Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/23/20

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
535 PM MST Sun Nov 22 2020 .UPDATE... Have gone ahead and issued a dense fog advisory for tonight for much of the east slopes of the central mountain chain, as well as the Pecos Valley and portions of east central NM. Dense fog already being reported at CLines Corners and Sierra Blanca Airport, and HRRR indicating the low visibilities becoming more widepsread over the advisory area as the evening progresses. May need to consider portions of ne NM as well, but will see how conditions progress during the next few hours. Updated ZFP transmitted as well as the NPW. && .PREV DISCUSSION...459 PM MST Sun Nov 22 2020... .AVIATION... 00Z TAF CYCLE Widespread terrain obscurations from the RGV eastward to the TX border in IFR to LIFR cigs/vsbys in clouds, br, fg, dz and -ra. Light shsn possible over the Sangre de Cristo mt peaks. Some improvment expected aft 23/19Z. From the RGV wwd, lcl MVFR to IFR conditions in clouds and precipitation occasionally obscuring terrain, with precipitation most likely over the nwrn mts. Occasional ely wind gusts at KABQ to around 35kt to continue until around 23/03Z before tapering off. && .PREV DISCUSSION...320 PM MST Sun Nov 22 2020... .SYNOPSIS... It`s beginning to feel like November weather, with cooler temperatures, drizzle across the eastern plains, and mountain snow showers (above 9500`) continuing through Monday. A stronger disturbance will cross the state Monday night into Tuesday, with several inches up to a foot forecast across portions of the northern mountains. It`ll be dry and mild for Thanksgiving, with another potential system on the horizon for Black Friday. && .DISCUSSION... SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)... 95 kt subtropical jet overhead while a surface backdoor cold front continues to push west-northwest through western NM this afternoon. Upslope stratus clouds with areas of drizzle and patchy fog will be the rule tonight from the east slopes of the central mountain chain eastward into West TX. Meanwhile, an upper-level trough is dropping south-southeastward just off-shore of the OR coast as of this writing. This feature is forecast to result in sufficient atmospheric lift to generate areas of drizzle or light rain across eastern NM while western locales see scattered rain showers, isolated thunderstorms along with snow above about 9500` late tonight through Monday night. The above mentioned upper-level trough is forecast to drop into southern UT/northern AZ Monday night, possible closing off over/near the Four Corners. Snow levels in northwest NM will drop rapidly in northwest NM behind the associated cold front Monday evening. Winter weather advisories may be necessary for the Tusas and northern Sangre de Cristo mountains Monday night into Tuesday with upwards of 10" possible above 8000` feet or so by Tuesday morning. LONG TERM...(TUESDAY THROUGH SUNDAY)... As the upper-level trough continues to pass north of the state Monday night into Tuesday and begin to close off, most areas along and east of the central mountain chain will experience impacts in the form of stronger winds, reaching near Wind Advisory speeds. Snow levels fall from 9500` Monday night to valley floors by Tuesday. Several inches up to a foot of snowfall are forecast for the Sangres and Tusas Mountains (marginal for any Winter Weather Advisories at this point), with potential travel impacts across these mountain passes. Drier air filters in behind the low late Tuesday, cutting off any precipitation and leaving 700 mb temperatures in the -5 to -6 C degree range. By Wednesday, it`ll be mainly zonal flow with a few stronger westerlies. Thanksgiving Day looks to be the warmest day of the week, with dry, mild conditions and temperatures near to a few degrees above normal across much of the state. Another system is on the horizon for Black Friday into Saturday of this week. Temperatures at the 700 mb level are showing in the -10 C, but latest models have gotten weaker with the amount of moisture. There are also some differences with placement and timing, as the GFS is predicting an open wave system, while the ECMWF remains a closed low. Stay tuned... 33/31 && .FIRE WEATHER... Weather more typical of November will keep critical fire weather out of the forecast through the work week. Areas of drizzle or light rain will increase across eastern NM tonight and Monday while a Pacific storm system brings rain and mountain snow chances to central and especially northern NM Monday through at least Tuesday morning. West winds will increase somewhat on Wednesday afternoon with very localized near critical condtions expected near Clines Corners. The next storm system on the horizon is forecast to bring chances for lower elevation rain and mountain snow to central and northern NM on Black Friday. 33 | && .ABQ WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory until 8 AM MST Monday for the following zones... NMZ212-222-223-226-228-229-233-235>240. && $$
Area Forecast Discussion
National Weather Service Boston/Norton MA
955 PM EST Sun Nov 22 2020 .SYNOPSIS... Strengthening low pressure tracks through New York overnight and across Northern New England Monday. This will swing a cold front across the region, bringing showers with locally heavy rain & warming temperatures. Behind the front Monday afternoon and Tuesday, drier, blustery and colder. High pressure moves offshore Wednesday with milder conditions into New England. Low pressure approaches the region Thanksgiving along with scattered showers. Behind the departing low, dry weather returns Friday. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... Main change is to the timing of precipitation, which is slowed until after 1 AM. 945 PM radar mosaics show showers over Central NY and PA moving east. There are some showers farther east in NY, and so widely scattered showers are possible in Western MA/CT during the middle hours of tonight. Movement of the main line extrapolates to the Berkshires around 1 AM/06Z and then across Srn New England to the eastern coast around 5-6 AM. Temperatures in NW Mass are roughly 37 with dew points 33-34. These will trend warmer overnight. So there is little/no likelihood of freezing/frozen pcpn overnight. Low level flow shifts from the southeast and south overnight with warm air moving up. Thus temps expected through the 50s to near 60 by daybreak, except rising thru the 40s across northwest MA. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... Monday... Column finally saturates high amplitude trough advects a deep moisture plume northward over the area with PWATs 1+ inches during the morning hours to midday day in eastern MA. Strong jet dynamics, mid level trough beginning to take on a negative tilt, RRQ of upper level jet streak, strong frontal convergence and some elevated instability supports heavy showers, local downpours and isolated thunder during the morning hours and spilling into early afternoon across eastern MA. Thus beneficial/soaking rains with qpf ranging from 0.25-0.75 inches and isolated amounts of 1+ possible across RI into southeast MA. Also, we will have to monitor the prospects of a fine line or broken line of low top convection along the cold front. However with core of the low level jet removed well to the northeast of our region along the ME coast, thinking threat of any strong to damaging winds is minimal. But will have to watch model trends and how it evolves Monday morning. Strong low level warm air advection during the morning hours will result in highs of 60-65 across eastern CT-RI and eastern-central MA, mid to upper 50s elsewhere. Even a touch humid as dew pts rise to near 60 across RI and southeast MA. Then temps crash with cold frontal passage, occurring late morning across CT into western- central MA, then into RI and eastern MA early afternoon. Expect drying trend along with some sunshine but blustery. In fact WNW post frontal winds could gusts up to 40 mph. Monday night... Dry but blustery and colder with lows in the upper 20s and lower 30s. However gusty NW winds will result in wind chills in the teens and 20s. Mostly clear conditions, however strong cold air advection across Lake Ontario combined with upslope flow over the Berkshires and Litchfield Hills, will result in lake effect clouds over western MA/CT. Low risk of scattered flurries or snow showers as well in this area. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Highlights * Cooler than normal Tuesday and Tuesday night with dry weather. May be a bit breezy early on Tuesday. * Near to above normal temperatures for the rest of the extended. Next shot of rain is late Wednesday or on Thanksgiving. * Another shot of unsettled weather over the weekend or early next week. Tuesday and Tuesday night... Ridge axis builds from the central Great Lakes/Ontario into Quebec/Ontario and the eastern Great Lakes by Tuesday evening. The ridge shifts into New England Tuesday night, but flattens out a bit as a trough lifts into the mid Mississippi River Valley. The surface high builds into northern New England from Ontario on Tuesday. The high moves offshore into the maritimes Tuesday night. Pressure gradient remains tight due to the exiting system and incoming high. This will relax as the day progresses as the surface high builds into northern New England. So, should be a bit breezy to start with winds diminishing as the day goes on. Will have -2 to -6 degree Celsius 925 hPa air advect in from the WNW to NW during the day. This will keep it colder than normal, but should see some downsloping keeping it a bit warmer across the Merrimack and CT River Valley. Went with the 75th percentile of guidance, which results in highs in the 30s across the higher terrain and low to mid 40s elsewhere. The high slides overhead Tuesday night into Wednesday morning. This will bring light winds. Should have clear skies at the beginning of the night, but mid to high clouds will move in as a warm front lifts into the eastern Great Lakes. This should inhibit radiational cooling a bit, so have only lowered temperatures to the 25th percentile of guidance. Results in the lows in the upper teens to 20s across much of the region. If it takes longer for the clouds to move in then temperatures will need to be lowered further in future updates. Wednesday through Thanksgiving... Neutrally tilted trough will be situated over the Mid Mississippi River Valley early on Wednesday. This feature will be deamplifying as it lifts into the central Great Lakes by Wednesday evening. The ridge axis will slide offshore. Expect the high to nudge in for much of the day and keep southern New England dry, but cloudy. Think there could be some light precipitation that spreads in associated with the warm front lifting through later on Wednesday into Wednesday night. Better chances of precipitation on Thanksgiving as the trough lifts into the eastern Great Lakes. Still some uncertainty amongst guidance with respect to the speed and amplitude of the wave lifting in. At this point in time it does appear that the wave will be deamplifying as the trough lifts in. The GFS, GEFS and EPS feature a more progressive system, whereas the ECMWF/UKMET and CMC are slow and a bit more amplified. Regardless of which camp the models fall in it does appear precipitation will be all rain. Though there could be a brief rain/snow mix across the higher elevations of western MA before changing over to all rain. The slower solution would bring more in the way of rainfall as a coastal low develops nearby/just south of the region. As with yesterday have gone with the NBM due to differences at this point in time. Have higher confidence in mild temperatures through this period and it being a bit gusty late on Wednesday into Thursday with a 30 to 45 kt low level jet in place. Temperatures will be in the 40s across the interior on Wednesday and the low to mid 50s across the south and east coast. For Thanksgiving will have +8 to +10 degree Celsius 925 hPa overhead. This yields highs in the 50s across much of the region. Though there will be a few spots across the south coast that get into the low 60s. Friday through Saturday... Drier on Friday as high pressure builds in, but this may be brief. Does appear that another trough may swing through on Saturday bringing chances of precipitation. Confidence is low past Friday given the differences in the mass fields, so have kept with the NBM guidance. This keeps temperatures around normal with highs in the mid 40s to mid 50s and chances of rain on Saturday. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Tonight...High confidence. MVFR conditions deteriorating to IFR and potentially some LIFR as precipitation spreads in late in the night. E/SE winds between 5-10 kts. Coastal locations may see gusts of 15-20 kts. Did introduce low level wind shear at all of the interior terminals as a 30-40 kt low level jet moves in and some places remain decoupled per the RAP guidance, which is doing well based on latest obs. Winds shifting to the S toward daybreak. Monday...High confidence. MVFR with IFR across the interior. May see spotty LIFR in areas of heavier rainfall or where there is isolated thunder. Best shot of isolated thunder across eastern CT into RI and eastern MA. Have not added in the latest update, but will likely need to be added in future TAF issuances. Turning drier and improving to VFR with the wind shift to west, beginning 14Z-16Z western MA/CT to 15Z-18Z eastern MA. W to NW winds will gusts up to 25-35 kt at times. Monday night...High confidence. VFR with dry weather, but gusty. Winds W to NW at 5-15 kts with gusts of 20-35 kt. Expect the highest gusts over Cape Cod and the Islands. KBOS TAF...High confidence in TAF. Low prob of isolated thunder 12Z-16Z. Wind shift to the west 16Z-18Z Mon with gusts up to 30 kt. KBDL TAF...High confidence in TAF. Wind shift to the west 14Z- 16Z Mon with gusts up to 30 kt. Outlook /Tuesday through Friday/... Tuesday: VFR. Windy with local gusts up to 30 kt. Tuesday Night: VFR. Breezy. Wednesday: Mainly VFR, with local MVFR possible. Breezy. Wednesday Night through Thanksgiving Day: Mainly VFR, with local IFR possible. Breezy. Chance SHRA. Thursday Night: Mainly VFR, with local IFR possible. Slight chance SHRA. Friday: Mainly VFR, with local IFR possible. && .MARINE... Tonight...E wind becoming SE then S toward morning, 15-20 kt. Spotty light rain/drizzle lowering vsby late. Monday...south winds 15-20 kt with heavy showers and isolated thunder until early afternoon. Then wind shift to the west with passage of a cold front. Behind the front, WNW winds gusting up to 35 kt late in the day. Vsby 1-3 miles but improving with the wind shift. Monday night...WNW winds gusting up to 40 kt. Dry weather and good vsby. Outlook /Tuesday through Friday/... Tuesday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Rough seas up to 10 ft. Tuesday Night: Winds less than 25 kt. Local rough seas. Wednesday: Winds less than 25 kt. Areas of seas approaching 5 ft. Wednesday Night: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Chance of rain showers. Thanksgiving Day: Winds less than 25 kt. Areas of rough seas. Chance of rain showers. Thursday Night: Winds less than 25 kt. Seas up to 5 ft. Chance of rain showers. Friday: Winds less than 25 kt. Seas up to 5 ft. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Gale Warning from 2 PM Monday to 7 AM EST Tuesday for ANZ231>235-237-250-251-254>256. Gale Warning from 4 PM Monday to 3 AM EST Tuesday for ANZ230- 236. && $$ SYNOPSIS...Nocera/BL NEAR TERM...WTB SHORT TERM...Nocera LONG TERM...BL AVIATION...WTB/BL MARINE...WTB/Nocera/BL
