Thursday, March 9, 2017  5 P.M.

GFS’s most recent snow forecast:

NAM is also trending toward zero.

Saturday, Feb. 11, 2017  1 P.M.

A weak Alberta Clipper will push rapidly eastward across the lower Great Lakes tonight.  Gusty southerly winds ahead of this system will bring us another unseasonably warm day although those winds are having trouble bringing moisture northward.  However, it does appear likely we’ll see a little rain late tonight as the Clipper’s cold front pushes through.  Rain will probably be only a few hundredths of an inch and end around daybreak tomorrow.  Another windy day Sunday, but this time the winds will be from the northwest.  Thus, colder weather – temperatures will be slowly falling through the 50’s during the day.

Intriguing photos

Got these from http://spaceweather.com   They show a funnel cloud near Rio de Janiero a few days ago.  They did not touch down and caused no damage.  In Brazil they are called “tubes.”

Saturday, Jan. 28, 2017

Update from earlier…first of two small snowfalls mentioned earlier will stay south of Louisville…southern KY may see  up to one-half inch.

Second (afternoon system) will have little moisture to work with so only a little snow shower activity is likely 2 P.M. to 6 P.M. with most areas getting no more than a dusting.  No road problems expected with temperatures remaining above 32 degrees.

Winter Weather Advisory seems misguided to me.

Wednesday, Jan. 4, 2017

Interesting Alberta Low-type system will pass north of the area tomorrow.  This system wasn’t given much credit as recently as yesterday (NWS had only a 40% chance for measurable snowfall Thursday. Now they’ve jumped to 2″-3″ of snow by late tomorrow.)

Models haven’t changed all that much, but the “official” forecast sure has.  Models continue to place the best chance for snow over southern Indiana with I-64 about the southern edge of a possible 1″-3″ snow band.  Louisville area should get around one inch (along with plenty of road problems).  Snow appears likely to begin in Louisville by late morning and end during the evening rush hour.

More later.

THINK SNOW!

Wednesday, Nov. 2, 2016  6 P.M.

After a very dry October, forecasts had been indicating a possibly rainy start to this month.  Unfortunately, that outlook has been drying quickly.  The models stated playing down the rain last night and the trend has continued.  There’s still a pretty high chance for rain tomorrow morning (50%-60%) but even if we do get rain, it won’t be much.  It’s likely to stay below .10″, so not much help to our dry conditions.

One thing the models have strengthened, though, is the magnitude of the colder air to follow – models are now running up to 5 degrees colder (than yesterday) for the weekend.  That still keeps us in above normal temperatures, however.

Looks like we’ll see a period of colder-than-normal weather setting up after Election Day.  More on that later.

Thursday, July 7, 2016

Storms fade…no threat to metro area.

Southeastward thrust to storms continues and any severe weather threat for the Louisville metro area has faded away.  Some heavy rain/gusty winds will hit southern Jefferson County and northern Bullitt County over next 30-45 minutes, but the storms will not be very strong.  Otherwise, rain is fading over southern Indiana.  So, it now appears that most of Jefferson County will get little, if any, rain.

Thursday, July 7, 2016  4:45 P.M.

Decreasing threat to Jefferson County

Most active part of line of thunderstorms approaching us has shifted southward into parts of Meade and Hardin Counties.  Hardin County could still see strong winds of 50 mph or more for the next hour.

Meanwhile, northern part of the line is now entirely south of I-64 in southern Harrison County.  Gusty winds are still likely, but they should stay in the 40-45 mph range.  This line will bring similar winds to areas of Jefferson Co. south of the Watterson X Way between 5:15 and 6 P.M.  Northern Jefferson County and southern Indiana (north of I-64) will be much calmer – not much rain and little wind threat.

Thursday, July 7, 2016  4 P.M.

After the wide model divergence this morning, it’s looking more and more likely as though the short-term models will win out over the big guys (GFS and NAM).  To their credit, the NAM and GFS are rapidly catching on.

Storm Prediction Center has a Severe Thunderstorm WATCH covering about the western half of KY, but it stops short of Louisville.  It doesn’t matter about the watch boundary, because we’re in just as much risk (low) for severe winds as the folks to our west are.  A line of thunderstorms covers southwestern IN and western KY and is rapidly moving eastward – pushing quite strong gusty winds our way.  Radar estimates suggest 60-70 mph winds, but surface results usually don’t match the estimates.  Nevertheless, extreme southern IN and the Louisville area can expect strong (perhaps severe) wind gusts as this line races  through the metro area between approximately 5:15 and 6:30 P.M.  Scattered minor damage and some power outages are likely during that time.

The threat of severe winds from this system drops to near zero very quickly north of I-64.  The above description and timing pertain mostly to the area of IN and KY along and south of I-64.

Thursday, July 7, 2016  11 A.M.

Looking at this morning’s forecast models and actual forecasts is almost a case of “What’s going on?”  Everything you look at has a different story to tell.  First, the NWS forecast includes a scant 20% chance for rain/t-storms today and another 20% chance tonight.  The backbone of our forecast system, the GFS produces a 1% chance today and about 40% tonight (LAMP) and a 4% chance today, 45% tonight (MOS).  Meanwhile, the NAM model output is also low…11% today and 53% tonight.  By the way, all of the “tonight” forecasts call for the rain after midnight.

On the other hand, the Storm Prediction Center gives us a 40% chance for thunderstorms today and just 10% tonight.   Then, the two primary short-term forecasts chime in with a slight different story.  Both the RAP and the HRRR predict a line of thunderstorms to reach the Louisville area between roughly 8 P.M. and Midnight.  Earlier today I saw WAVE TV’s in house model project a line of storms between 6 and 8 P.M..

What’s one to believe?  Good question!  First of all the GFS has been terrible lately as evidenced by a lot of forecasts we’ve heard recently.  Second, the short-term forecasts are better at picking up on the “outflow boundaries” created by previous storm systems, so they should be more reliable.  As a result, I’d lean toward the RAP/HRRR/WAVE forecast expecting a line of thunderstorms this evening.  We’ll see how it plays out.

Latest radar shows single remaining strong t-storm cell in area – just north of the Ohio River in southern Clark Co.  Storm is moving northeast along the river – probably reaching far NE Jefferson Co. and Oldham Co. by 4:50.  Strong, gusty winds possible.  Otherwise, nothing to be concerned about on metro area.