Saturday/Late Evening

Thanks Erik for the new stoplight system! I still have to get those loaded on my desktop, so until I do, Erik will be the only one to post the stoplight forecast.

Showers and thunderstorms currently in Central Illinois will impact our far southwestern counties after midnight, with the potential for a rumble of thunder or two. All of us will see some light showers overnight.

Tomorrow a SLIGHT RISK of severe weather has been highlighted from the Ohio River and on south. (LATEST SPC MAPS and DISCUSSION BELOW) I am not expecting a widespread severe weather event. However, isolated severe weather is fairly likely. Damaging winds, and marginally severe hail will be the best threats.

SEVERE WEATHER OUTLOOK-Sunday


SEVERE WEATHER PROBABILITY-Sunday


SPC SAYS: ...UPPER OH AND TN VALLEYS THROUGH PORTION OF THE SERN STATES... 27/12Z UPPER AIR DATA AND MID MORNING SURFACE ANALYSES INDICATED A RICH BOUNDARY LAYER EXTENDED FROM THE LOWER MS VALLEY THROUGH THE TN VALLEY WITH SURFACE DEWPOINTS IN THE LOWER 70S. THE ERN EXTENT OF THIS MOISTURE AXIS WILL ADVECT NEWD INTO THE UPPER OH VALLEY ON DAY 2. DESPITE MODEST MID LEVEL LAPSE RATES /6-6.5 C/KM/ ACROSS THE SLIGHT RISK AREA ON SUNDAY...SURFACE HEATING WITHIN THE VERY MOIST PRE-FRONTAL WARM SECTOR WILL RESULT IN MODERATE INSTABILITY. SOME STORMS MAY BE IN PROGRESS AHEAD OF THE FRONT EARLY SUNDAY ACROSS A PORTION OF THE OH VALLEY. ACTIVITY WILL MOST LIKELY BE SLIGHTLY ELEVATED ABOVE A STABLE SURFACE LAYER WITH LOW SEVERE POTENTIAL. STORMS WILL LIKELY REDEVELOP ALONG FRONT OR PRE-FRONTAL OUTFLOW BOUNDARIES AND SUBSEQUENTLY ADVANCE EWD AND SEWD AS THE ATMOSPHERE DESTABILIZES. THE MID LEVEL JET ROTATING THROUGH BASE OF THE UPPER TROUGH WILL RESULT IN 30-40 KT WLY UNIDIRECTIONAL BULK SHEAR...GENERALLY FROM OH VALLEY SWD TO THE KY/TN BORDER. STORMS SHOULD ORGANIZE INTO LINE SEGMENTS OR CLUSTERS AS THEY DEVELOP SEWD WITH A THREAT OF ISOLATED DAMAGING WIND AND HAIL THROUGH MID EVENING. ALTHOUGH DEEP LAYER SHEAR WILL BE WEAKER ACROSS THE TN VALLEY...STRONGER INSTABILITY SHOULD COMPENSATE AND SUPPORT A SEVERE WEATHER THREAT AS THE FRONT MOVES INTO THIS REGION.

FORECAST PREPARED BY: WEATHER FORECASTER PATRICK SUMNER