Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/12/21

forecast discussion below highlights. Have seen a slow erosion of
the low clouds from the west with satellite being masked some by
high cirrus but guidance and trends suggest a west to east clearing line for the overnight period across the northern valley. Patchy dense fog is developing from near Detroit Lakes north to near Thief River Falls with this area expected to have the worse conditions before improving late tonight into tomorrow morning. && .SHORT TERM...(This evening through Tuesday night) Issued at 324 PM CST Mon Jan 11 2021 HRRR/NAM have been pretty accurate with 925 mb and lower cloud trends the past few days and has been doing reasonable so far today. Once exception today, its 925 mb RH was progged too far south. Low clouds will gradually clear out of NE ND from the west and it is hopeful fog moves out too. Fog patches have remained persistent for days on end esp in Langdon/Cando/Park River ND areas. HRRR indicates main fog tonight will be more in NW/WC MN esp in that area just east of the valley from Fergus Falls up to Roseau. Will have fog mentioned there but maintain some fog mention into NE ND til 06z. When/if clouds clear out of NE ND fog may return in more ground fog situation but boundary layer winds remain sufficient it would appear to prevent it. But we have been down that rabbit hole before. Tuesday should see any fog/low clouds give way to a partly sunny sky. Mild with mostly low-mid 30s. .LONG TERM...(Wednesday through Monday) Issued at 324 PM CST Mon Jan 11 2021 Main focus within the long term discussion will be on a winter system to affect portions of eastern North Dakota into northwest and west-central Minnesota between the late Wednesday and Friday timeframe. While the severity and location of impacts remain uncertain, at least minor impacts from this system appear likely (i.e. four out of five chance), with around a two in five chance of advisory level impacts, and a one in ten chance of seeing warning level (i.e. significant) impacts. Because of these odds, this system should be monitored for impacts from accumulating and drifting snow, gusty winds, light icing, and reduced visibility. Analysis of WPC clusters, ensemble percentile tables, and deterministic runs yield high confidence in a well developed clipper- type system to move out of south-central Canada into the Upper Midwest around Wednesday-Thursday. This high confidence extends to the belief of a deeply amplifying upper trough into the western Great Lakes region Thursday-Friday timeframe helping maintain the strength of the clipper as it moves west of the area. As the wave pattern deepens, the clipper may slow as to moves west of the area, possibly increasing residence time of impactful sensible weather. There is also relatively high confidence in the presence of high winds over 40 mph associated with this system to spread over the Dakotas and into Minnesota. There are even some indications of very strong winds over 55 mph Thursday and Friday, mainly within the Dakotas into the Red River Valley. This is due to a strong jet of low level winds accompanying the clipper`s initial cold front late Wed into Thursday lingering around the backside of the clipper as the upper trough deepens Thursday-Friday. Lesser confidence revolves around the amount, location, and timing of snow/wintry mix which will dictate severity of impacts considering the likelihood of high winds to accompany wintry precip. Ensemble guidance from NBM, ENS, and GEFS all point toward a greater than 60 percent chance of at least minor QPF over 0.10 inches assoc with this system, and thus one can infer minor winter impacts are going to be likely. Guidance begins to diverge in suggesting greater amounts of QPF/wintry precip, although it is possible to see advisory level impacts (30-50 percent) with even at least some possibility of warning level impacts (10 percent). Warning level impacts translate to very difficult to impossible travel through relatively long duration (greater than 24 hrs) of near-blizzard conditions, significant drifting snow, and heavy snow. The presence of near-blizzard conditions will be dependent to locations that see falling and/or accumulated snow greater than 2 inches, and is something the CIPS analog is showing values greater than 50 percent in the typical Red River Valley. That being said, we shouldn`t focus on one particular scenario over the other. With the range of scenarios extending from minor, more nuisance type impacts to significant impacts, the forecast of this late Wed to Friday system should continue to be monitored. Beyond Friday, confidence deteriorates in sensible weather, although northwesterly flow looks to remain the dominant synoptic flow pattern. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 540 PM CST Mon Jan 11 2021 Stratus and fog to impact most sites for part of the period with FAR and GFK clearing this evening. Will see the worst conditions at TVF and BJI for the overnight period with LIFR. Expecting VFR conditions tomorrow once the remaining fog burns off. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. $$ UPDATE...JK SHORT TERM...Riddle LONG TERM...CJ AVIATION...JK
