Week of June 10th Heavy Rain and Thunderstorms Discussion

[Weathergun]

The GFS looks even more disjointed than the NAM.

[mupawxnut]

Wonder if the Euro will have some of the feedback issues that the rest of the 12z models are having. Sticking with Euro and previous runs of GFS, if trend continues then the 12z suite might be onto something.

Even if there is a south trend, I think the GFS is still too far south.

[snywx]

It's looking like most of us will be in somewhat of a "dead zone" between the really severe activity south of us and the heavy stratiform rain north of us, with the low tracking about directly overhead. I'd say a windy, showery day with the potential for a line of storms later tomorrow will be what most of us experience. This is looking like I-90 gets the heaviest rain. It would probably be wrist-slitting time if this were a winter system.

 

I think you meant I-84

[bluewave]

The GFS looks even more disjointed than the NAM.

 

The RGEM continues to track the low just south of LI like the Euro has been doing.

 

[IsentropicLift]

It actually tried to form a secondary low, what the hell...

Yeah, I think we may have to wait as long as tonights 00z runs till we can get a good grasp on exactly what the outcome will be.

[WE GOT HIM]

Like I said yesterday. This is a winter storm in June, so it figures the models would start going crazy.

[mupawxnut]

Anyone think TWC will give this a name?

[WE GOT HIM]

Anyone think TWC will give this a name?

lolol

[Stormlover74]

Anyone think TWC will give this a name?

lol I thought this was a joke but I wouldn't put anything past them...they probably have something in the works to start naming tornadoes

[IsentropicLift]

Anyone think TWC will give this a name?

Banned

[bluewave]

So it's the UK and GFS vs the NAM/RGEM so far today.

 

 

 

[mupawxnut]

So it's the UK and GFS vs the NAM/RGEM so far today.

130612161204456189000.gif

Can you post QPF from the UKMET?

[mupawxnut]

So it doesn't look so bad for tomorrow anymore, a lot less rainfall and severe weather stays south.

Amazing how quickly the models changed in one run a day ahead of it, this is why they seriously need those upgrades because it's a joke.

Let's wait for the Euro before making that call.

[bluewave]

Can you post QPF from the UKMET?

 

I don't have the total, but I am going to wait until I see the Euro in a few hours.

[jm1220]

The models may be having a hard time resolving the convective aspects to the storm, which is likely throwing off its precipitation parameters. Although it's not winter anymore, the same errors may be present. The low might be shifting south again a bit on some of the models, which would put us back in the heavy stratiform rain area. It makes sense to me that there will be a very heavy band of stratiform rain due to the warm, moist air being uplifted, and all of it being squeezed out via overrunning. I doubt there won't be a very heavy band somewhere that generates several inches of rain.

[bluewave]

The models may be having a hard time resolving the convective aspects to the storm, which is likely throwing off its precipitation parameters. Although it's not winter anymore, the same errors may be present. The low might be shifting south again a bit on some of the models, which would put us back in the heavy stratiform rain area. It makes sense to me that there will be a very heavy band of stratiform rain due to the warm, moist air being uplifted, and all of it being squeezed out via overrunning. I doubt there won't be a very heavy band somewhere that generates several inches of rain.

 

It's not everyday that such a deep low forms in conjunction a strong MCS on a High Risk day.

[bluewave]

12Z MODEL EVALUATION INCLUDING THE NAM/GFS/UKMET AND GEM REGIONAL

...SHORTWAVE TROUGH/SURFACE LOW CURRENTLY EJECTING ACROSS THE

NORTHERN PLAINS/UPPER MIDWEST...REACHING THE MID-ATLANTIC/SOUTHERN

NEW ENGLAND THURS...

PREFERENCE: NON-ECMWF CONSENSUS LED BY THE 12Z UKMET

CONFIDENCE: AVERAGE

OVERWHELMINGLY THE TREND IN THE 12Z GUIDANCE IS TO BE MORE

PROGRESSIVE WITH THE EVOLVING SHORTWAVE TROUGH AND ASSOCD SFC LOW

SEEN NOW MOVING ACROSS THE UPPER MIDWEST. THE MODELS TAKE THIS

ENERGY RAPIDLY INTO THE OH VLY OVERNIGHT AND ALLOW FOR ADDITIONAL

SHORTWAVE ENERGY DROPPING DOWN FROM ONTARIO TO REINFORCE THE HT

FALLS AS THE SYS MOVES ACROSS THE CNTRL

APPALACHIANS...MID-ATLANTIC AND SRN NEW ENGLAND ON THURS. THE 12Z

GFS AND 12Z UKMET ARE THE FASTEST FOLLOWED BY THE 12Z NAM AND 12Z

GEM REGIONAL. IT SHOULD BE NOTED THAT THE MODELS LATE THURS AND

THURS EVE SUGGEST SOME REDEVELOPMENT OF THE SFC LOW FARTHER SOUTH

DOWN OVER THE CHESAPEAKE BAY AREA BEFORE EXITING OFFSHORE SOUTH OF

NEW ENGLAND THURS NIGHT...AFTER INITIALLY CROSSING THROUGH OH/PA.

THE 12Z GFS REDEVELOPS THIS LOW FARTHEST SOUTH. THE 12Z GEM

REGIONAL AND 12Z NAM ARE A BIT FARTHER NORTH. THE 00Z ECMWF FOR

ITS PART...IS BY FAR A SLOW OUTLIER...AND IS ALREADY TOO SLOW WITH

THE CURRENT LOW PLACEMENT OVER THE MIDWEST. AS A RESULT...ITS MASS

FIELDS WILL NOT BE PREFERRED. THEREFORE BASED ON THE LATEST

AVAILABLE GUIDANCE AND TRENDS...WILL FAVOR A NON-ECMWF CONSENSUS

LED BY THE 12Z UKMET WHICH SPLITS THE LATITUDINAL PLACEMENT OF THE

SFC LOW OVER THE MID-ATLANTIC REGION BETWEEN THE GEM REGIONAL/NAM

AND THE GFS.

[mupawxnut]

12Z MODEL EVALUATION INCLUDING THE NAM/GFS/UKMET AND GEM REGIONAL

...SHORTWAVE TROUGH/SURFACE LOW CURRENTLY EJECTING ACROSS THE
NORTHERN PLAINS/UPPER MIDWEST...REACHING THE MID-ATLANTIC/SOUTHERN
NEW ENGLAND THURS...

PREFERENCE: NON-ECMWF CONSENSUS LED BY THE 12Z UKMET
CONFIDENCE: AVERAGE

OVERWHELMINGLY THE TREND IN THE 12Z GUIDANCE IS TO BE MORE
PROGRESSIVE WITH THE EVOLVING SHORTWAVE TROUGH AND ASSOCD SFC LOW
SEEN NOW MOVING ACROSS THE UPPER MIDWEST. THE MODELS TAKE THIS
ENERGY RAPIDLY INTO THE OH VLY OVERNIGHT AND ALLOW FOR ADDITIONAL
SHORTWAVE ENERGY DROPPING DOWN FROM ONTARIO TO REINFORCE THE HT
FALLS AS THE SYS MOVES ACROSS THE CNTRL
APPALACHIANS...MID-ATLANTIC AND SRN NEW ENGLAND ON THURS. THE 12Z
GFS AND 12Z UKMET ARE THE FASTEST FOLLOWED BY THE 12Z NAM AND 12Z
GEM REGIONAL. IT SHOULD BE NOTED THAT THE MODELS LATE THURS AND
THURS EVE SUGGEST SOME REDEVELOPMENT OF THE SFC LOW FARTHER SOUTH
DOWN OVER THE CHESAPEAKE BAY AREA BEFORE EXITING OFFSHORE SOUTH OF
NEW ENGLAND THURS NIGHT...AFTER INITIALLY CROSSING THROUGH OH/PA.
THE 12Z GFS REDEVELOPS THIS LOW FARTHEST SOUTH. THE 12Z GEM
REGIONAL AND 12Z NAM ARE A BIT FARTHER NORTH. THE 00Z ECMWF FOR
ITS PART...IS BY FAR A SLOW OUTLIER...AND IS ALREADY TOO SLOW WITH
THE CURRENT LOW PLACEMENT OVER THE MIDWEST. AS A RESULT...ITS MASS
FIELDS WILL NOT BE PREFERRED. THEREFORE BASED ON THE LATEST
AVAILABLE GUIDANCE AND TRENDS...WILL FAVOR A NON-ECMWF CONSENSUS
LED BY THE 12Z UKMET WHICH SPLITS THE LATITUDINAL PLACEMENT OF THE
SFC LOW OVER THE MID-ATLANTIC REGION BETWEEN THE GEM REGIONAL/NAM
AND THE GFS.

Should the WFO's cancel the Flood Watches for the NYC area?

[bluewave]

UKMET:

 

 

 

[WE GOT HIM]

