Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/17/19

Area Forecast Discussion
National Weather Service Binghamton NY
1058 PM EST Mon Dec 16 2019 .SYNOPSIS... A low pressure system will bring snow and a wintry mix to the area overnight into Tuesday as it slides through the Mid- Atlantic region. Temperatures turn much colder with numerous snow showers and possible snow squalls on Wednesday as an arctic cold front moves through. && .NEAR TERM /THROUGH TUESDAY/... This late evening update includes the 00z NAM, HRRR and RAP model into the forecast along with any trends late this evening. A snow and sleet mixture is spreading northward into northeastern PA as we head into the early morning hours. Some sleet has been reported in Luzerne county within the last hour. Modeling has trended away from a burst of moderate/ heavy snowfall driven by FGEN forcing in NE PA overnight, With only lighter precipitation, the warm-up is occurring faster in the mid- levels. So trends are toward a few hours of light snow changing to freezing rain and sleet for most of NE PA. Areas in the Wyoming valley should rise above freezing Tuesday and change to rain. The net result here is a decrease in expected to just a couple of inches in NE PA. Still the light snow along with an interval of freezing rain and sleet will lead to difficult travel. A changeover to sleet and freezing rain occurs Tuesday morning with icing amounts around a tenth of an inch in the higher elevations of the Poconos region and lesser amounts elsewhere. How far north the mixing line will make it is still uncertain, but thinking we will see some sleet and freezing rain to at least the Southern Tier of NY. the late evening update nudged this a bit further north based on the latest HRRR/NAM model runs. Also, the latest model data shows a secondary burst of moderate to perhaps heavy precipitation trending stronger Tuesday afternoon due to FGEN forcing. Where this is snow, snow totals have been increased a bit given the trends. Temperatures should be in the 20`s into the the low 30`s throughout the event with some mid 30`s in the Wyoming Valley. Summary... NE PA: Period of snow changing to sleet and freezing rain by sunrise. Lowered snowfall totals based on observations and model trends. Warming enough for rain Tuesday in the Wyoming valley. Southern Tier NY: Snow developing overnight. Mixing with sleet and freezing rain Tuesday. Increased forcing leading to narrow band of heavier snow with local 6 inch totals by Tuesday morning. Less snow where mixing occurs across the northern Tier of PA. Finger lakes/ NY Thruway: Few changes. Several inches of snow mainly Tuesday. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... With the plenty of instability Wednesday, some thunder is possible with the afternoon snow showers. Light snow showers in the area Tuesday night in the wake of the storm with the northwest flow. Main event in the period begins on Wednesday as an arctic cold front plunges into the area. Considerable, deep instability, for winter, accompanies the front with a sharp surface convergence and adiabatic lapse rate will lead to snow squalls along the front. Current timing pushes the front through around midday with strong cold advection firing additional lake enhanced squalls behind the front. With a quick inch of snow and very low visibility and strong wind gusts, snow squall warnings on Wednesday a definite possibility. Lake effect continues into Thursday with a NW flow event and near Advisory snow amounts likely over the northern zones into the Finger Lakes. Despite the extreme instability, limiting factors are evident including extremely dry air and a good amount of shear that may limit the intensity of the band(s). Also, subsidence inversion drops down to near 900mb by Thursday morning. With the cold, temperatures will drop into the single numbers across the area, with some lows below zero in Oneida county. Adding in the winds, wind chills will be approaching Advisory criteria Thursday morning. && .LONG TERM /FRIDAY THROUGH MONDAY/... Westerly flow across the Great Lakes will cause light lake effect snow showers over northern and western sections of the forecast area Thursday before high pressure builds in Thursday night. Temperatures will drop into the single digits Thursday night with below zero readings to the far north. Chilly but quiet weather is forecast for Friday as temperatures rise into the 20s. A weak wave could produce isolated snow showers on Saturday and Sunday. Temperatures will rebound into the middle 30s on Saturday and the upper 30s on Sunday. && .AVIATION /04Z TUESDAY THROUGH SATURDAY/... Conditions remain VFR at all terminals this evening. This will be short-lived, as lower ceilings and precipitation begin to move in from south to north, with KAVP the first terminal to likely see restrictions (likely after 02Z). Expecting all terminals to quickly lower to IFR later tonight as precipitation overspreads the area. While the majority of the precipitation across the area will be in the form of snow, snow is expected to transition to a wintry mix, especially at KAVP, but also briefly for KELM and possibly KBGM. Conditions gradually improve somewhat by the end of the TAF period as the storm system departs. Winds will be light and variable this evening, before becoming easterly, and eventually northerly by Tuesday afternoon at less than 10 knots. Winds shift to a more northwesterly direction as the storm departs late in the period. Outlook... Tuesday night...occasional MVFR in snow showers. Wednesday and Wednesday night...MVFR/IFR restrictions with snow showers and squalls in CNY. MVFR AVP. Thursday...VFR. Possible restrictions in CNY due to lingering lake effect snow showers. Thursday night through Saturday...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...Winter Weather Advisory until 4 PM EST Tuesday for PAZ038>040- 043-044-047-048-072. NY...Winter Weather Advisory until 4 PM EST Tuesday for NYZ022-024- 055>057-062. Winter Weather Advisory until 6 PM EST Tuesday for NYZ015>018- 023-025-036-037-044>046. && $$ SYNOPSIS...MPK NEAR TERM...MPK/MWG SHORT TERM...DGM/MWG LONG TERM...DGM/DJP AVIATION...BJG/DGM
Area Forecast Discussion
National Weather Service Buffalo NY
