Dark Snow Project: Crowd-Source Funded Science for Greenland

By: Dr. Jeff Masters , 3:03 PM GMT on April 26, 2013

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"There's no place on Earth that is changing faster--and no place where that change matters more--than Greenland." So said 350.org founder Bill McKibben, in a 2012 Rolling Stone magazine interview. As Earth Week 2013 draws to a close, I want to draw your attention to a unique effort to learn more about why Greenland is melting so fast--a crowd-funded research project that anyone can contribute to, which aims to answer the "burning question": How much does wildfire and industrial soot darken the ice, increasing melt? The Dark Snow Project, the first-ever Greenland expedition relying on crowd-source funding, hopes to raise $150,000 to mount a field research campaign to find out. The project is the brainchild of Dr. Jason Box, Professor at the Geological Survey of Denmark and Greenland (GEUS), and one of the world's leading experts on Greenland's glaciers. He has set up a website called darksnowproject.org to help raise the funds for the field campaign, and has raised about half of the needed amount as of mid-April.


Figure 1. Over the course of several years, turbulent water overflow from a large melt lake carved this 60-foot-deep (18.3 meter-deep) canyon in Greenland's Ice Sheet (note people near left edge for scale). Image credit: Ian Joughin, University of Washington.

2012: Unprecedented melting in Greenland
Watching the weather events of 2012 over Greenland made all seasoned climate watchers a little queasy. The vast ice sheet on the island holds enough water to raise global sea levels by 7.36 meters (24.15 feet) were it all to melt, and the ice melt season of 2012 gave notice that an epic melting of the Greenland Ice Sheet may be underway. According to NOAA's 2012 Arctic Report Card, the duration of melting at the surface of the ice sheet in summer 2012 was the longest since satellite observations began in 1979, and the total amount of summer melting was nearly double the previous record, set in 2010 (satellite records of melting go back to 1979.) A rare, near-ice sheet-wide surface melt event melted 97% of the surface of Greenland's ice sheet on July 11 - 12. While a similar melt event at the summit occurred 1889, but the 1889 event has no basis in the instrumental record from coastal Greenland. It's instead likely that 2012 was Greenland's warmest summer in at least 863 years, since the medieval warm period (see http://www.meltfactor.org/blog/?p=677 and http://www.meltfactor.org/blog/?p=725). The incredibly warm temperatures have been blamed on highly unusual atmospheric circulation and jet stream changes, which were also responsible for 2012's unusually wet summer weather in England. It would not be a surprise if this sort of summer began occurring more often, since temperatures on top of the Greenland Ice Sheet have been rising six times faster than the global average during the past twenty years. A May 2013 Geophysical Research Letters paper by McGrath et al., "Recent warming at Summit, Greenland: Global context and implications", concluded that by 2025, there is a 50% chance of ice sheet-wide melt events happening annually. The ice sheet reached its darkest value on record in 2012. The darkened surface was due to below average summer snow, soot particles from pollution and forest fires, and record melting. A darker ice sheet absorbs more solar energy, in a vicious cycle that raises temperatures, melts more ice, and further darkens the ice sheet. The amount of melting that was caused by soot from forest fires is important to know, since global warming is likely to increase the amount of forest fires in coming decades. However, the amount of forest fire soot landing on the Greenland Ice Sheet is almost completely unknown, which is why Dr. Box is determined to find out, via the Dark Snow Project.


Figure 2. Smoke from a fire in Labrador, Canada wafts over the Greenland ice sheet on June 17, 2012, as seen in this cross-section view of aerosol particles taken by NASA's CALIPSO satellite. Image credit: Dr. Jason Box, Ohio State University.

Greenland causing 25% of global sea level rise
In a landmark study published in November 2012 in Science, 47 researchers from 26 laboratories reported that the amount of ice being lost from Greenland and Antarctica has tripled since the 1990s, with Greenland contributing more than twice as much to global sea level rise than Antarctica. The study, "A Reconciled Estimate of Ice-Sheet Mass Balance", found that the two ice sheets were responsible for 20% of the global sea level rise of 3.1 mm/year during the 20-year period 1992 - 2011. The remainder of the rise was due to expansion of the water due to heating of the oceans, melting of mountain glaciers, and unsustainable pumping of ground water. Said co-author Erik Ivins of NASA's Jet Propulsion Laboratory, "The pace of ice loss from Greenland is extraordinary, with nearly a five-fold increase since the mid-1990s." As of 2011, Greenland's contribution to global sea level rise on its own had risen to 20 - 25%, according to an international research group led by the GFZ German Research Centre for Geosciences, in an article published in Earth and Planetary Science Letters on 1 June 2012. If the current exponential ice loss trends continue for the next ten years, Greenland's contribution to sea level rise will double to 1.4 mm/yr by 2022, the researchers said. Many sea level rise researchers expect global sea level to rise by about 1 meter (3.3 feet) by 2100. During the 20th century, global sea level rise was about 0.18 meters (7 inches.)


