963
ACUS02 KWNS 201722
SWODY2
SPC AC 201721
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1121 AM CST THU NOV 20 2025
VALID 211200Z - 221200Z
..NO SEVERE THUNDERSTORM AREAS FORECAST
..SUMMARY
SCATTERED THUNDERSTORMS ARE EXPECTED FROM THE TEXAS COAST TO THE
CENTRAL APPALACHIANS TOMORROW (FRIDAY). SEVERE THUNDERSTORMS APPEAR
UNLIKELY.
..SYNOPSIS
A MID-LEVEL SHORTWAVE TROUGH WILL TRAVERSE THE TN VALLEY AS AN UPPER
LOW MEANDERS OVER SOUTHERN CA TOMORROW (FRIDAY). ISOLATED LIGHTNING
FLASHES MAY OCCUR ACROSS SOUTHERN CA INTO SOUTHWESTERN AZ AS LIFT
AND COOLER TEMPERATURES ALOFT OVERSPREAD THE REGION IN ASSOCIATION
WITH THE UPPER LOW. ACROSS THE TN VALLEY, THE PASSAGE OF THE
AFOREMENTIONED MID-LEVEL SHORTWAVE TROUGH WILL ENCOURAGE A LOW-LEVEL
WARM-AIR ADVECTION REGIME. MODEST UPPER SUPPORT, IN TANDEM WITH
MEDIOCRE BUOYANCY (DRIVEN PRIMARILY BY LOW-LEVEL MOISTURE) WILL
SUPPORT ISOLATED TO SCATTERED THUNDERSTORMS FROM EASTERN TX TO THE
CENTRAL APPALACHIANS THROUGH THE DAY TOMORROW.
..TN VALLEY FRIDAY NIGHT
AS THE LOW-AMPLITUDE MID-LEVEL SHORTWAVE TROUGH OVERSPREADS THE TN
VALLEY, LOW-LEVEL FLOW (HOWEVER MOIST) SHOULD BECOME HIGHLY VEERED
THROUGH THE DAY FRIDAY, RESULTING IN UNIDIRECTIONAL WIND FIELDS AND
SUBSTANTIALLY REDUCED LOW-LEVEL CONVERGENCE. HOWEVER, BY FRIDAY
NIGHT (I.E. 03-09Z TIME FRAME), GUIDANCE DOES HINT AT A SMALL
MID-LEVEL IMPULSE TRAVERSING THE TN VALLEY. LOCALLY STRONGER FLOW
ALOFT WITH THIS IMPULSE WILL SUPPORT SOME SPEED SHEAR/ELONGATED
HODOGRAPHS, RESULTING IN 40+ KT EFFECTIVE BULK SHEAR ACROSS THE WARM
SECTOR AHEAD OF AN APPROACHING SURFACE COLD FRONT. AN UPTICK IN
THUNDERSTORM COVERAGE MAY OCCUR DURING THIS TIME, AND SOME OF THESE
STORMS MAY BECOME ORGANIZED. STILL, BUOYANCY WILL BE WEAK, WITH NO
MORE THAN A FEW HUNDRED J/KG OF THIN MLCAPE GIVEN POOR TROPOSPHERIC
LAPSE RATES. A STRONGER, SUSTAINED STORM CAPABLE OF PRODUCING A
DAMAGING GUST OR BRIEF TORNADO WOULD BE PLAUSIBLE WITH THE
ANTICIPATED VERTICAL WIND SHEAR GIVEN BETTER BUOYANCY. HOWEVER, THE
CURRENT THINKING IS THAT BUOYANCY MAY BE TOO LIMITED TO WARRANT
SEVERE PROBABILITIES AT THIS TIME.
..SQUITIERI.. 11/20/2025
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