A Tale of two seasons coming...winter's breathing again?

[Stormsfury]

Portions of the Heartland may get the best of BOTH seasons if the GFS/ECMWF verify.

GFS 108hr
http://www.nco.ncep.noaa.gov/pmb/nwprod ... 6_108m.gif
GFS 120hr
http://www.nco.ncep.noaa.gov/pmb/nwprod ... 6_120m.gif
GFS 132hr
http://www.nco.ncep.noaa.gov/pmb/nwprod ... 6_132m.gif

Now the ECMWF
Day 4 - 997mb Low swinging out into the Plains from Western KS
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
Day 4 850mb Temperatures
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Day 5 - 1001mb low in northern MO - Initially moisture will be limited Day 4 but by Day 5, Best Moisture is confined primarily north/west of the Low, thus not as aggressive with the severe wx threat as the GFS seems to indicate.
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
Day 5 850Temps - Notice the Eastern States in a CAD regime and the Plains where the 0C thermaline swings around behind the low.
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Day 6 - 997mb low in Michigan -
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
500 mb level - A very sharp full latitude trough carves out with a closed 500mb low NW IL/SW WI (cuts off)
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
850mb Temperatures - Look out MO (WX247) as RH values 100% indicate potential for a nice snow event - and the ECMWF finally returns good moisture to set up a potential for severe wx in the Southeast and Florida..
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
Day 7 - 500mb Geopotential Heights - A very sharp full latitude trough continues and begins to negatively tilt ... an interesting setup occurs where portions of the Northeast may likely be WARMER than portions of the Deep South
Surface Features - Low now in Canada at 990mb
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
850mb Temperatures - Ummmm, A little cold, but New England, warmer? May happen.
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest
And based on RH values in Tennessee suggest the potential for a late season snowfall.

[JQ Public]

hmmmm very interesting ...

[Amanzi]

Thanks for that SF. More Severe wx for us down here?

[Stormsfury]

Thanks for that SF. More Severe wx for us down here?

Hi Amanzi. The 06z GFS seems to think so ... develops a squall line and pulls it through most of Florida, and Southern GA. Last night's ECMWF also seems to think so as well (24 hour increments for the EC is a big drawback though), however, at 144 hr - The line strengthens further north into South Carolina, and the line loses some intensity in Florida.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 6_138m.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... 6_144m.gif

[Amanzi]

Thanks SF.
The Carolina's have really been under the gun, even with winter storms. Hope the canes dont decide to pay them a visit "cause it is the place to go if your a storm"....lol

[Stormsfury]

Thanks SF.
The Carolina's have really been under the gun, even with winter storms. Hope the canes dont decide to pay them a visit "cause it is the place to go if your a storm"....lol

Particularly North Carolina.
I only had one snow event (January 23rd) and it was only around ½" of snow.

Thunderstorms and heavy, and sometimes flooding, rains have been hitting us hard this month, that's for sure.

Yep, I'll be watching, of course, especially if a tropical system looks to coming my way. (Climatologically speaking, Late August, and Septemeber).

[Guest]

What does this have in store for Southeast Texas Stormsfury? Thanks for any input.

Patricia

[Stormsfury]

What does this have in store for Southeast Texas Stormsfury? Thanks for any input.

Patricia

ATT, the moisture return across SE TX looks somewhat limited (in the wake of the exiting low off the SE on Wednesday, however, this is the 108hr mark across the country depicted by the GFS 108hr QPF map.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 6_108m.gif

[JQ Public]

don't ya love nc weather

[Rainband]

Thanks for the info Stormfury. I am not worried about bad weather here, it always misses us I will keep an eye on it though


Johnathan

[Stormsfury]

Regarding the changing of seasons and the severe weather potential crunched in...tonight's 18z GFS run a little more loaded with QPF potential than last night's run, less CAD, and more southerly flow around the exiting high ... it has now downplayed the forerunning low.
18z GFS precip runs ...
GFS 42hr to 102hr - QPF potential - Look out Upper Great Plains!
http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_102m.gif
GFS 72 to 132hr - QPF Potential - Missouri/Illinois
http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_132m.gif
GFS 102 to 162hr - QPF Potential
Potential again for heavy rainfalls once again through the Carolinas and on up into the Mid-Atlantic/Northeast.
http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_162m.gif

18z GFS 144hr plot - Squall line with heavy rains through the Carolinas.
http://www.nco.ncep.noaa.gov/pmb/nwprod ... 6_144m.gif

This is beginning to appear that no one low will be totally dominant per the GFS which depicts a series of s/w's and lows riding along the cold front and full latitude trough while the ECMWF has (no surprise) a stronger and a more consolidated low than last night's run on Day 5 ... 993mb into the UP of Michigan. Day 4 has a 999mb low in IA with a fairly broad structure on the 1004mb isobar (which consolidates nicely on Day 5)

Day 4 - 500mb GEOPotential HGTS and SLP overlayed
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

Day 5 - 500mb GEOpotential HGTS and SLP overlayed
http://cyclone.plymouth.edu/cgi-bin/gen ... &cu=latest

The severe weather potential now looks a little stronger than last night's prognostication. There's plenty clashing of the seasons with sharp contrasts in temperature over a relatively short distance.

Reference to the Cold Snap in another thread.

[Amanzi]

Thanks for the update SF. Not good that the severe weather looks to be more intense.

Agree with ya Rainband...it always bypasses me too!

[Rainband]

Thanks for the update SF. Not good that the severe weather looks to be more intense.

Agree with ya Rainband...it always bypasses me too!

guess we should be careful what we wish for


Johnathan

[Anonymous]

Ok thanks for the info stormfury ! It's time to watch weather patterns more closely again between now and April.15 th as winter once again makes a comeback in many areas. JB mentioned that this April might be similar to April 1982, with lots of cold and snow.

Only thing I'm not seeing at this point is a freeze down to the lowcountry at this time for Sunday night - right now they expect surface temps from around 35 Columbia to 35 to 40 lowcountry. But then again, guidance temps might be lowered as we approach this time frame.

Let it storm...

Ken