Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Del Rio, TX...Minot, ND...Bozeman, MT...Moorhead, MN...Amarillo, TX...
SPC AC 131630
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CDT FRI JUN 13 2014
VALID 131630Z - 141200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER THE NRN PLAINS INTO WRN
NEB...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SRN HIGH PLAINS INTO
SERN CO AND SWRN KS...
...SUMMARY...
WIDELY SCATTERED SEVERE THUNDERSTORMS CAPABLE OF DAMAGING
WINDS...LARGE HAIL...AND PERHAPS A TORNADO OR TWO ARE POSSIBLE THIS
AFTERNOON INTO TONIGHT ACROSS THE NORTHERN PLAINS. ANOTHER AREA OF
WIDELY SCATTERED SEVERE STORMS IS POSSIBLE THIS AFTERNOON AND
EVENING OVER THE SOUTHERN HIGH PLAINS. LARGE HAIL AND DAMAGING WIND
GUSTS WILL BE THE PRIMARY HAZARDS.
...SYNOPSIS...
THE POLAR-BRANCH OF WESTERLIES WILL REMAIN PROGRESSIVE THROUGH THE
DAY ONE PERIOD WITH THE PRIMARY FEATURE OF INTEREST BEING A
POSITIVELY TILTED MIDLEVEL TROUGH WHICH WILL AMPLIFY FROM THE NRN
HIGH PLAINS TO GREAT BASIN. THIS SYSTEM WILL BE ATTENDED BY A 50-60
KT JET STREAK AT 500 MB WHICH WILL DEVELOP NEWD THROUGH PARTS OF MT
AND WY LATER TODAY. DOWNSTREAM FROM THESE DEVELOPMENTS...A
SHORT-WAVE TROUGH FROM THE UPPER GREAT LAKES TO CNTRL GULF COAST
STATES WILL SHIFT EWD TOWARD THE ATLANTIC COAST.
AT THE SURFACE...A LEE CYCLONE OVER SERN MT WILL DEVELOP SEWD INTO
WRN SD BY EVENING BEFORE REACHING S-CNTRL SD/N-CNTRL NEB BY DAYBREAK
SATURDAY. AN ASSOCIATED LEE TROUGH/DRYLINE WILL STRENGTHEN TODAY
OVER THE CNTRL/SRN HIGH PLAINS WHILE A COLD FRONT SHIFTS EWD/SEWD
THROUGH THE NRN HIGH PLAINS. ELSEWHERE...A COLD FRONT FROM THE LOWER
GREAT LAKES TO TN AND LOWER MS VALLEYS WILL ADVANCE EWD TOWARD THE
ATLANTIC SEABOARD WHILE THE TRAILING EXTENSION OF THIS BOUNDARY
DEVELOPS NWD THROUGH THE CNTRL AND SRN PLAINS AS A WARM FRONT.
...NRN PLAINS INTO WRN NEB THIS AFTERNOON INTO TONIGHT...
THE GEOSTROPHIC RESPONSE TO THE APPROACHING MIDLEVEL TROUGH WILL
MAINTAIN A SSELY 30-40+ KT LLJ ACROSS THE NRN/CNTRL
PLAINS...ALLOWING BOUNDARY-LAYER DEWPOINTS TO RISE INTO THE MID 50S
BY LATE AFTERNOON AHEAD OF THE DRYLINE AND LEE CYCLONE FROM THE WRN
DAKOTAS INTO WRN PARTS OF NEB/KS. THIS PROCESS WILL OCCUR BENEATH A
PRONOUNCED EML /SEE 12Z RAPID CITY SOUNDING/...YIELDING AFTERNOON
MLCAPE VALUES OF 1000-2000 J/KG. FARTHER W INTO MT/WY...THE
ENVIRONMENT WILL BE DRIER...BUT THE STEEP LAPSE RATES WILL LARGELY
CONTRIBUTE TO MLCAPE APPROACHING 500-1500 J/KG.
INCREASING HEIGHT FALLS COUPLED WITH TERRAIN INFLUENCES AND
LOW-LEVEL CONVERGENCE/UPLIFT ALONG THE COLD FRONT AND LEE LOW WILL
FOSTER WIDELY SCATTERED TSTMS BY MID TO LATE AFTERNOON FROM PARTS OF
MT AND WY INTO WRN SD AND PERHAPS WRN NEB. GIVEN THE PRESENCE OF
40-60 KT OF EFFECTIVE BULK SHEAR...THE SETUP WILL SUPPORT SUPERCELLS
AS THE INITIAL STORM MODE WITH A RISK FOR LARGE HAIL AND DAMAGING
WINDS. THE GREATEST TORNADO POTENTIAL WILL EXIST ACROSS WRN SD THIS
EVENING WHERE THE ISALLOBARIC RESPONSE TO THE SURFACE LOW WILL YIELD
LARGER NEAR-GROUND SHEAR.
