ECMWF continues to show significant SVR WX next week

Stormsfury · #1 Postby **Stormsfury** » Wed Mar 12, 2003 10:14 pm

Day 6 EURO 500mb heights - 500mb low cuts off in KS/NE region

http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Day 7 EURO 500mb heights - cutoff low moves very, very slowly. Pretty much in the same region.
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

And still not moving much for the Day 8, 9, and 10 day (3 day average). - only reaching the NW IL/SW WI border for a 3 day average.
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

The surface features bear out the potential - with a 985 mb low over North Central KS on Day 6.
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Day 7 the first surface low jets out into Northern IL/Southern WI region as a new strong disturbance at 988mb develops back in KS once again pinwheeling around the 500mb cutoff low.
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Now the wind streamlines - 850 mb
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

500mb Wind Streamlines
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

200mb Wind Streamlines - Very good divergence in the jet stream level will allow for nice convergence along the surface
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Day 7 Wind Streamlines - 850mb level
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Wind Streamlines - 500mb level
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Wind Streamlines - 200mb level - even at jet stream level, a low cuts off which will only prolong the threat for continued regeneration of waves of strong to severe thunderstorms with flooding potential, based on the overall slow movement of the entire almost vertically stacked storm system.
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Bottom line - Best potential for a significant severe weather and tornado outbreak lies on Day 6, and severe thunderstorms again on Day 7. The potential will exist for torrential flooding rains as well as repeated thunderstorms will continue to develop in waves as disturbances will likely continue to pinwheel around the massive cutoff system Day 7 and afterwards.

#2 Postby **wx247** » Wed Mar 12, 2003 10:39 pm

Stormsfury...what areas do you think stand to see the best chances of svr. wx and/or flooding?

Stormsfury · #3 Postby **Stormsfury** » Wed Mar 12, 2003 10:48 pm

Looking at the ECMWF RH profiles ... looks the best potential for flooding looks to be in the areas north of the actual warm front with consistent rains and embedded thunderstorms, and with where supercells develop and begin to finally evolve into a squall line setting up across maybe KS/MO then moving across those areas eastward or northeastward with the individual cells moving northward ... lessening the threat for potential severe flooding afterwards as the overall line moves eastward.

The GFS paints 60 hr from hr 120 to 180 such as this.

Stormsfury · #4 Postby **Stormsfury** » Thu Mar 13, 2003 9:50 pm

As the 60hr GFS map above shows, a flooding threat will now possibly exist for North Carolina/South Carolina from the 120-180 hr timeframe (60 hour QPF map).

The ECMWF tonight, paints a grim picture with quite a prolonged opportunity of severe weather and possibly significant tornadoes.

Day 5 EURO cuts off the 500mb low.
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
Day 6 - the cutoff moves slowly east.
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
Day 7 - The cutoff low drifts northward and continues to intensify at that level. - The 300mb GFS winds are quite terrifying, actually with tremendous divergence aloft, suggesting a significant potential for large tornadoes.
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Even at the Day 8, 9, 10 (3 day average) continues to have the cutoff feature pretty much locked nearly in the same place.
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Surface Features-
Day 5 - 989 mb low over Western IA
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
Day 6 - Intensifying "Bomb" moves slowly to Eastern MN/Western WI border as a 977 mb low.
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
Day 7 - Apparently a new 984 mb low continues now again back in IA.

The Wind Streamline Profile -
Day 5 - 850, 500, 200 mb levels - at 200 mb level - tremendous divergence aloft
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Day 6 - 850mb, 500mb, 200mb levels - At the 200mb level, another jet stream impulse is moving east from the Rocky Mountain States, and will set the stage for the Day 7 984mb low which takes shape. - Again, tremendous diverge aloft.
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Day 7 - 850mb, 500mb, and 200mb levels - Now at all 3 levels there's a vertically stacked cutoff low - which pretty much guarantees very slow movement, which only justs keeps the threat for many days, and in the Eastern States, particularly the Carolinas, per GFS, a flooding threat.
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Stormsfury · #5 Postby **Stormsfury** » Fri Mar 14, 2003 12:15 pm

Time for a bump before the later ECMWF run tonight.

ECMWF continues to show significant SVR WX next week

ECMWF continues to show significant SVR WX next week

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