Severe Storm Outlook Narrative (AC)
Issued by NWS

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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 290556
SWODY2
SPC AC 290555

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1255 AM CDT FRI MAY 29 2015

VALID 301200Z - 311200Z

...THERE IS A MRGL RISK OF SVR TSTMS FROM THE SOUTHERN HIGH PLAINS
TO THE OH VALLEY/NORTHEAST STATES...

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS PORTIONS OF MT...

...SUMMARY...
SCATTERED THUNDERSTORMS...SOME STRONG WITH GUSTY WINDS AND
HAIL...WILL DEVELOP NEAR AND AHEAD OF A COLD FRONT FROM PARTS OF THE
NORTHEAST STATES AND MIDWEST TO TEXAS ON SATURDAY.

...SYNOPSIS...
AS PART OF A STRONGER BELT OF LOW-AMPLITUDE WESTERLIES OVER THE
NORTHERN TIER OF THE CONUS INTO CANADA...AN UPPER TROUGH WILL
PROGRESS EASTWARD OVER EASTERN CANADA AND ADJACENT PARTS OF THE
NORTHEAST STATES/NEW ENGLAND ON SATURDAY. CONSIDERABLY WEAKER
WESTERLIES WILL EXIST OVER THE SOUTHERN TWO-THIRDS OF THE
CONUS...WITH A WEAK UPPER TROUGH SLOWLY OVERSPREADING THE OZARKS AND
LOWER MS RIVER VALLEY. SHOWERS/THUNDERSTORMS INCLUDING AT LEAST SOME
RISK FOR SEVERE THUNDERSTORMS WILL EXIST ALONG/AHEAD OF A
SOUTHEASTWARD-MOVING COLD FRONT THAT SHOULD EXTEND FROM SOUTHERN
PORTIONS OF ONTARIO/QUEBEC SOUTHWESTWARD TOWARD THE LOWER OH VALLEY
TO EAST/SOUTH-CENTRAL TX BY SATURDAY AFTERNOON.

...NORTHEAST STATES/NEW ENGLAND TO MIDWEST/OH VALLEY...
OWING TO THE PREVIOUSLY DESCRIBED LARGE-SCALE SCENARIO...THE
RELATIVELY STRONGEST FORCING FOR ASCENT IS EXPECTED TO OVERSPREAD
PARTS OF THE NORTHEAST STATES/NORTHERN NEW ENGLAND ON SATURDAY. THE
EXACT DEGREE/LOCATIONS OF PEAK DESTABILIZATION AHEAD OF THE COLD
FRONT ARE A BIT QUESTIONABLE GIVEN WEAK MID-LEVEL LAPSE RATES AND
THE POSSIBILITY OF SOME SHOWERS/CLOUD COVER ACROSS PARTS OF THE
MIDWEST SATURDAY MORNING. HOWEVER...CORRIDORS OF STRONGER HEATING
AND RELATED MODEST BUOYANCY SHOULD ALLOW FOR THE
DEVELOPMENT/INTENSIFICATION OF MOSTLY MULTICELLS/LINE SEGMENTS
DURING THE AFTERNOON HOURS AHEAD OF THE FRONT. ISOLATED DAMAGING
WINDS WILL LIKELY BE THE PRIMARY HAZARD...WITH SOME MARGINALLY
SEVERE HAIL POSSIBLE AS WELL.

...TX/NM...
LARGER-SCALE INFLUENCES/VERTICAL SHEAR WILL BE WEAK OVER THE REGION
ON SATURDAY...BUT SOME STRONG TO SEVERE PULSE-TYPE THUNDERSTORMS
CAPABLE OF HAIL/WIND MAY BE POSSIBLE WITHIN A MOIST/MODERATELY
ENVIRONMENT NEAR THE SOUTHEASTWARD-MOVING FRONT ACROSS PARTS OF
EAST/SOUTH-CENTRAL TX SATURDAY AFTERNOON/EARLY EVENING. A FEW OTHER
SEVERE THUNDERSTORMS COULD OCCUR ACROSS FAR SOUTHWEST TX AND/OR
CENTRAL/NORTHEAST NM COINCIDENT WITH INCREASING POST-FRONTAL
MOISTURE AND WEAK UPSLOPE...ALTHOUGH VERTICAL SHEAR WILL TEND TO BE
WEAK /PERHAPS 30 KT/ IN GENERAL PROXIMITY TO THE UPPER RIDGE.

...MT...
A LOW-AMPLITUDE SHORTWAVE TROUGH IS EXPECTED TO MOVE EASTWARD NEAR
THE CREST OF THE CENTRAL/SOUTHERN ROCKIES UPPER RIDGE. THUNDERSTORMS
SHOULD INITIALLY DEVELOP OVER THE MOUNTAINS/HIGHER TERRAIN OF
WEST-CENTRAL MT SATURDAY AFTERNOON...AND SUBSEQUENTLY DEVELOP
EASTWARD INTO ADDITIONAL PORTIONS OF CENTRAL/EASTERN MT THROUGH THE
LATE AFTERNOON AND EVENING HOURS. ADEQUATE MOISTURE/MARGINAL
BUOYANCY MAY ALLOW FOR SOME STRONGER/POSSIBLY SEVERE THUNDERSTORMS
CAPABLE OF STRONGER WINDS AND/OR ISOLATED HAIL SATURDAY
AFTERNOON/EVENING.

..GUYER.. 05/29/2015



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