november severe?

[Eric]

As mentioned before....the SPC Day 5:

TUE/D5...SEVERE WEATHER APPEARS MORE LIKELY AS THE UPPER WAVE BEGINS
   TO LIFT NEWD...BECOMES NEGATIVELY TITLED...AND AIDS IN DEEPENING OF
   SURFACE LOW. THE SPEED AND INTENSITY OF THE UPPER WAVE VARIES ON THE
   MREF RUNS AND DETERMINISTIC ECMWF AND GFS. USED A COMPROMISE AMONGST
   THE VARIOUS MODELS FOR INCLUDING A 30% SEVERE WEATHER THREAT AREA.
   THE MAGNITUDE AND INTENSITY OF THE EVENT IS DEPENDENT ON HOW THE
   WAVE EVENTUALLY LIFTS OUT AND SHOULD BE BETTER RESOLVED IN FUTURE
   OUTLOOKS.

[Eric]

MEG's take:

LARGE SCALE LIFT SHOULD INCREASE ACROSS MUCH OF THE MID SOUTH ON
TUESDAY AHEAD OF AN APPROACHING MID LEVEL SHORTWAVE TROUGH THAT
WILL MOVE EAST FROM THE SOUTHERN PLAINS TOWARDS THE MID SOUTH.
THIS SHOULD RESULT IN SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS DEVELOPING TUESDAY AFTERNOON WEST OF THE MISSISSIPPI
RIVER AND MOVING ACROSS THE REMAINDER OF THE AREA TUESDAY NIGHT IN
ADVANCE OF A SURFACE COLD FRONT. ATMOSPHERIC WIND FIELDS SHOULD
STRENGTHEN OVER THE MID SOUTH TUESDAY AFTERNOON AND NIGHT WITH
ENHANCED DEEP LAYER SHEAR DEVELOPING. THE MAGNITUDE OF THE SHEAR
WOULD FAVOR ORGANIZED AND POTENTIALLY SEVERE THUNDERSTORMS...BUT
MODELS CONTINUE TO INDICATE LIMITED INSTABILITY. THIS WILL NEED TO
BE MONITORED OVER SUCCESSIVE MODEL RUNS AS THE UPPER TROUGH DOES
APPEAR TO BECOME NEUTRALLY/NEGATIVELY TILTED WITH SURFACE
DEWPOINTS RISING INTO THE LOWER 60S. AT THIS TIME...PLAN TO
CONTINUE MENTION OF STRONG STORMS FOR TUESDAY AFTERNOON AND
NIGHT IN THE HWO. THE SEVERE WEATHER POTENTIAL WILL CONTINUE TO
BE MONITORED OVER THE NEXT FEW DAYS.

THE COLD FRONT SHOULD MOVE EAST OF THE REGION ON WEDNESDAY WITH
ABUNDANT LOW LEVEL CLOUDS AND WRAP AROUND SHOWERS EXPECTED AS THE
UPPER LEVEL LOW PRESSURE MOVES ACROSS THE AREA. TEMPERATURES ARE
EXPECTED TO BE COOLER BEHIND THE FRONT FOR THE END OF NEXT WEEK.

And LZK:

LONG TERM...TUESDAY THROUGH THURSDAY NIGHT
MODELS ALL AGREE IN THE SYNOPTIC SCALE THAT THE PROGRESSIVE...SPLIT
FLOW PATTERN WILL CONTINUE THROUGH THE EXTENDED PERIOD WITH SOUTHERN
STREAM DOMINATING THE OVERALL PATTERN. THERE ARE SOME STRENGTH AND
TIMING DIFFERENCES BETWEEN THE INDIVIDUAL MODELS WITH THE CMC/ECMWF
SOMEWHAT FASTER VERSUS ITS GFS COUNTERPART. REALLY CAN NOT SEE A
REASON TO FAVOR ONE MODEL VERSUS ANOTHER AT THIS POINT AND WILL TAKE
A MIDDLE OF THE ROAD APPROACH WITH A SLIGHT LEAN TOWARDS THE
SLIGHTLY MORE CONSISTENT GFS.

PERIOD INITIATES WITH UPPER LEVEL LOW PRESSURE/UPPER LEVEL TROUGH
OVER THE WESTERN HIGH PLAINS. ASSOCIATED SURFACE LOW WILL BE LOCATED
OVER NORTHERN OKLAHOMA WITH COLD FRONT EXTENDING THROUGH CENTRAL
TEXAS. ENTIRE SYSTEM WILL LIFT TO TO THE NORTHEAST DURING THE DAY
TUESDAY WITH FRONT PASSING ACROSS THE FORECAST AREA IN THE TUESDAY
AFTERNOON/TUESDAY NIGHT TIME FRAME AND REACHING THE MISSISSIPPI
RIVER EARLY WEDNESDAY.