Figure 3. Monthly smoothed (purple) and unsmoothed (blue) values of the total mass lost from the Greenland Ice Sheet (in Gigatons, Gt) from measurements by the GRACE satellites between March 2002-September 2012. An approximate equivalent global sea level rise figure is on the right axis. Note that the decline in ice mass lost from Greenland is not a straight line--it is exponential, meaning that more ice loss is lost each year than in the previous year. Image credit: 2012 Arctic Report Card.

Will Antarctica be more important than Greenland for sea level rise?
Although melting from Greenland is currently raising global sea level by about a factor of two more than Antarctica melting is, that situation may change later this century. A 2013 study by Dahl-Jensen et al. looked at a new ice core drilled from the bottom-most depths of the Greenland Ice Sheet. The core suggests that the ice in Greenland may have partially survived the warm Eemian period before the Ice Age, approximately 118,000 - 126,000 years ago, when Greenland temperatures were 5- 8°C warmer than present-day temperatures. Global sea level during the Eemian was 4 - 8 meters (13 - 26 ft) higher than the present sea level, and the scientists estimated that melting from Greenland was responsible for 2 meters (6.6 ft) of this sea level rise. This implies that Antarctica was responsible for 50 - 75% of global sea level rise during the Eemian, and thus we might expect Antarctica to take over as the dominant source of sea level rise later this century, when global temperatures may to rise to levels similar to those experienced during the Eemian.

Related posts
Greenland experiences melting over 97% of its area in mid-July (July 25, 2012)
Record warmth at the top of the Greenland Ice Sheet (July 18, 2012)
Unprecedented May heat in Greenland; update on 2011 Greenland ice melt (May, 2012)
Greenland update for 2010: record melting and a massive calving event

Dr. Jason Box's blog on Greenland and the Dark Snow Project is at http://www.meltfactor.org.

The http://www.greenlandmelting.com/ website looks like a great resource for following this year's melt progression in Greenland.


Video 1. Glaciologist Dr. Jason Box and 350.org founder Bill McKibben plug the Darksnow project in this January 2013 video by Peter Sinclair. There's some impressive footage of the record Greenland snow melt of summer 2012 sweeping away a 20-ton tractor that was attempting to repair a bridge washed out by the raging Watson River on July 11, 2012 in Kangerlussauaq, Greenland. The driver escaped unharmed.

Support the Dark Snow Project
One of Dr. Box's collaborators, photographer James Balog, who created the amazing time-lapse Greenland glacier footage in the fantastic 2012 "Chasing Ice" movie, puts it like this: "Working in Greenland these past years has left me with a profound feeling of being in the middle of a decisive historic moment--the kind of moment, at least in geologic terms, that marks the grand tidal changes of history." On that note, I encourage you all to support the Dark Snow Project. Have a great weekend, everyone!

Dark Snow Project Expedition Plan 2013
Prepare and gather science equipment including a field spectrometer, snow and ice coring device, and snow metrics kit.

Travel to Iqualuit, on Baffin Island, Nunavut from home locales in California, Ohio, Michigan, Vermont and rendezvous with Dash-6 "Twin Otter" ski-equipped airplane and flight crew.

Organize cold weather survival kit.

Ferry team from Iqualuit to Kangerlussuaq, Greenland.

Fly to and land at sampling sites high on the inland ice sheet.

At each site collect snow samples from a snow pit and obtain snow cores to a minimum depth of the previous year's snow surface, and record snow properties.

Transport of team and snow samples to Greenland's capital Nuuk, where the team will rest after hustling at field sites.

Return to Iqualuit, then to respective home locales to start the data analysis and reporting phase of campaign.

Jeff Masters

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Chance of rain all week 40% to 70%!!:)
Member Since: Posts: Comments:
Quoting FtMyersgal:


Those wave are starting to move up in latitude now.
Member Since: February 28, 2013 Posts: 6 Comments: 3328
Member Since: September 16, 2010 Posts: 0 Comments: 1219
Quoting SouthernIllinois:

Interesting. Up to now I thought the GFS was still King. LOL. Goes to show how fast things can change. I will add last year's tropical season really put these models to the raw test. Euro absolutely nailed Isaac.


GFS did nailed Debby last year but the Euro nailed Issac and Sandy.
Member Since: February 28, 2013 Posts: 6 Comments: 3328
Quoting SouthernIllinois:

Incredible. Exactly how accurate is this GGEM model? Can I use it to analyze precipitation projections like I can with the NAM or the GFS? Also, is the GGEM another name for the CMC?

Thanks, Scott! Good morning Buddy, btw...


It's now ranked better than the GFS. Euro and GGEM are ranked at the top. I beleive the GFS has slipped to either 3rd or 4th out of all the global models.
Member Since: February 28, 2013 Posts: 6 Comments: 3328
1274. pcola57
Good Morning All..
68 degrees here with 93%rh and dew at 66..
Overcast with winds 4.6mph out of the North..
No rainfall here today as of this post..

