Category Archives: forecast

Very Windy afternoon

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12:30 P.M. Thursday, Feb.17,2022

Powerful upper air system – weak surface low pressure.  That pretty well sums up today’s weather pattern.  Those upper winds will translate to the surface this afternoon and evening.  Most of Kentucky will see gusts of 40-50 mph between 3 P.M. and 7 P.M.  The strongest wind gusts will be over southern and eastern KY.  Southern Indiana winds will most likely be in the 35-45 mph range.  Expect to see scattered power outages and downed trees/limbs as well.

Heavy rains will be likely throughout the area this afternoon.  One to two inches possible in some spots (especially north of the Ohio River) in just a few hours.  Flash flood prone areas will likely see some flooding.

The biggest question regarding this system is the possibility of severe thunderstorms.  Sometimes  very strong dynamics will overwhelm weak (or no) instability and do all the work itself.  Most likely, this system will be one of the overachievers.  But, luckily, not for the Louisville area or southern Indiana.

A weak surface low pressure is expected roll up the Ohio River this afternoon/evening.  That provides us protection from severe thunderstorms.  However, along and south of the Western KY Parkway, enough instability will probably develop to allow damaging thunderstorms.  High winds will be the primary threat.

This type of system has a history of strong nighttime tornado outbreaks over the deep south.  Tonight should be no exception.  Most of Mississippi, northern Alabama and western Tennessee have the highest risk.

A Eureka moment?

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1 P.M. Thursday, Feb. 3, 2022

For several days I’ve been been looking at model after model after model etc trying to figure out today’s expected icy weather.  Even this morning, five different models are giving different outcomes.  Those results have told me one thing that I didn’t want to know – my expectation for mostly sleet was wrong.  But, it finally brought me the answer.  An old expression from my college days popped into my head – “The last wave on the train is always the strongest”.

I’m not going to explain that now.  Let’s just say the last wave will cross southern and eastern KY this afternoon and evening.  And, it’s a little stronger than the models picked up on earlier.  That changes everything.

In general, the added strength of the wave will slow the progress of the cold air south of the Ohio River and delay the onset of freezing rain entering Kentucky.  The predicted major ice storm won’t get started until most of the moisture is gone.  It’s doubtful that any part of the Commonwealth will get over .25″  of freezing rain.  Most of central and southern KY will see very little.  No big problems with ice.

This last wave will produce periods of moderate rain until about 5 P.M.  Then, as the rain intensity tapers, colder air will arrive.  So we’ll see a few hours of light freezing rain and sleet from about 6- 9 P.M.  After that,  periods of light snow/flurries will continue overnight. Total accumulation of sleet and snow of up to one inch by morning.  Icing of perhaps .1″ to .2″.

Travel conditions should remain generally good through the evening.  As always, the primary concern will be freezing of bridges and overpasses after 6 P.M.

In summary:  the predicted major ice storm will be a dud.

NOTE:  The above discussion refers to Kentucky only.  For Indiana (except for the extreme southern edge), A major winter storm is going on.  From freezing rain and sleet near the river to heavy snows farther north, the Hoosier state travel will be hazardous.

 

Icy Thursday

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5 P.M. Wednesday, Feb. 2, 2022

Forecast models for tomorrow’s ice storm are very close, but that still doesn’t clarify the situation too much.  Conditions that come together to produce freezing rain are squeezed into a very small box.  Conditions favoring sleet are also narrowly defined, but not nearly as much as for freezing rain.  So, we’re in the difficult situation of trying to figure out the timing when freezing rain mixes with, and then changes to, sleet.  A few hours either way will make a big difference in the result.  In general, the longer the freezing rain continues, the better the result for us.

So, here’s my attempt to play “model whisperer” to come up with a forecast.  Rain will continue off and on tonight.  Temperatures will remain in the 40’s until about 2 A.M. then drop into the lower 30’s by daybreak.  Temperatures should remain in the lower 30’s until mid afternoon.  Freezing rain will mix with rain during the morning.  This will have little or no impact on morning travel.  Sleet will begin to enter the mix shortly after Noon.  After 2 P.M.  sleet will become the dominate precipitation through about 7 P.M.  Then, a little light snow/flurries will mix in as precipitation diminishes overnight.

