Tracking Another Possible Godzilla Mon-Tues, March 12th-13th

billg315 wrote:Ok, here is my first call Snow Map. This will not necessarily be a case where it goes low to high, west-to-east within the band. It's more a "how close does the low come" scenario where if the low comes closer the higher totals are more likely in the whole band if it's further away the lower totals.
Yellow: 1-3" of Snow;
Blue: 3-5" of Snow;
Pink/Purple: 5-10" of Snow;
Orange: 10-15" of snow;

Bill that is a fantastic map the western edge of the precipitation field and the western edge of the heavy banding will be further west than what models are showing now. It almost always happens when you have a bombing low pressure system near the benchmark

Radz wrote:

CPcantmeasuresnow wrote:

SoulSingMG wrote:Sigh. Wishing on a snow flake...

They have Montauk on the expected snowfall for 8-12 and on the 10% chance on the upper end they have Montauk for 11 inches. That makes no sense.

Maybe taking mixing into consideration...

After the fact Radz I was thinking that.

I suppose the logic is if our areas N went high Probability and received 16-17 inches then Montauk would have mixing or rain concerns.

syosnow94 wrote:

CPcantmeasuresnow wrote:

SoulSingMG wrote:Sigh. Wishing on a snow flake...

They have Montauk on the expected snowfall for 8-12 and on the 10% chance on the upper end they have Montauk for 11 inches. That makes no sense.

It does.  In order for us to reach the upper level totals the storm would be close enough to introduce mixing areas out there.  CMON CP. YOURE BETTER THAN THAT

Yep I did figure that out later.

I'm getting older and slower.

CPcantmeasuresnow wrote:

Radz wrote:

CPcantmeasuresnow wrote:

SoulSingMG wrote:Sigh. Wishing on a snow flake...

They have Montauk on the expected snowfall for 8-12 and on the 10% chance on the upper end they have Montauk for 11 inches. That makes no sense.

Maybe taking mixing into consideration...

After the fact Radz I was thinking that.

I suppose the logic is if our areas N went high Probability and received 16-17 inches then Montauk would have mixing or rain concerns.

Yup, exactly- syos mentioned it too, now lets hope this is the case!!

algae888 wrote:

billg315 wrote:Ok, here is my first call Snow Map. This will not necessarily be a case where it goes low to high, west-to-east within the band. It's more a "how close does the low come" scenario where if the low comes closer the higher totals are more likely in the whole band if it's further away the lower totals.
Yellow: 1-3" of Snow;
Blue: 3-5" of Snow;
Pink/Purple: 5-10" of Snow;
Orange: 10-15" of snow;

Bill that is a fantastic map the western edge of the precipitation field and the western edge of the heavy banding will be further west than what models are showing now. It almost always happens when you have a bombing low pressure system near the benchmark

Thanks Al

SoulSingMG wrote:Hot off the gd press!

That is not going to verify.

as long as frank gives nyc stil a 75% chance of seeing 1 inch of snow cuz i dont see that now

One thing I do worry somewhat about is snow sticking (I know this contradicts what I said earlier today). Temps are only going to hit freezing in many areas around daybreak Tuesday (if then), so it will need to be coming down at a decent clip to stick even without the sun angle issue at night. Then once the sun comes up Tuesday morning accumulation will be hindered in areas where its not heavy or a base didn't accumulate overnight. I'm never good at figuring this issue out so I'll have to just wait and see what happens.

billg315 wrote:One thing I do worry somewhat about is snow sticking (I know this contradicts what I said earlier today). Temps are only going to hit freezing in many areas around daybreak Tuesday (if then), so it will need to be coming down at a decent clip to stick even without the sun angle issue at night. Then once the sun comes up Tuesday morning accumulation will be hindered in areas where its not heavy or a base didn't accumulate overnight. I'm never good at figuring this issue out so I'll have to just wait and see what happens.

