Jump to content
  • Member Statistics

    17,509
    Total Members
    7,904
    Most Online
    joxey
    Newest Member
    joxey
    Joined

2014 Mid-Atlantic Severe Discussion Thread


Kmlwx

Recommended Posts

The year is 52 weeks long, when you break it down we really only have about ten weeks of cold and snow and ten weeks of heat and humidity. The prime snow season for me begins on Christmas Day and lasts until President's Day. That's actually only about 8 weeks so I guess for posterity we'll add one week before and one week after. Once you get into March things begin reversing and snow chances are on life support. If you ever want to piss off a snow weenie remind them in mid February that the snow season is almost over.

 

The ten weeks of heat and humidity begin Fathers Day weekend and end about the third week in August. After that the sun angle gets noticebly lower, the days are noticebly shorter and you start to get that early Fall chill at night.

 

Of course there are exceptions, but that's how I see it. We then spend the remaining 32 weeks of the year moving in either direction.

Link to comment
Share on other sites

  • Replies 1.7k
  • Created
  • Last Reply

I've actually "researched" this, and IAD, DCA, and BWI destroy Chicago in terms of big storms. Chicago has only had 5 storms that dropped 18"+, and not even one storm produced 24".

 

DC - 18"+ (3), 24"+ (1)

Dulles - 18"+ (5), 24"+ (2)

Baltimore - 18"+ (10), 24"+ (4)

 

While DC doesn't beat Chicago's number of 18"+ storms, DC wins out with the 28" snowstorm from 1922.

 

I am actually surprised that IAD doesn't blow BWI away, since it seems to get snow so often when it's rain or mix to the east.  Maybe being closer to the ocean helps in really big storms?  Or does the short period of record keeping at IAD come into play here?  Interested in how the three compare since IAD records started being kept.

 

Also, I know we had 30+ at IAD in 2009-10; how many big cities has that even happened in?

Link to comment
Share on other sites

A few years ago up north we had so much snow roofs were collapsing. Kinda scary, kinda awesome. 

 

Davis, WV and surrounding towns had almost as much damage as the coast from Sandy, due to roofs collapsing from 4 feet of snow.  In October.

 

Speaking of Davis, at least one PWS out there recorded a low of 41 degrees last night.

Link to comment
Share on other sites

I believe you. I have personally experienced what I thought were two legitimate disasters in my life. Both were winter storms. GB13 goes without saying, but the October '11 snowstorm was a nightmare. It felt like I was one of 30 people in the state who didn't lose power for 10 days, but the damage and societal impact was massive. Heavy snow and fall foliage do not mix.  

 

 

 

Who knew BWI was money? I can vouch for Boston thoroughly sucking at times. Interior SNE is where you want to be. 

 

Boston has done well in a few recent years but it would still be torture being there when the city is getting rain and 10 miles inland, they are getting feet of snow

Link to comment
Share on other sites

It is funny, of the things we do well, it might be snowstorms that we are best at.  I wonder if anyone has a return-time map of 18"+ snowfalls.  I bet we would be better off than many of the places that we consider cold and snowy (Minneapolis, Chicago, Fargo, Detroit).

 

 

I actually made something like that a while back for the Midwest...not exactly a map of return rate but the number of 18"+ snowstorms on record for various cities.  I'll post it later for comparison.

Link to comment
Share on other sites

I am actually surprised that IAD doesn't blow BWI away, since it seems to get snow so often when it's rain or mix to the east.  Maybe being closer to the ocean helps in really big storms?  Or does the short period of record keeping at IAD come into play here?  Interested in how the three compare since IAD records started being kept.

 

Also, I know we had 30+ at IAD in 2009-10; how many big cities has that even happened in?

Well, IAD only began keeping records in the 50's, so I'm sure it would be up there with BWI. Regarding 30"+ storms, Philadelphia and Albany are the only other East Coast cities I know of that received 30"+.

Link to comment
Share on other sites

I am actually surprised that IAD doesn't blow BWI away, since it seems to get snow so often when it's rain or mix to the east. Maybe being closer to the ocean helps in really big storms? Or does the short period of record keeping at IAD come into play here? Interested in how the three compare since IAD records started being kept.

Also, I know we had 30+ at IAD in 2009-10; how many big cities has that even happened in?

Looking more carefully, I think IAD would beat BWI had the record been longer. IAD has approached 30" more than once in my lifetime...maybe surpassed once if I remember correctly?

Link to comment
Share on other sites

That said DC has the highest relative risk of seeing a violent tornado in the big cities of the northeast probably. Two have happened relatively close in the past 15 years not to mention events like College Park. If Ivan's outbreak was a bit east it would have been a fairly big deal for the area too.

I would think so. On a southerly to southeasterly flow, you'll get more of a marine influence in New York and Boston. Philly and Baltimore to some degree. Then you could argue that a marine influence in late summer/early fall could actually help drive up low-level moisture. If you look at climo, you'll see two things.  

 

1. Reports show a stronger clustering of tornadoes, including long-track and significant ones, relatively close to DC.

2. A peak of tornadoes in September near DC. It's kind of interesting really. but not shocking.

map.gif

Link to comment
Share on other sites

Is the September tornado peak significantly impacted by the fact that the period is more active in terms of tropical systems?

I'd have to think it's at least one of a number of factors. Much of the area also shares this September peak:

monthmap.gif

Link to comment
Share on other sites

I'd have to think it's at least one of a number of factors. Much of the area also shares this September peak:

monthmap.gif

I would think it's very heavily tropical related. This area has some of the densest tornado activity from tropical systems in the country. Probably because we see a lot of remnants pass by and also since they have time to get mid-level dry air injections by reaching us coming up from the south.  Of course we've also had some memorable non tropical tornadoes in Sep like the day of College Park that also had an F4 to the southwest of DC.  

Link to comment
Share on other sites

Here's the 18"+ snowstorm map for the Midwest.  There's a lot of gaps, mainly because some offices don't make the data easy to find. 

 

A couple of things about this map.  The number for St. Louis is either 0 or 1 but I went with 0 because that's what seems to be officially recognized (there was a storm that dropped over 20" in 1890).  Also, I didn't include places that are prone to massive pure lake effect snows (i.e. South Bend, IN) although it would probably not be difficult to sort out the pure lake effect storms.  I did include places like Chicago and Milwaukee and it's pretty clear that lake enhanced snow (system snow + some lake influence) plays a role in boosting totals in those areas.  For instance, Rockford IL, about 75 miles nw of Chicago and well removed from the lake, has had zero 18"+ storms. 

 

 

post-14-0-90637200-1405653903_thumb.png

Link to comment
Share on other sites

Here's the 18"+ snowstorm map for the Midwest.  There's a lot of gaps, mainly because some offices don't make the data easy to find. 

 

A couple of things about this map.  The number for St. Louis is either 0 or 1 but I went with 0 because that's what seems to be officially recognized (there was a storm that dropped over 20" in 1890).  Also, I didn't include places that are prone to massive pure lake effect snows (i.e. South Bend, IN) although it would probably not be difficult to sort out the pure lake effect storms.  I did include places like Chicago and Milwaukee and it's pretty clear that lake enhanced snow (system snow + some lake influence) plays a role in boosting totals in those areas.  For instance, Rockford IL, about 75 miles nw of Chicago and well removed from the lake, has had zero 18"+ storms. 

 

 

attachicon.gifbigsnowmap.png

 

Interesting.  Thanks.  Wonder if Madison, WI shows the same dropoff as Rockford.

Link to comment
Share on other sites

Next week has potential though hard to say much at this pt. Euro and GFS are fairly different on handling of trough (as usual I suppose).

 

Tomorrow should have some storms around.. maybe a low end slight close by tho there is not much shear. 

Link to comment
Share on other sites

Next week has potential though hard to say much at this pt. Euro and GFS are fairly different on handling of trough (as usual I suppose).

 

Tomorrow should have some storms around.. maybe a low end slight close by tho there is not much shear. 

 

Is the strength of the trough still in doubt? I was hoping for another decent cool shot.

Link to comment
Share on other sites

Is the strength of the trough still in doubt? I was hoping for another decent cool shot.

We'll get the cool shot to some degree it's more a matter of location of the ULL and timing of waves around it.  The Euro had a more favorable look than the GFS as of last night Euro/12z GFS. 

Link to comment
Share on other sites

Hmmm

 


DAY 4-8 CONVECTIVE OUTLOOK    NWS STORM PREDICTION CENTER NORMAN OK  0400 AM CDT THU JUL 24 2014    VALID 271200Z - 011200Z     ..DISCUSSION    A RELATIVELY ACTIVE SEVERE WEATHER PATTERN BEGINNING D3/SAT SHOULD  CONTINUE THROUGH D5/MON.      ..OH/TN VALLEYS TO THE MID-ATLANTIC ON D4/SUN    AMPLIFICATION OF THE ERN CONUS TROUGH IS ANTICIPATED WITH THE AID OF  A SHORTWAVE IMPULSE CROSSING THE UPPER MIDWEST TO GREAT LAKES. A  SWATH OF STRONG 700-500 MB WLYS SHOULD OVERSPREAD THE MID-MS VALLEY  TO MID-ATLANTIC. WITH A SURFACE CYCLONE GRADUALLY DEEPENING FROM THE  GREAT LAKES TO NORTHEAST...A COLD FRONT SHOULD PUSH SE ACROSS THE  NRN/CNTRL APPALACHIANS TO MID-SOUTH.     WITH AN EML PLUME POSSIBLY EXTENDING TO THE MID-ATLANTIC COAST  WITHIN A ZONAL FLOW REGIME...POTENTIAL INSTABILITY/SHEAR COMBINATION  WOULD FAVOR A BROAD AREA OF ORGANIZED SEVERE. THE PRIMARY  UNCERTAINTY IS WITH THE DEGREE OF CONVECTIVE OVERTURNING ON SAT INTO  EARLY SUN...WHICH COULD POTENTIALLY BE EXTENSIVE. THIS MAY HAVE  DELETERIOUS EFFECTS ON TOTAL BUOYANCY AND RENDERS THE NEED FOR  GREATER MESOSCALE PREDICTABILITY TO HIGHLIGHT 30 PERCENT OR HIGHER  PROBABILITIES. 
Link to comment
Share on other sites

Anyone expect a tornado this morning over southeast VA? I sure didn't. It had a nice front and the entrance region of an upper level jet streak going for it but the low level wind field was no great shakes.

Def somewhat surprising tho it could have been pretty weak just hit a bad spot. Cell looked solid after... Haven't seen a good radar from the time it hit. Wonder if it rose a boundary or something.
Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...