Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/02/20

Area Forecast Discussion
National Weather Service Bismarck ND
947 PM CDT Mon Jun 1 2020 .UPDATE... Issued at 943 PM CDT Mon Jun 1 2020 No changes to the forecast for tonight with this product issuance. Embedded wave and sfc boundary still expected to bring a chance of showers and thunderstorms to western and central North Dakota after midnight and through Tuesday morning. A few strong to severe storms remain possible across the southwest and south central, though uncertainty higher than desired. UPDATE Issued at 659 PM CDT Mon Jun 1 2020 Area of SCT-OVC mid/upper level clouds will move from west to east across western and central ND this evening, and have updated sky cover grids accordingly, using a blend of the HRRR and NBM. Will maintain overnight convection as inherited (see discussion below), but did make some minor tweaks based on latest high res guidance. Uncertainty remains on the high side. One of the more noticeable edits made for this forecast issuance was to winds 09Z early Tue morning into the day Tuesday (later half of the aviation period). Models in decent agreement with a frontal boundary moving southeast through the area associated with the mid level wave bringing the chance for showers/storms overnight-Tuesday AM. Increased winds out of the northwest behind the FROPA based on last few high res model runs and utilizing BUFKIT soundings. && .SHORT TERM...(This evening through Tuesday) Issued at 243 PM CDT Mon Jun 1 2020 The main concern for the short term period is the development of showers and thunderstorms over western North Dakota late tonight, shifting into central North Dakota Tuesday morning. There is a conditional threat for severe hail from southwest into far south central North Dakota. Quiet weather this afternoon with deep layer subsidence over the Northern Plains, although a bit breezy near the Canadian border in response to a surface low moving into central Manitoba. Shortwave energy is forecast to approach western North Dakota late tonight. Sufficient forcing in the form of mid level height falls and low level frontogenesis appears to be in place for the development of showers and thunderstorms after sunset over eastern Montana/western North Dakota. Thunderstorms are not expected across the northern third of the state due to weaker mid level lapse rates and little, if any, MUCAPE. Farther south, there is model consensus that a pool of MUCAPE exceeding 1000 J/kg will protrude into southwest North Dakota late tonight. If this instability gradient is able to intercept rising air parcels from the aforementioned forcing mechanisms, allowing for deep moist convection, a large hail threat would likely develop given the presence of at least 40 kts of effective bulk shear. There are variations among guidance on both the northward extent and degree of instability. An examination of model soundings seems to indicate that this uncertainty is being driven by the amount of relative humidity above the boundary layer. The NAM has been the most aggressive in advecting sufficient moisture to both increase CAPE and decrease CIN. An example 12Z initialized NAM sounding from Bowman valid at 09Z tonight shows 1735 J/kg CAPE and no convective inhibition near 700 mb (along with 52 kts of 2-6 km shear!). However, all deterministic models are at least hinting at moisture transport and theta-e advection being present at 700 mb, which gives us caution in not trying to downplay this threat too much, despite a lack of support from CAM reflectivity and UH fields. If a severe threat does develop, it may shift into south central North Dakota early Tuesday morning, with the only deterring factor being a weakening of mid level moisture transport and theta-e advection. Otherwise, expect scattered showers (north) and thunderstorms (south) to continue across central North Dakota Tuesday morning as the mid level shortwave propagates eastward, with forcing possibly being aided by the right entrance region of an upper level jet in southern North Dakota. While most of the area will experience dry weather Tuesday afternoon, there is potential for additional thunderstorm development across north central North Dakota Tuesday afternoon, but overall forcing looks weak. Any storm that develops would encounter a low CAPE/high shear environment. .LONG TERM...