Jump to content

  • Member Statistics

    17,515
    Total Members
    7,904
    Most Online
    amirah5
    Newest Member
    amirah5
    Joined

Wow..New Eurotrash clobbers Lakes Region Late Thanksgiving weekend

wxhstn74

By wxhstn74,
in Lakes/Ohio Valley

Recommended Posts

  • Replies 1.1k
  • Created
  • Last Reply
AppsRunner

AppsRunner

Posted
Posted

I get the sense that this is going to be one of those aggravating events almost to the end. When we have the general idea figured out then we will have to move into the finer details such as changeover timing and BL temps.

If we are just comparing changeover timing... Dec. 10th last year reminds me of this. Supposed to change @ around 3a.m., didn't until 9a.m. Those can be really fun though. Especially if fun means awful.

Link to comment
Share on other sites
kab2791

kab2791

Posted
Posted

MODEL DIAGNOSTIC DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD

130 AM EST SAT NOV 26 2011

VALID NOV 26/0000 UTC THRU NOV 29/1200 UTC

SOUTHERN STREAM DEEP CYCLONE FORMING/DRIFTING ACROSS THE DEEP

SOUTH...

PREFERENCE: 00Z UKMET/00Z ECMWF COMPROMISE WITH AVERAGE

CONFIDENCE

THE 00Z GFS DOES NOT LOOK WELL INITIALIZED WITH A SHORTWAVE IN

WYOMING. ITS HEIGHTS IN THE SHORTWAVES VICINITY AT 500 HPA ARE IN

ERROR ABOUT 20 METERS...BUT THIS COULD BE WHY ITS DEEP CYCLONE

ENDS UP NORTH OF THE OTHER DETERMINISTIC GUIDANCE. THE 00Z NAM

LOOKS BETTER INITIALIZED HERE.

MERCIFULLY...THE DETERMINISTIC/ENSEMBLE MEAN GUIDANCE IS IN MUCH

BETTER AGREEMENT WITH THIS SYSTEM THAN SEEN 24 HOURS AGO.

HOWEVER...THE GFS/UKMET/ECMWF SOLUTIONS HAVE CHANGED SOMEWHAT

SINCE THEIR PRIOR RUNS /TRENDING NORTHEAST TO VARYING

DEGREES/...IMPLYING THAT THE GUIDANCE MAY NOT HAVE COMPLETELY

SETTLED ITS ISSUES IN REGARDS TO THIS SYSTEM. INTERACTIONS

BETWEEN THE NORTHERN AND SOUTHERN STREAM REMAIN TRICKY/MORE

CHANGEABLE THAN MOST OTHER TYPES OF FLOW PATTERNS WITHIN NUMERICAL

WEATHER PREDICTION OUTPUT. THE OVERALL THE 12Z GLOBAL ENSEMBLE

GUIDANCE STILL SHOWS A BIT OF SPREAD WITH PROGRESSION /CENTRAL

TEXAS TO OFFSHORE NORTH CAROLINA/...THOUGH MOST OF THE MEMBERS NOW

LIE AT LOW LATITUDE...CLOSE TO THE 33RD PARALLEL. THE 12Z GEFS

MEMBERS/18Z GEFS MEAN SHOW A SLOWER PROGRESSION THAN THE 12Z ECMWF

ENSEMBLE MEMBERS AND MEAN...WHICH IS IN CONTRAST TO THE 00Z GEFS

MEAN WHICH IS QUICKER/NORTHEAST. IT DOES NOT APPEAR THAT THE

RUN-TO-RUN AND DAY-TO-DAY CHANGES IN THE GEFS MEAN ARE

DONE...LOWERING CONFIDENCE IN ITS USE. HOWEVER...AT LEAST ONE

PIECE OF DETERMINISTIC GUIDANCE IS SHOWING ITS NORMAL BIAS WITH

CLOSED CYCLONES...TOO SLOW IN THE CASE OF THE CANADIAN SOLUTION.

THE 00Z GFS IS THE DEEPEST ALOFT. WITHIN MOST OF THE

GUIDANCE...COMMA HEAD SNOWS FOR THE DEEP AND MID SOUTH ARE

POSSIBLE WHICH WOULD BE QUITE EARLY IN THE SEASON FOR SUCH AN

EVENT.

