Jump to content
  • Member Statistics

    17,600
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

Significant severe weather threats 4/8-10


OKpowdah

Recommended Posts

Yeah there continue to be some textbook soundings coming out of OK and KS on Monday evening, and there is convective initiation being hinted at.

 

If these trends continue, I'll be pretty impressed. Can't wait for the SPC day 3 outlook tonight.

Link to comment
Share on other sites

  • Replies 474
  • Created
  • Last Reply

Yeah there continue to be some textbook soundings coming out of OK and KS on Monday evening, and there is convective initiation being hinted at.

pretty good agreement on monday at this pt. looks pretty solid somewhere in there. it looks better overall than may 25 last yr but at the sfc it looks sorta similar at least with placement and where the focus of convection is. not that it won't change.. and there is seemingly a good bit more potential at least at mid-lvls etc, but prob some other negatives comparatively given it's 6 weeks earlier inj the season.

Link to comment
Share on other sites

Can't believe how many chasers are following the GFS around run-to-run.

 

The consistent ECMWF continues to be the way to go. Hard to put trust in a model (GFS) when it can't even stick with a solution for more than 6hrs.

 

Well, I can understand the chaser mindset of model hugging. They're looking for an optimum run for them. I've learned over the years to just sit back and wait. 

Link to comment
Share on other sites

Its the NAM, but its really been trending towards a much more interesting system overall. 

 

00z NAM 500mb winds

 

12z Tues 

 

attachicon.gifgrearth 2013-04-05 23-19-25-22.png

 

Incredible trough and synoptic cyclone, but strictly in terms of tornado potential, the extremely meridional flow over the warm sector there presents a serious problem for Tuesday. One could argue there's potential down south as the base of the trough veers flow aloft again later, but will the low-levels veer out too by then? I'll admit the ECMWF looks quite impressive, but with most of the other, faster solutions, Tuesday is likely a grungefest and perhaps even linear.

 

Furthermore, the NAM is swaying me toward pessimism on initiation Monday, for the time being. Not because of its QPF output, which can't be trusted, but moisture simply doesn't look quite sufficient to overcome the stout EML in most soundings. The CINH map is rather depressing. If there were a large area of -50 to -75 J/kg east of the dryline, I'd say that's perfect for allowing instability to build until ascent arrives late. But for the most part it's < -100 J/kg everywhere, and that's no bueno, judging from experience (even regarding CINH model depictions at this range). The GFS soundings have looked tantalizing for days and still do, but I'm afraid its 65+ dews could be a stretch.

Link to comment
Share on other sites

Incredible trough and synoptic cyclone, but strictly in terms of tornado potential, the extremely meridional flow over the warm sector there presents a serious problem for Tuesday. One could argue there's potential down south as the base of the trough veers flow aloft again later, but will the low-levels veer out too by then? I'll admit the ECMWF looks quite impressive, but with most of the other, faster solutions, Tuesday is likely a grungefest and perhaps even linear.

 

Furthermore, the NAM is swaying me toward pessimism on initiation Monday, for the time being. Not because of its QPF output, which can't be trusted, but moisture simply doesn't look quite sufficient to overcome the stout EML in most soundings. The CINH map is rather depressing. If there were a large area of -50 to -75 J/kg east of the dryline, I'd say that's perfect for allowing instability to build until ascent arrives late. But for the most part it's < -100 J/kg everywhere, and that's no bueno, judging from experience (even regarding CINH model depictions at this range). The GFS soundings have looked tantalizing for days and still do, but I'm afraid its 65+ dews could be a stretch.

 

Strongly agree on Tuesday.

 

Monday, certainly possible that the cap kills everything in OK, but southern KS, it's a little better. Also, the trough just keeps on trending sharper and sharper, and the surface low even deeper. I mean, we're down near 980mb Monday evening in SE CO!

 

And this sounding is just spectacular (aside from wanting a little more moisture in the BL)

 

post-128-0-63470600-1365220595_thumb.jpg

Link to comment
Share on other sites

Can't believe how many chasers are following the GFS around run-to-run.

 

The consistent ECMWF continues to be the way to go. Hard to put trust in a model (GFS) when it can't even stick with a solution for more than 6hrs.

Totslly agree. We feel the same way about the euro...as does Fort Worth...as stated in their afd basically. Nice to see the 28z and moreso 00z GFS FINALLY come more on board...now if it can just continue.

