2016 Severe Storm Thread

[Witness Protection Program]

Kind of interesting last night here in Nashville.  We had the typical NE to SW big line of storms move through and well off to the southeast around supper time.  Looked like that would be it for the rain, not paying much attention afterwards because the tornado threat was over, I thought it was the front moving through.  Then about 11pm  an east-west line of storms formed out of nowhere just to the south and came straight north, don't see that every day.  Turns out the front was still well to our west until early am.

 

CSB.

[jaxjagman]

Kind of interesting last night here in Nashville.  We had the typical NE to SW big line of storms move through and well off to the southeast around supper time.  Looked like that would be it for the rain, not paying much attention afterwards because the tornado threat was over, I thought it was the front moving through.  Then about 11pm  an east-west line of storms formed out of nowhere just to the south and came straight north, don't see that every day.  Turns out the front was still well to our west until early am.

 

CSB.

That was pretty cool.We got more claps of thunder closer to my house than the actual storm itself.Even some small hail in some spots.When the system itself went through the sun popped out for a brief time and made a little boundary west to east around us,you could see it on the radar,all the bugs.Then a dying out piece of energy came in from the SW with just enough juice to spark off some instabilty

[jaxjagman]

TNI  has made it into the postive phase

 

[jaxjagman]

Pretty active season so far in the lower 48.Since 2000 we've never had more than 30 days severe until this year through the first 3-months of the year

 

[Quincy]

Pretty active season so far in the lower 48.Since 2000 we've never had more than 30 days severe until this year through the first 3-months of the year

 

www.spc.noaa.gov exper archive events event days online.php.png

Interestingly enough, unless April has a hot second half, it risks at being toward the low end of that record since 2000.

[jaxjagman]

Interestingly enough, unless April has a hot second half, it risks at being toward the low end of that record since 2000.

I dunno,we still might  still be ahead.The AAM is headed into a volatile pattern,if it's right.We just have to get through the next several days

 

 

If by Ginsini and Marinaro papers plays out  we could be into a hostile period into the middle of the month when the AAM gets into phase 1,2

 

 

http://weather.cod.edu/~vgensini/files/pubs/Gensini%20and%20Marinaro%202015%20MWR.pdf

[jaxjagman]

[jaxjagman]

After an unusually warm March (note that virtually every location in the lower 48 states averaged above normal, with more than a few record-level positive deviation cases), many are wondering about the potential for continued warmth, perhaps even true heat, in the month of April. Seeing evidence, at least briefly, for a subtropical high over southern Mexico in the medium range, might make you think that the new month will turn out even hotter than the previous 31 days.

Alas, the evidence I see is positively tepid! The CFS series forecast into May makes sense, what with an established upper low or trough over the Southwest emitting impulses into the Great Plains and Ohio Valley. I have seen this pattern before, in 1973, 1977, and 1998. This would seem to be leading up to repeated cases of rain and thunderstorms, with more than a few cases for severe weather. The target zone would be from TX, OK, and KS through the Ohio and Tennessee Valleys. A slight gain in latitude to the subtropical jet stream would tend to make each system wetter, which in turn would mean curbing any rapid rise in heat. At least away from the Gulf Coast and Florida.

This is not to say that day-to-day weather over the following 60 days will be routinely miserable. In between each disturbance sunshine and relatively mild/warm readings will be in play. But if you live north of the storm track, your "70-75 and sunshine" will alternate with "55 and moderate/heavy rain". The Intermountain Region might see the most adverse conditions in terms of lacking warmth, what with upper air disturbance around.

But here is the rule you must follow if you want that routine "90-95, hot and humid" in your neighborhood. Look for a subtropical high or heat ridge. You will not see any such animal on any of the 500MB charts through the next 25 days, at least any that stick around for a while. I suspect that a strong low-latitude positive height anomaly may develop in May over Florida or the Sargasso Sea, if analogs of past declining El Nino episodes are an accurate guide (which of course was not the case this past winter...but do not get me started on that topic).

But we have a while to sit back, look at all of chances for severe thunderstorms and heavy rains that may take shape this spring, and speculate at chances for major heat waves and improved hurricane potential that should be apparent this coming summer.

And yes, I wonder about the impacts of the strong positive SST anomaly over the Indian Ocean, and the lack of a pronounced Saharan heat ridge could have on future outlooks for North America. We will be discussing these issues in future editions of WEATHERAmerica.

