Sept 11-12 Wednesday, Thursday Storm Threat

[ORH_wxman]

There's a chance - but the biggest threat for severe wx is clearly northwest of us through upstate NY and VT. 

 

 

Yep. I'd be way more excited if everything was like 200 miles south.

[Tropopause_Fold]

There's a chance - but the biggest threat for severe wx is clearly northwest of us through upstate NY and VT. 

yeah someplace out in C NYS could really get whacked if stuff fires off...which seems like a good bet.

[weatherwiz]

Tomorrow would be quite interesting with faster timing. Even if w do see a pre-frontal, which is likely, the better forcing still doesn't arrive until much later.

[CT Rain]

Yep. I'd be way more excited if everything was like 200 miles south.

 

There's also not much deep layer shear down this way compared to up north. While the instability is extreme we're a little short on shear for widespread severe.

[dryslot]

 

 

GYX had a warning storm 3-4 AM for the western mts. Nice looking patch of red was headed my way about 4, but it died at the doorstep - 0.02".

 

Looks like a couple decent cells went thru the Ashland area

[ineedsnow]

Some accas clouds in springfield fun day ahead?

[weatherwiz]

There's also not much deep layer shear down this way compared to up north. While the instability is extreme we're a little short on shear for widespread severe.

You would want to be right user the core as it collapses an in ths environment that could be freaking awesome.

[CoastalWx]

GYX had a warning storm 3-4 AM for the western mts. Nice looking patch of red was headed my way about 4, but it died at the doorstep - 0.02".

Oh well that's a little better. Didn't know GYX warned.

[eyewall]

82/72 in BTV at 10am with a surface trough/shortwave over southern Ontario. This is likely a potential trigger for the St. Lawrence Valley and eventually in my next of the woods late this afternoon. We shall see.

[OceanStWx]

 

 

This is pretty appetizing.

[CT Rain]

 

 

This is pretty appetizing.

 

CINful

[TalcottWx]

Im a little more bullish today. I think someone like chris m gets hit at home today. I bet the line looks ferocious entering western ne and thereafter everything will sort of slide along in the northeast direction. Berkshires litchfield southern nh/southern vt I think look good. Keene State might be a good spot.

[OceanStWx]

Oh well that's a little better. Didn't know GYX warned.

 

 

Did we? I see two for CAR, but none for GYX.

[weatherwiz]

Definitely have to watch tomorrow out ahead of the pre-frontal from the Hudson Valley into western CT/MA.  After 18z-21z, the NAM really wants to back sfc winds out ahead of the pre-frontal and develops a fairly strong LLJ so helicity vastly increases.  Seems like the LLJ is legit too b/c there is no convective feedback from what I can see and the trough is continuing to amplify which tightens the pressure gradient over the region.

[OceanStWx]

I do like seeing all the ACCAS back across PA, and bubbling Cu already going in the Adirondacks.

[CT Rain]

I do like seeing all the ACCAS back across PA, and bubbling Cu already going in the Adirondacks.

 

Yeah the high res models are all in pretty good agreement with the target area. Adequate height falls with that s/w over the mountains in W PA and WV should be enough over the mountains of PA to start blowing up convection. 

[CT Rain]

Lock it in.

 

 

[OceanStWx]

 

I do like that the orientation of the high theta-e air mass is aligned with forecast storm motion as well. I would keep my eye on that corridor.

[Modfan]

Is BOX bullish with the SWS that far east or is it jusy CYA in case the stuff in NYS/VT hold together?

[CoastalWx]

Did we? I see two for CAR, but none for GYX.

 

I thought Tamarack said that. Anyways, congrats NNE and NY state. In all seriousness, I think we have to watch out for any storm organization because if they can form a cold pool and move east, it may help storms bust through the cap for areas further east. 

[CT Rain]

I thought Tamarack said that. Anyways, congrats NNE and NY state. In all seriousness, I think we have to watch out for any storm organization because if they can form a cold pool and move east, it may help storms bust through the cap for areas further east. 

 

I agree - seems to be what the HRRR is showing. 

[weatherwiz]

RAP has some very hefty 0-1km shear values later on today 

[CT Rain]

From OKX... huh? 