Area Forecast Discussion
National Weather Service Caribou ME
1022 PM EST Sun Nov 22 2020 .SYNOPSIS... Low pressure will approach tonight and track across the state on Monday. High pressure will build in Monday night into Tuesday and crest over the area early Wednesday morning. The high will slide east of the region Wednesday afternoon. Weak low pressure will cross the area Wednesday night followed by high pressure Thursday into Friday. && .NEAR TERM /THROUGH MONDAY NIGHT/... 1020 PM Update...Starting to see snow reaching the sfc and the column has moisten quickly across the northern and western areas. Even seeing flurries here at the office in Caribou. The HRRR and WRF doing fine w/the placement. Brought pops up and brought snow a bit further s including Bangor initially given the high to the ne wedging in w/the colder air in place. Thinking attm after looking at the latest NAM soundings is that colder air could hang in longer across the southern areas where some light icing could occur, although attm, it looks to be brief. Attm, snowfall and ice amts that are forecast look ok, although midnight crew might need to make some adjustment if temps hang in colder especially across the southern areas. Decided to stay w/the current headlines that in place. Previous Discussion... Sfc low wl continue to move northeast this aftn. High pressure wl be building off into the Maritimes this evng with airmass saturating in return flow. Pcpn wl mv into far nwrn zones aft 00z tonight and with wet bulb temps blo 0C expect snow at onset and throughout most of the nighttime hrs. LLJ kicks in twd 09z tonight with significant surge of warm air aloft around H8 resulting mixed pcpn acrs central areas by 09z and slowly spreading north through 13z. As warm air surges northward there wl be a thin area of mixed pcpn including snow, sleet and freezing rain before going to all rain as entire column warms above 0C drg the daylight hrs. Likewise, sfc temps wl fall through 06z before beginning to rise. Snow will be moderate at times drg the overnight near the sfc low as it tracks into the Gulf of St. Lawrence. Pcpn wl then become moderate-possibly heavy at times fm late mrng into the early aftn hrs as occluded front comes thru. All in all it appears that qpf amnts wl average around one inch with all rain expected fm Bangor south twd the coast. Snowfall amnts to the north of Baxter will average around 1 inch across the Central Highlands into nern Aroostook. One to 3 inches of snow possible from nrn Somerset twd Frenchville. A glaze of ice is possilbe acrs nrn zones as mixed pcpn heads north in warm advection with amnts up twd 0.10 inches over the St. John Vly late morning. Due to uncertainty of fzg rain potential hv not made any chgs to Winter Wx Advisory at this time, though it may need to be expanded one tier of zones to the south with later updates. For the time being will update the HWO to mention potential. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... Low pressure exiting the area Monday evening will consolidate and intensify as it lifts northeast through New Brunswick. A strong gradient between the departing low and high pressure building down from central Canada will bring a rapidly increasing and gusty northwest wind overnight Monday night. A strong northwesterly gradient both surface and aloft combined with cold advection will result in strong gusty northwest winds on Tuesday. Gusts may reach 40 mph or more over the area during the day possibly resulting in some isolated power outages. Tuesday evening will remain a bit breezy, then winds will rapidly diminish late Tuesday night as high pressure builds in and then, by early Wednesday morning, crests over the area. This will bring a clear, calm and cold morning Wednesday morning. High pressure will slide east of the area Wednesday as a poorly organized low approaches from the west. One low, tracking through central Canada, will be pulling an occluded front east, linking to a secondary low over the Great Lakes. Some light snow may spread into the area, mostly western locations, late on Wednesday. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A bit of snow Wednesday evening will change to rain from south to north as the occluded front pulls warmer air north ahead of it. Rain will dissipate very late Wednesday night into Thursday as the front slides east of the region. Weak high pressure will build north of the area later Thursday into Friday. However, some moisture lifting out of a broad longwave trough centered in the west will bring a partly to mostly cloudy sky Friday as the high slides across the north. Clouds will increase Friday night as one low lifts north through east central Canada, connecting to another low in the Tennessee Valley supported by a southern branch trough. Weak high pressure returning to the north will slow the progress of the southern branch low Saturday into Saturday night. The low should finally lift northeast Sunday or Monday bringing rain, or snow changing rain, and wind as it lifts up to our northwest. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... NEAR TERM: VFR expected through this evening before diminishing to MVFR/IFR after 06z in low clouds. Light snow will break out after 08z at KFVE and after 07z at KCAR, KPQI and KHUL. -FZRASNPL will likely mix in after 10z at HUL and progressing north after this time. All rain expected early morning through end of TAF valid time. Downeast terminals likely to see IFR in -ra after 10z Mon. LLWS will affect all terminals after 10z with FL020 from the SE between 40-50kts until cdfnt moves through after the end of the period. SHORT TERM: Monday night: IFR, becoming VFR Downeast and MVFR across the north. Winds becoming strong and gusty out of the NW. Tuesday: VFR. Strong gusty NW winds. Tuesday night: VFR. Gusty NW winds, becoming calm late. Wednesday: VFR, becoming MVFR. Winds calm becoming SE. Wednesday night: MVFR lowering to IFR. S wind, becoming NE across the north. Thursday: IFR becoming MVFR, and possibly VFR N. NE winds. Thursday night: MVFR. Light NE winds. Friday: MVFR. SE winds. && .MARINE... NEAR TERM: Wind will be on the increase from the southeast after midnight tonight with gale force winds expected. Expect a brief lull as the boundary moves over the waters in the afternoon but cold advection wl bring gale force winds back to the waters after the near term pd. Seas will increase above 5ft late tonight and remain elevated through the day on Monday. SHORT TERM: Gales will continue Monday night into Tuesday for strong gusty NW winds. The winds will quickly diminish late Tuesday night and be tranquil Wednesday morning. A SCA may be needed Wednesday night for S winds gusting up to 25 kt. Winds should be below SCA Thursday into the start of the weekend. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...Winter Weather Advisory until noon EST Monday for MEZ001-003- 004. Wind Advisory from 6 AM to 4 PM EST Monday for MEZ029-030. MARINE...Gale Warning from 5 AM Monday to 4 PM EST Tuesday for ANZ050>052. && $$ Near Term...Hewitt
