Wednesday, January 30, 2013

Cold Front on the Move 01/30/13

A cold front has pushed through. However, temperatures are still in the 50's statewide. A large shield of rain and wind continues advancing eastward across eastern KY.

Now, as I look at the most recent hourly observations and radar data, the main cold air is still positioned just to our west in east central Illinois, just passing Mt Vernon. A thin line of moderately heavy showers are accompanying the front.

I wouldn't be surprised to see this line advance into the region with another round of precipitation. Regardless, the colder air is going to arrive, with or without the showers.

Summary of severe storm event. A rotating storm cell affecting Grayson County (Leitchfield) moved quickly northeast into Breckinridge, Meade, and Jefferson counties. A Tornado Warning was promptly issued for the possibility of a rain-wrapped tornado.

As far as I know, at least from my vantage point in Valley Station (near Prairie Village for you familiar with the area), I could not determine any rotation in the clouds. However, due to the 'swirly' nature of the winds, it was possible something could have been aloft. But, the rain was affecting any visibilities that seemed favorable for a nighttime viewing.

The main line of strongest gusts (45-50 mph) were what I call straight-line winds from the west and south. A few instances of winds coming from the north and west could have been related to the cold front pushing in at the same time thus producing the possible 'swirly' nature of the winds.

Damage to dead-wood limbs occurred at my residence. However, no impressive tree damage, at least in my neighborhood, and no power outages.

South of my location, about 4 or 5 miles, Auburndale trailer park' s residents lost power, possible due to trees blocking the roadway and affecting power lines along Pendleton road. I have also heard of tree damage in PRP, which I will look at in just a little bit. That's only a few miles away from my location.

MS




Tornado Warning for Louisville

I live in Valley Station near Prairie Village. Winds were strong, but below severe limits (45-50mph). No power outages here and this is usually an outage prone area. Pressure dropped from 29.39" to 29.34" as storm cell approached, about a 10 minute span. After strongest winds passed, 10 minutes later, pressure rose to 29.46". I've never seen my barometer act so erratically. I think something was up there. Thankfully, it didn't make it down here.

MS

Tuesday, January 29, 2013

HRRR Model Potential Wind Gust

With severe weather approaching the region well into the late night hours, I saw a  recent run of the HRRR model, a high resolution rapid refresh model, showing the 10m wind gusts (about 30 feet AGL). By 3am, the line of storms should be approaching the I-65 corridor with a line of 46-77mph winds.

I would hate to have widespread power outages since it appears colder air will be rushing in behind the front.

Don't forget the use the tool 'Mesonet Front Tracker on the side of my blog to keep up with the temps, precip, and wind gusts.

MS

Severe Wx Looking More Likely for Kentucky

















1:00pm Update
MODERATE RISK for severe weather for western KY (latest Day 1 Outlook @12:30pm)
Tornadoes are becoming more likely down that way. Could there be a rare 'HIGH RISK' later for some of those areas near Little Rock and Memphis?
------------------------------------------------------
Previous discussion:
It appears things are coming together for a significant severe weather outbreak across much of the midsouth and lower Ohio Valley regions. What I find most disturbing is the consistency of these analogs I've been following for the past couple of days now.

Analogs are somewhat different than models. By definition, an analog is "a historical instance of a given meteorological scenario or feature that is used for comparison with another scenario or feature."

I've been looking at the top 15 analogs that best represent this storm system. A combined mean or average of them yields a forthcoming, impressive outbreak of severe weather with damaging winds and tornadoes.

One of the analogs hits home for many of us here in western and north-central Kentucky. The number 2 analog of Feb 5-6, 2008 shows up consistently.

I've mentioned this in a previous post. There were 131 tornado reports for that storm system across much of Arkansas, western and central Tennessee, and Kentucky, 84 were confirmed. Also, there were 267 wind damage reports.

This storm system may be rightly compared to that one in Feb 2008. SPC has been on board, upgrading parts of the midsouth to a MODERATE risk for severe weather. It will be worth keeping an eye on the next assessment from the SPC's Day 1 Outlook. Parts of western KY may go into the MODERATE risk later.

Updates later.

MS






Monday, January 28, 2013

Moderate Risk for Severe Weather Tue/Wed 01/29 and 01/30

I've been talking about the analogs and how they have been suggesting a potentially widespread severe weather outbreak. I thought maybe a moderate risk for severe weather would go up soon for Arkansas, west Tennessee, and west KY.

