Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/16/22

Area Forecast Discussion...UPDATED
National Weather Service Amarillo TX
644 PM CDT Thu Sep 15 2022 ...New AVIATION... .SHORT TERM ... (This evening through Friday night) Issued at 241 PM CDT Thu Sep 15 2022 Upper level S/WV trough axis is currently position across the WRN half of the Panhandles. Expect enough moisture and instability for this disturbance to generate ISO to SCT storms this aftn/eve. 18 UTC RAP analysis indicated around 500 J/kg MLCAPE with around 25-75 J/kg CIN, but the CIN was wiped out in the 19 UTC analysis while MLCAPE increased to 500-1000 J/kg. We have certainly seen CU field develop in the past hour or so and there are even some isolated showers now as well, so convective initiation has begun. Wind shear will be a limiting factor initially, but effective bulk shear is shown to increase to 30-40 kts around 00 UTC which certainly supports the marginal SVR risk per SPC. The potential for svr storms could have been greater, but timing of the strongest lift, best shear and highest MLCAPE are not in perfect alignment mainly due to the location/timing of the S/WV already over the area. S/WV timing/location is the main reason that the highest POPs (30-40 percent) favor the east this aftn. Severe wind gusts will be the greatest threat from storms today, but there could be localized severe hail slightly greater than 1 inch as well. There is a little more cap in place on Friday, but the modest H7 theta-e ridge remaining over the area suggests a final very weak s/wv in the aftn could generate a storm or two in the east where forecast soundings show a period with weak SFC convergence, no cap and 500-1000 J/kg SBCAPE. Based on this, went above NBM POPs and included a mention of TSTMs for areas w/ 10-20 POP just east of AMA. Can`t rule out a severe storm given the combination of wind shear and CAPE, but things would have to really come together for that to occur and percentages remain low. Highs will reach the 90s most locations and this will be the first of several days of this to come as things heat up. Gittinger && .LONG TERM ... (Saturday through next Wednesday) Issued at 241 PM CDT Thu Sep 15 2022 Temps nearing triple digit territory again for the early part of the week. Dry until mid to late week when a front comes through. By Saturday there will be general troughing in the west with the axis over California and ridging in the east with the axis over the Ohio Valley. This will place the Panhandles in southwest flow aloft. The trough looks to dig through Sunday down the western coastline. This will allow for a closed high pressure dome to set up over the Ark-La-Tex region for the early part of the week. Long range models continue to bounce around the low around the California coast and the high pressure dome around Texas. As shortwaves ride around the ridge, the flow will likely take storms that form off the mountains northeastward into CO and KS. By midweek though, models indicate a front could enter the Panhandles. The frontal passage looks to bring precip chances with it. Models disagree on the timing of the passage through, which leaves the NBM with various low end precip chances from Wednesday afternoon through the end of the week. Will need to monitor trends for any consistency between models and runs to get a better sense of the frontal timing. Beat && .AVIATION... (00Z TAFS) Issued at 634 PM CDT Thu Sep 15 2022 A thunderstorm will still be possible at AMA early this evening, so have a TEMPO group in there. Otherwise, thunderstorms should stay to the east of the TAF sites for this forecast. Southerly winds will turn more to the west before sunrise at DHT and GUY, but then they will turn back out of the south and southwest in the afternoon. Southerly winds will continue at AMA and they will get gusty again by late morning. Skies are expected to remain VFR outside of the thunderstorms. && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 63 91 66 93 / 20 10 10 0 Beaver OK 63 94 68 96 / 50 10 10 10 Boise City OK 54 90 59 91 / 10 0 10 0 Borger TX 67 95 70 97 / 20 10 10 0 Boys Ranch TX 63 92 66 94 / 10 10 10 0 Canyon TX 63 91 64 93 / 10 10 10 0 Clarendon TX 63 91 67 93 / 20 10 10 0 Dalhart TX 57 90 60 92 / 0 0 0 0 Guymon OK 61 94 65 96 / 20 10 0 10 Hereford TX 62 92 64 94 / 10 10 10 0 Lipscomb TX 65 94 68 96 / 40 10 10 10 Pampa TX 64 91 67 93 / 20 20 10 0 Shamrock TX 63 94 67 95 / 20 10 10 0 Wellington TX 64 94 68 96 / 10 0 0 0 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...None. OK...None. && $$ SHORT TERM...88 LONG TERM....16 AVIATION...15
Area Forecast Discussion
National Weather Service Burlington VT
