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

National Weather Service Albany NY
934 PM EST Sat Feb 1 2020 .SYNOPSIS... Another weak disturbance will move across the region tonight into early Sunday, bringing some light snow showers or flurries. A stronger disturbance is then expected to move through late Sunday into Sunday night, bringing a widespread light snow accumulation with most occurring across the higher terrain. Dry and mild conditions will then occur on Monday as an upper level ridge builds in. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... As of 930 PM EST...Mid and upper level southwest flow continues over the Northeast. Cloudy or mostly clouds skies continue as an upper level short wave trough currently over the eastern Great Lakes Region and western NY approaches from the west. There is limited low-level moisture and synoptic forcing associated with this system, as chances for flurries and light snow showers increase shortly before or just after midnight especially west of the Hudson Valley. The cyclonic vorticity advection may be just enough for light pcpn amounts in some locations. Any accumulations will be very minor with a dusting to only a few tenths of an inch possible based on the latest 3-km HRRR and NAMnest. Low temps will be above normal again, ranging from upper teens in the Adirondacks to upper 20s to around 30F in the mid Hudson Valley. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... Some leftover isolated/scattered snow showers will pass through Sunday morning as the upper trough axis moves through. We are then expecting a brief break late Sunday morning into the afternoon in between systems. The next system will be quickly approaching from the upper Great Lakes region late Sunday afternoon associated with a strong upper level jet. Our region will be in the favorable left-exit region for increased ascent until the jet moves overhead Sunday night. A period of steady snow is anticipated along the leading edge of the low level isentropic lift and upper jet exit region from west to east Sunday evening. Will mention likely pops from around Albany westward, with chance pops east. Hi-res guidance including the HRRR and NAMNest in good agreement with this scenario. This could result in some slippery travel across much of the area, although some rain could be mixed in at the onset in valleys from around Albany southward. Any rain should quickly change to snow as the column cools. The steady snow will likely not last long as the best forcing quickly lifts north of the region, becoming more in the way of snow showers by midnight. Total accumulations should range from a coating to an inch in the valley, with 1-3 inches in the higher terrain. Upper level ridging will gradually start building Sunday night, with a surface warm front advancing northward. Some clearing is possible late Sunday night, allowing temps to drop in the mid 20s to lower 30s. Still, these readings are above normal for early February. A small area of surface high pressure will be in place on Monday, as upper level heights continue to rise. If sufficient mixing occurs and results in at least some sunshine, temperatures will respond with highs expected to reach the mid 40s to lower 50s in the Hudson Valley into southern Taconics/Berkshires and Litchfield Hills. Snowpack will limit warming in the Adirondacks and southern Greens. Westerly winds will be gusty due to the mixing and relatively strong wind field aloft. Winds look to be well below advisory criteria at this time with mainly in the 20-35 mph range. Dry and mild conditions to persist through Monday night, with the flow becoming southwest in the low levels and aloft. Clouds will start to increase ahead of an approaching front, resulting in a continued trend for above normal low temperatures. && .LONG TERM /TUESDAY THROUGH SATURDAY/... Forecast uncertainty remains high in the extended forecast especially the latter portion of the week, where a frontal boundary sets up and subsequent cyclone forms and tracks making ptype and temperatures a major challenge. Tuesday...Clouds increase in the west to southwest flow aloft with a frontal boundary situated across the Midwest and OH Valley. A weak wave migrating along the boundary with very weak thermal advection or over running pcpn may impact the forecast area. We kept PoPs in the slight or low chance category with temps slightly above normal with 30s north and west of Albany and upper 30s to mid and upper 40s south and east. Tuesday night into Wednesday...The forecast spread starts to increase, as the latest 12Z ECMWF has the frontal boundary sag south to the Mason Dixon line and slightly southward with a 1025 hPa sfc anticyclone building in from the northern Great Lakes Region and southeast Ontario over the Northeast. This solution has been rejected based on the national blend of models, and too stay in sync and not create chaos in consistency of the NDFD with our neighbors will keep chance PoPs TUE night into WED, but WPC guidance also supports this (the dry scenario). Again, even though blended guidance does not supports dry weather, it would not be surprising to have a period of cold and dry weather mid week. Lows are forecasted in the 20s and lower 30s with highs ranging from 20s over the southern Adirondacks to 30s south and east, except some lower 40s over the mid Hudson Valley and NW CT. Wed night into THU...A full latitude positively tilted mid and upper level trough moves into the Central Plains with a strong mid and upper level jet along the eastern portion of the trough over the eastern CONUS. Initially over running pcpn could break out Wed night with snow or a mixture of pcpn types. For now, we continue snow and rain as the main ptypes but the GEFS/ECMWF are indicating some sleet and freezing rain may be possible. Also, some light to moderate snow accumulations are possible. We will continue to wait for a non cacophonous tune from the medium range deterministic and ensemble guidance. Lows in the mid teens to 20s are likely Wed night with mainly mid 20s to mid and and upper 30s on Thu. Thu night through Friday...A large amount of spread continues in the guidance here with the 12Z ECMWF indicating the mid and upper level longwave trough becoming negatively tilted with the primary sfc wave remaining west of the northern Appalachian Mtns, which would support a warmer solution, while the 12Z CMC and some of the NAEFS/GEFS are similar, the latest WPC shows support with an an occluded front moving through. The 12Z GFS has a coastal wave moving from the Delmarva Region to eastern Long Island Friday morning with a decent snow event for a large portion of the area. WPC does not favor this scenario, and based on the muddled and chaotic medium range guidance we are not confident in the 12Z GFS either. The 12Z GFS has a much flatter mid and upper level trough too. Needless to say, a moderate to heavy pcpn system with rain/snow or mixed pcpn is possible. It could also be windy depending where the primary cyclone tracks. Temps still look to run above early FEB climatological normals. Friday night into Saturday...After some westerly orographic upslope snow showers early Friday night, some weak micro ridging could build in, but yet another short-wave trough could impact the region on Saturday with more rain and snow showers depending on the boundary layer temps. Overall, temps look above normal and pcpn above normal in the long term, but confidence remains low in the evolution of the upper level pattern, timing, ptypes and amounts. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... Another weak upper level disturbance will move across the region overnight trough the mid morning. A warm front will move across the region Sunday late afternoon through the night time period with some light snow. Widespread MVFR and low VFR conditions continue at KGFL/KALB/KPOU/KPSF in terms of cigs this evening. KPSF/KGFL have rise to VFR cigs around 3.5 KFT AGL, but the expectation is for them to lower back into the MVFR range 1.5-3 kft AGL shortly before or just after midnight. KALB/KPOU remain MVFR with cigs 1.5-2.0 kft AGL. These cigs may briefly rise, but another weak upper level disturbance will bring some isolated to scattered snow showers after midnight. We did include a TEMPO group at KGFL between 10Z-14Z/SUN for a brief period of IFR. The other TAF sites we kept MVFR with cigs and used VCSH groups since the probs were low. VFR conditions should return in the late morning into the early/mid pm at all the TAF sites. However, expect clouds to thicken and lower between 21Z/SUN and 00Z MON with some light snow breaking out close to 00Z. We did include some PROB30 groups with low MVFR or IFR conditions at KALB/KPSF between 22Z/SUN and 00Z/MON. The winds will be light and variable at 5 kts or less at most of the TAF sites except at KPSF/KALB where a north to northwest winds may persist. The winds will shift to the southwest to south at 4-6 kts tomorrow afternoon. Outlook... Sunday Night: Moderate Operational Impact. Likely SN. Monday: Low Operational Impact. Breezy. NO SIG WX. Monday Night: No Operational Impact. NO SIG WX. Tuesday: Low Operational Impact. NO SIG WX. Tuesday Night: Moderate Operational Impact. Chance of SHRA...SHSN. Wednesday: Moderate Operational Impact. Chance of RA...SN. Wednesday Night: High Operational Impact. Likely SN. Thursday: High Operational Impact. Likely RA...SN. && .HYDROLOGY... No hydro issues are expected through the next week. Some precipitation will occur through Sunday night, with mainly light snow, snow showers or flurries. Total QPF will range from a mere few hundredths to around two tenths over the western Adirondacks. A dry stretch of weather is then likely Monday into Tuesday before more unsettled weather returns mid week. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...JPV/Wasula NEAR TERM...JPV/Wasula SHORT TERM...JPV LONG TERM...Wasula AVIATION...Wasula HYDROLOGY...BGM/JPV
Area Forecast Discussion
National Weather Service Bismarck ND
945 PM CST Sat Feb 1 2020 .UPDATE... Issued at 945 PM CST Sat Feb 1 2020 The main changes for this update were to remove PoPs from northwest and north central North Dakota tonight and add a slight chance of rain/snow to far southwest North Dakota for Sunday afternoon/evening based on the latest model guidance and trends. All CAMs have removed precipitation from northern North Dakota tonight, and the radar reflectivity over southwest Saskatchewan appears to be weakening and not tracking toward our area. Despite the removal of PoPs in the High Wind Warning, which was thought to be a tipping point for reaching warning criteria winds, feel comfortable continuing with the warning. Last hour, a 58 mph wind gust was recorded at the Williston Airport. This is an isolated gust so far, and does prompt expansion of the warning to the west at this time. Further east, HRRR and RAP soundings at Rolla have shown increasing potential for +50 kt gusts later tonight per BUFKIT momentum transfer. Other minor changes include blending in current temperature, sky, and wind trends to the near-term forecast. Several locations, including Bismarck, are currently the warmest they have been all day. UPDATE Issued at 603 PM CST Sat Feb 1 2020 The main adjustments for this update were to add McKenzie County to the Wind Advisory and move up the start time for Divide, Williams, and McKenzie Counties to now. There have been a few instances over the past couple hours of sustained winds reaching 30 mph, mostly clustered in McKenzie County. The Wind Advisory for southwest North Dakota has been allowed to expire. Advisory criteria winds were barely reached there this afternoon, and do not see winds dramatically increasing this evening or tonight. Will leave the other wind headlines in tact for now. It appears that reaching warning criteria winds later tonight will be contingent on whether the cold front is accompanied by any precipitation. Upstream observations do show an area of light rain now entering southwest Saskatchewan, which is modeled well by the 22Z HRRR. However, the HRRR keeps this precipitation west of the High Wind Warning, and other CAMs have also backed off on precipitation potential along the cold front as it enters northern North Dakota later this evening. Another big adjustment for this update was to significantly increase cloud cover across southern and western North Dakota this evening. Models are doing a very poor job at simulating the large cirrus shield being generated from strong westerly flow aloft crossing the Northern Rockies. && .SHORT TERM...(This evening through Sunday) Issued at 215 PM CST Sat Feb 1 2020 Highlight in the short term is centered on a high wind warning that has been issued for north central North Dakota tonight into Sunday morning. A wind advisory was also issued for a tier of counties surrounding the high wind warning. Ongoing wind advisory in the southwest will continue as winds in eastern Montana are beginning to show sustained winds of 25kt and gusts to 35kt. Latest surface map and satellite imagery indicates warm air advection is dominating with a cirrus canopy continuing to stream across western and central North Dakota. Temperatures are mild, with 50s in the southwest, and into the 40s elsewhere. This will be short lived. A cold front over the Pacific Northwest will translate east this evening and push through overnight. Watching the trends in the model data and BUFKIT soundings the last few days, there has been little change in the overall data. Although the GFS soundings have backed off on the magnitude of winds from previous runs, as winds are slightly more elevated in the vertical, but still impressive with 40kt winds advertised at 400 feet above ground level across