812
ACUS11 KWNS 052010
SWOMCD
SPC MCD 052009
ORZ000-WAZ000-052215-
MESOSCALE DISCUSSION 2196
NWS STORM PREDICTION CENTER NORMAN OK
0209 PM CST WED NOV 05 2025
AREAS AFFECTED...COASTAL OREGON
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 052009Z - 052215Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...ISOLATED TO WIDELY-SCATTERED LOW-TOPPED STORMS ARE
EXPECTED TO MOVE ONSHORE OVER THE NEXT FEW HOURS. VERY STRONG SHEAR
PROFILES WILL SUPPORT SOME STORM ORGANIZATION, WITH DAMAGING GUSTS
AND A BRIEF WATERSPOUT/TORNADO POSSIBLE. CONDITIONS WILL BE
MONITORED, BUT A WW IS CURRENTLY NOT ANTICIPATED.
DISCUSSION...AS OF 2005 UTC, AFTERNOON WATER-VAPOR IMAGERY SHOWED A
STRONG SHORTWAVE TROUGH MOVING ONSHORE OVER THE PACIFIC NORTHWEST
WITHIN A BROADER PACIFIC UPPER LOW. REGIONAL VWPS CONTINUE TO SHOW
STRONG MID-LEVEL FLOW WITH AMPLE LOW-LEVEL SHEAR AS A JET STREAK
SOUTH OF THE MAIN TROUGH MOVES ONSHORE. BENEATH THE UPPER LOW, COLD
MID-LEVEL TEMPERATURES (-22 TO -24 C) AND FILTERED DIURNAL HEATING
WITHIN A MOIST MARITIME AIR MASS ARE STEEPENING LOW-LEVEL LAPSE
RATES AND SUPPORTING WEAK BUOYANCY (MUCAPE AROUND 500 J/KG). STRONG
ASCENT AND CONTINUED DESTABILIZATION SHOULD ALLOW FOR SEVERAL ROUNDS
OF THUNDERSTORMS TO MOVE ONSHORE OVER WESTERN OR THIS AFTERNOON AND
EVENING.
ALREADY, LOW-TOPPED CELLS HAVE GRADUALLY INTENSIFIED, WITH A NOTABLE
INCREASE IN LIGHTNING NEAR THE MOUTH OF THE COLUMBIA RIVER AND
FATHER OFFSHORE. AS THESE STORMS MOVE INLAND, DOWNWARD MOMENTUM
TRANSFER OF THE STRONG MID-LEVEL FLOW (50+ KT AT 4KM AGL) SHOULD
ALLOW FOR ISOLATED DAMAGING GUSTS AS DOWNDRAFTS BECOME ESTABLISHED.
ENLARGED VEERING HODOGRAPHS (ESRH 200-250 M2/S2) MAY ALSO SUPPORT
THE POTENTIAL FOR A WATERSPOUT/BRIEF TORNADO WITH ANY TRANSIENT
ROTATING STORMS. HOWEVER, THE WEAK BUOYANCY SHOULD LIMIT BROADER
ORGANIZED SEVERE POTENTIAL.
..LYONS/SMITH.. 11/05/2025
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...MFR...PQR...
LAT...LON 42912311 42572423 43172506 44332503 44652499 45502516
45972511 46282429 46302372 45762318 42912311
MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
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