1030 PM EST Mon Dec 16 2019 .SYNOPSIS... Thickening high clouds will give way to light snow later tonight as area of low pressure moves by just to the south of New York. Snow will continue into Tuesday, with the greatest amounts across the Southern Tier and Finger Lakes region, though even some minor accumulations are expected over the Niagara Frontier, including at Buffalo and Rochester. Lake effect snow will develop Tuesday night and Wednesday, as a much colder airmass arrives for the middle of the week. && .NEAR TERM /THROUGH TUESDAY/... Recent runs of the RAP and HRRR and now the 00z NAM have trended toward more QPF farther north into the Niagara Frontier, including at Buffalo and Rochester. Nudged total snow amounts up around 1 inch, so now looking at 2-3, maybe isold 4 inch amounts in these areas. Still will keep the advisory where it was in place originally, but even in those areas have bumped up totals more into the 4-6 inch range, with isold 7 inch amounts not out of the question. This all occurs as shortwave trough over central CONUS causing the snow from eastern MO into central IN this evening shifts east-northeast and interacts with inverted sfc trough extending to the north of primary area of low pressure vcnty of Tennessee that continues to cause all sorts of severe weather issues this evening. As it has looked for a while, the whole shield of snow will be enhanced due to upper divergence from right entrance region of strong upper jet and low-mid level frontogenesis (especially H85-H7 layer). Think main surge of snow occurs 10z-17z/5 AM through 12 PM. So the commute on through the morning will be impacted over much of the area. Right now SLRs are expected to be in the 10-15:1 range and there will be little wind, so it will just be the snow that impacts travel instead of snow and blowing snow. Now there have been a few obs well upstream to south of main shield of snow over IL/IN that show unknown precip or even freezing drizzle. This lines up well with where moisture strips out at temps colder than -10c (so losing the ice nucleation aloft). This drying aloft still on track to try to push as far north as NY/PA border late tonight and into mid morning Tue, so kept the mention of at least a chance of freezing drizzle for those areas. As low pressure tracks across New Jersey and off the southern New England coast by Tuesday afternoon, widespread snow will gradually diminish and it may transition to more of a showery regime mid to late afternoon as axis of shortwave trough/colder air aloft crosses. With enough moisture, a few of those snow showers could briefly drop vsby locally. Highs on Tuesday will range from the upper 20s to low 30s across the higher elevations to the low to mid 30s across the Lake Plains. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... The widespread synoptic snow from Tuesday will be exiting the eastern Lake Ontario region early Tuesday evening. There will be at least some limited lake effect snow developing in the wake of this system as temperatures aloft become marginally cold enough. Off Lake Erie... Expect lake enhanced upslope snow showers to continue through the first half of the night across the Chautauqua Ridge and Boston Hills on northwest flow. Overnight, boundary layer flow will begin to back to the west and southwest ahead of the next system. This will allow the upslope snow showers to re-organize into a more shore parallel band along the Chautauqua County shoreline after midnight. This band will then move northward towards Buffalo by the pre-dawn hours of Wednesday. The ever changing mode and location of the lake snow should keep accumulations relatively light, with 2-3 inches possible where the snow persists. Off Lake Ontario... Lake effect snow will organize in the evening over Wayne County in northwest flow. Boundary layer flow will then back to westerly overnight. This will push the lake effect snow eastward along the south shore of the lake from Wayne to Oswego counties. The steady movement of this band should also limit accumulations to the 2-3 inch range. A very interesting setup then evolves for Wednesday. A very strong and sharp mid level trough will move southeast across Ontario, reaching New England Wednesday night. Despite the closed off 500MB low, this system will remain very progressive. An associated cold front will cross the eastern Great Lakes Wednesday morning. The cold front will combine with pre-existing lake effect snow bands to produce a brief burst of heavy lake effect snow east of the lakes, and raise the possibility of fast moving snow squalls even inland from the immediate lake effect areas. Off Lake Erie... Expect the band of lake snow to briefly make it up to about Buffalo and Batavia. Note, this idea is north of most of the high resolution model guidance, which often has a notable southward bias in these situations. This will occur right during the morning commute. The cold front will then capture the lake band and drive it rapidly south and east through the western Southern Tier from mid morning through midday. The rapid band movement during this time should keep accumulations in the advisory range, even if the snow becomes heavy. Expect accumulations of 3-5 inches on average for Wednesday where the bands persist the longest. Late Wednesday and Wednesday night boundary layer flow continues to veer to the northwest. This will carry the lake effect snow into the western Southern Tier, primarily Chautauqua and western Cattaraugus counties. Mesoscale model guidance suggests an upstream connection to Lake Huron will develop and enhance the snow in this area despite the short fetch across Lake Erie. The upstream connection may support an additional 3-5 inches in persistent bands. The lake effect snow will begin to weaken later Wednesday night, then end Thursday morning as high pressure builds over Lake Erie. Off Lake Ontario... Lake effect snow will re-organize to the northeast of the lake by mid morning with the approach of the cold front. A combination lake effect snow band and frontal squall will then move east across the eastern Lake Ontario region late morning and early afternoon, dropping a quick 2-4 inches, with 3-5 inches possible on the Tug Hill with added orographic enhancement. By mid to late afternoon boundary layer flow will become WNW, allowing lake effect snow to focus southeast of the lake from Wayne to southern Oswego counties. Wednesday night boundary layer flow will continue to veer to the northwest. This will allow the lake effect snow band to move onshore and back westward along the south shore, from Wayne County westward to at least Orleans County, including the Rochester Metro area. Mesoscale model guidance suggests an upstream connection to Georgian Bay will develop during this time, enhancing the Lake Ontario snow. This will bring a good chance of 3-5 inches across much of the south shore of the lake from Orleans to Wayne counties, including the Rochester area. There could be locally more if the band and upstream connection stall for several hours in one location, but right now it looks like this band will keep moving. Northwest flow will maintain a spray of multiple bands southeast of Lake Ontario through Thursday, but additional accumulations should be light during this time as inversion heights lower, synoptic scale moisture continues to decrease, and the Georgian Bay connection is lost. Wednesday and Wednesday night winds will become quite strong, with gusts of 35-40 mph common on the lake plains and 30-35 mph farther inland. This will produce areas of blowing and drifting snow. It will turn very cold Wednesday night, some of the coldest air we have seen this early winter season. Lows will drop into the single digits away from the immediate lakeshores, and below zero east of Lake Ontario. Wind chills will drop below zero, and may approach wind chill advisory criteria for a brief time late Wednesday night and Thursday morning across the eastern Lake Ontario region and the higher terrain of the Southern Tier. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... An unusually quiet period of weather looks to set up late this week through early next week as the pattern becomes more zonal across the US with an expansive ridge dominating the mid section of the nation. Our region will remain on the edge of the above normal temperatures that will build across much of the US. The upper level pattern leaves the door open for the potential of weak fronts moving south out of Canada, which may prevent the well above normal temperatures from reaching the eastern Great Lakes. Looking at the details, any lingering light lake effect snow showers southeast of Lake Ontario will end Thursday night. High pressure will then dominate the eastern US Friday through the weekend. Sunday night and Monday the Canadian GEM, and to some extent the GFS, bring a trough through Ontario and Quebec, with a weak front possibly moving south into our region. The ECMWF keeps this system much farther north and west. Given the weak signal, kept the forecast dry through Monday for now. Despite the lack of systems, the warming temperatures aloft at this time of year will likely support a steepening low level inversion, so we may end up with low stratus clouds much of the time. Temperatures aloft will warm through the period, although surface temperatures may lag behind with the expectation of a steepening inversion. Went with a gradual warming trend through the weekend to slightly above normal. && .AVIATION /04Z TUESDAY THROUGH SATURDAY/... VFR conditions will continue through early overnight with only JHW seeing some MVFR cigs at times. Weak low pressure will track south of the area and bring widespread steady snow to New York State late tonight and Tuesday. Prevailing cigs will start to lower to MVFR across the Southern Tier by 06z, then areas south of the NYS Thruway will deteriorate to IFR in light snow by 12z Tuesday. While periods of heavier snow is possible, light snow is expected through this event for the TAF sites. IFR vsbys are likely across western NY Tuesday. Steady snow doesn`t reach KART until Tuesday morning. Expect improvements from west to east late Tuesday afternoon. A brief period of VFR conditions will then occur on Tuesday evening before localized IFR develops late Tuesday night east of the lakes as lake effect snow develops. Outlook... Wednesday...IFR in lake effect snow east of the lakes, with VFR elsewhere. Thursday...IFR in lake effect snow showers southeast of the lakes, VFR elsewhere. Friday and Saturday...VFR. && .MARINE... Light winds and waves will be replaced by another period of stronger winds later Tuesday night through Wednesday as a strong cold front crosses the region. Expect widespread small craft advisory conditions by this time. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...Winter Weather Advisory until 4 PM EST Tuesday for NYZ012>014- 019>021-085. MARINE...Small Craft Advisory from 7 AM Wednesday to 1 AM EST Thursday for LEZ020. Small Craft Advisory from 10 PM Tuesday to 7 AM EST Thursday for LEZ040-041. Small Craft Advisory from 7 AM Wednesday to 1 AM EST Thursday for LOZ030. Small Craft Advisory from 4 AM Wednesday to 1 PM EST Thursday for LOZ042>045. && $$ SYNOPSIS...EAJ/HSK/JLA NEAR TERM...HSK/JLA SHORT TERM...Hitchcock LONG TERM...Hitchcock AVIATION...HSK/JLA MARINE...HSK/JLA/Thomas
Area Forecast Discussion...UPDATED
National Weather Service Cheyenne WY
856 PM MST Mon Dec 16 2019 .UPDATE... Issued at 853 PM MST Mon Dec 16 2019 Mid-evening update included lowering temperatures a few degrees through the early morning most locations as winds have dropped off in the lower elevations a bit (for now) and winds have partially decoupled allowing for a more rapid fall of readings. We still expect to see the winds start to pick up after midnight and will leave the High Wind Warning as is for now. Wind chill readings for the western areas will be around 20 below zero for a period of time in the early morning before seeing mixing increase a bit and temps warm (especially where downsloping will have an effect). No other changes to the forecast at this time. /JG && .SHORT TERM...(Tonight - Tuesday) Issued at 249 PM MST Mon Dec 16 2019 A challenging wind forecast across southeast Wyoming over the next 12-24 hours. Low-level gradients are expected to increase markedly during the evening/overnight, with the GFS showing 850/700 mb CAG- CPR gradients climbing to 65-75 meters between 9z and 15z Tue. The considerably less aggressive NAM shows gradients peaking around 55 meters during the same time frame, still sufficient for high winds at ARL. This may be a fairly quick-hitting high wind episode, with the main driver being a fast moving disturbance diving from north- west to southeast across the state tonight through Tuesday AM. The subsidence in the wake of this feature could be a major player for 60+ MPH wind gusts. Flow aloft appears to be fairly modest over the majority of our SE WY wind corridors, but models agree on a narrow ribbon of 50+ knot flow in the vicinity of Bordeaux at 800 millibars at some point on Tuesday AM. A 3-5 mb surface pressure gradient oriented from west- east along the Laramie Range appears quite favorable for Bordeaux, and despite largely northwesterly flow aloft, significant WAA will be present near mountain tops leading to trapping of stronger flow in the low levels due to a significant inversion. X-sections along the central Laramie Range, coupled w/ recent HRRR projections & in house probabilistic guidance strongly suggests 60-70 MPH gusts for the BRX area. The I-80 Summit is a bit tricker as that area is not impacted by gap mechanisms, but significant subsidence & downslope enhancements could bring winds near warning criteria. Arlington is probably the least impressive zone based strictly on 700 to 800 mb flow, but it is hard to ignore those gradients and we have already seen gusts 45-50 MPH with gradients expected to double in the next few hours. That said, High Wind Watches were upgraded to Warnings for ARL and BRX from 11 PM this evening until 5 PM MST Tue. We included the I- 80 Summit based on the above reasoning. It is quite possible for a few gusts to spill into the S. Laramie Range foothills, but models show subsidence dropping off considerably east of Buford. The next couple of shifts will need to monitor trends closely. .LONG TERM...