Thursday, February 2, 2012

7:00 PM CST February 2-6 Snowstorm Update

The Weather Centre
Winter Weather Message
7:00 PM CST

Discussion-
Latest Water Vapor imagery indicates large amounts of precipitation are developing in the Blizzard Warned areas, including Kansas, Colorado and Nebraska. As of now. . .the threat of a dry slot is not a big concern for those areas as abundant moisture is surrounding the dry air that would otherwise be moving into the storm's center.
Now seeing rain break out in west Kansas, thus validating my concern of a possible flash freeze when snow begins falling in that area.

For now. . .will not adjust concerns from our 4:00 PM CST update (click here).
Will not be issuing a snow accumulation map for the rest of the storm due to undisclosed reasons.

-Andrew

Notice

Sorry everyone. The Severe Weather Spring Forecast has been delayed for a temporary time.

The 7:00 PM CST snowstorm update is still on.

February 2-6 Significant Snowstorm Discussion (2/2/12)

This is a formal discussion and not a briefing.
No graphics will be provided.

The Weather Centre
Winter Weather Message
Concerning: Feb. 2-6 Winter Storm
Level of Concern: High
4:00 PM CST

Discussion. . .
Expecting strong storm system to impact the West Plains in the next few days, bringing with it significant snowfall and rain. This discussion concerns the snowfall aspect.
Currently seeing a spinning motion on infrared imagery, indicating the presence of the storm system in question. The storm system is currently in the Wyoming/Colorado vicinity and should begin producing snow shortly, if not already. 
Infrared looping indicating a burst of precipitation possible in far west Kansas. Do feel that this is the beginning of the storm system's rapid strengthening, as the very distinct spinning motion on satellite loops is showing the eagerness to pull any air into itself. 
It looks like the big snows are beginning now for those areas now under a Blizzard Warning, including northwest Kansas, southwest Nebraska and east Colorado.These big snows are indicated by the aforementioned burst of precipitation on infrared. As the system begins to move into the Plains. . .feel that this is the beginning of a long night tonight and day tomorrow of snow.
Recent GFS trends have really backed off snowfall totals in Iowa, with the 'winners' in Iowa receiving maximum 4 inches. The NAM, known to overdo snowfall amounts, is putting out a good 6 inches in or near Iowa. After recent trends. . .do feel that GFS is on a right but unfortunate track following our big snowstorm prediction. This is a traditional February Curveball, with many more sure to come.
Have seen several short range models indicate the potential for up to a foot of snow in KS/NE. Feel that those amounts are close to what the totals should be, as the storm is starting now even as the system itself has not exactly emerged into the Plains just yet.


Further Concerns. . .
System does not appear to currently have a defined tilt. However. . .have noted in recent 500mb observations that the system is pushing for a negative tilt. If a neg. tilt is to arise. . .thundersnow would be likely, considering the amount of Gulf air available to the system as well as the negative tilt indicating maturity of the system.
Temperatures currently in the 30 degree corridor for west Kansas. Main concern with this is potential flash freeze in the event rain falls first before the snow in KS. Also concerned of the changeover and how much sleet/freezing rain may fall. . .but that is not a huge concern ATTM. Colorado is sitting pretty with temperatures in the 20s in the mountains. However. . .those in the lower elevations of CO are on the lower end of the 30 degree corridor. Think that concern for an icy changeover is lessened as temperatures should be falling soon, if not already.


Next Update. . .7:00 PM CST
Questions can be asked below.
-Andrew

Februrary 2-6 Snowstorm Update at 4:00 PM CST


Today's Schedule

February 2-5 Snowstorm Update at 4:00 pm CST

Severe Weather Spring Forecast Update at 5:00 PM CST