Wintry Mix 12/31/12

Looking at radar returns this morning, I'm forecasting 2-3" of virga for many locations in our region. That's the only thing guaranteed.

Once the column saturates, precipitation will finally reach the ground. Could start as early as 10:00am in Louisville, most likely by 12:00pm. However, what type of precipitation falls is still 'up in the air'.

Therefore, a bag of wintry goodies will be doled out just in time for party festivities.

I'd like to take a look at the 12z NAM coming out by 9:30 this morning. I'll be more interested in looking at those levels in the atmosphere where the 'goodies' will be coming from.

However, the latest HRRR run shows 12pm 925 mb temps of 1-3 degrees C, should support a cold rain. 850mb levels at 12pm shows the freezing line right through Louisville (-2 to 2 degrees C), supporting snow, rain, and sleet.

This is not an efficient precipitation producer. QPF amounts fairly light. However, anytime a mixed bag that includes a chance of ice is included, travelers will be and should be wary.

More later...

MS

Weather Summary and Forecast 12/30/12

First, the most recent snowfall has been tallied and graded....

The official amounts are listed below for 12/28 and 12/29.

Louisville  2.7"
Evansville 3.0"
Paducah   1.1"
Cincinnati 3.6"
Lexington 3.0"

Final Call for Snowfall amounts listed and graded.

NWS said...

Louisville   2-4"    100
Evansville  2-4"    100
Paducah   1-3"     100
Cincinnati 3-5"     100
Lexington 1-3"     100
GRADE    100     A+

MrHP said...

Louisville   2-4"    100
Evansville  3-5"    100
Paducah    2-4"      85
Cincinnati  3-5"    100
Lexington  1-3"    100
GRADE     97     A

MikeS said...

Louisville   2-4"    100
Evansville  3-5"    100
Paducah   2-4"       85
Cincinnati 3-6"     100
Lexington 1-3"     100
GRADE     97     A

For the most part, this was an easy forecast because snow was the predominant precipitation. Lexington almost surprised everybody because of it's transition to snow sooner along with bands of snow pushing through.

The next storm system is already poised to affect the region. The NAM has trended somewhat cooler during its few runs today. However, it keeps this as a mixed bag of precipitation for Louisville. Some minor icing is possible. Snow could accumulate generally north of the River, from Cincinnati to Seymour IN. Generally south of that should be a mix of all kinds of stuff. Hopefully, future model runs will help determine precip types for these locations, as this will be a busy period for party animals.

MikeS 66 Index  30.7 (12/29/12)
3.4 degrees below normal

Climate Regions:
High Plains:        8.3 degrees below normal
Midwest:            1.6 degrees below normal
Northeast:          0.1 degrees below normal
Southeast:          1.1 degrees above normal
Southern:           7.9 degrees below normal
West:                  3.7 degrees below normal

I'll be posting a monthly report during the first part of the year. The above data was just for one day. As cold as it has been recently, the month of December's temperatures has proven to be above normal for most, if not all of the climate regions, excluding Hawaii and Alaska.

Speaking of temperatures, as of 12/29, Louisville was on pace to record a top ten warmest winter (like 6th). However, today's temperatures and tomorrow's temperatures may knock them out of the top ten list.

Two locations in my MikeS 66 Index have posted impressive snow totals for the month.
Sault St Marie Michigan   27.9"
Burlington Vermont  24.3"

Again, speaking of snow, Mt Rainier's Paradise Ranger station in Washington state has recorded 246.5" for the season, starting July 1, 2012. Normal for this date should be 259".

More on our next wintry weather event coming soon...
MS

'Overachiever' 12/29/12

Generally, this storm put out more than expected, what we like to call an overachiever, a surprising surprise.

So far, the highest amounts I found in the region include 8" at French Lick IN and 7" in Paoli, both in Orange County.

