Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/18/22

Area Forecast Discussion
National Weather Service La Crosse WI
1102 PM CDT Tue May 17 2022 .DISCUSSION...(Tonight through Tuesday) Issued at 228 PM CDT Tue May 17 2022 Key Messages: - Strong to severe storms possible Thursday night into Friday - Cooler this weekend A few short wave troughs to work with in the near term, including one that has well established frontogenetic forcing brushing our southern counties today. This is coinciding with southerly moisture transport. The increased moisture and lift will continue to produce showers for the area tonight into tomorrow morning. The highest precipitation amounts /0.3-0.6"/ will be along and south of the I-94 corridor. Elsewhere, 0.1-0.3" are expected. RAP and HRRR model soundings suggest little to no CAPE in the area overnight, so can expect primarily rain showers. More favorable conditions for strong storms stays to the southwest of the area, though a rumble or two of thunder in far SW Wisconsin, SE Minnesota, or NE Iowa is not out of the question if whatever CAPE is available can be tapped into. The precipitation is expected to move out of the area Wednesday evening/night. Storm chances Thursday night into Friday: Focus shifts to convective threat going into Thursday night. While Thursday morning should start off quiet and pleasant, a digging short wave trough dropping out of Canada will lead to a changing pattern as the day progresses. Response from this wave will lead to a fairly narrow but rapid return of low level moisture northward along an approaching cold front. This is seen well in moisture transport fields and model mixed layer CAPE fields streaming northeast ahead of boundary reaching in excess of 1500 J/kg. Confidence is lower in how far north higher dewpoints may get attributing to these values. Could be a hint of a warm front in there as well, likely advecting northeast as the day goes on. Based on the strength of the wave certainly see the possibility of strong to severe storms as front comes in Thursday night. Timing seems a bit more delayed than previous forecasts so this may work against the overall threat. But given dynamics of stronger wind field, convection could still be potent with a wind or hail threat from late evening into the overnight hours. See Day 3 Storm Prediction Center for other details on risk. Convection will work east early Friday morning as front clears the area. Medium range guidance a bit varied in how far north any precipitation may form along this so will keep in small chances but gut tells me this will likely remain south of the immediate area. Weekend and early next week / Cooler weather: The big story will be the cool down in temperatures for the weekend as longwave troughing builds into the northcentral CONUS. Highs will be in the 50s with some freeze possibilities Sunday and Monday morning at least in the central Wisconsin cold spots. Saturday could still bring some rain chances it appears. There are a group of model solutions that stripe a post-frontal frontogenetic rain band through southern 30-40% rain chances remain there. Otherwise, a few instability showers may be around, or at least diurnal stratocumulus. A general warming trend begins on Monday in a fairly swift progressive zonal flow as a series of shortwave troughs shift through. On and off shower chances into midweek look reasonable with storm chances returning later Tuesday. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1102 PM CDT Tue May 17 2022 Rain showers will continue through most of the overnight hours. However, MVFR ceilings have been slow to develop this evening. As rainfall continues to moisten the surface and temperatures slightly decrease overnight, MVFR ceilings are still likely, but just closer to early morning by 12z. A heavier and more intense shower passing directly over a TAF site could temporarily reduce visibilities to MVFR conditions. Winds will be on the lighter side of less than 10 knots, but several wind shifts will occur over this forecast period. Easterly winds will prevail through a majority of the period, but late morning/early afternoon is when winds will rotate from the west to then even southwesterly by the evening. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ DISCUSSION...Dahl / Shea / Baumgardt AVIATION...Peters
Area Forecast Discussion
National Weather Service El Paso TX/Santa Teresa NM
530 PM MDT Tue May 17 2022 .AVIATION...00Z TAF CYCLE Generally VFR conditions through period with SKC-FEW250, but there will be more FU creating some areas of BKN040-060 around KTCS once again starting after 03Z. Could see some VSBY reductions to around 5SM around Sierra County. Farther south, less confident with FU causing VIS restrictions, but it is possible and will be monitored at KLRU and KELP. Winds generally light tonight, 5 to 15 KTs, with similar values continuing into Wednesday. May be brief and minor LLWS at KELP around 06 to 12Z as winds aloft increase but values should remain below 30 kts. .PREV DISCUSSION...250 PM MDT Tue May 17 2022... .SYNOPSIS... Warm and dry weather with breezy afternoon west winds will persist through the end of the work week. Afternoon west winds will