Hudson Bay Winter of 2011-2012 Tracking Thread

[skierinvermont]

You were definitely right about that.

I had an epic bust which I will continue to learn from. I was extremely ignorant and arrogant when I created this thread about how much I knew.

I've done things like that too. And of course it's still possilbe a huge west -NAO block develops over the bay and prevents the last bit from freezing in late December. But I think that we're far enough ahead of last year and the weather looks to be sufficiently cold that that is becoming less and less likely.

i wish we could get some blocking but it doesn't look likely to me over the next 2 weeks.

[tacoman25]

Skier

In Table 1, page 9 they show the present (2009) median freeze up date as December 4, then add 25 days in their warmer climate model.

I don't see how this has them forecasting a freeze up date in late January in 2040-2070.

We have already experienced one (anomalous) year in which freeze up did not occur until late January. I would expect that substantially less ice volume, and the reduced energy needed to effect melt, will usher in a period of earlier than median melts as well as later than median freeze up dates.

Weather may dominate in the short term, but I can see no reason for the system to revert to the patterns experienced prior to 2010.

Hoping I'm Wrong

Terry

Your hopes have been answered!

[tacoman25]

I think that the abnormally slow freeze the last two years is due to the deep and extended Greenland blocks that have been present. Weather patterns such as this will have a much more enormous impact than above average SST's....

I'm going with 12/17-12/24

Looking good.

[skierinvermont]

Looking good.

Ehh I don't know if it will be able to freeze 100% by 12/17-24.. I'd go with more like 12/20-12/30 at this point. Best guess a bit earlier than my 12/28 guess but still a lot will depend on weather. Freezing that SE corner can often be difficult.

[tacoman25]

Ehh I don't know if it will be able to freeze 100% by 12/17-24.. I'd go with more like 12/20-12/30 at this point. Best guess a bit earlier than my 12/28 guess but still a lot will depend on weather. Freezing that SE corner can often be difficult.

Model guidance indicating colder weather coming soon to that SE corner. -18C by the 19th per the latest GFS.

[Alpha5]

Called December 17th-24th

baring any torches...I think I win

[ORH_wxman]

Called December 17th-24th

baring any torches...I think I win

If guidance holds, you probably will...the coldest airmass looks to be over the eastern part of the bay over the next 10-12 days in the means...which is where you want it for the remaining open water to freeze.

What are people using as threshold for freezing? Like 99%? Because I bet on most maps at any given time you can find a little dot or crack with open water even into January.

[TerryM]

If guidance holds, you probably will...the coldest airmass looks to be over the eastern part of the bay over the next 10-12 days in the means...which is where you want it for the remaining open water to freeze.

What are people using as threshold for freezing? Like 99%? Because I bet on most maps at any given time you can find a little dot or crack with open water even into January.

Check beginning of thread.

[ORH_wxman]

Check beginning of thread.

I have read this thread...I saw skier say "it was 100% frozen" but he was using the crude cryosphere maps it looked like. I'm not sure exactly what people are going to constitute freezing dates...so which is it?

[skierinvermont]

I have read this thread...I saw skier say "it was 100% frozen" but he was using the crude cryosphere maps it looked like. I'm not sure exactly what people are going to constitute freezing dates...so which is it?

this for example would not be 100% frozen until water in the SE corner filled in as it did two days later (see second image). Small cracks which aren't visible on these low res images do not count and neither does open water in the NW part of the bay due to strong NW winds which occurs sometimes long after it has frozen. Only significant open water counts against 100% frozen.

2 days later:

[skierinvermont]

Called December 17th-24th

baring any torches...I think I win

I would still take 24-30 if I had to chose but it could go either way. any time between 12/20 and 12/30 seems likely.

A little early to be declaring victory I think.. people throughout this thread have gotten way too confident in their predictions.

[LithiaWx]

BREMEN 6.25KM GRID RES MAP WILL BE USED FOR THE OFFICIAL DATE:

Wasn't this based off the AMSR-E which is non-operational now? Sounds like depending on which map you use now you could have a number of first freeze dates. Some are close to frozen over now while others have much more water showing up.

[tacoman25]

I would still take 24-30 if I had to chose but it could go either way. any time between 12/20 and 12/30 seems likely.

A little early to be declaring victory I think.. people throughout this thread have gotten way too confident in their predictions.

True. But as we get closer and the vast majority is frozen over, there is good reason to be more confident.

[LithiaWx]

maps...

[tacoman25]

I think most of those maps will show it completely frozen over by the 20th. Models show temperatures normal/below normal over the area through the 20th at least.

[The_Global_Warmer]

Those navy maps are modeled fotecasts.

[TerryM]

Those navy maps are modeled fotecasts.

And hindcasts ;-)

[The_Global_Warmer]

And hindcasts ;-)

This thread is extremely ironic and very stable evidence to aways stay humble.

Looks like I am going to be off by 30 days.

The Hudson went from ice free to 80% in two weeks. Need to store that one in the memory banks

[LithiaWx]

Those navy maps are modeled fotecasts.

Ah, I see the dates now, not sure how I missed that originally. Thanks.

And hindcasts ;-)

hindcasts? what in the world are you talking about?

[LithiaWx]

I think that the abnormally slow freeze the last two years is due to the deep and extended Greenland blocks that have been present. Weather patterns such as this will have a much more enormous impact than above average SST's....

I'm going with 12/17-12/24

Looking good.

Ehh I don't know if it will be able to freeze 100% by 12/17-24.. I'd go with more like 12/20-12/30 at this point. Best guess a bit earlier than my 12/28 guess but still a lot will depend on weather. Freezing that SE corner can often be difficult.

Not just the date that looks good. Taco can correct me if I'm wrong but I think he was mainly referring to the reasoning behind my choice of dates. Weather Patterns have more impact than SST's. I could pull out my winter forecast from late September-early October, that I posted in the SE forums where I said that this year would not see near as much blocking as the last two.

[Alpha5]

This thread is extremely ironic and very stable evidence to aways stay humble.

Looks like I am going to be off by 30 days.

The Hudson went from ice free to 80% in two weeks. Need to store that one in the memory banks

Given how cold the surrounding land was and the fact that we have an enhanced vortex in this +AO regime, it really is not that surprising.

[TerryM]

Ah, I see the dates now, not sure how I missed that originally. Thanks.

hindcasts? what in the world are you talking about?

http://www7320.nrlssc.navy.mil/hycomARC/arctic.html

Each animation begins with 2 days of old data (hindcast)

one day of real time data

then 6 days of forecast

for today's stuff go to snapshot archive, far left column, 3 down from top

At times, real time data is updated/corrected and designated as hindcast (at least colloquially)

[tacoman25]

Looking at previous years, it can go from little ice to completely ice covered in a couple of weeks. Just depends on what weather patterns you get when.

[Alpha5]

Just took a look at the GFS and there appears to be a cold front moving across the bay during the next 60 hours as a weak clipper moves off to the NE. This will bring sub 500 heights over the entire bay for several days.

[The_Global_Warmer]

Given how cold the surrounding land was and the fact that we have an enhanced vortex in this +AO regime, it really is not that surprising.

The +AO really nailed this one in.

And I am pretty grateful. On one hand walking from the the train to work in rain cold nasty rain sucks.

On the other a highly negative AO would have reinforced my ignorant and misguided beliefs about this subject.

This really tells me alot. And really shows where the warming signal is. I would say on average its impact is 10-14 days.

I can't see how it grows the next decade unless the bay became ice free in EARLY june. Don't see that happening.

For the decade I am thinking Christmas Day will be the average freeze over date...

With the freeze up starting 1st week of December lasting 2-6 weeks pending local weather.

[TerryM]

The +AO really nailed this one in.

And I am pretty grateful. On one hand walking from the the train to work in rain cold nasty rain sucks.

On the other a highly negative AO would have reinforced my ignorant and misguided beliefs about this subject.

This really tells me alot. And really shows where the warming signal is. I would say on average its impact is 10-14 days.

I can't see how it grows the next decade unless the bay became ice free in EARLY june. Don't see that happening.

For the decade I am thinking Christmas Day will be the average freeze over date...

With the freeze up starting 1st week of December lasting 2-6 weeks pending local weather.

Remember that Hudson Bay's summer ice cover has been receding at 11%/ decade since the late '60's - and the trend does not appear linear to me.

[The_Global_Warmer]

Remember that Hudson Bay's summer ice cover has been receding at 11%/ decade since the late '60's - and the trend does not appear linear to me.

Is that just summer or the ice free period?

In order for that to continue

SATs will have to rise at an ever increasing rate. The further that is in lower solar insolation the harder.

I think june is most likely target for more ice loss.

But that is not a guarentee.

Canada is way on snow depth which plays a big role in april and may.

[TerryM]

Is that just summer or the ice free period?

In order for that to continue

SATs will have to rise at an ever increasing rate. The further that is in lower solar insolation the harder.

I think june is most likely target for more ice loss.

But that is not a guarentee.

Canada is way on snow depth which plays a big role in april and may.

The chart simply refers to summer.

http://www.statcan.gc.ca/pub/16-002-x/2011004/t006-eng.htm

However a fuller explanation might be found at

http://www.statcan.gc.ca/pub/16-002-x/2011004/part-partie3-eng.htm

If warmer SST's are not related to the next years ice coverage, it follows that surface temperatures and/or insolation must be increasing at a very rapid rate.

I'm inclined to believe that high summer SST's lead to much lower ice volume the following year, which in turn leads to more rapid melt - weather excepted.

[skierinvermont]

Not just the date that looks good. Taco can correct me if I'm wrong but I think he was mainly referring to the reasoning behind my choice of dates. Weather Patterns have more impact than SST's. I could pull out my winter forecast from late September-early October, that I posted in the SE forums where I said that this year would not see near as much blocking as the last two.

That was my point as well (weather >>>>> Fall SSTs in the Hudson Bay). But that doesn't necessarily make the reasoning good for a Dec 17-24 forecast. The average freeze date is after the 24th the past 8 years. Combine that with the record warm SSTs and I see no reason to have predicted the 17-24th instead of the 24th -30th.

[skierinvermont]

maps...

It is the first chart which will be used.