Feb 2-3 Tn Valley Severe Storms OBS

[jaxjagman]

NATIONAL WEATHER SERVICE MORRISTOWN TN
250 AM EST SAT JAN 30 2016

.SHORT TERM (TODAY AND TONIGHT)...

THE SURFACE HIGH PRESSURE IS CENTERED OVER THE AREA CURRENTLY WITH
CLEAR SKIES AND LIGHT WINDS. THIS HAS CREATED IDEAL RADITIONAL
COOLING CONDITIONS WITH A CHILLY START THIS MORNING WITH
TEMPERATURES IN THE 20S AND LOW 30S. THE SURFACE HIGH WILL SHIFT TO
THE EAST TODAY WITH SOUTHERLY FLOW RETUNING TO THE AREA. AN AMPLE
SUPPLY OF INSOLATION...SOUTHERLY LOW LEVEL WINDS AND HIGHER UPPER
LEVEL HEIGHTS WILL ALL LEAD TO HIGH TEMPERATURES IN THE MID 50S TO
LOW 60S THIS AFTERNOON. THIS TREND WILL CONTINUE INTO THE OVERNIGHT
WITH TEMPERATURES ONLY DROPPING INTO THE MID 30S TO MID 40S.

.LONG TERM (SUNDAY THROUGH FRIDAY)...

ANOTHER VERY PLEASANT JANUARY DAY ON SUNDAY WITH SOUTHERLY FLOW
BRINGING IN WARM AIR FOR HIGHS EXPECTED TO REACH INTO THE UPPER 50S
AND 60S ACROSS MOST VALLEY LOCATIONS. WE THEN TRANSITION INTO AN
ACTIVITY WEATHER PATTERN FOR THE MIDDLE PART OF THE EXTENDED. A
WEAK FRONTAL BOUNDARY MOVES THROUGH ON SUNDAY NIGHT AND MONDAY.
INCREASING LOW LEVEL MOISTURE WILL AID THE DEVELOPMENT OF SCATTERED
SHOWERS WITH THE FRONTAL PASSAGE. BEST CHANCE OF SHOWER ACTIVITY
WILL BE OVER NORTHERN LOCATIONS. THEN...THE MAIN CONCERN THROUGH
THE EXTENDED WILL BE A STRONGER COLD FRONT EXPECTED TO MOVE THROUGH
TUESDAY NIGHT INTO WEDNESDAY. MODELS CONTINUE TO SHOW SOME
DIFFERENCES WITH THIS SYSTEM ESPECIALLY WITH TIMING AND STRENGTH.
HOWEVER...CONFIDENCE HIGH WITH REGARD TO EXPECTED STRONG LOW LEVEL
JET ACCOMPANYING THE FRONT. A STRONG 50 TO 60KT 850MB JET WILL MOVE
THROUGH WITH THE FRONT AND ESPECIALLY HIGH ELEVATIONS SHOULD EXPECT
STRONG...GUSTY WINDS. SHOWERS AND EVEN A FEW THUNDERSTORMS ARE
EXPECTED ALONG THE FRONTAL BOUNDARY. THIS CONVECTION WILL BE AIDED
BY INCREASING LOW LEVEL MOISTURE...GOOD WIND SHEAR AND FAVORABLE
UPPER LEVEL JET DYNAMICS. HOWEVER... INSTABILITY WILL BE LIMITED
AND STRONG WIND FIELD MAY INHIBIT HEIGHT OF CONVECTION. THAT
SAID...ANY SHOWER OR STORM THAT CAN REACH INTO THE STRONG WINDS
ALOFT COULD POTENTIAL BECOME STRONG...POSSIBLY SEVERE. CURRENT
TIMING OF CONVECTION LOOKS LIKE LATE EVENING INTO THE OVERNIGHT
HOURS. A FEW SCATTERED SHOWERS WILL CONTINUE INTO WEDNESDAY AS THE
FRONT PULLS OUT OF THE REGION. DIFFERENCES IN MODELS INCREASING
LATE IN THE EXTENDED...ESPECIALLY IN THE POSITION AND TRACK OF THE
UPPER LOW ASSOCIATED THE EXITING FRONT. MODELS TRENDING DRIER BUT
COULD SEE FLOW AROUND THE UPPER LOW ROTATE IN COOLER TEMPERATURES
AND SOME ADDITIONAL LIGHT PRECIP WEDNESDAY NIGHT INTO THURSDAY. THE
COOLER AIR WILL TRANSITION ANY LINGERING LIGHT RAIN TO LIGHT
SNOW/FLURRIES. DRY WITH SEASONAL TEMPERATURES EXPECTED BY FRIDAY.

