Category Archives: commentary

Potential storms update

Sat. Nov.18, 2017  3:10 P.M.

Severe Thunderstorm WATCH expanded  WHY?

The Storm Prediction Center has seen fit to expand the Tstorm Watch to cover most of Kentucky.  At least for northern half of KY and southern half of IN, watch seems pretty useless.  As mentioned earlier, the part of the storm line approaching our region has lost any severe weather characteristics.

So, risk of severe thunderstorms for Louisville area is extremely low.  Southern KY has a very slight risk.

Strong Storms likely early tonight.

Sunday, November 5, 2017  5 P.M.

A cold front will sweep across the area tonight bringing an end to the recent warm weather.  The warm air has brought an unusually large amount (for November) of moisture into the lower Ohio Valley, so the colder air looks as thought it’ll arrive along with rain, thunder and strong winds. just how strong the winds will be is the primary concern now.

This system has plenty of wind fields, convergence patterns and overall dynamics which provide an important side of the severe weather equation.  However, the thermodynamic part of the equation, while sufficient for severe storms now (from southern Missouri to central Indiana), is forecast to weaken quickly over the next few hours.

A similar system last spring stayed active all night creating probably our worst severe weather outbreak of this year. Chances for a repeat don’t look too high to me – storms along the front are not nearly as strong or widespread as the previous case.

Here’s what I expect to happen: A line of strong-to-severe thunderstorms to our west will move rapidly (30-40 mph) east this evening and be located from about western Ky to Evansville to Indy by 9 P.M.  This line of thunderstorms will cross the Louisville area from about 10 P.M. until 1 A.M.  After that, the frontal storms will race eastward across the rest of KY.

In terms of what is called “sensible” weather, the Louisville area can expect…

8 – 10 P.M. – Strong, gusty southerly winds will precede  the line of thunderstorms.  Winds should gust from 25-35 mph with some gusts reaching to around 40 mph.

10 P.M. – 1 A.M.  Line of strong storms sweeps rapidly through the area.  Winds should gust to 40-50 mph with a few higher gusts.  Gusts over 50 mph should occur mostly north of Louisville.  Brief periods of heavy rain are likely and some of the strongest storms may produce small hail.  Power outages and some tree/limb damage are likely.  However, such areas should be localized and not widespread.

AFTER 1 A.M. – Rain fades quickly but wind gusts remain in the 25 – 35 mph range for a couple of hours before fading  by morning.   One note of caution:  The area  roadways will probably be covered in leaves by morning.  Wet leaves on the roads can be almost as slippery as ice.  Be advised.

Hurricane Irma, part 6

3 P.M. Sunday, Sept 10, 2017

Irma Should hit land soon

“Ground truth” so far has been far below NHC predictions

Weakening Irma is now a low Cat 3 and could drop to a 2 in a few hours.  Cuba took out a lot of Irma’s punch yesterday and she did rebound a bit overnight.  Now, however, even with the eye still at sea, a large part of the eastern half of Irma is over Florida.  Plus, a pocket of drier air is invading the southwestern quadrant of the storm.  The result is a weakening Irma.  Her current path should put her over Marco Island within a hour.  Then move north to Naples, Sanibel Island and Cape Coral during the next 4-5 hours.  With the exception of some of the Keys, the above mentioned places will most likely see the worst that Irma has to offer.  While certainly significant, the current wind field contains only about 73% of the force compared to the wind field predicted yesterday.

So, Irma in her present condition poses much less of a threat than had been predicted for days.  A lot of the extreme conditions that had been hyped for days will not happen, but 110-120 mph winds can still cause a LOT of damage.

Note:  It still looks like the remnants of Irma will bring rain to Kentucky beginning Tuesday and ending Thursday.  So kudos to the GFS model which was the first model I know of that picked up on this idea. (2-3 days ahead of the other major models.)  A lot of forecasters deride the GFS and prefer to use the European Model.  But, in this case the GFS was the clear winner.