National Weather Service Hastings NE
602 PM CST Mon Jan 11 2021 .DISCUSSION...(This evening through Monday) Issued at 355 PM CST Mon Jan 11 2021 The area has seen a welcome relief from persistently cldy, dreary conditions today with nearly "wall to wall" sunshine across south central Nebraska and north central Kansas. The only cld cover on regional satellite is a narrow band of high cirrus associated with quick-moving clipper system moving from Dakotas into MN. WV imagery and RAP analysis indicates fairly active upper flow across the CONUS as a whole, with strong vort maxima noted over S AZ, AR, Great Lakes and New England, along with aforementioned wave closer to home over Dakotas. None of these look to be particularly impactful to local area, however. Shortwave ridging extends from CA to N Rockies and will be main weather influencer next few days ahead of a much stronger upper trough late week. Highs today have been mild in the mid 40s to low 50s. The main forecast concern is the potential for prolonged strong winds Thu into Fri associated with an intense upper low forecast to dig from N Rockies Wed night into the Mid MS Valley by Thu PM. Appears the initial cold front and surge of strong winds will arrive Wed night into Thu AM. Right off the bat, deterministic EC and several of its ensembles indicate potential for fairly widespread wind gusts of 50 to 60 MPH. The wind potential with this system has gone nowhere but up on last several runs of EC ensemble, with the mean coming more in line with higher deterministic solution with each run. In fact, EC ensemble max wind gust for GRI on Thu has incr from 36kt on 09/12Z run, to 47kt on latest 11/12Z run. Also...not only has the magnitude been steadily incr, but the length of time of strong winds has incr as well, as more and more model solutions drastically slow the system down over Mid MS Valley Thu night into Fri. Gut feeling is that we`ll lose enough mixing to avoid widespread issues Thu night, but seems to be some consensus towards another wind incr for daytime Fri. GFS and EC differ on location and intensity of H85 winds by Fri, though, so still some uncertainty. Agree with previous shift that if current trends continue may soon need a High Wind Watch for late Wed night into Thu. Pcpn continues to look scant with this system, but will obviously need to monitor the location of stalled upper low and associated wrap- around pcpn closely, given how strong the winds will be. If there`s a shift to the SW, pcpn chcs, and perhaps blowing snow, will incr. Don`t want to draw direct comparisons to the system we had Dec 23rd, though, as temps look to be several deg warmer. Finally, would be remiss not to mention risk for incr fire weather concerns, as well, esp for S/SW portions of CWA that have seen less snow cover as of late. Model RH progs are already at near- critical levels, but even if RH remains somewhat marginal, the magnitude of wind gusts would alone be concerning. Otherwise, enjoy and mild temps and relatively lgt winds thru Wed. Have continued trend of going on warmer side of guidance for Tue and Wed, though didn`t go straight CONSMOS just yet for Wed as there could be incr high clds. Temps will turn colder Thu-Sat, and the wind will make it feel even colder, but this appears short lived as both GEFS/EPS have near to above normal temps Jan 17-20. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Wednesday) Issued at 601 PM CST Mon Jan 11 2021 VFR conditions expected with light wind. Confidence is high with this persistent forecast. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ DISCUSSION...Thies AVIATION...Heinlein
Area Forecast Discussion
National Weather Service Goodland KS
