Monday, January 28, 2019
Sunday, January 27, 2019
Winter '18 / '19 - Snow Storm #3: Call for Forecasts!
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| Conservatory Lake - Central Park - NYC (10-FEB-34) |
Numerical weather prediction models sometimes don't converge on a consensus solution and don't show systems like this their 'game face' until ~24 hours before flakes start flyin' for real.
Seeing how there have been so few chances to forecast storm-total snowfall this winter ... we're issuing a 'Call for Forecasts' for Snow Storm #3.
The contest for Snow Storm #3 may be cancelled prior to the deadline if fewer than six stations are likely to observe at least a 4" storm-total snowfall.
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Forecast element: each station's storm-total snowfall
Deadline for entries: 10:00 PM EST ... MON ... 28-JAN-19
Verification begins: 12:01 AM EST ... TUE ... 29-JAN-19
Verification ends: 11:59 PM EST ... WED ... 30-JAN-19
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Enter your forecast at the NEWxSFC/s home page here. http://www.newx-forecasts.com/
Follow the top-of-page link from 'Enter Storm Forecast.
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As always ... there/s no cost ... no fee ... no advertising ... or annoying requests for personal information to enter a forecast. It's just a fun exercise for winter wx enthusiasts to see who can make the best synoptic-scale snowfall forecast.
You also get the chance to see how well your forecast stacks up against NWS Eastern Region Weather Forecast Offices (turns out they're pretty easy to beat!)
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If you are issuing your first forecast this winter ... or you entered the 'season-total' forecast contest ... you/ll need to create an account -- user name / password / valid e-mail (if you want a copy of your forecast sent to your Inbox).
Saturday, January 26, 2019
Winter '18 / '19 - We're the Heckawi
- High amplitude ridge to the West.
- Full latitude trof in the East.
- Sub-tropical jet in a split flow
- Split stratospheric polar vortex with the stronger daughter vortice over eastern North America to boot.
So WTF?
If times be so good ... then bro ... where's my fookin' snow?
Us snow crows nesting here in the eastern half of the mid-Atlantic will most often get our winter wx fix when ...
1) LOW pressure spawns over the Gulf of Mexico & proceeds to crawl slowly up the east coast and
2) A strong Arctic HIGH (1040-ish mb; 30.70" Hg) parks herself over Maine and
3) The wavelength between the Ridge-West / Trof-East pattern contracts i.e., becomes shorter. As the wavelength shortens ... storms spin-up (intensify) the same way ice skaters spin-up when when they draw their arms inward (see Conservation of Angular Momentum)
Wicked winter wx 'round here has always been a tricky combination of having a deep layer of Arctic / Polar air in place ... ready to interact with moisture surging from the south.
The current long wave flow regime is certainly delivering in spades with the cold air component; however ... it's coming on too strong ... in effect suppressing moisture from coming north.
FWIW ... the world-wide federation of numerical weather prediction (NWP) models have been tilting toward an adjustment to the long wave pattern in mid-range; a shuffling of the deck so to speak (more like re-setting the tumblers in a one-armed bandit).
Climatologically for snow crows ... FEB is our time 'round here ... especially the period either side of mid-month. Whether the coming pattern change produces the weather we be waiting for is anyone's guess.
Even though long-range NWP offers us nothing more than possible outcomes ... outcomes more often fantasy than fact ... it's one of those j'ne sais WTF reasons why we all be Weather Weenies.
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Friday, January 25, 2019
Tuesday, January 22, 2019
Winter '18 / '19 - Snow Storm #2: FINAL Results
Forecasters' station verifications and the storm summary at NEWxSFC/s home page.
