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.

4 P.M. Fri., Feb 15, 2019

Slight model changes

Most recent runs of HRRR and RAP are shifting the expected precipitation northward.  1″ – 2″ of snow still remain likely over the lower two-thirds of KY.  The Louisville area still looks like a strong “no accumulation” but some spots south of I-64 could get a dusting this evening.  Chances for measurable snowfall still fall in the 10% – 20% range.

Presidents Day

The Federal holiday commonly called Presidents Day will be Monday – the third Monday in February.  But something is wrong with the that statement!  Here’s the story…Congress approved a holiday named Washington’s Birthday in 1879.  By 1885 the February 22nd holiday became widespread across the country.  Later Lincoln’s birthday also became a federal holiday.  When Congress passed the Uniform Holidays Act of 1968, the date was changed to the third Monday of February BUT the name was never changed.  So, Monday’s holiday we’ll celebrate will be Washington’s Birthday, not what most people call it.

Wed., Feb. 13, 2019  5 P.M.

Two chances for wintry weather later this week

Big winds last night, but they couldn’t push in much cold air.  Wind direction stayed from the SW to W last night and today, so not much cold air pushed southward.  And as winds go back to SW  tomorrow, a very quick warm up is due.  Temperatures are expected to reach about 60 tomorrow.

Then, a weak cold front will pass by tomorrow night with a small (20%) chance for some rain showers after midnight.  Then some colder air arrives for Friday.  And with the colder air, the chance for some light snow returns as well.

Weekend snow?

Two weak upper air disturbances will arrive from the west coast.  The first one arrives Friday night and (at this time) appears as though the southern half of KY could see an inch or two of snow by Saturday morning.  We’ll be on the northern edge of this system and any snow we get would be less than an inch.  NOTE:  At this time, this system is very “iffy”.  The description above is portrayed only by the GFS.  The NAM pretty much ignores this system.  So, I suspect we’ll be hearing changing forecasts in the next few days.

The second system is expected to be a little stronger.  It arrives Saturday night and continues into Sunday.  Temperatures are likely to remain above 32 during this event.  The majority of the precipitation will be rain and/or drizzle.  However, it may start briefly as some light snow.  The GFS and NAM are in pretty close agreement with this system.

Ohio River

The Ohio’s still above flood stage and climbing slowly.  Crest is still expected Friday at around 28′ to 28.5′.  However, the river will fall slowly and will not drop below flood stage until next week.

Strange weather in Hawaii

A major storm rocked Hawaii Sunday and Monday.  Some coastal waves were estimated to be as high as 60 feet!  A wind gust of 191 miles per hour was recorded.

The Haleakala Observatory, which sits atop the 10,023 foot Haleakala Volcano on Maui, contains several of the worlds finest telescopes.  They were frozen in place and covered with snow. The photo below is from Monday’s snow. More snow was expected Wed/Thu.

Photo from http://www.spaceweather.com