Hurricane Irma

Irma’s a Category 5

 

Irma is a long way from the U.S., but some islands like the U.S. and British Virgin Islands will get hit hard soon.  After that the various models seem to fall into two central ideas – both bring Irma WNW staying just north of Puerto Rico and Cuba (while wiping out the Turks and Caicos) until things change while she’s just south of Florida.  About half the models bring the storm north either over Florida or just off the east coast.  Then a move inland anywhere between Georgia and Myrtle Beach. (Hilton Head ?)
   Second set of models brings Irma along the west coast of Florida with landfall over the panhandle to as far west as Mobile.
   It’s anybody’s guess at this time – a few minor changes over the next few days could alter the forecast significantly.
As to intensity, Irma’s a Category 5 now.  The strongest hurricane ever observed purely over the Atlantic Ocean.  Stronger hurricanes have formed over the Atlantic Basin, but they were in either the Gulf of Mexico or the Caribbean Sea.
     While hurricane position forecasting has steadily improved, the same cannot be said for intensity forecasts.  They are notoriously poor!  Just yesterday the forecast for Irma was to remain a Cat 3 through tomorrow, then slowly weaken; today she’s a Cat 5. Today’s prediction is for Irma to slowly weaken over the next five days, but remain a major hurricane.
P.S. Just a final thought…The morning run of the U.S. workhorse forecast model, the GFS, brings Irma northward along the Florida Coast this weekend with landfall near the Georgia/South Carolina border.  The GFS then weakens the storm as it drifts northwest.  Finally, the GFS has Irma’s remnants fading away over Kentucky next Wed/Thu.  Just something to think about.
(I think you should NEVER believe  a weather forecast that far in advance – let’s see what happens.)

 

Hits and Misses

Thursday, August 3, 2017

Quote of the day.

Yesterday, as part of my waking-up ritual, I turned on NOAA Weather Radio to get my daily morning update.  Within seconds, I burst out laughing.  I thought I must have mis-understood what I heard.  But, a second time around I heard the same thing.  from the Hazardous Weather Outlook came this statement:  Some Thunderstorms may produce lightning.

Your tax dollars at work.

And, speaking of our tax dollars…is it just me, or do others believe that our “official” forecasts have been pretty bad this summer?  I know as well as anyone about the frustrations of forecasting convective systems.  But, we’ve been bombarded with forecasts of “rainageddon”, severe storms and chaos several times with nothing to show for it.  In fact, the biggest rain we’ve had recently (July 23) was barely given any attention.  That situation was fun to watch while it unfolded – the NWS changed/updated their forecast 4-5 times over about 8 hours AND the only one that was correct came out about 3 hours after the rain ended!    NOTE:  The NWS had another case of “the cat chasing its tail” a few days back when they issued a spurious heavy thunderstorm forecast about three hours after the threat had ended.

El Nino/La Nina outlook

Most of the first half of the year, NOAA’s long term climate forecast model, Cfsv2, was predicting a climb  back into mild El Nino conditions for late fall and winter.  Over the past couple of months, the model has done a flip.  Now, it’s forecasting a mild La Nina to develop.

The consequences/forecast for North America has also flipped -early forecasts indicated a below normal temperature for our winter.  Now, they are strongly indicating a very mild winter.

And, by the way… the current NWS forecast for tomorrow is just plain not going to happen.  No way.  We have about a 30% chance for showers around 8-10 A.M.  Nothing close to the “numerous showers and thunderstorms” in the forecast.

A very confusing situation…

Thursday, March 30, 2017

The atmosphere may, or may not, be primed for severe storms later this afternoon/evening.  The confusion was apparent yesterday as the GFS and NAM far apart in their solutions for today’s weather/thunderstorm possibilities – the GFS wasn’t too keen on severe thunderstorms while the NAM jumped on severe weather big time.  Today, the GFS and NAM are closer, but still at odds.  Meanwhile the short term models, while agreeing in general about how things will evolve, are also divergent about the expected strength of any thunderstorms.

