Watching the Tropics

It will take some more time, but I am still convinced that the cluster of thunderstorms down in the Caribbean will become our 1st named tropical storm, Arlene, of the season.  It should not become a "monster", but few storms do this early in the hurricane season.  In fact, this, if it even does earn the honor of a name, may not achieve hurricane status.  However, that does not mean it will not bring heartache to an area of our earth that needs no more of nature's wrath at this time.  The heavy rains will produce major landslides in Haiti and the Dominican Republic along with Jamaica-mon.  This is not a good week to have cruise plans in the Caribbean!  The satellite below shows the persistent cluster of storms that may evolve into Arlene.

The Euro does develop a tropical storm with a closed low and rotary circulation by Tuesday.  The Navy No Gaps model, (yes...even the Navy has an atmospheric global model!) creates an even stronger tropical storm by later next week.  Shown below is the European's depiction by Tuesday.  If that trough were a bit further east in the Atlantic and the ridge then further east as well, Florida to LA should be worried about that storm gaining strength and propagate northward. 

In fact, that deep trough in the central Atlantic actually gets reinforced with a piece of heat that escapes from this disturbance in the Caribbean.  In fact all of the global guidance suggests this scenario.  Here is the GFS guidance for next Friday.  Note the very deep cyclone in the Atlantic.  It became that way as a piece of energy from the deep tropics phased with a wave coming off the continent to create quite the fish storm.

You all say...."well that's nice Smitty...but what does that mean for us?"  Glad y'all asked!  Essentially, we should remain in a relatively dry with seasonable temps to maybe even slightly above normal with such dry air in place.  With the dry air, we cool off nicely in the evening but can warm up very quickly with the strong June sun.  In fact, last evening at 7 pm, KMDT reported a dewpoint of 37ºF with an air temp of 76ºF creating a RH of 22%!  Now that is dry!  As for the strong June sun, today at "noon" which is actually 1:06 pm EDT today for Harrisburg, PA, the sun will have an altitude angle of slightly more than 72º!  Now that is truly a "high sky".  Sorry I digress.....the map below is the GFS 500 mb for next Friday as well.  Note the strong winds 3-4 miles up flowing from the NW over PA.  These winds can often lead to some surprisingly warm wx at this time of year assuming the northern plains are able to tap into the heat from further south.  Couple that with downsloping off the Allegheny Front and we are looking at temps easily in the mid-80s...but I do not think 90ºF will not be attained.  Our surface winds will be more northerly as shown in the map above.  Do the counterclockwise thingy around that low off New England and we find ourselves breathing air straight from the Nordiques. Either way, this is not a conducive pattern to bring some now much needed rain to our area for the lawns, gardens, and fields.

On a side note, I've had many of you tell me or tell friends tell me "Man...look at the time he is posting".  Well, there are a few reasons for this.  Sometimes, the blog time uses Pacific time and sometimes it uses Eastern time......not sure why!  But yes, I am a morning person and part of my routine is check out the global modeling and share my insights with y'all.  Wx is 24-7; it is really that simple.  When I miss a day's worth of computer runs, I feel that I am so out of the wx loop.  I try to see little differences in run to run to look for pattern shifts, etc....I'll not bore you with details.  But I love this stuff....and whether it is confirming my own thoughts through this medium or tweaking a PowerPoint presentation for my captive audience of adolescents for 3/4 year, I will try to best explain my thoughts on the topic at hand.  That, plus I really don't have a life......many have also told me that I was more fun several years ago.....oh well!  Now I'm just an old boring old weather weenie whose life revolves around his family and his 2 four-leggeds. 

Have a great week's end!

Smitty

AA:  Still monitoring the tropics for hurricane development.  A bit of rain overnight Saturday into Sunday morning.  But basically warm and dry for our area for the remainder of the week.