(Tuesday night - Monday) Issued at 302 AM MST Mon Dec 16 2019 Winds will continue to be strong and gusty through Tuesday night as temperatures cool down again. The gustier winds may introduce some lower wind chills to the west. However, current guidance doesn`t suggest the need for any wind chill products at this time. Skies should again remain clear overnight Tuesday and through Wednesday. Surface pressure gradients will weaken slightly Wednesday morning but should start to increase again Wednesday evening. By Thursday morning, partly cloudy skies are expected as a fast moving upper level storm system moves in from the south and west. Winds aloft will be on the increase, and gusty winds are again expected. This appears to be the more promising high wind event with some potential for gusty winds to spill off the mountain and on to the plains Thursday afternoon. With dry downslope flow, temperatures will be on the rise and dry weather is expected. The rest of the week and through the weekend looks mostly dry as a zonal jet aloft and westerly winds are expected to keep things quiet and warmer. There are some indications of a more active winter pattern develop late in the day 8 to 10 range but model difference preclude any meaningful forecast at this point. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 430 PM MST Mon Dec 16 2019 VFR conditions are expected through the forecast period with gusty westerly winds picking up tonight across SE WY terminals. Gusts of 20-25 kts are possible near KCYS and KRWL overnight tonight and into Tuesday. NE Panhandle terminals will begin to see winds increase after 16z Tuesday. && .FIRE WEATHER... Issued at 302 AM MST Mon Dec 16 2019 Fire weather concerns are expected to be low due to snow cover and cold temperatures. Gusty winds will likely develop by mid week but fuel curing is not expected due to snow cover. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...High Wind Warning until 5 PM MST Tuesday for WYZ106-110-116. NE...None. && $$ UPDATE...JG SHORT TERM...CLH LONG TERM...AL AVIATION...MB FIRE WEATHER...AL
Area Forecast Discussion
National Weather Service Green Bay WI
602 PM CST Mon Dec 16 2019 Updated aviation portion for 00Z TAF issuance .SHORT TERM...Tonight and Tuesday Issued at 231 PM CST Mon Dec 16 2019 The latest RAP analysis and satellite/radar imagery show a high pressure ridge axis extending east across southern Wisconsin. Low clouds are holding steady across much of northeast Wisconsin early this afternoon, though partial clearing continues slowly over northwest and far northern WI. Scattered flurries have persisted across far north-central WI despite a few holes in the cloud cover at times. Looking upstream, mostly clear skies prevail across much of central and northern Minnesota. but the next area of cloud cover is moving southeast over the Dakotas. Forecast concerns include sky trends and snow shower chances on Tuesday. Tonight...The surface ridge axis will extend across southwest to northeast Wisconsin. Cloud cover remains difficult to forecast, but counting on a slow clearing trend to take place from northwest to southeast this evening as models continue to indicate a drying of the low levels. Did slow down the clearing trend as clouds will be tough to dissipate beneath the inversion, and lack of any diurnal heating. After the brief period of clearing, clouds are expected to increase again from the northwest overnight. It doesn`t appear that there will be enough saturation depth for light snow, especially since winds are too westerly for a lake effect component off Lake Superior. Due to the cloud cover and light winds of 5 to 10 mph, remained conservative for temps, which should range from the low single digits above zero to the middle teens near Lake Michigan. Tuesday...A shortwave digging southeast across the northern Great Lakes will push a reinforcing arctic front across northern WI. After mainly dry conditions in the morning under partly to mostly cloudy skies, arrival of stronger forcing and deeper saturation should lead to scattered light snow showers in the afternoon along the front. Not expecting much in the way of accumulations, perhaps a tenth or two over north-central WI. Temps will be slightly cooler than todays readings, and range from the middle teens to low 20s. .LONG TERM...Tuesday Night Through Monday Issued at 231 PM CST Mon Dec 16 2019 Quiet weather is expected through much of the extended forecast. The main concerns will be the well below normal temperatures through Wednesday along with some light lake effect snow near Lake Superior. In fact, wind chill values may approach advisory criteria for central and north-central portions of the area Tuesday night into Wednesday morning. Tuesday night and Wednesday: A fairly strong shortwave and arctic cold front are expected to slide through the area for this time period. Along the cold front and shortwave axis, light snow showers or flurries will likely develop and slide from northwest to southeast across the area. The best chance will be Tuesday night as upper jet supports large scale forcing. Clearing skies are expected behind these features. The main limiting factor for any appreciable precipitation will be the lack of moisture in the lower levels of the atmosphere. Still enough moisture to give a few snow showers or scattered flurries. The better chance of seeing any light accumulation, will be across north-central Wisconsin, where lake effect/enhanced snow is expected to develop. Winds will be from the favored north to northwest direction through Wednesday morning, before quickly shifting to the west and southwest by the afternoon hours. This would quickly end any ongoing lake effect snow. The very cold airmass in place will likely limit snow to liquid ratios as the DGZ is very close to the ground. Only expecting an inch of two of snow with visibility reduction being the main impact due to small flake size. Otherwise, temperatures are expected to be well below normal with lows dropping into the teens below zero across central WI with much of the rest of the area in the single digits above zero. Light winds/CAA to the east of the approaching high, may lead to wind chill values dropping into the -15 to -25 degree range Tuesday night into Wednesday morning across central and north- central WI. Temperatures may be kept a bit warmer where lake clouds linger the longest. High temperatures Wednesday are expected to be in the single digits to mid teens above zero, coldest central and north-central. The rest of the extended looks to be fairly quiet with only a few subtle/moisture starved features passing through the area. Upper- level ridging will build across much of the area into the upcoming weekend. This will result in steadily warming temperatures, with many places warming above normal by the end of the work week into the weekend. A weak system will likely brush through the area Friday into Friday night, allowing for increased clouds and perhaps a flurry or sprinkle, but generally looks dry for that time period. && .AVIATION...for 00Z TAF Issuance Issued at 558 PM CST Mon Dec 16 2019 Cloud trends again present a major aviation forecast issue. A low deck with MVFR bases was across most of the area, but the edges were close to the northwest and southeast parts of the area. Opted to hold onto the current bases for a while this evening, then trended toward the normally reliable LAV and GLAMP guidance later tonight into tomorrow. Some low-end LLWS is again possible across mainly the north and west late tonight. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......Cooley AVIATION.......Skowronski
Updated for 00Z Aviation Forecast Discussion below.

