March 26th-28th Severe Thread

[cyclone77]

It certainly is an idea, but there is resistance to that as well. There is resistance to a severe weather forum as well. Honestly there is no perfect way to tackle the problem. The resistance to taking the discos out of the subregions is it takes away the local discos/observations that subregions tend to create.

Yeah I can see how that could create a problem. Although, a lot of that could be taken care of with a general monthly or even weekly disco thread in each sub region that could include this for greater detail/IMBY type stuff.

[tornadotony]

It certainly is an idea, but there is resistance to that as well. There is resistance to a severe weather forum as well. Honestly there is no perfect way to tackle the problem. The resistance to taking the discos out of the subregions is it takes away the local discos/observations that subregions tend to create.

But if we want to see obs from different areas, we have to sort through three or four different subforums. When stuff is happening fast, that becomes a challenge. Thus, that argument holds no water.

[Minnesota Meso]

This topic was started in the wrong thread. Plains/MN belongs in central/western.

Baro....with the warm temps in the gulf, and this set up I think a new region should be created to high light where I think the most severe will set up. Call it UP/Mississippi/Central Mississippi/OH Valley...this is where I think the most active zone will set up

[baroclinic_instability]

But if we want to see obs from different areas, we have to sort through three or four different subforums. When stuff is happening fast, that becomes a challenge. Thus, that argument holds no water.

I agree, but not everyone has similar ideas or wants to go in this direction. It takes time to change minds and come to a reasonable solution which everyone agrees to. It certainly is a discussion we are having among the staff.

[baroclinic_instability]

Baro....with the warm temps in the gulf, and this set up I think a new region should be created to high light where I think the most severe will set up. Call it UP/Mississippi/Central Mississippi/OH Valley...this is where I think the most active zone will set up

It would not be possible to dynamically create a new subregion for every individual threat.

[andyhb]

Although I'm not gonna go deeper into it, the pattern beyond this on the 00z GFS looks like it may hold problems as well.

[Minnesota Meso]

It would not be possible to dynamically create a new subregion for every individual threat.

I'm not thinking a sub region for every threat, I'm thinking that by late April it will be done with as far as TX/OK/KS...to a certain degree, no science involved, just a gut feeling. I think this is setting up like 2010 where MN of all states led the country in tornadoes. I'm not saying we will this year, but it may be SD/IA/WI/IL or OH and Indiana. Again just a gut feeling at this time, but I think this is where the zone will be.

[andyhb]

I'm not thinking a sub region for every threat, I'm thinking that by late April it will be done with as far as TX/OK/KS...to a certain degree, no science involved, just a gut feeling. I think this is setting up like 2010 where MN of all states led the country in tornadoes. I'm not saying we will this year, but it may be SD/IA/WI/IL or OH and Indiana. Again just a gut feeling at this time, but I think this is where the zone will be.

Huh...

[baroclinic_instability]

I'm not thinking a sub region for every threat, I'm thinking that by late April it will be done with as far as TX/OK/KS...to a certain degree, no science involved, just a gut feeling. I think this is setting up like 2010 where MN of all states led the country in tornadoes. I'm not saying we will this year, but it may be SD/IA/WI/IL or OH and Indiana. Again just a gut feeling at this time, but I think this is where the zone will be.

Umm...I am glad we have a new MN member...but that makes zero sense. High Plains is where it is at midsummer...topography is part of the reason, but you can not simply deny large scale seasonal patterns combined with the unique US topo.

[Chicago Storm]

Create a locked/pinned thread in each affected sub-forum, with a link to the main thread in Weather Discussion.

Problem solved.

There's no reason to have the same discussion over and over again when you have something this easy that can be done.

[cyclone77]

Create a locked/pinned thread in each affected sub-forum, with a link to the main thread in Weather Discussion.

Problem solved.

There's no reason to have the same discussion over and over again when you have something this easy that can be done.

Yeah that's a pretty good idea.

[Minnesota Meso]

Huh...

you never heard that MN led the nation in tornado's for 2010??

[andyhb]

No, it was the rest of the post that, as baro mentioned, didn't make a whole lot of sense at all.

