Jump to content
  • Member Statistics

    17,606
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

PHL Jan 11-12 Miller B Thread


am19psu

Recommended Posts

From pro met baroclinic instability in the NYC thread

Such epic dynamic height falls keep everything cool through the layer. This will undoubtedly have lighting with such extreme dynamically induced height falls. Such an unstable dynamic system...this thing may take on hurricane type characteristics late. I bet this will have an eye.
Link to comment
Share on other sites

  • Replies 944
  • Created
  • Last Reply

* ACCUMULATIONS: 3 TO 6 INCHES.* TIMING: SNOW WILL OVERSPREAD THE AREA FROM SOUTHWEST TO NORTHEAST LATE THIS AFTERNOON AND EARLY THIS EVENING. THE SNOW WILL THEN CONTINUE TONIGHT BEFORE TAPERING OFF TO SNOW SHOWERS OR FLURRIES DURING WEDNESDAY MORNING.* IMPACTS: SNOW WILL STICK TO UNTREATED ROADWAYS. SNOWFALL RATES CAN CAUSE THE VISIBILITY TO DROP TO UNDER ONE MILE FOR A PERIOD OF TIME, WITH THE HEAVIER SNOW OCCURRING OVERNIGHT. DRIVING WILL BECOME HAZARDOUS. THIS EVENINGS COMMUTE COULD BECOME SLIPPERY IN SPOTS, HOWEVER THE WEDNESDAY MORNING COMMUTE COULD BE RATHER HAZARDOUS.* WINDS: ARE EXPECTED TO INCREASE FROM THE NORTHWEST AND TURN GUSTY AFTER THE SNOWFALL, WITH AREAS OF BLOWING AND DRIFTING SNOW OCCURRING WEDNESDAY.

Dropped to an advisory for 3-6 ...

I guess they do not believe the NAM or the ECM

Link to comment
Share on other sites

* ACCUMULATIONS: 3 TO 6 INCHES.* TIMING: SNOW WILL OVERSPREAD THE AREA FROM SOUTHWEST TO NORTHEAST LATE THIS AFTERNOON AND EARLY THIS EVENING. THE SNOW WILL THEN CONTINUE TONIGHT BEFORE TAPERING OFF TO SNOW SHOWERS OR FLURRIES DURING WEDNESDAY MORNING.* IMPACTS: SNOW WILL STICK TO UNTREATED ROADWAYS. SNOWFALL RATES CAN CAUSE THE VISIBILITY TO DROP TO UNDER ONE MILE FOR A PERIOD OF TIME, WITH THE HEAVIER SNOW OCCURRING OVERNIGHT. DRIVING WILL BECOME HAZARDOUS. THIS EVENINGS COMMUTE COULD BECOME SLIPPERY IN SPOTS, HOWEVER THE WEDNESDAY MORNING COMMUTE COULD BE RATHER HAZARDOUS.* WINDS: ARE EXPECTED TO INCREASE FROM THE NORTHWEST AND TURN GUSTY AFTER THE SNOWFALL, WITH AREAS OF BLOWING AND DRIFTING SNOW OCCURRING WEDNESDAY.

Dropped to an advisory for 3-6 ...

I guess they do not believe the NAM or the ECM

if 12z runs are the same they may bump it in aft package. But i agree you can't just go off 1 run of the nam

Link to comment
Share on other sites

if 12z runs are the same they may bump it in aft package. But i agree you can't just go off 1 run of the nam

Thats the thing it has not been one run of the NAM . It has been pretty consistent and with all the mesoscale models more west..the ecm more west...and every model but the GFS...which is lower resolution...time will tell but bumping it up in the afternoon does not let people know in enough time IMHO

Link to comment
Share on other sites

gfs looks further east than 0z at hr 18

From pro met Baroclinic Instability in the NYC thread again

GFS is at a HUGE disadvantage both because it is global and runs at an approximate 25 km resolution...but it is not non-hydrostatic and as a global model...it is aggressively filtered. This storm is such a compact low there is a chance the GFS never fully catches on.
Link to comment
Share on other sites

Chester, MOntCo, and Bucks now upgraded to the warning....

CHESTER-MONTGOMERY-BUCKS-

INCLUDING THE CITIES OF...WEST CHESTER...NORRISTOWN...DOYLESTOWN

424 AM EST TUE JAN 11 2011

...WINTER STORM WARNING IN EFFECT FROM 2 PM THIS AFTERNOON TO

10 AM EST WEDNESDAY...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A WINTER

STORM WARNING FOR HEAVY SNOW...WHICH IS IN EFFECT FROM 2 PM THIS

AFTERNOON TO 10 AM EST WEDNESDAY. THE WINTER STORM WATCH IS NO

LONGER IN EFFECT.