322 PM MST Mon Jan 11 2021 .SHORT TERM...(This evening through Tuesday night) Issued at 131 PM MST Mon Jan 11 2021 Satellite and 500 mb RAP analysis showed a closed low over eastern Arkansas this afternoon. Meanwhile, a shortwave trough continued southeast across Arizona and New Mexico as upper ridging extended from the west coast eastward towards the central Rockies. At 1:30 PM MST, skies were sunny, with west/northwest winds at 10 to 15 mph. Temperatures mainly ranged in the low 40s to low 50s. Quiet weather persists tonight while northwest flow develops aloft and the southeastern CONUS shortwave closes off and heads towards Texas. Behind this disturbance, ridging continues to push into the Plains. Expect lows in the teens and low 20s, with light west winds under clear skies. Tuesday looks to be even warmer than today, with highs in the 50s and westerly surface flow. Am not anticipating much of a pattern change in our area as the aforementioned low travels further into Texas. However, dry air will be in place and attention turns to fire weather conditions. Relative humidities are expected to fall into the 15 to 25 percent range across the region in the afternoon. Fortunately, west winds will be light at 10 mph or less. For Tuesday night, temperatures should be a bit warmer, mainly in the 20s. Dry weather prevails with mostly clear skies. .LONG TERM...(Wednesday through Sunday) Issued at 253 PM MST Mon Jan 11 2021 At the start of the long term period, long term guidance shows the CWA under the front part of an upper air ridge with an upper air low over the LA/AR border yielding a north-northwesterly flow aloft on Wednesday. On Wednesday evening, an upper air trough moves toward the CWA from the northwest with the base reaching the CWA by Thursday morning. On Thursday, the long term models show a low developing in the Great Plains area with some discrepancy in its placement. As the low intensifies and progresses slowly east- southeastward during Thursday, the flow over the CWA changes to northwesterly as the back part of the trough advances over the CWA. Going into Friday morning, the low appears to start to close off in the western Great Lakes region which causes the flow over the CWA to become more northerly. By late Friday going into Saturday, the low progresses eastward allowing a trailing upper air ridge to start to move over the CWA. By Saturday afternoon, another trough begins to move in from the west reaching down to the TX/OK border and places the CWA under the back end of this trough by Sunday morning. Later Sunday, the flow aloft turns westerly as another jet streak digs into the western CONUS. As models show some discrepancy in placement and timing of upper air features later in the long term period, this situation will be monitored to see if better agreement is seen in future runs. At the surface, the Tri-State area continues to see mostly dry conditions as well as possible near critical elevated fire weather conditions during the long term period. On early Thursday, models show a cold front associated with a surface low near the ND/MN/Canada border quickly making its way through the CWA bringing windy conditions with forecasted northwesterly sustained winds up to 30 mph and gusts possibly reaching 50 mph in some areas. On Friday, similar windy conditions continue in the CWA through the day as the surface low tightens its gradient on its way in the Great Lakes region. As both days show these windy conditions, near elevated fire weather conditions are possible for the Tri-State area particularly the extreme eastern portions on Wednesday and southwestern quadrant on Thursday as forecasted minimum RH values look to dip below 20%. On Saturday, models show a cold front passing through the area as well as slight chance for light snow showers in the far western parts of CO counties of Kit Carson and Cheyenne during the afternoon evening hours. While long term models show a minimal amount of snowfall associated with the slight chance of snow, this coverage area may expand eastward depending on how the system plays out in future model runs. The Tri-State area expects Wednesday to be the warmest day in the long term period with high temperatures in the upper 50s to middle 60s. As a cold front passes through the Tri-State area early Thursday, highs for the day expect to range from the lower 40s in the western portion to the lower 50s in the eastern portion. Friday sees lows in the lower to middle 40s followed by highs in the lower to upper 40s for the remainder of the extended period. Tri-State area overnight lows for Wednesday expect to range from the upper 20s in the western portion to the middle 30s in the eastern portion. Tri- State area overnight lows for Thursday drop to the upper teens in the western areas to the middle 20s in the eastern areas. The remainder of the long term period expects to stay between the upper teens and lower 20s range. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 322 PM MST Mon Jan 11 2021 VFR conditions are expected at KGLD and KMCK terminals through the TAF period. Mostly clear skies are forecast. West winds at 5 to 10 knots prevail through Tuesday morning before shifting to the southwest in the afternoon. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JBH LONG TERM...076 AVIATION...JBH
Area Forecast Discussion
National Weather Service Green Bay WI
