Potential New Year's Eve Storm Update

Just for fun, thought I'd show a graphic of the latest on the New Year's Eve/Day storm. Models continue to show a monster coming into our area. Take a look at this.



You can visually see how strong the cold front it and you can also see the major low pressure centered near Chicago. Ahead of the front in the green you see 12C temps (about 54F) and right behind the front in the blue you see -4C (about 25F)! That's a sharp front! I would expect to see severe storms in a squall line with temps like this and I'd think snow showers would be most likely behind the front, with blizzard conditions to our north. This will definitely be one to watch closely in upcoming days.

(12-24-10) White Christmas Almost Here!

Models continue to come into agreement that main surface low will move into the Gulf of Mexico. However, a nice dip in the jet stream in the mid layers of the atmosphere will cause enough spin in the atmosphere to produce upward motion needed to produce snow. The timeline still looks like the main brunt of the snow will beging late this evening. At 8am this morning, snow is already moving into southern Illinois, but I think that since the air is not saturated yet, it will take a while for this to reach the ground. It still looks like it will be late afternoon into the evening hours before we start to see much in the way of snow here in Dubois County.

To that effect, the National Weather Service in Louisville has placed us under a Winter Weather Advisory beginning at 6pm tonight and lasting through Noon on Christmas. While this won't be a major blizzard by any means, a few inches are expected to fall. Bufkit sounds place snow ratios in the 13:1 to 17:1 range with a QPF (quantitative precipitation forcast - liquid precip in other words) at about a quarter of an inch. That would be just over 3 inches of snow at the 13:1 ratio and about 4 inches at the 17:1 ratio. All in all, I think a solid 2-4 inches is a pretty good estimate of what to expect. Some areas of Southern Indiana may get less and I hope we're one of them!

As you can see in the graphic below, the HPC has placed us at the edge of a moderate risk (40%) for having snowfall at least 4 inches. There is some pretty strong agreement among all models and forecasters now that we'll see a decent snowfall.






Again, travel conditions tonight could get very rough, so pay close attention to the road, slow down to a reasonable speed and don't go out unless you have to once the snow begins. Have a very Merry Christmas and I'll return to blogging in a couple of days.

(12-22-10) New Year's Eve Nightmare?

Just wanted to make a quick post about the potential storm heading in over the New Year's Eve weekend. It's way too early to see how this will truly pan out. The models are all over the place at this time, but almost every model run is showing a massive storm...somewhere! The exact placement is to be determined, but someone is going to get hit hard. Look at this graphic:




If this pans out, we'd have temperatures in the 50s ahead of the front with severe thunderstorms somewhere along that frontal boundry! Then it would turn sharply colder into the 20s behind the front and give us a quick inch or two of snow in the wrap-around moisture!

Yuk! Almost gives you a headache just thinking about all of this! The models have been consistent in that a major storm is brewing...it's only a matter of where it seems like. I think someone could get slammed with some strong storms and someone else could get a major blizzard out of this. We'll see how it pans out. I'll post more on this in coming days as we get past this Christmas system and as we get closer to the actual event with better model guidance.

(12-22-10) Diminishing Snow Chances!

All kinds of chatter out there as to this winter storm right now and all kinds of opinions about it. At least the idea of what is headed our way is becoming clearer...a bit anyway.

The leading edge of this system is just now pushing onto shore as you can see from the enhanced infrared satellite image below. I've placed a low where the system is currently located. You can see the counter-clockwise circulation quite well.

The last of the models that were hanging onto a more norther track have now went south. In fact, the trend is to push this low into the Gulf of Mexico by Christmas. I think over the next couple of model runs overnight and into early tomorrow morning, we'll get a much better feel of this system - simply because of the increased data points to be entered into the equations the model relies on to produce the maps. There will be much more data available on this system now that it is on shore.

As I mentioned yesterday, the models are in disagreement as to how the northern and southern tracks of the jet stream will go and when they will phase together. I've looked at a lot of model runs over the past two days and it seems that the trend is to take the low into the deep south and phase the two jet streams over the Atlantic Ocean before the storm moves up the east coast and turns into a noreaster for the New England area.