DISCUSSION... Tonight...main story will be continued severe weather threat over our southern and southeastern counties. CAPE values have reached 500-1000 J/kg over northern/northeastern MS. Vertical wind shear remains favorable for storm organization and rotation. Line of storms is becoming organized over NW MS, with some smaller more discrete cells ahead of line. Most favored area for severe will persist ahead /east-southeast/ of the line. Meanwhile, over our far northern counties, may see a brief mixture of frozen precip as precipitation clears out. Will include mention of rain or light snow overnight, with no accumulation expected. Tuesday through Friday...mainly dry and cool conditions expected as surface high pressure builds in. Surface ridge should remain over the area into early Thursday with northerly winds persisting. Falling pressures to the west in advance of upstream system will generate return southerly flow late Thursday into Friday night. Saturday through system will swing across the region on Saturday. GFS and ECMWF both keep system south of our area, with the GFS a little stronger with the system. Will go with low POPs and low QPF over our southern counties. Upper level ridging builds over the area Sunday-Monday, which will bring southerly winds and mild temperatures into the area for the beginning of next week. GW && .AVIATION... 00Z TAFs Back edge of -DZ/-RA moving through the MEM TRACON at 00Z. Widespread IFR ceilings were noted upstream over northeast AR and southern/central MO. NAM and RAP soundings depict lifting ceilings to MVFR with frontal inversion depth overnight, but MOS-based guidance such as the LAV and MET guidance maintains IFR. Give the lack of frontal depth increase in upstream ceiling observations, have maintained the status quo for most of the overnight. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion
National Weather Service Marquette MI
637 PM EST Mon Dec 16 2019 .SHORT TERM...(This evening through Tuesday) Issued at 421 PM EST MON DEC 16 2019 Water vapor imagery and RAP analysis show a weak shortwave swinging across northern Ontario and the Upper Lakes. Upstream, a stronger shortwave is dropping se across northern Saskatchewan. Behind the associated arctic cold front, it`s bitter cold with early aftn temps across northern Manitoba/northern Saskatchewan in the -20s F. Closer to home, associated with the weak shortwave moving across the Upper Lakes, a sfc trof has settled over Lake Superior. This trof brought a burst of mdt/hvy snow to the Keweenaw earlier today. The trof is now weakening and becoming more w-e oriented across southern portions of Lake Superior. KMQT radar shows a less organized band of heavier shsn along the trof over s central Lake Superior, and vis imagery indicates this band extends w across the Keweenaw in the vcnty of KCMX. Weakening sfc trof over southern Lake Superior may slip a little far s over eastern portions of the lake, resulting in heavier shsn brushing the remote shoreline e of Grand Marais this evening. Otherwise, LES will continue across the Keweenaw thru the evening with a tendency for the shsn to lift n as winds back slightly ahead of approaching shortwave. Localized accumulations of an inch or two will be possible thru the evening. Ongoing flurries elsewhere will dissipate over the next several hrs as drier air/clearing per satellite imagery progresses eastward. Arctic cold front associated with the Manitoba shortwave will move out across western Lake Superior late tonight. As it does so, a band of mdt/hvy snow will develop along it, sweeping onshore over the Keweenaw probably in the 10-13z time frame. A quick inch or two of snowfall will be possible. This cold front will continue se across the area Tue morning into the early aftn, accompanied by a brief period of mdt/hvy shsn, especially e of Marquette. After the front passes, incoming dry arctic air mass combined with some directional wind shear will work to keep developing nw-se oriented LES bands on the light side. Additional snow accumulations after passage of the snow band along the cold front should not be more than 1 to perhaps 2 inches thru the aftn hrs. As for temps, expect clouds to scatter out at times to allow temps to fall into the single digits above zero in the interior. Favored the colder bias corrected CMC over interior e where temps may fall to around -5F at the traditional cold spots due to expected less cloud cover. Highs on Tue, generally mid teens to lower 20s, will be reached prior to fropa. Temps will slowly fall after fropa with readings generally down into the upper single digits over the nw half by 00z Wed. .LONG TERM...(Tuesday night through Monday) Issued at 421 PM EST MON DEC 16 2019 Model analysis shows troughing across the western CONUS this morning that will propagate to the east, spinning up the potential for severe thunderstorms across the Gulf Coast this afternoon. A building ridge across the West Coast, will assist pushing an arctic cold front across the Upper Great Lakes region Tuesday night into Wednesday. Falling temperatures aloft will create a period of steady LES through Wednesday afternoon before rising heights back winds more from the south, ending LES. A weak clipper-system will bring another quick chance for -SHSN on Thursday, mainly across the Keweenaw and east. Global ensembles suggest rising heights and temps into the weekend as positive 500mb height anomalies build across the central and eastern CONUS. Deterministic models suggest a weak wave to pass through the Plains to the north of Lake Superior on Friday as a clipper wave traverses south and east across Canada Friday night into Saturday. Both of these waves bring the chance of light precipitation across the area, but confidence in specifics remains on the lower side for now. Overall rising temps into the low to mid 30s with drier conditions going into the weekend. Compared to the last few days, not much has changed in regards to the forecast Tuesday night into Wednesday. Winds become more steady from the NW overnight as 850 mb temps fall through the night. Snow amounts remain close to the same with 3 to 5 inches in the NW wind snow belts across the west and 4 to 6 across the east. These snow totals are from Tuesday through Wednesday. Late Tuesday night into Wednesday, 850 temps fall blo the DGZ as snowflakes may become smaller...limiting visibility further at times. Wednesday night going into Thursday, heights begin to rise as winds back more from the south. A quick passing wave will move across Lake Superior Thursday bringing weak associated WAA and isentropic lift. This will bring snow showers primarily across the Keweenaw and east. Expect any snow accumulations to remain light. This weekend into Monday, 850 temps rise above 0C as Upper Michigan gets a chance at a "December Thaw". It looks to remain dry through the weekend, with any precipitation chances remaining light. Some model differences show a passing low Friday into Saturday that looks to remain north of the area. High temperatures will remain at or above 30 degrees Friday through Monday. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 633 PM EST MON DEC 16 2019 Under westerly winds, lake effect -shsn and mostly MVFR conditions will continue at KCMX into tonight. Late tonight/Tue morning, passage of a cold front should result in prevailing IFR conditions setting in. At KIWD, the approach and passage of cold front late tonight/Tue morning should bring in prevailing MVFR to occasional IFR conditions. At KSAW, MVFR cigs should break out to VFR in the next couple of hrs. VFR conditions will then continue until MVFR cigs arrive with cold fropa Tue afternoon. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 421 PM EST MON DEC 16 2019 Main attention during this fcst issuance is the arctic cold front that will sweep across Lake Superior on Tue. Front will reach western Lake Superior late tonight and will exit the se part of the lake around 18z. Tonight, expect westerly winds mostly in the 20- 30kt range. Winds on the w half of the lake will be closer to 30kt late tonight, just ahead of the cold front. In the wake of the arctic front passing on Tue, expect nw winds to 30kt, which will continue into Tue night/early Wed morning. Incoming pres rises combined with increasingly colder air flowing across the lake support a good potential of gales to around 35kt Tue aftn/night and into early Wed morning, at least over the e half of Lake Superior. Thus, a gale warning has been issued for that part of the lake. Winds will quickly diminish from w to e on Wed as a sfc high pres ridge arrives. Should see a short period with winds under 15kt as the ridge passes. After the ridge exits, expect an increase in southerly winds heading into Thu, possibly up to around 25kt over the e half of the lake. Approaching low pres trof on Fri will bring a further increase in winds, again strongest across the e half of Lake Superior where s to se winds up to 30kt are expected. Winds may settle back some on Sat. There will be some freezing spray tonight into Tue morning, but the more significant freezing spray will arrive after the arctic cold front passes. Heavy freezing spray will likely develop later Tue aftn and continue into Wed morning. Heavy freezing spray warnings have been issued for much of Lake Superior. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Heavy Freezing Spray Warning from 10 PM Tuesday to 3 PM EST Wednesday for LSZ251-267. Gale Warning from 3 PM Tuesday to 8 AM EST Wednesday for LSZ243>245-248>251-264>267. Heavy Freezing Spray Warning from 3 PM EST /2 PM CST/ Tuesday to 1 PM EST /noon CST/ Wednesday for LSZ240>245-249-250-263- 264-266. Heavy Freezing Spray Warning from 5 PM EST /4 PM CST/ Tuesday to 9 AM EST /8 AM CST/ Wednesday for LSZ162. Heavy Freezing Spray Warning from 5 PM Tuesday to 11 AM EST Wednesday for LSZ246>248-265. Lake Michigan... None. && $$ SHORT TERM...Rolfson LONG TERM...JAW AVIATION...Voss MARINE...Rolfson
Area Forecast Discussion
National Weather Service New York NY
1022 PM EST Mon Dec 16 2019 .SYNOPSIS... A low pressure system will impact the region tonight through Tuesday. A polar cold front approaches Wednesday and moves across Wednesday night. Canadian high then pressure builds into the region through Saturday, weakening Sunday and Monday, but remaining the dominant feature in the weather pattern. && .NEAR TERM /THROUGH TUESDAY/... The forecast remains mainly on track. Minor changes were made to hourly temperatures, dewpoints, and weather based on the latest observations and trends. Made the intensity for the remainder of the evening light as radar echoes have been stronger aloft than they are closer to the surface. As a result of the lighter intensity, not as much wet bulb cooling is occurring and there is a general light sleet, light rain, light snow mix occurring. Warm nose from RAP soundings show an above freezing layer around 850mb moving in around midnight, which would lead to some more freezing rain which already is in the forecast for some parts of the area overnight. Low pressure continues to develop over the Tennessee Valley with a warm front well to the south across NC/VA border. This warm front will gradually approach through tonight as the low nears the northeast. Surface high pressure and ridging remains in control into this evening. Steady precipitation should hold off until large scale lift and better dynamics approach from the south and west ahead of the warm front and low pressure. The dry air currently in place will allow for evaporative cooling and wet-bulbing as the precipitation intensity increases. Even at the coast/NYC/LI, a brief period of accumulating snow is possible. However, it should transition to a mixture of snow and sleet and eventually plain rain early Tuesday morning. Away from the NYC metro and coast, snow may hang on longer as the heavier intensity of the precip and northerly flow should hold the warm advection at bay for a few hours longer. Eventually, the warm nosing aloft will win out and transition the precip to a mixture of snow/sleet and freezing rain. Model soundings reveal an isothermal layer in the lower/middle levels which may promote moderate to heavy snow. This will be brief near the city and coast, but likely last several hours longer inland. There is also a deeper cold layer just above the surface on soundings which may bring a prolonged period of sleet as the warm nose melts the snow aloft. The morning commute will see its greatest impacts inland and away from the NYC metro and Long Island. The I-95 corridor in southern CT and rest of interior will see a mix of freezing rain and sleet during the morning commute. Warmer surface temperatures will try to move inland through the morning, but the northerly flow and further proximity to the warm front should keep temperatures at or below freezing for much of the day. Elsewhere, temperatures warm into the middle and upper 30s with some locations on Long Island potentially reaching 40. The models seem to have a good handle of the track of the low and location of the warm front through the day Tuesday. The main uncertainty revolves around the timing of the transitioning precipitation. Temperatures may also run a bit colder across northern Long Island and northern NYC for a time between 3 am and 6 am where some freezing rain may occur. However, temperatures should rise above freezing during the morning commute. Total snow accumulations range from 2-4 inches away from the coast to about an inch or less over NYC and Long Island. A reasonable worst case scenario is around 5 inches inland to 2-3 near the coast. For freezing rain accretion, around 0.1 to 0.2 inches of ice are anticipated in the advisory area. Will have to monitor any locations outside of the advisory that stay colder and see freezing rain early Tuesday. An SPS or brief advisory may be needed to account for this. Freezing rain amounts inland could exceed 0.25 inches where through Tuesday where temperatures do not rise above freezing. Precip should taper off from west to east late in the day as the low pressure moves offshore and N-NW flow takes over. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... Lingering low chances on PCPN continue Tuesday evening as the storm heads farther NE out to sea. PCPN types still in the form of rain right at the coastal areas, but freezing rain and sleet still possible inland. Weak high pressure then follows for the overnight hours of Tuesday night, keeping us dry. A cold front approaches on Wednesday, accompanied by a strong shortwave. Moisture is lacking, but could be enough for a snow shower or two in the afternoon to evening hours. The front exits by midnight with a much colder air mass and gusty winds being ushered in behind it. Lows Wednesday night drop into the teens for most locations with some single digit readings well inland. Wind chills late at night drop to near zero around the city, and down into the single digits below zero elsewhere. && .LONG TERM /THURSDAY THROUGH MONDAY/... Deep-layered ridging moves into the Northeast Thursday through Saturday with an extended period of dry weather as a sufficient combination of moisture and lift remains lacking. Temperatures for Thursday and Thursday night will be well below normal with highs only in the 20s and lows again mostly in the teens. The upper ridge flattens Saturday night with a weak shortwave aloft, but weakened surface high pressure should still manage to keep us dry through Sunday. High pressure then strengthens somewhat on Monday as we`ll be in between two storm systems - one over SE Canada and the other moving off the US SE coast. The air mass over us will have had time to moderate, so expecting to see temperatures closer to normal Saturday, and possibly even a few degrees above normal for Sunday and Monday. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... Low pressure approaches from the west overnight, and passes south of Long Island late Tuesday. Mainly VFR through about 04Z as dry air aloft continues to prevent the ceilings from lowering with generally a mixture of light rain and ice pellets falling across the area. MVFR conditions are possible in some of the heavier precipitation that moves through during this time frame, which could change any precipitation to snow for a brief period, lowering visibility, and this is reflected with a TEMPO group. Ceilings and visibility then lower after 04Z as steadier precipitation overspreads the area. Snow or wintry mix will change to plain rain from south to north (except for KSWF where snow will change to a wintry mix). Around an inch or less of snow generally expected for the NYC airports, but a period of icing is possible mainly for KTEB and KEWR. Interior areas will have icing at least into Tuesday morning. Precipitation ends from west to east after 18Z Tuesday, but ceilings are likely to remain close to or below 1000 ft. Light and variable winds become northeasterly around 10 kt late tonight into Tuesday morning. Winds increase slightly late Tuesday as they become northwesterly. .OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY... .Tuesday night...Becoming VFR after 00Z. NW wind gusts to around 20Z at times overnight. .Wednesday...Mainly VFR. Pockets of IFR or lower possible late afternoon and evening with isolated to scattered +SHSN. W winds becoming NW and strengthening late. .Thursday through Saturday...VFR. && .MARINE... Sub-SCA conditions are expected through tonight. Winds on the waters east of Moriches Inlet increase to around SCA gusts Tuesday morning and seas will build on the ocean with low pressure passing across the waters. Have issued an SCA for the ocean, first east of Moriches Inlet at 11z Tuesday, and for the remaining ocean waters at 17z as seas build. Winds and seas remain at advisory criteria levels Tuesday night on the ocean. Winds diminish on Wednesday morning, however ocean seas probably remain elevated. Winds pick up ahead of a cold front Wednesday afternoon with the cold front passing through Wednesday evening. Gales will then be possible on all waters Wednesday night. Winds subside on Thursday, but with advisory level conditions as the pressure gradient remains relatively tight over the region. A high pressure ridge then brings more tranquil conditions on all waters for Friday and Saturday. && .HYDROLOGY... A widespread precipitation event tonight through Tuesday will bring a liquid equivalent of around an inch. The precipitation will mainly be frozen away from the coast. No hydrologic impacts are anticipated. No significant precipitation is expected Tuesday night through the weekend. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO35 (162.55 MHz) is still operating at reduced power. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Winter Weather Advisory until 6 PM EST Tuesday for CTZ005>008. Winter Weather Advisory until 10 AM EST Tuesday for CTZ009>012. NY...Winter Weather Advisory until 6 PM EST Tuesday for NYZ067>070. Winter Weather Advisory until 10 AM EST Tuesday for NYZ071. NJ...Winter Weather Advisory until 6 PM EST Tuesday for NJZ002-103. Winter Weather Advisory until 10 AM EST Tuesday for NJZ004- 104>108. MARINE...Small Craft Advisory from noon Tuesday to 6 PM EST Wednesday for ANZ353-355. Small Craft Advisory from 6 AM Tuesday to 6 PM EST Wednesday for ANZ350. && $$ SYNOPSIS...JC/DS NEAR TERM...JC/JM/DS SHORT TERM...JC LONG TERM...JC AVIATION...JP MARINE...JC/DS HYDROLOGY...JC/DS EQUIPMENT...
Area Forecast Discussion
National Weather Service Tallahassee FL
743 PM EST Mon Dec 16 2019 ...SEVERE WEATHER STILL POSSIBLE ACROSS PORTIONS OF SOUTHEAST ALABAMA AND THE FLORIDA PANHANDLE LATE TONIGHT AND SPREADING EASTWARD INTO THE DAY ON TUESDAY... .UPDATE... The previous forecast of a marginal to slight risk of severe weather from late tonight into the day on Tuesday still looks on track. Looking at the forecast environment from the RAP runs this evening, the best overlap of CAPE and shear is expected to arrive in our far western counties after midnight. RAP forecast soundings near Dothan around 3 am CDT show SBCAPE values over 500 j/kg with minimal CINH, low LCL heights, and strong low level and deep layer shear (near 30 and 50 knots, respectively). The hodograph is strongly curved in the low level with 0-1 km SRH values over 250 m2/s2. Some of the HRRR runs this evening have shown new convection developing out ahead of the main line currently in Mississippi later tonight. If this convection develops and the RAP is correct about the forecast environment, then a tornado threat could develop across portions of southeast Alabama and the Florida panhandle late tonight along with the potential for damaging straight line wind gusts. This threat would spread eastward across the remainder of the area through the morning hours and into the early afternoon. The main limiting factors and uncertainties include the fact that the 18z NAM and GFS are a little weaker overall with both the instability and shear, and there is uncertainty on whether or not new convection will develop ahead of the main line later tonight. The main things to watch on the mesoscale tonight will be if the surface winds remain backed across the western counties and how much the surface dewpoints increase in southeast Alabama. The RAP runs generally forecast upper 60s dewpoints reaching Dothan, which is a degree or two higher than other guidance. These small differences in surface dewpoints and wind direction can really make a difference in the resulting instability and shear. && .PREV DISCUSSION [652 PM EST]... .NEAR TERM [Through Tuesday]... Currently a surface low pressure system is developing across northern Louisiana and southern Arkansas, which is expected to propagate to the north and east through the Tennessee valley today and tomorrow. This system is expected to bring unsettled weather to our western areas later this evening. Scattered thunderstorms will be the main storm mode ahead of the cold front which is expected to move through the region through the very early morning hours in our western and central areas. The cold front is expected to clear the eastern zones of our region by the early evening hours on Tuesday. Some storms along the cold front may become severe. This entirely depends on the timing of the cold front, and whether some instability can hang around before the main forcing for ascent lifts to our north. Tonights low temperatures will be above normal with much of the region holding onto the 60s. Highs across the region will depend greatly