Monday, September 29, 2014

Louisville and Lexington's Last Top Ten Snowiest Month

It's Fall and you know what that means? Beautiful colors, right? Uh, raking leaves? Um, cooler temperatures? No, just winter. Who cares about Fall? Nothing to see here, move along.

I sometimes think people believe that Fall is an appetizer, something that whets the appetite for the main course, which, in our case here in the Ohio Valley, means winter.

In fact, I have read many comments about how neat it would be to have snow in October. In other words, just skip the appetizer. Bring on the meat!

Well, since it is not October yet, I am going to dole out a spoonful of winter to you, you know, just to whet your appetite.

The 2013-2014 winter season was productive in terms of snowfall for both Louisville and Lexington. But, looking at each month and its contribution to the 'white quilt patchwork', there were absolutely no months that achieved a top ten snowiest month status.

Louisville and Lexington's last top ten snowiest month came in the year 2010. February was a snowy month for both cities at 13.9" and 12.1" respectively. However, Lexington achieved another top ten snowiest month later that year in December with 12.4".

Here is a breakdown of the MINIMUM amount of snow needed to achieve top ten snowiest month status for each month....

Louisville
October - 1.2"
November - 2.0"
December - 7.7"
January - 11.8"
February - 10.9"
March - 9.4"
April - 0.4"

Lexington
October - 0.1"
November - 2.9"
December - 9.0"
January - 15.6"
February - 10.7"
March - 8.6"
April - 1.0"

Some of these numbers are certainly achievable especially if we have an unusual cold snap early in the Fall and early in Spring. If the same old pattern continues, I would not be surprised if a cold snap involves a little bit of the white stuff.

MS

Thursday, September 25, 2014

Changes Coming to SPC's Day 1-3 Convective Outlook

The experimental 1-3 day convective outlook from the Storm Prediction Center (SPC) will soon become operational beginning October 22. What is this all about?

Remember how convective outlooks would be issued displaying slight, moderate, and high risk areas with their appropriate colored shadings?

Well, the upcoming changes will add to the levels of risk as depicted below....

Current:
1. See Text
2. Slight (SLGT)
3. Moderate (MDT)
4. High (HIGH)
Proposed:
1. Marginal (MRGL) - replaces the current SEE TEXT and now is described with Categorical line on the SPC Outlook.
2. Slight (SLGT)
3. Enhanced (ENH) - will replace upper-end SLGT risk probabilities, but is not a MDT risk
4. Moderate (MDT)
5. High (HIGH)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
MS 

Wednesday, September 24, 2014

Experimental Forecast II - ECMWF vs GFS (Sep 25 - Oct 02 2014)

ECMWF won the first one by a landslide in predicting high temperatures. This next round might be closer as both models are very even in their forecast highs during this time.


25th - GFS  79
          Euro  78

26th - GFS  79
          Euro  79

27th - GFS  80
          Euro  79

28th - GFS  80
          Euro  80

29th - GFS  79
          Euro  80

30th - GFS  78
          Euro  78

01 - GFS  81
       Euro  81

02 - GFS  81
       Euro  83

MS

Looking Two Weeks Down the Road Sep 24 - Oct 8 2014

It's always fun trying to figure out what could happen several days down the road. Unfortunately, accuracy of available information is still in its developing stages. So, think of it as 'for intelligent entertainment purposes only'.

Now, I will say that some computer models are really doing a better job forecasting out some 10 days in advance. I just completed the results of one study comparing the 850 hPa of the ECMWF and GFS and performing my interpretation of the high temperatures expected during a 9-day stretch.

The ECMWF performed very well over that period. The GFS, well, it is the GFS. Hopefully in the coming years, more money can become available to enhance our medium-range computer models. A high resolution type like the ECMWF can be very useful, not just for temperatures, but the whole range of weather.

Therefore, I relied quite a bit on the 'Euro' forecast model for this two week period.

First, very nice, tranquil weather will continue on into this weekend. Even the GFS has no problem with that.

Next week, still does not look that bad. According to a recent run of the Euro, a storm system does appear that it will affect the region early on. However, the bulk of the precipitation may not affect the entire state of Kentucky. Perhaps more southern and eastern Kentucky counties will see the most rainfall.

Then, that's outta here.

