May 26-27th Mid Atl/NE Severe Weather, SPC Risk Level: Slight Risk- Forecasts & OBS Options

[yankees]

SPC has a slight risk up for parts of the region for Friday. Models also are indicating a pretty high cape and moderate shear environment.

SPC Outlook



http://www.spc.noaa.gov/products/outlook/day3otlk.html

This post has been edited by yankees: May 25 2011, 05:41 AM

[NYCSuburbs]

Friday could end up as an interesting severe weather event, especially for central PA into NY. Places further east, such as NJ, shouldn't see much, if any storms, but the torch will be the main story, with parts of NJ reaching the 90 degree mark.

Here's a map I made for my blog last night showing my thoughts for Friday, which have not changed at this time:



This post has been edited by NYCSuburbs: May 25 2011, 02:09 PM

[justintime2989]

shouldnt we add the 26th to the date since slight risk for that to with high cape and lift and all.

[NYCSuburbs]

shouldnt we add the 26th to the date since slight risk for that to with high cape and lift and all.

It should be added as well. The 26th should also bring a moderate-high end slight risk but for places further west, into western PA/NY.

[justintime2989]

yea there is talks on facebook about it maybe being moderate risk and i can say im going out to pa storm chasing.

[albanyweather]

HRRR has some early morning "leftovers" for western areas.

[albanyweather]

ARW is pretty bullish for Friday. NMM not so much.


NAM looks about the same as the ARW.

This post has been edited by albanyweather: May 25 2011, 07:46 PM

[yankees]

Friday could end up as an interesting severe weather event, especially for central PA into NY. Places further east, such as NJ, shouldn't see much, if any storms, but the torch will be the main story, with parts of NJ reaching the 90 degree mark.

Here's a map I made for my blog last night showing my thoughts for Friday, which have not changed at this time:

Looking at the GFS cape is around 2000 even into our area and shear looks pretty good as well around 40-60 knts. These two factors make me think you should extend he 15 percent risk into our area if not the 30 percent.

[so_whats_happeni...]

Tomorrow well the parameters are rather high! Especially across eastern PA. With left over energy coming east from overnight convection from the midwest storms may ignite. There may also be a S/W that comes across the region as there is a front draped near the region the will help spawn storms. I don't see these storms being that widespread but they may be enough to cause isolated damage across the region. I would like to see how the afternoon plays out. Friday doesn't look as abundant with parameters but enough to help keep storms in the region with a front coming near the region.

[so_whats_happeni...]

Friday could end up as an interesting severe weather event, especially for central PA into NY. Places further east, such as NJ, shouldn't see much, if any storms, but the torch will be the main story, with parts of NJ reaching the 90 degree mark.

Here's a map I made for my blog last night showing my thoughts for Friday, which have not changed at this time:

I don't see it looking like this i see it more straight up and down if not slightly NNW to SSE the way the storm is moving allow for this kinda setup to occur but overall i like the placement. I would like to see the actual storm track to know how far north to put the risks.

[NYCSuburbs]

ARW is pretty bullish for Friday. NMM not so much.


NAM looks about the same as the ARW.

Strange... usually it's the NMM that's the more bullish model with the ARW not as much.

Looking at the GFS cape is around 2000 even into our area and shear looks pretty good as well around 40-60 knts. These two factors make me think you should extend he 15 percent risk into our area if not the 30 percent.

Parameters are rather good in our area, but just the parameters alone don't mean that we'll get the storms. I can't rule out an isolated thunderstorms north and west of NYC, but all of the moisture and precipitation on Friday will stay to our west, and with these factors missing, even with the supportive parameters I doubt we'll see much, if any thunderstorms. Of course, with the supportive parameters, any thunderstorm that pops up could easily be strong/severe, but the best chance of that will be towards PA/NY.

I don't see it looking like this i see it more straight up and down if not slightly NNW to SSE the way the storm is moving allow for this kinda setup to occur but overall i like the placement. I would like to see the actual storm track to know how far north to put the risks.

I agree, I am going to be making some revisions to the map tonight, and I'm going to make it more of a N/S direction. For now, I'll keep the potential 30% risk in place.

[yankees]

Strange... usually it's the NMM that's the more bullish model with the ARW not as much.
Parameters are rather good in our area, but just the parameters alone don't mean that we'll get the storms. I can't rule out an isolated thunderstorms north and west of NYC, but all of the moisture and precipitation on Friday will stay to our west, and with these factors missing, even with the supportive parameters I doubt we'll see much, if any thunderstorms. Of course, with the supportive parameters, any thunderstorm that pops up could easily be strong/severe, but the best chance of that will be towards PA/NY.
I agree, I am going to be making some revisions to the map tonight, and I'm going to make it more of a N/S direction. For now, I'll keep the potential 30% risk in place.

