Our first legit shot at some severe weather?

[weatherwiz]

I understand just a few days ago we saw our first slight risk of the 2011 season, however, in my eyes there was never really any legit shot at severe weather on Wednesday. I understand that if we were able to get into the 70's or even higher there would have been a threat but there were really no indications that we were ever going to reach temperatures of that level. Yes, the GFS MOS had temps into the 70's but it was fairly obvious given the setup we were not going to see that occur.

We have seen what may end up becoming one of the most historic months of all time when it comes to severe weather and tornadoes and much of the central Plains/Ohio Valley/Mississippi Valley/Southeast regions have been absolutely crushed with severe weather over the past several weeks. We saw what may end up being the largest 3-day tornado outbreak on record just over a week ago and saw a very impressive damaging event just a few days ago. We have been in a very volatile weather pattern over these past few weeks and this pattern looms to hold firm over the next one to perhaps even two weeks. As we continue to grow later into the spring season and gear towards summer we should see the threat for severe weather continue to spread eastward towards the mid-Atlantic and Northeast regions.

When dealing with next week's cold front, which right now is progged to come through the area sometime next Thursday it is important to note that we will still be in late April, while this is a better period than early April climatologically it is still on the early side for parts of the Northeast (mainly southern New England, especially towards the coast) to experience a good deal of severe wx. Isolated severe wx is certainly possible but higher end events are much harder to come by. With this said the areas that are usually much more favored are NY/PA and parts of VT, and extreme western MA. Until we get closer to the event and details can be further worked out it's safe to say these areas would likely stand a much better chance for the threat of severe weather.

Now that this is out of the way lets take a look at the storm system and the potential pattern setup which could lead to some favorable conditions for the possibility of severe weather in portions of our region.

As we move into and through the weekend yet another trough will be ejecting into the west coast. A surface low will once again develop across the southwestern part of the US and then move northeastward towards the Plains and then through the Ohio Valley and then finally towards far western NY state before departing into Canada.

Tonight's 0z/23 GFS and today's 12z/22 Euro both depict a sub-992 mb sfc low near MI come 12z Thursday morning. Both the GFS/Euro actually continue to strengthen the sfc low as it moves through the Ohio Valley region towards MI and into Canada. This is something to watch for as if this does occur this would really help to propel the warm front northward and could give us a much better shot at seeing the warm front actually lift through placing us in the warm sector. It should be noted, however, that often in this timeframe the models really like to continue deepening the sfc lows as they move into or towards the Northeast or they are a little too deep with the sfc lows.

Due to the tight gradient between the high pressure off the east coast and the sfc low off to our west the GFS develops a pretty strong LLJ in associated with the warm front, the GFS right now has between 40-60 knots at 925/850mb coming in from the southwest. This will help to transport a good deal of moisture northward from the south and also bring in some much warmer air aloft as 925mb temps near +15C and 850mb temps near +12C.

The one issues regarding sfc temps will be cloud cover (when is this not an issue here?). This time of year the water temperatures across the Atlantic and Long Island Sound are still rather chilly and this can really hamper the northward progression of the sfc warm front, especially when the winds at the sfc are from the south/southeast. As of now the GFS is showing sfc winds mainly from the south/southeast. With the time of year and a source of lift around with the warm front in the vicinity it is possible we deal with a major low-level stratus deck to begin the day. Given how the sun angle still isn't quite strong (although it is getting there) it could take a while to really burn through this deck which could really hamper us from receiving the sufficient sfc heating needed to generate some decent instability. There does appear to be a good deal of dry air aloft though in the mid levels of the atmosphere though and with some mixing as the sun warms the atmosphere up above the cloud deck this drier air could mix down into the lower-levels which could help to increase the rate at which the low-level cloud deck tries to erode.

Mid level temperatures will also be on the cooler side with 500mb temps in the -12C to -14C range, with some cooling as the cold front/trough work closer. This should yield to some marginally steep mid-level lapse rates.

Dynamics aloft (at least right now) look sufficient enough.

One of the keys will be how warm can we get at the sfc? If we can somehow get a good deal of sunshine we could see temperature soar into the lower to mid 70's but this is highly dependent on how much sun we can see, and often times even in the summer this can be a tough feat.

Regardless right now the best threat for any severe weather may be just to our west across NY/PA where they have a much better chance at seeing more sunshine and stronger destabilization.

