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Weekend Storm Discussion 2/18-2/19


stormtracker

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Despite what DT says, didn't this GFS run have the Pacific dropsonde data included? Perhaps dtk or chris87 can comment on how much more robust the solution might be for that reason. It should at least mean the strength and relative positions of the shortwaves are well initialized. Is that data also sent for inclusion in the other globals?

Those observations get sent out for all the operational centers to use through the usual channels.

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dtk can provide specific details...but i think the general theme is that it hopefully provides better sampling of the feature they targeted...does the additional sampling lead to a better forecast is the bigger question and one that is not easy to answer.

i would imagine that the dropsonde data are shared with other forecast centers but I'm unsure of that.

Well, according to HPC per Grothar, the GFS is still crap today:

From HPC...

THE GFS APPEARS TO HAVE WORSE INITIALIZATION OF THE TROUGH'S PLACEMENT OVER BRITISH COLUMBIA AND NUNAVUT THIS MORNING COMPARED TO THE NAM/ECMWF. MEANWHILE...THE GFS IS MOST AGGRESSIVE IN ALLOWING AN UPSTREAM PERTURBATION CURRENTLY OVER THE PACIFIC TO CUT THROUGH THE SHORTWAVE RIDGE OVER THE CANADIAN ROCKIES ON THURSDAY...WHICH THEN PHASES WITH THE NORTHERN STREAM AND SLOWS THE ENTIRE GFS SOLUTION. THE COMBINATION OF WORSE INITIALIZATION AND QUESTIONABLE AND EVEN SUSPICIOUS PHASING OF THE SEPARATE STREAMS IS SUFFICIENT TO DISCARD THE GFS PARTICULARLY LATE IN THE PERIOD. AMONG THE REMAINING SOLUTIONS...THE NAM BECOMES SLIGHTLY FASTER THAN THE 00Z ECMWF/UKMET/CANADIAN WHICH ARE ALL IN AGREEMENT. GIVEN THE NARROWER WINDOW FOR DATA ASSIMILATION IN THE NAM VERSUS THE OTHER REMAINING SOLUTIONS...ALONG WITH THE CLUSTERING OF THE NON-NCEP MEMBERS...THE PREFERENCE IS FOR THE ECMWF.

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96 ORF area... 120 its east of NS... so it should be moving ENE/NE from its 96 hr position to reach its 120 position

You are correct...I was looking at the laughable French website where it is tilted sideways.

The UK website surface pressure map (w/o precip) seemed to indicate that the low was slightly NW of ORF at 994 mb...that's really all I was trying to point out I guess.

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You are correct...I was looking at the laughable French website where it is tilted sideways.

The UK website surface pressure map (w/o precip) seemed to indicate that the low was slightly NW of ORF at 994 mb...that's really all I was trying to point out I guess.

I understand.... we might go snow-rain-snow in that solution

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Wow...individual members of the GEFS look VERY nice for the most part. Only 2 are surpressed/OTS. Every other member gives us precip with 850s <0C. A couple are probably MECS range storms. Helpfully, most do not show that Great Lakes low, although a few do. Not sure if we should disregard these for the same reasons that HPC is ignoring the Op. Maybe we can keep these and throw out the Op? :P

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Wow...individual members of the GEFS look VERY nice for the most part. Only 2 are surpressed/OTS. Every other member gives us precip with 850s <0C. A couple are probably MECS range storms. Helpfully, most do not show that Great Lakes low, although a few do. Not sure if we should disregard these for the same reasons that HPC is ignoring the Op. Maybe we can keep these and throw out the Op? :P

looks like a mixed bag of members that show some mostly snow, mix, mostly rain, and suppressed...what a mess..haha

EDIT: a great example of when an ensemble mean is meaningless.

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Wow...individual members of the GEFS look VERY nice for the most part.  Only 2 are surpressed/OTS.  Every other member gives us precip with 850s <0C.  A couple are probably MECS range storms.  Helpfully, most do not show that Great Lakes low, although a few do.  Not sure if we should disregard these for the same reasons that HPC is ignoring the Op.  Maybe we can keep these and throw out the Op? :P

Paint me crazy but the mean appeared to be right in the middle of the road between the north and south outliers. Doesn't seem to be a bad ensemble run to ride until we reach a consensus between the two outliers. Also encouraging because it snows here. A definite benefit!
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Wow...individual members of the GEFS look VERY nice for the most part. Only 2 are surpressed/OTS. Every other member gives us precip with 850s <0C. A couple are probably MECS range storms. Helpfully, most do not show that Great Lakes low, although a few do. Not sure if we should disregard these for the same reasons that HPC is ignoring the Op. Maybe we can keep these and throw out the Op? :P

16blxz9.gif

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Wow...individual members of the GEFS look VERY nice for the most part. Only 2 are surpressed/OTS. Every other member gives us precip with 850s <0C. A couple are probably MECS range storms. Helpfully, most do not show that Great Lakes low, although a few do. Not sure if we should disregard these for the same reasons that HPC is ignoring the Op. Maybe we can keep these and throw out the Op? :P

Definitely seems to be an encouraging sign. Though, I won't hold my breath yet with this one.

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looks like a mixed bag of members that show some mostly snow, mix, mostly rain, and suppressed...what a mess..haha

EDIT: a great example of when an ensemble mean is meaningless.

Although I wouldn't be surprised if some of these ensemble members had some rain mixing in, particularly S/E of I-95, I don't really see any obvious signs that any are predominately rain. Do you have the 2m temps for the individual members? Just basing off the 850 temps, I'd say the ones that show us with precip are either all snow or predominately snow for most of the LWX forecast area.

Storm total precip for the members...they are juicy:

http://www.meteo.psu.edu/~gadomski/ENSPCN72NE_12z/f120.html

7 members give us 1"+ of QPF.

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Although I wouldn't be surprised if some of these ensemble members had some rain mixing in, particularly S/E of I-95, I don't really see any obvious signs that any are predominately rain. Do you have the 2m temps for the individual members? Just basing off the 850 temps, I'd say the ones that show us with precip are either all snow or predominately snow for most of the LWX forecast area.

Storm total precip for the members...they are juicy:

http://www.meteo.psu...E_12z/f120.html

7 members give us 1"+ of QPF.

No I haven't seen any surface temperatures...I was just basing it off the zero 850 line being very close to I-95...they sure are wet though

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