Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/03/19

Area Forecast Discussion
National Weather Service Denver/Boulder CO
737 PM MST Sat Mar 2 2019 .UPDATE... Issued at 737 PM MST Sat Mar 2 2019 Widespread snow will continue through the evening and then decrease after midnight. Several bands of heavy snow are lightning up the radar. Snowfall rates are likely an inch or high under the bands of heavy snow. Going forecast is on track with only minor changes made. Cold air continues to pour into northeast Colorado overnight with wind chill values falling to -10 to -20. Will mention these in the Winter Weather Advisory statements. For Sunday, cloudy and cold conditions will prevail. Areas of snow continue in the mountains, while light snow/flurries will be possible east of the mountains. && .SHORT TERM...(This evening through Sunday) Issued at 318 PM MST Sat Mar 2 2019 Radar data shows coverage of snowfall beginning to increase up and down the I-25 urban corridor as moisture aloft continues to increase. Satellite imagery shows solid cloud cover all the way back to central Nevada as the surge of Pacific moisture continues its eastward track. HRRR models have been indicating that precipitation would be increasing after about 3 PM. This should lead to several hours snowfall across the forecast area this evening. At the surface, cold air has been moving down from the Cheyenne ridge with temperatures in northern Weld County now in the upper single digits. Cold air will also be coming in from an easterly and northeasterly direction overnight. Low level upslope, abundant moisture aloft and upper level jet dynamics will all combine to spread light to moderate snow across the forecast area. Mountain areas have been receiving light to moderate snow all afternoon, which should continue. Indications from the HRRR and RAP models are that the primary band of snow over northeast Colorado will be over the Denver Metro area and Palmer Divide. These areas will probably see something like 4 to 6 inches of snow overnight. Most of the snow should fall by midnight with a decrease in intensity after that. The current list of Winter Storm Warnings and Winter Weather Advisories are in agreement with the latest thinking, so no changes will be made at this time. On Sunday, the central mountains may continue to see light to moderate snowfall while locations further to the north will only see light snow showers. On the plains, the entrenched cold airmass will support snow flurries and some light snow showers, but not much additional accumulation. High temperatures will only be in the mid teens. .LONG TERM...(Sunday night through Saturday) Issued at 318 PM MST Sat Mar 2 2019 An active pattern continues in the long term, but with a general warm up through the period. An upper jet maximum will push over the state with the right entrance region to pass over the forecast area Sunday night. Most models place the area where banding will likely occur over and along the I-70 corridor, from the mountains down onto the plains. This band will likely put down 2 to 5 inches over the mountains and another 1 to 2 inches over the plains. This will be covered by the Winter Storm Warning for the mountains around I-70, to cover the bad driving conditions for the end of the weekend back from the mountains. Won`t issue anything for the plains at this point, as it`s hard to pinpoint the band location. As the whole system sinks south, cold arctic air will continue to filter in from the north, and with partially clearing skies, the coldest temperatures will occur. Ended up nudging the forecast to the coldest guidance for the night, which brings readings close to record values, but still a couple degrees warmer. We may need to look at the need for a Wind Chill Advisory Sunday night for the plains, as readings are currently forecasted to be between -15 to -25 degrees, with the coldest expected over Logan, Phillips and Sedgwick counties. Moisture in the northwest flow will be decreasing Monday for a drier day, though will still see scattered orographic snow over the mountains. Cooled the max temperature forecast over the plains as northeast winds will keep the arctic airmass in, though expecting some sun to peak through the clouds to get them into the teens to low 20s. The warming trend will continue Tuesday as an upper ridge builds and moves across the state. Look for temperatures to be about 10 degrees warmer, but still below normal. A weather system off the Pacific will push onshore Wednesday to bring moisture into the mountains in the morning, as well as a warmer airmass over the state. Temperatures should warm another 10 degrees. Then increasing lift Wednesday night should allow for a chance of showers over the far northeast plains, where cold air from the Great Plains surface high will still be found. As that system kicks out Thursday morning, this will finally push out the cold arctic air over the far northeast plains. Thursday temperatures will be another 5 to 10 degrees warmer, though moisture in the flow will keep snow in the mountains. Another Pacific system is expected to push onshore Friday for the next chance of snow forecast area wide. GFS wants to be deepest and close the trough into a low, which would help wrap moisture into the plains, whereas the Canadian and EC wants to keep it open, which would tend to downslope at least the western plains. Warmer temperatures may allow for rain showers over the plains as well. EIther way, the mountains are expected to see more snow to continue to add to the above normal snowpack. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 737 PM MST Sat Mar 2 2019 Snow will decrease after 07Z. However ceilings will remain around 1000 feet with visibility less than 5 miles. Even though not much snow is expected for Sunday, low clouds, fog, and flurries will continue to limit visibility. Winds are expected to stay northerly into Sunday morning. Winds then become light and turn easterly after 18Z Sunday. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 11 AM MST Sunday for COZ030-032- 037-039>051. Winter Storm Warning until 11 AM MST Sunday for COZ031-033-035- 036. Winter Storm Warning until 5 AM MST Monday for COZ034. Winter Weather Advisory until 11 AM MST Sunday for COZ038. Winter Storm Warning until 9 PM MST this evening for COZ038. && $$ UPDATE...Meier SHORT TERM...Dankers LONG TERM...Kriederman AVIATION...Meier
National Weather Service Wilmington OH
933 PM EST Sat Mar 2 2019 .SYNOPSIS... A fast moving low pressure system will spread snow into the region later tonight and through the day on Sunday. After the low moves through, a much colder airmass will settle into the region through the first part of the upcoming week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... HRRR and RAP have picked up on the potential for a stripe of light precipitation overnight that has been depicted in the GFS and now NAM as well. Looks like it might be a bit of seeder feeder that is creating this band that may affect parts of southwest and south central Ohio. Still a fair amount of uncertainty, so kept PoPs low. Road temperatures are still generally in the 40s and model suggests that pavement does not get below freezing overnight. So even if a quarter inch of snow falls tonight, it seems that it would have minimal impact. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... Models have finally settled on a more more muted system, with a southerly track of the surface low through the southeastern U.S. Isentropic lift ramps up Sunday morning, with snow overrunning the fa during that time. Expect snow to be the main ptype Sunday, but locations in the far southeast could see some rain mix in with the snow during the late morning into early afternoon. Road temperature forecast models are showing that road surface temperatures are expected to stay above freezing throughout the day, which may limit snow accumulations to only grassy surfaces and maybe overpasses. Updated snow totals have 1-2 inches, approximately south of I-70ish, with the possibility of some locations making 3 inches. Will issue an advisory I-70 south. The snow could be tapering off in the far west as early as late afternoon. Highs on Sunday will range in the 30s. The mid level s/w energy will work quickly to the east Sunday night, pulling the backedge of the precipitation into the Appalachians. Snow should be over in the east by midnight. Arctic high begins to build in late in the night. Temperatures will drop into the mid teens to lower 20s by morning. && .LONG TERM /MONDAY THROUGH SATURDAY/... High pressure and dry conditions will be working into the region at the start of the long term period. Cloud cover will decrease through the day, however temperatures will be cool with high temperatures in the 20s. With clear to mostly clear skies Monday night temperatures will drop down around 10 to the low teens. An upper level disturbance will work through on Tuesday allowing for scattered snow showers. There are steep low level lapse rates and expect winds to be gusty around 25 to 35 mph. Snow showers will exit the area by the evening hours. The coolest wind chill values will be Tuesday night into Wednesday morning with wind chill values in the negative single digits to single digits. Dry conditions will then be in place until Thursday morning. Another system will move through Thursday afternoon into Friday bringing a mix of precipitation. Another round of precipitation will move into the region for Saturday. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... Expect MVFR ceilings to spread into the Cincinnati and Dayton areas during the early part of the TAF period while other locations are forecast to remain VFR until after 12Z. A fast moving system will spread snow across all terminals on Sunday. This will cause prevailing ceilings to drop below 2000 ft with a period of IFR ceilings and visibility possible. Winds will generally be out of th north at 10 kt or less. OUTLOOK...MVFR ceilings will continue into Sunday night. MVFR ceilings are possible Tuesday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...Winter Weather Advisory from 7 AM to 7 PM EST Sunday for OHZ053-060>062-070>072-077>080. Winter Weather Advisory from 10 AM Sunday to 1 AM EST Monday for OHZ054>056-063>065-073-074-081-082-088. KY...Winter Weather Advisory from 7 AM to 7 PM EST Sunday for KYZ089>099. Winter Weather Advisory from 10 AM Sunday to 1 AM EST Monday for KYZ100. IN...Winter Weather Advisory from 7 AM to 7 PM EST Sunday for INZ050-058-059-066-073>075-080. && $$ SYNOPSIS...JGL/Sites NEAR TERM... SHORT TERM...Sites LONG TERM...Novak AVIATION...