strengthen Thursday and Friday, becoming gusty in the higher terrain. Elevated to critical fire weather conditions for most areas Thursday and Friday afternoon. A backdoor cold front will move through the area this weekend and cool temperatures down. Nocturnal east winds overnight will increase moisture values area wide Sunday through Tuesday, with afternoon west winds scouring out the moisture during the day. && .DISCUSSION... .SHORT TERM...Tonight and Wednesday... Pretty quiet in the short term with a persistent surface low over NE NM which will keep a little pressure gradient over the area which could keep overnight lows mild again tonight, especially on eastern mountain slope locations. Most areas should fall back into the mid 50s to mid 60s. Smoke could be a bigger issue than last night over Sierra and northern Dona Ana counties looking at the HRRR Smoke model. Kept mention of patchy to areas of smoke across these locations. For Wednesday, surface winds remain westerly but lighter than today as a weak ridge moves into the region. Besides some morning smoke lingering, should see another sunny day. High temperatures look similar to today with highs mainly in the lower to mid 90s over the lowlands with 70s and 80s in the mountains. && .LONG TERM...Thursday through Wednesday... A shortwave trough with a weaker closed low will approach the NM/AZ border early Thursday morning. At the same time, stronger upper level westerly winds over the Rockies will induce a lee side trough in CO. The surface pressure gradient will strengthen over the area Thursday. The upper level short wave will dig too far south to impact the area, keeping stronger winds aloft out of the CWA for the most part. Southwest winds will still become breezy in the afternoon hours for most of the area. As the air remains dry and warm, fire weather concerns build for Thursday afternoon. Temperatures will remain around 5 to 10 degrees above normal and skies clear. Friday, a broad and large upper level ridge starts to drop south, increasing upper level winds above the northern parts of the CWA. The lee side trough will shove southward over northern NM Friday afternoon from a surface cold front moving down the plains. Winds Friday afternoon will be breezy to windy with gusts possible in the higher terrain areas of Gila Wilderness and Sacramento Mountains. Critical fire weather conditions will continue Friday with the air remaining dry. As pressure heights above the southern part of the CWA drop, temperatures will cool to near normal for most of the lowlands Friday. Saturday, the backdoor cold front will approach the area. Deterministic guidance is in strong agreement that the boundary will stall near the Sacramento Mountains for most of Saturday. This is due to westerly winds aloft over the western part of the CWA persisting and mixing heights rising in the afternoon hours to mix those west winds down to the surface. Overnight into Sunday morning, the cooler airmass will surge westward increasing humidity values temporarily. Sunday will be cooler with temperatures around normal or a few degrees below. West winds will reestablish later in the afternoon, but east winds will dominate again over night into Monday morning. For next week the deterministic guidance starts to disagree. More shortwaves will pass through the area, increasing winds in the afternoon hours with easterly winds brining in more moisture overnight. Precipitation chances are slim as the moisture scours out during the day, however temperatures will remain near normal through mid week next week. && .FIRE WEATHER... Not much change in the weather pattern through the end of the week with temperatures remaining above normal and winds out of the west. Tomorrow will see winds drop off a little bit before starting to increase for the end of the week when near critical conditions are likely. High temperatures will continue to be above normal with highs in the 90s for the lowlands. A back door cold front moves in this weekend which will drop highs about 3 to 5 degrees and also bring in some higher dew points to at least eastern zones and min RH`s into the 10-15% range early next week. No precipitation on the horizon. && 26-Grzywacz && .PRELIMINARY POINT TEMPS/POPS... El Paso 68 96 63 96 / 0 0 0 0 Sierra Blanca 67 92 60 91 / 0 0 0 0 Las Cruces 60 94 59 95 / 0 0 0 0 Alamogordo 57 94 58 95 / 0 0 0 0 Cloudcroft 45 73 48 72 / 0 0 0 0 Truth or Consequences 61 93 61 95 / 0 0 0 0 Silver City 58 85 57 84 / 0 0 0 0 Deming 55 94 54 93 / 0 0 0 0 Lordsburg 56 91 53 90 / 0 0 0 0 West El Paso Metro 65 95 63 95 / 0 0 0 0 Dell City 55 96 53 96 / 0 0 0 0 Fort Hancock 63 97 58 98 / 0 0 0 0 Loma Linda 60 89 59 88 / 0 0 0 0 Fabens 65 97 60 96 / 0 0 0 0 Santa Teresa 60 94 58 93 / 0 0 0 0 White Sands HQ 68 94 65 94 / 0 0 0 0 Jornada Range 50 93 57 93 / 0 0 0 0 Hatch 58 96 58 94 / 0 0 0 0 Columbus 64 95 60 93 / 0 0 0 0 Orogrande 60 95 59 95 / 0 0 0 0 Mayhill 52 86 53 85 / 0 0 0 0 Mescalero 48 83 50 83 / 0 0 0 0 Timberon 46 81 54 80 / 0 0 0 0 Winston 47 90 50 90 / 0 0 0 0 Hillsboro 60 91 60 91 / 0 0 0 0 Spaceport 53 93 57 93 / 0 0 0 0 Lake Roberts 36 86 48 86 / 0 0 0 0 Hurley 52 87 52 88 / 0 0 0 0 Cliff 42 91 42 93 / 0 0 0 0 Mule Creek 39 87 52 86 / 0 0 0 0 Faywood 56 86 55 88 / 0 0 0 0 Animas 57 92 51 91 / 0 0 0 0 Hachita 55 92 53 90 / 0 0 0 0 Antelope Wells 56 91 54 89 / 0 0 0 0 Cloverdale 53 87 53 84 / 0 0 0 0 && .EPZ WATCHES/WARNINGS/ADVISORIES... NM...None. TX...None. && $$ 99/99/99
