DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 131617
SWODY1
SPC AC 131614

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1114 AM CDT SUN OCT 13 2013

VALID 131630Z - 141200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...

12Z UPPER-AIR DATA INDICATE THE PRESENCE OF MID AND UPPER-LEVEL JET
STREAKS ALONG THE PACIFIC COAST...IMMEDIATELY UPSTREAM FROM THE BASE
OF THE EVOLVING WRN U.S. TROUGH. AND LATEST MODEL GUIDANCE SUGGESTS
THAT THESE WIND MAXIMA WILL PROGRESS THROUGH THE TROUGH BASE DURING
THE D1 PERIOD...CONTRIBUTING TO THE EWD PROGRESSION OF THE SYNOPTIC
SYSTEM INTO THE ROCKIES BY 12Z MON. IN THE LOW LEVELS...A
QUASI-STATIONARY BOUNDARY FROM E-CNTRL INTO SWRN TX WILL SHIFT
POLEWARD THROUGH THE SRN AND CNTRL PLAINS IN RESPONSE TO LEE
CYCLOGENESIS OVER NERN CO/SERN WY. FARTHER TO THE WEST...A PACIFIC
FRONT WILL STRENGTHEN WHILE PROGRESSING EWD THROUGH THE GREAT BASIN
AND LOWER CO VALLEY INTO THE CNTRL AND SRN ROCKIES.

...CNTRL SRN HIGH PLAINS THIS AFTERNOON INTO TONIGHT...

LEE CYCLONE DEVELOPMENT WILL MAINTAIN A SLY LLJ ACROSS THE REGION
WITH THIS FEATURING DIURNALLY STRENGTHENING TONIGHT TO 50+ KT. THIS
WILL HASTEN THE NWD FLUX OF AN INCREASINGLY MOIST BOUNDARY LAYER
THROUGH THE HIGH PLAINS...ALONG AND SOUTH OF THE RETREATING WARM
FRONT. THROUGH THIS AFTERNOON...THIS MOISTURE INCREASE WILL OCCUR
BENEATH A NWD-EXPANDING CIRRUS PLUME EMANATING FROM TROPICAL CYCLONE
OCTAVE WHICH WILL TEMPER THE DEGREE OF AIR MASS DESTABILIZATION.
NONETHELESS...THE 12Z MAF SOUNDING DID SAMPLE THE PRESENCE OF
MODESTLY STEEP MIDLEVEL LAPSE RATES WHICH WERE CO-LOCATED WITH A
LOWEST 100-MB MEAN-MIXING RATIO OF AROUND 11.5 G/KG. WHEN COUPLED
WITH A VEERING WIND PROFILE WITH STEADILY STRENGTHENING FLOW THROUGH
THE DEPTH OF THE TROPOSPHERE...A LOW-PROBABILITY RISK OF SEVERE
STORMS WILL EXIST OVER ERN NM/WRN TX THIS AFTERNOON INTO EVENING.

FARTHER TO THE NORTH OVER THE CNTRL HIGH PLAINS...LOW-LEVEL MOISTURE
WILL INCREASE IN EARNEST DURING THE LATTER HALF OF THE FORECAST
PERIOD ALONG THE AXIS OF THE DEVELOPING NOCTURNAL LOW-LEVEL WIND
MAXIMUM. THIS MOISTURE RETURN WILL COINCIDE WITH INCREASING HEIGHT
FALLS/DCVA WHICH WILL BEGIN TO SPREAD EAST OF THE ROCKIES AFTER
14/06Z. THESE FACTORS WILL SUPPORT AN INCREASE IN ELEVATED TSTMS
WITHIN AN ENVIRONMENT FEATURING WEAK INSTABILITY BUT STEADILY
STRENGTHENING VERTICAL SHEAR. AS SUCH...ISOLATED OCCURRENCES OF
HAIL CANNOT BE RULED OUT.

..MEAD/MOSIER.. 10/13/2013

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