to take a more southeasterly path later tonight and somewhat mirror last night`s MCS. The HRRR has latched on to this scenario over the past 2 runs. Currently the HRRR is more favored, but for now PoPs will be kept below the likely category given the many possible outcomes. The severe threat is less than yesterday with the main threats being wind gusts up to 60 mph and possibly hail up to the size of quarters. Convection is expected to be ongoing across portions of the Rolling Plains tomorrow morning before dissipating and pushing off to our east. Convection is likely to develop again in eastern New Mexico during the late afternoon before reaching our western zones by the early evening. Storms will continue to be limited in forward speed due to the overhead ridge. A slow forward speed along with high available moisture will allow a continued risk for heavy downpours and localized flash flooding both tonight and tomorrow. && .LONG TERM... (Friday night through next Wednesday) Issued at 215 PM CDT Thu May 25 2023 While there remains some discrepancy amongst the models regarding an upper level short wave trough rotating out of the Desert Southwest and northern Mexico late in the weekend, the trend remains toward the trough passing east to the Rolling Plains or beyond in the Sunday/Monday time frame. This will continue to result in lower PoPs and thunderstorm mention focused more toward the eastern half to third of the forecast area. The return of a dirty ridge Wednesday with diurnally-driven convection on the upstream side of the ridge axis across eastern New Mexico that then moves into the forecast area is expected toward the end of the forecast period Wednesday and Thursday. NBM temperatures continue to look fine. All-in-all, the blend has been accepted with only some minor adjustments to precipitation chances made at this time. && .AVIATION... (00Z TAFS) Issued at 638 PM CDT Thu May 25 2023 VFR ceilings prevail until early tomorrow morning when MVFR ceilings will move in at PVW/LBB. In addition, showers and thunderstorms are possible again but timing is much later into the morning hours tomorrow. Confidence on timing of the line of storms, so a tempo group was used as a best guess for the higher confidence sites of PVW/LBB. Confidence is lower on storm extent east towards the CDS site, so have opted for a period of vicinity thunderstorms at this time. With any thunderstorms, winds may become erratic strong wind gusts. MVFR ceilings should lift through the late morning and VFR conditions will return to all three TAF sites through the afternoon. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...51 LONG TERM....07 AVIATION...11
Area Forecast Discussion
National Weather Service Norman OK
544 PM CDT Thu May 25 2023 ...New AVIATION... .SHORT TERM... (This evening through Friday) Issued at 234 PM CDT Thu May 25 2023 As has been the case the last several days, weak flow and MCV`s meandering about the area have led to scattered slow-moving showers and thunderstorms. Activity will likely weaken with loss of daytime heating early this evening, with renewed shower and storm chances across our western counties late tonight into Friday morning as high plains convection once again approaches. Instability will be rather weak today and tonight, so thunderstorms are expected to remain subsevere, however localized heavy rainfall and flooding could be a concern given slow storm motions. Redevelopment of isolated showers/storms will once again be possible tomorrow afternoon, with higher chances in the western half of the area. Ware && .LONG TERM... (Friday night through next Wednesday) Issued at 234 PM CDT Thu May 25 2023 The combination of shortwave ridging overhead and drier air advecting into the area on the backside of an upper low to our east will lead to precipitation chances retreating westward on Saturday, mainly across western Oklahoma and western north Texas on the western periphery of the upper ridge as high plains convection potentially moves out of the panhandles. Rain chances may expand a bit further eastward on Sunday as models depict the potential for an MCV to drift into the area, but confidence in this scenario is low. Shear and instability remain rather weak so severe weather is not expected. As we head into next week, model guidance suggests that the cutoff low over the southeastern US will begin to shift eastward, but our area will continue to see very weak mid-upper level flow as the southwestern US trough remains parked well to our west. Slightly better surface moisture and a weakening of the upper ridge over the local area should allow for isolated to scattered shower/thunderstorm activity to return to more of the area Monday through the middle of next week, but chances for organized severe weather continue to be very low through the period given such weak flow aloft and only modest instability. Temperatures will remain near or below normal through much of next week. Ware && .AVIATION... (00Z TAFS) Issued at 534 PM CDT Thu May 25 2023 Light E/SE winds are expected tonight with some reduction in cloud cover possible. Broken to overcast mid-level to high-level clouds then stream in by early Friday morning. Decaying thunderstorm complex could move across the Texas panhandle and enter western Oklahoma by mid-morning. However, the HRRR model has trended slower with this rain shield and uncertainty is high on timing and whether it will reach Oklahoma. Have left out of TAFs for now. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 62 80 61 79 / 10 10 10 10 Hobart OK 60 79 60 78 / 20 30 20 30 Wichita Falls TX 63 84 63 81 / 10 20 10 10 Gage OK 58 74 59 77 / 60 70 40 50 Ponca City OK 61 82 58 81 / 20 20 10 10 Durant OK 62 85 62 84 / 10 10 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && $$ SHORT TERM...08 LONG TERM....08 AVIATION...01
Area Forecast Discussion...CORRECTED
National Weather Service Pueblo CO
338 PM MDT Thu May 25 2023 .SHORT TERM...(This evening through Friday) Issued at 320 PM MDT Thu May 25 2023 Key Messages: 1) Scattered storms this evening, a few severe storms possible across the plains. 2) Another day with severe thunderstorms possible for the southeast plains on Friday. Currently, another day of weak shear (0-6km 20-30 kts) but strong instability (CAPE of 1500-2500 J/KG) across the area, with convection firing over the eastern mountains and along a weak surface boundary (stretching from near TAD to just south of LHX) as of mid-afternoon. Most CAMs move storms eastward from the higher terrain across the plains this evening, though perhaps in a less organized fashion as last night, as dynamic lift today is less pronounced. Still a low end severe threat for most of the plains into the evening, with HRRR suggesting some storms along the Palmer Divide after sunset until close to midnight. Convection farther west over the mountains and interior valleys has been weaker/more isolated in nature, and expect most storms here to diminish this evening. Will maintain high end sct pops for locations east of the mountains until late evening, then taper precip chances off from west to east toward midnight. On Friday, upper level swly flow continues across CO, with perhaps a subtle increase in mid/upper level winds by late day as jet streak noses into the swrn part of the state. Over the eastern mountains and plains, moist/unstable air mass will remain in place, leading to another round of afternoon/evening thunderstorms, though orientation of the upper jet suggests best dynamic forcing may shift north of the Palmer Divide by evening. Again, 0-6km shear looks fairly weak, in the 25-35 kt range, while instability by afternoon climbs into the 1000-2000 J/KG range. Marginal risk of severe storms looks warranted, though strongest storms may end up north of the Palmer if lastest iteration of the NAM is correct. Farther west over the mountains and interior valleys, air mass looks slightly drier, leading to a downturn in convective strength and coverage, though still at least isolated activity expected. Max temps will remain little changed from the past couple days. .LONG TERM...(Friday night through Thursday) Issued at 320 PM MDT Thu May 25 2023 Key Messages: 1) Heightened chances for daily afternoon rain showers and thunderstorms for southern Colorado into next week. 2) Near to above average temperatures expected for much of southern Colorado into next week. Saturday - Thursday... The weekend and into much of next week will maintain a rather consistent, but active, weather pattern. Both deterministic and ensemble model guidance are in strong agreement about developing an overall, but messy, ridge pattern across the central US, with broad and disorganized troughing to the west. Colorado will be situated generally on the western periphery of the ridging and eastern periphery of the troughing. This pattern will allow for numerous weak short waves and ripples in the flow to pass over the southern Colorado region. In addition to that, given the broader troughing to the west, deeper moisture is expected to stay further into Colorado, though exact moisture quality will depend highly on how the waves and ripples in the flow ultimately evolve. Given all of this, daily chances of afternoon rain showers and thunderstorms are anticipated for the southern Colorado area each day to some extent. Also, with the moisture, and therefore instability, expected, along with modest upticks in shear from the waves and ripples, some stronger storms are possible across the area, but particularly across the eastern plains, where moisture will be greatest. As for temperatures, a more steady state of temperatures is anticipated given the ridging and no major storm systems/cold fronts. This pattern is expected to keep much of southern Colorado near to slightly above average for this time of year. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 320 PM MDT Thu May 25 2023 VFR conditions at all terminals the next 24 hrs, though there will be sct tsra across the area this evening, with storms most numerous across the southeast plains. Will carry a vcsh at all terminals until 01z-02z, and may upgrade to a vcts mention at KPUB 22z-02z, and KCOS 22z-04z, as storms move off the mountains. Most activity will diminish/shift east toward KS after 03-05z, though HRRR holds onto some storms until 05z-07z over the higher terrain north of KCOS. Very little change in the pattern for Friday, with a risk of afternoon convection again at all terminals after 20z, and the potential for severe storms around KCOS and KPUB 21z-00z. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PETERSEN LONG TERM...SIMCOE AVIATION...PETERSEN
Area Forecast Discussion
National Weather Service Blacksburg VA
1031 PM EDT Thu May 25 2023 .SYNOPSIS... High pressure will fill in over the central Appalachians tonight. Low pressure developing off the southeast coast on Friday will track into the Carolinas by Sunday, bringing rain and below normal temperatures to the region for the weekend. This low is expected to move off to sea by the middle of next week. && .NEAR TERM /THROUGH FRIDAY/... As of 1020 PM EDT Wednesday... Showers should fade after midnight in southwest VA/NC mtns. Surface inverted trough with convergent boundary across the upper TN Valley into southwest VA will linger through midnight but should wane overnight with showers fading. Already had some observed precip amounts around a half inch across Bland and Smyth Counties, but most have been under a quarter inch. Fog may very well creep in late tonight if we clear enough but for now kept it over toward the NC mtns/far SW VA. Previous discussion... Expect a few showers this evening in the mountains, then dry... Notch of higher theta-e along inverted trough across the southwest VA mountains will keep a few showers, maybe a rumble of thunder going til 10pm, then expect activity to end. Will potentially see some fog, however, cloud cover may linger tonight to prevent this, so for now leaving fog out of the forecast where it rained. No other major changes to the forecast. Previous discussion... Confidence high for showers this evening... HRRR and HREF both depict showers forming in southeast West Virginia this afternoon then expanding past Bluefield into the Mountain Empire area after 6PM/22Z before dissipating around 03Z/11PM. Isolated thunderstorms are possible along this axis, especially from Bluefield to Richlands. Clouds will clear out of the mountains overnight. Low clouds behind the cold front were dissipating as they moved into southern Virginia this afternoon. Central and eastern Virginia and North Carolina will be on the northern fringe of the high clouds swirling around the low developing off the southeast coast tonight. These clouds will spread northwest on Friday and will cover much of the Mid Atlantic region during the afternoon. Surface dew points will be in the 40s tonight and Friday. Temperatures will lower faster as the wind speed diminishes overnight but this drop will be highly dependent on the amount of clouds. MAximum temperatures on Friday will also be largely influenced by the timing and opaqueness of the clouds. Using a ConShort/NBM blend for temperatures. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... As of 215 PM EDT Thursday... Upper low brings rain for the Memorial Day weekend... High pressure will continue to wedge south Friday night into Saturday morning. Meanwhile, surface low will develop Saturday morning in response to an upper level wave over the southeast states. This upper wave will eventually close off and the surface low will move inland by Saturday afternoon. Rain from this low will push northwest and should arrive by late Saturday morning and become widespread across the area Saturday night and continue into Sunday. May see rainfall coverage taper a bit by Sunday night as the upper low pivots east. Strong cool air wedging will be firmly in place and being on the northwest side of the low, expect well below normal temperatures for Saturday and especially Sunday. Temperatures in the highest elevations may struggle to reach the lower 50s during the day on Sunday. As expected, instability will be nearly non-existent so not expecting any thunder within this period. Winds will be out of the northeast throughout the period as well, gusting to as much as 20-30mph at times. This will make for a very chilly weekend with wind chills (yes, talking wind chills at the end of May) in the 40s in the higher elevations. Highest rainfall amounts will be along and east of the Blue Ridge where 1 to 2 inches of rainfall appears to be likely. Amounts of 1 inch or less west of the Blue Ridge. && .LONG TERM /MONDAY THROUGH THURSDAY/... As of 215 PM EDT Thursday... Rain chances continue into Memorial Day, but will taper some throughout the week... Closed upper low continues to slowly drift east, but it will eventually pick up some forward speed as ridging builds to the west and a north Atlantic trough swings south just enough to pick it up and pull the low into the Atlantic. However, should still see some rain showers continue, but will become less of a chance each day through the week. May have a chance for an isolated storm or two Monday, but after that, dry high pressure wedges south again from New England and cuts off any chance of instability. Therefore, kept only showers in the extended. Ridging builds east somewhat and temperatures begin to warm by later in the period. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... As of 720 PM EDT Thursday... Think showers will stay in vicinity of BLF/LWB/BCB til 02z, with potential 2-3kft cigs but mostly VFR. Also lower cigs at DAN should clear toward 02z. Clouds will clear out of the mountains overnight from north to south, though keeping some high clouds around. Low pressure developing off the southeast coast will likely send high clouds into the entire area Friday, but no flight restrictions through 00z/Sat. Above average confidence in all elements, except average on vsby/cigs this evening in the mountains. EXTENDED AVIATION OUTLOOK... Saturday, showers will expand northwest, reaching southern Virginia and KDAN in the morning and southeast West Virginia and KLWB/KBLF by the end of the day. Widespread IFR to MVFR conditions are expected Saturday night into Sunday across the region. Confidence in sub- VFR ceilings and occasional showers is rising for Memorial Day as the upper level low continues to wobble near the Mid Atlantic. Tuesday, long range models take east, ending the rain. The Memorial Day and Tuesday part of the forecast are low confidence. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...AMS NEAR TERM...AMS/WP SHORT TERM...BMG LONG TERM...BMG AVIATION...AMS/WP
Area Forecast Discussion
National Weather Service Salt Lake City UT
413 PM MDT Thu May 25 2023 .SYNOPSIS...An unsettled pattern will continue across northern Utah through the weekend, while a gradual drying trend continues across southern Utah. && .SHORT TERM (Through 12Z/6AM Saturday)...A broad trough situated over the western U.S. has made very little movement over the past 12 hours, bringing yet another rough of showers and thunderstorms over mainly the northern two-thirds of Utah and southwest Wyoming. As has been the case for the past couple of days, the threat of showers and thunderstorms will exist across the region through roughly sundown, with activity coming to an end overnight. Until then, the threat of gusty winds in excess of 40 mph, small hail, and heavy rain leading to potential flash flooding on recent burn scars will remain. Through the next 24-36 hours, the axis of the mean trough will begin shifting into the region and increase the overall broad synoptic forcing for ascent. With moisture remaining in place over the lower to mid levels, this increased ascent will provide better forcing for afternoon shower and thunderstorm activity across the forecast area (primarily focused on the northern two- thirds of the area). The most recent (12Z) SPC HREF run continues to be supportive of anywhere from 250-1000 J/kg/K of CAPE across mainly the northern two-thirds of the forecast area, however, 18Z HRRR and NAMNest forecasts for 0-6km shear values are ~20-25kts less than today`s values. What this really means is that while the overall threat for afternoon showers and thunderstorms will exist again tomorrow, the threat of more organized storms will be lower... which also lowers the overall threat for hail and wind hazards. As a slow progression of this trough occurs through the next 24 hours, lower level flow will increase across the eastern half of the forecast area. Utah`s eastern valley areas will lack the surface moisture that has been seen across northern Utah and southwest Wyoming, which will combine with surface wind gusts in excess of 25 mph to create an area of critical fire weather conditions. No headlines will be made at this point in the season since fuels are still being sampled with a higher than normal fuel moisture content in this region. .LONG TERM (After 12Z/6AM Saturday)...Long term period begins with the axis of a shortwave trough translating eastward into Utah. Guidance remains in fair consensus that limited moisture across the southern third or so of Utah will largely preclude precipitation potential accordingly. However, from central Utah northward, PWATs increase such that in combination with modest PVA and diurnal heating, scattered convective development is expected by late morning, becoming more widespread through the afternoon hours. Coverage is expected to