Hurricane Seasonal Forecast from Dr. Wm.Gray

ATLANTIC BASIN SEASONAL HURRICANE FORECAST FOR 2011 Forecast Parameter and 1950-2000 Climatology (in parentheses)	Issue Date 8 December 2010	Issue Date 6 April 2011	Issue Date 1 June 2011
Named Storms (9.6)	17	16	16
Named Storm Days (49.1)	85	80	80
Hurricanes (5.9)	9	9	9
Hurricane Days (24.5)	40	35	35
Major Hurricanes (2.3)	5	5	5
Major Hurricane Days (5.0)	10	10	10
Accumulated Cyclone Energy (96.1)	165	160	160
Net Tropical Cyclone Activity (100%)	180	175	175

The table above shows Dr. Bill Gray's Atlantic basin forecast for this year's upcoming hurricane season.  As you can see, the forecast gets updated as greater analysis and data scrutinizing occurs.  Dr. Gray has been a leader in tropical forecasting for the last 2 decades and does the bulk of his research while working at Colorado State University.  His forecast is based on a new extended-range early June statistical prediction scheme that utilizes 29 years of past data. Analog predictors are also utilized. Overall, according to Dr. Gray, conditions remain conducive for a very active hurricane season.  Below are a few more probabilities as determined by Dr. Gray.

PROBABILITIES FOR AT LEAST ONE MAJOR (CATEGORY 3-4-5) HURRICANE LANDFALL ON EACH OF THE FOLLOWING COASTAL AREAS:

1) Entire U.S. coastline - 72% (average for last century is 52%)
2) U.S. East Coast Including Peninsula Florida - 48% (average for last century is 31%)
3) Gulf Coast from the Florida Panhandle westward to Brownsville - 47% (average for last century is 30%)

PROBABILITY FOR AT LEAST ONE MAJOR (CATEGORY 3-4-5) HURRICANE TRACKING INTO THE CARIBBEAN (10-20°N, 60-88°W)

1) 61% (average for last century is 42%)

It does appear as if by early next week, we will be looking at Arlene forming in the Caribbean and delivering copious amounts of precip to Cuba, Haiti, Jamaicamon, & the Dominican Republic.  As the satellite pic shows below, there are a large number of thunderstorm clouds just to the south of Hispaniola and upon close inspection, you can see a hint of rotation with the clouds.  What the satellite image doesn't show is that the upper winds are actually pretty favorable for these clouds to get named Arlene by next Monday or Tuesday at the latest!

This numerical guidance from the UKMET shows most decidedly a tropical storm starting to develop by Sunday evening.

2011 STATE IMPACT PROBABILITIES (NUMBERS IN PARENTHESES ARE LONG-PERIOD AVERAGES) State	Hurricane	Major Hurricane
Texas	50% (33%)	20% (12%)
Louisiana	47% (30%)	20% (12%)
Mississippi	18% (11%)	8% (4%)
Alabama	26% (16%)	4% (3%)
Florida	71% (51%)	34% (21%)
Georgia	19% (11%)	2% (1%)
South Carolina	28% (17%)	7% (4%)
North Carolina	44% (28%)	13% (8%)
Virginia	11% (6%)	1% (1%)
Maryland	2% (1%)	<1% (<1%)
Delaware	2% (1%)	<1% (<1%)
New Jersey	2% (1%)	<1% (<1%)
New York	13% (8%)	6% (3%)
Connecticut	12% (7%)	3% (2%)
Rhode Island	10% (6%)	4% (3%)
Massachusetts	12% (7%)	3% (2%)
New Hampshire	2% (1%)	<1% (<1%)
Maine	7% (4%)	<1% (<1%)

Upon quick scrutiny of the table above showing the likelihood of a state being hit by a hurricane or a major hurricane, no wonder the "U" of Miami is the "Hurricanes"!

Have a good week's end!

Smitty

AA:  Watching for Arlene to develop south of Cuba by Sunday night.

Nice Weekend Following Cool Friday Morning

In the short term, we are looking at a rather cool morning Friday as temps will fall across the entire state into the 40s except for the urban areas in SE PA.  Under clear skies and subsiding winds and with low dewpoints, temps will fall to some rather chilly levels overnight into tomorrow morning.  The strong June sun will quickly allow temps to rebound, but sunrise temps will be in the mid 40s!  Wow!

The map below shows the light winds with a very gentle NW flow.

But then by Saturday evening, a warm front will be advancing across PA.  Note the temps for around midnight Saturday night-Sunday morning.  The cool air is retreating northeastward while the warm air is invading from the SW.

This could touch off some showers and thunderstorms as the warmer air invades PA.  It is not a major warm up, just getting temps and dewpoints back to mre seasonable levels for what is now summertime.  I can hear Janis Joplin crooning away.....Summer..........time.......

 You can see the wind convergence at the surface of the earth which can dynamically lift the air producing the showers.  I'm not real bullish on much rain from this, but if you get under a heavier shower, you may not need to water the gardens for a couple of days!

