RNS and Erica's Winter Outlook 24 hours early>>>>

Constructionwx · #41 Postby **Constructionwx** » Fri Nov 21, 2003 7:39 pm

Excessive heat in Europe!

Constructionwx · #42 Postby **Constructionwx** » Fri Nov 21, 2003 7:41 pm

How many 90+ days did you have SF? I had a grand total IMBY of 1 !

Stormsfury · #43 Postby **Stormsfury** » Fri Nov 21, 2003 7:45 pm

Constructionwx wrote:How many 90+ days did you have SF? I had a grand total IMBY of 1 !

I had quite a few but as for the highest temperature of the summer ... 97º ... That's it ... (95º CHS and that's only ONE DAY .. July 9th) ... coolest summer IMHO that I've had in a decade or more ...

This is the first year that CHS didn't record a 100º temperature in many years (need to do a little research to find the last time) but based on my records and since I've lived here, this was the first year that my location has failed to reach 100º.

SF

Constructionwx · #44 Postby **Constructionwx** » Fri Nov 21, 2003 8:10 pm

I agree, cool year. But when folks look at the climate record for this year, it will appear fairly "normal" because of the warmer than norm low temps.

Mr Bob · #45 Postby **Mr Bob** » Fri Nov 21, 2003 8:52 pm

RNS wrote:
there should be four 2" events and one 4 to 8" inch storm

This would be a truly remarkable winter for Atlanta if this were to occur....where is larry when you need a good climo research. I would be shocked if this were to verify, I do not recall any Atl winter with more than two or three events much less 4 two inches and then a major 4-8 inch storm...kids would be in school until July! Once again, RNS, I wish you good luck!

Mr Bob · #46 Postby **Mr Bob** » Fri Nov 21, 2003 9:17 pm

Some quick research shows that there has not been a single year to meet this criteria since 1930 in Atlanta. 1936 featured 1 6" event and two 2" events and 1940 featured an 11" and an 8" (what a time to be an Atlantan!) event but there is nothing else that is even close to this forecast....

Squall52 · #47 Postby **Squall52** » Fri Nov 21, 2003 9:18 pm

I love the specifics you're putting out, but i'm going to be very unsure of all this verifying for awhile. But I'll bite.

Fairport, New York(just se of Rochester, might as well refer to that as the local)
Thanks in advance, RNS/NeWxgirl.

#48 Postby **RNS** » Fri Nov 21, 2003 9:27 pm

its very interesting that you bring up Ana. It was the first atlantic tropical system of this year...occuring in April, and pretty much for one set the tone for the remainder of the season activity wise.

the last time such an event occured was 1992, during an inactive tropical season. 1992/93 has showed up in many composites and i also believe it may serve as a good analog to the events which take place this march.

now i know what most of you would be thinking reading that...Sh!t...he's calling for a repeat of march '93, and that would not be correct either. what i do think however is that one of the limited number of severe coastal storms we have this year may occur around the same time period in march.

Stormsfury · #49 Postby **Stormsfury** » Fri Nov 21, 2003 9:33 pm

And interesting in March, during some of the stronger El Niño seasons, typically, the coldest winter month occur during this month. The March Superstorm was a pure aberration with the subtropical jet, the polar jet, and the arctic jet phasing (triple-phased storm) ...

For those that haven't read this write-up and viewed some of the reanalysis maps for the Superstorm 93 plus a 2 day Satellite loop ... here's your chance ...

The Superstorm began as a strong baroclinic leaf over the GOM and quickly and deepened rapidly eventually bottoming out at 960mb over Chesapeake Bay ...

http://www.stormsfury1.com/Weather/Wint ... storm.html

March Superstorm 2 day Satellite Loop (2.8 MB)
http://www.stormsfury1.com/Weather/Wint ... atLoop.gif

#50 Postby **RNS** » Fri Nov 21, 2003 9:36 pm

first off its simple analogging... if our years are correct...these ideas should pan out. however, they are just to give you a general idea of where things are going. its not unusual for atlanta to have a 2" event, this year however, there may be more one or 2" events than normal. however, our seasonal totals are by no means even close to records for that area.

FAIRPORT NY:

SNOWFALL: 95-110" predominantly from LES
TEMPERATURE: -0.5 TO -1.5

it will take the lakes much longer this year to freeze, and open the door for more significant LES events.

#51 Postby **RNS** » Fri Nov 21, 2003 9:38 pm

hey SF...you have any H85 maps from the event...

Stormsfury · #52 Postby **Stormsfury** » Fri Nov 21, 2003 9:41 pm

RNS wrote:hey SF...you have any H85 maps from the event...

I just viewed some maps I made (but I didn't save) ... hold on, I'll post them (I was doing Relative Vorticity and Absolute Vorticity) but wind speeds at 850mb, 500mb, and 200mb

SF

#53 Postby **RNS** » Fri Nov 21, 2003 9:44 pm

ok great...thanks.

i wanted to see how tight the H85 thermal gradient became as the low bombed over the chesapeake

Stormsfury · #54 Postby **Stormsfury** » Fri Nov 21, 2003 9:45 pm

850mb Absolute Vorticity March 13th, 1993 0z

850mb Absolute Vorticity March 13th, 1993 12z

850mb Absolute Vorticity March 14th, 1993 0z

850mb Absolute Vorticity March 14th, 1993 12z

Stormsfury · #55 Postby **Stormsfury** » Fri Nov 21, 2003 9:51 pm

850mb Temperatures (2ºC increments)

March 13th, 1993 00z

March 13th, 1993 12z

March 14th, 1993 0z

March 14th, 1993 12z

March 15th, 1993 0z

March 15th, 1993 12z

Stormsfury · #56 Postby **Stormsfury** » Fri Nov 21, 2003 9:57 pm

Temperature Advection 1ºC increments

March 13th, 1993 00z

March 13th, 1993 12z

March 14th, 1993 00z

March 14th, 1993 00z North American View

March 14th, 1993 12z NA View

#57 Postby **RNS** » Fri Nov 21, 2003 10:00 pm

thats definately an impressive vorticity maximum. what i was looking for was weak positives or slight negatives in the absolute vorticity to the north and east of the main vortmax which might be able to telegraph regions which may be unstable to slantwise parcel displacements.

when the absolute vorticity of the geostrophic flow is weakly positive, close to zero or slightly negative...it can telegraph for us regions which may be unstable to slantwise parcel displacements (CSI) given sufficient saturation within that layer.

for those that are unaware...CSI is what is normally responsible for the thundersnow that you sometimes observe with systems such as the march 1993 superstorm. it can enahnce snowfall rates locally and result in higher totals that may deviate above the overall totals in areas which do not see banded snowfall.

CSI predictors can be analyzed by models, however...the location at which the bands set-up cannot be resolved by the models themselvs. radar obs indicating enhanced snowfall in banded features is one good indicator that the environement is symmetrically unstable. the other would be satelite obs shwoing multiple clouds bands paralell with the direction of the thermal wind.

#58 Postby **RNS** » Fri Nov 21, 2003 10:09 pm

Ah...notice how on the GFS (MRF) analysis for 0Z (in 2C incriments) 3/14/93...how there is a strong thermal gradient at H85 between the warm sector, and the very cold air thats being drawn in behind the low.

anytime one observes the tightening of the thermal gradient like that at any level, it usually indicates the presence of enhanced frontogenesis (which is a tightening of the thermal gradient over a particular area), in addition to enahncing precipitation, forntogenesis tends to prolong the life cycle of CSI.

the best overall set-up for this is one would want to have the symmetrically unstable layer above the sloping frontogenesis, in an environment which is sufficiently saturated.

Stormsfury · #59 Postby **Stormsfury** » Fri Nov 21, 2003 10:10 pm

If I recall correctly, a lot of the thundersnow activity also occurred with the deformation zone around the 500mb low ...

#60 Postby **RNS** » Fri Nov 21, 2003 10:16 pm

its possible that there was unstable layers in the deformation zone as well.

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