Dec 24-25 Snowstorm part 2

[daddylonglegs]

I see the 18z GFS really cut totals here. No biggie. Looks like nothing until the New Years rainstorm

[Thundersnow12]

0z NAM

really think a good 3-4" is possible here.

[A-L-E-K]

0z NAM

really think a good 3-4" is possible here.

NAM really has been trending up on the synoptic snows. Good run in that department.

I should go over .5" again on this run, maybe .6"

[BeastFromTheEast]

As ChiStorm posted earlier the nam was the driest of the models so this bump up in qpf is nice.

ORD:

ECMWF: 0.29"

GFS: 0.34"

NAM: 0.22"

GGEM: 0.25-0.50"

[Stebo]

Anyone catch what that high over Greenland initialized at? 1072mb is pretty insane.

[Thundersnow12]

NAM really has been trending up on the synoptic snows. Good run in that department.

I should go over .5" again on this run, maybe .6"

ya I think you got a pretty good shot at 6"

[Chicago WX]

Anyone catch what that high over Greenland initialized at? 1072mb is pretty insane.

Very impressive.

[A-L-E-K]

ya I think you got a pretty good shot at 6"

.5" QPF this run and with a real weak LE reflection.

[Chicago WX]

.5" QPF this run and with a real weak LE reflection.

So I take that's a yes.

Pretty good run for Hoosier, going back home to NW IN. Nice blob of blue in his hood.

[A-L-E-K]

So I take that's a yes.

Pretty good run for Hoosier, going back home to NW IN. Nice blob of blue in his hood.

yeah it's a good run and more believable without the exaggerated west side lake band.

[Chicago WX]

yeah it's a good run and more believable without the exaggerated west side lake band.

I got to bump you to 3-6" now. Seems like a fairly decent/safe call at this point.

Other nice thing is there should be snow flying just about the entire weekend for quite a few of us.

[janetjanet998]

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE LINCOLN IL

838 PM CST THU DEC 23 2010

DISCUSSION

ISSUED 838 PM CST THU DEC 23 2010

ONGOING FORECAST ON TRACK. UPPER SHORTWAVE THAT WILL BE BRINGING THE

SNOW TO CENTRAL IL IS NOW MOVING SEWD THROUGH THE DAKOTAS. LEADING

EDGE OF MID LEVEL FORCING HAS PROGRESSED ABOUT MIDWAY THROUGH

IA...WHICH IS ABOUT ON SCHEDULE. RADAR MOSAICS SHOWING

LOW-REFLECTIVITY ECHOES OVER THE WESTERN HALF OF IL...BUT THIS IS

MID LEVEL MOISTURE THAT IS MOSTLY EVAPORATING BEFORE REACHING THE

GROUND. 00Z LINCOLN AND DAVENPORT SOUNDINGS BOTH SHOWED CONSIDERABLE

DRY AIR BELOW 10K FT...AND MODEL FORECAST SOUNDINGS SHOW THAT IT

WILL BE A WHILE BEFORE THE MOISTURE CAN OVERCOME THE DRY AIR. SO

FAR...THE CLOSEST STATION REPORTING SNOW IS CEDAR RAPIDS IOWA...

ALONG WITH A SPOTTER REPORT OF VERY LIGHT SNOW NEAR HANNIBAL MO.

VERY LIGHT FLURRIES HAVE ALSO JUST BEEN REPORTED JUST SOUTHWEST OF

SPRINGFIELD. WILL THEREFORE KEEP POPS GOING AS IS...WITH LITTLE

CHANCE OF ANYTHING MEASURABLE BEFORE 06Z.

THE NEW 24/00Z NAM HAS NOT COME IN COMPLETELY YET...BUT A LOOK AT

THE FIRST FEW PROJECTIONS SHOW THE SNOW COMING IN A LITTLE SLOWER...

PERHAPS NOT UNTIL 18Z FRI. THIS SEEMS A BIT TOO SLOW. WILL STILL

COUNT ON LIGHT SNOW MAKING IT TO PIA TOWARD DAWN AND INCREASE EWD

AND SEWD THRU THE AREA DURING THE DAY. THE PRIME TIME PERIOD FOR THE

WORST CONDITIONS STILL APPEARS TO BE FROM ROUGHLY 3PM TO 9PM. SNOW

AMOUNTS AROUND 3 TO 4 INCHES IN THE NORTH...WITH 2 TO 3 INCHES

ELSEWHERE. NO CHANGES TO WINTER WEATHER ADVISORY.

[cyclone77]

Snow bands beginning to become more enhanced from central into southeast Iowa. 00z NAM was drier for the QC at around 0.3". The 12z had 0.5-0.6". I'm still sticking with 4" for here for now.

[ukrocks]

NAM brings in a nice swath of precip over northern Kentucky. I think the LMK area could very well end up with 3-6 inches of snow by Monday.