942 PM EDT Thu Sep 15 2022 .SYNOPSIS... A cold night is on tap for the North Country with lows expected to drop into the mid 30s to mid 40s. Some patchy frost will be possible across the Adirondacks and Northeast Kingdom given the cooler temperatures and light winds. Friday will be a rinse and repeat of today but a degree or two warmer across the region. Dry weather continues through much of Saturday before rain chances increase Saturday night. && .NEAR TERM /THROUGH FRIDAY NIGHT/... As of 938 PM EDT Thursday...Forecast is on track, with clear skies currently but mid and high clouds approaching from the northwest/Canada. Made some minor updates to temperatures, dew points, and winds/wind gusts to keep up with the latest obs, but it`s still dry, slightly breezy, and chilly out there across the forecast area. Previous discussion below: Previous Discussion...We should continue to see some light winds through the overnight period with a well mixed boundary layer. The HRRR vertically integrated smoke shows a plume of elevated smoke (like 20,000 ft high) nosing into the North Country around 7 PM. Be rest assured, no smoke will be anywhere near the surface so we don`t anticipate any air quality issues. Temperatures will fall quickly through the first part of the evening with clear skies and mostly light winds in place. A deck of high clouds will move into the region and should help moderate temperatures a bit from truly bottoming out. Still, it should be quite the chilly night with lows in the mid 30s to mid 40s. Patchy frost is expected across the Adirondacks and Northeast Kingdom but should patchy enough and only around for a brief period to not warrant a frost advisory tonight. Another fall-like day is on tap for Friday with highs once again in the 60s but only in the mid 40s at the higher elevations. Mostly clear skies with a few high clouds will be on tap so be sure to enjoy the great outdoors if you`re able to. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... As of 300 PM EDT Thursday...Saturday continues to look like the better of the 2 weekend days as high pressure centered over the Northeast in the morning slowly drifts off the eastern seaboard by the afternoon/evening. Increasing southerly flow on the backside of the high will push a warm front northward through the region during the morning hours with perhaps a few sprinkles around, but drier and warmer conditions will develop for the afternoon in the warm sector as the front moves north of the Canadian border. Highs will be seasonal ranging from the upper 60s to mid 70s. More unsettled weather is then expected for the remainder of the weekend as model consensus shows the aforementioned warm front stalling just north of the Canadian border with several weak pieces of shortwave energy passing through the forecast area. This energy combined with an increase in low/mid level moisture marked by PWATs rising to around 1.5" give or take a quarter inch, will support scattered to numerous showers developing Saturday night through Sunday, mainly across central/northern zones closer to the frontal boundary. After a few cool nights, Saturday night will be much milder with increased clouds and precipitation around. Look for lows only in the mid 50s east to mid 60s west. Highs Sunday will be variable based on where precipitation sets up, with current thinking being upper 60s to mid 70s across the mid/northern zones and mid 70s to around 80 south. && .LONG TERM /MONDAY THROUGH THURSDAY/... As of 300 PM EDT Thursday...Heading into next week the focus remains on the aforementioned frontal boundary which looks to interact with a potent northern stream shortwave trough dropping southeast from Ontario Monday afternoon and evening. After a brief lull Monday morning, this interaction will bring more widespread showers to the region Monday afternoon into Tuesday morning until the trough shifts east Tuesday afternoon when a brief ridge of high pressure builds in for Tuesday night. Thereafter, guidance diverges on the timing of our next strong frontal boundary which when it comes through will bring a period of showers, potentially heavy, followed by the coldest air of the early fall season. The GFS is the most progressive with this feature with fropa occurring Wednesday night, while the ECMWF isn`t until Thursday afternoon, and the GDPS is even more delayed until Friday. Will offer chance PoPs for now given this uncertainty. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... Through 00Z Saturday...Very quiet aviation weather expected over the next 24 hours as high pressure builds in. Seeing a thin layer of smoke from western US fires high up in the atmosphere on satellite, but this will stay well above 10kft. Otherwise, a mid-level cloud deck will spread over our area overnight into Friday, but widespread VFR conditions are expected to continue. Winds overnight will be from the northwest generally between 5 and 15 knots through the TAF period, with some occasional afternoon gusts to 20 knots possible. Outlook... Friday Night: VFR. NO SIG WX. Saturday: VFR. NO SIG WX. Saturday Night: VFR. Chance SHRA. Sunday: Mainly VFR, with local MVFR possible. Chance SHRA. Sunday Night: MVFR/IFR conditions possible. Chance SHRA. Monday: Mainly IFR, with local MVFR possible. Likely SHRA. Monday Night: IFR. Chance SHRA. Tuesday: Mainly IFR, with areas MVFR possible. Chance SHRA. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Clay NEAR TERM...Clay/Storm SHORT TERM...Lahiff LONG TERM...Lahiff AVIATION...Duell
Area Forecast Discussion
National Weather Service Cheyenne WY
531 PM MDT Thu Sep 15 2022 .SHORT TERM...(This evening through Friday night) Issued at 230 PM MDT Thu Sep 15 2022 Scattered showers and thunderstorms have begun developing early this afternoon over southeast WY. An uncapped region of 500 J/kg MLCAPE off the latest RAP has developed along and east of the South Laramie Range ahead of a shortwave passage expected today. This area of instability looks to expand this afternoon leading to increasing storm coverage, especially within the area from Cheyenne to Alliance and south towards Sidney. Latest GOES WV imagery shows the shortwave over south-central WY that will continue to propagate northeast throughout the day. While severe thunderstorms are not expected this afternoon and evening with shear values maxing out around 20 kt, occasional lightning, brief periods of heavy rainfall, and gusty winds will be the main hazards. QPF amounts will mostly be around 0.25" with storms, but WoFS guidance has hinted at 0.50" possible, especially within the areas mentioned above. As for gusty winds, drier boundary layers are present, but would not consider this an inverted-V sounding. Latest radar imagery has shown a few outflow boundaries form north of Cheyenne from these initial storms with gusts up to 32 mph being reported at the Whitaker WYDOT station. As this afternoon goes on, stronger storms should be able to produce stronger outflow boundaries with gusts to 40-45 mph possible. Latest WoFS guidance shows 90th percentile max 10m gust around 35-40 kt across much of the southern NE Panhandle through 00z. Most hi-res guidance shows storms dissipating and exiting the eastern boundary of the CWA by 11 PM MDT. Another round of storms will be possible Friday with another shortwave passage under this active pattern. Increasing convergence along a developing lee side trough should aid in storm development along with better instability profiles. Upper level flow increasing from 15 kts at 500mb with Thursday`s shortwave to 35 kt will elevate shear parameters across the region. Fairly uni- directional shear with weak boundary layer winds should assist with vertical momentum transfer of stronger winds near the surface. Main hazards look to be strong outflow winds, but cannot rule out small hail. SPC Day 2 Outlook does have a Slight Risk over much of the NE Panhandle mainly for the wind threat. In addition to the storms, cooler weather will continue for areas along and west of the Laramie Range in the 60s and points east in the 70s up to 80 in spots. .LONG TERM...(Saturday through Thursday) Issued at 230 PM MDT Thu Sep 15 2022 Long Range models continue to be in good agreement this weekend and early next week. All models show the upper level ridge axis rebuilding over the Front Range and adjacent Great Plains states late this weekend. For Saturday, Still a good chance for showers and thunderstorms Saturday afternoon, but coverage should be a little lower compared to Friday. Models have trended a little more favorable for widespread convection Saturday afternoon with moderate southwest flow aloft and decent instability. Models now show a weak shortwave moving northeast across southeast Wyoming in the afternoon which will likely enhance convection into the evening. High temperatures should be a little warmer compared to Friday and generally in the 70s across southeast Wyoming with low 80s across western Nebraska. Another drying trend is expected Sunday and Monday with highs climbing back into the upper 70s to upper 80s for southeast Wyoming and into the low to mid 90s for western Nebraska. Other than fire weather concerns and gusty winds between 30-40 MPH each afternoon, not much weather related impacts expected. As we head into the middle of next week, there is the potential for a wet pattern to set up across most of southeast Wyoming and western Nebraska, but models are not locking in on the specifics too well as we approach Thursday. All models and even