Cold Rain

26 minutes ago, calculus1 said:

 

If you guys think I am arguing against using ensembles in forecasting, I am not.  I am arguing against displaying a map that gives precision probabilities.  If WRAL derives their “probabilities” from ensembles, I still disagree with their language.  If they said “14 out of 50 ensemble members indicated 3 inches or more of snow for Clinton” or even “28% of ensemble members indicated 3 inches or more of snow for Clinton”, I would have no issue with those statements.  Those are indisputable facts based off model output.  But equating such fractions of ensemble members to probabilities is a misuse of statistics, in my opinion.

The probability of a success (getting three inches of snow or more, in this case) is equal to the number of successes divided by the number of possible outcomes (failures + successes).  The ensemble members do not represent all the possible outcomes; they only represent approximately 50 of the infinite number of possible outcomes.  Thus, we can’t really say there is a 28% probability of something happening based off ensemble members.  In fact, I would argue there’s really no way to calculate such a probability, because it’s impossible to account for all the possible outcomes that arise from tweaking just one minuscule atmospheric condition somewhere over the entire globe.

It’s the language that I take issue with, not the use of ensembles.  If they were to change their title to “Percent of Ensemble Members that Predict 3 Inches of Snow”, I would see that as much more transparent.  As it is, I think it’s a misleading graphic.

My head exploded, but I agree with you.  I don't know how you could give a realistic probability of snowfall occurring at a given location 5 days out.  If you had 10 possible outcomes and knew only 3 led to snowfall but didn't know which of the 10 would occur but did know that each had an equal chance of occurring, then it would be easy to conclude that there is a 30% chance of snow.  That's unrealistic though.

On the other hand you have to develop messaging that is framed within a forecast that the general public can consume and understand.  It's probably always going to have a subjective quality to it because you can't quantify the entire possibility set or the likelihood of each possibility for any future event (or non-event) on any given date.  Idk

Just now, lilj4425 said:

SEND BEER!!!!

Where?

6 minutes ago, cbmclean said:

Please lower your snow shields.

Every snow we get takes them down by a percentage. 

Just now, Brick Tamland said:

In the meantime it's funny seeing them going in opposite directions. Hopefully the ensembles are correct and the ops will correct course.

They're really not going in opposite directions though.  Oversimplifying for concept illustration, but the Ops are going from a preferred track (good) to a left track (bad).  The Ensemble mean is going from  a right track (bad) to a preferred track (good).  If the Ops stay left, then you can eventually expect the ensembles to go from preferred to left.

42 minutes ago, Brick Tamland said:

Also funny that the ops have come in worse today but WRAL has been increasing the talk more today about snow here.

They heavily use ensembles, which have been been trending from flatter and weaker to stronger and more wintry as the Ops have trended from adequately strong and favorable to more amped warmer aloft.  If the Ops continue to trend in that direction, you can expect the ensembles to follow and WRAL to follow that.

4 hours ago, lilj4425 said:

Cold rain. 

Yes?

We haven't had an abundance of great patterns over the last bunch of years.  If we had, I would see the point about great patterns don't produce like they used to.

I do think there is something to the point about easterly flow off the oceans affecting eastern parts of the state under certain circumstances.  But that's a small part of the problem. 

We just need to start to buckle the jet in the east again, instead of having winter after winter with troughs sitting in the west.

Anyway, we should see a better period ahead soon.  I expect we'll be able to track a few storms this winter.

Pattern is starting to look supportive of a legit winter storm soon.  It would be better if north Atlantic ridging migrated near Greenland/eastern Canada, but we can definitely work with the pattern shown.  Fingers crossed.

Looks like it's shaping up to be a cold 2nd half of the month.  Certainly will be nice if we can start winter early, as opposed to waiting until mid-February.

On 10/5/2021 at 12:10 PM, yotaman said:

To those who have purchased the Tempest, how do you like it so far?

I love mine.  Just got to clean the bird crap off of it.  Birds think it's for them.  Also, the rain usually autocorrects.  But that's normal with that system.