Prepared by Meteorologist LARRY COSGROVE

[Mr Bob]

After an unusually warm March (note that virtually every location in the lower 48 states averaged above normal, with more than a few record-level positive deviation cases), many are wondering about the potential for continued warmth, perhaps even true heat, in the month of April. Seeing evidence, at least briefly, for a subtropical high over southern Mexico in the medium range, might make you think that the new month will turn out even hotter than the previous 31 days.

Alas, the evidence I see is positively tepid! The CFS series forecast into May makes sense, what with an established upper low or trough over the Southwest emitting impulses into the Great Plains and Ohio Valley. I have seen this pattern before, in 1973, 1977, and 1998. This would seem to be leading up to repeated cases of rain and thunderstorms, with more than a few cases for severe weather. The target zone would be from TX, OK, and KS through the Ohio and Tennessee Valleys. A slight gain in latitude to the subtropical jet stream would tend to make each system wetter, which in turn would mean curbing any rapid rise in heat. At least away from the Gulf Coast and Florida.

This is not to say that day-to-day weather over the following 60 days will be routinely miserable. In between each disturbance sunshine and relatively mild/warm readings will be in play. But if you live north of the storm track, your "70-75 and sunshine" will alternate with "55 and moderate/heavy rain". The Intermountain Region might see the most adverse conditions in terms of lacking warmth, what with upper air disturbance around.

But here is the rule you must follow if you want that routine "90-95, hot and humid" in your neighborhood. Look for a subtropical high or heat ridge. You will not see any such animal on any of the 500MB charts through the next 25 days, at least any that stick around for a while. I suspect that a strong low-latitude positive height anomaly may develop in May over Florida or the Sargasso Sea, if analogs of past declining El Nino episodes are an accurate guide (which of course was not the case this past winter...but do not get me started on that topic).

But we have a while to sit back, look at all of chances for severe thunderstorms and heavy rains that may take shape this spring, and speculate at chances for major heat waves and improved hurricane potential that should be apparent this coming summer.

And yes, I wonder about the impacts of the strong positive SST anomaly over the Indian Ocean, and the lack of a pronounced Saharan heat ridge could have on future outlooks for North America. We will be discussing these issues in future editions of WEATHERAmerica.

Prepared by Meteorologist LARRY COSGROVE

How'd his winter outlook do? (rhetorical question)

[jaxjagman]

How'd his winter outlook do? (rhetorical question)

Not good  But who did?

[jaxjagman]

http://www.srh.noaa.gov/ohx/?n=20060407

 

Looking back 10 years ago

[jaxjagman]

Slight risk today,still looks more wind than anything

 

http://www.spc.noaa.gov/products/outlook/day1otlk.html

[nrgjeff]

Last night, Wednesday, was a nice lightning show in Chattanooga. Predictably with meager moisture return storms were not severe. I was still impressed with how thunderstorms blossomed. Mid-afternoon one could see all the alto-cu hinting at instability aloft.

 

SPC has introduced a Day 5 outlook valid for Monday in parts of the Mid-South, mainly Memphis and surrounding areas. System will have 2.5 days of return flow, vs just a day or so last time, so I guess I believe the moderate moisture return on models. Some hint at morning rain in Middle Tennessee sending an outflow boundary southwest back toward West Tennessee. Could be MS/AL. Day 5 is a little far out to talk such mesoscale details, but in my opinion the said outflow will be required to make the set-up interesting. Otherwise the chance of low levels veering off is greater.

 

Current forecast timing does not favor East Tennessee, but it is 5 days out. Right now thunderstorms look to weaken and lumber east Monday night.

[jaxjagman]

Last night, Wednesday, was a nice lightning show in Chattanooga. Predictably with meager moisture return storms were not severe. I was still impressed with how thunderstorms blossomed. Mid-afternoon one could see all the alto-cu hinting at instability aloft.

 

SPC has introduced a Day 5 outlook valid for Monday in parts of the Mid-South, mainly Memphis and surrounding areas. System will have 2.5 days of return flow, vs just a day or so last time, so I guess I believe the moderate moisture return on models. Some hint at morning rain in Middle Tennessee sending an outflow boundary southwest back toward West Tennessee. Could be MS/AL. Day 5 is a little far out to talk such mesoscale details, but in my opinion the said outflow will be required to make the set-up interesting. Otherwise the chance of low levels veering off is greater.

 

Current forecast timing does not favor East Tennessee, but it is 5 days out. Right now thunderstorms look to weaken and lumber east Monday night.

That wasn't bad yesterday.We didn't get warned but taking my son to gymnastics practice seen a couple trees split and some limb damage.

 

Left this early morning to head to Jekyll Island for his regional meet and going through Georgia they talked about the storms they got  with golf ball sized hail on the radio.Seen that on the radar also last  night

[jdrenken]

Speaking of the day 5...

 

 

 

Testing: Severe Weather Pattern Projection Based on the Recurring Rossby Wave Train, Bering Sea Rule, and Typhoon Rule. The RRWT oscillation period average is used to project the initial future date that is expected to hold similar weather pattern ingredients as previous oscillation period weather patterns, +/- 3 days. The projections will be maintained once the projection date is ~30 days from realization. Methods used to confirm original projection will consist of modeled BSR(~30 days), current RRWT oscillation period(~30 days), observed BSR(~20 days), modeled TR(~16 days), observed TR(~8 days), and GFS/GEM/EURO model guidance(~3 days).

[nrgjeff]

Monday does not look so good now, at least not for a storm chaser. Ingredients are still there for wind or hail in the Mid South. However the forecast wind profiles do not have much turning. Down in Mississippi anything can happen if dews get above 65 but they would still need locally backed winds which appears unlikely.

 

After April 15 it looks like a more favorable pattern for severe develops. Note it is not necessarily for our region; could be Plains. Well, I guess climo could tell us that, but the dynamical models are also showing more trough west ridge east out that far. Weeklies concur. Some of the upstream Pacific signals are probably influencing the numerical guidance, a plus for confidence.

[jaxjagman]

Nice HP going through East Asia ,going SE through Japan D5 on the EPS.GFS is already showing upper 60 DP's in the Valley long range around the 20-21 of the month,it should have some merit to it but this might be to slow.Should be a possible CF coming through by the looks during this time and it might creep through for some big rains somewhere,maybe a wavy front?

[jaxjagman]

Still like the looks around the dates i mentioned above,HP looks even better today

[jaxjagman]

US regional tornado outbreaks and their links to spring ENSO phases and North Atlantic SST variability
Sang-Ki Lee1,2, Andrew T Wittenberg3, David B Enfield1, Scott J Weaver4, Chunzai Wang2 and Robert Atlas2
Published 7 April 2016 • © 2016 IOP Publishing Ltd
Environmental Research Letters, Volume 11, Number 4

 

http://iopscience.iop.org/article/10.1088/1748-9326/11/4/044008/meta#erlaa1ca0f5

[nrgjeff]

Excellent journal article makes my day! I recommend reading the whole thing esp Section 1 and Section 3, Intro and Results. Section 2 Stats methods/data is vital in the peer review process, but not required for the casual reader. Section 4 Discussion mainly looks forward to future research. 

 

Figure 5 linked above (previous post) is the Atlantic SST tripole chart. Currently we are in the positive phase. It favors the Mid South over the eastern Tennessee Valley for severe/tor. However the charts study the Atlantic side only. Perhaps this year Figure 2 ENSO is more relevant; I link it below.

 

http://iopscience.iop.org/article/10.1088/1748-9326/11/4/044008/meta#erlaa1ca0f2

 

We are somewhere between the Nino persistence and early terminating charts. El Nino is weakening fast but we probably will not be to La Nina by May. Regardless, both charts show no increase in Tennessee Valley severe/tor over climatology. Once could infer a Gulf Coast late winter peak followed by a shift to the Upper Midwest and Northern Plains late season.

 

Combining the charts I still get nothing of note in the Tennessee Valley. Mid South could get it again before things shift north later in the season. All that said, charts are only positive anomalies. Normal climatology still holds. Spring is still severe weather season!

[jaxjagman]

Possibly something to watch, something towards the end of the month

 

Hazards already has the Valley at 20%,above avg temps

 

For Thursday April 21 - Wednesday April 27: For Week-2, the predicted 500-hPa flow pattern features broad positive height anomalies over much of the CONUS. Model guidance today depicts a much more substantial ridge building across the northern CONUS early in the period that will shift south and east through the rest of the week. This solution has become consistent among the GEFS, European, and Canadian solutions. Consideration was also given toward potential anomalous warmth over much of the Northeast given the operational GFS forecast, however teleconnection analysis of the blocking ridge across Greenland hints at anomalous troughing and potential back-door frontal influences maintaining a cooler solution here that is also supported by the GEFS.

