Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/26/19

Area Forecast Discussion
National Weather Service La Crosse WI
1103 PM CDT Thu Jul 25 2019 .SHORT TERM...(This evening through Friday) Issued at 235 PM CDT Thu Jul 25 2019 Shortwave trough heading toward the area continues to produce rain shower activity as it heads eastward. Have increased rain chances west of the Mississippi river for this afternoon and early evening and will continue to trend based on radar. Enough lift generated to produce 10kft ceilings and light rain or sprinkles. Currently there are no lightning strikes nor appreciable MUCAPE over the area. Just a smidge of instability to get enough vertical motion for SHRA production. Would expect this area to diminish before reaching WI - but it has overachieved so far today. Thunderstorms further NW in the SPC Slight risk over MN/ND will try to work southeast toward the area overnight. It will likely fail to arrive but the low-levels have a nice moisture tongue headed into the western forecast area coincident with theta-e convergence per RAP guidance. This isentropically rising low-level jet could initiate higher-based TSRA/SHRA in the sunrise hours, I-90 and north. Thus, rain chances have been refined for Friday morning. Severe threat looks minimal with 250-500 J/Kg of MUCAPE. The strong longwave trough now located north of Montana will continue east and drive a cold front into MN Friday. Wind shear will increase in the afternoon to support supercells along the front - all to the northwest. Instability may limit coverage of storms, and it will be most intense to the northwest. Areas north and west of La Crosse may see this activity in the evening, with higher chances in north-central WI. This will need to be monitored, as it could pose an isolated severe storm threat Friday evening /wind, hail/. Confidence in the coverage and timing is limiting an upgrade in severe weather messaging /and SPC from upgrading to a slight risk/. Further north, closer to the attendant forcing, has the best potential. .LONG TERM...(Friday night through Thursday) Issued at 235 PM CDT Thu Jul 25 2019 Cold frontal boundary from Friday hangs up across the area for Saturday, and the results in the model guidance are mixed on IF this boundary generates storms, but it seems to be trending. The boundary in the NAM /which goes bonkers with storms/ has ~2500 J/Kg of MLCAPE that could be uncapped and need only a bump with weak frontal convergence. This is mainly WI and have increased rain chances Sat aft/eve. Isolated pulse severe storms cannot be ruled out. Sunday brings more dynamics to the region and consensus on increasing storm trends with a moderately strong shortwave trough. Moisture transport into a developing warm front shifting northward looks to provide elevated instability. This warm front could be active in the afternoon for areas north and west of La Crosse, with storms shifting southeast Sunday night. A bit too early to discern severe weather threats but definitely on our radar to monitor :) Monday through Thursday... Looking out into next week, the upper level ridge is expected to remain over the Rockies putting the Upper Midwest into a weak northwest flow pattern. There are some differences between the 25.00Z ECMWF and 25.12Z GFS on how amplified this pattern will be which will impact the potential track of a short wave trough topping the ridge. The ECMWF shows a less amplified flow than the GFS and brings this short wave trough across the region. The GFS with a more amplified pattern dives the short wave trough well to the southwest of the region. Both models are showing convective development ahead of this short wave trough over the High Plains Monday night that looks to upscale into a MCS. With the differences aloft, the ECMWF brings this MCS into and across the southwest sections of the area Tuesday night/Wednesday while the GFS drops this through the Missouri River Valley. For now, to reconcile these differences, will have some rain chances across the southwest half to three-quarters of the area late Tuesday night into Wednesday morning. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1058 PM CDT Thu Jul 25 2019 A short wave trough will produce showers mainly south of Interstate 90 overnight. Due to this, did not include them in the TAFS. While the precipitation will not impact them, there will be a broken mid and high deck of clouds. On Friday, another shortwave trough will move through northern Minnesota and northern Wisconsin. This will bring another round of mid and high clouds. These clouds will mainly impact the KLSE TAF. Any showers and storms will be mainly north of Interstate 94 this afternoon and evening. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...Baumgardt LONG TERM...04 AVIATION...Boyne
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
