Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/21/21


Area Forecast Discussion
National Weather Service Denver/Boulder CO
746 PM MST Sat Feb 20 2021 .UPDATE... Issued at 737 PM MST Sat Feb 20 2021 Intense snow band from northern Park county across Denver and up along I-76 looks on track to produce 1-2 inches of snow in 1-2 hours, but then the snow should be much lighter and probably ending on the plains shortly behind the band. We`re seeing some slush on the roads in the colder places around Denver, but not everywhere. out in Fort Morgan this has been mostly rain, though it should be getting cold enough for snow about now. Overall the forecast looks on track, so only minor changes, mainly higher PoPs over the next few hours. && .SHORT TERM...(This evening through Sunday) Issued at 222 PM MST Sat Feb 20 2021 A storm system will bring a variety of impacts to the mountains and portions of the Denver metro and Palmer Divide late this afternoon into the early overnight hours. Upper level jet streak is currently overhead and slowly sinking south. Meanwhile, a positively tilted shortwave continues to slide east into Utah, with a broad area of southwesterly flow aloft. Moisture has also increased notably over the past few hours. This has combined with 700-500mb lapse rates approaching 9C/km, and QG ascent to form several shallow convective bands over the mountains early this afternoon. Over the plains, fairly strong mixing allowed temperatures to reach the 50s across much of the plains, but temperatures should quickly cool as a cold front advances through the area this afternoon. Over the mountains... Snow showers have increased in coverage this afternoon, and widespread snow is expected over the higher terrain through late this evening. Conditions seem ripe for a period of moderate to heavy snow as these bands slowly shift south. Would expect some travel concerns across the I-70 corridor from about 4 to 8PM as the heavier snow shifts through that region. While snowfall totals won`t be robust, the heavier snowfall rates over a short period of time could still cause significant issues. Snowfall totals through tonight will range from 4 to 10 inches, with the highest totals falling in the Park range. Over the plains... A very difficult snow forecast for this afternoon and evening, as guidance continues to struggle with multiple aspects of the precipitation forecast. What we do know is that there will be plenty of lift across the area, via upper divergence from the left exit quadrant of the jet streak, and by frontogentical forcing. What remains to be seen is (1) how much moisture is left in the boundary layer and how quickly can we saturate the column, and (2) where the best forcing sets up. Model solutions vary significantly in regards to each of these points. The HRRR has been notably drier and produces significantly less precipitation over the plains, while many of the other CAMs and coarser resolution guidance are wetter and a little further north with the axis of heaviest precipitation. The forecast itself is very similar to the previous forecast, with a couple inches of snow falling in the southern half of the metro and into the southern Foothills/Palmer Divide. However, it should be noted that there could be locally higher totals in this area, depending where banding sets up and how long snow lasts as the cold front sinks south. Regardless of snowfall totals, expect some travel impacts along I-70, as well as I-25 from the Denver metro into the Palmer Divide. Tomorrow will be a much quieter day. Temperatures should remain fairly cool under brisk northwest flow, with highs in the upper 30s to near 40 across the plains. Clouds will gradually clear through the day. A few mountain snow showers could linger around, but any accumulations will be minor. .LONG TERM...(Sunday night through Saturday) Issued at 122 PM MST Sat Feb 20 2021 Sunday night through Monday night, a large upper level trough of low pressure will cover much of the Central and Eastern U.S. with a moderate northwesterly flow aloft over Colorado. This pattern will produce breezy and mild conditions across North Central and Northeastern Colorado. There may be enough moisture caught up in the flow combined with some orographic lift to produce isolated to scattered light snow showers over the northern mountains, mainly over the higher peaks. Some wind prone locations along the Front Range Mountains and higher foothills may see wind gusts to 60 mph at times. The best chance for the stronger winds look to be on Sunday night due to the presence of a mean state critical layer. On Tuesday, the upper flow becomes westerly ahead of an upper level shortwave moving across the Northern Great Basin. This should result in lighter winds along with continued mild and dry conditions across the CWA. However, increasing moisture ahead of the shortwave may produce scattered snow showers across the Park Range of Zone 31 by afternoon. A series of shortwaves and associated cold fronts will bring colder unsettled weather to North Central and Northeastern Colorado Wednesday through Saturday with temperatures dropping below seasonal averages. The first two systems will impact Colorado Tuesday night through Thursday morning with a chance of snow and colder temperatures. The best chance of snow will be in the high country with lesser chances across the plains. Moisture and instability with this system looks somewhat limited, therefore snowfall should generally be on the light side. Drier weather is expected on Thursday as upper level high pressure briefly builds over the Rocky Mountain Region and Northern Great Plains States. Another system will bring more snow to the high country Friday and Saturday with mostly dry conditions on the plains. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 737 PM MST Sat Feb 20 2021 The snow band over Denver is moving off of the field at KDEN this hour, and should be past KAPA by 06z. 1-2 inch snow accumulation is likely at KAPA. MVFR conditions should prevail, becoming VFR 05z-07z though a cloud deck at 5000-7000 ft AGL may require instrument approaches to KDEN until 09z-12z. North winds gusting to 20 knots will continue to diminish this evening. For Sunday, VFR conditions with northwest winds gusting to 20 knots at KDEN/KBJC. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 5 AM MST Sunday for COZ031-033-034. && $$ UPDATE...Gimmestad SHORT TERM...Hiris LONG TERM...jk AVIATION...Gimmestad
Area Forecast Discussion
National Weather Service State College PA
1021 PM EST Sat Feb 20 2021 .SYNOPSIS... High pressure will build into the region tonight, as upper trough passes east of Pennsylvania. A fast moving system will bring a burst of snow (perhaps rain/snow mix in the S) late Sunday night and Monday morning. Beyond the Monday system, the weather pattern looks less stormy through the end of February with temperatures trending warmer, becoming near to above average by mid week. && .NEAR TERM /THROUGH SUNDAY NIGHT/... Expect decreasing clouds areawide and diminishing snow showers over the Alleghenies late this evening, as large scale subsidence overspreads the region behind departing shortwave. Some meager latent heat flux from the largely frozen Lake Erie will result in the best chance of an additional dusting this evening over the northwest mountains. High pressure building in from the Ohio Valley will result in diminishing wind and clearing skies overnight. The most favorable radiational cooling will be over the western half of Pa, where winds are likely to become calm by dawn. Therefore, have undercut NBM min temp forecast in this part of the forecast area. Expect the normally colder valleys of the Alleghenies to drop to around zero by dawn, as the latest RAP suggests. A more persistent breeze over eastern Pa should hold readings to the teens in the Susq Valley, still well below average for late February. The center of a 1038mb high will pass just south of Pa on Sunday, ensuring mostly sunny skies and light winds. Forecast 850mb temps moderate rapidly, as flow turns to the south. However, snow cover and weak mixing should result in highs several degrees below average, with afternoon readings peaking between 30-35F over most of the region. Thickening cloud cover is expected Sunday night, as waa aloft overspreads the region ahead of low pressure lifting through the Grt Lks. Models indicate an initial band fgen forcing will lift through the area during the evening hours, perhaps accompanied by a brief period of light snow/flurries over parts of northwest Pa. However, the best chance of snow will come toward dawn over western Pa, as southerly low level jet and surge of waa arrive. A coating of snow appears likely by dawn over most of the Allegheny Plateau, with around an inch over the northwest corner of the forecast area. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... The main period of snow will be during the day on Monday, done by late afternoon. Low level temperatures will support some rain mixing in Monday, especially across the south. I did not change the QPF or snowfall amounts by much. Models last night and today have lower QPF than yesterday. Also timing of the event and warming temperatures as the clouds move in will support less impact than recent events, given warmer low level temperatures. Left high temperatures close to what we had in the fcst. Some upslope and lake effect snow showers Monday night into Tuesday. Temperatures not real cold and Lake Erie has a lot of ice cover now. I did edge high temperatures down a little on Tuesday. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... Medium range guidance supports fair weather Wednesday with some of the warmest conditions we`ve seen since December, as a broad upper ridge pushes off the east coast. An increasing southwest flow between the retreating ridge and a low over the Grt Lks should push readings to around 50F over much of the region. A cold front is progged to sweep through the region Wednesday night, perhaps accompanied by a few rain/snow showers, then followed by fair and seasonable conditions later Thursday. All guidance tracks a potent looking shortwave and secondary cold front through the state Friday, which is likely to be accompanied by scattered snow showers and a brief return to below normal temperatures. Latest ECENS and GEFS currently support fair and milder weather next weekend, as an upper ridge builds along the east coast. However, a minority of ensemble members indicate a dying cold front could approach late in the weekend with a chance of rain showers. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... At 03z, MVFR cigs are hanging on over the western highlands (BFD and JST) along with spotty light snow showers. Clouds are expected to scatter overnight at JST, while BFD may hold onto a deck of low /MVFR/ clouds. Elsewhere, downsloping flow will continue to produce VFR conds. Conds should improve to VFR area-wide on Sunday, as high pressure passes overhead. Clouds will begin to thicken from west to east late in the day. Light snow will overspread central PA Sunday night, producing widespread restrictions. Outlook... Sun night-Mon...Widespread restrictions developing in light snow. Could mix with rain south on Monday. Tues...Scattered -SHSN to bring reductions to primarily the northern and western highlands. Wed...VFR conds. Wed night-Thu...Restrictions possible mainly N/W in light rain/snow showers. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Lambert/Martin NEAR TERM...Fitzgerald SHORT TERM...Martin LONG TERM...Fitzgerald AVIATION...Evanego
Area Forecast Discussion
National Weather Service Dodge City KS
530 PM CST Sat Feb 20 2021 ...Updated Aviation Discussion... .SHORT TERM...(This afternoon through Sunday Night) Issued at 1200 PM CST Sat Feb 20 2021 Temperatures warming nicely at midday, as warmer air aloft finally mixes to the surface and the last vestiges of the arctic air mass are removed. Many locations presently warming into the lower to mid 50s for the first time since February 5th. The temperature at the Dodge City Airport as of 1122 am was 54, which is the warmest temperature since February 3rd. As balmy as this feels, it is only a few degrees above late February normals. Southeast winds will increase sharply this afternoon, in response to leeside cyclogenesis on the Colorado Front Range. SE wind gusts of 30-35 mph will be common this afternoon. This will also drag in some cooler boundary layer air to our southeast (still snowpack in NW Oklahoma) and cap our temperatures in the lower 50s. Welcome to life on the other side of the arctic outbreak. As the shortwave approaches tonight, the associated surface low is forecast by HRRR to be over the western zones at midnight. After midnight, models are in good agreement that stratus will overspread much of SW KS east of the surface low, with the lowest ceilings favoring the eastern/NE zones. 12z NAM is displaying its classic light QPF drizzle signature after midnight mainly along and east of US 283, with best opportunity for something measurable along the border with WFO Wichita. Current thinking is surface temperatures will be below freezing, but not by much, in the 28-32 range as any drizzle falls. Carrying areas of freezing fog and freezing drizzle in the grids for several hours late tonight across the eastern zones. A light accretion of icing on elevated surfaces is plausible east of US 283 late tonight, and a short term winter weather advisory may be required. Surface low will exit the southeast zones near Medicine Lodge around sunrise Sunday, followed by increasing NW winds and dry advection. Any light wintry mix across the eastern zones tonight will only last about 3-4 hours, before the drier NW winds arrive early Sunday. Clouds will decrease from west to east Sunday, with full sunshine by late afternoon. NW winds will be strong, with gusts of 35-40 mph common. With cool advection masked by NWly downslope compression, Sunday will be only a few degrees cooler than Saturday, with mid to upper 40s expected. .LONG TERM...(Monday through Saturday) Issued at 120 PM CST Sat Feb 20 2021 Strong warming expected Monday and Tuesday, as NWly midlevel flow trends zonal. Afternoon temperatures will respond, near 60 Monday and well into the 60s Tuesday. Downslope westerly breezes will encourage the warmup Monday, with winds trending southerly Tuesday ahead of a surface low over the SW zones...but all the winds appear light at 10-20 mph. We have earned this fantastic weather this February; get out and enjoy! A dry cold front will bring a northerly wind shift Tuesday night, followed by temperatures returning to February reality in the 40s Wednesday. Another weak shortwave trough will approach from the central Rockies early Thursday. 