Severe storms 2015 general chatter

[high risk]

  it's on the mag.ncep.noaa.gov page.   go to the NAM-HIRES displays.

 

 

Do you have the link to that?

[yoda]

  it's on the mag.ncep.noaa.gov page.   go to the NAM-HIRES displays.

 

Thanks... hoping we can get some good storms tomorrow afternoon into tomorrow night

[high risk]

   would be nice, but the 00z NAM has definitely backed off on the cape for tomorrow evening.   northern VA might at have at least a small chance of severe, but the cape values are really sad northeast of DC.

 

 

Thanks... hoping we can get some good storms tomorrow afternoon into tomorrow night

[Kmlwx]

   would be nice, but the 00z NAM has definitely backed off on the cape for tomorrow evening.   northern VA might at have at least a small chance of severe, but the cape values are really sad northeast of DC.

Yoda keeps reeling me back in somehow but I'm pretty much out for my area a little north of DC. 

[high risk]

   yeah, I'm not too excited about severe prospects on the northeast side of town, but I still like our chances for some heavy showers/thunderstorms tomorrow evening.

 

 

Yoda keeps reeling me back in somehow but I'm pretty much out for my area a little north of DC. 

[yoda]

From 0600 Day 1 SPC OTLK:  (15hail/ 15wind/ 5tor)

 

 

 

 

..MID-ATLANTIC  

 
A WARM FRONT WILL ADVANCE NORTHWARD ACROSS THE AREA AND A VERY MOIST  
AND UNSTABLE AIRMASS WILL BE IN PLACE TO THE LEE OF THE APPALACHIANS  
FROM NORTHERN VA INTO THE NC PIEDMONT. FORCING FOR ASCENT WILL BE  
LIMITED...BUT ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP BY MID  
AFTERNOON. MODERATE INSTABILITY AND EFFECTIVE SHEAR NEAR 35-40 KT  
WILL FAVOR SUPERCELL STRUCTURES WITH HAIL AND STRONG WINDS THE MAIN  
THREATS. A TORNADO MAY BE POSSIBLE CLOSER TO THE WARM FRONT BOUNDARY  
ACROSS PARTS OF NORTHERN VA TOWARD THE CHESAPEAKE WHERE HODOGRAPHS  

WILL BE MAXIMIZED.

[yoda]

Both 00z local model runs from LWX are pretty decent for all... the ARW looks to have a discrete cell in NW VA/ moving SE and about to impact DC at the end of the run (8pm)

[yoda]

Looks nice for us around 8pm or so -- http://www.americanwx.com/wow/model_center/get_orig_img.php?model=hiresearw&run_time=00z&run_hour=24&map=NE&param=dbz&init=&valid=&ts=20150625

[yoda]

LWX morning AFD:

 

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
357 AM EDT THU JUN 25 2015

.SYNOPSIS...HIGH PRESSURE WILL WEAKEN LATER TODAY. LOW PRESSURE WILL
MOVE ACROSS NORTHERN VIRGINIA THURSDAY NIGHT. COLD FRONT WILL
MOVE SOUTH OF THE AREA FRIDAY. ANOTHER STORM SYSTEM WILL IMPACT
THE AREA SATURDAY NIGHT BRINGING UNSETTLED WEATHER TO THE
REGION WITH HEAVY RAINS AND POSSIBLE FLOODING.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...LOW PRESSURE IS LOCATED ACROSS
THE CENTRAL PLAINS WHILE WEAK HIGH PRESSURE IS LOCATED ACROSS THE
MID-ATLANTIC THIS MORNING. A DIFFUSE WARM FRONT IS STRETCHED FROM
THE TN VALLEY TO THE CAROLINAS.

