CONTEST STATUS - Updated: SAT ... 17-APR-21 @ 5 PM EDT

Winter '20 / '21 - Snowfall Forecast Contests
22nd Annual 'Snow Storm' Snowfall Forecast Contest
FINAL results here

20th Annual 'Season-total' Snowfall Forecast Contest
FINAL results here

DEC snowfall totals here
JAN snowfall totals here
FEB snowfall totals here
MAR snowfall totals here

Winter '19 / '20 - Snowfall Forecast Contests
21st Annual 'Snow Storm' Snowfall Forecast Contest
Season ended as quickly as it started.
No winner this go'round ... too few storms (minimum of three required)

19th Annual 'Season-total' Snowfall Forecast Contest
FINAL Results here

Saturday, November 28, 2009

Winter '09 / '10 - 9th Annual 'Season-total' Snowfall Forecast Contest - Last Call!

Deadline:  Monday...November 30 2009 @11:59 PM EST

Full details here.

Hope to have forecaster summary posted Tuesday evening...01 December.

Thursday, November 26, 2009

Winter '09 / '10 - WSI - November Update

"WSI expects the upcoming period (December-February) to average cooler than normal in the eastern and south-central US, with above-normal temperatures common across the western and north-central US. The WSI seasonal outlooks reference a standard 30-year normal (1971-2000).

"The combination of the current El Nino event, abundant Eurasian snow cover, and a favorable pattern of ocean temperatures in the Atlantic Ocean suggest that this winter will be a cold one in the eastern US, especially after the New Year" said WSI seasonal forecaster Dr. Todd Crawford.

"There are even indications that a significant pattern change will occur in late November and that December may be colder than we are currently forecasting.

"In December, WSI predicts...
Northeast - Warmer than normal

"In January...
Northeast - Colder than normal

"In February...
Northeast - Colder than normal"

NOAA Stays Put in World Wx Building

"The National Oceanic and Atmospheric Administration has extended its lease at its World Weather Building in Suitland, providing an alternative for space as its legal dispute over a new College Park location drags on with the bankrupt Opus East, according to Grubb & Ellis Co., which represents the current landlord.

"The agency will remain for an unspecified time at its longtime home of the National Centers for Environmental Prediction and the National Weather Service. NOAA occupies the 137,004-square-foot facility at 5200 Auth Road.

"Opus East stopped work this summer and sued the General Services Administration for back payments on the College Park project, which was nearly completed. Opus said it put more than $36 million into the complex but that the GSA held up payments over disputed add-on work. The resulting liquidity crunch contributed to Opus Corp. of Minneapolis declaring bankruptcy for Opus East of Rockville."

Wednesday, November 25, 2009

Winter '09 / '10 - C-C-C-O-L-D December

Takes ~3 weeks for 10 mb signatures to reach the troposphere

Unless your winter outlook is all-in for a mild DEC in the eastern CONUS...what's not to like about HIGH pressure parked in PNA-land as the winter solstice approaches?

Winter '09 / '10 - Pattern Change

NWP has been hinting at a change in the flow regime for some time.  As early DEC draws near...more and more evidence points toward the arrival of winter wx.

ECMWF height-latitude cross-section forecast for 01-DEC depicts deep layer easterlies near the North Pole...supporting the -AO forecast from the GFS shown above.   Note the long period (into week2) where AO remains well-below zero.

Cold pool aloft shown over central Canada in the 100-mb height-field.  Warm stratosphere ==> cold troposphere.

Excellent antecedent conditions for the season/s 1st coastal teaser.  500 mb heights are a little high but with the 'event' still a week away...taking it one step at a time.  Never want the progs looking too good this far out.

Winter '09 / '10 - Do Different Flavors of +ENSO Affect BWI Snowfall?

"Looking back at past winters since 1950, approximately 17 were influenced by an El Niño episode.

"Seasonal snowfall averaged above normal for weak and moderate El Niño winters while below normal for strong El Niño episodes."

 - El Niño and DC/Baltimore Winters (WFO LWX - NOV-09)

Judging from the LWX chart...those conclusions would appear reasonable and true.  The lime green column is tallest of them all.  The red column is below climo.

Frank Royance...quoting LWX 'Warning Coordination' meteorologist Chris Strong in his Maryland Wx blog...

"With moderate strength El Nino's (sic) [like this one] we have statistically the greatest chance of above-normal snowfall."

"What they're saying is that not all El Niño winters are alike for the mid-Atlantic states. Some will be snowy; some not. Here's how they tend to break down, according to Klein:

"On average, weak El Niño winters bring below-average temperatures and below-average precipitation. Not generally conducive to lots of snow.

"Strong El Ninos, on average, bring us above-normal temperatures and precipitation. The cold air tends to remain well to our north, so most of the precipitation falls as rain rather than snow."

The LWX analysis lacks any significance testing to determine whether the average season-total snowfall for the various +ENSO states are statistically different from each other or climatology (1971 - 2000) or the period-of-record since 1950.

Bottom line up-front:  BS.  Despite appearances...they are not different.  There is no statistically significant difference...between average season-total snowfall observed during weak...moderate...or strong +ENSO winters when compared to each other nor to the period-of-record since 1950 or climatology (1971 - 2000).

The study's conclusions about the probability of observing more or less season-total snowfall relative to 'normal' is unsupported at the 95% confidence level.  There is weak the 90% confidence conclude 'moderate' +ENSO winters observed more snowfall...on average...compared to climatology (1971 - 2000) and the period-of-record beginning in 1950...which is pretty weak tea.

Data and analysis after the jump.

Tuesday, November 24, 2009

Winter '09 / '10 - Outlook - Eric Horst

Eric Horst - Director...Wx Information Center  @Millersville University of Pennsylvania

"...we could see about 36 inches of snow this year, about 10 inches (ed:  ~40%) above normal, and about two to three times more than we've had in the last two winters combined.

"...I am anticipating...a greater frequency of coastal storms...

"That can have a notable effect on snowfall here. For example, last nor'easter, on March 2...gave us 6 inches of snow.

"This winter, ...will be watching that southern storm track...  'That may mean four, five, six storms take that track.  It doesn't mean we get hammered four, five, six times, but there is going to be the opportunity to develop these.

"The only caveat...if the waters in the equatorial Pacific cool (sic) too much, we could have a "super El Niño" winter, which would be more wet than white."


Eric Horst's '08 / '09 outlook here.

Monday, November 23, 2009

Winter '09 / '10 - WSI - Europe

Todd Crawford - WSI seasonal forecaster: 
"The combination of the current El Nino event, abundant Eurasian snow cover, and a favourable pattern of ocean temperatures in the Atlantic Ocean suggest that this winter will be a cold one across much of northern and central Europe, especially after the New Year...
"WSI also expects below normal temperatures during the three-month period in eastern and south-central parts of the United States..."

Sunday, November 22, 2009

Winter '09 / '10 - ENSO Rising

"This image was created with data collected OSTM/Jason 2 during a 10-day period centered on November 1, 2009. Red and white areas in the central and eastern equatorial Pacific were 100 to 180 millimeters (4 to 7 inches) above normal. In the western equatorial Pacific, blue and purple areas show where sea levels were between 80 and 150 millimeters (3 and 6 inches) below normal.

"Sea surface height is an indication of temperature because water expands slightly as it warms and contracts as it cools. The elevated sea levels in the central and eastern Pacific are equivalent to sea surface temperatures more than one to two degrees Celsius above normal (two to four degrees Fahrenheit)."

NASA image by the Jet Propulsion Laboratory Ocean Surface Topography Team

Friday, November 20, 2009

Winter '09 / '10 - Heavy Snow Across China

"At least 38 people have died in some of the worst snows to hit northern China in decades...

"Major highways in north China have been shut down, leaving at least 10,000 vehicles and up to 30,000 people stranded on roads in Shanxi alone..."

"The 19-inch thick snow that fell in Hebei province's capital of Shijiazhuang was the heaviest ever recorded since 1955."
"Parts of southern China are now suffering low temperatures and snow, while almost all of northwestern China can expect continuing low temperatures and gales. Local governments are taking practical measures to cope with the cold weather and heavy snow.

"Meanwhile, parts of northwestern China, including Gansu and Shaanxi, are suffering a new round of snow storms, with temperatures in some areas dropping sharply by 20 degrees Celsius (36°F)."

"Early and heavy snow storms in north China have killed 32 people, destroyed nearly 300,000 hectares of winter crops, and caused nearly 7 billion yuan (about one billion US dollars)...

"More than 15,000 buildings collapsed..."

More about the 12-NOV event here.

Image courtesy 'Image of the Day' from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite.

