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.
SPC AC 030559
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1259 AM CDT FRI APR 03 2015
VALID 031200Z - 041200Z
...THERE IS AN ENH RISK OF SVR TSTMS ACROSS KY...TN...MS AND NRN
AL...
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE OH VALLEY SWD INTO THE
LOWER MS VALLEY...
...THERE IS A MRGL RISK OF SVR TSTMS FROM THE OH VALLEY EWD INTO THE
DELMARVA AND SWWD INTO TX...
...SUMMARY...
SEVERE STORMS ARE EXPECTED FRIDAY FROM THE OHIO VALLEY INTO THE
TENNESSEE AND LOWER MISSISSIPPI VALLEYS. LARGE HAIL AND DAMAGING
WIND WILL BE THE MAIN THREATS...WITH ISOLATED TORNADOES POSSIBLE
MAINLY OVER KENTUCKY AND TENNESSEE. OTHER ISOLATED STRONG STORMS ARE
POSSIBLE ACROSS SOUTHERN TEXAS...AND FROM VIRGINIA INTO SOUTHERN
PENNSYLVANIA.
...SYNOPSIS...
A BROAD BUT STRONG UPPER TROUGH WILL MOVE EWD TOWARD THE MID MS
VALLEY DURING THE DAY WITH EXPANSIVE AREA OF STRONG CYCLONIC FLOW
ALOFT SPREADING EWD TO THE E COAST. AT THE SURFACE...LOW PRESSURE IS
FORECAST TO TRANSLATE NEWD FROM NRN AR/SRN MO AT 12Z FRI ACROSS THE
OH RIVER VALLEY AND INTO PA BY EVENING ALONG A SLOW-MOVING WARM
FRONT. MEANWHILE...A COLD FRONT WILL TRAIL SWWD FROM THE LOW AND
WILL BE SITUATED ROUGHLY FROM CNTRL KY INTO NWRN MS AND NRN LA BY
00Z.
SLY WINDS S OF THESE BOUNDARIES WILL MAINTAIN 60S F DEWPOINTS
BENEATH COOL PROFILES ALOFT WHICH WILL RESULT IN A LARGE AREA OF
INSTABILITY FOR SEVERE STORMS GIVEN AMPLE SHEAR IN PLACE.
...MS RIVER EWD ACROSS THE OH AND TN VALLEYS...
NUMEROUS THUNDERSTORMS ARE EXPECTED TO BE ONGOING EARLY ALONG THE
WARM FRONT FROM SRN MO EWD ACROSS KY. THIS MAY REINFORCE THE
BOUNDARY INITIALLY...BUT SOME LIFTING OF THE WARM FRONT IS EXPECTED
DUE TO A STRONG SWLY LOW-LEVEL JET AND AS THE LOW DEVELOPS NEWD.
SHEAR PROFILES AND FORCING FOR ASCENT WILL BE MAXIMIZED NEAR THE LOW
TRACK...WITH SUPERCELLS AND PERHAPS A FEW TORNADOES POSSIBLE. THE
STRENGTH OF THE WIND FIELDS FURTHER SUGGESTS DAMAGING WINDS ARE
LIKELY...AND COOL TEMPERATURES ALOFT WILL ALSO FAVOR HAIL. THE NRN
EXTENT OF THE ENHANCED THREAT AREA MAY DEPEND ON WHERE THE
FRONT/OUTFLOW COMPOSITE BOUNDARY ENDS UP IN THE WAKE OF THE EARLY
STORMS.
...LOWER MS VALLEY TO THE SABINE RIVER...
THE CAP IS EXPECTED TO BE BREACHED BY MID-AFTERNOON ALONG THE
ADVANCING COLD FRONT DUE TO STRONG HEATING AND PERSISTENT LIFT. THE
STRONGEST FORCING FOR ASCENT WILL BE TO THE N...BUT THIS MAY FAVOR
MORE OF A CELLULAR STORM MODE GIVEN LACK OF STRONG LINEAR FORCING.
VEERING WIND PROFILES WITH HEIGHT WILL STRONGLY FAVOR SUPERCELLS AND
LARGE HAIL AND DAMAGING WINDS ARE LIKELY. A BRIEF TORNADO CANNOT BE
RULED OUT BUT LOW-LEVEL SRH DOES NOT APPEAR OPTIMAL IN THIS REGARD.
...VA...MD...SRN PA AND NJ...
UPSTREAM SURFACE TRAJECTORIES ARE FORECAST TO BE ONLY MARGINALLY
MOIST DUE TO THE PRESENCE OF HIGH PRESSURE ACROSS THE SERN STATES.
HOWEVER...SHEAR PROFILES WILL STRENGTHEN THROUGH THE PERIOD...AND
WILL CONDITIONALLY FAVOR SEVERE STORMS INCLUDING SUPERCELLS. AREAS
OF PRECIPITATION ARE LIKELY TO BE ONGOING THROUGHOUT THE DAY ALONG A
NWD-MOVING WARM FRONT FROM WV EWD INTO NJ. AS INSTABILITY INCREASES
DUE TO UPSTREAM HEATING...AND THE LOW-LEVEL JET STRENGTHENS AND
BACKS...A FEW STRONG TO SEVERE STORMS MAY DEVELOP. WEAK INSTABILITY
IS THE MAIN LIMITING FACTOR...BUT SEVERE POTENTIAL WILL BE MAXIMIZED
SHOULD A SUPERCELL DEVELOP. DAMAGING WINDS AND/OR A BRIEF TORNADO
WOULD BE POSSIBLE.
..JEWELL/GLEASON.. 04/03/2015
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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