Showers/storms south, pleasant north

By: sullivanweather , 9:06 AM GMT on May 31, 2009

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Fig.2 - USDA plant hardiness zone map of the eastern United States circa 1990. Credit: USDA

Garden Series

Blog 1: Planning the Garden

Blog 2: Cool season crops

Blog 3: Companion Planting

Blog 4: Container Gardening

Blog 5: Warm Season Crops(1)


Soil Conditions

**Please note**
These soil condition charts are self-updating and occasionally display corrupted data (more often than not lately).

Soil moisture and anomalies 0-200cm
Soil moisture 0-200cm
Fig.3 - Weekly averaged soil moisture and anomalies 0-200cm. Credit: NOAA

Soil temperature 0-10cm
Soil temperature 0-10cm
Fig.4 - 6-hourly updated 0-10cm soil temperature. Credit: NOAA

Soil temperature and anomalies 10-40cm
Soil temperature 10-40cm
Fig.5 - Weekly updated 10-40cm soil temperature and anomalies. Credit: NOAA

Kelvin temperature scale
273.15°K = 0°C


**Updated with data to May 31st**

Julian Day 145

------- Extent (km^2)----Difference (km^2)
2003 – 11,873,594……..……….-36,094
2004 – 11,375,313……..……….-1,406
2005 – 11,652,031……..……….-51,875
2006 – 11,270,781……..……….-53,750
2007 – 11,500,781………………-70,938
2008 – 11,674,375………..…….-22,813
2009 – 11,739,063………..…….-99,218


Julian Day 146

------- Extent (km^2)----Difference (km^2)
2003 – 11,799,688……..……….-73,906
2004 – 11,355,313……..……….-20,000
2005 – 11,583,906……..……….-68,125
2006 – 11,216,094……..……….-54,687
2007 – 11,438,125………………-62,656
2008 – 11,625,938………..…….-48,437
2009 – 11,669,531………..…….-69,532


Julian Day 147

------- Extent (km^2)----Difference (km^2)
2003 – 11,720,313……..……….-79,375
2004 – 11,351,875……..……….-3,438
2005 – 11,519,844……..……….-64,062
2006 – 11,179,531……..……….-36,563
2007 – 11,401,563………………-36,562
2008 – 11,586,250………..…….-39,688
2009 – 11,624,375………..…….-45,156


Julian Day 148

------- Extent (km^2)----Difference (km^2)
2003 – 11,689,844……..……….-30,469
2004 – 11,364,688……..……….+12,813
2005 – 11,455,000……..……….-64,844
2006 – 11,145,156……..……….-34,375
2007 – 11,398,906………………-2,657
2008 – 11,534,531………..…….-51,719
2009 – 11,586,719………..…….-37,656


Julian Day 149

------- Extent (km^2)----Difference (km^2)
2003 – 11,646,250……..……….-43,594
2004 – 11,362,500……..……….-2,188
2005 – 11,389,375……..……….-65,625
2006 – 11,104,531……..……….-40,625
2007 – 11,368,750………………-30,156
2008 – 11,497,031………..…….-37,500
2009 – 11,552,656………..…….-34,063


Julian Day 150

------- Extent (km^2)----Difference (km^2)
2003 – 11,611,719……..……….-34,531
2004 – 11,340,625……..……….-21,875
2005 – 11,340,156……..……….-49,219
2006 – 11,058,594……..……….-45,937
2007 – 11,307,188………………-61,562
2008 – 11,490,156………..…….-6,875
2009 – 11,478,125………..…….-74,531


Julian Day 151

------- Extent (km^2)----Difference (km^2)
2003 – 11,578,438……..……….-33,281
2004 – 11,325,313……..……….-15,312
2005 – 11,270,156……..……….-70,000
2006 – 11,009,375……..……….-49,219
2007 – 11,258,594………………-48,594
2008 – 11,448,750………..…….-41,406
2009 – 11,398,125………..…….-80,000


Sea-ice notes this week:

·As expected, 2009 slipped into 2nd on the JAXA AMSR-E time series on May 23rd. 2003 is now the highest daily extent over the last 7 years, 71,407km^2 higher than 2009, for Julian Day 144.

