DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 140051
SWODY1
SPC AC 140049

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0749 PM CDT MON MAY 13 2013

VALID 140100Z - 141200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NRN ID AND
MT...

...NRN ROCKIES/NRN HIGH PLAINS...
WATER VAPOR IMAGERY CURRENTLY SHOWS A PROGRESSIVE SHORTWAVE TROUGH
NEAR THE WEST COAST OF WA. SCATTERED THUNDERSTORMS HAVE DEVELOPED IN
NRN ID AND WRN MT JUST AHEAD OF A BAND OF FOCUSED LARGE-SCALE ASCENT
ASSOCIATED WITH THE APPROACHING SHORTWAVE TROUGH. THIS CONVECTION IS
LOCATED JUST TO THE NORTH OF A WIND SHIFT WHERE OBJECTIVE ANALYSIS
ESTIMATES MLCAPE VALUES RANGE FROM 250 TO 750 J/KG. THE STORMS ARE
ALSO LOCATED JUST TO THE EAST OF A 80 TO 95 KT MID-LEVEL JET WHICH
IS CREATING STRONG DEEP LAYER FAVORABLE FOR SEVERE STORMS. THERE IS
SOME UNCERTAINTY CONCERNING SEVERE THREAT COVERAGE IN THE NRN
ROCKIES MAINLY DUE TO THE DRY BOUNDARY LAYER...SEE MCD 638.
UNIDIRECTIONAL WIND PROFILES WITH 50 KT OF FLOW JUST ABOVE THE SFC
COULD HELP THE FASTER MOVING LINE-SEGMENTS TO CONTAIN A WIND DAMAGE
THREAT. COLD TEMPS ALOFT AND STEEP LAPSE RATES SHOULD ALSO ENCOURAGE
HAIL PRODUCTION.

FURTHER TO THE EAST ACROSS ERN MT...WEAK INSTABILITY IS ALSO PRESENT
BUT SFC TEMPS HAVE WARMED TO NEAR 90 F. THIS IS RESULTING IN VERY
STEEP LOW-LEVEL LAPSE RATES WITH TEMP-DEWPOINT SPREADS APPROACHING
50 DEGREES F IN SOME AREAS. THIS SHOULD HELP ENHANCE DOWNDRAFT
SPEEDS RESULTING IN SOME DAMAGING WIND GUSTS WITH THE MORE INTENSE
CELLS. THE SEVERE THREAT MAY EVENTUALLY REACH WRN ND AS THE
UPPER-LEVEL TROUGH APPROACHES THE REGION FROM THE WEST LATE THIS
EVENING. HOWEVER...ANY SEVERE THREAT THAT CAN PERSIST INTO THE LATE
EVENING SHOULD BECOME MARGINAL.

..BROYLES.. 05/14/2013

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