 

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STILL ON TRACK FOR HIGHS 10-15 DEGREES ABOVE NORMAL...WITH 12Z
KALY AND KOKX SUGGESTING MID 90S POSSIBLE AWAY FROM AREAS
INFLUENCED BY SEABREEZE. HOWEVER...DO EXPECT A FAIRLY STRONG
SEABREEZE GIVEN UNUSUAL WARMTH AND HUMIDITY HELPING TO DRIVE
NEARSHORE DENSITY GRADIENT RESPONSIBLE FOR SEABREEZE...SO NOT
EXPECTING TEMPERATURES TO GENERALLY REACH QUITE THAT HOT
INLAND...THOUGH A FEW ISOLATED READINGS IN THE MID 90S CANNOT BE
COMPLETELY RULED OUT. APPEARS DEWPOINTS WILL MAINLY BE IN THE
LOWER 70S THIS AFTERNOON DUE TO MIXING...THIS SHOULD KEEP HEAT
INDICES BELOW HEAT ADVISORY CRITERIA...THOUGH CANNOT COMPLETELY
RULE OUT AN ISOLATED 100 DEGREE HEAT INDEX READING FOR AN HOUR IN
NE NJ/LOWER HUDSON VALLEY. THE SEABREEZE SHOULD PRECLUDE THIS IN
NYC. SEE THE CLIMATE SECTION OF THE AFD FOR DETAILS ON POTENTIAL
FOR RECORD HIGHS.

12Z SOUNDINGS SUGGEST UPPER BOUND TO CAPES THIS AFTERNOON OF
3500-4500 J/KG BUT ALSO SHOW A STRONG CAP - RUNNING FROM 525-425
HPA IN KALY SOUNDING AND FROM 550-475 HPA IN KOKX SOUNDING.
LATEST MESO-SCALE GUIDANCE SUGGESTS CAP SHOULD HOLD OVER MOST IF
NOT ALL THE CWA TODAY...SO HAVE GONE WITH A DRY FORECAST OVER ALL
BUT FAR NW ZONES...WHERE HAVE SLIGHT CHANCE POPS...EXCEPT FOR FAR
W ORANGE COUNTY WHERE CONTINUE CHANCE POPS. IN ADDITION TO THE
CAP...ALSO HAVE NEGATIVE VORTICITY ADVECTION AT 700 HPA AND TO A
LESSER EXTENT AT 500 HPA WORKING AGAINST CONVECTION. THIS IS TRUE
FOR THE ENTIRE CWA UNTIL LATE IN THE DAY OVER FAR W ZONES. ALSO
WILL HAVE SHEAR OF 15 KT OR LESS WITH BULK RICHARDSON NUMBERS OF
OVER 100 - SO WOULD EXPECT ONLY PULSE STORMS...IF ANY DO FORM -
AND MOST LIKELY NOT STRONG OR SEVERE. MAIN THREAT WOULD BE FROM
LOCALLY HEAVY RAINFALL - REFER TO THE HYDRO SECTION OF THE AFD FOR
DETAILS.

THERE IS A MODERATE RISK FOR RIP CURRENTS AT THE ATLANTIC OCEAN
BEACHES TODAY.

[weatherwiz]

Very interesting...definite some sort of subtle feature.

 

[OceanStWx]

From OKX... huh? 

 

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

STILL ON TRACK FOR HIGHS 10-15 DEGREES ABOVE NORMAL...WITH 12Z

KALY AND KOKX SUGGESTING MID 90S POSSIBLE AWAY FROM AREAS

INFLUENCED BY SEABREEZE. HOWEVER...DO EXPECT A FAIRLY STRONG

SEABREEZE GIVEN UNUSUAL WARMTH AND HUMIDITY HELPING TO DRIVE

NEARSHORE DENSITY GRADIENT RESPONSIBLE FOR SEABREEZE...SO NOT

EXPECTING TEMPERATURES TO GENERALLY REACH QUITE THAT HOT

INLAND...THOUGH A FEW ISOLATED READINGS IN THE MID 90S CANNOT BE

COMPLETELY RULED OUT. APPEARS DEWPOINTS WILL MAINLY BE IN THE

LOWER 70S THIS AFTERNOON DUE TO MIXING...THIS SHOULD KEEP HEAT

INDICES BELOW HEAT ADVISORY CRITERIA...THOUGH CANNOT COMPLETELY

RULE OUT AN ISOLATED 100 DEGREE HEAT INDEX READING FOR AN HOUR IN

NE NJ/LOWER HUDSON VALLEY. THE SEABREEZE SHOULD PRECLUDE THIS IN

NYC. SEE THE CLIMATE SECTION OF THE AFD FOR DETAILS ON POTENTIAL

FOR RECORD HIGHS.