You'll recall from yesterday's post that some of the older model runs were taking the low into Tenneesee and Alabama and some forecasters are still holding out to that option. But I disagree. I think that's too far north for a number of reasons. For starters, there is a blocking high situated in Canada at the 850mb level. That is forcing everything to the south. Secondly, the low coming on shore right now is just too far south to make it much farther north and overcome that blocking high. It would really need to be moving on shore in mid-California to overcome this and take a Tenneessee/Alabama track. Thirdly, based on the latest model guidance, I don't think the two waves of the jet stream will phase together until late Christmas day over the Atlantic Ocean. Amd there will not be enough energy and momentum to shift it north until that happens. Over the ocean is too late to take it north into our area!

Here's a visual idea of what I'm talking about. The model run on the left is the GFS 0Z run (7pm last night). Notice that it takes the low right over New Oreleans. To the right is the GFS 12Z run (7am today). Notice that it takes the low even further south over the Gulf of Mexico and slows down the timing quite a bit.

I think the low will eventually turn out to travel somewhere in the deep south near the Gulf. And frankly, I don't think it will have much of an effect on our weather. The mositure that you see in our area on these two models is actually from a dip in the northern section of the jet stream in our area and there just isn't enough precipitable water associated with that stream to be able to produce much in our area. Consider the latest snowfall map from the GFS 12Z run:

This seems more on track with what I'd expect from just a small upper-level distrubance from the jet stream in our area. This takes us at about 2 inches of snow by Saturday. With the low largly out of the picture for our weather, I really think we'll see less than 3 inches total with this storm and I think that the 1-2 inch range is a much better bet. I do think we will see something and I do think it will make travel rough for a while. I still expect it to start late Friday afternoon or evening. If you are planning to travel on Friday, take caution and stay tuned as the days get closer. I'll blog more about this tomorrow as more model solutions come out.

(12-21-10) I'm Dreaming of a White Christmas...

Well, some people are anyway! If you're a snow lover, this could be the storm for you. Sorry to be so slow in updating this. I've had a pretty busy week and all my family including me have colds, but plan to blog more over the next few days as the storm approaches.

It's looking like we'll almost certainly have a white Christmas this year. The models are in disagreement on the exact timing of the system, but almost all models are now agreeing on a southern track for this low moving in. Some have it near Tenneesee and other have it near Alabama. Either way, it appears we will be all snow. Just how much snow we get will depend on the exact track, with more with a Tenneesee track and less the further south it goes.

Right now the system is just moving onto the west coast and as it moves on over the next day, we'll be able to get more data points into the models. There aren't many data points over the ocean! With more data on this system, the models will come into much more agreement and we'll have a better feel for what to expect.

One thing worthy of note is that over the last few model runs, the forecasted snow has continued to increase. Consider the graphic below. The graphic on the left is the snow accumulation predictions from the GFS model at 7pm last night (0Z). The one on the right is the same model at 1pm today (18Z).

In just a few short model runs, it has went from about 1 inch in our area to 5 inches! Yikes! Again, this is just preliminary and may well change, but it serves as a good warning that we need to take caution. This will likely be one of the busiest travel weekends of the year and this storm could well have a major effect on travel plans for many people. I suspect that the National Weather Service will be issuing winter storm advisories and/or warnings for our area in the next day or so as we get closer to this event.

Much of what we get will depend on how the jet stream acts out for us. Right now there is a strong high pressure system in Canada that will be acting as a blocking mechanism for us, keeping this winter storm on a southerly track. How strong this blocking mechanism is will depend on how far south this storm is pushed. Also, the southern track and northern track of the jet streams are predicted to phase together, increasing the strength of this winter storm. If that phasing happens over the plains, expect a stornger system with more snow for us. If that phasing happens over the deep south, expect a weaker system for us with less snow. I think the models will get a better handle on this over the next day or so as the system moves onshore.

