Tuesday, June 11, 2013

CometWeather Alert: DERECHO, a potentially Wildly Severe weather event

KMSP Minneapolis - St. Paul

NEWS on the potentiality of a coming severe "Derecho" storm system weather pattern has hit the Trib and KDKA.

A REASONABLE SKEPTIC and measured critic of the doomsday alarms is at WaPo.

INFOGRAPHIC: Google conveys as of 5:30 PM Tuesday that we should expect this:


THE ANTHEM for this Weather Anticipation Event is on YouTube.

COMET HISTORY: The last time we did CometWeather, a flurry of August storms predictably enough caused problems for Girty's Run creek in Millvale. A state grant to build swales to address such flooding issues recently came through.

LATEST: Severe Weather Team 11 is reporting that on Wednesday we face a "moderate" risk for severe weather, "high" risk for winds, and "moderate" risks for both flooding and hail in descending order. It was a pretty awesome bar graph. [6:25 pm Tue]

VERY LATEST: Accuweather suggests the "ingredients are coming together" for severe weather, which may hit Pittsburgh in the wee hours of the morning, according to this map color-coded on a scale from bright red to dark, bright red [2:00 pm]


MORE LATEST: The city's Dept. of Public Safety issues an alert for storms starting at 8:00PM, citing the NWS warning of "high probability" of severe weather. [3:37 pm]

SAFETY TIPS: Retweeted c/o US Sen. Bob Casey, at the W. PA Red Cross.

MOST LATEST: We saw some rain, and some thunder. Sounds like we all got to mobilize some resources. Drill baby drill.

12 comments:

  1. I've spent my entire life in the the Derecho zone and never heard of it until now.

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  2. I think Mesoscale Convective System is playing in the American Thermoplastic Jazz Tent tonight at the arts festival.

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  3. From the NWS at 7:30 this morning (quick take: there's a slight chance of severe weather happening overnight in Pittsburgh)

    BASED LARGELY ON THE SPC STORM-SCALE ENSEMBLE DATA...HIGHEST SEVERE
    PROBABILITIES AND THE MOST SIGNIFICANT SEVERE WEATHER
    POTENTIAL...STILL APPEAR FOCUSED IN A CORRIDOR ACROSS EAST CENTRAL
    IOWA INTO NORTHERN ILLINOIS LATE THIS AFTERNOON AND EVENING...INTO
    NORTHERN INDIANA AND WESTERN OHIO LATER TONIGHT.
    IN THE PRESENCE OF STRONG SHEAR AND INSTABILITY...DISCRETE SUPERCELL
    STORMS MAY OCCUR INITIALLY...BEFORE CONVECTION CONSOLIDATES AND
    GROWS UPSCALE INTO ONE OR MORE ORGANIZED CONVECTIVE CLUSTERS.

    STRENGTHENING SOUTHWESTERLY 850 MB FLOW TO 30-50 KT ACROSS THE LOWER
    OHIO VALLEY THIS EVENING MAY CONTRIBUTE TO THE RISK FOR A FEW VERY
    STRONG AND DAMAGING WIND GUSTS ACROSS PARTS OF NORTHERN AND CENTRAL
    ILLINOIS/INDIANA INTO OHIO. THE WESTERN FLANK OF THE ANTICIPATED
    EVOLVING MESOSCALE CONVECTIVE SYSTEM AND ASSOCIATED SURFACE COLD
    POOL PROBABLY WILL TEND TO PROPAGATE SOUTHWARD OR SOUTHEASTWARD
    TOWARD THE LOWER OHIO VALLEY...AND MODERATE RISK SEVERE
    PROBABILITIES HAVE BEEN ADJUSTED SOUTHWARD ACROSS ILLINOIS AND
    INDIANA TO ACCOUNT FOR THIS.

    THE RISK FOR POTENTIALLY DAMAGING WIND GUSTS MAY PERSIST WITH
    VIGOROUS CONVECTION THROUGH THE WESTERN SLOPES OF THE CENTRAL
    APPALACHIANS...AND PERHAPS ACROSS THE UPPER OHIO VALLEY INTO THE MID
    ATLANTIC COAST REGION...OVERNIGHT.

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  4. Derecho sounds like the kind of thing that ordinarily doesn't decide to happen even when the stars are aligned, but then again it's notable the stars are still aligned. Today Dr. Jeff Masters raised the possibility w/o embarrassment. Looks like a fair chance of thunderstorms late tonight / tomorrow in any event.

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  5. Thanks for the warnings, Bram - much appreciated by a biker.

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  6. If they start showing pictures of "the potential Derecho," take a look if the eastern side is more or less one long, straight line... like the storm almost squares-off on right-hand stheide. That's bad news.

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  7. CM - Can you make it to the weekend on what you have now?

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  8. Bram, this site never fails to disappoint.

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  9. "Consistently generates high expectations" ... Anonymous

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  10. i ordered the new Derecho at Taco Bell last week and it was delicious! When does the Cool Ranch version come out?

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    Replies
    1. Did it blow you away?

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