on the timing of the front. Our eastern zones will likely peak into the mid 70s before the front arrives, but areas in the Florida Panhandle and SE Alabama will struggle to reach the upper 60s before the front passes through. Temperatures will slowly decrease throughout the day in these areas. .LONG TERM [Tuesday Night Through Monday]... Much cooler and drier air will work in behind the cold front with temperatures dipping into the 30s for much of the area Tuesday Night. Chilly conditions on Wednesday as high pressure builds in with temperatures struggling through the 50s. For the rest of the workweek we`ll see a slow moderating trend with chilly locally frosty mornings and mild sunny afternoons as temps rebound into the 60s for most of us. The weather then gets interesting for the weekend as some manner of low will likely form in the Gulf as a strong upper wave digs in from the NW. It needs to be noted up front that the predictability with this demonstrated by incredible dispersion among model ensembles and big model to model very low. For now given that we`re looking at days 5-7 we`ll follow the general trends of our blended guidance and maintain low PoPs and seasonable temperatures through the weekend. Stay tuned to see how this one evolves...especially as we get into mid-week and the energy associated with the digging upper wave begins to get sampled upstream. .AVIATION... [Through 00Z Wednesday] Low cigs and vsbys are expected tonight ahead of a cold front w/some patchy fog possible for TLH and VLD in the overnight hrs. A line of TSRA (some may be strong to severe) will arrive at DHN and ECP first around daybreak, and move thru other terminals in the 12-13z timeframe. SW winds (may be gusty at times) will shift quickly to NW as front passes, and become northerly in its wake. Conds should improve to MVFR after frontal passage for all terminals. .MARINE... Moderate southerly winds tonight will become strong and northerly as a cold front moves through Tuesday afternoon and evening. A line of thunderstorms will accompany the frontal passage on Tuesday. Small Craft Advisory conditions are expected Tuesday evening through Wednesday night behind the front. Winds will then decrease into the moderate range for the rest of the work week. .FIRE WEATHER... An approaching cold front will cause southwesterly transport winds to veer to the northwest and north, and bring showers/storms to our area Tuesday thru early Wednesday. High dispersions are expected for east/southeast Big Bend late Wednesday morning thru the afternoon. Otherwise, red flag conditions are not expected as RH values will remain above critical thresholds. .HYDROLOGY... Rainfall amounts over the next 24 hours will generally be an inch or less and cause only minor rises on area waterways. The next chance of rain for the area will be next weekend as low pressure develops in the Gulf. .SPOTTER INFORMATION STATEMENT... Spotter activation is requested. Spotters should safely report significant weather conditions and/or damage by calling the office or tweeting us @NWSTallahassee. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 61 74 38 55 31 / 30 80 30 0 0 Panama City 64 71 39 54 35 / 60 90 10 0 0 Dothan 59 68 35 51 29 / 80 90 0 0 0 Albany 63 70 38 53 31 / 50 80 10 0 0 Valdosta 61 74 40 54 32 / 20 90 50 0 0 Cross City 60 76 43 58 34 / 10 80 60 0 0 Apalachicola 64 73 41 54 36 / 40 80 30 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk until 1 AM EST /midnight CST/ Tuesday for Coastal Bay-South Walton. GA...None. AL...None. GM...None. && $$ UPDATE...DVD NEAR TERM...Bunker SHORT TERM...Johnstone LONG TERM...Johnstone AVIATION...IG MARINE...Johnstone FIRE WEATHER...IG HYDROLOGY...Johnstone
...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Tuesday) Issued at 310 PM CST Mon Dec 16 2019 Light snowfall along and east of the Turnpike ends this evening with a cold night in store. A strong H500 shortwave and embedded speed max noted distinctly on water vapor imagery is lifting out of Oklahoma into southeastern Kansas. With this trough axis lifting through eastern Kansas, the mid-level H600-700 baroclinic zone associated with the ongoing snowfall is also beginning to shift eastward. This trend should continue through the remainder of the afternoon and evening, with snow ceasing across the area by 6 to 7 pm. Narrow banding features noted in radar imagery associated with the realization of minor CSI may result in another half inch to inch of snowfall before the event winds down. Attention then turns to temperatures and cloud cover in the wake of this system. Despite the ample high clouds, visible satellite imagery does show a steady erosion of the low-level stratocumulus cloud deck over far northern and central Kansas. At this going rate, clouds should clear the area by midnight. It is interesting that the RAP and HRRR saturate the near-surface profiles and redevelop a stratus shield in eastern Kansas overnight. The saturated layer is quite shallow and might be an artifact of the weak CAA overnight. The NAM/GFS are devoid of such a feature and for how have continued with the going forecast of clearing skies. However, this will be an item worth monitoring overnight as it will have a large impact on low temperatures tonight. With the fresh snowpack and subtle surface ridge axis shifting overhead, trended the forecast on the colder side of the guidance envelope. Even if clouds hold for most of the night, a short- lived clearing could result in a rapid temperature plummet. With an amplified longwave ridge building out west and broad surface ridging settling in for Tuesday, clearing skies and light winds are expected. While winds do back to the west, WAA will not arrive until after sunset. The residual snowpack should persist through the day and have nudged highs closer to the freezing mark given the dry nature of the airmass in place, which should be easily modulated by the snowpack. .LONG TERM...(Tuesday night through Monday) Issued at 310 PM CST Mon Dec 16 2019 Little sensible weather is forecast through next weekend with a gradual warming trend. Longwave ridging dominates the pattern for the extended with predominantly southwesterly flow ushering in warmer air through next weekend. The one exception is Thursday into Friday as a decaying shortwave propagates through the mean longwave ridge. This will usher a very weak boundary into the Central Plains, but no precipitation is forecast with its passage. Temperatures for Wednesday through Friday hinge on how quickly the snowpack melts. The going forecast for eastern Kansas is likely on the high side of the guidance envelope, with some raw solutions still depicting highs in the 30s to low 40s through Friday. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 531 PM CST Mon Dec 16 2019 Expect VFR conditions through 6Z TUE. Through the early morning hours of Tuesday, patchy freezing fog may develop at the terminals while a few models show IFR stratus ceilings developing which would limit the dense freezing fog. At this time I placed scattered stratus with bases of around 800 feet and added BR to lower visibilities down to 1 mile. If skies stay clear then there may be freezing fog at the terminals between 8Z and 13Z MON with visibilities of 1/2 SM or less. By 14Z, any freezing fog should have mixed out. After 14Z, expect VFR conditions at the terminals. && .TOP WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 6 PM CST this evening for KSZ059. && $$ SHORT TERM...Skow LONG TERM...Skow AVIATION...Gargan