If it does not come down at a high enough rate it will not stick to the lower specific heat surfaces during the day. Even it it does, if the rate isn't constant, or the cloud deck is not thick enough, melting will occur between heavier banding such that accumulation is limited. This can be overcome though with a very thick cloud deck and heavy rates, but good luck with the set up as is anywhere except Long Island and parts of Conn...

algae888 wrote:

billg315 wrote:Ok, here is my first call Snow Map. This will not necessarily be a case where it goes low to high, west-to-east within the band. It's more a "how close does the low come" scenario where if the low comes closer the higher totals are more likely in the whole band if it's further away the lower totals.
Yellow: 1-3" of Snow;
Blue: 3-5" of Snow;
Pink/Purple: 5-10" of Snow;
Orange: 10-15" of snow;

Bill that is a fantastic map the western edge of the precipitation field and the western edge of the heavy banding will be further west than what models are showing now. It almost always happens when you have a bombing low pressure system near the benchmark

I say good map but whats with the odd curl in the pink/orange? And you have very western S. westchester in the pink, I would think all of southern westchester Oand not just cuz that would include me lol) would see bout the same Id move the pink to the western boarder, its a fine line though, overall great.

18z GFS further East.

Quietace wrote:

SoulSingMG wrote:Hot off the gd press!

That is not going to verify.

In what way, less or more? So your not buying this is going to happen at all? Noted by your absensce I am guessing the latter. Frank come home LOL we need your input.

Quietace wrote:

billg315 wrote:One thing I do worry somewhat about is snow sticking (I know this contradicts what I said earlier today). Temps are only going to hit freezing in many areas around daybreak Tuesday (if then), so it will need to be coming down at a decent clip to stick even without the sun angle issue at night. Then once the sun comes up Tuesday morning accumulation will be hindered in areas where its not heavy or a base didn't accumulate overnight. I'm never good at figuring this issue out so I'll have to just wait and see what happens.

If it does not come down at a high enough rate it will not stick to the lower specific heat surfaces during the day. Even it it does, if the rate isn't constant, or the cloud deck is not thick enough, melting will occur between heavier banding such that accumulation is limited. This can be overcome though with a very thick cloud deck and heavy rates, but good luck with the set up as is anywhere except Long Island and parts of Conn...

Thanks Ryan. Yeah, those factors worry me especially in the more western parts of our area where I think there is a chance for steady snow for a while, but how heavy it gets I'm not sure. I'd feel better about this if the temps were a few degrees colder. But it is mid-March so everything with these storms is a battle.

18z GFS much further east, not a good run at all. Even beantown sees only a few inches.

Quietace you think the NWS forecast won’t verify? Which way. Is it too high?

18z GFS snow intensity and duration (except easter LI) is slightly less than earlier runs. But I'm not changing anything now based on one run. If I feel I need to revise my map I'll do it tomorrow.

syosnow94 wrote:Quietace you think the NWS forecast won’t verify?  Which way. Is it too high?

You need heavy rates or cold temps to accumulate in mid-march...This storm has neither for most of your area. If you are not at elevation or in heavy banding it probably will only accumulate with associated melting, on cold surfaces. ELI and E Conn have the best shot....

Thanks JMan for the comments on the map (rather than quote and repost I figured I'd just do an independent post). If I was inclined right now (especially after the GFS run and taking to heart some of Ryan's comments) if anything I might push the blue a little east. As for the strange orange curl on the northern shore of LI near the center of the island -- I'm told local climatology favors slightly higher totals in that spot. lol. Someone may chime in on that later. ;-)

But Ryan the majority comes down overnight. It should offset any thermal issues outside of NYC proper

18z GFS isn't "way further east" IMO, but precip shield is smaller and more centralized... If the storm takes a track closer to the coast, and we get heavy banding, with most of the precip falling at night, it should stick even with marginal surface temps no?

billg315 wrote:One thing I do worry somewhat about is snow sticking (I know this contradicts what I said earlier today). Temps are only going to hit freezing in many areas around daybreak Tuesday (if then), so it will need to be coming down at a decent clip to stick even without the sun angle issue at night. Then once the sun comes up Tuesday morning accumulation will be hindered in areas where its not heavy or a base didn't accumulate overnight. I'm never good at figuring this issue out so I'll have to just wait and see what happens.

If this storm does happen the one thing I've always liked about it is the timing.

If the bulk of the precip falls after sunset Monday (almost certain) and before 11am Tuesday likely, the sun angle will not be a factor.

Falling from 11am to 5pm this time of year is when it could affect totals in some areas.

CPcantmeasuresnow wrote:

billg315 wrote:One thing I do worry somewhat about is snow sticking (I know this contradicts what I said earlier today). Temps are only going to hit freezing in many areas around daybreak Tuesday (if then), so it will need to be coming down at a decent clip to stick even without the sun angle issue at night. Then once the sun comes up Tuesday morning accumulation will be hindered in areas where its not heavy or a base didn't accumulate overnight. I'm never good at figuring this issue out so I'll have to just wait and see what happens.