[Minnesota Meso]

In 2010 MN at least at MSP and I think state wide we had no measurable snow. This year we have had very little. like 1..3. this smells a lot like 2010 where the baroclinic zone set up way further north

[andyhb]

It takes a lot more than comparisons between snowpacks to determine the overall setup of baroclinic zones...

By the way, the fact that MN had the most tornadoes in 2010 was almost entirely due to the June 17th outbreak...which is typically when the Northern Plains and Upper MS Valley see their most potent threats. We did not have the baroclinic zone set up way far north that year, otherwise we wouldn't have had the outbreaks on April 24th, April 30th/May 1st and May 10th...

[Minnesota Meso]

No, it was the rest of the post that, as baro mentioned, didn't make a whole lot of sense at all.

OK Baro's response makes complete sense, but given climatology, something is screwy, we will see, but the pattern is that we up here will see PW values 1-2 times greater than climatology in my opinion.

[Hoosier]

Personally, I view the main forum as "prime time." I only support severe threads there when the threat looks rather high and covers more than 1 subforum. Admittedly there is a drawback to this line of thinking, and it's that it's often hard to anticipate how significant an event may be when it's still several days out. I also support subforum severe threads as this helps to absorb some of the more IMBY/local chatter that could clog a main forum thread. It's a tricky balance but from the GLOV perspective, I thought it worked pretty well on March 2...the subforum severe thread became more of a local obs/banter thread and was not a detriment to the main forum thread.

[andyhb]

Whoa (and that's for the day before, mind you):

Euro lifts it north at 144, but I'd have to think that in between 120 and 144, you'd have a somewhat similar situation to what the GFS is showing.

[MnWeatherman]

ECMWF is magically delicious!

[andyhb]

GGEM similar to the GFS:

[MnWeatherman]

Let the ECMWF lead the way.... hopefully

[Stebo]

To the discussion about one topic or one forum for severe, I would be for both. Meaning if it is a regional or 2 region situation then one topic would work, a forum would work also if it is a multi region situation ala March 2nd. Either way all the topics would reside in one part of the forum. Of course as many noted here, this makes too much sense so obviously it won't happen...

[andyhb]

New ARX Discussion:

DEPENDING ON THE TIMING OF THE FRONT ON

TUESDAY...COULD SEE A BOUT OF SEVERE WEATHER. GFS INDICATING 0-1KM

MLCAPE AROUND 1200J/KG WITH PLENTY OF BULK SHEAR NOSING UP INTO

NORTHEAST IA/SOUTHEAST MN DURING THE AFTERNOON. TIMING OF THE

FRONTAL PASSAGE WILL BE OF THE ESSENCE HERE AND WILL HAVE TO BE

MONITORED CLOSELY. THE GFS AND TO A LESSER EXTENT THE ECMWF SHOW THE

AREA IN LINGERING DRY/BREEZY CYCLONIC FLOW ON WEDNESDAY. PLAN ON

HIGHS IN THE MIDDLE 50S TO MIDDLE 60S.

DVN beginning to hit on it too:

DEPENDING ON POTENTIAL PRE-FRONTAL HEATING AND WHERE MAIN UPPER JET AXIS SHEARS

OUT AT...THERE COULD BE A POTENTIAL FOR SVR STORMS ALONG THIS PROCESS

WITH THE MAJORITY OF THE LATEST MEDIUM RANGE MODELS AND ENSEMBLES

SUGGESTING THIS WINDOW OCCURRING IN THE LOCAL AREA LATE TUE OR TUE

NIGHT. FRONT WILL PASS AND LAY OUT ALMOST WEST-TO-EAST PARALLEL TO

STEERING MID CONUS WESTERLIES SOMETIME MID NEXT WEEK. STILL LARGE

UNCERTAINTIES HOW FAR NORTH OR SOUTH THIS FEATURE LAYS OUT AS WELL AS

ASSOCIATED CONVECTIVE POTENTIAL THIS FEATURE WILL HAVE ALONG ITS

PERIPHERY BY NEXT WED.

