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My blog is now active...but I have moved it to a more user friendly FB page. You can find my forecasts and thoughts at this address now

http://www.facebook.com/Wxeast

Or you can just visit our Forum

http://www.tnweatherspot.com/

Boring Weather Alert

This Blog is not currently active...and will likely not be updated again until sometime around Hurricane season or Fall. If you are still interestsed in discussing the current weather then there is a link to the right that will get you to our weather forum...where there is active discussions going on :)

Thanks
Toot

Late Season Snowfall North of I-40 Sunday Night

Good Afternoon...After a rough night of severe thunderstorms old man winter could pay one last visit before taking a vacation. A late season clipper system will race into the region sunday and bring clouds and limited moisture. However enough moisture apprears likely for light snow accumulations on the plateau.. the mountains and areas in the valley north of I-40 up into the Tri Cities. Since this snow looks to fall of the night wet accumulations appear likely. Temps sunday night will drop below freezing so hazardous driving conditions will also be possible.

Significant Tornado Outbreak Possible Tomorrow

A vigorous low pressure system will traverse the western midsouth into the great lakes region. This low will probably be very well organized and will likely go sub 990 milibars as the LPS matures. As it starts to move northeastward an associated warm front will move through the area overnight and there could be a few severe storms that fire along this warm front tonight into the early a.m.

IMO this warm front will be the most important equation that will ultimately decide how significant tomorrows threat will be. If the warm front moves through rather quickly then look out... its gonna get nasty. The slower the warm front retreats northward the less significant this threat will be. With a slower moving warm front you will have junk convection trying to stabilize the atmosphere ahead of a very powerful cold front.

There's gonna be severe weather either way but if that warm front and its associated convection moves through the area rather quickly the surface layer airmass will establish a very favorable thermodynamic enviroment where the sun will begin to break through the clouds warming surface temps...then the atmosphere will become VERY unstable due to the high cape/high shear.

If that happens discrete rotating supercells will likely invade middle and east Tennessee transforming into line segments as the cold front nears the spine of the Appalachians. There could also be embedded supercells in these line segments. If things do go downhill tomorrow it looks like the western plateau area would be right in the bullseye and folks in east TN will have to endure a nocturnal Tornado threat which is a whole other creature itself.

There's alot of if's involved in this setup and this event could wind up being either a standard severe weather outbreak or an extreme one... so I would just stay tuned to my local NWS office and its radar.

~ Toot

2012 Severe Weather Outlook

Well...It looks like spring is almost here (even though as I type this there is strong cold advection doing its dirty work outside my window) and its time to try and poke my head into the future to see what spring may hold in terms of severe weather. Ive looked at a few sign and signals and this post will portray if they point to a more normal season which is pretty intense itself here in the southeast...or if the potential for severe weather is above or below normal.

I was gonna do some analogs for this season but since that didnt work out to well for the winter outlook I will stick to the facts here..nothing but the facts.

First lets look at where we are headed in terms of ENSO


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What we see here is us headed out of La Nina and into weak El Nino territory most likely... but during spring we should be near neutral ENSO conditions and that will not hamper severe weather in any way that I can find. The important thing here is that we have two major changes going on with winter transitioning into summer and La Nina transitioning into El Nino.


Next we will look at severe weather trends over the first part of 2012 and compare them to the same time last year in 2011

Here we have the spc reports since the first of January this year..as you can see its been pretty active for what is supposed to be a cold time of the year.



When we look back at last years graph we can see that severe weather was almost nil for this time of year before the active timeframe spike occured.


One can draw several different conclusions from that... but the conclusion I am drawing already is that the Gulf of Mexico is very warm and will be primed by the time our "spike" gets here.


Now speaking of the Gulf of Mexico lets look at the water temps because this is the fuel for severe weather in our area.

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Sure enough they are above normal. The lack of an extended period of colder weather over the southeast has allowed the waters of the gulf of Mexico to stay pretty warm and this is a pretty important signal that says an above normal severe wx season is likely. Now before you get too worked up there are some things that could possibly argue for a more normal or even below normal severe weather season.

The main thing that comes to mind is that the North Atalntic Oscillation has been mostly positive for many months and one could argue that it should be mostly negative this spring and this could offset an above average season to more of a normal type season. A negative NAO would try to suppress a Jet stream thats trying to come north due to seasonal change and could keep the stormtrack right over us or to our south mostly.

After looking at these and several more features I expect an average to above average severe weather season in terms of reports and there will likely be at least one major and widespread severe weather outbreak in the southeastern United States.

Snowstorm set to hit Tennessee

Im too busy to post a wrietup with this so here is my call map...If u have questions...register on our forum if youre not a member and you can read my thoughts there...the link is to the right of this post

Wintry Mess of Ice Sleet Snow and Rain

This is a forecast put together with todays SREF and NAM models..this forecast is highly dependant on the temp profiles of those models. If they are off a hair it could make for big changes in the outcome...this will ultimately be a nowcast situation but it seemed to be a rough one so I thought I would give it a shot

Light snow...sleet and freezing rain accumulations will be possible across most of the state on Monday and Tuesday. Particularly concerned for the East TN valley where I think the most ice accumulations will be possible.

Looking at soundings and mostly SREF data it appears that a mixed bag of weather will move into the state from west to east. With very low dewpoints already in place precip will move into the area as Virga but as the column becomes saturated precip will start to fall in the form of snow.