12z ECMWF solution strongly favors any accumulating snow with this system being relegated to the I-25 corridor in Colorado, with only light snow potential sneaking across the CO/KS border. NBM pops were similar to this and were accepted. Models dampen this wave significantly daylight Thursday, and most locations will remain dry, and seasonably cool in the 40s. Southwest flow aloft quickly reestablishes Friday, allowing temperatures to moderate once again temporarily. This warming appears short lived, as another progressive open trough is due to come through early in the weekend. While NBM pops are dry, noticed 12z ECMWF has some light snow potential eastern zones Friday night. Kept forecast dry for now. At any rate, progressive pattern will keep any precipitation of consequence in central/eastern Kansas early in the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 514 PM CST Sat Feb 20 2021 Gusty southeast winds will decrease some this evening but a southeasterly flow at around 15 knots can be expected through at least the first half of the night as cold front approaches from the west northwest. This southeasterly flow near the surface will draw an area of low level moisture quickly back into southwest Kansas, especially in the Dodge City and Hays areas. Ceilings are expected to fall back into the MVFR category after midnight with ceilings as low as 1000 ft AGL or less being possible for several hours at Dodge City and Hays between 09z and 15z Sunday. There will also be a chance for some scattered freezing drizzle in the Hays area around daybreak. As the cold front passes between 06z and 12z Sunday a gusty northwest wind at 15 to 20 knots will develop across southwest Kansas. Northwest winds around 25 knots with gusts as high as 40 knots will be possible at times during the day on Sunday. && .PRELIMINARY POINT TEMPS/POPS... DDC 28 46 24 60 / 10 10 0 0 GCK 26 44 21 58 / 0 10 0 0 EHA 28 43 22 59 / 0 0 0 0 LBL 27 47 20 60 / 0 0 0 0 HYS 25 44 24 60 / 30 20 0 0 P28 28 47 25 60 / 20 20 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 9 PM this evening to 6 AM CST Sunday for KSZ031-046-065-066. && $$ SHORT TERM...Turner LONG TERM...Turner AVIATION...Burgert
Area Forecast Discussion
National Weather Service Des Moines IA
551 PM CST Sat Feb 20 2021 .SHORT TERM.../Tonight through Sunday/ Issued at 321 PM CST Sat Feb 20 2021 Forecast Highlights: -Accumulating snow expected across most of central Iowa on Sunday. -Winter Weather Advisory expanded southward. -Snow amounts ranging from 1-5" expected, locally higher amounts possible. Tonight into Sunday...Attention today was mainly focused on the snow potential for Sunday across much of Iowa. Warm air advection today has helped push high temperatures above freezing in southern Iowa and into the upper 20s in northern Iowa. Low temperatures tonight will be more moderate, mainly in the upper teens to mid 20s, with a strong push of gulf moisture in the low levels. This low level moisture is aided by some mid-level moisture from the Pacific causing pwts over 0.5 through much of Sunday and QPF values between .25 and .40 right across the central CWA. This QPF is expected to mainly fall as snow along and north of I-80 with total snow accumulations of 2-5 inches. Although visibilities will be lower during snowfall, widespread blowing snow is not expected as winds will be lighter during this storm. Further south, along and just north of the IA/MO border, mixed precipitation is expected with lighter snow accumulations between 1-3 inches along with a light glaze of ice. Snow will spread west to east tomorrow morning with the bulk of the snow falling in central Iowa between 12-18Z. The latest HREF and HRRR still suggest the most intense snowfall rates could be upwards of 1" per hour with an omega bullseye in the dendritic layer around midday Sunday. Will also not rule out the possibility for locally higher 6" snow totals. Travel impacts are expected during much of the day tomorrow from the snow amounts forecasted. .LONG TERM.../Sunday night through Saturday/ Issued at 321 PM CST Sat Feb 20 2021 Near-normal temperatures and quiet weather will be the main weather story for this upcoming work week. Ridging and increasing west-northwest flow will encourage warming temperatures from the western CONUS initially following Sunday`s system. We transition to (weak) southwest flow on Tuesday which will help push high temperatures into the 40s for much of the CWA and lead to some melting of the current snowpack. Overnight temperatures below freezing could cause some re-freezing impacts on any wet surfaces from the melting snow Tuesday night into Wednesday morning but any additional impacts from the melting snow are not anticipated at this time. Tuesday looks to be the warmest day of the week as another low pressure system tracks across the Rockies and into the Central Plains by Tuesday night. Some models are hinting at a weak mid-level disturbance on Wednesday but at this point just left Wednesday to be a little cooler with highs in the 30s and cloudy. Slightly colder air looks to return towards the end of the work week into the weekend but rest assured, not to the same extent as earlier this week. && .AVIATION.../For the 00Z TAFS through 00Z Sunday evening/ Issued at 550 PM CST Sat Feb 20 2021 MVFR conditions due to fog and haze were in place across northern IA at 00z with high cloudiness increasing north and west. MVFR and possibly IFR conditions in fog and haze may expand later tonight preceding snow advancing west to east starting early Sunday morning. The snow will persist well into the afternoon in most locations with widespread IFR conditions anticipated. Confidence in all these trends is medium. && .DMX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 6 AM to 6 PM CST Sunday for IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075- 081>085-092>096. && $$ SHORT TERM...KCM/Donavon LONG TERM...KCM/Donavon AVIATION...Small
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
617 PM EST Sat Feb 20 2021 .AVIATION... Clouds associated with the Lake Michigan moist plume have been undergoing a diminishing trend this afternoon amidst large scale subsidence across srn Mi. Latest RAP and NAM solutions suggest that the subsidence will lower the inversion a bit tonight with just enough remnant moisture to support some occasional low end VFR/high end MVFR based stratus. However, observational trends suggest conditions are a bit drier. The HRRR actually suggests clear skies through the night. In leaning toward the drier solution, forecast skies will be kept scattered through the night. Under southwest flow, MBS may however be more apt to experience periodic broken conditions this evening given that the low level flow will not veer from southwest to south over Lake Mi until after midnight. There will be a strengthening of the wind field atop the nocturnal stable layer overnight, perhaps enough to limit the degree of boundary layer cooling and thus inhibit fog development. For DTW...The surface winds will shift to the southeast overnight. Winds atop the shallow boundary layer will remain south-southwest, with current indications