* PRECIPITATION TYPE: SNOW.

* ACCUMULATIONS: 4 TO 8 INCHES.

* TIMING: SNOW WILL OVERSPREAD THE AREA FROM SOUTHWEST TO

NORTHEAST LATER THIS AFTERNOON, THEN CONTINUE TONIGHT AND BECOME

STEADIER AND HEAVIER. THE SNOW IS EXPECTED TO TAPER TO SCATTERED

SNOW SHOWERS OR FLURRIES DURING WEDNESDAY MORNING.

* IMPACTS: SNOW WILL STICK TO UNTREATED ROADWAYS. SNOWFALL RATES

CAN CAUSE THE VISIBILITY TO DROP TO ONE-HALF MILE FOR A PERIOD

OF TIME, WITH THE HEAVIEST SNOW OCCURRING OVERNIGHT. DRIVING

WILL BECOME HAZARDOUS. THIS EVENINGS COMMUTE COULD BE SLIPPERY

HOWEVER THE WEDNESDAY MORNING COMMUTE COULD BE RATHER HAZARDOUS.

* WINDS: ARE EXPECTED TO INCREASE AFTER THE SNOWFALL AND TURN

GUSTY FROM THE NORTHWEST, WITH AREAS OF BLOWING AND DRIFTING

SNOW OCCURRING WEDNESDAY.

Link to comment
Share on other sites

Thats the thing it has not been one run of the NAM . It has been pretty consistent and with all the mesoscale models more west..the ecm more west...and every model but the GFS...which is lower resolution...time will tell but bumping it up in the afternoon does not let people know in enough time IMHO

The NAM has been awfully inconsistent with this storm the last 36 hours. It was giving Philadelphia a foot of snow in the 0z run on Sunday night and then giving it 4" in the 6z just six hours later.

Not saying the NAM isn't on to the right idea but it can't hold a consistent idea on handling the storm's development.

Edit: This isn't to say that I'm in the GFS' camp...but I think the NAM is overdoing QPF a fair amount on this morning's 6z run.

I've pretty much followed the Euro, which has generally (although it did get a bit more wet last night) been consistent run-to-run with the storm...generally 4-6, 6-8 with each run in Philadelphia.

Link to comment
Share on other sites

The NAM has been awfully inconsistent with this storm the last 36 hours. It was giving Philadelphia a foot of snow in the 0z run on Sunday night and then giving it 4" in the 6z.

Not saying the NAM isn't on to the right idea but it can't hold a consistent idea on handling the storm's development.

The NAM may have shifted QPF around but the NAM has been consistent with a much further west track then the GFS. The NAM has the support of the ECM. The ECM brought .50-.75 into this region. Yes the NAM is higher but that is because it came further west at 6 Z as composed to 00z. Remember reading earlier that the more compact the storm is the sharper the gradient but if it moves west that would move that sharper gradient to the west and that is what the NAM did..

And as stated above its the resolution of the GFS and you can literally see it in the model from 18 how it is well east of 00z to coming back west 6 hrs later. This is also why the means have been more supportive of the NAM then they are of the GFS OP.

Pro met Dark Energy

as I said to earthlight via phone earlier tnt, the GFS was the first to latch onto the blizzard vice the other guidance so it DOES have history of performing well given the new upgrade. However, with such a strong, closed h5 feature...which would lend to capturing the sfc low and going frther W, the NAM seems to be the best bet now. I will note, I have seen the Nam plenty of times do this. It is stubborn with a storm all the way thru the short term, then at the last moment, it suddenly shifts twds the other guidance. If we see the nam do this, i wouldnt be shocked. But synoptics argue against it.
Link to comment
Share on other sites

Pro Met Baroclinic Instability again

FWIW, and I think it is worth a lot now, the GFS at 06Z does not initialize well with the HPC surface map at 06Z or the RUC at 06Z with the coastal low. The NAM looks much more realistic--and with feedback development soon, being off a little here will make a big difference.

Earthlight

Latest RUC runs look literally like a carbon copy of the 06z NAM through their medium range.

This is why the threads should be together because these threads miss the great MET and NON MET input!