[jaxjagman]

[jaxjagman]

[Runman292]

Well, my interest in this storm has plummeted. Obviously, there's still time for things to change, but it's not looking good at this time.

[jaxjagman]

[jaxjagman]

Not a whole lot of changes on the euro this afternoon,maybe to a tad slower and stronger.Models are showing low clouds  down to the gulf coast ,Euro shows some decaying around 18z Tues.not sure at this time frame it'd make a difference for instability though it wouldn't hurt any.GFS is being the GFS,wild swings.

[Runman292]

Not a whole lot of changes on the euro this afternoon,maybe to a tad slower and stronger.Models are showing low clouds down to the gulf coast ,Euro shows some decaying around 18z Tues.not sure at this time frame it'd make a difference for instability though it wouldn't hurt any.GFS is being the GFS,wild swings.

Interesting. I would think that the slower it moves, the lower the chances for Severe weather in the eastern valley.

[jaxjagman]

Interesting. I would think that the slower it moves, the lower the chances for Severe weather in the eastern valley.

Heat of the day never hurts.This is more of low level convection with weak embedded twisters.Don't see right now any mid and high tops.This isn't no super cell out break right now.Still looks like more wind than anything.

[Runman292]

Heat of the day never hurts.This is more of low level convection with weak embedded twisters.Don't see right now any mid and high tops.This isn't no super cell out break right now.Still looks like more wind than anything.

I agree. There won't be a lot of height with the strong wind field in place. If the storms move into the eastern valley after midnight, there won't be much heat left to feul the storm. Reading the latest HWO from MRX, it sounds to me like we'll be lucky to get thunderstorms at my place.

[Runman292]

Double post.

[Quincy]

With respect to instability, temperatures today were running 5-10F warmer than forecast by the 12z GFS from the Deep South into the Tennessee Valley and Ohio Valley. We'll have to watch moisture return and low-level temperature trends closely. If the models are downplaying instability, this could still be a higher-impact event.

[jaxjagman]

With respect to instability, temperatures today were running 5-10F warmer than forecast by the 12z GFS from the Deep South into the Tennessee Valley and Ohio Valley. We'll have to watch moisture return and low-level temperature trends closely. If the models are downplaying instability, this could still be a higher-impact event.

So true.I believe the disco that Nashville said a couple days ago mentioned the same thing you talk about,the models when it gets closer will show this.The departures in the OV are being shown +19-20,into the Valley 17-18

[jaxjagman]

NATIONAL WEATHER SERVICE MEMPHIS TN
251 PM CST SAT JAN 30 2016

.DISCUSSION...

WARM AND WINDY THIS AFTERNOON...WITH WIND SPEEDS IN THE DELTA
HANGING JUST BELOW WIND ADVISORY CRITERIA. TEMPERATURES RANGED
FROM THE LOW 60S TO LOW 70S. A FEW PATCHES OF CU AND CIRRUS WERE
NOTED ON VISIBLE IMAGERY.

FOR TONIGHT THROUGH MONDAY...THE UPPER LEVEL FLOW WILL SLOWLY BACK
FROM WEST TO SOUTHWEST THIS PERIOD...WHILE STRONG SOUTHERLY WINDS
CONTINUE TO SLOWLY INCREASE GULF MOISTURE TONIGHT. AS ONE SHORTWAVE
CROSSES THE GREAT LAKES TOMORROW A COLD FRONT WILL MOVE INTO THE
MIDSOUTH DURING THE OVERNIGHT HOURS. DEWPOINTS WILL BECOME STEADY
IN THE MID 50S AHEAD OF THE FRONT LEADING TO SCATTERED SHOWERS AND
A FEW STORMS STARTING LATE IN THE DAY OVER THE NORTH. BEST TIMING
AND LOCATION FOR MEASURABLE PRECIPITATION WILL BE IN THE OVERNIGHT
HOURS ACROSS THE EASTERN COUNTIES WHERE A WEAK WAVE ALONG THE
BOUNDARY WILL PROVIDE FOR BETTER LIFT. GUSTY SOUTHWEST WINDS WILL
AGAIN FLIRT WITH WIND ADVISORY CRITERIA ACROSS THE DELTA...BUT
ONLY BECAUSE LOW LEVEL CLOUD COVER WILL HELP TO DAMPEN THEIR FULL
POTENTIAL. ANY SIGNIFICANT BREAKS WOULD WARRANT THE ADVISORY.
MODEL SOLUTIONS BECOMING BETTER ALIGNED IN STALLING THE FRONT
IN NORTH MISSISSIPPI...INSTEAD OF FURTHER SOUTH. FOR THIS REASON
HAVE INCREASED HIGHS ON MONDAY A DEGREE OR TWO FROM ROUGHLY
TUPELO TO CHARLESTON AND POINTS SOUTH. AN MORNING SHOWER WILL
REMAIN POSSIBLE ACROSS THE SOUTHEAST...OTHERWISE MONDAY APPEARS
MOSTLY CLOUDY AND DRY...WITH EASTERLY LOW LEVEL FLOW.