less bullish with low cloud development off Lake Erie. So a more optimistic overnight cloud forecast will be introduced for metro. .DTW THRESHOLD PROBABILITIES... * Low in ceilings at or below 5000 feet tonight. && .PREV DISCUSSION... Issued at 246 PM EST Sat Feb 20 2021 DISCUSSION... A high pressure ridge will bring one more very chilly night tonight as light south winds and partly to mostly clear skies lead to decent radiational cooling off of widespread snowpack. After topping out in the mid 20s late today, expect lows to drop into the single digits overnight. Southerly winds will then increase on Sunday within the strengthening pressure gradient between the departing ridge of high pressure and low pressure racing out of the central plains into the mid Mississippi Valley. With this flow, expect temperatures to climb into the 30 to 35 degree range by late afternoon to early evening, ending a 15 day streak of below 30 degree weather (assuming DTW remains in the mid to upper 20s through late this afternoon). The southern stream shortwave that will be responsible for lee side cyclogenesis over the plains is currently digging through parts of California today per WV satellite imagery. As this system continues east, expect the low pressure center to track into southern lower Michigan by Sunday evening/overnight. Within an area of strong isentropic lift/warm air advection in advance of this system, expect an expanding area of snow Sunday evening. Given climbing surface temperatures, except some rain to possibly mix with the snow into the overnight hour as the low crosses over the forecast area. All in all, expect a wet 1 to 2 inch (locally 3) snowfall accumulation from Sunday evening into the overnight with any lingering snow showers ending early Monday morning. Relatively mild readings will then set up into mid next week as high temperatures reach the mid 30s on Monday, around 40 on Tuesday and upper 30s Wednesday as a short ridging translates through the region in advance of the next northern stream shortwave and attending cold front. This front will work through the area late Wednesday and bring a return to cooler weather for the late week period as the temperatures return to the 20s to lower 30s Thursday/Friday with lows in the single digits/teens by Friday morning. This cold shot is the first in a series of more progressive intrusions of polar/arctic air that will sweep through the area every 3 or 4 days (each latest a few days). This will be a more characteristic of February weather as compared the persistent cold conditions of late. MARINE... The central Great Lakes will remain under the influence of a strengthening area of high pressure moving through the Ohio Valley. Favorable marine conditions will continue this evening into tonight as a result. This high then moves to the eastern seaboard Sunday as a new low develops over the central Plains. The central lakes will reside in the interface of these two systems causing winds to shift to south-southeast by Sunday afternoon. Winds strengthen over the course of the day Sunday as the low approaches the region causing a tightening the local pressure gradient. Peak winds are expected Sunday night with a couple hour period during the first half of the night where gusts could touch 30kts over central Lake Huron. As mentioned in prior discussions, the thermal profile still is looking to be relatively neutral to stable limiting mixing depths and making stronger gusts (near gales) difficult to achieve. Moderate W-SW winds follow behind the low and will linger through the first half of the work week before slowly weakening midweek. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...NONE. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ AVIATION.....SC DISCUSSION...DG MARINE.......KDK You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.
AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
932 PM CST Sat Feb 20 2021 .UPDATE... Issued at 915 PM CST Sat Feb 20 2021 A couple of noteworthy points in the latest initial 00z guidance and ongoing conditions... A subtle warm nose around 850 mbs has resulted in freezing rain west of a Mitchell to Brookings line this evening with scattered icy roads reported in these areas. Calls to local law enforcement suggest that these conditions are not widespread or severe enough currently to warrant an official headline but this will continue to be monitored closely. Additionally, the heaviest precipitation has now pushed north of the Hwy 14 corridor with cooling of the column expected to result in a change over to snow for any remaining precipitation over the coming hour or two. The other key takeaway from evening guidance has been the focus for two areas of potentially elevated snow totals. The first runs roughly from Tyndall to Madison and is in response to compact frontogenesis focused in the 800:700 mb layer. The HRRR has been most robust with this feature and has produced as much as 0.5-0.6 QPF at times. NAM, NAM Nest, WRFs and RAP all show hints at a similar feature but would place any banding potential closer to the 1-2 inch range. With all of that in mind, still low confidence in the occurrence of an enhanced band over this area but have increased snow total in this area to highlight this potential. Second focus area for elevated snow totals continues to key in on portions of Northwest Iowa, mainly south and east of a Sioux City to Spencer line. This would occur as better support from the incoming vort max arrives around the base of the trough and reflective surface low deepens to the south. While latest guidance appears to have trended a touch south, HREF would suggest the potential for snowfall rate of up to 1 inch per hour at times and thus some potential for snowfall enhancement. Inherited forecast for 2-4 inches across this area still seems appropriate and will continue to message the potential for locally higher amounts. && .SHORT TERM...(This Evening through Sunday Night) Issued at 328 PM CST Sat Feb 20 2021 Early this afternoon, an area of stratus and patchy fog lingers along and east of I-29, mainly across southwest MN and northwest IA. Further west, cirrus builds in ahead of an approaching mid level shortwave. Expect temperatures to fall only modestly overnight, back into the 20s, as cirrus aloft and low level stratus collectively blanket the region amidst continued warm air advection. Temperatures should rise to near or above the freezing mark Sunday, warmest further west in southeast and central SD where more sunshine will prevail. Main focus is on impactful winter weather expected tonight through Sunday in the form of freezing drizzle and snow. This occurs as a mid level shortwave, coupled with warm air advection ahead of an inverted sfc trough, tracks through the region. Early this evening, precipitation should initially spread into south central and southeast SD and northeast NE. Soundings imply a saturated DGZ, but a stout, warm mid level dry layer will take significant time to saturate overnight, especially further south near the SD/NE border. This would imply potential for freezing drizzle across southeast SD and parts of northeast NE this evening. However, it will take quite a while for the low levels to saturate deep enough to warrant any significant icing potential, so very little if any