Going with the suspicion that each model has something good to add to the discussion, here’s how I believe the weather will evolve this afternoon/evening:                                                                First, the amount of cloud cover that remains this afternoon is very important.  Remains from storms to our west overnight have been hanging around this morning.  We should get enough brakes in the clouds this afternoon to allow some sunshine to build up heat (and energy) for some storms.  More sunshine is likely over KY than IN.  Lack of sunshine will diminish the severe storm threat.  Satellite data shows the clouds thinning as of Noon.

Second,  we have strong upper air dynamics over the midwest working their way slowly eastward, but surface conditions are a mishmash ( a highly technical term) of ill-defined air masses, outflow boundaries, and, so-far, ill-fated attempts to form a surface low pressure center and a cold front.  It looks as though it’ll take 4-8 hours or longer for things to get more organized.  By that time, the main threat for severe weather will shift east of the I-65 corridor.

Third, with lack of coordination between the upper and lower levels, things are just going to happen in a seeming random fashion this afternoon.  Quick-moving thunderstorms should pop up in a “hit ‘n’ miss” fashion over western and central KY and (mostly)  IN.  Most of these will be strong with gusty winds and hail possible.  Some could even reach “severe” limits, though these are likely to be few and far between.  By 6-7 P.M. the majority of these pop-up storms should be east of the I-65 corridor.  By this time, any severe weather threat should be over for the Louisville area.  Primary threat for severe storms this afternoon will be over central and northern Indiana.

Four,  by 7-8 P.M. the surface part of this system will be better organized and is expected to create a large area of rain and thunderstorms (non-severe)  over western KY and IN.  This will bring us a very wet evening.  Even a little flash flooding is possible.  Rain should diminish shortly after Midnight.

Comment

I see from this morning’s CJ  that  Rick and Cal are the two highest paid college basketball coaches in the land.  But, the educational ratings of the schools they coach are low.  We should gain an important bit of knowledge from the first two sentences.

Quick update – storms weakened quickly

Monday, March 27, 2017  5:50 P.M.

Storms are fading fast as they advance quickly northeast.  Louisville metro will see weak thunderstorms between 6 and 7 P.M.  There is no threat for severe weather – just some brief gusty winds and heavy downpours.

I suspect the NWS will drop the Watch for our area soon.  However, even if they let the WATCH linger, the threat for severe storms is already over.

Snow possible Saturday night!

Tuesday, March 7, 2017  7 P.M.

Today’s GFS is predicting a nice snowfall Saturday night (see below).  Of course, a lot can, and will, happen between now and then.  But it is exciting to at least have the thought that we still could have a good snow before the season ends.  Unfortunately, the GFS stands alone at this time…the European model keeps the chance for significant snow north of us.

Meanwhile, here’s the GFS’s snow forecast for the 24-hour forecast ending at 7 A.M. Sunday:

Think snow!

Stuff
Streetside parking meters are illegal in the state of North Dakota.

Charity begins in the home…in this case.  An 87 year old preacher and his wife run an on-line ministry as a “non-profit” organization.  Last year they reported a net income for the website of 7 million dollars.  Their combined salaries added up to $4 million.  That reminds me of the old joke about what to do with the offering plate each Sunday.  “i take the plate, throw it up in the air.  God takes his share and whatever falls back down is mine.”  Only is this case, it’s not a joke!

 

 

Severe Storms Possible Tonight

Friday, Feb.24, 2017 Noon

A strong storm forming between St. Louis and Chicago will intensify rapidly during the day as it moves quickly northeast into Michigan.  North and west of the storm track heavy snow is likely.  However, the “warm sector” south and east of the storm will remain dry most of the day as we wait for a supply of moisture to arrive from the south.  Once the moisture gets north,  the strong dynamics of the parent storm should have no problem producing some severe thunderstorms.  Primary threat will be strong winds.  Hail is a slight risk while tornado chance is pretty close to zero.

