Skip to main content

610PM EDT Update:

A line of severe storms with winds up to and possibly in excess of 60 MPH continues to move through southeastern Pennsylvania. Philadelphia is now under the warning, but shouldn't see the storms for another hour or so.

537PM EDT Radar Update:

Allentown and Reading PA are the first in line for a new line of severe storms. Philly and Trenton are the two biggest cities next in line if the storms hold up.

515PM EDT UPDATE: The line isn't getting the organization it needs to be a powerful system, so the likelihood of a derecho is waning. I'm not feeling too confident that the line is as bad as it could be. I still defend the use of calling this a possible derecho, because the conditions were there for it to turn into a dangerous situation, but it didn't follow through. Better to be safe than sorry.

Regardless, the storms still have a history of producing damage to trees and winds around 60 MPH. Warnings are now in effect for the areas around Pottsville, Allentown, and Reading PA.


A strong line of storms is starting to develop in northern Pennsylvania right now, and renowned severe weather expert Dr. Greg Forbes sounded the alarm a few minutes ago:

A derecho (widespread damaging windstorm associated with a line or bow of thunderstorms) could drive from north-central to southeast PA and possibly into MD, NJ, and DE this afternoon and evening.
The NWS is tracking a line of storms northeast of State College, PA that has a history of producing winds of 60-75 MPH. The line shows no signs of weakening right now, and continues to move southeast at 30 MPH. Here's the wording the NWS is using in their warnings:
* SEVERE THUNDERSTORM WARNING FOR...
  COLUMBIA COUNTY IN CENTRAL PENNSYLVANIA...
  MONTOUR COUNTY IN CENTRAL PENNSYLVANIA...
  NORTHERN SNYDER COUNTY IN CENTRAL PENNSYLVANIA...
  SOUTHERN SULLIVAN COUNTY IN NORTH CENTRAL PENNSYLVANIA...
  UNION COUNTY IN CENTRAL PENNSYLVANIA...
  NORTHUMBERLAND COUNTY IN CENTRAL PENNSYLVANIA...
  NORTHEASTERN CENTRE COUNTY IN CENTRAL PENNSYLVANIA...
  SOUTHERN LYCOMING COUNTY IN NORTH CENTRAL PENNSYLVANIA...
  SOUTHERN CLINTON COUNTY IN NORTH CENTRAL PENNSYLVANIA...

* UNTIL 530 PM EDT

* AT 423 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS. THESE SEVERE STORMS EXTENDED FROM
  KASSON BROOK TO MUNCY VALLEY TO MUNCY TO MCELHATTAN TO KEATING...
  MOVING SOUTHEAST AT 30 MPH. THESE STORMS ARE CAPABLE OF PRODUCING
  QUARTER SIZE HAIL...AND DESTRUCTIVE WINDS IN EXCESS OF 70 MPH
.

The development of the line over the next few hours will determine how severe it is and how long it lasts. Environmental conditions are favorable for the line to maintain intensity and/or strengthen. If the line is able to continue to organize, it could turn into a small "powerhouse" that produces a long swath of intense winds and wind damage. The term "derecho" only means that this could be a long-lived, widespread wind damage event.

Here's the line of storms as of 4:30PM EDT:

If you live in southeastern Pennsylvania, northeastern Maryland, or anywhere in New Jersey or Delaware, you need to keep a very, very close eye on this system. These storms are fast paced and can develop or dissipate rapidly and without much reaction time. Prepare for the potential for wind damage and/or power outages. Also prepare for the potential that the line could shift more more southerly and threaten the Baltimore/Washington DC area.

Even if this alert turns out to be a false alarm, it's better to be prepared than to be blindsided.

NOTE: A "derecho" is just a line of storms that produces extensive wind damage over a span of 240 miles. Even if the storms only last 100 miles, it's still dangerous and can produce a lot of damage. Don't let the term "derecho" fool you. Any severe storm is dangerous no matter what it's called.

See the Storm Prediction Center's "About Derechos" page for more information, and see my writeup from the system that went from Chicago to Atlantic City.

EMAIL TO A FRIEND X
Your Email has been sent.
You must add at least one tag to this diary before publishing it.

Add keywords that describe this diary. Separate multiple keywords with commas.
Tagging tips - Search For Tags - Browse For Tags

?

More Tagging tips:

A tag is a way to search for this diary. If someone is searching for "Barack Obama," is this a diary they'd be trying to find?

Use a person's full name, without any title. Senator Obama may become President Obama, and Michelle Obama might run for office.

If your diary covers an election or elected official, use election tags, which are generally the state abbreviation followed by the office. CA-01 is the first district House seat. CA-Sen covers both senate races. NY-GOV covers the New York governor's race.

Tags do not compound: that is, "education reform" is a completely different tag from "education". A tag like "reform" alone is probably not meaningful.

Consider if one or more of these tags fits your diary: Civil Rights, Community, Congress, Culture, Economy, Education, Elections, Energy, Environment, Health Care, International, Labor, Law, Media, Meta, National Security, Science, Transportation, or White House. If your diary is specific to a state, consider adding the state (California, Texas, etc). Keep in mind, though, that there are many wonderful and important diaries that don't fit in any of these tags. Don't worry if yours doesn't.

You can add a private note to this diary when hotlisting it:
Are you sure you want to remove this diary from your hotlist?
Are you sure you want to remove your recommendation? You can only recommend a diary once, so you will not be able to re-recommend it afterwards.
Rescue this diary, and add a note:
Are you sure you want to remove this diary from Rescue?
Choose where to republish this diary. The diary will be added to the queue for that group. Publish it from the queue to make it appear.

You must be a member of a group to use this feature.

Add a quick update to your diary without changing the diary itself:
Are you sure you want to remove this diary?
(The diary will be removed from the site and returned to your drafts for further editing.)
(The diary will be removed.)
Are you sure you want to save these changes to the published diary?

Comment Preferences

skybluewater, filkertom, Timaeus, glitterscale, Cali Scribe, Gooserock, Danno11, sphealey, Avila, Wintermute, akeitz, celdd, Mnemosyne, rubyr, Christian Dem in NC, opinionated, antirove, high uintas, RLF, Nag, sockpuppet, 2laneIA, QuoVadis, defluxion10, betson08, lcrp, vcmvo2, Bluesee, NoMoreLies, Ckntfld, KnotIookin, Alice Venturi, triciawyse, citizenx, juliesie, Dobber, fixxit, Dr Squid, blue jersey mom, PinHole, Anna M, Ginny in CO, coolbreeze, Lindy, peacestpete, JanL, Ekaterin, JanF, kathny, 417els, Compost On The Weeds, tobendaro, tonyahky, HoundDog, Rosaura, plf515, BlueMississippi, CA Nana, doingbusinessas, Texdude50, blueoregon, ms badger, Nulwee, Tamar, old wobbly, Sapere aude, Noor B, pgm 01, ninkasi23, Dartagnan, jeanette0605, Dave in Northridge, dclawyer06, joedemocrat, jayden, mudslide, SeaTurtle, gchaucer2, uciguy30, gizmo59, davidseth, bythesea, Its any one guess, Lujane, royce, luckylizard, JamieG from Md, slathe, MrsTarquinBiscuitbarrel, Louisiana 1976, nchristine, carolyn urban, bobatkinson, FrugalGranny, elziax, stevenwag, rebel ga, Larsstephens, tash123, Sarbec, mamamorgaine, flitedocnm, NJpeach, politik, BenderRodriguez, tapu dali, cany, kerflooey, Hill Jill, nervousnellie, slowbutsure, asterkitty, itzik shpitzik, deeproots, boomerchick, marleycat, thomask, Wheever, Ojibwa, BarackStarObama, rk2, MRA NY, Imhotepsings, Mets102, jadt65, ParkRanger, Christian Democrat, DawnN, jacey, stormicats, Siri, CA ridebalanced, Horace Boothroyd III, jan4insight, belinda ridgewood, Margd, cassandracarolina, jennyp, Hammerhand, BobTheHappyDinosaur, Prospect Park, DamselleFly, broths, weck, Ree Zen, Scottie Thomaston

Subscribe or Donate to support Daily Kos.

Click here for the mobile view of the site