THE 00Z GFS IS A COMPLETE OUTLIER WITHIN THE DETERMINISTIC

GUIDANCE WITH THIS SYSTEMS PLACEMENT AND DEPTH...LYING ON THE

NORTHERN FRINGE OF THE 12Z GLOBAL ENSEMBLE GUIDANCE LIKELY DUE TO

ITS IMPROPER INITIALIZATION...SO WILL CONSIDER ITS SOLUTION TOO

FAR NORTH. HOWEVER...THE 00Z UKMET/00Z ECMWF SHIFTED NORTHEAST

FROM ITS PREVIOUS RUN...MATCHING THE 12Z ECMWF ENSEMBLE MEAN. THE

GUIDANCE HAS DEFINITELY TRENDED DEEPER WITH THIS SYSTEM SINCE THIS

TIME YESTERDAY...CONVERGING UPON THE DEPTH SEEN ON CANADIAN RUNS

24-36 HOURS AGO...WHICH MEANS THEIR STANDARDIZED ANOMALIES AT 500

HPA ACROSS LOUISIANA ARE QUITE SIGNIFICANT...OVER FIVE STANDARD

DEVIATIONS BELOW CLIMATOLOGY BY TUESDAY MORNING...IMPLYING A

RECORD/VERY UNUSUAL EVENT FOR LATE NOVEMBER IS IN THE CARDS. TO

ACCOUNT FOR RECENT NORTHEAST TRENDS ALOFT...WILL PREFER A

COMPROMISE BETWEEN THE 00Z UKMET/00Z ECMWF. CONFIDENCE IS AVERAGE

BECAUSE OF THE LARGE SPREAD STILL SEEN AMONGST THE GLOBAL ENSEMBLE

GUIDANCE IN A FEW DAYS...CONTINUING RUN-TO-RUN AND DAY-TO-DAY

INSTABILITY IN THE DETERMINISTIC GUIDANCE...AND THE

UNCLIMATOLOGICAL DEPTH SHOWN BY THE DETERMINISTIC GUIDANCE. THE

21Z SREF MEAN/00Z NAM NOW APPEAR TO BE TOO FAR TO THE SOUTH WITH

THIS SYSTEM AND LESS USEFUL. FOR WINTER WEATHER IMPACTS OF THIS

SYSTEM...CONSULT HPC WINTER WEATHER PRODUCTS AND OUR HEAVY

SNOW/ICING DISCUSSION...WHICH ARE DUE AT 0930Z/0430 AM EST.

Link to comment
Share on other sites
Thunder Road

Thunder Road

Posted
Posted

Just took a quick peek at the GGEM precip type plots and they are an absolute mess.

It looks like they try to change over the areas of heavier precip where you get enchanced evap cooling but leaves the fringe areas as rain. Sure that can, and does, happen on a relatively small scale, but I'm skeptical of Chicago seeing light rain while N IN sees heavy snow and C IN sees moderate rain. It just seems weird to see such a long band of snow embedded in rain like that.

Overall though it's neat that the GFS, GGEM and ECM all seems to be bullseye-ing SE MI, NE IN and NW OH. Now we just need consistency. lmaosmiley.gif

Link to comment
Share on other sites
Jim Martin

Jim Martin

Posted
Posted

FDY FTW?

WED 00Z 30-NOV 2.9 -0.2 1000 97 97 0.39 548 548 WED 06Z 30-NOV 1.1 -3.6 1000 99 98 0.42 540 540 WED 12Z 30-NOV -0.1 -4.8 1008 87 89 0.24 545 539

Weird run... low is over Erie PA by 96hr

Did I just hear you say possibly accumulating snow for Findlay at the end of the weekend into early next week?!?

Link to comment
Share on other sites
AppsRunner

AppsRunner

Posted
Posted

so is the 12z GFS...sfc low occludes in eastern IN then heads northeast to CLE.

Here is a sounding for around here at 84hr on the NAM, very shallow but quite the shallow warm layer.

Yeah, I'm not sure what to do with the NAM, given that the SREF mean is well east, pretty much just the ARW (or ARN- can't see it too well on the ewall) are that far west.

Link to comment
Share on other sites
Thunder Road

Thunder Road

Posted
Posted

Yeah, I'm not sure what to do with the NAM, given that the SREF mean is well east, pretty much just the ARW (or ARN- can't see it too well on the ewall) are that far west.

Just from my experience, it seems that the NAM, once it latches on to a storm, usually starts off farther west/more amplified, then tends to settle in with the other guidance in 24 hours or so. I think that's what'll happen here as well.

Link to comment
Share on other sites
Chicago Storm

Chicago Storm

Posted
Posted

Just from my experience, it seems that the NAM, once it latches on to a storm, usually starts off farther west/more amplified, then tends to settle in with the other guidance in 24 hours or so. I think that's what'll happen here as well.

The 12z GFS also came in farther west.

Edit: The same can be said about some of the ensemble members.

Link to comment
Share on other sites
AppsRunner

AppsRunner

Posted
Posted

The 12z GFS also came in farther west.

Edit: The same can be said about some of the ensemble members.