In closing, I had a couple people mention that they were not familiar with Tinkers to Evers to Chance.  Then there were some who actually mentioned the Cubs with that famous combo.  So I'll leave you with this poem in honor of the most famous Chicago double play aside from Wrigley in the day and Comisky at night.

These are the saddest of possible words:
“Tinker to Evers to Chance.”
Trio of bear cubs, and fleeter than birds,
Tinker and Evers and Chance.
Ruthlessly pricking our gonfalon bubble,
Making a Giant hit into a double –
Words that are heavy with nothing but trouble:
“Tinker to Evers to Chance.”

By Franklin Pierce Adams
New York Evening Mail July 10, 1910

Have a good Friday......

Smitty

AA:  Nice weekend following a cool morning Friday.  A chance of showers Saturday overnight into Sunday morning.

Hurricane Season Runs June 1 to November 30

And just on cue, there looks to be an area of disturbed wx in the Caribbean just south of Cuba and Jamaica, mon.  The 2 graphics below show the area most concerning; the top image from the Hurricane Center with their yellow circle emphasizing areas of concern.  The 2nd is the latest IR satellite image with some very deep thunderstorms.  This area will slowly move northward over the weekend and give lots of rain to these tropical areas.  We may have our first named depression by next Monday!  No worries about the area just south of LA.....me thinks.

Gotta go since this is all I see on my way to work!

Enjoy the refreshing air mass compliments of our friends from O Canada!

Have a great Thursday!

Smitty

AA:  Watching the Caribbean for hurricane development.

Use the 850 mb to Forecast Surface Temperature

I like to look at the guidance for the 850 mb level temps for a variety of reasons.  In the winter, the 0C line is a good approximation of the rain-snow line.  In the warmer seasons, the 850 mb temps give one a good idea as to what the surface temp might be in a well mixed atmosphere (i.e. breezy day).  Thursday will be a breezy day as shown by the map below.  Winds will be NW at all levels and near the surface, we will see winds routinely hitting 20-25 mph during the afternoon when the sun also helps in the differential heating and mixing of the atmosphere.  Note the streamlines advecting air from Huron to Erie to Harrisburg....doesn't have that same sound as Tinkers to Evers to Chance now does it?

That graphic above is a well mixed atmosphere!  So tomorrow we have the opportunity to try the forecast of the surface temps based on the 850 mb temps.  Using the normal dry adiabatic rate of 5.5F/1000 feet and considering that the 850 mb is roughly 5,000 feet up, lets look at the forecast temps at a mile up.
Upon close inspection of the map below, KMDT appears to be around the 8C isotherm (46.4F).  Thus at 18Z tomorrow, KMDT should be very close to 46.4 + 27.5 = 73.9F!  If it is warmer than that, we can blame it on global warming.  If it is cooler than that, we can blame that on global warming as well since the warmer global temps created a more energetic atmosphere to create a stronger NW wind to bring in even cooler air from further north in O Canada! 

When looking at the straight model guidance for temps tomorrow at the surface, this is what the model paints for 18Z tomorrow:

What a difference a day makes!  Just like my colleague stated at the end of today that he is now 40% lighter!  I bit???.....the seniors bonehead!  I also spoke with some others about the temps not hitting 90F in quite some time again here at KMDT.  We do have chance on Sunday, but I think clouds and potentially some thunderstorms will prevent that from happening.  Then we lock into a sustained NW flow of seasonable and dry wx for the foreseeable future.  I just watered the garden this evening as the storms passed to our east as I suspected might happen.  Believe it or not, agricultural and gardening interests could use some rain after that bout of early season heat.  The numerical guidance is also hinting at tropical development in the next 10-15 days as well....different post for a different day.

Enjoy the beginning of the end of the school year 2010-11!

Smitty

AA:  74F at 2 pm tomorrow at Harrisburg International Airport and we could use some rain again and the seniors are gone!

Typhoon Songda Recurve to Bring Trough into Eastern US

While we were celebrating the Memorial Day holiday the last few days, a half world away, nature's fury was manifest in Super Typhoon Songda.  At its maximum strength, this storm produced winds ~150 mph and wreaked havoc on Luzon and the Philippines.  This storm, due to interactions of the large Asian landmass and the wind fields produced by it, began to recurve ENE prior to hitting Taiwan and just scraped Honshu Japan.  So why do I tell you this?  When this much energy gets entrained into the earth's atmospheric circulation, the atmosphere must compensate and react to this energy injection.  Hence, this typhoon a half a world away will help change our pattern here in North America bringing much cooler and drier air into the eastern half of the continent.  Below is a satellite image of Super Typhoon Songda.