Area Forecast Discussion
National Weather Service Green Bay WI
522 PM CST Sun Nov 22 2020 Updated aviation portion for 00Z TAF issuance .SYNOPSIS... Issued at 219 PM CST Sun Nov 22 2020 A round of snow Tuesday--changing to a wintry mix across much of the area Tuesday night, and a rain/snow mix and then mainly rain across east-central Wisconsin. Quiet weather is expected from Thanksgiving Day through most of the holiday weekend. The upper flow across North America will be slowly progressive as a series of shortwaves migrate across the CONUS during the period. The main westerlies will split and then phase back together at times--making it difficulty to reliably add detail to the later periods of the forecast. The pattern will allow some Gulf moisture to be transported into the region, so the total precipitation for the period will range from near normal across the NW part of the area to above normal elsewhere. Temperatures will be near normal tomorrow, then modestly above normal for the rest of the time. && .SHORT TERM...Tonight and Monday Issued at 219 PM CST Sun Nov 22 2020 The latest RAP analysis and satellite/radar imagery show shortwave energy and a surface troughing moving east across the northern Mississippi Valley and western Wisconsin early this afternoon. Snow showers along the trough have been dissipating as the move east due to ample dry air in the mid-levels, as shown on the KGRB 12z sounding. Scattered light snow showers, possibly mixed with rain over eastern WI, remain expected to move east across the area during the afternoon. Perhaps a few tenths of snow accumulations will be possible over north-central WI where temps are colder, but accumulations will likely be confined to grassy surfaces. Forecast concerns continue to revolve around precip trends, and if any impacts on travel could occur. Tonight...The trough of low pressure will slowly weaken as it moves across northeast Wisconsin during the evening. A narrow moisture channel will provide the highest chance of light rain and snow over northeast Wisconsin, but forecast soundings indicate that spotty drizzle/sprinkles could persist over much of the area for a few hours into the evening. Based on obs upstream, visibilities remain relatively high so it appears doubtful that any drizzle or freezing drizzle will lead to travel difficulties. As the trough exits, light snow showers will likely continue over the snowbelt of far north-central WI overnight, while central to northeast WI could see clearing take place late. With ample cloud cover and a brisk northwest wind, don`t see temps falling much tonight. Lows ranging from the lower 20s over central WI to the lower 30s near the lake. Monday...Cyclonic flow will gradually abate as a surface ridge axis moves from the west. Northwest flow over north-central WI will subside in the process, and therefore should see decreasing clouds through the day. Elsewhere, partly to mostly sunny skies are anticipated. High temperatures will mostly range from the low to middle 30s. .LONG TERM...Monday Night Through Sunday Issued at 219 PM CST Sun Nov 22 2020 Temperatures Monday night could drop quickly under mostly clear skies and light winds, but some recovery should occur later in the night as clouds arrive. A full-latitude trough that was coming ashore along the West Coast today will progress east across the country during the next several days. The wave will tend to split as the main westerlies undergo at least some separation into northern and southern streams, with the northern piece of energy progressing slightly faster. Forcing with the system is still expected to be sufficient to bring a substantial round of precipitation to the area, especially give an expected influx of Gulf moisture. Timing has slowed a bit since yesterday, and a little additional slowing is possible. That should allow most of the area to get through the Tuesday morning commute before the snow begins to accumulate. The initial slug of precipitation will continue across the area Tuesday and should be mainly snow everywhere except possibly right along the Lake Michigan shoreline where boundary layer temperatures will probably support a mix. The details of the precipitation forecast rapidly become fuzzy after Tuesday as the splitting of the upper support starts to result in differences among the models. A warm layer aloft will likely arrive late Tuesday/Tuesday evening across the S/SE part of the area, resulting in a transition to a mix and then mainly rain (especially in east-central Wisconsin). The north will remain colder, but may lose mid-level moisture and have precipitation change to FZDZ at times. At least occasional precipitation will probably linger over east-central Wisconsin Wednesday and into Wednesday night as the southern stream portion of the shortwave closes off and a vertically stacked cyclone tracks into southern Lower Michigan. Thermal profiles will probably continue to favor mainly rain in E-C WI. The NW part of the area will probably be in the col in the upper wind flow, so other than perhaps a little lingering light DZ/FZDZ not much precipitation is expected there after midnight Wednesday. Quiet weather is expected for Thanksgiving Day at least into Sunday. The medium range models continue to suggest there is the potential for a significant storm system to affect the area at the very end of the forecast period or shortly thereafter. But the track and intensity of that system will depend on if/when/how much phasing of the streams occurs, so it is likely to remain a highly uncertain aspect of the forecast for at least a few more days. && .AVIATION...for 00Z TAF Issuance Issued at 521 PM CST Sun Nov 22 2020 A trough of low pressure will move across the region this evening. This trough will bring scattered rain and snow showers that will drop vsbys to MVFR occasionally, mainly over central and north-central WI. Cigs will also likely fall to MVFR and IFR at times this evening at most locations. The light precip will pull out later this evening except for the Vilas county snow belt, where light snow showers and flurries could persist through the overnight hours. Clouds will likely erode late tonight into Monday morning with cigs lifting. VFR conditions are then expected through Monday afternoon once the clouds clear out. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......Skowronski SHORT TERM.....MPC LONG TERM......Skowronski AVIATION.......Kurimski