Area Forecast Discussion
National Weather Service Goodland KS
528 PM MDT Tue May 17 2022 .UPDATE... Issued at 524 PM MDT Tue May 17 2022 Storms have formed along a warm front/dryline that is currently across Northwestern Kansas. A Severe Thunderstorm Watch for counties along and southeast of a line from Tribune to Greeley counties has been issued until 11pm MT/midnight CT. These are counties along and ahead of the line. Hail and strong winds are expected to be the main threat as this line moves to east across the next few hours. Also storms have formed along the Palmer Divide and are moving east into the area. These storms are expected to move east with most of them dissipating shortly after the Colorado state line. A few may continue eastward with latest guidance giving the highest chances in Southwestern Nebraska. A few storms may produce strong wind gusts. && .SHORT TERM...(This evening through Friday Morning) Issued at 234 PM MDT Tue May 17 2022 The main concerns for the short term period are the potential for severe weather this afternoon and tomorrow afternoon. A developing low pressure system just off the Front Range is leading to an increase in a CU field along with a developing storm near Ft. Collins/Greeley area. The expectation is that this will continue to move towards the east towards Yuma/Kit Carson county through the afternoon with the main threat being damaging wind gusts with inverted v soundings present along with a copious amount of DCAPE being present. This activity should weaken as it nears or just after it cross the Kansas state line as we lose diurnal heating. The other area for potential severe weather appears to be along and east of a Tribune to McCook line along a weak cold front/wind shift boundary. A stout CAP is in place but is anticipated to break late this afternoon as the better forcing from the Colorado low and convective temperatures are met. A Slight risk from the SPC is in place where large hail and damaging winds appear to the main hazard. RAP forecast soundings near Hill City indicate MUCAPE near 2600 j/kg resulting in a high large hail and significant hail parameter which may support isolated instances of 2+ inch hail. A caveat to this would be weak 0-6km shear of 25-35 knots will would support more of a multicell/cluster to develop; as a result feel the significant hail potential will be reserved to initiation time frame of 22-00Z unless a dominant more discrete cell can occur. Due to the rapid upscale development expected am anticipating more of a damaging wind threat to eventually develop as storms move to the east out of the CWA around 05-06Z. A couple hour landspout potential may develop over portions of Cheyenne County (CO), Greeley and Wichita counties as the cold front/wind shift boundary appears to be stationary and SPC Mesoanalysis depicts and overlapping SFC Vorticity/MLCAPE area, this is dependent on if any developing updrafts occur in this area. Wednesday, low level moisture returns to east Colorado. Anticipated strong diurnal heating to result in high based updraft development along and near the Front Range. Forecast soundings indicate the potential for 0-6 shear of 25-35 knots which would result in a multicell convection solutions as damaging winds would be the main threat with some potential for large hail with the strongest storms. High temperatures are forecast to be in the upper 70s to mid 80s across the area, winds will however be variable around 5-15 mph across the area. Overnight, lows will be seasonal in the 50s over the the CWA. Thursday, high pressure develops over the High Plains with gusty southwesterly winds advecting dry air as RH values approach the single digits over western portions of the area. Southwesterly winds of 15-25 mph and wind gusts up to 35 mph look likely across the majority of the area. After collaboration with surrounding offices have went with a Fire Weather Watch for counties along and west of Kansas Highway 27 for Thursday afternoon. As of 5/14 Fire Weather Fuel Status for the CWA fuels are dry across the entire area with a few burn bans remaining in place. The potential for rainfall due today and tomorrows convective potential does exists which may inhibit short term fire weather concerns, opted to go for the watch due to the very dry recent conditions and not making any assumptions on how much rainfall each county may receive as a widespread rain is not currently expected at this time. Thursday evening a strong cold front is expected to move into the area which will allow winds to shift from the SW to the NE during the evening hours, which would pose the risk for a rapidly changing wildfire direction if one were to be ongoing. Cooler temperatures then move into the area behind the front into Friday morning with overnight lows in the upper 30s across east Colorado to the low 50s over eastern portions of the area. .LONG TERM...(Friday through Tuesday) Issued at 1245 PM MDT Tue May 17 2022 Friday will be breezy and much cooler with high temperatures ranging from the lower 50s in northeast Colorado to the lower 70s in Hill City. Upper trough approaching the Rockies will cause increasing clouds through the day. Precipitation chances start in northeast Colorado Friday afternoon and spread across the remainder of the area Friday night, ending Saturday morning. As temperatures drop into the lower 30s, rain will mix with or change to snow, mainly in northeast Colorado, but possibly into northwest Kansas and southwest Nebraska as far east as Highway 25. Models still aggressively accumulating snow, but with warm ground temperatures expecting quite a bit of melting. Nonetheless, an inch or so of slushy accumulation possible during this time. Frost and freeze highlights will probably be necessary as the growing season is well under way. Might see some sun Saturday afternoon and optimistically have highs in the 50s and 60s. Another late season frost or freeze possible Saturday night as well, mainly along and west of Highway 25 and into northeast Colorado, as temperatures drop into the 30s once again. For Sunday and Monday, another shortwave trough will be moving out of the northern Rockies and across the central High Plains. Temperatures will warm into the upper 60s to lower 70s Sunday afternoon before scattered showers develop Sunday night with the upper system. Temperatures will be warm enough for all rain this time around, with lows Sunday night in the 40s. Showers will continue into Monday morning before ending Monday afternoon. High temperatures on Monday will be in the upper 60s to lower 70s with lows Monday night in the 40s. Tuesday currently looks dry as upper flow turns southwest ahead of the next system digging into the central Rockies Tuesday night. Downsloping wind component will allow temperatures on Tuesday to warm to around 80. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 445 PM MDT Tue May 17 2022 For KGLD... VFR conditions are expected through the period. However, a round of thunderstorms may reach the terminal during the evening hours (likely between 01-03Z). Ahead of the thunderstorms, the outflow may kick up blowing dust and reduce visibility a bit. If the thunderstorms or outflow goes over the terminal, expect strong wind gusts potentially in excess of 50 kts and a sudden wind change. After the thunderstorms pass, relatively quiet conditions and lower wind speeds are expected. For KMCK... VFR conditions are expected through the period. However, thunderstorms may move near and through the terminal closer to midnight local time (around 03-05Z). The blowing dust potential is not expected to reach the terminal. If the thunderstorms or outflow goes over the terminal, expect strong wind gusts potentially in excess of 50 kts and a sudden wind change. Conditions will then be relatively quiet with winds reducing in speed. && .FIRE WEATHER... Issued at 234 PM MDT Tue May 17 2022 Fire weather concerns again return to the area Thursday as southwesterly flow advects dry and warm conditions back into the area. High temperatures in the 90s will aid in RH values dropping to near the single digits across western portions of the area. Southwesterly winds will gust up to 35 mph as diurnal mixing increases during the afternoon. Fuels currently remain receptive for wildfire development, as result a Fire Weather Watch was issued for counties along and west of Kansas Highway 27 on Thursday. An advancing cold front during the evening hours will cause winds to turn the northeast resulting in unpredictable changing of wildfires if one were to be occurring. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...Fire Weather Watch from Thursday morning through Thursday evening for KSZ001-013-027-041. CO...Fire Weather Watch from Thursday morning through Thursday evening for COZ252>254. NE...NONE. && $$ UPDATE...KAK SHORT TERM...TT LONG TERM...024 AVIATION...KAK FIRE WEATHER...TT
National Weather Service Jackson KY
1056 PM EDT Tue May 17 2022 .UPDATE... Issued at 1055 PM EDT TUE MAY 17 2022 The current forecast remains on track so have merely added the latest obs and trends into the T/Td/Sky grids. These updates have been sent to the NDFD and web servers. UPDATE Issued at 800 PM EDT TUE MAY 17 2022 23Z sfc analysis shows high pressure in control of the weather across eastern Kentucky. The mid level based fair weather cu are now dissipating leaving behind just some high clouds over the southwest. Currently temperatures are running in the mid 70s most places, though some of the valleys have already fallen into the upper 60s. Dewpoints, meanwhile, are similar to yesterday at this time - generally in the lower 50s with some mid 50s in the valleys, amid light winds mostly from the west. Have updated the forecast mainly to fine tune the sky cover and valley fog threat through the night. Did also include the latest obs and trends for the T/Td grids. These updates have been sent to the NDFD and web servers. && .SHORT TERM...