Now, based on what the SPC is showing, its updated outlook has put most of Arkansas, extreme southwest Tennessee, parts of Louisiana and Mississippi within the moderate shading.

For everybody else in Kentucky, a high-end slight risk for far west KY while areas along and west of I-65 are in a slight risk shading.

Outside of thunderstorms, very windy conditions should prevail. I look for Wind Advisories to go into effect for most of our region for Tuesday and Wednesday.

More later.

MS

Ominous Analog Shows Up

While researching data from the top 15 analogs, one that shows up brings back memories for me. My little girl had just been born a few days earlier. However, on February 5, 2008, a super tornado outbreak occurred that affected several areas of Kentucky and even Indiana.


















This is just one of the 15 analogs that has showed up for this storm system. It does not mean things will be exactly as it happened in 2008. In fact, last I heard was this would be a squall-line event with some embedded tornadoes possible.

More updates later...

MS

Analogs Depicting Severe Weather Chances 01/28/13

At times, especially during the spring, analogs have proven to be useful indicators of what types of severe weather can be expected. In fact, I followed some analogs last year that predicted the violent weather that eventually played out across southern IN and parts of eastern KY.

I'll be updating with additional posts concerning these analogs as we get closer to a possible severe weather outbreak.

Today, I'm looking at a 48-hour NAM based on the top 15 analogs' input made at 7pm last evening. So far, just looking at this run, an impressive outbreak of severe weather for this time of the year could occur. According to the latest run, wind damage appears to be the primary threat. However, tornadoes also look likely in some areas.

Breaking it down, the most likely areas to see severe weather will be central and northern Arkansas, much of  western Tennessee, and western Kentucky. Based on percentages I'm looking at this morning, the top 15 analogs are suggesting a 20-30 percent chance for damaging wind across these areas. Also, an impressive 5-10 percent chance for tornadoes looks greatest across eastern and northern Arkansas along with southwestern Tennessee. An area of southern Missouri south of I-44 may be impacted as well.

However, across our region here in Kentucky, tornado chances do exist (2-5 percent). The  most likely scenario will be the threat for wind damage.

Currently, the SPC has issued its Day 2 Probabilistic Outlook and has much of Arkansas in a high-end slight risk category. I may be going out on a limb here, but I do expect some areas to be upgraded to a moderate risk for severe weather. I would include Arkansas, western Tennessee, and maybe western Kentucky.

Updates will be coming this afternoon.

MS

Saturday, January 26, 2013

Ice and De-ice













Good morning, Somerset KY. A little souvenir left over from yesterday's overachieving ice event. You received 0.2 - 0.25" ice accumulations, a common amount for several areas of south-central KY. Things look to improve dramatically today. Still, beware of leftover moisture on the ground that is likely frozen this morning.

Even here in Louisville, black ice looks to be an issue on some untreated subdivision roads, like my street.  Thanks to barely any snowfall, temperatures should rebound above the freezing mark for many locations across Kentucky, except the usual cold spots of far northern Kentucky and elevated parts of eastern Kentucky.

A nice warmup is in store starting tomorrow and should last into parts of Wednesday before we get slapped with another backhand of Ole Man Winter's dry, cracked, and calloused knuckles.

Here's your next teaser. From the CPC, an updated page from yesterday shows the 6-14 day outlook that features below normal temperatures for all of Kentucky and above normal precipitation for parts of the state, roughly from I-71 and I-75 corridor east including all of eastern KY. Well, you figure it out. Probably means nothing, though.

MS

Thursday, January 24, 2013

First Call for Snowfall 01/24/13

Well, I've had a chance to examine the recent runs of the NAM and do lean heavily toward this model as I forecast these amounts. I will throw in what my MrHP forecast will be along with my personal expectations.

First, let me say there will be quite a bit more of mixed precipitation than snow for this event. To summarize, I expect all snow from Carrollton northeast to Cincinnati and east to Ashland. Louisville should expect a mix of snow and sleet. Lexington also a mix of snow and sleet, although more snow than Louisville. Bowling Green could see freezing rain and sleet throughout the event while Somerset could see freezing rain and sleet before changing to all snow later in the event. Again, a very complex setup.