IF – and I do mean IF – the above scenario is essentially what actually happens, this is what will result.  The freezing rain may accumulate up to a quarter-inch of ice  on tree limbs, power lines, etc.  but that amount doesn’t cause much damage.  Roadways will remain wet for the most part and driving should remain ice-free through early afternoon.  Sleet will ice the roads quickly and accumulations could amount to 1″-2″ by 6 P.M.  Evening rush hour will be very difficult.

By Friday morning  temperatures will have dropped into  the low to mid 20’s and we’ll have that 1″- 2″ coating of sleet with a small topping of snow.

NOTE:  The National Weather Service is really going gung-ho with the icing forecast.  The top edge of their forecast is greater than one half inch of ice accumulation.  That kind of ice accumulation would be highly destructive.  A large part of our area would be without power due to downed power lines.  Tree damage would be a widespread.

 

 

Thursday’s main concern looks to be sleet.

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5 P.M. Tuesday, Feb. 1, 2022

Basic ideas put forth in yesterday’s post still hold.  However, some subtle changes in the models since yesterday, to my mind anyway, seem to be shifting the primary focus away from freezing rain toward sleet.  And we’re not talking about just a little sleet.  Over an inch of sleet is possible!  We don’t see that very often.

Here’s my current idea about this will play out.  Rain begins around rush hour tomorrow and continues off and on through the day and night.  Temperatures will be about 50 tomorrow morning and slowly fall into the lower 30’s by Thursday’s morning rush hour.

Thursday morning the rain will become freezing rain but, with daylight and temperatures in the lower 30’s, the freezing rain should create few problems.  Things get really interesting during the afternoon.  Sleet will mix in with the freezing rain and quickly become the dominate precipitation form until all precipitation fades away during the evening.  A brief period of snow will be possible as the sleet ends.

The big question in my mind is when the sleet begins.  An early afternoon start could result in significant accumulations while a late afternoon onset would create far fewer problems.  At this time, an earlier start looks more likely.  That would produce a 1″-2″ sleet accumulation – a major driving mess.

Things can still change in the next 48 hours.  Another update tomorrow.

Stuff

Over the past two years the Corona Virus has killed 0.3% of the U.S. population.  World War II  also killed 0.3% percent of our population, but it took twice as long.

Ice Storm possible Thursday

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6 P.M. Monday, Jan. 31, 2022

Three days ahead is a very difficult time to figure out what a storm system is going to do.  Never one to shy away from the attempt, however, here’s what the models are telling me today.

1).  Heavy rains are likely Wednesday and Thursday.  2″-3″ are possible.

2).  Another huge mass of cold air is dropping out of Canada and will be dropping only very slowly southward.  Upper upper air winds will be opposing the southward push of cold low level air.  The result will be a very shallow cold air mass reaching us during Thursday.  That is a big indicator for freezing rain and sleet, not snow.

3).  Thursday morning we’ll see rain with slowly falling temperatures during the day.  About 40 deg at morning rush hour sliding to the lower 30’s by evening rush hour.  The southern half of Indiana should be in freezing rain by morning with sleet farther north of the Ohio River.

As temperatures cool  freezing rain could move south of the Ohio during the afternoon.  Freezing rain should be of little consequence for Louisville during the day.

4).  Thursday evening,  precipitation will diminish quickly with a period of sleet/snow.  Accumulation of snow/ice should be less than one inch.

5).  A significant ice storm is likely over southern Indiana (except counties bordering the Ohio River).

6).  Snow will not be a factor locally.  However, the northern half of Indiana should expect 6″ – 12″ of snow Thursday.

Exciting few hours ahead

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Fri. Jan 28, 2022  3 P.M.

A small, fast moving and potent upper disturbance will race across our area from now until about 7 P.M.