545 PM CST Mon Jan 11 2021 Updated aviation portion for 00Z TAF issuance .SHORT TERM...Tonight and Tuesday Issued at 235 PM CST Mon Jan 11 2021 The latest RAP analysis and satellite/radar imagery show shortwave energy passing across the central Great Lakes early this afternoon. Meanwhile, a second shortwave is sliding southeast over North Dakota. Weak warm advection in the low levels, ahead of this 2nd shortwave, contributed to increasing moisture levels just enough to produce freezing drizzle over northern WI this morning. Visibilities have improved over the northwoods this afternoon, so think freezing drizzle is no longer a threat for the rest of the day. However, freezing drizzle could be a concern again late tonight and is the focus of this forecast. Tonight...A weak shortwave impulse be traversing the region during the evening. Mid-levels remain very dry, so the threat of snow is very low. But convergence along a surface trough may be just enough to touch off some patchy freezing drizzle, mainly after midnight over central to east-central Wisconsin. Will add to the forecast, but remain skeptical that it could produce widespread travel impacts. Otherwise, another low overcast night with patchy fog developing by late evening. Lows mainly in the low to mid 20s. Tuesday...Low clouds will likely continue to blanket all of northeast Wisconsin during the morning. But as warmer/downsloped air invades the region from the west, there are indications of thinning low level moisture that could lead to partial clearing in the afternoon. As a result, went with warmer highs into the lower 30s for most locations. .LONG TERM...Tuesday Night Through Monday Issued at 235 PM CST Mon Jan 11 2021 Quiet weather is expected through the middle of the week, with with warmer air arriving ahead of a cold front approaching from the Northern Plains. Highs are expected to reach 35 to 40 degrees on Wednesday, roughly 15 degrees above normal. Models support a significant pattern change for late in the work week, and are in better agreement regarding timing of the incoming surface and upper lows. The main difference is that the ECMWF is a bit farther south with the surface/upper lows than the GFS. Mixed rain/snow is expected to develop on Thursday as the vertically stacked low moves into the western Great Lakes. This system will drift east across the area Thursday night into Friday night, producing scattered to numerous snow showers through the period. As the low shifts to our east on Saturday, potential for minor lake-effect snow showers will develop in north central WI, then taper off Saturday night. Will probably see some snow accumulations over the region with this slow-moving system, with several inches possible in north central and parts of central WI over a couple day period. The prospects for strong winds appear to be less than earlier expected. Temperatures will settle back to near-normal for the weekend and early part of the next work week. && .AVIATION...for 00Z TAF Issuance Issued at 541 PM CST Mon Jan 11 2021 The main concerns this TAF issuance will be the continued low clouds and fog potential. Eastern TAF sites have seen some improvement to VFR ceilings this evening; however, more low MVFR/IFR clouds are expected to redevelop late this evening and overnight. There is a small chance of freezing drizzle, but the possibility is low enough to leave out with this issuance. Otherwise, IFR/LIFR clouds and visibilities will continue/develop across central and north-central Wisconsin tonight into Tuesday morning. Some improvement is expected Tuesday afternoon; however, models continue to point toward additional, possibly more widespread fog, Tuesday night. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......Kieckbusch AVIATION.......Cooley
Area Forecast Discussion
National Weather Service Louisville KY
916 PM EST Mon Jan 11 2021 .Forecast Update... Issued at 916 PM EST Mon Jan 11 2021 A band of light snow developed over southern Kentucky earlier this evening. A very light dusting has appeared in grassy areas in Franklin and Scottsville. The roads on area traffic web cams look like they are in good shape and most traffic appears to be moving at normal speeds. Warren, Simpson, and Allen counties are spot treating. The band continues from Franklin to Jamestown but within the past hour has shown signs of widening and weakening. This trend is expected to continue as the 5H wave over the Tennessee Valley weakens and continues to push off to the east. Also, satellite animations show a large area of dry air spreading from the Blue Grass into southern Kentucky. The snow is already light and should be reduced to flurries by midnight Central. && .Short Term...