TUESDAYS STORM...THE ECMWF REMAINS MORE BULLISH WITH SEVERE
WEATHER PARAMETERS...WHILE THE GFS REMAINS SKEPTICAL ON BOTH
MOISTURE RETURN AND FAVORABLE LAPSE RATES. THE SYSTEM IS AT THE
EDGE OF THE NAM RUN...BUT EVEN THE NAM SHOWS CAPE AMOUNTS
APPROACHING 800 J/KG BY THE MID-AFTERNOON EAST OF THE MISSISSIPPI
RIVER. ONE AGREEMENT IS THAT THE STORM TIMING IS SLOWING...TYPICALLY
SEEN BY MODELS AS A STORM IS DEEPENING/OCCLUDING. THE ATMOSPHERE
WILL START OFF CAPPED TUESDAY MORNING AS THE AFOREMENTIONED FRONT
STARTS IT`S PUSH NORTHWARD. WARM FRONTAL PASSAGE SHOULD OCCUR IN
THE MEMPHIS METRO JUST BEFORE SUNRISE REACHING THE KY/MO BEFORE
NOON. A FEW SHOWERS WILL DOT THE RADAR BUT ONGOING STORMS DOESN`T
APPEAR FAVORABLE. THE SURFACE LOW WILL QUICKLY MOVE FROM NORTHERN
OKLAHOMA TO NEAR KANSAS CITY THIS TIME FRAME...WITH A PREFRONTAL
TROUGH EXTENDING SOUTH THROUGH CENTRAL ARKANSAS BY NOON. BACKED
WINDS FROM THE SOUTH SOUTHEAST WILL INCREASE RAPIDLY TUESDAY
MORNING AND WILL PROVIDE FOR MORE THAN ADEQUATE LOW LEVEL TURNING
FOR STORM ROTATION. QUESTIONS STILL ARISE ON HOW MUCH WARM SECTOR
CLOUD COVER WILL BE IN PLACE TRAPPED UNDER THE CAP...HOLDING OFF
THE INSTABILITY. SO FAR FORECAST SOUNDINGS SUGGEST ALL MORNING
LONG WITH NO BREAKS UNTIL NOONISH SUGGESTING THAT POINTS ALONG AND
EAST OF THE MISSISSIPPI RIVER STILL RUN THE BEST POTENTIAL FOR THE
CAP TO BREAK/BETTER INSTABILITY AND THE RESULTANT SEVERE WEATHER.
SO THE ONLY CHANGE TO THE AFTERNOON HWO WILL BE DIFFERENT WORDING
CONCERNING THE TORNADO THREAT...WHICH ACCORDING TO THE EURO AND
NAM MAY BE ON THE SAME LEVEL AS DAMAGING WINDS. THE FRONT WILL
EXIT THE CWA IN THE 6-8PM TIME FRAME WHILE A CLEAR DRY SLOT
OVERTAKES THE REGION. WEST WINDS AND PARTLY CLOUDY SKIES WILL KEEP
LOWS ABOVE FREEZING.

WEDNESDAY THROUGH SATURDAY...ONLY SIGNIFICANT CHANGE DONE THIS
FORECAST PERIOD IS TO BUMP UP HIGHS FRIDAY AND SATURDAY AS AN
UPPER LEVEL HEIGHTS BUILD OVER THE PLAINS AND MIDSOUTH.

JAB

[jaxjagman]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
316 PM CST SAT JAN 30 2016

.DISCUSSION...

