Jump to content
  • Member Statistics

    17,606
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

January 11-12 Snow/Mixed Precip


Hoosier

Recommended Posts

ILN goes WWA.

 

 

 

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE WILMINGTON OH
400 PM EST SAT JAN 10 2015

INZ050-058-059-066-073-074-OHZ026-034-035-042>046-051>056-060>065-
070>072-077-110500-
/O.NEW.KILN.WW.Y.0002.150111T1800Z-150112T2100Z/
WAYNE-FAYETTE IN-UNION IN-FRANKLIN IN-RIPLEY-DEARBORN-HARDIN-
MERCER-AUGLAIZE-DARKE-SHELBY-LOGAN-UNION OH-DELAWARE-MIAMI-
CHAMPAIGN-CLARK-MADISON-FRANKLIN OH-LICKING-PREBLE-MONTGOMERY-
GREENE-FAYETTE OH-PICKAWAY-FAIRFIELD-BUTLER-WARREN-CLINTON-
HAMILTON-
INCLUDING THE CITIES OF...RICHMOND...CONNERSVILLE...LIBERTY...
BROOKVILLE...VERSAILLES...LAWRENCEBURG...KENTON...CELINA...
WAPAKONETA...GREENVILLE...SIDNEY...BELLEFONTAINE...MARYSVILLE...
DELAWARE...PIQUA...URBANA...SPRINGFIELD...LONDON...COLUMBUS...
NEWARK...EATON...DAYTON...XENIA...WASHINGTON COURT HOUSE...
CIRCLEVILLE...LANCASTER...HAMILTON...LEBANON...WILMINGTON...
CINCINNATI
400 PM EST SAT JAN 10 2015

...WINTER WEATHER ADVISORY IN EFFECT FROM 1 PM SUNDAY TO 4 PM EST
MONDAY...

THE NATIONAL WEATHER SERVICE IN WILMINGTON HAS ISSUED A WINTER
WEATHER ADVISORY FOR A MIX OF SNOW...SLEET...AND FREEZING RAIN...WHICH
IS IN EFFECT FROM 1 PM SUNDAY TO 4 PM EST MONDAY.

* ACCUMULATIONS...SNOW ACCUMULATION OF 1 TO 4 INCHES NORTH OF
INTERSTATE 70 AND LESS THAN AN INCH OF SNOW ACCUMULATION SOUTH
OF INTERSTATE 70. ICE ACCUMULATIONS WILL BE AROUND A TENTH OF AN
INCH. SOME LIGHT SLEET ACCUMULATIONS WILL ALSO BE POSSIBLE.

* IMPACTS...TRAVEL DIFFICULTIES ARE EXPECTED DUE TO REDUCED
VISIBILITIES AND SNOW ACCUMULATIONS. LIGHT AMOUNTS OF ICING WILL CAUSE
SOME ROADS AND SIDEWALKS TO BECOME SLIPPERY.
Link to comment
Share on other sites

  • Replies 616
  • Created
  • Last Reply

LOT

 

 
THE MAIN QUESTION WITH THIS DEVELOPING PRECIPITATION OVER MY AREA  
DURING THE PAST COUPLE OF DAYS HAS NOT BEEN SO MUCH WITH  
PRECIPITATION TYPES...BUT WITH FAR NORTH TO GO WITH SNOW CHANCES AND  
AMOUNTS. A RATHER STOUT COLD CANADIAN SURFACE HIGH WILL BE BUILDING  
SOUTHWARD OVER THE DAKOTAS THROUGH SUNDAY NIGHT...WITH A COLD FRONT  
MOVING SOUTHWARD ACROSS THE AREA BY EARLY MONDAY. WITH A MUCH COLDER  
DRIER AIRMASS TRYING TO SAG BACK SOUTHWARD OVER THE AREA...THIS WILL  
ACT TO PUT AN END TO THE NORTHWARD PROGRESS OF PRECIPITATION SUNDAY  
NIGHT. HOWEVER...THIS COLD AIRMASS WILL ALSO ACT TO STRENGTHEN THE  
LOWER LEVEL BAROCLINIC ZONE ACROSS THE AREA. AS A RESULT...IT STILL  
APPEARS THAT A BAND OR TWO OF ENHANCED FRONTOGENESIS IS LIKELY TO  
SET UP OVER PORTIONS OF THE AREA SUNDAY NIGHT SUPPORTING  
ACCUMULATING SNOWFALL.  
 