RAIN WILL LIKELY BE ONGOING AT LEAST OVER THE WESTERN HALF OF THE
FORECAST AREA EARLY TUESDAY AND LOOKS TO BE SPREADING EAST DURING
THE DAY. SOUTHWEST FLOW ALOFT AND SURFACE FLOW OFF THE GULF WILL
ADVECT IN PLENTY OF LOW LEVEL MOISTURE WITH PWATS IN EXCESS OF 1.5
INCHES WITH LOCALLY HEAVY RAIN A CONCERN. POTENTIAL EXISTS FOR
STRONG TO SEVERE STORMS ALONG AND IN ADVANCE OF THE FRONT AS THE
VERY DYNAMIC SYSTEM MOVES THROUGH WITH PLENTY OF FAVORABLE JET
DYNAMICS/WIND ENERGY IN PLACE. ONE LIMITING FACTOR AT THIS POINT IS
LACK OF INSTABILITY SO WILL NOT GO OVERBOARD AT THIS POINT.

ONCE THE SYSTEM BLOWS THROUGH...CONSIDERABLY DRIER AIR AND RAIN FREE
CONDITIONS ARRIVE FOR THE REMAINDER OF THE PERIOD. TEMPERATURES
WILL START THE PERIOD ABOVE NORMAL AND FINISH BELOW IT. MAV/MEX
NUMBERS LOOK REASONABLE AND ARE GENERALLY ACCEPTED.

[Kevin]

Still doesn't look like anything particularly impressive, especially for TN. Perhaps a "decent" Slight risk day to the W on Tuesday but even then nothing screaming a significant event at this point. We'll see if that changes over the weekend...

[toastido]

Still doesn't look like anything particularly impressive, especially for TN. Perhaps a "decent" Slight risk day to the W on Tuesday but even then nothing screaming a significant event at this point. We'll see if that changes over the weekend...

Yup.  Most of the energy looks to remain confined to the outer edges of the ULL, with only a weak shortwave passing through the AR/MO/TN area.  After that, the energy looks to be shunted into the midwest/lakes region. 

[Cyclonicjunkie]

12z IPS wrf




Good get rocky in west TN

[toastido]

12z IPS wrf




Good get rocky in west TN

Looks like a bunch of rain to me.

[Cyclonicjunkie]

Looks like a bunch of rain to me.

Lookis like a bunch of big supercells heading towards West TN this Ips wrf shows large SS'S

[toastido]

Lookis like a bunch of big supercells heading towards West TN this Ips wrf shows large SS'S

That is QPF, not cells. It can show up like that for many reasons...my bet is on a QLCS based on the upper air charts and surface guidance.

[Cyclonicjunkie]

That is QPF, not cells. It can show up like that for many reasons...my bet is on a QLCS based on the upper air charts and surface guidance.

Yes I know but the high qpf readings in the small looking qpf segments mean it is cells....I read a study on this and small segments of qpf mean supercellsl

[toastido]

Yes I know but the high qpf readings in thr small looking qpf segments mean it is cells....I read a study on this and small segments of qpf mean supercellsl

No. I'm sorry, but that is a completely outlandish and irresponsible assumption. It is almost impossible to determine storm mode from QPF alone.

[Kevin]

Yes I know but the high qpf readings in thr small looking qpf segments mean it is cells....I read a study on this and small segments of qpf mean supercellsl

Completely untrue. Blotchy QPF can mean any number of things - in very specific cases, they can suggest a celluar mode of thunderstorms (not even going as far as "supercells" which is a totally different situation), but you've applied this to nearly every severe weather situation you've seen on a simple, singluar model run for the last year or more.

You need to leave the severe weather to those that are basing their ideas on more than simple QPF patterns. Its shown many times already this year not to work...

[Cyclonicjunkie]

No. I'm sorry, but that is a completely outlandish and irresponsible assumption. It is almost impossible to determine storm mode from QPF alone.

I will hunt the study that proves that small high qpf segments are indeed SS's in climatological severe wx sytems.... give me a while it exists.

[tennessee storm09]

while this threat coming up next week turns out nuch or not, the pattern looks ripe for severe for the better part of this month. the 18zgfs has nice wind profiles and a very troughy west. going to be an intersting to see how this pattern plays out the next two to three weeks

[Cyclonicjunkie]

Supercells...if im wrong you dog me out and I will admit that im a doofus when it comrse to svr wx

[tennessee storm09]

Supercells...if im wrong you dog me out and I will admit that im a doofus when it comrse to svr wx

while thats a very interesting picture toot, most of the time super cells will be modeled more of a scattered scale with more seperation in between the cells. more of a mcs type perhaps modeled there.