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1001 PM EST Sun Nov 22 2020 .SYNOPSIS... A cold front with limited moisture will cross our region from the northwest early Monday. A cold front with more moisture is expected to move through the area during the middle of the week. The active pattern continues as low pressure and a cold front is expected to cross the southeastern states next weekend. && .NEAR TERM /THROUGH MONDAY/... As of 950 PM: A cold front is encroaching on the NC mountains attm; obs across the Cumberland Plateau and portions of East TN are now gusty and northwesterly. A band of light to moderate rain accompanies the front. Although a modest amount of DPVA is progged to cross the CWA with the front tonight, the majority of the moisture seems to be eaten up by the mountains; the HRRR in particular depicts this, and it seems to have initialized well. Revised PoPs feature slightly more rain shadowing, keeping more areas dry east of the mtn spine. The HRRR seems to be doing better than the NAMNest so far, and the former ends the precip earlier, too. Temps look to remain somewhat elevated beneath the cloud cover, until the fropa occurs; these trends have also been updated. For the high elevations this will bring temps down near freezing. It is now looking still more likely the precip will end before changing to snow. Even if it were able to change over, SLRs would be small due to shallow moisture. Areas south and east of Charlotte still look likely to see some fog form in the next couple hours, where not already present, due to the saturated boundary layer lingering after the earlier light precip. The fog may advect into some areas that didn`t see precip, but likely will dissipate before the morning commute as the front induces drying. After the full fropa occurs early in the morning, expect post-frontal conditions with bright blue skies for the rest of the near-term as cooler, drier air slowly filters into the region. Winds will be breezy, especially near the Blue Ridge Escarpment, but well below advisory criteria. Max Ts will be around or slightly below-climo on Monday. && .SHORT TERM /MONDAY NIGHT THROUGH THURSDAY/... As of 135 PM Sunday: Full latitude upper ridge axis briefly moves over the area Tuesday. The axis moves east Wednesday as an upper low moves into the OH River valley. There is some phasing with this low and a short wave over Canada as the associated trough axis crosses the area Wednesday night. Short wave ridge moves in behind this system on Thanksgiving Day. At the surface, a cold air mass associated with high pressure centered to our north moderates by Wednesday as the center of the high moves off the New England coast and a warm, moist southerly flow develops. Moisture deepens and forcing increases Wednesday afternoon into the evening as an associated cold front moves into the area. There`s also good low level isentropic lift and upper divergence. Precip develops along and west of the Blue Ridge first then spreads east across the area through the evening. Precip then tapers off Wednesday night as the forcing and front move east of the area. Little in the way of instability with this system, so no thunderstorms expected. Doesn`t look like any heavy precip expected with moderate QPF over the mountains and Blue Ridge with mainly light QPF elsewhere. Should be warm and dry on Thanksgiving Day as a dry but moderate air mass moves in. Lows and highs 5 to 10 degrees below normal Tuesday rise to 5 to 10 degrees above normal for Thanksgiving Day. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... As of 240 PM Sunday: Uncertainty remains high in the long term as models continue to have difficulty resolving the developing split upper flow and resulting surface patterns. The GFS shows an initially phased system becoming un-phased, then the southern stream phases with a second northern stream wave by the end of the period. The ECMWF shows a closed low developing over the Southern Plains as the initial northern wave moves east. This low then phases with a second northern stream short wave as it moves into the MS valley. At the surface, the GFS shows a faster weaker cold front moving into the area Saturday and moving to our east Sunday as the phasing takes place. The ECMWF has a strong low pressure system and cold front crossing the MS valley on Sunday. The GFS would suggest precip developing late Friday, containing through Saturday, then drying on Sunday. The ECMWF has a dry Friday, maybe some light precip on Saturday, and a wet Sunday. The GFS ensemble mean seems to favor its operational run, while the Canadian favors the ECMWF. Given the differences and low confidence, have trended toward the guidance blend, but kept any PoP below 50 percent. Show lows remaining above normal through the period with highs above normal Friday then falling slowly to near normal by && .AVIATION /03Z MONDAY THROUGH FRIDAY/... Overall: Abundant cirrus already cover the region ahead of an approaching shortwave; nearer the attendant cold front, low VFR cigs are beginning to fill in as midlevel moisture increases. The front will bring precip mainly to the higher mtn elevations overnight; KAVL may see some cigs possibly down to MVFR, but the small chance of precip only warrants VCSH. The front will scour out low clouds in the morning, leaving mostly SKC for the remainder of the period. Winds will turn NW and gusty across the region following fropa, likely before dawn at all the TAF sites. At KCLT: Prefrontal convergence continues to drive -SHRA SE of KCLT; these likely will continue to track just east of the field. Cigs are rapidly lowering beneath them, such that areas of IFR to LIFR are likely thru the evening. With precip unlikely to actually reach KCLT, there remains the possibility that some of those cigs will advect in later this evening. This has prompted prevailing MVFR and TEMPO LIFR. Outlook: Dry weather expected Tuesday, while increasing clouds and better rain chances enter the region Wednesday into Thursday with next fropa. Unsettled weather could continue after that as we go into the upcoming weekend. Confidence Table... 03-09Z 09-15Z 15-21Z 21-00Z KCLT Med 78% High 86% High 100% High 100% KGSP High 100% High 100% High 100% High 100% KAVL High 100% Med 68% High 88% High 100% KHKY High 100% High 100% High 100% High 100% KGMU High 100% High 100% High 100% High 100% KAND High 100% High 86% High 100% High 100% The percentage reflects the number of guidance members agreeing with the scheduled TAF issuance flight rule category. Complete hourly experimental aviation forecast consistency tables are available at the following link: && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...DEO NEAR TERM...CAC/Wimberley SHORT TERM...RWH LONG TERM...RWH AVIATION...Wimberley
Area Forecast Discussion
National Weather Service Louisville KY
943 PM EST Sun Nov 22 2020 .Forecast Update... Issued at 943 PM EST Sun Nov 22 2020 Surface cold front is just about to exit the state of Kentucky this evening. In its wake, low cloudiness extends back to near the I-65 corridor. Under the clouds, temperatures have dropped into the lower 40s. Skies are scouring out nicely out to our west with the clearing line nearing the I-65 corridor. This clearing line should continue eastward through the remainder of the overnight hours. Where skies have already cleared, temperatures have dropped into the upper 30s across far western KY. For the overnight period, we anticipate skies slowly clearing from west to east. I think we`ll get a little more cloud cover moving back over southern IN later this evening, but that should mostly clear out by sunrise. Some patchy fog will be possible later tonight where skies clear out. Overnight lows dropping into the 32- 38 degree range still look on target. Overall, forecast remains on track. Have made some slight edits to the cloud cover forecast to better align with current IR satellite imagery. Updated products will be available shortly. && .Short Term...