MrHP says...
Cincinnati 1-2"
Louisville <1" + sleet
Lexington 1" + sleet
Ashland  1-3"
Somerset  0.1 - 0.2" ice, <1" snow + sleet
Bowling Green 0.1 - 0.2" ice + sleet

MikeS says...
Cincinnati  1-2"
Louisville <1" + sleet
Lexington  1-2" + sleet
Ashland  2-3"
Somerset  1" + sleet, 0.1 - 0.2" ice
Bowling Green 0.1 - 0.2" ice + sleet

NWS says (as of 12:30pm est)
Cincinnati  1-3"
Louisville 1" + sleet
Lexington 2"
Ashland  1-3"
Somerset  <1"
Bowling Green 0.2" ice

Very subtle differences in the forecasts above. I will say that the NWS has the best track record . However, I'm beating my MrHP forecast model for the season. The most obvious differences are that Lexington is expecting no sleet and Somerset no ice according to NWS offices.

MS

Wednesday, January 23, 2013

Forecasting Snow For the Region - Try This One

Sure, we can look at the forecast models, you know, GFS, NAM, Euro, GEM. Often, we leave it to the pros to interpret what those models will spit out in terms of precipitation for the area. And yes, all eyes are glued to the same models again as they fluctuate in their various runs for the next upcoming system.

Folks, this is basketball country around here. We live and breathe this stuff, the tickling of the nylon, the diaper dandies, and the thunderous throwdowns. The atmosphere around here gets so heated, I think we can alter the weather at times. You know, it could be true.

Looking at our most recent heaviest snowfall in January, it was January 20, 2011 that Louisville recorded 3.6" and Lexington 3.3". I can't remember how the meteorological computer models fared with their forecasts but I found an interesting correlation that may prove useful for our next storm system in a couple of days.

Introducing the NCAA model.

Something else noteworthy occurred in January 2011. The University of Louisville and Kentucky Men's NCAA basketball teams suffered a loss in the same week.

In fact, UL lost to Villanova 88-74 at Villanova on 1/12. UK fared no better at Tuscaloosa on 1/18 when Alabama beat the Cats 68-66.

Two days later, on January 20, 2011, Louisville and Lexington recorded their respective snowfall amounts previously mentioned.

Last night, UL lost to Villanova at Villanova and UK lost to Alabama at Tuscaloosa. Could this be deja vu? Well, if history repeats itself, then two days or so later, Louisville and Lexington should be looking at possibly 3" of snow on the ground.

Hey, this model makes just as much sense as the ones we hear about on a daily basis from our weather heroes. Take care and I'll give the NAM a few more chances to catch up with the NCAA model.

MS



Snow Chances 01/23/13

Ah, I said beware of the 'snow job' fallacy during a prior post. Data for our upcoming storm system comes in weaker mainly because the phasing aspect may not materialize as assumed. Nevertheless, my low end conservative guidance remains in play (2-3"). And things can still change. I'll be taking a look at the NAM model throughout the day. It is perhaps the main driver in my MrHP (Mid-range Highest Probability) snow forecast. The other factors include the timing (24-36 hours out), upper air forecasts, surface temperature forecasts, and to a limited extent (and I do mean limited) my personal expectations based on observed data.

Even if this forecast does not favor snow enthusiasts' expectations, winter is not over yet. So far, the CPC has put out these mid-range forecasts that have been surprisingly accurate, at least for our region. They predicted the above average warmth and wetness just before the middle of the month. They predicted the below normal cold and below normal precipitation for this period, again some 6-14 days out.

Mark this on your calendars. The January 28 - February 03 time frame is expecting above normal precipitation. Interestingly, the first part of February could be looking at below normal temperatures. Coincide the cold with the precipitation and we could be looking at the elusive 'big one' for our region. Or at the very least, our biggest snowfall of the winter season is in store.

You can check out their predictions at the link below...

CPC Outlook and Information Page

MS

Tuesday, January 22, 2013

Another 'Snow Job'?

Snow Job - "an attempt to deceive or persuade by using flattery or exaggeration" (Dictionary.com)

For at least a couple of days now, NWS offices and other mets have been advertising an 'impactful' winter storm for the Jan 24-26 time frame.