most of the ensembles suggest that a tropical system near the Mexico coastline will lift north ahead of the next approaching Pacific upper level trough. Deep moisture looks to transport northward as the westerlies take over ahead of the approaching Pacific system. In addition, the ECMWF and Canadian models show the upper level trough stalling while slowly drifting northeast towards Montana for Thursday and possibly next Friday, which may result in a prolonged moderate to heavy rain event. The GFS is more progressive, showing the trough rapidly ejecting northeast towards the Canadian border. Thankfully, not much cold air is associated with this upper level trough with snowlevels above 9500 feet, which is considerably warmer than yesterday. However, we`ll see if this changes as we approach the weekend. Kept POP between 40 to 60 percent since we`re still 6 to 7 days out, but if current models verify, expected rainfall may make quite a dent in the current drought across the state. High and low temperatures during this period will be highly depended on the quantity of clouds and rainfall across the area. Therefore, forecast temperatures Wednesday through Friday may be subject to high variability depending on model trends over the next several days. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 522 PM MDT Thu Sep 15 2022 Wyoming TAFS...VFR. Thunderstorms in the vicinity until 03Z. Wind gusts to 20 knots at Rawlins and Cheyenne until 02Z, then to 30 knots at all terminals after 15Z Friday. Nebraska TAFS...VFR. Occasional thunderstorms producing wind gusts to 35 knots at Alliance and Sidney until 03Z. Thunderstorms in the vicinity at Scottsbluff until 04Z. Wind gusts to 25 knots at Sidney until 03Z, then gusts to 20 knots at all terminals after 15Z Friday. && .FIRE WEATHER... Issued at 230 PM MDT Thu Sep 15 2022 Minimal fire weather concerns the next few days with daily chances for showers and thunderstorms continuing through Saturday. Temperatures will begin to warm back up Sunday and Monday leading to elevated fire weather conditions. The return of above average temperatures will help drive afternoon RHs into the teens for much of the area. Monday will be the main day to watch as winds west of the Laramie Range will approach critical thresholds. Cool and wetter weather pattern looks to return middle of next week. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...MB LONG TERM...TJT AVIATION...RUBIN FIRE WEATHER...MB
Area Forecast Discussion
National Weather Service El Paso Tx/Santa Teresa NM
521 PM MDT Thu Sep 15 2022 ...New AVIATION... .SYNOPSIS... Issued at 100 PM MDT Thu Sep 15 2022 Quiet and drier weather has moved into the region. This pattern will give us mostly clear skies with high temperatures moving around 5 degrees above average for Friday through the weekend. The moisture and rain chances will try to return to the region for the start of next week, along with some slightly cooler high temperatures. && .SHORT TERM... (This afternoon through Friday) Issued at 100 PM MDT Thu Sep 15 2022 Current satellite imagery shows our recent disturbance over the Northern Great Plains and Upper Midwest, about to bring some heavy rains to northern Minnesota and southwest Ontario. Closer to home across the Borderland region, southwesterly flow continues to advect in dry air across the region. In fact, this morning`s EPZ sounding continued the trend in drying with a PW value of 0.9 inches and decent mid to upper level dry layer. That being said, low level moisture is still present across the area will dew point temperatures in the upper 50s. Latest visible satellite imagery confirms the presence of low level moisture with a growing cumulus field predominately along and over the mountains chains of southern NM and far west TX. With the dry air aloft, further cloud growth will be limited with updrafts failing to ascend through the dry layer. RAP and other high-res model guidance shows minimal amount of CAPE over the area (mainly east) with CAMs hinting at a very slim chance of seeing an isolated shower or storm over Otero or Hudspeth County. SREF prob guidance shows eastern Hudspeth/Otero Counties have a 20-40% probability of seeing 0.01 inches of rain this afternoon and evening, those numbers don`t offer a lot of confidence. With that being said, went ahead and left 10% PoPs in the grids for isolated areas in eastern Hudspeth/Otero Counties. Temperatures this afternoon across the desert lowlands will top out around 90 degrees. For tomorrow quiet and dry weather conditions can be expected with temperatures in the lower 90s across the desert lowlands. && .LONG TERM... (Friday night through next Wednesday) Issued at 100 PM MDT Thu Sep 15 2022 As the long term forecast