TEMPERATURES THIS AFTERNOON HAVE CLIMBED ABOVE MOST GUIDANCE AS
ENHANCED MIXING HAS BROUGHT TEMPS UP AS WELL AS WIND SPEEDS.
SUSTAINED SOUTHERLY WINDS FROM 15 TO 20 MPH OR SO AS WELL AS GUSTS
INTO THE 30 MPH RANGE HAVE IMPACTED MOST OBS SITES THIS AFTERNOON.
WINDS SHOULD CALM DOWN A BIT OVERNIGHT BUT REMAIN ABOVE 10 MPH.
HIGHER WINDS ALONG WITH INCREASING CLOUD COVER WILL HELP KEEP
TEMPERATURES UP OVERNIGHT. MOST OF THE AREA SHOULD HAVE LOWS IN
THE MID 40S TO MID 50S. WINDS WILL PICK UP AGAIN TOMORROW AND SOME
MODELS ARE INDICATING THAT WINDS COULD BE SLIGHTLY STRONGER THAN
TODAY. SOME AREAS MAY SEE SUSTAINED WINDS AROUND 20 MPH IN THE
EARLY AFTERNOON...AND WIND ADVISORY CRITERIA IS CLOSE ATTM. MAY
NEED A WIND ADVISORY SHOULD MODELS SUGGEST STRONGER WINDS IN THE
NEXT RUNS.

CHANCES FOR SHOWERS LOOK TO HOLD OFF UNTIL LATER IN THE AFTERNOON
TOMORROW AND LOOKS TO BE WEST OF I65. AFTER 00Z SHOWERS LOOK TO
SPREAD OVER THE AREA OVERNIGHT. SHOWERS WILL BE FORCED BY SOME
WEAK SHORTWAVE ACTIVITY AND ASSOCIATED FRONTAL BOUNDARY THAT WILL
MOVE THROUGH ON MONDAY. IN ADDITION...ADDED IN MENTION FOR THUNDER
OVERNIGHT MONDAY AND INTO THE MORNING AS MODEL SOUNDINGS ARE
HINTING AT SOME ELEVATED INSTABILITY MAINLY FOR THE EASTERN THREE
QUARTERS OF THE CWA. WINDS WILL VEER AROUND TO THE NORTH BUT
QUICKLY RETURN TO THE SOUTH OVERNIGHT INTO TUESDAY AHEAD OF THE
NEXT TROUGH. MODELS HAVE BEEN TRENDING DRIER FOR MONDAY EVENING
INTO TUESDAY MORNING...SO TRENDED POPS DOWN FOR THIS TIMEFRAME.
WOULDNT BE SURPRISED TO SEE ALL MENTION OF PRECIP OUT OF THE
FORECAST FOR MONDAY NIGHT IN THE NEXT FEW RUNS.

TUESDAYS EVENT LOOKS TO BE A BIT LESS IMPRESSIVE WITH THE CURRENT
MODEL RUNS...BUT THAT CAN CHANGE QUICKLY AS SHORT TERM MODELS ARE
STARTING TO GET INTO THE RANGE OF TUESDAY EVENING. MAIN BAND OF
PRECIP HAS SLOWED DOWN A BIT TO BE RIGHT OVER THE CENTRAL PART OF
THE CWA BY MIDNIGHT AND CONTINUE FOR THE EAST OVERNIGHT. MUCAPE
VALUES LOOK TO DECREASE RAPIDLY AFTER 00Z...BUT CAPE VALUES HAVE
INCREASED SLIGHTLY FOR AREAS WEST OF I65 BEFORE 00Z. THE ECMWF NOW
HAS ABOUT 200-700 J/KG FOR THE TN RIVER VALLEY AND THE GFS IS UP
TO AROUND 400 J/KG. AFTER 00Z THOUGH...THE MUCAPE VALUES ARE MORE
THAN CUT IN HALF. CONVECTION WILL BE ONGOING SO DAMAGING WINDS
WILL STILL BE A THREAT AS 0-6KM BULK SHEAR LOOKS TO BE 60 TO 80
KNOTS WHICH IS THE SAME AS IT LOOKED WITH PREVIOUS RUNS. OVERALL
THIS EVENT STILL LOOKS TO BE IMPACTFUL WITH THE MAIN THREATS WITH
THUNDERSTORMS WILL BE DAMAGING WINDS AND EVEN ISOLATED
TORNADOES...ESPECIALLY IF THERES CONVECTION OUT AHEAD OF THE MAIN
BAND. SHORT TERM MODELS WILL BE WITHIN THE TIMEFRAME OF THIS EVENT
TONIGHT AND TOMORROW...SO SHOULD GET A BETTER HANDLE ON TIMING AND
MAGNITUDE IN THE COMING DAYS.

