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 051624
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1124 AM CDT Tue Sep 05 2017
Valid 051630Z - 061200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON/EVENING FROM EASTERN PA INTO NEW ENGLAND...
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST
TX TO NORTH GA...AND SURROUNDING THE SLIGHT RISK IN THE NORTHEAST...
Severe thunderstorms are possible especially this afternoon through
early evening across portions of the Northeast and Mid-Atlantic
States. Additional strong thunderstorms are possible ahead of a cold
front extending across the northern Gulf coast states.
...Eastern PA into New England this afternoon/evening...
A midlevel trough will continue to dig slowly south-southeastward
over the MS and OH Valleys, as an associated surface cold front
moves southward into the Gulf coast states and eastward across the
Appalachians. Deep-layer southwesterly flow will persist through
the period downstream of the trough, from the Appalachians into New
England, with a few embedded/subtle speed maxima enhanced by
Clouds from lingering convection are slowing surface heating from
TN/KY to PA/NY, and destabilization has been hampered east of the
Appalachians by a pocket of relatively dry air across the piedmont.
Thus, there is some uncertainty regarding the evolution of
convection along the cold front through the afternoon, and it is
possible that new development will be focused along the differential
heating zone on the east edge of the thicker clouds. Weak-moderate
buoyancy (MLCAPE of 500-1500 J/kg) and effective bulk shear in
excess of 40 kt will support a threat for damaging gusts and
marginally severe hail with the stronger storms, some of which could
have supercell structures.
...Northern Gulf coast states to the southern Appalachians...
Scattered thunderstorms are expected this afternoon/evening along
the surface cold front from northeast TX to north GA. This corridor
will remain a little south of the stronger midlevel flow, but
isolated downbursts will be possible with multicell clusters in an
environment with MLCAPE near 2000 J/kg and DCAPE near 1000 J/kg.
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z