North American Mesoscale Model Verification on January 26-27...

By: Zachary Labe , 10:34 PM GMT on January 29, 2011

Share this Blog
5
+

The North American Mesoscale Model (NAM) is a high resolution model courtesy of the National Center for Environmental Prediction. Another very common and referenced name for the model is the Weather Research and Forecasting Model (WRF). They are the same model and run out to 84 hours. The purpose of the model is to run a higher resolution determining mesoscale features that often cannot be picked up by the global models due to their larger scale. The NAM can be run on an 80km resolution with a broad view of the United States, or 40km which allows the viewer to zoom in on a localized region to put up on mesoscale features. Also a very high resolution form of the NAM exists using a 12km parametric and can zoom into different states. The model is released four times a day at 0z, 6z, 12z, and 18z. Keep in mind that time is zulu or more commonly known as greenwich mean time.

Computer models are critical to forecasting the weather as they use parametric and other mathematical equations to derive the current and predicted state of the atmosphere using a physical and chemical explanation as the background for the predictions. The NCEP is associated with the National Oceanic Atmospheric Administration (NOAA) to be the developer of these computer models. Each meteorological organization worlwide uses their own developed computer models to serve as a basis for the forecasts. Without computer models, we are not able to derive predictions on the weather greater than 24 hours out.

Like all computer models, the NAM shows all layers of the atmosphere in maps determining positioning and speed of the jet stream, surface precipitation amounts (quantitive precipitation forecast QPF), temperatures throughout the entire core of the atmosphere, convective indices, simulated radars, etc. Due to the higher resolution of the NAM, several problems do exist. It often produces convective elements in many middle latitude cyclones and these are known as convective feedback problems. This is where it developed these unstable regions and often associates them as surface lows causing the surface depiction to be distorted. This was a problem in the recent prediction of the January 26-27 winter storm and will be noted below. Also the NAM has a tendency to produce higher than normal precipitation amounts. I typically find myself cutting totals nearly by 30% as shown on the NAM. Finally the NAM has a bias to overamplify a low pressure and close them off to early particularily on eastern United States cyclogenesis off the coast.

The January 26-27 winter storm featured many model headaches do to some interesting variables. Early on it appeared likely for a low pressure to track up inland along the coastal plain. There was a lacking 50/50 low, unfavorable position of the western trough axis, neutral NAO, natural baroclinicity along the coastline, and stale antecedent cold air mass. This would produce rain along I-95 with heavy snows inland. The 500mb synoptic pattern showed very strong signals for this time of setup with most computer model guidance also in support. The GGEM and ECMWF led the pack with the heavy snows from I-81 on westward. The GFS suffered major problems with varying solutions for each run. But then the computer models began to delay the storm. In fact it was delayed nearly 48-60 hours from the original starting time. This caused a different scenario to unfold. The lacking high pressure to the north was still a problem as the anticyclone zoomed east-northeast, but now a high pressure and associated shortwave out ahead of it allowed sunk east-southeast across the Midwest and western Great Lakes. This acted as a 'kicker' helping to push the cyclonegenesis farther off the coast. This in turn allowed for a colder scenario along with precipitation to occur farther east. Therefore a turn of events allowed for a major I-95 snowstorm with 6in+ totals from Washington DC to Boston. This was very fortunate for snow lovers in that corridor due to pure luck given the poor synoptic setup.

Given the NAM's high resolution, it often overanalyzes prognostics post hour 60. It tends to enhance QPF, overamplify lows, and pick up on mesoscale features that really do not exist. Therefore I typically throw out hours 60-84. It would be a rare event where you would find the NAM 84 hour verifying anywhere close to accurate. But in the near term range, the NAM does an excellent job locating temperature thermals, QPF ranges, and picking up on mesoscale features; coastal fronts, enhanced convection, deformation bands, etc. But in this recent storm, it suffered a plethora of problems and even the 6 and 12 hour surface maps had poor verification especially in the QPF department.