Pensacola NAS (KNPA)

Another sticky gloomy morning at the beach..



Member Since: Posts: Comments:
Quoting SouthernIllinois:

Incredible. Exactly how accurate is this GGEM model? Can I use it to analyze precipitation projections like I can with the NAM or the GFS? Also, is the GGEM another name for the CMC?

Thanks, Scott! Good morning Buddy, btw...

The GGEM = CMC. It's a good model overall, but does have a tendency to exaggerate, especially when dealing with tropical cyclone development and intensification.
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Quoting FtMyersgal:


Yeah it does. I want to see rain but not that much. I remember there was alot of flooding in 2009. I'd be happy with 5 inches.


In May 2009 we had a cut off low sit right over FL and this week appears very similar. GFS however is not as robust as all the other models however. Nogaps, Euro, & GGEM all are painting a wet scenario for FL.
Member Since: February 28, 2013 Posts: 6 Comments: 3328
Quoting Levi32:
Interesting. The Caribbean has supposedly changed a lot in just one week.

April 20th:



April 27th:



CFSR reanalysis has much lower values than AOML:



I have seen warmer sea surface temperatures than that before down there before at this time of year, however; I can not recall seeing that much tropical cyclone heat potential at such an early time in the season. Rather concerning...
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Quoting StormTrackerScott:


The GGEM & Euro are showing rainfall totals approaching 10" to 20" in some areas. This situation unfolding this week reminds me of May 2009 when the state was deluged with as much as 36" of rain in Bunnel just north of Daytona.


Yeah it does. I want to see rain but not that much. I remember there was alot of flooding in 2009. I'd be happy with 5 inches.
Member Since: September 16, 2010 Posts: 0 Comments: 1219
Quoting FtMyersgal:
Good morning folks. Looks like Florida is gonna get some rain this week. Early start to the rainy season maybe?


The GGEM & Euro are showing rainfall totals approaching 10" to 20" in some areas. This situation unfolding this week reminds me of May 2009 when the state was deluged with as much as 36" of rain in Bunnel just north of Daytona.
Member Since: February 28, 2013 Posts: 6 Comments: 3328
1266. WxLogic
Morning...
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1265. ncstorm
well the rain is here for us..looks like for the next four days.

Member Since: August 19, 2006 Posts: 13 Comments: 15696
Good morning folks. Looks like Florida is gonna get some rain this week. Early start to the rainy season maybe?
Member Since: September 16, 2010 Posts: 0 Comments: 1219
1263. ncstorm
WPC Day 3-6 sea level pressure map





Member Since: August 19, 2006 Posts: 13 Comments: 15696
Quoting ncstorm:


Good Morning Everyone..

Scott is that Sub tropical?


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
330 AM EDT MON APR 29 2013

THU-SUN...BOTH MODELS SHOW AN OMEGA BLOCK EVOLVING ACROSS THE
CENTRAL-EASTERN US AND WESTERN ATLANTIC BY LATE WEEK...THE
DISAGREEMENT OF COURSE REMAINS IN THE DETAILS.

THE NE SURFACE HIGH WILL EXPAND SOUTHWARDS ON THURSDAY BRINGING THE
WEAK LOW FROM THE EARLIER FRONT BACK INTO THE FL PENINSULA WHERE IT
WILL MEANDER IN THE VICINITY INTO THE WEEKEND. THE ECMWF KEEPS
SIGNIFICANTLY MORE MOISTURE ACROSS THE REGION THROUGH THE
PERIOD...ALONG WITH A SLIGHTLY DEEPER SURFACE LOW UNDER LOWER UPPER
HEIGHTS.
THE RESULT IS A MUCH WETTER FRI-SUN WHERE THE GFS HAS POPS
AT 20-30 PERCENT.

HAVE KEPT THE ONGOING FORECAST AT 30-40 PERCENT RATHER THAN GOING
QUITE AS HIGH AS THE ECMWF AS THE FINAL SOLUTION WILL ULTIMATELY
DEPEND ON WHERE THE TROUGH/SFC LOW SETS UP IN RELATION TO THE COAST.
WITH BRISK ONSHORE FLOW DEVELOPING...THERE WILL BE A POSSIBILITY FOR
A FEW HEAVY COASTAL CONVERGENCE BANDS TO SET UP.
Member Since: February 28, 2013 Posts: 6 Comments: 3328
I have more information the Droughtmonitor is full of crap.

Minnesota is under water, Fargo has had 68" of snow this winter, The Red river is over flowing, yet the Drought monitor says there under a severe drought, I looked through their site, saw the data, it never adds up to the real story is.
I've looked in the southeast, south, southwest portions of the Country, it's the same all over the United States.
I will admit, sometimes they are right with their predictions,and analysis, with regarding droughts.
But other times, they just the typical big Government lying to the public for their own survival.

My post in here is to demonstrate how analysis is not always true or might be exaggerated for future funding or political recourse!
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1260. VR46L
Quoting indianrivguy:


Pay no attention Liz, I love your pictures and consider you a favorite poster.