·With continuous 24 daylight now over much of the arctic snowcover on the ice will melt into ponds, supported by the ice below. These melt ponds are sometimes mistakenly processed as open water on the current processing algorithm. On June 1st, in recent years, the JAXA AMSR-E data shows a jump in sea-ice extent on/around this date. This is due to a change in the processing algorithm to account for these melt ponds as ice covered.

·Over the last 9 days the average decline in extent has been 67,014km^2. This is a highest rate of decline for the same 9 days in any of the last 7 years and far exceeds the runner-up, 2008, which saw an average rate of decline of 60,503km^2 over the period.

·Ice-melt through the end of May should be strong in Baffin Bay and especially so along the Labrador Coast, where much of the ice left will be eroded by the 30th and 31st as warm air and moist southeasterly winds move into this region. Sea-ice melt will be less than average over the Barents Sea and the Bering/Chukchi Seas as cold air moves down from the high arctic due to a developing low pressure over mainland Alaska. Meanwhile, the consolidated area of ice Sea of Okhotsk will begin to fracture and break up. There may also be increasing fracturing of ice in the Kara Sea as warmer temperatures spread over this region during the next 3 days.

Extent difference

Fig.6 - Difference in sea-ice extent between 2009 and recent years.

Melt Rate

Fig.7 - 2009(blue) daily melt rate of Arctic sea-ice compared to 2008(red).


Fig.8 - 2009(blue) daily melt rate of Arctic sea-ice compared to 2007(magenta).

*Data retrieved from JAXA


Current watches, warnings and advisories.

Eastern US current watches/warnings
Fig.9 - Current watches, warning and advisories issued by the National Weather Service. Courtesy of NOAA.


Forecast Discussion

Synopsis - Issued - 5/31 @5:10am

A vigorous shortwave trough will rocket through the Northeast today setting off showers and thunderstorms, some of which may be severe. An anomalously cold airmass will blast into the region following the passage of the trough with widespread frost and freezing conditions expected over much of upstate New York and western New England. The airmass moderates considerably by Monday as the flow shifts from the west in advance of an approaching trough. This will be the first of several shortwave disturbances to move along an increasingly baroclinic environment from the Mid-Mississippi Valley region, through the Ohio Valley to southern New England. By weeks’ end the Hudson Bay low responsible to the recent string of cold air outbreaks will once again flex its muscles as troughing digs into the Upper Midwest and heads east. Southward shifted and anomalously strong jet stream over the Great Lakes and Northeast could lead to a significant severe weather outbreak next weekend.

Short-term - Issued - 5/31 @5:10am

Showers, some with a rumble or two of thunder, are traversing western and central New York out ahead of an approaching trough of low pressure. These should persist during the overnight hours and continue pushing east into the northern Catskills and Mohawk Valley by daybreak. The remainder of the region is precipitation free with mainly clear skies over much of New England. High cloudiness extends over much of central and eastern Pennsylvania as a shield of cirrus spreads north and east from MCS activity entering western Virginia. Across northern New York and Vermont mid/high levels clouds will increase towards daybreak in advance of the trough. Temperatures will begin the day in the 40’s across much of interior New York and New England with 50’s across Pennsylvania and the coastal plain.