be maximized through the northern third or so of Utah, as well as southwest Wyoming. Convection will then gradually wane moving into the late evening and overnight hours with loss of diurnal heating. Aside from the aforementioned precipitation potential, the trough migrating more into the region will bring a slight cooldown of a few degrees or so to the northern half of Utah as well as southwest Wyoming. By Sunday, initial shortwave ejects out of the region as a reinforcing shortwave drops southward out of the PacNW into northern California and western Great Basin. This will continue a messy southwesterly flow atop the region with embedded energy, leading to a similar convective trend to that of Saturday. That said, with modest mid level height rises noted, expect a bit less overall coverage. Additionally, will see 700mb temps nudge upwards as the initial trough departs, resulting in the start of another gradual warmup that will continue on into the upcoming week for the northern half of the forecast region. From Monday onward into midweek, the aforementioned shortwave begins to close off along the California coast, with uncertainty increasing due to low confidence and diverging model solutions in regards to its subsequent motion and evolution thereafter. For Monday and Tuesday, local forecast region is largely expected to remain between this feature and ridging through the southern Plains. In turn, warming trend continues, and afternoon convection will remain possible (~15-30% chance) from central Utah northward during the afternoon hours. The remainder of the forecast period sees guidance diverge further, and thus lower confidence is noted, but for now expect similar trends/pattern to that of the last several days. With subcloud layers remaining fairly dry, convection most days will be capable of gusty erratic outflow winds. Additionally, any thunderstorms that form, especially more mature thunderstorms, will be capable of periodic frequent lightning and heavy rain, and those planning outdoor recreation should remain weather aware accordingly. && .AVIATION...KSLC...VFR conditions will persist at the KSLC terminal through the TAF period outside of any thunderstorm activity. Breezy northerly winds stick around as showers and isolated thunderstorms move across northern Utah. Precipitation lingers into the overnight hours before drying up with a brief period of winds flipping back to the south. Similar conditions return on Friday with mostly persistent northerly flow and vicinity showers and storms. .REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will persist at the all terminals in Utah and SW Wyoming through the TAF period outside of any thunderstorm activity. Breezy southerly winds stick around down south with northerly flow up north as showers and isolated thunderstorms move across the CWA. Precipitation lingers into the late evening hours before drying up. Similar conditions return on Friday with mostly diurnally driven flow with showers and storms. && .FIRE WEATHER...A broad trough positioned over the West Coast states has kept a period of disturbed southerly flow over the state of Utah, leading to shower and thunderstorm activity over roughly the northern two-thirds of the state. This big picture system will remain in place through the upcoming weekend, however, an ejecting shortwave disturbance will bring some cooling across the northern half of the region on Saturday. Low level flow will increase tomorrow afternoon ahead of this ejecting wave, which will generate critical fire weather conditions across the eastern valley areas of Utah and elevated fire weather conditions over southern and western Utah. With increased shower and thunderstorm coverage expected over the northern half of Utah through the next 7 days, humidity values will remain more moderated in this region while the southern half of the area will sit mostly below the 20% humidity mark. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...Flood Watch through Thursday afternoon for UTZ107. WY...None. && $$ SHORT TERM...Webber LONG TERM...Warthen AVIATION...Selbig FIRE WEATHER...Webber For more information from NOAA`s National Weather Service visit... http://weather.gov/saltlakecity
Area Forecast Discussion
National Weather Service Tulsa OK