Aw thanks IRG !!

I think you are great to !
Member Since: March 1, 2012 Posts: 0 Comments: 6927
Close to 20" of rain along FL's East coast thru 240hrs on the GGEM.

Member Since: February 28, 2013 Posts: 6 Comments: 3328
1258. ncstorm
Quoting StormTrackerScott:
Euro 96hrs


Euro 120hrs


Good Morning Everyone..

Scott is that Sub tropical?
Member Since: August 19, 2006 Posts: 13 Comments: 15696
1257. VR46L
Looks like a viable Wave around East Central Africa

Member Since: March 1, 2012 Posts: 0 Comments: 6927
Thanks Scott, looks like the predicted low starts to form by 120 hours..
Member Since: September 23, 2006 Posts: 1 Comments: 2564
Quoting VR46L:


Good Morning Folks !!

I was in a great mood until I read Back.....





If you believe that posting images of weather on the main blog of a weather site is a form of trolling then I suggest you minus and flag the images as inappropriate .... and if they are removed I will stop posting them …

Personally I love looking at the images and weather info that is shared on here and I can tell some folk on here really seem to like the images posted .. and I like sharing the images that I post ... but if images such as the images I post are a problem I just wont bother anymore .... Going to post a couple of images now , I guess I will judge how they are received ….


Pay no attention Liz, I love your pictures and consider you a favorite poster.
Member Since: September 23, 2006 Posts: 1 Comments: 2564
1254. VR46L
World weather in one Image

Member Since: March 1, 2012 Posts: 0 Comments: 6927
Euro 96hrs


Euro 120hrs
Member Since: February 28, 2013 Posts: 6 Comments: 3328
1252. VR46L


Good Morning Folks !!

I was in a great mood until I read Back.....


Quoting BobChecks:
Am I correct in my suspicion that when the discussion turns in directions that bothers some people they then post images in an attempt to disrupt?



If you believe that posting images of weather on the main blog of a weather site is a form of trolling then I suggest you minus and flag the images as inappropriate .... and if they are removed I will stop posting them …

Personally I love looking at the images and weather info that is shared on here and I can tell some folk on here really seem to like the images posted .. and I like sharing the images that I post ... but if images such as the images I post are a problem I just wont bother anymore .... Going to post a couple of images now , I guess I will judge how they are received ….
Member Since: March 1, 2012 Posts: 0 Comments: 6927
Rainy Season?

Member Since: February 28, 2013 Posts: 6 Comments: 3328
Quoting LargoFl:


any rain by you last night as I saw some heavy rain near Largo last evening?
Member Since: February 28, 2013 Posts: 6 Comments: 3328
533 AM EDT MON APR 29 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL FLORIDA.

.DAY ONE...TODAY AND TONIGHT.

.THUNDERSTORM IMPACT...
SOUTHEAST AND SOUTHERLY LOW LEVEL WIND FLOW WILL RESULT IN AN
INCREASINGLY MOIST AND UNSTABLE AIR MASS OVER EAST CENTRAL
FLORIDA BY THIS AFTERNOON. THE COMBINATION OF LOCAL SEA AND LAKE
BREEZES WITH INCREASING LIFT FROM AN APPROACHING UPPER LEVEL JET
STREAK WILL PRODUCE SCATTERED TO NUMEROUS SHOWERS AND LIGHTNING
STORMS ACROSS THE REGION TODAY.

THE BEST CHANCE FOR...AND HIGHEST COVERAGE OF...LIGHTNING STORMS
WILL OCCUR BETWEEN ABOUT 400 PM AND 1000 PM. EXPECT ISOLATED
SHOWERS AND POSSIBLY A STORM TO INITIALLY FORM FROM THE TREASURE
COAST TO AROUND LAKE OKEECHOBEE IN THE AREA OF DEEPEST MOISTURE
AND SEA AND LAKE BREEZE INTERACTION. COVERAGE OF STORMS WILL
INCREASE AND SPREAD NORTH AND INLAND AS THE EAST AND WEST COAST
SEA BREEZES PUSH TOWARD THE INTERIOR...AND INTERACTIONS WITH
THUNDERSTORM OUTFLOW BOUNDARIES BECOME MORE FREQUENT.

ACTIVITY WILL MOVE TOWARD THE NORTHEAST AT 20 TO 25 MPH. DUE TO
COLD TEMPERATURES ALOFT...THE STRONGEST STORMS MAY PRODUCE STRONG
GUSTY WINDS...FREQUENT LIGHTNING...COIN SIZED HAIL AND TORRENTIAL
RAINFALL AMOUNTS OF ONE TO THREE INCHES IN A 60 TO 90 MINUTE
PERIOD. MOVE INDOORS TO SAFETY IF YOU HEAR THUNDER...OR IF SKIES
LOOK THREATENING.
Member Since: February 28, 2013 Posts: 6 Comments: 3328
Good Morning!

