Groundwater Response to Recent Rains

I have and everyone else has by now shown y'all the surface hydrographs for the flooding rivers and streams in PA.  But here is a quick gander at the sub-surface water response to the recent heavy rains of the last month.  All of the graphs below show the last 120 days of data with the graph showing the water level BELOW GROUND LEVEL.  You can clearly see the stint of very hot and very dry weather from late June into early August.  Then the faucet was opened!  First the Dauphin County Test Well run by the USGS located near Indiantown Gap.  Note the response to the flash flooding event of August 6!

Here is the York County Test Well located just 2 miles SW of me!  Not so much rain on Aug 6!

And the test well in Lebanon County located in the thriving metropolis of Myerstown.  This well shows very rapid response times to thunderstorm activity and in fact it flooded with surface water if the data can be trusted with our most recent rains.  This is how groundwater can easily become contaminated.  The rapid response times indicate usually an abundance of fractured limestone in the subsurface rock strata, the fractures acting as rather large conduit or piping to allow the rapid movement of groundwater and very rapid response rates. 

In terms of the atmosphere, I will leave you with the day 3 NAM showing two potential threats to the eastern half of the USA once again.  Nate in the gulf is forecast to drift westward into MX and south TX while Maria is forecast to recurve and miss the US mainland not too differently than what Katia just did.  I just don't buy either of those scenarios quite yet!  Persistence is a forecasting technique that the atmosphere often repeats itself given similar circumstances.  And although the set-up is not 100% identical to what we just went through, there is that trough to the north of the gulf.  At least it is positively tilted (NE to SW).... and showing signs of being progressive.  If it were negatively tilted (from NW to SE), I would be very nervous for yet another heavy rain event 10 days hence.....

The last graphic is the precip and temps for KMDT to yesterday.  It looks like a lock that we will break the annual rainfall record of just over 59" in 1972.  As of yesterday, we are just under 57"!  Welcome to Miami, FL!

Hope everyone can dry out...but don't count on Ol Sol to help much the next 3-4 days!

Smitty

AA:  Groundwater responds to surface rains too.  2 tropical systems must be monitored.  No $%!* Sherlock, it's been wet outside!

Historic Flood Update

This is just a quick update for all in the historic flood we are now experiencing as a result of tropical moisture interacting with a strong mid/upper level difluent jet running SW to NE thanks to the trough and the old circulation of tropical storm Lee!  This is the radar derived totals to this point since 3 am yesterday morning....

And there is more yet to come as the training showers and storms are setting up to once again take aim in our general area......may they not fall over the "red" zone above, but it sure looks like ~2"+ is almost a sure bet by this evening in many locations in the Harrisburg area!  This is the Sterling VA radar as this is the source of our heavy rain.

And here is the official forecast from HPC for the 24 hours ending 8 am Friday morning....

And here is what I've personally reported over the last 2 weeks!  Simply incredible!

From a very personal standpoint, Kay and I truly feel for those of you who are dealing with flooding conditions of whatever proportion.  This flooding event is statistically a 1 in 100 yr event at least and more likely going to approach the 1:500 yr event like Hurricane Agnes was in 1972.  There was lots of hardship with that flooding I recall as a pup and I'm sure now as adults, these hardships are comparable to that massive flood.  It is incredible, but all of the major locations along the main stem of the Susquehanna are forecast to approach the Agnes record of 1972.  Here is the latest MARFC prediction for Harrisburg.....this would be the 3rd highest crest at Harrisburg since records began 120 years ago!  If the rains continue as forecast by HPC, it appears 30' would not be out of the question!

And the historical flood of the Swatara Creek in lower Dauphin County....note how the forecast (green) is below the obs as of 6 am this morning!  Not good!

Take care everyone...and be safe!

Smitty

AA:  Living through weather history yet once again in the greater Harrisburg, York & Lebanon areas!

Them There Cricks Are "Blown Out"

One of my esteemed colleagues educated me about the status of streams and creeks when they are at flood.  That central PA trout fishing term is "blown out".  Well, I would have to say that the tropical connection partially thanks to Lee, partially thanks to Katia, and partially thanks to the lifted jet far to the north over eastern North America.  Here is the water vapor image as of Wednesday afternoon.  Note the deep moisture being advected from the Bay of Campeche near the Yucatan Peninsula!  It is disconcerting that a small amount of Katia's moisture is actually getting involved with this plume of moisture....ouch!