(Tuesday night through Monday) Issued at 243 PM CDT Mon Jun 1 2020 A quasi-zonal flow pattern is forecast for mid week, with near to slightly above normal temperatures. A mid level shortwave with an attendant surface boundary is forecast to move across the state on Wednesday. Scattered thunderstorms may develop from southwest into central North Dakota Wednesday afternoon and evening. Modest buoyancy and increasing deep layer shear may support a severe threat. A discrete storm mode is favored, with shear vectors oriented perpendicular to the boundary. There may be other pieces of energy that pass through the zonal flow through Thursday, but predictability is lower. Upper level ridging will quickly amplify over the Northern Plains on Friday as longwave troughing digs over the western CONUS. There is general model consensus that a potent shortwave will approach the region in southwest flow aloft on Saturday. The GFS continues to be more progressive with this wave than the ECMWF, which delays any precipitation in North Dakota until Saturday night. Nevertheless, chances for showers and thunderstorms will be increasing on Saturday. Anomalously high precipitable water and deep warm cloud layer depths may support a heavy rain threat on Saturday. A severe threat cannot be ruled out, but this looks more uncertain. Additional pieces of energy are forecast to pass through the region in southwest flow aloft Sunday into early next week. Given the time of year and forecast instability and shear, strong to severe storms cannot be ruled out, though details remain very far from certain. Temperatures should continue to trend near to above normal. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 659 PM CDT Mon Jun 1 2020 VFR flight conditions through the 00Z period. There will be a chance for showers and thunderstorms after 06Z starting in western ND, then shifting into central ND through Tuesday morning. The better chances for thunderstorms remain at KBIS and KDIK. MVFR to IFR visibility will be possible with a storm, but ceilings should remain VFR. High uncertainty on shower and thunderstorm potential, and will fine tune TAFs as certainty increases and/or when storms start developing into the area. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...NH SHORT TERM...Hollan LONG TERM...Hollan AVIATION...NH
Area Forecast Discussion...Updated
National Weather Service Billings MT
853 PM MDT Mon Jun 1 2020 .UPDATE... Evening showers and thunderstorms have cleared out a little quicker than expected, but another line of just some showers is just west of the area. This will continue to move east. Still have a chance across much of the area through this evening. The latest HREF that is just coming in does still have a hint at some stronger convection in Carter and Fallon counties after midnight, but has trended farther east with the strong convection. Will continue to monitor. Reimer && .DISCUSSION... Tonight through Wednesday Night... Showers have been moving NE through ID into NW MT for much of the day. New convection was seen near Challis, ID moving NE. This convection will continue to develop due to jet energy and vorticity moving through the flow, and will move into the WNW zones by 23Z or 00Z. It will shift E tonight. RAP KLVM sounding showed limited CAPE and strong shear before CIN develops this evening. The sounding was inverted-V and supported a gusty wind threat. Elevated CAPE increases in the evening, which could support some hail if lift was strong enough. HREF updraft helicity tracks were weak, so would not expect any large hail. Lift moves E overnight and may trigger elevated convection in Fallon/N Carter Counties with HREF showing stronger convection there. KBHK sounding from the RAP did not show any CAPE/shear concerns. Flow becomes zonal Tuesday through Wednesday night with pieces of energy moving through the flow. Had PoPs over and near the mountains on Tue. and Tue. evening. Vorticity will bring a chance of precipitation to SE MT late Tue. night through Wednesday. Wednesday night will be mostly dry. Tuesday will have highs in the 70s again and temps will be in the 80s on Wednesday. Arthur Thursday through Monday... W flow on Thursday will give way to weak upper ridging on Friday. Will have chances for orographic precipitation on Thu. and energy in the flow will bring low chances to the E Thu. night. Energy will move into the area on the back side of the ridge ahead of a NE moving wave Fri. and Fri. night for low chances of convection. A low-level jet will set up Fri. night and Saturday, increasing precipitable waters to an inch or higher. Upper flow will be SW on Sat. on the front side of an upper low off the BC/Pacific NW coast, which is a severe weather pattern. High PWAT`s also supported a flash flooding threat. Thus, chances for convection increase on Saturday. Models differed on the position of the upper low on Sunday and differed with how the system moves inland on Monday. Kept PoPs across the area with the highest PoPs W of KBIL. There was spread in the models regarding QPF amounts late in the week and spread in the temps. This made sense given the uncertainty with the system`s position. Arthur will prevail at midweek limiting any precipitation to mainly the higher terrain, and keeping afternoon temperatures in the 80s. However, by late Friday the upper flow will back to the S/SW as troughiness moves into the Pacific NW and extends into the Great Basin. This will start to advect moisture and impulses into SW Montana and the high plains. So look for an increasing chance of thunderstorms Friday