Category Archives: forecast

Two rounds of thunderstorms this evening

Thursday, March 12, 2020  4 P.M.

Cluster of rain/thunderstorms in the area now is not showing any signs of severe weather,  Instability is very low, but the dynamics are quite strong.  Nevertheless, severe weather is not expected with this area.  However, stronger storms appear likely later this evening.

Current showers/t-storms are forming along a warm front slowly pushing north.  Once we get into the warmer/moister air south of the front, we’ll have the potential for slightly higher instability for a few hours.

During that time, a cold front will be moving over southern IN/western KY.  That system should pass through our area between 6 and 8 P.M.  The front is already creating severe weather to our west.  Instability should still be weak, but the wind fields will be strong enough to create a strong wind threat – possibly severe (58 mph or more) in a few areas.  Atmospheric structure favorable for tornadoes should remain south and west of Louisville.

After 8 P.M., threat for severe weather will move south and east of Louisville area.

Even less snow tomorrow

Fri., Feb. 7,2020

Weak Clipper brings a little more snow

A weak Alberta Clipper dropping into the Ohio Valley tonight and tomorrow morning will leave a minor calling card in its wake.  Available moisture is lacking and the clipper does not appear strong enough to force much lifting this far south.  The clipper’s path is expected to pass over southern IL/IN.  That sets up central IN for a possible 1-3″ accumulation tonight and early tomorrow.

Meanwhile, south of a clipper’s path, not much happens.  In reaction to the clipper moving north of us, we’ll see southerly winds tonight.  That’ll hold temperatures in the low to mid 30’s.  Precipitation south of a clipper’s path historically is little or none.  So, even though some light snow is possible late tonight and tomorrow morning, accumulation will be in the “little or none” category.  Probability for measurable snowfall is about 50%.

Tomorrow morning marks the last snow chance for about a week, at least.

Grasping at more straws

Thursday,Feb. 6, 2020

Light snow possible late tonight

Snow chances have been few and far between this winter.  We started with tad about an inch of grass-only snow in November and haven’t been able to match it since.  However, we’ll see two chances over the next two days.  Best chance for breaking past one inch will come Saturday morning.

A strong upper level trough is passing over today, but so far is having trouble with surface development.  That problem should end tonight as a major surface storm will be developing/accelerating northeastward along and just east of the Appalachians tonight.  Latest forecasts have the storm path a bit farther east than earlier models.  That’s bad news for the Louisville area.

We were expected to be in the western edge of snowfall from this system.  Now, it looks like we’ll be “really” on the edge.  Far southeastern KY could get up to 6″ overnight.  As you head northwest from there, snowfall will lessen.  Bowling Green, Lexington and NE KY should be in the 2″-4″ range.  E-town, Bardstown, Shelbyville, and Henry County will likely be in the 1″-2″ zone.  West of that, snow will fall off quickly. SE Jefferson County could get up to .5″ while downtown will probably get a dusting.  North of the Ohio River…little to nothing.

In the Louisville area, snow is likely to begin about 3-4 A.M. and probably be over around 7-8 A.M.  Any accumulations will be on grassy areas.  Roads should be wet, but icy conditions are likely on some bridges and overpasses.

As the upper trough moves eastward tomorrow, a (probably) weak Alberta Clipper will run southeastward along the backside of the trough.  Models are projecting another area of light snow with the clipper and put us in its projected path.  I’ll check back on that tomorrow.

Stuff

Together, Kobe Bryant and LeBron James played in every NBA Championship Finals from 2008 until 2018.  But, they never played each other.

Shaky forecast models

Wed., Jan 22, 2020 4 P.M.

Flip flops are the latest model fashion

Two weeks ago, the models were forecasting a major pattern reversal over North America.  Winter was finally on the way.  Seven days ago, the models had reversed themselves – abnormally warm weather would remain well into next month. Now, the models have undergone a “reversal reversal.”  In other words, the forecast again favors below normal temperatures taking over during the next 7-10 days.  This time, however, the Euro model is even colder than the GFS.

It’s all very confusing, but here’s what’s most likely for the next few days.  A deepening upper level low will push from the southern Rockies tonight to a position right over top the IN/KY by late Friday.  Ahead of the storm we’ll be mild with periods of rain from late tomorrow into Friday.  As the low moves over us rain showers will probably change to snow showers Friday night into Saturday.  It’ll be too warm for any accumulation on roads, but some minor accumulations are possible on grassy areas.

After that, warming will be back early next week followed by rain, then colder.  GFS and Euro predict another storm with rain to snow next Fri/Sat, but forecasts that far in advance this winter have met with pretty poor results.  We’ll see.

 

 

 

Is the GFS messing with us again?

Thursday, Jan. 16, 2020

Not again?!

Today’s GFS is really cutting back on its pattern-reversal forecast.  Today’s runs push any cold phase arrival back a week, at least.  It’s quite a bit weaker than last weeks storm, but another west coast storm is developing and heading toward a northern cut across the central U.S. Saturday.  Following that, Sunday thru Tuesday will be the coldest days we’ve seen in almost a year.

That was supposed to be start of a long term cold period. But, now the GFS is predicting yet another major west coast storm moving into the central Plains the next weekend.  Even after that, it’s holding off on a pattern shift.

The Euro model has been a little hesitant on the magnitude of any pattern change for the past week.  Now, it too is backing off.

The GFS has been doing this to us for six months.  I’m still hoping that one of these times, it’ll actually happen.

Winter arrives (finally) next week.

