[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 281737
SWODY2
SPC AC 281735

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1135 AM CST TUE NOV 28 2006

VALID 291200Z - 301200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM TX/OK NEWD TO WRN IL...

...SYNOPSIS...
SIGNIFICANT LARGE SCALE PATTERN CHANGE IS FORECAST OVER THE CNTRL
U.S THROUGH WEDNESDAY AS A DEEP UPPER TROUGH...CURRENTLY
ENCOMPASSING THE INTERMOUNTAIN WEST...TRANSLATES EWD. WHILE A
PORTION OF SHORT WAVE ENERGY ASSOCIATED WITH THE LARGER SCALE TROUGH
SYSTEM EJECTS NEWD FROM MT INTO SRN CANADA...ANOTHER VIGOROUS LOBE
OF VORTICITY AND ITS ASSOCIATED JET SEGMENT WILL TRACK ACROSS THE
GREAT BASIN AREA THROUGH TONIGHT...AND RESULT IN HEIGHT FALLS
SPREADING EWD/SEWD ACROSS THE SRN HIGH PLAINS THROUGH THURSDAY
MORNING. DYNAMIC FORCING ACCOMPANYING THE EWD TRANSITION OF THE
LARGE SCALE TROUGH WILL ENHANCE DEEP-LAYER FRONTOGENESIS AND LIFT
ALONG A STRONG COLD FRONT FORECAST TO SURGE INTO THE WRN GREAT
LAKES...MIDWEST...AND SRN PLAINS REGIONS THROUGH LATE TOMORROW
NIGHT.

...NRN TX...ERN OK...OZARKS...
MOIST AXIS HAS BECOME WELL ESTABLISHED ACROSS THE SRN PLAINS GIVEN
PERSISTENT SLY LOW LEVEL FLOW AND PASSAGE OF DEAMPLIFYING SHORT WAVE
TROUGH EARLIER TODAY. CONTINUED MOISTURE TRANSPORT AHEAD OF THE COLD
FRONT WILL MAINTAIN LOW TO MID 60S F DEWPOINTS ACROSS THE SRN PLAINS
AND SUPPORT MUCAPES CLIMBING TO NEAR 1000 J/KG PERHAPS AS EARLY AS
WEDNESDAY MORNING. LATEST NAM AND GFS ARE TRENDING A BIT FASTER WITH
COLD FRONTAL PASSAGE ACROSS NWRN/CNTRL OK BY WEDNESDAY AFTERNOON BIT
THERE ARE DIFFERENCES IN CONVECTIVE INITIATION NEAR THE FRONT WITH
THE GFS SUGGESTING AN EARLIER START TO MORE VIGOROUS DEEP CONVECTION
ACROSS OK/NORTH TX BY AFTERNOON.

GIVEN FAVORABLE LARGE SCALE SUPPORT IN THE FORM OF INCREASINGLY
DIFFLUENT/DIVERGENT FLOW IN RIGHT ENTRANCE REGION OF INTENSIFYING
UPPER JET...AND GENERALLY WEAK CAP ACROSS MOIST AND UNSTABLE
PRE-FRONTAL AIR MASS...TSTMS SHOULD INCREASE THROUGH THE AFTERNOON.
SHEAR ACROSS THE REGION WILL STRENGTHEN THROUGH THE DAY AND SUPPORT
ORGANIZED AND PERSISTENT UPDRAFTS CAPABLE OF HAIL AND DAMAGING
WINDS. A SUPERCELL TORNADO AND/OR VERY LARGE HAIL THREAT APPEARS
POSSIBLE ACROSS THE RED RIVER REGION DURING THE AFTERNOON OR EARLY
EVENING WHERE THERMAL TROUGH/COLD FRONT INTERSECTION MAY ENHANCE LOW
LEVEL MESOSCALE FORCING.

BULK OF CONVECTION ACROSS THE REGION IS LIKELY TO LINE UP ALONG OR
IMMEDIATELY BEHIND THE DEEPER FRONTAL CIRCULATION DEVELOPING SEWD
ACROSS THE AREA THROUGH THE EVENING. IT IS POSSIBLE A LINEAR MCS
WITH A CONTINUING SEVERE THREAT COULD EVOLVE ACROSS PARTS OF NERN OK
AND NCNTRL TX INTO THE LATER EVENING.

...NRN MO TO IL...
MOIST AXIS WILL BE NARROW AND CAPE WILL BE WEAKER FROM THE OZARKS
NEWD ACROSS THE MS VALLEY INTO WRN IL. NONETHELESS...LIFT ALONG THE
FRONT...AND INCREASINGLY STRONG UNIDIRECTIONAL SHEAR
PROFILES...SUGGEST SOME POTENTIAL FOR NEAR SURFACE-BASED CONVECTION
TO POSE A THREAT OF EITHER MARGINALLY SEVERE HAIL AND/OR HIGH WINDS.
GIVEN CONSENSUS IN AVAILABLE GUIDANCE THAT A NARROW CORRIDOR OF AT
LEAST 500 J/KG MUCAPE WILL BE AVAILABLE TO CONVECTION DEVELOPING
NEAR THE ADVANCING FRONT...AND STRONG SIGNAL THAT VIGOROUS
CONVECTIVE DEVELOPMENT WILL OCCUR WITHIN HIGH MOMENTUM REGIME...NEWD
EXTENSION OF THE HIGHER SEVERE PROBABILITIES APPEARS PRUDENT AT THIS
TIME.

..CARBIN.. 11/28/2006