evening into the weekend. Details are murky this far out, but we would not be surprised to see at least an isolated threat of severe thunderstorms by next weekend for portions of the CWA. BT && .AVIATION... VFR conditions will prevail over the next 24 hours. A chance for showers and thunderstorms remains overnight mainly near KMLS and KBHK. Expect areas of mountain obscuration over the western mountains tonight. Reimer && .PRELIMINARY POINT TEMP/POPS... Tue Wed Thu Fri Sat Sun Mon ----------------------------------------------------------- BIL 056/077 056/084 055/079 054/085 062/086 057/077 052/071 42/W 10/B 11/B 11/B 13/T 43/T 44/T LVM 051/077 051/080 051/078 049/082 055/080 051/070 045/065 52/T 21/U 23/T 22/T 37/T 76/T 66/T HDN 056/077 055/084 053/079 053/087 062/089 057/080 052/074 32/W 00/U 11/B 11/B 14/T 53/T 44/T MLS 057/077 053/083 053/078 054/084 064/087 059/080 054/076 31/U 00/U 21/B 21/B 23/T 52/T 33/T 4BQ 055/076 052/082 053/079 053/084 062/087 056/081 053/077 20/U 01/U 10/B 21/B 13/T 42/T 32/T BHK 054/075 049/081 050/077 051/079 058/081 057/079 053/076 41/U 02/T 11/B 21/B 23/T 52/T 32/T SHR 054/074 052/082 052/079 052/087 061/086 054/080 050/075 12/T 20/U 11/B 11/B 23/T 33/T 33/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$
National Weather Service Hastings NE
648 PM CDT Mon Jun 1 2020 .SHORT TERM...(This evening through Tuesday Night) Issued at 329 PM CDT Mon Jun 1 2020 Another day of gusty southwest winds under a upper level ridge axis has allowed temperatures to reach the 90s for the first day of June. This is about 10-15 degrees above our climatological average. Dewpoints have also pushed into the low 60s, which will make for another relatively warm night tonight with lows in the mid to upper 60s. A few thunderstorms may develop this evening in the Nebraska panhandle and western Sandhills. Short-term models continue to show that this activity will largely dissipate before reaching the local area, though. On Tuesday, temperatures are once again forecast to reach the mid 90s as a cold front approaches from the northwest. Some spots in western portions of the area could even make a run at 100 degrees. By late afternoon, thunderstorms are expected to develop near the cold front in or just northwest of the forecast area. These storms may initially be strong to marginally severe. There is no shortage of instability, with the 15Z RAP showing 3-4000 J/kg of MLCAPE, but bulk shear is pretty lackluster at only 10-20kts for most of the area. Farther north, the shear is a bit more favorable, hence SPC`s upgrade to "Slight" for our north. Even so, we are not looking at a significant severe threat by any means. These storms will then gradually move southeast through the evening and early overnight before diminishing after midnight. Southeastern portions of the area will likely remain dry. .LONG TERM...(Wednesday through Monday) Issued at 329 PM CDT Mon Jun 1 2020 On Wednesday, this front will stall in the area or even lift back northward. Temperatures is forecast to be a few degrees cooler, but we should still see good destabilization by late afternoon in the vicinity of this front. Meanwhile, an upper shortwave will push into the area in the evening, initiating storms and providing an uptick in deep-layer shear. With the better shear and upper level forcing, the threat for severe weather appears to be greater Wednesday night than on Tuesday. On Thursday, temperatures are forecast to return to the upper 80s and 90s, and the daytime should remain dry as we remain in-between shortwaves aloft. Slight chances for thunderstorms then return in the late afternoon through the overnight as a subtle shortwave rounds the ridge. The model consensus continues daily slight chances for thunderstorms Friday and Saturday over northern portions of the area as one or more shortwaves eject out of SW CONUS. That being said, there is relatively high confidence that southern portions of the area, especially northern Kansas, will remain dry through this period. We will also see temperatures trend back up as the ridge axis shifts overhead. Beyond that, it is looking like a trough will set up over the western CONUS, ejecting across the central or northern Plains by the middle of next week. Of course, model solutions differ on location and timing, but this could bring us a bit of a cooldown and additional rain/thunderstorm chances next week. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Wednesday) Issued at 625 PM CDT Mon Jun 1 2020 VFR conditions are expected through the period with any convection to our west this evening expected to dissipate well before reaching either terminal. Do expect some marginal LLWS to develop as surface winds start to decouple around dark...and to continue through the early morning hours Tuesday...with much lighter winds out of the southwest expected during the day Tuesday. A shift in winds along with a chance for thunderstorms is expected near or just beyond the current scope of the TAF period as a weak cold front crosses the local area. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...Mangels LONG TERM...Mangels AVIATION...Rossi