MID-LEVEL CLOUDS WILL CONTINUE TO MOVE ACROSS THE REGION THIS
MORNING IN THE W-NW FLOW ALOFT. LOW PRESSURE WILL CONTINUE TO MOVE
EASTWARD INTO THE MIDWEST TODAY AND THE WARM FRONT TO THE SOUTH OF
THE MID-ATLANTIC WILL MOVE NORTHWARD. CONDITIONS ARE EXPECTED TO
RAPIDLY CHANGE TODAY AS HEAT AND HUMIDITY COME BACK INTO THE REGION.
AS MOISTURE MOVES IN FROM THE SOUTH TODAY...SHOWERS ARE POSSIBLE DUE
TO STRONG WARM AIR ADVECTION. DUE TO WEAK HIGH PRESSURE AT THE
SFC...ACTIVITY SHOULD JUST BE SHOWERS THIS MORNING. THAT WILL CHANGE
THIS AFTERNOON AND EVENING AS THE WIND FIELD
STRENGTHENS...ATMOSPHERE BECOMES SATURATED AND TEMPS WARM INTO THE
UPPER 80S. A FEW LIFTING MECHANISMS ARE EXPECTED THIS AFTERNOON AND
EVENING. THE WARM FRONT SHOULD TO BE ACROSS THE MID-ATLANTIC THIS
AFTERNOON...A LEE TROUGH SHOULD FORM AND DISTURBANCES OR CONVECTIVE
ENERGY FROM THE MCS IN THE MIDWEST SHOULD MOVE RIGHT OVER THE REGION
IN NW FLOW ALOFT. LAPSE RATES LOOK MARGINAL THIS AFTERNOON BUT WITH
SFC HEATING AND DEWPTS RISING 500-1500 J/KG OF CAPE IS EXPECTED. AS
STATED EARLIER...WIND FIELDS STRENGTHEN TODAY AND BY TONIGHT FCST
HODOGRAPHS LOOK FAVORABLE FOR STRONG TO SEVERE THUNDERSTORMS
PRODUCING DMG WINDS AND LARGE HAIL. A SE COMPONENT TO THE SFC WIND
THIS EVENING MAY PRODUCE A TORNADO MAINLY EAST OF THE BLUE RIDGE.
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS REGION THROUGH
8AM/12Z FRIDAY.

 

[mappy]

HRRRRRRRRR looks lame. 

[snowfan]

RPM baby

[yoda]

1300 OTLK from SPC has SLGT risk up the Mason-Dixon line... 15 hail/15 wind/ 5 tor

 

[yoda]

Relevant disco

 

A NOCTURNAL MCS HAS BECOME ELONGATED IN W-E FASHION EARLY THIS  MORNING WITH THE LEADING EDGE OF THIS SYSTEM ADVANCING THROUGH WRN  OH AS OF 12Z.  EXTRAPOLATION OF CURRENT MOTION AND RECENT  CONVECTION-PERMITTING MODEL GUIDANCE INDICATE THAT THE REMNANT GUST  FRONT/COLD POOL ASSOCIATED WITH THIS MCS WILL REACH THE VA PIEDMONT  BY LATE AFTERNOON WHERE IT WILL ENCOUNTER A NWD-MOVING WARM FRONT  AND LEE TROUGH.  THESE SURFACE FEATURES WILL FOSTER AN INCREASE IN  STORM COVERAGE AND INTENSITY OWING TO THE PRESENCE OF A MOIST AND  MODERATELY UNSTABLE AIR MASS WITH MLCAPE OF 1000-1500+ J/KG.   VERTICAL SHEAR WILL STEADILY STRENGTHEN THROUGH THE DAY WITH  SUPERCELL AND/OR BOWING LINE CONVECTIVE MODES POSSIBLE.  WHILE  DAMAGING WIND GUSTS WILL BE THE PRIMARY HAZARD AS ACTIVITY SPREADS  EWD INTO THE TIDEWATER THIS EVENING...SEVERE HAIL AND A TORNADO OR  TWO ARE ALSO POSSIBLE. 

[yoda]

Local LWX models are decent for this afternoon into tonight

[yoda]

12z 4km NAM develops a discrete sup (or small complex) in W VA around 7pm... 7-9pm DC/N VA gets rocked

 

 

 

[Eskimo Joe]

Looks like everything stays west of the Potomac, no?  Hoping we can get in on the action south of I-70.

[EastCoast NPZ]

In my experience, elongation usually precedes a nocturnal MCS.

[yoda]

Looks like everything stays west of the Potomac, no?  Hoping we can get in on the action south of I-70.

 

Just added the 12z 4km NAM image in my post above yours

[yoda]

Updated morning LWX disco:

 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1033 AM EDT THU JUN 25 2015

.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN LATER TODAY. LOW PRESSURE WILL
MOVE ACROSS NORTHERN VIRGINIA THURSDAY NIGHT. COLD FRONT WILL
MOVE SOUTH OF THE AREA FRIDAY. ANOTHER STORM SYSTEM WILL IMPACT
THE AREA SATURDAY NIGHT BRINGING UNSETTLED WEATHER TO THE
REGION WITH HEAVY RAINS AND POSSIBLE FLOODING.

