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....

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

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.


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....

1. See Text
2. Slight (SLGT)
3. Moderate (MDT)
4. High (HIGH)
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)

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


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.