DAY48SVR: Nws Storm Prediction Center Norman Ok

ACUS48 KWNS 170914
SWOD48
SPC AC 170914

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0314 AM CST TUE DEC 17 2013

VALID 201200Z - 251200Z

...DISCUSSION...
SIGNIFICANT MODEL DIFFERENCES EXIST BY FRI/D4 WITH THE LOCATION AND
SUBSEQUENT MOTION OF THE SWRN U.S. UPPER LOW AND TROUGH. GIVEN THE
POTENTIAL FOR THIS LOW TO DIG RELATIVELY FAR S BEFORE EJECTING EWD
ACROSS THE SRN PLAINS AND EVENTUALLY MS/TN/OH VALLEYS...MODELS ARE
HAVING DIFFICULTY AGREEING ON TIMING.

IT DOES APPEAR THAT THE VARIOUS ENSEMBLE MEMBERS ARE IN BETTER
AGREEMENT THAN 24 HOURS AGO...BUT PREDICTABILITY IS STILL TOO LOW TO
CONFIDENTLY PLACE A 30 PERCENT OR HIGHER COVERAGE SEVERE AREA.
HOWEVER...CLIMATOLOGY WOULD SUGGEST ARKLATEX NEWD INTO THE LOWER OH
VALLEY.

WHILE THE SPEED OF THE SYSTEM WILL DRIVE THE ERN EXTENT OF THE
SEVERE THREAT...THE PRESENCE OF A COLD AIR MASS N OF THE LOW TRACK
WILL DEFINE THE SHARP NRN EXTENT. IN ADDITION...THE DEGREE OF
SHORTWAVE TROUGH AMPLIFICATION WHEN IT OVERSPREADS THE MOIST SECTOR
WILL PLAY AN IMPORTANT ROLE WITH WIND PROFILES AND STORM MODE. IF
THE TROUGH EMERGES TOO POSITIVELY-TILTED AND PARALLEL TO THE COLD
FRONT...THE THREAT WOULD LIKELY BE LOWER THAN IF A MORE SUBSTANTIAL
SURFACE LOW DEVELOPS AND MOVES RAPIDLY NEWD. REGARDLESS...AT LEAST A
DAMAGING WIND THREAT WOULD BE LIKELY WITH A MORE CONDITIONAL TORNADO
THREAT.

WHILE THE FASTEST MODEL SOLUTIONS WOULD ONLY INDICATE A THREAT ON
SAT/D5...A SLOWER TROUGH MOVEMENT COULD RESULT IN SOME THREAT ACROSS
THE CNTRL GULF COAST STATES NWD INTO THE TN/OH VALLEYS ON SUN/D6.

..JEWELL.. 12/17/2013

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.