|
Post by jmg378s on Dec 26, 2019 15:12:03 GMT -6
Observations for the last 1.5 hours at KSTL and KSUS having been around 70.
|
|
|
Post by jmg378s on Dec 17, 2019 12:24:15 GMT -6
One thing I found interesting with this storm is how poor the euro did with Monday’s storm..... UKMET didn't pick up on the strength of Monday's event either if recall.
|
|
|
Post by jmg378s on Dec 17, 2019 12:20:44 GMT -6
Heres the current temp anomalies forecasted for Christmas. Anybody dreaming of a warm and humid Christmas? May need some...ahem...heat advisories Christmas week...
|
|
|
Post by jmg378s on Dec 17, 2019 8:51:59 GMT -6
I'm on the southeastern side of that 6+ along I-70, but I measured only 5.0" for storm total. Nice storm, I'll take it.
|
|
|
Post by jmg378s on Dec 16, 2019 21:26:21 GMT -6
Chris you picked a good game to go to!
|
|
|
Post by jmg378s on Dec 16, 2019 12:47:16 GMT -6
Thanks...I thought things looked a little different on the webcam when I checked. Just checked thickness on elevated surface at >.20". Roadways and even most objects at ground level still wet, however anything elevated more than about 10' is accruing ice at a good clip. Still a lot of precip upstream too. If it stays FZRA you may start having some power issues.
|
|
|
Post by jmg378s on Dec 16, 2019 12:42:45 GMT -6
Ah ok there we go. Tornado emergency for Alexandria.
|
|
|
Post by jmg378s on Dec 16, 2019 12:37:57 GMT -6
Yeah, been watching that. Not sure why the local office isn't tagging that with confirmed. I image they're busy...but still.
|
|
|
Post by jmg378s on Dec 16, 2019 12:08:48 GMT -6
Just hit 1.0" here at my location in St. Peters...can't speak for the rest of the city.
|
|
|
Post by jmg378s on Dec 16, 2019 12:02:09 GMT -6
The debris lofting is 24,000 ft. Is that on the one in the middle of nowhere or the one to the SW of Alexandria? Also, sleet is winning the battle here the last half hour. Yes rural area, SW of Alexandria after passing near DeRidder. I think it's been the ground for a while too. There's a few town out ahead of it so let's hope it dissipates.
|
|
|
Post by jmg378s on Dec 16, 2019 11:56:46 GMT -6
The debris lofting is 24,000 ft.
|
|
|
Post by jmg378s on Dec 16, 2019 11:50:21 GMT -6
Debris ball on that supercell in LA. Yikes.
Oh and I have a little bit of light snow in St. Pete...yay.
|
|
|
Post by jmg378s on Dec 15, 2019 22:29:40 GMT -6
GFS/NAM are insane. I'm kinda having trouble reconciling the quick shearing nature of 500mb wave and the still messy 850mb low with the crazy QPF. To be honest the splotchy looking 500mb vertical velocity fields with absurdly high omega look flat out convective to me.
|
|
|
Post by jmg378s on Dec 15, 2019 18:25:10 GMT -6
Couldnt agree more Chris.
|
|
|
Post by jmg378s on Dec 15, 2019 17:38:27 GMT -6
I measured 2.4" in eastern St. Peters
|
|
|
Post by jmg378s on Dec 15, 2019 15:05:53 GMT -6
What's happening in Brighton? 45-50dbz returns there!
|
|
|
Post by jmg378s on Dec 15, 2019 9:02:13 GMT -6
Here's a fresh aircraft sounding out of Lambert. Very dry, but thin, layer just below 850mb where temp maxes out at 0.3C...which is probably still snow anyway. That layer should wetbulb down in temperature initially with no p-type issues. Then the question is does warm advection more than offset lift/wetbulbing and bring us back over 0C in the metro?
|
|
|
Post by jmg378s on Dec 14, 2019 22:40:10 GMT -6
Somebody asked earlier and I can't remember if it was answered, but I don't think wind is going to be a big factor with this storm.
|
|
|
Post by jmg378s on Dec 14, 2019 22:36:07 GMT -6
As for the second phase it seemed to me the 12z Euro was a bit too robust with the low level cyclone given the sorta strung out nature of the 500mb vorticity. I think the messier/weaker solution with the second phase like the GFS is showing seems more reasonable. Will be interesting to see what tonight's Euro does though...I guess I'll probably stay up for that .
