Baroclinic Zone Posted February 23, 2014 Share Posted February 23, 2014 Keep the discussion going here. 18z NCEP runs yesterday were whacked out on something. 00z runs came back to reality. Looks like a light QPF event. Maybe 0.1". Trace to 2" looks to be about it. BOX maps have highest concentration of 1-2" amounts over the SE MA area. Link to comment Share on other sites More sharing options...
Baroclinic Zone Posted February 23, 2014 Author Share Posted February 23, 2014 ***PERIOD OF LIGHT SNOW LIKELY TONIGHT MAINLY SOUTH OF THE MASSACHUSETTS TURNPIKE*** TONIGHT... GRADUALLY SHARPENING MID LVL SHORTWAVE WILL MOVE SE FROM QC AND THE GREAT LAKES REGION WITH ATTENDANT SFC COLD FRONT DURING THE OVERNIGHT HOURS. GUIDANCE NOW HAS GENERAL AGREEMENT THAT SFC LOW PRES FORMING ON THIS FRONT WILL OCCUR LATE...MAINLY AFTER 12Z AND MUCH FURTHER OFFSHORE THAN MANY OF THEIR 18Z COUNTERPARTS. THEREFORE...EXPECT THE SFC-MID LVL WAVE TO REMAIN WEAKER AND MAINLY OPEN. IN ANY CASE...A PERIOD OF PRECIP...LIKELY STARTING AS LIGHT RAIN...GRADUALLY MIXING WITH SNOW IS EXPECTED WITH THE COLD FRONT DURING THE OVERNIGHT HOURS. THE WAVE WILL NOT ACT ON THE APPROACHING FRONT UNTIL ITS CLOSE TO THE MASS PIKE...SO MOST OF THE PRECIP WILL BE FOCUSED FROM THERE SOUTHWARD. HELPING THIS THINKING IS THE FACT THAT MOISTURE WILL BE GRADUALLY INCREASING IN THE MID LVLS...WITH OVERALL COLUMN PWAT VALUES APPROACHING 0.5 INCHES AFTER 06Z. COMBINE THIS WITH MODERATE OMEGA IN THE SNOW GROWTH REGION AND LAPSE RATES OF 6-7C/KM ABOVE THE BEST OMEGA...AND CONDITIONS LOOK RIPE FOR POTENTIAL BURSTS OF SNOW ESPECIALLY BETWEEN 04-10Z. THIS DESPITE THE FACT THAT SFC TEMPS WOULD BE MARGINAL FOR SNOW. THERE ARE SOME MITIGATING FACTORS THOUGH WHICH ARE LIKELY TO AFFECT ACCUMS. THE MARGINALLY WARM SFC TEMPS TO START THE NIGHT /MAINLY ABOVE FREEZING/ WITH DWPT DEPRESSIONS ON THE ORDER OF 10F WHICH WILL NEED TO BE OVERCOME INITIALLY. WHILE THERE IS MODERATE LIFT IN THE SNOW GROWTH REGIME AND INSTABILITY ABOVE IT...RECENT TREND IN GUIDANCE IS TO SUGGEST THE TRUE OMEGA CORE IS JUST OUTSIDE OF THE SNOW GROWTH REGION...WHICH MAY LIMIT SNOW RATIOS AS WELL. WHAT THIS ALL MEANS IS THAT THERE MAY BE LIGHT RAIN...MIXING WITH BURSTS OF SNOW AS A GRADUAL CHANGEOVER OCCURS...ENDING AS ALL SNOW. HOWEVER...WITH MARGINAL SFC TEMPS AND RATIOS NOT BEING AS HIGH AS THEY COULD BE...ACCUMULATION MAY BE LIMITED. THEREFORE...WILL HIGHLIGHT THE THREAT FOR A FEW BRIEF BURSTS OF MOD-HEAVY SNOW BUT WITH ONLY LIGHT ACCUMS...MAINLY ON THE ORDER OF A COATING TO 2 INCHES AT MOST. THIS DOES NOT SUPPORT AN ADVISORY...BUT IF MODEL LIFT BECOMES STRONGER IN THE SNOW GROWTH REGION AND INCREASES OVERALL QPF...ITS NOT OUT OF THE QUESTION ONE MAY BE NEEDED. FURTHER N OF THE MASS PIKE...IT APPEARS DRY AIR WILL BE MOVING IN TOO RAPIDLY FOR MUCH IF ANY SNOW ACCUM. AT THIS POINT IT APPEARS THAT FOR MOST AREAS EXCEPT FOR THE CAPE/ISLANDS MOST OF THE PRECIP SHOULD BE WRAPPING UP BY THE BULK OF THE MON MORNING COMMUTE. Link to comment Share on other sites More sharing options...
forkyfork Posted February 23, 2014 Share Posted February 23, 2014 the euro is bone dry Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted February 23, 2014 Share Posted February 23, 2014 Coating to 0.5" If that Link to comment Share on other sites More sharing options...
moneypitmike Posted February 23, 2014 Share Posted February 23, 2014 Coating to 0.5" If that Shouldn't even get a flake here---might even get some glimpses of starts. Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted February 23, 2014 Share Posted February 23, 2014 Shouldn't even get a flake here---might even get some glimpses of starts.Oh I anticipate nothing hereI meant for SE areas Link to comment Share on other sites More sharing options...
dendrite Posted February 23, 2014 Share Posted February 23, 2014 NAM has literally nada. What the hell was 18Z smoking? Link to comment Share on other sites More sharing options...
dendrite Posted February 23, 2014 Share Posted February 23, 2014 0.01" for ACY and DE. lol Link to comment Share on other sites More sharing options...
moneypitmike Posted February 23, 2014 Share Posted February 23, 2014 0.01" for ACY and DE. lol Thread cancel? Link to comment Share on other sites More sharing options...