AFTER TUESDAY...THE REST OF THE FORECAST LOOKS QUITE DRY AND
SEASONAL. TEMPS WILL BE AROUND NORMAL FOR THIS TIME OF YEAR AS
ANOTHER LOBE OF THE UPPER TROUGH REINFORCES THE COLD AIR OVER THE
EASTERN CONUS. UPPER FLOW LOOKS TO GO MORE ZONAL BY THE WEEKEND
HOWEVER EVEN INTO THE SECOND WEEK OF FEB...TEMPS DONT LOOK TO
WARM UP TOO MUCH ABOVE AVERAGE UNTIL NEXT TUESDAY OR WEDNESDAY.

[jaxjagman]

GFS went from hardly no winds in Mid Tn and the eastern Valley to 60-65 @ 850 mb  kts to Mid tn to the east,quite funny the changes  the 18z showed

[Runman292]

GFS went from hardly no winds in Mid Tn and the eastern Valley to 60-65 @ 850 mb kts to Mid tn to the east,quite funny the changes the 18z showed

GFS must be drunk right now.

[Carvers Gap]

GFS went from hardly no winds in Mid Tn and the eastern Valley to 60-65 @ 850 mb kts to Mid tn to the east,quite funny the changes the 18z showed

Men, I want none of that. Ground is saturated from melting snow up here. Would be a mess. On the other hand...thunderstorms in late winter seem to be coupled with winter wx a few weeks later.

[jaxjagman]

Men, I want none of that. Ground is saturated from melting snow up here. Would be a mess. On the other hand...thunderstorms in late winter seem to be coupled with winter wx a few weeks later.

This is what i've been saying the last couple days.The system before hand keeps showing signs  of getting stronger and  more moisture before hand.Even without a tornado threat this could be a sig wind damage event

[Runman292]

This is what i've been saying the last couple days.The system before hand keeps showing signs of getting stronger and more moisture before hand.Even without a tornado threat this could be a sig wind damage event

I could see that for areas west of the plateau, but I'm not so sure about the eastern valley. Severe thunderstorms in East Tennessee is similar to Snow.

[Runman292]

The day 3 outlook (Tuesday) has been released, and areas west of Nashville are under an enhanced risk for Severe Thunderstorms. Nashville to the plateau has a Slight risk, while the Eastern Valley has a marginal risk (in other words, Rain, 40-50 mph gusty winds, and some lightning as the main threats).

[jaxjagman]

 

DAY 3 CONVECTIVE OUTLOOK 
   NWS STORM PREDICTION CENTER NORMAN OK
   0202 AM CST SUN JAN 31 2016

   VALID 021200Z - 031200Z

   ...THERE IS AN ENH RISK OF SVR TSTMS FROM NRN MS INTO WRN KY...

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE OH RIVER VALLEY SWD TO
   THE CNTRL GULF COAST...

   ...THERE IS A MRGL RISK OF SVR TSTMS FROM IL/IN SWD TO THE GULF
   COAST...

   ...SUMMARY...
   SCATTERED SEVERE STORMS CAPABLE OF DAMAGING WINDS AND A FEW
   TORNADOES ARE POSSIBLE ACROSS THE LOWER MISSISSIPPI VALLEY INTO THE
   LOWER OHIO VALLEY ON TUESDAY WITH A FEW STRONG STORMS ACROSS THE
   CENTRAL GULF COAST OVERNIGHT.

   ...SYNOPSIS...
   AN UPPER LOW WILL MOVE FROM KS TO LAKE SUPERIOR WITH AN EXPANSIVE
   AREA OF STRONG SWLY FLOW ALOFT SPREADING EWD ACROSS THE MS AND OH
   VALLEYS. AT THE SURFACE...LOW PRESSURE WILL MOVE FROM ERN KS INTO IL
   DURING THE DAY...WITH A COLD FRONT EXTENDING S FROM THE LOW ALONG
   THE MS RIVER BY 00Z. DEWPOINTS IN THE 60S F WILL SPREAD NWD ACROSS
   THE WARM SECTOR WITH SUFFICIENT INSTABILITY DEVELOPING TO SUPPORT
   SCATTERED SEVERE STORMS WITH THE GREATEST RISK FROM MS NWD TO THE OH
   RIVER DURING THE AFTERNOON.