COALESCING STORM-SCALE OUTFLOWS COUPLED WITH INCREASING MOISTURE
FLUX/INFLOW ALONG A NOCTURNALLY STRENGTHENING LLJ WILL LIKELY
PROMOTE UPSCALE GROWTH OF STORMS INTO AN MCS ACROSS THE DAKOTAS
TONIGHT WHERE AN ISOLATED RISK FOR DAMAGING WINDS AND HAIL WILL
CONTINUE.
...SERN CO/SWRN KS SRN HIGH PLAINS THIS AFTERNOON INTO EVENING...
MORNING WATER VAPOR IMAGERY SUGGESTS THE PRESENCE OF A
SUB-TROPICAL-BRANCH SHORT-WAVE TROUGH OVER THE LOWER CO VALLEY WHICH
WILL CONTINUE EWD INTO THE FOUR-CORNERS REGION...ENHANCING MIDLEVEL
FLOW AND FORCING FOR ASCENT ACROSS THE SRN ROCKIES BY AFTERNOON.
THIS FEATURE COUPLED WITH HEATING ALONG THE HIGH TERRAIN WILL FOSTER
WIDELY SCATTERED TSTMS FROM SERN CO SWWD THROUGH NM INTO FAR WRN
TX.
THE 12Z MIDLAND TX SOUNDING AND CURRENT SURFACE CONDITIONS E OF THE
ROCKIES INDICATE THE PRESENCE OF A MOIST AIR MASS IN PLACE WITH
DEWPOINTS IN THE MID 50S TO LOWER/MID 60S. WHILE VERTICAL MIXING MAY
REDUCE MOISTURE CONTENT SOME BY AFTERNOON...THE PRESENCE OF STEEP
LAPSE RATES WILL SUPPORT AFTERNOON MLCAPE VALUES OF 1000-2500 J/KG.
WHEN COUPLED WITH VERTICALLY VEERING WIND PROFILES WITH AROUND 30 KT
OF VERTICAL SHEAR...THE ENVIRONMENT WILL FAVOR MULTICELL AND SOME
SUPERCELL STRUCTURES INITIALLY WITH LARGE HAIL AND DAMAGING WINDS
BEING THE PRIMARY HAZARDS. STORMS MAY GROW UPSCALE INTO ONE OR MORE
MESOSCALE COMPLEXES BY EVENING WITH THE WIND/HAIL THREAT SPREADING
EWD INTO WRN TX.
...FL THIS AFTERNOON...
TSTMS HAVE DEVELOPED EARLY TODAY OVER CNTRL FL WITHIN A VERY MOIST
AND MODERATELY UNSTABLE ENVIRONMENT WITH MLCAPE OF 1500-2500 J/KG. A
FURTHER INCREASE IN STORM COVERAGE AND VIGOR IS ANTICIPATED THROUGH
THE AFTERNOON ALONG EXISTING CONVECTIVE OUTFLOW BOUNDARIES AND
DEVELOPING SEA-BREEZE FRONTS WHERE LOCALLY STRONG DOWNBURST WINDS
ARE POSSIBLE.
...MID ATLANTIC THIS AFTERNOON...
TSTMS CURRENTLY DEVELOPING FROM CNTRL/ERN PA TO NRN VA SHOULD
INCREASE IN COVERAGE AND INTENSITY THIS AFTERNOON AS FORCING FOR
ASCENT/DCVA ASSOCIATED WITH THE PROGRESSIVE MIDLEVEL TROUGH
INTERACTS WITH A MOIST AND MODERATELY UNSTABLE AIR MASS. VERTICAL
SHEAR WILL INCREASE THROUGH THE PEAK OF THE DIURNAL HEATING CYCLE AS
STRENGTHENING MIDLEVEL FLOW OVERSPREADS BACKED SURFACE WINDS INVOF A
STALLED FRONT FROM S-CNTRL/SERN NY TO CNTRL NJ. LOCALLY DAMAGING
WIND GUSTS APPEARS TO BE THE PRIMARY HAZARD WITH THE MOST INTENSE
STORMS.
..MEAD/ROGERS.. 06/13/2014
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
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