Jump to content
  • Member Statistics

    17,606
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

Mid-June severe threats


Ian

Recommended Posts

  • Replies 311
  • Created
  • Last Reply

  Looking at the hourly NAM output, the temperature cools during the evening tomorrow as expected, but that is offset somewhat by the dew points rising (into the mid to upper 70s!) as the southeast flow increases.    The progged 0-1 km helicity for 3z is in the 150-200 range with slightly higher values over north-central MD.

 

 

3z is tricky.. can work but often the boundary layer is stabilizing by then. It's definitely close though... shift it up a little more plz. 

Link to comment
Share on other sites

00z 5KM ARW shows a line of cells moving in around 5pm.... then brings in another strong line around 8pm.  The 00z 5KM NMM is bringing in a powerful line of storms around 8pm. 

 

Both the 12z 5KMM NMM and the 12z 5KM ARW is updating now as I post this

Seems among the NAM and the hires models there's pretty good agreement on some sort of line of either heavy rain with iso storms or a line of strong storms coming through. Now we just need to nail down the intensity and whether those storms will tap into the strong helicity. 

Link to comment
Share on other sites

Seems among the NAM and the hires models there's pretty good agreement on some sort of line of either heavy rain with iso storms or a line of strong storms coming through. Now we just need to nail down the intensity and whether those storms will tap into the strong helicity. 

 

12z HIRES NAM brings in the "line" around 10pm or so, give or take an hour.

 

ETA:  Looks like GFS would be between 10pm-12am for the "heaviest" stuff... give or take an hour

Link to comment
Share on other sites

One thing to consider is that a ton of our severe events come in earlier than expected - either in the form of a line ahead of the "main" line or just an earlier line as a whole. Not sure if this will hold true in this case or with the tropical influence but it is something to consider. Going off our track record - a 0-3z arrival could actually be easily pushed to 21-0z if things come together well enough. 

Link to comment
Share on other sites

12z HIRES NAM brings in the "line" around 10pm or so, give or take an hour.  Will check on when GFS comes in

10pm is too late for us to max potential - tho as high risk said we do get higher dewpoints. Take those away and our chances diminish a lot. Our best bet for severe lovers is to hope it comes in closer to the 5pm-8pm timeframe than the 10pm. I think it's doable but that's also the weenie in me. 

Link to comment
Share on other sites

      We don't want it TOO early, as any gains from higher cape will be offset by weaker shear.   perhaps there will be a "sweet spot" in the 8PM or so hour in which we find a decent cape/shear balance.

 

 

10pm is too late for us to max potential - tho as high risk said we do get higher dewpoints. Take those away and our chances diminish a lot. Our best bet for severe lovers is to hope it comes in closer to the 5pm-8pm timeframe than the 10pm. I think it's doable but that's also the weenie in me. 

Link to comment
Share on other sites

Lol- that was the day my buddies house in Ches Beach got hit by an ef0. Blew his garage door in, ripped off half his shutters, a bunch of shingles and even had a shingle piece embedded through his siding. Topped trees as well. I'll let him know that the weather super computers are using that date as the most similar to Saturday. He'll like that.

Link to comment
Share on other sites

   pretty awesome day.   big squall line raced through the area during the early/mid afternoon hours with widespread wind damage and even a few tornadoes embedded.    second weaker line, but still with some damage, moved through DC and the northern burbs during the early evening.   The first line didn't extend too far south of DC, and it left an outflow boundary across central VA and southern MD.    Those areas heated all day, and supercells with some tornadoes tracked along/near that boundary during the early evening.

 

     I see why this analogue came up, but this day didn't have the remnants of a tropical system.

 

Link to comment
Share on other sites

Yeah, I'm not entirely sure how CIPS works.. though, for one thing it's a sector analysis so it's probably mainly keying in on the vort pass which is similar. The CONUS pattern was fairly different with a deep trough in the west kicking waves out.  I certainly wouldn't expect a repeat of that but it probably highlights there's some higher end potential in theory. 