   ...LOWER MS VALLEY/CNTRL GULF COAST NWD TO THE OH RIVER...
   A CAPPING INVERSION WILL RESULT IN A LACK OF EARLY THUNDERSTORM
   ACTIVITY ACROSS THE REGION...BUT STRENGTHENING LIFT AHEAD OF THE
   ADVANCING SFC LOW/TROUGH SHOULD RESULT IN STORMS DEVELOPING BY 18Z
   ACROSS LA...ERN AR...AND SERN MO AHEAD OF THE LOW. AS STRONG WIND
   SHEAR ACTS ON THESE STORMS...THEY ARE EXPECTED TO GRADUALLY ORGANIZE
   INTO A LINE OF STORMS...WITH A MIXTURE OF BOWING SEGMENTS AND
   EMBEDDED. BOTH DAMAGING WINDS AND A FEW TORNADOES WILL BE POSSIBLE.

   ALTHOUGH THE LOW AND STRONGEST LIFT WILL DEPART NWD ACROSS THE GREAT
   LAKES TUE EVENING AND NIGHT...SUFFICIENT LIFT AND A MOIST AIR MASS
   NEAR SRN PORTIONS OF THE FRONT FROM AL INTO THE FL PANHANDLE MAY
   SUPPORT A FEW SEVERE STORMS THERE AS WELL.

[jaxjagman]

 

DAY 2 CONVECTIVE OUTLOOK 
   NWS STORM PREDICTION CENTER NORMAN OK
   1237 AM CST MON FEB 01 2016

   VALID 021200Z - 031200Z

   ...THERE IS AN ENH RISK OF SVR TSTMS ACROSS MUCH OF MS...NWRN
   AL...WRN TN AND  KY...EXTREME SRN IL AND INDIANA...

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM SRN IL AND INDIANA SWD TO
   THE CNTRL GULF COAST...

   ...THERE IS A MRGL RISK OF SVR TSTMS IMMEDIATELY SURROUNDING THE
   SLIGHT RISK AREA...

   ...SUMMARY...
   SCATTERED SEVERE STORMS CAPABLE OF DAMAGING WINDS AND A FEW
   TORNADOES ARE LIKELY FROM MISSISSIPPI AND ALABAMA NORTHWARD INTO THE
   OHIO VALLEY TUESDAY AFTERNOON AND EVENING.

   ...SYNOPSIS...
   AN UPPER LOW WILL MOVE NEWD FROM THE CNTRL PLAINS INTO THE UPPER
   GREAT LAKES WITH INTENSE JET ALOFT TRANSLATING NEWD ACROSS THE MS
   AND OH VALLEYS. A SFC LOW WILL MOVE FROM ERN KS TUE MORNING INTO NRN
   IL BY 00Z WED...WITH A COLD FRONT EXTENDING SWD ACROSS IN/KY/TN/MS
   BY EVENING...AND A WARM FRONT LIFTING NWD ACROSS THE LOWER OH VALLEY
   IN ANTICIPATION OF THE SFC LOW. DEWPOINTS NEAR 60 F WILL EXTEND TO
   THE OH RIVER...WITH MID 60S F ACROSS THE CNTRL GULF COAST STATES.
   STRONG LIFT WILL SUPPORT AN EXTENSIVE CORRIDOR OF THUNDERSTORMS
   BEGINNING AROUND MIDDAY AND CONTINUING INTO THE EVENING ACROSS THE
   SLIGHT AND ENHANCED RISK AREAS.

   ...LOWER MS VALLEY NEWD INTO THE OH VALLEY...
   A CAPPING INVERSION WILL DELAY THE BULK OF THE THUNDERSTORM ACTIVITY
   UNTIL AFTER 18-21Z AS THE MOIST BOUNDARY LAYER GRADUALLY DEEPENS.
   ONE OR MORE LINES OF STORMS ARE EXPECTED TO FORM ACROSS IL...WRN
   KY/TN AND NRN MS...GRADUALLY ADVANCING EWD TO AN OH TO SERN LA LINE
   BY AROUND MIDNIGHT.

   WIND SHEAR WILL BE QUITE STRONG ACROSS THE ENTIRE REGION...WITH ONE
   LIMITING FACTOR BEING INSTABILITY LEVELS DUE TO A RELATIVELY COOL
   SFC AIR MASS IN COMBINATION WITH LESS THAN OPTIMAL TEMPERATURES
   ALOFT. AS A RESULT...STORMS WILL BE HIGHLY SHEARED AND TILTED.
   DAMAGING WINDS WILL BE THE PRIMARY THREAT BUT A FEW CELLS EMBEDDED
   WITHIN THE LINE MAY PRODUCE TORNADOES.

[jaxjagman]

Latest SREF still shows the STP @ 2 from roughly west of 65 to the Miss River in the Valley.Latest NAM is still very bullish but looking at the latest soundings for BNA off the GFS12z looks much better for Mid Tn.850mb winds are around 65kts with 0-1km shear @ 45kts with better convection and dp's now at 64F  some better surface base cape at 233 j/kg @3Z Wed with this.

[jaxjagman]

N/Miss off the 12z NAM

 

 

 

 

[Runman292]

It sounds like MRX just isn't that worried about this system for East Tennessee. I would say that the fact that the line won't reach the valley until Wednesday morning is the reason for that.

[jaxjagman]

It sounds like MRX just isn't that worried about this system for East Tennessee. I would say that the fact that the line won't reach the valley until Wednesday morning is the reason for that.

The line will reach you,you just start to lose the dynamics as the system lifts N.

[Runman292]

The line will reach you,you just start to lose the dynamics as the system lifts N.

Hence why they are saying that the damaging wind threat is isolated and will likely only happen in areas west of interstate 75.

[nrgjeff]

Great wind fields with low instability is like winter storm low press swinging through Georgia and the Carolinas while our 850 temps are +2C. Oh but things can change. If the surface heats up better than forecast the CAPE LI and EHI will respond accordingly. I am not really excited about that prospect, but anything can happen.

 

Basically the mid levels are a touch warm on the sounding. It is true upstream; and, it should advect in here for Tuesday. Keep in mind the parent system has been trending north for 48 hours now. All the splicing of levels and/or indices aside, a quick look at fundamentals helps. Low press going through Wisconsin is just not the same as going through Illinois for Mid South mayhem.

 

SPC looks good at ENH; no MDT unless instability spikes. I am not going to lose any sleep over this. Event would be totally un-chasable with high storm speeds and possibly best low-level mesoscale details toward dark. I never like a big outbreak in a populated area anyway. Prefer local set-ups impacting far fewer people.

 

All my skepticism aside, I am thrilled to see so much interest in this thread. Great to see the list of members interested in severe weather is growing!

[Runman292]

Great wind fields with low instability is like winter storm low press swinging through Georgia and the Carolinas while our 850 temps are +2C. Oh but things can change. If the surface heats up better than forecast the CAPE LI and EHI will respond accordingly. I am not really excited about that prospect, but anything can happen.

Basically the mid levels are a touch warm on the sounding. It is true upstream; and, it should advect in here for Tuesday. Keep in mind the parent system has been trending north for 48 hours now. All the splicing of levels and/or indices aside, a quick look at fundamentals helps. Low press going through Wisconsin is just not the same as going through Illinois for Mid South mayhem.

SPC looks good at ENH; no MDT unless instability spikes. I am not going to lose any sleep over this. Event would be totally un-chasable with high storm speeds and possibly best low-level mesoscale details toward dark. I never like a big outbreak in a populated area anyway. Prefer local set-ups impacting far fewer people.

All my skepticism aside, I am thrilled to see so much interest in this thread. Great to see the list of members interested in severe weather is growing!

I wish I could be more interested in this system, but I just don't see any potential in it for the East TN Valley.

[Chinook]

Here is my outlook. I was looking at supercell composite parameter values, as well as surface based CAPE values, for the different forecast hours tomorrow (Tuesday.) Threat-wise, I think it is at least a 15% wind/5% tornado risk, if not higher. (Not trying to go crazy here, but maybe 10% tornado risk.) I think there is a minor threat of severe weather north of the Ohio River. My best guess for supercell activity in northeast Mississippi is based off the 4km NAM reflectivity, and the area where the CAPE/shear/helicity is the highest. This includes a considerable 0-3km SRH of 400 m2/s2 in northeast Mississippi, up to Nashville. Dew points should max out in the upper 60's at the Mississippi/Alabama border.