Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS01 KWNS 230112
SWODY1
SPC AC 230111

DAY 1 CONVECTIVE OUTLOOK RESENT 1
NWS STORM PREDICTION CENTER NORMAN OK
0811 PM CDT FRI MAY 22 2015

VALID 230100Z - 231200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS EASTERN NM AND SOUTHWEST
AND WEST TX THROUGH TONIGHT...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS A PART OF EAST-CENTRAL
AND NORTHEAST CO THIS EVENING...

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS THE SOUTHERN HIGH PLAINS
THROUGH TONIGHT...

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS EAST AND NORTHEAST CO
THIS EVENING...

...SUMMARY...
ISOLATED SEVERE STORMS ARE POSSIBLE THIS EVENING ACROSS SOUTHWEST
TEXAS...AND A SMALL PART OF NORTHEAST COLORADO.  THUNDERSTORM
COVERAGE INCLUDING SOME SEVERE THREAT WILL INCREASE THROUGH TONIGHT
ACROSS EASTERN NEW MEXICO AND WEST TEXAS.

...SOUTHERN HIGH PLAINS...
A PROGRESSIVE CLOSED LOW/UPPER TROUGH WILL MOVE EWD FROM THE LOWER
CO RIVER VALLEY...REACHING THE FOUR CORNERS TO NWRN MEXICO BY 12Z
SATURDAY.  DEEP-LAYER WIND FIELDS /SELY TO SLY LLJ AND SWLY 500-MB
FLOW/ WILL STRENGTHEN THROUGH TONIGHT AS FORCING FOR ASCENT/HEIGHT
FALLS BEGIN TO SPREAD ACROSS THE SRN HIGH PLAINS WITH THE APPROACH
OF THE UPSTREAM TROUGH.  THE INCREASE IN LOW-LEVEL WINDS WILL
MAINTAIN POLEWARD MOISTURE RETURN...SUCH THAT FORECAST SOUNDINGS
INDICATE SURFACE-BASED INHIBITION WILL TEND TO WEAKEN AND
INSTABILITY WILL INCREASE FROM SOUTH-NORTH OVERNIGHT.  THESE FACTORS
COMBINED WITH A PLUME OF STEEPENING MIDLEVEL LAPSE RATES SPREADING
EWD SUPPORTING MODERATE INSTABILITY AND STRENGTHENING DEEP-LAYER AND
LOW-LEVEL SHEAR WILL FAVOR ORGANIZED STORMS INCLUDING SUPERCELLS
WITH ALL SEVERE HAZARDS POSSIBLE.

THERE WILL BE TWO MAIN LOCATIONS FOR STRONG TO SEVERE STORMS:
1/ IN ADDITION TO UPSLOPE FLOW INTO THE HIGHER TERRAIN OF FAR WEST
TX...INCREASED CONVERGENCE ALONG A PORTION OF THE DRY LINE EXTENDING
FROM 15 NE MRF TO APPROXIMATELY 25 W MAF AS THE SELY LLJ STRENGTHENS
SUGGEST NEW STORM DEVELOPMENT WILL BE POSSIBLE THIS EVENING.

2/ AS GREATER DEEP-LAYER ASCENT SPREADS ENEWD INTO THE SRN HIGH
PLAINS LATER THIS EVENING THROUGH LATE TONIGHT...A SEPARATE ZONE FOR
CONVECTIVE INITIATION /PER SEVERAL MODELS/ APPEARS TO BE ACROSS
EAST-CENTRAL AND NERN NM ALONG THE LEE TROUGH...WITH ACTIVITY MOVING
INTO WEST TX LATER TONIGHT.

...EAST-CENTRAL AND NORTHEAST CO...
FURTHER STRENGTHENING OF LOW-LEVEL E/SELY WINDS IS EXPECTED THIS
EVENING IN E AND NE CO...TO THE NORTH OF A DEEPENING AREA OF LOW
PRESSURE ACROSS SERN CO.  THIS LOW-LEVEL FLOW SHOULD SUSTAIN SURFACE
DEW POINTS IN THE UPPER 40S TO AROUND 50 F...BENEATH STEEPENING
MIDLEVEL LAPSE RATES FOR MARGINAL INSTABILITY.  EFFECTIVE BULK SHEAR
OF 30-40 KT WILL SUPPORT ADDITIONAL ORGANIZED STORMS INCLUDING A
SUPERCELL...WITH THE INCREASE IN LOW-LEVEL SHEAR SUGGESTING THE
TORNADO THREAT CANNOT BE RULED OUT.  THE SEVERE WEATHER THREAT
SHOULD DIMINISH LATER THIS EVENING AS THE INSTABILITY EVENTUALLY
WEAKENS.

..PETERS.. 05/23/2015



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