Let's talk about a timeline for this event. Right now I'm thinking that most of the snow will not begin until Friday afternoon. The low will be moving to our south during this time frame and will pull in some significant moisture for us. How much is yet to be determined, but I do think it will be signifcant enough to cause travel problems Friday evening and night. Snow will get heavy at times and last overnight into Christmas morning. As the low moves off to the east and out to the Atlantic Ocean on Christmas day, expect snow to taper off and light snow showers to continue into Sunday as wrap-around moisture comes into play. Overall I'd say 3-4 inches or more is not out of question if these current model solutions verify.

Next week looks to be quite cold! As this system moves out to sea, it could turn into quite a noreaster for the New England area. That will turn our winds around to the north and push bitter cold temperatures back into our area. Also taking into consideration the snow pack from this system that will still be on the ground, we won't get out of the 20s for the first half of next week. The long range model also have a winter storm moving in over the New Year's Eve timeframe. It's too soon to predict anything definite, but it could be quite a system if it verifies out.

For now, here's your updated 7 day forecast.

(12-17-10) Mon-Tue Wintry Weather

The latest model guidance is trending warmer for next week, which is a good thing. For the past three days, the model output statistics (MOS - a numerical prediction of high temps) have trended warmer for our area. Monday's MOS has went from 35 to 37 all the way up to 39 on this last run. I stil don't think it's accounting for the snow that's still on the ground in our area, but I do like the trend, though I doubt we'll see 39 on Monday. I'd say 35 is more likely.

These latest models have also shown a dramatic shift in the tracking of the surface low coming into our area next week. Yesterdays model was sort of apocalyptic in some ways, with the low tracking to our north and 5 or so inches of snow in our area. This latest model tracks the low south of us and puts us with a light snow event to start and then changing over to plain 'ol rain by the end of it. So which will it be? I'm hoping for the latter, as I'm sick of snow! I'll wait for the model runs to come out again later tonight and tomorrow. If it keeps trending south of us, I'll be able to fine tune the forecast more. South of us would also send us warmer air, lending more toward rain.

To get an idea of what I'm talking about, here's a small part of these past two GFSX 0Z Models from yesterday on the left and today on the right. You can see how the low was predicted to be in Illinois at 7am on Tuesday. The latest model takes it into Arkansas at 7am on Tuesday. This would be a dramatic shift in what we would get with this system! You can also notice that the low was forecasted to be at 1006mb and the new one takes it to 1014mb. This means it would be weaker, with less fuel to work with and much less wind for us. All in all the new set up is much nicer!

Now for what everyone is really thinking about - Christmas! What will it be like? Below is the current model run for Christmas day. You can see it's showing a bit of snow activity on a broad level in our area. This would be light snow showers/flurries. No major system around us, just a small dip in the jet stream over our area that might spark up a few things. Cold NW winds will push highs only into the 20s on Christmas.

(12-16-10) Outlook for Next Week

The freezing rain event is now over for the Dubois County area. All in all we had about a quarter of an inch of ice accumulate on the roadways here. Conditions were slick and the schools closed for good reason. Now we turn our attention to next storm heading our way. It does look like we'll have a break from the winter weather for a few days. The weekend looks to be nice, just really cold.

Monday and Tuesday will usher in another round of wintry weather into our area. At this time, the models are making it out to be an all snow event. I see no indication that we'll be getting another freezing rain/sleet system into our area like this one last night was. The big difference will be the direction this system is coming from. This next system looks to have its center to our north and it'll probably be a wrap-around snow type of deal similar to the last snow we had on Dec 12th. The main difference here is that this system looks to have quite a bit more moisture to work with.

It's way to early to start talking about definite amounts for what to expect. If the current models verified, we'd easily get five inches of snow out of this next system, but I think it's way too early to start believing these models. For starters, this system has not even formed yet. It's expected to form over Idaho on Sunday afternoon. The jet stream will then give it ample fuel and it'll be in our area by Monday night/Tuesday morning. We'll really need to wait to see if we see a trend with the future model runs and it's also possible this system could change storm tracks dramatically this far out. This is still five days out. The higher resolution models won't even begin picking this system up for a couple of days. Right now we're relying solely on a long-range model for this data. A lot can change over the next couple of days. I'll keep an eye on this system and blog more about it as time gets closer.

