Jump to content
  • Member Statistics

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

Severe Threat June 23rd


IsentropicLift

Recommended Posts

For several days now models have shown the potential for a significant severe threat on Tuesday. Despite the best forcing being a bit further North closer to the strong shortwave, things still look ripe for activity as far south as NYC.

 

SPC has accordingly placed the area in a slight risk for severe thunderstorms

 

day2otlk_0600.gif?1434991169743

 

...NRN APPALACHIAN MTNS/MID-ATLANTIC/NEW ENGLAND...
AN UPPER-LEVEL TROUGH IS FORECAST TO MOVE EWD INTO NERN STATES ON
TUESDAY AS A COLD FRONT ADVANCES EWD FROM THE LOWER GREAT LAKES INTO
THE NRN APPALACHIAN MTNS. THE EXIT REGION OF A 60 TO 80 KT MID-LEVEL
JET IS FORECAST TO OVERSPREAD NY AND NEW ENGLAND DURING THE EARLY
AFTERNOON. THIS WILL CREATE STRONG DEEP-LAYER SHEAR PROFILES THAT
COULD BE FAVORABLE FOR SEVERE STORMS AS SFC TEMPS WARM UP DURING THE
DAY. THE MODELS SUGGEST THAT CONVECTION MAY BE ONGOING ALONG THE
FRONT AT THE START OF THE PERIOD WITH AN MCS MOVING QUICKLY EWD
ACROSS THE REGION DURING THE LATE MORNING AND EARLY AFTERNOON. AHEAD
OF THE FRONT...A MOIST AIRMASS SHOULD BE IN PLACE WITH MODERATE
INSTABILITY DEVELOPING BY MIDDAY. THIS COMBINED WITH FOCUSED
LARGE-SCALE ASCENT AND STRONG DEEP-LAYER SHEAR MAY ENABLE
THUNDERSTORMS THAT DEVELOP ALONG THE FRONT TO HAVE A WIND DAMAGE
THREAT DURING THE EARLY TO MID AFTERNOON.

Link to comment
Share on other sites

  • Replies 462
  • Created
  • Last Reply

MT HOLLY 

.LONG TERM /TUESDAY THROUGH SUNDAY/...

**TUESDAY NEAR RECORD HEAT AND SEEMINGLY STRONG POTENTIAL FOR SCT
SVR STORMS**

 

 


AS FOR THE SEVERE THREAT: THE LOW LEVEL SOUTHWESTERLY FLOW AHEAD
OF THE FRONT WILL AIDE IN LOW LEVEL MOISTURE ADVECTION AND
INCREASING LAPSE RATES/INSTABILITY. BY THE AFTERNOON, CAPE VALUES
OF 1500 - 2000 J/KG ARE POSSIBLE (NAM SHOWS EVEN ABOVE 2000 J/KG,
BUT IT ALSO APPEARS TO BE TOO HIGH ON SURFACE DEW POINTS SO THINK
THIS IS HIGHER THAN WHAT WILL BE REALIZED). THERE IS CONSIDERABLE
BULK SHEAR IN THE 0-6KM LAYER (AROUND 40KT), THOUGH FLOW IS ALMOST
ENTIRELY UNIDIRECTIONAL SO SHEAR IS ALMOST ENTIRELY SPEED SHEAR.
THERE ARE A FEW THINGS THAT MIGHT LIMIT THE SEVERE THREAT HOWEVER.
FIRST, IF THE TREND FOR A FASTER COLD FRONT CONTINUES IT COULD
BEGIN MOVING THROUGH THE REGION BEFORE PEAK HEATING LEADING TO
SLIGHTLY LOWER INSTABILITY. SECOND...THE MID AND UPPER LEVEL JET
AS WELL AS THE BEST LIFT (ASIDE FROM MESOSCALE LIFT ALONG THE
FRONT) STAY WELL NORTH OF OUR REGION. IN FACT, BY MID DAY WE LOOK
TO BE UNDER THE RIGHT EXIT REGION OF THE UPPER LEVEL JET WHICH
COULD INHIBIT CONVECTIVE INITIATION. ALL THAT BEING SAID THOUGH,
STILL LOOKS TO BE ENOUGH OF A THREAT FOR DAMAGING WINDS TO
CONTINUE MENTION IN THE HWO AS WELL AS THE GRIDS. HAIL THREAT IS
POSSIBLE
, BUT THE VERY ELEVATED MELTING LAYER IN THE PRE FRONTAL
ENVIRONMENT WILL LIMIT THAT THREAT. TORNADO THREAT APPEARS VERY
MINIMAL GIVEN HARDLY ANY DIRECTIONAL SHEAR.
Link to comment
Share on other sites

There will most definitly be a rather potent squall line crossing the area tomorrow afternoon into early evening. The NAM is spitting out 3000-4000 J/KG of SBCAPE with strong speed shear and directional shear. The forecasted lifted index is -8 valid 23z tomorrow. The main limiting factor for super cells appears to be mid-level lapse rates which have gradually become less impressive, but that won't have any bearing on the squall line.

Link to comment
Share on other sites

It's a very solid threat, this isn't a winter storm and model output isn't gonna look like much (in terms of amounts) but look at instability and forcing, as well as high resolution short term models. If you don't "feel" tomorrow's potential just based on prior events not working out, then you probably haven't looked at what's progged.

Link to comment
Share on other sites

It's a very solid threat, this isn't a winter storm and model output isn't gonna look like much (in terms of amounts) but look at instability and forcing, as well as high resolution short term models. If you don't "feel" tomorrow's potential just based on prior events not working out, then you probably haven't looked at what's progged.

If your directly talking to me, I think the more impressive severe would be more to the north.

Link to comment
Share on other sites

It's a very solid threat, this isn't a winter storm and model output isn't gonna look like much (in terms of amounts) but look at instability and forcing, as well as high resolution short term models. If you don't "feel" tomorrow's potential just based on prior events not working out, then you probably haven't looked at what's progged.

Best forcing and lift is well north of the area...(at least my area anyway) 

Instability is decent  and SWEAT is also decent... 

Minimal directional shear is also going to hurt.. 

 

Not saying there will not be storms but i think it will be more scattered in nature, not widespread across the PA/ NJ region and you will have to go WELL north for the greatest severe threat where it should be more concentrated..

Link to comment
Share on other sites

If your directly talking to me, I think the more impressive severe would be more to the north.

I wasn't, just in general. The best forcing is indeed well north but the really good parameters overlap is not, we will see tomorrow I guess but even if the event isn't widespread we'll still likely see severe reports in our area.
Link to comment
Share on other sites

Part of the problem is that the leftover MCS in the morning really limits instability as the storms arrive too soon before the atmosphere has had sufficient time to recover. That doesn't appear to be a problem however from about the LHV south. I don't expect much in the way of discrete convection but I do think we see a solid line of storms around this time tomorrow. 

Link to comment
Share on other sites

NAM has 95 degrees at EWR ahead of the line with dews in the low to mid 70's. You don't get more fuel than that.

People downplaying this event are in for a surprise. I fully expect a large MCS barreling twords the area this time tomorrow. I doubt we hit severe criteria on the island but 40 mph gusts should be common

Link to comment
Share on other sites

I'll take anything at this point, so far the severe weather season has been a dud. Even a decent t-storm would do.

 

We are in prime position to see numerous severe wind reports throughout the area. As it always is, some people will see strong storms and some people will see severe storms. 

Link to comment
Share on other sites

I think tomorrow is going to end up surprising a lot of people. It's not that often that we get such ridiculous CAPE into the region and a significant shortwave moving through Ontario to set things off. Probably not widespread severe but about as best as we can hope for in the northeast. I'm sure somewhere it will end up being quite meh and in some places there could be damaging winds and hail, all within the greater metro.

Link to comment
Share on other sites

I think tomorrow is going to end up surprising a lot of people. It's not that often that we get such ridiculous CAPE into the region and a significant shortwave moving through Ontario to set things off. Probably not widespread severe but about as best as we can hope for in the northeast. I'm sure somewhere it will end up being quite meh and in some places there could be damaging winds and hail, all within the greater metro.

 

Thinking we see an upgrade to ENH risk either at 2AM or 9AM with 30% wind. 

Link to comment
Share on other sites

Getting impressed by the soundings for tomorrow afternoon. Will be a conditional threat since the evolution of the crapvection in the OHV is still up in the air for the most part. Wouldn't be surprised to see a few large hail reports and the potential for flash flooding. PWATS are around 2" in some spots and wet micro-bursts may also be a possibility if we can get convection to develop in NE Pennsylvania and converge into a QLCS 

 

8e91941ac49946666cac78eb6a1e75ae.png

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...