Cold Weather In Store; Wednesday Light Snow?

Image from HPC

 A cold front is expected to pass through the area Monday night. This event will allow clearing and, more importantly, cause large cooling behind the front. Arctic air will flood the region on Tuesday, and highs will struggle to reach the high teens. Below are sections of the 12z GFS and 12z NAM NWS MOS bulletins.

GFS MOS (MAV)
 KUES   GFS MOS GUIDANCE   12/30/2012  1200 UTC                      
 DT /DEC  30/DEC  31                /JAN   1                /JAN   2 
 HR   18 21 00 03 06 09 12 15 18 21 00 03 06 09 12 15 18 21 00 06 12 
 N/X                    23          24           8          15     6 
 TMP  22 24 23 25 28 28 27 24 22 21 18 15 14 11  9  8 13 14 10 10  9 
 DPT  14 17 18 20 23 24 23 21 20 17 13  9  7  5  4  2  2  1  1  0  2 
 CLD  OV OV BK OV BK OV OV OV OV OV BK BK OV OV CL FW CL CL CL CL FW 

NAM MOS (MET)
 KUES   NAM MOS GUIDANCE   12/30/2012  1200 UTC                      
 DT /DEC  30/DEC  31                /JAN   1                /JAN   2 
 HR   18 21 00 03 06 09 12 15 18 21 00 03 06 09 12 15 18 21 00 06 12 
 N/X                    19          25           7          16     5 
 TMP  19 21 22 23 24 23 21 21 23 23 20 16 14 11  8  8 13 15 13  8  7 
 DPT  12 15 16 18 18 18 17 16 15 13 11  9  7  5  2  1  3  4  3  1  1 
 CLD  OV BK BK BK BK OV OV OV OV OV OV OV OV BK SC CL CL CL CL BK FW 

 (Both of the MOS texts listed above are from the NWS/ NOAA)

There are a couple things to look at in these MOS texts. First is a very quick cool-down to occur early Tuesday morning. The GFS has temperatures around 14 degrees at 06z Tuesday, and around 9 degrees at 12z Tuesday.  The NAM is forecasting temps around 14 degrees as well at 06z Tuesday, and 8 degrees at 12z Tuesday. 

The second item that I want to highlight is the cloud cover-- Both models are showing clearing behind the front, so expect a very cold, clear day on Tuesday.  Several models are in agreement for this to occur.

Winds could add to the problem as well-- While extremely high wind gusts are not in the forecast, a steady breeze is possible, which will create wind chill problems (possibly below 0 during the night).

. . .

Light snow is possible on Wednesday as a weak low system will pass through the region. With little moisture, expect very small snow accumulations.

Summary

To summarize, expect a fast cool down this week-- starting late Monday night. Temperatures will struggle to reach the high teens, and winds might create wind chills below 0 during the nights. Bundle up! There is also a chance for light snow Wednesday-- very little accumulations expected.

-Chris

Snow Expected Thursday Night - Friday

Snow is once again in the forecast. While this system will not even compare to the massive blizzard that dropped nearly two feet of snow in Madison,  accumulations are expected. Read on for more.

. . . .

The models are in good agreement for a weak system to pass through the area Thursday night into Friday. Overall, weak lift is being shown throughout the event, but the air is almost saturated in the snow growth zone (Dendrite).  BUFKIT runs are showing the highest amounts of lift/ omega generally outside of the snow growth area.


Snow Forecast:

1-3" with isolated spots of 4" in most of SE Wisconsin.


Sorry for the brief update, but the common cold has me captive again. I will get back to longer posts once I feel better.


Thanks for reading,

Chris

Major Winter Storm Approaching Wednesday/ Thursday

A significant winter storm/ blizzard is expected to pulverize southern Wisconsin Wednesday night into Thursday.

Instead of updating the blog during this major event, I will be sending updates over Twitter, which can be found on the right-hand sidebar, or by clicking HERE.

Stay in touch with the newest NWS warnings, and watch the news for the latest snow forecasts.

-Chris

Major Winter Storm Next Thursday?

Confidence is increasing that a major winter storm will strike southern Wisconsin later this week (most likely Wednesday-Thursday). Many models used in forecasting are beginning to trend toward a snowy solution. If these forecasting tools continue to trend in this fashion, SE Wisconsin could be in store for a heavy snow storm. There is also potential for a blizzard, although the heavy, wet snow will make it difficult to create widespread blowing snow.

One model used in forecasting is the GFS. Let's take a look at that model first. Below is the 12z run:

Image from NWS

As you can see, this run is showing a narrow band of heavy snow from eastern Iowa to SE Wisconsin. The 5400 thickness line is also below us, which is a good indicator that precipitation above that line will be snow (this is not always the case, and the 5400 line is not the only tool used to forecast who gets snow and who gets rain).

Here is the 12z GFS snow forecast:

Image from InstantWeatherMaps.com

Again, you need to look at soundings and other charts to identify where the heaviest band of snow will be, but the map above is indicating the potential for 6+ inches of snow.

The next model that is used is the ECMWF/ European model. Let's take a look at its 00z run. This certain run is showing the 5400 line cutting through extreme SE Wisconsin-- this is one factor which I am uncertain about. Extreme SE Wisconsin has the potential to have a rain/snow mix throughout the entire event, which would result in very little snow accumulation there. 

Image from Wunderground.com

There are many other forecasting models that are used, but I will not be mentioning them in the post. Stay tuned for more updates, watch the news, and follow the latest NWS updates.

