Monday, November 26, 2012

UPDATE Snow For Louisville?

Yesterday's post dealt with the chances for measurable snow here in Louisville. I was not very impressed by the NAM and GFS 850mb forecast temperatures. Readings between 0 and -2 degrees Celsius may denote a mix at best but not good enough for a complete changeover.

Today, my thinking remains mostly in line with yesterday's thinking. However, the NAM has trended slightly cooler with 850mb readings between -1 and -3 degrees Celsius. Also, the freezing line (the 540 line) looks to be just along the river, perhaps just north as the main precipitation shield plans to exit the area here in Louisville.

If the precip can hang around long enough, as colder air filters into the region, rain could mix and change completely to snow later. However, accumulations continue to look negligible as surface temperatures will be  too warm.

Look for mostly rain, with snow mixing in at times. I still don't forecast a complete changeover.]

MS

Sunday, November 25, 2012

Snow For Louisville?

The 12z NAM is in...This will be the one that I go by.

Moisture placement is right over Louisville by 1:00am Tue. Expect up to 0.25" liquid equivalent.

How much will fall as snow? NAM 850 mb forecast keeps temps in the 0 to -2 Celsius range, not really good enough for all snow. However, it appears that some snow will mix in with the rain.

Some locations could see some whitening on the grassy surfaces. Right now, snow accumulations look negligible.

More updates later.

MS

Wednesday, November 21, 2012

MikeS 66 Index 112112

My biweekly index for today (actually yesterday's data) was an impressive 51.5 degrees. That's an average of the high and low temperatures from 66 locations across the U.S.

All 6 climate divisions of the U.S. experienced above normal temperatures.

Here's a breakdown of those climate divisions...

High Plains 13.1 degrees ABOVE NORMAL
Midwest 9.7 degrees ABOVE NORMAL
Northeast 0.4 degrees ABOVE NORMAL
Southeast 0.4 degrees ABOVE NORMAL
Southern 6.6 degrees ABOVE NORMAL
West 10.3 degrees ABOVE NORMAL

66 Index 51.5 degrees
6.8 degrees ABOVE NORMAL

However, look for a cool down across the north and northeast. We'll see colder readings here in Louisville by the weekend. Enjoy it for now.

MS

Monday, November 19, 2012

Flood Advisory Grand Canyon?

I'm looking at the RADAR and can't find a single drop within a few hundred miles of the Grand Canyon. Yet, there is a flood advisory???

Well, on Sunday, a High-Flow Experimental (HFE) release of nearly 42,000 cubic feet per second (cfs) was being conducted for 24 hours from the Glen Canyon Dam.

Typical releases from the Glen Canyon Dam range from 8,000 to 25,000 cfs. This has been a normal event since 1996 and is part of a mandate called the Grand Canyon Protection Act. However, the increase in flow to 42,000 cfs should help move sand from the river channel and deposit it to rebuild sandbars and beaches at the National Park.

Still, those along the Colorado river should exercise caution when conducting recreational activities for the next several hours.

More information found at the link below...
http://www.nps.gov/GRCA/NATURESCIENCE/HFE.HTM

MS


Rain, Rain, Go Away...

Ok, not much rain around here in Kentucky and Southern Indiana. In fact, our weather looks outstanding for most of the holiday week.

For a moment, let's turn our attention to the northwest. Rain is in the forecast for the next several days.

One of the wettest locations in the U.S. is a place called Forks WA. As of early this morning, precipitation has finally surpassed the 100" mark. To date, there has been measurable precipitation of at least 0.01" for 197 days this year. Last year, Forks received a little over 120". They recorded precipitation 237 days last year.

Measurable precipitation of at least 0.01" in Seattle has occurred 143 days this year. However, only 35.86" has been measured.

In contrast, here in Louisville, we have had measurable precipitation 102 days this year. Precipitation amounts have totaled 38.46".

On the snow side of things, mountain passes near Mt Baker and Paradise near Rainier could see 1-3 feet of snow this week. Locally heavier amounts may occur if temperatures remain cold enough.

I'll be posting rain and snow amounts for Washington later this week.

MS

Climate Prediction Center - Preliminary Winter Outlook

On November 15, the Climate Prediction Center (CPC) put out a preliminary winter outlook for the three-month period of December through February.