I just took a snapshot of the current radar from State College.  It has looked this ugly most of the day.  The amount of rain has been training over the same region for most of the daylight hours today.  The greatest rainfall rates I observed from a co-op observer was 3"+ from the 11-12 noon hour.  The observation from a dedicated reader was 7.2" in Watts Twp in Perry County for the storm total.  At my humble abode in Etters, my wife reported 2.91 inches as of 11 am and that was from our 6 am report.  That makes just over 8.25" since Saturday in northern York County!  Wow!  What the radar below doesn't show is the copious amounts of radar returns that are aimed right at central PA.

So with all of this rainfall, here are the latest predictions of some of the streams in our area.  This flooding if it materializes on the Susquehanna will be the 3rd highest on record behind Agnes, the 1996 Walnut Street Flood and exceed Ivan in 2004.  It looks ugly for Harrisburg River flooding!  The crest as of now is forecast to top out early Saturday morning.  Please understand that river forecasting is one of the most difficult forecasts to make in the world of hydrology.  So many variables enter into the equations and the modeling is truly a work in progress.

And here is the Swatty's latest forecast....that record was back in June of 2004 due to simply tropical thunderstorms that fell for 3 days on/off over eastern Dauphin County and Schuylkill County.

Another reason why I am so concerned about the Susky is the forecast precip from HPC for this evening through tomorrow evening.  That bullseye of 4"+ in the upper drainage of the Susquehanna does not bode well.  I hope Dauphin County Emergency Management monitors the situation a bit more closely than they did today!

Well I always try to leave you with a bit of humor or something that is "off-the-wall".  Well this is too much of a good thing.....Enjoy the tunes if you're not bailing....

See everyone Friday?  Maybe? 

Smitty

AA:  It's raining, it's pouring, and Timmy, please report to the office along with countless others!

Deep Moisture From The Deep Tropics

Just a quick update on the deep moisture feed from deep in the Gulf Of Mexico.  The IR picture clearly shows this moisture streaming up the Appalachians and towards the Mid-Atlantic states.  This moisture plume is poised to dump copious amounts of rainfall over PA during the mid-week period.  Note Katia off to the east of the Bahamas.

Speaking of plumes, here are the plume diagrams from the Short Range Ensemble Forecasts (SREF) showing that most of the runs indicate at least a 4" rain event to affect KMDT.  Let's hope that 11"+ run doesn't verify!  I usually like to use these plumes for winter weather precipitation events, but the quantity of the rainfall can be quickly analyzed with these plots.

As can be done with a normalized plot on a map.  However, when normalizing the model output, the extremes are smoothed and often what is mapped is less than what actually falls from the sky.  That is not a good scenario for the Mid-Atlantic as seen below.  This map is quite disconcerting for the flooding potential that will occur over PA later this week.  And the Susquehanna is not outside the possibility of flooding either as this rainfall would be onto already saturated ground....nearly 100% runoff.  Here is that most concerning map.

As for Katia, the upper air graphic below argues that Katia could just as easily be pulled towards the continent as getting swooshed out to sea by the westerlies.  The ridge to her east and the trough to her west are in such a position that this hurricane could get moved either way.  If the trough is just a bit deeper to the west or the ridge just a bit higher to the east, that storm will hit the US, likely on Long Island and then up into New England.  Either way, very large surf will be present all up and down the east coast this week.

So off to finish watching the Phillies...here's hoping they get 5 innings complete as some fairly heavy rain is on the doorstep at the Bank!

Enjoy your Tuesday.

Smitty

AA:  Heavy rain a near certainty this week with us receiving ~5" in total by Thursday!

Ug-Lee Week Ahead

Weatherwise, we will have an U-G-LEE week as the tropical moisture fetch streams northeastward from the remnants of Lee.  Poised just to our west this morning is a strong frontal boundary separating very humid air to the east (we are in the soup this am) and very autumnal air to the west.  You can clearly see this divide as per the water vapor image below.  Note how the dry air has moved south all the way to gulf coast of western LA and TX!  At DFW the winds are northerly at 20 gusting to 40 with a dewpoint of 45 as of 6 am!  Shreveport, LA has similar surface conditions.  remember, the black is very dry whereas the white is very wet in the middle and upper levels of the atmosphere. That large moisture blob is moving northeast and WILL affect our wx here in PA for most of the upcoming week.

Here is the latest computer generated precip for the eastern US as per the GFS through next weekend.  Look at that bulls eye of 10+" rainfall over central PA!  I guess some sump pumps will be getting a workout this week.....ouch! 

You can also see the path of Katia and that the GFS keeps this storm well offshore....and that is a good thing.  But not all of the modeling is in agreement as the Canadian (Reggie is its nickname in the meteo circles (GGEM)) clearly has an east coast situation that the people of NJ, LI, and New England just don't want to see!  This map is progged for Friday afternoon!

