1/2/2005: Ice Storm

[Robert Dewey]

Looks like a pretty good ice event is setting up for the Great Lakes region. Models keep a pretty strong high near the Hudson Bay, ushering in cold SFC air below a layer of >4-5C temperatures at 850mb. Currently, it appears to be a classic setup for an ice storm, but things will likely change as ice storms require the perfect ingredients, more so than snowstorms...

 

[Robert Dewey]

NWS forecast discussions starting to show some concern for an ice event, primarily for southern WI eastward into MI. Currently, there is still a solid 4-5 inches of snow on the ground, and even with a brief spike to 50-53F tomorrow, I don't see this completely melting. This may also give the ETA some credibility as far as dipping the arctic boundary further south than the GFS. The high pressure has been getting stronger with each run as well, and a bit further south -- Now nearing 1050mb. Only thing that could hamper a big event could be the heavy precip rates, which could pull down some of the +5C temps from aloft, and as the precip begins to freeze, temperatures could rise a little...

 

[Mickey Ptak]

Well according to the ETA N. KS all the way up to Chicago are for sure going to be slick. With the forecast surface temps and the amount of precip I would say that could be one heck of a mess. You can keep that crap up there all you want.

Mick

 

[mikegeukes]

NWS Grand Rapids only mention this from the latest AFD

IF THE ETA TRENDS CONTINUE...SUNDAY MAY BE AN ICY DAY ACROSS MUCH OF THE FORECAST AREA.

I hope the ice storm will miss my area, Grand Rapids Michigan,
Last big ice storm for us was April 3-5, 2003.
http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dl...howEvent~505193

We had no power for almost 3 days. I rather see 6 inches of snow, than a ice storm.

Looking at 3 PM Temps, We never get the warm ups.
Grand Rapids 42, Lincoln NE 64, Topeka KS 70, Oklahoma City OK 70.
High Temperature for December for us 50 degrees. One 50 degree day.

Talk about Cloudy Weather, for December through the 29th.
Grand Rapids 18 Cloudy Days, 3 Cloudy Days for Lincoln and Oklahoma City and 2 Cloudy Days for Topeka.

Mike

 

[Patrick Kerrin]

Looking at the latest ETA - don't see a huge areal overlap with > 0C at 850 and <= 0c at the sfc - in my area of interest (along the WF from WI into S ON) and the WAA looks to be pretty strong with this system so the warm air will follow closely at the sfc.

Not saying there won't be ice but if this run is a correct forecast it probably won't be a prolonged event and any accretion should be short lived (this run has the WF at both the sfc and 850 being quite progressive - interesting to see how tight the gradient is in both - again implying, to me at least, strong WAA and me gut says the ETA maybe even underplaying this). Bears watching but not excited yet.

 

[Robert Dewey]

Originally posted by Patrick Kerrin
Looking at the latest ETA - don't see a huge areal overlap with > 0C at 850 and <= 0c at the sfc - in my area of interest (along the WF from WI into S ON) and the WAA looks to be pretty strong with this system so the warm air will follow closely at the sfc.

Not saying there won't be ice but if this run is a correct forecast it probably won't be a prolonged event and any accretion should be short lived (this run has the WF at both the sfc and 850 being quite progressive - interesting to see how tight the gradient is in both - again implying, to me at least, strong WAA and me gut says the ETA maybe even underplaying this). Bears watching but not excited yet.

Yeah, the ETA has been getting warmer with each run, the GFS is now colder than the ETA! ETA has really been strengthening this system with each run, and pushing it further north, which allows much warmer temps at 850mb AND at the SFC...

 

[Bill Schintler]

Upper Midwest Freezing Rain Event

It looks like some light freezing rain will start in SERN IA Saturday morning, with the precipitation reaching I-80 around noon. South of I-80, it will changed over to rain fairly early, so the only real hazard there will be icy roads for a short time duration. It looks like a more significant icing event along and north of US-20 in ERN IA, where more then 0.5" of ice could accumulate in the afternoon and evening before it ends after midnight.

Discussion:
As we know - two key things affecting the forecast here: 1) vertical temperature structure
vs. precip. timing, and 2) QPF. Regarding the QPF forecast, I see a number of
positives: an impressive 40+ kt moist LLJ pumping Td's >= 8C into the
forecast area, 2) consistant PVA resulting in healthy UVV's starting
in the 18Z timeframe and continuing past 06Z. 3) Good isentropic lift
reaching -5 ub/s through 0Z. A major negative for both temperature
and QPF is the speed with which the WF is surging NWRD. It looks
like the models (GFS and Eta) are converging better on the surface
low strength and track - the GFS has been more consistant for the
last 3 runs on the surface low track and strength. Still, there
appears to be a huge disparity in the surface temperatures. The Eta
is probably still too cold but I would lean more towards that
solution instead of the GFS - Or a "blend" of the two - say 1/3 GFS
and 2/3 Eta. bill

 

[Andy Wehrle]

MKX sounds kind of ho-hum about this. No advisories or watches are in effect for southern WI.