(This evening through Wednesday night) Issued at 530 PM EDT TUE MAY 17 2022 The latest upper level map features fairly zonal flow west of the Appalachians, with embedded pockets of traversing short wave energy. East of the Appalachian chain, troughing is pushing to the Eastern Seaboard. At the surface, a cold front is draped from New England through the Ohio Valley, before becoming more quasi-stationary across the Midwest and through the central Plains. Meanwhile, a warm front is aligned from the southern Plains through the lower Mississippi Valley and along the southeastern CONUS. Modest high pressure is sandwiched in between these two fronts, generally residing from the central Appalachians through the middle/lower Mississippi Valley. Eastern Kentucky has been enjoying plenty of sunshine and another day of lower humidity, with temperatures currently in the upper 70s and lower 80s at most locations. The models are in good agreement aloft through the short term, with zonal flow continuing, with a tighter gradient inbound from the Pacific Northwest, as a vigorous vorticity lobe makes it way east across southwest Canada. Further east, an embedded short wave trough will shift from the Plains through the Ohio Valley by late Wednesday, with another more prominent upstream wave moving east southeast across the Great Lakes/Ohio Valley regions Wednesday night. At the surface, low pressure will generally move east from the Plains through the Ohio Valley into Wednesday, pulling the quasi-stationary boundary currently draped across our north further to the northeast as a warm front. Secondary low pressure will then move along a quasi-stationary boundary just to the southwest of the track of the first low, likely being influenced by mesoscale processes to some degree. By early Thursday, a cold front will be approaching eastern Kentucky from the northwest. This all spells a return to stormier conditions across our area by late Wednesday and especially Wednesday night. Tonight will feature mostly clear skies, with temperatures bottoming out in the low to mid 50s in cooler eastern valleys that take advantage of the drier low level air and calming winds. Ridges will stay up in the upper 50s, with perhaps some patchy fog in the river valleys once again, although this should be less pronounced compared to this morning. Clouds will be on the increase on Wednesday, with a weakening MCS inbound from upstream. Depending on how quickly the thicker clouds dissipate, temperatures could be a little warmer than currently forecast, generally lower 80s. The model agreement is good regarding weaker instability initially across our area through the early afternoon; however as we head into late Wednesday afternoon and especially Wednesday evening, CAM guidance varies quite a bit on how vigorous the convection could potentially be. Have the highest PoPs set up from northwest to southeast, with PoPs more conditional to the south. The HRRR is more tame in general; however, the NAM Nest and especially the NSSL show more potential for severe storms taking advantage of ample instability (ML CAPE values of 1000-2000 J/kg) and effective shears(around 40 kts) that will be place, especially west of I-75, our more typical locations for severe. The main hazards would be damaging wind gusts and large hail; however, with a boundary in play, an isolated tornado can not be ruled out as well. As we head deeper into the night, more widespread convection is expected, thanks to an increasing low level jet of 30-40 kts, and perhaps some influence from traversing short wave energy to our north. PWATs will increase to around 1.5 inches or slightly higher. Any leftover mesoscale/convective boundary will likely align nearly parallel to the steering flow aloft, setting up the potential of training cells and inevitably a threat for at least isolated flash flooding. The main question is where this sets up exactly. Given the lower confidence, will forego a watch for now, but have beefed up the wording in the HWO. The higher influx of humidity will keep temperatures much milder overnight, generally lower 60s. .LONG TERM...(Thursday through Tuesday) Issued at 302 PM EDT TUE MAY 17 2022 Lingering showers and possibly a rumble of thunder will be possible as a cold front slowly exits the region to start the period. Therefore, Thursday looks to be a warm but potentially a rainy day. Behind the exiting front, high pressure will build into the region. This high will bring the return of warmer and drier temperatures for the end of the week and into the weekend. Widespread temperatures of upper-80s and lower-90s will be possible but coupled with moist, southwesterly flow it could be a couple of very uncomfortable days. Some temperature records could be broken this weekend if this forecast trend continues. As a split-flow trough digs out of Canada and the western CONUS, the dome of high pressure will eject offshore bringing an end to the heat and humidity. However, with the trough continuing to dig and the associated low moving across the northern Great Lakes, a strong cold front is progged to move through the area through the day Sunday. Some timing differences exist with the long- term models with the GFS bringing the front through Sunday morning and the ECMWF later in the afternoon. This will be something to pay attention to because of the severe weather potential and the potential timing of the front. High pressure briefly builds in again for Monday before model consensus brings another trough out of the western CONUS, which will bring more chances for showers and thunderstorms, for Tuesday into Wednesday. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) ISSUED AT 820 PM EDT TUE MAY 17 2022 VFR conditions will prevail through the period, although there will be another window of MVFR or lower fog possible in the deeper river valleys between 05 and 12Z. Look for increasing high clouds and eventually mid-level clouds to move in late in the TAF period. West to northwest winds of 5 to 10 kts will become light and variable this evening and continue overnight. Winds will then pick up to between 5 and 8 kts out of the south southwest by the mid to late morning on Wednesday. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...GEOGERIAN LONG TERM...VORST AVIATION...GEOGERIAN/GREIF
Area Forecast Discussion
National Weather Service North Platte NE
620 PM CDT Tue May 17 2022 .SYNOPSIS... Issued at 341 PM CDT Tue May 17 2022 H5 analysis from earlier this morning had a closed low over southern Quebec with a trough extending south into the New England states. A low amplitude ridge was present from western North Dakota and eastern Montana into northern Saskatchewan and eastern Alberta. south of this ridge, zonal flow extended from the central plains west to the Pacific coast. Within this flow, shortwaves were noted over central Nebraska, as well as western Wyoming. Further west, closed low pressure was located over eastern portions of the Gulf of Alaska while a secondary low was located over Hudson Bay. Thunderstorms had impacted portions of southwestern into portions of central Nebraska earlier today. Additional activity passed through the eastern Sandhills and had cleared the area by noon CT. At the surface, a frontal boundary extended from near North Platte to Bassett Nebraska. This was more of wind shift line as temperatures ranged from the middle 70s in the northeastern panhandle to the middle 80s in far southwestern Nebraska. && .SHORT TERM...(This evening through Wednesday night) Issued at 341 PM CDT Tue May 17 2022 The main forecast challenge in the near term continues to be thunderstorm chances and severe potential tonight. A messy situation setting up across the area this afternoon with ongoing convection exiting eastern Nebraska, a frontal boundary draped across the forecast area and convection beginning to fire off to the west along the front range of Colorado and Wyoming. The CAMS including the HRRR continue to differ run to run with their convective forecast for this evening. This coupled with the exiting convection in the east, which the models didn`t initialize with this morning, has made for a low confidence forecast for tonight. Thinking here is that convection will take on two modes this evening: The first mode will be elevated convection which will track east of the front ranges late this afternoon, emerging onto the western forecast area around 00z tonight. As this elevated convection and instability hits the cold front, we should see a second round (second mode) of storms develop during the mid evening time frame. Based on the latest model guidance, this boundary will be oriented from McCook to Kearney to Columbus. Convection may also fire INVOF of a warm front/occlusion in our far northeastern forecast area. Confidence in this convection materializing is less certain as this area saw a decent amount of thunderstorms earlier today and may be less conducive to storm initiation. With a lack of confidence in the short range models tdy, will generally go with isolated pops in the central and west and pops of the scattered variety along the front this evening. This activity will exit the forecast area by late evening with some clearing skies expected toward 12z Wednesday. As for severe mode tonight, large hail and damaging winds will be the main threats. This is supported by modest DCAPE which is predominately located over the western Sandhills. As for the large hail threat, mid level lapse rates are highest along a corridor from far southwestern into central Nebraska. This is in proximity to the frontal boundary while the gusty wind threat (highest DCAPE) is located across the western Sandhills. The tornado threat appears very minimal across the eastern forecast area given the very weak low level flow expected tonight. Wednesday and Wednesday night will see generally benign conditions with a warm front lifting through the forecast area Wednesday. This feature will stall along the SD/Nebr. border Wednesday night. I did go ahead and expand pops across the northeastern forecast area late Wednesday night as the latest NAM12 and GFS developed some qpf. This seems plausible given the warm frontal boundary and an increasing low level jet, the nose of which is positioned from central into northeastern Nebraska. .LONG TERM...