651 PM EDT Thu Jul 25 2019 .AVIATION... Clear and nearly calm conditions will persist overnight with high pressure centered over the region. Light southerly flow will emerge with some scattered flat cumulus developing during the late morning and early afternoon on Friday. Lake breeze boundaries with a little bit of enhanced cloud may make further inroads for the Detroit area terminals during the late afternoon, as the broad pressure gradient will provide less resistance to inland propagation. .DTW THRESHOLD PROBABILITIES... * Low confidence in ceilings around 5kft with lake breeze boundary Friday 20-23z. && .PREV DISCUSSION... Issued at 344 PM EDT Thu Jul 25 2019 DISCUSSION... Deep column ridging is in place directly over Southeast Michigan with anticyclonic flow trajectories from the surface through 20 kft agl. Plan view progs throughout the vertical show a coherent circulation with a stacked center near the Thumb by this evening. Splendid summertime weather for all of Southeast Michigan with surface dewpoints in the middle to upper 50s. There is some slight model signal that suggests an isolated shower could be possible within the enhanced lake convergence zones particularly for the corridor from Detroit northward through Port Huron. RAP and HRRR soundings show some potential for a parcel to squeeze by the inversion at 12.5 kft agl. Given nil synoptic support for ascent and lack of cumulus field this afternoon over the area will forgo any change/introduction of PoPs to the eastern forecast area. Center of midlevel high pressure will push east of Southeast Michigan for Friday. The area will remain under dry southeast flow throughout the day, therefore, not expecting any significant difference in weather conditions. It is interesting to note that some drier midlevel air will lift into the state during the late afternoon and evening which will help in maintaining stability in the 10.0 to 15.0 kft agl layer. Dewpoints should creep up a couple of degrees for all areas as some shallow Lake origin moisture will be advected into the area, as well some some slight moderation of airmass with temperatures. High Friday are expected to be in the middle 80s. Warming of both surface temperatures and dewpoints will occur on Saturday as southwesterly return flow finally washes back across Southeast Michigan. However, midlevel moisture will be lacking with only a narrowing plume of 800-600mb theta e folding down across the area during the late afternoon hours. The uncertain aspect of the forecast really comes down to what precipitation chances and timing be on Saturday. Currently, it appears not that favorable as strong capping is forecasted at roughly 800mb. High temperatures are expected to reach the upper 80s to around 90 degrees. Low-level jet oriented southwest to northeast across the Midwest into the Great Lakes to strengthen Sunday into Monday which will allow a push of even warmer air to enter SE MI, marked by h850 temperatures increasing to an average of 18-19C (from 16C on 18Z Sat). This will allow daytime highs to peak in the mid to upper 80s for most locations across SE MI and potentially the lower 90s across the urban Metro region. Operational GFS and MOS output less aggressive regarding the chances to hit upper 80s/lower 90s, but GEFS ensemble mean suggests otherwise. A series of weak upper-level waves are expected to ripple across the region throughout Sunday which will bring the slight chance to see pop-up showers and storms. Low pressure across the northern Plains will travel northeast over Lake Superior on Monday which will drag a cold front Michigan sometime between Monday morning and evening. Given the current projected timing of the front and strengthening LLJ ahead of the boundary, temperatures will have another chance to peak in the mid to upper-80s (especially over the urban Metro area). Plenty of room for adjustment regarding timing of the front so additional tweaks may be needed for temperature highs on Monday. Otherwise, the best chance to see rain showers and thunderstorms will be tied to the cold front Monday afternoon and evening. Increase in low level winds with diurnal mixing could also make for breezy conditions Monday morning and afternoon with potential gusts between 20 - 30 mph. Behind the cold front a sprawling high pressure system will fill in from the Plains, eventually settling over the Great Lakes region. This will bring an extended period of dry weather Tuesday into late next week. The front will also act to return temperatures to normal/slightly below normal values with highs in the low to mid-80s (cooler in the Thumb). MARINE... High pressure remains in control over the marine conditions through the end of the week with dry weather and light winds bringing favorable marine conditions through Friday. There will be an increase in southwest winds with gusts of 15 to 20 knots on Saturday, especially across Saginaw Bay and central Lake Huron, late Friday night into Saturday as pressure gradient tightens ahead of a weak cold front sagging south across the northern Great Lakes. This front will also bring a chance of showers with a few thunderstorms mostly across northern and central Lake Huron on Saturday. This front will stall across southern Lake Huron and sag slightly further south into Lower Michigan by Sunday. Another uptick in southwest winds as a low pressure system moves over Lake Superior. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...NONE. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ AVIATION.....Mann DISCUSSION...CB MARINE.......AA You can obtain your latest National Weather Service forecasts online at
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
909 PM CDT Thu Jul 25 2019 .SYNOPSIS... Issued at 332 PM CDT Thu Jul 25 2019 H5 analysis from earlier this morning had high pressure over northeastern New Mexico. North of the high, a closed low was located over central Saskatchewan. A weak shortwave trough of low pressure extended from northern Minnesota into portions of central Nebraska. This feature has led to mid level cloudiness and showers earlier today. This activity has since moved east of the area with dry conditions noted across the forecast area. Skies were generally clear across north central Nebraska, while a shroud of mid to high level cloudiness extended from the southern Nebraska Panhandle, east across the southern third of Nebraska. At the surface, a weak frontal boundary was situated from west of O`Neill, southwest to just southeast of Thedford, then west southwest into northern Colorado-just south of the NE/CO border. Temperatures as of 2 PM CDT, ranged from 81 at Broken Bow to 90 at Valentine. && .UPDATE... Issued at 908 PM CDT Thu Jul 25 2019 A mature MCS is underway across sern Colo and swrn KS this evening and this should stabilize swrn Nebraska. A forecast update is in place which removes any rain chance across swrn Nebraska tonight. && .SHORT TERM...(This evening through Friday night) Issued at 332 PM CDT Thu Jul 25 2019 Fairly quiet weather conditions are expected across western and north central Nebraska over the next 12 to 18 hours. Low pressure aloft over southern Canada will track east overnight. The frontal boundary will remain stalled across the central Sandhills. With little or no forcing aloft and good subsidence on the western axis of the northern stream low and trough, dry conditions will be expected for the bulk of the forecast area. Some isolated convection will develop on the northern and nern periphery of the upper level high over northeastern New Mexico. Some of this activity may clip the far southwestern forecast area this evening and have placed a slight chance pop in western Chase county through mid evening. Across far northern Nebraska overnight, the NAM12 and HRRR are indicating some convective development toward 12z Friday. After chatting with UNR, it was decided to insert some low pops overnight across far northern Nebraska. For the first half of Friday, the frontal boundary will lift north into northern Nebraska, stalling there in the afternoon. Moisture will pool along the frontal boundary with PWATS eclipsing 1.5 inches by 21z Friday. At the same time, an upper level disturbance will approach the forecast area from the northwest. With surface heating along the front and steepening lapse rates, thunderstorm development is possible INVOF the front late Friday afternoon into Friday evening. Deep layer shear is on the order of around 30 KTS, which could favor strong to low end severe storms. ATTM, the greatest threat is over the Sandhills and into north central Nebraska and have included some low end pops accordingly. .LONG TERM...(Saturday through Thursday) Issued at 332 PM CDT Thu Jul 25 2019 The upper level high across the sw CONUS will retreat west Saturday. At the same time a decent shortwave trough of low pressure will traverse southern Canada forcing a cold front into the area Saturday night. Showers and thunderstorms will develop along the front Saturday night as it passes through western and north central Nebraska. After 90s on Saturday, readings will cool back into the 80s for Sunday and Monday. The upper level high and ridge will build east on Tuesday, with warmer temperatures arriving mid week next week with readings back in the 90s. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 618 PM CDT Thu Jul 25 2019 VFR conditions expected through Friday afternoon at the TAF sites. Concerns in the near term will be two distinct low confidence chances at rain and thunderstorms. Late tonight isolated to scattered thunderstorms may develop off the Black Hills. Should these occur, steering flow will push them into GRN and VTN area overnight. Think greatest potential for these storms is north of the area so will cover with a VCTS for now at VTN. Then, scattered thunderstorms are possible along the surface boundary Friday afternoon. Precise location of boundary is low for now, but current thinking is placement will favor northern Sandhills and thus highest probabilities of storm development in that local area. Will again defer to later forecasts and cover idea with VCTS at VTN for now. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...CDC SYNOPSIS...Buttler SHORT TERM...Buttler LONG TERM...Buttler AVIATION...Jurgensen
