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Winter 2014-2015 Pattern Discussion Thread III


BIG FROSTY

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This has definitely been a classic El Nino winter in terms of temperature & precipitation, December & January are fairly typical looks for a traditional, east-based El Nino...

 

 

& it's actually been wetter than normal in your region & the precipitation distribution is about as classic as it gets for an El Nino, w/ wetter than normal conditions east of the Appalchians & thru the coastal southeast & w/ drier than normal conditions over the Tennessee & Ohio Valleys

 

 

 

 

Nope.....unless you are saying just around the Florence area, as it's slightly above. The rest of the area(CAE) is normal to slightly below, with mby just to the sw of CAE is slightly below along with Augusta and a portion of the upstate. CAE is about 1.25" under for the year so far

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Nope.....unless you are saying just around the Florence area, as it's slightly above. The rest of the area(CAE) is normal to slightly below, with mby just to the sw of CAE is slightly below along with Augusta and a portion of the upstate. CAE is about 1.25" under for the year so far

 

Lol, we are talking of course about meteorological winter... (December-February)

 

The overall precipitation distribution is very close to what is expected in an El Nino...

 

Over the last 60 days according to AHPS precipitation analysis, it's actually above normal in Columbia... Womp

US-Precipitation-Correlation-DJF-NINO-3.

 

 

image.jpg

 

 

Yeah this is completely uncharacteristic of a warm ENSO neutral-weak El Nino event...

 

:)

US-Precipitation-Anomalies-Warm-ENSO-Neu

 

US-Precip-Anomalies-Last-90-days-Feb-9-2

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Lol, we are talking of course about meteorological winter... (December-February)

 

The overall precipitation distribution is very close to what is expected in an El Nino...

 

Over the last 60 days according to AHPS precipitation analysis, it's actually above normal in Columbia... Womp

 

 

 

 

 

 

Yeah this is completely uncharacteristic of a warm ENSO neutral-weak El Nino event...

 

:)

 

 

 

Dec.....+.79 thanks to the 2.51 that fell on the 24th

Jan......-.98

Feb......-.33

 

Soooo....that would still be below normal precipitation for Met winter.  MBY 10 miles sw of the airport has had even less rain as noted by the 75% of normal precip shown in the map above.......womp  

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Dec.....+.79 thanks to the 2.51 that fell on the 24th

Jan......-.98

Feb......-.33

 

Soooo....that would still be below normal precipitation for Met winter.  MBY 10 miles sw of the airport has had even less rain as noted by the 75% of normal precip shown in the map above.......womp  

 

The entire point of seasonal forecasting is to derive a general idea of the upcoming pattern based on a blend of persistence, hindcasted/backtested analogs, & boundary conditions, etc, all of which vary rather elusively according to background climatic, intraseasonal, and external pre-conditions & forcings... Nit-picking a specific backyard doesn't offer adequate verification of these forecasts & in fact according the NCDC for climate division 6 (Central South Carolina) in December & January is right at normal precip-wise, w/ 7.05 inches of precipitation & is ranked 73rd since 1895... Womp.

http://www.ncdc.noaa.gov/cag/

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The entire point of seasonal forecasting is to derive a general idea of the upcoming pattern based on a blend of persistence, hindcasted/backtested analogs, & boundary conditions, etc, all of which vary rather elusively according to background climatic, intraseasonal, and external pre-conditions & forcings... Nit-picking a specific backyard doesn't offer adequate verification of these forecasts & in fact according the NCDC for climate division 6 (Central South Carolina) in December & January is right at normal precip-wise, w/ 7.05 inches of precipitation & is ranked 73rd since 1895... Womp.

http://www.ncdc.noaa.gov/cag/

At normal, above normal and below normal are different things. Using met winter(Dec, Jan and Feb) You stated a few times that the precip was above normal at CAE and I'm just correcting your statement  ;) 

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At normal, above normal and below normal are different things. Using met winter(Dec, Jan and Feb) You stated a few times that the precip was above normal at CAE and I'm just correcting your statement   ;)

 

It is correct for Columbia specifically, but as usual, & quite frankly to be spiteful, you're purposely ignoring the entire main point of this discussion... The isolated, singular report says little-if anything about the regional precipitation distribution that carries far more weight in assessing the validity of the seasonal temperature/precipitation predictions which in all, (taking into account a multitude of observations that effectively normalize the data & quell outliers) are unlike some have claimed, very typical for our current ENSO base state... +Neutral-Weak El Ninos are usually .5-1.0 inch below normal precipitation wise in central South Carolina in the winter, conditions at the moment are actually on the average, slightly wetter than what's to be expected in a "borderline" El Nino event.

