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

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

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

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

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

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