What about Christmas? Right now it looks to be very cold with temperatures only in the mid to upper 20s. It doesn't appear that we'll see any accumulating snow unless something changes. Some flurries are showing up on the models, but nothing that will stick. So travel will be OK.

Here's your updated 7 Day Forecast.

Pictures from 12-16-2010 Ice Storm

Pictures from my house in Huntingburg the morning of the ice storm.

(12-15-10) Winter Storm Warning in Effect

As expected, we've now been upgraded to a Winter Storm Warning in effect until 1pm Thursday. The last few model runs since yesterday have started to trend a bit warmer in our area, seeming to put the rain/snow changeover line to our north. It's now looking like Dubois County will get a fair amount of freezing precipitation.

So what can we expect? Tonight temperatures will stay nearly steady. At 6pm it's 28F and we'll stay in the upper 20s through most of the night, possibly rising to near freezing by morning. Right now the temperatures in the mid-atmosphere (around the 850mb level) have not risen above freezing. As warmer air surges in from the south overnight into that layer, expect it to go above freezing and produce freezing rain for us. In fact, the National Weather Service has placed us under a moderate risk for freezing rain. What this means is that we'll likely start out as an all snow event and then transition to a snow/sleet mixture before changing over to all freezing rain sometime overnight.

So how much can we expect? It appears that we'll have plenty of QPF to work with. QPF is Quantitative Precipitation Forecast and it is a graphic the National Weather Service puts out to give forcasters an idea of how much precip to expect. It puts our area in the 0.25 - 0.5 inch range. Remember this is liquid, so we have to convert to snow using a 10:1 ratio for wet snow. If it were all snow, we'd be in the 2.5 - 5 inch range. Since it won't be all snow, it's really going to depend on how much falls initially as snow and when the changeover occurs. It's highly likely that we could see some heavy snow showers at the outset of this event as it moves into our area overnight. That could give us a quick 1-2 inches of snow, followed by a solid quarter inch of ice in the form of sleet and freezing rain. This storm is really tricky to predict and really the best way at this point is to stop looking at the models and see what actually happens in Kentucky in a few hours. That will give us a solid idea of what to expect.

As for the rest of the week, it will be cold. Friday looks to be a gloomy day with highs in the upper 20s. The weekend looks dry overall, with just a passing flurry or two. Nothing significant, but highs will only be in the upper 20s again. In fact the whole 7 day outlook looks to be well below normal for us in temps. Lows will be in the teens throughout the forcast.

(12-14-10) Mid-week Winter Storm Update

Another winter storm is on the way to the tri-state area and this one looks very messy! Whereas the storm over the weekend brought light, powdery snow with liquid to snow ratios of 20:1, this next storm will be a wintry mix of sleet, freezing rain and wet snow. The good news is that this system appears to be a fairly fast moving, short lived system. Still this one could be one to watch, as road conditions on Thursday could get very hazardous.

Right now a low is forming over the Oklahoma panhandle and is predicted to move into the Tennessee Valley overnight on Wednesday and into Thursday. While temperatures here at the surface will stay below or near freezing, as the winds shift to the south, temperatures aloft in the upper layers of the atmosphere will rise into the 30s, producing sleet, freezing rain and wet snow over our area.

So what can we expect? The further north you go, the better off you will be. Here in Dubois County, I don't think freezing rain will be a major play at this time. The latest models are showing the freezing rain south of the Ohio River. Right now if these current models verify, we're looking at a sleet/snow event. Don't expect much in accumulations. Just expect a mess! South of here, look for freezing rain and sleet changing over to an all rain event in Kentucky.

So what can we expect as a timeline? The National Weather Service has issued a Winter Weather Advisory for our area, effective at 7pm Wednesday evening going through Thursday. It looks like the bulk of the precip will start after dark on Wednesday, with the main event between 5am - Noon on Thursday. No matter what we get, when we get it, it's gonna be a mess! Stay safe out there. I'll have more updates tomorrow. For now, here's your updated 7 day outlook.

