Thursday severe wx, svr outlook for Mid Atlantic Tuesday

[WXBUFFJIM]

Hey folks. Lots going on in the weather department recently. Back on Thursday June 16, 2004, severe thunderstorms with flooding rains occurred just south of the Baltimore area. Annapolis at the Naval Academy saw 2 1/2 inches of rain in a short period of time flooding most of the Naval Academy. There was widespread flooding in Prince Georges, Charles, and St Marys Counties in this huge complex of storms. In addition we had a tornado warning issued for Charles County, MD. La Plata, MD saw a 59 mph gust from that particular storm. It was after it passed east of La Plata that the storm showed a tornadic vortex signature on it.

It wasn't until around sunset that I witnessed several breathtaking aspects. #1 was a rainbow to my south as another thunderstorm developed just south of us. Then after that passed by, I noticed mammatus storm tops, which came from that huge complex over southern Maryland. The updrafts so powerful, we had mammatus storm tops observed. The pictures I took of the rainbow and mammatus are here below. I even got a few ominous pics of an intensifying thunderstorm taken from earlier in the year also.

http://community.webshots.com/album/124089384cvsgfY/1

Looking ahead, another frontal system is expected to make it's way through the Middle Atlantic on Tuesday afternoon with showers and storms. Surface winds will be south southwesterly while winds aloft will be from the west southwest. The combination of some instability and shear could fire off some severe storms. If any sustained supercells develop, they could easily rotate and go tornado. Otherwise I'm expecting mainly bowing segments with damaging winds the primary threat on Tuesday. The areas under the line of fire will likely be from Philly, Baltimore, and Washington DC south and west through the Virginia's.

More updates will be given on this threat as the day wears on.

Jim

[Skywatch_NC]

Could be an interesting day tomorrow in parts of NC, also.

http://www.spc.noaa.gov/products/outloo ... 00_any.gif

Eric

[WXBUFFJIM]

Definitely so.

Jim

[Stephanie]

Poor La Plata! They really get hit hard, don't they Jim?

[Allexpert Mike]

Tuesday,

Not a big deal,,,,,storms will remain elevated due to a stable layer right above the PBL. Plus dynamics seem to be trending less severe with each run. ETA sounding from 12z shows ample low level moisture which will bring low LCL heights which will lead to high LCL-LFC RH which will favor deep convection but no cap will be in place in the morning hours,,,therefore instability won't build and MUCAPE values will remain on the weak side.

Strong deep layer shear and vertical shear with BL-6km shear to 40KTS,,,updraft growth will be supportive for hail but marginally severe if that. LAck of UVM and CAPE and rather warm H5 temps should keep hail threat to a minium.

Moisture fields look good through H5,,,,lapse rates shouldnt be too impressive so damaging wind threat will be miniumal also.

But I do see potential for a few bowing segments with the primarily unidirectional flow.....so wind threat might be the only thing to really worry about.

[Colin]

I agree...tomorrow really shouldn't be much to write home about, unfortunately...but we have the rest of the summer.

[Stephanie]

Good to see ya AllExpert!

[WXBUFFJIM]

Poor La Plata! They really get hit hard, don't they Jim?

It seems like they do get hit plenty. What's amazing about La Plata is they didn't get 1 F4 tornado, but 2. The last one was of course April 28, 2002. But the other F4 tornado was back in November of 1926 when 17 people were killed. School was held on that fateful day in November 1926. On April 28, 2002, it was a Sunday and no one was in school. That alone probably saved more lives in addition to more advanced warning systems. Heck back in the 1920s, people didn't even know about the term tornado. We sure came a long way since then, huh?

As for tomorrow, it's looking less impressive for tornadoes. In fact I think the tornado threat is gone for tomorrow. Wind and brief heavy rain maybe the issue. But there is that negative factor for severe tomorrow including lack of insolation potentially and also poor steep lapse rates limiting the overall threat. With that in mind, I think isolated severe is the best wording to go with Tuesday PM and evening. The only real pro to tomorrow is the timing of peak heating for severe possibilities and also good moisture supply. But with the strongest dynamics outrunning the front, it doesn't look too widespread at all in the severe wx dept. The focus maybe more towards heavy rains in many areas.

Oh by the way, good to see you back here AEMike!!

Jim

[WXBUFFJIM]

Poor La Plata! They really get hit hard, don't they Jim?

NWUS51 KLWX 210949
LSRLWX

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
548 AM EDT MON JUN 21 2004

..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..

0710 PM TORNADO LA PLATA 38.53N 76.97W
06/17/2004 F0 CHARLES MD NWS STORM SURVEY

THE NWS SURVEYED DAMAGE IN AND AROUND LA PLATA MARYLAND
IN CENTRAL CHARLES COUNTY ON SUNDAY JUNE 20TH. IT WAS
DETERMINED A WEAK F0 TORNADO BRIEFLY TOUCHED DOWN ON THE
NORTH SIDE OF LA PLATA NEAR ROUTES 301 AND 255. A FEW
DOZEN TREES WERE EITHER TOPPED OR UPROOTED IN A SEVERAL
BLOCK AREA NEAR HARFORD STREET. PATH LENGTH WAS
ONE-QUARTER MILE LONG WITH THE MAX PATH WIDTH OF 75
YARDS. MAX WINDS WERE ESTIMATED AT 65 MPH. OTHER THAN
DAMAGE TO TREES LITTLE PROPERTY DAMAGE WAS REPORTED OR
OBSERVED.




TORNADO SUMMARY - LA PLATA MD...CENTRAL CHARLES COUNTY MARYLAND

DATE...................17 JUNE 2004 (THURSDAY)
TOUCHDOWN..............LA PLATA (NORTH SIDE)
F-SCALE................F0 (65 MPH PEAK WIND-ESTIMATED)
PATH LENGTH............0.25 MILES
MAXIMUM WIDTH..........75 YARDS
TIME OF TOUCHDOWN......7:10 PM (APPROXIMATE)



http://iwin.nws.noaa.gov/iwin/md/public.html

[weatherfan]

A lot of factors have to come togeather for major severe weather outbreaks in the Middle Alantic and Northeast.90 percent of the time our severe weather events come from squll lines or Mcs which are bows and or clusters.It could be argured that patterns issolated with the negative EPO tends to faver a pattern more condsive for severe weather in the spring and summer months.As we saw in the spring of 2002 where the Northeast and parts of the middle Alantic had one of the worse severe weather spring seasons in some years.

[WXBUFFJIM]

I think the primary mode tomorrow will be line segments and I think isolated severe seems appropriate at this time with wind and heavy rain the main threats. See that survey on la Plata?? Like they needed another tornado. They got one Thursday night June 17th, I'll tell ya that.

Jim

[Stephanie]

Another one! GEEZ!!

[weatherfan]

Yeah that was one hect of a line of storms that formed.And the worst thing about it was it stalled for a time and trained right over the same locations.Some place in that line must have been reshaveing heavey rains thunder and a loads of lighting for at least a few hours.In Annapolis Maryland some locations had 2 to 3 feet of water in spots from all the rain that came from those storms.