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1019 PM CDT Thu Jul 25 2019 .UPDATE... Issued at 1019 PM CDT Thu Jul 25 2019 Updated to include 06Z aviation discussion below. && .SHORT TERM...(This evening through Friday night) Issued at 245 PM CDT Thu Jul 25 2019 A pronounced circulation (noted by regional satellite imagery) over southwest Minnesota early this afternoon, was associated with convection that occurred in South Dakota overnight. There remains enough energy with this circulation to continue high chance percentages in south central Minnesota through the late afternoon. However, instability is weak, and lapse rates are not conducive for anything more than an isolated storm. Farther to the northwest across far eastern North Dakota/northwest Minnesota, the combination of modest instability along the surface front, and upper level energy from a storm system in south central Canada, has led to a line of showers and thunderstorms to form this afternoon. This area of convection will likely move east/southeast during the late afternoon/early evening before becoming weak and disorganized as it runs into weaker instability. There is enough surface convergence along the front to continue chance percentages in west central/central Minnesota this evening. Slowly the area of convection will move southeast across southwest, and into east central Minnesota toward early Friday morning. Severe weather will be limited to areas of west central Minnesota before 9 pm. Precipitation will likely weaken Friday morning before reforming late Friday afternoon along the slowly moving frontal boundary. This boundary will likely washout in southern Minnesota Friday evening setting the stage for isolated storms on Saturday. Temperatures will be dependent on how much sunshine develops once the precipitation stops/weakens Friday morning and skies become sunnier. The best chance of 90s will occur in west central Minnesota, with 70s/80s in west central Wisconsin where the cloud cover will likely hold. Due to the proximity of the weakening frontal boundary Friday night, I can`t rule out isolated showers or storms. However, most of the energy with the storm system moving across south central Canada today, will have moved farther away to have little affect in our region for large scale lift. .LONG TERM...(Saturday through Thursday) Issued at 245 PM CDT Thu Jul 25 2019 Forecast concern in the longer term remains convective potential Saturday afternoon to the south, developing again later Saturday night and continuing into Sunday Night. Trend is cooler early next week with a warming trend late in the week. Frontal boundary associated with Friday night convection is forecast to exit to the southeast Saturday afternoon. This should take the chance of thunder with it. Timing may still be an issue with The GFS a bit slower and may continue at least a small threat over the far southeast CWA in the afternoon. We continues the dry trend for now. This remains short lived however, as the deterministic models drive another potent short wave trough over the upper ridge across the CWA Saturday night into Sunday night. The GFS is a bit faster and pretty much brings a rainy day for the region for Sunday. This will likely affect overall instability and significant thunder threat. If this system is slower, closer to the ECMWF, we could see warmer temperatures, especially across the south with some lower 90s a possibility Saturday afternoon. Following the front, cooler and drier high pressure should dominate the weather through Wednesday. We could see a threat of showers/isolated thunder skirt mainly the southwest CWA Tuesday night as a weaker short wave travels across that region, closer to possible stationary boundary southwest of the state. The GFS is drier with this system. Both the GFS and ECMWF begin to build heights across the western CONUS the second half of next week. The ECMWF is a bit warmer as it builds in higher heights by Friday. The GFS continues to leave the CWA in the transition zone with the stationary/warm front remaining mainly west of the area with leaving us in weak northwest flow and possible shower/thunder threat returning with frontal passages. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1019 PM CDT Thu Jul 25 2019 Convection has had a tough time developing southward along the instability axis to our west this evening, but there are some indications that a few storms could develop over night (in the HRRR and some other CAM solutions). However, don`t have enough confidence in development, particularly with the expecation that coverage would be limited even if storms develop, to include too much mention in the TAFs at this point. However, updates could certainly occur if/when the atmosphere shows its hand. Still look to have another chance later in the day on Friday when the frontal boundary moves through the area, but most of the guidance suggests limited coverage with that activity as well. KMSP...Main concerns continue to be with chance for SHRA/TSRA late tonight and again late Friday afternoon. Will need to keep an eye on it and update if needed, but otherwise didn`t see a need to be too pessimistic at this point. /OUTLOOK FOR KMSP/ Saturday...VFR. North to northwest wind 5 kt or less. Saturday night...VFR. Variable wind less than 5 kt. Sunday...MVFR possible with a chance of SHRA/TSRA. Southeast wind 5 to 15 kt becoming southwest. Sunday night...MVFR possible with a chance of SHRA/TSRA. Southwest wind 5 to 15 kt becoming northwest. Monday...VFR. Northwest wind 10 to 15 kt. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ UPDATE... SHORT TERM...JLT LONG TERM...DWE AVIATION...