http://www.newx-forecasts.com/
| 1st - TQ | ||||
| SUMSQ: | 219 | |||
| SUMSQ Z: | -0.950 | |||
| STP: | 38.0 | (4) | ||
| TAE: | 46.6 | (2) | ||
| AAE: | 2.12 | (1) | ||
| 2nd - HWSNBN | ||||
| SUMSQ: | 233 | |||
| SUMSQ Z: | -0.914 | |||
| STP: | 25.9 | (3) | ||
| TAE: | 45.5 | (1) | ||
| AAE: | 2.53 | (3) | ||
| 3rd - Shillelagh | ||||
| SUMSQ: | 280 | |||
| SUMSQ Z: | -0.792 | |||
| STP: | 50.4 | (5) | ||
| TAE: | 56.4 | (3) | ||
| AAE: | 2.97 | (5) | ||
| HM - Roger Smith | ||||
| SUMSQ: | 349 | |||
| SUMSQ Z: | -0.612 | |||
| STP: | 9.6 | (1) | ||
| TAE: | 62.6 | (5) | ||
| AAE: | 2.32 | (2) | ||
SUMSQ Z: Z-score
STP: storm total precipitation error (")
TAE: total absolute error (")
AAE: average absolute error (")
(#): category rank
Dotted blue line below (above) solid red line ==> under (over) forecast
Monday, January 21, 2019
Winter '18 / '19 - Snow Storm #2: Preliminary STP Verification
Preliminary verification of storm-total snowfalls for Saturday & Sunday from CDUS41 ... CXUS51 ... and PNS bulletins.
Less than perfect coverage and reporting.
ABE
2.4" snowfall observed SAT.
No daily climate report for SUN/s snowfall.
METARs reported no frozen precipitation on SUN.
HYA
storm-total snowfall estimated by inverse distance weighting of vicinity reports carried in BOX PNS.
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Stations observing at least Trace - 17 (63%)
Given a forecast station observed measurable snowfall ... stations observing at least:
4" - 9 (53%)
6" - 7 (41%)
8" - 5 (29%)
12" - 4 (24%)
14" - 2 (12%)
Two new daily records
SUN ... 20-JAN-19
BTV - 15.6" (10.6"; 1978)
ALB - 10.4" (8.7"; 1978)
Also set on SUN ... new daily liquid records at ALB (1.25") ... CAR (1.45") ... and PVD (2.04").
Please report any errors in Comments along with a link to the correct data.
Final results TUE evening.
Sunday, January 20, 2019
Winter '18 / '19 - Snow Storm #2: The Forecasts
Rookie 1
Intern 1
Journey -
Senior 11
GOVT 1
PWSP 1
TOT 15
Welcome Rookie forecaster chefjustin.
Good Luck!
Forecaster table (supposed to be) ranked ascending by storm-total precipitation (STP)*
* didn't come off the printer quite right
BLUE ==> 25th percentile.
RED ==> 75th percentile.
White and grey STP cells range between the 25th and 75th percentile.
Heaviest snowfall (+12") consensus along and the the right of CAR - BGR - PWM - CON - BGM - ALB - BTV - CAR. Lollypop expected at BGR.
Arctic Oscillation (AO) coming up for air.
North Atlantic Oscillation (NAO) floating high above the fray (again).
Pacific-North American (PNA) bottoming out ... then arriving late to the party.
Everyone/s station-by-station forecast at the Contest/s web site.
Direct link to forecasts.
Friday, January 18, 2019
Thursday, January 17, 2019
Winter '18 / '19 - Snow Storm #2: Call for Forecasts!
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| Brattleboro ... VT |
Lee-side cyclogenesis over CO on FRI expected to race east reaching the western stations of the forecast area by SAT afternoon.
Moisture-rich mid-latitude cyclone advancing into a quasi-stationary Arctic air mass over eastern Canada offers an excellent opportunity for widespread bonus snowfalls.
Contest for Snow Storm #2 may be cancelled prior to the deadline if fewer than six stations are likely to observe at least a 4" snowfall.
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Forecast element: each station's storm-total snowfall
Deadline for entries: 10:00 PM EST ... FRI ... 18-JAN-19
Verification begins: 12:01 AM EST ... SAT ... 19-JAN-19
Verification ends: 11:59 PM EST ... SUN ... 20-JAN-19
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Enter your forecast at the NEWxSFC/s home page here. http://www.newx-forecasts.com/
Follow the top-of-page link from 'Enter Storm Forecast.
---
As always ... there/s no cost ... no fee ... no advertising ... or annoying requests for personal information to enter a forecast. It's just a fun exercise for winter wx enthusiasts to see who can make the best synoptic-scale snowfall forecast. See how well your forecast stacks up against NWS Eastern Region Weather Forecast Offices.
---
If you are issuing your first forecast this winter ... or you entered the 'season-total' forecast contest ... you/ll need to create an account (user name / password / valid e-mail ... if you want a copy of your forecast sent to your Inbox). sent to your Inbox.
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