The NWS Louisville office reminds us that despite high confidence for a storm system to affect the region, precipitation types are still 'up in the air'. At this time, a southern track remains the preferred choice.

If the southern track should verify, then sizable snow amounts can be expected, generally north of a line from Beaver Dam to Richmond. However, as usual, Kentucky seems to be the battleground for transitional precipitation.

Any shift in the storm track will impact snow and ice amounts significantly. However, there seems to be growing confidence that a wintry scenario will unfold across the state due to the presence of a retreating yet still present Arctic air mass by Thursday.

Since this type of cold air is difficult to budge at the surface, how thin will the Arctic layer become? If precipitation falls later than expected, warmer air will nudge in from the south in the upper layers of the atmosphere, possibly falling as rain for some of us. The problem then becomes, if temperatures are below freezing, perhaps 3-5 degrees below freezing, any liquid rain that falls will freeze on contact with surfaces and other objects (thus freezing rain).

I'm not here to exaggerate precipitation amounts and types. The storm system is still just offshore. Remember, as I know from personal experience, Arctic air masses are typically stubborn. Cold air likes to hang around, especially near snow-packed areas. There's not much snow out there. Also, these air masses have a great deal of dry air with them. Any precipitation that falls generally have a difficult time making it to the surface.

Depending on the speed, strength, and track of the storm system, it will be interesting to forecast how a developing winter storm will fare against a retreating yet somewhat strong Arctic air mass.

Nevertheless, 2-6" looks like a conservative guesstimate for those who get mostly snow. Although this sounds like an appreciable amount, any mixing of precipitation will reduce those totals in a hurry.

The main concern that I have with this upcoming system is the ice potential. It could become a widespread issue, not like the last storm where only a relatively few locations were significantly impacted.

If the current track remains, ice accumulations for Campbellsville to Corbin  appear possible, at least somewhere in that region, maybe even more locations of eastern KY as well.

For now, let's just wait and see as the storm system comes ashore. Upper air data can then be calculated and storm track along with p-types will become a little clearer.

Looks like another tough snow job to forecast, or should I say, beware of those snow job forecasts that persuade you this will be an easy storm to forecast.

MS


Thursday, January 17, 2013

January Mid-Month Report

A good time to look at what has and what will happen.

Overall, it's been wet and mild...thru 1/16
Louisville  234% of normal precip
Louisville 4.8 degrees above normal

Lexington 181% of normal precip
Lexington 5.3 degrees above normal

Bowling Green 203% of normal precip
Bowling Green 5.8 degrees above  normal

Jackson 179% of normal precip
Jackson 5.5 degrees above normal

The CPC says for the time frame of Jan 22-26, temps retreating from below normal readings. In fact, Jan 24-30 time frame shows above normal readings across much of the south, including KY.
I'll be interested in seeing how this unfolds as some are pointing toward a very cold period during this latter period.

Here is what the CPC says for the month of February...

February Temps
February Precip

MS

Tuesday, January 15, 2013

Mix It January 15, 2013

Wintry mix for many locations today. Therefore, WWAdvisories posted, generally south of Louisville.

Things to think about...

NAM radar shows mostly rain, with freezing rain/sleet along the Ohio river.
This seems to contradict with forecast surface temps, especially south of Louisville.
For Louisville, NAM suggests liquid equivalent of 0.18". Sounds excessive.
According to upper air forecasts, the freezing point will be right over Louisville (how many times have we seen that?); therefore, any precipitation that falls will be a mix of rain and sleet. Surface temps look to be near the freezing mark.
I think main roads should be okay here in Louisville. The usual bridges and overpasses along with secondary roadways could receive a slight glazing at best. However, this does not appear to be a significant event.
Temperatures will need to be monitored, though.
Don't know if WWAdvisory will be posted for Louisville. It will be a close call. Still, exercise caution, regardless.

The way I see it, you already know the forecast. Areas NOT under the WWAdvisory can still expect a mix of sleet and possible freezing rain. Therefore, treat the situation as if we were under the Advisory. If you know that you're running low on gas, you don't need to wait for the gas light to come on to get gas. Similarly, you know there will be a wintry mix for some, which requires caution when driving. You don't need to wait for the NWS to issue an Advisory to decide if you're going to drive with caution.

HPC Freezing Rain Probability Jan 15-16

MS

Southern Ice Storm 01/15/13

An ice storm is in progress across parts of the south. Ice storm warnings are in effect from Shreveport LA to Memphis TN.

At 10:00am, I have been listening to scanners out of Shreveport LA. Bridges are now slick and hazardous. One particular bridge has yielded accidents, including injuries. Law enforcement and other officials are trying to divert traffic from the bridge so that medical personnel can get to those injured.

Shreveport LA scanners

MS

Sunday, January 13, 2013

Heavy Rain Event January 10-14, 2013

For some, this has been a memorable rain producer. Plenty of water fell from the skies across the state. Here is a list of final rainfall totals for those of us generally along and west of I-65. These totals cover the time period from Thursday, January 10 through this evening at 9:30pm est.

Crittenden County      6.29"
Fulton County            5.87"
McLean County         5.15"
Graves County           4.45"
Marshall County         4.39"
Simpson County         3.90"

Louisville                    3.60"
Bowling Green           3.31"
Lexington                   2.38"

In Jefferson County...
Valley Station            4.16"
Camp Horine             3.91"
Valley Station (MS)   3.80"
Fairdale                     3.76"
PRP                          3.68"

More totals possibly forthcoming for the eastern part of the state.

MS

Weather Summary and Forecast 1/13/13

I'll be posting rainfall totals by tomorrow evening. I'm keeping a running total on my RainWatch post. You can check that out to keep current.

Impressive rain totals across western KY with some amounts exceeding 5" since Thursday Jan 10.

Cold front blasting through the state today, promises to crush our January thaw. In fact, some residual moisture may freeze, causing black ice concerns and the dreaded I-can't-open-my-car-door syndrome.

In other news, the western United States is undergoing quite the cold spell. They're talking about possible frost on the beaches of San Diego and for Tijuana's sunrise.

Las Vegas, NV recorded low temperatures at or below freezing only 3 times last year, and that was in December last month. So far this year, counting today, this is Las Vegas' 8th day at or below 32 degrees.

On the flip side, if you want to call it that, Alaska has been 'enjoying' much above normal temperatures lately. Despite Fairbanks recording 8 consecutive mornings below zero, their average temperature is 9.5 degrees above normal for the month.. At Bethel, they're running 18.7 degrees above normal.

One of the snowiest locations in Alaska is Valdez. They have received nearly 80" for the season. However, that is way below average for them. Normally, Valdez should have recorded 151.8 inches by now for the season. Last year, at this time, they had already recorded 322".

In Texas, so far, it's been very wet this month. At Navarro Mills Dam, about 35 miles east of Waco, 5.28" rain has been recorded. Waco has had 4.83", most of that occurring on January 9th when they received a record 3.79" for the date.

Our forecast is calling for an extended cold spell. However, the NWS seems to think temperatures will run about normal for the area. They're holding off on precipitation chances for the rest of the week. There will be systems out there that will be worth keeping an eye on, though.

The CPC has put out a medium-range forecast that has the region in below normal temperatures for the January 18-26 period. However, precipitation looks to come in at below to much below normal for the same time period. It figures.

MS

Friday, January 11, 2013

RainWatch Jan11-14 2013


I'll be updating this page throughout the next few days, using a combination of Mesonet sites and MSD rain gauges and the NWS offices.
\
UPDATED Sun pm at 2:00est
The next wave of precipitation has been riding along the slow-moving cold front. The temperature at my house in Valley Station (sw Jefferson County) is still 55 degrees. About 30 minutes away in Brandenburg (Meade County), temperature is 44. So, the front is getting much closer. Several areas in Jefferson county are now over 2" since midnight. Some locations in west KY are over 3" since midnight. Here are some updated totals since midnight and total storm amounts since Thursday.

McLean County near Calhoun  3.13"  4.88"
Crittenden County near Marion  3.04"  6.17"
Fulton County near Hickman  3.03"  5.84"
Graves County near Mayfield  2.90"  4.43"

Louisville 2.17"  3.05"
Lexington  0.86"  1.53"
Bowling Green  1.54"  2.67"

Valley Station 2.63"  3.63"
Camp Horine  2.34"  3.29"
PRP  2.32"  3.23'
Fairdale  2.28"  3.16"

Check out more later today.
---------------------------------------------
UPDATED Sun am at 3:00est...
Cold front pushing through western KY. Cadiz at 70 degrees and dry. About 25 miles west at Benton, it's 47 with 1.20" rain since midnight.
Crittenden County near Marion has had 1.73" since midnight for a Thr-Sun total of 4.86".
The heavy rain shield is on the move. Just started at my house several minutes ago with a quick half-inch of rain in southwest Jefferson county near Valley Station. Several locations in far west KY reporting amounts in excess of 1-2" since midnight. Temps plummeting behind front now in the low 40's in the farthest western parts of KY.