Winter '09 / '10 - ENSO Outlook - November

From The International Research Institute for
Climate and Society (IRI)
"By mid-November 2009, the NINO3.4 SST anomaly index had risen to values indicative of the moderate El Niño category. Up until recently, the event had maintainined (sic) only a weak magnitude, but strong and persistent westerly wind anomalies during September, and especially those during October, substantially increased the SST anomalies in the central and eastern equatorial Pacific.

"Those wind anomalies also had a substantial impact on the sub-surface ocean, deepening the thermocline. This could allow for further growth and will certainly provide several months of persistence to the current event. The wind anomalies in the western Pacific have become easterly since early November, suggesting that much of the rrecent (sic) wind anomalies are due to passage of a very strong MJO, or intraseasonal (sic) variability.El Niño conditions are expected to persist through the end of the calendar year and possibly a few additional months.
"Out of a large set of dynamical and statistical forecast models, nearly all indicate maintenance of El Niño conditions during the Nov-Dec-Jan season currently in progress. Overall, based on model forecasts and current observations of the ocean surface and subsurface, for the coming Dec-Jan-Feb season the probability for El Niño conditions is estimated at 96%, and for ENSO-neutral conditions approximately 3%. The estimated strength of this El Niño event now appears moderate, and the most likely period of duration is through early 2010."
Recent performance trends show the models respond too quickly (slowly) when temperature anomalies are rising (falling).

Winter '09 / '10 - National Wx Circus - Final Call

The Climate Prediction Center issued its final winter outlook (0.5 month long-lead) today.  Essentially unchanged from last month's outlook.

Cooler in the SE...warmer in the Northern and Central Plains...Northern Rockies...and Alaska.

Above normal precipitation along the southern tier of states ...consistant with typical +ENSO storm track.

+ENSO has reached moderate strength in recent weeks.  Latest Region 3.4 weekly temperature anomaly is  1.7°C.  The 12-week moving average is 1.06°C.

The CPC's forecast for below normal temperatures in the SE suggests a winter where the average Arctic Oscillation below zero.

Tuesday, November 17, 2009

Winter '09 / '10 - Early Season Stratospheric Warming

Joe D'Aleo has a post up at ICECAP about an incipient warming event @50 and 30 mb that may herald an early start to winter.

He notes the current spike in temperature above the long-term average and draws upon an historical analog where the Arctic Oscillation (AO) collapsed.

Not much support found for warming in today/s 10 mb height field.  There is a small broad region of -45°C air over the northern Canada and NE Siberia.

Stratospheric forecasts from the ECMWF show a short-lived transient flow reversal on the 21st...but no warming in the height - latitude chart (not shown).  The closest to a bifurcated flow over the pole is projected for today...which the analysis from U of Wyoming indicates did occur.

NCEP GFS forecast offers a decidedly different solution @144 hours (NOV 23) and 240-hours (NOV 27). 

D'Aleo concludes with "(i)f this warming in the stratospheric persists, look for a rapid cooling to begin around Thanksgiving."

More from ICECAP (.pdf)...

50mb time-height cross section courtesy CPC Global Temperature Time Series
10mb planar temperature forecast courtesy CPC Stratospheric Analyses and Forecasts
Zonal wind anomalies courtesy CPC Stratosphere-Troposphere Monitoring

Thursday, November 12, 2009

Amazing Snow

Gorgeous snow pr0n from all over the world.

Well worth a visit.

Amazing Snow

Tuesday, November 10, 2009

Winter '09 / '10 - European Snow Outlook - AccuWeather

Winter '09 / '10 - Pig Spleens as Predictors

Norbert Schulz - North Dakota pig farmer:
“It is a bad winter... It’s going to turn real nasty.
“In March it looks even worse than it does (in January)...”

"Mr. Schulz uses the width and height of pig spleens to determine if the up-coming winter will be mild and dry or cold and snowy.

"His outlook this year: buy a new shovel."
More ...

Monday, November 9, 2009

Winter '09 / '10 - Quasi-biennial Oscillation - October


A stronger negative value was expected b/c the cycle is five months into its easterly phase.

1991 continues to be the best YTD-analog...followed by 1986...1981...2000...and 1967.  Note its close fit...including the slight upturn through NOV before resuming its decline into spring.

Other 1991 Teleconnections

Strong measured by MEI...was in excess of +1.5 and reached a max value of +2.248 during spring 1992.  The analog year is the highest-ranked of those matching the top-5 QBO years.

