768
ACUS03 KWNS 200731
SWODY3
SPC AC 200730
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0230 AM CDT TUE OCT 20 2026
VALID 221200Z - 231200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
DESERT SOUTHWEST INTO THE GREAT BASIN...
..SUMMARY
AT LEAST ISOLATED SEVERE WIND/HAIL PRODUCING STORMS ARE POSSIBLE
ACROSS PORTIONS OF THE GREAT BASIN INTO THE DESERT SOUTHWEST ON
THURSDAY.
..SYNOPSIS
A MID-LEVEL LONGWAVE TROUGH WILL OVERSPREAD THE CONUS WEST OF THE
ROCKIES ON THURSDAY, RESULTING IN THE CONTINUED NORTHWARD ADVECTION
OF A MOIST, MARGINALLY UNSTABLE LOW-LEVEL AIRMASS ACROSS THE DESERT
SOUTHWEST INTO THE GREAT BASIN. A BROAD 50-70 KT MID-LEVEL JET WILL
OVERSPREAD THESE REGIONS DURING THE DAY, RESULTING IN STRONG
VERTICAL WIND SHEAR, THAT COUPLED WITH THE MARGINAL INSTABILITY WILL
YIELD SCATTERED STRONG TO SEVERE THUNDERSTORMS.
..DESERT SOUTHWEST INTO THE GREAT BASIN
THE AFOREMENTIONED 50-70 KT SOUTHWESTERLY 500 MB JET STREAK WILL
OVERSPREAD SOUTH-SOUTHEASTERLY LOW-LEVEL FLOW, RESULTING IN
ELONGATED HODOGRAPHS AND OVER 50 KTS OF EFFECTIVE BULK SHEAR. THOUGH
WIDESPREAD CLOUDS MAY INHIBIT SURFACE HEATING TO SOME DEGREE,
CONTINUED LOW-LEVEL MOISTURE ADVECTION (E.G. 60+ F SURFACE
DEWPOINTS) BENEATH 7+ C/KM MID-LEVEL LAPSE RATES WILL YIELD UP TO
1000 J/KG MLCAPE. SUCH CONDITIONS WILL FAVOR MULTICELLS AND
SUPERCELLS CAPABLE OF PRODUCING AT LEAST ISOLATED INSTANCES OF
SEVERE HAIL AND/OR WIND AND PERHAPS A TORNADO. A MARGINAL RISK HAS
BEEN INTRODUCED TO ADDRESS THE SEVERE THREAT. HOWEVER, IF AREAS OF
LOCALLY GREATER SURFACE HEATING (I.E. BREAKS IN CLOUDS) BECOME
EVIDENT, THEN HIGHER SEVERE PROBABILITIES MAY BE NEEDED IN FUTURE
OUTLOOKS.
..SQUITIERI.. 10/20/2026
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page