(12-13-10) Wintry Mix Possible on Wednesday

With one storm system now behind us, another lies in wait. Huntingburg received about an inch and a half of light, fluffy snow on Sunday. With winds howling in the 20s mph range, road conditions were quite hazardous Sunday evening and into Monday morning. Those winds should be dying down later today as bitter cold temperatures are on the way. The low cloud base will recede later today as we move to an overnight low of 5 degrees!

As this system races off to the east, we now turn our attention to the next round of wintry precipitation heading our way on Wednesday. A new low is trying to form over the Rocky Mountains and is forecast to move to our south Wednesday night and into the day on Thursday. As the high pressure that is in charge of us right now pushes eastward, expect slightly warmer temperatures to move into the area, pushing us near the freezing mark. Warm air from the south will also infiltrate the upper layers of the atmosphere, which means that precipitation could come in the form of sleet or even freezing rain. Expect hazardous road conditions again on Wednesday and Thursday if this scenario pans out.

I'll have more on what to expect later today or tomorrow as more model runs come out. Right now it looks to be a mess. We'll see if the next runs continue this trend. Saturday also looks to be in question. I'm going with a 30% chance of snow at this point. Hopefully the next models will take this away!

For right now, here's your updated 7 day outlook.

(12-11-10) Dry Slot Now Visible

As predicted by the models I discussed earlier, a nice dry slot is setting up behind the cold front. A dry slot is a pocket of relatively low moisture in the atmosphere caused by a low sucking in cold air from Canada. This can be seen clearly in the water vapor image below. I've placed a Low on the spot where the low currently sits. The white images you see are not clouds, but rather water vapor in the atmosphere. Water vapor in large quantitites is needed to form any significant weather system. The brighter the white, the more the vapor is present. You can see that this system is bright white along the cold front and the Low. But you can also see a darker swath of air coming into the center of the low pressure. This represents the absense of moisture.

Lows move in a counter-clockwise direction and essentially its sucking down cold, dry air from Canada into this low. This is partly why the cold front will be so impressive, bringing significantly colder temperatures to our area once it passes. This is the dry slot I've been talking about. This can also be seen by looking at the radar image below. Rain is only infront of the cold front and none behind.

What does this mean for us? It means that we shouldn't get much in the way of snow accumulation overnight once the front passes. I expect we will see some, but it won't be much and this will drastically cut down on our totals.

(12-11-10) Winter Weather Advisory Issued

As expected, the Louisville National Weather Service has issued a Winter Weather Advisory for Dubois County and all the Louisville NWS area. The Paducah office has chosen to issue just a statement rather than an advisory.

The text of Advisory in effect for Dubois County is below:

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE LOUISVILLE KY
301 PM EST SAT DEC 11 2010

...PERIODS OF SNOW AND BLOWING SNOW EXPECTED TONIGHT THROUGH
MONDAY MORNING...

.A STRONG COLD FRONT WILL MOVE THROUGH THE OHIO VALLEY OVERNIGHT
TONIGHT. TEMPERATURES BEHIND THE FRONT WILL FALL QUICKLY...CHANGING
THE RAIN OVER TO A WINTRY MIX AND FINALLY TO SNOW BY SUNDAY
MORNING. THERE WILL THEN BE A BRIEF BREAK IN PRECIPITATION BEFORE
MOISTURE FILTERS BACK IN FROM THE NORTH AND WEST. PERIODS OF SNOW
WILL BE POSSIBLE ACROSS THE REGION THROUGH MONDAY MORNING.
ADDITIONALLY...WINDS WILL PICK UP SUNDAY MORNING WITH GUSTY WINDS
CAUSING BLOWING SNOW WITH VISIBILITY REDUCTIONS.