We'll have to just watch and see how things unfold over the next several days. Regardless the weather pattern looks highly active and there should be multiple threats for severe weather across a good deal of the country over the next few weeks, perhaps eventually we will see some of this spill into our region.

[weatherwiz]

Some timing differences between the GFS and the Euro and some timing issues potentially for us here in New England but things still looking possible for some severe wx possibly in the Thursday timeframe, especially just off to our west.

[free_man]

It's basically impossible to get svr this time of year with a S flow, forget it. Sure NY/PA and south west does fine. Hopefully we get a few nice heat ridges to start building in, if only to get ssts up. Just miserable out there, thank God for next weeks warmup.

[ineedsnow]

wiz you would have loved the storm that just went threw paducah!!

Paducah, Barkley Regional Airport

Lat: 37.07 Lon: -88.77 Elev: 407

Last Update on Apr 23, 2:53 pm CDT

' Heavy Rain Fog/Mist Squalls and Breezy'

62 °F

(17 °C)Humidity:93 %Wind Speed:NW 24 G 79 MPHBarometer:29.99" (1015.3 mb)Dewpoint:60 °F (16 °C)Visibility:0.75 mi.More Local Wx:3 Day History

[weatherwiz]

It's basically impossible to get svr this time of year with a S flow, forget it. Sure NY/PA and south west does fine. Hopefully we get a few nice heat ridges to start building in, if only to get ssts up. Just miserable out there, thank God for next weeks warmup.

I'm kind of hoping we can see a more SW flow than a southerly flow but the southerly flow would just probably kill any threat for much of CT and SE MA...interior New England could still have a ****.

[weatherwiz]

wiz you would have loved the storm that just went threw paducah!!

Paducah, Barkley Regional Airport

Lat: 37.07 Lon: -88.77 Elev: 407

Last Update on Apr 23, 2:53 pm CDT

' Heavy Rain Fog/Mist Squalls and Breezy'

62 °F

(17 °C)Humidity:93 %Wind Speed:NW 24 G 79 MPHBarometer:29.99" (1015.3 mb)Dewpoint:60 °F (16 °C)Visibility:0.75 mi.More Local Wx:3 Day History

WOW...that's sick!

[weatherwiz]

This could actually be a pretty solid setup for NY/PA.

[Typhoon Tip]

Good effort but I'd have to be real conservative until such time that SSW BL flow can be ruled out.... This is a dirty marine tainted warm sector for much of the region as it stands now....setting up the impenetrable wall of SB CAPE reduction from western CT to roughly SE VT.

[weatherMA]

This could actually be a pretty solid setup for NY/PA.

8 days till May 1st!!

[weatherwiz]

Good effort but I'd have to be real conservative until such time that SSW BL flow can be ruled out.... This is a dirty marine tainted warm sector for much of the region as it stands now....setting up the impenetrable wall of SB CAPE reduction from western CT to roughly SE VT.

Yeah it might be incredible difficult to get some severe wx out this way, especially as you get closer to the coastline and such. Where the boundary ends between the good Cape values and virtually nothing this area can sometimes be a good hot spot for something, dynamics here are still usually great, lapse rates can be better and you have some good thermal gradients plus the instability.

This thread would probably be better suited for the NY forum but that doesn't get as much traffic as this one.

[Typhoon Tip]

Yeah it might be incredible difficult to get some severe wx out this way, especially as you get closer to the coastline and such. Where the boundary ends between the good Cape values and virtually nothing this area can sometimes be a good hot spot for something, dynamics here are still usually great, lapse rates can be better and you have some good thermal gradients plus the instability.

This thread would probably be better suited for the NY forum but that doesn't get as much traffic as this one.

it gets worse, too.... the 12z NAM is cutting a bd down from down east maine on wednesday. i was wondering about this yesterday, though didn't mention, with that fairly robust high moving just n of maine mid week, whether or not that tuesday morning warm fropa would collapse on us thereafter.

it is just April.

[weatherwiz]

it gets worse, too.... the 12z NAM is cutting a bd down from down east maine on wednesday. i was wondering about this yesterday, though didn't mention, with that fairly robust high moving just n of maine mid week, whether or not that tuesday morning warm fropa would collapse on us thereafter.

it is just April.

It will be interesting to see if that high pressure has any influence on us at all, with the sfc low off to our west continuing to deepen through mid morning Thursday that should really help in trying to swing the warm front as far north as possible, I suppose there could be some sort of BD boundary but how far south would it actually make it and how strong would it be?

