SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 AM CDT Thu Aug 03 2023 Valid 041200Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE NORTHEAST... ...SUMMARY... Severe thunderstorms producing hail and damaging gusts are possible across parts of the Northeast on Friday afternoon. Additional strong storms are possible along a broad arc from the central Plains to the Southeast. ...Northeast... An upper trough will be oriented over the Northeast and mid-Atlantic on Friday. Around 30-40 kt of mid/upper flow will overlap a seasonally moist/unstable airmass ahead of a southeastward-advancing surface cold front. While temperatures will be relatively cool (70s to near 80 F), modest midlevel lapse rates and 60s F boundary-layer dewpoints will support MLCAPE to around 1500 J/kg. Effective shear magnitudes around 25-35 kt will foster organized cells capable of producing hail to around 1.5 inch diameter, along with widely scattered damaging gusts. Convection should weaken by evening as storms approach the coast. ...AR to Southern GA/Northern FL... Convection will be ongoing during the morning in an arc roughly from MO to TN into GA/SC. Outflow and a zone of differential heating related to this early day activity will be focus for thunderstorm development/intensification during the afternoon, and a Marginal risk (Level 1 of 5) has been included. Moderate northwesterly flow aloft will persist over the region, similar to the past few days, atop a very moist and strongly unstable airmass. Thunderstorm clusters posing a risk for damaging gusts are possible. Some forecast guidance suggests a forward-propagating MCS may develop somewhere from MS/AL into southern GA/northern FL. However, this will largely depend on how convection from the Day 1/Thu into early Day 2/Fri evolves. Confidence in the corridor of greater severe potential is too low at this time to include a Slight (Level 2 of 5) risk, but upgrades may be needed in subsequent outlooks. ...Central Plains... Another day of moist, upslope low-level flow within moderately unstable environment will support thunderstorm development near the central High Plains by late afternoon. A cold front is also forecast to develop southward across NE into KS during the evening/nighttime hours, while a southwesterly low-level jet strengthens across the southern Plains into KS. Thunderstorm clusters, initially posing a risk for hail and strong gusts, are expected to develop into and east/southeast progressing MCS. It is unclear at this time how severe this developing MCS may be. Quite a bit of MLCINH is noted in forecast guidance across KS toward the MO Valley near the 850-700 mb thermal ridge, and potentially associated with areas of morning convection. This precludes higher than Marginal (Level 1 of 5) risk probabilities at this time, though upgrades may be needed in subsequent outlooks. ..Leitman.. 08/03/2023