picks up we will see an upper level ridge strengthening to our east and an upper level trough strengthening to our west. Initially all this will do for us is change our upper level flow from the west to the southwest on Saturday. This pattern will continue our mostly clear and dry weather on Saturday. On Sunday, both the upper level ridge and upper level trough will continue to strengthen and that will continue to turn our upper level flow from the southwest to the south. This will begin to draw moisture up from northern Mexico. Sunday will still be mostly dry and warm, but by Sunday night we will see enough moisture to see some rain chances mainly west of the Rio Grande. There are still some differences in the extended range. The ECMWF model continues to strengthen the upper level ridge to our east on Monday and Tuesday and this begins to push the moisture tap back into Arizona. The GFS is somewhat trending in that direction. I went ahead and left some rain chances in the extended forecast for most of the area, to avoid flip flopping back and forth, but if later model runs keep the drier solution going forward, we will likely have to reduce or even pull rain chances for the start and middle of next week. Looking at high temperatures, now that the moisture has cleared out of the region and we will begin to feel more of the effects of the upper level ridge, we will see our high temperatures trending higher. High temperatures on Saturday and Sunday will run three to five degrees above average. The high temperatures for the first of next week, will depend on how much moisture and clouds get in to the area. For now I have trended the high temperatures down a few degrees, but they are still running two to four degrees above average, maybe closer to seasonal averages for locations near the NM/AZ border. && .AVIATION... (00Z TAFS) Issued at 520 PM MDT Thu Sep 15 2022 VFR conditions expected through the forecast period. FEW-SCT cumulus may linger into this evening outside of KDMN. SKC otherwise, although FEW CU around 080 could develop tomorrow afternoon. Winds AOB 12kts generally from SW. && .FIRE WEATHER... Issued at 100 PM MDT Thu Sep 15 2022 Zonal flow and drier air can be expected through the first half of the period (through the weekend) with LOW fire weather concerns. Min RHs will decrease each day through Saturday with 15-30% values areawide. Winds will become low-end breezy each afternoon/evening over the mountains due to increased southwest flow and terrain effects. The increase in the HDWI aforementioned in yesterday`s fire weather discussion continues to show a decent increase for tomorrow and Saturday over mountain zones, with a probability of 90th percentile exceedance of 20-40% on Saturday. That being said, ground fuels and vegetation remain quite saturated with Energy Release Component (ERC) values at or below the average for the middle of September. Temperatures will continue to increase each day with high in the low 90s across the desert lowlands and temps slight above or right around average for mountain zones. - Again, fire weather conditions/concerns are LOW through the weekend due to very saturated vegetation and fuels. Increased moisture and rain chances can be expected at the beginning of next week. && .PRELIMINARY POINT TEMPS/POPS... El Paso 68 94 69 95 / 0 0 0 0 Sierra Blanca 63 87 63 87 / 0 0 0 0 Las Cruces 61 92 63 93 / 0 0 0 0 Alamogordo 63 90 65 92 / 0 0 0 0 Cloudcroft 47 67 49 69 / 0 10 0 0 Truth or Consequences 59 90 60 91 / 0 0 0 0 Silver City 57 82 58 82 / 0 0 0 0 Deming 58 92 59 93 / 0 0 0 0 Lordsburg 61 89 61 90 / 0 0 0 0 West El Paso Metro 67 93 69 94 / 0 0 0 0 Dell City 63 92 64 93 / 0 0 0 0 Fort Hancock 65 93 65 94 / 0 0 0 0 Loma Linda 62 85 63 86 / 0 0 0 0 Fabens 66 93 66 95 / 0 0 0 0 Santa Teresa 63 91 65 93 / 0 0 0 0 White Sands HQ 65 91 66 92 / 0 0 0 0 Jornada Range 63 89 64 90 / 0 0 0 0 Hatch 60 91 61 93 / 0 0 0 0 Columbus 62 90 62 92 / 0 0 0 0 Orogrande 62 90 64 92 / 0 0 0 0 Mayhill 53 79 54 80 / 10 10 0 10 Mescalero 52 77 54 79 / 0 10 10 10 Timberon 51 77 53 78 / 0 10 0 0 Winston 53 82 52 83 / 0 0 0 0 Hillsboro 58 87 58 89 / 0 0 0 0 Spaceport 60 89 61 90 / 0 0 0 0 Lake Roberts 51 80 52 81 / 0 0 0 0 Hurley 58 88 58 89 / 0 0 0 0 Cliff 53 89 53 90 / 0 0 0 0 Mule Creek 56 82 55 84 / 0 0 0 0 Faywood 59 86 59 87 / 0 0 0 0 Animas 59 90 59 91 / 0 0 0 0 Hachita 59 90 59 90 / 0 0 0 0 Antelope Wells 58 88 59 91 / 0 0 0 0 Cloverdale 58 83 58 85 / 0 0 0 0 && .EPZ WATCHES/WARNINGS/ADVISORIES... TX...None. NM...None. && $$ SHORT TERM...38 LONG TERM....15 AVIATION...39-Aronson
Area Forecast Discussion
National Weather Service Grand Forks ND
