Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS02 KWNS 311726
SWODY2
SPC AC 311725

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1225 PM CDT FRI OCT 31 2014

VALID 011200Z - 021200Z

...NO SVR TSTM AREAS FORECAST...

...SUMMARY...
ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS PARTS OF THE GREAT
BASIN AND ROCKY MOUNTAIN STATES...AS WELL AS PARTS NORTHEAST SOUTH
CAROLINA...CENTRAL AND EASTERN NORTH CAROLINA AND THE MID-ATLANTIC
COAST.

...SYNOPSIS...
A HIGHLY AMPLIFIED MID- AND UPPER-LEVEL FLOW PATTERN WILL PREVAIL
THROUGH DAY 2 ACROSS THE LOWER 48 STATES...AS A DEEP TROUGH OVER THE
EASTERN STATES MOVES TO THE ATLANTIC SEABOARD BY 12Z SUNDAY...WHILE
A CENTRAL U.S. RIDGE SHIFTS SLOWLY EWD.  IN THE WEST..A SPLIT-FLOW
REGIME IS EXPECTED TO DEVELOP ACROSS WESTERN NORTH AMERICA WITH THE
PACIFIC TROUGH...IN THE SOUTHERN BRANCH...ADVANCING SLOWLY EASTWARD
ACROSS THE INTERIOR WEST.

...NORTHEAST SC/CENTRAL AND ERN NC TO COASTAL MID-ATLANTIC...
A RATHER SUBSTANTIAL INCREASE IN UPWARD VERTICAL MOTION IS EXPECTED
FROM 12Z SATURDAY INTO THE AFTERNOON ACROSS NERN SC AND CENTRAL/ERN
PORTIONS OF NC AS A DEEPENING...CLOSED LOW AND ATTENDANT STRONG
SHORTWAVE TROUGH MOVE THROUGH THE BASE OF THE PARENT ERN U.S.
LONGWAVE TROUGH.  THIS COMBINED WITH LOW-LEVEL MOISTENING/
DESTABILIZATION AND FRONTOGENESIS WHILE A SURFACE LOW DEVELOPS EWD
FROM NERN SC SUGGESTS THE LIKELIHOOD FOR CONVECTION SATURDAY MORNING
AND AFTERNOON.  COLD MIDLEVEL TEMPERATURES /-24 TO -26 C AT 500 MB/
WILL RESULT IN STEEP LAPSE RATES FOR BUOYANCY /THOUGH WEAK/ TO
BECOME SUFFICIENT FOR LOW-TOPPED TSTMS.  WEAK INSTABILITY /MUCAPE
AOB 100 J/KG/ WILL LIMIT THE SEVERE WEATHER THREAT...THOUGH SMALL
HAIL MAY OCCUR WITH THE STRONGER UPDRAFTS.

...GREAT BASIN TO ROCKIES...
STEEPENING LAPSE RATES ASSOCIATED WITH THE WRN U.S. TROUGH WILL
SUPPORT AFTERNOON DEVELOPMENT OF SHOWERS AND EMBEDDED/ISOLATED TSTMS
ACROSS PORTIONS OF THE INTERIOR WEST AND ROCKIES.  THE GREATEST
CONVECTIVE COVERAGE SHOULD OCCUR AS FORCING FOR ASCENT ATTENDANT TO
A STRONG LEAD SHORTWAVE TROUGH AND ATTENDANT COLD FRONT ADVANCE FROM
NV THROUGH UT TO THE NRN ROCKIES.  THE RISK FOR SEVERE WEATHER
REMAINS MINIMAL DUE TO THE LACK OF APPRECIABLE CAPE.

..PETERS.. 10/31/2014




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