12Z SOUNDINGS SUGGEST UPPER BOUND TO CAPES THIS AFTERNOON OF

3500-4500 J/KG BUT ALSO SHOW A STRONG CAP - RUNNING FROM 525-425

HPA IN KALY SOUNDING AND FROM 550-475 HPA IN KOKX SOUNDING.

LATEST MESO-SCALE GUIDANCE SUGGESTS CAP SHOULD HOLD OVER MOST IF

NOT ALL THE CWA TODAY...SO HAVE GONE WITH A DRY FORECAST OVER ALL

BUT FAR NW ZONES...WHERE HAVE SLIGHT CHANCE POPS...EXCEPT FOR FAR

W ORANGE COUNTY WHERE CONTINUE CHANCE POPS. IN ADDITION TO THE

CAP...ALSO HAVE NEGATIVE VORTICITY ADVECTION AT 700 HPA AND TO A

LESSER EXTENT AT 500 HPA WORKING AGAINST CONVECTION. THIS IS TRUE

FOR THE ENTIRE CWA UNTIL LATE IN THE DAY OVER FAR W ZONES. ALSO

WILL HAVE SHEAR OF 15 KT OR LESS WITH BULK RICHARDSON NUMBERS OF

OVER 100 - SO WOULD EXPECT ONLY PULSE STORMS...IF ANY DO FORM -

AND MOST LIKELY NOT STRONG OR SEVERE. MAIN THREAT WOULD BE FROM

LOCALLY HEAVY RAINFALL - REFER TO THE HYDRO SECTION OF THE AFD FOR

DETAILS.

THERE IS A MODERATE RISK FOR RIP CURRENTS AT THE ATLANTIC OCEAN

BEACHES TODAY.

 

 

Yeah there's a cap, but I don't think that's where it is.

[CT Rain]

Yeah there's a cap, but I don't think that's where it is.

 

You're not capped around 500mb when you have a LI of -10C lol.

 

And as for the second part... vorticity advection becoming less negative with height.... It's time to review our forcing terms in the QG-Omega equation. 

[OceanStWx]

You're not capped around 500mb when you have a LI of -10C lol.

 

And as for the second part... vorticity advection becoming less negative with height.... It's time to review our forcing terms in the QG-Omega equation. 

 

 

Sometimes midnight shifts get a little squirrely.

[CT Rain]

Sometimes midnight shifts get a little squirrely.

 

Fair point. When I get up for work at 2 a.m. for the morning show I barely know my own name. 

[Typhoon Tip]

Strong wording associated:  "...DEEPLY UNIDIRECTIONAL WSWLY FLOW WITH 40+ DEEP SHEAR SHOULD FOSTER DEVELOPMENT OF SUSTAINED STORMS/SUPERCELLS...ESPECIALLY FROM NRN NY INTO NRN NEW ENGLAND. THESE LIKELY WILL EVOLVE INTO SEVERAL BANDS...CLUSTERS...AND LEWPS...WITH AN ASSOCIATED RISK FOR DMGG WIND AS WELL AS HAIL. A CONDITIONAL THREAT ALSO WILL EXIST FOR A TORNADO OR TWO...ESPECIALLY IN NE VT..NRN NH...AND ME...WHERE LOW-LVL FLOW MAY REMAIN SOMEWHAT BACKED. THE SVR THREAT SHOULD BE MORE LIMITED FARTHER S OVER PARTS OF PA AND CNTRL NEW ENGLAND...WHERE SHEAR WILL BE MARKEDLY WEAKER AND PULSE/MULTICELL STORMS ARE LIKELY TO ERUPT OVER THE HIGHER TERRAIN..."   Maybe we can get a derecho out of that later tonight...

 

[weatherwiz]

LOL, sorry for the OT.

 

This is actually pretty funny...and wx related in a way