precipitation may occur. Have chosen to hold off on any headline given lower confidence and will continue to monitor freezing drizzle potential this evening. Late tonight, stronger forcing from the deepening wave should prompt mid level saturation and a transition to snow, likely after midnight and perhaps even as late as mid morning for some sites. Further east, confidence is a little higher in seeing patchy freezing drizzle before the column saturates ahead of the deepening wave given the better forcing, but ice accumulations would likely only be a glaze. The bulk of the snow for most won`t occur until Sunday morning. Altogether, expect very little snow for much of southeast SD and southwest MN. Further southeast, generally 1-3 inches of snow can be expected for northwest IA and the I-29 corridor from Beresford to Sioux City, a little higher than previous forecasts. The heaviest snowfall rates are expected Sunday morning southeast of Hwy 60 across northwest IA, where mesoscale Fgen banding and weak instability are expected to set up, locally enhancing snowfall rates. This means a narrow band of 3-4 inches, perhaps isolated 5-6 inches, is possible for parts of northwest IA, with heightened threat along and southeast of a Spencer to Cherokee to Onawa IA. As the system continues to track east, deformation-related light snow will taper off by mid day for much of southeast SD and by Sunday night for areas east of I-29. Could see potential for fog with a strong nocturnal inversion developing amidst low level warm air advection from westerly flow. Otherwise expect temperatures to dip into the teens to 20s. .LONG TERM...(Monday through Saturday) Issued at 328 PM CST Sat Feb 20 2021 Colder, snowy weather from the weekend will be short-lived, as heights building aloft and westerly low level flow brings warming for early in the week. A stronger sfc pressure gradient combined with 850mb jet and good mixing on Monday will bring west winds gusting into the 20s and 30s. Despite the fresh snow, there is pretty good model agreement that high temperatures will rise into the 40s Monday and Tuesday. On Tuesday night, right entrance region jet forcing combined with an upper trough digging into the Central U.S. brings a chance for period of flurries or light snow. At this point, model guidance favors a dry scenario with better precipitation chances remaining to our north, but this could certainly change over the course of the next few days. For the second half of the work week, expect temperatures to remain generally above normal values with no significant chances for major winter weather impacts. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 447 PM CST Sat Feb 20 2021 Several aviation concerns through the period with low stratus, fog, snow and perhaps freezing drizzle all in the mix. Currently still seeing some remnant areas of fog across portions of SW MN and NW IA with perhaps some potential for this to build back to the west over the next few hours. Regardless, will see ceilings lower into the IFR/LIFR ranges by the second half of the overnight hours with the focus being for KFSD/KSUX. In terms of precipitation, seeing an initial area of radar returns working through central SD as of late afternoon although a dry layer is precluding much of this from reaching the surface with the exception being K9V9 currently reporting UP. Not out of the question to see a period of mix at KHON over the next few hours. Will see a more coherent area of snow work in later tonight through Sunday morning, again focusing across NW IA. Still some potential for this to start as a period of FZDZ although saturation depth in the soundings isn`t quite there for any sort of confidence to include this in the TAFs. During periods of heavier snow, will see fairly stout visibility reductions with KSUX the most likely culprit. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...Winter Weather Advisory from 4 AM to 6 PM CST Sunday for SDZ071. MN...Winter Weather Advisory from 4 AM to 6 PM CST Sunday for MNZ090. IA...Winter Weather Advisory from 4 AM to 6 PM CST Sunday for IAZ002- 003-012>014-020>022-031-032. NE...Winter Weather Advisory from 4 AM to 6 PM CST Sunday for NEZ013- 014. && $$ UPDATE...Kalin SHORT TERM...BP LONG TERM...BP AVIATION...Kalin
Area Forecast Discussion...UPDATED
National Weather Service Chicago/Romeoville, IL
920 PM CST Sat Feb 20 2021 .UPDATE... 918 PM CST The going forecast message for the rest of tonight and into Sunday`s snow event look good. Continue to see a slight nudging back of onset snow time in 00Z HRRR/RAP/NAM guidance, but that was already decently accounted for in the going forecast, so only minor tweaks made this evening. Onset time of the main snow in the Chicago metro looks to be after 4 pm, and possibly just after 6 pm for downtown. A primarily clear sky across much of the CWA this mid-evening. Southeast winds around 5 mph at the surface and around 20 mph just a few hundred ft up (per elevated platforms and estimating with lowest level VWP data), have prevented as rapid of a temperature drop as last night. In general this should prevent a fog threat such as we saw this morning with high confidence, however some patches of shallow fog are still possible, probably a little more in the area along/east of I-57. Satellite imagery shows our Sunday system nicely depicted at present from Wyoming toward the Four Corners region, with a stout 150 kt upper jet leading the way as sampled by the 00Z DNR sounding. RAOB data between there and here sampled low-level warm advection above the surface, with +3C as far north as OAX, which is about 1.5C warmer than both the RAP and NAM depict. There is plenty of room to wet-bulb cool though with a fairly dry layer. This is where more dynamic and precipitation-induced cooling later Sunday afternoon/early evening will be needed to have the precipitation stay as a snow to accumulate. Still do not see that as an issue with the evolution of the system, especially along/north of I-80. South of there the profiles are more marginal, including on the 00Z HRRR, which would not have much for snow accumulation at all there. If the degree of forcing is not strong enough south of I-80 for at least a period of time, a lean toward a little more rain may unfold. That is already noted in the forecast, and still a fair amount of uncertainty on how far north that snow/rain line, or at least snow/very low quality snow line reaches. Again too will have to watch for some slick untreated pavement if/where any rain occurs. Snowfall amounts look good with the ingredients shown. It remains that north central Illinois area west of the Chicago suburbs (Boone, DeKalb, Lee, Ogle, Winnebago Counties) where the juxtapose of deeper forcing for ascent, stronger warm advection aloft, some steeper lapse rates, and a little colder profiles could support some 3+ inch totals due to a 3-5 hour period of regular heavier rates. The steeper lapse rates were noted aloft upstream on the OAX and TOP soundings, with the latter showing near 8C/km from 850-500 mb, although fairly dry in that layer too. The expected impacts messaging from this afternoon continues to look good at this time, with some snow-covered roads expected and potential for locations with hazardous travel in the late day/eve. MTF && .SHORT TERM... 332 