Just wondering what you think of the threat for Monday through Wedensday the GFS and ERCM have a very high Cape and pretty good shear environment for me with a cold front coming through.

[so_whats_happeni...]

Strange... usually it's the NMM that's the more bullish model with the ARW not as much.
Parameters are rather good in our area, but just the parameters alone don't mean that we'll get the storms. I can't rule out an isolated thunderstorms north and west of NYC, but all of the moisture and precipitation on Friday will stay to our west, and with these factors missing, even with the supportive parameters I doubt we'll see much, if any thunderstorms. Of course, with the supportive parameters, any thunderstorm that pops up could easily be strong/severe, but the best chance of that will be towards PA/NY.
I agree, I am going to be making some revisions to the map tonight, and I'm going to make it more of a N/S direction. For now, I'll keep the potential 30% risk in place.

Yea if I were making a map i would also go with a N/S direction risk. Slight risk down to southern MD to just near saranac lake or just south of the canadian and NY border. The risk would likely be to just about west of the NYC area with the highest risk from binghamton down to about harrisburg just west of allentown and near state college.

If something changes that area as well will change.

[Fire/Rescue]

Friday could end up as an interesting severe weather event, especially for central PA into NY. Places further east, such as NJ, shouldn't see much, if any storms, but the torch will be the main story, with parts of NJ reaching the 90 degree mark.

Here's a map I made for my blog last night showing my thoughts for Friday, which have not changed at this time:

Looks good, and very possible

[NYCSuburbs]

Just wondering what you think of the threat for Monday through Wedensday the GFS and ERCM have a very high Cape and pretty good shear environment for me with a cold front coming through.

Monday and Tuesday, same story as Friday. Parameters are decent (missing bulk shear though), but other than scattered activity, there's nothing to really trigger a severe weather outbreak until we get to Wednesday, when the cold front should come through. Scattered showers and thunderstorms are possible in parts of the NE where the front will be, but Wednesday's cold front brings a better risk of more significant severe weather.

Looks good, and very possible

Thanks.

[yankees]

Monday and Tuesday, same story as Friday. Parameters are decent (missing bulk shear though), but other than scattered activity, there's nothing to really trigger a severe weather outbreak until we get to Wednesday, when the cold front should come through. Scattered showers and thunderstorms are possible in parts of the NE where the front will be, but Wednesday's cold front brings a better risk of more significant severe weather.
Thanks.

Yea tuesday night into wednseday does look to also have the best paramaters and with the front moving in it could be interesting.

[yankees]

SPC AC 260540

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1240 AM CDT THU MAY 26 2011

VALID 271200Z - 281200Z

...THERE IS A SLGT RISK OF SVR TSTMS FRI ACROSS PARTS OF THE NRN MID
ATLANTIC COAST STATES INTO NEW ENGLAND...

...THERE IS A SLGT RISK OF SVR TSTMS LATE FRI AFTN AND EVE ACROSS
PARTS OF THE S CNTRL PLAINS AND OZARK PLATEAU...

...SYNOPSIS...
MODELS CONTINUE TO INDICATE THAT SOME AMPLIFICATION WILL OCCUR
WITHIN THE LARGE-SCALE PATTERN AS A STRONG UPPER JET EMERGING FROM
THE MID-LATITUDE PACIFIC GRADUALLY PROGRESSES INLAND. BROAD UPPER
TROUGHING IS PROGGED TO EVOLVE OVER THE EASTERN PACIFIC AND WESTERN
U.S...WITH DOWNSTREAM RIDGING ACROSS THE PLAINS AND MISSISSIPPI
VALLEY TOWARD THE END OF THE PERIOD...AS THE EXIT REGION OF THE
UPPER JET NOSES EAST OF THE ROCKIES.

DOWNSTREAM...REMNANT UPPER TROUGHING OVER THE EASTERN STATES APPEARS
LIKELY TO GRADUALLY SPLIT...WITH AN INCREASINGLY SHEARED NORTHERN
PORTION LIFTING NORTHEASTWARD WITHIN STRONGER FLOW AROUND THE
NORTHWESTERN PERIPHERY OF RIDGING CENTERED OFF THE NORTH ATLANTIC
COAST. WITHIN A WEAKER FLOW REGIME...THE SOUTHERN PORTION IS
PROGGED TO TURN SOUTHEASTWARD ACROSS THE SOUTH ATLANTIC COAST
STATES.