If this storm does happen the one thing I've always liked about it is the timing.

If the bulk of the precip falls after sunset Monday (almost certain) and before 11am Tuesday likely, the sun angle will not be a factor.

Falling from 11am to 5pm this time of year is when it could affect totals in some areas.

agree with all of you, ace not sure why your thoughts about that are way they are but I respect ur analysis nonetheless, needless to say I hope your wrong lol

syosnow94 wrote:But Ryan the majority comes down overnight. It should offset any thermal issues outside of NYC proper

Timing is somewhat lucky with this event, but I am still not convinced with surface temps the way they are. Here is why.

For your specific location, precip initiates about 02z with surface temps in the mid 30s (10pm at night). The heaviest precip falls between 12z and 18z(Surface temps still above 32, timing is 8am to 2pm). Yes, you can evap-cool the surface overnight with limited heating(this depends) but radiational cooling is non-existent overnight (as well as general cooling as there is no cold air advection prior to the system, and with the early cloud cover there will be a gentle drop from the day time highs) with the cloud shield (a give and take). Thus, the question is how much precip will you waste overnight getting to the point of accumulation on certain surfaces after a 40 degree day (the potency of the the initial precipitation is also important when trying to factor this out), before the sun comes up during which the heaviest rates are occurring with surface temps still hovering near or just above/below freezing (this is where all my previous comments come into play). Slight adjustment in timing, track, etc. matter here.

Wow navy came west

Quietace wrote:

syosnow94 wrote:But Ryan the majority comes down overnight. It should offset any thermal issues outside of NYC proper

Timing is somewhat lucky with this event, but I am still not convinced with surface temps the way they are. Here is why.

For your specific location, precip initiates about 02z with surface temps in the mid 30s (10pm at night). The heaviest precip falls between 12z and 18z(Surface temps still above 32, timing is 8am to 2pm). Yes, you can evap-cool the surface overnight with limited heating(this depends) but radiational cooling is non-existent overnight (as well as general cooling as there is no cold air advection prior to the system, and with the early cloud cover there will be a gentle drop from the day time highs) with the cloud shield (a give and take). Thus, the question is how much precip will you waste overnight getting to the point of accumulation on certain surfaces after a 40 degree day (the potency of the the initial precipitation is also important when trying to factor this out), before the sun comes up during which the heaviest rates are occurring with surface temps still hovering near or just above/below freezing (this is where all my previous comments come into play). Slight adjustment in timing, track, etc. matter here.

Now, if there is a correction toward the coast like some meso-models suggested earlier today due to some H5 biases at play, precip rates will lead to evap-cooling and moderate accumulations for most with higher on ELI, however observing H5, there is still a bit of uncertainty in certain features that lead to my discussion here. Personally, I think we end up with a near benchmark track, however I am not yet certain of the precip dynamics of the western precip shield in the tri-state area.

jmanley32 wrote:

CPcantmeasuresnow wrote:

billg315 wrote:One thing I do worry somewhat about is snow sticking (I know this contradicts what I said earlier today). Temps are only going to hit freezing in many areas around daybreak Tuesday (if then), so it will need to be coming down at a decent clip to stick even without the sun angle issue at night. Then once the sun comes up Tuesday morning accumulation will be hindered in areas where its not heavy or a base didn't accumulate overnight. I'm never good at figuring this issue out so I'll have to just wait and see what happens.

If this storm does happen the one thing I've always liked about it is the timing.

If the bulk of the precip falls after sunset Monday (almost certain) and before 11am Tuesday likely, the sun angle will not be a factor.

Falling from 11am to 5pm this time of year is when it could affect totals in some areas.

agree with all of you, ace not sure why your thoughts about that are way they are but I respect ur analysis nonetheless, needless to say I hope your wrong lol

Well if you look impartially look at the system you can see the forecast problems with this set up.

From our own Isotherm on the NAM and GFS.





If we can get the phase earlier as the NAM is showing then we MAY see a Navy type of reflection but a tad more east in my opinion.

March snow storms are usually difficult to the air mass involved. If it was early to mid Feb no brainier but not so with this one.
Not throwing in the trowel at all waiting to see when I wake up in the morning where we are at.