Northeast Weather Blog

Last Updated: 1:43 PM GMT on July 08, 2009 — Last Comment: 12:55 AM GMT on July 12, 2009

	Showers and storms continue

Posted by: sullivanweather, 1:41 PM GMT on July 08, 2009

**Updated with data to July 2nd**

Julian Day 178

------- Extent (km^2)----Difference (km^2)
2003 – 10,259,844……..……….-62,969
2004 – 10,179,531……..……….-46,719
2005 – 9,761,094……..……….-83,281
2006 – 9,526,719……..……….-58,281
2007 – 9,743,750………………-79,844
2008 – 9,992,344………..…….-62,061
2009 – 10,024,688………..…….-36,718

-------

Julian Day 179

------- Extent (km^2)----Difference (km^2)
2003 – 10,198,281……..……….-61,563
2004 – 10,155,156……..……….-24,375
2005 – 9,704,688……..……….-56,406
2006 – 9,435,625……..……….-91,094
2007 – 9,664,844………………-78,906
2008 – 9,949,844………..…….-42,500
2009 – 9,964,844………..…….-59,844

-------

Julian Day 180

------- Extent (km^2)----Difference (km^2)
2003 – 10,123,281……..……….-75,000
2004 – 10,138,125……..……….-17,031
2005 – 9,667,031……..……….-37,657
2006 – 9,366,563……..……….-69,062
2007 – 9,545,156………………-119,688
2008 – 9,870,781………..…….-79,063
2009 – 9,887,969………..…….-76,875

-------

Julian Day 181

------- Extent (km^2)----Difference (km^2)
2003 – 10,047,813……..……….-75,468
2004 – 10,102,656……..……….-35,469
2005 – 9,640,938……..……….-26,093
2006 – 9,314,063……..……….-52,500
2007 – 9,432,188………………-112,968
2008 – 9,783,438………..…….-87,343
2009 – 9,811,406………..…….-76,563

-------

Julian Day 182

------- Extent (km^2)----Difference (km^2)
2002 – 10,043,906……..……….-9999
2003 – 9,967,031……..……….-80,782
2004 – 10,092,969……..……….-9,687
2005 – 9,615,469……..……….-25,469
2006 – 9,238,594……..……….-75,469
2007 – 9,288,906………………-143,282
2008 – 9,722,656………..…….-60,782
2009 – 9,722,813………..…….-88,593

-------

Julian Day 183

------- Extent (km^2)----Difference (km^2)
2002 – 10,007,813.…..……….-36,093
2003 – 9,895,938……..……….-71,093
2004 – 10,060,625……..……….-32,344
2005 – 9,556,719……..……….-58,750
2006 – 9,159,063……..……….-79,531
2007 – 9,126,875………………-162,031
2008 – 9,645,000………..…….-77,656
2009 – 9,620,313………..…….-102,500

(*denotes extrapolated figure)

Sea-ice notes this week:

Weekly melt rate (6/21-28)

2009 – 56,429km^2
2008 – 62,411km^2
2007 – 79,129km^2
2006 – 87,969km^2
2005 – 68,951km^2
2004 – 56,518km^2
2003 – 57,679km^2

The melt rate for 2009 has slowed over the last week with an average rate of decline of 56,429km^2. This is likely due to the extensive cloud cover over the arctic in the western hemisphere. Near average to slightly below average temperatures is also aiding in this reduced melt rate, despite much of the ice edge consisting of first year ice.

-------

During the period of Julian Day 178-183 the year 2004 has an extremely slow melt rate relative to all years in the JAXA record. The 23,781km^2/day melt rate of 2004 during this period is 17,088km^2/day less than the runner-up 2005, which has a melt rate of 40,869km^2/day. Conversely, the year 2007 has a melt rate of 123,375km^2/day over the same period.

-------

Pics from the cryosphere

Fig.6 - Melt ponds forming on the Greenland ice cap as seen from space.

Fig.6a - Weakening shorefast ice along the Siberian coast.

Extent difference

Fig.7 - Difference in sea-ice extent between 2009 and recent years.

*Data retrieved from JAXA

___________________________________________________________

Current watches, warnings and advisories.

Fig.10 - Current watches, warning and advisories issued by the National Weather Service. Courtesy of NOAA.

--------

Forecast Discussion

Synopsis - Issued - 7/8 @9:30am

Yet another closed low descended upon the Northeast yesterday, touching off numerous rounds of showers and thunderstorms. Reports of hail were numerous and widespread with the most severe hail coming in a late-night supercell which tracked through the urban corridor of northern New Jersey and into Yonkers, New York where golf ball sized hail was reported. This intense cell also uprooted many trees and caused some minor structural damage to buildings. National weather service is being deployed to see if damage left in the wake of the storm is consistent with a tornado. Doppler radar indicated a vortex signature as this cell passed from Yonkers into New Rochelle. The severe weather wasn’t only limited to hail and high winds as Worcester, Massachusetts fell under a torrent. Three to five inches of rain fell in training thunderstorms over the city which left many roads flooded and some washed out.

This anomalous low, in any other year, has weakened markedly overnight and is beginning to fill and lift. Despite this weakening it will still serve as impetus for continued showers and thunderstorms today, albeit, not nearly as widespread or severe. High pressure builds in on Thursday and slowly translates offshore as heights build aloft. The end result will be a couple of mostly fair days and temperatures moderating back to near seasonal averages to close out the week. Another strong trough approaches this weekend and with a fairly warm and humid airmass in place, showers and thunderstorms seem like a good bet. The strong cold front plows offshore with a much cooler and drier Sunday behind it.