...PARTS OF THE NRN MID ATLANTIC COAST STATES INTO NEW ENGLAND...
MODELS APPEAR TO HAVE TRENDED WEAKER WITH THE STRENGTH OF THE
LOWER/MID TROPOSPHERIC FLOW FIELDS ON THE WESTERN/NORTHERN PERIPHERY
OF THE ATLANTIC RIDGING. HOWEVER...DEEP LAYER SHEAR IS STILL
PROGGED TO BE STRONG AND SUPPORTIVE OF ORGANIZED CONVECTIVE
DEVELOPMENT AS A SEASONABLY MOIST BOUNDARY LAYER DESTABILIZES WITH
HEATING...FROM THE LEE OF THE NORTH CENTRAL APPALACHIANS THROUGH
WESTERN/SOUTHERN NEW ENGLAND. RELATIVELY STEEP MID-LEVEL LAPSE ARE
EXPECTED TO CONTRIBUTE TO MIXED LAYER CAPE ON THE ORDER OF 1000-2000
J/KG...AND FORCING ASSOCIATED WITH THE SHEARING IMPULSE IS EXPECTED
TO BE SUFFICIENT TO SUPPORT STORM DEVELOPMENT. SOME MAY TAKE ON
SUPERCELLULAR STRUCTURE WITH AN ENHANCED RISK FOR LARGE HAIL...
WHICH APPEARS TO BE THE PRIMARY SEVERE THREAT...THOUGH CONSOLIDATING
STORM CLUSTERS MAY BE ABLE TO GENERATED STRONG WIND GUSTS.

...S CNTRL PLAINS AND OZARK PLATEAU...
BENEATH MODEST AND DIFLUENT WEST NORTHWESTERLY MID/UPPER FLOW...
MODELS CONTINUE TO INDICATE SUBSTANTIVE LOW-LEVEL MOISTENING EAST OF
A WEAK SURFACE LOW...AND ALONG A DEVELOPING WARM FRONT...ACROSS THE
SOUTH CENTRAL PLAINS FRIDAY. THIS MAY YIELD MODERATE CAPE IN THE
PRESENCE OF STEEP LAPSE RATES ASSOCIATED WITH VERY WARM ELEVATED
MIXED LAYER AIR ADVECTING OFF THE PLATEAU /ROCKIES. MID/UPPER
FORCING FOR CONVECTIVE DEVELOPMENT IS UNCLEAR...AND COULD BE
WEAK...BUT STRENGTHENING WARM ADVECTION NEAR A 30-50 KT SOUTHERLY
LOW-LEVEL JET MAY BE SUFFICIENT TO SUPPORT SCATTERED STORMS. IT
STILL APPEARS POSSIBLE THAT SOME OF THIS ACTIVITY MAY BE BOUNDARY
LAYER BASED...INITIATING PRIOR TO NIGHTFALL OVER PARTS OF CENTRAL
AND EASTERN OKLAHOMA...WHERE VERTICAL SHEAR PROBABLY WILL BE
SUFFICIENT FOR SUPERCELLS.

http://www.spc.noaa.gov/products/outlook/day2otlk.html

This post has been edited by yankees: May 26 2011, 05:49 AM

[NYCSuburbs]

http://www.spc.noaa.gov/products/outlook/day2otlk.html

Friday doesn't look very impressive. It would be a very good idea to add today to this thread though, today should be the bigger day out of the two days focusing on Pennsylvania and New York. Friday's storms should be slightly weaker, but I still haven't changed my thinking on most of them staying to the west of NYC.

This post has been edited by NYCSuburbs: May 26 2011, 06:00 AM

[albanyweather]

Friday doesn't look very impressive. It would be a very good idea to add today to this thread though, today should be the bigger day out of the two days focusing on Pennsylvania and New York. Friday's storms should be slightly weaker, but I still haven't changed my thinking on most of them staying to the west of NYC.

Friday looks to have stronger storms for my area but less coverage with the trough going pos. to neutral.

HRRR and WRF look nice for a nocturnal event tonight

[Dave12308]

Friday looks to have stronger storms for my area but less coverage with the trough going pos. to neutral.

HRRR and WRF look nice for a nocturnal event tonight

Odd, the latest forecast discussion out of Albany doesn't back up what you are saying. They think the activity will be more widespread on Friday.

"FRIDAY...THIS MAY BE THE DAY WHEN THE SEVERE THREAT IS MORE
EXPANSIVE AND WIDESPREAD OVER THE REGION. MOST OF THE REGION WILL
BE ENTRENCHED IS A VERY HUMID AIR MASS."

Source link:

http://forecast.weather.gov/product.php?si...p;highlight=off

This post has been edited by Dave12308: May 26 2011, 08:43 AM