Let us first look at the actual accumulated precipitation totals for the storm.

Given this is a 24 hour accumulated precipitation amount, about .01-.1in of additional precipitation fell south of the Mason-Dixon line in the previous 24 hours.

Here are the preceeding NAM total QPF forecasts...


(January 24; 18z) (January 25; 6z)


(January 25; 12z) (January 25; 18z)


(January 26; 0z) (January 26; 6z)

As you can see, the NAM had a lot of variance with the northwestern sharp precipitation gradients. These tight gradients this year have been caused by the rapid intensification of the coastal lows allowing the heaviest moisture to be confined closer to the center of circulation. Also in this instance, a very cold and dry air mass along with associated cold front was quickly advancing southeast across the Great Lakes and was even picked up on by the 700mb RH charts. This allowed the flow out of the northwest to dry up some moisture for areas more inland.

The NAM simulated radar vs. the forecast QPF did not match up. Often the NAM simulated radar showed the heavier mesoscale bands lining up in northern Maryland and southern Pennsylvania where as it only showed total QPF to be .25in-.5in. In fact looking at total verification, the NAM did very well for its simulated radar.


(Actual NEXRAD National Radar) (6z NAM January 26 Simulated Radar)

The NAM did seem to have a hold on the 500mb map showing the negatively tilted trough producing the coastal low along with the placement of the upper level low and associated shortwave kicker just to the west.


(18z NAM January 24; 500mb) (0z NAM January 26; 500mb)

In general the differences in the 500mb maps were very subtle with just a general strengthening in the closed 500mb low, which verified a tad north of the January 24 18z model run.

The NAM did a very excellent job in identifying mesoscale band using the UUV/700mb RH charts.

(6z NAM January 26; 700mb)

It indentifed the enhanced snow growth over southeastern Pennsylvania up through New Jersey and New York City. The problems with the NAM generally existed in the QPF fields. The model likely suffered a very convective feedback issues in QPF totals. This is why it is important to note other maps than surface maps to help locate the heaviest precipitation. The 700mb map screamed that snow totals would be farther inland with the enhanced deformation band and UUV rates. In general the high resolution models handled this the best with the HRR scoring an amazing victory for QPF along with the ECMWF. The GFS/NAM did a very poor job for QPF, but as noted above QPF does not always tell the story. Sometimes it is important to note other layers of the atmosphere to help make a forecast. This point is why many forecasters missed the boat. Many forecasters (especially broadcoast meteorologists) are drawn to the easy to understand QPF/surface maps, but one has to look at all layers of the atmosphere to make a prediction.

Lower Susquehanna Valley Doppler...

(Courtesy of WGAL)

"Here northeast of Harrisburg 2010-2011 winter statistics"
(Snow Stats)
Current Snow Cover- 0-3in
Monthly Total (November)- Trace
Monthly Total (December)- 0.6in
Monthly Total (January)- 18.90in
Monthly Total (February)- 1.35in
Seasonal Total- 20.85in
Winter Weather Advisories- 7
Winter Storm Warnings- 2
Ice Storm Warnings- 0
Blizzard Warnings- 0
Freezing Rain Advisories- 1
Winter Storm Watches- 2

(Temperature Stats)
Lowest High Temperature- 23.7F
Lowest Low Temperature- -1.7F
Wind Chill Advisories- 0
Wind Chill Warnings- 0

(Snow Storms Stats)
First accumulating snow - December 10 - 0.50in of snow
Clipper light snow - January 7-8 - 2.25in then another 1in of snow
Double Barrel Low - January 11 - 4.5in of snow
Coastal Low - January 17-17 - 1.8in of snow/sleet
Arctic Front - January 20-21 - 2.1in of snow
Upper level/coastal low - January 26 - 5.75in of snow
Two clippers - January 28-29 - 1.5in of snow

