• We've made some major changes to the website. You can view a short list : Here
  • Hello guests. Please take a minute to sign up and join in the conversation. It's free, quick, and easy!

Severe November 5th-6th Severe Weather Threat (1 Viewer)

PEA_RIDGE

FIREFIGHTER
Member
Joined
Jan 20, 2017
Messages
260
Likes
135
Location
MONTEVALLO, AL
#35
Capture.PNG SPC AC 030733

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0233 AM CDT Sat Nov 03 2018

Valid 051200Z - 061200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM A PORTION
OF THE LOWER MISSISSIPPI VALLEY INTO THE TENNESSEE VALLEY...

...SUMMARY...
Numerous severe storms with potential for damaging wind and
tornadoes are expected Monday evening into the overnight from a
portion of the lower Mississippi Valley into the Tennessee and Ohio
Valleys.

Primary change to previous outlook for Monday has been to expand the
severe risk areas farther north and east based on latest trends in
model guidance.

Potential still exists for significant severe weather to transpire
Monday evening and overnight, mainly from the lower MS Valley into
the Tennessee Valley regions. Though the NAM and GFS are slightly
less amplified with approaching upper trough compared to the ECMWF,
models have demonstrated reasonably good consistency. Cyclogenesis
should commence by Monday evening over the lower MS Valley in
response to ascent within exit region of an approaching, intense jet
streak within base of an amplifying shortwave trough. The low is
forecast to deepen as it lifts northeast into the OH Valley
overnight with trailing cold front advancing through the TN and
lower MS valley regions. Richer low-level moisture residing over the
northern Gulf will advect rapidly northward through the warm sector
in response to the strengthening low-level jet, contributing to
destabilization with modest instability (1000-1500 J/kg MLCAPE).
Mixed storm modes including a squall line and supercells are likely
to develop along and ahead of advancing cold front Monday afternoon
initially over the lower MS Valley, and continuing east into the TN
Valley and Southeast States Monday night. Impressive wind profiles
with large hodographs and an intense upper jet will promote a threat
for mainly damaging wind and tornadoes, though some hail will also
be possible.

..Dial.. 11/03/2018

CLICK TO GET WUUS03 PTSDY3 PRODUCT

NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0830Z
CURRENT UTC TIME: 0751Z (2:51AM), RELOAD THIS PAGE TO UPDATE THE TIME
 

PEA_RIDGE

FIREFIGHTER
Member
Joined
Jan 20, 2017
Messages
260
Likes
135
Location
MONTEVALLO, AL
#36
From the BMX NWS office as of 0420hrs 03 Nov 2018

THE CHANNEL JET IS EXPECTED TO TRANSITION INTO A NEGATIVELY-TILTED
OPEN WAVE TROUGH AS IT EJECTS INTO THE MISSISSIPPI VALLEY MONDAY
NIGHT, BUT THERE IS CRITICAL DISAGREEMENT BETWEEN THE AMOUNT OF
AMPLIFICATION INDICATED BY THE NAM/GFS VERSUS THE ECMWF
. THE
LESSER AMPLIFIED NAM/GFS WOULD RESULT IN SOMEWHAT WEAKER PRESSURE
FALLS AND LOW-LEVEL SHEAR ACROSS NORTH ALABAMA, WHILE THE MORE
CONSISTENT AND MORE AMPLIFIED ECMWF CONTINUES TO SHOW A DANGEROUS
SETUP ACROSS A GOOD PORTION OF OUR FORECAST AREA.

DEWPOINTS SURGING INTO THE UPPER 60S AND A WELL-MIXED BOUNDARY
LAYER MAY RESULT IN SBCAPE AS HIGH AS 2000 J/KG DURING THE
OVERNIGHT HOURS. VALUES THIS HIGH WILL NOT BE EXPLICITLY SHOWN BY
MODEL OUTPUT DUE TO THE TYPICAL ERROR OF DECOUPLING THE BOUNDARY
LAYER IN THE WARM SECTOR DURING THE OVERNIGHT HOURS. THIS AMOUNT
OF INSTABILITY IS QUITE RARE IN THE COOL SEASON, AND WILL BE
COMBINED WITH STRONG LOW-LEVEL AND DEEP-LAYER SHEAR. WITH A WIDE
WARM SECTOR IN PLACE AND 500 MB HEIGHT FALLS BEGINNING TO OCCUR
DURING THE EVENING, ISOLATED PRE-FRONTAL SUPERCELLS APPEAR POSSIBLE
AFTER 7 PM MONDAY NIGHT ACROSS OUR NORTHWESTERN COUNTIES. THE
THREAT SHOULD INCREASE DURING OVERNIGHT HOURS, WITH A PEAK THREAT
OCCURRING IN THE MIDNIGHT TO 6 AM TUESDAY TIME FRAME. THIS IS WHEN
SEMI-DISCRETE SUPERCELLS AND/OR A QLCS COULD PRODUCE LONG-TRACK,
SIGNIFICANT TORNADOES. CURRENTLY THE BEST OVERLAP OF INSTABILITY,
SHEAR, AND LIFT, APPEARS TO BE ALONG AND NORTHWEST OF I-59.
HOWEVER, THE MAIN THREAT AREA COULD SHIFT NORTHWARD AND AWAY FROM
OUR FORECAST AREA IF THE UPPER-LEVEL TROUGH TRENDS LESS AMPLIFIED
AS INDICATED BY SOME MODELS.

87/GRANTHAM
 
Joined
Jan 5, 2017
Messages
108
Likes
139
Location
Chattanooga
#37
I dont buy the SLT for southeast TN / northwest GA. The Cumberland Plateau is littered with the carcasses of overnight severe outbreaks that arrive after 6z. Unless timing speeds up a good 6 hours i dont see it happening here.
 

deltadog03

Meteorologist
Member
Joined
Jan 4, 2017
Messages
2,089
Likes
2,832
Location
Kmcn
#38
The only thing that gives me a slight pause for GA and the Carolinas to see a bigger threat is that the whole system is really pulling away from us
 
Joined
Jan 5, 2017
Messages
108
Likes
139
Location
Chattanooga
#51
Little change to the SPC outlook for Monday night for you guys in northwest AL/north MS/west TN, although parts of the enhanced risk area may be upgraded to moderate.

I still dont buy the slight risk for southeast TN and northwest GA. 12z ETA plus a weakening/increasingly linear line unlikely to do more than a gust of 40-45mph here, but we shall see.
 

PEA_RIDGE

FIREFIGHTER
Member
Joined
Jan 20, 2017
Messages
260
Likes
135
Location
MONTEVALLO, AL
#55
Looks like a good line of cells over N MS and W TENN
Capture.PNG

STP for 06Z tuesday
Capture2.PNG

PDS sounding for NW Jefferson CNTY Alabama associated with above STP model
Capture1.PNG
 

Arcc

Supporter
Member
Joined
Jan 5, 2017
Messages
1,885
Likes
2,415
Location
Extreme North Coosa County
#59
Looks like a good line of cells over N MS and W TENN
View attachment 7169

STP for 06Z tuesday
View attachment 7170

PDS sounding for NW Jefferson CNTY Alabama associated with above STP model
View attachment 7171
The issues I see is the very meager laspe rates. Along with the strong wind fields and EML it will be hard to get updrafts going in front of the line to take advantage of the wind shear. As the front approaches upper level wind become parallel with the front and unidirectional through the column that will effectivly greatly reduce the tornado threat.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top