vortex95

Uh oh, Scott may be in for a surprise!

See attachment It is said that for ML models, the equations of motion and thermodynamics are not satisfied, so that is going to lead to unrealistic output and egregious errors at times. Not that physics-based models are immune to these same problems, but we often know why they occur due to the limitations of simulating the atmosphere best, as one example. For ML models, does that same apply? That is, would we be able to detect why they are wrong for a given forecast? How far do ML models not satisfying equations go? For instance, Navier-Stokes? The paper states: "New forecast methods based on statistical estimation, including neural networks and ML, are neither designed nor constrained to yield dynamically coherent, physically consistent evolutions of the atmosphere." The above would appear to be a huge problem. The paper also discusses ML models lacking in resolution detail, and give a more broad overview. That's fine within itself, but modeling has come so far, getting the broad strokes right as to what is going on, say synoptically, is no longer an issue. What matters most now are the details and fine-tuning on a more local level and shorter time frames in weather forecasting. That's what the public/partners want and demand. How vulnerable are ML models to chaos theory? More or less than physics-based? Another item suggested in the paper, it seems that ML models can not exist or do well/improve without physics-based models. This would ask the question, how much of a statistical database of weather history/analogs do we need for an ML model to perform better? bams-BAMS-D-25-0214.1.pdf

Snow weenies rejoice! GFS V17 goes from 13 to 9 km for horizontal resolution in Oct. Scott counting the days now for the first day of meteorological winter! LOL. pns26-29_Science_for_GFSv17.pdf

One last chance this season for it to look "VIOLENTLY BEAUTIFUL" out there!

SE MA OES in later April? "Unprecedented!" CoastalWx will be out during overnight shaving off every tenth of an inch for max total snow! NORLUN apparent. I like the -31 C at 500 and -10 at 850 and the axis of the 500 trough right overhead.

Instant PT?

From my contact in Woburn, 5 days w/ thunder this month now. 5 TS days is pretty good. That's what normal in July this area. CoastalWx still MEH though I bet!

I'll save CoastalWx the trouble -- WCWGTH??

4/18/1996 27 inches of snow over the last three days from an upper level low pressure system raised the snow cover on top of Mount Mansfield, Vermont to an impressive late season 135 inches.

Try that week in third week of May 2006, "endless Nor'easter" capped off by the bow echo and tornado at Hampton Falls NH later.

Peterborough NH Thu evening. Photo by Thomas Bensenhaver.

Or winter equivalent "DIAMOND DUST AT 30,000 FT!"

Scott needs another 6/1/11 wicked CG supercell show like he had when living in Dorchester. Right, biggest svr wx day in years and he still has a Bruins playoff party at his house, and of course he loses power! I know, another "PC jolt" he got from the +CG strike some years ago!

Reports from ME/NH/VT absolutely spectacular LTG show for April this evening, and still going strong Downeast ME as I type this! Find me an event in April w/ more CGs in several hours in New England! I checked the mid-level lapse rates plots on the NAM, nothing special, but that is 700-500. If you look at 750-600 on the soundings, they were as high as 7.0 C/km. so there you go. MUCAPE ahead of the SQLN were as high 1500, most of it elevated. 0-6 km shear 50-60 kt. Even CoastalWx *has* to be impressed! He recalls the crazy LTG shows that overnight in Feb 2016 RI/SE MA? Basically a ring of fire in April this week. Strong ridge SEUS and direct feed flow straight from Plains to put an EML into NEUS. BDF?, no problem!

Had nice white VIL core on Radarscope for two scans. Usually, that is enough for a SVR.

Scott PT?

It is. Best week for tstms in April I can recall in SNE w/ more on the way.

Conversely, from mid June to mid August 2008 (I think that was the year), we could not get clean CFROPA at all in the NEUS, and the tstm action was pretty sweet!

"My lawn is thirsty"

Some kind of mesolow. No wonder it sustained itself so well overnight. Any rotation, miso/meso/synoptic, is a *good* thing for convection! Did Scott "WE THUNDER" in Weymouth? He told me in PM that he is all excited for tstms this summer b/c of impending super El Nino. I told him, "well, 1997 and 1998 svr wx seasons in NEUS were quite good, spinners and more!"

Not bad for April w/ the storms in western MA/CT currently. HRRR 18 and 00z insisting isolated long-tracked supercell NY into NH later Thu. Then a :sun destroyed itself" day Fri w/ RW/TRW peppered all over the place by noon. Best tstm week in April for New England I can recall offhand. But somehow Scott will find a way to say MEH! LOL. SPC 2% tor western section Thu. Only 3 confirmed spinners in April in New England on record. Path Path Time(EST) Width Length --------- ------ ------ MA APR 15, 1925 1700 0k 0inj unk unk F1 HAMPDEN - Brief tornado in Chicopee. One house and five garages destroyed. Damage $50,000. CT APR 26, 1961 1115 0k 0inj unk unk F1 TOLLAND - Two silo roofs destroyed in Ellington. CT APR 21, 2021 1349 0k 0inj 30y 1.0m EF0 LITCHFIELD - Sporadic tree damage in Kent. Also in 2021, we have our first confirmed tor in Mar in New England. VT MAR 26, 2021 1240 0k 2inj 75y 0.7m EF1 ADDISON - Tornado associated with bow echo segment moved through Middlebury. Many trees downed and some structural and vehicle damage.

Thrilled for the BDF Wed?

And then we had accumulating snow a month later from a 500 that was kinda MEH. Snow the third week in May in SNE? You need quite the anomaly (you'd think) like a MONSTA 5-contour cut off at 500 that happened May 9-10, 1977 or something like this in 1967. 5/25 A slow moving nor'easter battered New England with high winds, heavy rain, and record late season snow on this day and into the 26th. Winds 70 to 90 mph in gusts occurred along the coast. Over 7 inches of rain fell at Nantucket, Massachusetts with 6.57 inches falling in 24 hours to set a new 24 hour rainfall record. Severe damage occurred along the coast from very high tides. 24.9 inches of snow fell at Mount Washington, New Hampshire to set a new May snowfall record. 10 inches of snow fell near Keene, New Hampshire and 6 inches was recorded at Dublin, New Hampshire.