&&

.NEAR TERM /THROUGH TONIGHT/...
LOW PRESSURE IS TRACKING THROUGH THE MIDWEST AND AN MCS IS MOVING
THROUGH THE OHIO VALLEY LATE THIS MORNING. A WARM FRONT IS LOCATED
OVER CENTRAL VIRGINIA.

THE WARM FRONT OVER CENTRAL VIRGINIA WILL MOVE NORTHWARD INTO OUR
AREA THIS AFTERNOON AND EVENING. A SOUTHERLY FLOW BEHIND THE
BOUNDARY WILL USHER IN MUCH MORE MOISTURE...WITH DEWPOINTS
RETURNING TO THE UPPER 60S AND LOWER 70S. THE INCREASED MOISTURE
WILL ALLOW FOR INSTABILITY TO DEVELOP THIS AFTERNOON. THE MCS OVER
THE OHIO VALLEY WILL ALSO BE MOVING THROUGH OUR AREA. THIS WILL
CAUSE SHOWERS AND THUNDERSTORMS TO INCREASE IN COVERAGE FROM WEST
TO EAST LATE THIS AFTERNOON INTO THIS EVENING. THERE IS A THREAT
FOR SEVERE THUNDERSTORMS...WITH DAMAGING WIND GUSTS AND LARGE HAIL
BEING THE PRIMARY THREATS. CERTAINTY IS STILL A BIT LOW DUE TO
QUESTIONS ABOUT EXACTLY HOW UNSTABLE THE ATMOSPHERE WILL BE.
ALTHOUGH SEVERE WEATHER CANNOT BE RULED OUT ACROSS THE ENTIRE
CWA...THE BEST CHANCE FOR SEVERE THUNDERSTORMS AT THIS TIME
APPEARS THAT IT WILL BE ACROSS CENTRAL VIRGINIA INTO THE
WASHINGTON METROPOLITAN AREA AS WELL AS THE VIRGINIA PIEDMONT AND
SOUTHERN MARYLAND. THIS IS WHERE CONFIDENCE IS HIGHEST FOR MORE
INSTABILITY DUE TO SOUTHERLY WINDS. ALSO...WITH THE BOUNDARY
OVERHEAD THERE IS A THREAT FOR AN ISOLATED TORNADO AS WELL

[high risk]

while today's setup is intriguing, the 12z NAM suggests that the Saturday rain may shift north during the early afternoon, allowing the warm front to either move through the area or at least sit across it.   Any destabilization would allow late day storm development, and the progged wind field is extremely strong with some potentially fantastic directional shear.

[mappy]

while today's setup is intriguing, the 12z NAM suggests that the Saturday rain may shift north during the early afternoon, allowing the warm front to either move through the area or at least sit across it.   Any destabilization would allow late day storm development, and the progged wind field is extremely strong with some potentially fantastic directional shear.

 

Yes, this is what i want to hear. Rain north and out of the area. 

[mappy]

HRRRRRRRRRR still looks really lame. 

[high risk]

   If you take the NAM verbatim, it will be a lot tougher to end the rain and break into the warm sector north of I-70, but it would only take a slight shift north to change that.

 

 

Yes, this is what i want to hear. Rain north and out of the area. 

[Kmlwx]

while today's setup is intriguing, the 12z NAM suggests that the Saturday rain may shift north during the early afternoon, allowing the warm front to either move through the area or at least sit across it.   Any destabilization would allow late day storm development, and the progged wind field is extremely strong with some potentially fantastic directional shear.

 

So tor risk for sat?

[snowfan]

4K really seems to like C VA and the Delmarva for Saturday storms. Doesn't look too far off in our area.

 

And for today, there's a blob approaching the west side of DC at 0Z that appears to blow up south and east of town later tonight.

[yoda]

I am going to guess that the WF is just north of us somewhere... 11am at DCA had winds out of the S

[StudentOfClimatology]

Winds here are SSE, so yeah it's either nearby or has passed.

[Kmlwx]

BWI is also reporting southerly winds. Rockville too. 

[Eskimo Joe]

I am going to guess that the WF is just north of us somewhere... 11am at DCA had winds out of the S

The really juicy dew points are down at I-64.  Really meh setup today it seems.  Even Saturday looks like a low end rain storm...was hoping for a more substantial event.

[Kmlwx]

The really juicy dew points are down at I-64.  Really meh setup today it seems.  Even Saturday looks like a low end rain storm...was hoping for a more substantial event.

 

Okay excellent. We have one prerequisite for a moderate risk event now