Severe or Heavy Rain out to 48 hours ahead of ap. cold front

[LMolineux]

Well it looks like the Battle Lines are made from the Ohio Valley East towards the Delaware Valley are up to the Addorondacks (sorry i cant spell that good). But it looks very likely that this battle area will take place from 36 to 48 hours away from now. IMO i feel it is going to be either Severe Weather with gusty winds or some heavy rain. Only time will tell but it looks very likely and then afterwords some nice cool air behind that first front. Then the Second more potant cold front will usher in the colder air finally.

[RNS]

The Cold shot coming should not be underestimated. This evening/s 18z GFS has the -10C isotherm at H85 all the way down to new york city.

Soundings per the 18z GFS further west into eastern PA would be supportive of snowfall IF lake-effect were to occur. Note that there is weak surface based cape areound 77 J/kg, and no CIN, however that said, we must assume that there is something in the way of a lifting maximum in order to form convective snowfall. since WBZ heights are below ground and actual FRZ height w/o evaporational cooloing is already down to 1000mb (at KABE)... thus dynamical cooling will not be an issue, however as stated we must have the lifting. there does appear to be a 500mb vorticity maximum passing over the lakes at 96hrs which could support additional lifting further east capible of allowing the snow shrs. or squalls to make it across the mountains.

with very cold H85 temps...the lakes rather warm...and a NW flow coming directly over the waters...some LES is likely...at the very least.

[Stormsfury]

The Cold shot coming should not be underestimated. This evening/s 18z GFS has the -10C isotherm at H85 all the way down to new york city.

Soundings per the 18z GFS further west into eastern PA would be supportive of snowfall IF lake-effect were to occur. Note that there is weak surface based cape areound 77 J/kg, and no CIN, however that said, we must assume that there is something in the way of a lifting maximum in order to form convective snowfall. since WBZ heights are below ground and actual FRZ height w/o evaporational cooloing is already down to 1000mb (at KABE)... thus dynamical cooling will not be an issue, however as stated we must have the lifting. there does appear to be a 500mb vorticity maximum passing over the lakes at 96hrs which could support additional lifting further east capible of allowing the snow shrs. or squalls to make it across the mountains.

with very cold H85 temps...the lakes rather warm...and a NW flow coming directly over the waters...some LES is likely...at the very least.

Glad to see you here RNS ... and definitely look forward to seeing your discussions, outlooks, and forecasts ...

[LMolineux]

Yes But no Snow for the Major Cities just yet. Something i am looking forward to having and seing.

[RNS]

the snow is coming...dont worry. last winter was an outlier with regard to such early season snowfall in the EUS. normally the big cities dont get in on the act until December.

BTW...Thanks SF.

[LMolineux]

oh i know i was hoping this year would also be the same in that reguard.

[RNS]

and for those that are concerned...the call for this winter is as hard as it gets (IMO) for the major cities. but right now i would have to say that while yes the big cities will average normal to above normal in the snowfall category...inland areas (perhaps just as little as 20 to 30 miles N/W of the major cities) could see the greatrest deviation above normal.

there will be much more STJ interaction this winter than 00/01...since the pacific SSTA signal is much more consistent with El nino...but since it is not as strong as last winter...we will not see storm after storm in the same place. other areas especially the midwest will receive considerably more snow this year than last.

it is inland sections of the middle atlantic and Northeast on up through new england which stand the best chance to match 02/03 or for some exceed. which is not out of the relm of possibility either.

[LMolineux]

The only thing i am worried about is this so called same effects as of 01/02 winter due to the solar activity being just about an issue causing changes in weather patterns if this si any indication of to what is to come.

[RNS]

LMolineux...consault my post from yesterday on WWBB regarding the solar activity----->

This is exactly my point Ken, the ridge is there but its being supressed...meanwhile there are signs of the block retrograding westward, notice that heights across iceland are already beginning to rise...while the center of the blocking however is still back to the east over SCAND

Also,,,we have troughing coming into spain...another signal of an increasingly negative NAO in this case. also...remember we can have blocking centered as far east in the means as Ireland and it would still qualify as a negative NAO (though not the classic version).