INZ076>079-083-084-089>092-KYZ023>043-045>049-053>057-061>067-
070>078-081-082-121000-
/O.NEW.KLMK.WW.Y.0014.101212T0600Z-101213T1800Z/
ORANGE IN-WASHINGTON IN-SCOTT IN-JEFFERSON IN-DUBOIS IN-
CRAWFORD IN-PERRY IN-HARRISON IN-FLOYD IN-CLARK IN-HANCOCK KY-
BRECKINRIDGE KY-MEADE KY-OHIO KY-GRAYSON KY-HARDIN KY-BULLITT KY-
JEFFERSON KY-OLDHAM KY-TRIMBLE KY-HENRY KY-SHELBY KY-FRANKLIN KY-
SCOTT KY-HARRISON KY-SPENCER KY-ANDERSON KY-WOODFORD KY-
FAYETTE KY-BOURBON KY-NICHOLAS KY-NELSON KY-WASHINGTON KY-
MERCER KY-JESSAMINE KY-CLARK KY-LARUE KY-MARION KY-BOYLE KY-
GARRARD KY-MADISON KY-BUTLER KY-EDMONSON KY-HART KY-GREEN KY-
TAYLOR KY-CASEY KY-LINCOLN KY-LOGAN KY-WARREN KY-SIMPSON KY-
ALLEN KY-BARREN KY-MONROE KY-METCALFE KY-ADAIR KY-RUSSELL KY-
CUMBERLAND KY-CLINTON KY-
INCLUDING THE CITIES OF...PAOLI...SALEM...SCOTTSBURG...MADISON...
JASPER...MARENGO...TELL CITY...CORYDON...NEW ALBANY...
JEFFERSONVILLE...HAWESVILLE...HARDINSBURG...BRANDENBURG...
BEAVER DAM...LEITCHFIELD...ELIZABETHTOWN...FORT KNOX...
MOUNT WASHINGTON...SHEPHERDSVILLE...LOUISVILLE...LA GRANGE...
BEDFORD...NEW CASTLE...SHELBYVILLE...FRANKFORT...GEORGETOWN...
CYNTHIANA...TAYLORSVILLE...LAWRENCEBURG...VERSAILLES...
LEXINGTON...PARIS...CARLISLE...BARDSTOWN...SPRINGFIELD...
HARRODSBURG...NICHOLASVILLE...WINCHESTER...HODGENVILLE...
LEBANON...DANVILLE...LANCASTER...RICHMOND...MORGANTOWN...
BROWNSVILLE...MUNFORDVILLE...GREENSBURG...CAMPBELLSVILLE...
LIBERTY...STANFORD...RUSSELLVILLE...BOWLING GREEN...FRANKLIN...
SCOTTSVILLE...GLASGOW...TOMPKINSVILLE...EDMONTON...COLUMBIA...
JAMESTOWN...BURKESVILLE...ALBANY
301 PM EST SAT DEC 11 2010 /201 PM CST SAT DEC 11 2010/

...WINTER WEATHER ADVISORY IN EFFECT FROM 1 AM EST /MIDNIGHT CST/
SUNDAY TO 1 PM EST /NOON CST/ MONDAY...

THE NATIONAL WEATHER SERVICE IN LOUISVILLE HAS ISSUED A WINTER
WEATHER ADVISORY FOR SNOW AND BLOWING SNOW...WHICH IS IN EFFECT FROM
1 AM EST /MIDNIGHT CST/ SUNDAY TO 1 PM EST /NOON CST/ MONDAY.

* TIMING: AS COLD AIR FILTERS IN BEHIND THE COLD FRONT TONIGHT
RAIN WILL CHANGE TO LIGHT SNOW. SNOW WILL TAPER OFF BETWEEN 7AM
AND NOON EST SUNDAY MORNING AS DRYING MOVES ACROSS THE REGION.
SNOW CHANCES WILL INCREASE AREA WIDE SUNDAY AFTERNOON THROUGH
MONDAY MORNING AS PRECIPITATION WRAPS AROUND THE UPPER LEVEL LOW
PRESSURE SYSTEM.