The last weekend of May will close with quite an active day of weather for the Northeast. An anomalously strong mid/upper level low will race through northern New York and New England today. In fact, this afternoon the lowest 500mb heights in North America will be located just along the US/Canadian border of only some 528dm! Intense vorticity advection in addition to the rapid movement of the shortwave will provide strong forcing out ahead of this system to support the development of several lines of showers and thunderstorms. A dynamically favorable upper atmosphere will also be present, with a coupled jet structure in place during the afternoon hours, each with 100kt+ jet streaks. On the downside, the atmosphere isn’t particularly moist with surface dewpoints in the upper 40s to low 50’s and precipitable water values barely cracking three-quarters of an inch in the ribbon of moisture preceding the front. However, given the cold, dry airmass that will be moving into the region, the current moisture present should be more than sufficient. Once storms get going they may quickly become severe. 850mb winds will be in the 30-35kt range with 500mb winds in the 60-65kt range, yielding 30-40kts of effective shear. This should organize storms into bowing line segments capable of damaging winds. In addition to the high wind threat, freezing levels will be quite low, in the 6-7,000asl range as convection moves through across the north and 8-9,000asl across the south. Hail over 1” in diameter may occur in a few of the stronger cells. The highest concentration of storms will be across central and northern New England with more cellular and isolated activity south of the NY/PA border and across southern New England where the atmosphere will be drier, displaced to the south of the core of the disturbance. The airmass behind the cold front, as mentioned, will be anomalously cold. 850mb temps fall to -3°C to -6°C by evening across northern New York and Vermont with snow levels dropping to ~2,500’! Any leftover precipitation across the higher terrain may coat the summits with a light accumulation of snow. Something to look out for if you live surrounding Mt.Marcy or Mt.Mansfield on the first morning of meteorological summer! There will be a wide range of temperatures across the region today. Across the southern tier of Pennsylvania and the coastal plain temperatures should easily make it into the 70’s under bright sunshine for much of the day. As one heads further inland, closer to the core of colder air, the temperatures will drop off dramatically. 60’s will do for the northern tier of Pennsylvania, interior southern New York and interior New England. Further northwest into upstate New York and Vermont temperatures will likely remain stuck in the 50’s and may actually fall after noon into the 40’s and even 30’s in the higher terrain as strong cold air advections ensues. It will also be quite blustery behind the front as good momentum transfer of winds in the boundary layer to the surface will result in 20-30mph winds with higher gusts, especially across elevated terrain above 2,000’.

The cold front blasts offshore tonight with northwesterly winds delivering much colder and drier air to the Northeast. Showers and a few storms may begin the period over Maine but these will quickly be swept offshore by the front. Orographic lift in cyclonic flow may yield a few rain showers or even some snow showers across the higher terrain of northern Vermont and New Hampshire during the first half of the overnight before the atmosphere become too dry to support precipitation. Weak high pressure will slide across Pennsylvania during the overnight allowing winds to become light under the clear skies and dry atmosphere. These ideal radiational cooling conditions will lead to the development of frost across northern Pennsylvania, much of upstate New York and western New England. The normally colder locations across sheltered valleys where cold air drainage is maximized, temperatures will even dip below freezing for a couple hours just before daybreak. The growing season is many weeks old across the region and the late nature of the upcoming frosty weather may have consequences for the agriculture industry and home gardeners. Low temperatures in the above mentioned areas will fall into the upper 20’s to mid 30’s. The presence of winds across the remainder of New England will inhibit any frost development but it will be quite brisk and wind chills, yes wind chills, will likely fall into the 20’s and 30’s as lows dip into the mid 30’s to mid 40’s from north to south. Along the coastal plain and across the southern tier of Pennsylvania, the airmass will be considerably warmer, but still below normal for the first morning of June. Lows will bottom out in the mid 40’s to low 50’s, warmest in the urban centers and along the immediate coast.

A sunny start to the morning across much of the region will quickly give way to advancing mid/high level cloudiness as another rapidly moving shortwave heads into the Great Lakes region. Temperatures will quickly recover from their chilly, some cases, frosty, start but as clouds move in that rise will be capped, especially across upstate New York where clouds are expected to be the thickest. Further south and east, the cloud cover will be less extensive and the moderating airmass will actually make for a stunning day, with low humidity levels and temperatures in the mid 60’s to lower 70’s. Under the cloud canopy temperatures will only rise into the 50’s and 60’s.

