Keeping It Simple

Now that Isaac has decided to SLOWLY drift away from southern Louisiana and up the Mississippi River Valley, the question begs "what will happen with Isaac's remnants?".  Well....I'm glad you asked!  I'm going to keep it simple and illustrate what the GFS depicts as the movement of the deeper tropical moisture at the 700 mb level (10,000') and where the computer modeling suspects it will travel.  You might be wondering why I am showing you the 700 mb level.  Essentially, when the relative humidity is 100% or higher (different story/different day), precipitation is likely to occur in those saturated clouds and be observed on the surface of the earth.  I will show you the 12Z run (8am EDT) of the GFS for each 24 period starting with the initialization of the parameters for Thursday morning. 

Do you remember this morning?  A beautiful, almost full moon shining brightly in the pre-dawn sky with nary a cloud to be found!  In fact, as I type this on my humble patio watching the hummingbirds feast on the Mexican salvia, I can't find a cloud in the sky!  Hence, the air is dry including the 700 mb level.  If there was ample humidity at the 700 mb level, clouds would be quite prevalent across the sky.  That is not the case...the deep blue below indicates LOW humidity.  The yellows; 'bout half, greys=rain!

Thursday morning:

Friday morning:  Isaac northward of the Arklotex region...still sunny and HOT here in PA!

Saturday morning:  Some thin cirrus moving into PA thanks to the broad circulation around Isaac.  Still some very dry air being advected SE from the northern lakes over southern NY and northern PA...

Sunday morning:  With the church bells ringin', clouds will be increasin'!  In meteorology, we often talk about pressure and temperature gradients.  Well, that is one heck of a humidity gradient over PA running NW to SE!  While it's raining in Washington County, PA, nary a cloud will be found in Dauphin & Lebanon Counties!

Monday morning:  The wx deteriorates rapidly from west to east with rainfall likely across the entire state for Labor Day.

Tuesday morning:  WET!

Wednesday morning:  Front whisks Isaac's remnants out to the sea, with a refreshing NW flow replacing the damp air with much drier air once again!  Note Leslie out near Bermuda...she must be watched!

Gut feeling...about a 24-36 hour period of moderate to at times heavy rain for our region amounting to about 1-2" in tote.  Once things become more clear, I'll update on the Labor Day wx...but until then, enjoy your Football Friday and the kickoff of the 2012 High School Football Season!  Go Rams and Go Panthers!  Rams over the Streaks and the Panthers over the Greyhounds!  Gotta love it!

Hey...at the very least, I posted a slew of psychedelic maps in at which y'all can stare...they are pretty cool!  Enjoy your week's end...and remember, the whiter the shade of grey (in the models above), the more likely for rain...so I'll leave you with this...enjoy this old classic.

Smitty

AA:  Isaac's remnants to affect PA's wx later Sunday through Tuesday with a healthy amount of rain...enjoy your Labor Day weekend my friend!

Miscounted Isaac

My title of this brief posting is simply to let y'all know that Isaac was underestimated by many of what this tropical cyclone was/is capable of doing!  For most of Monday, the National Hurricane Center continued to call this beast a "tropical storm" in spite of pressures worthy of it becoming a Cat 1 storm.  Just prior to landfall, Isaac's central pressures dropped to 965 mb!  He produced a maximum wind gust of 113 mph at Belle Chasse Ferry Dock in Plaquemines Parish just prior to landfall.  The gauge at Shell Beach, LA recorded a storm surge of nearly 11 feet!  By using the above bold faced criteria, it appears to me that Isaac should have been classified as a strong Cat 2 or a weak Cat 3!  Here is a graphic of the storm surge observation at Shell Beach...

And not as strong as the 113 mph wind gust, look at the winds at this same sensor.  24+ hours of winds in excess of 50 mph!  Wow!

Here is the pic and locator of this sensor...the large yellow diamond locates this tower.  Picture extremely turbulent water 10+feet higher than in the below pic...unreal!

