From Facebook: Hmm........

Hmm…….. winter storm a comin'.. we'll see!

TUESDAY AFTERNOON. A LEAD SPIRAL OF 500MB CYCLONIC VORTICITY IS
SHOWN TO LIFT INTO PORTIONS OF FAR SOUTHEASTERN MICHIGAN PRIOR TO
18Z TUESDAY. THIS IS A GOOD INDICATOR THAT OPAQUE MID CLOUD WILL BE
BLANKETING A GOOD PORTION OF THE CWA BY THE AFTERNOON. IMPORTANT AS
IT SHOULD LIMIT THE DIURNAL TEMPERATURE HEATING RESPONSE UNDER THE
CANOPY AS MAXT OCCUR AHEAD OF THE MIDCLOUDS. THIS IS NON-TRIVIAL
WITH SURFACE TEMPERATURES TODAY PUSHING 40 DEGREES. THE MAIN BAND OF
PRECIPITATION IS EXPECTED TO LIFT ACROSS THE OH/MI STATELINE
AT/AROUND 21Z TUESDAY. THIS PRECIPITATION WILL BE FORCED ON THE
MIDLEVEL OCCLUDED FRONT LIFTING NORTHWARD AWAY FROM THE
MAIN/CONSOLIDATED PV ANOMALY OVER PORTIONS OF SOUTHERN IN/KY (00Z
WEDNESDAY). VIRTUALLY ALL MODEL SOUNDINGS SUPPORT MEANINGFUL
PRECIPITATION AS SNOW FROM THE START. ANY WARM LAYER CENTERED OFF
THE DECK BETWEEN 900-800MB SHOULD RAPIDLY WET BULB DOWN TO THE
FREEZING MARK. VARIOUS ALGORITHM TYPE PARAMETERS…INCLUDING MOS AND
SOME OTHERS ARE REALLY STRUGGLING WITH PTYPE DUE TO WARM SFC
TEMPS…33-35 DEGREES F. THESE TOOLS SEEM TO BE KEYING OFF SOME
INNOCUOUS WARM LAYERS ALL OF WHICH WILL BE COOLER THAN 3C. LOOKING
THROUGH THE MODELS IT IS REALLY DIFFICULT TO GET A HANDLE WHERE THE
MID 30 DEGREES SURFACE TEMPS ARE COMING FROM AFTER THE START OF
PRECIPITATION. DEWPOINTS THIS AFTERNOON FROM WV/PA THROUGH OHIO AND
ONTARIO ARE ALL IN THE TEENS TO 20S…A POSITIVE FOR THE ALL SNOW
PTYPE. THE BAND WILL LIFT NORTHWARD…DETROIT SOUTHWARD AFTER 2PM
EST…NORTHERN BURBS…AFTER 4PM EST…FLINT AND THE TRI CITIES
AFTER 6PM.

THE MAIN POTENTIAL VORTICITY ANOMALY RESPONSIBLE FOR THIS SYSTEM
WILL HAVE CLOSED OFF INTO A BOWLING BALL OVER ARKANSAS BY 12
TUESDAY. OUTSIDE OF A LOBE/OR PV FILAMENT ROTATING AROUND THE
NORTHEAST PERIMETER OF THE ANOMALY BETWEEN 12-15Z…THE SYSTEM
WILL BE IN A FILLING MODE. THE AFOREMENTIONED OCCLUSION EMANATING
NORTHEASTWARD WILL BRING GOOD PRECIPITATION RATES IN DURING THE
LATE AFTERNOON. GIVEN THE SYSTEM IN A MATURE STATE…MOISTURE
DEPTH ALONG THIS MAIN BAND WILL BE OUTSTANDING…UPWARDS OF 30 KFT
AGL…WITH LOW STATIC STABILITY ABOVE 700MB. SYSTEM RELATIVE
ISENTROPIC ASCENT WILL BE CENTERED AT ROUGHLY THE 285K SURFACE
DURING THE AFTERNOON BEFORE LOWERING DOWN TO AROUND 300K DURING
THE EVENING. SPECIFIC HUMIDITIES MOISTURE WILL BE APPROXIMATELY 4
G/KG SHOWN THROUGHOUT THE COLUMN. PROGGED UVVS ARE SHOWN TO BE
HIGH AND WITH EVERYTHING CONSIDERED…1 INCH PER HOUR TYPE SNOW
RATES ARE EXPECTED AT THE ONSET. THE REAL QUESTION AND
UNCERTAINTY WILL BE WHAT SORT OF SNOW ACCUMULATING EFFICIENCY
WILL BE EXPERIENCED WITH THE SNOWFALL RATES DURING THE LATE
AFTERNOON/EVENING. OVERALL DURATION FOR ANY ONE AREA WILL BE
ROUGHLY 3 TO 4 HOURS. THE CURRENT THINKING IS THAT 1 INCH PER HOUR
RATES WILL ALLOW THE SNOW TO ACCUMULATE ON THE ROADS. SNOWFALL
ACCUMULATIONS DURING THE EVENING WITHIN THE BAND ARE EXPECTED TO
BE IN THE 2 TO 4 INCH RANGE.