* MAIN IMPACT: LIGHT SNOW ACCUMULATIONS OF UP TO HALF AN INCH WILL
BE POSSIBLE OVERNIGHT TONIGHT. AN ADDITIONAL ONE TO THREE INCHES
OF SNOW IS POSSIBLE ACROSS THE AREA SUNDAY THROUGH MONDAY
MORNING. LATE SUNDAY NIGHT AND EARLY MONDAY MORNING WINDS WILL
INCREASE TO 20 TO 25 MPH WITH WIND GUSTS OF 30 TO 35 MPH. THIS
WILL CAUSE BLOWING SNOW WHICH MAY REDUCE VISIBILITIES AT TIMES
CAUSING TRAVEL DIFFICULTIES.

* OTHER IMPACTS: TEMPERATURES WILL FALL QUICKLY BEHIND THE FRONT
TONIGHT. A WINTRY MIX WILL BE POSSIBLE BEFORE THE PRECIPITATION
CHANGES TO ALL SNOW OVERNIGHT. IN ADDITION ANY WATER REMAINING
ON AREA ROADS OVERNIGHT COULD FREEZE FORMING BLACK ICE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY FOR SNOW MEANS THAT PERIODS OF SNOW
WILL CAUSE PRIMARILY TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW
COVERED ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

A WINTER WEATHER ADVISORY FOR BLOWING SNOW MEANS THAT
VISIBILITIES WILL BE LIMITED DUE TO STRONG WINDS BLOWING SNOW
AROUND. USE CAUTION WHEN TRAVELING...ESPECIALLY IN OPEN AREAS.

(12-11-10) Winter Storm Update

The deeping low pressure system has now brought widespread rain to to Southern Indiana area. As the low continues to strengthen tonight, expect a drastic change in temperatures to come after midnight. The latest 0Z and 12Z GFS Model Runs are still indicating a dry slot forming just after the passing of the cold front somewhere close to midnight tonight. This dry slot should keep snow accumulations down to a minimum for us. If current predictions in the models hold up, we should get up to one inch of snow tonight and a little more from wrap around moisture on the day Sunday, with lingering snow showers into Monday. It looks like 3" is the absolute maximum we could get with this system unless something drastic changes and it really looks like 1-2" would be much more reasonable at this point. In looking at some other sources of weather info, it looks the the Louisville National Weather Service will be issuing a Winter Weather Advisory later today. Dubois County is the farthest county west in their warning area, so we'll likely be under it and it may be possible that Spencer, Pike and counties to our west will not be since they are in the Paducah NWS office's warning area. Regardless of whether an official Advisory is issued or not, please take caution. This is a potent storm that heeds our attention.

A timeline of what to expect from this system is below:

The cold front will pass somewhere around mindnight-1am tonight, ushering in bitter cold temperatures with it. During the day on Sunday, expect widespread snow showers to form and blustery conditions. Winds will be from the Northwest at 15-25mph sustained, gusting into the 30s! This could create hazardous road conditions if enough snow falls and is blown around. In addition, expect wind chills to be in the single digits to below zero as temperatures steadily fall throughout the day on Sunday as we head to an overnight low of 13. Winds will continue to be sustained in the 20 mph range on Monday as we only rebound to a high of 19 before dropping back to 9 Monday night!

Next week looks to be unseasonably cold, with highs only rebounding to near freezing by Wednesday. Another round of wintry weather could come into play on Thursday, but it does not appear to be as strong a system. I've only forecasted a 30% chance of rain/snow mix at this point. I'll have more on that system as we get closer to Thursday. Here's your updated 7-Day Outlook:

(12-10-10) Updated Snow Forecast

With the last two model runs, it now appears that the Low will indeed move farther to the north in Indiana, which will decrease our chances for large amounts of snow accumulation. As seen in the graphics below, the main bulk of accumulation will be in Northern Indiana and Michigan. The left image is from the 12z GFS Model and the right image is the 12z NAM Model from today. Purple indicates 1 inch, blue 2 inches, yellow 3 inches, light green 4 inches and so on.

While the models don't agree fully on the amount of snow in our area, what is certain is we will get something. It likely won't be much, but with winds on Sunday gusting to 30-35mph as this strong low pressure moves to the north and east of us, blowing snow which can make dangerous road conditions will come into play.