Now, here is a chart of the various categorization of storms based on various oceanic and atmospheric parameters to arrive at a storm strength.  Remember from above...113 mph gust, 965 mb, ~11' surge...you tell me what Cat storm Isaac was just prior to landfall.  Maybe they will revise this upon perusing the data more closely like the infamous downward revision in the political unemployment rates we see here in the US!  Oh well...

So where will Isaac decide to venture once he's done his welcome is worn in LA?  The precip modeling suggests a northward, then an ENE turn across the upper Ohio Valley and ultimately into the northern Mid-Atlantic and finally off into New England.  Take a look at the latest modeling for precip amounts...

Here is the modeling for late Saturday evening into early Sunday morning as the first few drops from Isaac arrive in central PA...

...and it continues through early Tuesday!

Now its waaaaay too early to determine the quantity of liquid sunshine, but it is now becoming a bit clearer, at least to me, that we will receive a generous amount of rainfall from this newsworthy tropical cyclone.  Here are the latest model runs through the next 5 days as to where this atmospheric menace will travel...

And, just in case you forgot what he looked like...first an IR view...

...and now how we would see it with our eyes if we were in a geosynchronous orbit of ~23,000 miles above this big blue marble...

My heart truly goes out to those suffering in the path of Isaac and many of those hearty folks simply say "that's part of livin' here".  If I were better with my French, it would probably be spoken in some Frenchy type lingo...but that is a different discipline for me and one in which I greatly struggled!  But knowing some folks around here that dealt with the disaster of Lee's remnants in Sept 2011 and kept a great attitude about where they lived...I think of this song from Jackson Browne...and I'll leave you with this...

Enjoy your end of the week! It will be getting hot (90+ for Friday) in these parts before Isaac pays a visit.

Smitty

AA:  Isaac is a force to be reckoned with!  Like me in fantasy football!  His moisture likely to affect PA Sunday-Tuesday time frame.

Quick Buoy Observation

NOAA has a network of buoys located around the North American continent to monitor sea and atmospheric conditions.  I find it interesting to look at these from time to time especially when the "eye" of a hurricane is approaching or a nor'easter begins to crank along the east coast of the USA.  Here is the latest plot (Air pressure, wind speed and gusts) of a buoy just south of Morgan City, LA, just 10 miles off the coast in the Gulf of Mexico.  Note that when the air pressure drops, the wind speeds increase as air tries to fill the void of air!  Pretty neat...huh?

For those of you who like to view maps...the location is the large yellow diamond.

And here is the latest cloud pic (IR) of Isaac...

...along with its associated radar reflection in the lower parts of the atmosphere...

OK...gotta run and go stroll the parking facilities of CDHS while trying to still figure out the number system in the lot itself?!?

Have a great Wednesday!

Smitty

AA:  Isaac creating some hardships down in Cajun Country!

Incredible Isaac

This hurricane name too will be retired once the saga of Isaac plays out.  As of early Tuesday morning, here are 2 satellite pictures of Isaac just 100 SSE of the mouth of the Mississippi River moving to the NW at 7 mph.  Technically a tropical storm, Isaac's winds and storm surge along with its low 976 mb pressure will make this undoubtedly a hurricane.  We're splitting hairs here on this one.  Listen, if you were in Cajun country, this ain't just your ord'nary typical ocean blow!

You can sorta see an eye developing (green) with the deep convection (red) around this developing eye. 

From the above satellite pic, there is some dry air trying to become entrained into the system which may help inhibit the rapid intensification of Isaac as it approaches landfall.  Time will tell...
As Isaac approaches the continent, here is a map from the NWS from New Orleans describing the impacts of the potential flooding and storm surge as the ocean water gets piled onshore.  Here's hoping the newly reconstructed levees help keep the majority of New Orleans from being inundated once again.

The map below shows the exact landfall region as per the guys from HPC...that is one scary track for the city of New Orleans...

And here is the Geophysical Fluid Dynamics Lab's model for where Isaac will go once ashore...

With that above map in mind, here is what HPC suggests as rainfall totals over the next several days...through early Sunday morning.

Most of our region around the Harrisburg area will receive some effects from the remnants of Isaac as there will be a "triple point" low pressure system reflected at the surface of the earth come Labor Day.  Synoptically, whenever a map looks like the one below, moderate to heavy rain will fall over our region...Take a look below.

OK....gotta run...this school thing kinda cramps my wx hobby...but was able to keep my loyal minions informed!  And not only that, the school thing keeps food on the table!

Enjoy your Tuesday!

Smitty

AA:  Isaac to adversely affect New Orleans!  Could be nastier than Katrina!  It's remnants will head our way for later this Labor Day weekend.

Wet First Half of September

Hurricane Isaac will affect the northern Gulf coast and unfortunately, it appears that New Orleans will once again bear the brunt of the storm as it did back in 2005.  Although the NWS Hurricane center only strengthens Isaac to a Cat 1, I believe the environment will allow it to achieve Cat 2 prior to landfall.  Here is Isaac as of 5 pm EDT Monday as seen from the electronic visible eye of the satellite:

And the National Hurricane Center's official prediction...

The question that I encountered most today aside from where is Room ____ (you fill in the blank) was will Isaac have an influence on our wx...and I believe the answer to that question is "yes".  This weekend, Labor Day weekend, will be a rather soggy time for most of the Mid-Atlantic and New England as the remnants of Isaac teams up with a sagging cold front from O Canada.  As a result, a fairly wet weekend will result in our region.  In fact, the Climate Prediction Center paints an anomalous precipitation forecast for the next 6-10 days!  Take a look...

When we look at the GFS and its precip print out for once Isaac makes landfall, and then meanders north and east from its landfall, it is easy to see where the storm will likely travel.  The map below shows the total precip over a 2.5 day period ending Labor Day.

Here is the surface map for later Saturday evening...

And as the title indicates, this will not be our only tropical system to impact the eastern part of the USA.  Take a look at the surface map for Sat. September 8.

And take a look as to where it might travel along the eastern seaboard by looking at a graphic showing total rainfall over a 2.5 day period ending the morning of September 9.  If this were to verify, the 2nd week of the high school football season would be in jeopardy due to squally conditions due to the tropical system that seen above.  This is a long shot, but something that the global modeling is sniffing.  In addition, "'Tis the season"!

With the heat and humidity and a few tropical cyclones thrown in for good measure over the years, its no wonder such upbeat music has it roots in the delta country of LA and the low lying regions of the MS.  Enjoy this classic blues song from Muddy Waters...

Enjoy your "Back-to-School" week gang!

Smitty

AA:  Isaac taking aim on New Orleans!  Could be UGLY!  Gas prices likely to increase rapidly by this weekend even though oil prices dropped Monday.  Refineries could be offline for a few days.  We may see some rain from Isaac this weekend and then yet another tropical system 2 weeks hence.  Hope your alarm works tomorrow.

Isaac to Rock Margaritaville

It looks fairly certain, that is in wx certainties, that developing and quickly strengthening hurricane Isaac will rock Key West, FL with a direct hit of a Category 1 storm some later Sunday!  Hurricane warnings are now posted for the the Florida Keys as seen in the map below...

Here is what the storm currently looks like from above...

And here are 3 models' predictions as to where it will end up once it passes through the eastern part of the Gulf of Mexico...1st the Euro for Tuesday evening:

And the America's GFS depiction:

Finally, the regional higher resolution grid of the North American Model or NAM for the same time:

As you can see, there is good agreement, dare I say, excellent agreement amongst the various models!  So Pensacola, FL...beware!  The storm will continue to gather momentum and its atmospheric dynamics will continue to improve as it moves over the favorable heat laden waters of the Gulf!  The graphic below simply equates the tropical cyclone heat potential per the waters it traverses.  These Gulf waters at this time of year are ripe full of potential...needless to say!