Link to comment
Share on other sites

Thats the thing it has not been one run of the NAM . It has been pretty consistent and with all the mesoscale models more west..the ecm more west...and every model but the GFS...which is lower resolution...time will tell but bumping it up in the afternoon does not let people know in enough time IMHO

There are winter storm warnings and winter weather advisories in effect with several inches of snow in the forecast. I think people know a snowstorm is coming.

Link to comment
Share on other sites

The NAM may have shifted QPF around but the NAM has been consistent with a much further west track then the GFS. The NAM has the support of the ECM. The ECM brought .50-.75 into this region. Yes the NAM is higher but that is because it came further west at 6 Z as composed to 00z. Remember reading earlier that the more compact the storm is the sharper the gradient but if it moves west that would move that sharper gradient to the west and that is what the NAM did..

And as stated above its the resolution of the GFS and you can literally see it in the model from 18 how it is well east of 00z to coming back west 6 hrs later. This is also why the means have been more supportive of the NAM then they are of the GFS OP.

The NAM is struggling with how this storm will develop. It's going to be quick and the NAM's solution does have some merit but given its inconsistency in qpf fields I wouldn't completely trust what it's spitting out.

Higher totals for some (specifically in NJ)...yes...the 6z for all verbatim...call me a skeptic. It's an off hour run of the NAM and it hasn't had two consecutive runs that have been consistent.

Link to comment
Share on other sites

There are winter storm warnings and winter weather advisories in effect with several inches of snow in the forecast. I think people know a snowstorm is coming.

:lol:

Great read this morning from the overnight hours analysis and conversation. I know I need sleep for work, but some of you guys......wow!!! Anyway, here's to hoping that everyone gets a decent snowstorm out of this one.

Link to comment
Share on other sites

The NAM is struggling with how this storm will develop. It's going to be quick and the NAM's solution does have some merit but given its inconsistency in qpf fields I wouldn't completely trust what it's spitting out.

Higher totals for some (specifically in NJ)...yes...the 6z for all verbatim...call me a skeptic. It's an off hour run of the NAM and it hasn't had two consecutive runs that have been consistent.

I would actually say that the GFS is the one that is struggling and it seems like the pro mets such as Dark Energy and Baroclinic Instability also see and agree with the same evaluation. Yes,the NAM has been on the higher QPF train of thought in some runs etc but it has never wavered in the further west track. It seems kind of funny that all the higher resolution mesoscale models are all NAM like...and the latest RUC is a carbon copy of the NAM...and the 6 Z NAM took the low onto Eastern LI and so did the ooz ECM from tombos play by play & the ECM increased QPF (which the NAM has always been higher on) which kind of suggests it is playing catch up as well....

Oh and probably the greatest part of all is this very solution that the RUC is now showing and the ECM is now showing is the very solution that the NOGAPS started off with! scooter.gif

Link to comment
Share on other sites

HPC

OH VLY TO NRN MID ATLC/NORTHEAST...TWO ENERGETIC UPPER JET STREAMS WILL MERGE ON TUES TO FORM ARAPIDLY DEEPENING AREA OF LOW PRESSURE... WHICH WILL SLIDE UP THENRN MID-ATL AND NORTHEAST COAST LATE TUES THROUGH WED. THERESULTANT WILL BE ANOTHER VERY HVY SNOWFALL EVENT FROM NJ/PORTIONSOF ERN PA NEWRD INTO NEW ENGLAND... INCLUDING LARGE METROPOLITANCITIES OF NEW YORK AND BOSTON. A WEAK SURFACE LOW STARTING OFF THENC COAST... PART OF THE DECAYING SRN STREAM... WILL GRADUALLY FEELTHE INFLUENCE OF A DYNAMIC CLOSED 500 MB LOW... FORMING OVER NRNMO AND EXPECTED TO SLIDE EWRD ACROSS THE OH VLY. UNTIL THE TWOFEATURES PHASE... TWO POCKETS OF WINTRY PRECIP IS EXPECTED FORMOST OF TUES... LIGHT SNOW/FREEZING DRIZZLE FROM NC/VA NEWRD INTOTHE DELMARVA AND A SOLID DEFORMATION ZONE OF MDT TO HVY DRY FLUFFYSNOW FROM IL EAST INTO OH/LWR MI. BY TUES EVENING... THEIMPRESSIVE UPPER JET STREAK ASSOCIATED WITH THE CLOSED LOW FEATUREOVER THE OH VLY WILL BEGIN TO INTERACT WITH THE COASTAL LOW ALONGTHE MID-ATL COAST. THE LEFT EXIT REGION OF THIS STREAK SHOULDALLOW A SOLID SHIELD OF HEAVIER PRECIP TO FLOURISH ACROSS DE/NJAND THROUGH PA TO THE UPPER LOW CENTER OVER WRN PA. THEN STARTINGEARLY MORNING WED... THE SURFACE LOW WILL BEGIN GO THROUGHCOMPLETE CYCLOGENESIS AS IT SLIDES UP THE NORTHEAST COAST...PRODUCING STRONG DYNAMIC COOLING AND SOLID AXIS OF FRONTOGENESISOR LIKELY BANDING SNOW FROM NJ/ERN PA TO THE NEW ENGLAND COAST.THEN BY THURS... THE SYSTEM WILL BE OUT OF THE REGION ANDDOWNSTREAM NEAR THE CANADIAN MARITIMES. NOW THERE STILL REMAINSENOUGH SLIGHT SPREAD WITH THE GUIDANCE FOR A SHIFT TO THE HVYSNOWFALL POTENTIAL BUT HPC RELIED ON THE MORE CONSISTENT DUO OFTHE ECMWF AND PSEUDO BIAS CORRECTED GUIDANCE FOR QPF AMOUNTS ANDTHE HVY SNOW PROBS TUES AND WED. RIGHT NOW THE AXIS OF HVYSNOWFALL POTENTIAL OF 8 TO 16 INCHES APPEARS POSSIBLE ALONG THEI95 CORRIDOR FROM NJ NORTH TO NEW ENGLAND.