Well, after that, it starts getting interesting. A storm system with cold Canadian origins will make its trek sliding down the jet stream toward the U.S. A rush of warm air advection ahead of the front could push high temperatures into the 80's for the first part of October. Not bad.

However, the cold air will begin spilling into the area by the first weekend of October. At this time, temperatures appear to be similar to the air mass we've been experiencing, maybe a tad cooler.

Finally, a potent low pressure system will be following on the heels of the prior system. Temperatures will be hard pressed to recover during this time. Therefore, I'm expecting high temperatures not making it out of the 50's perhaps even here in Louisville toward the beginning of the first full week of October, say the 5th or 6th, and possible frost in here by the 6th.

At this time, it is hard to say whether October will be a cold month overall, like 1987 (an analog I'm using). Nevertheless, I'll be cleaning out my garden by the first few days of October, harvesting whatever is left before the possible first frost a few days afterward.

MS

Friday, September 19, 2014

Crunching Numbers...Statistics for Louisville 2013

The other day I was wondering what was the most common daily temperature reported for all of last year at the airport here in Louisville. Now, this would be defined by both the daily high and low temperatures for any given day totaling 365 days, or 730 entries.

After performing a histogram on the data, here's what it revealed...

Louisville International's most common daily temperature was...(drum roll please)...64 degrees.

Here is a list of the top 5:

64 degrees       21x
68 degrees       19x
34 degrees       18x
70 degrees       17x
73 degrees       17x

The mean or average temperature for 2013 was 57.5 degrees and a standard deviation of 20.4 degrees.

The maximum temperature was 96 and the minimum was 9.

Below is a summary of the statistical data...notice the 'Mode' shows 64, which is the most common temperature reported for last year. - MS


Column1
Mean 57.53836
Standard Error 0.755293
Median 59
Mode 64
Standard Deviation 20.40688
Sample Variance 416.4409
Kurtosis -1.01645
Skewness -0.14554
Range 87
Minimum 9
Maximum 96
Sum 42003
Count 730

Thursday, September 18, 2014

9-Day Forecast Sept 19-27

Beautiful weather. It has been a while since I've enjoyed this kind of weather. And you know what? We're going to have some more.

Temperatures will return briefly to the 80's and then cool back down for the rest of next week.
Except for a shower chance later this weekend, the remainder of next week appears dry and tranquil...and pleasant.

Expect some pretty cool readings for Tuesday morning. Some locations could be flirting with 40 degree low temperatures.

Enjoy the week ahead.

Friday 19th  78
Saturday 20th  64/83
Sunday 21st   66/79  Shower chance
Monday 22nd  60/68
Tuesday 23rd  49/70
Wednesday 24th  51/73
Thursday 25th  54/76
Friday 26th  55/78
Saturday 27th 55/79

MS

Wednesday, September 17, 2014

Cold Blast At the Start of October???

I remember the first few days of October 1987. Man, it got cold. Especially since earlier during that week temperatures were well into the 80's but dropped into the upper 50's for highs toward the end of the week.

However, it was the nighttime temperatures that got me. Where I was camping, somewhere along the Green river in a cornfield near Beaver Dam, we had lows in the 33-34 degree range. My buddy and I still laugh about the moment that when the fire died down, I decided to shed my sleeping bag and walked toward his tent and demanded "Let me in...C'mon, let me in.

For Louisville, October 1987 finished as the 6th coldest October on record. The following year, October 1988 would become the 4th coldest October on record.

Now, I am not going to go all out and say October will be one of the coldest that we've had in years, but there are signs that the first week of October could start out very cool, if not downright cold.

I do not see any model showing how cold it will be yet. However, there is a storm system that is forecast to ride up the west coast over a High pressure ridge, tap into cold Canadian air that is building at present, and should be poised to follow a similar track that we have seen for many months it seems.

Cold air will spill into the northern U.S. and begin overspreading more real estate. How far south will that cold air reach? Where will the core of the cold air set up? Will it be of any consequence anyway?

Well, if parts of Kentucky do not get in on some frost by next week, heading toward the latter part of this month and into the first part of October looks like some locations could be staring at their first frost.

That's when I'll be getting out the big stainless steel pot for some chili and home-grown habaneros. Yee-hah!