12Z MODEL EVALUATION INCLUDING THE NAM/GFS/UKMET AND GEM REGIONAL...SHORTWAVE TROUGH/SURFACE LOW CURRENTLY EJECTING ACROSS THENORTHERN PLAINS/UPPER MIDWEST...REACHING THE MID-ATLANTIC/SOUTHERNNEW ENGLAND THURS...PREFERENCE: NON-ECMWF CONSENSUS LED BY THE 12Z UKMETCONFIDENCE: AVERAGEOVERWHELMINGLY THE TREND IN THE 12Z GUIDANCE IS TO BE MOREPROGRESSIVE WITH THE EVOLVING SHORTWAVE TROUGH AND ASSOCD SFC LOWSEEN NOW MOVING ACROSS THE UPPER MIDWEST. THE MODELS TAKE THISENERGY RAPIDLY INTO THE OH VLY OVERNIGHT AND ALLOW FOR ADDITIONALSHORTWAVE ENERGY DROPPING DOWN FROM ONTARIO TO REINFORCE THE HTFALLS AS THE SYS MOVES ACROSS THE CNTRLAPPALACHIANS...MID-ATLANTIC AND SRN NEW ENGLAND ON THURS. THE 12ZGFS AND 12Z UKMET ARE THE FASTEST FOLLOWED BY THE 12Z NAM AND 12ZGEM REGIONAL. IT SHOULD BE NOTED THAT THE MODELS LATE THURS ANDTHURS EVE SUGGEST SOME REDEVELOPMENT OF THE SFC LOW FARTHER SOUTHDOWN OVER THE CHESAPEAKE BAY AREA BEFORE EXITING OFFSHORE SOUTH OFNEW ENGLAND THURS NIGHT...AFTER INITIALLY CROSSING THROUGH OH/PA.THE 12Z GFS REDEVELOPS THIS LOW FARTHEST SOUTH. THE 12Z GEMREGIONAL AND 12Z NAM ARE A BIT FARTHER NORTH. THE 00Z ECMWF FORITS PART...IS BY FAR A SLOW OUTLIER...AND IS ALREADY TOO SLOW WITHTHE CURRENT LOW PLACEMENT OVER THE MIDWEST. AS A RESULT...ITS MASSFIELDS WILL NOT BE PREFERRED. THEREFORE BASED ON THE LATESTAVAILABLE GUIDANCE AND TRENDS...WILL FAVOR A NON-ECMWF CONSENSUSLED BY THE 12Z UKMET WHICH SPLITS THE LATITUDINAL PLACEMENT OF THESFC LOW OVER THE MID-ATLANTIC REGION BETWEEN THE GEM REGIONAL/NAMAND THE GFS.

Wow Bold, should have waited for 12z EURO first...

[Brian5671]

Should the WFO's cancel the Flood Watches for the NYC area?

Doubt it-we're still likely to see 2 inches of rain and we're sitting on saturated ground...

[SnoSki14]

Should the WFO's cancel the Flood Watches for the NYC area?

Why, a likely 1-3" is still probable with locally higher amounts and add on recent heavy rains and the flood risk still remains, the Ukmet still drops a lot of rain.

[Dsnowx53]

Similar to the 4km which may be bumping the warm front and overrunning about 30 miles too far north.

So I would slide the 4km rain shield about 30 miles south.

 

ptot48.gif

 

 

I share your thoughts. 

[Dsnowx53]

The WPC is making the wrong move, here. The Ukie has an odd suppressed bias in the shorter range. I honestly think today's 12z NAM...perhaps slightly adjusted southward is the way to go. I was always skeptical for the NYC area for severe for reasons I have stated many times, but going all the way the other way before the Euro comes out is just plain silly.

 

The NAM as a mesoscale model should be able to handle the location of boundaries pretty well. 

[Dsnowx53]

Should the WFO's cancel the Flood Watches for the NYC area?

 

 

The theoretical southward shift would put NYC back in the heavier rain threat. 

[earthlight]

The WPC is making the wrong move, here. The Ukie has an odd suppressed bias in the shorter range. I honestly think today's 12z NAM...perhaps slightly adjusted southward is the way to go. I was always skeptical for the NYC area for severe for reasons I have stated many times, but going all the way the other way before the Euro comes out is just plain silly.

 

The NAM as a mesoscale model should be able to handle the location of boundaries pretty well. 

 

They definitely jumped a little bit with the GFS's solution. But it will come down to a matter of miles. I still think there's a big time wind/tornado threat along the warm front and south of it. At this point its just a matter of whether that front moves up north of Philly or not. 

[mupawxnut]

They definitely jumped a little bit with the GFS's solution. But it will come down to a matter of miles. I still think there's a big time wind/tornado threat along the warm front and south of it. At this point its just a matter of whether that front moves up north of Philly or not.

Is the heavy rain threat for NYC and the western suburbs still alive and well?

[earthlight]

Is the heavy rain threat for NYC and the western suburbs still alive and well?

 

Nothing has changed in that regard. The best threat for heavy rain still seems to be a little north of NYC. 

[mupawxnut]

Nothing has changed in that regard. The best threat for heavy rain still seems to be a little north of NYC.

So do you think a NAM solution--with hardly any rain for NYC--will be what happens?

[Dsnowx53]

They definitely jumped a little bit with the GFS's solution. But it will come down to a matter of miles. I still think there's a big time wind/tornado threat along the warm front and south of it. At this point its just a matter of whether that front moves up north of Philly or not. 

 

 

Agreed. I think the WF moves north of Philly, but won't get north of Central NJ...which is why you and I have been more focused on S NJ and SE PA than we have Central NJ itself...Central NJ is still a bit borderline for discrete, truly surface based convection, but may be on the northern fringe of it depending on exact WF placement. They're still in the game, but just do not have the same level of concern -- or perhaps more appropriately, there is more uncertainty there than for areas further south.  

 

I just really hope the WPC doesn't think that C NJ is out of the woods because of the GFS's south shift.