north central North Dakota. The inversion per GFS soundings remain weak and cold air advection/sinking motion continues to brink the winds very close to the surface. The NAM/RAP are on in good agreement but weaker with then mixed layer winds, between 30kt and 35kt. This is mainly because of a consistent signal that a stronger inversion will be in place. So, averaging/blending these soundings comes to around 35kt. Enough confidence at this point to where we will see 40 mph sustained across the north central. One important factor that tipped in favor of a high wind warning is the high resolution models advertising weak reflectivities along and into our northern counties which is associated with the cold frontal passage. This is all it will take to for the stronger winds aloft to surge towards the ground. This scenario played out a couple weeks ago, and although no two situations are exactly the same, it needs some consideration. Weak ascent is also noted in the data aloft, and have taken this into account. In addition, the pressure bubble rise (3-5mb) and low level lapse rates of 6.5 to 7.5 C/Km scoot across southern Canada and northern ND tonight, in tandem with 850mb winds of 60kt to 65kt. Any weak spot in the advertised inversion, or precipitation developing, will make these winds reaching the ground a reality. With these factors, and after collaborating with Grand Forks, have opted to issue the High Wind Warning for North Central ND, which includes the Turtle Mountains. As mentioned, a wind advisory surround the High Wind Warning tonight with winds. Winds will subside Sunday morning, however brisk northwest winds will continue through the day as cold air advection dominates. Highs Sunday will be in the 30s. .LONG TERM...(Sunday night through Saturday) Issued at 215 PM CST Sat Feb 1 2020 Cold air advection continues Sunday night as the low level baroclinic zone from Saturday nights cold front will be pushed into southeastern Montana, eastern Wyoming, and far western South Dakota. Trends over the last couple of days have been to lessen PoPs across the southwest and far south central Monday as the baroclinic zone continues to push farther away. Surface high pressure over over eastern Alberta/western Saskatchewan Monday will provide for northwesterly flow and much colder air. Highs Monday will range from the mid teens in the Turtle Mountains to the 20s elsewhere. Dry and cold Tuesday as high pressure slides into eastern South Dakota. Low level warm air advection begins in the west Tuesday afternoon and will spread east with time, continuing into Thursday morning. Surface temperatures will respond with highs returning into the 30s. The next clipper type warm/cold front will move from Alberta Wednesday night, then working into western/central North Dakota during the day Thursday with a chance of snow. Cyclonic flow and cold air advection continue the chances of light snow behind the system into Friday. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 603 PM CST Sat Feb 1 2020 VFR conditions are expected through this forecast period. Strong surface winds and low level wind shear will continue to be a major concern through tonight and into Sunday morning. Expect winds 1000-2000 ft above the ground around 60-70 kts this evening, diminishing overnight. At the surface, expect westerly winds increasing to 20-25 kts sustained this evening into the overnight, with 30-40 kt gusts. Stronger winds are possible at KMOT. Winds will slowly diminish on Sunday while turning more northwesterly. && .BIS WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 9 AM CST Sunday for NDZ021>023-025. High Wind Warning until 9 AM CST Sunday for NDZ002>005-010>013. Wind Advisory until 6 AM CST /5 AM MST/ Sunday for NDZ001-009- 017. && $$ UPDATE...Hollan SHORT TERM...KS LONG TERM...KS AVIATION...Hollan
Area Forecast Discussion
National Weather Service Duluth MN
745 PM CST Sat Feb 1 2020 .UPDATE... Issued at 743 PM CST Sat Feb 1 2020 Looking at latest HRRR and RAP guidance and HREF probs, it looks like tomorrow will be quite a windy day, so opted to raise a wind advisory highlighting this threat for Sunday morning through the early afternoon. UPDATE Issued at 451 PM CST Sat Feb 1 2020 Radar indicates dry air is rapidly saturating at the low levels, so upped PoPs and QPF giving a quick half an inch to the Twin Ports and north and eastward. Cloquet and INL ob just started reporting snow too. && .SHORT TERM...(This evening through Sunday night) Issued at 315 PM CST Sat Feb 1 2020 A wintry mix across across northeast Minnesota late this afternoon through Sunday morning, and a windy Sunday for most of the Northland highlights the short term forecast. The enhanced radar returns thus far this afternoon across northeast Minnesota have yet to yield precipitation at the surface with dry low levels. This is expected to change as saturation increases especially between 00-03 UTC across the arrowhead of Minnesota with the approach of the warm front and series of mid level impulses. The predominant precipitation type is expected to be snow, with light freezing drizzle possible late tonight into Sunday morning with ice loss in the column per 12 UTC NAM/GFS Bufr soundings. Do not anticipate a Winter Weather Advisory at this time given the very light precipitation amounts, and a rather mild overnight in the wake of the warm front which may help to limit how much drizzle could freeze on roads and sidewalks. A cold front will be quick in trail behind the warm front late tonight and Sunday morning as it propagates east across Minnesota and Wisconsin in association with a clipper system across Ontario. Sunday looks to be windy for most of the area behind the cold front with cold air advection and steep low level lapse rates supporting momentum transport to the surface with 40-50kts at the top of the mixed layer. The strongest winds are expected across the higher terrain of the North Shore and Mesabi range where near advisory level gusts around 40kts are possible. Similar gusts are also forecast across northern Bayfield county and the Apostle islands. Northwest winds should peak around 17-21Z when forcing from pressure rises is greatest. Have highlighted the wind threat in the HWO for now. .LONG TERM...(Monday through Saturday) Issued at 315 PM CST Sat Feb 1 2020 Continuing the theme of the past few weeks, generally quiet conditions will persist for the extended. Temperatures will begin near normal before cooling below normal and then back above normal by the end of the period. A longwave trough will be present across the Intermountain West at the start of the period with generally high pressure over the Northland. This will keep mainly dry conditions in place through Wednesday. There may be some light lake effect snow showers in the Iron County area for Monday night into Tuesday, but a lack of moisture and overall forcing will keep this threat minimal. Heading into midweek, the longwave trough will emerge from the Rockies and start to translate eastward, passing over the Upper Midwest for the Wednesday night into Thursday timeframe. Surface low pressure in association with the trough will remain well to our south with dry conditions persisting in our area. As the low moves northeast later Thursday into the Great Lakes, it may spread light snow showers into our far southeastern zones. A 500mb shortwave on the back side of the longwave trough will move through for Thursday night into Friday and will drag a cold front through the region. This may bring a few light snow showers, but overall this feature looks unorganized with significant model differences, so will keep a blended approach for now, although leaned more on the ECMWF as the GFS seems too progressive. The coldest air in nearly a month will be overhead to start the period with temperatures running near to below normal Monday through Wednesday. As the trough approaches later Wednesday into Thursday, southerly low level flow will usher in warmer air with temperatures warming near to slightly above normal for the latter half of the week. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 536 PM CST Sat Feb 1 2020 IFR conditions in snow bands KDLH and northeast. Otherwise VFR. Timing should not effect terminals much after 03Z. LLWS becomes the main concern overnight and towards sunrise. Surface winds increase and become strong Sunday afternoon. && .PRELIMINARY POINT TEMPS/POPS... DLH 29 39 18 22 / 20 0 0 0 INL 31 35 12 16 / 40 30 10 0 BRD 31 38 17 21 / 0 0 0 0 HYR 31 42 21 27 / 20 0 0 0 ASX 32 41 22 27 / 40 0 0 0 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...Wind Advisory from 7 AM to 2 PM CST Sunday for WIZ001>003- 006>008. MN...Wind Advisory from 5 AM to 2 PM CST Sunday for MNZ012-018>021- 025-026-033>038. LS...None. && $$ UPDATE...Wolfe SHORT TERM...PA LONG TERM...BJH AVIATION...Wolfe
Area Forecast Discussion
National Weather Service Green Bay WI
742 PM CST Sat Feb 1 2020 New Information added to update section .UPDATE... Issued at 735 PM CST Sat Feb 1 2020 Have made a significant upward adjustment in winds on Sunday, especially over central and eastern WI, where gusts to around 40 mph are anticipated. With breaks in the clouds expected, temperatures should warm significantly, allowing for deeper mixing into the strong west flow aloft. Will let the midnight crew decide if further upward adjustments or a Wind Advisory will be needed. We will be issuing a Gale Warning for our Lake Michigan marine zones, with the greatest likelihood of gale force gusts expected south of Sturgeon Bay. && .SHORT TERM...Tonight and Sunday Issued at 216 PM CST Sat Feb 1 2020 The latest RAP analysis and satellite/radar imagery show shortwave troughing moving east across eastern Lake Superior and the lower peninsula of Michigan. Meanwhile, warmer and drier air is moving into western Wisconsin, and helping to scour out the persistent low clouds that have been present for days. The leading edge of the clearing is now moving into north-central WI, and expect this trend to continue southeast through the rest of the afternoon. Looking further west, a warm front is quickly moving east over the Dakotas and south-central Canada. Light precip chances with this warm front are the main forecast concern tonight, followed by temps/winds on Sunday. Tonight...The warm front will rapidly move east and across the state. Mid-level fgen is forecast to spread southeast along the front and into far northeast Wisconsin by mid-evening and lingering over the Door Peninsula into the overnight hours. The higher resolution models continue to be less than impressed with precip potential, and only spit out a hundredth of precip. Most of this should fall as snow or flurries, but perhaps there is a chance of freezing drizzle on the back edge of any precip band that does develop. Not anticipating widespread slippery conditions, but maybe the precip could create a few slippery stretches where temps fall below freezing. Temps remain a challenge. Given how little temps have fallen the past few nights, and ample cloud cover and warm advection tonight, think will stay on the warm side of guidance and only have lows fall a couple degrees off today`s highs. Sunday...Low clouds in the wake of the warm front will likely lead to a cloudy start across most of the area early in the morning. But with daytime heating and mechanical mixing from the strong winds above the inversion, think will see relatively quick clearing take place, except for far northern WI. It is quite possible that the mechanical mixing will lead to a warmer and windier day than currently forecast, but uncertainty is high regarding how the stout inversion will hold up. Trended slightly warmer with this latest forecast considering the current temps over the western Dakotas and eastern Montana, which would place temps in the low to mid 40s and near record highs over central to northeast WI. .LONG TERM...Sunday Night Through Saturday Issued at 216 PM CST Sat Feb 1 2020 Pretty quiet weather looks to be in store for Northern and Central Wisconsin next week with split upper flow that phases a bit by the middle of the week. The northern jet is far enough north to keep temperatures generally at or above normal except for Wednesday and Thursday. Gulf moisture is not forecast to get any further north than the Ohio Valley, so any snow we might see from weak systems will be light. The best chance of any snow accumulations should be Wednesday or Thursday on the northern fringe of a synoptic scale system well to our south. && .AVIATION...for 00Z TAF Issuance Issued at 541 PM CST Sat Feb 1 2020 Mid-level clouds and VFR conditions will prevail early this evening, though clouds are expected to thicken during the mid to late evening as a warm front approaches from the west. This front is expected to bring a brief period of light mixed precipitation to the region during the late evening and overnight hours. The steadiest precipitation is expected over far northeast WI. Have added a brief period (2-4 hours) of light precipitation and associated MVFR conditions at the TAF sites, but at least partial clearing should occur after the precipitation ends. The best chance of lingering cloud cover on Sunday should be over northern WI, but ceilings are expected to be in the VFR category. With expected sunshine and warmer temperatures on Sunday, there is potential for windy conditions to develop by late morning. Strong west-northwest winds aloft will also lead to LLWS, which will begin overnight, and continue through the day on Sunday. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE.........Kieckbusch SHORT TERM.....MPC LONG TERM......RDM AVIATION.......Kieckbusch
Area Forecast Discussion
National Weather Service Grand Rapids MI
