T-storm update

Wednesday, July 13, 2016  4 P.M.

Looks like my earlier forecast is going to be a bust.  Radar showing nothing happening nearby.  So the heat and humidity rule.

My (former?) friends, the RAP/HRRR have backed off from the idea of afternoon thunderstorms, but still show high chances for a line of t-storms tonight – probably between 8 P.M. and Midnight.  So, at least part of my forecast may still happen.  Could be a good light show tonight.

8 P.M. update

Currently strong line of thunderstorms east of Evansville is racing eastward about 30-40 mph.  It should sweep across the metro area between 10 – 11 P.M.  It is weakening ( and will continue on that path) so no problems are expected.

Forecast models in conflict again

Wednesday, July 13, 2016  11 A.M.

Once again, the short term models are at odds with the primary models.  Everyone agrees that it’ll be hot and humid today, but the chances for thunderstorms vary considerably.

First, the big models…the NAM doesn’t produce any  chance for t-storms anywhere over KY or southern IN.  The GFS hints at a small chance especially north of the Ohio River, but it’s numerical statistical output is less than 10% for this afternoon.

Meanwhile, the short-term regional models are much more enthusiastic with t-storm development.  The RAP predicts a large cluster of storms over our area late this afternoon.  The HRRR is even more aggressive with an afternoon and an evening storm cluster moving over us.

The Weather Service is sticking with the NAM/GFS, but with a slight nod toward the short term models.  They give us a 20% rain chance today and tonight.

But, the RAP/HRRR were developed for situations such as this.  They are designed to do the fine-tuning between the gaps in the larger models.  And, last week in a similar situation, they did a great job.  I expect the RAP/HRRR to continue doing their jobs well.  So, I’d expect a much higher chance we’ll see t-storms later today…60% chance or higher.

We’ll see how this battle works out in a few hours.

 

5 P.M. update

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.

Storm update – good news

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.

Late afternoon could get stormy

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.

 

 

Interesting forecast problem today

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.

More odds and ends

Tuesday, June 14, 2016  (Flag Day)

Current Weather:

Humidity rushed into the area in a BIG way late this morning.  Dew points jumped from the mid 50’s to near 70 degrees in three hours!  That has set the stage for some classic popup “hit ‘n’ miss” showers and thunderstorms.  So, far they are mostly west of I-65 but they should advance slowly eastward later this afternoon.  They are moving very slowly – about 10 mph, so if you get caught under one, watch out for some heavy rain in a short time.  As with most so-called “popups” they form quickly then rain themselves out in about an hour.

Looks like a smaller chance for thunderstorms tomorrow, but if any arrive they should be stronger than today’s.

Muhammad Ali:

With the recent death of The Champ and all the television coverage celebrating the international life of our home town hero, the story of the beginning trail of the future “Greatest” was repeated many times.  The story of the stolen bike which began the Joe Martin connection which  led to the boxing ring and future greatness is well known.  WAVE’s tv boxing show for young boxers, “Tomorrow’s Champions”, turned out to be well-named because of some appearances by a young Cassius Clay.  That story is also well known.  But apparently not all of it.

When I arrived at WAVE in 1969, the most popular story included additional details that I didn’t hear anyone relate last week.  So, as the late Paul Harvey would have said, “Here’s the rest of the story…”  Apparently, on Cassius’s first appearance on “Tomorrow’s Champions,” it came time for his match.  But, he was nowhere in sight.  Not in the studio, not in the halls, not in the rest rooms.  Finally WAVE’s legendary Ed Kallay found him in a broom closet…hiding and fighting back tears!  STAGE FRIGHT.  Ed cheered him (as he did countless children over the years),  and got him into the ring.  As they say, the rest is history.

Ali 2:

(Continued later)

4:30 update

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.

More showers/t-storms rumbling toward us.

Thursday, March 31, 2016

Today is another situation where we have a very fine line between strong thunderstorms and a marginally “severe” storm or two.  Nothing really to worry about as the situation just can’t quite get its act together.

Large trough dropping into the midwest will slowly push eastward tonight and tomorrow.  A strong short wave disturbance is rotating around this trough and aiming for the south.  The northern halves of AL and MS as well as western TN  should see a significant severe storm outbreak this evening and tonight.

Meanwhile, a much weaker short wave is moving over western KY right now and is generating a cluster of showers and thunderstorms as it moves toward us.  Look for this rain to reach Louisville about 4 P.M. and depart before 7 P.M.  Some of the embedded thunderstorms could be strong but should not reach into the “severe” range.  (Although with the trend of recent years for the NWS declaring almost any strong thunderstorm “severe”,  I would not be surprised if a  warning or two is issued.)  Keep in mind that a 58 mph wind (the lower limit of severe storms) will do a lot of damage.  Compared to a 50 mph wind gust (which doesn’t do a lot of damage, a 58 mph wind gust has about 35% MORE FORCE!

Later tonight, a cold front will cross IN into KY.  This front should become very active in the next few hours.  Severe thunderstorms will be possible with this front, especially over western and south central Indiana from about 6 P.M. to 9 P.M. EDT.  The southern end of this area will reach the Louisville between 9 P.M. until midnight.  No severe weather weather is expected with this line.  In fact, there’s a reasonable chance it’ll die out before reaching us.

 

 

 

 

You can WATCH all night, but you aren’t likely to see any severe storms

Easter Sunday, 8 P.M.

Severe storm WATCH for the area – looks like the forecasters at SPC were a little bored and tried to get a little excitement in today’s weather.

But the models are showing any instability to grind down to near zero by 9 P.M. AND since the major line of showers/t-storms won’t arrive in Louisville area until after 9 P.M., any threat for severe thunderstorms is close to zero.  Just a few hours of nice rain to help bring us our April showers.

Happy Easter.