9 P.M. Tuesday, Jan. 14, 2020

Mild weather continues a few more days

I don’t know how many times over the past six months, our forecast models have predicted a reversal in the upper air pattern over North America, but it’s been often.  Only once (November) did it actually happen.  Now, it’s seems like it will reverse for a second time, starting Sunday.

The shift to west coast ridge/east coast trough is underway.  The strong northwesterly winds aloft will definitely put us into below normal temperatures.  When pattern reversals occur, they generally persist at least 2-3 weeks.  But, this has been unusual winter, to say the least.  When the “cold phase” hit us in November, it lasted about 3 weeks before the “warm phase” took over.  And the warm phase has been around ever since.  Since November 25, we’ve only had six days with below normal temperatures.  For those keeping score, that’s 45 above normal days and only 6 below.

So, are we going to have a “3 week” winter, or will be longer?  Good question.  Answer unknown.

Old rule of thumb:  After 3 weeks, if the upper air winds over us are stronger than when the cold regime began,  it will persist another 3 weeks.  If the winds are weaker than originally, the warm regime will return quickly.

Rest of this week

Official forecast gives Louisville a chance for rain tomorrow.  I’m not buying that although some light rain will be possible over southern KY.

Another midwestern storm is likely late Friday, but it’ll be much weaker than last week’s storm.  We’ll probably see periods of rain from Friday into Saturday.

Then, winter arrives Sunday!  Next chance for snow comes from a weak clipper next Tuesday.

 

Worst of storm is over

Saturday, Jan. 11, 2020  1:30 P.M.

Potential damage area moves east.

After following this storm system for a week,  I still didn’t get it right.  The rain and heavy downpours arrived long before I expected them to – the heaviest rain passed through Jefferson County between Noon and 1 P.M.  Also, in spite of the rain acting as a break, wind gusts reached 50+ mph in a few spots.  Surprisingly, the number of power outages locally are less than 1000 customers.  Even an average spring/summer thunderstorm produces many more than that.

So, overall, the system proved to be a pretty typical midwestern winter storm for us.

This afternoon, the rain will continue, then fade away around dark.  The winds have been silenced for awhile.   They’ll get stronger again as the rain ends, but top gusts tonight will be in the 25-35 mph range.  They’ll be pushing colder air across the Ohio Valley, but nothing unusual for January.  In fact, tomorrow’s temperatures will remain above normal.

Heavy snow tonight…for central Indiana

Sunday, Dec. 15, 2019  2 P.M.

Just rain for Louisville area.

Fairly weak disturbance working northeast will push through the area tonight.  As often, we’re near the borderline between rain and snow.  As moisture increases this afternoon a few spots of very light snow/sleet/rain will probably develop over southern Indiana.

Larger area of rain/snow will probably move to the I-65 corridor by 7-8 P.M.  At onset, some snow and/or sleet may mix in, but will quickly become all rain for most of the night around Louisville.  Any snow of a half inch or more should be at least 30 miles north of Louisville.  But, total snowfall could easily reach 2″-4″ over central Indiana.

Tonight’s precipitation event is part of a much larger storm system that will bring us heavier rain late Monday and Monday night.  As the system moves east, the rain could change to the period of light snow early Tuesday.

Christmas weather

Today’s GFS predicts unseasonably warm weather for most of Christmas week.  Temperatures could reach the 60’s at least a couple of days, including Christmas Day.  No White Christmas this year.

Snow tonight

Not much, but it’s a good start

Monday, November 11, 2019

Forecasters and forecast models all seem to be on the same page with the cold front moving through this evening.  Late afternoon rain should change over to light snow between 7 – 8 P.M. around the metro area.  Snow should be light and be over by midnight.  Then a wintry blast of cold air takes over for a few days.

It’ll probably take about 1-2 hours after the snow begins before temperatures drop below freezing. Nevertheless, we’ll probably see a little snow on grassy areas – up to 1″ in colder suburban areas.  No more than a few icy spots on roads, especially bridges and overpasses.  No problems are expected for the morning rush hour(s).

Stuff:

No wonder squirrels seem busy these days.  It takes at least 100 acorns for an average squirrel to make it through a winter.

 

Take your pick

Sat. Oct 26, 2019 3 P.M

Windy and wet

As I usually do when I get up in the morning, I turn on NOAA Weather Radio to get an idea on what the latest ideas are.  I didn’t get much help today.  Rain…yes, but that has been pretty obvious for the past couple of days.

But, high winds were also expected today.  Here’s what I got… from the “official forecast” the winds were predicted for this afternoon to be 15-25 mph with gusts to 30 mph.  However, there was also a Wind Advisory.  That said late afternoon gusts would be 40-45 mph with a few gusts possibly reaching 50 mph.  Well, there is quite a difference between 30 mph and 50 mph gusts.  Thirty is pretty ordinary; fifty can create significant damage. So we’re getting two very different forecasts at the same time!  Probably should have just used the word “windy” and let everybody decide for themselves.

At least the Noon forecast updated the gusts up to 35 mph, but that doesn’t change the situation very much.

Meanwhile, the latest short term models have been lowering their wind predictions.  Current indications point to the strongest wind gusts should be between 4 and 7 P.M.  My best current estimate is for gusts reaching 35 and 40 mph with perhaps into the low 40’s

U of L’s Homecoming game should see those gusty winds and about a 50-50 mix of showers/no showers during the game.

UK’s game should also see a rain/no rain mix.  However, the winds should be quite a bit weaker.  Top gusts around 30 mph or so.