(This evening through Tuesday) Issued at 240 PM EST Mon Jan 11 2021 ...Light Snow Accums Possible Across Southern KY This Evening... The closed upper low is now over eastern Arkansas, and is expected to move ENE through the Tennessee Valley tonight, weakening into more of an open wave as it does so. Current water vapor imagery shows a nice deformation axis stretching from Arkansas up through SE Kentucky and into the central Appalachians. This is focusing a lot of mid level moisture streaming over the southern half of the CWA, and is expected to result in some light precipitation later this afternoon into the evening hours across our far south and southeast CWA. Some of the higher res models like the HRRR and NAM have been hinting at a small deformation induced band of snow mainly in the 21z to 03 z time frame across our south, and given the setup and familiarity from a recent event we tend to believe the output. As a result, will mention a trace to a half an inch of snow from south of Bowling Green over to the Lake Cumberland region. An isolated amount closer to an inch cannot be ruled out somewhere along that axis if the band persists/pivots enough. Temperatures have barely gotten to freezing this afternoon under heavy cloud cover, so do expect the low levels will be conducive to some light accums, especially the later into the evening we get. A few slick spots on area roadways seem possible. Plan on handling the potential with a Special Weather Statement and continue mention in the HWO and social media graphics. Evening shift will have to monitor any band development in case stronger messaging is needed. Outside of the snow/precipitation potential, cloud cover over the rest of the CWA is the other issue/concern. Have seen some breaks at times, and the western edge of the stratus out over MO/IL seems to be thinning, but overall stayed fairly pessimistic with the clouds through the remainder of the afternoon and evening. Do have pretty rapid improvement toward and after midnight, with expected mostly sunny skies by Tuesday. This should result in slightly "warmer" temperatures peaking in the low to mid 40s. .Long Term...(Tuesday night through Monday) Issued at 234 PM EST Mon Jan 11 2021 Quasi split flow regime develops across the southern Plains into the Tennessee/Lower Ohio Valley to start off the long term period. This will result in dry weather for much of the week for central Kentucky and southern Indiana as systems generally stay off to our north and/or south. Temperatures should stay mild through the end of the week as highs push into the upper 40s and low 50s under plentiful sunshine. The mild conditions won`t last long, though. Toward the end of the week and into the weekend, long range guidance is in fairly good agreement of a large scale trough/upper level low (ULL) digging into the Midwest and Great Lakes region and impacting the eastern third CONUS. Moisture return ahead of the cold front associated with the trough will be very limited as most flow around and above 900mb does not tap into the Gulf of Mexico. As a result, vast majority of models and their ensemble members only paint light QPF amounts (<.10") with fropa. Depending on how the trough/ULL tracks, there may be some opportunities for light bouts of wintry weather over the weekend, though these remain too unpredictable to narrow down for a specific day/period at this time. && .Aviation...(00Z TAF Issuance) Issued at 618 PM EST Mon Jan 11 2021 MVFR stratus continues to plague the region, although a large clear patch has opened up from LEX and CVG into southern Ohio. Satellite animations show that the westward push of this clearing has slowed, so for now in the TAFs will keep HNB/SDF/HNB under the stratus. LEX has cleared out but may regain clouds later tonight. Winds will be light and variable. BWG may see a few flurries as a weakening upper level disturbance passes by to the southeast. We should finally lose the low clouds tomorrow (if not tonight) as high pressure builds into the region and and low level winds freshen and come in from the southwest. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Update...13 Short Term...BJS Long Term...DM Aviation...13
Area Forecast Discussion
National Weather Service Marquette MI
559 PM EST Mon Jan 11 2021 .SHORT TERM...(This evening through Tuesday) Issued at 414 PM EST MON JAN 11 2021 WV imagery and RAP analysis indicated a multi-stram mid/upper level pattern with one shortwave exiting the region toward northern Quebec and another moving from northern Manitoba into northwest Ontario. Farther south, a shrtwv was sliding through the eastern Dakotras. At the surface, a southwest flow of shallow low-level moisture ahead of a trough through MN has supported persistent stratus deck and mist/fog or fzdz that has resulting in some slippery untreated surfaces. The clouds have been thick enough to limit temps to the mid and upper 20s. Tonight, weak to moderate 700-300 qvector conv with the Manitoba shrtwv is expected to brush mainly northern Lake Superior into eastern Upper Michigan. wsw low level winds with 850 mb temps around -8C may be enough to support some light lake effect snow showers of flurries through portions of the Keweenaw. Otherwise, little or no pcpn is expected. However, cannot rule out some patchy fzdz, given the abundant low level moisture. Clouds will also limit diurnal range with min readings only into the low to mid 20s. Tuesday, mid level and weak sfc ridging building into the area with increasing wsw flow should bring some clearing by afternoon. The sunshine and WAA will push temps into the mid 30s. .LONG TERM...(Tuesday night through Monday) Issued at 327 PM EST MON JAN 11 2021 Beginning Tuesday night, weak ridging with WAA will start us off. This looks to be largely a continuation of the previous few nights, with overcast skies and lows near 20F in the interior and mid-upper 20s by the lakeshores. The ridging will give way to a weak shortwave sinking southeast into the Upper Great Lakes late overnight. Some light snow may be possible in the east, but maintained a dry forecast given the better forcings look to stay outside of our forecast area. During the day on Wednesday, 850mb temps will stay between 1-4C across the area. This warm air aloft will help raise temps to ~15 degrees above normal. With the southwest flow, some should climb into the upper 30s to near 40F. The warm air aloft will continue overnight Wednesday and lows will respond with only dropping into the mid 20s in the cold spots and near 30F by the lakeshores. Attention then turns upstream. An amplifying ridge off the west coast will introduce broad troughing into the region. As this longwave pattern begins to establish itself, a shortwave will eject out of the Canadian Rockies late on Wednesday. From here, the guidance continues to project varying solutions as the shortwave evolves into a closed circulation. There are still notable differences among the guidance, but the general consensus is that the feature will occlude as it pivots from its southeast trajectory and begin migrating toward the northeast somewhere between Lake Superior and central Wisconsin early Friday. These spatial differences result in difference locations for the system`s dry slot and where any lake enhancement could occur. Ultimately the estimated snow totals vary, but overall it still looks to be a good shot for some widespread synoptic snow. Guidance has slowed the system`s progression through the region. Overall it looks to linger over the region into late Friday/early Saturday, when it lifts out into Ontario. This delay will also delay the colder air sinking south. 850mb temps look to break the -10C mark early Saturday and fall to around -15C by the afternoon. With the lake surface hovering around +3-4C, the resulting instability will be enough for lake effect snow to develop within the north to northwest wind snow belts Saturday into early Sunday. From there, guidance again becomes mixed and most models have dialed back the lake effect snow potential with winds taking on a more westerly and perhaps even southwesterly direction. With the colder airmass, daytime highs during the weekend look to peak in the 20s and lows to fall into the teens with single digits possible Sunday night. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 559 PM EST MON JAN 11 2021 Persistent low level moisture will maintain IFR/low MVFR conditions. Conditions are expected to lower back down to IFR/LIFR tonight. As southwest winds increase late, conditions could lift back to MVFR and even VFR toward Tue morning at KSAW but confidence is low. && .MARINE...(For the 4 AM Lake Superior forecast issuance) Issued at 437 AM EST MON JAN 11 2021 A trough moving across Lake Superior will result in west to southwest winds of 25-30 kts over the west and north-central portions this morning, with a few gale force gusts possible at higher platforms. Winds will subside below 20 kts by this afternoon and generally remain below 20 kts tonight despite the passage of a weak trough. West to southwest winds will increase again to 25-30 knots Tuesday into Tuesday night over west and north central portions of the lake in advance of another trough passing over the area late Tue night. Winds die down below 20 knots by late Wednesday morning and remain that way into at least Thursday morning. A storm system moving across the area could bring an increase in winds late Thursday into Friday, but the strongest winds will likely occur on Saturday when colder air advects in behind the system creating more unstable conditions along with gusty north to northwest winds to at least 30 knots. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JLB LONG TERM...JP AVIATION...07 MARINE...Voss