Below, I circled in red where the "blob" of heat and humidity is being entrained into jet coming off of Asia.  This is what will lead to a pattern change here in North America.  The general rule of thumb is when a major storm recurves east of Asia, about 10 days later a trough will dig into eastern North America. 

The modeling below depicts the energy from the typhoon in the central Pacific, creating much amplification of the long wave pattern such that we in the eastern portion of the US should be seeing a trough digging from O Canada.  The Euro on the left shows quite a trough off the east coast while the American model on the right has a much flatter look, albeit still with NW flow. 

Personally, I believe the look of the Euro with such a strong typhoon adding much energy to the jet stream configuration.  Both models do have yet again another blocky look to them with High up over Greenland.  If this would occur, we would be looking at normal or slightly below normal temps from about June 8th onward.  Unfortunately for agricultural and gardening interests, this is often a dry flow of air as well at this time of the year with only a minimal chance of diurnal storms.  Here is the operational run of the Euro, not the ensembles, for next Thursday.  Note the strong NW flow where the air over PA comes directly from Lake Gitchigomee with the deep trough off the coast into the Atlantic Ocean.

As for the short term, the Storm Prediction Center has us under a slight chance of severe wx for Wednesday afternoon.  I have a gut feeling that the strongest storms and heaviest rain will fall to our east on Wednesday and leaving most of us here in the Harrisburg area looking east at some towering cumulus and not receiving much beneficial rain.  That is my tepid take on the short term weather situation.  We will see in 24 hours.

Hope everyone has a good mid-week.

Smitty

AA:  Typhoon over in Japan will help bring cooler wx to us here in PA ~10 days from now.  I think the bulk of tomorrow's storminess will be to our east.

Snow Thoughts on Near Record Heat Memorial Day

As I was relaxing this Memorial Day holiday, I found an article that I thought I would share for those of you who care to have it shared.  Its main premise was describing the amount of snow that still exists in the high country of the western USA.  I decided to further investigate the story and see just how extreme the conditions truly are in the western USA.  The picture below was from the article; a media that often has a global warming bias, but I bit and read the entire article.  Astoundingly, the article suggested that the snowfall was cyclical and that we are ramping up towards a colder period of weather for the next decade or two.  Imagine that, the earth behaving cyclically!  (Sunspots, La-Nina-El Nino, even seasons!)  Essentially, the amount of snow has altered holiday plans for many that utilize the mountains as their playground.  This winter has been gracious to the western USA in as they need a deep snow pack to recharge reservoirs for their ever increasing water needs. Indeed, this snowier than normal winter was a godsend for them.  In this May 18th photo provided by the Colorado Department of Transportation, a sign for Independence pass is nearly obstructed by snow in Colorado near Mt Evans. Trail Ridge Road is closed because of snow, It is the first time in 17 years that Aspen-area cyclists had to cancel their Ride over Independence Pass and campers are being warned that there is still 16 feet of snow in much of the Routt National Forest, northwest of Denver. (see map below) Colorado is still coping with record snows. Some western states are experiencing flooding as the snow melts and recharges the reservoirs.

And it is quite expansive across the west!  Much of the map below in purple squares are experiencing 200%+ of normal water equivalents in the snow pack upping the risk for flooding. 

And it is still snowing as this graphic shows the last 24 hours of snow across the western USA!

 Essentially, the map below shows that the bulk of the mountains in the Colorado region is well above 200% of normal snow pack as of last Thursday!  And the trough of the jet stream is still located in the means out in the western US as you can certainly tell with the early season heat we are currently experiencing.

Now I know some of you are saying, well....that's nice but what about around here???  After all, we don't live in the western USA!  Just trying to keep everyone cool in the midst of this early season heat.....OK?  The forecast is essentially the same.  Hot through Wednesday with the potential to break a max record for KMDT for either Monday or Tuesday.  The record for tomorrow is 97F (1939) and the record max for today (Monday) is 95F (1895).  Wednesday will still achieve 90F.....maybe.....it depends on the progression of the front ushering in drier and slightly cooler air for Thursday-Saturday.  I still don't believe the storms will be too severe with the passage of this front, but the potential certainly exists with this type of heat and humidity.   I am now officially issuing a BEAUTIFUL WEATHER WARNING for late Thursday afternoon, through Friday and Saturday.  Then Sunday will be getting a tad bit hot and humid once again....until a true shot of O Canada air will invade in the Tuesday-Wednesday time frame, 8-9 days from today, Decoration Day.  The jet stream forecast for next Tuesday shows a refreshing shot of much cooler air being discharged directly south on northwesterly jet stream level winds.