Link to comment
Share on other sites

I would actually say that the GFS is the one that is struggling and it seems like the pro mets such as Dark Energy and Baroclinic Instability also see and agree with the same evaluation. Yes,the NAM has been on the higher QPF train of thought in some runs etc but it has never wavered in the further west track. It seems kind of funny that all the higher resolution mesoscale models are all NAM like...and the latest RUC is a carbon copy of the NAM...and the 6 Z NAM took the low onto Eastern LI and so did the ooz ECM from tombos play by play & the ECM increased QPF (which the NAM has always been higher on) which kind of suggests it is playing catch up as well....

Oh and probably the greatest part of all is this very solution that the RUC is now showing and the ECM is now showing is the very solution that the NOGAPS started off with! scooter.gif

Actually the NAM did waver on the "west" track some on the off runs yesterday (6z 24 hours ago). Just think it's fair to point that out.

Link to comment
Share on other sites

Actually the NAM did waver on the "west" track some on the off runs yesterday (6z 24 hours ago). Just think it's fair to point that out.

Well I do not have access to the off runs (archives of the NAM) but i just looked at 18 Z from yesterday if you mean yesterday as in the 10th and it was still close to the coast...

12 Z

I do not think the NAM has ever been as far east as the GFS....

Oh i am sure in its longer range but we are now in the 24 and under and i remember reading last night that if the NAM showed the further west track it would start to be taken seriously and yet here it on that same further west track (QPF fluctuating) and yet it still is not being taken seriously in this area. I suppose if at 12 Z it stays the same or is even better...it has a high chance of not being taken seriously ... (kind of reminds me of the GFS with the boxing day blizzard but this time the NAM is the model & this time its not alone!)

Link to comment
Share on other sites

If you take out the off runs, then it's fair to say that the NAM performance in the last 48 hours was superior to other models. off runs are for trends. No more, no less.

Euro has been very consistent as well although less snowy. The off run point is very true but I wouldn't compare 6 to 0 or 18 to 12 since there can be jumps. 18 and 6 should be compared to each other as 12 and 0 should be since the upper data on the 12 and 0 is fresher. Off run is useful guidance but shouldn't be considered gospel, IMHO.

Link to comment
Share on other sites

StormTotalSnowFcst.png

For Ocean/Monmouth Counties...WINTER STORM WARNING REMAINS IN EFFECT FROM 4 PM THISAFTERNOON TO NOON EST WEDNESDAY...A WINTER STORM WARNING REMAINS IN EFFECT FROM 4 PM THIS AFTERNOONTO NOON EST WEDNESDAY.* PRECIPITATION TYPE: SNOW.* ACCUMULATIONS: 6 TO 10 INCHES.Where the green is on the map along the coast - that's my commute whistle.gif
Link to comment
Share on other sites

They decreases there amounts in Monmouth a bit but increased in N Ocean County - at this point anything above 6" in a short time span for that area after is going to be a nightmare - still tough to get by with the snow mounds of 12/26.

On a side note spoke to friend in Islip - said they are expecting upwards of 20"

Link to comment
Share on other sites

Archived

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

Guest
This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...