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At normal, above normal and below normal are different things. Using met winter(Dec, Jan and Feb) You stated a few times that the precip was above normal at CAE and I'm just correcting your statement   ;)

 

OTH, I think we can both agree that it's really frustrating to watch a low pressure center w/ a category 1 hurricane equivalent low pressure center (<~990mb) scoot harmlessly out to sea near & below the latitude of Cape Hatteras over the next few days... The 1000mb pressure anomalies are in excess of 4 standard deviations below normal, 500mb heights greater than 3.... We've had some near-misses this year, but this one in particular was a huge one.

http://www.atmos.albany.edu/student/kgriffin/maps/1000hght_stdanom/1000hght_stdanom_namer_loop.html

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It is correct for Columbia specifically, but as usual, & quite frankly to be spiteful, you're purposely ignoring the entire main point of this discussion... The isolated, singular report says little-if anything about the regional precipitation distribution that carries far more weight in assessing the validity of the seasonal temperature/precipitation predictions which in all, (taking into account a multitude of observations that effectively normalize the data & quell outliers) are unlike some have claimed, very typical for our current ENSO base state... +Neutral-Weak El Ninos are usually .5-1.0 inch below normal precipitation wise in central South Carolina in the winter, conditions at the moment are actually on the average, slightly wetter than what's to be expected in a "borderline" El Nino event.

I'm not being spiteful  :lol:   In your first response to Tamp you stated it is a classic El Nino with CAE(his area) in above normal precip. I was just correcting the statement  ;) 

OTH, I think we can both agree that it's really frustrating to watch a low pressure center w/ a category 1 hurricane equivalent low pressure center (<~990mb) scoot harmlessly out to sea near & below the latitude of Cape Hatteras over the next few days... The 1000mb pressure anomalies are in excess of 4 standard deviations below normal, 500mb heights greater than 3.... We've had some near-misses this year, but this one in particular was a huge one.

http://www.atmos.albany.edu/student/kgriffin/maps/1000hght_stdanom/1000hght_stdanom_namer_loop.html

We live in the south......near misses are how we roll   :P  

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MJO: Being inside the circle during much of the upcoming cold is consistent with the Jan stats idea of the best opportunities for persistent cold in general being when inside the circle within the nonbad phases for a decent period of time. That being said, I didn't actually look at Feb data due to time constraints. However, I don't see why a similar idea couldn't hold for Dec and Feb.

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Folks,

 As we head toward the cold Feb. pattern, I'd like to reiterate the following for ATL as a proxy for much of the SE US:

 

1. For all analyzed Feb.'s, ATL had 1+ major winter storms 15 times or during 11% of them. So, I'm calling 11% the best estimate of the overall climo based chance for 1+ FEB majors at ATL

 

2. For the 111 Feb's that were 42 F or warmer (longterm normal is ~46), only a mere 3 had a major winter storm...so, only 3% of them had a major winter storm or only ~1/4 of climo.

 

3.  For the 13 Feb.'s that were a quite cold 40-41.9 F (where ATL likely will end up if the overall cold pattern of the models is right), 5 of 13 had 1+ major winter storms (an impressive 38%, which is 3.5 times climo) for a total of 6 majors.

 

4.  When Feb. was an extremely cold < 40 F (12 times), a whopping 7 of 12 (58%, which is 5.3 times climo) had 1+ major winter storms for a total of 9 storms! That's in the stratosphere vs. overall Feb. climo!

 

 So, to summarize ATL Feb. winter storm chances:

- Feb 42+ F: 1/4 of climo

- Feb 40-41.9 F: 3.5 times climo 

- Feb <40 F: 5.3 times climo

 

 

 Bottom line: The correlation of major winter storm frequency and avg. Feb. temperatures is quite strong and quite possibly stronger than that for Dec and Jan. The colder, the better. Assuming the rest of Feb. will be dominated by a cold pattern as per model consensus, I will have plenty reason to at least hope for a widespread SE major winter storm at some point this month. At this point, 40-41.9 is looking likely per models. However, I'm still not counting out the chance for a sub 40 F Feb.

 

**Edited for typo

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Two multiinch IP's within one winter much less within four days as per the 0Z Euro would be unprecedented since at least the late 1800's in ATL. So, take with a grain of course. Interestingly, ATL has gotten 2 major SN's (4"/6") within four days in 2/1895 (weak Nina) & 2 major ZR's within 4 days in 2/1905 (weak Niño) & in 12/1935 through 1/1936 (high end neutral +). So, two majors within four days happened 3 times within 41 years (twice with similar ENSO) (twice in Feb). So, it has decent precedent & we are probably overdue in a sense since it has been 79 years after having 3 of them within 41 years.

The two major ZR's in 1/2000 were a week apart. 2/1979's 2 majors (ZR/IP) were ~11 days apart. So, there have been 3 Feb's with 2 majors. The great 1/1940 weak Niño had 2 majors (ZR/SN) but they were ~2.5 weeks apart. The great weak Niño of 1884-5 had 2 majors (1 in jan & 1 in Feb). Those were 2 of my top analogs fwiw.

ATL has had 2-3 majors ~once every 13 years. The last one was 15 years ago.

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Comments from HM on today's Euro weeklies...

 

"New ECMWF weeklies continue to suggest a gradual building of the southern US / SE ridge in March (weeks 3-4). Surface temps respond week 4.  Week 2 spatially is similar to week 1 but moderates cold. Week 3, the cold shrinks further and finally reversed week 4."

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Comments from HM on today's Euro weeklies...

"New ECMWF weeklies continue to suggest a gradual building of the southern US / SE ridge in March (weeks 3-4). Surface temps respond week 4. Week 2 spatially is similar to week 1 but moderates cold. Week 3, the cold shrinks further and finally reversed week 4."

Should make Pack happy. After next week, the end of winter seems inescapable. :(

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