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Mark Ellinwood

Mid-Atlantic Discussion – September 16

A shortwave trough will be packing a big punch of energy as it moves east over the Mid-Atlantic region. In the high shear/low CAPE category, this system has plenty of upper-level support from a vort. max and the left-exit region of a developing upper-level jet. A strong 850mb jet will also be developing this morning and afternoon, which will provide nice bulk shear values in WV and W PA. This low-level jet will also rapidly transport 60s dewpoints into the region, which will help fuel storms as they initiate west of the Appalachians.

Visible satellite and radar looks rather poor this morning, with widespread cloud cover and precipitation in OH, WV and W PA. However, given the good amount of upper-level support and orographic lift from the Appalachians, storms could still fire soon after the rain passes through. Water vapor looks favorable for dry-slot initiation, which can be rather potent with the upper-level support. This would lead me to generally agree with the SPC forecast with the overall severe risks.

There is also a risk for severe weather near the East Coast as unstable air moves in off the Atlantic, but it will not have as much support from the upper-level features, so it will have to rely more on daytime heating to initiate storms.


Chase potential: 60% (would be higher if travel distance was shorter)

Chase target(s):

T.S. Karl hits the Yucatan as it tries to get back to water

Tropical Storm Karl made landfall on the Yucatan Peninsula earlier today as it continues its WNW movement towards the East Pacific. Karl will move over the Bay of Campeche tomorrow and is expected to rapidly intensify before making landfall in central Mexico. Karl stands a good chance of making it to a category 1 hurricane before its second landfall… a feat it almost accomplished this morning as it hit the Yucatan as a strong tropical storm.

Here’s some Karl awesomeness for you all… still a very nice structure despite now having spent about 10 hours over land (taken at 5:45pm EDT).

Igor and Julia continue to chug away in the Atlantic as both weaken slightly from their maximum winds they achieved earlier today. No U.S. landfall should come from any of these storms, but models are strongly hinting at a storm (or two) that could impact the U.S. towards the end of the month.

T.S. Karl forms as Igor tries to go cat. 5

Tropical Storm Karl has formed in the western Caribbean as of 5:00pm ET, and it is forecast to head WNW towards the Yucatan Peninsula, making landfall there sometime tomorrow before sliding into the Bay of Campeche. Once off the Yucatan, Karl will have the opportunity to strengthen into a hurricane before making landfall again in northern/central Mexico early this weekend. Karl is not expected to make landfall on U.S. soil, but clouds and rain associated with the tropical system could impact Texas as it meanders into the East Pacific.

Igor is re-intensifying tonight following a period of weakening, and has another shot at becoming a category 5 hurricane. If successful, Igor will be the first Atlantic Basin category 5 hurricane since Dean and Felix in 2007. Dean had the most impressive center of low pressure at 907 mb, while Felix bottomed-out at 930mb. This year, Earl hit 928 mb as it peaked as a category 4 hurricane, and Igor is currently at its peak of 933 mb with wind speeds of 145 mph.

Not to be outdone, Julia continues to slowly strengthen, and it is currently a category 1 hurricane with wind speeds of 85 mph. Julia has not been talked about much since it is shadowed by the powerful Igor and the practically-imminent landfalls of Karl. Julia is expected to recurve much further east than Igor, and it should not pose any huge threat to land.

IR Satellite:

What to Watch Fore(cast) – Sep 13-19


Tropics in full gear – Igor is a strong category 4 hurricane in the central Atlantic, with Tropical Storm Julia further to the east. There is another area of interest in the Caribbean, which could form into a named system later this week.

Variable weather in the East – A disturbed weather pattern will bring several shots of wet weather into the Northeast and northern Mid-Atlantic.

Heat cranks away in the South – An area of high pressure will keep the South above normal throughout the week as the summer heat continues.

Cool air working into the northern Plains – A low pressure system diving south from northern Canada will bring below normal temperatures into the northern Plains through most of the week.


Igor is continuing its westward track early this week as it gets ready to recurve to the north and east during the second half of the week. It will continue to be a major hurricane through the first half of the week, but its strength will be in question during the second half of the week depending on how quickly it moves north. The current forecast will keep Igor well away from the U.S. coastline, but I wouldn’t be surprised if Igor ended up a bit further west than expected (though it would still be offshore). Julia is currently near the Cape Verde Islands and is expected to stay east of Igor throughout it’s lifespan, eventually recurving into the North-Central Atlantic.

A series of low pressure systems will bring cooler conditions overall to the Northeast as rain and afternoon thunderstorms roll across the Northeast and Mid-Atlantic today and during the second half of the week. These systems will entrain cold air down from northern Canada into the northern Plains during the second half of the week. Fall is coming to the North!

Meanwhile, a sub-tropical high is parked over the southern U.S., and it will keep most of the South, from the Desert Southwest to the Southeast, under warm temperature anomalies throughout the week. Areas along the Gulf of Mexico that experience onshore flow will have closer to normal temperatures.

Igor now a Category 4 Beast

Since becoming a category 1 hurricane as of 11:00pm EDT last night, Igor has rapidly strengthened into a category 4 hurricane as of 1:30pm EDT. Igor is now an absolute beast of a hurricane, and it should continue to be a major hurricane through the next week! The current forecast for Igor is to miss the U.S. as it recurves to the north and east about a week from now.

Here’s a recent shot of Igor on satellite (from

230 PM AST SUN SEP 12 2010


LOCATION…17.7N 46.1W

MAD US Weather goes 1.0!

After a long week of editing and troubleshooting, we are now in the 1.0 stage of the web site. I still need to get some info/feedback from Jason, but the site is set to go at this point.

I hope you all enjoy the layout and design! Questions/comments are always appreciated. We are always looking for ways to enhance the site, so we’ll see how long version 1.0 lasts until we dive back into the editing process.

To give you all an idea of what’s been done, this is the original template’s design:

Hermine spawns tornadoes in the South

Over the last couple of days, Hermine has spawned a decent amount of tornadoes in the South, including a tornado that went through the Dallas, TX metro area. So far, only one injury in Oklahoma has been reported from these tornadoes.

All of these tornadoes formed in the northern and eastern quadrants of Hermine, which is where nearly all tornadoes form in any tropical system.

Here is a video of the Dallas tornado from yesterday (no audio):

Storm reports, 9/7/10 and 9/8/10: