HPC thinks up to Des Moines gets in on some of the heavier stuff(not the heaviest of course being on the N edge of this system).
http://www.hpc.ncep.noaa.gov/qpf/p120i00.gif
Weather Thread 1/30-2/2: Possible Major Storm
- Thread starter Iastfan112
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HPC thinks up to Des Moines gets in on some of the heavier stuff(not the heaviest of course being on the N edge of this system).
http://www.hpc.ncep.noaa.gov/qpf/p120i00.gif
You can't use that map.
There is a storm before the one on Tuesday. Half of the precip in the map you linked above comes on Monday from the first wave of stuff from the Northwest.
http://www.hpc.ncep.noaa.gov/qpf/fill_98qwbg.gif
HPC Day 3 would be the one you're looking for for the storm from the south... http://www.hpc.ncep.noaa.gov/qpf/fill_99qwbg.gif
Thanks for the map for the storm from the south. I'm assuming the numbers on it correspond to inches of snow/precipitation predicted?
inches of rain (water) depending on temp it could be 10 inches for one inch of rain. Again depends heavily on temp.
What is the natural range on inches of water for inches of snow? 10-15 inches snow?
I remember seeing it anywhere from 8-20 inches per inch of water. What you've listed is probably close.
So I'm in the 1.75 area. If I understand you guys right, that means ~8-15 inches of snow with temps around freezing? Granted probably this will end up being sleet followed by snow, but still, snowpocalypse. I might have to stock up on groceries because I think they don't believe in snowplows down here.
They are all a part of the same system, the first snows are just warm air advection out in front of the main system in that will be "forming" in Texas. Also in places of Iowa there either won't be a break or it will be very brief between when the WAA ends and the main storm synoptic snow begins.http://www.crh.noaa.gov/bufkit/dmx/nam_kotm.dat A 2 hr break between and on some of the runs on the gfs and nam its shown no break at all.
The GFS and NAM both shifted north at 06z last night to show a track similar to the Euro. Now the NAM has held the same at 12z. The short range RGEM(Canadian) seems to be showing a similar track to the NAM.
Track uncertainty has had one major piece resolved, both pieces of energy are onshore and sampled thus giving both forecasters and the models more certainty on how strong they are. If your in an area currently under a Winter Storm Watch you will likely be upgraded to a Warning sometime tomorrow.
Track uncertainty has had one major piece resolved, both pieces of energy are onshore and sampled thus giving both forecasters and the models more certainty on how strong they are. If your in an area currently under a Winter Storm Watch you will likely be upgraded to a Warning sometime tomorrow.
Yeah, it is extremely dependent on temperature/pressure within the snow growth zone, which is why you see forecasted snow ranges that will be 4-6 inches of difference (i.e. 4-8, 6-12).
Even if you knew it was going to be exactly .75" of liquid equivalent, the difference of a few degrees either direction on what the temperature is 2000-4000m up wherever the snow is being produced can really make a huge difference.
Our heavy wet snows typically are around 6 or 8 inches of snow per inch of water.
The lightest fluffiest stuff can get up to around 25 inches in the extreme cases. (This is the snow we get when temps are really cold aloft.)
Typically, I think the average snow in Iowa is probably around 10 or 12:1, a little lower as you move through March with the heavy wet stuff.
Over or under shooting that ratio is a big part of what accounts for the higher ranges in forecasts.
Well, as doom and gloom as that sounds, the worst is still to the southeast. Over a foot in MO.
I am still a little nervous about actually seeing the huge totals moving into the DSM area. SE Iowa looking better, but this storm seems like a classic trap for forecasting.
It is a beast, but that also means that we are likely to see extremely heavy snow around/north of St Louis, and likely some convective elements and thundersnow in that area.
Plus the low is still pegged to be on a track SE of the ideal track for DSM to see really heavy snow.
What can happen with storms like this is the really intense convective stuff can sort of get in the way and kind of block us out, while the models over-do the Northern extent of the storm.
Plus the arctic high will be trying to dive into the state and pushing northerly winds in that will carry dry air that could fight the northward extent as well. Lots of moving parts here.
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What are the chances this storm keeps pushing North into higher amounts for the Des Moines Area?
While it could nudge a bit more to the north or west its limited due to the strength of the high to our west(its a beast, high 1040's to 1050's mb), and the location of the Polar vortex to our north(just east of Hudson Bay) which acts as a block.
latest models are showing 8-10 inches for DSM. Over on the accuweather.com message boards, someone posted comments from Tom Skilling of WGN and he wrote that Chicago could see "record amounts" of snow out of this storm.
http://www.meteor.iastate.edu/~ckarsten/bufkit/image_loader.phtml?site=kdsm
http://www.meteor.iastate.edu/~ckarsten/bufkit/image_loader.phtml?site=kdsm