This system is similar to the last time severe weather was widely advertised, but failed to show up.  The problem is with the moisture.  The dynamics with the system are tremendous, but the thermodynamics are quite weak.  So, once again, the various models are relatively low on the “probability” of storm formation, but the so-called “conditional probability” for severe storms is high.  What that means in normal people-speak is that the overall chance for a thunderstorm hitting you is small (about 30%).  But IF a thunderstorm forms, there is a high chance it’ll reach severe levels (about 50%).    So, if you multiply the two numbers you get a roughly 15% chance for severe winds within 25 miles of your home tonight. Obviously, the chance at any single point (your home)  is much lower.

The models agree well on timing.  The arrival of the cold front trailing the surface storm and sufficient moisture to generate thunderstorms should be about the same time.  Best timing for Louisville looks like between 8 and 10 P.M.  While some storms should form west of Louisville earlier, this system shouldn’t get well organized until it gets east of I-65.  Areas east of Louisville have a greater chance for wind damage than we do.  Best chance looks like 9 P.M. until Midnight for areas east of I-65.

Caution

As always, you’ll be hearing a lot of hype about storm potential this afternoon/evening.  What you’ll be hearing will be “the worst case scenario.”  Luckily, nature rarely reaches our hyped up expectations.

Interrupted sleep?

Monday. Feb. 6, 2017

Yes, it appears that thunder and lightning will be visiting our area during the late night hours tonight.  Also, the Severe Storms Center has us in a “slight” risk area for severe thunderstorms tomorrow.  However no severe storms are expected with tonight’s rain/thunder/lightning.

The situation looks like this:  a weak upper air disturbance will float slowly over the Ohio Valley between (roughly) Midnight and Noon tomorrow.  This system is starting to pick up some  Gulf moisture and rain/thunderstorms are popping up over northern TX, AR, west TN and southern KY.  Rain should become widespread over our area after Midnight and finally end around midday.  Thunderstorms will be embedded in the rain shield with the best chance for thunder here about 5 A.M. to 10 A.M.  Overnight instability will be low and the upper air dynamics, while good for an April/May severe weather situation, are actually pretty low for a winter system.  As a result, I don’t expect any severe storms overnight or tomorrow morning.  The dynamics aloft will have a hard time overcoming the lower level thermodynamics.

Then, atmospheric conditions change tomorrow afternoon/evening.  The morning system will drag most of the deep layer of moisture northeast of us.  But, a cold front will be approaching from the northwest.  The dynamics with this coupled surface/upper air system are expected to be much stronger than the overnight system.  However, most of the moisture will have disappeared.  So, the chances for thunderstorms to form along this front are quite small – about 10-20%.  But, if thunderstorms do manage to form, strong gusty winds and hail will be likely.  So, severe storms are possible late tomorrow afternoon , but the chances we’ll have any in the area are less than 10%.  Not much to worry about.  (But a few flurries will be possible early Wednesday.)

February

A couple of weeks ago, a major change in the upper air pattern looked like a good possibility for North America for this month.  The models were leaning toward temperatures being below normal for much of this month.  That trend lasted several days, but since then has shifted back to the primary pattern it has shown much of the winter – cold and wet over the western states and warm and wet over the east.  It looks well locked in, so not much hope for snow lovers.  Bad winter in that regard.

Super Bowl

It was amazing to watch New England turn the tide and rally last night.  You’ve got to give Tom Brady and the Pats credit for putting themselves to win the game, but to my mind, they NEVER should have won the game.  Atlanta just outright “gave” the game away.  With time running out, Atlanta had a second down with the ball in easy field goal range AND an 8 point lead.  Keep the ball where it was.   Run down the clock with a couple of runs – kick the field goal – game over – Super Bowl winners!  But, wait!  Somebody (I assume it was the offensive coordinator) calls a pass play that requires a deep dropback  by the quarterback.  Play starts, qb drops back and gets sacked.  13 yards lost – no longer in field goal range – Patriots get the ball back with a chance to tie the game.  And, they did –  then made it look easy in overtime.

Whoever called that play must have thought he’d catch New England off guard.  Seattle thought the same thing two years ago.  Look where it got them.

Stuff

The popcorn you buy at a movie theater costs more per pound than a filet mignon.