DMX too:

SURFACE BASED STORMS COULD

DEVELOP MONDAY NIGHT INTO TUESDAY AND WOULD BRING A CHANCE FOR

SEVERE WEATHER. AT THIS TIME...PRECIPITATION CHANCES LIKELY OVERDONE

FOR TUESDAY NIGHT WITH CURRENT PROJECTED TIMING THOUGH THESE SYSTEM

HAVE TYPICALLY BEEN DELAYED RECENTLY. 00Z GUIDANCE IS NOT DRAGGING

AS MUCH COLD AIR IN BY WEDNESDAY THUS THE ABOVE AVERAGE TEMPERATURES

SHOULD PERSIST THROUGH THE FORECAST PERIOD.

FGF:

MONDAY THROUGH WEDNESDAY STILL LOOK QUITE ACTIVE AS A POTENT

SHORT-WAVE MOVES ACROSS THE NORTHERN PLAINS. WARM AIR ADVECTION RAIN

SHOWERS ARE POSSIBLE ON MONDAY BEFORE INSTABILITY INCREASES AND THE

THREAT FOR ELEVATED THUNDERSTORMS MATERIALIZES MONDAY NIGHT. SURFACE

BASED CONVECTION IS POSSIBLE TUESDAY AS THE COLD FRONT MOVES ACROSS

THE REGION AND CANNOT RULE OUT THE THREAT FOR SEVERE THUNDERSTORMS.

Latest Day 4-8 from SPC:

DAY 4-8 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0350 AM CDT THU MAR 22 2012

VALID 251200Z - 301200Z

...DISCUSSION...

THE GFS AND ECMWF ARE IN DECENT AGREEMENT DAY 4 /SUN 3-25/ REGARDING

THE PROGRESSION OF THE ERN U.S. UPPER LOW -- WITH BOTH MODELS MOVING

THIS FEATURE SLOWLY OFF THE CAROLINA COAST -- THE GFS A BIG MORE

QUICKLY THAN THE ECMWF. WHILE LIMITED SEVERE THREAT COULD ACCOMPANY

THE UPPER SYSTEM AS THE COLD CORE CROSSES THE ATLANTIC COAST

STATES...THREAT LEVEL IS INSUFFICIENT TO WARRANT ISSUANCE OF A RISK

AREA.

MEANWHILE...DIFFERENCES ARE ALREADY APPARENT DAY 4 IN THE WRN U.S.

AS THE WRN U.S. TROUGH MOVES INLAND AND WEAKENS WITH TIME DUE TO THE

PERSISTENT CENTRAL U.S. RIDGING. DURING THE AFTERNOON OF DAY 5 /MON

3-26/...THE GFS SHOWS THIS SYSTEM CROSSING THE GREAT BASIN...WHILE

THE ECMWF SHOWS A MORE COMPACT/NEGATIVELY TILTED SHORT-WAVE FEATURE

ENTERING THE NRN HIGH PLAINS. WITH THESE DIFFERENCES

CONTINUING/INCREASING WITH TIME...PREDICTABILITY/CONFIDENCE ISSUES

ARISE REGARDING DEGREE AND LOCATION OF ANY SEVERE POTENTIAL

ACCOMPANYING THIS SYSTEM. WHILE SOME THREAT WOULD APPEAR LIKELY

ACROSS THE NRN AND CENTRAL PLAINS DAYS 5-6...AND POSSIBLY INTO THE

UPPER MIDWEST DAY 7...NO THREAT AREAS WILL BE HIGHLIGHTED ATTM OWING

TO AFOREMENTIONED PREDICTABILITY ISSUES.

..GOSS.. 03/22/2012

[Derek30]

I'm trying to diagnose the threat of elevated convection here in southern MB on Monday night/early Tuesday.

Last run of the GFS showed around 1,000 J/KG of MLCAPE around here on Monday night.

I'm not sold on the low getting far enough north, though.

ECMWF would be nice for me!