So if you've ever visited the southern most point in the USA in Key West, imagine how it would be weather-wise Sunday evening if you were 90 miles north of Cuba!  Meanwhile, Isaac will be wasting away in Margaritaville, Key West, FL!

Enjoy your weekend...and to my colleagues...our last weekend of summer vacation!  It's a real shame that the ensembles are printing out about 0.25" of rain for late Saturday into Sunday afternoon as a pesky low will slowly grind north across the Mid-Atlantic...oh well!

Happy week's end!

Smitty

AA:  Isaac to hit Key West, FL then move up west of Florida and make a 2nd landfall somewhere near Pensacola, Florida.  Look to get a little rain here this weekend, too.

Intriguing Isaac

Well...I'm back.  Just like Mr. Kotter...and the start of school for 2012-13!  I felt compelled to add my 2 cents since everyone and their brother is opining on the ultimate path and effects of what is currently Tropical Storm Isaac.

Here is a current satellite pic of TS Isaac as seen through the infrared eyes of a wx satellite.  Note the central dense overcast (deep red near 15N) that surrounds what is trying to become an eye.

And here is the water vapor image of Isaac at the present time.  The purplish color has some very deep moisture throughout the atmosphere which allows for tremendous thunderstorms to develop and generate even more energy though the process of condensation as heat energy is released to the immediate environment in the vicinity of the physical process of the condensing water vapor into clouds!  (Latent heat of condensation).  The darker regions around the colors are actually very dry regions of the atmosphere.  So a tropical cyclone is merely a powerful region of the atmosphere that is an organized "blob" of deep moisture traversing through the tropical waters...

...and feeding off of not only the heat the condensing water vapor is supplying but also the heat from the very warm surface of the tropical oceans.  Here is an analysis of the potential heat energy of the tropical waters around the Gulf of Mexico and the Caribbean.  Note how the gulf stream ocean current carries vast amount of heat north and east along the eastern seaboard of the US. 

The picture below shows essentially the same data but this time comparing it to "normal".  Note that the waters just east of FL are actually a bit cooler than normal whereas the Gulf is primed for tropical cyclone development based solely on sea surface temps.  Also note the anomalous warmth off the Delmarva, possibly a pre-season sign of some power nor'easters if the ocean warmth holds into the winter season!

The last couple graphics I'd like to share are both the Euro's and the GFS' take on where Isaac may end up sometime near the end of NEXT week.  First, the American GFS...

Obviously a major hit in the northeast portion of FL or along the GA-SC coast.  Now here is the Euro's prog for the same time late NEXT week.

Again, just to keep things in a global perspective, here is the wide view of the North American continent and the location of TS Isaac east of the Leeward Islands in the western Atlantic.  Also note the tropical wave that is on the heels of TS Isaac!  'Tis the season!

So where is Isaac heading?  Here are the latest runs from the numerical modeling indicating that Floridians best be advised for a potential major hit from this tropical cyclone.

However, if one uses analogs from the global atmospheric patterns of the past and what has occurred in terms of the sensible weather, it is of a major concern the the GFS ensembles have the week of Hurricane Katrina (dates in the lower right...20050829) as its 6th analog from its runs from yesterday!  Ouch!

So time will tell...as it will too with how the AL east winds up this September.  It is kinda hard to believe that as well as the Yankees have been playing this year they hold only a 4 and 5 game lead over the Rays and the Os respectively!  Here's hoping from yours truly that the Os can somehow manage to hold it together to make a legitimate run for some October baseball since my Phillies have checked out...sometime back in late April or May!  In fact, it would be very cool to see a Washington vs Baltimore World Series!  I wonder if Strasburg would pitch in Game 1 under that scenario?!?

Enjoy the end of the week...and your start of school my working colleagues!

Smitty

AA:  Watching for a potential major hurricane (Isaac) to affect the US east coast or Gulf coast...still waaaaay to early to say for sure!  See you soon my friend!