GFS/NAM having issues again:

...DEEP CLOSED LOW FORMING OVER THE SRN STATES...PREFERENCE: 00Z ECMWF/00Z UKMET/06Z GEFS MEAN BLEND ADJUSTED NOMORE THAN 1/3 TOWARD THE 12Z UKMET BY MON-TUETHE 250 MB GFS WIND SPEED ANALYSIS IS 10-17 KTS WEAKER THANREPORTED BY RAOBS OVER MONTANA AND ALBERTA. NAM ERRORS OF SIMILARMAGNITUDE ARE CONFINED TO WRN MT/ALBERTA. NOTE THAT THE 00Z ECMWFFCST VALID AT 12Z COMPARES BETTER TO OBS VALUE OVER CNTRL ALBERTABUT IS 20 KTS WEAK AT GGW AND ABOUT 15 KTS WEAK AT TFX.PRIMARILY FROM SUN INTO MON THE NAM SHOWS A LITTLE MORE SEWDAMPLITUDE THAN CONSENSUS WITH THE OVERALL TROF CONTAINING THEDEVELOPING CLOSED LOW. AT SOME FCST HRS THE NAM CLOSED LOW IS ALITTLE DEEPER THAN MOST OTHER SOLNS BUT NOT TO AN EXTREMEDEGREE... AND THE 12Z GFS RIVALS THE NAM DEPTH BY MON NIGHT-TUE. THE GFS STRAYS TO THE FASTER SIDE OF THE GUIDANCE SPREAD BY F84LATE TUE. THE 00Z ECMWF/ECMWF MEAN AND 00Z UKMET ALONG WITH THE06Z GEFS MEAN HAD FORMED A MAJORITY CLUSTER THAT IS SOMEWHATSLOWER THAN THE GFS/NAM WITH NEWD PROGRESSION OF THE CLOSED LOWALOFT WHILE THE 09Z SREF MEAN AND 00Z CMC WERE EVEN SLOWER TOVARYING DEGREES. SLOWER TREND OF THE 12Z UKMET ALONG WITHRELATIVE PERSISTENCE OF THE 12Z CMC PLUS 12Z CANADIAN REG GEM THRUF48 EARLY MON APPEAR TO INCREASE POTENTIAL FOR TIMING SLOWER THANTHE 00Z ECMWF CLUSTER. SLOWER TRENDS IN THE GFS/NAM OVER THE PASTDAY AS WELL AS PSBL IMPACT OF INITIALIZATION DIFFS WITH WIND SPEEDAT 250 MB OVER MT/ALBERTA PROVIDE FURTHER SUPPORT FOR CLOSING OFFTHE LOW A LITTLE WWD OF THE NAM/GFS IN PARTICULAR AND PERHAPS EVENTHE 00Z ECMWF. POOR AGREEMENT/CONTINUITY OF VARIOUS GUIDANCE WITHTHIS SYS OVER RECENT DAYS ALONG WITH SLIGHTLY FASTER TREND OF 12ZGEFS MEAN FAVOR HOLDING ONTO THE PREVIOUSLY FAVORED 00Z ECMWF/06ZGEFS MEAN/00Z UKMET BLEND OR SLOWER ADJUSTMENT NO MORE THAN 1/3TOWARD THE 12Z UKMET BY MON-TUE. CONFIDENCE IS BELOW AVERAGE.

Link to comment
Share on other sites
kab2791

kab2791

Posted
Posted

12z EURO destroys parts of S-C MI, particularly in the Lansing-Saginaw corridor. I'm sure the wundermaps are every bit as clownish as the Earl Barker NAM maps, but still, verbatim we're talking ~18" of cement.

Not quite, more like 4-7" given the marginal temps earlier.

KLAN

WED 00Z 30-NOV   1.1 	0.8    1009      96 	100    0.81 	554 	547    
WED 06Z 30-NOV   0.7    -0.7    1004      92 	100    0.57 	547 	544    
WED 12Z 30-NOV  -0.2    -3.9    1006      89      98    0.54 	543 	539    
WED 18Z 30-NOV   0.9    -2.8    1009      66      83    0.11 	547 	540

However, Euro snow maps would suggest more. Good dynamic cooling?

Link to comment
Share on other sites
snowstormcanuck

snowstormcanuck

Posted
Posted

Not quite, more like 4-7" given the marginal temps earlier.

KLAN

WED 00Z 30-NOV   1.1     0.8    1009      96     100    0.81     554     547    
WED 06Z 30-NOV   0.7    -0.7    1004      92     100    0.57     547     544    
WED 12Z 30-NOV  -0.2    -3.9    1006      89      98    0.54     543     539    
WED 18Z 30-NOV   0.9    -2.8    1009      66      83    0.11     547     540

However, Euro snow maps would suggest more. Good dynamic cooling?

I just added every three hour interval for the area just W of KLAN to come up with that number. I have no idea what goes into the algorithms to make those clown maps. I think your methodology of using the text output is a lot more sound :)

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...