Precipitation from the weakening shortwave moving into the region from the Great Lakes will begin Monday night, mainly across the northwestern portions of the region, around the lake shores of Erie and Ontario. Will need to keep an eye on any MCS development in the warm sector south of the front that may sneak into western Pennsylvania, but these chances are rather low. Elsewhere across the region skies will be partly to mostly cloudy helping to keep temperatures mild during the overnight, in some cases, up to 30 degrees higher than the night previous. Lows will range from the 40’s over northern New York and New England to the 50’s across much of the remainder of the region. The urban centers and along the coast temperatures may even hold in the low 60’s.

Mid-term - Issued - 5/31 @5:10am

The building of heights over the Southeast due to the western extension of the Bermuda High combined with the unrelenting Hudson Bay low spinning in place over eastern Canada will yield a strengthening west-east flow over the eastern half of the United States along with a steepening baroclinic environment during the midweek period. A couple of shortwaves will move along this west-east boundary spawning showers and thunderstorms. Though difficult to time at this juncture, the best chances for precipitation appear to be Tuesday night and Wednesday late afternoon into the overnight. Temperatures are expected to be below normal across the north with near to slightly above normal temperatures across the south.

Long-term - Issued - 5/31 @5:10am

The midweek pattern quickly breaks down as the Bermuda high pulls back east and a trough sharpens across the center of the country. Another rather potent shortwave is expected to rotate down from northern Canada and become incorporated into the westerlies, forming low pressure over the Northern Plains Thursday, moving to the Great Lakes by Friday. This buckling of the jet stream will allow warm moist air to flow north from the Gulf, eventually making it into the Northeast leading to a warm and humid Friday with the chance for scattered diurnal convection. The cold front associated with the low looks to come through the Northeast on Saturday. With the warm, moist airmass in place out ahead of the front and stronger winds aloft it would not be surprising to see a widespread severe weather outbreak. This situation will be monitored throughout the week as we draw closer to the potential event.

Deep trough settles over the eastern half of the nation behind the cold front for the second half of next weekend. Temperatures will once again dip well below normal as the 850mb 0°C isotherm may once again make a visit into the Northeast. This cool weather may persist into the beginning of the following week.


Radar: Northeast Region Loop

NE radar
Fig.10 - Radar loop of the Northeast region. Courtesy of Weather Underground.


Local SST's

Northeast SST's
Fig.11 Sea-surface temperatures off the Northeast Coast. Courtesy of NOAA.


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17. charlesimages
1:16 AM GMT on June 02, 2009
Quoting sullivanweather:

Hey Chuck!!

How's it going, bro?
It's going really boring outside of that move.. Just waiting extremely impatiently for storms.
Member Since: May 25, 2006 Posts: 347 Comments: 29278
16. TheDawnAwakening
1:10 AM GMT on June 02, 2009
Hi Listener, how is it going?
Member Since: October 21, 2008 Posts: 246 Comments: 3970
15. listenerVT
7:19 PM GMT on June 01, 2009
Hey all! ♥

How has everyone been?

We had hail last evening here...only about half the size of a pea, but surprising nonetheless.

We are home from Maine.
Our son and his family have officially moved from NC to ME!
Yayy! All our kids and grandkids live in New England again! :~D

I'm sitting here with bronchitis, though.
Member Since: July 11, 2007 Posts: 0 Comments: 5525
14. TheDawnAwakening
2:32 AM GMT on June 01, 2009
Nothing much, I just want to get a great video of a storm this summer. That would be great. Dew point already dropped to 43F, from an early high of 59F today.
Member Since: October 21, 2008 Posts: 246 Comments: 3970
13. bigtrucker
2:19 AM GMT on June 01, 2009
Sully, today was under control of building high pressure, which means sinking air. Temps in the low 70's. Dew point around 51. Cold front well to the east. Question is how did we recieve a thunderstorm,albiet small, with sinking air above conditions?
I am puzzled by this and just goes to show how much weather is puzzling.

