SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK
0250 PM CDT Fri May 10 2019 Valid 102000Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
THE MID-ATLANTIC TO EASTERN NEW YORK... ...SUMMARY...
Tree damage from locally strong wind gusts will be possible late
this afternoon from parts of eastern New York to northern Virginia. ...DISCUSSION...
A couple changes have been made to the outlook for this issuance.
The first change is to add a 5 percent hail probability across the
northern part of the marginal risk area where a few warnings are
ongoing. Associated with this change, the northwestern edge of the
marginal has been trimmed in central New York. Finally, the thunder
line has been trimmed across parts of western New York and western
Pennsylvania behind a southeastward moving cold front. ..Broyles.. 05/10/2019 .PREV DISCUSSION... /ISSUED 1120 AM CDT Fri May 10 2019/ ...NY to VA...
Minimal change to previous forecast. A low-amplitude shortwave trough across Lake Ontario will eject
across the St. Lawrence Valley through this evening. A well-defined
cold front over western NY to the Upper OH Valley will reach the
Hudson Valley to central Appalachians by early evening. Pockets of
greater insolation are underway ahead of the front in
western/central NY south through central PA into VA. Owing to the
presence of lower 60s surface dew points, meager MLCAPE up to around
500 J/kg should develop. Scattered showers have already formed along
the front and lee trough, likely deepening through the afternoon as
destabilization continues. Vertical shear will decrease
substantially from north-to-south with the best chance for transient
mid-level updraft rotation existing with a couple cells across the
NY portion of the risk area. Poor mid-level lapse rates and the
scant buoyancy will mitigate the overall severe threat. ...LA and Southeast TX...
Removed MRGL risk area. Latest CAM guidance appears woefully inadequate with the near-term
simulations of both ongoing MCSs and attendant MCVs. Convective
outflow associated with the decaying lead MCS across southeast
LA/southern MS has pushed well into the northwest Gulf. Upstream MCS
off the TX Gulf Coast will probably evolve along the prior outflow
in a more eastward manner versus the northeast evolution
consistently progged by CAMs. An eastward progression across the
northwest Gulf would render negligible severe potential inland.