Another issue is the timing of the cold front, does it come through in the late morning/early afternoon or does it hold off until the evening? If it can hold off until the evening I think some locations could have a chance to see some sun and get temps close to 70F...perhaps the lower 70's which would be enough to produce some marginal instability. If we see a faster fropa I could see some elevated storms with a threat for some small hail...perhaps a strong gust or two.

I'm not sure how long we are going to sustain this pattern wee are in nation wide but if can hold another 3-5 weeks we could have some good fun come late May.

[Typhoon Tip]

It will be interesting to see if that high pressure has any influence on us at all, with the sfc low off to our west continuing to deepen through mid morning Thursday that should really help in trying to swing the warm front as far north as possible, I suppose there could be some sort of BD boundary but how far south would it actually make it and how strong would it be?

Another issue is the timing of the cold front, does it come through in the late morning/early afternoon or does it hold off until the evening? If it can hold off until the evening I think some locations could have a chance to see some sun and get temps close to 70F...perhaps the lower 70's which would be enough to produce some marginal instability. If we see a faster fropa I could see some elevated storms with a threat for some small hail...perhaps a strong gust or two.

I'm not sure how long we are going to sustain this pattern wee are in nation wide but if can hold another 3-5 weeks we could have some good fun come late May.

I suppose it is possible the NAM is just over-doing the strength of that high. Time will tell...

Yes, there is a transitory pattern of alternation between warm and cool anomalies... That, in the means, is a good start.

[weatherwiz]

I suppose it is possible the NAM is just over-doing the strength of that high. Time will tell...

Yes, there is a transitory pattern of alternation between warm and cool anomalies... That, in the means, is a good start.

I also like the fact were seeing dry precipitation anomalies across parts of the south and plains...if this continues as we move through the spring and into the early part of summer this could help with some good EML's over that area and depending on how the heat ridge sets up later in the year any of this breaking off could mean we may have a shot at getting a solid EML working this way.

[OKpowdah]

Meh, upper low wraps up way to our west, keeping temperatures aloft pretty warm, winds unidirectional with height, and kinda lousy upper level support overall.

Paul, I don't think you can do this to the English language: "one of the most historic months of all time"

[weatherwiz]

Meh, upper low wraps up way to our west, keeping temperatures aloft pretty warm, winds unidirectional with height, and kinda lousy upper level support overall.

Paul, I don't think you can do this to the English language: "one of the most historic months of all time"

I hope this continues through May and into June.

[OKpowdah]

I hope this continues through May and into June.

Our time will most certainly come. I think the last week of May and into June will become very active for the northeast.

If nothing else, I'll be in Oklahoma May 22nd -- July 29th, so that's a pretty good sign for multiple massive tornado outbreaks in SNE

[weatherwiz]

Our time will most certainly come. I think the last week of May and into June will become very active for the northeast.

If nothing else, I'll be in Oklahoma May 22nd -- July 29th, so that's a pretty good sign for multiple massive tornado outbreaks in SNE

Oh wow...what are you doing out in OK?

Perhaps you'll catch some action while you're there.

Yeah I think as well that period could be very active for us, this weather pattern were in is highly volatile and looks to stay that way for some time, the atmosphere is still going through the abrupt change from strong Nino to borderline strong Nina.

[OKpowdah]

Oh wow...what are you doing out in OK?

Perhaps you'll catch some action while you're there.

Yeah I think as well that period could be very active for us, this weather pattern were in is highly volatile and looks to stay that way for some time, the atmosphere is still going through the abrupt change from strong Nino to borderline strong Nina.

I got accepted to the REU program in Norman! Hopefully the drought ends, and we can get some action in the first few weeks before the death ridge takes over

[weatherwiz]

I got accepted to the REU program in Norman! Hopefully the drought ends, and we can get some action in the first few weeks before the death ridge takes over

Oh that's awesome dude, congrats

Yeah I hate those death ridges, we can get some awesome instability values (3000-4000 J/KG of SBcape) however, this cape is usually shallow b/c it's generated from strong sfc heating. Temps aloft in the mid levels are just so baking we have horrible ML lapse rates and virtually no instability aloft. MLcape values will be like 1000-1500 J/KG...if lucky.

