La Nina Watch

[StormNine]

http://www.crh.noaa.gov/news/display_cmsstory.php?wfo=fgf&storyid=53633&source=0
^^ La Nina Watch^^

It looks like our lady is back for the winter.  She could be a strong one.
This is the topic where we can watch La Nina, and it's possible affects come next fall, and winter.

Be prepared for:
- Big Time NW Trend on Models
- Pesky SE Ridge
- Wetter than average conditions for West KY, maybe even NW TN
- Possibly of Winter Time Tornado events
- Strong Arctic (several polar fronts, and lot of air mass collisions across the Midwest, Mid South, OH/TN valleys)
- Did I mention this area being the battleground of air masses.

La Nina may also affect the hurricane season.

[Adam]

- Did I mention this area being the battleground of air masses. Isn't Tennessee always the battleground of air masses, looks like southern middle tennessee is gonna get left out again this winter.

[Charles L.]

- Did I mention this area being the battleground of air masses. Isn't Tennessee always the battleground of air masses, looks like southern middle tennessee is gonna get left out again this winter.

When it comes to snow and middle TN...we are always borderline. We could have the perfect setup yet something could go wrong. Winter weather forecasting is the hardest thing to predict as so many factors go into it ranging from snow or no snow, snow ratios, how long it will last, how much we will get, and etc.

[tennessee storm09]

i think we will have a moderate to strong la nina. with it peaking out about early winter. i would be and i am more concerned about severe weather aspect. iss very litte winter events. mite get one in mid to late february. but la nina havent been very fond of west tn. ususally have a shot at a major tornado outbreak. just going by the numbers. time will tell, but yeah it could be a stron la nina.

[StormNine]

i think we will have a moderate to strong la nina. with it peaking out about early winter. i would be and i am more concerned about severe weather aspect. iss very litte winter events. mite get one in mid to late february. but la nina havent been very fond of west tn. ususally have a shot at a major tornado outbreak. just going by the numbers. time will tell, but yeah it could be a stron la nina.

I agree.  In a Moderate to Strong La Nina I am concerned of two things.  One is a potential for a severe/tornado outbreak because we are in that battleground zone.  The second thing is usually there is potential for a ice storm in Moderate to Strong La Nina events. Especially from say Northern Arkansas into Western and Central Kentucky, but it could also include Western and Middle Tennessee as well. 

[Curt]

Weak La Ninas are usually great for this region if you like winter storms. The stronger LN gets tho usually = disappointed winter time fans.

LOTs of variable and WAY too early to speculate. In general if there is a mod-strong LN, one wants to be further NW for a decent winter event.

[Kevin]

As of right now...I don't see how this isn't at least a moderate La Nina...if not strong. It also appears more east-based in the early going as well. Of course...pinpointing this stuff is very difficult...so it could change...but right now I'd be thinking more of "severe" (if you get the hint) winter season rather than one like last year as that is what stronger and especially more east-based La Ninas bring...

[Curt]

If this were to be true, one could speculate that Oklahoma could be the target of several winter storms yet again. When isnt that state a target???

[StormNine]

If this were to be true, one could speculate that Oklahoma could be the target of several winter storms yet again. When isnt that state a target???

The NW Trend will be in the works this winter.  That means that models will be, and I don't like to use this word.  Models for winter weather events will more than likely be useless past 72 hours.  I think our best chances of winter wx (although my not be great) if we get into a strong la nina will be.  Overrunning ice events, and a rogue Late February/March storm.  The clash of air masses(the cold fronts running into the SE Ridge) could set the battleground for some not so nice severe thunderstorms.  

The Last 4 stronger La Nina featured the following:
07-08- Super Tuesday Outbreak of Feb 2008, plus several other events.
99-00- Featured Jan, 3rd, 2000 outbreak, plus several other tornado events across the Southeast that winter.
98-99- Featured Jan, 17th, 1999, then it featured Jan 21st-22nd Tornado Outbreak.
88-89- The Franklin/Brentwood TN Christmas Eve Tornado of 1988.

[Charles L.]

Can't ignore those events Steven and the stage is being set for yet another strong La Nina, IMO.

[Curt]

I wouldnt be so quick to write off winter wx in '10-11. With a declining moderate to strong La Nina there are some possibilites for winter weather lovers. Looks like this Nina may be somewhere between -1.0 to -1.5 and declining as the winter progresses. The best winters for most of our area usually occur in weaker to moderate La Nina's. The possibilities look to drop off when the Nina is less than -1.5. So if we can hold it to a moderate one, the chances are better to see some ice/snow. My bet is overall we will see our area in the clash zone for arctic fronts and mild/warm air. Severe season could certainly be more active, but we could see ice and snow during a period of colder weather. La Nina's seem to turn cold on a dime and stay thay way for a couple of weeks in which winter wx is certainly a possiblity.

Mod-Strong La Nina's since 1950

Year/ LN Stregnth and Peak)/ Snow adn Ice in inches at KMEM
49-50 (0.7) (declining) Trace
50-51 (1.0) (declining) 7.9in including one of the worst ice storms to hit the area
54-55 (1.0) (declining) 0.3in
55-56 (1.3) (declining) 5.2in
56-57 (0.5) (declining) Trace
62-63 (0.6) (declining) 5.0in
64-65 (0.8 ) (declining) 7.9in
67-68 (0.7) (increasing)23.8in
70-71 (1.3) (peak)9.3in
71-72 (0.7) (declining) 1.2in
73-74 (1.9) (declining) 1.6in major ice storm in January for Memphis
74-75 (0.6) (declining) 6.0in
75-76 (1.6) (declining) 0.4in
84-85 (0.9) (declining) 20.7in amazing winter snow totals in January
88-89 (1.7) (declining) 0.3in
95-96 (0.7) (declining) 0.4in this was a blockbuster winter for many, not KMEM
98-99 (1.4) (declining) 0.8in featured a tornado outbreak in January
99-00 (1.6) (declining)3.0in blockbuster snow for Arkansas- up to 18in in south AR
00-01 (0.6) (declining) 2.6in very cold December with ice and snow;Jan-Mar mild
07-08 (1.4) (declining) 7.0 March snowstorm for western half of TN/Super Tues outbreak
08-09 (0.8 ) (declining) 8.0 Late Feb-early March snowstorm

The most likely witner for modeling puposes would be 50-51, 54-55, 55-56, 70-71, 73-74, 98-99, 99-00, and 07-08. Some of those years were not at all bad in the snow department, and actually beat snow totals last year at Memphis and Nashville. Also, there were a couple of almost snowless winters as well.

Also interesting to note are the winters in the past where El Nino rapdily transitioned to La Nina which are 64-65, 70-71, 73-74, 88-89, 95-96, 07-08. All featured some winter storms except 88-89 in which there was little snow. Most of these winters also featured some arctic outbreaks and severe weather at times. So basically, we could see a little bit of everything next winter as an early prediction based on past history. Time will tell and we have a long way to go before I really can get into winter.

[Charles L.]

Great write-up ctbpharmd .

[tennessee storm09]

the temps in the pacific keep getting cooler n cooler. we may be staring at a record la nina not just a strong one. could be the strongest la nina in 50 years or so.

[dwagner88]

I hope that a record la nina will at least up the precip a bit. The last precip here was on August 21, and there is no rain in sight for at least another week.