Severe Wx Threat for the East?

[TNE]

...Another Cut-Off forecasted for March 22 (Thursday) on the 18z GFS, and the threat is MOST similar to January 11th, 2012 and March 4, 2008 (analogs).

The severe threat comes on the Backside of a potentially strong Warm Spell that blankets most of our area next week.

1.Analogs:

January 11 2012: Associated with Cut-Off Energy. Warm Sector tightly wrapped in the South and a limited severe threat originated. Onshore flow in the Northeast. A Good Rain-Maker overall.

March 4 2012: Associated with Cut-Off Energy. Strong Forcing associated with the Phasing with the Leading Trough; Warm Sector quickly expanding into the Northeast. Widespread Wind Damage in the East. A Good Rain-Maker.

Both Analogs: 1.Rain-Maker. 2.Severe Weather in the Warm Sector.

1.CUT-OFF(S) ANIMATION:

Includes Analogs and Future Threat

2.18z GFS has a Cut-Off Low Pressure moving toward the East for Thursday, March 22, 2012. There is a Ridge positioned over most of the East on the 22nd. The Cut-Off Center is positioned over IL. The Cut-Off Low is in IN on the 23rd/ 15z. There is a strong moisture flow coming from the Gulf toward the East by Late Thursday ahead of the cut-off and into the very warm air mass over the East. If enough instability builds out ahead of the propagating Cut-Off Low, parts of the East might be looking at a severe weather event given enough instability. The Instability would be affiliated with a supportive moisture flow and High Dew-points, and High Daytime Temperatures. At this point given the forecast and the analogs presented, there is potential for 1. A Cut-Off Low on or near Thursday, March 22, 2012. 2. A Strong Moisture Flow to be associated with the Cut-Off 3. Severe Weather in the Warm Sector. 4. The Warm Sector to be Extensive considering the warm temperatures forecasted for all of next week...

2.18z GFS (7 DAY FORECAST):

TNE

[Amped]

Surface low looks too weak. That and the ocean isn't too warm north of SC.

[TNE]

The Surface is "May" Warm on the Recent Model Runs, but the Higher Dewpoints and Surface Instability is suppressed(reference to images posted under 1).Winds are SW, S, SE (close to front), NW behind the front (reference to images posted under 1).

The intensity of the Front and Surface Low and the higher dewpoints spreading north will depend on the phasing. The Cut-Off feature shows signs of the moisture circulating into the Leading Trough (reference to images posted under 2). If Full Phasing occurs and there is a tight temperature gradient, there will be a stronger Upper Trough in place. Something to watch as it appears the ECMWF allows the Upper Trough to push into the Lakes, while the GFS keeps it sequestered in Canada. On the other-hand, the GFS keeps the Cut-Off closer to the Lakes while the ECMWF shows the Cut-Off passing in the Mid-South (reference to images posted under 3).

1.Surface & Instability Look:

2.700MB and Moisture Circulation into the Leading Trough:

2.

3.18z GFS vs. 12z ECMWF:

[TNE]

The 06z GFS tracks the Cut-Off energy Northward and shows signs of Phasing with the Primary Low in Canada (for reference see animation under 1). Instability axis has shifted from the Mid-South to the Great Lakes (for reference see animation under 2). A solution like this would be key for Severe Weather for areas in the Northeast. On the other side, there is little to no change on the ECMWF, the 00z run continues to show the Cut-Off in the Mid-South. The 00z ECMWF solution would resemble more the previous 18z GFS run rather than the 06z GFS run.

March 18, 2012 [sunday] 06z GFS Vs. 18z GFS:

1.850:

2.Instability Axis: