Latest eta/gfs have missed something, possibly important

[lookout]

guys and gals, the last few runs of the eta/gfs were hugely inconsistant with previous runs with respect to precip amounts over north georgia and south carolina. Indeed this morning it looked like the latest runs were right with vastly differant rainfall axis to the south than progged earlier. HOWEVER, look at the heavy rainfall exploding in south Alabama and along the coast back to the La coast due to the expected surface low development of the La coast. but if you look at the 12z eta/gfs NEITHER shows this precip at all. Both are too far east with the precip along the gulf coast this afternoon. the direction of this precip is a good bit more northerly, say nne to ne, rather than east to northeast of the earlier axis of precip across central georgia and south carolina. latest ir satellite also shows an increase in colder cloud tops shooting off to the nne and ne from the gulf coast. So with that in mind, does it continue to increase and if it does, does it make it into the cad regions of north ga and the upstate late this afternoon and this evening? if so then what looked like a complete non event for areas north of highway 78 and west of highway 441 in georgia could be completely wrong. and naturally this would spill over into the upstate much further north than earlier precip. so whats others opinions on this?

still 28.8 here, 29/30 in athens depending on the station and almost universally 27 in south carolina. 12z eta still keeps temps well below freezing through the night.

[Weather4Life23]

Yes, I have noticed the same thing. It looks like another disturbance is coming out of the Gulf of Mexico. Something that needs to be watched carefully.

[2001kx]

hey Weather4Life23 what storm is that in your avatar?

[Weather4Life23]

The January 2000 2 feet snow storm that surprised everyone.

[Dan]

guys and gals, the last few runs of the eta/gfs were hugely inconsistant with previous runs with respect to precip amounts over north georgia and south carolina. Indeed this morning it looked like the latest runs were right with vastly differant rainfall axis to the south than progged earlier. HOWEVER, look at the heavy rainfall exploding in south Alabama and along the coast back to the La coast due to the expected surface low development of the La coast. but if you look at the 12z eta/gfs NEITHER shows this precip at all. Both are too far east with the precip along the gulf coast this afternoon. the direction of this precip is a good bit more northerly, say nne to ne, rather than east to northeast of the earlier axis of precip across central georgia and south carolina. latest ir satellite also shows an increase in colder cloud tops shooting off to the nne and ne from the gulf coast. So with that in mind, does it continue to increase and if it does, does it make it into the cad regions of north ga and the upstate late this afternoon and this evening? if so then what looked like a complete non event for areas north of highway 78 and west of highway 441 in georgia could be completely wrong. and naturally this would spill over into the upstate much further north than earlier precip. so whats others opinions on this?

still 28.8 here, 29/30 in athens depending on the station and almost universally 27 in south carolina. 12z eta still keeps temps well below freezing through the night.

yeah, I noticed the same thing on a national radar loop. Let's see what's going on about 3 hours from now, and then we can determine if the Altanta area and NE GA has dodged the bullet.

[Dan]

NOW, this is interesting...

http://www.srh.noaa.gov/radar/loop/DS.p ... kmob.shtml


Could this developing batch of precip have implications later on this evening?

[JQ Public]

mmm delicious

[JQ Public]

oo yeh one question...that radar is the composite reflectivity and the other is short range...whats the difference?

[Weather4Life23]

Im beginning to wonder if this is the batch of precip we need to watch.

[lookout]

oo yeh one question...that radar is the composite reflectivity and the other is short range...whats the difference?

composite simply looks further up in the air to find precip that has not reached the ground yet. this is usefull a lot of times because it will show trends before the actual reflectivity shows it and also allows you to see if the precip is forming/falling higher up or developing more toward the surface.

[Dan]

oo yeh one question...that radar is the composite reflectivity and the other is short range...whats the difference?

I don't know technically the difference between short range and composite radar, but I do notice that on short range, you can easily detect the areas of heavier precip within a batch of precip. Short range is better radar in severe weather situations, in winter weather I would think a composite view would give the better indication.

[beanskip]

Based on that Mobile radar, this new HPC QPF map is ALREADY obsolete!

http://www.hpc.ncep.noaa.gov/qpf/fill_91ewbg.gif

[chrisGA]

the new 18z eta came out and kidna shows the precip in the 12-18 hour range moving over central and north bama. the problem is that the cold fromt is moving in and the wedge should be scoured out by the front. could there be snow in north alabama with this new impulse b/c the cold air will be rushing in later tonite and eventually into north ga by tomorrow morning

[lookout]

the new 18z eta came out and kidna shows the precip in the 12-18 hour range moving over central and north bama. the problem is that the cold fromt is moving in and the wedge should be scoured out by the front. could there be snow in north alabama with this new impulse b/c the cold air will be rushing in later tonite and eventually into north ga by tomorrow morning

chris, thats something totally differant and is actually associated with the upper level low/frontal boundary. what we are seeing in alabama/ms is precip with a weak low pressure area. again, the 18z eta is completely wrong in its precip fields. its totally missing the rain in southern/central alabama, south ms, eastern la, and off the gulf coast. take a look at the composite and you will see redeveloping precip aloft now taking place south of athens and atlanta. precip northern edge near columbus is now moving slowly nne instead of east-northeast and returns are continueing to increase and moving northeastinto now south central alabama. its hard to figure what to make of this and what possible impacts it could have for areas east of atlanta that are still 28-30. (28.7 here). its hard to imagine the eta/gfs could be off this much but the returns are impressive, especially on composite imagery.

[JQ Public]

will it make it here or rob the moisture for us up north?

[Weather4Life23]

JQ, I am wondering the same thing. We are still locked in below freezing.

[Wannabewxman79]

I was wondering the same thing, maybe Stormfury can shed some light or is he without power down in SC?

[polarbear]

Composite reflectivity on the NWS radars shows the highest dBZ return for all the tilts that were scanned for that volume. Basically, each pixel block on the composite image shows the highest reflectivity value in a vertical column that the radar received from all the elevation scans that the radar performed during the last volume scan. The radar might of performed 14 different scans at 14 different elevation tilts and would display the highest return for each vertical point on the display.

[JQ Public]

thanks guys!

[Stormsfury]

I was wondering the same thing, maybe Stormfury can shed some light or is he without power down in SC?

No, I was at work today and did post a small thread ... Still with power and sitting at 34º ... no ice yet, but I'm under a winter storm warning, and expecting possibly as much as ¼" of ice accum. by tomorrow morning ...

I'm trying to catch up on all the datasets and will take quite a bit of time to put something together ...

SF