Area Forecast Discussion
National Weather Service Pocatello ID
846 PM MST Mon Jan 11 2021 .UPDATE... Updated low temps tonight based on evening trends. 13 && .PREV DISCUSSION... /issued 145 PM MST Mon Jan 11 2021/ SHORT TERM...Tonight through Wed night. Next 24 hours or so from this afternoon should be quiet with continued cool temperatures and nearly calm wind. Main issue would be the potential for isolated freezing fog issues laying down ice on road surfaces. By Tuesday afternoon, a very wet, warm, and windy winter storm is expected to enter the western zones, and slowly spread eastward, reaching the Wyoming border later Tue night. This is very warm subtropical air and snow levels along the Utah border will soar to 8000ft elevation, and even 7000ft in the central Idaho mountains. The eastern Magic Valley will see warming temperatures during the overnight on Tue night, and should stay above freezing. As long as that happens, the risk of freezing rain due to the elevated warm layer is very low. But if the temperatures there cool to below freezing, the risk spikes upward. Snow will develop at first even in the Snake River plain, but during Wed afternoon the rain-snow line will rise in elevation there, not quite getting to the 7000-foot elevation. Temperatures on Wed will reach 40 degrees even at Idaho Falls, and will be around 50 in the Burley area, so the snow at lower elevations will not linger and will not accumulate to much. Temperatures come crashing down Wed night as a northerly wind kicks in. This large temperature difference is indicative of a strong cold front that comes in from the north and northwest. This will bring 20 to 30 mph wind with stronger gusts during the day Wed, mainly in the Snake River plain and along the ridges of the central Idaho mountains. With the mild air, the snow will be heavy and would expect some avalanche concerns, but that will be determined by avalanche experts as the storm approaches. Messick LONG TERM...Thursday through next Monday. Cool, dry and breezy northwest flow is expected to be in place across the region behind our departing system. A ridge of high pressure will then briefly settle over the region Friday morning, bringing lighter winds and a continuation of dry conditions. A weak but strengthening area of low pressure is then seen swinging through the region Friday afternoon through Saturday morning. Like so many of our systems this winter, this one will be relatively moisture-starved, and snow showers associated with the system will be confined to primarily higher terrain areas. Given the relative lack of moisture and relatively fast forward motion of this system, amounts should be confined to an inch or two (with locally higher amounts) across higher terrain areas. Locally breezy conditions are expected with this system as well. Cool, dry and breezy northwest flow will then return to the area late Saturday and early Sunday. Another system is then expected to move through the region late Sunday to early Monday. This system is nearly an identical copy of the Friday afternoon-Saturday morning system, with a nearly identical track and strength. Expect another round of mainly light, high elevation snow showers and locally breezy conditions with this system before dry conditions return later Monday. Global models and ensembles are all in excellent agreement, thus forecaster confidence is fairly high through the long-term forecast period at this point. AD AVIATION...Central and eastern Idaho remains within the relative calm before the storm through the end of the forecast period at 18Z Tuesday, when an incoming storm system and its associated precipitation will be on the doorstep. Until then, relatively benign conditions are expected. Fog and stratus is once again a concern tonight, and some combination of both are possible at KDIJ and KIDA. Have included fog at KDIJ starting at 03Z and 09Z at KIDA based on 3km NAM, HRRR and NBM trends. IFR and LIFR conditions are possible. However, confidence is typically low on fog/stratus trends. Southerly winds begin to increase just above the boundary layer tonight after 06Z, but fall just short of LLWS criteria through the end of the period, with winds forecast to remain largely in the 15- 20kt range in the 1kt-2kt ft layer. After any lingering stratus/fog burn off after mid-morning, thickening/lowering clouds will be on the increase from the west, with precipitation onset at KSUN expected Tuesday evening. At this time, outside of fog/stratus concerns, VFR conditions are expected through 18Z Tue. AD && .PIH WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 11 AM Tuesday to 5 PM MST Wednesday for IDZ072-073. && $$