Area Forecast Discussion
National Weather Service Grand Rapids MI
749 PM EDT Mon Jun 1 2020 LATEST UPDATE... Aviation .SYNOPSIS... Issued at 328 PM EDT Mon Jun 1 2020 - Showers and isolated storms tonight - Slight risk for Severe Weather Tuesday Night - Dry late week && .UPDATE... Issued at 601 PM EDT Mon Jun 1 2020 With some elevated instability moving in this evening I did bump up the risk for a thunderstorm. There is some forcing with the wave moving in as well which could result in increased coverage of precipitation. TAFs will be updated as well. && .DISCUSSION...(This evening through next Monday) Issued at 328 PM EDT Mon Jun 1 2020 - Showers and isolated storms tonight A warm front will focus development of showers and a few thunderstorms tonight as elevated instability increases north of the front. This potential will also be added to by forcing from a rather strong low level jet. The best chance for showers and storms will be over our northern and northeast forecast area as shown by latest HRRR and 3 km NAM as well as the 12Z HREF and 00Z ECMWF ensemble mean. This is also supported by rgnl radar trends. No severe weather is expected although isolated stronger storms may contain frequent lightning and brief heavy rain. - Slight risk for Severe Weather Tuesday Night The cold front will bring convection late Tuesday through the overnight. A few strong to marginally severe storms are possible given the moderate to strong instability expected to develop ahead of the front. Kinematics also become more favorable overnight as deep layer shear will increase to around 35 to 40 knots, supportive of organized convection. Overall severe weather threat is slight given unfavorable timing of the cold front passage in terms of surface based instability. Sfc based convection will usually decrease crossing Lake Michigan given the relatively cold water temperatures this time of year. Given these considerations, he threat will be greater off to the west, across Wisconsin and northern Illinois. - Dry late week A few storms may linger into Wednesday morning across southern Lower Michigan then fair weather returns as sfc high builds in with cooler air and lower humidity into the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 730 PM EDT Mon Jun 1 2020 Showers will cross the TAF sites this evening. There is some elevated instability that may move in so an isolated thunderstorm is possible. Brief reductions to visibility could occur with any downpour...right now MVFR looks possible. MVFR clouds could move in during the late night or early morning period for KMKG and possibly inland...which we will need to monitor. Otherwise VFR should prevail by noon Tuesday with the storms to hold off til after 00z Wed. && .MARINE... Issued at 328 PM EDT Mon Jun 1 2020 Small Craft Advisory and Beach Hazards Statement continue through Tuesday afternoon. Fairly strong southerly winds tonight into Tuesday will increase waves to 3 to 6 feet. Winds and waves will then decrease below advisory threshold by Tuesday afternoon. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Beach Hazards Statement through Tuesday afternoon for MIZ064-071. Beach Hazards Statement through Tuesday afternoon for MIZ037-043- 050-056. LM...Small Craft Advisory until 2 PM EDT Tuesday for LMZ846>849. Small Craft Advisory until 2 PM EDT Tuesday for LMZ844-845. && $$ UPDATE...MJS SYNOPSIS...Laurens DISCUSSION...Laurens AVIATION...MJS MARINE...Laurens
Area Forecast Discussion
National Weather Service North Platte NE
655 PM CDT Mon Jun 1 2020 .SYNOPSIS... Issued at 250 PM CDT Mon Jun 1 2020 Mostly sunny skies and light winds prevailed across western Nebraska at 2 pm CT. Temperatures ranged from the low to mid 90s. Dewpoints were holding in the low 60s east of Ainsworth through North Platte. Towering cumulus with a few thunderstorms developing from near Lusk, Torrington and Cheyenne WY south along the CO Front Range. Also an isolated storm near Fort Robinson/Crawford. && .UPDATE... Issued at 652 PM CDT Mon Jun 1 2020 A forecast update is in place to introduce slight chance PoPs across the Sandhills into portions of north central Nebraska through the evening hours. A few storms may be capable of briefly gusty winds and small hail and should weaken with loss of daytime heating over the next few hours with activity expected to dissipate by Midnight CDT. && .SHORT TERM...