GGEM precip accum.
Member Since: February 28, 2013 Posts: 6 Comments: 3328


TROPICAL CYCLONE ADVICE NUMBER 1
Issued at 5:05 pm EST on Monday 29 April 2013

A Cyclone WATCH has been declared for a developing tropical low for coastal
areas from Thursday Island to Cooktown.

At 4:00 pm EST a Tropical Low was estimated to be
1030 kilometres east of Lockhart River and
890 kilometres east northeast of Cairns and
moving west at 6 kilometres per hour towards the coast.

The low is expected to develop into a tropical cyclone in the next 24 hours.

A deepening Tropical Low situated over the northern Coral Sea is moving slowly
in a westwards direction and is expected to deepen further while continuing to
move in westwards direction tonight.

STRONG GALES may develop about coastal areas between Thursday Island and
Cooktown during Wednesday.

Areas of heavy rain, which may lead to flash flooding, are expected to develop
across parts of far northern Queensland late Tuesday and during Wednesday as
the deepening Tropical Low approaches the coast.
People between Thursday Island and Cooktown should consider what action they
will need to take if the cyclone threat increases.
- Information is available from your local government
- For cyclone preparedness and safety advice, visit Queensland's Disaster
Management Services website (www.disaster.qld.gov.au)
- For emergency assistance call the Queensland State Emergency Service (SES) on
132 500 (for assistance with storm damage, rising flood water, fallen trees on
buildings or roof damage).

Details of Tropical Low at 4:00 pm EST:
.Centre located near...... 12.7 degrees South 152.8 degrees East
.Location accuracy........ within 85 kilometres
.Recent movement.......... towards the west at 6 kilometres per hour
.Wind gusts near centre... 85 kilometres per hour
.Severity category........ below cyclone intensity
.Central pressure......... 1001 hectoPascals

The next advice will be issued by 11:00 pm EST Monday 29 April.

................................................. .............................................

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - EASTERN REGION
Issued by BRISBANE TROPICAL CYCLONE WARNING CENTRE
at: 0645 UTC 29/04/2013
Name: Tropical Low
Identifier: 18U
Data At: 0600 UTC
Latitude: 12.7S
Longitude: 152.8E
Location Accuracy: within 45 nm [85 km]
Movement Towards: west [278 deg]
Speed of Movement: 3 knots [6 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 1001 hPa
Radius of 34-knot winds NE quadrant:
Radius of 34-knot winds SE quadrant:
Radius of 34-knot winds SW quadrant:
Radius of 34-knot winds NW quadrant:
Radius of 48-knot winds NE quadrant:
Radius of 48-knot winds SE quadrant:
Radius of 48-knot winds SW quadrant:
Radius of 48-knot winds NW quadrant:
Radius of 64-knot winds:
Radius of Maximum Winds:
Dvorak Intensity Code: T2.0/2.5/D0.5/24HRS
Pressure of outermost isobar: 1006 hPa
Radius of outermost closed isobar: 120 nm [220 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
12: 29/1800: 12.7S 151.1E: 070 [130]: 035 [065]: 999
24: 30/0600: 12.8S 149.1E: 095 [175]: 040 [075]: 996
36: 30/1800: 12.4S 146.8E: 115 [210]: 045 [085]: 994
48: 01/0600: 11.8S 144.4E: 135 [245]: 045 [085]: 994
60: 01/1800: 10.6S 141.8E: 150 [280]: 030 [055]: 1003
72: 02/0600: 9.6S 139.0E: 170 [320]: 025 [045]: 1005
REMARKS:
Dvorak analysis based on a curved band pattern with 0.3 degree wrap on a log10
spiral, giving a DT of 2.0. MT and PT both suggest 2.0. FT based on MT.

The Tropical Low has developed in general over the last 24 hours while moving
over the warm sea surface of the northern Coral Sea in a low wind shear
environment. The Tropical Low is expected to continue to move within this
favourable environment for further development over the next 24 hours and it
should intensify into a tropical cyclone during Tuesday.

The Tropical Low has been moving slowly in a westwards direction over the last
12 hours and should continue to move in this direction during Tuesday under the
influence of a developing mid-level ridge across Queensland and the central
Coral Sea.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 29/1300 UTC by Brisbane
TCWC.
Member Since: Posts: Comments:
Good morning, everyone. Evening, Aussie. A pleasant 61 degrees here with a high of 82 expected later.

Breakfast's on the sideboard: scrambled eggs, bacon, toast, yogurt and fresh fruit and orange juice. Enjoy!
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Good morning to all,evening Aussie.

A big rain event is forecast to begin by Thursday and last thru next weekend bringing heavy showers and thunderstorms thru the PR/USVI and BVI area. Is early to say if this will spread to the Leewards. Stay tuned for more information as the days progress.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
552 AM AST MON APR 29 2013

.SYNOPSIS...AT MID AND UPPER LEVELS...A STRONG UPPER LEVEL JET
WILL MAINTAIN CLOSE PROXIMITY TO THE LOCAL AREA IN GENERALLY ZONAL
FLOW. HIGH PRESSURE DOMINATES THE CARIBBEAN AND THE TROPICAL
ATLANTIC.