|
|
|
Post by jmg378s on Dec 14, 2019 22:27:26 GMT -6
Looking like there could be some mesoscale banding and/or some slantwise convective enhancement in the first wave on Sunday. SPC SREF ensemble charts are showing 70% probability of low MPV(EPV) numbers combined with strong frontogenesis in the key 700-600mb layer. Time/height diagrams are showing a period of vertically oriented theta-e contours and soundings show 100kts of nearly unidirectional shear above the low level boundary up to 200mb. All this is occurring in the right entrance region of a 160kt upper level jet streak across the Lakes region. So some of the indicators are there. You can sorta see this in the long range HRRR/HRRRv4 sim reflectivity as well. If this does occur it can be great (if it's snow) for those under one of these county-wide bands and suck for those that aren't.
|
|
|
Post by jmg378s on Dec 14, 2019 14:29:03 GMT -6
Yeah first phase is stout on the NAM. That's a pretty impressive wave that develops along the boundary too.
|
|
|
Post by jmg378s on Dec 14, 2019 14:27:18 GMT -6
On the other hand the GFS features are messier on the second phase and I continue to be less than thrilled about the omega bullseye largely below (or even straddling) the DGZ. Soundings continue to indicate some notable dewpoint depressions at the top of the DGZ too. Going to make ideal flakes harder to come by. I think sleet will definitely be a concern for the first wave south of I-44. The second wave will be snow which is good, but this is an interesting analysis you bring up. What does the omega bullseye mean? Positive omega is upward vertical motion right, I feel silly bc I don't remember haha. Omega is defined in a pressure coordinate system, so delta pressure per time (usually microbars/s). When air is rising omega is negative. By omega bullseye I'm just speaking off the cuff and referring to the max (ok technically min) value within all those concentric contours. We want the omega (red) showing up inside the layer bounded by the purple lines...the dentritic (snow) growth zone which is often referred to as the "cross-hair signature".
|
|
|
Post by jmg378s on Dec 14, 2019 13:30:38 GMT -6
I need an exact amount of everything that falls at the Super 8 in Union from 3pm Sunday to 3 am Tuesday. Thanks. No problem. Now if you want to know exactly how much accumulates we'll need more specifics on the surface type.
|
|
|
Post by jmg378s on Dec 14, 2019 13:27:31 GMT -6
12z GEFS looks good, whAt did the 12z UKMET showing? Has any one looked at the SREF plumes today? Don't have much to go on with the UKMET, so have to infer a lot from the QPF fields. Fairly unimpressive compared to the other global models though...at least in the immediate metro. Maybe 0.5" or less. More precip down south but very marginal surface temps so some of that may be plain rain. SREF mean snowfall is 3" with a pretty even spread between 0-10".
|
|
|
Post by jmg378s on Dec 14, 2019 13:16:01 GMT -6
On the other hand the GFS features are messier on the second phase and I continue to be less than thrilled about the omega bullseye largely below (or even straddling) the DGZ. Soundings continue to indicate some notable dewpoint depressions at the top of the DGZ too. Going to make ideal flakes harder to come by.
|
|
|
Post by jmg378s on Dec 14, 2019 12:48:10 GMT -6
Wouldn't completely discount the utility of GYB with this system...at least for the second phase. On the latest Euro I'm seeing a distinct closed & deepening 850mb low moving from about Joplin right through the sweet spot...Cape G. 700mb low is very nearly closed (certainly is in a storm relative frame) with a wave axis moving very close to the metro. 500mb vorticity max is way off but I've always thought that was the sketchiest part of the process anyway. Hour 54 850mb Hour 60 850mb
|
|
|
Post by jmg378s on Dec 14, 2019 7:31:14 GMT -6
uh. The 6z euro is obscene Go on. About 1" of liquid equivalent precip with most of it being snow along I-70.
|
|
|
Post by jmg378s on Dec 12, 2019 22:26:25 GMT -6
But on the other hand the moist ascent in the low levels is actually pretty impressive during the initial WAA phase with 30-35kts winds perpendicular to the tightly packed isobars on the isentropic chart. Though again the lift is concentrated below the DGZ so take some of the p-typing with a grain of salt. However, I have no expectation that the other models will come in this juiced and this probably just about represents the upper bound of possible outcomes.
|
|
|
Post by jmg378s on Dec 12, 2019 22:11:47 GMT -6
Yeah, hard to believe those qpf/snow totals with that ribbon of mid-level dry air never fully saturating during the event. Certainly it's going to be hard to get ice crystals to grow at least...
|
|
|
Post by jmg378s on Dec 11, 2019 17:20:39 GMT -6
Trust me......no snow this time......I already put plows on trucks today to make they were operable!! All is good and spreaders will go on them Friday afternoon. Man, you always jinx it. That's it, just winterize...err...summerize(?) your equipment now!
|
|