Here's a combo you rarely see put together; -Wind Gust Potential-I start at 30 Knots & up (55k/hr.+) -SFC Visibility (in Miles) -I only plot 5 miles or less Grey blobs=Visibility, Orange/Red blobs=Wind Gusts >30kts-1knot=~2k/hr. Colour scale for both at the top. #onwx #onstorm

Hot off the computational press-Latest 0Z HRRR48 -"Just the total snowfall" (in inches) from now till Monday 7PM,-mainly all system snow but there will be some LESnows development for a short while off L. Huron, maybe G.Bay on the backside of the departing Low. #onwx #onstorm

7pm EST (00Z) Synoptic "Snapshot" of the weather for S. Ontario. #onwx #onstorm. System seems to be moving a bit faster/concerned about the up-tick the NBM has-(5pm run)-the NBM is no slouch. Still think there will be mixing along shorelines. ECCC alerts: shorturl.at/rP3t9

7pm EST (00Z) Synoptic "Snapshot" of the weather for N. Ontario. #onwx #onstorm Variable amounts of cloud still the risk of the odd light flurry, more active snow wise in S. sections of NEONT. Much colder night overall in the north.

Latest WPC Winter Snow Guidance (in inches) -overall overview for SONT-Just used the 50th percentile-"what is expected", and the 75th percentile (if it overachieves a bit) Colour scale is at the top in inches *1"=~2.5cm from 7PM tonight-thru. 7PM SUN. #onwx #onstorm

Approx. timing of colder air-“cross-section approach” (Temp C). Now thru Dec/9. N-S line: -Timmins-Sudbury-Barrie-Toronto (reviewed) Several shots of colder air-more significant in NONT-"if” the storm track shift’s further south-may see more colder air intrusions into SONT #onwx #onstorm

Latest aft. run of the HRRR48 -Radar 4cast-and in it's wake-"the snow trail" left behind (blue/purple fill) (Snow in inches *HRRR only-Scale is on top. 1"snow=~2.5cm) Probable mixing (RA/wet SN) along the Northern shorelines #onwx #onstorm some LESnows do pop up after passage.

Some estimate of snowfall (in cm) till from now till 7PM Sunday. (using the CAN, NBM and the SREF ens. mean) #onwx #onstorm

Latest hourly run of the HRRR model-Radar 4cast-(P-type) from now till 1AM Sun. periods of snow enter SWONT later this evening and works it's way across the rest of SONT thru the day Sunday. #onwx #onstorm

Latest Regional radar loop/trend, 6hr. history,-till 8:40 AM EST. LESnows are weakening and our next system to invade SONT is to the west, and enter SWONT later this evening. #onwx #onstorm

7am EST (12Z) Synoptic "Snapshot" of the weather for S. Ontario. #onwx #onstorm Variable mix of sun/cloud, with risk of a few flurries. The LESnows have weakened as the winds continue to slacken and change direction.

7am EST (12Z) Synoptic "Snapshot" of the weather for N. Ontario. #onwx #onstorm Variable sun/cloud mix overall, colder, risk of a few scattered flurries.

Looking at the general pattern trends, and by no means will this will play out as is,-but the CAN/Euro want to shift the main storm track a bit further south, which would increase the risk of Clipper type storms (increasing LES) and a colder air regime for SONT #onwx #onstorm

Looking at the various "Precipitation Type" 4casts (several model suggesting some mixing) along the N. shores of L. Erie/ONT. -but before that happens-many hrs. of snow first,-then the risk of mixing.-rn I prefer the 0Z NAM3k solution. #onwx #onstorm Loop:Sat.-7PM-SUN MidNite

Looking at the SREF ens. probabilities % to get a better idea of tomorrow Low moving into SONT (Sat. eve. thru late Sun.) and the amount of snow it may deliver, late aft. run (21Z) of the SREF. #onwx #onstorm

Better late than never...OY! 7pm EST (00Z) Synoptic "Snapshot" of the weather for S. Ontario. #onwx #onstorm Current ECCC SONT alerts can be found here; shorturl.at/E7b24 added the snowfall rate loop cm/per hr. for the overnight till 7 AM Sat for SONT (attached)

Better late than never...OY!...🫤 7pm EST (00Z) Synoptic "Snapshot" of the weather for N. Ontario. #onwx #onstorm

