MATTNOYES.NET - Weather Website & Blog

HURRICANE BERTHA SETTING RECORD FOR LONGEST-LIVED JULY TROPICAL CYCLONE IN ATLANTIC BASIN

(Photo courtesy NOAA) Hurricane Bertha continues to spin over the Central North Atlantic.  Although she has begun a trend that will eventually lead her to become a non-tropical system, and therefore be pronounced dead by the National Hurricane Center, every moment she's alive and well adds to her history-making feat.  Bertha may not be remembered for her intensity - reaching hurricane strength but bringing only tropical storm force winds to Bermuda and her center never making landfall, but she will be remembered in the meteorological community for her duration.  Bertha continues to churn as the longest-lived July tropical cyclone on record in the Atlantic Basin.  This article from MSNBC examines Bertha's feat.

DELIGHTFUL STRETCH OF WEATHER LEADS NEW ENGLAND INTO THE WEEKEND...INCREASING TROPICAL MOISTURE UP THE EASTERN SEABOARD BY LATE SUNDAY/MONDAY

A reminder to check out the Meteorology Memos and More Page for some fun new posts lately.

The next several days will bring relatively quiet weather to most of New England, and though this brings a much deserved break in the action, the longwave pattern of a Northeast U.S. trough will continue for the foreseeable future, to the end of July.

In the short term, the departure of Thursday night's cold front has meant a rapid infusion of dry air to all levels of the New England atmosphere.  The lower relative humidity air came rushing in aloft around dawn, clearing clouds quickly from west to east as the storm center strengthening to our northeast and the bubble high pressure center over the Ohio Valley teamed to increase the pressure gradient and corresponding westerly flow at 10-20 mph.  Winds verified a bit lighter than I'd thought they would yesterday, with mixing to 900 mb but only about 20 knots at the top of the boundary layer available to mix down.  Dewpoints dropped steadily through the morning but should level off this afternoon before decoupling occurs in sheltered valleys this evening, allowing min temps in the 40s in cooler spots, 50s elsewhere, and a dry 60s in cities that hold the heat, like Boston and Providence.

For most, Friday is straight-forward: a quick temperature rebound as sunshine quickly modifies cool, dry air.  Mixing slightly exceeds 900 mb in models progs, which would yield middle or even upper 80s, but I've gone a bit cooler than this given the proximity of the surface high and light wind, implying mixing may not be as deep as it's advertised by the computers.  Nonetheless, mid 80s is supported for most spots, cooler in the higher terrain with a steep low level lapse rate lingering.  It's this same lapse rate that becomes a forecasting challenge on Friday, as the cold pool aloft keeps mid level lapse rates rather steep as well.  This actually lowers lifted indices to -2 all the way into Worcester County, MA, by late afternoon and evening, at the same time a shortwave swings through aloft.  This shortwave is moderate in strength and with the steep lapse rates, it won't take a very high convective top to get showers.  A thunderstorm may be a bit more difficult with active ice nuclei at about 450 mb, but where orographic lift assists, low-topped thunder is certainly possible.  Large dewpoint depression (temp/dewpoint spread) indicates some hailstones are a possibility in the North Country.  The toughest call is storm coverage, and with so much dry air around, I have to believe the most likely spot for scattered thunder will be where dynamic lift is greatest, which will be in the path of the vorticity maximum.  The NMM indicates that'll be across Southern New England, while the GFS is farther north, which is the solution I favor given the fast and relatively flat flow, not to mention the surface high moving just south of the South Coast during the day, holding dry low level air in place.  For these reasons, I've held the chance of scattered showers and possible thunder to the North Country.

Thereafter, I expect Saturday to be dry regionwide with a gradual moderation in temperature, and upstream temps supporting middle to upper 80s Saturday and Sunday, with dewpoints creeping back up Sunday.  Disagreement among the guidance comes later Sunday and Monday with regard to thunderstorm threat, based largely upon when the feed of southern stream moisture sets up.  At this point, the undeniable trend has been slower among the guidance.  That said, the upper level flow is southwesterly while the low level flow becomes more southerly through 850 mb, tapping tropical moisture directly from Cuba, and with a mid to lower level shortwave embedded in the flow later Sunday, blossoming tropical showers/thunder are possible later Sunday.  We're right on the cusp of a major rain event Sunday night and Monday, and this will largely depend upon how the tropical low level jet and the incoming cold front out of Ontario interact...likely to breed a band of thunderstorms and heavy rain from New York into Northern and Western New England heading into Monday.  Timing on this remains tricky, but again, the trend is to keep the two features separate on Sunday - a northern stream cold front over NY and blossoms of showers in the southern stream that may move over parts of Southern new England late Sunday, with a greater interaction Monday.

This interaction doesn't last too long, with midweek high pressure settling in and anomalously cool air through the middle of the week.  Thereafter, the Northeast US trough dominates, but flexes over the next couple of weeks, allowing continued shots of deep summer warmth, as we've been seeing.

No discussion slated for tomorrow...enjoy the wonderful weekend!
Matt

QUAKES MORE PREDICTABLE THANKS TO RESEARCH

This report was filed by ABC News, and posted by NECN.com.  It appears some progress is being made toward earthquake prediction.

METEOROLOGY MEMOS AND MORE PAGE UPDATED...

Just a brief post to remind you that the Meteorology Memos and More Page is always being updated - a special reminder today because there's some fun posts I think you'll enjoy on there!

Today's weather discussion to follow on this page later today...

-Matt

CONAN O'BRIEN CHIMES IN ON WEATHER CHANNEL SALE

Yesterday, I posted about the sale of The Weather Channel to NBC and a pair of private equity groups.  Conan O'Brien had something to say about the network that broadcasts his show deciding to purchase the all-weather network.  This will keep you laughing!!