1002 PM EST Sat Feb 1 2020 LATEST UPDATE... Update/Marine .SYNOPSIS... Issued at 204 PM EST Sat Feb 1 2020 - Risk for light precipitation later tonight - Breezy and unseasonably mild Sunday - Less of a risk for mixed precipitation Tuesday - Snow accumulations possible Wednesday Night to Thursday && .UPDATE... Issued at 1004 PM EST Sat Feb 1 2020 No big changes seen at this point. Some light snow over our NE CWA (like MOP - LEO ) otherwise just a lot of clouds. I still believe we will see clearing of the low clouds by midday Sunday. That being so we will have record or near record highs. For Grand Rapids, the 2nd of Feb is our lowest record high for the year, 48 degrees. In fact it is the only day we have a record high below 50 degrees. Meanwhile, there is an area of warm advection snow over Wisconsin heading toward Michigan but only a few northern stations near IWX had snow from it and that was 7sm -SN. As the warm front crosses Michigan the depth of the moisture does increase but over most of southern and western CWA the mid cloud deck does not get below 8000 ft. So I am thinking very little will reach the ground from this. Maybe a few sprinkles or flurries. Our NE CWA has better moisture depth but still I see only a few hours of very light precipitation. The models sounding say snow up there and surface temperatures will be near to just below freezing N and E of GRR so a few flurries or a period of light snow with less than a 1/2 inch of snow is possible near MOP and EVA (Evart) between 11 pm and 4 am. Both the ECMWF, the RAP model and the HRRR show the low clouds breaking up and given the dynamic setup for Sunday, with a deep low tracking well north of Lake Superior and the upper level jet going north of central Lower Michigan by mid afternoon. The cyclonic flow at low levels should help clear the low clouds. So, given that I do believe we have a good chance to tie or break our record high Sunday. && .DISCUSSION...(This evening through next Saturday) Issued at 204 PM EST Sat Feb 1 2020 - Risk for light precipitation tonight The warm air advection will strengthen tonight. This will likely result in lift. If we do clear out this evening...the low clouds should return as a result of this lift. With low temperatures falling to near freezing...we will need to monitor the risk for a few slick spots if we can generate drizzle or flurries. Overall the greatest potential for this to happen will be to the northeast of a Muskegon to Lansing line. - Breezy and unseasonably mild Sunday Warm air advection strengthens tonight into Sunday ahead of a cold front dropping out of the Northern Plains. The temperature at 925 mb rises to near 2 to 3 deg C. Assuming we mix to that level...high temperatures on Monday should reach the upper 40s for many locations. The low clouds are shown to push off to the east during the the added sunshine will support the warmer temperatures and better mixing. A couple of limiting factors on the temperature will be that the wind will be out of the west. Lake MI will act to offset any warming. In additions as the mixing height deepens during the day...we will tap into stronger winds just off the ground. High res models show a potential for wind gusts in the 30 to 40 mph range for the afternoon. - Less of a risk for mixed precipitation Tuesday While the risk still exists for some precipitation...trends in the models show the surface high pressure system building in during the day. The upper levels will feature some lift with the right entrance region of a jet located over southern parts of the CWA...however the mid levels are drying out as subsidence moves in. For now we will only feature low POPs...but the highest values will be south of Interstate 94. - Snow accumulations possible Wednesday Night to Thursday Most models show a deep upper trough setting up across the MS Valley with one or more waves of low pressure to track up the OH Valley or the west side of the Appalachians during this time. The GFS is an outlier showing the storm track mainly east of the Appalachians. How far northwest of these systems can produce accumulating snow is uncertain. With most models showing the trough still west of the CWA it appears likely that we will see some snow then...especially with the DGZ becoming saturated for a while. This pattern will need to be monitored closely in the coming days. The combination of an open Gulf and a coupled upper jet could support heavier qpf. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 647 PM EST Sat Feb 1 2020 A fairly strong warm front is headed our way. MVFR conditions dominate the TAF sites as I write this but the clearing of the low clouds is just reaching the west shores of Lake Michigan on our IR image loop. The recent MET observations over WI show this to be true. However just about all of our high resolution models show the low clouds not really clearing the area till late morning or early afternoon Sunday. The ECMWF and HRRR are the only models that really clear the low clouds Sunday, but based in the low level wind flow is cyclonicly curved Sunday the upper level jet core manages to get north of this area by early afternoon, I do believe the clouds will finally clear. The cyclonicly curved low level wind will help mix down gusty winds Sunday, we could see gusts near 30 knots in the afternoon. If the clouds do not clear more likely the strong winds would not mix down and there would be strong low level wind shear near 2000 ft agl. One other thing to watch for, there is a band of precipitation over northern WI now that is nearly entirely aloft but as it moves over Michigan ahead of the warm front passage here, there could be a brief period of light rain. The greatest risk of this would be at Lansing but I did not feel the risk was high enough at this point to actually put that in our TAF forecasts, && .MARINE... Issued at 1004 PM EST Sat Feb 1 2020 There was an issue of whether to issue a gale warning for our Near Shore for Sunday and it is surely possible we could see some isolated gusts to gale force but since this is a warm advection event and the air over Lake Michigan is forecast to be in the lower to mid 40s while the water temp is in the upper 30s, meaning the air is warmer than lake surface I am thinking we will not get good mixing and thus not get the gales mixing to the lake surface. So I have decided not to go with a gale warning at this point. && .CLIMATE... Issued at 204 PM EST Sat Feb 1 2020 Record high temperatures for Feb 2 Grand Rapids...48 (1903) Lansing........51 (1973) Muskegon.......44 (1987) Kalamazoo......54 (1968) For GRR, LAN, and MKG, these are the lowest record high temperatures of any day in the year. For AZO, the lowest daily record high temperature was 51 on Feb 5, 1964. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...Small Craft Advisory until 4 AM EST Monday for LMZ844>849. && $$ UPDATE...WDM SYNOPSIS...MJS DISCUSSION...MJS AVIATION...WDM CLIMATE...CAS MARINE...WDM