And the 850 mb temps show the heat once again for next Sunday.

And how the pattern change will bring in much cooler weather by the middle of the first full week of June.

I hope everyone has a very enjoyable Memorial Day holiday and let's all be cognizant of the fact that freedom isn't free.

Smitty

AA:  Tid-bit on western USA impressive snow pack....and for here, hot!  Hotter than the hinges of Hades through Wednesday....then a frontal passage cooling and drying things out for a period of beautiful weather Thursday-Saturday.  Then hot once again Sunday-Monday.  Looking for pattern change to cooler and refreshing wx next week.  Happy Memorial Day my friend!

Tornadoes Confirmed by NWS

Below is a quick summary of 2 tornadoes that were confirmed by the NWS Survey team from the storms that were so violent Thursday evening:

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1221 AM EDT SAT MAY 28 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0720 PM     TORNADO          HOGESTOWN               40.23N  77.04W
05/26/2011                   CUMBERLAND         PA   NWS STORM SURVEY

            A TORNADO TOUCHED DOWN NEAR ROUTE 114 SOUTH OF WILLOW
            MILL PARK AROUND 720 PM EDT AND TRAVELED NORTHEAST FOR
            ABOUT 2.5 MILES...OCCASIONALLY LIFTING OFF THE GROUND
            DURING THE PATH. THE TORNADO CROSSED ROUTE 81...THEN
            ENDED NEAR SEARS RUN BEFORE REACHING ROUTE 944 AROUND
            724 PM EDT. THE TORNADO RESULTED IN ABOUT 100 TREES
            BEING UPROOTED OR SNAPPED ALONG ITS PATH. SOME MINOR
            DAMAGE TO HOMES WAS OBSERVED. A SMALL OUTBUILDING WAS
            SEVERELY DAMAGED ALONG LAMBS GAP ROAD NEAR THE END OF
            THE TORNADO PATH.


And the 2nd report:


PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1204 AM EDT SAT MAY 28 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0715 PM     TORNADO          DAUPHIN                 40.37N  76.93W
05/26/2011                   DAUPHIN            PA   NWS STORM SURVEY

            A TORNADO TOUCHED DOWN AROUND 715 PM EDT AROUND ONE
            QUARTER MILE EAST OF DAUPHIN BOROUGH ON RIVER ROAD. THE
            STORM LIFTED ABOUT 1.5 MILES EAST OF DAUPHIN BOROUGH ON
            SECOND MOUNTAIN. SIX HOMES SUFFERED MODERATE TO MAJOR
            DAMAGE...AND 150 TREES WERE DOWNED. STORM DAMAGE WAS
            CONSISTENT WITH MAXIMUM WIND GUSTS AROUND 90 MPH...WHICH
            RATES THE TORNADO AN EF1 ON THE ENHANCED FUJITA SCALE.
            IN ADDITION TO THE TORNADIC WIND DAMAGE...SOME DOWNBURST
            STRAIGHT LINE WIND DAMAGE OCCURRED ALONG THE RIVER.

Quite impressive, to be sure!  Here are some other notables on tornadoes for spring 2011 for the entire USA:
1) Preliminary, the most tornadoes ever counted in one day on 4/27 at more than 180 (188 is the current number). This total is still being finalized.
2) The Joplin, MO tornado was the single deadliest tornado since 1947 and is now #7 on the list of all-time deadliest tornadoes!  (#6, Woodward, OK, 1947)
3) Deadliest year overall since 1936, with the updated total of 520 mortalities.
4) Most individual tornadoes that caused 20+ deaths since 1920.  There are now 7 this year!

Below is a picture from NASA that shows the destruction of the Tuscaloosa, AL.  The bluish colored lines are the trails of total tornado destruction!

Al Gore blames this on global warming.  But I say that if we had quality data for the last 200,000,000 years for North America, this year would most likely be in the top 25 percentile or so........

Hope everyone's AC is working!

Smitty

AA:  Tornadoes confirmed in our area Thursday night and some other tidbits of tornado info.