AT LOWER LEVELS...HIGH PRESSURE NORTH OF THE AREA GRADUALLY
WEAKENS THROUGH THE END OF THE WEEK. A LOW PRESSURE FORMS
NORTHEAST OF FLORIDA TUESDAY AND MOVES NORTH OF PUERTO RICO AND
THE U.S. VIRGIN ISLANDS FRIDAY NIGHT. IT THEN MOVES NORTHEAST
PULLING A TROUGH BEHIND IT WHICH REMAINS IN THE LOCAL AREA THROUGH
AT LEAST MONDAY. MOISTURE INCREASES EACH DAY THROUGH LATE SUNDAY.

&&

.DISCUSSION...SHOWERS FORMED OVER THE ATLANTIC AND CARIBBEAN
WATERS. THOSE IN THE ATLANTIC MOVED INTO PUERTO RICOS COASTAL
REGIONS OVERNIGHT LEAVING AS MUCH AS ONE QUARTER TO SEVEN TENTHS OF
AN INCH ALONG THE WESTERN AND CENTRAL PORTIONS OF THE NORTH COAST.
ALTHOUGH NO RAIN WAS RECORDED AT EITHER OF THE MAIN AIRPORTS IN
THE U.S. VIRGIN ISLANDS...SHOWERS WERE SEEN IN THE SURROUNDING
WATERS SKIRTING THE ISLANDS. LOCAL SOUNDERS REVEALED BETWEEN 1.3
AND 1.6 INCHES OF PRECIPITABLE WATER.

WINDS AND STABILITY WILL BE SIMILAR TO YESTERDAY WITH MUCH THE
SAME RESULTS EXPECTED. IN FACT TUESDAY AND WEDNESDAY WILL ALSO
HAVE SIMILAR PATTERNS WITH EASTERLY SURFACE FLOW AND STRONG
CONVERGENCE INLAND AND FAVORABLE STABILITY PROFILES SUCH THAT
MODERATE TO STRONG THUNDERSTORMS WILL BE ABLE TO FORM IN THE
INTERIOR PORTIONS OF PUERTO RICO WITH A STRONG LIKELIHOOD. LOCAL
URBAN AND SMALL STREAM FLOODING ARE EXPECTED IN THE AREAS WITH THE
HEAVIEST RAIN.

AS THE WEEK PROGRESSES LOW PRESSURE APPROACHING THE ATLANTIC NORTH
OF THE AREA WILL DRAW UP MORE MOISTURE FROM THE ITCZ. A 120 KT JET
WHICH PASSES ABOUT 300 NM NORTH OF THE AREA WILL PRODUCE AREAS OF
GOOD DIVERGENCE OVER THE LOCAL AREA AND THE AMOUNT AND INTENSITY
OF SHOWERS AND THUNDERSTORMS WILL INCREASE OVER PUERTO RICO. AT
THIS SAME TIME LOW LEVEL WINDS WILL SHIFT TO THE SOUTH AND EVEN
THE SOUTH SOUTHWEST CAUSING THE AREAS OF MAXIMUM RAIN TO SHIFT
FROM THEIR USUAL AREAS IN THE WEST AND FOCUS MORE ON THE HIGHER
TERRAIN IN THE CENTER OF THE ISLAND AND THE NORTHERN COASTAL
PLAINS DURING THE AFTERNOONS. THE SOUTH COAST WILL ALSO SEE
SIGNIFICANT RAINS INCREASING FRIDAY AND OVER THE WEEKEND.

THE PLUME OF THE MOISTURE WILL SHIFT TO THE EAST AND BEGIN TO
AFFECT THE U.S. VIRGIN ISLANDS SATURDAY THROUGH MONDAY WHILE
CONTINUING TO YIELD GOOD MOISTURE OVER PUERTO RICO. CURRENT
INDICATIONS ARE THAT DRIER CONDITIONS DO NOT RETURN UNTIL MID-WEEK
NEXT WEEK.

THE LATEST RUNS OF BOTH THE UKMET AND THE ECMWF ARE IN GENERAL
AGREEMENT WITH THIS SCENARIO AS PRESENTED IN THE 29/00Z RUN OF THE GFS.
AFTERNOON CAPE WILL INCREASE FRIDAY AND SATURDAY. THE BULK
RICHARDSON NUMBERS WILL DROP TO BELOW 50 ON FRIDAY...SATURDAY...SUNDAY
AND MONDAY. BY FRIDAY MODEL SOUNDINGS BEGIN TO SHOW VERY GOOD
MOISTURE AND STRONG OMEGA VALUES. FURTHER THE JET WILL BE IN A
POSITION TO DEVELOP EXCELLENT DYNAMICS.