NOAA: REPORT STATES HALF OF U.S. CORAL REEFS IN "POOR" OR "FAIR" CONDITION

Nearly half of U.S. coral reef ecosystems are considered to be in "poor" or "fair" condition according to a new NOAA analysis of the health of coral reefs under U.S. jurisdiction.

LANDMARK SELLS THE WEATHER CHANNEL, WSI TO NBC AND EQUITY FIRMS

The Weather Channel and Weather Services International (WSI) have been sold for a cool 3.5 BILLION dollars to NBC, Bain Capital and the Blackstone Group - two private equity firms.  Of course, The Weather Channel is well known as a 24-hour cable network for weather, along with their website, while WSI operates Intellicast.com and also develops television graphics software for private businesses, including television stations like NECN.  What does this mean for the Weather Channel?  How will it interact with NBC's own weather network, WeatherPlus?  This New York Times article lays out the answers to most of these questions, save for the final one.

HANSEN: PUT OIL CEOS ON TRIAL FOR CRIMES AGAINST HUMANITY

The "hot" topic of climate change hasn't cooled down any for James Hansen.  A NASA scientist who heads the Goddard Institute for Space Studies in New York, Hansen was the first to raise alarm over global warming and the call for immediate, radical steps to avoid climate change at the hands of man.  Though sound scientific research has been done illustrating both sides of such an argument, Hansen's latest recommendation is to put oil firm chief executives on trial for high crimes against humanity.  With regard to an issue once scientific, and now borderline religious in its scope, this is a tremendous statement for a scientist to make.  For years, scientific theories of all sorts and focused upon many subjects have been thought to be infallible, only to be rendered incorrect years, decades, or more, later, when nature proves we understand less than we think we do.  To try these individuals for crimes against humanity would fly in the face of scientific reasoning, and conjures up memories of the Salem Witch Trials.  Nonetheless, you can read the article highlighting this idea from the Guardian in Britain by clicking here.

SCATTERED TUESDAY STORMS...WEDNESDAY STORMS TO BE STRONGER...WEEK ENDS ON A FINE NOTE

Scattered convection is firing this afternoon with warm and humid airmass providing plenty of surface based instability.  What's lacking is a focused trigger mechanism, with a weak vorticity maximum drifting overhead.  An upper level cool pool migrating over Central/Southern New England was the focus for scattered convection in NY/PA yesterday, and today is aiding convective processes in New England.  Terrain is also aiding in upward vertical motion, as evidenced in the Green Mountains.  Weather enthusiasts have seen quite a severe weather season already, and with the Northeast U.S. jet stream trough expected to continue into the end of July, we should continue to find repeated thunderstorm days, though a bit of a break is in sight by the end of this week.

For now, the greatest concerns associated with Tuesday afternoon convection will be heavy rain and lightning, though most spots won't see these features.  A wet microburst isn't impossible but also isn't all that likely within the storms given the relatively weak wind field aloft, and part of the reason I'm not real jazzed up about storm potential for growth - aside from the weak wind field - is the presence of very dry air in the mid and upper levels.  This dry air is evident on water vapor imagery and was well progged by the guidance.  Of course, where the cap can be broken a storm could strengthen and tap that very same dry air for a downburst, but I actually think it's so overwhelming that it will instead hold pulsing convective storms to a threshold of development that will keep them from becoming much more than downpours scattered across New England, though limited coverage in Maine where not so much surface based instability is available.

Wednesday brings the approach of the active cold front from the Great Lakes and Southern Canada, but the entirety of the day will be spend warm sectored.  The southwest gradient flow strengthens ahead of the front with surface gusts to 35 mph possible, but the loading of dewpoints around 70 with temps rising to around or perhaps just over 90 will mean surface based CAPE values near or greater than 2000 J/kg in much of Southern and Central New England northeast through Maine.  Very little indication of cloud pollution, so hearty insolation should be attainable.  Mid-level lapse rates leave something to be desired, but LIs still creep down to -2 to -5 Wednesday afternoon.  Perhaps the most precarious of locations in New England is late Wednesday afternoon to Wednesday evening in Central Maine, where backing winds ahead of a strengthening surface wave of low pressure moving just south of the Canadian border will increase low level helicity values dramatically.  Farther south, helicity values are less impressive but still some veering with height in mostly unidirectional southwest flow aloft but southerly surface winds.  850 mb winds 30 to 40 kts combined to a core of 30-40 kt 700 mb wind will mean a straight-line damaging wind threat would be the biggest concern in most of the Southern half of New England.  Very warm boundary layer and lower atmosphere will limit hail potential significantly.

Though the slow moving front takes its time to clear Southeastern New England Wednesday night into early Thursday morning, it should clear the coast early Thursday and allow the anticyclone responsible for great early week air in the Upper Midwest and Upper Great Lakes to spread that refreshment into New England on Thursday.   Though the air will remain much less humid, temps will rebound on Friday without much surface cold available, and by the weekend a southwest wind returns to not only keep temps up but also reload humidity - which may only gradually rise Saturday, but should be high again on Sunday with thunderstorms back into the forecast.

As mentioned at the start of the discussion, there's good agreement among the ensemble members on holding the Northeast US trough pattern - at least weakly - into the end of July.

Matt

PHEW! WE GOT THE TORNADO VIDEO FOR YOUTUBE! NOW WHAT DO WE DO?

I thought this was an interesting story to ponder - perhaps the quest for fame and fortune has officially trumped the presence of common sense in society?  An intriguing read and account of one author's time through a tornadic storm, regardless.