[B-Rent]

To the discussion about one topic or one forum for severe, I would be for both. Meaning if it is a regional or 2 region situation then one topic would work, a forum would work also if it is a multi region situation ala March 2nd. Either way all the topics would reside in one part of the forum. Of course as many noted here, this makes too much sense so obviously it won't happen...

Anyone feel like making a thread in Wx or OT about this stuff, so we don't have to troll through pages discussing where the discussion should be?

[baroclinic_instability]

MEX guidance brings in 91 degrees for North Platte Monday afternoon before the wave ejects through the plains. I will say I am getting more excited about this event. These ejecting and rapidly deamplifying waves are tough to time correctly, so a lot of details to work out, but it looks like an interesting event for portions of the northern and central plains.

[SquatchinNY]

Would the storms be cold core?

[andyhb]

I'm trying to diagnose the threat of elevated convection here in southern MB on Monday night/early Tuesday.

Last run of the GFS showed around 1,000 J/KG of MLCAPE around here on Monday night.

I'm not sold on the low getting far enough north, though.

ECMWF would be nice for me!

Yes it would have been...I noticed that, although I have relatives that live in Winnipeg and Portage la Prairie so that would be a bit concerning.

In addition to Monday looking better and better (aside from possible capping), if the instability can get there on Tuesday, there looks to be some impressive wind profiles across the Upper MS Valley for storms to work with.

ARX (Trusting GFS Instability values this far out is never a very good idea):

SHEAR PROFILES STILL APPEAR FAVORABLE FOR SEVERE THUNDERSTORMS. HOWEVER...THE LATEST

GUIDANCE HAS BACKED OFF ON CAPE VALUES. THE GFS IS SHOWING 0-3 KM

MUCAPE VALUES OF 300 TO 800 J/KG. 0-6 KM BULK SHEAR LOOKS TO BE

AROUND 40 TO 45 KTS...WITH 0-1 SHEAR OF 25 TO 35 KTS. WILL HAVE TO

CONTINUE TO CLOSELY WATCH THE NEXT FEW MODEL RUNS.

MPX:

SEVERE WEATHER LOOKS POSSIBLE ACROSS WEST CENTRAL THROUGH SOUTH

CENTRAL MN MONDAY NIGHT WITH ANOTHER CHANCE FOR SEVERE STORMS

ACROSS EASTERN MN AND WEST CENTRAL WI TUESDAY AND TUESDAY NIGHT

AS A COLD FRONT MOVES THROUGH.

DMX:

POPS ARE FINALLY INTRODUCED MON IN CONTINUING THETA-E ADVECTION AND INCREASING LARGE SCALE FORCING.

COULD SEE SURFACE BASED DEVELOPMENT DURING PEAK HEATING BUT MODELS

HAVE YET TO COME TO A CONSENSUS WITH RESPECT TO NORTHWARD EXTENT OF

WARM FRONTAL POSITION...WHETHER IN IA OR MN. MAY ALSO BE A BIT TOO

SLOW TO GET INTO OUR FORECAST AREA. MON AND MON NIGHT MAY HAVE A

WINDOW FOR SEVERE SEVERE WEATHER WHICH SEEMS TO HAVE THE BEST PERIOD

OF DEEP SHEAR. LOW LEVEL SHEAR IS ADEQUATE FOR INCREASED TORNADO

POTENTIAL AS WELL BUT FAVORABLE THERMODYNAMIC ENVIRONMENT...CINH

REDUCTION...IS QUESTIONABLE. SURFACE BASED POTENTIAL REDEVELOPS

ALONG FRONT EAST TUE POSSIBLY LINGERING INTO THE EVENING.

[Derek30]

Andy, do you think the threat for elevated convection would at least extend into southern MB? Looks like a rather impressive warm air advection regime. Would be a classic elevated scenario for sure in North Dakota. Not sure how far north, though..

[brettjrob]

Monday looks pretty nice on the 12z EC. It's quite a bit faster, with the shortwave trough axis already into CO by 00z Tue, resulting in a 988 mb SLP on the NE/SD border. Nice triple point setup for parts of SD and northern NE, with further dryline activity possible down through KS and the Panhandles. GFS is less enthusiastic due to less-favorable timing (for Monday).