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The feb 4-5 storm (Obs/Discussions)


Ji

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gfs has more interaction in the streams than the nam and a considerably better solution qpf wise. i'd be tempted to think it's more right tho some blend probably still best.

Yea was doing a side by side comparison to 18z and 12z and I liked the earlier stream interaction. I wouldn't discount the NAM because we may get absolutely nothing out of this system, but there is minimal guidance taking a certain side yet were so close to the storm. One does wonder the meaning of the lower res ensembles being much more agressive for us, but that happens with operational models all the way up until the storm, so for us to say it is going to trend to them simply because they are showing something different is not a guarantee, something which dtk would likely agree with. All and all though, 0z is an improvement from the last run and gives us a bit of a bone to come back for some more model watching.

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Yeah. Looks like 0.35? So how is this going to work? Starts raining at 2-3pm tomorrow and rains all night and then stops? So when I walk outside at 1am it will be raining?

it's still more agressive than the euro tho and the nam moved sorta toward the euro. ee rule? i don't think we change over till after midnight here and it could be closer to morning. even if it snows we might only get down to like 34-35?

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it's still more agressive than the euro tho and the nam moved sorta toward the euro. ee rule? i don't think we change over till after midnight here and it could be closer to morning. even if it snows we might only get down to like 34-35?

Steady light snow at 34 at night accumulates. I'm going to ignore BL issues.

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uh.....we *do* get snowstorms down here. "Awesome" is probably not the appropriate adjective to describe what our best case scenario is.

ha. i set my initial response invisible after posting it. was not that diplomatic.

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Waiting for a met or ddweatherman to tell me how deep the freezing layer has to be to get -sn. 925mb? 950?

You probably want it down to 0C at about 950mb...though 925mb will work if the precip is coming down pretty hard...this is what to look for on a sounding, not what actually happens...usually the model sounding will have the 0C wetbulb a little too high if the precip is coming down well.

The GFS has the wetbulb 0 height at 928mb at 06z and down to 956mb by 12z Sunday...so if its pretty close to accurate, you'd likey flip to snow sometime after 06z...or even around 06z is the precip is coming down good...but the latter component could be an issue.

The NAM is actually quite similar but it has a steeper lower level lapse rate below the wetbulb height...I'm not sure if that's correct, but it would make it tougher if it was.

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You probably want it down to 0C at about 950mb...though 925mb will work if the precip is coming down pretty hard...this is what to look for on a sounding, not what actually happens...usually the model sounding will have the 0C wetbulb a little too high if the precip is coming down well.

The GFS has the wetbulb 0 height at 928mb at 06z and down to 956mb by 12z Sunday...so if its pretty close to accurate, you'd likey flip to snow sometime after 06z...or even around 06z is the precip is coming down good...but the latter component could be an issue.

The NAM is actually quite similar but it has a steeper lower level lapse rate below the wetbulb height...I'm not sure if that's correct, but it would make it tougher if it was.

NAM is dry-adiabatic in the lowest levels... with precip falling on the north side of a warm front, I find it incredibly hard to believe that it would be that warm at the surface.

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NAM is dry-adiabatic in the lowest levels... with precip falling on the north side of a warm front, I find it incredibly hard to believe that it would be that warm at the surface.

Yeah it did look a bit extreme...esp with that north wind draining down. Looks more like a sounding you'd see with a wind off the water.

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You probably want it down to 0C at about 950mb...though 925mb will work if the precip is coming down pretty hard...this is what to look for on a sounding, not what actually happens...usually the model sounding will have the 0C wetbulb a little too high if the precip is coming down well.

The GFS has the wetbulb 0 height at 928mb at 06z and down to 956mb by 12z Sunday...so if its pretty close to accurate, you'd likey flip to snow sometime after 06z...or even around 06z is the precip is coming down good...but the latter component could be an issue.

The NAM is actually quite similar but it has a steeper lower level lapse rate below the wetbulb height...I'm not sure if that's correct, but it would make it tougher if it was.

thanks...It actually looks like we get a nice thump after 6z on the GFS...conceivably we could get some accumulation even with a surface temp of 34 or so

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So is that good or bad news?

more bad than good...It's dry..though I thought it looked better at 500mb.....but the general idea is the same...precip starts at 2-3pm and ends 8-9am....after a little thump late afternoon we manage to get around ~0.08"!! of QPF in 12 hours...I don't know...spitting rain and tons of lulls?.....whatever

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I really think getting snow tomorrow night is more for morale than anything else-- to "prove" to ourselves that the rest of this winter is not going to be a shut-out. Widely spaced, but still existing, snowfalls (even the ones that don't stick well) help us keep the hope that something like a 3/09 will come along down the road.

For me outside of the beltway, just having a grass accumulation on Sunday morning will be enough to keep me still optimistic that something better will happen...

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It did cool noticeably at the surface...so might give a better chance for light snow even if precip is limited.

looks like we waste over 50% of our bountiful QPF in the 1st few hours, leaving us with a snow that in an ideal temp situation would fall at a rate of 1"/15hrs

I can't even conceive of what radar will look like...probably pathetic....maybe we can get a band or something at some point

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I really think getting snow tomorrow night is more for morale than anything else-- to "prove" to ourselves that the rest of this winter is not going to be a shut-out. Widely spaced, but still existing, snowfalls (even the ones that don't stick well) help us keep the hope that something like a 3/09 will come along down the road.

For me outside of the beltway, just having a grass accumulation on Sunday morning will be enough to keep me still optimistic that something better will happen...

I'd like to see some flakes flying tomorrow before bed.....I still like the idea of a relative "over-performer"....I'm calling for 0.5" IMBY to push me over 2" for the season

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