402
ACUS48 KWNS 050951
SWOD48
SPC AC 050949
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0349 AM CST MON JAN 05 2026
VALID 081200Z - 131200Z
..DISCUSSION
THE NOTICEABLE MODEL DIFFERENCES ON D3/WEDNESDAY IN THE EVOLUTION OF
A LOW-LATITUDE SHORTWAVE IMPULSE, EJECTING AHEAD OF AN AMPLIFYING
UPPER TROUGH OVER THE WEST, PERSIST INTO D4/THURSDAY. THIS RENDERS
LOW CONFIDENCE IN A GREATER THAN LOW-PROBABILITY SEVERE RISK ON
THURSDAY, WHICH APPEARS ROUGHLY CENTERED ON THE ARK-LA-TEX TO
MID-SOUTH.
PEAK SEVERE POTENTIAL STILL APPEARS CENTERED ON D5/FRIDAY.
PREDICTABILITY REMAINS SUB-OPTIMAL WITH THE BASAL PORTION OF THE
AMPLIFIED UPPER TROUGH FROM THE SOUTHWEST. THIS RENDERS LARGE SPREAD
ACROSS GUIDANCE IN TIMING AND AMPLITUDE OF DOWNSTREAM CYCLOGENESIS
FROM THE SOUTH-CENTRAL GREAT PLAINS TOWARDS THE GREAT LAKES,
IMPACTING THE BREADTH OF SEVERE POTENTIAL. HOWEVER, WITH PRECEDING
DAYS OF AIRMASS MODIFICATION FROM THE WESTERN GULF, A PRONOUNCED
WINTERTIME WARM-MOIST SECTOR SHOULD BECOME ESTABLISHED TOWARDS THE
LOWER OH VALLEY VICINITY. THIS SHOULD BE COINCIDENT WITH A BROAD
SWATH OF STRONG SOUTHWESTERLY MID-LEVEL FLOW THAT SHOULD BE
STRENGTHENING DURING THE PERIOD.
THE TRIO OF LATEST NCAR ECENS-BASED AND SPC-CSU GEFS-BASED ML
PROBABILITIES HAVE TRENDED UPWARD AGAIN WITH SIMILARLY LARGE 15
PERCENT REGIONS. MEANWHILE, THE NSSL GEFS-BASED V1.2 HAS INCREASED
BACK TO A 10 PERCENT, BUT DISPLACED FARTHER SOUTH. FOR THIS
FORECAST, HAVE OPTED TO INCLUDE A 15 PERCENT HIGHLIGHT, CENTERED ON
THE LOWER MS TO LOWER OH VALLEYS WHERE CONFIDENCE IS GREATER FOR A
FAVORABLE CONVECTIVE ENVIRONMENT ON FRIDAY AFTERNOON TO NIGHT
DESPITE THE MODEST SYNOPTIC-SCALE PREDICTABILITY.
ML PROBS FOR D6/SATURDAY REMAIN LOW, WITH ONLY THE NCAR_PANGU
HIGHLIGHTING A 5 PERCENT AREA. BUT GIVEN THE AFOREMENTIONED TIMING
DIFFERENCES WITH THE EVOLUTION OF THE UPPER TROUGH/SURFACE
CYCLOGENESIS, VERY FAST DEEP-LAYER WIND FIELDS COULD PERSIST ATOP A
MORE LIMITED THERMODYNAMIC ENVIRONMENT. A CONDITIONAL CONVECTIVE
DAMAGING WIND THREAT SEEMS APPARENT, WITH LOW CONFIDENCE ON SPATIAL
EXTENT/AMPLITUDE AT THIS TIME RANGE.
..GRAMS.. 01/05/2026
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