1002 PM CDT Thu Sep 15 2022 .UPDATE... Issued at 959 PM CDT Thu Sep 15 2022 Low pressure is in northeastern SD west of Sissteon. Frontal boundary is pretty much stalled northeast from the low to north of Wahpeton to Barnesville to Mahnomen to Bemidji. Activity tried to get going some in far SE ND near the front and low but has dissipated. T-storms have formed and continue in a zone from east of Thief River Falls to north of Bemidji and this is in a zone of 850 mb warm advection per SPC meso analysis. This band will likely continue a few more hours before shifting more east. Farther west rain showers continued west toward Grafton and Devils Lake. They are slowly drifting northeast. Latest guidance shows sfc low ever so slowly moving northeast toward Bemidji by Friday aftn. Showers will be more likely in north central and northwestern MN and far northern RRV and into S Manitoba as we head into daytime Friday. Adjusted pops, winds and temps a bit for current conditions. UPDATE Issued at 707 PM CDT Thu Sep 15 2022 Cold front only slowly slipping south this early evening. It runs from Bemidji to Lake Park MN to in between Fargo and Wahpeton to Forman ND. T-storms tried to get going south of the front in the warm sector in far SE ND and WC MN, but bulk shear is blo 20 kts and despite 2000 j/kg sfc cape not much is able to get going. So what is left is an area of light rain showers from Devils Lake through Grand Forks/Grafton area to Baudette. Rain amounts from these are light and no thunder. So update was done to remove thunder from the north but keep it in far SE ND into MN. NBM pops were too high with 90s as coverage is scattered (even isolated) all but band from DVL to BDE. Not expecting much change overnight as light rain showers will continue around the area with the more persistent rain shower area likely to diminish or shift more into N MN overnight. Rain amounts light though. && .SHORT TERM...(This evening through Friday night) Issued at 226 PM CDT Thu Sep 15 2022 We continue to see isolated showers and storms across the area this afternoon and this looks to continue throughout the rest of today and into tomorrow. A frontal boundary is draped across the forecast area helping to ignite these showers and isolated storms. Guidance continues to show through HREF and HRRR showers and storm development throughout the evening hours along this frontal boundary. Moisture through the 850mb level continues to push into the region helping to bring high PWAT values. Instability is rather weak around 500 J/kg and shear is <25kts. We don`t expect any severe thunderstorm development, but a stray stronger storm at times can`t be ruled out especially along and east of the front. Areas in NW MN and into northern MN could see some locally heavy rainfall at times, as atmospheric soundings in those region have saturation through the upper levels and higher instability. Flash flooding is not a concern as the ground has been dry for several months and should be able to absorb additional rainfall. QPF totals through today and into the early portion of the weekend will vary across the forecast area. Areas toward Lake of the Woods and Beltrami could see up to 2 inches which is a 30-40% chance of occuring, whiles areas into the valley have a chance of 40-50% of seeing up to 0.75 inches. These rain chances will be isolated to scattered and not widespread. Temperatures are expected to be on the cooler side behind the front, with lows tonight dropping to the upper 40s near the Cando and Langdon area and lower 60s ahead of the front in Ottertail county. Continued rain will help keep temperatures cooler tomorrow, with highs only in the 50s in NE ND and the low to mid 60s in west central and NW MN. Impacts are possible from any stronger storms that develop or locally heavy rainfall in NW and northern MN. .LONG TERM...(Saturday through Thursday) Issued at 226 PM CDT Thu Sep 15 2022 Saturday through Thursday: The models and cluster analysis show an upper low digging into the western seaboard throwing our region into an upper ridging pattern for the early half of next week. There are some transient shortwaves to accompany this weather pattern. This may lead to an increase in instability ahead of the next wave that is progged to travel through the upper flow pattern late Monday into Tuesday. There is significant disagreement on the location and timing of this wave within ensemble guidance at this time, however, leading to lower confidence in precipitation potential. The 850mb dewpoints suggest sufficient moisture between 8-12C over our area Sunday through Tuesday. Some light rain showers are possible within this time period. NBM has a 20-30% of showers (not exceeding 0.25 inches) for the Red River Valley and NW Minnesota area Monday and Tuesday. Wednesday looks to be the end of the rainy pattern as we enter a dry northerly flow. The high temperatures are expected to be in the high 60`s over the weekend but temperatures will warm back up into the 70`s starting Monday. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 707 PM CDT Thu Sep 15 2022 IFR ceilings anticipated to continue through Friday northeastern ND and far NW Minnesota. IFR cigs (or low end MVFR) will push south into Fargo and Bemidji overnight as cooler air spreads south. Winds north-northeast 8 to 15 kts. Wahpeton-Wadena zone south wind to 20 kts before turning light/variable overnight. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Riddle SHORT TERM...Spender LONG TERM...Spender/MM AVIATION...Riddle