I've been killing myself the past month trying to work on a summer outlook and I am just totally lost...I've done outlooks for winter/summer for the past 3-4 years I think and have been completely wrong each time so I know I have to go about things differently...I used to just basically find ENSO matches and go from there but seeing how wrong I've been that just tells me that there is much more to things than ENSO, you have the NAO/AO/PNA/EPO/WP/EA and then QBO/GLAAM/solar, etc...

Trying to figure each of these out and their influences on the overall weather pattern is a killer

[weatherwiz]

Wednesday could be very fun across NY/PA depending on the degree of instability.

[Damage In Tolland]

Thursday looks like it's our day. Front has really slowed down on guidance..and looks like it's coming thru on Thursday during max heating time. Only worry will be any leftover cloud debris from Wed storms to our west

[weatherwiz]

Thursday looks like it's our day. Front has really slowed down on guidance..and looks like it's coming thru on Thursday during max heating time. Only worry will be any leftover cloud debris from Wed storms to our west

The timing does look like it will favor us, however, the question is how much clouds will we have over the region? Not only will we have to contend with clouds from convective debris but if sfc winds are aligned in a more southerly direction that could really make for a PITA morning low-level stratus deck which may take forever to burn off. Right now I would see the best chance for anything being in extreme western SNE.

Gotta watch the lapse rates though, ML lapse rates look like they could really suck with the CAA in the mid-levels really being halted.

[OSUmetstud]

Still looks like too much southerly flow Wiz. I also don't like the cutting-off to our west with ridging at all levels. That typically spells very poor lapse rates.

[weatherwiz]

Still looks like too much southerly flow Wiz. I also don't like the cutting-off to our west with ridging at all levels. That typically spells very poor lapse rates.

Yeah the lapse rates are going to blow.

I'm leaning towards thinking perhaps some elevated convection with potential for some strong gusts. Winds on Thursday are going to be rather gusty anyways but how strong will all depend on the level of mixing and the strength of the low-level inversion.

This might be a bit more fun out in NY/PA on Wednesday, although they may have poor lapse rates to contend with as well but they may generate more in the way of instability than we will.

Not disappointed though, even through the next few weeks the pattern looks very active and this takes us through the first week of May so were getting closer to a more favorable period for us.

[free_man]

Epic bust for Blizz in the other thread, regarding Henrys call. I'd love to be staying in TN/KY for a few weeks right about now

...PA/NW SSWWD TO THE GULF COAST...

YET ANOTHER DAY OF POTENTIALLY VERY SIGNIFICANT SEVERE WEATHER IS

EXPECTED DAY 3 /WED. AND EARLY THU. APR. 27 AND 28/ -- WITH ELEVATED

THREAT FOR A TORNADO OUTBREAK EVIDENT ACROSS THE MID SOUTH AND INTO

PORTIONS OF THE CENTRAL GULF COAST STATES.

STRONG/SEVERE STORMS SHOULD BE ONGOING AT THE START OF THE PERIOD

ACROSS THE NWRN PORTIONS OF THE SLIGHT RISK AREA...AS THE POTENT

SHORT-WAVE TROUGH AND ASSOCIATED MID-/UPPER-LEVEL SPEED MAX ROUNDS

THE BASE OF THE LARGER-SCALE TROUGH. WHILE AN INITIAL SURFACE LOW

SHOULD SHIFT NNEWD ACROSS THE OH VALLEY/MIDWEST...SECONDARY SURFACE

LOW DEVELOPMENT IS FORECAST DURING THE AFTERNOON IN THE KY/TN

VICINITY...WITH LOCALLY-BACKED SURFACE FLOW VEERING/INCREASING

SUBSTANTIALLY WITH HEIGHT RESULTING IN SHEAR PROFILES VERY

SUPPORTIVE OF SUPERCELLS AND TORNADOES. THE MOST FAVORABLE

COMBINATION OF RICH LOW-LEVEL MOISTURE...STRONG SHEAR...FOCUSED

LARGE-SCALE ASCENT...AND ANTICIPATED LACK OF APPRECIABLE PRIOR

CONVECTION INDICATES A RELATIVELY HIGH-CONFIDENCE AREA OF

CONCENTRATED SIGNIFICANT THREAT FOR POTENTIALLY STRONG TORNADOES AND

WIDESPREAD WIND DAMAGE CENTERED OVER THE MID SOUTH/TN VALLEY REGION.

THEREFORE...WILL INTRODUCE MODERATE RISK FORECAST ATTM --

INDICATIVE OF OUTBREAK POTENTIAL.