I completely agree w/ everyone that is anticipating the zonal flow to takeover after the cold shot this week...note the flat ridging to the south of Japan, and the strong contrast in heights over the northwest pacific. this type of stuff is common in times when there is no controlling pacific signal (i.e...El nino / la Nina) and the atlantic is in an idle state as well. although the atlantic tendency by day 10 will begin shifting toward blocking and a -NAO.

furthermore...enhanced solar activity (which we have been delaing with lately) also favors such zonal patterns. the effects of the geomagnetic activity do several things...however most notably result in the strengthening of the icelandic low and a weakening of the alleutian low. which obviously is not good for the EUS. in addition...warming resulting from different chemical proceses on ozone also can lead to a pattern more reminicent IMO of a weak atlantic thermohaline...in which the contrast in height anomalies between the equator and the poles is enhanced as well as the overall thermal gradient. thus the reason why a zonal flow is prevalent during those periods, and there tends to be a large contrast in temperatures between the mid-latitudes and the polar regions. thus also the decreased tendency for blocking as was noted during many of the winters of the late 1980s and 1990s.

so while, yes this is good for NH snowcover since the cold air is locked up in canada (and siberia for the caspian connection)...it rarely ever makes it southward. this is one of the reasons why IMO the winter of 01/02 sucked...and most of the winters of the late 80s and 1990s aside from those which were dominated by a strong El Nino or la Nina.

Also...keep an eye on stratospheric temperature (as i have stressed in a few posts before)...releases of stratospheric heat can be precursors to high latitude blocking events. the idea is that the warming works its way down thru the atmosphere and results in ridging across the high latitudes.

here are some links on stratospheric temperature:

temperatures:

http://www.cpc.ncep.noaa.gov/produc...strat_a_f/#emct

heights:

http://www.cpc.ncep.noaa.gov/produc...strat_a_f/#emcz

CPC stratosphere homepage:

http://www.cpc.ncep.noaa.gov/produc...here/strat_a_f/

Some things to think about...

[Stephanie]

Cool! Another expert joins the S2K ranks! Welcome RNS!

[LMolineux]

Thank you RNS. It helped out greatly

[RNS]

point is...i am very confident that this high activity is transient. if it were to remain this high into and or thru the winter it would be no less than historic. as the activity would qualify as the third peak in one cycle (SS#23).

thus the activity should quiet down in the next few weeks...

also...consault another post of mine on the current activity--->

well i take comfort in the fact that at least were coming back down (in the short term...what influence this next flare has...we/ll have to see) note that 10.7cm flux peaked at 2900 around 10/25, and has since fallen back to 1900 (still a little too high).

notice that in the middle of OCT we were around 990...what a jump.

I won/t even bother to mention the sunspot number since not only does it speak for its self its so rediculously high that its nearly off the chart.

http://www.dxlc.com/solar/[/b]

[RNS]

thanks for the welcome and compliments guys...

[RNS]

I failed to mention in my post that NH snowcover can influence (or increase) the strength of the siberian high and lead to a predominantly negative AO during the NH winter. less snowcover can inhibit the siberian high and therefore promote less in the way of blocking...and therefore a tendency for a positive AO. I use the word tendency becasue the AO is influenced by many other factors such as solar activity, stratospheric temperature...the condition of the atlantic thermohaline and so on...

[LMolineux]

i understand ya. no worries.

[LMolineux]

ok then thereforth
RNS
what is your takes on snowfall this winter for our region?

[RNS]

above normal snowfall...below normal temperature (though not significantly). if i had to guess on a number (and dont hold me to this...YET) i would say 30-40" at PHL. Much more if storm tracks are favorable, or if the "big one(s)" comes to pass. inalnd sections stand to see the heaviest snowfall in the means as well as in deviations from normal.

ice storms will also be more of a threat this winter as compared to last considering the more variable storm track...or during any coastal events in which sufficient cold air does not exist above the surface to sustain all snow, however surface temps remain (at) below freezing.

[RNS]

PHL is in such a place where just one major event of just 12 to 20 inches can set snowfall close to normal w/o a mass quantity of moderate events. that is to say...PHL can have a winter in which only one major event (like Jan 1996) giving the city 30" of snow (which is above the normal seasonal total)...and the city would not have to record even a trace the remainder of the season and still end up above normal in the seasonal mean.

[LMolineux]

Well my Prelim #'s were goign to Reflect 35-55 inches for Philly but i have dropped them down to 30-45 a big change all due to me seing how tough that SE Ridge held on but still keeping it up in there because of the weak El Nino and rocking NAO at times of it being Negative and Tanking at times so ia m still holdign those #'s

[JCT777]

We should be getting some decent rains today into early tomorrow (probably no less than 1" and maybe as much as 2"). And I look forward to the cooler weather this weekend. High temps for Saturday and Sunday in my area look to be no better than 46 degrees either day. And I would not be surprised to see low 20's on Sunday morning. Nice!

BTW - welcome to storm2k, RNS. Great to have you here.