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Winter storm for the 25th of February is imminent.


Typhoon Tip
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10 minutes ago, SnowGoose69 said:

The SPC HREF mean sure seems to be something between the NAM and RGEM based on snow amounts...no doubt its indicating the Euro is probably out to lunch

 

 

The HREF is a 10 member ensemble which includes the previous (most recent) two runs of the HiresW (2 different versions - I'm assuming it's the HRW-ARW and the HRW-ARW2), FV3, 3km NAM, and and HRRR (for the conus only). I think the model runs at 18UTC might be skewing the mean. If it warms up or stays consistent by its next cycle, then I'd agree with you.

Correct me if I misread it: https://nomads.ncep.noaa.gov/txt_descriptions/HREF_doc.shtml

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I'm letting my weenie out. Someone mentioned it a little while ago, but the RAP is quite bullish for snowfall accumulations. The image below is using its imbedded SLR algorithm (computed between PBL time-steps) which is a conditional function of hydrometeor type (ice densities for snow and sleet is calculated separately then weighted as one) and the lowest model layer's air temperature. I like the spatial extent of the accumulations, but the magnitude is too high imo...

image.thumb.png.f2641fd9612f779c7fa76af5a589e74f.png

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29 minutes ago, WinterWolf said:

But That can go both ways too. You’re gonna be/your area is the winner in this I believe.  
 

Depending how quickly the sleet comes in..will be the difference here between 6” or   8+” here.   Never expected pure snow. But that high means business this time…it’s stout and entrenched.  

I agree the NAM was crap...all I mean is some of the other guidance will tic north and compromise some. I think the south trend is done, save for the NAM.

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3 minutes ago, MegaMike said:

I'm letting my weenie out. Someone mentioned it a little while ago, but the RAP is quite bullish for snowfall accumulations. The image below is using its imbedded SLR algorithm (computed between PBL time-steps) which is a conditional function of hydrometeor type (ice densities for snow and sleet is calculated separately then weighted as one) and the lowest model layer's air temperature. I like the spatial extent of the accumulations, but the magnitude is too high imo...

image.thumb.png.f2641fd9612f779c7fa76af5a589e74f.png

What is up with the ATARI graphics..

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I actually prefer the RAP over the NAM. I conducted research on analysis data and found that the NAM tends to overestimate moisture related fields at initialization. I hate to self promote my videos, but here's the evaluation I conducted (February-2020) on numerous analysis/reanalysis datasets. If you scroll to the end of the video, note that the box and whisker plots are skewed to the right for moisture related fields (radiosonde plots). I imagine that these problems plague forecast simulations as well (for the NAM).

 

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2 hours ago, MegaMike said:

I actually prefer the RAP over the NAM. I conducted research on analysis data and found that the NAM tends to overestimate moisture related fields at initialization. I hate to self promote my videos, but here's the evaluation I conducted (February-2020) on numerous analysis/reanalysis datasets. If you scroll to the end of the video, note that the box and whisker plots are skewed to the right for moisture related fields (radiosonde plots). I imagine that these problems plague forecast simulations as well (for the NAM).  

That is Amazing Work MegaMike!  Can't imagine How many hours it took JUST to come up with the plan of what you'd do, let alone go through with it.  And Glad to know the Rap is better.  

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6 minutes ago, Sey-Mour Snow said:

I’d love nam to verify - the melts would be epic doesn’t change much here sleet storm 2022

I’m just so tired of weenies trying to shove it back into our faces when we try to actually use our experience with these and warn about risks to the warmer side. 
Euro looks to be too cold right now and has been. NAM still may be aggressive, but honestly it hasn’t had a whole scale change and if anything got warmer at 6z. So that means something, even if it’s too aggressive.

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11 minutes ago, CoastalWx said:

I’m just so tired of weenies trying to shove it back into our faces when we try to actually use our experience with these and warn about risks to the warmer side. 
Euro looks to be too cold right now and has been. NAM still may be aggressive, but honestly it hasn’t had a whole scale change and if anything got warmer at 6z. So that means something, even if it’s too aggressive.

It took longer than expected but the north shift is here! NAM is starting to be concerning bc it's not doing the normal nap flip flop HREF and RGEM are warm as well.. It's really GFS EURO and HRRR vs the NAM and RGEM

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  • Typhoon Tip changed the title to Winter storm for the 25th of February is imminent.
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