757
ACUS03 KWNS 091931
SWODY3
SPC AC 091930
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0230 PM CDT FRI OCT 09 2026
VALID 111200Z - 121200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY ACROSS
THE MID ATLANTIC AND PORTIONS OF THE LOWER COLORADO VALLEY INTO
EASTERN GREAT BASIN...
..SUMMARY
STRONG THUNDERSTORMS ON SUNDAY MAY IMPACT PARTS OF THE MID ATLANTIC,
AND THE LOWER COLORADO VALLEY INTO EASTERN GREAT BASIN, ACCOMPANIED
BY AT LEAST SOME RISK FOR DAMAGING WIND GUSTS AND A COUPLE OF
TORNADOES.
..DISCUSSION
MODELS INDICATE FURTHER CONSOLIDATION OF TROUGHING WITHIN INITIALLY
SEPARATE BRANCHES OF THE WESTERLIES, WITH SLOW PROGRESSION INLAND OF
THE PACIFIC COAST SUNDAY THROUGH SUNDAY NIGHT. WITHIN SOUTHERLY
FLOW AHEAD OF THE EVOLVING LARGE-SCALE TROUGH AXIS, REMNANTS OF
TROPICAL STORM RACHEL ARE FORECAST TO RAPIDLY ADVECT FROM THE
SOUTHEASTERN CALIFORNIA SONORAN DESERT TOWARD THE WESTERN SLOPES OF
THE WASATCH THROUGH THE DAY SUNDAY. AS DOWNSTREAM MID/UPPER RIDGING
BUILDS THROUGH THE SOUTHEASTERN GREAT PLAINS AND MIDDLE/LOWER
MISSISSIPPI VALLEY, IT APPEARS THAT AN UPPER TROUGH AND REMNANT
MID-LEVEL CYCLONIC CIRCULATION WILL BE FORCED EAST-NORTHEASTWARD
ACROSS THE APPALACHIANS THROUGH MID ATLANTIC. ASSOCIATED FORCING
FOR ASCENT MAY SUPPORT MODEST SECONDARY SURFACE CYCLOGENESIS TO THE
LEE OF THE BLUE RIDGE, SOUTHEAST OF THE WEAKENING REMNANTS OF ISAIAS
ACROSS THE CUMBERLAND/ALLEGHENY PLATEAU VICINITY, AND IN THE WAKE OF
WEAKENING SURFACE RIDGING SHIFTING OFFSHORE OF THE ATLANTIC
SEABOARD.
SPREAD AMONG THE MODELS REMAINS SUBSTANTIVE CONCERNING THE SHORTER
WAVELENGTH PERTURBATIONS, BUT A COUPLE AREAS WITH AT LEAST SOME
POTENTIAL FOR SEVERE THUNDERSTORM DEVELOPMENT ARE EVIDENT.
..MID ATLANTIC
GIVEN THE SEASONABLY HIGH BOUNDARY-LAYER MOISTURE CONTENT ADVECTING
NORTHWARD TOWARD THE MID ATLANTIC IN ADVANCE OF THE DEVELOPING
SURFACE LOW, THERE APPEARS POTENTIAL FOR BOUNDARY-LAYER
DESTABILIZATION COINCIDENT WITH STRENGTHENING LOW-LEVEL AND
DEEP-LAYER SHEAR. MODELS SUGGEST THAT A DEVELOPING MID-LEVEL DRY
SLOT COULD PROVIDE A FOCUS FOR THE MOST SUBSTANTIVE BOUNDARY-LAYER
DESTABILIZATION BY LATE SUNDAY AFTERNOON ACROSS PARTS OF EASTERN
VIRGINIA INTO EASTERN NORTH CAROLINA, WHERE INSOLATION PRIOR TO THE
ONSET OF MID-LEVEL ASCENT/COOLING MAY SUPPORT A PERIOD OF VIGOROUS
THUNDERSTORM DEVELOPMENT. IT APPEARS THAT THIS COULD INCLUDE
SUPERCELL STRUCTURES WITHIN AN EVOLVING BROKEN LINE OF STORMS, WHICH
MAY POSE A RISK FOR A COUPLE OF TORNADOES AND/OR LOCALLY DAMAGING
WIND GUSTS.
..LOWER COLORADO VALLEY INTO EASTERN GREAT BASIN
BOUNDARY-LAYER DESTABILIZATION AND CONVECTIVE POTENTIAL IS MORE
UNCLEAR ALONG THE FORECAST TRACK OF RACHEL FOR SUNDAY. HOWEVER,
GIVEN THE DEVELOPMENT OF SUFFICIENT INSTABILITY, THE REMNANT STRONG
SOUTH-SOUTHWESTERLY WIND FIELDS COULD PROVIDE SUPPORT FOR ORGANIZED
CONVECTION, INCLUDING SUPERCELL STRUCTURES, POSING AT LEAST A RISK
FOR DAMAGING WIND GUSTS.
..KERR.. 10/09/2026
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