ALONG WITH FAIRLY SUBSTANTIAL SEVERE POTENTIAL EXTENDING FARTHER

NNEWD INTO PA/NY -- INCLUDING THREATS FOR DAMAGING WINDS AND

ISOLATED TORNADOES...SEVERE STORMS WILL LIKELY ALSO EXTEND E OF THE

APPALACHIANS INTO THE ATLANTIC COAST STATES. ALONG WITH THE

LIKELIHOOD FOR AFTERNOON SEVERE CONVECTION...SEVERE CONVECTION MAY

CONTINUE INTO THE OVERNIGHT HOURS AS THE SURFACE FRONT CRESTS THE

APPALACHIANS.

[weatherwiz]

This is going to be the most impressive month of our lifetimes. It's not even over yet as we still have 6 days to go in the month and at least 3 of them will be active then potentially something Friday or Saturday.

May should start off hot as well.

[eekuasepinniW]

I always get amped up when weatherwiz makes a post that's too long to read.

This is going to be a tremendous thunderstorm year for everyone, I can feel it. The forkyfork derecho is finally coming.

[Damage In Tolland]

Epic bust for Blizz in the other thread, regarding Henrys call. I'd love to be staying in TN/KY for a few weeks right about now

...PA/NW SSWWD TO THE GULF COAST...

YET ANOTHER DAY OF POTENTIALLY VERY SIGNIFICANT SEVERE WEATHER IS

EXPECTED DAY 3 /WED. AND EARLY THU. APR. 27 AND 28/ -- WITH ELEVATED

THREAT FOR A TORNADO OUTBREAK EVIDENT ACROSS THE MID SOUTH AND INTO

PORTIONS OF THE CENTRAL GULF COAST STATES.

STRONG/SEVERE STORMS SHOULD BE ONGOING AT THE START OF THE PERIOD

ACROSS THE NWRN PORTIONS OF THE SLIGHT RISK AREA...AS THE POTENT

SHORT-WAVE TROUGH AND ASSOCIATED MID-/UPPER-LEVEL SPEED MAX ROUNDS

THE BASE OF THE LARGER-SCALE TROUGH. WHILE AN INITIAL SURFACE LOW

SHOULD SHIFT NNEWD ACROSS THE OH VALLEY/MIDWEST...SECONDARY SURFACE

LOW DEVELOPMENT IS FORECAST DURING THE AFTERNOON IN THE KY/TN

VICINITY...WITH LOCALLY-BACKED SURFACE FLOW VEERING/INCREASING

SUBSTANTIALLY WITH HEIGHT RESULTING IN SHEAR PROFILES VERY

SUPPORTIVE OF SUPERCELLS AND TORNADOES. THE MOST FAVORABLE

COMBINATION OF RICH LOW-LEVEL MOISTURE...STRONG SHEAR...FOCUSED

LARGE-SCALE ASCENT...AND ANTICIPATED LACK OF APPRECIABLE PRIOR

CONVECTION INDICATES A RELATIVELY HIGH-CONFIDENCE AREA OF

CONCENTRATED SIGNIFICANT THREAT FOR POTENTIALLY STRONG TORNADOES AND

WIDESPREAD WIND DAMAGE CENTERED OVER THE MID SOUTH/TN VALLEY REGION.

THEREFORE...WILL INTRODUCE MODERATE RISK FORECAST ATTM --

INDICATIVE OF OUTBREAK POTENTIAL.

ALONG WITH FAIRLY SUBSTANTIAL SEVERE POTENTIAL EXTENDING FARTHER

NNEWD INTO PA/NY -- INCLUDING THREATS FOR DAMAGING WINDS AND

ISOLATED TORNADOES...SEVERE STORMS WILL LIKELY ALSO EXTEND E OF THE

APPALACHIANS INTO THE ATLANTIC COAST STATES. ALONG WITH THE

LIKELIHOOD FOR AFTERNOON SEVERE CONVECTION...SEVERE CONVECTION MAY

CONTINUE INTO THE OVERNIGHT HOURS AS THE SURFACE FRONT CRESTS THE

APPALACHIANS.

It was a terrible forecast from Margusity. Awful

[free_man]

It was a terrible forecast from Margusity. Awful

You said 300 tors in two weeks was impossible. That was awful, you are ignoring the stats still?...huge numbers being put up and this next series should be pretty spectacular, too.