Link to comment
Share on other sites

Personally I don't think there is anything wrong with using aspects of the NAM, in conjunction with the global models, at this juncture. I think it is more usable in severe weather events than in winter events even if the synoptics may be off. It tends to get boundary layer dews slightly closer to reality than the GFS (as Brett mentioned), and it usually has more realistic low level wind fields with trough ejections than what the GFS depicts. Obviously using verbatim solutions at this point is not advised, however. 

Link to comment
Share on other sites

Personally I don't think there is anything wrong with using aspects of the NAM, in conjunction with the global models, at this juncture. I think it is more usable in severe weather events than in winter events even if the synoptics may be off. It tends to get boundary layer dews slightly closer to reality than the GFS (as Brett mentioned), and it usually has more realistic low level wind fields with trough ejections than what the GFS depicts. Obviously using verbatim solutions at this point is not advised, however. 

 

Thank you for restoring sanity. Jesus. We get it; it's cool to say "lolz NAM" and disregard anyone or anything mentioning it. Yet, it's becoming plainly obvious the GFS is handling the BL poorly, as it always does. Since most of us only have access to NCEP model soundings, I'm afraid some discussion involving NAM soundings is inevitable.

 

Also, over the years, I've found the NAM to perform no worse than the GFS inside its range for severe weather in this region, and possibly better. (Granted, it's undergone serious changes over that time, and every year is a new test). Winter is another story, as you said.

Link to comment
Share on other sites

Thank you for restoring sanity. Jesus. We get it; it's cool to say "lolz NAM" and disregard anyone or anything mentioning it. Yet, it's becoming plainly obvious the GFS is handling the BL poorly, as it always does. Since most of us only have access to NCEP model soundings, I'm afraid some discussion involving NAM soundings is inevitable.

 

Also, over the years, I've found the NAM to perform no worse than the GFS inside its range for severe weather in this region, and possibly better. (Granted, it's undergone serious changes over that time, and every year is a new test). Winter is another story, as you said.

 

But it's so cool to put down the NAM because it shows that you know the models so well. </sarcasm>

 

In all seriousness, for now I'm using the NAM and ECMWF for this event with GFS as spot check

Link to comment
Share on other sites

Yeah I don't get the whole 'lolz it is the NAM' stuff. It is all in interpretation of the models, none of them are meant to be the gospel because if so then there wouldn't been a need for meteorologists, they would just pump out model forecasts and that is that. Sure the NAM has foibles but all the models do and it is up to our interpretations of all the models that matters. 

Link to comment
Share on other sites


DAY 3 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0226 AM CDT SAT APR 06 2013

VALID 081200Z - 091200Z

...THERE IS A SLGT RISK OF SVR TSTMS FOR PARTS OF THE CNTRL/SRN

PLAINS...

...SYNOPSIS...

AN AMPLIFIED UPPER-LEVEL TROUGH SHOULD GRADUALLY PROGRESS EWD ACROSS

THE WRN CONUS WITH A VIGOROUS MID-LEVEL SPEED MAX POTENTIALLY

EJECTING THROUGH THE BASE OF THE TROUGH BY EARLY TUE. AT THE

SURFACE...PRIMARY CYCLONE SHOULD REMAIN NEARLY STATIONARY IN THE LEE

OF THE SRN ROCKIES. A SHARP DRYLINE WILL MIX INTO FAR WRN OK AND THE

TX BIG COUNTRY. A COLD FRONT SHOULD SWEEP SWD ACROSS THE NRN PLAINS

MERGING WITH A QUASI-STATIONARY FRONT FROM THE CNTRL HIGH PLAINS TO

MID-MO VALLEY BY EARLY TUE.

...CNTRL/SRN PLAINS...

TWO PRIMARY UNCERTAINTIES RENDER LOWER-THAN-AVERAGE CONFIDENCE IN

MAKING ANY SUBSTANTIAL ADJUSTMENTS TO THE INHERITED 30 PERCENT AREA

THAT BEGAN ON D5. FIRST AS ALLUDED TO IN THE CURRENT D2

OUTLOOK...LOW-LEVEL MOISTURE RETURN APPEARS TO BE SOMEWHAT OVERDONE

IN MOST MODELS GIVEN THAT RICHER TROPICAL MOISTURE HAS BEEN

CURRENTLY RELEGATED INTO THE CARIBBEAN. STILL...PRECEDING DAYS OF

SLY RETURN FLOW BENEATH A STOUT EML SHOULD YIELD A MODIFIED GULF AIR

MASS WITH WIDESPREAD SURFACE DEW POINTS IN THE 50S...INCREASING TO

THE LOWER 60S ALONG THE DRYLINE IN OK/TX. THIS SHOULD BE ABLE TO

YIELD AT LEAST A MODERATELY UNSTABLE WARM/MOIST SECTOR GIVEN THE

PRESENCE OF VERY STEEP MID-LEVEL LAPSE RATES.

THE SECOND UNCERTAINTY IS WITH REGARD TO THE EVOLUTION OF THE WRN

CONUS TROUGH AND EJECTION/TIMING OF SHORTWAVE IMPULSES. THE ECMWF

APPEARS MORE REASONABLE AND CONSISTENT WITH A SLOWER PROGRESSION OF

THE TROUGH GIVEN THE ATTENDANT INTENSE MID/UPPER-LEVEL SPEED MAX.

THIS SUGGESTS THAT UPPER-LEVEL FORCING MAY NOT BE PHASED WELL WITH

THE DIURNAL HEATING CYCLE. IN ADDITION...TIMING THE EJECTION OF ANY

SUBTLE LEAD IMPULSES IS PREMATURE AT THIS POINT. THE MORE LIKELY

FORCING MECHANISM FOR SUSTAINING TSTMS WILL BE LOW-LEVEL WAA

OCCURRING ALONG THE FRONTAL ZONE MON EVENING/NIGHT...AS CONTINUED

STRONG CAPPING WILL LIKELY MITIGATE OPEN WARM SECTOR DEVELOPMENT.

HOWEVER...SUFFICIENT LOW-LEVEL CONVERGENCE MAY EXIST FOR INITIATION

IMMEDIATELY ALONG THE DRYLINE FROM WRN OK INTO SWRN KS.

ELONGATED/CURVING HODOGRAPHS WILL BE QUITE FAVORABLE FOR

SUPERCELLS...WITH A PRIMARY RISK OF VERY LARGE HAIL ALONG WITH A FEW

TORNADOES.

Link to comment
Share on other sites

day48prob.gif

 

 

DAY 4-8 CONVECTIVE OUTLOOK     NWS STORM PREDICTION CENTER NORMAN OK   0345 AM CDT SAT APR 06 2013      VALID 091200Z - 141200Z      ...DISCUSSION...   MULTI-DAY SEVERE WEATHER EPISODE IS EXPECTED ACROSS PARTS OF THE   S-CNTRL AND PERHAPS EVENTUALLY THE SERN CONUS IN ASSOCIATION WITH AN   UPPER-LEVEL TROUGH PROGRESSING EWD FROM THE WRN CONUS. PRECEDING   DAYS OF SLY RETURN FLOW OF A MODIFIED GULF AIR MASS BENEATH A STOUT   EML SHOULD YIELD AT LEAST MODERATELY UNSTABLE CONDITIONS AHEAD OF   THE PLAINS DRYLINE BEING OVERTAKEN BY A COLD FRONT THAT WILL   PROGRESS EWD DURING THE PERIOD. WITH STRENGTHENING OF MID-LEVEL   SWLYS AS THE SPEED MAX EJECTS FROM THE BASE OF THE WRN CONUS   TROUGH...SETUP SHOULD BE FAVORABLE FOR SUPERCELLS AND AN EVENTUAL   SQUALL LINE WITH ALL MODES OF SEVERE /SOME SIGNIFICANT/ PROBABLE   DURING D4-5. STILL...CONFIDENCE IS ONLY AVERAGE FOR HIGHLIGHTING   CORRIDORS OF ENHANCED COVERAGE PROBABILITIES /AOA 30 PERCENT/ AS   MODELS REMAIN MODERATELY DIVERGENT WITH TIMING OF THE KEY SYNOPTIC   FEATURES DURING THIS TIME FRAME. DISCREPANCIES WITH EVOLUTION OF THE   UPPER-LEVEL TROUGH AND ATTENDANT COLD FRONT BECOME EVEN GREATER BY   D6-7...WHERE SEVERE WEATHER AREAS COULD EVENTUALLY BE WARRANTED IN   PARTS OF THE SOUTHEAST.      ..GRAMS.. 04/06/2013

 

Link to comment
Share on other sites

Slightly OT here - I just got an email from F5 Data with a discount offer.  I see certain products like this for sale and I am wondering if they really add that much beyond what is available to the general public for free.  

 

I guess my real question is, that as a hobbyist who does not sit there and deeply analyze models/alter my schedule to view them, is something like F5 really "worth it"?   Or if not, is there one thing in particular that you could recommend among all the services available. Thanks.

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...