Link to comment
Share on other sites


FLOOD WATCH

NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC

311 PM EDT FRI JUN 19 2015

DCZ001-MDZ003>006-011-013-014-503>508-VAZ028-031-039-040-051>054-

501-502-505-506-WVZ050>053-200315-

/O.NEW.KLWX.FF.A.0002.150621T0000Z-150621T1200Z/

/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

DISTRICT OF COLUMBIA-WASHINGTON-FREDERICK-CARROLL-

NORTHERN BALTIMORE-SOUTHERN BALTIMORE-PRINCE GEORGES-ANNE ARUNDEL-

NORTHWEST MONTGOMERY-CENTRAL AND SOUTHEAST MONTGOMERY-

NORTHWEST HOWARD-CENTRAL AND SOUTHEAST HOWARD-NORTHWEST HARFORD-

SOUTHEAST HARFORD-CLARKE-MADISON-RAPPAHANNOCK-CULPEPER-

PRINCE WILLIAM/MANASSAS/MANASSAS PARK-FAIRFAX-

ARLINGTON/FALLS CHURCH/ALEXANDRIA-NORTHERN FAUQUIER-

SOUTHERN FAUQUIER-WESTERN LOUDOUN-EASTERN LOUDOUN-HAMPSHIRE-

MORGAN-BERKELEY-JEFFERSON-

INCLUDING THE CITIES OF...WASHINGTON...HAGERSTOWN...FREDERICK...

BALLENGER CREEK...ELDERSBURG...WESTMINSTER...REISTERSTOWN...

COCKEYSVILLE...BALTIMORE...BOWIE...SUITLAND-SILVER HILL...

CLINTON...COLLEGE PARK...GREENBELT...LAUREL...CAMP SPRINGS...

GLEN BURNIE...ANNAPOLIS...SEVERN...SOUTH GATE...SEVERNA PARK...

ARNOLD...ODENTON...GERMANTOWN...DAMASCUS...BETHESDA...ROCKVILLE...

GAITHERSBURG...SILVER SPRING...LISBON...COLUMBIA...

ELLICOTT CITY...JARRETTSVILLE...ABERDEEN...WINCHESTER...

BERRYVILLE...MADISON...CULPEPER...DALE CITY...MANASSAS...

WOODBRIDGE...LAKE RIDGE...MONTCLAIR...RESTON...HERNDON...

ANNANDALE...CENTREVILLE...CHANTILLY...MCLEAN...FRANCONIA...

ARLINGTON...ALEXANDRIA...WARRENTON...PURCELLVILLE...LEESBURG...

ASHBURN...STERLING...ROMNEY...PAW PAW...MARTINSBURG...

CHARLES TOWN...SHEPHERDSTOWN

311 PM EDT FRI JUN 19 2015

...FLASH FLOOD WATCH IN EFFECT FROM SATURDAY EVENING THROUGH

SUNDAY MORNING...

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A

* FLASH FLOOD WATCH FOR PORTIONS OF MARYLAND...THE THE DISTRICT

OF COLUMBIA...VIRGINIA AND NORTHEAST WEST VIRGINIA...INCLUDING

THE FOLLOWING AREAS...IN MARYLAND...ANNE ARUNDEL...CARROLL...

CENTRAL AND SOUTHEAST HOWARD...CENTRAL AND SOUTHEAST

MONTGOMERY...FREDERICK...NORTHERN BALTIMORE...NORTHWEST

HARFORD...NORTHWEST HOWARD...NORTHWEST MONTGOMERY...PRINCE

GEORGES...SOUTHEAST HARFORD...SOUTHERN BALTIMORE AND

WASHINGTON. THE DISTRICT OF COLUMBIA. IN VIRGINIA...

ARLINGTON/FALLS CHURCH/ALEXANDRIA...CLARKE...CULPEPER...

EASTERN LOUDOUN...FAIRFAX...FREDERICK...MADISON...NORTHERN

FAUQUIER...PRINCE WILLIAM/MANASSAS/MANASSAS PARK...

RAPPAHANNOCK...SOUTHERN FAUQUIER AND WESTERN LOUDOUN. IN

NORTHEAST WEST VIRGINIA...BERKELEY...HAMPSHIRE...JEFFERSON AND

MORGAN.

