Severe Storm Outlook Narrative (AC)
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
000
ACUS02 KWNS 030600
SWODY2
SPC AC 030559

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1259 AM CDT MON AUG 03 2015

VALID 041200Z - 051200Z

...THERE IS A MRGL RISK OF SVR TSTMS FROM PORTIONS OF THE PLAINS
THROUGH THE MIDDLE MS VALLEY...TN VALLEY AND SRN PORTION OF THE OH
VALLEY...

...THERE IS A MRGL RISK OF SVR TSTMS FROM PORTIONS OF THE MID
ATLANTIC INTO NEW ENGLAND...

...SUMMARY...
A FEW STRONG TO SEVERE STORMS WILL BE POSSIBLE FROM THE CENTRAL HIGH
PLAINS THROUGH THE MIDDLE MISSISSIPPI VALLEY AND TENNESSEE VALLEY
AREAS. OTHER STRONG STORMS MAY OCCUR FROM A PORTION OF NEW ENGLAND
INTO THE MIDDLE ATLANTIC REGION.

...SYNOPSIS...

BLOCKING PATTERN WILL PERSIST THROUGH TUESDAY WITH UPPER LOW
REMAINING IN PLACE FROM THE OH VALLEY INTO THE NERN STATES. A SERIES
OF IMPULSES WILL ROTATE THROUGH THIS FEATURE. AT LEAST A COUPLE OF
VORTICITY MAXIMA WILL UNDERCUT WRN U.S. UPPER RIDGE AND CONTINUE
THROUGH THE CNTRL AND NRN PLAINS AND MID MS VALLEY AREAS. AT THE SFC
A COLD FRONT WILL MOVE THROUGH REMAINDER OF NEW ENGLAND WITH
TRAILING PORTIONS OF THIS BOUNDARY EXTENDING SWWD THROUGH THE MID
ATLANTIC AND THEN WWD INTO THE CNTRL PLAINS.

...CNTRL/SRN PLAINS THROUGH MID MS VALLEY AND TN/OH VALLEY AREAS...

AREAS OF THUNDERSTORMS SHOULD BE ONGOING 12Z TUESDAY WITHIN ZONE OF
ASCENT NORTH OF THE QUASI-STATIONARY FRONT FROM THE MIDDLE MS VALLEY
WWD INTO THE CNTRL PLAINS. OTHER THUNDERSTORMS SHOULD BE IN PROGRESS
FROM WRN KS NWWD INTO THE CNTRL/NRN ROCKIES IN ASSOCIATION WITH
ASCENT ATTENDING A COUPLE OF SLOW MOVING SHORTWAVE TROUGHS THAT WILL
UNDERCUT UPPER RIDGE. POTENTIAL EXISTS FOR THE ATMOSPHERE TO BECOME
MODERATELY UNSTABLE WITHIN PORTIONS OF THE MOIST WARM SECTOR...BUT
AREAS OF WIDESPREAD CLOUDS AND ONGOING THUNDERSTORMS LOWER
CONFIDENCE IN WHERE THE BEST DESTABILIZATION WILL OCCUR. MOST OF
THIS REGION WILL REMAIN SW OF STRONGER WINDS ALOFT WITH VERTICAL
SHEAR SUPPORTIVE OF MULTICELLS. AN EXCEPTION WILL BE POSSIBLY OVER
WRN KS WHERE MODELS INDICATE ESELY WINDS WILL DEVELOP NORTH OF WEAK
SFC LOW AND BENEATH SLIGHTLY STRONGER WLY WINDS ALOFT WITHIN BASE OF
A LOW-AMPLITUDE SHORTWAVE TROUGH. WHERE SUFFICIENT BOUNDARY LAYER
WARMING OCCURS...STORMS SHOULD UNDERGO SOME INTENSIFICATION DURING
THE AFTERNOON AND POSE A THREAT FOR MAINLY A FEW INSTANCES OF
DAMAGING WIND. DUE TO THE POTENTIAL MITIGATING INFLUENCE OF ONGOING
STORMS ON THE THERMODYNAMIC ENVIRONMENT...WILL MAINTAIN THE MARGINAL
RISK CATEGORY THIS UPDATE.

FARTHER EAST INTO THE MIDDLE MS AND TN/OH VALLEYS ADDITIONAL STORMS
SHOULD DEVELOP IN VICINITY OF THE STALLED FRONT AS THE ATMOSPHERE
DESTABILIZES. THE STRONGEST DIABATIC WARMING AND DESTABILIZATION ARE
EXPECTED FROM PORTIONS OF TN AND SRN KY. THIS REGION WILL ALSO
RESIDE SOUTH OF THE STRONGER WINDS ALOFT...BUT THE THERMODYNAMIC
ENVIRONMENT MAY SUPPORT A FEW INSTANCES OF MAINLY DAMAGING WIND
DURING THE AFTERNOON.

...NEW ENGLAND THROUGH THE MID ATLANTIC AREA...

MODERATE INSTABILITY IS POSSIBLE AHEAD OF COLD FRONT TUESDAY OVER
PORTIONS OF NEW ENGLAND AND SWD INTO THE MID ATLANTIC. STORMS ARE
EXPECTED TO REDEVELOP AS SFC LAYER DESTABILIZES. SOME RISK WILL
EXIST FOR A FEW STRONG TO SEVERE STORMS FROM LATE MORNING THROUGH
MID AFTERNOON...ESPECIALLY GIVEN FAVORABLE WIND PROFILES IN THIS
REGION. HOWEVER...OVERALL MAGNITUDE OF THREAT WILL DEPEND ON FRONTAL
TIMING AND EXTENT OF CLOUDS AND EARLY CONVECTION WHICH REMAINS
UNCERTAIN AT THIS TIME.

..DIAL.. 08/03/2015




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.