The snow could fall at impressive rates at times in the western and southern parts of the state. At some point the snow will transition to wintry mix and then to rain over most of the state. I imagine the plateau and mountain regions of the state could pick up several inches of snow in a fairly quick fashion.

The east TN valley poses a unique threat for Ice accumulation in excess of more than .10 inches due to the nature of local topography. After some possible light accumulations of snow the cold air might become trapped in low lying valley areas and freezing temps could stick around for a longer period of time but meanwhile the upper atmosphere temps will warm to above freezing resulting in longer periods of ice accumulations on top of light snow accums. Light Ice accums appear likely for parts of East TN valley

Old man winter has returned

A well developed southern stream shortwave will merge with a strong spoke of energy from a Upper low diving down out of canada and winter weather will result as a baroclinic zone sets up. A band of precip will develop along and in advance of an arctic cold front and will slide through the state tomorrow and Saturday. Where these two energies meet up will be ever important as to the outcome.

This precip will probably start as rain in most places but will quickly and dynamically change to snow due to strong cold air advection and wet bulbing. Flash like freezes will take place and driving conditions could become hazardous very quickly.

Due to the uncertainties I have just made a probability map and counties in grey have the best shot of seeing an inch or more of snow.

Eastern US Snow Storm threat Feb 11th-14th

Good Morning

After what has been an extremely warm winter things are changing as part of the Polar vortex relocates itself in Southeastern Canada. This feature may combine itself with a couple of other large scale features to produce a Noreaster the weekend before Valentines day. It all depends on where a subtropical jet strean shortwave starts to phase with the polar jet stream and its related vortex. This will set up a baroclinic zone along the east coast and a powerful low pressure system may form and ride up this zone in Miller A fashion.

The GFS has been the most consistant model showing this possibility and this remains the biggest eastern US winter threat of the season. The trend all winter has been for these southern stream shortwaves to cuttoff in the southwestern United States and remain cuttoff... but this shortwave is modeled to continue across the southern part of the conus without getting cuttoff from the polar jet and will likely phase with the northern stream at some point.

At the same time a northern stream wave of energy is moving across the northern tier of the US in tandem with the southern one. This will likely result in the most signifigant snowstorm in the eastern US this season but where the snow falls has yet to be determined. At this time guidance suggests a Gulf low threat and I have a higher than normal confidence level in accumulating snow in the Tennesseee valley.

Nothing written in stone yet but there is certainly a threat of winter weather in the eastern US near Valentines day or a couple of days before...the exact track of the stormcenter will decide who sees the accumulating snow.

My Feb - March Forecast for the SE

As you know...you have heard signs of a colder pattern change coming. I can somewhat agree with that although I think it will be short lived.The NAO/AO are already moderately negative.... I expect our area to end January on a frigid note as a deep trough with accompanied snow drops down into the Southeast. This pattern will be locked in place for at least the first half of Febuary and this will be the coldest around here its been all winter.








With the fading NINA and a pronounced NAO block in the baffin island to greenland location you will get that deep trough here in the united states. With 2-3 winter threats. Enjoy the first half of Febuary because I think the PNA and EPO will start to overwhelm the pattern by Feb 20th.





The old SE ridge will start flexing his muscle then... and that will spring us towards spring weather.






Thats not to say we wont get a bowling ball ULL come rolling out of Texas and produce snow in Late Feb or Early March..but by March the 15th cold winter weather will be all but gone.





Current NAO/AO is heading torwards the tank




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Severe Weather Likely In Late January

Being that there is a substancial warm up coming in about a week or so the chances for severe weather will be higher than normal for this time of year...so I went to looking for something to track and wa la..look what the euro model is showing at Hr 240.

Its still a long ways out but what some models show is definately a severe look with arctic air just pouring down into the western US and moist tropical like air being sucked up into the warm sector in the eastern US. This would cause fireworks where those two airmasses butted heads..not only that but that type of storm could definately flip a pattern completely over.

This storm could possibly bring the change that us winter wx lovers have been looking for since winter began. But there have many things that have fooled us on that particular aspect.

Alberta Clipper Round Two

Snow accumulations will be likely tonight/early morning as an Alberta clipper system will quickly track across the area tonight and producing light snow accumulations. Snow accumulations of a dusting to two inches will be possible.

Clipper To Bring Snow To The TN Valley

This setup is pretty unique being that the current system will continue to pull away and its NW flow off of the lakes will combine with the clipper trying to tap the gulf. This was a very confusing aspect of this timeframe and lead me to believe that this would be a pure NW flow event several days ago..but that is not the case. Anyways it will be interesting to see how this evolves on radar. At any rate I think the plateau area will do extremely well with this one as they will change over very quickly but everybody in east TN looks to get in on the action although places in SE TN may get downsloped pretty badly.

I would think that most of the snow will stick to the roads and ground with the very strong cold advection being modeled. Look for temps to drop like a bat out of hell tomorrow evening making for an exciting night.

Snow will be in the air tomorrow

A vigorous upper level disturbance will swoop thru the region on monday and bring a period of snow to the tennessee valley. I expect the snow to accumulate up to 6 inches in the highest elevations of east TN. The plateau counties and the northern valley could also see an inch or two...while most of the valley could see a dusting but I wouldnt rule out a little more than that due to the expected intensity of some of the snow showers and the long duration of the event. These snow showers will be accompanied by strong NW winds that will usher in the coldest air of the season...Glad to see the prospect of some real winter weather finally