 

 

Negative PNA during this time period being shown

 

 

In East Asia there is a building area of HP being shown by next Wed., on all the models

 

 

Overlay map,what it possibly might look like just for fun

 

H5

 

 

MSLP

 

Who knows right now,it's still along ways out.

 

 

JR's BSR site

 

[jaxjagman]

2016 Tropical Cyclone Landfall Probabilities

 

Released today if anyone is interested

 

http://landfalldisplay.geolabvirtualmaps.com/

[jaxjagman]

4-16-98 Outbreak

 

http://www.srh.noaa.gov/ohx/?n=19980416

[jaxjagman]

Climo would suggest we could get active towards the end of the month into May

 

 

 

 

 

 

 

 

 

 

 

[PowellVolz]

Climo would suggest we could get active towards the end of the month into May

3.png

EXtended CPC Analogs Model EXCAM .png

ERTAF.png

0424.0430.png 1144×859 .png

7.png

But what about the pattern?

[jaxjagman]

But what about the pattern?

Doesn't look that bad.Towards the end of the month the NAO/PNA..is showing signs of going =

[nrgjeff]

Looks like weather could get active over in the Missouri Valley next week and/or the following week. For the members who do not like severe weather in the Tennessee Valley, the trend may be your friend.

 

Mid South / Tennessee Valley: Analogs will point to severe conditions the next few weeks but I am highly skeptical. Troughs will enter the West and Plains. Wind shear will appear favorable some days. At the same time forecast temperature profiles without rain will look warm and unstable. Old fashioned thickness method shows lots of 564+ which will be warm when it does not rain.

 

However the wind shear comes from the southern stream in the split flow. Bowling balls from Texas may clip the Mid South with storms before weakening or filling on the way to the eastern Tennessee Valley. Even the Mid South could see too much rain. Sure morning rain sets up boundaries, but midday rainouts keep things stable.

 

Meanwhile the northern stream still has weak but non-zero influence. Great Lakes troughs followed by continental surface highs do not promote the moisture return of a good Bermuda high. For big Southern severe one needs a SER giving way to a phased trough out of the southern Plains. Instead split flow reigns.

 

While I am skeptical of above normal severe, April 15 through May is severe season. Even normal or slightly below normal activity still yields some severe. I just do not see anything major in our region. Look northwest...

[jaxjagman]

Looks like weather could get active over in the Missouri Valley next week and/or the following week. For the members who do not like severe weather in the Tennessee Valley, the trend may be your friend.

 

Mid South / Tennessee Valley: Analogs will point to severe conditions the next few weeks but I am highly skeptical. Troughs will enter the West and Plains. Wind shear will appear favorable some days. At the same time forecast temperature profiles without rain will look warm and unstable. Old fashioned thickness method shows lots of 564+ which will be warm when it does not rain.

 

However the wind shear comes from the southern stream in the split flow. Bowling balls from Texas may clip the Mid South with storms before weakening or filling on the way to the eastern Tennessee Valley. Even the Mid South could see too much rain. Sure morning rain sets up boundaries, but midday rainouts keep things stable.

 

Meanwhile the northern stream still has weak but non-zero influence. Great Lakes troughs followed by continental surface highs do not promote the moisture return of a good Bermuda high. For big Southern severe one needs a SER giving way to a phased trough out of the southern Plains. Instead split flow reigns.

 

While I am skeptical of above normal severe, April 15 through May is severe season. Even normal or slightly below normal activity still yields some severe. I just do not see anything major in our region. Look northwest...

To bad the storm isn't tomorrow,we could use the rain here like everyone.Euro this afternoon has some good moisture convergence with theta-e.Would be some good rain in Mid Tn into Ky,with even what would be a decent light show with the other instability being shown.But i agree with you,the MO Valley looks to be the place for the best severe right now and also into parts of the S/Plains

[Mr Bob]

Climo would suggest we could get active towards the end of the month into May

 

3.png

 

EXtended CPC Analogs Model EXCAM .png

 

ERTAF.png

 

0424.0430.png 1144×859 .png

 

7.png

There is quite a skew in the last week of April data from 2011....

[jaxjagman]

There is quite a skew in the last week of April data from 2011....

My bad,left wk2 out

 

 

 

 

 

 

http://models.wxmidwest.com/