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
916 PM CST Sat Feb 1 2020 .UPDATE... 915 PM CST The going forecast has trends well in hand through tomorrow, with much milder and windy conditions on Sunday. Did make a few adjustments though, namely to bump up winds and bump up high temperatures slightly on Sunday. Based off forecast wind fields and soundings from the guidance expected to capture best the mixing depths across the region, particularly RAP and ECMWF, concerned that gusts over areas with little or no snow cover could be up to or over 40 mph. A corridor of 40 to 45+ kt westerly speeds at 925 mb will move overhead during the daytime and exit by sunset. As mentioned above, RAP BUFKIT and ECMWF soundings are showing mixing up to about 925 mb, so we should be able to tap into at least some of this momentum aloft. The westerly surface wind direction from the deeper snow cover over the northwest 1/3 of the CWA does add a bit of uncertainty exactly how effective mixing will be. This is especially the case for areas due east of the existing snowpack. With a very small inversion at best on the soundings over snow covered areas, think that gusts there should still top out at least 30-35 mph range. Will brief midnight shift on the wind concerns, as with advisory criteria (39+ kt) speeds at or just under 1000 feet AGL, we could end up needing a Wind Advisory for portions of area with little/no snow cover. Peak wind gusts should be from 10-11AM hour to 3-4PM hour and then rapidly drop off toward sunset as the low- level jet core exits east. Turning to the high temperatures, the warm up has been well advertised, and that it will be slightly muted over areas expected to keep some snow cover vs areas with little to none. That said, discounting the cold biased models, suspect that going forecast was a bit too cool, and solidly mid 40s are likely, with upper 40s to near 50F on the edge of the melting snow pack. For the rest of the area, confidence is high in attaining 50+F readings. Entire 51 member ECMWF ensemble has 90-100% probabilities of 50+F highs from Mendota to Lake County (and just north into SE WI). Didn`t go quite that far, but did adjust temperatures up slightly from previous, with ~50 up to eastern Lake IL. Have some upper 50s in the southern CWA, and if the very consistent ECMWF guidance comes to fruition, some 60 degree readings will be possible. There will be some cirrus overhead, but not expecting it to interfere with the warming. Chicago (at ORD) has a very realistic chance of setting a new record high. It is a bit unfortunate though that after the endless cloudy stretch, our warm up will come with windy conditions, which will keep some chill to the air. Castro && .SHORT TERM... 205 PM CST Through Sunday night... Visible satellite images early this afternoon reveal something we haven`t seen--at least in our immediate vicinity--for over a week: (snow) covered ground! Day Snow/Fog RGB imagery shows the edge of the omnipresent stratus deck is inching closer and closer to Rockford, with deep red/orange hues depicting the snow pack west of the Mississippi River. Farther upstream, we`re watching a fairly sharp trough axis digging into western Minnesota and as the associated low-level mass response (a robust increase in the 925-850 mb flow) occurs, do expect a resurgence of low stratus development through the evening hours as attendant warm advection spreads back across the region. This feature will begin to really re-saturate the airmass above 700 mb through the mid evening hours as well, but a well-defined wedge of very dry air in the 900-700 mb layer should preclude any precipitation development as this last feature in the shortwave-parade pivots through. Suppose I couldn`t rule out a stray flurry this evening, but that`s about it. As this feature passes by, low cloud cover should finally begin to erode more solidly from southwest to northeast during the overnight hours and into Sunday morning. May see some patchy light fog development as dewpoints start to inch up, but fog potential looks too spotty to warrant a mention in the gridded forecast at this point. While a veil of high cirrus may be streaming overhead Sunday morning, it does look like we`ll finally get more than a fleeting glance at the sun tomorrow. West-northwesterly low-level flow will also help pump the northeastern fringes of a much warmer airmass across the area which should help temperatures finally break out of the 30s. The warmest conditions look to occur east and south of I- 55/57 where the snowpack is minimal to nonexistent and 925 mb temperatures will be warmest. Farther to the northwest, a lot of energy will be spent sublimating/melting the deeper snowpack such that we may only be able to realize temperatures in the lower to mid 40s. As a result, it does look like we`ll be within a stone`s throw of the record high for the date at O`Hare (51 set in 1992), while the 52 record at Rockford seems to be safe. Finally, breezy west- southwesterly winds look like a good bet during the late-morning and afternoon hours as we begin to tap into some 35-40 kt flow immediately off the deck. Could see some fog development take place by Sunday night as 925-850 mb flow turns more southerly and injects some additional moisture into the near-surface layer. Surface winds will be turning more east to northeasterly which, unfortunately, will herald the plunge back into cloud cover and unsettled conditions into next week. Carlaw && .LONG TERM... 215 PM CST Monday through Saturday... Forecast concerns for the coming week are several throughout due to multiple impulses bringing chances for precipitation. While we had that this past week, that was a series of low amplitude features with an existing stratus layer. The week ahead is different, with a amplified pattern and impulses Monday night through Wednesday emanating from a larger trough to the west, which itself will potentially impact the area later Wednesday into Thursday (and some guidance indicates this may be the primary time of any precipitation). It continues to remain unsettled behind that too, so needless to say numerous precipitation chances within the forecast. The primary times of interest for heavier QPF at least are within the Tuesday night through Thursday time frame, and maybe particularly later Wednesday into Thursday. Also needless to say, we return to clouds and stunted high temperatures in the 30-35 range. For Monday, the cold front that will have sneaked into the area later Sunday night will continue to inch southward. This should result in fairly widespread clouds by afternoon. North of the boundary temperatures will likely have trouble climbing out of the 30s while south should see well into the 40s, and at present that has trended southward to only the southern portion of the CWA and into northwest Indiana. The daytime period looks dry on most guidance with saturated profiles looking too shallow on most guidance for any light precip. A split flow upper jet pattern will prevail over the middle and eastern parts of the country through the first half of the week, with potential for phasing later in the week. A closed upper low within a polar jet stream buckle is forecast to be over Utah by Tuesday morning and to lift northeastward as an opening wave within the split flow. This will provide the slightly higher precipitation chances Tuesday night-early Wednesday. Southern stream energy will translate eastward during the Wednesday and Thursday period and thats where additional higher chances may be needed in time with modest precip possible likely in the form of snow. For Monday night-Tuesday, the area will be under gradually increasing diffluence and an upper jet entrance region. Mainly light precip would be the type if it can develop and a focus along a frontogenetic vertical circulation could be seen given a baroclinic zone aloft forecast to be draped across or near northern Illinois. Also, forecast GFS soundings for this period show potential for broad drizzle with the increasing low-level moisture depth and a sharply turning wind profile with the elevated warm layer above the low-level cooler layer. Preventing any higher PoPs in this period for now are that the footprint of precip may be concentrated and the QPF looks low, even if a more widespread drizzle/light precip were to develop. Surface temperatures should be dipping below freezing in the north later Monday night into early Tuesday morning, and with some overrunning there is the conditional possibility of a narrow area seeing some freezing drizzle. For Tuesday night into early Wednesday, the first stronger wave is expected to lift out. Guidance is showing a large spread in this but the trend over the past 24 hours has mainly south. This is especially true with today`s 12Z ECMWF run which keeps much of the forecast area void of any modest forcing for ascent Tuesday night and Wednesday during the day. This is a particularly lower confidence period here. There would still be some overrunning thermal profiles here that could support a narrow stripe of freezing precip if any can occur. As the southern stream wave ejects across the southern U.S. and lifts northeast, the track of this will be key especially where it lifts northeast. Models are in fair agreement with a deepening low, some guidance significantly deepening given upper phasing. The further west this is the more likely our area will be impacted, and again snow would be the likely precipitation type with cold air dragged into the area with the system. Something we will have to watch. Behind this a broad trough results across Canada into the northern and northeastern U.S. with an active jet continuing around this with multiple clipper/Pacific impulses forecast into next weekend. MTF && .CLIMATE... Here are the record highs Sunday: Sun Feb 2 Record High Chicago 51 (1992) Rockford 52 (1987) && .HYDROLOGY... According to the US Geological Survey, most rivers across northern Illinois remain above average to much above average for late January. CPC soil moisture estimates are also greater than the 90th percentile. These water level and soil conditions reduce the amount of rain and snowmelt required for significant river rises. NOHRSC estimates about 1 inch snow water equivalent across portions of northern Illinois and southern Wisconsin, with isolated areas up to 1.5 inches. Temperatures and dewpoints this weekend are expected to climb high enough to possibly cause quick snowmelt although some uncertainty remains due to the density of snow and ice cover. Although no significant rainfall is forecast, snowmelt may be enough to cause some rises on area rivers, particularly those in the Rock and Fox Basins. WSL && .AVIATION... For the 00Z TAFs... Main aviation forecast concerns: -MVFR ceiling trends this evening, with some potential for a brief lowering to IFR and possibly MVFR vsby. -LLWS potential, especially for RFD late tonight and Sunday. -Gusty west-southwest winds Sunday for Chicago metro terminals. MVFR ceilings have been slowly eroding from west to east across northern IL this afternoon, with the trailing edge roughly KDPA to KPIA at this time. Another approaching upper disturbance, and an associated surface trough/warm front are expected to redevelop lower clouds later this evening however, as strong warm advection develops above moist surface-based layer. Some guidance develops ceilings into the IFR range this evening, and though I suspect this may be overdone, the idea that more than one model is depicting this does not lend enough confidence to pull this from the forecast just yet. Precip potential looks quite minimal however, with a substantial dry layer noted in model forecast soundings above the moist low level layer and a mid-level cloud deck. There is pretty good agreement in guidance in pushing whatever low cloud cover does reform out of the area after about 10Z however. VFR conditions then are expected through the remainder of the forecast period. Tightening surface pressure gradient will produce windy conditions on Sunday, with forecast soundings indicating 40+ kts above about 2500 ft agl. Have increased winds for Chicago terminals a bit, with gusts near 30 kt after 15Z, and that could even be a bit low if we mix a little deeper. RFD, which remains in and downstream of an area of deeper snow cover, will likely not experience mixing as deep as non-snow covered areas to the southeast. For this reason, have maintain lower surface wind speeds with low level wind shear indicating the 45 kt winds above 2000 ft agl. Will likely see winds diminish Sunday evening, as the gradient weakens and mixing becomes more shallow after sunset. Ratzer && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Small Craft Advisory...nearshore waters until 9 AM Sunday. Gale Warning...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...9 AM Sunday to 6 PM Sunday. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Portland OR