MS

Monday, September 15, 2014

9-Day Forecast for Louisville KY Sep 16-24

Benign weather will rule most of the week. Rain chances increase by the end of the weekend ahead of the next cold front. Pleasant temperatures in the 70's for the rest of the work week. Look for 80's as we head into the weekend. The start of next week appears to cool off, although models vary on how much cooling takes place. I will side with the ECMWF for now. We will have to watch how a tropical system in the west will interact with the aforementioned front for the weekend and any development in the Atlantic / Caribbean.

Tue 70
Wed 51 / 72
Thr  52 / 73
Fri  53 / 77
Sat 57 / 82
Sun 63 / 81   PM Rain
Mon 64 / 75  AM Rain
Tue 54 / 71
Wed 50 / 73

Climate Prediction Center's 6-10 day outlook for September 20-24 shows above normal temperatures for the western half of the state while equal chances for the rest of the state. However, if the ECMWF is correct, then the trend will be toward cooler than normal for this time period from Saturday through Wednesday (for Louisville).

MS

Friday, September 12, 2014

Experimental Forecast Using ECMWF and GFS Temperatures September 13-21

09/15/14 UPDATE
Oops...I never mentioned the forecast below is for Louisville, KY. I'm betting people in Florida were probably upset with me about this forecast. Okay, probably not.

By the way, so far, the highs were 68 Saturday and 75 Sunday for Louisville. The models have done a pretty good job over the weekend as far as my interpretation of the 850mb forecast. One has to remember that 850mb forecasts can be misleading because warm air advection and cold air advection can skew results. -- MS

During the past week, I've been able to use the ECMWF or the European Medium-Range forecast model and have found it fairly accurate at forecasting temperatures some 5-7 days out.

I favor the European model instead of the American model (GFS) at this many days out. However, I do like the NAM model, but it only goes out a few days.

Temperatures for the upcoming week...Fri 12 Sep 00Z run

Saturday...
GFS near 70
NAM 69
ECMWF 67

Sunday
GFS 75
NAM 74
ECMWF 74

Monday
GFS 79
ECMWF 77

Tuesday
GFS 75
ECMWF near 70

Wednesday
GFS 72
ECMWF 71

Thursday
GFS 74
ECMWF 76

Friday
GFS 76
ECMWF 79

Saturday
GFS 77
ECMWF 81

Sunday
GFS 80
ECMWF 83

The models agree about another cool day for Saturday before moderating well into the 70's by Monday. Then another shot of cooler air arrives for Tuesday and Wednesday. The Euro and GFS differ on how cool by Tuesday but then show a gradual warming trend for Thursday thru Sunday. It looks like the best chance for widespread precipitation won't be until sometime next weekend. So, enjoy the upcoming weather and the nice temperatures.

MS

Thursday, September 11, 2014

How Wet Was August 2014???

August was a record setting wet month for Bowling Green KY while Lexington and Louisville finished in the top ten wettest Augusts on record.

Here is a breakdown on how we did....

August 2014 precipitation

U.S. 11th wettest

Kentucky 13th wettest

Central Kentucky Division 7th wettest
------------------------------

As far as the United States, several states of the Great Plains and part of the Great Basin experienced near all-time wettest Augusts ever. Montana actually had its wettest August ever...

Map of United States Statewide Precipitation Rank

MS

Wednesday, September 10, 2014

Replacing Human with Computerized Voices in Alaska

In June 2014, it was announced that the weather offices using live human voices for the All-Hazards Weather Radio in Nome and Kodiak will be switching to the computerized generation of voices dubbed as "Tom", "Donna", "Paul", and "Javier".

I must have been sleeping under a rock when the announcement was made. But, if you would like to read more, here's the link below...

http://phys.org/news/2014-06-humans-weather.html

MS

Monday, September 8, 2014

My Thoughts for the Next Two Weeks (Sept 8 - 22 2014)

Fall is in the air. Love it.

At times, I like to gather whatever resources I have at my disposal and make a prognostication about what will happen over the next two weeks.

From the CPC, below normal temperatures are a sure bet over the next several days. In fact the 6-10 day outlook places Kentucky within a 70-80 percent probability for below normal temps.

Next, precipitation outlook finally levels off. It appears we will finally normalize or even be slightly below normal during this period.

Medium-range models like the ECMWF show two shots of cooler air invading the region, not counting the one we have currently.

The first one has been well-advertised on this blog and continues to show a chunk of very cool air carving out a large piece of atmospheric real estate that will include us here in Kentucky.

