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.

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.

Ohio Valley part of storm fades

Oct. 21, 2019 4 P.M.

Since late last week I’ve been hearing all these horror stories about today’s weather – heavy rain, flash flooding, possible severe storms, strong winds, etc.

Well, Monday has arrived and only (mostly) one part of the forecast will be correct.  We have had strong winds – gusts in the mid 30’s.  Although we were led to believe they’d be about 10 mph stronger.

Periods of rain are likely through about 9 P.M. though total rainfall should be about a quarter-inch or less.   A little lightning will be possible around 8 P.M.  Winds will still remain gusty- gusts possible of 30-35 mph late afternoon but diminishing this evening.

Stuff

This situation brought back a story about a former WAVE weathercaster from waaaay back.  He had predicted the next day to be sunny, windy and warm.  Instead, we had a cloudy, cool, rainy and windy day.

His next broadcast began this way…”See, I told you it was going to be windy today!”

Wed., March 13, 2019  6 P.M.

Thunderstorms likely tomorrow

This is the third time in recent weeks that the Storm Prediction Center(SPC) has put us in an area of potential severe storms.  We are in a “slight risk” region tomorrow.

The first two times, the situation was the same.  Very strong dynamics (wind fields) but little support from the thermodynamics (heat and humidity).  As the old song goes, it takes two to tango.  Both times, the partnership never happened, so the weather didn’t get to dance.

As is common in the early spring, the (almost) same situation exists again.  But, there are some differences.  Strong dynamics (upper winds, strong surface storm) are once again the prominent feature.  But, the dynamics over the midwest/Ohio Valley will be weakening through tomorrow.  Northward flow of heat and humidity is currently strong, but it also is expected to weaken.

So, overall the threat for severe storms over KY and southern IN tomorrow looks pretty small.  The GFS is weak with storm development while the NAM is a little stronger and more in line with the SPC ideas.  However, it keeps storms pretty weak over KY, but does point out a stronger threat over the northern two-thirds of IN tomorrow afternoon.

Here’s my forecast:

Mostly cloudy and breezy tonight…low…58.  70%  chance for showers and/or thunderstorms after 4 A.M. continuing into mid-morning.  (Rain/storms will be most likely along and west of I-65.)

Another area of showers and thunderstorms will likely cross the area between 4 P.M. and 7 P.M.  tomorrow.  Gusty winds around thunderstorms, but severe weather threat is quite low.  Cooler weather arrives Friday.

Stuff

Tomorrow is Pi Day.  3.14 on the calendar.  Use some math, it won’t hurt (much).

4 P.M. Feb. 20, 2019

Ohio River on the rise again.

Current hydrological forecasts have the Ohio in Louisville rising to just a inch or so from flood stage by Monday morning.  In the short term, I think that forecast will be revised downward since rainfall last night and today has fallen, in general, a half-inch to one inch shy of forecasts.  Plus, the highest amounts (southwestern Indiana) fell in areas that will drain into the Ohio downriver from Louisville.

Mostly light rain will move east of I-65 by 6-7 P.M. this evening.  Then two dry days lie ahead.  We’ll keep plenty of clouds around, but temperatures will reach about 50 tomorrow and a few degrees warmer on Friday.

Looking ahead

The next big storm to reach us will arrive Saturday and persist about 24 hours.  This one also projects as a big rain-maker.  Current estimates are in the 1″ to 2″ range, down a bit from earlier forecasts.  This storm will determine the fate of the Ohio River here in Louisville.  Another rain in the forecast range could easily put the river out of its banks by early next week.

Looking farther ahead

A lot has been said about an abrupt change back to a much colder pattern around March 1.  Call it “Polar Vortex, Chapter 2”!  Well, the GFS has been predicting some snow on arrival (now looks like Feb.28th) and a substantial snow about March 4 or 5.

Unfortunately, that all changed with this morning’s GFS.  It is now pushing much less cold air southward, as happened last time.  We could still have some light snow upon the cold air’s arrival, but it won’t hang around long enough to prevent the March storm from being rain.

DON’T give up hope!  The GFS has been acting very shaky (wild forecasts) since yesterday’s 18Z (1.P.M.) run, so it could all shift again.

Stuff

Of the world’s “big cats” (lions, tigers, leopards and cheetahs), only the cheetah cannot roar. They , however, can purr.  They also can accelerate to 70 mph in three seconds!

4:30 P.M. Monday, Feb. 18, 2019

Most likely rain will start as snow

A quick look at the primary weather charts today would give you the idea that there’s no chance for snow tomorrow night.  But, today’s forecast models allow you to dive much deeper – and they say we’ll see a few hours of snow/sleet before we warm enough for rain.

The  mid and upper atmosphere will warm rapidly tomorrow, but there be some air in the lower 5000 feet of the atmosphere that remains cool enough to create snow before rain takes over.  Even though surface temperatures should reach 40 or higher, the near surface air will remain very dry.  So, as precipitation begins aloft, it will be evaporated before it reaches the surface. Evaporation of water cools the air.  In this case, just enough cooling to allow the snow from aloft to NOT melt before reaching the surface.   Temperatures will probably only drop into the mid 30’s, so it’ll be a very “wet” snow.  Nevertheless, much of the area along and north of I-64 could easily see a 1″-2″ accumulation on grassy areas before the changeover to rain.  Areas south of I-64 will see a rapid drop in snow  – probably 30-40 miles south – should expect no accumulation.

Roadways may see a brief slushy period, but little (if any) accumulation.  Rain will wash away icy spots on the roads by shortly after Midnight, so no trouble with the morning rush – expect for water.  Rain tomorrow night until midday Wednesday should be add up to about 1″-1.5″.  While that’s a good sized rain, it will not be enough to bring back flooding.  After that the next heavy rain is not expected until Saturday.

Stuff

36 degrees    If something is falling out of the sky and it’s 36, there’s 50% chance it’ll be rain and 50% chance it’ll be snow (or some other frozen type).  Above 36, the odds increasingly move toward liquid.  Below 36, the odd increasingly favor frozen types of precipitation.