Area Forecast Discussion
National Weather Service North Platte NE
727 PM CDT Thu Sep 15 2022 .SHORT TERM...(This evening through Friday night) Issued at 417 PM CDT Thu Sep 15 2022 The main forecast challenges heading into the weekend revolve around thunderstorm chances. With an upper level trough digging into the Western US and some surface boundaries passing through the forecast area, precip/thunder chances increase over the next couple days. This evening and tonight... Nebraska lies in quasi-zonal or broadly southwest flow aloft with the upper trough axis near the Pacific Coast. Near the surface, a cool front bisects the forecast area, generally stretching from KANW to KIML as of 20z. The front slowly pushes east through the rest of the evening and overnight, along with an H7 wave. These features will be the foci for additional thunderstorm development, as there has been ongoing activity over far north central Nebraska for much of the day. Expect some growth farther southwest and some additional development in the panhandle in the post-frontal environment, but that should not be as dominant. Ahead of the front, near the CWA borders with OAX and GID, some instability and fairly steep mid-level lapse rates exist. Deep layer shear is marginal at best, ranging from 10 to 25 kts across the forecast area. A low level jet develops tonight across central and eastern Nebraska, which aids in strengthening low level shear. The bigger impact would likely be that flow getting mechanically mixed to the surface in/near any thunderstorms. Besides the wind, brief torrential rain is a concern due to seasonably high PWAT in place and decent moisture advection, partly shown by dew points in the lower 60s. Used a general blend of HRRR and HREF guidance for PoP coverage and timing, which suggests more organized activity along the eastern edge of the CWA and more scattered showers/storms that gradually weaken across the west. Most precip should dissipate or move out of the area by 12z. For min temps, made little change from previous forecast as they agree with the 12z model suite and NBM envelope. Values range from the upper 40s northwest to near 60s central. Friday and Friday night... The upper trough nudges east, while a stout H7 wave approaches the Sandhills and a surface cool front drops through the Dakotas. A lull in the activity is anticipated for much of the morning and into the afternoon, but the atmosphere recharges for the evening. Continued low level southeasterly flow keeps the moisture component around with dew points around 60F. When combined with highs in the lower to mid 80s and steeper mid-level lapse rates around 7-8C, CAPE values will be modest. The convective parameter that really stands out is deep layer shear, which improves drastically compared to this evening`s setup. Hodographs indicate some slight veering in the low levels, but an elongated and straight signature in the mid/upper levels. The main shear vector is largely parallel to the front along the state line but perpendicular to a weak surface trough in the panhandle. Convective mode appears rather complex right now, with cells or clusters favored near and shortly after initiation and possibly larger clusters or a linear system after dark. Somewhat significant discrepancies exist amongst the solutions, but overall the environment favors an active late afternoon (far west) through late evening (central Neb). The main threats appear to be strong winds and heavy rain, although some smaller hail will probably accompany the cells or clusters. .LONG TERM...(Saturday through Thursday) Issued at 417 PM CDT Thu Sep 15 2022 This weekend... Nebraska lies in a battle zone aloft between the deepening West Coast trough and a building Southern Plains ridge, and a surface cool front crosses the forecast area. The frontal passage presents another chance of thunder, mainly Saturday evening into early Sunday. Severe parameters are marginal for western Neb with the better instability to the east. Despite the front, temperatures remain near or above normal with highs generally in the 80s and lows in the 50s. Monday and beyond... The upper ridge gains influence over the central Plains, which enables a return to summer-like conditions. Another round of highs in the 90s is likely Monday and Tuesday with the help of fair skies and southerly winds. Humidity levels drop in the west, but winds should remain light enough to preclude any significant fire weather concern. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 725 PM CDT Thu Sep 15 2022 Isolated showers and thunderstorms will continue to impact portions of north central Nebraska this evening. Storms will gradually diminish after 06Z with overcast skies giving way to scattered skies by mid-morning Friday. VFR conditions will then continue through Friday afternoon before another round of thunderstorms arrives after 00Z Saturday. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Snively LONG TERM...Snively AVIATION...Kulik
Area Forecast Discussion
National Weather Service Topeka KS
916 PM CDT Thu Sep 15 2022 .UPDATE... Issued at 916 PM CDT Thu Sep 15 2022 With the boundary layer continuing to cool across north central KS, surface based instability will continue to diminish. RAP forecast soundings still show some elevated instability around 500 MB. But deep layer shear remains very weak so just some general thunderstorms are expected as the upper level shortwave passes overhead tonight. Most of the latest 00Z CAM guidance shows the convection weakening before it gets to far east, so areas east of MHK may not even hear thunder. && .DISCUSSION... Issued at 227 PM CDT Thu Sep 15 2022 Key points: * Small risk for severe thunderstorms early tonight in north-central Kansas * Periodic shower and thunderstorm chances tonight through Sunday * Record/near-record hot temperatures likely early next week Recent water vapor imagery showing several weak waves from the central Rockies into north Texas moving northeast over high pressure centered over the southeast CONUS. A few areas of convection formed over north-central Oklahoma in recent hours along the edge of deeper moisture but have struggled to maintain themselves. The mean upper trough axis looks to move across the local area late tonight into midday Friday. Precipitable water levels push up to near 1.5 inches tonight and linger in this range into the weekend. The main convective activity tonight looks to be well west and somewhat delayed in recent guidance. The chances for storms reaching the western counties before sunset is diminishing with MLCAPE falling off to a few hundred J/kg in this area. If a multicell line in a faster scenario reaches the area, a few near-severe wind gusts would be possible with downdraft CAPE value around 1000 J/kg. There is still good consistency with the mean wave interacting with the increasing moisture for at least isolated precipitation moving across the area tonight into midday Friday. Decent clearing and south winds from 10-15 knots would support another warm afternoon. Attention Friday night into early Saturday focuses to the northwest with another wave passing over surface low pressure in western Nebraska. A convective cluster should form there and may build south into a modest low-level jet as it pushes east. This could bring precip to northern portions of the area late Friday night into early Saturday. There are suggestions of an outflow boundary lingering into the afternoon, and with MLCAPE in the 1000-2000 J/kg range and modest shear, severe storms can`t be ruled out. Convection could linger into early Sunday morning as the low-level jet returns. The upper ridge remains on track to rebuild to the south/southeast early next week with very warm temps resulting. ESAT data from the NAEFS and ECMWF are quite similar with 850 mb temps reaching record to near-record values. NBM is on track with highs and lows in record- warm range Monday and Tuesday. An upper trough passing across the northern Plains Wednesday may bring a cold front into the area for a cooler Wednesday and Thursday, though consistency with this pattern change has not been high. && .AVIATION...(For the 00Z TAFS through 00Z Saturday) Issued at 548 PM CDT Thu Sep 15 2022 Most guidance keeps the instability west of the terminals, and a lot of the CAMs are showing precip diminishing as it moves east overnight. There could still be a few showers around through mid- morning as the upper trough swings overhead. But confidence in timing something at a terminal is to low to go with anything other than the VCSH for now. CIGS and VSBY should remain VFR thanks to relatively dry air in the lower atmosphere. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Wolters DISCUSSION...65 AVIATION...Wolters