CoastalWx Posted February 23, 2014 Share Posted February 23, 2014 Kevin FTL? Link to comment Share on other sites More sharing options...
moneypitmike Posted February 23, 2014 Share Posted February 23, 2014 Kevin FTL? LOL--I didnt' realize this was a pinned thread. Link to comment Share on other sites More sharing options...
Baroclinic Zone Posted February 23, 2014 Author Share Posted February 23, 2014 What the hell were the NCEP models smoking? Nothing has really changed all that much as far as track is concerned but they have just gotten drier over the last 18h. Link to comment Share on other sites More sharing options...
CT Rain Posted February 23, 2014 Share Posted February 23, 2014 NAM has literally nada. What the hell was 18Z smoking? It shows you how useless ensemble modeling can be in the short range. If you were to go by 18z GEFS and 21z SREFs we'd have a decent advisory event. I don't understand why the models can't sniff this stuff out better with a 36 hour lead time. The red flag should have been that non of the foreign models wanted anything to do with Kev's fail snow... UK, RGEM, Euro. Link to comment Share on other sites More sharing options...
CoastalWx Posted February 23, 2014 Share Posted February 23, 2014 It shows you how useless ensemble modeling can be in the short range. If you were to go by 18z GEFS and 21z SREFs we'd have a decent advisory event. I don't understand why the models can't sniff this stuff out better with a 36 hour lead time. The red flag should have been that non of the foreign models wanted anything to do with Kev's fail snow... UK, RGEM, Euro. This is the third time the GFS op and ALL the ensemble members were juiced and all failed. So much for ensembles and individual tweaks of physics and parameterizations. Seems like more of an inherent flaw in something. Even the euro op yesterday however, was too wet it seems. In a more LOL kind of moment..this is also the third time where the GFS has more QPF than the RPM. You know it's a red flag when that happens... Link to comment Share on other sites More sharing options...
dendrite Posted February 23, 2014 Share Posted February 23, 2014 What the hell were the NCEP models smoking? Nothing has really changed all that much as far as track is concerned but they have just gotten drier over the last 18h.Looks like it overestimated the strength of that vortmax/shortwave. 18Z looked more consolidated and stronger with more PVA. The latest runs look a little more strung out through the longwave trough. Link to comment Share on other sites More sharing options...
Baroclinic Zone Posted February 23, 2014 Author Share Posted February 23, 2014 Ryan, even yesterday you said the s/w looked potent. Still looks it to me. About the only discernible differences I can see is that the flow looks a little more progressive and the trajectory into SNE looks changed as well. Link to comment Share on other sites More sharing options...
CT Rain Posted February 23, 2014 Share Posted February 23, 2014 Looks like it overestimated the strength of that vortmax/shortwave. 18Z looked more consolidated and stronger with more PVA. The latest runs look a little more strung out through the longwave trough. There was a subtle phase the American models were sniffing out too. There were 2 s/ws that phased just to our west and resulted in stronger DCVA over us. Considering the shortwaves were over NOAM and we were only 36 hours out... ensembles SHOULD have been able to take care of any initialization issues. Clearly they didn't. Link to comment Share on other sites More sharing options...
TauntonBlizzard2013 Posted February 23, 2014 Share Posted February 23, 2014 Honestly, I'm expecting nothing here,and have been expecting nothing. I don't know what the blip was at 18z last night was, but what a fail Link to comment Share on other sites More sharing options...
Bostonseminole Posted February 23, 2014 Share Posted February 23, 2014 lol, might as well lock this thread up, <1" for everyone? hopefully SE can cash in on an 1" Link to comment Share on other sites More sharing options...
Baroclinic Zone Posted February 24, 2014 Author Share Posted February 24, 2014 Not even a rain drop. American Models fail. Link to comment Share on other sites More sharing options...
TauntonBlizzard2013 Posted February 24, 2014 Share Posted February 24, 2014 lol i can't beleive there were models printing out advisory amounts on Saturday night. Not even a single drop or flake here. Sky's are clearing Link to comment Share on other sites More sharing options...
CoastalWx Posted February 24, 2014 Share Posted February 24, 2014 Horrible fail. Even the euro was too wet. Every single GEFS member failed too, so an inherent flaw. Not the first time either. Link to comment Share on other sites More sharing options...
Brian5671 Posted February 24, 2014 Share Posted February 24, 2014 what a bust. Link to comment Share on other sites More sharing options...
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