------------------------------------------------
UPDATED Sat pm at 9:00est...Since Thursday
Fulton County near Hickman 2.65"
Union County near Morganfield 2.89"
Crittenden County near Marion 2.55"
McLean County near Calhoun 1.75"
Graves County near Mayfield 1.43"

Louisville 0.88"
Lexington 0.67"
Bowling Green 1.13"

Morris Forman 1.00"
Valley Station 0.99"
Camp Horine 0.95"
PRP 0.91"
Fairdale 0.88"
-----------------------------------------------------------------
In Jefferson County KY...based on MSD rain gauges since Midnight Thursday morning

Since Thursday...
Camp Horine (southern) 0.94"
Morris Foreman (Algonquin Pkwy) 0.95"
Hite Creek (northeast) 0.82"
Fairdale 0.88"
Valley Station 0.98"
Lea Ann Way (near Jefferson Mall) 0.74"
St Matthews 0.78"
PRP 0.88"

Louisville 0.88"
Bowling Green 1.09"
Lexington 0.41"

McLean County 1.63"
Crittenden County 2.08"
Trigg County 1.41"
Marshall County 1.42"

MS

Tuesday, January 8, 2013

Rain And Warm Temperatures for January 9-13

HPC shows the well-advertised wet pattern getting ready for splashdown. Perhaps 2-4" rain should accumulate, especially from I-65 west over the next 5-7 days.

Some Mets are expecting strong to isolated severe storms by Thursday. Right now, SPC has posted a very low probability for far west KY. However, adjustments will be made as additional atmospheric data and timing issues continue to be updated. So stay tuned.

The above normal temperatures should continue at least through the rest of this week. Get out there and get those outside chores done while you can.

MS

Sunday, January 6, 2013

January Thaw And Then More Snowfall?

Temperatures are poised to spike during the next week, providing a welcome relief for those of us with 'cabin fever'. However, a wet pattern looks in store for many as well.

The CPC shows a wetter pattern through mid-month. Also, the first part of the period, which includes this upcoming week's warmth, should transition to a colder mid-month.

If the below normal air arrives as anticipated, look for a cold and snowy second part of the month.

Meanwhile, enjoy the nice warmup coming.

MS

MikeS 66 Index December 2012 Report

I compiled the data for the month of December at the 66 locations I've chosen across the United States. Although not official, the index takes a look at the climate regions across the country and calculates the temperature and precipitation data for the month. This in turn will help me as I compare the data to various teleconnections such as the North Atlantic Oscillation (NAO) and others for the month.

Summary:
Despite a cold pattern for many during the last week of the month, December 2012 was a warm month for much of the United States. The U.S. monthly temperature report from my index was 40.6 or 3.8 above normal.

Also, precipitation amounts varied across the country. However, compilation of the data shows that the U.S. was slightly wetter than normal.

A look at specifics by climate region includes:
The northeast was wetter and warmer than normal. Coastal areas of Maine and Massachusetts contributed the wettest amounts.
The southern part was drier and warmer than normal. Oklahoma and southern Texas contributed the driest amounts.
Although the High Plains and the West were cooler than the rest of the United States, their temperatures still showed above average, just not as much. It was wet, though, along the coast from Washington to California.
While the Midwest basked in overall warmth, some of the above normal precipitation took place in the form of snow.Parts of Wisconsin and the favored areas along the Great Lakes recorded between 20-30 inches for the month.
Finally, the Southeast generally enjoyed warmer than normal readings. Rainfall was a welcome sight for some areas of drought-stricken Georgia. However, southern Florida recorded very little rainfall.

MS

Tornadoes on Easter Sunday

This is a worse case scenario. Tornadoes and flooded, blocked roadways making for great difficulties reaching residences affecting hard hit ...