Area Forecast Discussion
National Weather Service Lincoln IL
912 PM CST Sat Mar 2 2019 .UPDATE... Issued at 912 PM CST Sat Mar 2 2019 Cloudy skies prevail across central Illinois this evening...with temperatures mainly in the upper 20s and lower 30s. Surface analysis shows next storm system slated to impact the region still well to the southwest over New Mexico. As this low tracks eastward, snow will spread across the Plains overnight...then into central Illinois by Sunday morning. 00z NAM and HRRR both delay onset of precip by a couple of hours from previous forecast, which seems quite reasonable given presence of sprawling high pressure ridge from the Northern Plains into the Ohio River Valley. Have therefore dropped PoPs late tonight except across the far SW KILX CWA around Jacksonville. Once the atmosphere moistens from the top-down, snow will quickly spread across the area by mid to late morning. 00z model trends still suggest the heaviest snowfall of 1-3 inches will be focused along/south of I-72...with locations from Peoria and Bloomington northward seeing less than 1 inch. && .SHORT TERM...(This evening through Sunday) ISSUED AT 226 PM CST Sat Mar 2 2019 Clouds will continue to impact the region tonight through the end of the weekend, as another weather making system approaches the Midwest. Current radar returns are indicating precipitation falling from the sky across central Illinois, however with dry air still overhead much of this is dissipating before reaching the ground. The region should remain dry through the evening and into the overnight. Models continue to trend slowly with the approaching system, as well as a slight decrease in total snowfall amounts around the region. Northerly winds will help to tighten the precipitation gradient for this system. This will also usher dry air into the region ahead of the system, meaning saturation will take a little extra time before precip finally begins to reach the ground Sunday morning. Current position of the low remains in the Rockies, but a rapid ejection of the system will occur this evening as it races through the Plains and arrives into the mid-Mississippi Valley early Sunday morning. It will arrive as a disorganized low, before redeveloping a core in the southeast US. Models agree that snowfall will start after 12z in the south-western portion of the CWA. It will then spread to the east north-east through the morning, with the majority of snowfall occurring along and south of I-72. Locations north of I-72 are expected to receive up to 2 inches of snowfall, while locations south of I-72 will get 2-3 inches. Surrounding offices to the southwest and south have issued a Winter Weather Advisory, after understanding this event is on a Sunday with lowered impacts, I will continue the SPS already ongoing. This system will quickly move through the region Sunday, exiting between 00-03z. .LONG TERM...(Sunday night through Saturday) ISSUED AT 226 PM CST Sat Mar 2 2019 Behind the exiting system, a blast of cold Arctic air will filter into the Midwest for the first half of the upcoming week. A 1044mb high will develop across the northern Rockies, and with a tight pressure gradient, enhanced northwesterly winds will move across the northern Plains into the Midwest. This will bring another round of cold air, and frigid wind chills, to the region. Monday morning lows will be in the single digits, with wind chills around advisory criteria of -15 to -20 from I-72 northward. At this time no surrounding offices have initiated a wind chill advisory, but that will need to be addressed tonight. No issuance was given, as to not confuse the public with different advisories. Clear skies will return Monday behind the frontal passage, however temperatures will be quite chilly in the teens to mid 20s. The low will drop out of the northern Rockies and deepen as it heads into the central Plains. This will provide one more frigid night, Monday into Tuesday, as temperatures dip to the single digits around much of the area. Westerly winds will remain elevated near 10-15mph, dropping wind chills back into the negative double digits Tuesday morning. The high will continue to dominate the region through mid-week before giving way to another weather producing system. Temperatures will warm during the second half of the week, as southerly winds return. However, the region will remain below normal (mid 40s) for this time of year. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 546 PM CST Sat Mar 2 2019 MVFR ceilings linger at both KBMI and KCMI late this afternoon: however, these will likely improve over the next couple of hours. Main aviation weather concern will an approaching storm system late tonight into Sunday that will spread snow into the area. Forecast soundings suggest ceilings will lower back to MVFR at KPIA by 06z...then further east to KCMI by around 12z. Snow will develop from west to east Sunday morning, but will be heaviest and most persistent at the I-72 terminals where visbys will be reduced to around 2 miles. The snow will quickly come to an end between 18z and 22z. Winds will initially be N/NE at around 10kt through tonight, then will back to NW and increase to 10-15kt by Sunday afternoon. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Barnes SHORT TERM...Baker LONG TERM...Baker AVIATION...Barnes