And Katia is beginning to strengthen quite nicely as it has moved into a very favorable location atmospherically overnight....take a look at this Cat 2 storm with a beautiful eye!  This is an IR pic, the visible is not as contrasting due to the sun angle at this early time of day.  But I'll post it anyway....

Here is the visible cloud shot of Katia early Labor Day morning.....

So lots of wx this week.  As the week progresses, we will see how Katia pans out for the northeast US.  It is still not out of the question that this storm does DIRECTLY affect NJ or points north.  And if you believe the UKMET, the Outer Banks of NC are not out of harms way as of this posting.  But the official wx map from the NWS looks something like this for Friday this week with Katia moving away from the US Mainland.  Time will tell......

So wild is the weather word this week.  Wild like the Phillies game on Sunday in south FL where the Marlins left 23 on base in the 14 inning marathon.  But the real story of that game is that replay has now been made arbitrarily the manner in which to judge and officiate ALL calls, not just home runs!  Cowboy Joe West seems to think that "after further review" should not be relegated to the NFL  any longer.  Charlie seemed to think that was not kosher and was asked to leave the game without West listening to any of his rationale!  Charlie played the game in protest.  And now we wait and see what the spineless commissioner will do...but the Phillies should have won the game by regulation as they were a lofty 2 for 12 with runners in scoring position!  Oh well.......

You go Charlie!

Have a great Labor Day....albeit a wet one.  Etters is reporting 1.56" so far thanks to the overnight storms!  The week long deluge has begun....

Smitty

AA:  Wet week with tropical remnants of Lee affecting us with the potential of easily seeing 6" of rain by Friday.  Hoping that Katia stays out to see.  Phils in a lengthy game played under protest yesterday in Miami.

Lots of Water Available for Rain

The water vapor image above shows very nicely ALL of the fuel the atmosphere is holding in terms of the creation of showers and thunderstorms over the upcoming several days.  The strong front that is currently over the Midwest will slowly move eastward over the next 36 hours.  As it does, this will most certainly create the little bit of umph to get the air in our area to discharge storms later Sunday and all day Labor Day.  If you scrutinize the WV image, you'll see the flow pattern across the US and note that the flow is parallel to the front (in IA and WI) and that is why the front will limp through PA later tomorrow.  It is also easy to see Lee swirling in the northern gulf.  Note the pocket of very dry air at the western edge of the map on the NV CA border marking the driest place in North America; Death Valley!

The guidance for Lee is very erratic at best.  However, the global models have been consistent in moving Lee up the spine of the Appalachians delivering copious amounts of rainfall over the eastern US this upcoming week.  First the "spaghetti" looking guidance from the tropical models for Lee.  Note how some of the models take this storm to SE TX, some to MO, and some to PA and points northeast......

And now the total rainfall modeled by the GFS through next weekend.  Central and southeastern PA is looking at ~5" of rain.....and that is if Katia stays out to sea....and that is a HUGE IF since 2 of the global models are now beginning to bring Katia much further west and the moisture if not the wind field will certainly have an impact on the along the coast and possibly a bit inland.

Here is the modeling for Katia again first with the "spaghetti" of the tropical models.

If the trough out over the northern plains translates across the US and deepens as it does so, then the recurve of Katia is nearly certain.  However, if that trough "misses" Katia, all bets are off and Katia could and more likely will impact the coastal US.  Yesterday it was appearing the trough would deflect Katia towards the fish.  Today, the consensus is not as great.  So we will see how the global pattern evolves.  Here is the worst global model where Katia is farthest south and west and would most certainly affect the eastern US, quite adversely I might add.  This is the UKMET (England's) and is often capable of sniffing out the global patterns as astutely as the Euro and the GFS.  That map below is ugly for any/all east coast interests.  Note the placement of Lee in TN with the inverted trough moving into OH and sw PA!  That map is actually very exciting in a "sick" way!

Below if the official forecast map for Wednesday.  If Katia is a bit further south and west at that point, then the moisture from Katia in the upper levels of the atmosphere will most certainly become entrained into the now baroclinic Lee.

That upper level scenario would look something like this......note how the isobars join from Katia to the upper level weakness over the TN Valley.  This is potentially a very wet scenario for the piedmont as the air would orographically be lifted from sea level!



So....much to watch this weekend weatherwise.  Enjoy your Labor Day weekend.  Kind of a misnomer since at least 1 in 10 Americans are not laboring in this political policy crushing economy.  Maybe in 14 months, the public will choose for economic growth and not these progressive socialistic ideals that have gotten most of the world economy in the tank!  This is the UE rate in PA...

Have a great Sunday!

Smitty

AA:  Showers and storms frequent through Monday.  Then watching the moisture from Lee Tuesday pm to Thursday.  Then watching Katia.  We are lucky to have a job this labor day holiday!