The lull ends

[Updates follow original entry; latest as of 11am EDT Wed.]

The long road to recovery continues in the wake of Hurricane Ike from Texas (nearly a million people still without power) and Louisiana all the way to Ohio and nearby states. There are also indirect repercussions such as those here in the Atlanta metro area, where gasoline has become increasingly hard to find.

In fact, the direct effects from Ike only recently subsided, per this from the National Weather Service issued a couple nights ago:

COASTAL HAZARD MESSAGE
NATIONAL WEATHER SERVICE LAKE CHARLES LA
938 PM CDT SAT SEP 20 2008

...STORM SURGE FLOODING CONTINUES TO SLOWLY DIMINISH ALONG THE COAST...

BOWLED-UP GULF WATER CONTINUES TO COVER LARGE AREAS OF LAND. IN ADDITION...THE ACTUAL TIDES ARE RUNNING ABOUT A FOOT ABOVE THE LUNAR TIDE TABLE VALUES.

CONSEQUENTLY...A COASTAL FLOOD WARNING WILL REMAIN IN EFFECT UNTIL THIS AWASHED SEA WATER DRAINS...AND/OR FURTHER INFILTRATES INTO THE GROUND...AND/OR EVAPORATES.

A COASTAL FLOOD WARNING WILL REMAIN IN EFFECT UNTIL HIGHWAYS AND SECONDARY ROADS ARE PASSABLE IN THE WARNED AREA.

Finally yesterday that statement was allowed to expire and was not reissued, but given how agitated the tropical atmosphere has been since July, one would think it'd be too much to ask for the recent lull in weather since Ike to continue, and indeed it has come to a screeching halt.

A few days ago, on Thursday, there was a flare-up of convection (deep rain clouds and thunderstorms) over the Windward and Leeward Islands as a tropical wave interacted with an upper-level trough.

That convection has been peskily persistent, and although the system is still disorganized, meaning no tropical storm (Kyle) or even tropical depression yet, this statement from the Puerto Rico office of the NWS on Sunday illustrates yet again how tropical systems of different intensites, structures, and sizes can produce a variety of significant impacts, from wind to surge/waves to rain, with a tropical cyclone not even being necessary for the latter:

... SOME AMAZING RAINFALL AMOUNTS. PER U.S.G.S. RAIN GAGES...ALREADY 4" TO 12"+ OF RAIN HAVE FALLEN OVER PARTS OF EAST AND SOUTHEAST PUERTO RICO AND IT CONTINUES TO RAIN HEAVILY.

ALREADY MANY RIVERS FLOODED AND THE SLOW-MOVING NATURE OF THIS SYSTEM MEANS THE POTENTIAL FOR SOME EXTREME TO CATASTROPHIC FLOODING IN SOME LOCATIONS.

And, this morning:

STORM TOTAL RAINFALL AMOUNTS HAVE EXCEEDED 20 TO 30 INCHES IN PARTS OF SOUTHEAST PUERTO RICO WHERE RIVERS ARE WELL ABOVE FLOOD STAGE. BECAUSE THIS SYSTEM IS MOVING SO SLOWLY THE POTENTIAL FOR FLOODING IS VERY HIGH AND THAT FLOODING WILL BE...AND INDEED ALREADY IS...MORE SERIOUS THAN ANY THAT HAS OCCURRED IN RECENT MEMORY.

This set of user videos submitted to weather.com gives a flavor of the scene with ominous storm clouds, gusty winds, torrential downpours, and streets turning into rivers. Alas, there are reports of lives already having been lost from the flooding, and radar still shows plenty of heavy rain in and around Puerto Rico and the Virgin Islands, and encroaching upon the Dominican Republic.

At the same time, there's a situation brewing not far away, as a strong high pressure system builds over the northeast U.S.

During the next couple of days the pressure "gradient" that now exists between the high and relative low pressure just offshore of the Carolinas will increase. That means winds of gale (tropical storm) force blowing across a sizeable fetch toward the shore, which in turn means pounding waves and rip currents, and the likelihood of at least some beach erosion and coastal flooding. The focal point will be the Mid-Atlantic region, though high surf will be experienced down to Florida (it already has from a precursor system) and the effects from this weather situation could eventually be felt in the Northeast.

What's uncertain is to what extent and in what manner the system from the tropics will interact with the other goings-on ... Stay tuned ...

UPDATE 5PM TUE SEP 23

The East Coast system is still on track to produce a strong onshore flow, peaking tomorrow into Thursday; the tropical disturbance is still weak and disorganized wind-wise with its future track and intensity uncertain, but is continuing to produce locally heavy rain in Puerto Rico and the Dominican Republic.

UPDATE 11AM EDT WED SEP 24

The system near the East Coast is developing on schedule; it has a combination of non-tropical characteristics (a low pressure system on a front along with a broad wind field) and tropical characteristics (convection concentrating near a low-level center, within the smaller red circle on the satellite image).

The National Hurricane Center is sending a Hurricane Hunter plane in to investigate and probably won't do anything with the official classification until the plane arrives this afternoon.

Regardless of what they call it, the effects will include gusty winds, high surf, and elevated water levels on the coast. So in that sense it doesn't matter; however if the cyclone were to truly become more tropical in structure then it could also have a concentrated area of stronger winds near its center.

Meanwhile, good news is that the disturbance which was of tropical, not non-tropical, origin has, at least for now, become even weaker and more disorganized (green circle).