I cannot remember too many Decembers in my lifetime that has been this warm overall. I am not talking about a day here or there that set a record high. I am not even talking about a regional thing with a few days in record high territory. This has been nearly a month-long event.
Fargo ND - over 13 degrees above average for the month.
International Falls MN - over 15 degrees above average with not a single day below zero yet this month. And they are supposed to be the Icebox Capital of the United States (there is still debates raging over that one).
Sault Ste Marie MI - over 12 degrees above average with just over an inch of snow for the month.
Buffalo NY - almost 11 degrees above average. With barely a flinch, the lake-effect snow machine has basically been shut down eeking out a robust 0.1".
In addition to a top ten wettest years on record, Louisville will be flirting with at least top ten warmest Decembers and a shot at a top ten warmest year on record. Oh forgot to mention, but Louisville will possibly break more local daily records as well before the month is over.
MS
Wednesday, December 23, 2015
Tuesday, December 15, 2015
Projection Time: Louisville's Winter Temperatures
Ok. Try and follow me here. The logic and numbers may seem distorted, so you might need a pencil and paper to help. Remember, though, these are just projections, not anything set in stone.
My winter outlook simply says that Louisville and surrounding region would be milder than the previous two winters.
In Louisville, the last two winters of December through February averaged at least 3 degrees below normal. Right now, or as of December 14, Louisville is averaging over 10 degrees above normal.
Today and tomorrow we should see readings at least 10 degrees above normal. Even though below normal temperatures are expected for 2 or 3 days later this week, we're only talking about 3-4, 5 degrees maximum of below normal values. Then, we go right back up from there, averaging more than 5 degrees above normal for a stretch of a few days.
As you can see, I am highlighting more higher 'above normal' readings than 'below normal' readings. In other words, we don't have 10 degrees above normal one day and 10 degrees below normal the next day. But, we might have days of 10 and 12 degrees above normal versus a couple of days of 4 or 5 degrees below normal. The 10 and 12 quite simply overwhelm the 4 or 5 so that the average remains above normal.
Now, for the sake of argument, let's assume that after today and tomorrow with double-digit temperatures above normal, the rest of the month, every day, the high temperature and low temperature met its normal value. What would be the result?
December would still finish 5-6 degrees above normal, not too far from top ten warmest Decembers on record status.
That means January and February would need to average about 8 degrees below normal per month for my outlook to be wrong.
I guess it could still happen, but I am already expecting a concession speech from Old Man Winter already.
MS
My winter outlook simply says that Louisville and surrounding region would be milder than the previous two winters.
In Louisville, the last two winters of December through February averaged at least 3 degrees below normal. Right now, or as of December 14, Louisville is averaging over 10 degrees above normal.
Today and tomorrow we should see readings at least 10 degrees above normal. Even though below normal temperatures are expected for 2 or 3 days later this week, we're only talking about 3-4, 5 degrees maximum of below normal values. Then, we go right back up from there, averaging more than 5 degrees above normal for a stretch of a few days.
As you can see, I am highlighting more higher 'above normal' readings than 'below normal' readings. In other words, we don't have 10 degrees above normal one day and 10 degrees below normal the next day. But, we might have days of 10 and 12 degrees above normal versus a couple of days of 4 or 5 degrees below normal. The 10 and 12 quite simply overwhelm the 4 or 5 so that the average remains above normal.
Now, for the sake of argument, let's assume that after today and tomorrow with double-digit temperatures above normal, the rest of the month, every day, the high temperature and low temperature met its normal value. What would be the result?
December would still finish 5-6 degrees above normal, not too far from top ten warmest Decembers on record status.
That means January and February would need to average about 8 degrees below normal per month for my outlook to be wrong.
I guess it could still happen, but I am already expecting a concession speech from Old Man Winter already.
MS
Monday, December 14, 2015
MikJournal Monday 12/14/15
Well, we're just about to the halfway point of the month. Wow. What a month! I really like this warmer than usual air. Don't get me wrong, because I'm a snow lover. But, I also enjoy outdoor activities while basking in a measure of the comfort of spring. Bonus weather, right? Don't fret, winter's coming, right?
Ok, yes it is finally looking like we will see some December weather by the end of the week...briefly.
My winter overview and December Prediction highlighted the balmy weather mixed with a cold shot here and there, though not of Arctic origin.
Looking forward to the rest of the month, I am still expecting average to above average temperature readings just like I said late last month.
But, I also mentioned severe weather chances for the end of the year. The jury is still out on that one, but with above average temperatures, a colder air mass is bound to collide with that one, possibly causing some stormy issues.
I have been harping on teleconnections for a while. The AO, NAO, and EPO need to be negative for true lasting cold air to take place. Currently, there are no signals yet showing this alignment.
In addition, the current CPC 8-14 day outlook has the entire U.S. in a higher probability for above average temperatures, again.
This takes us through the 27th.
As far as wintry weather worth talking about, honestly I don't foresee any serious contender until either side closest to the 2nd week of January...I guess around the 7th -12th. But, that's for another post. My January Prediction comes out later this month.
MS
Ok, yes it is finally looking like we will see some December weather by the end of the week...briefly.
My winter overview and December Prediction highlighted the balmy weather mixed with a cold shot here and there, though not of Arctic origin.
Looking forward to the rest of the month, I am still expecting average to above average temperature readings just like I said late last month.
But, I also mentioned severe weather chances for the end of the year. The jury is still out on that one, but with above average temperatures, a colder air mass is bound to collide with that one, possibly causing some stormy issues.
I have been harping on teleconnections for a while. The AO, NAO, and EPO need to be negative for true lasting cold air to take place. Currently, there are no signals yet showing this alignment.
In addition, the current CPC 8-14 day outlook has the entire U.S. in a higher probability for above average temperatures, again.
This takes us through the 27th.
As far as wintry weather worth talking about, honestly I don't foresee any serious contender until either side closest to the 2nd week of January...I guess around the 7th -12th. But, that's for another post. My January Prediction comes out later this month.
MS
Saturday, December 12, 2015
Rare Cooling Degree Days in December
Cooling Degree Days? Perhaps you have heard of it. Heating Degree Days and Cooling Degree Days are useful in helping to determine energy demands along with other factors when moving to another location.
It is based on a standard numerical value of 65 degrees. A high temperature and low temperature are added together and divided by two for the day's average temperature. If the average temperature is < 65, then a heating degree day is computed based on the difference between the standard and the actual average.
For example, if the day's high temperature is 60 and the day's low temperature is 40, then the average is 50 (60 + 40 = 100; divide by 2 = 50). Since the average temperature of 50 is less than 65, heating degree days are applied, in this case, 15 Heating Degree Days.
But, in Louisville, the day's high temperature was 73 degrees. Let's assume that the low temperature for today will be 65 degrees, since today has not officially ended until midnight. It was actually 66 early this morning but may push slightly lower just before midnight soon.
If we add 73 and 65, this equals 138; divide by 2 and we get a 69 degree average. Since the average value is higher than 65, cooling degree days are applied, in this case, 4 Cooling Degree Days.
It is very rare to obtain an average temperature of greater than 65 degrees in Kentucky during the month of December. Louisville typically averages 1 Cooling Degree Day for the month. But most years, we simply record zero.
The last December we recorded Cooling Degree Days was in 2012, also 4 CDD's. Since 2000, including the year 2012, during the past 15 years, we in Louisville have recorded a total of 5 CDD's, not counting any CDD's that will be computed by tomorrow morning.
Sunday, it is possible we may record a very rare second consecutive day of Cooling Degree Days for the month of December.
The record for CDD's in Louisville for December is 8, set in 1982, yes another El Nino year. Two consecutive days of average temperatures greater than 65 degrees were achieved.
I do not know if Louisville will be able to tie or break the mark set in 1982, but it will be close.
Another record that may be in jeopardy is the all-time high temperature for December here in Louisville, which is 76. It would be quite coincidental if Louisville should tie the all-time high temperature and the all-time Cooling Degree Days records on the same day in December.
MS
It is based on a standard numerical value of 65 degrees. A high temperature and low temperature are added together and divided by two for the day's average temperature. If the average temperature is < 65, then a heating degree day is computed based on the difference between the standard and the actual average.
For example, if the day's high temperature is 60 and the day's low temperature is 40, then the average is 50 (60 + 40 = 100; divide by 2 = 50). Since the average temperature of 50 is less than 65, heating degree days are applied, in this case, 15 Heating Degree Days.
But, in Louisville, the day's high temperature was 73 degrees. Let's assume that the low temperature for today will be 65 degrees, since today has not officially ended until midnight. It was actually 66 early this morning but may push slightly lower just before midnight soon.
If we add 73 and 65, this equals 138; divide by 2 and we get a 69 degree average. Since the average value is higher than 65, cooling degree days are applied, in this case, 4 Cooling Degree Days.
It is very rare to obtain an average temperature of greater than 65 degrees in Kentucky during the month of December. Louisville typically averages 1 Cooling Degree Day for the month. But most years, we simply record zero.
The last December we recorded Cooling Degree Days was in 2012, also 4 CDD's. Since 2000, including the year 2012, during the past 15 years, we in Louisville have recorded a total of 5 CDD's, not counting any CDD's that will be computed by tomorrow morning.
Sunday, it is possible we may record a very rare second consecutive day of Cooling Degree Days for the month of December.
