Tn Valley Severe Weather 2017

[PowellVolz]

it looks like the central and eastern valley will be missed by anything worth talking about even tho we didn't have any rain this am you would think with the higher dp and temps we would but we strike out again according to the hrr and nam models they are not giving us anything anymore but showers.

I don't agree with this


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[Witness Protection Program]

3 tor warns for Cookeville and to the north and south.

[JayCee]

Not overly impressed with what's going on this evening in the foothills of the Smokies.  Cooling temps, and dewpoints remaining in the mid-50's at TYS.  That's not severe outbreak weather.  Maybe a line of gusty strong or marginally severe storms, perhaps, with some hail.  I guess we'll see, but there's not a great deal of instability to work with now in my area. 

In any event, it's an enjoyable evening out planting a tree.

[1234snow]

The broken line of storms is having a hard time rotating thankfully. Hopefully as the night time comes these storms will lose their luster.

[JayCee]

Storms moving into the central Great Valley now.  Only warning seems to be down near Chattanooga, but some approaching Knoxville look potent.  Could be a severe t-storm warning with those at some point.  In any event, they'll probably have some very heavy rain. 

[PowellVolz]

T Storm warning for Knox Co


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[weathertree4u]

10 hours ago, PowellVolz said:

T Storm warning for Knox Co


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Hail from mby yesterday 

[nrgjeff]

Couple notes about Wednesday MDT risk. Had northwest Georgia showers ended 2 hours earlier, it would have been 5-8 degrees warmer in the target zone. LLJ was backed and screaming. Clearly we got lucky (safe), but the MDT was the right call even in hindsight.

Nowcasting lessons are worth noting though. HRRR was running too dry for the Southeast/High target. However it was not really relevant for Tennessee/Alabama. Any HRRR error would only impact the Southeast/High target first in line for moisture. Tenn/Bama was always a separate wave too. The Arkansas wave did get the LLJ cranking, but the LLJ was advecting in stable air from Georgia. My day ahead suspicions realized.

Looking ahead still hints at brief Northeast troughs next 10-15 days which tempers return flow even for robust waves (esp before April 15). Weekly charts still go with a trough west ridge east late April into early May. I would hope severe migrates seasonally toward the Plains. Too much work in the Southeast. Regardless of where, April may stay active.

[jaxjagman]

On 4/7/2017 at 11:33 AM, nrgjeff said:

Couple notes about Wednesday MDT risk. Had northwest Georgia showers ended 2 hours earlier, it would have been 5-8 degrees warmer in the target zone. LLJ was backed and screaming. Clearly we got lucky (safe), but the MDT was the right call even in hindsight.

Nowcasting lessons are worth noting though. HRRR was running too dry for the Southeast/High target. However it was not really relevant for Tennessee/Alabama. Any HRRR error would only impact the Southeast/High target first in line for moisture. Tenn/Bama was always a separate wave too. The Arkansas wave did get the LLJ cranking, but the LLJ was advecting in stable air from Georgia. My day ahead suspicions realized.

Looking ahead still hints at brief Northeast troughs next 10-15 days which tempers return flow even for robust waves (esp before April 15). Weekly charts still go with a trough west ridge east late April into early May. I would hope severe migrates seasonally toward the Plains. Too much work in the Southeast.,Expect Regardless of where, April may stay active.

Been in Ga for my sons regional meet,will be back Sunday,but looking at Asia we could be fixing to rock and roll after the mid month.Expect some ridging and a dry period coming up before hand

 

[nrgjeff]

Honestly the break will be nice. Much as I enjoy storms, work was busy for 3 weeks straight. This week, nothing and I feel fine. When it does recharge late month it could settle farther out toward the Plains per seasonal adjustments. On the other hand, the South peaks late April into early May.

Latest Euro weeklies (4/11) are probably wrong going into May. While they keep our region and the Southeast warm, the 500 heights are probably too low. Figure the SER will be stronger with only a glancing New England trough. Despite 500 troubles, the 850 chart hints at warmer surface. Clusters show lots of confusion and divergence, but majority members are closer to persistence. Carry on..

[jaxjagman]

Broke the record here today,hit 89.Previous record was 88 set in 2006,to early for this.

Front looks to stall out in the lower OV Monday then lifts N.Good chance of rain and thunderstorms especially Monday it seems for everyone,not the greatest severe look.Looking ahead into next weekend the models show a long wave trough upcoming,GFS and Euro of course in the long range don't agree with each other.Cips shows a risk of severe thunderstorms in the Valley during this time frame.