(This evening through Tuesday night) Issued at 250 PM CDT Mon Jun 1 2020 For this evening, isolated thunderstorms are shown by the latest HRRR and RAP in the panhandle and northeast CO. The RAP indicates a small area of development early this evening possible from the Alliance area east to near Hyannis through mid evening. Have included a slight chance for this area. Remaining areas of the west should remain dry, although an isolated storm can`t be ruled out. Overnight, a weak cold front will drop into the northwest Sandhills. Lows tonight will again be mild in the mid 60s. On Tuesday, this weak cold front will advance through most of the area by 18Z. There is a slight chance for showers or thunderstorms in the afternoon for areas south of Ainsworth through Ellsworth. With further advancement of the front, a 20-30 percent chance only across far southeastern zones late afternoon. MUCAPES will range as high as 2500-3500 J/KG near and ahead of the front, although deep layer shear is weak at up to 15KT. Due to slow storm movement, brief heavy rain is also possible. Most of these storms should be east of the area soon after 00Z. Although overall coverage of storms looks limited Tuesday afternoon and evening, a Marginal Risk for severe storms exists across all of the area Tuesday afternoon/Tuesday night, with a Slight Risk area east of Broken Bow through O`Neill. Another focus area for thunderstorms Tuesday night will be in the post frontal environment across southwest SD into northwest Nebraska. A disturbance will exit northeast WY Tuesday evening and move eastward overnight. Areas west of a line from Valentine through Oshkosh can expect at least a slight chance overnight, with the highest POPS near 40 percent in Sheridan County. A few storms could be strong to briefly severe as deep layer shear remains at least 25-30KT. .LONG TERM...(Wednesday through Monday) Issued at 250 PM CDT Mon Jun 1 2020 Daily chances for thunderstorms will exist Wednesday through Saturday as highs range from the mid 80s to lower 90s each day. A weak cold front will be draped across Kansas Wednesday morning and will lift north into northern Nebraska by Thursday morning. Mid and upper level winds will increase for Wednesday with 0-6km shear from 25-35kt and MUCAPES as high as 1500-2500 J/KG. A slight risk area will extend across all areas west of Valentine through Broken Bow. Dewpoints from the upper 50s to around 60 across the area, will be followed by a dryline advancing east from the panhandle into the western Sandhills afternoon/early evening. This will be a focus for thunderstorm development, in addition to a mid level disturbance moving from eastern wyoming into western Nebraska. Large hail and damaging winds will be possible with any storms. Storm chances remain Thursday/Thursday night as an active flow pattern extends over the region as the upper ridge extends near and south of the Four Corners and strong westerlies exist across the Northern Plains. SPC has a slight risk for severe area forecast for areas northeast of Ainsworth through Burwell. Strong storms look favorable across the remainder of the area. For Friday and Saturday, the upper ridge will build north into the Northern Plains and western Great Lakes. Meanwhile, a closed low and rather deep upper trough will extend across the northwestern U.S. A warm front across Kansas Friday will lift north as a warm front Saturday. Surface high pressure over the Great Lakes and Upper Mississippi Valley will bring a persistent easterly to southeasterly flow. The 12Z GFS continues to forecast a lead disturbance in southwest flow arriving Friday night followed by a rather strong disturbance crossing the area Saturday into Saturday evening. This would suggest sustained storm inflow will be in place Friday night into Saturday morning. This would support the potential for an MCS developing first across the panhandle/northeast CO Friday evening, then eastward across Nebraska overnight into Saturday. The ECMWF, is about 6 hours slower with the main disturbance and also does not indicate a lead disturbance moving in Friday night. As a result, POPS are in the forecast Friday night through Saturday night, with the highest POPS as high as 30-40 percent Saturday and Saturday evening. Sunday into Monday looks fairly dry with a southerly surface flow expected to return. An upper trough persists across western U.S. and a large upper ridge extends from the High Plains to the Mississippi Valley. Highs will remain in the upper 80s to lower 90s. Storm chances appear limited, with just a slight chance of storms across nctrl NE Sunday night and again Monday aftn. Highs Sunday and Monday should continue to range in the upper 80s to mid 90s. Another interesting note, medium range models bring a tropical system across the Gulf of Mexico toward the Texas Gulf Coast by Sunday. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 629 PM CDT Mon Jun 1 2020 VFR is expected across western and north central Nebraska tonight and Tuesday. The ongoing isolated storm activity throughout the region should dissipate by midnight this evening. Additional isolated to perhaps scattered strong to severe storm activity is expected Tuesday afternoon from 22z onward affecting areas along and east of a line from KIML- KONL. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Jurgensen SYNOPSIS...Roberg SHORT TERM...Roberg LONG TERM...Roberg AVIATION...CDC