237 PM PST Sat Feb 1 2020 .SYNOPSIS...Much cooler air will move into the region as a cold front moves southeast across Oregon this afternoon. Rain will change to snow for the Cascade passes later this afternoon and evening, and snow levels will fall as low as 1000 feet overnight as showers linger across the forecast area. Chilly weather and a few showers will linger through Monday, then a warm front will bring a return to milder temperatures and occasional rain for the middle to latter portion of the week. && .SHORT TERM...Tonight through Tuesday...Satellite and radar imagery from this afternoon show a cold front moving southeast across Oregon. Further analysis shows a significant air mass change coming in behind the front, with 20z HRRR suggesting -7 deg C temps at 850 mb already moving into Cape Flattery. This is a stark contrast from the +7 deg C 850 mb temps reported by the 12z KSLE sounding. It is still raining at Santiam and Willamette Passes as of 145 PM per ODOT webcams, but this should change over to snow within the next few hours as colder air advects into the area. By then, snow showers should be decreasing, so expect just a couple inches of snow for the passes. The more significant issue tonight may be refreezing of roads in the Cascades as the night wears on and roads get a chance to respond to the much cooler air temperatures. Much cooler air will affect the lowlands as well, with snow levels falling to around 1000 feet and perhaps locally lower. By the time this occurs, showers should be few and far between, so it appears the risk is low for accumulating snow below 1000-1500 feet tonight/Sunday morning. The upper level trough axis swings through the Pac NW Sunday for additional showers, and it is not out of the question for anyone to see snowflakes or graupel in the air as this occurs. That said, any lowland accumulations would be minor, slushy, and fleeting as daytime temps are expected to reach the 40s for the lowlands. The foothills could locally pick up an inch or two, including the Coast Range summits, so those heading to the coast from inland should be prepared for winter travel conditions Sunday if traveling across the Coast Range. Most high-res models suggest another band of showers moving onshore sometime late Sunday afternoon, likely associated with a shortwave pushing in on the back side of the upper trough. This looks like a weak reinforcing shot of cool air being pushed inland on NW flow aloft. Based on latest (18z) NAM soundings, it does appear showers will initially be deep enough to hold together while they cross the Coast Range Sunday night, but they will be fighting an increasingly hostile environment for convection as surface temps cool and the air mass stabilizes. It is not out of the question that a lowland location or two could see light snow or graupel accumulations out of the more vigorous showers, but this should be isolated and not likely worth the mention in the forecast. Maintained a slight chance of thunder for these showers along the coast and coastal waters Sunday afternoon through Sunday night. High pressure moves into the area Monday, but lingering moisture and onshore flow will provide a slight chance for showers, mainly across the higher terrain. Airmass remains cool with the daytime highs staying in the 40s. There will be a brief break in precipitation Monday evening. Any clearing Monday night could lead to freezing fog. A warm front is expected to bring some rain and rising snow levels Tuesday, but latest forecast guidance suggests this may hold off until the latter part of the day or even Tue evening. Weagle/TJ .LONG TERM...Tuesday night through Friday...Longer range forecast models attempt to nose a flat upper level ridge into the NE Pacific behind Tuesday`s warm front. However the Pacific jet stream remains close enough to warrant at least a chance of rain throughout the extended forecast period. Latest guidance suggests the heaviest rain during this period will be aimed toward northwest Washington, but we will still need to keep a close eye on the Willapa Hills as the Grays River has been rather sensitive to rainfall much more than 1.00 to 1.50 inch over a 24-hour period. It appears many basins are saturated from all the rain we have received over the past month, but hopefully the 24-48 hour break from significant rainfall will raise the bar a bit in terms of the rainfall required to push our more sensitive small streams and rivers to flood stage. Weagle && .AVIATION...The cold front has moved inland and the cold air is beginning to settle in the post-frontal environment. Cigs are mainly VFR/high-MVFR which will persist through much of the evening. Northwest flow expected through Sun morning. A shortwave, and associated weak cold front, will advance towards the area around 20Z Sun which will bring another round of rain showers and switch winds to the southwest. Cigs will drop to MVFR ahead of the front after 16Z Sun. The main portion of the front will move over the area late Sun afternoon. Despite falling temperatures overnight, the dewpoint depression remains large and fog is less likely to form. If fog does form anywhere, it will most likely be around fog prone KHIO or the southern Willamette Valley. This northerly pattern is favorable for fog in the southern valley which, in combination with a weak inversion, may create patchy fog around sunrise at 15Z Sun. Freezing levels will drop to near 1500 ft ASL Sun morning, then rise again in the afternoon. KPDX AND APPROACHES...VFR cigs will persist through the evening as a weak ridge builds over the area. North-northwest winds will persist through Sun morning. As the front approaches Sun afternoon, winds will transition to be more southwesterly. Rain and stronger winds are expected with this front, but it will most likely occur outside of this next 24-hr period. May be some brief periods of LLWS with wind shifts Sun, but not significant enough for the TAF. -Muessle && .MARINE...Conditions have significantly calmed over the last 24 hours as the front has moved inland. Winds still remain west-northwest around 15 to 20 kt. There are some isolated gusts to 25 kt, but generally below small craft level winds. Seas have been fairly persistent around 13 ft with a 13 second period, and that should continue through the next several days. Models are hinting at a shortwave passing over the waters Sun afternoon which may cause winds to temporarily increase. This would increase the wind waves and raise the overall significant wave height to near 14 ft. However, given the steady state of the westerly swell, it looks like there will be little impact to the sea state. High pressure builds on Mon morning and will persist through Tue as yet another cold front moves over the waters. This front lies on the leading edge of a trough the extends from the Gulf of Alaska to the Pacific Northwest. Models are hinting at the potential for seas to build with this next system around 16 ft. However, models have been trending on the high side for seas so ended up bumping heights down. Winds will pick up gusting to near 30 kt on Wed, especially in the northern waters. In general, conditions appear to remain fairly stable through the next week. -Muessle && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory until 4 PM PST Sunday for coastal waters from Cape Shoalwater WA to Florence OR out 60 NM. Small Craft Advisory until 4 AM PST Sunday for Columbia River Bar. && $$ Interact with us via social media: This discussion is for Northwest oregon and Southwest Washington from the Cascade crest to 60 nm offshore. This area is commonly referred to as the forecast area.