 

Looking even further past this time.The SOI has taking a big dip recently.Jeff mentioned up above he likes the end of the month into the first of May.Looks like a volatile period he mentioned.Now we'll see how this effects us.

 

11 Apr 2017	1010.11	1005.60	15.28	3.79	-1.26
12 Apr 2017	1009.51	1005.60	10.96	3.97	-1.13
13 Apr 2017	1008.80	1008.65	-16.15	3.22	-1.27
14 Apr 2017	1008.58	1011.00	-34.68	2.08	-1.53

Last updated: 29 June 2010

 

 

[nrgjeff]

Slight risk of something interesting Saturday 4/22. Dewpoints should actually be lower than on Friday, and low level winds a bit veered. On the up side some turning is noted with height, and it does not look like any morning washout. Gut says meh, but it is now late April. Maybe some wind, hail, and a shelfie.

Next week the Plains indeed looks active. Can something slide east late week or the weekend of the 29th? We will have a stout ridge in place here.

[jaxjagman]

RAOBS shows the front stalled out into the Valley right now.WPC  shows this should be further south along with the GFS.I'm liking  what the NAM is showing,there seems to be a good chance for some strong storms in Mid/Tn tomorrow afternoon along the boundary.Nam shows the front along the Tn and Ky line in the afternoon

[jaxjagman]

Models not showing much of anything in our area now.RAOBS shows the cold front well south of us now.Looks like a good dump of rain upcoming though

[Witness Protection Program]

I can confirm that it is thundering in Nashville quite loudly at 4 in the freakin' morning....

[Witness Protection Program]

Now shake the whole house loud.

[Witness Protection Program]

tor warn southeast of Lawrenceburg

[jaxjagman]

Decent hail from that cell

[jaxjagman]

Even better hail marker,cell is getting stronger

[jaxjagman]

Maybe starting to weaken,huge tops on that cell still

[jaxjagman]

Decent chance of some severe storms in the western Valley Mid week.Believe though the best chance  will come Friday when by the looks the boundary will stall out somewhere in the Valley and lift North into the lower OV.Some good instabilities being shown right now in the warm sector.Should be another severe potential when the front passes though maybe next Monday?

[nrgjeff]

Saturday 4/22 the cell that traversed far North Alabama spawned an EF-1 tornado in Cullman County and an EF-0 in Franklin County, AL. Storm originated in Mississippi, so it was not the same one in southern Middle Tenn. These two more robust cells were in the vicinity of a lifting outflow boundary intersecting with the cold front. 

[jaxjagman]

 Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0403 AM CDT Tue Apr 25 2017

   Valid 281200Z - 031200Z

   ...DISCUSSION...
   Active severe-weather regime in store for days 4-6 from the southern
   Plains into the lower Mississippi and Tennessee Valley regions, with
   models trending similar regarding evolution of the upper pattern
   during this period.

   Friday (day 4)  - A lead shortwave trough will shift northeast
   through the OH Valley during the day with upstream height rises from
   the southern Plains into the TN Valley. Quasi-stationary front will
   reside from the TN valley into northern TX with a dryline evolving
   across west central or northwest TX where it will intersect the
   front. Limited synoptic forcing for ascent and capping due to
   eastward expansion of EML may limit thunderstorm initiation during
   the day with best chance being at the intersection of dryline and
   front over west-central or northwest TX. Large CAPE and strong
   vertical shear would favor a conditional risk for supercells with
   very large hail and a few tornadoes should such initiation occur.
   Farther east thunderstorms including supercells are more probable
   during the day near the warm front from the lower MS Valley into the
   TN Valley where the cap should be weaker. Other more numerous storms
   including supercells with large hail will occur overnight north of
   warm front over OK in association with strengthening LLJ.

   Saturday (day 5) - Current indications are the upper trough will
   amplify over the southern Rockies and continue east through the
   southern Plains accompanied by a strong cold front. Numerous severe
   storms are expected to develop along this boundary and progress east
   through TX and the lower MS Valley where the atmosphere will be
   strongly unstable.

   Sunday (Day 6) - As the trough and its associated cold front
   progress eastward, the severe-storm threat will spread into the TN
   Valley and southeast states where favorable vertical shear will
   coexist with a moderately unstable warm sector downstream from an
   ongoing MCS.

[jaxjagman]

Memphis Friday from what the NAM shows tonight

 

 

[jaxjagman]

We'll see

[jaxjagman]

[samadamsuk]

Hey All,

Nice cell just gone up over Milan - went from 30 to 50 kft in a single radar update. Nearest live stream is about 50 miles away at the mo ..