The record for CDD's in Louisville for December is 8, set in 1982, yes another El Nino year. Two consecutive days of average temperatures greater than 65 degrees were achieved.
I do not know if Louisville will be able to tie or break the mark set in 1982, but it will be close.
Another record that may be in jeopardy is the all-time high temperature for December here in Louisville, which is 76. It would be quite coincidental if Louisville should tie the all-time high temperature and the all-time Cooling Degree Days records on the same day in December.
MS
Wednesday, December 9, 2015
Winter is Coming...Sure It Is, Uh Huh
We keep hearing about cold air poised to invade our region of Kentucky soon. While the coldest air continues to dance to our north and expected to penetrate into the western part of the U.S., it sure appears likely that it will overtake us very soon.
Then, just when it seems like this is the cold front to do it, forecast temperatures are now expected not to be that cold, yes cooler than the 15-25 degrees above average we'll be experiencing this week, but not THE cold front to usher in wintertime cold.
What's going on? I have not read or heard too many meteorologists out there talk about the Arctic Oscillation lately, a familiar teleconnection that gave name recognition to the overhyped Polar Vortex from a couple of years ago.
Instead I read about EPO's, which by itself cannot guarantee the cold air we need. It needs to be used in conjunction with PNA and AO and the closely related NAO.
Once these teleconnections align themselves, then we can start talking about cold air. Right now, as one should surmise by now, these teleconnections are not quite aligned yet.
This is the time of year I turn my attention to the Arctic Oscillation index. Because the stormy low pressure area has been centered over the Arctic region somewhat persistently as of late, a rather mild stretch of weather has occurred here while the Arctic cold has been confined to its home base.
But signals are beginning to show a possible flip in that pattern. At the very least, the Arctic region will begin to see higher heights in terms of the average geostrophic 500mb reading. Think of it as high pressure in the Arctic. But a troughy pattern will begin to ensue for the middle latitudes where we are.
Therefore, the strong, stormy winds that were keeping the coldest air locked up in the Arctic will ease thereby allowing chunks of cold air to sink south. Then when the troughy conditions in the middle latitudes come to be, the interaction will help transport more of the real cold stuff toward the northern US.
In addition, a familiar pattern we have seen before will happen again. The Greenland Block is expected to develop and strengthen by the end of the year. This will make cold air transport even easier.
The ideal teleconnection combination involving the EPO, AO, and NAO would be -EPO, -AO, -NAO if you like really cold air here.
Nevertheless, I strongly caution that this is a strong El Nino winter. It is possible that such blocks will not be able to be sustained over a prolonged period of time. I am still expecting much variability in our winter weather.
MS
* The term geopotential should have been used instead of geostrophic.
(12/13/15 - MS)
Then, just when it seems like this is the cold front to do it, forecast temperatures are now expected not to be that cold, yes cooler than the 15-25 degrees above average we'll be experiencing this week, but not THE cold front to usher in wintertime cold.
What's going on? I have not read or heard too many meteorologists out there talk about the Arctic Oscillation lately, a familiar teleconnection that gave name recognition to the overhyped Polar Vortex from a couple of years ago.
Instead I read about EPO's, which by itself cannot guarantee the cold air we need. It needs to be used in conjunction with PNA and AO and the closely related NAO.
Once these teleconnections align themselves, then we can start talking about cold air. Right now, as one should surmise by now, these teleconnections are not quite aligned yet.
This is the time of year I turn my attention to the Arctic Oscillation index. Because the stormy low pressure area has been centered over the Arctic region somewhat persistently as of late, a rather mild stretch of weather has occurred here while the Arctic cold has been confined to its home base.
But signals are beginning to show a possible flip in that pattern. At the very least, the Arctic region will begin to see higher heights in terms of the average geostrophic 500mb reading. Think of it as high pressure in the Arctic. But a troughy pattern will begin to ensue for the middle latitudes where we are.
Therefore, the strong, stormy winds that were keeping the coldest air locked up in the Arctic will ease thereby allowing chunks of cold air to sink south. Then when the troughy conditions in the middle latitudes come to be, the interaction will help transport more of the real cold stuff toward the northern US.
In addition, a familiar pattern we have seen before will happen again. The Greenland Block is expected to develop and strengthen by the end of the year. This will make cold air transport even easier.
The ideal teleconnection combination involving the EPO, AO, and NAO would be -EPO, -AO, -NAO if you like really cold air here.
Nevertheless, I strongly caution that this is a strong El Nino winter. It is possible that such blocks will not be able to be sustained over a prolonged period of time. I am still expecting much variability in our winter weather.
MS
* The term geopotential should have been used instead of geostrophic.
(12/13/15 - MS)
Monday, December 7, 2015
...Where Two Oceans Meet???
