Category Archives: commentary

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.

Friday flurries!

Friday, January 27, 2017  4 P.M.

A weak upper air disturbance this morning brought us some flurries and a second one will bring us some more flurries for the evening rush hour.  With temperatures safely above the 32-degree mark, no problems are expected.

Cold weather should remain through the weekend with additional weak disturbances bringing additional periods of flurries.  Finally, a much stronger upper air system will cross the area Sunday afternoon and evening.  This is expected to upgrade the flurries to  a period of light snow and/or snow showers.  This morning the GFS and NAM were far apart on their portrayals of what the result will look like, but now the NAM upping its game toward the GFS solution.  But, don’t get too excited – even the “stronger” GFS still keeps snow expectations below one inch.

The current outlook for Sunday calls for some light snow/snow showers between (roughly) 3 P.M. and 8 P.M.  This should not have much of an effect on surface roadways, but bridges/overpasses/etc. could get some slick spots.  Snow accumulation should be light – anywhere from a dusting up to an inch.  For Louisville, about a half inch seems likely.

Bummer

My post earlier this week has already proven me right and wrong.  My long time conviction that long range prediction is  a fool’s game has been proven yet again.  But, my insistence to try it anyway is where I went wrong (probably).  My idea that the cold air arriving this weekend would hold through next week will not happen – unseasonably mild weather will return for next week.  Further, I said that some really cold weather should arrive around Super Bowl time – that part will probably hold, although it’s not looking quite as cold.  The worst part of my “outlook” was that the below normal trend should continue through most of February.  Sadly, that appears to no longer the case.

Moral of the story:  I should follow my own advice!

Pattern change ahead.

Monday, November 7, 2016

Another weak cold front will pass through the area tomorrow evening.  And, the expected weather will be very similar to last week’s light rain.  The front and the upper energy will be arriving from the northwest and will not have much moisture with which to work.  So, same idea as last week – a pretty high probability for a little bit of rain.  For those who received some rain last week (unfortunately not my yard),  it’ll be about the same again – a trace up to about .10″ of water.  So, the dry conditions will continue.

Changes ahead

For most of this fall, our warm, dry weather pattern has been caused by a strong upper level ridging pattern (upper air high pressure) pushing the primary jet stream far to our north over Canada.  The ridging pattern has been dominate, but has weakened at times to allow some weak cold air masses to invade the eastern U.S.  But the ridge has always rebuilt quickly to bring back the above normal temperatures.  That’s been the basic upper air pattern since late August with the predictable result of a warm, dry autumn.

Last week, however, the global forecast models started pointing toward a breakdown of that system.  In general, the upper air ridge sitting over the central U.S. is expected to retrograde (shift westward) to the southwestern U.S./eastern north Pacific.  This will open the door for an upper level trough (upper low) to dig into the eastern half of North America.  This will not happen quickly.  It is starting now and will bring us some Canadian air by Wednesday, then a second burst of energy will bring us even colder air by the weekend.  Then, a third system will bring even colder air early next week.

How long this trend will continue is an open question.  Yesterday, the GFS brought a massive storm into the Ohio Valley (with snow!) on the Tuesday before Thanksgiving.  Today, it has forgotten all about that storm idea, at least for the Ohio Valley.  Meanwhile, the European model is generally a little colder than the GFS with the upcoming colder trend AND it still is hinting at a major pre-Thanksgiving storm over the Ohio Valley or the southeastern states.  It’s still far to early to do any serious speculation on any storms.  But, it does appear very likely that we’e going to drop into the “below normal” temperature category for the next 10 days to two weeks.

Election Day

Ever wonder why our Federal elections are held on a Tuesday?  If your answer is “no”, stop reading and be sure to VOTE tomorrow.

If, however, your answer is “yes”, continue reading.  Back in the early days (late 1700’s and early 1800’s) there were no national laws governing elections.  States could chose to hold them whenever they wanted…as long as they had their votes counted before an early December meeting of the members of the Electoral College in Washington.  That worked pretty well until the number of states starting growing larger.  In the 1810’s Congress tried to organize some of the randomness by mandating that the state elections had to be held within a 34-day period of the fall.  By the 1840’s, as communication methods improved, the varying dates of state’s elections started to play a role with the later-voting states’s voting patterns, or so it was believed.

So Congress agreed that everyone should vote on the same day.  But how to chose the day?  Back then, the country was mostly agrarian, so it should be a time after the crops were harvested.  But, the winter had frequent snow storms (remember, most of the U.S was in the northeast back then), so the winter months were too risky.  That left November as the logical choice.  But which day of the week?   Sunday was out because it was church day and a day of rest.  Monday was out because of Sunday.  Back in the horse and buggy days, many voters would have to travel the day before (Sunday) so they’d have the time to vote and get home on Monday.  So, Monday lost out due to possible Sunday travel (not a good idea in those times).  Wednesday was Market Day – when the farmers brought their goods to town to sell to the city-dwellers.  To Congress, the logical winner was Tuesday.  In 1845 the matter was settled by Federal Law – Election Day would be on  the Tuesday immediately following the first Monday in November.

That’s tomorrow…please VOTE.

I don’t want to complain, but…

Saturday, August 13, 2016  11:45 P.M.

What a miserable week of forecasting we’ve been victimized by all week and the worst is still happening.  Thursday and Friday the forecasts, aided by the ever-willing media hype made it sound like we were due for ark-building rains.  Only one thing was wrong – the models had already backed off of the extreme rain forecast by THURSDAY.  By Friday, the models had backed off the threat of heavy rain even more.  It was obvious that heavy, flooding rains were out of the picture for today and Sunday.  So, the NWS did the “obvious” thing – issued a Flash Flood Watch for Louisville area and southern Indiana.

Today worked out just the way the models predicted – a few very light showers in the metro area with heavier rain over central Indiana.  However, the Flash Flood Watch was expanded over a larger area Sat. morning…ever though the NWS forecast had reduced the chances for rain by about 20% or so for next 48 hours!

A few showers are possible overnight, but very little, if any, rain is likely for Sunday and heavy rain Monday will stay far to our west.  But, the Flash Flood Watch remains in effect through Monday.  My advice to the NWS is pretty simple:  Stop hyping a dead forecast…it died a long time ago.

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.

 

 

 

 

Windy and colder tonight

Wednesday, Feb. 24, 2016

As the major surface low pressure area moved right over the area this morning, we actually got a break from the heavy rain and even saw some sunshine with temperatures in the upper 50’s for an hour or two.  Then, as the low moved northeast, the colder air on it’s backside dropped temperatures in a hurry…and the rain resumed.

But, we’ve seen the worst  of it now.  Winds will start decreasing this evening and the rain, possibly changing to snow, will be diminishing between 7 P.M. and 9 P.M.  After 9 P.M., light rain showers and/or snow flurries will be scattered around the area during the night.  Whether we have  rain or snow  showers doesn’t make any difference.  If it’s snow, it’ll melt on impact so there’ll be no accumulation – so it essentially makes a situation I like to call “white rain.”  It has the same impact as rain.

Temperatures should remain above freezing in the Louisville area, so traffic problems should be no worse than wet roads.

4-5 days ago the models were predicting a major cold air outbreak to hit the eastern half of the country this weekend.  But, nature didn’t seem to get the message – in reality the cold air is pushing east rather than south.  So, now it looks like a cold day tomorrow followed by warming Friday into the weekend.  Not as warm as last weekend, but still very nice for late February.

Note:    I know some forecasts floating around include the possibility of up to an inch of snow (on grassy areas), but that idea seems to me to be a real outlier.