Near-term - Issued - 7/8 @9:35am

Satellite imagery this morning shows the upper level low pressure slowly pivoting southward into eastern Ontario with a large arc of cloud cover extending eastward away from the center, across northern New York and much of New England. Under this cloud canopy it’s damp and dreary with temperatures only in the 50’s. The greatest concentration of precipitation is over New Hampshire and Maine where several pockets of steadier, heavier showers will deposit a quarter to a half inch of rain this morning. Other lake-enhanced (believe it, or not) showers and thundershowers are moving off the southern shores of Lake Ontario into the Mohawk Valley of New York as the relatively warm lake waters are providing localized instability in this quite cool airmass. Meanwhile, much of Pennsylvania, New Jersey and southern New York are currently enjoying mostly sunny skies with patchy valley fog. Temperatures here are in the 60’s, heading into the 70’s by mid/late morning.

Short-term - Issued - 7/8 @9:35am

The showers over northern New England will continue throughout the afternoon, though they will weaken as the day progresses as the trough responsible for them becomes more diffuse. Further to the west, under the core of the cold pool aloft, showers and thunderstorms will develop as the strong July sun heats the boundary layer creating instability (CAPE values expected to be in the 400-800J/kg range). The lack of a well-defined surface feature will mean that storms will likely fire off boundaries leftover from yesterday’s convection or the terrain. A weak shortwave is also forecast to rotate through this afternoon, adding a bit of lift. However, much of the moisture has been shunted offshore, ahead of the more significant trough passage yesterday. This will lead to more scattered to isolated coverage of the precipitation. With little shear to maintain convection the storms that do develop will likely be of the pulse variety. Wet bulb zero heights are April-like, between 6-8,000asl region wide, so small hail will be present in many of the storms today and a couple large hail reports in the stronger updrafts is not out of the realm. The highest concentration of these convective showers that do develop will be across central/eastern New York and southern New England. The further south and west one heads the less the chances are for running into precipitation. In fact, much of the western two thirds of Pennsylvania will have little, if any, precipitation to speak of with mostly sunny skies under fair-weather cumulus clouds. Temperatures here will rise into the 70’s to around 80°F. Temperatures will also climb into the 70’s along the coastal plain and interior valleys. However, higher terrain and much of northern New York and New England, where clouds will be socked in, highs today should only climb into the 60’s.

Showers will continue to wane this evening as diurnal activity weakens from the loss of insolation and the upper trough shears out. Still plenty of moisture hanging around within the lingering trough axis tonight so skies will be mostly cloudy for a good chunk of real estate from eastern New York into central and southern New England. A few lingering light showers and sprinkles may dot the landscape with mist and locally dense fog developing overnight. Elsewhere across the region skies will be mostly clear as high pressure building down from Canada begins to assert itself. Under the developing subsidence inversion some locally dense fog may form in the river valleys and low lying areas, especially given how wet the ground is. Another cool July night is in store temperature-wise. Many locations will see several hours of clear skies and light winds in this rather dry airmass, allowing for optimized radiational cooling. Lows across the interior should range from the mid 40’s to low 50’s, slightly warmer under the cloud covered areas. Along the coastal plain lows will range from the upper 50’s to mid 60’s.

Mid/long-term - coming later

___________________________________________________________

Radar: Northeast Region Loop

NE radar

Fig.11 - Radar loop of the Northeast region. Courtesy of Weather Underground.

___________________________________________________________

Local SST's

Fig.12 Sea-surface temperatures off the Northeast Coast. Courtesy of NOAA.

___________________________________________________________

All hits.

.

Unique hits.

My weather dragon!

View Comments (40)

Updated: 1:43 PM GMT on July 08, 2009

Permalink | A A A

	Arctic sea-ice update

Posted by: sullivanweather, 12:48 PM GMT on July 01, 2009

**Updated with data to July 2nd**Julian Day 178 ------- Extent (km^2)----Difference (km^2)2003 – 10,259,844……..……….-62,9692004 – 10,179,531……..……….-46,7192005 – 9,761,094……..……….-83,2812006 – 9,526,719……..……….-58,2812007 – 9,743,750………………-79,8442008 – 9,992,344………..…….-62,0612009 – 10,024,688………..…….-36,718-------Julian Day 179 ------- Extent (km^2)----Difference (km^2)2003 – 10,...

Summer afternoon along the Delaware

View Comments (91)

Updated: 11:40 PM GMT on July 03, 2009

Permalink | A A A

	Strong to severe storms today/Arctic sea-ice watch

Posted by: sullivanweather, 6:04 AM GMT on June 30, 2009

**Updated with data to June 28th**Julian Day 169 ------- Extent (km^2)----Difference (km^2)2003 – 10,809,844……..……….-78,7502004 – 10,685,156……..……….-67,1882005 – 10,362,188……..……….-66,8752006 – 10,228,438……..……….-57,0312007 – 10,450,469………………-72,0312008 – 10,542,500………..…….-70,4692009 – 10,603,125………..…….-68,594-------Julian Day 170 ------- Extent (km^2)----Difference (km^2)2003 �...

View Comments (8)

Updated: 12:32 PM GMT on June 30, 2009

Permalink | A A A

	Severe weather likely today

Posted by: sullivanweather, 3:35 PM GMT on June 26, 2009

Fig.2 - USDA plant hardiness zone map of the eastern United States circa 1990. Credit: USDAGarden SeriesBlog 1: Planning the GardenBlog 2: Cool season cropsBlog 3: Companion PlantingBlog 4: Container GardeningBlog 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...