Natester

1 minute ago, hlcater said:

GFS continues to be one of the wettest models by far. 

Realistically those totals should be slashed in half, no way that'll verify.

Calling it, CR only gets 3-4 inches of snow from this while IC gets 5-6 inches.  Chicago doesn't get much either due to the drying.  At least we had the December 29, 2020 dumping of 8 inches here.

40 minutes ago, mimillman said:

Sadly our 6 year double digit drought continues 

Speaking of that, it's been 11 years since we had a 10"+ inch storm.

I don't see CR getting 6 inches from this storm.  I'd say we'd get 4-5 inches from this.

Spoke too soon, light snow here now.  Likely won't get much from this though.

No precip at here whatsoever.  The edge of the snow shield stopped just SE of Cedar Rapids.  Not complaining since we got over 8 inches on Tuesday.

In other news, no substantial power outages in Iowa even though the ZR got pretty far north (up to Johnson county).

DVN update:

AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE QUAD CITIES IA IL  
1227 PM CST FRI JAN 1 2021  
   
UPDATE  
  
ISSUED AT 1227 PM CST FRI JAN 1 2021  
  
VERY TRICKY SITUATION WITH THIS FORECAST. MODEL ICE NUCLEATION HAD  
SUGGESTED MORE ICE IN THE COLUMN, AND THIS MORNING MANY OF THE  
AWOS SITES REPORTED SNOW WHEN IT WAS ACTUALLY FZRA. AS ADDITIONAL  
GROUND TRUTH CAME IN IT WAS EVIDENT THAT EVEN THOUGH THE FORECAST  
WAS COLDER THAN PREVIOUS DAYS, THE EXISTENCE OF ICE WAS NOT THERE.  
AS A RESULT ICE TOTALS INCREASED IN THE ADVISORY AND WARNING  
AREAS. REPORTS OF WARNING CRITERIA ICE IN THE WARNING HAVE BEEN  
RECEIVED AND UP TO .15 IN THE ADVISORY AREA. RADAR DATA NOW  
SUGGESTS THE WARM LAYER IS COLLAPSING AND SNOW IS BEGINNING TO  
TRANSITION THROUGH THE AREA. THE SNOW BAND HAS SETUP FURTHER NW  
AND AS A RESULT HAD TO ADD COUNTIES TO ADVISORY.  

DMX radar is down due to a communications error, so there is no way of telling if it's snowing in southern Iowa anymore.  Going to be a close call here.  It's all snow in NW Missouri, though.

From LSX:

 

AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE SAINT LOUIS MO  
823 PM CST THU DEC 31 2020  
   
UPDATE  
  
ISSUED AT 804 PM CST THU DEC 31 2020  
  
A BAND OF WINTRY PRECIPITATION HAS MOVED NORTH INTO SOUTHEAST  
MISSOURI AND THE FAR SOUTHERN REACHES OF THE CWA AHEAD OF THE  
PREVIOUS FORECAST. THIS BAND IS EXPECTED TO MAKE IT TO THE ST.   
LOUIS METRO/COLUMBIA METRO REGION AROUND 04Z. WHILE THE LEADING  
EDGE OF THIS PRECIPITATION COULD START AS SNOW OR A WINTRY MIX, IT  
IS ANTICIPATED TO QUICKLY TRANSITION TO FREEZING RAIN. FREEZING  
RAIN HAS BEEN REPORTED IN FARMINGTON, MO WITH THIS FIRST BAND.  
  
A BRIEF BREAK IN PRECIPITATION IS POSSIBLE AFTER THIS FIRST SHOT  
OF WINTRY MIX/FREEZING RAIN, HOWEVER THE GAP IN REFLECTIVITY HAS  
BEEN FILLING IN OVER THE PAST HOUR. I CANNOT RULE OUT LIGHT  
PRECIPITATION FALLING IN THE GAP BETWEEN THE FIRST ROUND OF  
PRECIPITATION AND THE SECOND, MORE ROBUST ROUND OVERNIGHT.  
  
MRM  

In other words, it's moving an hour ahead of schedule.

7 minutes ago, WeatherMonger said:

NAM comes in less bullish yet still alarming. I'll take all the ice they can give if the power stays on. 

 

Yikes!  Significant shift north.  Wouldn't be surprised if the edge of the precip shield clips us.  At least winds won't be strong here.

EDIT: Nevermind.  Previous NAM run has the precip shield clip us too.

ILX going for an Ice Storm warning for their NW CWA according to the point forecast matrix.

Just now, WeatherMonger said:

New WPC Ice Accrual map

 

Wouldn't be surprised to see substantial power outages in Missouri and Illinois tomorrow, especially with the wind gusts forecast to be at or over 35 mph.

Just now, ILSNOW said:

15Z RAP 

Ice

 

 

Snow

 

Major ice storm for SW Missouri if that verifies.

Day 2 ice map by WPC:
 

10 minutes ago, CoachLB said:

2 bad you gotta pay to play lol.

Yeah, you'd have to shell out 7 dollars a month to get those kind of maps.  The best products on pivotal weather aren't free.

0z HRRR freezing rain accumulation map at hour 48.

Major SE shift in the 0z HRRR.  Keeps the ZR out of Iowa entirely.

7 minutes ago, bl5585 said:

It seems like this is okay to share based on Pivotal Weather's terms.

Here is the latest RGEM with FRAM instead of QPF that was mentioned above.

That spells borderline major ice storm for a lot of places if that verifies.

2 minutes ago, Hoosier said:

Regarding the freezing rain, something I am noticing on the guidance is that a portion of the higher precip rates happen while temps are around 28-30 degrees.  Obviously that would make a difference in how much accretes as you can get away with some heavier rates at those temps.  

That is a verbatim read of the models though, so if it ends up more like 31-32 during that time, then more will run off.

Wait, does heavy freezing rain run off at 28F?  I thought it was 31-32F that it runs off in heavy rates.

Yep, it's official.  All the models have trended southeast, including the GFS.

WPC Ice map for Friday.

Right on cue, 18z NAM (both 12k and 3k) trended southeast where the precip shield only skirts us.

18z HRRR at hour 48.  HRRR really ramps up the evaporative cooling.  Not sure if that's actually realistic since all the other models have a much bigger zone of freezing rain.

The chance of siggy ice here is decreasing although siggy ice would be really bad here because:

1. gusty winds of 35 mph

2. weakened and damaged trees from the derecho over 4.5 months ago.

If we do get any siggy ice, I doubt the power outages will be as long lasting as from the derecho.

12z NAM 12k came in slower, has the freezing rain arriving in Cedar Rapids after noon on Friday.