NON GFS MODEL GUIDANCE HAS TRENDED A BIT SLOWER WITH THE TIMING OF  
THE COLD FRONTAL BOUNDARY APPROACHING THE AREA FROM THE NORTH...AND  
NOW SUGGESTS THAT A BAND OF 700 MB FRONTOGENESIS COULD SET UP RIGHT  
OVER THE CHICAGO AREA SUNDAY EVENING. THIS WOULD FAVOR SNOWFALL  
GETTING FARTHER NORTH ACROSS ILLINOIS THEN PREVIOUSLY THOUGHT. IN  
ADDITION TO THIS...GUIDANCE IS ALSO SUGGESTING THAT THE AREA WILL BE  
WITHIN THE ENTRANCE REGION OF AN UPPER LEVEL JET STREAK ACROSS THE  
UPPER GREAT LAKES AND INTO SOUTHEASTERN CANADA. WITH THIS IN  
MIND...I HAVE TRENDED THE FORECAST IN THIS DIRECTION.  
 
MOISTURE IS EXPECTED TO BE RATHER IMPRESSIVE AHEAD OF THE  
APPROACHING COLD FRONT. IN FACT...MODEL SOUNDINGS ALL INDICATE THAT  
MID LEVEL LAPSE RATES WILL STEEPEN NICELY ATOP A LOWER LEVEL AIRMASS  
FEATURING MEAN MIXING RATIOS BETWEEN 3 AND 3.5 G/KG WITHIN THE  
LOWEST FEW HUNDRED MB...AND OVERALL COLUMN PRECIPITABLE WATER  
VALUES OF 0.6 TO 0.7 INCHES. SO...ALTHOUGH UNCERTAINTY STILL IS  
EXISTS WITH WHERE THE BEST BAND OF FGEN WILL SET UP...IT IS COMING  
INCREASINGLY APPARENT THAT A BAND OR TWO OF DECENT SNOWFALL WILL  
OCCUR OVER PORTIONS OF THE AREA. THE INGREDIENTS SEEM TO BE FORECAST  
TO BE IN PLACE TO SUPPORT SOME HEAVIER SNOW RATES. FOR  
INSTANCE...THE GARCIA METHOD ALONE WOULD SUGGEST AMOUNTS POSSIBLY  
UP AS HIGH AS 6 INCHES IN A 12 HOUR PERIOD. HOWEVER...I AM NOT SURE  
THIS MUCH SNOWFALL WOULD OCCUR GIVEN THAT THE MESOSCALE BAND OF FGEN  
APPEARS THAT IT MAY BE SOMEWHAT PROGRESSIVE ACROSS NORTHERN  
ILLINOIS. HOWEVER...THE THREAT OF MODERATE TO POSSIBLY EVEN SOME  
HEAVIER SNOW RATES COULD STILL PUSH AMOUNTS INTO THE 2 TO 4 INCH  
RANGE ACROSS THE AREA FROM THE CHICAGO METRO  
AREA...WEST-SOUTHWESTWARD TO NEAR MENDOTA AND POINTS SOUTH.  
 
AT THIS POINT...IT APPEARS THAT SNOWFALL WILL BEGIN TO DEVELOP  
NORTHWARD ACROSS AREAS ALONG AND SOUTH OF INTERSTATE 88 BY MID TO  
LATE SUNDAY AFTERNOON ALONG A DEVELOPING BAND OF FGEN CENTERED NEAR  
850 MB. THE SNOW COULD TRY TO MIX WITH SLEET ACROSS MY FAR SOUTHERN  
COUNTIES...BUT UNLESS SOME WARMER AIR SHIFTS OVER THE AREA...IT  
APPEARS THE MAIN THREAT FOR MIXED PRECIPITATION WILL REMAIN TO THE  
SOUTH OF MY AREA OVER CENTRAL ILLINOIS. BY SUNDAY EVENING...IT  
APPEARS AN ADDITIONAL BAND OF SNOW WILL DEVELOP ACROSS NORTHERN  
ILLINOIS IN ASSOCIATION WITH A DEVELOPING BAND OF FGEN AROUND 700  
MB. THIS BAND OF FGEN...AND THE ACCOMPANYING AREA OF SNOW...THEN  
LOOKS TO SLOWLY SHIFT TO THE SOUTHEAST THROUGH THE NIGHT SUNDAY.  
ACCUMULATIONS OF 1 TO 3 INCHES...WITH PERHAPS SOME HIGHER AREAS UP  
AROUND 4 INCHES CERTAINLY APPEARS POSSIBLE ACROSS MOST OF THE AREA  
ALONG AND SOUTH OF THE LINE MENTIONED AT THE END OF THE PREVIOUS  
PARAGRAPH OF ABOVE.

Link to comment
Share on other sites

LOT

 

 

THE MAIN QUESTION WITH THIS DEVELOPING PRECIPITATION OVER MY AREA  

DURING THE PAST COUPLE OF DAYS HAS NOT BEEN SO MUCH WITH  

PRECIPITATION TYPES...BUT WITH FAR NORTH TO GO WITH SNOW CHANCES AND  

AMOUNTS. A RATHER STOUT COLD CANADIAN SURFACE HIGH WILL BE BUILDING  

SOUTHWARD OVER THE DAKOTAS THROUGH SUNDAY NIGHT...WITH A COLD FRONT  

MOVING SOUTHWARD ACROSS THE AREA BY EARLY MONDAY. WITH A MUCH COLDER  

DRIER AIRMASS TRYING TO SAG BACK SOUTHWARD OVER THE AREA...THIS WILL  

ACT TO PUT AN END TO THE NORTHWARD PROGRESS OF PRECIPITATION SUNDAY  

NIGHT. HOWEVER...THIS COLD AIRMASS WILL ALSO ACT TO STRENGTHEN THE  

LOWER LEVEL BAROCLINIC ZONE ACROSS THE AREA. AS A RESULT...IT STILL  

APPEARS THAT A BAND OR TWO OF ENHANCED FRONTOGENESIS IS LIKELY TO  

SET UP OVER PORTIONS OF THE AREA SUNDAY NIGHT SUPPORTING  

ACCUMULATING SNOWFALL.  

 

NON GFS MODEL GUIDANCE HAS TRENDED A BIT SLOWER WITH THE TIMING OF  

THE COLD FRONTAL BOUNDARY APPROACHING THE AREA FROM THE NORTH...AND  

NOW SUGGESTS THAT A BAND OF 700 MB FRONTOGENESIS COULD SET UP RIGHT  

OVER THE CHICAGO AREA SUNDAY EVENING. THIS WOULD FAVOR SNOWFALL  

GETTING FARTHER NORTH ACROSS ILLINOIS THEN PREVIOUSLY THOUGHT. IN  

ADDITION TO THIS...GUIDANCE IS ALSO SUGGESTING THAT THE AREA WILL BE  

WITHIN THE ENTRANCE REGION OF AN UPPER LEVEL JET STREAK ACROSS THE  

UPPER GREAT LAKES AND INTO SOUTHEASTERN CANADA. WITH THIS IN  

MIND...I HAVE TRENDED THE FORECAST IN THIS DIRECTION.  

 

MOISTURE IS EXPECTED TO BE RATHER IMPRESSIVE AHEAD OF THE  

APPROACHING COLD FRONT. IN FACT...MODEL SOUNDINGS ALL INDICATE THAT  

MID LEVEL LAPSE RATES WILL STEEPEN NICELY ATOP A LOWER LEVEL AIRMASS  

FEATURING MEAN MIXING RATIOS BETWEEN 3 AND 3.5 G/KG WITHIN THE  

LOWEST FEW HUNDRED MB...AND OVERALL COLUMN PRECIPITABLE WATER  

VALUES OF 0.6 TO 0.7 INCHES. SO...ALTHOUGH UNCERTAINTY STILL IS  

EXISTS WITH WHERE THE BEST BAND OF FGEN WILL SET UP...IT IS COMING  

INCREASINGLY APPARENT THAT A BAND OR TWO OF DECENT SNOWFALL WILL  

OCCUR OVER PORTIONS OF THE AREA. THE INGREDIENTS SEEM TO BE FORECAST  

TO BE IN PLACE TO SUPPORT SOME HEAVIER SNOW RATES. FOR  

INSTANCE...THE GARCIA METHOD ALONE WOULD SUGGEST AMOUNTS POSSIBLY  

UP AS HIGH AS 6 INCHES IN A 12 HOUR PERIOD. HOWEVER...I AM NOT SURE  

THIS MUCH SNOWFALL WOULD OCCUR GIVEN THAT THE MESOSCALE BAND OF FGEN  

APPEARS THAT IT MAY BE SOMEWHAT PROGRESSIVE ACROSS NORTHERN  

ILLINOIS. HOWEVER...THE THREAT OF MODERATE TO POSSIBLY EVEN SOME  

HEAVIER SNOW RATES COULD STILL PUSH AMOUNTS INTO THE 2 TO 4 INCH  

RANGE ACROSS THE AREA FROM THE CHICAGO METRO  

AREA...WEST-SOUTHWESTWARD TO NEAR MENDOTA AND POINTS SOUTH.  

 

AT THIS POINT...IT APPEARS THAT SNOWFALL WILL BEGIN TO DEVELOP  

NORTHWARD ACROSS AREAS ALONG AND SOUTH OF INTERSTATE 88 BY MID TO  

LATE SUNDAY AFTERNOON ALONG A DEVELOPING BAND OF FGEN CENTERED NEAR  

850 MB. THE SNOW COULD TRY TO MIX WITH SLEET ACROSS MY FAR SOUTHERN  

COUNTIES...BUT UNLESS SOME WARMER AIR SHIFTS OVER THE AREA...IT  

APPEARS THE MAIN THREAT FOR MIXED PRECIPITATION WILL REMAIN TO THE  

SOUTH OF MY AREA OVER CENTRAL ILLINOIS. BY SUNDAY EVENING...IT  

APPEARS AN ADDITIONAL BAND OF SNOW WILL DEVELOP ACROSS NORTHERN  

ILLINOIS IN ASSOCIATION WITH A DEVELOPING BAND OF FGEN AROUND 700  

MB. THIS BAND OF FGEN...AND THE ACCOMPANYING AREA OF SNOW...THEN  

LOOKS TO SLOWLY SHIFT TO THE SOUTHEAST THROUGH THE NIGHT SUNDAY.  

ACCUMULATIONS OF 1 TO 3 INCHES...WITH PERHAPS SOME HIGHER AREAS UP  

AROUND 4 INCHES CERTAINLY APPEARS POSSIBLE ACROSS MOST OF THE AREA  

ALONG AND SOUTH OF THE LINE MENTIONED AT THE END OF THE PREVIOUS  

PARAGRAPH OF ABOVE.

 

 

nice

Link to comment
Share on other sites

Since IND mentioned about having to watch for a possible upgrade to ice storm warning, I went back and took a look at significant ice events (0.25" or greater) in central IN, specifically Indianapolis.  Looking at 50+ years of data, almost every single occurrence took place with surface winds out of the E/NE/N or something like that.  The only possible exception that I could find was 1/15/1997, which had S/SE flow.  I'm unsure of ice amounts in Indianapolis but Storm Data suggests a band of healthy ice (.25 to .5") from IL into IN.  It was very cold in the days prior to that storm as it is for this one.

 

If there's an unfavorable setup (in terms of surface wind direction) that would be able to pull it off, it's probably this one.  We've had a pretty cold airmass leading in, background pressures remain fairly high and there's no real organized low pressure to speak of.

Link to comment
Share on other sites

DVN not too enthused about snow rates, pointing out lack of forcing in the DGZ..

 

HOWEVER... GLANCING BOUT OF FORCING ON NORTH SIDE OF SYSTEM LOOKS TO
INTERACT WITH FRONT FOR DEVELOPMENT OF LIGHT SNOW BY MID TO LATE
AFTERNOON FOCUSING MAINLY IN CORRIDOR BETWEEN IOWA CITY AND GALESBURG
ESPECIALLY NEAR SQI-MLI-MPZ AXIS IN RIBBON OF ENHANCED FRONTOGENETICAL
FORCING AIDED BY RIGHT ENTRANCE REGION OF GREAT LAKES JET. FORCING
LOOKS PRIMARILY JUST OUTSIDE OF DENDRITIC GROWTH ZONE AND THUS
MAINLY LIGHT ACCUMS LESS THAN AN INCH WHICH WILL BE CHEWED SOME BY
TEMPS NEARING THE FREEZING MARK IN SOME AREAS
.

Link to comment
Share on other sites

FWIW, the 21z SREF plume mean for DTW is down slightly to about 2.5".

 

There's still a tight cluster up to around 3.5", but the one member that showed 5"+ has fallen below 4.5" while a couple more members have fallen below 1.5" with that one loon still showing roughly 0".

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...