AT THIS TIME IT IS STILL TOO FAR OUT TO MAKE SPECIFIC PREDICTIONS
ALTHOUGH MODELS HAVE CONTINUED TO RUN WITH THIS SOLUTION FOR
SEVERAL DAYS. THEY HAVE ON SUCCESSIVE RUNS PUSHED THE WET EVENT
LATER IN TIME...BUT AT THE SAME TIME THEY HAVE INCREASED THE
INTENSITY OF THE DYNAMICS AND MOISTURE.

IMPACTS: SHOULD THE MODELS VERIFY THEIR SOLUTIONS...WOULD EXPECT
RAINFALL TO CREATE SERIOUS FLOODING AND MUDSLIDES OVER THE AREA
IN MANY AREAS...ESPECIALLY IN THE AREAS WHERE STRONG THUNDERSTORMS
FORM. MODELS ARE SHOWING SURFACE WINDS TO BE RELATIVELY LIGHT AND
GENERAL CONVECTION WILL THEREFORE MOVE LITTLE AND BE CONCENTRATED
OVER MOUNTAINOUS TERRAIN AND LEEWARD VALLEYS. THE U.S. VIRGIN
ISLANDS COULD RECEIVE SIGNIFICANT RAINFALL AS WELL AS THE PLUME
FORMS OVER THEM SATURDAY AND CONTINUES OVER THE GENERAL AREA THROUGH
MONDAY WITH EVEN BETTER DYNAMICS THAN APPEAR OVER PUERTO RICO.
RAINFALL OVER PUERTO RICO COULD EXCEED 12 TO 16 INCHES IN PLACES
FROM THURSDAY THROUGH MONDAY. RAINFALL IN THE U.S. VIRGIN ISLANDS
COULD APPROACH OR EXCEED 4 INCHES...OR MORE THAN WHAT HAS FALLEN
SO FAR FOR THE ENTIRE YEAR...IF MODELS CONTINUE TO HOLD THIS
SOLUTION.

ACTIONS: EMERGENCY MANAGERS SHOULD CONSIDER MAKING CONTINGENCY
PLANS FOR HEAVY RAINS THURSDAY THROUGH FRIDAY THAT SPREAD AND
CONTINUE OVER THE AREA THROUGH THE WEEKEND. GENERAL RESIDENTS
SHOULD ALSO REVIEW THEIR PROVISIONS FOR WET WEATHER AND REVIEW
THEIR ACTION PLANS FOR GENERAL AND FLASH FLOODING. LATER WHEN
CONDITIONS ARE MORE CERTAIN ACTUAL PREPARATIONS CAN THEN BEGIN.

&&

.AVIATION...
VFR CONDITIONS WILL CONTINUE TO PREVAIL AT ALL TAF SITES THROUGH
THE FORECAST PERIOD...WITH A FEW PASSING SHOWERS IN AND AROUND
TJSJ/TIST AND TISX DURING THE MORNING HOURS. AFT 29/16Z AND TIL
29/22Z...SHRA/ISOLD TSRA DEVELOPMENT WILL LEAD TO INCR CLOUDINESS
ACROSS THE CORDILLERA CENTRAL AND WEST SECTIONS OF PUERTO RICO.
THIS MAY RESULT IN BRIEF MVFR CONDS EN ROUTE BTW LCL TAF SITES
ESPECIALLY IN AND AROUND TJSJ...TJBQ...TJMZ AND TJPS.

&&

.MARINE...THE HIGH SURF ADVISORY CONTINUES FOR THE NORTH COAST OF
PUERTO RICO...CULEBRA...SAINT THOMAS...AND SAINT JOHN UNTIL 3 PM
AND RIP CURRENTS ARE EXPECTED TO BE WIDESPREAD...ESPECIALLY AS
SEAS BEGIN TO SUBSIDE LATER TODAY. SMALL CRAFT ADVISORIES AT THIS
TIME ARE EXPECTED TO COME DOWN AS EARLY AS TUESDAY AS SWELL
SUBSIDES. GENERALLY MORE INCLEMENT WEATHER BEGINS ON THURSDAY.
STRONGER WINDS MAY APPEAR EARLY NEXT WEEK AS HIGH PRESSURE IN THE
WESTERN ATLANTIC AT MID LATITUDES BUTTS UP AGAINST A CARIBBEAN
LOW.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 74 85 74 / 50 40 40 30
STT 84 74 86 76 / 20 30 30 30
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1244. LargoFl
Member Since: August 6, 2011 Posts: 4 Comments: 39301
1243. LargoFl
Member Since: August 6, 2011 Posts: 4 Comments: 39301
1242. LargoFl
THIS HAZARDOUS WEATHER OUTLOOK IS FOR WEST CENTRAL AND SOUTHWEST
FLORIDA.

.DAY ONE...TODAY AND TONIGHT.