(This evening through Monday) Issued at 243 PM EST Sun Nov 22 2020 Latest surface analysis places the surface low center between Cincinnati and Columbus, OH with the cold front stretching SW along the OH River before dipping more southward between HNB and SDF and just west of BWG. Radar continues to show light rain and drizzle along and ahead of the front with rainfall totals so far amounting to around 0.20" north of the OH River and generally less than 0.15" across KY. Quite the temperature drop behind the front with readings behind the front in southern Indiana in the low 40s and mid to upper 50s ahead of the front across much of central and eastern KY. Winds are also picking up just ahead of and behind the front with KY Mesonet showing gusts in the 20-25mph range across much of the area. Latest hi-res guidance pushes the bulk of the rain associated with the front out of our eastern counties by around 23/00Z, but RAP model soundings continue to show potential drizzle for a couple of hours behind FROPA. Expect to see lingering low clouds through the overnight period and into most of the morning, especially along and east of I-65, until dry air aloft is able to mix down Monday afternoon. Did add mention of patchy fog across portions of our western CWA that could result from early clearing overnight, but variable cloudiness should keep any widespread dense fog from occurring. With that said, expect Monday to start off cloudy with morning min temps bottoming out in the low to mid 30s. Lingering cloud cover could delay diurnal warming a bit, so decided to back off of max temps a bit with highs in the upper 40s across southern Indiana and in the low 50s across the Commonwealth. But again, do expect most to see some sunshine at some point Monday afternoon as high pressure builds in across the region. .Long Term...(Monday night through Sunday) Issued at 245 PM EST Sun Nov 22 2020 Quiet wx expected Mon night and Tue under shortwave upper ridging. Developing southerly flow on the back side of sfc high pressure will allow Tuesday highs to climb just above normal even in the face of increasing cloud cover. By Tuesday night southerly flow develops through a deepening layer ahead of strong low pressure over the Plains. We`ll stay dry through the evening, but expect precip chances to ramp up before daybreak Wednesday, especially west of Interstate 65 as a strengthening low- level jet edges closer. The low will be vertically stacked but still fairly potent as it tracks across northern Illinois and Indiana on Wednesday. Low-level jet cranks up to 60-65 kt, so gusty winds are a good bet. What is more uncertain is any severe wx potential, as it will be a strongly sheared sounding with long and looping hodographs, but little or no sfc-based instability. Will not play up the severe threat just yet, as surface-based storms still appear unlikely, but this bears watching over subsequent forecast cycles. Have gone with categorical POPs on Wednesday, but this system is progressive enough that QPF will average a half to less than 1 inch. Thanksgiving Day looks dry with seasonable temperatures, but beyond Friday model solutions start to diverge a bit. Split flow will set up, and the pattern will eventually amplify an upper trof over the eastern CONUS, but sensible wx and timing will both depend on the degree of phasing between the northern and southern streams. ECMWF is more phased, and therefore slower and potentially colder, while the GFS is more progressive with less phasing between the streams. Bottom line is we will have a system this weekend, but the timing and nature of that are in doubt. Will carry chance POPs both Sat- Sun, and those will likely increase as we narrow down the time period. All of the significant precipitation will be rain, though that could prove to be quite a cold rain if the more amplified solution verifies. There will be mention of rain/snow mix for parts of the area Sat night/Sun morning, but any flip to snow would mean the environment supports less QPF, so little or no impact is expected. && .Aviation...(00Z TAF Issuance) Issued at 555 PM EST Sun Nov 22 2020 Surface low continues to push off to the northeast while surface cold front continues to move eastward across eastern Kentucky. In the post frontal wake, low clouds will remain in place even though drier is working in. We`ll see the cloud continue into the overnight hours as the moisture remains trapped under a temperature inversion. Latest guidance is a little more optimistic on these low clouds mixing out late tonight, so have cautiously trended the forecasts in that direction. Depending on how much clearing takes place, fog could be an issue as well. Current guidance suggests that KHNB/KLEX would have the best threats of at least some MVFR fog overnight (23/08-12Z roughly). After 23/12-13Z, VFR conditions are expected for the remainder of the TAF period. Winds this evening will remain out of the west/northwest and will be gusty at times. We expect the winds to diminish towards late evening and overnight. Winds look to veer back to the west and southwest for Monday. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Update.......MJ Short Term...CG Long Term....RAS Aviation.....MJ
Area Forecast Discussion
National Weather Service Memphis TN
815 PM CST Sun Nov 22 2020 .DISCUSSION...02Z Surface analysis places a cold front from East Tennessee back through Northern Alabama and into Central Mississippi. Rain ended just before sunset and GOES-16 satellite trends indicate post frontal stratus quickly pushing to the south with clearing skies north of I-40 thus far. Will be doing another update to decrease cloud cover more rapidly for the remainder of the night and make a few minor adjustments to temperatures. Updated grids will be published shortly. CJC && .PREV DISCUSSION... /issued 613 PM CST Sun Nov 22 2020/ UPDATE... See aviation discussion below. PREV DISCUSSION... /issued 332 PM CST Sun Nov 22 2020/ DISCUSSION... A more typically progressive late November weather pattern has returned, after a recent extended dry period. Active pattern notwithstanding, dry and mild conditions appear on track for Thanksgiving Day. For the short term, a cold front and accompanying showers will exit northeast MS through late afternoon, as an upper trof over the Ozarks lifts to the lower/mid MS River valley. Primary short term forecast concern will be cloud trends, which will impact overnight temperatures and fog potential. NAM and RAP soundings concur with HRRR ceiling progs showing a complete dissipation of of low clouds overnight at all but northeast MS. GOES East visible imagery showed developing breaks in the low clouds over east central AR and southern MO. Post-frontal cool season stratus often persist for days over the Midsouth, but it appears that sufficient drying will occur in the lowest 2kft for some clear spots to develop, and perhaps expand even after sunset. Official grids won`t go full clear as NBM and and short blends suggest, but will reflect some clearing and patchy fog. Fair weather will prevail Monday, under low amplitude ridging. By Tuesday morning, an upper low will drop into the 4-corners region. A low level warm sector will develop over the southern plains and translate east with the the deepening upper low. By midnight Tuesday night, the upper low will lift into northeast KS. An associated surface cold front will likely hang across the western Ozarks, until a shortwave trof ejects through the Ozarks early Wednesday morning, taking the front east with it. For the Midsouth, prefrontal elevated showers and thunderstorms are expected late Wednesday evening, mainly along and west of the MS River. GFS depicts only modest 0-1km MUCAPE of 200 J/KG at 9Z/3 AM. This narrow band of instability will lift east of the MS River after sunrise Wednesday, along and ahead of the cold. A post sunrise bump MUCAPE to around 750 J/KG may develop over northeast MS (beyond the SPC Day 3 outlook period) suggestive of some strong wind potential. Rain should exit the TN River valley by late Wednesday afternoon, with fair conditions prevailing Thanksgiving Day. Expect some increase in high clouds during the day, in advance of the next rain event on Friday. Model timing with this next system remains a bit scattered, due to its potential to cut-off from the main westerlies. The main take-away is that unsettled weather will be possible over the Midsouth through the upcoming weekend. As we get closer in time, model consensus should improve, helping to better pinpoint weekend rain timing. PWB && .AVIATION... 