WINTER WEATHER
description
Transcript of WINTER WEATHER
![Page 1: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/1.jpg)
WINTER WEATHER
• FORECAST PROBLEMS INCLUDE:– SNOW– ICE– STRONG WINDS
![Page 2: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/2.jpg)
Scenes from a massive pile-up
![Page 3: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/3.jpg)
Scenes from a massive pile-up
![Page 4: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/4.jpg)
Deaths, injuries …
![Page 5: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/5.jpg)
Destruction
![Page 6: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/6.jpg)
Blame it on the ….…
![Page 7: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/7.jpg)
01-07-04
The number of people dead in a massive pileup of more than 50 cars on Interstate 80 rose to six Wednesday as police and rescue crews finished combing through about 3,000 feet of wreckage. The accident -- involving at least 50 vehicles, 30 of which were tractor-trailers -- happened around 11 a.m. Tuesday. A snow squall caused a whiteout on I-80 near the Milesburg exit, just east of Bald Eagle Creek.
![Page 8: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/8.jpg)
At least six people were killed and dozens injured Friday in a massive pileup snarling miles of I-80 during a heavy snow squall.State police at Lamar said the accident occurred shortly before 1 p.m. when whiteout conditions apparently caused more than 50 vehicles to rear-end one another in the westbound lanes at mile marker 186 near Loganton."You couldn't see in front of you, it was a whole mess of cars," Frank Valley of Massachusetts, who was involved in the wreck here, told the Williamsport Sun-Gazette. "You couldn't avoid it, you just had to get into the pile."
12-29-01
![Page 9: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/9.jpg)
WINTER WEATHERSNOW CLIMATOLOGY
![Page 10: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/10.jpg)
WINTER WEATHERSNOW CLIMATOLOGY
![Page 11: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/11.jpg)
WINTER WEATHERSNOW CLIMATOLOGY
![Page 12: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/12.jpg)
TERRAIN AND PRECIPITATION
80” 60”
40”20”
![Page 13: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/13.jpg)
WINTER WEATHERSNOW CLIMATOLOGY
![Page 14: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/14.jpg)
WINTER WEATHER
• TYPES OF SNOW STORMS– SYNOPTIC-SCALE
• Classic Cold Conveyor (i.e. ‘Noreaster)• Overrunning (Strong cyclone, Alberta clipper)• Jet streak
– MESO-SCALE• Lake-effect• Oragraphic• Convective
![Page 15: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/15.jpg)
WINTER WEATHER
The “Classic” Cold Conveyor Snowstorm
![Page 16: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/16.jpg)
WINTER WEATHER
->>> Northwest of sfc/850mb low
The “Classic” Cold Conveyor Snowstorm
About 150 miles NW of surface low
About 50 miles NW of 850mb low
![Page 17: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/17.jpg)
WINTER WEATHER
Often yields widespread/ heavy snow
The “Classic” Cold Conveyor Snowstorm
CSI banding - model bias: underdoes amounts - model bias: not far enough to NWDuration
![Page 18: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/18.jpg)
WINTER WEATHERThe “Classic” Cold Conveyor Snowstorm
Narrower FZRA/PE zoneIn Cold conveyor area
![Page 19: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/19.jpg)
SNOW STORMS: TYPES
• Classic Cold Conveyor– Northwest of sfc/850mb low– Often yields widespread/ heavy snow
• These are the 1 to 3’ storms
– Impressive snowfall rates• Often have 1-3”/hr rates
– Narrow FZRA/PE zone – Can yield blizzards
![Page 20: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/20.jpg)
SNOW STORMS: TYPES
• Overrunning– Less accumulation
• Typically 2-6”, can be more
– Shorter-lived snows– Snowfall rates can be impressive
• Can reach 1-3”/hr rates
– Followed by PE/FZRA/RN (Large cyclones)
![Page 21: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/21.jpg)
WINTER WEATHER
Overrunning snowstorm (Strong cyclone)
![Page 22: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/22.jpg)
WINTER WEATHEROverrunning snowstorm (Alberta Clipper)
![Page 23: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/23.jpg)
WINTER WEATHER
• FORECASTING AMOUNTS:– THREE FACTORS
• QPF … How much liquid will fall?• Temperature … Will it be cold enough to snow?
– Critical thickness … 850 0C … soundings
• What will the liquid-to-solid ratio be?
COOL WX website
EWALL
![Page 24: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/24.jpg)
WINTER WEATHER
• FORECASTING AMOUNTS:– QPF:
• Consider CSI if ‘rip roaring cyclone• If max VV occurs where T near -15C … expect higher QPF
– Temperature:• When its precipitating hard, models likely too warm• For coastal cities, model low-level T’s too slow to transition to
colder values when surface flow turns offshore (after being onshore)
– Ratios:• Temperature dependent• Cold conveyor: 8:1 to 20:1• Warm advection (strong cyclone): 7:1 to 15:1• Warm advection (Alberta clipper): 15:1 to 25:1
![Page 25: WINTER WEATHER](https://reader035.fdocuments.net/reader035/viewer/2022070417/568153da550346895dc1cecd/html5/thumbnails/25.jpg)
WINTER WEATHER