* FROM SATURDAY EVENING THROUGH SUNDAY MORNING

* SHOWERS AND THUNDERSTORMS WILL INCREASE IN COVERAGE FROM WEST TO

EAST LATE SATURDAY AFTERNOON AND CONTINUE INTO SUNDAY MORNING.

SOME OF THE STORMS WILL CONTAIN TORRENTIAL DOWNPOURS WHICH COULD

LEAD TO FLASH FLOODING. WIDESPREAD RAINFALL AMOUNTS OF ONE TO

THREE INCHES CAN BE EXPECTED WITH LOCALLY HIGHER AMOUNTS

POSSIBLE. RAINFALL RATES OF ONE TO TWO INCHES PER HOUR COULD

OCCUR WITH THE STONGEST THUNDERSTORMS.

Link to comment
Share on other sites

Should we use this thread or make a new thread for the Bill remnants and chance of severe?

might as well just keep it here since we've been discussing it here.. could start another for the next threat 

Link to comment
Share on other sites

LWX afternoon disco

 

BY SATURDAY MORNING...THE SFC CIRCULATION AND COMPACT MID LEVEL
TROUGH WILL BE CROSSING THE OHIO VALLEY. AHEAD OF THESE FEATURES...A
WARM AND MUGGY DAY IS ON TAP. THERE ARE NOT ANY DISTINCT FORCING
MECHANISMS THROUGH MUCH OF THE DAY...AND THUS AM EXPECTING A MORE
DIURNAL ENHANCEMENT TO ANY CONVECTION. THE STRONG FORCING WILL BE
REACHING THE MOUNTAINS BY MID TO LATE AFTERNOON. QUESTIONS REVOLVE
AROUND THE AMOUNT OF INSTBY...BUT SHEAR WILL BE INCREASING. SPC HAS
INTRODUCED A SLIGHT RISK OF SEVERE WX. GREATEST STORM COVERAGE MAY
BE WEST OF THE BLUE RIDGE...BUT GREATEST INSTBY MAY BUILD TO THE
EAST. DMGG WINDS WILL BE THE PRIMARY THREAT WITH HAIL SECONDARY. LOW
LEVEL WINDS ALSO BACK...WHICH COULD RESULT IN A BRIEF/WEAK TORNADO.

THE TROPICAL AIRMASS WILL ALSO RESULT IN HEAVY RAIN...AND WILL BEGIN
THE FLASH FLOOD WATCH FOR WESTERN AREAS AT 2 PM. MAX T FORECAST IS A
TOUCH BELOW MOS GUIDANCE BECAUSE CLOUD COVER MAY BE THICK AT
TIMES...BUT SUN COULD ALLOW TEMPS TO REACH NEAR OR ABOVE 90 IN THE
EAST.


&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THE REMNANTS OF BILL
WILL OVERSPREAD THE ENTIRE FORECAST AREA SATURDAY EVENING AND
CONTINUE OVERNIGHT INTO SUNDAY MORNING. THIS WILL LIKELY BE THE
PERIOD OF HIGHEST IMPACT. WIDESPREAD RAINFALL AMOUNTS OF ONE TO
THREE INCHES CAN BE EXPECTED WITH LOCALLY HIGHER AMOUNTS POSSIBLE
IN THE HEAVIEST THUNDERSTORMS. RAINFALL RATES OF ONE TO TWO INCHES
PER HOUR COULD ACCOMPANY THE STRONGER STORMS
AND LEAD TO FLASH
FLOODING OF CREEKS...STREAMS AND URBAN AREAS.

CONDITIONS WILL IMPROVE FROM WEST TO EAST SUNDAY MORNING INTO THE
AFTERNOON BUT THERE COULD BE A FEW SHOWERS LEFTOVER UNTIL THE
FRONT AND UPPER TROUGH PASS THROUGH THE REGION. HIGHS ON SUNDAY
SHOULD REBOUND INTO THE 80S TO NEAR 90 EAST OF THE BLUE RIDGE.
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...