PM CST Through Sunday night... Somewhat of an uncertain low temperature forecast for tonight. Earlier guidance had been hitting the re-development of low cloud cover pretty hard, but has since backed up a bit. We`ve already begun warm advecting aloft, and this will only increase with time tonight, so envision we will eventually development at least patchy lower stratus. However, if skies remain somewhat clear into the mid- late evening, temperatures should once again be able to fall readily -- certainly not to the degree they did last night since dewpoints are quite a bit higher -- but based on upstream satellite, it`s looking like we`ll have enough time to radiate here to justify lowering temperatures a bit. After midnight or so, would expect temperatures to remain steady or even begin slowly rising. With the higher dewpoints and potential for several hours of mainly clear skies, there is a threat for additional fog development. With the flow immediately off the surface forecast to increase with time, modified Richardson numbers don`t look overly supportive of a dense fog threat. So while some 4-6 mile type visibilities certainly appear possible, have left out a fog mention at this time. One last round of snow to cap off our unseasonably cold and snowy pattern then awaits us on Sunday. A shortwave trough swooping through the Rockies into the Central Plains will trigger a robust low-level mass response that will thrust a plume of relatively warm and moist air up into the region. Isentropic ascent will spur the growth of precipitation over the lower Missouri River Valley that will then track eastward into our area Sunday afternoon. The system will initially have a bit of work to do to erode a stubborn wedge of dry antecedent 850-600 mb air, which will delay the onset of initial precipitation until the afternoon for most, but expectations are that this wedge of dry air will be no more by the mid-late afternoon hours as a substantial amount of lift and moisture advection through the region shouldn`t have too much trouble dynamically cooling and saturating this air. At around this time, most of the area will find itself under the main precipitation shield with most seeing a steady, wet (i.e. not the fluffy snow that we`ve seen with each of our previous snow events) snow, but some across our southern counties could begin to see some rain mixing in with the snow by the late afternoon. The snow and rain/snow mix will last through the evening before ending overnight as the surface cyclone occludes to our northeast. With 7-8 C/km lapse rates atop the dendritic growth zone (possibly even pushing 9 C/km across our northwestern counties) and a considerable amount of attendant forcing being driven by the incoming shortwave, isentropic upglide, and a conveniently located left exit region of the upper jet, the potential is there for snow to come down at a pretty good clip, especially if any f-gen support comes into the fray. With much lower snow ratios than we have recently seen being progged (likely spanning a range from 7:1 down south to up to 12:1 across our north), it doesn`t seem like we will quite get to seeing snow rates on the order of 1" or more per hour, but any bursts of heavier snow will still pose a problem for anybody traveling with abrupt reductions in visibility likely along with the usual slippery roads that accumulating snow will cause. The main point of forecast uncertainty at this time is how far north the rain/snow mix will reach and how long it might last over a given area. Guidance remains mixed on just how warm we will get with the incoming warm advection. Most guidance suggests that areas along and south of I-80 will climb above freezing into the mid and even upper 30s, with some of the more aggressive guidance shoving these warmer temperatures farther north into the Chicago metro. Think that this guidance may be overdoing the warm advection a bit with the deep snowpack in place and ongoing thermodynamic cooling processes, and thus think that any rain/snow mix will remain confined to areas south of I-80. If we get some more sunshine during the daytime then currently expected, then could foresee a scenario where warmer temperatures allow some rain to mix in with snow in the heart of the Chicago metro which would eat into final snow totals there a bit, but confidence on this remains low. Overall, snow totals remain on track from the previous forecast with 2-3" likely along and north of I-80, 1-2" just south of I-80, and less than an inch expected generally south of the Kankakee River Valley where precipitation will be more of a rain/snow mix and perhaps even just rain at times rather than snow. There remains potential for localized snow totals up to around 4" with the likelihood of at least brief heavier snow rates. Have honed in on north-central and northwest Illinois being the favored region for this with lapse rates forecasted to be slightly higher there than elsewhere. We did discuss the need for an impacts-based Winter Weather Advisory, mainly for our northwest Illinois locales near the I-39 corridor where snowfall rates and amounts may be locally maximized. However, with snowfall amounts overall trending just a bit lower, we elected to hold off on issuing one at this time and will defer any headline decision to the evening and overnight shifts to take another look at things. As we`ve already mentioned, slick roads and visibility reductions will still occur as they do for most accumulating snow events, and we will still message these potential impacts via graphics and SPSs. One last item to note is that despite air temperatures being just above freezing where rain manages to mix in with snow, it is possible that actual surface temperatures may not be, especially as we cool off a bit overnight. As a result, it`s possible that some of the rain that falls in the rain/snow mix region across our south could freeze on some roads (especially elevated and untreated ones) and make for some slippery travel during the early morning hours on Monday, potentially including the morning commute. Carlaw/Ogorek && .LONG TERM... 248 PM CST Monday through Saturday... Conditions will become more seasonable across the area for the upcoming week as we finally break out of the extended period of well- below normal temperatures. Monday and Tuesday: The area will remain in continued WNW/NW flow aloft in the wake of Sunday`s system, with stronger mid to upper- level flow remaining just north of the CWA on Tuesday. While temperatures above freezing are expected both Monday and Tuesday, there are still questions as to how far above freezing they can rise. Strong WAA aloft will be ongoing through this period from downsloping flow across the northern and central Great Plains, producing a rather strong inversion as low as 1500ft over the area. The amount of low-level cloud trapped under this inversion is unclear with the competition of drying from the west and periods of enhanced lift from weak waves traversing the WNW/NW mid-level flow. Cooling via sublimation/evaporation from gusty west winds acting on the relatively deep snowpack throw another wrench into the mix and may end up being the most pronounced limiting factor for warmer conditions. Temps in the mid 30s Monday and upper 30s Tuesday are likely, with the potential to over- achieve up to 5 degrees higher each day if clouds are minimal. Wednesday through Saturday: A long-wave trough shifting east from the western CONUS will cross the region Wednesday under a loosely- coupled pair of upper-jet streaks. A vast majority of guidance suggests the best dynamics will remain north of the CWA late Tuesday night into Wednesday morning, with the deterministic GFS basically the lone outlier indicating notable forcing and associated precip across the CWA through the day Wednesday. The forecast was kept dry during this period, but an eventual addition of slight chance PoPs across the north may be warranted Wednesday morning unless more guidance falls in line with the GFS. A brief shot of colder air is expected behind the trough Thursday and Friday, with a potentially more-active period of weather next weekend into the following week as consensus guidance indicates a transition back to a rather amplified pattern across North America. Kluber && .AVIATION... For the 00Z TAFs... The main concerns through the TAF period are as follows: - Mist and pockets of fog after midnight tonight lasting a few hours after sunrise - Period of steady snow Monday evening through beyond the end of the 24-30 hour TAF period, with a small/wet snowflake type expected - Possibility of blowing snow late Monday evening right before the onset of snow. - Marginal low-level wind shear between 21-03Z as a 45 kt southwesterly low-level jet moves overhead Outside a narrow band of clouds based near 5000 feet expected to swing over the terminals between now and 06Z, mostly clear skies are expected overnight. Similar to last night, mist and even pockets of fog are expected to develop during the early morning hours but comparatively stronger southeast winds tonight should prevent widespread low visibility from developing. Modest visibility restrictions will likely persist after daybreak as high clouds move in ahead the well-advertised system approaching from the west. Flurries are possible as early as 16-17Z, especially at RFD, before a "wall" of snow moves in toward the 22-00Z. At the same time, southeasterly winds will increase, becoming sustained at 10-15 kt with gusts to 20-25 kts by late afternoon. Confidence is lower than normal on when snow will start (questions on how fast we`ll be able to get rid of a low- level dry layer), but eventually a wall of snow will sweep from west to east across northern Illinois and northwestern Indiana. We opted to maintain the 22-23Z start time of snow at all terminals inherited from the previous set of TAFs, though adjustments may be made with the scheduled 03Z AMD after examining the 00Z suite of model guidance. After snow starts, it will be steady for several hours before becoming light as the overnight hours progress. Snow rates of 0.25 to 0.5"/hr are expected especially between the 00-05Z, with a small and wet snowflake type likely being quite effective at reducing visibility. At ORD/MDW where the TAF window extends to 06Z, we opted to aggressively offer a TEMPO for 1/2SM visibility with medium confidence already that such conditions will be observed. Surface temperatures are expected to be around 31 to 32 degrees as the snow falls. With southeast winds gusting 20-25 kts, blowing snow will be possible especially around the onset of snow considering the inches powdery snow siting on top of the existing deep snowpack. For now, we decided to leave out any formal mention of BLSN in the TAFs given otherwise unfavorable low- level temperatures and the wet type of snow expected to fall. Finally, a brief period of low-level wind shear is possible Monday evening from 21-03Z as a southwesterly 45 kt (at 2000 feet) low- level jet moves overhead. With surface winds expected to be sustained in the 10-15 kt range and gusts even higher, no formal mention will be made in the TAF package. Borchardt && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Small Craft Advisory...LMZ740-LMZ741...noon Sunday to midnight Monday. && $$ Visit us at weather.gov/chicago Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/NWSChicago www.twitter.com/NWSChicago www.youtube.com/NWSChicago
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
608 PM CST Sat Feb 20 2021 .SHORT TERM...(This evening through Sunday night) Issued at 256 PM CST Sat Feb 20 2021 The long-awaited warming trend has arrived and we have finally made the 20s for the first time since Feb 4th. The sky is mostly clear with patches of low cloud cover across southern Minnesota and even some dense fog over southwest Minnesota. High and mid level clouds are spreading eastward across South Dakota which will reach our area this evening. Some fog could expand across the area tonight, but the mid cloud cover should keep it from becoming widespread and dense. Low level moisture is increasing over a very cold snow pack, however, so the fog potential will need to be watched this evening. The system for late tonight and Sunday has trended a bit weaker with most guidance exhibiting an open wave at 500 mb. NAM remains the strongest with a closed low across Iowa and unrealistically high QPF across southern Minnesota. The snow will spread from west to east late tonight and Sunday morning. Kept QPF near the ensemble means, which still do show some spread, but the spread isn`t such that deviating up or down from the mean will make too much difference with resultant accumulation. Maybe one inch. Accumulations from this forecast package call for an inch south of a line from Redwood Falls to the Twin Cities and Ladysmith, with 2 to 3 inches along I-90 in far southern Minnesota. Left the Winter Weather Advisory alone for now with the potential for 3+ inches remaining if the system shifts slightly north. .LONG TERM...(Monday through Saturday) Issued at 256 PM CST Sat Feb 20 2021 A strong upper level jet will send a relatively warm Pacific airmass our way to start the week. Temperatures still look to climb into the upper 30s and low 40s for highs, which is nearly 10 degrees above average for late February. This will be a welcome relief to most, as we have spent the majority of the month well below average. Westerly winds look to be on the breezy side Monday, particularly across western portions of the area, but will decrease into the evening hours. Tuesday will be another warm day with highs once again approaching 40 ahead of a surface low over the Dakotas. This system may bring some precip across the area late Tuesday into Wednesday, and given that temperatures are slated to be above freezing for at least a portion of the precip onset, a rain/snow mix is possible. Behind the aforementioned low, highs for Wednesday and Thursday will fall slightly back to normal late February readings in the upper 20s and low 30s. Another chance of some precip may be in the cards to end the week as a 500mb trough moves across the upper Midwest, but will leave low PoPs as is for now until model consensus improves. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 608 PM CST Sat Feb 20 2021 Main change to the TAFs was to follow more of the HRRR idea where pre-snow MVFR/IFR cigs hang out more or less where they are now, western and central MN given the lack of low clouds across southern MN/northern IA. For the snow, followed the idea of the GFS/RAP. 18z NAM only produces snow at MKT and EAU, which is probably a little too aggressive given the moist atmosphere and weak forcing we`ll have much of the day ahead of the trough moving through Sun afternoon. Snow accums look to be mainly under one inch, just a prolonged period of 1 1/2sm to 3sm visibility snow. With the light southeast winds along the trough, we could see cigs lower than currently forecast with the snow, but for now kept things mostly in the 008 to 012 range. KMSP...Heaviest snow will remain south of MSP, with snow possible as early as 12z. Highest snow rates will occur a couple of hours on either side of 18z. Continued to be optimistic with cig heights Sunday, though something around 800 feet may be possible for much of the afternoon. Some improvements in cigs are expected Sunday night, but will wait for later TAFs to try and refine that timing. /OUTLOOK FOR KMSP/ Mon...VFR. Wind WSW 10-15kts. Tue...Chc MVFR/IFR and -SN late. Wind SW 5-10 kts. Wed...Chc MVFR cigs. Wind NW 10-15 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...Winter Weather Advisory from 6 AM to 6 PM CST Sunday for Blue Earth- Faribault-Freeborn-Martin-Steele-Waseca. WI...None. && $$ SHORT TERM...Borghoff LONG TERM...Dye AVIATION...MPG
Area Forecast Discussion
National Weather Service Pocatello ID
130 PM MST Sat Feb 20 2021 .SHORT TERM...Tonight through Monday night. Early afternoon satellite imagery highlighted a low amplitude trough-ridge couplet situated from the Aleutian Islands eastward through the NE Pacific with NW flow extending downstream across Idaho. Looking through the forecast charts this pattern remains firm clear through 186hrs (next Saturday). The only real change is the weak impulses that will drop SE through the NRN rockies almost daily and two substantial waves embedded in that flow translating through the region Monday night/Tuesday and then again Thursday. As for the specifics here in the short-term, it looks as if the enhanced upslope flow across the NE highlands will come to an end shortly with gusty winds continuing through about 6 PM before tapering off. Thus the Winter Weather Advisory will continue across the NE highlands through about 8 PM MDT this evening. Weak features embedded in the NW flow aloft will translate through the Montana divide region Sunday through Monday resulting in periods of snowfall in the favored NW upslope flow regions of the CNTRL and NE mountains. Light sub-advisory accumulations are favored under these conditions. As mentioned previously, a more substantial short-wave will migrate through the region Monday night through Tuesday. For now, snow totals run up towards the lower end of Advisory criteria and may yet require some sort of highlight as the event draws near. Temperatures continue to run below normal through Monday morning and then begin to warm Monday afternoon and Monday night ahead of the incoming trough. Huston .LONG TERM...Tuesday through next Saturday. A moist NW flow regime is forecast to continue throughout all of next week into next weekend. This patten unto itself will support continued snow shower activity in many of our mntn regions as those air parcels are lifted and cool/saturate against the terrain, but we`ll also see multiple shortwaves riding the flow that will tend to "focus" our precip chances and bring lower elevations into play as well. The first wave is expected Tue-Wed. A 50-70kt 500mb jet remains forecast on the leading nose of this shortwave Tue, which will likely mix down at least 15-25kts to the sfc (if not better... NAM and GFS forecast soundings carry steep/unstable low-level lapse rates potentially exceeding 7 degC/km), so we continue to adjust the wind forecast higher than NBM guidance. Snowfall amounts look relatively light (highest values of 2-5" or so in the Sawtooths, ern Fremont County, the Tetons, and Big Holes), but the combination of winds and even light snowfall amounts could certainly result in highway impacts due to blowing/drifting snow (esp in the normal trouble spots east of I- 15 where the winds will overlap with higher snow totals). Best potential for impacts will be daybreak through sunset Tue. Winds should be lighter Wed. The next shortwave arrives Thurs afternoon and continues into Fri/Sat, again with the flow supporting best accums in locales that do well with NW-induced upslope such as the Sawtooths, Tetons, Big Holes, and Bear River Range. Both shortwave periods this week light up nicely on the GFS/EC ensemble meteograms...these are definitely the impact periods, but even for mntn point locales such as Stanley and Driggs (which we often use as proxies in these coarser/lower resolution models to feel out how the surrounding mntns may do), snow totals over any 24-hour period are generally less than 5 inches (with only a few outliers...highest on the GFS). So...unsettled yes, but no death or destruction on the horizon. High temps throughout the week will generally top out in the mid 20s-mid 30s each day (about 5-10 degrees below climo norms for this time of year), supporting all snow with these systems. -KSmith && .AVIATION...-SN continues to fall at KDIJ. Most high-res models have already ended snowfall there, but radar trends are lagging 1-2 hours behind most of the HREF reflectivity members, AND KDIJ is infamous for not shutting down on time. Thus, have maintained -SN with MVFR- IFR vsby reductions through 22z/3pm before backing off to VCSH and VFR cigs/ vsbys. Otherwise, satellite trends are progressively scattering the region out, and HRRR cigs/HREF mean cloud product both support a SCT or better VFR regime this afternoon into tonight which is verifying well (expect perhaps KDIJ...guidance has a hard time resolving the Teton Valley and perhaps sometimes leans too pessimistic, but we held on to a VFR/borderline MVFR deck there into Sun). Thus, the main consideration for aviation at most terminals for the rest of the day will be winds with a strong W/SW flow up the Snake Plain through KBYI/KPIH/KIDA. Strong winds draining out of the Central Mntn valleys MAY turn winds NW after 20z/1pm at KIDA which is supported by the HRRR and RAP, but it will be a battle to see if those winds can dominate that far east over the SW flow coming up the plain (MOS guidance favors that SW flow). Have bitten off on this for now in the TAF but confidence is low...the interface between these two flows is currently just west of the terminal per sfc obs. Tonight, the big question is whether fog/low stratus will develop at KIDA and/or KDIJ. Given recent snowfall and a reasonably saturated boundary layer, it seems like this could occur (strong support from MOS guidance), yet the HRRR and HREF carry very little development. Maintained an inherited drop to IFR for KIDA (backed it up to 07z/midnight) since I don`t have confidence to remove it, but only gently leaned in to some VCFG/MVFR cigs at KDIJ for now. Swing shift will have 2 TAF packages to continue evaluating. IF we crash, we`ll crash hard (lower cigs than currently forecast). If not, cigs will likely hold MVFR or better. Moist NW flow and breezy conditions persist on Sun, but any resultant snow showers should generally hug the mntns with the TAF terminals staying dry. - KSmith && .PIH WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory continues until 8 PM MDT this evening for IDZ063>066. && $$