Since the final map may be different than the preliminary, I'll give you the link but discuss the outlook here.

Temperatures are expected to be warmer than average across much of the western U.S., from Louisiana to Kansas to parts of Oregon and southern Montana.

Below normal temperatures are expected in southern Alaska, the northern plains including the U.P. of Michigan, and a large part of Florida.

As far as precipitation probabilities, above normal chances exist across parts of the south, the lower Ohio Valley and Tennessee Valley. Some states include Arkansas, Kentucky, and Tennessee.

Below normal precipitation chances exist in southern Alaska and California, generally north of Los Angeles and into parts of Nevada.

Link:
CPC Preliminary 3-Month Winter Outlook Dec-Feb

MS

Sunday, November 18, 2012

MikeS 66 Index 111812

66 Index (Temperature)  for Saturday 11/17/12
47.8
Above Average

The 6 climate divisions of the U.S.
West   6.1 above
Southern 1.5 below
Southeast 3.6 below
Northeast 2.3 below
Midwest 3.2 above
High Plains 10.9 above


Last Reading 11/13/12
42.9
Much Below Average

MS


Saturday, November 17, 2012

'Cool' High

For the 50 states, the highest temperature was 83 degrees yesterday in San Nicolas CA and Barbers Point NAS in Oahu. In fact, only 16 reporting stations had temperatures of at least 80 degrees.

The coldest temperature was at Fort Yukon AK at -35. They're already in a streak of several days below zero. The forecast through next Friday keeps temperatures below zero. Brrrr.

http://pafg.arh.noaa.gov/zonefcst.php?zone=AKZ220

MS

Thursday, November 15, 2012

OFFICIAL 2012/2013 Winter Forecast

Although I'm offering my thoughts for Kentucky and Southern Indiana, I do provide a summary of how this winter will affect the various climate sections of the United States. Therefore, those who live outside of the Kentucky/Southern Indiana region can figure out how their winter may unfold based on the data I selected.

The first thing you will notice is that there is no map. I have the paper and the technology. So, let me explain  why I chose not to use a map.

I shared some research data the other day in a post while working on the winter forecast. Reviewing the information, expect more extreme weather for the upcoming year based on startling data from the Arctic region.

Arctic Sea Ice Extent reached an all-time low in September. Here is a term you're going to love, Arctic Amplification. Enhanced warming of the Arctic slows the west-east jet stream there and promotes more of a north-south flow. Pinpointing when and where that north-south flow (amplification) will be is still quite difficult. However, one thing is for sure. As more solar energy penetrates the Arctic Ocean where ice used to be, expect more extreme weather here in the States and Western Europe.

That's why I chose not to use a map. One just cannot predict where the extreme weather will set up. The intensity will vary as well.

Next, I don't promote global warming. However, one cannot escape the data that supports it.

For example, the October CO2 data from Mauna Loa, Hawaii continues to show an uptrend. The data from last October was 388.92 ppm. This October, the reading was 391.01 ppm.

Apparently, rising CO2 emissions continue contributing to extreme weather events.

Pay attention to the Sea-Surface temperatures. El Nino and La Nina do not appear to be factors this upcoming winter. However, there's been a cool fetch from Hawaii to Southern California. We'll see how this affects moisture transport.

Pacific North American pattern (PNA) values registered negative during October. As we approach the colder months, if the PNA remains negative, expect more split flows in the jet stream. That makes life exciting around here in Kentucky. However, there are indications that the PNA will turn positive again in December, thus shutting off the split flows.

Snowpack in North America and the Northern Hemisphere is more widespread than last year at this time. That could bode well for snow lovers.

The main event could be related to the Arctic Oscillation. Negative values in October mean average to above average snowfall for Louisville Kentucky. While professionals focus more on the NAO, both of these teleconnectors are short term prognosticators, unreliable for anything outside of two weeks.

However, look to the Arctic regions for our upcoming winter weather. The amplification could rear its head here. Pay close attention to the AO in the upcoming weeks. Negative values will support colder transport of air. Any strong systems from the Alaskan/Northwest regions along with colder values may set the stage for tremendous snowfall amounts for some.