National Weather Service Jackson KY
1103 PM EST Sat Mar 2 2019 .UPDATE... Issued at 1103 PM EST SAT MAR 2 2019 Hourly temperature and dewpoint grids were freshened up based on recent observations and trends. The forecast for the overnight hours remains on track and no changes were needed at this time. For Sunday and Sunday night, no changes have been made at this time. Much of the event, at least prior to 21Z, will have very low snow to liquid ratio, well below 10 to 1. Snow to liquid ratios will be increasing after that from northwest to southeast, but deeper moisture will also be starting to depart. The 0Z NAM and 18Z NAM from Sat did indicate the potential for a higher snowfall in a band near or just south of the Mtn Parkway that develops as the surface low beings to deepens in the Carolinas late Sunday afternoon/evening. Confidence in that occurring is low as much of the other guidance, such as the 18Z GFS from Sat and 0Z GFS and 0Z HRRR however, do not support this. Instead that guidance supports relatively low amounts for valley locations and somewhat higher amounts on ridges. For the most part, it still appears that snowfall will be about an inch or less for the vast majority of the area. Ridgetops, generally along or north of the Mountain Parkway, and especially near and north of I 64, may receive slightly more. Temperatures on average will be coldest in Fleming County and the Winter Weather Advisory remains in effect there. An SPS has been issued for the remainder of the area where impactful accumulating snow is less certain. Later shifts will evaluate the entire suite of 0Z for any changes that might be needed. UPDATE Issued at 744 PM EST SAT MAR 2 2019 Some minor adjustments have been made to hourly grids at this time. The main change is to adjust temperatures across the higher elevations closer to recent trends. 18Z guidance supports the ongoing forecast for the most part through Sunday night. With temperatures expected to be very marginal if not outright too warm at times for any accumulations, in the mid 30s to upper 30s in the north, outside of grassy or elevated surfaces during the early March day on Sunday, daytime accumulations should be very limited even there. Precipitation type may also shift back and forth between rain and snow and forecast soundings indicate that rates may never be high enough for full wetbulbing of the near surface layer to closer to the freezing mark. As temperatures begin to cool late afternoon and evening, at the same time as the deeper moisture will be shifting southeast some impacts are more probable. The 18Z HRRR which runs out to 6Z on Monday supports the ongoing forecast. Ridgetops generally near and north of I 64 will have the highest chances for accumulations. No changes to the WSW areal extent or the SPS are planned at this time. 0Z guidance should shed more light on the event. && .SHORT TERM...(This evening through Sunday night) Issued at 454 PM EST SAT MAR 2 2019 A messy period of weather is in store. A mid/upper level wave currently crossing east over the central/southern Rockies will coincide with a developing northern stream trough and plunge of arctic air. A wave will develop on a frontal boundary to our south and bring precip or the JKL forecast area, mainly on Sunday. Temperatures will be marginal for snow, especially near the ground. Based on forecast soundings, a mix of rain and snow is forecast, tending toward more snow in our northern counties, and largely rain in the south. Even in the north, surface temps a little above freezing on Sunday will limit accumulations. If the snow can come down hard enough at times, it will depress the temps a bit and probably result in slushy accumulations. At this time, only in Fleming County does it appear that an advisory may be warranted. One has been issued there for up to two inches, especially on ridges, and this blends in with advisories from surrounding offices. On Sunday evening the deep moisture will be pulling out to the east as colder air arrives with the departure of the surface low. Forecast soundings show some potential for freezing drizzle due to lingering low level moisture where clouds temps are too warm for ice. This will be monitored, and if it looks like a large enough threat, it will need to be emphasized more in future forecast updates. .LONG TERM...(Sunday night through Friday) Issued at 413 AM EST SAT MAR 2 2019 A low pressure system tracking to our SE will begin to exit east of the region Sunday night, pulling the QPF with it and out of the CWA fairly quickly. With strong northerly flow taking hold at the surface as the system departs, cold air will begin to filter in from Canada, and temperatures will fall well below freezing throughout the overnight. This, coupled with any lingering moisture, will translate to snowfall. However, given the general consensus between the latest model runs that the qpf will be exiting the CWA rather quickly, this will limit accumulations amounts between 0 and 12Z Monday. The latest forecast is for generally between 0.5 and 1.0 inch, mainly across the eastern CWA. Given the falling temperatures, some of this snow could adhere to the roads and may cause some travel impacts. Once this system exits to our east, upper level troughing will take hold across much of the central and eastern U.S., with strong pressure gradients and NW flow into the region. This will couple with a large area of high pressure moving in from our NW to keep dry but much colder conditions in place through at least mid week. Highs Monday will be in the low to mid 30s, and maximum radiational cooling on Monday night will allow temps to fall into the teens. Can`t rule out a few single digits in the north and deeper eastern valleys as well. Temperatures will remain similar through Wednesday. After this point, the upper level troughing and low heights across the state will finally shift eastward with the GFS and ECMWF both showing rising heights across the state. The models then start to diverge in their solutions, with the ECMWF keeping ridging across the central U.S. through Friday, while the GFS brings a shortwave eastward towards the Mississippi River Valley. Either the ridge or the shortwave will traverse Kentucky Friday night, but depending on which it is will have major implications on the sensible weather. Stuck with the Superblend for pops and QPF during this time, but it does seem to be very heavy on the GFS solution bringing higher pops across the CWA Thursday night into Friday. Any precip that falls Thursday night will be in the form of snow with temps below freezing. Surprisingly, despite the large differences in the models during this time period, they actually do come into better agreement about a upper level low developing across the Rockies and ejecting eastward towards the Ohio Valley later in the weekend. This system will weaken as it traverses the Ohio Valley Sunday, but will likely bring another round of widespread precip to the region just past the forecast period. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) ISSUED AT 735 PM EST SAT MAR 2 2019 Conditions at TAF issuance were mainly in the MVFR range across the area with some IFR in the higher elevations right along the VA border. Although MOS and Lamp data do not indicate, most of the rest of the guidance indicates at least a brief window of improvement, with most places becoming VFR by around 03Z to 4Z, but generally maintaining ceilings from around 3500 to 6000 feet AGL. This should persist for a few hours, but another deterioration ahead of the next system back into the MVFR range is expected around 9Z. Mainly IFR is expected by 15Z. A mixture of rain and snow should overspread the area 10Z to 16Z, with a mixture of rain and snow developing. IFR vis and some reductions to near or perhaps below airport mins are possible at times thereafter. This will persist through the remainder of the period. && .JKL WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 7 AM to 6 PM EST Sunday for KYZ044. && $$ UPDATE...JP SHORT TERM...HAL LONG TERM...JMW AVIATION...JP
Area Forecast Discussion
National Weather Service Tulsa OK
933 PM CST Sat Mar 2 2019 ...UPDATE... .DISCUSSION... Forecast looks to be more or less on track, with freezing line slowly sinking into northeast OK with areas of ongoing drizzle/freezing drizzle. Light snow continues to track east through southwest KS into far northwest OK and this will spread into the area later tonight. Latest few runs of the HRRR suggest the snow may arrive a bit later than previous forecast, although overall amounts look about the same. Expect around a half inch to perhaps an inch along the TUL-FYV corridor, with higher amounts closer to the OK/KS and AR/MO borders. && .PRELIMINARY POINT TEMPS/POPS... TUL 26 27 8 23 / 90 70 10 10 FSM 38 39 17 30 / 90 80 0 10 MLC 31 32 13 27 / 80 50 0 10 BVO 21 22 6 22 / 100 70 10 10 FYV 31 32 9 24 / 90 100 0 10 BYV 30 30 7 23 / 90 100 0 10 MKO 29 31 10 25 / 80 70 0 10 MIO 24 24 5 20 / 100 100 0 10 F10 28 29 10 24 / 90 60 10 10 HHW 37 39 20 33 / 80 50 0 10 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...Winter Weather Advisory until noon CST Sunday for OKZ054>070. AR...Winter Weather Advisory until noon CST Sunday for ARZ001-002-010- 011. && $$ SHORT TERM...18