On 9/16/2021 at 5:02 PM, NC_hailstorm said:

Euro and GFS both show a nice cool down around day 6/7 with a fairly strong cold front. Seeing the 564 dm pressing into parts of NC,impressive for late September.

What are you seeing wrt solar that might impact the upcoming cold season?

4 hours ago, WinstonSalemArlington said:

Cool early August 

How awesome would it be to see this in winter?

On 7/6/2021 at 7:05 AM, frazdaddy said:

We have 3 units. One is circa 1996. I'm sure that trains coming. Good to see you in here sir, hope all is well.

Yes sir.  Things are going pretty well.  Hope you're doing well also.

20 hours ago, magpiemaniac said:

My downstairs HVAC is acting up which makes me immediately long for cooler fall temps. At least upstairs is fine.

It’s always something.

My house was built in 1993 and we just replaced the upstairs unit in 2019, after about 5 years of it going out at least once per summer.  The downstairs one is still kicking.  Fortunately, with having installed new windows, the downstairs temp doesn't change very rapidly even if that unit isn't on.  HVAC is so expensive to replace. 

And I guarantee you if the synoptic setup occurs just like the Euro is showing, CAD is undermodeled at this range.

2 minutes ago, WinstonSalemArlington said:

Judah Cohen:  I believe that I have a reputation as one who hypes the #cold & #snow so here is a tweet for those who like their winters mild, not wild. Last night's GFS says "PV, shmevee!" i.e., despite the #PolarVortex's antics no meaningful cold for North America into the foreseeable future. https://t.co/sZ9U1PRc0m

To be fair, his rep is more that he is just not a good forecaster and his indexes generally provide little value.

On 1/16/2021 at 1:16 PM, SnowDawg said:

This was a nice call. GFS immediately delivered a big dog fantasy run within just a few hours lol.

And then, just like that, things turned back around lol.  At least we don't have a super consolidated PV.  However, the problem seems to remain with the Pacific. The NAO has helped suppress the storm track somewhat, but we can't seem to get a buildup of truly cold air to get transported into the SE.  The LR looks like a mess right now, if you're looking for a real shot at a big SE winter storm, unfortunately.

Of course, the other day, things looked to be trending better.  Guess that was a false start and things could look to turn around again in a couple of days.

The thing I tend to look at and weigh heavily when looking at LR model data is seasonal trends.  The trends so far have been for a rare -NAO to be a stable feature and for the Pacific to remain unhelpful, regardless of what the models show beyond D10.  Until we see a deviation from those things make it to within a few days of happening, it's probably best to just expect more of the same. 

8 hours ago, griteater said:

Yeah we’re not far off in the mid and extended range. One thing to watch for is to see if the pattern can become more suppressed than currently shown - sometimes that happens on the modeling in the bigger -NAO’s like this 

Not a huge fan of the tendency for lower heights out west.  But with a tPV up in central/eastern Canada and a big -NAO you can get NW to SE moving systems kind of like what's shown on the 6z GFS, out in time anyway.  I think pretty soon, we'll start to see some legit big dogs show up.

5+" here and piling up quickly.  Don't see FFWs that expansive very often. 

Just passed 5" here in SE Wake.  What a rain event!

La Nina time.

Looks like a pretty good SE soaking over the next 10 days, with SC bearing the brunt, according to the GFS, where several inches are possible over central and eastern sections.  Euro is very wet also.  Anytime we can get away with 70s and 80s and clouds and rain in summer, I'll take it!

18 minutes ago, snowinnc said:

I am the most happy for you CR!!!

Thank you!!  It's amazing to watch it snow.  Seems like it's been forever.  Coming down moderately.  Can't wait for the heavier stuff later.

All snow in SE Wake.  Ground, cars, roofs getting frosted.

19 minutes ago, mcblimp95 said:

Interesting to note the HRRR initialized its 11Z run with the 850 line running through Cornelius, yet the SPC observed 850 line is almost all the way to Monroe. The short range stuff is not going so hot. This is why model watching at this point is a no go.

I'd like to throw the Hrrrr out, but it's hard to do.  It still eventually gets to snow but it takes a long time.  Hopefully, it's wrong.  I assume it's solely due to the boundary layer.