(Thursday through Tuesday) Issued at 341 PM CDT Tue May 17 2022 A fairly active pattern will highlight the long term period across the forecast area. A strong cold front will approach the forecast area late Thursday. Model differences in frontal timing will make for a tricky high temp forecast Thursday. MET and MAV guidance were 93 and 81 for highs respectively for North Platte Thursday. With the front approaching, and southwesterly winds in the boundary layer, am weighing the forecast toward the warmer MET forecast. This agreed with the NBM which had a high of 92 degrees for a high Thursday. Behind the cold front, much colder temps are expected with highs in the 50s forecast for Friday and Saturday. Temperatures Saturday morning and Sunday morning will cool enough to hit the lower to middle 30s west of a line from Broken Bow to Ainsworth. Was planning on inserting a mention of frost in the forecast for all areas. However, the latest GFS, which has some support from the EC soln, develops a swath of precipitation from the western Sandhills into southwestern Nebraska Friday night into Saturday morning. The model even gets cold enough to support some snow in far SW Nebraska and the eastern Nebraska Panhandle. Not anticipating any accumulations as soil temps are in the lower 60s attm. Will leave this to the front ranges and NE Colorado where snowfall rates will be higher and accumulation potential much greater. Forcing for precipitation will be in the form of very strong mid level frontogenesis, so not expecting a lot of wind Friday night and Saturday in association with the precipitation. Saturday and Sunday will be dry with a better threat for frost Sunday morning as cloud cover will be limited compared to Saturday morning. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 620 PM CDT Tue May 17 2022 Isolated thunderstorms are likely until around 06z this evening, generally affecting areas along and south of highway 20. The better chances for storm development will be along and south of Interstate 80. No storms are expected from 06z tonight through 00z Wednesday evening. MVFR/IFR ceilings and vsby in stratus are possible along and east of highway 183 from 06z this evening through 15z Wednesday. Otherwise VFR will prevail across wrn and ncntl Nebraska. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Buttler SHORT TERM...Buttler LONG TERM...Buttler AVIATION...CDC
Area Forecast Discussion
National Weather Service Memphis TN
853 PM CDT Tue May 17 2022 .UPDATE... Not much going on at the moment across the Mid-South and that will continue through most of the overnight period. A complex of thunderstorms over the Central Plains will move southeast late tonight, potentially holding together long enough to move into the Mid-South. These storms will weaken as they move into a less favorable environment with weaker deep-layer shear and a good amount of convective inhibition. Most of the instability will be elevated at this time and could support a few thunderstorms toward sunrise into Wednesday morning. This activity is forecast to pull off to the east by midday. The afternoon air mass will be pretty unstable with SBCAPE forecast to exceed 3000 J/kg. However, we may be in a somewhat subsident regime in the wake of the shortwave trough passing to our north during the morning hours. This should limit, if not preclude, convective initiation during the afternoon. While confidence is low that diurnal storms will develop along the residual outflow boundary from the morning convection, there is a conditional threat for strong to severe storms. Thus, we will include a slight chance of afternoon thunderstorms, mainly across northwest TN and the MO Bootheel, given this conditional threat. MJ && .PREV DISCUSSION... /issued 331 PM CDT Tue May 17 2022/ DISCUSSION... Relatively quiet weather expected over the Midsouth through Friday, as daytime temperatures prevail above normal. Midafternoon satellite and radar analysis showed a remnant MCV lifting east across AR. This feature was encountering progressively drier air while also gradually weakening. To the north, a well- organized MCS east of Omaha was ongoing at discussion time. Post- sunset, expect southward propagation component to develop over MO. By 12Z Wednesday, the remnant MCV is progged by the 18Z HRRR to lift into central IL, while storms over southern MO and southern IL become outflow-dominate and weaken. Chance PoPs will be maintained over northern portions of the Midsouth Wednesday morning, and could see storms reintensify a bit with daytime heating before crossing the TN River late in the morning. Otherwise, low amplitude ridging aloft and returning southwesterly low level flow will result in daytime highs around 10 degrees above normal Wednesday afternoon. A near repeat expected Wednesday night, with storms lifting east through the Ohio River valley, perhaps skirting far northeast AR, the MO bootheel and far northwest TN Thursday morning. Upper level flow will transition to southwesterly by Thursday night, in advance of a broad, progressive longwave trof over the Rockies. Airmass should remain capped to deep convection by an elevated mixed layer Friday afternoon. This EML will erode Friday night, concurrent with midlevel height falls and strengthening low level moisture advection. Today`s 12Z medium range models showed relatively tight consensus with respect to cold frontal passage and thunderstorm timing - depicting frontal passage through east AR into northwest TN during the afternoon and early evening, and north MS through late Saturday evening. This timing