MESOSCALE DISCUSSION 0916

NWS STORM PREDICTION CENTER NORMAN OK

0337 PM CDT WED MAY 25 2022



AREAS AFFECTED...PORTIONS OF NORTH AND EASTERN ILLINOIS INTO

NORTHEAST INDIANA...EXTREME SOUTHWEST LOWER MICHIGAN...FAR NORTHWEST

OHIO



CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 



VALID 252037Z - 252230Z



PROBABILITY OF WATCH ISSUANCE...40 PERCENT



SUMMARY...THE THREAT FOR A COUPLE OF BRIEF TORNADOES EXISTS WITH THE

STRONGER STORMS THAT CAN EFFECTIVELY INTERACT WITH THE WARM FRONT.

CONDITIONS ARE BEING MONITORED FOR THE NEED OF A TORNADO WATCH

ISSUANCE PENDING FAVORABLE TRENDS IN SEVERE STORM COVERAGE.



DISCUSSION...A SURFACE WARM FRONT CONTINUES TO ADVANCE NORTHWARD

ACROSS NORTHERN IL/IN IN ADVANCE OF A 1002 MB SURFACE LOW CENTERED

OVER WESTERN MO. ALONG AND SOUTH OF THE WARM FRONT, SKIES HAVE

REMAINED PARTLY CLOUDY, ALLOWING FOR AMPLE INSOLATION TO DESTABILIZE

A DEEP, MOIST BOUNDARY LAYER. SURFACE TEMPERATURES WARMING INTO THE

LOWER 80S AMID 68-69 F DEWPOINTS SUPPORTS 1000 J/KG MLCAPE DESPITE

THE PRESENCE OF RELATIVELY POOR TROPOSPHERIC LAPSE RATES.

UPPER-LEVEL FLOW ALONG WITH DEEP-LAYER SHEAR AND ASCENT SHOULD

REMAIN MODEST ACROSS THE OH VALLEY THROUGH THE AFTERNOON SINCE THE

SURFACE LOW AND ACCOMPANYING MID-LEVEL TROUGH ARE EXPECTED TO

MEANDER WEST OF THE MS RIVER. AS SUCH, THERE ARE QUESTIONS REGARDING

HOW ROBUST AND ORGANIZED STORMS WILL BECOME ACROSS THE OH VALLEY.

CAM GUIDANCE (INCLUDING THE LAST FEW RUNS OF THE WARN-ON-FORECAST

ENSEMBLE) HAS SHOWN SOME DECREASE IN CONVECTIVE COVERAGE AND

INTENSITY THROUGH THE AFTERNOON. NONETHELESS, BACKED WINDS NEAR THE

WARM FRONT OVERSPREAD BY 30-40 KT 925-850 MB SOUTHERLY WINDS (PER

20Z MESOANALYSIS) SUPPORTS MODESTLY CURVED 0-3 KM HODOGRAPHS AND

CORRESPONDING 150-200 M2/S2 OF SRH, AS SHOWN BY LOT AND IWX VAD

PROFILERS JUST AFTER 20Z.



ANY STORMS THAT MANAGE TO ORGANIZE AND INTERACT FAVORABLY WITH THE

WARM FRONT MAY EXHIBIT TRANSIENT SUPERCELL STRUCTURES WITH LOW-LEVEL

ROTATION, AND ISOLATED TORNADOES WOULD BE POSSIBLE. HOWEVER,

CONFIDENCE IS NOT PARTICULARLY HIGH IN A MORE ROBUST TORNADO THREAT

GIVEN THE MEDIOCRE LAPSE RATES/DEEP-LAYER SHEAR. AS SUCH, CONDITIONS

WILL CONTINUE TO BE MONITORED FOR SIGNS OF LOCALLY MORE ROBUST STORM

ORGANIZATION AND THE SUBSEQUENT NEED FOR A TORNADO WATCH.