And right as it's about to happen, NWS changes their damn tune again:
http://forecast.weather.gov/product...&format=CI&version=1&glossary=1&highlight=off
.NEAR TERM /THROUGH TONIGHT/... ...WINTER STORM UPDATE... VERY COMPLEX FORECAST WITH EVOLVING MODEL DEPICTION OF CRITICAL WARM LAYER ALOFT IMPACTING TONIGHT/S WINTER STORM. BASED ON TRENDS SEEN OVERNIGHT FROM 04.06Z TO 04.12Z...INCLUDING NEW 04.12Z RAP/
NAM AND NEW 04.09Z SREF MEMBERS...HAVE MADE SIGNIFICANT CHANGES TO FORECAST IN PREVIOUS TRANSITION ZONE FROM HEAVY SNOW/ICE AREA ALONG I-71.
HAVE DECIDED TO CHANGE HEADLINES TO FOCUS ON WHAT IS
LIKELY TO BE IMPACTFUL ICE ACCUMULATION EVENT FOR AREAS OF NORTHERN KENTUCKY INTO SW/SC OHIO. HAVE CHANGED PREVIOUS WINTER STORM
WARNING TO ICE STORM
WARNING FROM DEARBORN/RIPLEY COUNTIES EASTWARD THROUGH HAMILTON AND THEN NORTHEAST FROM THERE TO HOCKING COUNTY.
AS MENTIONED ABOVE...TRENDS FROM DEARBORN/RIPLEY THROUGH HAMILTON AND NORTHEAST INTO HOCKING COUNTY HAVE BEEN FOR A WARMER ELEVATED WARM LAYER...ADVECTING IN NOSE OF VERY IMPRESSIVE
LOW LEVEL JET. 04.12Z
SOUNDING AT BNA /NASHVILLE/ ALREADY +7C AT H85 AND SEE NO REASON WHY THIS WON/T BE ADVECTED BODILY NORTHWARD TO COINCIDE WITH ARRIVAL OF HEAVY PRECIPITATION RATES.
THIS IS A QUICK BUT INTENSE STORM...AND RATES WILL BE HEAVY. INITIALLY THE WET BULB PROCESSES /SEE VERY DRY LAYER ON 04.12Z KILN
SOUNDING/ WILL ALLOW FOR A
BURST OF SNOW FOR MOST ON THE LEADING EDGE OF THE HEAVY PRECIPITATION...BUT ELEVATED WARM LAYER BULLIES IN...WITH CRITICAL 0C TO +1C LAYER /PARTIAL MELTING YIELDING SLEET/ TO LIFT QUICKLY NORTHWARD FROM NORTHERN KENTUCKY INTO SOUTHERN OHIO. THIS WILL BE FOLLOWED QUICKLY BY A DEEPER/WARMER LAYER...WITH +2C TO +3C ALLOWING FOR MORE COMPLETE
HYDROMETEOR MELTING IN A ZONE FROM VERSAILLES INDIANA INTO THE CINCINNATI
METRO TO HILLSBORO AND CHILLICOTHE. THIS ZONE WILL
LIKELY SEE PLENTY OF SLEET AND FREEZING RAIN...BUT THE IMPACTS APPEAR TO BE MORE CONCERNING FOR
GLAZE ICE ACCUMULATION THAN THEY WILL FOR SNOW ACCUMULATION. AM QUITE CONCERNED FOR A BAND OF UP TO 0.40 OR 0.50"
GLAZE ICE IN THIS CORRIDOR...WHICH MAY CAUSE TREE DAMAGE AND
SCATTERED POWER OUTAGES. IF THERE IS A GOOD NEWS...THE RATE OF PRECIPITATION WILL ACTUALLY HELP...AS ICE ACCUMULATION EFFICIENCY DECREASES AS RATES GO UP...SO SHOULD HELP KEEP MORE SIGNIFICANT
ICING AT BAY. NOT TO MAKE THINGS MORE UNCERTAIN...BUT
SFC-WET BULB TEMPS WILL CREEP CLOSE TO 32F OR 33F OVER NORTHERN KENTUCKY...AND A CHANGE TO PLAIN RAIN IS NOT AT
IT CAN/T BE STRESSED ENOUGH THAT IN DYNAMIC/EVOLVING WEATHER SYSTEMS WITH NARROW/TRANSITION CORRIDORS AND ELEVATED WARM LAYERS...THIS REPRESENTS THE BEST ESTIMATE OF IMPACT/SENSIBLE
WX OFF THE LATEST TRENDS/DATA. STILL FEELING QUITE CONFIDENT IN A HEAVY SNOW EVENT NORTH OF I-70 IN EAST-CENTRAL INDIANA...UP INTO THE MARYSVILLE/DELAWARE AREAS AND TO THE NORTH WHERE 6-9" IS
LIKELY.
HOWEVER...SLEET WILL LIKELY PUSH ALL THE WAY TO DAYTON METRO AND FOR SURE INTO CMH METRO...AND MAY EVEN DOMINATE THE EVENT IN CENTRAL OHIO FROM COLUMBUS/LICKING COUNTY DOWN INTO WASHINGTON COURT HOUSE AND LANCASTER. THUS...THE FORECAST IN THESE CORRIDORS HAS SHIFTED AWAY FROM HEAVIER SNOW...AND MORE TO A BIG WINTERY MIX WITH ACCUMULATIONS FROM ALL FORMS...FROM A LITTLE
GLAZE ICE...TO SEVERAL INCHES OF SLEET/SNOW. BUT STILL OF MOST CONCERN...LIES FROM NORTHERN KENTUCKY THROUGH CINCINNATI INTO AREAS OF SOUTH CENTRAL OHIO...WHERE PROBABILITIES OF IMPACTING ICE ACCUMULATION NOW WARRANT AN
ICE STORM WARNING. THE PROSPECTS OF PRECIPITATION BEING HEAVY IN NATURE...WITH RAPID ONSET /AND TAPER DUE TO
DRY SLOT/ SEEM
LIKELY...AND MUCH OF HEAVY RATES WILL BE DONE BY MORNING COMMUTE...BUT IMPACT WILL LINGER WELL INTO THE MORNING.