00Z TAFs Expect MVFR conditions to prevail through the early evening hours. Some improvement is expected throughout the overnight hours and we should be mostly VFR by daybreak at all sites. Winds will shift to the north, but should diminish over the next few hours. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion
National Weather Service Marquette MI
645 PM EST Sun Nov 22 2020 .SHORT TERM...(This evening through Monday) Issued at 319 PM EST SUN NOV 22 2020 Latest satellite imagery at 1930Z shows the slowly rotating upper low over NW Wisconsin. At the surface, the surface trough boundary is approximately near the Wisconsin and Upper Peninsula of MI border. MSAS analysis has the surface cold front draped from International Falls, WI southward to Sioux Falls, SD. The frontal boundary will slowly propagate toward the CWA as the afternoon and evening progresses. Surface obs are showing a gradual transition from BKN to OVC skies from Ironwood earlier this morning eastward toward the rest of the CWA, with snow showers also occurring there. Radar is beginning to get scans of the snow showers slowly to the northeast the last couple of hours. Temperatures have been hovering around the freezing mark or slightly below that threshold. As the broad swath of precip continues to move east, it is lightly to have a rain/snow mix and/or become light rain showers from MQT eastward due to the lowest layer of the atmosphere having a greater than 2Kft warm layer above freezing and melting the frozen precip to liquid. BUFKIT soundings show that after 0Z tonight, the column begins to dry out for CMX/IWD/MQT, with MQT having slightly moistened layer to about 3Z. From this point, CAA from the upper and mid-level of the atmosphere will certainly help keep the area below freezing overnight, but there will also be dry air infiltrating into the area. Northwest winds will begin to ramp up overnight, especially over the marine areas of Lake Superior with gusts over 30 knots possible, 15 to 25 knots over land. While there may be dry air aloft, Hi-Res guidance from the HRRR is hinting at surface convergence of winds over the Lake Nipigon area overnight with a potential snow band developing and reaching the northwest snowbelt areas of Keweenaw and Marquette Counties causing potential orographic terrain enhancement. Snowfall totals over the area look to be minimal however, with amounts in the 1-2 inch range at most over the CWA. It is possible to have a stray 3 inch report over the higher terrain of Marquette/Baraga counties. The potential for light snow showers to continue after 18Z Monday looks pretty low at this time of inspection due to the lowest 100-200mb of the atmosphere drying out through the column. A secondary cold front will propagate over the region between 18Z and 0Z Monday afternoon. This will keep temperatures on the chilly side where temps will likely decrease as the afternoon progresses behind the surface cold front. The sky coverage will decrease from southwest to northeast by late Monday afternoon. Winds should dissipate from west to east by afternoon as well across the CWA where winds will be 10 knots or less by sunset over land. .LONG TERM...(Monday night through Sunday) Issued at 248 PM EST SUN NOV 22 2020 Outside of a nuisance snow event Tuesday afternoon/evening...the remainder of Thanksgiving week looks extraordinarily tranquil with temperatures continuing to average a few degrees above normal. Surface ridge axis will move across the Upper Lakes Monday night with a seasonably cold night expected. Trends continue of northern and southern stream energy phasing looking less and less likely for Tuesday. Better dynamics with northern stream shortwave will stay primarily just north of the area. Warm advection ahead of stronger southern stream system will be the main precipitation driver across the U.P. Tuesday afternoon through the evening. Total QPF amounts of just under .20 inches are expected far west and Keweenaw to perhaps as high as .40 inches over southern Menominee county. This will yield 1-3 inches of sloppy slushy snow inland away from the Lakes. GFS continues to show enough warming Tuesday evening to change all precipitation to some light rain as the precipitation winds down. Temperatures will stay steady or even rise a few degrees Tuesday night. Any lingering light rain/snow mix will move out of the eastern U.P. Wednesday morning. Surface ridging will build over the Upper Lakes by late Wednesday through Thanksgiving day. Another shortwave/weak front will move across the area on Friday but with no appreciable moisture to work with not anticipating any precipitation. Extended models are trying to come in agreement with a brief surge of cold air by the end of next weekend which could temporarily invigorate the lake effect machine. But after that...the pattern looks to return right back to zonal flow with mild temperatures and minimal precipitation chances especially for early December standards. With only 5.1 inches of snow measured thus far this November at our office...a top ten least snowy November is still within reach. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 630 PM EST SUN NOV 22 2020 IFR conditions at KIWD and KCMX in light -shsn early this evening should improve to MVFR late evening/overnight and then to VFR Mon afternoon as high pressure and associated drier air move in from the west. MVFR conditions will persist at KSAW through much of the fcst period in a developing nw-n flow. Winds will become gusty to around 23-28 knots tonight at CMX and IWD, with the highest gusts at KCMX due to local terrain influences. Wind gusts will increase above 20 knots by late tonight/Mon morning at SAW. Winds will then slowly diminish from west to east during the day on Monday as high pressure builds in from the west. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 319 PM EST SUN NOV 22 2020 A slow moving cold front will make its way over the lake tonight bringing NW gusts up to 32 kts tonight into Monday morning. A few gale force gusts will be possible over the eastern half of the lake at times. Winds will dissipate through the remainder of Monday. A new surface low pressure developing over the great Plains of the U.S. will move toward the region by late Tuesday. A few marginal gale force gusts to 35 knots will be possible across the east half of the lake late Tuesday. Winds will diminish back to 20 kts or less for Wednesday and Thursday behind the departing surface low. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...BW LONG TERM...MZ AVIATION...Voss MARINE...BW