Ice Storm 2011... (Blizzard92)
.4-.5in of freezing rain
Ice Storm 2011...
Ice Storm 2011... (Blizzard92)
.4-.5in of freezing rain
Ice Storm 2011...
Ice Storm 2011... (Blizzard92)
.4-.5in of freezing rain
Ice Storm 2011...
Ice Storm 2011... (Blizzard92)
.4-.5in of freezing rain
Ice Storm 2011...
Ice Storm 2011... (Blizzard92)
.4-.5in of freezing rain
Ice Storm 2011...
Ice Storm 2011... (Blizzard92)
.4-.5in of freezing rain
Ice Storm 2011...
Ice Storm 2011 (Blizzard92)
Melting begins...
Ice Storm 2011
Ice Storm 2011 (Blizzard92)
Melting begins...
Ice Storm 2011

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 117 - 67

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36Blog Index

Hope you are right CTWXGUY, that would make it very interesting for us. You being located about 40 miles NE of me and further inland, should do better than me in any case with this storm. I'll check back in later, off to dinner now LT
Member Since: January 31, 2009 Posts: 0 Comments: 7504
Quoting ConnecticutWXGuy:


sorry yeah I see it now. Actually I think that still looks pretty accurate. I expect the low to end up slightly further south and east than models have recently told us - and such a trend is already indicated in the latest GFS, backed by the NAM - to a colder/further south and east solution. It's last week's storm all over again, except it's doubled in size, twice as slow, and twice as strong.


CtWX: So does this mean you think that we (Central Mass and northern CT) are going to end up with big snow rather than icy mix?
Member Since: Posts: Comments:
Quoting originalLT:
Hi Connecticutwxguy, no I'm not questioning the NAM post, post # 93 is a map that was drawn up on Friday the 28th from the NWS, it's their NWS hazzards assessments map, that is the one that is old. Check post's #93 map.


sorry yeah I see it now. Actually I think that still looks pretty accurate. I expect the low to end up slightly further south and east than models have recently told us - and such a trend is already indicated in the latest GFS, backed by the NAM - to a colder/further south and east solution. It's last week's storm all over again, except it's doubled in size, twice as slow, and twice as strong.
Member Since: Posts: Comments:
Quoting Matlack:
So I must have it backwards. They have the 18Z as the first map then a dropdown to the 12Z run. So is the 18Z I see on the site yesterdays run?


Z means HOURS/TIME in Universal Time, not DAYS. So the later the run the more recent it is. There are 4 runs per day
Member Since: Posts: Comments:
Hi Connecticutwxguy, no I'm not questioning the NAM post, post # 93 is a map that was drawn up on Friday the 28th from the NWS, it's their NWS hazzards assessments map, that is the one that is old. Check post's #93 map.
Member Since: January 31, 2009 Posts: 0 Comments: 7504
Quoting originalLT:
Looking at post # 93 closer though, I see it was initiated 2 days ago, -Jan. 28th. Keeper do you have a more up to date map like that?


that must be an error because that is the latest NAM
Member Since: Posts: Comments:
Looking at post # 93 closer though, I see it was initiated 2 days ago, -Jan. 28th. Keeper do you have a more up to date map like that?
Member Since: January 31, 2009 Posts: 0 Comments: 7504
Yeah, Matlack, the timing is abit confusing, I know what you are saying. THis last run, on the GFS anyway keeps me nearer to the freezing line could be quite a mess on WED. and on the NAM precip map that Keeper posted and on the Precip. potential map,(post #93), that puts me in an area for possible heavy snow. I think we really won't know till Monday, like Blizz was saying all along.
Member Since: January 31, 2009 Posts: 0 Comments: 7504
Pghnurse just a heads up, my friend told me accu has Pgh and 25 miles south under snow and ice for the duration of the storm...KOTG---looking at the nam pulls the freezing line would be way north in Pennsylvania, how is accu making that call for this???Blizz how do you now that the turnpike area is straight frzing rain, am I missing something? THX for the input!!!
Member Since: Posts: Comments:
Winter Storm Watch for the Pittsburgh region. Expecting 0.25 to .50 inches of ice, then 1-3" of snow, then all rain from tomorrow evening through late Tues night.

Rats! What a royal dangerous mess.
Member Since: October 14, 2006 Posts: 1 Comments: 639
we are under a special statement now

Special weather statement issued for..
City of Toronto
Windsor - Essex - Chatham-Kent
Sarnia - Lambton
Elgin
London - Middlesex
Simcoe - Delhi - Norfolk
Dunnville - Caledonia - Haldimand
Oxford - Brant
Niagara
City of Hamilton
Halton - Peel
York - Durham
Huron - Perth
Waterloo - Wellington
Dufferin - Innisfil
Barrie - Orillia - Midland
Belleville - Quinte - Northumberland
Kingston - Prince Edward
Peterborough - Kawartha Lakes
Stirling - Tweed - South Frontenac
Brockville - Leeds and Grenville.

..Threat for Major snowstorm Tuesday night and Wednesday..

A low pressure system is forecast to develop over Texas on Monday and
then track northeastward to pass just south of the lower lakes as a
major winter storm Wednesday.

Meanwhile periods of light snow are expected to develop over many
regions Monday night or Tuesday. A lake effect snow band could also
affect areas near the west end of Lake Ontario Tuesday morning.

The heavy snow associated with the major storm will overspread the
region Tuesday night then taper off Wednesday afternoon.
Potential widespread snowfall amounts will be in the order of 20 to
30 cm with local higher accumulations as well as blowing and drifting
snow.

Listen for further statements watches and warnings.

END/OSPC
Member Since: July 15, 2006 Posts: 171 Comments: 53779
\

remember black line is freeze line north of it snow and ice south of it rain
Member Since: July 15, 2006 Posts: 171 Comments: 53779
18Z NAM PRECIP UPDATE
Member Since: July 15, 2006 Posts: 171 Comments: 53779
18Z NAM UPDATE
Member Since: July 15, 2006 Posts: 171 Comments: 53779
based off last weeks storm, I would stick with the 18z from yesterday which would bring the storm south, this is not scientific but just based on how the models are behaving...Any thoughts or proof?
Member Since: Posts: Comments:
102. DM125
Quoting KEEPEROFTHEGATE:



So much of PA is still in for the heavy snow?
Member Since: Posts: Comments:
Quoting Blizzard92:
18z NAM = crippling ice storm along Pennsylvania turnpike


What about jersey? Says the high is 32 but rain on Wednesday. Seems like west of i95 may stay below freezing. Thoughts?
Member Since: Posts: Comments:
18z NAM...

KMDT...

1.217in of pure freezing rain with the temperature stay below 30F
Member Since: December 14, 2007 Posts: 284 Comments: 15112
18z NAM = crippling ice storm along Pennsylvania turnpike
Member Since: December 14, 2007 Posts: 284 Comments: 15112
Member Since: July 15, 2006 Posts: 171 Comments: 53779
Quoting PalmyraPunishment:


Where's my chicken wings/!!??!!


You must mean the "Turducken" with 10 legs.
Member Since: Posts: Comments:
Quoting SilverShipsofAndilar:


This looks like something John Madden would draw - "And, if you're in the red zone, then BOOM! it's gonna snow."


Where's my chicken wings/!!??!!
Member Since: Posts: Comments:
O-LT -> I guess I get the donkey ears. I always thought that the model runs being UTC were out earlier than EST. So I thoght the 18Z would be out by 1:30 EST since there is a 5 hour differential. I guess the models take some time to run.
Member Since: Posts: Comments:
Quoting KEEPEROFTHEGATE:


This looks like something John Madden would draw - "And, if you're in the red zone, then BOOM! it's gonna snow."
Member Since: December 1, 2008 Posts: 0 Comments: 600
Member Since: July 15, 2006 Posts: 171 Comments: 53779
Member Since: July 15, 2006 Posts: 171 Comments: 53779
Yes, Matlack, that 18Z run is from yesterday, just checked on the WU model page and that 18Z run was initialised on Jan. 29TH. I guess we have to wait 2-3 hours for todays run.
Member Since: January 31, 2009 Posts: 0 Comments: 7504
So I must have it backwards. They have the 18Z as the first map then a dropdown to the 12Z run. So is the 18Z I see on the site yesterdays run?
Member Since: Posts: Comments:
18Z NAM Precip type:


12Z NAM Precip Type:
Member Since: Posts: Comments:
Quoting originalLT:
Looking at those maps of temp. above, looks to me like the Harrisburg area and my area ,Sw CT. are a couple of degrees Above freezing, so it looks like frozen precip going over to rain.


That's correct, LT. It's going to be a wet sloppy mess.
Member Since: January 20, 2009 Posts: 0 Comments: 1503
Looking at those maps of temp. above, looks to me like the Harrisburg area and my area ,Sw CT. are a couple of degrees Above freezing, so it looks like frozen precip going over to rain.
Member Since: January 31, 2009 Posts: 0 Comments: 7504
Look at all the pretty colors:

Member Since: January 20, 2009 Posts: 0 Comments: 1503
is it still possible for this storm to move SE at all?
Member Since: Posts: Comments:
It looks like my family in Southern Michigan will be clobbered with this storm. They're happy about it. They get snow all winter that adds up because of the cold temps, but big storms are rare. Looks to me like they could get a foot or more, which would rank in their top ten all time snowstorms.
Member Since: January 20, 2009 Posts: 0 Comments: 1503
Quoting KEEPEROFTHEGATE:
its not out yet when it is it will be posted here


Good, I always wonder how you guys find them earlier than me, but that was even earlier still.
Member Since: January 20, 2009 Posts: 0 Comments: 1503
Quoting KEEPEROFTHEGATE:
HERE IS 18Z PRECIP NAM RUN


Doesn't look like the Harrisburg area sees that much rain...looks ugly!
Member Since: Posts: Comments:
Off the Weather Underground model page:
18Z


12Z
Member Since: Posts: Comments:
HERE IS 12Z PRECIP NAM RUN
Member Since: July 15, 2006 Posts: 171 Comments: 53779
Quoting originalLT:
Matlack, where did you find the 18Z NAM, I was just on the NOAA model page and they show only up to 12Z on Sunday?
its not out yet when it is it will be posted here
Member Since: July 15, 2006 Posts: 171 Comments: 53779
Blizz, your review is great. Nicely done.

We appreciate it - but you know us illiterate snow-fiends. All we want or care about is snow, snow, snow so a tease of a forecast will win out to your thoughtful postcast.

But still, thats not to say we dont appreciate it!
Member Since: Posts: Comments:
TT just said that everything is trending more NW with every run(post#72) but Matlack just said the 18Z is 200 miles further SE, what gives?
Member Since: January 31, 2009 Posts: 0 Comments: 7504
Matlack, where did you find the 18Z NAM, I was just on the NOAA model page and they show only up to 12Z on Sunday?
Member Since: January 31, 2009 Posts: 0 Comments: 7504
Quoting TrentonThunder:
Everything trending slightly northwest now with each model run.
Quoting Matlack:
So the 18z NAM 850MB shows the low about 200 miles SE of the 12Z run. Is that Artic high strengthening and pusing the storm SE? Would be worse for us in Jersey with more ice.


The 18Z WTF shows polar opposites colliding on the blog at this time.

This could be cause for concern.

We'll have to keep an eye on it.
Member Since: January 20, 2009 Posts: 0 Comments: 1503
So the 18z NAM 850MB shows the low about 200 miles SE of the 12Z run. Is that Artic high strengthening and pusing the storm SE? Would be worse for us in Jersey with more ice.
Member Since: Posts: Comments:
don't be suprised this might be a columbus, pgh, state college, pa upper ny big time event ice and heavy snow---any shift 50-100 miles south will hammer our area again
Member Since: Posts: Comments:
Everything trending slightly northwest now with each model run.
Member Since: December 17, 2009 Posts: 0 Comments: 796
URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE CHICAGO IL
1134 AM CST SUN JAN 30 2011

...MAJOR WINTER STORM TO IMPACT THE REGION TUESDAY INTO WEDNESDAY...

.THE FIRST PHASE OF THE UPCOMING WINTER STORM WILL BEGIN MONDAY
AFTERNOON THROUGH EARLY TUESDAY MORNING FOR NORTHERN ILLINOIS AND
NORTHWEST INDIANA. SNOWFALL TOTALS FROM THE FIRST PHASE APPEARS TO
BE BETWEEN 2 AND 4 INCHES ACROSS NORTHERN ILLINOIS AND NORTHWEST
INDIANA. THE FOCUS TURNS TOWARDS THE LARGER EVENT THAT PUSHES INTO
THE REGION TUESDAY AFTERNOON AND WILL PERSIST THROUGH WEDNESDAY.

A DEVELOPING AREA OF LOW PRESSURE IS EXPECTED TO SLIDE EAST OF THE
ROCKIES INTO EASTERN TEXAS MONDAY NIGHT AND RAPIDLY STRENGTHEN AS
IT SLIDES NORTH TUESDAY. THE PRECISE TRACK OF THE LOW CONTINUES TO
WOBBLE WITH EACH NEW MODEL RUN...HOWEVER RELATIVE CONSISTENCY OF A
TRACK FROM CENTRAL ARKANSAS NORTH TO CENTRAL INDIANA BY WEDNESDAY
MORNING LOOKS TO BE THE MOST PROBABLE TRACK. THIS WOULD PLACE THE
AXIS OF THE HEAVIEST SNOWFALL TO THE NORTHWEST OF THE TRACK OF THE
LOW PRESSURE...OR ACROSS MUCH OF NORTHERN ILLINOIS AND NORTHWEST
INDIANA.

AS THE LOW PRESSURE CONTINUES TO SLIDE NORTH AND STRENGTHEN...NORTHEAST
WINDS OF 20 TO 30 MPH ARE EXPECTED TO DEVELOP AND BRING A FLOW OF
COLD AIR ACROSS LAKE MICHIGAN AIDING IN THE GENERATION OF LAKE
EFFECT SNOW TUESDAY EVENING. WINDS WILL CONTINUE TO RAMP UP WITH
SUSTAINED WINDS TUESDAY EVENING BETWEEN 25 AND 35 MPH WITH GUSTS
UP TO 40 MPH POSSIBLE. NORTHEAST WINDS THEN CONTINUE TO STRENGTHEN
TUESDAY NIGHT INTO EARLY MORNING WEDNESDAY WITH GUSTS UP TO 45 MPH
POSSIBLE. THIS IN COMBINATION WITH THE FALLING SNOWFALL MAY CREATE
BLIZZARD CONDITIONS AND WHITE OUT CONDITIONS. AS THE LOW PRESSURE
CONTINUES TO LIFT NORTH INTO CENTRAL INDIANA WEDNESDAY
MORNING...WINDS WILL BEGIN TO TURN NORTHERLY AND BRING THE LAKE
ENHANCED SNOWFALL TO NORTHWEST INDIANA.

BY LATER WEDNESDAY THE SNOW FROM THE DEPARTING WINTER STORM WILL
BE WINDING DOWN ACROSS THE AREA BUT A BAND OF SIGNIFICANT LAKE
EFFECT SNOW IS EXPECTED IN NORTHWEST INDIANA WHERE SEVERAL
ADDITIONAL INCHES OF SNOW ARE POSSIBLE BEFORE THE LAKE EFFECT
SHIFTS FURTHER OFF TO THE EAST INTO SOUTHWESTERN LOWER MICHIGAN
AND NORTH CENTRAL INDIANA.

BETWEEN THE INITIAL LIGHTER SNOW MONDAY INTO TUESDAY MORNING...
THE HEAVY SNOWFALL FROM THE MAJOR WINTER STORM DURING TUESDAY
AFTERNOON THROUGH WEDNESDAY MORNING...AND THE INCREASINGLY INTENSE
LAKE EFFECT SNOW DEVELOPING DURING WEDNESDAY...IN EXCESS OF A FOOT
AND A HALF OR MORE OF SNOW WILL NOT BE UNCOMMON OVER MUCH OF
NORTHERN ILLINOIS AND FAR NORTHWEST INDIANA. SNOWFALL RATES UP TO
3 INCHES PER HOUR WILL BE PROBABLE AT THE HEIGHT OF THE STORM
TUESDAY NIGHT.

THE STORM SYSTEM WILL BE AFFECTING A LARGE PORTION OF THE
SOUTHERN GREAT LAKES...MIDWEST AND OHIO VALLEY REGIONS. ANYONE
WITH TRAVEL PLANS TUESDAY AND WEDNESDAY...INCLUDING THOSE
TRAVELING THROUGH CHICAGO OHARE AND MIDWAY AIRPORTS...SHOULD
CONTINUE TO MONITOR LATER FORECASTS REGARDING THE DEVELOPMENT OF
THIS WINTER STORM..

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
310145-
/O.CAN.KLOT.WS.A.0001.110201T1800Z-110203T0000Z/
/O.NEW.KLOT.BZ.A.0001.110201T1800Z-110203T0000Z/
WINNEBAGO-BOONE-MCHENRY-LAKE IL-OGLE-LEE-DE KALB-KANE-DUPAGE-COOK-
LA SALLE-KENDALL-GRUNDY-WILL-KANKAKEE-LIVINGSTON-IROQUOIS-FORD-
LAKE IN-PORTER-NEWTON-JASPER-BENTON-
INCLUDING THE CITIES OF...ROCKFORD...BELVIDERE...WOODSTOCK...
WAUKEGAN...OREGON...DIXON...DEKALB...AURORA...WHEATON...CHICAGO...
OTTAWA...OSWEGO...MORRIS...JOLIET...KANKAKEE...PONTIAC...
WATSEKA...PAXTON...GARY...VALPARAISO...MOROCCO...RENSSELAER...
FOWLER
1134 AM CST SUN JAN 30 2011 /1234 PM EST SUN JAN 30 2011/

...BLIZZARD WATCH IN EFFECT FROM TUESDAY AFTERNOON THROUGH
WEDNESDAY AFTERNOON...
...WINTER STORM WATCH IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A BLIZZARD
WATCH...WHICH IS IN EFFECT FROM TUESDAY AFTERNOON THROUGH
WEDNESDAY AFTERNOON. THE WINTER STORM WATCH HAS BEEN CANCELLED.


* TIMING...HEAVY SNOWFALL WILL SPREAD NORTHEASTWARD ACROSS THE
AREA MIDDAY TUESDAY AND CONTINUE THROUGH TUESDAY NIGHT. AS THE
SNOWFALL FROM THE STORM SYSTEM STARTS TO WIND DOWN DURING
WEDNESDAY MORNING AND EARLY AFTERNOON...LAKE EFFECT SNOW WILL
HAVE DEVELOPED ON THE ILLINOIS SIDE OF THE LAKE. INCREASINGLY
HEAVY AND MORE CONCENTRATED LAKE EFFECT SNOW WILL SHIFT INTO
FAR NORTHWEST INDIANA DURING WEDNESDAY AFTERNOON AND PERSIST
INTO WEDNESDAY EVENING BEFORE SHIFTING FURTHER OFF TO THE EAST
INTO SOUTHWEST LOWER MICHIGAN AND NORTH CENTRAL INDIANA.

* ACCUMULATIONS...TOTAL ACCUMULATIONS FROM MONDAY MORNING THROUGH
WEDNESDAY EVENING ARE EXPECTED TO BE IN EXCESS OF 8 INCHES IN
NORTH CENTRAL ILLINOIS...AND IN EXCESS OF 18 INCHES OVER
NORTHEAST AND EAST CENTRAL ILLINOIS...AS WELL AS NORTHWEST
INDIANA. LOCAL AMOUNTS IN EXCESS OF 24 INCHES ARE POSSIBLE IN
FAR NORTHWEST INDIANA...DEPENDING ON EXACTLY WHERE THE LAKE
EFFECT SNOW BAND SETS UP AND HOW PERSISTENT IT IS OVER ANY ONE
LOCATION.

* HAZARDS...BLIZZARD CONDITIONS WITH CONSIDERABLE BLOWING AND
DRIFTING SNOW AND FREQUENT WHITE OUT CONDITIONS.

* IMPACTS...NEARLY IMPOSSIBLE TRAVEL CONDITIONS AS SNOW WILL BE
ACCUMULATING AT A RAPID RATE DURING THE PEAK OF THE SNOW STORM
TUESDAY AFTERNOON AND NIGHT. HEAVY LAKE EFFECT SNOW IN NORTHWEST
INDIANA LATER WEDNESDAY AND WEDNESDAY EVENING WILL CONTINUE TO
SNARL TRAVEL THERE.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A BLIZZARD WATCH MEANS THERE IS A POTENTIAL FOR FALLING AND/OR
BLOWING SNOW WITH STRONG WINDS AND EXTREMELY POOR VISIBILITIES.
THIS CAN LEAD TO WHITEOUT CONDITIONS AND MAKE TRAVEL VERY
DANGEROUS.
Member Since: Posts: Comments:
Quoting originalLT:
Hoy, when is your flight schedualed for on Wed.?


4 PM :(
Member Since: January 20, 2009 Posts: 0 Comments: 1503
Member Since: July 15, 2006 Posts: 171 Comments: 53779
Member Since: July 15, 2006 Posts: 171 Comments: 53779
Quoting Hoynieva:
What a mess...

Monday Night
Mostly cloudy. A chance of snow after midnight. Lows around 19. Northeast winds 5 to 10 mph. Chance of snow 50 percent.

Tuesday
Snow likely. Highs in the lower 30s. Northeast winds 5 to 10 mph. Chance of snow 60 percent.

Tuesday Night
Freezing rain and snow likely. Sleet likely after midnight. Lows in the upper 20s. Chance of precipitation 70 percent.

Wednesday
Freezing rain likely in the morning. Rain likely. Highs in the upper 30s. Chance of precipitation 70 percent.

Wednesday Night
A chance of rain in the evening. Mostly cloudy with a chance of snow. Breezy with lows in the lower 20s. Chance of precipitation 50 percent.
yep north of that in my area all snow we could be looking at a foot or more from this event

mess to the south of me
Member Since: July 15, 2006 Posts: 171 Comments: 53779

Viewing: 117 - 67

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36Blog Index

Top of Page

About Blizzard92

Cornell University- Atmospheric Sciences Undergrad; Research Assist.- Onset of Spring Indices Toolbox; Interests- Small spatial scale climatolology

Local Weather

Scattered Clouds
88 °F
Scattered Clouds

Blizzard92's Recent Photos

Personal Weather Stations

Linglestown, PA
Elevation: 520 ft
Temperature: 24.2 °F
Dew Point: 15.2 °F
Humidity: 68%
Wind: Calm
Wind Gust: 9.0 mph
Updated: 10:37 AM EST on January 18, 2014

About Personal Weather Stations