[janetjanet998]

Snow bands beginning to become more enhanced from central into southeast Iowa. 00z NAM was drier for the QC at around 0.3". The 12z had 0.5-0.6". I'm still sticking with 4" for here for now.

you can see the south end of a slow moving band moving NE...south and west of this are faster moving echoes almost moving due east. The north band will be similar to the last systems wherever it stalls out meansbigger snows...\

the north band is over me now but will be too far north once it really gets going

00z NAM SIM radar shows this nicely...the "band" will be north of me and I will get "dry slotted" until a batch moves in around 18z tomorrow

RUC hits you pretty good over night

[buckeye]

yeah it's a good run and more believable without the exaggerated west side lake band.

00z nam now gives us 2-3"....however it's over a 48 hr period. Things could get ugly, i would imagine visibilities dropping to 3 miles at times

[cyclone77]

you can see the south end of a slow moving band moving NE...south and west of this are faster moving echoes almost moving due east. The north band will be similar to the last systems wherever it stalls out meansbigger snows...\

RUC hits you pretty good over night

Yeah it seems the high res models pick up on a narrow band of heavy snow setting up somewhere. Amounts in a band like that could exceed 7", but wherever that sets up is hard to say at this point. Either way eastern Iowa and northern Illinois looks good for 3-4" at least. The new 00z high res models will be interesting.

[jhamps10]

you can see the south end of a slow moving band moving NE...south and west of this are faster moving echoes almost moving due east. The north band will be similar to the last systems wherever it stalls out meansbigger snows...\

the north band is over me now but will be too far north once it really gets going

00z NAM SIM radar shows this nicely...the "band" will be north of me and I will get "dry slotted" until a batch moves in around 18z tomorrow

RUC hits you pretty good over night

don't be so sure.. it's hitting the ground already at Springfield.

[Powerball]

Amazing, Minneapolis somehow still managed to get a relatively decent hit out of this.

They were upgraded to a winter weather advisory for 3-6" and they're currently under a heavier (narrow) band of snow.

[janetjanet998]

New RUC rather wet over southern IA into IL .3-.5 inhces down by 14z

[Chicago Storm]

Skilling going with 2-4" of system snow, then the additional LES accumulation of possibly 6"+ for lakeside counties.

His RPM model actually popped an SLP tomorrow in Missouri, south of KC within an inverted trough feature.

[cyclone77]

Skilling goign with 2-4" of system snow, then the additional LES accumulation of possibly 6"+ for lakeside counties.

His RPM model actually popped an SLP tomorrow in Missouri, south of KC within an inverted trough feature.

Yeah you could tell he was pretty excited about the potential, but was doing his best not to go too crazy. I'm not very good at LES forecasts, but to me this looks like a pretty good setup for the Chicago lake front.

[janetjanet998]

DVN sees the band too

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE QUAD CITIES IA IL

940 PM CST THU DEC 23 2010

UPDATE

RADARS ARE NOW SHOWING THE LOCATION OF A MODERATE TO LOCALLY HEAVY

BAND OF SNOW SETTING UP...FROM NEAR BOONE IOWA...TO GALESBURG

ILLINOIS. WHILE THE EASTERN EDGE OF THIS BAND IS STILL IN THE

SATURATION PROCESS...THE PORTION IN IOWA LOOKS TO BE HITTING THE

GROUND. VISIBILITY AND WEBCAMS SUPPORT 1/2 MILE VISIBILITIES

WITHIN THE BAND...AS WELL AS LARGE DENDRITIC FLAKES. THIS BAND

WILL AFFECT THE METRO AREAS OF CEDAR RAPIDS...IOWA

CITY...MUSCATINE...THE QUAD CITIES...AND CLINTON OVERNIGHT. IN

THIS AXIS...2 TO 4 INCHES BY 7 AM SEEMS LIKELY...WITH SOME HIGHER

AMOUNTS POSSIBLE WHERE THE BAND STALLS TOWARD DAWN. EVENT TOTALS

FOR THE CWA STILL SEEM TO REPRESENT A HIGH END ADVISORY...BUT AN

AXIS OF 5 TO 7 IS NOW EXPECTED...MAINLY WITHIN THE DISCUSSED

LOCATION OF CITIES ABOVE. THESE AMOUNTS WILL FALL BEYOND A 12 HOUR

WINDOW...AND STILL SHOULD REPRESENT ADVISORY LEVELS...VS WINTER

STORM WARNING CRITERIA WHICH WOULD REQUIRE 8 PLUS INCH AMOUNTS IN

24 HOURS...OR 6 PLUS IN 12 HOURS.

HOWEVER...WE WILL WATCH FOR A RAPID ACCUMULATION TONIGHT...AND A

NARROW COUNTY OR TWO WIDTH UPGRADE TO WARNING WOULD BE POSSIBLE IF

THIS OCCURS.

..ERVIN..

[janetjanet998]

dsm

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE DES MOINES IA

935 PM CST THU DEC 23 2010

UPDATE

MAIN QUESTION TONIGHT IS WHETHER TO TINKER WITH THE PROJECTED SNOW

AMOUNTS. 18Z MODELS SHOWED SNOW INITIATING THIS EVENING WHICH IS

OCCURRING BUT PIECEMEAL DUE TO MORE INTENSE MESOSCALE BANDING AND

PATCHY LOW LEVEL SATURATION. COLUMN HAS SATURATED IN STRATIFORM

SNOW WITH VSBYS DOWN TO 1-2SM...NARROW MESOSCALE BANDING HAS DROPPED

VSBYS TO 1/2SM IN MODERATE SNOW...WHILE DRY HAS ALSO PRECLUDED MUCH

IN THE WAY AT ALL IN SPOTS. THESE REPORTS HAVE ALL BEEN OCCURRING

WITHIN JUST A FEW COUNTIES OF EACH OTHER MAKING FORECAST QUITE

PROBLEMATIC. WE ARE ENTERING CRUNCH TIME WITH BEST DGZ UVM EXPECTED

04Z-10Z. IF THIS DOES NOT OCCUR IN A FAIRLY WIDESPREAD

MANNER...PROJECTED SNOW TOTALS WILL BE TOO HIGH. HOWEVER

CONSIDERING 00Z NAM IS FAIRLY CLOSE TO 18Z GFS AND NAM...CONFIDENCE

IS NOT GREAT ENOUGH TO CHANGE THINGS BEFORE 1000 PM NEWS AND WILL

LET AMOUNTS RIDE FOR NOW WITH NO CHANGES TO AMOUNTS OR HEADLINES.

[Tony]

0z GFS looks good for NE IL. Still snowing in 63hr frame. That is so far what I have seen

[Thundersnow12]

0z GFS with .30"-.40" liquid for northern IL. more by DBQ and eastern IA

[hawkeye_wx]

The RUC is odd. The 00z 12 hr precip had a 0.40" bullseye over Cedar Rapids with little elsewhere. The 02z and 03z are pretty much the total inverse of the 00z. There is a dry hole over CR where almost nothing falls while there is a 0.60" bullseye over sw Iowa.

[Thundersnow12]

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL

827 PM CST THU DEC 23 2010

DISCUSSION

825 PM CST

FOR EVENING UPDATE...

NO SIGNIFICANT CHANGES TO FORECAST THIS EVENING.

00Z ANALYSIS DEPICTS SFC RIDGE AXIS ACROSS NORTHWEST/NORTH CENTRAL

IL. DESPITE THICKENING HIGH CLOUD COVER HAVE SEEN QUICK EVENING TEMP

DROP INTO THE TEENS IN MANY LOCALES ACROSS NORTHERN IL WEST OF THE

FOX VALLEY. WOULD EXPECT WITH CONTINUED THICKENING OF CLOUD COVER

OVERNIGHT THAT TEMPS WILL LIKELY HOLD STEADY OR EVEN RISE A COUPLE

OF DEGREES AS FLOW BECOMES LIGHT ESE WEST OF CHICAGO AREA.

GOING SNOW FORECAST WITH APPROACHING SHORT WAVE APPEARS LARGELY ON

TRACK THROUGH EARLY FRIDAY. REGIONAL RADAR MOSAIC HAS DEPICTED AREA

OF ELEVATED PRECIP ACROSS EASTERN IA/WESTERN IL THIS EVENING...

THOUGH THIS REMAINS ALOFT AS NOTED BY ONLY MID LEVEL CLOUD DECK

ALONG MISSISSIPPI RIVER AT 02Z...AND A RESULT OF DRY LOW LEVEL AIR

DEPICTED NICELY IN DVN 00Z RAOB. DEVELOPING HEIGHT FALLS AND

INCREASE IN LOW LEVEL WAA/ISENTROPIC ASCENT OVERNIGHT WILL WORK TO

GRADUALLY SATURATE FROM ABOVE...WITH LIGHT SNOW EVENTUALLY EXPECTED

TO REACH THE GROUND OVER FAR WESTERN PARTS OF THE CWA IN 09-12Z

RANGE. UTILIZING A BLEND OF MODEL QPF/HPC 00Z GUIDANCE...AND LEANING

TOWARD THE LOWER END OF THE SPECTRUM GIVEN DRY LOW LEVELS...LOOKS

LIKE ONLY LIGHT ACCUMS OF AN INCH OR LESS FAR WEST BY SUNRISE

FRIDAY. AM CURRENTLY IN PROCESS OF RE-EVALUATING QPF/SNOW FORECAST

INTO FRIDAY...THOUGH OVERALL CHARACTER OF FORECAST AND PLACEMENT OF

WINTER WEATHER ADVISORY STILL APPEARS TO BE SPOT ON.

UPDATED GRIDS/ZFP WITH MINOR NEAR TERM TEMP TREND TWEAKS AVAILABLE

SHORTLY.

RATZER

[cyclone77]

Looks like Cedar Rapids may be the big winner. Most of the models show at least 0.50" of precip there. With the fluffy dendritic flakes tonight combining with higher ratios they could easily pick up 7-9". That's in the area where the heavier bands will sort of pivot later tonight. DVN may indeed have to bump up a few counties in eastern Iowa to a warning.

[Thundersnow12]

0z DVN