SUMMARY

Wet/Snowy Northwest
Drier than normal southern California and southwest U.S.
Cold Midwest and average snowfall
Average to above average snowfall in CO, OK, MO, KY, VA, and WV.
Average snowfall in the mid-Atlantic
Cold and Average to Above average snowfall in the Northeast
Wetter than normal in southern Florida
Drier than normal in northern FL and GA

CONCLUSION

Louisville KY (Dec-Feb) 12-19"
Lexington KY                  13-20"
Bowling Green KY           9-16"
Paducah KY                    10-17"
Jackson KY                     14-22"
Indianapolis IN                 14-21"
Cincinnati OH                   14-21"

Remember, these values are based on my traditional 60-30 percent forecast. There is an increased chance for extreme winter weather for our part of the world that is not factored into the above numbers.

I will post this to the blog for easy access.

MS

MikeS 66 Index UPDATE

Yesterday, I introduced an index designed to take the 'temperature' of the U.S. I gathered data from 66 locations around the United States. Typically, I will just show the one number and provide a brief explanation of average, above average, below average, much above average, or much below average.

I will be featuring the index twice a week, on Wednesdays and Sundays. As I continue working on the database, I'll be dividing the U.S. into its climate sections and offer an opinion for each section based on the '66' locations I've chosen.

You can use this data to compare how well the NAO, AO, PNA, and other data from the Climate Prediction Center is faring.

As described on Wednesday, I'll use the high and low temperatures from these locations and take the average, thus giving the number for the index.

November 14's index number was based on November 13's data. Therefore, here was the final tally given on Wednesday, November 14

MikeS 66 Index - 42.9
Much Below Average

My official 2012/2013 winter forecast is coming very soon. Be looking for it.

MS

Wednesday, November 14, 2012

MikeS 66 Index

I'm introducing an index for measuring temperature data across the United States. It takes into account 66 representative locations and their high and low temperatures averaged out.

For example, November 13's data showed these numbers...

Average High
53.65

Average Low
32.08

Index = (AH + AL)/2 = 42.86
MikeS 66 Index = 42.9 degrees (rounded)

I'm still working on how the number will represent departures from normal.

Stay tuned....

MS

Winter Weather Forecast 2012/2013 - Research Data

I'm still working on it. I should have my data ready to go in about a week or so.

However, as I perform numerous amounts of data research in preparation for the upcoming winter forecast, I can't help but share some interesting news stories and links along the way.

On September 16 2012, the Arctic Sea Ice Extent reached a lowest daily extent of 1.32 million square miles. The average extent of 1.39 million square miles for the month of September was an all-time minimum extent since records started being kept in 1979.

The total melt of 4.57 million square miles during the season amounts to the size of the United States and Mexico combined.

Below, I'm also providing a press release from NOAA about the possible connection between the Arctic region and extreme weather events here in the U.S. and Europe.

NOAA Press Release

On the other hand, Antarctic Sea Ice reached an all-time highest daily extent on record with a maximum of 7.51 million square miles on September 26. This record was set despite the continued warming over the past several decades.

Source: http://www.ncdc.noaa.gov/sotc/hazards/2012/9

MS

Wednesday, November 7, 2012

Winter Coming Early???

Here we go again. It's about time for all of the prognosticators or wannabes to throw their darts at the elusive winter weather bull's eye.

Last year, I believe my dart landed somewhere on the other side of the room.

What about this year? Surely, I'll do better than last year.

Already, a historic beginning to the winter 2012/2013 season. Superstorm Sandy produced all-time record snows for the month of October in locations like Beckley, Charleston, and Elkins WV.

The Weather Channel just named its first winter storm, Athena. The Nor'easter will impact several locations that Sandy affected just over a week ago. Philly expects 3-5" of snow. However, more coastal problems are expected and additional power outages could occur.

Locally, Louisville averages between 12-14" snow each season. One parameter that I did not factor into my equation for last year is what's called the Arctic Oscillation (AO).

I strongly believe that the month of October can have an effect on the future winter weather season of Dec-Feb. 

I found this interesting tidbit for you snow lovers.

Historically, here in Louisville, looking at the past five years, look what I've discovered...

AO positive for October, snow below average for Louisville
AO negative for October, snow above average for Louisville

The latest AO index for October: NEGATIVE
This should mean that Louisville will see more than 12-14" this winter.

And I'm just getting warmed up...uh, no pun intended.
More updates later this month.

MS 


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