would provide access to diurnally- maximized mixed-layer CAPE, which the GFS and ECMWF suggests could be as high as 2000 J/kg. Absent a frontal wave, low-level helicity should be weak, given the tendency of pre-frontal winds to veer during the day. Midlevel lapse rates will favor some large hail in any pre-frontal discrete cells that develop Saturday afternoon. Otherwise the main threat appears to be damaging winds and flash flooding. Saturday`s cold front should stall over south MS Sunday, before returning north Monday. Latest guidance keeps subtropical moisture in place over northeast MS, reflected in continuing low end rain chances Sunday and Monday. Deterministic GFS appears overdone with the intensity of an approaching shortwave next Tuesday, and is out of agreement with the GFS ensemble mean and the ECMWF. Most likely scenario early next week: warm and more humid with thunderstorm chances favoring the heat of the day. PWB && .AVIATION... /00z TAFs/ VFR conditions will continue through the period. A disturbance will push through north Tennessee, and possibly affect JBR, so have added vcsh. South/southwest winds will start at 5 to 10 kts tomorrow morning then eventually increase and gust up to 20 kts by the afternoon. SWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion
National Weather Service Norman OK
632 PM CDT Tue May 17 2022 ...New AVIATION... .SHORT TERM... (This evening through Wednesday) Issued at 212 PM CDT Tue May 17 2022 Instability is increasing again as the clouds associated with this morning`s convection moves out and dissipates. A number of the models have been showing precipitation developing in the west near or ahead of the dryline and added POPs this morning for this afternoon and this evening, and have expanded the POPs in time through 06Z based on the current model trends. Any storms that do develop are expected to be widely scattered given that there is still a bit of convective inhibition, so currently do not think that POPs higher than 20 percent are needed. Although the dryline itself looks to remain farther west in the panhandles, surface moisture will still mix out some in far western Oklahoma leading to high temperature-dewpoint differences supporting an environment where thunderstorms could produce strong downbursts. There will be some hail potential as well given the expected instability. The HRRR is explicitly forecasting some heatbursts with dissipating convection late tonight. We did have some heatbursts overnight and this morning, and the environmental set up would support additional heatbursts this evening if convection does develop. Another very warm day is expected tomorrow with triple digit temperatures expected in the southwest. A surface front will slide into at least the northwestern part of the area tomorrow taking a little of the edge of the forecast temperatures northwest of the boundary. With the hot temperatures and low dewpoints in the southwest, minimum humidity values will fall to 10-15 percent in the southwest elevating fire weather concerns, but fortunately the winds will not be too strong as the surface pressure gradient relaxes near the front. && .LONG TERM... (Wednesday night through next Monday) Issued at 421 PM CDT Tue May 17 2022 A fairly unstable upper-air pattern is expected to continue Wednesday night through Friday, where a zonal flow with frequent perturbations and shortwaves. Across southeastern Colorado through the Texas panhandle, another round of storms will likely develop along a boundary, however they are anticipated to dissipated before making it into western Oklahoma and north Texas. A more established troughing pattern arrives in the northern US Friday morning, with an upper level cyclone moving through North Dakota/Minnesota on Friday. A cold front extending from the associated surface low will begin moving through the region Friday night through Saturday, bringing much cooler, below average temperatures on Saturday. Precipitation chances increase through Friday night into Saturday, mainly along and east of I-35. Large differences continue within the long range models/ensembles on the upper air pattern early next week, in particular the development of a trough across the southwestern US and the possibility of a trough moving through the region, bringing widespread precipitation chances. For now, low precip chances have been included, but trends be monitored through the weekend. Zwink && .AVIATION... (00Z TAFS) Issued at 630 PM CDT Tue May 17 2022 VFR will apply through the forecast. A few storms may try to move into western OK from the TX panhandle, but confidence is not high enough to include a mention at WWR or CSM. Mid to high clouds will increase, however, over most terminals tonight. Wind speeds will decrease overnight and then a shift from the north and northeast is expected Wed afternoon and evening. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 73 95 67 95 / 20 0 10 0 Hobart OK 71 99 66 102 / 20 0 0 0 Wichita Falls TX 75 106 69 105 / 10 0 10 0 Gage OK 60 91 60 99 / 20 0 10 0 Ponca City OK 68 90 64 93 / 20 0 10 0 Durant OK 70 95 71 94 / 10 0 10 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && $$ SHORT TERM...26 LONG TERM....50 AVIATION...03