932 PM CDT Thu May 25 2023 ...New SHORT TERM... .SHORT TERM... (The rest of tonight) Issued at 932 PM CDT Thu May 25 2023 Isolated showers and storms that have been ongoing this evening have dissipated with the loss of daytime heating. Patchy mid and high clouds will likely prevail across the forecast area overnight. Forecasted overnight lows look reasonable per latest trends, as do the remaining first period elements. Updated zones will reflect removal of evening PoPs. Updated ZFP/PFM/AFM out shortly. && .LONG TERM... (Tomorrow through Thursday) Issued at 236 PM CDT Thu May 25 2023 The CWA remains awkwardly positioned under the current omega block pattern as we transition to a rex block over the E CONUS Friday into the weekend. Another round of isolated showers and some thunderstorms are possible tomorrow afternoon before drier air is pulled into the area from the northeast this weekend. As a result, pleasant conditions are expected for the holiday weekend with seasonable high temps generally in the 80s and light winds. Weak southerly flow then returns to the area late in the weekend as the blocking pattern breaks down and an upper level shortwave slowly moves toward the area from the desert southwest. May see another decaying W Oklahoma MCS affect western portions of the CWA Sunday morning, but much of the area should remain dry. Beginning on Monday, would expect an increase in afternoon PoPs again as moisture advects into the area through the end of the period. The ECMWF was generally drier as it attempts to shunt this feature south and builds another ridge into the area. Other solutions keep the trough closer to our area with more rain and storms. Given the uncertainty with diverging solutions and minimal changes to the airmass, will stick with continued slight chance to chance PoPs each day, slightly above NBM guidance. The chance for showers and storms currently looks to be the highest Tuesday through Thursday. Temps should remain near to slightly above seasonal averages, though if the ridge pattern verifies next week, may see hotter temperatures build into the region. Generally light winds will prevail through the period. Rada && .AVIATION... (00Z TAFS) Issued at 608 PM CDT Thu May 25 2023 After storms dissipate by 01Z near KTUL and KBVO, VFR conditions are expected areawide with sct to bkn mid and high cloud and light sfc winds. The latest HRRR does show isolated afternoon showers and storms, but chances of affecting a terminal pretty low and will not be included. Followed lead of previous forecast and included afternoon cu at all sites. Lacy && .PRELIMINARY POINT TEMPS/POPS... TUL 62 84 57 82 / 10 20 0 10 FSM 63 85 57 84 / 0 20 0 0 MLC 60 84 57 83 / 10 10 0 0 BVO 57 84 52 82 / 10 20 0 10 FYV 58 82 52 81 / 0 20 0 0 BYV 59 79 50 79 / 0 10 0 0 MKO 60 82 58 81 / 10 20 0 0 MIO 60 82 52 79 / 0 20 0 0 F10 60 82 59 80 / 10 10 0 10 HHW 63 84 61 82 / 10 20 0 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ SHORT TERM...23 LONG TERM....43 AVIATION...30
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
531 PM MDT Thu May 25 2023 .DISCUSSION...(This Evening Through Thursday) Issued at 108 PM MDT Thu May 25 2023 Water vapor shows upper ridge over the Upper Midwest with trof over the western CONUS. AT the surface, trof extends from northeast WY into far western ND. A few -shra are bubbling in the northern Black Hills along an east-west surface boundary. Geocolor RGB shows area of smoke encompassing the western Dakotas. MLCAPE has risen to around 1000J/kg along and east of aforementioned surface trof, and will continue to rise close to 2000J J/kg this afternoon. As ejecting short wave lifts out of the Central Rockies, scattered convection will develop across our far western zones and continue into the evening. Effective bulk shear is quite low, so not expecting much in the way of severe storms. RAP smoke model does show much of the smoke lifting north/northeast of the area tonight as southwest flow aloft increases. On Friday, stronger short wave approaches in the afternoon/evening. MLCAPE should be a little higher than today, up to about 2000J/kg, and shear will be slightly stronger. This could lead to a few more stronger to severe storms, especially over our far western zones later in the day. Continued southwest flow with embedded waves will persist through the weekend, resulting in daily chances for showers/storms. Some strong to severe storms possible at times. By early next week, west coast trof splits with our area more under the influence of zonal flow with the northern stream. While unsettle conditions will likely continue, the overall severe threat should be somewhat limited. Temps should remain slightly above average. && .AVIATION...(For the 00Z TAFS Through 00Z Friday Evening) Issued At 531 PM MDT Thu May 25 2023 SHRA/TSRA will continue over portions of northeastern WY and far western SD thru 03-06z before activity wanes. Localized MVFR conditions and strong, erratic wind gusts are possible in association with stronger storms. After 09z, model consensus suggests low stratus with MVFR/localized IFR cigs could develop across southwestern SD and northeastern WY. If so, these lowered cigs could persist thru 12-15z before conditions improve. Additional TSRA, some of which could produce wind gusts over 40 kt and hail of quarter sized or larger, are expected across northeastern WY and western SD tomorrow afternoon. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION...Johnson AVIATION...Sherburn