So what about timing? Right now it looks like Saturday will be an all rain event with temperatures peaking into the 40s during the afternoon hours. A strong cold front with this deeping low moves towards us during the daytime and should be moving through the area late Saturday night.

As seen in the graphic at left the 540 thickness line (the rain/snow changeover line, first blue line on these graphics) is just to our west at 7pm on Saturday. It moves well past us by 1am Sunday morning, indicating the passing of the frontal system. What this means is that any precipitation after say midnight on Sat/Sun will fall in the form of snow. And it appears that there will be an ample amount of wrap around moisture from this deepening low to provide some accumulation.

The GFS Model is also showing a dry slot moving through just after the front passes. This may mean that accumulations could be lighter during the overnight hours and we may see the bulk of the snow accumulate during the wrap around moisture on Sunday. This would lessen our totals, but some models are not showing this dry slot. We'll have to see how it pans out.

So what does this mean for us? It looks like we should see somewhere in the range of 1-3" across our area, with more to the north and less to the south of us. Based on current model data, this seems the most conservative estimate. If the low moves a little more south than expected, these totals could rise, but the models aren't indicating that at the time. Temperatures will take a significant plummit overnight on Saturday into Sunday and it appears that we will be in the upper to mid 20s by daybreak with falling temps throughout the day on Sunday. Look for a low in the mid teens on Sunday night.

I've posted an updated snow prediction map of my own below. I'll have more on this as the system gets closer.

Updated 7 Day Forecast

(12-9-10) A Tricky System to Forecast!

If you've been following the forecast for the past few days, you will no dobut have seen much variation in what is expected to fall on our area over the weekend. The graphic at left shows the reason why.

Depending on which model you go with, different results are given. Most models were predicting a more southerly track and the latest models are now taking the center of the incoming Low pressure area about 200 miles more north than they were taking it! Keep in mind that this is only one model run showing the far north scenario and should be taken lightly at this point. We'll need to wait to see if future runs show this or if it goes south again. It could just be a hickup in the data.

I still like the GFS Model Run from 0Z on Wed. It seems to be a reasonable scenario among all the differing models. This run takes the Low through the center of Kentucky and into Ohio, shown on the yellow line in the graphic above. The top blue line shows the varying northerly track given by the latest 0Z model run last night. The bottom blue line shows the more southerly track, which some models have also hinted at. This track would result in a major snow storm for us, but seems unlikely at this point.

So what's the take away from all of this? At this point, I am going to forecast rain on Saturday with highs in the 40s. That rain will change over to snow during the overnight hours into Sunday morning, with lingering snow throughout the day on Sunday. At this point, snow accumulations appear to be minor for Huntingburg, somewhere in the 1-3" area. I'd say three would be pushing it if this track holds out.

The big story may not be the snow coming our way, but the winds that will be associated with this deepening system. Some models have the Low moving into our area near the 999mb range, which means there will be quite a steep pressure gradient associated with this system. The steeper the gradient, the stronger the winds. Sunday will turn out to be quite a blustery day and if the models hold up, it's looking like we could see winds sustained in the 20+mph range, with gusts into the 30s. Whatever snow we do get will get blown around, making driving conditions unfavorable.

I look for winter weather advisories to be issued in the next couple of days. Once the models runs come out tonight, I'll have a better idea of how this system is shaping up. Right now the initial wave is in the Pacific Ocean, moving into the Northwest Coast area. With few weather buoys in the area, once the system moves on shore and more data points are available for entry into the models, look for us to have a much clearer picture of what is going to happen. In the next 24 hours we would be able to start fine tuning the forecast and getting a clear picture of the tracking and the potential snow totals. I'll update more once the next models come out.

Reviving This Blog

With winter fast approaching, I am planning on reviving this weather blog as best I can. I had let it go due to time commitments, but I am wanting to post as often as I can, and especially during winter weather storms. You'll be able to read my analysis and predictions of upcoming of weather events as I post. It looks like a major storm is coming in this weekend for someone in our area, but it is unclear who will receive the bulk of the snow at this time. I'll be posting an update soon.