In Louisville, amounts varied as expected, due to its proximity to the rain/snow line and the infamous dry slot that nosed its way into the area. I recorded 1.5" in Valley Station in southwest Jefferson County (more possibly fell, since temperatures remained at or just above freezing the entire event; therefore, settling occurred during the dry slot because I was not able to measure at that point). However, up to 4" fell in the Lyndon area in eastern Jefferson County. The NWS at the Airport, which is the official site for precipitation measurement, has been 2.7" as of 7:00am.

Lexington proved to be the biggest winner, relatively speaking. Already near 3" as of 7:00am this morning, additional snow showers this afternoon may produce another inch or so for them. In Anderson county at Lawrenceburg, had a report of 3.5".

In Evansville, which is Paducah's coverage area, I saw a daily climate report listing 10 inches as the new snow amount for December 28 as well as the Preliminary Montly Climate Data.. That would have given Evansville over 17" this month. I thought that seemed overdone. After investigating various storm reports around the area, I saw a report of 4.5" of new snow for a total of 10 inches on the ground (what we know as snow depth). At 5:00am, I informed the Paducah NWS office about the error and it has since been corrected. By the way, as of midnight, Evansville had recorded 2" for a monthly total of 9.7". Still, varied reports of 3-4.5" were reported throughout Vanderburgh County for the entire event thus far. So, Evansville now enjoys double-digit snowfall for the month.

MS

Lightning With Our Snow??? 12/28/12

Just experimenting with the HRRR model, 2-4" snow expected across Jefferson County KY. Of interest was the lightning threat. Some of the heavier bands of snow may contain lightning from Louisville west back toward Evansville and western KY.

This may enhance snow rates for a time over 2" per hour.

It's been a while since Louisville has had thundersnow.

MS

Final Call For Snowfall 12/28/12

Earlier, I posted amounts for 5 locations for snow. I will use the NWS official amounts. The forecast covers the entire storm event through Saturday evening. Therefore, I will be adding up the totals from Friday and Saturday, posting results by Sunday.

MrHP says...

Louisville    2-4"
Evansville   3-5"
Paducah     2-4"
Cincinnati   3-5"
Lexington   1-3"

MikeS says...

Louisville    2-4"
Evansville   3-5"
Paducah     2-4"
Cincinnati   3-6"
Lexington   1-3"

NWS says... (as of 4pm est)

Louisville    2-4"
Evansville   2-4"
Paducah     1-3"
Cincinnati   3-5"
Lexington   1-3"

I might add, keep an eye on the HRRR model. It updates hourly and extends out 15 hours. For example, the 18z run that projects out 15 hours (or about 5am) shows Louisville in a 2-3" range.

MS

Midday Update 12/28/12

At 12:50pm, a few peeks of sunshine here at my location. In addition, NAM 12z simulated radar shows bulk of snow will reside just north of Louisville. Up to 5" for some of us. However, heavy snow is possible locally. Also, during the day, snow showers will develop that may contribute 0.2" - 1.5" additional accumulations across the state. Hard to say where those snow showers will develop. It's not unlikely that isolated areas could record a total in excess of 6" for the entire event through Saturday evening.

Could be adjusting totals in my Final Call for Snowfall coming soon....

MS

First Call for Snowfall 12/28/12

This looks like a slam dunk...Sorry, had to use such terminology since this is a big basketball weekend for the state of Kentucky.

Widespread snow is anticipated with a rather over-achieving southwest system. Models keep increasing QPF totals, mostly snow.

The last run that I saw from the NAM puts an axis of heavy snow along the Ohio River from Owensboro to Cincinnati.

The rain/snow line is critical as it runs through the state, as usual. Just north of the rain/snow line should realize the heaviest snow amounts, in my opinion.

Therefore, this latest run from the NAM looks good. However, they have consistently kept surface temperatures above 32 degrees throughout the event. Accumulations would be confined mostly to grassy surfaces while roadways could become partially snow-covered to slushy depending on how heavy the snow falls.

I've chosen 5 'official' weather locations for this forecast...

Paducah 2-4"
Evansville 2-5"
Louisville 2-5"
Cincinnati 2-5"
Lexington 1-3"

I will issue my Final Call for Snowfall sometime this afternoon, after 3:30pm

MS