High temperatures look to be somewhere in the 60's to near 70 with lows from 40-50 degrees by Saturday and Sunday morning.

PNA teleconnection suggests a  positive reading for the west coast. That may not sound familiar, but this should. Ridge west, trough east.

With cold air building in Canada, storm tracks will go up and over the western ridge, tap into the Canadian Cooler, and dive south into our part of the world. That's what happens with this first setup.

The next setup is intriguing. Model indications favor a system with tropical characteristics moving up the Atlantic coast in about a week. Deepening low pressure within the Gulf Stream current will cause the counter-clockwise flow around low pressure to reach into the Canadian provinces as it intensifies thereby bringing additional cool air into our region, though perhaps not as cool as the first one.

Of course, we'll have to wait and see how that works out. In between the cool shots, we will have some warmth, though the summer-like heat may just about be over.

MS

ECMWF Model Modifies the Impending Cool Air

A couple of days ago, the medium-range model was spitting out very impressive numbers regarding a Hudson Bay Low sending a chunk of cold air into the nation's northern sections spreading well into the Midwest by next weekend.

Well, the air still looks very cool for this early part of Meteorological Fall but has modified somewhat. Nevertheless, daytime temperatures still look to be in the 60's for many locations in Kentucky with overnight lows ranging from 40-50 degrees during the coolest feature of this air mass.

A projected 1030-1036 mb air mass that should settle into the nation's Heartland is the type that is straight out of Canada. Right now, current forecasts have the core of the coolest air just west and north of our region.

Places like Kansas City may only see temperatures in the low to mid 60's by Friday. I like to use KC as a barometer as to how our weather will behave in a pattern like this. Typically, Louisville's daytime temperatures will run about 2-5 degrees warmer. Therefore, 65-70 looks good for Saturday with lows between 48 and 53 in the city with low and mid 40's in the rural areas.

MS

Saturday, September 6, 2014

Still Seeing Cold By Next Saturday

There's nothing like crisp, fall weather and football. Well, you might want to put those chili ingredients on your grocery list because by next Saturday, we could be looking at high temperatures struggling to reach 60 degrees for some areas along and north of I-64.

If the ECMWF's forecast model holds true to form, overnight low temperatures could very well dip into the upper 30's and low 40's for many locations by next Sunday morning if we have a clear sky and calm wind.

Before that happens, look for seasonal temperatures in the 80's through at least midweek before cooling to the 70's before week's end and then ranging from 60-65 for next Saturday's high temperatures.

I'll be posting further updates regularly about this fall-like shift for the next few days.

MS

Friday, September 5, 2014

Coldest Air of the Season On the Horizon

UPDATE 09/06/14
Updated dates below to reflect model runs of the Euro Model. 7-10 days out does not go beyond the 16th. I had posted dates beyond that for some reason.
-------------------------------

Here we go again...talk of another Polar Vortex coming soon to the United States? I hope the media and some meteorological sources do not hype this thing up again like previous instances.

However, admittedly, when I looked at a recent run of the ECMWF, which is the model of choice for me at 7-10 days out, the depiction of a deep trough spinning above the Hudson Bay with spokes of cold air funneling toward the U.S. border tells me that the growing season may be coming to an end soon for some residents of Minnesota and the U.P. of Michigan.

Now, I am not talking this weekend but maybe next weekend. But, a consistent signal is showing up that by the September 13-15 time frame, a nice blast of very cool air may be invading initially the northern portions of the upper Midwest then surging southward toward our region of Kentucky.

The 00z run for Sunday evening of September 14 shows some serious cold near the Hudson Bay. The question is how much modification of that cold air will take place as it surges southward toward the northern U.S.?

Looking down the road, I would not be surprised to see overnight low readings here in Louisville drop to the mid 40's with upper 30's to low 40's in the outlying areas by the 14th. And that may be conservative. Depending on cloud cover, some areas may struggle with getting out of the 50's for highs!

This is just a preliminary look at what could happen. There's a lot of uncertainty concerning the details but does show our first blast of autumn air poised to infiltrate the region within the next two weeks.

Stay tuned...

MS

MikJournal Monday 09/18/2017...Remembering Hurricane Hugo and Maria Looming

Welcome to another installment of MikJournal Monday. It looks like a pretty quiet week in terms of weather. Yes, there will be a few showers...