 

Samos

[jaxjagman]

2 hours ago, samadamsuk said:

Hey All,

Nice cell just gone up over Milan - went from 30 to 50 kft in a single radar update. Nearest live stream is about 50 miles away at the mo ..

 

Samos

Welcome to the Tn Valley.Nice to see neighbors across the pond,think you're the first to post here.

[jaxjagman]

HWRF shows two lines tomorrow,the first would be severe,probably an outlier though.This would pose a more flood risk in Mid Tn Valley with the 2nd line 

[jaxjagman]

Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1241 AM CDT Sun Apr 30 2017

   Valid 301200Z - 011200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TODAY AND TONIGHT
   NEAR/EAST OF THE MISSISSIPPI VALLEY THROUGH PORTIONS OF THE SOUTHERN
   GREAT LAKES...LOWER OHIO VALLEY AND CENTRAL GULF STATES...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS AREAS
   SURROUNDING THE SLIGHT RISK...

   ...SUMMARY...
   Severe thunderstorms are possible today into tonight, from the
   vicinity of the Mississippi River eastward through portions of the
   the southern Great Lakes region, lower Ohio Valley and central Gulf
   states.  This includes a risk for storms capable of producing
   tornadoes, a couple of which could be strong.

   ...Synopsis...
   Models indicate that a belt of westerlies emanating from the
   mid-latitude Pacific will remain amplified through this forecast
   period, with large-scale ridging across the eastern Pacific into the
   Pacific coast, and across the Atlantic Seaboard into the western
   Atlantic, and large-scale troughing over much of the interior United
   States.  The large-scale troughing appears likely to take on an
   increasing negative tilt orientation, as a significant embedded
   short wave perturbation pivots northeast out of the central and
   southern Plains through the Mississippi Valley by late tonight.

   Substantive further deepening of a lower/mid tropospheric cyclone is
   forecast as it tracks northeast of the southern Plains.  At the
   surface, the low may occlude early in the period across and
   northeast of the lower Missouri Valley, with secondary low
   development likely migrating across northeastern Missouri through
   northern Illinois this afternoon and evening.

   Within the potentially broad warm sector of the cyclone, models
   indicate 50-70 kt southerly 850 mb will develop near/east of the
   Mississippi Valley today.  The core of a 100+ kt south/southwesterly
   500 mb jet may lag to the west of the warm sector, but mid/upper
   flow fields above the warm sector should still be more than
   sufficient to support potential for organized severe storm
   development, including supercells.

   Uncertainties abound concerning the extent to which thermodynamic
   profiles within the warm sector will become conducive to severe
   weather potential.  It appears that the northeastward advection of
   elevated mixed layer air will become disrupted or cut-off from much
   of the warm sector, and with the mid-level cold core lagging to the
   west of the surface cold front, mid-level lapse rates are not
   expected to become particularly steep.  Furthermore, considerable
   remnant pre-frontal convective development/cloud cover may be
   present early in the period, and drying associated with ridging
   centered off the Atlantic coast appears likely to slow boundary
   layer moistening across much of the Southeast into portions of the
   Ohio and Tennessee Valleys.

   ...Mississippi Valley to western slopes of the Appalachians...
   Taking into account the preceding discussion, uncertainties seem too
   large to allow for more than an outlook of a categorical slight risk
   at the present time.  But given the strength of the synoptic system
   and associated wind fields, and at least a corridor of pre-frontal
   boundary layer moisture characterized by surface dew points in the
   mid 60s to near 70F, it may not be out of the question that a window
   of opportunity for considerable severe weather potential could
   develop this afternoon and evening.  This seems mostly likely to be
   focused near or just east of the Mississippi Valley, and mostly in
   the wake of an initial north/south oriented band or two of
   thunderstorms spreading east of the Mississippi Valley, where
   guidance appears suggestive that breaks in the overcast could allow
   insolation to contribute to at least pockets of mixed layer CAPE on
   the order of 1000-2000 J/kg.  Of particular concern is that the
   environment could become conducive to at least isolated to widely
   scattered long lived discrete supercell development, initially
   anywhere from portions of eastern Missouri into Illinois, southward
   through portions of western Kentucky and Tennessee into northern
   Mississippi.  In the presence of clockwise curved low-level
   hodographs characterized by strong to extreme shear, some of these
   could become capable of producing strong tornadoes.

   It is possible thunderstorm activity could eventually consolidate
   into one or two organized eastward advancing lines, into portions of
   the southern Great Lakes region, and across the central Gulf states
   by late this evening.