Monday, March 2, 2015

Mar 3-5


3-4 evening

Have to go with a 3-6 inch storm. In support of the storm:
12z Euro per below
12z Ukie (has 3" but 5" worth of precip)
18z GFS  .93 of precip, most after the front passes and with -10c temps at 850
18z GEFS mean has 6" 

12z and 18z RGEM has 6"


Latest HRRR with 3-4 inches, through 9am
 RAP also with 3-4 inches

SREF's now have 6"  (but they've been all over)



Going against it:  NWS has us 1-2", not even an advisory, NAM, 0z-12z GFS runs, earlier SREF's


@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
3-4 noon  No idea - GFS/NAM say nothing.  Even GFS ensembles have a good amount. 

The 12z US maps below say it all - then compare with the 0z euro and 12z GGEM????


Euro 6" snow


gfs no snow

NAM no snow


3-3 afternoon

18z GFS goes even further south, now with only .13 qpf falling as snow over 24 hrs once it changes back.  At that rate, it doesn't accumulate.

12z GFS goes a bit further south as well.  UKMET also drifted south.  Both now the I84 area getting only a minor nuisance snow.  Cold air has been impressive this year pushing weak systems south. With no upper feature behind to dive down, and there really being no well organized low to pump a ridge in front, the southern solution may be the right one, especially if the cold front doesn't lift north as much as modeled.   Then it becomes how the waves time with the frontal passage.  NAM's .9 qpf is not .49.  Euro's .66 qpf down to .29.  GFS .4 qpf down to .23.



3-3   Nothing changing too much overnight.  Models still have brief snow on front end turning to sleeet, freezing rain then drizzle. SREF's are all over the place.   Second round is where most of these totals are.

NAM seems to be drifting south, but still gives us a good amount. 6-7"

GFS clobbers SNJ - gives DXR 7-8"

Euro ens control 8-10"
Euro deterministic 9-10"

Then the 12z Hires NAM  10-12"



3-2  Complex system with stalled frontal boundaries coming up for a two day period.  Looks like a LP will ride up through Canada bringing a weak warm front up on Tuesday, into still very cold air.  Originally temps were forecast near 50, are down to 40 now and I am skeptical we get that unless some sun breaks through after the warm front passes.  There really isn't a strong surface wind and even Upton is skeptical as to how far north this front gets. 18z GFS from today only gets to 33.  Euro to 39.   This means a snow, sleet, freezing rain to possibly rain (definitely further south) scenario.  But the last snow never changed over as the warm front barely made it to LI.  Temps aloft look pretty warm though, so I like 2-3" for Tuesday into Tues night. QPF on the 18z GFS for this first part are .27 which will be a mix, then .19 as rain before it turns to the third part.  Euro is also .27, colder to start at 850 and then warmer.  Then .09 over 18hrs as drizzle before going back to snow.

NAM is juicier to start, with .5 for the first portion, .18 for the 18 hr drizzle.  Then .89 as snow!   Temps at surface make it to 35, but NAM has been warm at surface and aloft lately.  Its also slower than the Euro and GFS.

For the snow on the backend, the Euro has .41; NAM .89 and GFS .38.   It should be noted the GFS pulled back far to the NW with the axis of qpf between the 6z and 12z runs and a little more at 18z.  GFS also has Atlantic City getting a foot.

Some snow maps - note the accuweather gfs and nam include melting so it assumes that most of the front end melts. Also posting Instant Weather Maps version  which doesn't include melting

One last point on this storm - there really isn't an organized LP on the maps just yet.  Just waves moving along the frontal boundary as it lifts north, then south .

Euro

GFS
NAM


GFS via IWX

NAM via IWX







No comments:

Post a Comment

Storm 3 - could be the one! (spoiler, it was)

 2/9  Set up is an upper low over TX that heads northeast into TN valley and then transfers off the coast. At the upper levels, there's ...