-Chris

Wet Saturday; When is it Going to Snow?

Image from MeteoCentre.net

A low pressure system is expected to pass almost directly through the area this weekend. Confidence is very high that this system will be all rain. The surface temperature is too warm, and soundings are showing an atmosphere too warm for snow. To the left is the UKMET model showing the high thickness values and the placement of the 994 mb low. Plain rain is expected this weekend-- no thunder.

Image from NWS

A cease in weather action is expected Monday - Wednesday. A ridge of high pressure will pass through the region temporarily before the approach of a new system. Precipitation type is very uncertain, but the model consensus is showing the system to reach SE Wisconsin by Thursday.  To the right is the 12z GFS model for Thursday. It shows a fairly weak low with warm temperatures and little precipitation.

The Euro is showing a snowier solution, which is promising. The GFS isn't having an impressive Winter 2012 resume so far... the Euro has been more consistent. This system is still nearly one week out, so the current forecast is bound to change. Stay tuned as we near Thursday.

. . . .

When is the next chance for snow? The models are not giving us much love-- with not much snow activity before Christmas. We'll have to watch the next couple weeks closely, but, at this point in time, the chance for a white Christmas is low (unless that Thursday system mentioned above can give us some snow that will last until the 25th).

Thanks for reading!

-Chris

Mix Today; A Look Ahead

SnowCrystals.com

A mix will continue to pass through the area as a large blizzard attacks northern Wisconsin and Minnesota. Below is the NWS snow accumulation forecast for Sunday.

Extreme SE Wisconsin will see all rain, with no snow accumulations. As you move farther north, you can see accumulations of 4-6" in central Wisconsin. The Green Bay/ Detroit Sunday night game will likely be a snow game (should be a good game). NW Wisconsin will receive the heaviest accumulations, with amounts possibly exceeding a foot.

Image from NWS MKX.

The soundings are showing cooler profiles, so advisories and watches are extended farther south. Even if you aren't under a watch, you still need to drive slowly on the roads, as a mix can create very slippery conditions.

A Look At the Week Ahead

After the Sunday system finally passes through, you can expect dry conditions for several days. Highs will struggle to reach the mid 30s due to cold air advection. Depending on how much snow you receive this weekend, snow covers could also assist in creating cooler temperatures this week. 

The next system will enter the region next weekend. As with any system nearly one week out, there is much uncertainty with this storm. Many models are showing mostly rain. The latest GFS, however, trended the storm out of the area, leaving us dry for Saturday. The Euro gives us rain, as do most models.

As I said before, there is much uncertainty with this storm, but most of the models are showing rain. We will have to watch the system as it is very likely that the models will bounce back and forth over the next week. 

Thanks for reading the update!

-Chris

Several Snow Chances Approaching

There are several chances for snow in the forecast, and this update will be highlighting some of those systems. Thanks for reading!

• • • •

The first chance for snow will occur on Friday.  Due to the warm air, we are expecting to see showers first before transitioning over to a mix. A couple models are showing a possible transition to all snow during the weekend, but we'll have to watch the latest soundings to see if the thermodynamics will support such a change. Minor accumulations are possible with this disturbance, and will depend on if we do change to an all-snow event during the weekend. 

18z GFS run (Model from NWS/ NOAA)

• • • •

The second chance for snow will be early next week as a shortwave trough enters. Cooler air is expected with this system, so an all-snow event is very possible. Since this system is nearly one week away, there is very much uncertainty. As for the GFS, today's 0z run showed a large snowstorm for the region, with a potential for a 1-2 punch. Below is the 0z model for Tuesday.

(Model from NWS/ NOAA)

As I said before, there is much uncertainty with this system, proven by the fact that the 6z, 12z, and 18z models all pushed the storm away from us.

This is just one model that I'm showing you. While I'm not going to post every single model type and run, other models are trending toward a potential snowstorm early next week. For example, the DGEX is currently projecting snow. 

• • • •

Other chances for snow are also possible later this month, but they are still very far away, and will most likely change.

-Chris

New Record Knocking On The Door

Milwaukee is approaching a new weather record... If we do not record snow by December 9th, the area will have broken its snow-less weather streak. It has been 272 days since we have last seen snowfall. We will have to watch the forecast closely to see if snow will be popping up in the forecast soon. Chances for snow are possible next week, possibly even on December 9th.

We will see precipitation today, but not in the form of snow. Let's take a look at this morning's current satellite image:

Image from NWS (weather.gov)

We will be engulfed in clouds for much of the day. We are also experiencing fog right now. The fog is expected to clear by the next hour.

As stated before, rain is expected today... mainly in the afternoon hours.

14Z run of RAP model. 

Warm temperatures will also be the norm for the next couple days. Clouds will clear on Sunday to allow more sunlight to reach the surface. Winds will also be coming in from the south, allowing for warmer temperatures. With clear skies and south winds, I think highs might go over MOS consensus predictions tomorrow, and we might be teased with temperatures near 60. DPs will remain fairly high, so temps won't soar too high.

Rain returns to the forecast again on Monday as moisture is pushed into the region. Highs will also be very warm on Monday, due to breaks of sunshine also being expected. Fairly moist air will limit temperatures though (Highs in mid 60s?). CAPE is also being shown on the models and soundings, so an isolated thunderstorm is not out of the question.

Cooler temperatures are anticipated after the Monday system passes through.

-Chris