ATL: Why I'm not excited for 2/21 vs. very excited for 1/29

[LarryWx]

**I meant for my header to say, "ATL: Why I'm not excited for 2/21 vs. very excited for 1/29" Sorry about any confusion!!


I've just closely examined the 2/14 12Z ECMWF run in order to make comparisons to the 1/23/05 12Z run, which was six days in advance of Atlanta's major icestorm. On 1/23, I had posted on another BB:

"12Z EC says ice/sleet storm threat for ATL next wkend and wintry threat most of SE"

In strong contrast, for Pres. Day (2/21), even with the significant southward track change on this latest ECMWF run, I still don't see anything remotely as threatening for ATL on today's 12Z ECMWF at day 7. Here are my points:

1) On the 1/23 run, there was a MUCH stronger surface high (1039 mb) vs. only 1029 mb on today's run. A pressure of ~1030 mb was shown wedging into Atlanta on the 1/23 run vs. a mere 1020 mb on today's run. The wedging then was about as strong as any in recent times in ATL vs. the ordinary/unimpressive wedging on today's run. Moreover, that 1/23 run's high center actually verified in the low 1040's for that time period (vs. 1039) and as high as 1047 mb 12 hours earlier!

2) Despite the big southward shift, the sfc low on today's run is still ~250 miles further north and a bit stronger than what was shown on the 1/23 run, thus not allowing for nearly as much wedging into the ATL area.

3) Whereas the high center was nearly stationary for well over 24 hours in perfect CADDing position for our area and modeled that way by the ECMWF well in advance, this upcoming event's high is moving offshore much more quickly per the ECMWF and other models.

4) Related to the above, today's EC has 850's for ATL that already are as high as +6C near the start of the precip. and go to as high as +7C before it ends. Contrast this with the +2C at the start of the 1/05 ice storm and reaching to near +6C to
+7C only near the end. (The EC had accurately predicted near +2C at the start of the storm all the back to the 1/23 12Z run!) A range of +2.5 to +5C is the most favored range based on historical weather maps for ice in ATL.

Things could still change, but as of now the setup is still a far cry from the nearly ideal 1/05 icestorm setup. If future runs don't change significantly, I'll very likely never get excited for anything significant for ATL from this particular storm. (I'm not directly addressing areas like NC, maybe upstate SC, and perhaps extreme NE GA, which would likely be in a better position than ATL at least initially for some wintry precip. due to being colder.) Regardless, I'll still be looking at later next week into early MAR for a POSSIBLE wintry event (snow?) strictly based on weak El Nino analog winters, especially with the current -NAO that is forecasted to get quite strong.

[krysof]

The 18z gfs looks horrible for anyone who wants wintry weather.

[JenyEliza]

The 18z gfs looks horrible for anyone who wants wintry weather.

You do know that there are other models besides GFS, right?

[LarryWx]

Ooops, I meant 2/21 (Pres. Day), not 2/20.

[LarryWx]

The 18z gfs looks horrible for anyone who wants wintry weather.

Then again, the GFS is a "horrible" model. So, I honestly hardly care what it shows. I haven't seen it.

[LarryWx]

Dang it, I meant for my header to say, "ATL: Why I'm not excited for 2/21 vs. very excited for 1/29".

I originally had it as "ATL: Why I'm not excited for 2/20 vs. very excited for 2/23". Sorry about any confusion!!

[Stormsfury]

The 18z gfs looks horrible for anyone who wants wintry weather.

LMFAO ... dude, really. you're getting on my last nerve.

First of all, if you would take the time to READ why the GFS is SO HORRIBLE in the MR, ESPECIALLY WRT cold air damming scenarios, even just 48 hours out in advance, you would understand why that most of the PROS and well versed amateurs do NOT look at SFC details (and 500mb patterns sometimes) WRT to the GFS at that timeframe.

The GFS is a good SHORT RANGE MODEL.... right now, there's more than an overwhelming consensus with the ECMWF/UKMET/GGEM WRT to a damming scenario with a TON of overrunning moisture from the SBJ, and the SBJ moisture MIGHT be underdone! ... We are dealing with the state of the NAO about to FINALLY go NEG, and what a good many people are missing WRT to El Niño winters, especially weak ones that climo favors the COLDEST Niño winter months to be in February and March....

SF

[LarryWx]

I've just seen today's (2/15) 12Z ECMWF run and remain totally unexcited about any chance for wintry precip. of any consequence for the Atlanta area this SUN/MON. Compared to the ECMWF maps out this far in advance of the 1/29/05 icestorm, it is like night and day for the Atlanta area.