Jump to content
  • Member Statistics

    17,587
    Total Members
    7,904
    Most Online
    LopezElliana
    Newest Member
    LopezElliana
    Joined

Severe Weather potential 9/8/12


weatherwiz

Recommended Posts

  • Replies 1.1k
  • Created
  • Last Reply

Hello there 30% hatched risk...

day2prob.gif

DAY 2 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1225 AM CDT FRI SEP 07 2012

VALID 081200Z - 091200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID ATLANTIC AREA

THROUGH THE NERN STATES...

..SYNOPSIS

QUASI-ZONAL SYNOPTIC PATTERN WILL TRANSITION TO A MORE AMPLIFIED

REGIME BY SATURDAY. THE POSITIVE TILT UPPER TROUGH NOW EXTENDING

FROM ONTARIO WSWWD THROUGH MT WILL AMPLIFY SEWD THROUGH THE GREAT

LAKES AND INTO THE OH VALLEY LATER FRIDAY. THIS FEATURE WILL THEN

BECOME NEGATIVELY TILTED AS AN EMBEDDED SHORTWAVE TROUGH EJECTS NEWD

THROUGH THE REMAINDER OF THE OH VALLEY INTO THE NERN STATES SATURDAY

AFTERNOON. SFC LOW WILL DEEPEN IN ASSOCIATION WITH THIS PROCESS AND

LIFT NEWD INTO SRN QUEBEC...WHILE TRAILING COLD FRONT SWEEPS

EWD/SEWD AND OFF THE ATLANTIC SEABOARD AND GULF COAST SATURDAY

NIGHT.

..ERN PORTIONS OF OH VALLEY...MID ATLANTIC THROUGH NERN STATES

A PRE-FRONTAL SQUALL LINE WILL LIKELY BE IN PROGRESS SATURDAY

MORNING FROM THE OH VALLEY SWWD INTO THE TN VALLEY. RICH GULF

MOISTURE /UPPER 60S TO 70F DEWPOINTS/ NOW RESIDING OVER THE MID

ATLANTIC AND SRN PORTIONS OF NERN STATES WILL ADVECT THROUGH

REMAINDER OF THE WARM SECTOR SATURDAY AS SLY LLJ STRENGTHENS IN

ASSOCIATION WITH EJECTING SHORTWAVE TROUGH AND DEEPENING SFC LOW.

WEAK MID LEVEL LAPSE RATES AND AREAS OF CLOUDS WILL MITIGATE

INSTABILITY SOMEWHAT. HOWEVER...BREAKS IN CLOUDS SHOULD ALLOW FOR

SOME DIABATIC WARMING OF THE MOIST BOUNDARY LAYER...CONTRIBUTING TO

MLCAPE FROM 500-1000 J/KG. STORMS ARE EXPECTED TO INTENSIFY ALONG

AND AHEAD OF PRE-EXISTING PROGRESSIVE OUTFLOW BOUNDARY AS WARM

SECTOR DESTABILIZES. DEEP LAYER WINDS WILL INCREASE IN ASSOCIATION

WITH THE SHORTWAVE TROUGH AND ITS ATTENDANT SFC LOW WITH LARGE

HODOGRAPHS AND 40+ KT 0-6 KM SHEAR. ORGANIZED STORMS INCLUDING

LEWP/BOWING STRUCTURES AND EMBEDDED SUPERCELLS WILL BE POSSIBLE AS

ACTIVITY DEVELOPS EWD. DAMAGING WIND AND MAYBE A FEW TORNADOES WILL

BE THE PRIMARY THREATS.

VERTICAL SHEAR PROFILES SHOULD BE WEAKER WITH SWD EXTENT INTO NC

SUGGESTING DOMINANT MULTICELL MODES. HOWEVER...INSTABILITY WILL

PROBABLY BE GREATER IN THIS AREA...AND THESE STORMS MAY BECOME

CAPABLE OF PRODUCING ISOLATED DAMAGING WIND AS THE BOUNDARY LAYER

DESTABILIZES DURING THE AFTERNOON.

Link to comment
Share on other sites

Yeah I saw. While it may extend into CT, I favor areas to the west...but it doesn't mean it's limited to that area.

The best combination of higher instability and shear actually occur across much of CT (according to the NAM) around 21z-0z. Cape values in excess of 2000 J/KG along with 0-3 helicity near 300 m2s2 with 0-1km helicity of around 200-250 m2s2. The potential certainly exists here. How many times before have we seen SPC go from SEE TEXT to 30% hatched?

Link to comment
Share on other sites

The best combination of higher instability and shear actually occur across much of CT (according to the NAM) around 21z-0z. Cape values in excess of 2000 J/KG along with 0-3 helicity near 300 m2s2 with 0-1km helicity of around 200-250 m2s2. The potential certainly exists here. How many times before have we seen SPC go from SEE TEXT to 30% hatched?

Yeah maybe. I just favor areas to the west. Better dynamics and daytime heating. Doesn't mean it's confined to that area though. NAM has something causing through at 21z on Saturday from the south. Batch of shwrs and iso thunder it seems. As usual with SNE, just gotta see as we get closer, but I'd rather be west in NY and PA.

Link to comment
Share on other sites

Yeah maybe. I just favor areas to the west. Better dynamics and daytime heating. Doesn't mean it's confined to that area though. NAM has something causing through at 21z on Saturday from the south. Batch of shwrs and iso thunder it seems. As usual with SNE, just gotta see as we get closer, but I'd rather be west in NY and PA.

I could see several breaks in cloud cover here. NAM soundings have a decent amount of dry air above 800mb and it's quite moist below it with winds staying SW so dry air shouldn't mix down.

Could have some pockets of warming temps aloft though which not only hurts lapse rates but could perhaps be a factor tomorrow...might have some CIN to work with but we'll see. NAM is forecasting temps into the 80's and the NAM is usually the one which tends to overdo cloud cover.

Link to comment
Share on other sites

I could see several breaks in cloud cover here. NAM soundings have a decent amount of dry air above 800mb and it's quite moist below it with winds staying SW so dry air shouldn't mix down.

Could have some pockets of warming temps aloft though which not only hurts lapse rates but could perhaps be a factor tomorrow...might have some CIN to work with but we'll see. NAM is forecasting temps into the 80's and the NAM is usually the one which tends to overdo cloud cover.

There will be breaks for sure.

Link to comment
Share on other sites

I also like the fact that Kevin is downplaying it...usually means we get something.

I'm not excited about tomorrow. I would guess theres some renegade stuff out ahead of the main line..that might cause some wet micros here and there..and then we all get excited as the radar to the west looks great and it then weakens as it moves into CT. Hope I'm wrong, but that's how I see it.

I certainly wouldn't pin the tail on the donkey that the NAM is right.

Link to comment
Share on other sites

I'm not excited about tomorrow. I would guess theres some renegade stuff out ahead of the main line..that might cause some wet micros here and there..and then we all get excited as the radar to the west looks great and it then weakens as it moves into CT. Hope I'm wrong, but that's how I see it.

I certainly wouldn't pin the tail on the donkey that the NAM is right.

It's just all going to depend on the timing...if we can get action to move through between say 21z and 0z that's when the best combination of shear/instability is in place.

I could see a couple rounds of storms too actually...stuff out ahead of the front and then a forced line right along the front producing some gusty winds.

Link to comment
Share on other sites

It's a high shear/low CAPE overall deal I think, unless there is more sun...or you are further west into PA and NY.

GFS timing would be better. however, i can't see this upper system not producing a big line that makes it to the coast (double negative, sry)

Link to comment
Share on other sites

Thanks Wizzy. I was on NPR yesterday and they plugged my blog a few times so I thought I had to go home and freshen it up with a new post lol.

I actually had been thinking quite a bit lately as to what state had the highest tornado average per square mile and was going to do that in the upcoming days but don't need to now!

That's a pretty crazy statistic, especially considering how much CT leads the other states around us.

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...