A chance of storms was in the forecast, but I had said no way. LOL
Member Since: January 9, 2006 Posts: 80 Comments: 6119
12. TampaFLUSA
1:33 AM GMT on June 01, 2009
Mt Washington
Member Since: June 21, 2007 Posts: 10 Comments: 1657
11. sullivanweather
11:07 PM GMT on May 31, 2009
Hey Dean!

I'm doing pretty good, you?

Not looking forward to another frost tonight, that's for sure.
Member Since: March 8, 2007 Posts: 273 Comments: 12612
10. sullivanweather
11:06 PM GMT on May 31, 2009
Saranac Lake, Adirondack Regional Airport
Lat: 44.39 Lon: -74.2 Elev: 1706
Last Update on May 31, 6:51 pm EDT

Heavy Snow Fog

33 F
(1 C)
Humidity: 96 %
Wind Speed: W 8 MPH
Barometer: 29.86" (1012.0 mb)
Dewpoint: 32 F (0 C)
Wind Chill: 26 F (-3 C)
Visibility: 0.25 mi.
Member Since: March 8, 2007 Posts: 273 Comments: 12612
9. TheDawnAwakening
10:51 PM GMT on May 31, 2009
Hi Sully, how are you doing?
Member Since: October 21, 2008 Posts: 246 Comments: 3970
8. sullivanweather
8:39 PM GMT on May 31, 2009
Quoting charlesimages:
Nice to see you online Sully =)

Hey Chuck!!

How's it going, bro?
Member Since: March 8, 2007 Posts: 273 Comments: 12612
7. sullivanweather
8:38 PM GMT on May 31, 2009
Quoting cyclonebuster:
Hows your garden Sully?

Haven't been able to install one with my new apartment. I think, however, after this frost I'll start some containers.
Member Since: March 8, 2007 Posts: 273 Comments: 12612
6. charlesimages
8:17 PM GMT on May 31, 2009
Nice to see you online Sully =)
Member Since: May 25, 2006 Posts: 347 Comments: 29278
5. TampaFLUSA
8:11 PM GMT on May 31, 2009
Quoting sullivanweather:
Saranac Lake, Adirondack Regional Airport
Lat: 44.39 Lon: -74.2 Elev: 1706
Last Update on May 31, 3:51 pm EDT

Light Snow Fog/Mist

34 °F
(1 °C)
Humidity: 92 %
Wind Speed: W 10 G 35 MPH
Barometer: 29.77" (1009.0 mb)
Dewpoint: 32 °F (0 °C)
Wind Chill: 26 °F (-3 °C)
Visibility: 1.00 mi.

Wow! makes me miss upstate...wish I could have the best of both worlds...The next cold front here is on tap for late October...
Member Since: June 21, 2007 Posts: 10 Comments: 1657
4. cyclonebuster
8:06 PM GMT on May 31, 2009
Did you plant this year?
Member Since: January 2, 2006 Posts: 127 Comments: 20415
3. cyclonebuster
8:03 PM GMT on May 31, 2009
Hows your garden Sully?
Member Since: January 2, 2006 Posts: 127 Comments: 20415
2. sullivanweather
8:01 PM GMT on May 31, 2009
Saranac Lake, Adirondack Regional Airport
Lat: 44.39 Lon: -74.2 Elev: 1706
Last Update on May 31, 3:51 pm EDT

Light Snow Fog/Mist

34 °F
(1 °C)
Humidity: 92 %
Wind Speed: W 10 G 35 MPH
Barometer: 29.77" (1009.0 mb)
Dewpoint: 32 °F (0 °C)
Wind Chill: 26 °F (-3 °C)
Visibility: 1.00 mi.
Member Since: March 8, 2007 Posts: 273 Comments: 12612
1. TheDawnAwakening
1:16 PM GMT on May 31, 2009
Once again Sully, a great write up. Thanks for the update. yesterday I was thinking I was the only one who thought we could have severe weather today.
Member Since: October 21, 2008 Posts: 246 Comments: 3970

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About sullivanweather

Thomas is an avid weather enthusiast, landscaper and organic gardener. This blog is dedicated to Northeast and tropical weather forecasting. Enjoy!

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