Area Forecast Discussion
National Weather Service Topeka KS
454 PM CST Sun Nov 22 2020 ...AVIATION UPDATE... .DISCUSSION... Issued at 338 PM CST Sun Nov 22 2020 Early this afternoon an upper level trough was located along the norther and central MS River Valley. Eastern KS was on the west side of the upper trough axis, with stronger isentropic downglide which has shifted the cloud cover from this morning, east into MO and southeast KS. The insolation was helping temperatures to warm into the mid 50s this afternoon. A low amplitude trough embedded within the southern stream of the mid level jet across southern CA will be kicked, by a more amplified upper level trough digging southeast onto Pacific northwest and northern CA coastline, northeast into the central Plains on Monday. A lee surface trough will deepen across the high plains Tonight as a surface ridge of high pressure over northeast KS this evening will shift east into MO. Overnight lows will occur from midnight to around 4 AM with temperatures slowly rising through the 30s due to the surface winds becoming southerly across the CWA, along with increasing cloud cover due to weak WAA and DCVA ahead of the minor H5 trough lifting northeast across the central high Plains. A few numerical models show there may be enough ascent along with residual moisture return for light rain or light snow mixed with rain to develop across north central KS between 6 AM and 9 AM. By the time the light precip reaches northeast and east central KS, surface temperatures should be warm enough for light rain. Several of the CAMs shift the weak H5 trough northeast across the central Plains and the better ascent ahead of the H5 trough and isentropic lift will shift northeast across northeast KS and northwest MO by afternoon. Much of the CWA may see a break in the rainfall during the afternoon hours. The cloud cover with periods of light rain will keep high temperatures on Monday in the mid to upper 40s. Monday night, the amplified H5 trough along the western US coastline will dig into the southwestern US. The stronger southwest mid-level flow across the Rockies will cause a deeper lee surface low to develop along the CO/KS border along with a deeper 850mb low across western KS. The strong 850m flow of 40 to 50 KTS will advect richer Gulf moisture northward across the Plains. The resulting isentropic lift will cause widespread showers and perhaps a few elevated thunderstorms to develop. Low temperatures in the upper 30s to mid 40s will occur during the early evening hours with temperatures rising through the 40s overnight due to the stronger WAA. Tuesday, the amplified upper level trough across the southwestern US will move east across the Plains Tuesday night. Stronger DCVA ahead of the upper trough combined with isentropic lift and richer moisture transport will cause widespread showers and scattered elevated thunderstorms to develop. If MUCAPES approach or exceed 500 J/KG, then a few of the storms may produce small hail with some hail reaching over quarter size with any type of mid-level storm rotation. The surface based storms will remain south of the CWA across southeast KS and eastern OK, which will spread northeast into western MO and AR through the evening hours. Tuesday night through Wednesday, as the H5 trough axis shifts east across the state of KS, the surface cold front will move east across the CWA dropping temperatures into the 30s during the evening hours. The ECMWF and NAM show a TROWAL developing within the deformation zone on the northwest side of the amplifying trough, which may become a closed upper low across northeast KS as it shifts northeast across northwest MO. If the TROWAL develops along the NE/KS border, then there may be a period of accumulating snowfall across the northern counties of the CWA through the morning hours of Wednesday. The GFS solutions does not show a TROWAL developing and is less amplified with the upper low. As the upper low shifts east-northeast into northern IL by afternoon, stronger isentropic downglide should clear skies from southwest to northeast across the CWA. the southern counties may see more insolation through the afternoon hours and highs may reach the lower 50s, while the northeast counties will hold on to the clouds longer with highs only in the mid 40s. Thursday (Thanksgiving), looks mild and dry as an upper ridge shifts from the Plains into the east central US. An upper level trough will move onshore across the western US and dig southeast into the Southwestern US. The northern stream branch of the H5 trough will move east into the northern high plains. Skies will be mostly sunny with highs in the mid to upper 50s. Thursday night through Friday night, the northern branch upper level trough will move east across the northern Plains Thursday night. The resulting low-level CAA will cause a surface front to push southward across the CWA late Thursday night into Friday morning. Northerly winds will drop temperatures back into the upper 40s to lower 50s. On Friday, a surface ridge of high pressure will build southward across KS. The southern stream H5 trough across the southwestern US will amplify into a closed upper low as if shifts east into the southern high plains. At this time any precipitation will remain well south and southwest of the CWA. Saturday through Sunday, The 00Z run of the ECMWF kept the upper low well south across TX but the 12Z run lifts the upper low east-northeast across OK into south-central MO, much like the solution from 24 hours ago. If the 12Z ECMWF were to verify light rain would develop Saturday evening and as the upper low moves east- northeast across OK, vertical temperature profiles would cool enough through the night for the rain to change over to snow, and the snow may continue into Sunday. Based on the 12Z ECMWF track of the upper low, the best chance for measurable snowfall would be along and southeast of the KS turnpike. The 12Z Canadian model is in good agreement with the 12Z ECMWF. There still remains a lot of uncertainty with how the upper low will develop over time and its track. The GFS keeps a positive tilt H5 trough across the center of the country with no amplification of the southern stream trough. If the GFS solution were to verify it would lead to a dry and cool forecast. Highs on Saturday will probably reach the upper 40s to lower 50s. Highs on Sunday may be in the 30s if the ECMWF and Canadian model solutions verify. If the GFS verifies then highs on Sunday will once again be in the upper 40s to lower 50s. Stay tuned to the latest forecast since Sunday is usually a high volume travel day to end the Thanksgiving Day weekend. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday) Issued at 454 PM CST Sun Nov 22 2020 Increasing warm air and moisture advection is expected to bring some mid level clouds over the terminals late tonight. RAP forecast soundings show quite a bit of low level dry air through a good portion of the day, so CIGS are forecast to remain VFR. Models showing some QPF developing by the late morning. Given the dry layer around 850MB, any precip may be more along the lines of sprinkles. So may only mention of VCSH for now with any precip causing minimal impact. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...Gargan AVIATION...Wolters