Have you ever seen the picture below?
It's a picture taken in the Gulf of Alaska. The picture is said to represent where two bodies of water merge but not actually mix.
Actually, the lighter-shade of blue represents glacial sediment containing iron that is flowing from one of Alaska's rivers into the Gulf of Alaska. While the snapshot seems to depict a boundary or demarcation separating the two, they eventually do mix and the sediment line is not stationary.
There are actually several of these 'where two oceans meet' phenomena. Here is another...
In this case above, we call this a confluence of two rivers. Also, the confluence of the Ohio and Mississippi rivers results in a similar phenomenon...
taken from Earth Observatory
MS
It's a picture taken in the Gulf of Alaska. The picture is said to represent where two bodies of water merge but not actually mix.
Actually, the lighter-shade of blue represents glacial sediment containing iron that is flowing from one of Alaska's rivers into the Gulf of Alaska. While the snapshot seems to depict a boundary or demarcation separating the two, they eventually do mix and the sediment line is not stationary.
There are actually several of these 'where two oceans meet' phenomena. Here is another...
In this case above, we call this a confluence of two rivers. Also, the confluence of the Ohio and Mississippi rivers results in a similar phenomenon...
taken from Earth Observatory
MS
MikJournal Monday 12/07/15
Good morning. The first week of December is coming to an end. Our region has experienced 1-2 degrees above average temperatures and near average precipitation.
The rest of this week features a warmer than average scenario resembling late October or early November readings. That translates to temperatures running at least 10-15 degrees above average!
However, by the end of the week, signs of change will already be looming. A shock to the senses with a heavy dose of meteorological reality is expected to overcome this sweet pattern.
The gatekeeper of the Arctic, the Arctic Oscillation teleconnection, is expected to trend toward neutral and slightly negative after a tremendous run of positive readings. What does that mean for us?
Well, recently, some in our region dealt with low temperatures in the teens. This was modified Arctic air, since the AO was still neutral to slightly positive during that time. In addition, some saw their first snowflakes of the season.
With a neutral to slightly negative AO, a taste of true Arctic air will make a run at the United States. How far south that air mass can make it remains to be seen.
At the very least, temperatures returning to the 30's for highs may be possible. But, I think the coldest air will not quite reach us yet. Ahead of a another storm system, temperatures should recover enough to preclude any significant snowfall for most of us. But, I am still hoping that additional data may help enhance our chances while the air could still be cold enough to support snow. Hopefully no ice.
According to my prediction for the rest of the month as noted in my December Prediction, near average to above average temperatures is still expected. But, as more data comes in this week, the AO index could help me fine tune this outlook.
A popular study has linked an above average Eurasian October snowfall will lead to a decisively negative AO winter, which means more shots of cold air for us and the Eastern United States.
Interpreting the study along with their current data, the second half of December would be below average in terms of temperatures.
But the models, at least some, are not in agreement with this happening in December, perhaps because of El Nino's influence.
Right now, I am in that boat. But, if I'm wrong, someone throw me a line and pull me into the other boat please.
MS
The rest of this week features a warmer than average scenario resembling late October or early November readings. That translates to temperatures running at least 10-15 degrees above average!
However, by the end of the week, signs of change will already be looming. A shock to the senses with a heavy dose of meteorological reality is expected to overcome this sweet pattern.
The gatekeeper of the Arctic, the Arctic Oscillation teleconnection, is expected to trend toward neutral and slightly negative after a tremendous run of positive readings. What does that mean for us?
Well, recently, some in our region dealt with low temperatures in the teens. This was modified Arctic air, since the AO was still neutral to slightly positive during that time. In addition, some saw their first snowflakes of the season.
With a neutral to slightly negative AO, a taste of true Arctic air will make a run at the United States. How far south that air mass can make it remains to be seen.
At the very least, temperatures returning to the 30's for highs may be possible. But, I think the coldest air will not quite reach us yet. Ahead of a another storm system, temperatures should recover enough to preclude any significant snowfall for most of us. But, I am still hoping that additional data may help enhance our chances while the air could still be cold enough to support snow. Hopefully no ice.
According to my prediction for the rest of the month as noted in my December Prediction, near average to above average temperatures is still expected. But, as more data comes in this week, the AO index could help me fine tune this outlook.
A popular study has linked an above average Eurasian October snowfall will lead to a decisively negative AO winter, which means more shots of cold air for us and the Eastern United States.
Interpreting the study along with their current data, the second half of December would be below average in terms of temperatures.
But the models, at least some, are not in agreement with this happening in December, perhaps because of El Nino's influence.
Right now, I am in that boat. But, if I'm wrong, someone throw me a line and pull me into the other boat please.
MS
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