...THUNDERSTORM IMPACT...
SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP TODAY...SOME OF
WHICH COULD BECOME STRONG THIS AFTERNOON INTO EARLY THIS EVENING.
THE MAIN HAZARDS FROM THE STRONGEST STORMS THAT DEVELOP WILL BE
DAMAGING STRAIGHT LINE WINDS...LARGE HAIL...FREQUENT LIGHTNING AND
HEAVY RAINFALL.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

...THUNDERSTORM IMPACT...
SCATTERED THUNDERSTORMS WILL BE POSSIBLE THROUGH THE END OF THE
WORK WEEK...WITH FREQUENT LIGHTNING AND GUSTY STRAIGHT LINE WINDS
BEING THE MAIN HAZARDS WITH THE STRONGEST STORMS THAT DEVELOP.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS SHOULD MONITOR THE WEATHER AND SELF ACTIVATE IF NEEDED.

$$

JELSEMA
Member Since: August 6, 2011 Posts: 4 Comments: 39301
1241. LargoFl
Good Morning Folks!..7-day Tampa Bay area.............
Member Since: August 6, 2011 Posts: 4 Comments: 39301
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1238. HadesGodWyvern (Mod)
Tropical Cyclone Warning Center Brisbane
Tropical Cyclone Advice #1
TROPICAL LOW 18U
5:05 PM EST April 29 2013
===========================================

At 4:00 PM EST a Tropical Low (1001 hpa) located at 12.7S 152.8E or 1030 km east of Lockhart River and 890 km east northeast of Cairns has 10 minute sustained winds of 30 knots with gusts of 45 knots. The tropical low is reported as moving west at 3 knots towards the coast.

Dvorak Intensity: T2.0/2.5/D0.5/24 HRS

The low is expected to develop into a tropical cyclone in the next 24 hours.

A deepening Tropical Low situated over the northern Coral Sea is moving slowly in a westwards direction and is expected to deepen further while continuing to move in westwards direction tonight.

STRONG GALES may develop about coastal areas between Thursday Island and Cooktown during Wednesday.

Areas of heavy rain, which may lead to flash flooding, are expected to develop across parts of far northern Queensland late Tuesday and during Wednesday as the deepening Tropical Low approaches the coast. People between Thursday Island and Cooktown should consider what action they will need to take if the cyclone threat increases.

Tropical Cyclone Watch
========================
A Cyclone WATCH has been declared for a developing tropical low for coastal areas from Thursday Island to Cooktown.

Forecast and Intensity
========================
12 HRS: 12.7S 151.1E - 35 knots (CAT 1/Tropical Cyclone)
24 HRS: 12.8S 149.1E - 40 knots (CAT 1/Tropical Cyclone)
48 HRS: 11.8S 144.4E - 45 knots (CAT 1/Tropical Cyclone)
72 HRS: 09.6S 139.0E - 25 knots (Tropical Low)

Additional Information
========================
Dvorak analysis based on a curved band pattern with 0.3 degree wrap on a log10 spiral, giving a DT of 2.0. MT and PT both suggest 2.0. FT based on MT.

The Tropical Low has developed in general over the last 24 hours while moving over the warm sea surface of the northern Coral Sea in a low wind shear environment. The Tropical Low is expected to continue to move within this favorable environment for further development over the next 24 hours and it should intensify into a tropical cyclone during Tuesday.

The Tropical Low has been moving slowly in a westwards direction over the last 12 hours and should continue to move in this direction during Tuesday under the influence of a developing mid-level ridge across Queensland and the central Coral Sea.
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Quoting Levi32:


African waves are the single greatest source of incipient disturbances that become tropical cyclones in the Atlantic. More robust waves always increases the chance of more TCs forming in the Atlantic relative to the environmental conditions in the Atlantic basin, which may be favorable or unfavorable.

If you mean the monsoon's affect on the environmental conditions in the Atlantic, then that could use further research, though I have noticed a tendency for the Indian and Atlantic basins to be coupled as the opposite convective signal to the Pacific, though that usually only happens when the ENSO is in a high amplitude state (Nino or Nina). If it's not, then perhaps things get more complicated than that.
Yes, that is what I was referring to. I'm aware of the significance of AEWs but if conditions are too hostile over the Atlantic basin then stronger waves over Africa doesn't mean much.

And interesting observations. Perhaps you could do further research on the topic one day as you continue with your meteorological career. For me, this blog is as far as my met career is going lol.
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Quoting Civicane49:
According to JTWC, 92P has winds of 30 knots.






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1235. Skyepony (Mod)
Fresh Cloudsat of the Low near Alaska.
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1234. Skyepony (Mod)
GEOS-5 wants to make it into a STD but than it gets sheared badly.
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According to JTWC, 92P has winds of 30 knots.
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Quoting KoritheMan:
The global models have become unenthusiastic regarding the potential for subtropical development off the southeast coast that was previously noted. This is the second day now, which totals up to between 4 and 8 separate runs depending on the model. Unless things change, Andrea must wait another day.

Ah well, it was fun while it lasted.


Tropical/subtropical development just never made any sense to me with the type of pattern that is forecast. Low pressure everywhere = difficult time consolidating one entity into a circulation robust enough to support tropical/subtropical cyclogenesis, especially when the lowest pressures are over land.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.