Quickly/crazy busy. Latest HRRR Radar 4cast~now till Sun.-1PM. The underlay image is WPC' s latest snow guidance-7pm tonight-Mon. 7PM -kept it simple & at the 50th Percentile-"What's expected" in the swath of snow (in inches, 1"snow=~2.5cm)-then a quick probe scan 4 amounts. #onwx #onstorm Later👋

...and here comes our weekend weather maker🙄😒❄️... (besides the big ole LESnows) Latest hourly run of HRRR Radar 4cast + SFC Vis (less than 5 miles)-from now till midnight. ...Have to run🫤busy day🏎️👋. Have a good safe Friday. #onwx #onstorm

7am EST (12Z) Synoptic "Snapshot" of the weather for N. Ontario. #onwx #onstorm LE squall continue for most of the day, elsewhere scattered flurries from the debris of those squalls. Snowfall rate loop cm/hr. from now till midnight (attached). Current ECCC alerts👉 tinyurl.com/598kjbpy

7am EST (12Z) Synoptic "Snapshot" of the weather for N. Ontario. #onwx #onstorm Variable cloud in NWONT with a few scattered flurries. More cloud and more snow flurries/periods of light snow in NEONT-added snowfall rate cm/per hour (attached) - now till Midnight. Have a good safe day!

Radar "foot print" of the snowfall that the squalls left behind-as of 7 AM. Numbers (inches) are water equivalent, melted down, numbers are OK to ball park, but Snow is much harder to capture good data. Will leave that to the wx observers/spotters on the ground . #onwx #onstorm

Current Radar + SFC Visibility (less than 5 miles-grey blobs) loop/trend, last 6 hours history till 6:45 AM EST. Those squalls have been going hard most of the overnight, with a slight sink to the south and minor realignment. #onwx #onstorm

Latest WPC Winter Snow Guidance (inches) overview for most of SONT. Just used the 50th percentile-"what is expected" -some spot values. Colour Scale on top in inches👉 1”=~2.5cm -4cast out 24 hrs. 7PM tonight thru to Fri. 7PM. #onwx #onstorm Always follow ECCC Alerts/guidance

Latest hourly run of the HRRR model -Radar 4cast (Winter mode) + SFC Visibility (less than 5 miles (or ~8 km) Very intense LES underway and will probably intensify as the flow in the lower boundary layer smooths out, that helps the LE become better organized) #onwx #onstorm

7pm EST (00Z) Synoptic "Snapshot" of the weather for S. Ontario. #onwx #onstorm full-fledged LES event underway, they should get stronger as the evening progresses into overnight. ECCC current SONT alerts can be found here; ow.ly/MqmI50XypNw Stay Safe!

7pm EST (00Z) Synoptic "Snapshot" of the weather for N. Ontario. #onwx #onstorm Snow and flurries dominate and continues in the the north on the back side of the departing Low. ECCC alerts are still active-ECCC alerts can be found here: ow.ly/QRPI50XypJA

Long day😫, making din's - One quick Radar update for SONT. LES is in full swing across the traditional snow belts and reaching a bit further at this hour. #onwx #onstorm

Updating the “Holy Trinity “sites for LES this week-and beyond (Goderich-Mount Forest-Stratford) in SWONT-snow plume’s from the CAN ens. 12 Z -to see how the members r doing. Blue line=model control, Green=Mean. From ~now - Dec. 13. #onwx #onstorm (~1mm of QPF=~1cm❄️approx.)

Current Eastern Lakes radar loop/trend, past 6 hrs. till 8:15 AM EST-added current SFC Visibilities analysis (grey blobs) less than 5 miles (~or 8km) #onwx #onstorm. ...gotta run🏎️ later👋 have a good, safe day!

Latest hourly run of the HRRR -Radar 4cast (P-type) till Midnight for SONT, some very intense LES bands crossing the region. Stay Safe! #onwx #onstorm

7am EST (12Z) Synoptic "Snapshot" of the weather for S. Ontario. #onwx #onstorm Flurries & snow squalls overall, windy with blowing/drifting. ECCC New Alert system info & current SONT alerts can be found here- ow.ly/MqmI50XypNw added cm/per hr. snowfall rate till Midnight. (attached)

7am EST (12Z) Synoptic "Snapshot" of the weather for N. Ontario. #onwx #onstorm Overall cloudy, windy and scattered flurries the periods of snow will continue in the N. regions of NEONT. ECCC New Alert system info and current NONT alerts can be found here; ow.ly/QRPI50XypJA

" An oldie but a goodie" - still one of my fav's 😅 (taken from my MTO road weather training course notes/PPT) #onwx

...eessshhh...just look at that storm track...out thru Dec. 6th...for now. Target zone - Great Lakes. #onwx #onstorm

...that's right...get used to seeing this👇 the next few weeks. #onwx #onstorm -Drive safe, -Be Safe, -Stay Safe!

NBM Thunder Guidance still hinting, or trying to "sniff" out the odd bolt⚡️ in the more intense squalls -again, it's very low risk...we'll see...but would not be surprised to see a few bolts pop up on my display #onwx #onstorm

Fresh hourly run of the HRRR model -Radar 4cast (P-type) for the overnight thru 1PM Thurs. Multiple, strong and long LE squalls are very evident across the snow belts By tomorrow morning. #onwx #onstorm

Current Radar loop/trend for most of Ontario, last 6hr. history till 8:20 PM EST. showers still continue in extreme EONT, while Snow Squall begin to develop off L. Huron at this hour. #onwx #onstorm

7pm EST (00Z) Synoptic "Snapshot" of the weather for S. Ontario. #onwx #onstorm Strong winds, and scattered flurries thru-out SONT in the overnight, LES begin to develop off the lakes. ECCC New Alert system info and current SONT alerts can be found here; ow.ly/MqmI50XypNw

7pm EST (00Z) Synoptic "Snapshot" of the weather for N. Ontario. #onwx #onstorm Snow and blowing snow will continue in the overnight for Eastern regions of NWONT and most of NEONT. ECCC New Alert system info and current NONT alerts can be found here; ow.ly/QRPI50XypJA

Latest WPC Winter Snow Guidance (in inches). Just an overall overview of their thinking this AM. Just used the 50th percentile-"what is expected"-Colour Scale on top-in inches. 1”=~2.5cm -4cast 7PM Wed-Sat. 7PM. #onwx #onstorm (Again-follow all ECCC alerts & Guidance) Stay Safe!

Very quick update on cold front location as of 1 PM EST. using re-analysis (WPC lagged) -latest Ob's, and Radar and regional SONT Satellite Image (all taken a few mins of the 1 PM Ob's ingestion) #onwx #onstorm

Latest Radar loop (P-type) + Max Wind gusts (in mph) from various weather stations across the US/CAN. Last 6 hrs. playback -till 11:41 AM EST. #onwx #onstorm you can see that front just march across SWONT entering the GTAH now. (Colour fill=wind field analysis)

Thought I'd throw this on the pile-Overnight HRRR48 "Graupel production" values -since intra-cloud lightning is tied to this (graupel helps) areas of darker lime green/yellow colours thru red have a better chance of sparking a bolt⚡️ here & there. #onwx #onstorm have to run🏎️👋

Current Regional Great Lakes Radar (P-type) loop/trend, 6hrs. history till 8:16 AM EST (added SFC Visibility less than 5 miles analysis-the light grey blobs) NECEP/WPC frontal locations are lagging,- very dynamic system. #onwx #onstorm

7am EST (12Z) Synoptic "Snapshot" of the weather for S. Ontario. #onwx #onstorm Fog was extensive in the overnight till this AM. Active day thru-out Ontario, a plethora of ECCC alerts, please check your location with ECCC alerts web page, and follow their warnings/guidance

7am EST (12Z) Synoptic "Snapshot" of the weather for N. Ontario. #onwx #onstorm Periods of snow and blowing snow. Main areas SW-NWONT thru mid- NEONT. ECCC Alerts issued earlier have not changed much, Always follow ECCC alerts/guidance -Please check their Alerts web page for all current Alerts.

Latest 0Z (HRRR48) reduced street level horizontal "Visibility" 4cast (in miles) -due to weather (rain/snow/blowing snow, etc.) I only plot significant values of 5 miles or less VIS. #onwx #onstorm Sure fit's the LE squalls nicely & the reduced Vis underneath & around them.

Latest HRRR48 0Z run-Wind gust potential (in knots) the loop runs from 11PM this this evening thru to Thurs. 7PM. The deep oranges/red colours you're in the 40+ knots range (or upper 70's k/hr.) Brown's r around 50knts (~90k/hr.) #onwx #onstorm (scale on top in knots)