PDO was weakly positive during the winter...dipping close to zero in JAN before turning strongly positive by mid-spring.  It/s the fourth ranked analog.

1991 is the top analog for AO and 4th for NAO.  AO was above zero NOV through MAR...and above +1 DEC and FEB.  Similar tale for NAO...altho JAN/s dip to -0.13 did little to affect the winter/s +0.568 index average.

Sunspots for the period D-J-F-M totaled 576...not a good match for this year/s extreme minima values.

The two tables show the top-5 analog years for QBO.  The top table displays the rank of the corresponding years for other teleconnection indexes, i.e., the 1991 PDO is ranked fourth of all PDO analog years.  The 'Total' column sums all 'rank' values for the analog year.  Low score wins with this decision analysis scheme.  North American snow cover (NA SN) is not included in the scoring b/c data are not available for all analog years.

The bottom table assigns a score relative to all rankings in the same column and assumes every column carries equal weight.  Further refinement to this decision analysis table would assign relative weights to each teleconnection index.  MEI might be weighted 35% and the contribution from sun spots set to 10%.

Note the 1991 PDO is ranked 1st among the other PDO years and has the top score of 1.  The 1991 'Sun Spots' has a low score of 0.10 b/c more sun spots are not associated with colder winters.  1986 has the lowest sun spot count and is scored 1.

1991 QBO has the highest total score of 4.01.  Its score is more than twice as high as the second best analog year 1986...50% higher than 2000...and a strong choice when paired with other teleconnection indexes.

The winter of 1991 produced much below normal snowfall in the mid-Atlantic and southern New is typical for QBO-east and +ENSO winters.

Richmond...VA - 0.9"
DC - 6.6"
Baltimore...MD - 4.1"
Philadelphia...PA - 4.7"
NYC - 12.6"
Binghamtom...NY - 56"
Boston...MA - 19.1"
Concord...NH - 33.6"

Previous QBO post here.

Monday, November 2, 2009

Winter '09 / '10 - NHEMI Snowcover - October

Snow cover over-spread EURASIA rapidly in October...just as it does every year.

NHEMI snow cover is above normal...a somewhat common phenomenon this decade.  Recovery was rapid...after falling ~2% below normal seven or so days into the month.

Snow cover anomaly is over land areas between 35°N and 55°N is currently +6%.

Good autumn snow cover over EURASIA plays an important role in defining winter's character. It perturbs the troposphere in such a way as to weaken the polar vortex (PV).  Arctic air masses are better able to drain into lower latitudes when the PV is weak. The PV is also weaker when the QBO is it will be this winter.  More about EURASIAN snowcover/s predictive role in winter/s wx here.

The combination of rich snow cover in EURASIA and QBO-east could provide the impetus for hi-latitude blocking and a persistently negative state of the northern annular oscillations known as the Arctic Oscillation and the North American Oscillation... which favors above-normal season-total snowfall in the NE and mid-Atlantic regions.  +ENSO-related +PNA and an active lo-latitude / southern-tier storm track should provide ample opportunity for phasing and strong Miller-A cyclogenesis along the eastern seaboard.

More global snowcover charts @ FSU...NOAA...and Rutgers

Winter '09 / '10 - SOI - October

-14.7 and falling!

October registers a rather robust value compared to historical values for the month (data) and a sharp decline from September (+3.9).  Last month's SOI is almost two standard deviations (2STD = -19.5) below the period of record normal. 

The Southern Oscillation index (SOI) has been oscillating about 0 since early contrast to Multivariate ENSO Index (MEI) which has been bullish on +ENSO during the same period.

With the addition of October's SOI...the 'Top-5' analog years (using a least-squares and coefficient of determination method) are...
1 - 2001 (also top-ranked analog year for NHEMI snow cover and 4th for NOAM snow cover)
2 - 1984 (also 5th rank for NOAM snow cover)
3 - 1999 (also 3rd rank for NOAM snow cover and 5th rank for NAO)
4 - 1963
5 - 1967

SOI turned positive during the '01 / '02 winter.  Not a good match given the widespread expectation for a moderate +ENSO event.

1984 would be a slightly better analog.  QBO was will be the case this winter; however...MEI indicated -ENSO conditions.

1999 was a moderate -ENSO winter.

1963 has a good association with MEI...which was moderate +ENSO.  QBO was west and  PDO negative.

1967 was not quite a moderate -ENSO winter.

Not a lot of corroborating support for choosing SOI as a leading indicator for the upcoming winter.