Most of the area will see snow showers and flurries with accumulations up to one inch.  However, a narrow swath of much heavier snow showers, about 25-40 miles across, will be embedded in the wider snow area.  Forecast models are currently projecting the axis of heavier snow to run from southern Indiana (west of I-65)  through Louisville metro then southsoutheastward  through KY.

Models project 2″-4″ of quick hitting snow squalls in narrow lines within this snow swath.  Meanwhile spots only a few miles from the heavy snow will see very little.  Wouldn’t it be cool to be lucky enough yourself in the middle of the action?  Unfortunately, most of us will be in the “near-miss” category.

Little, if any, snow tonight

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4 P.M.  Wed., Jan. 19, 2022

Short term models continue to push tonight’s area of accumulating snow south.  Latest GFS isn’t out yet, but the trend is clear from the NAM, Nam HiRes, RUC and HRRR.  Louisville area should see possibly a dusting (less than a half inch) (two models) or nothing (two models).  So the pickings are pretty lean for snow lovers locally.

It’s a different story, however, for southern and eastern KY.  Wide area south and east of a line from southern Hardin County to  Frankfort to Ashland will see accumulations from 2″ to 4″.  Some spots will probably top 4″.

Louisville appears destined to see just a short period of snow.  Rain-to-snow changeover should happen between 6 and 7 P.M.  Any significant precipitation will end shortly thereafter.  That should add up to a dusting, at best.

Seasonably cold weather air takes over tonight and should last through Friday.

Stuff

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Snow chances fading

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Three Chances for snow ahead

6 P.M. Friday, Jan. 14, 2022

Major upper air disturbance dropping south through central U.S. tonight will continue dropping heavy snows from southern Minnesota to Iowa to northern Missouri.  Some spots (especially central Iowa) could get 8″+.  Snow falls will lessen as the storm loses the upslope surface winds from central Missouri into Arkansas.  Any significant snows from this system will stay west of us, but the Louisville could get snow showers tomorrow morning.  No accumulation expected here.

Meanwhile, the upper air storm is expected to drop all the way to southern Louisiana, drift eastward for awhile, then head up the Appalachians Sunday afternoon and night.  This, too, should become a major snow-maker.  Highest snow totals will ride along and east of the mountains.

As the storm intensifies Sunday, the precipitation shield will expand westward.  This could reach as far west as Louisville, but we’ll be too far west to see anything significant.  Less than an inch, if anything for Louisville.  A little rain could mix in as well. East of a line from Bowling Green to Lexington to Ashland could see several inches.

As the storm accelerates northeast Sunday night, a cold front will sweep across IN/KY early Monday morning.  This will bring us our third chance for snow.  It’ll probably just be some flurries and/or snow showers.  Little, if any, snow expected.

Frustrating!

Model reversal

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Thursday, Jan. 13, 2022  5:30 P.M.

Models still far apart

Yesterday, the GFS was predicting a big snow Sunday while the Blend of models was predicting little to no snow.  Today’s the Nam’s forecast reaches out to Sunday and offers another opinion.

Today, the GFS takes the storm considerably farther south before heading north along the Appalachians.  That means for us:  1″-2″ Sunday.

The BLEND continues on it’s southern track and a little east along the mountains.  For us: little, if any, snow.  If yes to snow, up to an inch.

The latest NAM has the storm track a little north and west of the GFS prediction.  Projection for us:  2″ – 4″ starting late Saturday.

Tomorrow: check back to see if the models get any closer to agreement.

Stuff

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Snow Thursday

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Little change since yesterday

11 P.M. Wednesday, Jan. 5, 2022

Model outlooks are little changed since yesterday.  The GFS predicts the lowest accumulation with the NAM products and model blend about an inch to two higher.

GFS – 1″-2″

Nam- 2-3″

Blend has 2.3″ for Louisville

Snow should begin around 11 A.M. and end before 6 P.M.

My thoughts:  Many times I’ve wished the NAM would be correct, but most of the time the GFS turns out better.  So I’d say Louisville area 1-2″ with increasing snowfalls south and east.  Could top 8″ over southeast KY.

Think snow!