Category Archives: forecast

Very windy day Saturday

Friday, Nov. 17, 2017

Strong storm system will move through the area tomorrow.

A  storm system will form tonight over MO/AR and develop rapidly as it races across Illinois and Indiana into Ohio by late tomorrow.  Two active fronts will move across our area by tomorrow evening.

First, a warm front will push northward through the area tonight.  This should produce widespread showers over KY and so.IN after midnight.  A few scattered elevated thunderstorms will be possible along the front.  If you hear thunder in your neighborhood, there’s a good chance you’ll get some small hail mixed in with the rain.  Rain connected with the warm front should be out of the Louisville area by 8 A.M.

Then we’ll have a period of 4-7 hours of mostly dry weather as the winds increase dramatically.  By late morning into the evening, winds will become quite strong thanks to that strong storm passing to our north.  Southerly winds should gust into the 30-40 mph range during that time.

Second, the cold front associated with the storm system.  That should arrive between 2 P.M. and 5 P.M.  It will sweep rapidly through the area from northwest to southeast.  Ahead of the front will be a narrow line of gusty showers and possible thunderstorms.  Winds could briefly gust to 40-50 mph during this time.  Rain should last only a short while, probably less than one hour.  During this time, temperatures will tumble quickly from the sixties before the rain down to near 50 as the rain ends.

Then back to colder weather by Sunday.

I realize the scenario looks bad for UL’s game with Syracuse.  Lamar Jackson’s possible (probable?) last game in Louisville will be played with a wet field (which has very good drainage, by the way) but it looks to me as though most (maybe all) of the game will be played in dry weather.  It all depends on the cold front’s ability to create thunderstorms.  When the front arrives, if thunder is in the area the game will be delayed.  When the thunder leaves the area, the game will start or resume with dry weather the rest of way.  But, they’ll still have to contend with those strong winds.



Update on tonight’s weather

Sunday, Nov. 5, 2017  8 P.M.


Good news from earlier update.

1).  Storms have weakened faster than expected.  Still an outside chance for some near severe storms over south central IN – more than 30 miles north of Louisville.

2).  Winds locally will probably average a little below the values mentioned earlier, but 40-45 mph wind gusts will still be likely for many of us.

3).  System is a little faster than mentioned earlier.  Now looks like the line/area of storms will pass through the metro area between 9:30 P.M. and 12:30 A.M.

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.

Weekend rain clarification

5 P.M. Saturday, Oct 7, 2017

Turns out we don’t need Hurricane Nate to get some much-needed rainfall.  A weak cold front entering the lower Ohio Valley has been squeezing out some brief light showers around the Louisville area this afternoon.  So far, the rain has not been enough to ease any soil dryness.  However, from 7 P.M. until Midnight they should become more numerous.  Some spots could get as much as half an inch this evening.

Rains from Nate should reach us tomorrow morning and continue through the afternoon.  Models have shifted Nate’s path slightly west again so my earlier prediction for Nate’s rains will have to pushed up somewhat.

My latest estimates for the Louisville area:

This evening:  about .25″ to .40″  of rain (higher amounts west and north of Louisville)

Sunday:  about .35″ to .80″

NOTE:  Sunday’s rainfall totals will rapidly increase as you head southeast from Louisville.  Southeastern KY may see as much as 6″+ of rain.

Irma continues to fade

Monday, Sept 11, 2017

Irma continues to fade

Damage estimates far below early expectations

Irma’s winds keep getting weaker and weaker, but she still has plenty of water as northern Georgia is now finding out.  Heavy rains will be hard to transport westward over the Appalachians but Irma is going to try tonight and tomorrow.  Heaviest rains (2″-4″) should fall over eastern TN with lighter amounts working into Kentucky.  Some showers could reach as far north as the Ohio River toward morning.  Then, we’ll continue to see a few periods of rain around the Louisville area through Wednesday, at least.  An inch of rain is possible.

One forecaster who specializes in storm damage estimates yesterday predicted around $200 billion in insured damages from Irma.   By this morning, his forecast had dropped to $50 billion.  Other predictions were lower to start, but were down to $20 to $40 billion.  Still massive totals, but far less than authorities had led us believe.  What’s that old comment?  Question authority.

Hurricane Jose is still a potential problem.  Jose has been weakening and wandering aimlessly over the Atlantic for the past few days.  Today’s GFS model keeps Jose wandering for another day or two.  Then, the GFS pushes him westward for a few days then northwestward.  He should also be strengthening, but probably not to “major” hurricane.  Eventually, according to the GFS, Jose ends up in the vicinity of the Outer Banks by about next Tue/Wed and into New England a day or two later.

So, we may not see an end to Jose’s story until late next week.

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, part 5

Sat. Sept 9, 2017

Landfall likely tomorrow in southwest Florida

Strongest winds still an open question

Not much more to say than in yesterday’s part 4 post.  Storm path pretty much the same forecast with adjustments probably no more than a few miles east or west.  Landfall should be around midday Sunday between Cape Coral (Fort Myers) and Port Elizabeth.  Then a slow journey north over Florida through early Monday.

I’m still not buying the wind forecast from the hurricane center.  As expected, Cuba has reduced Irma’s winds – now about 125 mph (Cat 3).  NHC predicts they will rebound to about 140 mph by landfall.  Continual interaction with Cuba and Florida should keep Irma from regaining that much strength.  I expect no more than 130 mph, and probably a little less.  Nevertheless, still a very potent hurricane.

It’s going to be a very agonizing wait for Floridians.

Hurricane Irma, part 4

Friday, Sept. 8, 2017

Irma down to a strong Category 4

Worst-case scenario coming into focus

At this point, it is mostly a case of waiting and waiting.  Forecast models have converged into a pretty strong consensus.  The only lingering question is how strong she’ll be at landfall?

After mostly giving up on the west coast (of Florida) solution on Wednesday, the models came roaring back yesterday.  Today, most of the holdouts have joined the chorus.  Irma will hit land over southwestern Florida Sunday morning and continue slowly north over the state for at least 24 hours.  Of the various ideas suggested by the models this week, that’s the “worst case scenario.”  And, now that’s the solution that seems to be most likely.

We can now be pretty confident  as to the where and when of landfall, but the strength remains a question.  NHC has it still with winds of 145 mph at landfall.  I feel that estimate is too high because from now until landfall its circulation will be affected by land masses.  That will disrupt the storm enough to weaken its winds by at least 10-15 mph.  That’s the low end of Cat 4, but Cat 3 is still a possibility.  Even with reduced winds, this storm is very bad news for Florida.

interim Irma update

6 P.M. Thursday, Sept.7.2017

Trend highlighted in earlier post today is now showing up strongly in latest GFS output.

Idea of landfall Sunday morning over southwest Florida is looking more and more likely.  If trend continues, it’s VERY bad news for Florida.  Latest NHC update is starting to incorporate these ideas.

Hurricane Irma, part 3

Thursday, Sept.7, 2017

Models shift a bit…looking worse for Florida

Model solutions converge as U.S. landfall gets closer.  However, an old model idea is regaining favor and that, if it happens, could be really bad news for Florida.  More on that later.

First, The official National Hurricane Center’s forecast track has shifted a little westward from yesterday.  That’s in line with the model consensus which tracks Irma either along, or just east of Florida’s east coast.   A similar storm last fall followed this path and Florida fared pretty well.  Irma is stronger, however, so this path would create more problems this time around.

Following that path, landfall would occur somewhere around the GA/SC coast.  That area would have the highest risk of devastating winds/storm surge.

The current forecast follows the path described above with Irma either over Miami or just off the coast by about 7-8 P.M. Saturday, slowly moving north overnight and Sunday.  During this time it is expected to be either a strong Category 4 or Category 5. (winds 145 mph or higher).  Landfall would occur Sunday night near the GA/SC border.

New thoughts:

While the above remains the official forecast, I’ll wait awhile before I totally agree.  Tuesday, I mentioned that the forecast models fell into two camps.  One brought Irma up the Florida east coast; the other took it inland over the Gulf side.  That idea disappeared yesterday as the models shifted to a more easterly path.  Today, several models have brought back that idea, in what amounts to a very ugly way.

Hurricanes are purely tropical systems, but as they approach North America and recurve (turn) northward mid-latitude wind systems also get involved in the steering mechanism.  Our current cool weather has arrived do to an unseasonably strong upper level trough digging into eastern North America.  Apparently, yesterday the models felt the trough was stronger (and slower) than it actually is.  The result was to predict the storm path farther east.  Today, however, the models have corrected yesterday’s overreach.  That greatly reduces the trough’s ability to encourage Irma to turn northeast over the weekend as mid-latitude winds will become very weak.  How does that change things?

The models predicting the movement of Irma into the Gulf have also slowed her speed, probably due to the relaxing of the wind fields over the U.S.  They have also delayed the northward turn.  The result is Irma drifting between Florida and Cuba Saturday night, then turning northward Sunday into southwest Florida.  Furthermore, the delay will allow steering currents to weaken even more.  As a result, this model idea would allow a dying Irma to remain over Florida 24-36 hours!  You don’t even want to think about that scenario.

I’m hoping the models will present a clearer picture by tomorrow.  I’m also hoping that the current NHC prediction is very close to correct.  If it isn’t and the slower developing idea wins out, Irma will become a name we’ll remember for a long, long time.

Personally, I’m getting very worried about Florida.