ETA MODEL IS GENERATING FZRA AS STRONG WARM LAYER ADVECTS IN
ALOFT. HOWEVER...ETA 2 METER TEMPS SUFFER FROM A COLD BIAS. WILL DEFINITELY LEAN MORE TOWARD WARMER GFS MODEL. THIS WOULD BRING A BRIEF SHOT OF MIXED PCPN TO NRN CWA SAT AFT AND EARLY EVENING...BEFORE THE WARM FRONT ARRIVES AND ALL RAIN FOR PCPN TYPE.

 

[Alex Lamers]

Most prolonged icing will occur in SE MN and WC WI where the ETA is projecting between 0.50 and 0.75" of ice in some locales.

...Alex Lamers...

 

[Bill Schintler]

Upper Midwest Freezing Rain Event

So far (11AM CDT), it appears as though the bulk of the freezing precipitation is occurring along the 850mb WF near the IA/MN border. Look for that area to expand and intensifiy in response to PVA in exit region of upper trough - bill

 

[Robert Dewey]

Originally posted by Andy Wehrle
MKX sounds kind of ho-hum about this. No advisories or watches are in effect for southern WI.



ETA MODEL IS GENERATING FZRA AS STRONG WARM LAYER ADVECTS IN
ALOFT. HOWEVER...ETA 2 METER TEMPS SUFFER FROM A COLD BIAS. WILL DEFINITELY LEAN MORE TOWARD WARMER GFS MODEL. THIS WOULD BRING A BRIEF SHOT OF MIXED PCPN TO NRN CWA SAT AFT AND EARLY EVENING...BEFORE THE WARM FRONT ARRIVES AND ALL RAIN FOR PCPN TYPE.

Guess they didn't really fly too well on that one, as I now see southern WI under a FZR advisory (ice storm warning a bit further north of that), and potential headlines for the GRR and DTX area as far as an advisory goes. Icing situations are very tricky indeed.

Also of interest, another storm appears likely in the next few days which may hold an even greater threat for an ice storm, for places a but further south, and extending eastwared. The boundary sets up for a solid 12 hours, with overrunning precipitation taking place... The difference is, the GFS is colder than the ETA with 850mb temps, and paints more of a snow/sleet situation. Since the ETA performed better in the current situation, I would tend to give it more weight over the GFS for this next event...

 

[mikegeukes]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
323 PM EST SAT JAN 1 2005

.SHORT TERM...
A FREEZING RAIN ADVISORY WILL BE ISSUED FOR ROUGHLY THE NORTHERN TWO
THIRDS OF THE FORECAST AREA FROM THIS EVENING THROUGH 6 AM. EXPECT
FROM 4 TO 8 HOURS OF ICING POTENTIAL OVERNIGHT ACROSS THE ADVISORY
AREA..
Source: http://kamala.cod.edu/offs/KGRR/0501012023.fxus63.htm
http://kamala.cod.edu/offs/KGRR/0501012058.wwus43.htmll

Mike

 

[Todd Rittinger]

Originally posted by Environment Canada
Freezing rain warning for
Kitchener - Cambridge - region of Waterloo upgraded from winter storm watch
A weather system out of Kansas will bring freezing rain ice pellets
then rain to southern Ontario.

This is a warning that an extended period of freezing rain is
Imminent or occurring in these regions. Monitor weather conditions..
Listen for updated statements.


A low pressure disturbance currently over Kansas will begin To affect southwestern Ontario early Sunday morning but the freezing rain in the regions close to Lake St Clair and Erie will likely be brief. North and east of these regions freezing rain will be the main threat along with ice pellets in the Ottawa Valley. The precipitation will eventually change to rain.

Be well, TR

 

[Joel Wright]

Hmmm, very interesting here tonight. Even though we had no freezing rain at all, We have had some very heavy downpoors with the temp just above freezing. I'd have to say I've never seen rain come down this hard EVER with this low of a temp. Right now it's 33.6° here. What's interesting is the temp is going to start rising and may be in the 50's by morning. Right now in NW MO in the warm sector it's in the 60's!! I wouldn't be surprised if we give 60° a run by late tonight!!! :lol: