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Posted at 9:30 AM ET, 09/ 2/2010

Intense Hurricane Earl barrels toward East coast

By Capital Weather Gang

Answers to frequent questions about Earl

* Awaiting weekend relief: Full Forecast | BeachCast *
* Hurricane Tracking Center | Warmest summer on record *


Satellite image of Hurricane Earl this morning. Credit: NOAA.

updated at 11:15 a.m.

At 11 a.m., Hurricane Earl was 300 miles south of Cape Hatteras, N.C., heading north at 18 mph. Maximum sustained winds were 140 miles per hour and Earl remains a powerful Category 4 hurricane, with hurricane-force winds extending outward up to 90 miles from its center and tropical storm-force winds out to 230 miles.

We imagine you have many questions about this dangerous storm, so here are some Qs and As:

What is expected for the D.C. Metro area?

At the moment, the track of Earl should be sufficiently far off the coast to only bring high clouds and an outside (20%) chance of some gusty showers.

Could these impacts be worse than expected and even bring severe conditions into the Washington metro area?

Yes but very unlikely. As hurricane track prediction is an imperfect science, there is a very slight possibility of significant storm effects in D.C. However, computer models have consistently kept Earl sufficiently far offshore, due to a cold front coming from the west that should push Earl away. Therefore, we're confident that chances for heavy rain and wind in the metro region are low. The models (and the National Hurricane Center) would have to be catastrophically wrong for the D.C. metro region to experience a repeat of Hurricane Isabel, for example.

Closer to the coast, however, the margin for error is smaller -- and even a slight shift in track closer to the shoreline (to the west) would mean more rain and wind, bigger waves and more damage. The Outer Banks of North Carolina, in particular, could experience devastating impacts if Earl maintains its current intensity and passes directly overhead. The more likely scenario, however, is that the core of Earl will remain offshore as it passes the Outer Banks, where serious impacts expected even though sustained hurricane-force winds are not a certainty.

Keep reading for more Qs and As...

Could the impacts be not as bad as expected for the coastal region?

Yes. A slight jog in Earl's track to the east might mean only tropical storm conditions for the NC Outer Banks and even more mild conditions for VA/MD/DE beaches -- which might only experience some gusty showers and high surf under this scenario.

Should I cancel my trip to the beaches this weekend?

The worst of the storm will occur from tonight through tomorrow morning in the NC Outer Banks and late tonight through early afternoon for the VA/MD/DE beaches. We would recommend postponing travel plans to these areas until at least Friday afternoon. And at that point, you should check what the local conditions are like where you're traveling and whether officials have deemed those areas safe.

By Friday night and Saturday, the storm will have accelerated to the northeast and will be clear of the mid-Atlantic. However, travel may not be advisable to locations where there have been severe impacts (e.g. power outages, wind damage and/or flooding).

What kind of flooding might occur in the tidal Potomac and Chesapeake Bay?

Minor flooding is possible, primarily overnight tonight. A Coastal Flood Advisory & Coastal Flood Watch are in effect for the tidal Potomac and Maryland Chesapeake Bay. From the National Weather Service in Sterling:

WHEN HURRICANE EARL REACHES IS CLOSEST POINT TO THE WATERS...OFF THE DELMARVA PENINSULA...TIDAL ANOMALIES MAY INCREASE FURTHER FOR THE WATERS OF THE TIDAL POTOMAC RIVER AND MARYLAND CHESAPEAKE BAY...POTENTIALLY 1 TO 3 FEET ABOVE NORMAL. THE SPEED AND PROXIMITY TO LAND OF HURRICANE EARL WILL BE KEY IN HOW HIGH WATER LEVELS GET. THERE IS THE POSSIBILITY OF MINOR TO MODERATE TIDAL FLOODING TONIGHT ACROSS PORTIONS OF THE MARYLAND CHESAPEAKE BAY AND TIDAL POTOMAC RIVER.

What is expected for the Outer Banks of North Carolina?

The National Weather Service Office in Newport/Moorehead City, NC predicts the following:

WINDS ARE EXPECTED TO INCREASE TO TROPICAL STORM FORCE LATE THIS AFTERNOON ACROSS PORTIONS OF THE AREA AND WILL CONTINUE THROUGH FRIDAY MORNING. THE MOST SIGNIFICANT THREAT OF HURRICANE FORCE WINDS WILL BE FROM DOWNEAST CARTERET COUNTY THROUGH OCRACOKE AND THE OUTER BANKS. THIS WILL BRING A SIGNIFICANT THREAT OF WIND DAMAGE AND POWER OUTAGES TO COASTAL LOCATIONS IN EASTERN NORTH CAROLINA. PLEASE NOTE THAT THE EXACT FORECAST TRACK IS SUBJECT TO SHIFT. DUE TO THE STRENGTH OF THE STORM AND PROXIMITY TO THE COAST...EVEN A SMALL CHANGE IN TRACK COULD RESULT IN SIGNIFICANTLY DIFFERENT CONDITIONS IN
EASTERN NORTH CAROLINA.

HEAVY RAINFALL OF 3 TO 5 INCHES WILL BE POSSIBLE ALONG THE OUTER BANKS...WITH AROUND TWO INCHES POSSIBLE OVER DOWNEAST CARTERET COUNTY. ISOLATED FLOODING OF LOW SPOTS WILL BE POSSIBLE ON THE OUTER BANKS. RAINFALL WILL DECREASE TO LESS THAN AN INCH IN THE WESTERN PORTION OF THE WARNED LOCATIONS.

SIGNIFICANT SWELLS WILL BRING A HIGH RISK OF STRONG RIP CURRENTS TODAY THROUGH FRIDAY. LARGE BREAKING WAVES OF 15 FEET OR HIGHER ARE EXPECTED ALONG THE OUTER BANKS AND 10 TO 15 FEET ALONG THE CRYSTAL COAST. STORM SURGE OF 2 TO 4 FEET IS POSSIBLE OCEAN SIDE LOCATIONS NORTH OF CAPE LOOKOUT. THIS COMBINED WITH SIGNIFICANT WAVE ACTION WILL RESULT IN SIGNIFICANT EROSION AND OVERWASH. INUNDATION OF 3 TO 5 FEET IS ALSO POSSIBLE SOUNDSIDE ON THE OUTER BANKS AND IN THE LOWER NEUSE RIVER AND SOUTHERN PAMLICO AND CORE SOUND AREAS IN CARTERET COUNTY.

What is the story for the MD/DE beaches?

A tropical storm warning and hurricane watch are in effect. Here is a summary of what to expect from the National Weather Service Forecast Office at Mount Holly, Pa:

...PROBABILITY OF TROPICAL STORM/HURRICANE CONDITIONS...
THE CHANCE FOR HURRICANE CONDITIONS AT THIS TIME IS VERY SMALL. ALSO...THE CHANCE FOR TROPICAL STORM CONDITIONS AT THIS TIME IS UP TO 50 PERCENT. THIS REPRESENTS A GENERAL UPWARD TREND SINCE THE LAST FORECAST.

...WINDS...
AS HURRICANE EARL APPROACHES...SUSTAINED TROPICAL STORM FORCE WINDS ARE EXPECTED TO BEGIN FRIDAY MORNING AND LAST INTO FRIDAY. ISOLATED POWER OUTAGES WILL BE POSSIBLE.

...STORM SURGE AND STORM TIDE...
THE IMPACT FROM COMBINED STORM SURGE AND TIDE WATERS IS EXPECTED TO BE MINOR TO MODERATE. THE STORM SURGE IS FORECAST TO RANGE FROM 1 TO 2 FEET...PERHAPS LOCALLY 3 FEET.

...COASTAL HAZARDS...
HIGH SURF IS EXPECTED FROM THURSDAY NIGHT INTO FRIDAY WITH MINOR TO MODERATE BEACH EROSION.

...RIP CURRENTS...
THERE WILL BE A HIGH RISK OF RIP CURRENTS THURSDAY AND FRIDAY AT AREA BEACHES. BEACH GOERS ARE URGED TO STAY OUT OF THE WATER.

What are the predicted conditions around Virginia Beach and the Tidewater?

A tropical storm warning and a hurricane watch is in effect. Here is a summary of what to expect from the National Weather Service Forecast Office at Wakefield, Va.:

THE WINDS WILL BEGIN TO INCREASE THURSDAY EVENING...REACHING TROPICAL STORM STRENGTH AFTER MIDNIGHT THEN SPREAD NORTHWARD OVERNIGHT....WITH HURRICANE FORCE WIND GUSTS ANTICIPATED ALONG THE NORTHEAST NORTH CAROLINA COAST. THE STRONG WINDS WILL CONTINUE INTO FRIDAY MORNING OVER THE WARNED AREAS. STORM SURGE VALUES BETWEEN 2 AND 3 FEET ARE ANTICIPATED ACROSS THE ATLANTIC COAST IN NORTHEAST NORTH CAROLINA DURING HIGH TIDE OVERNIGHT TONIGHT AND AGAIN FRIDAY AFTERNOON...WHICH WOULD RESULT IN MODERATE TO SEVERE COASTAL FLOODING. OVER THE TIDEWATER REGION ALONG SOUTHERN CHESAPEAKE BAY...STORM SURGE VALUES EXPECTED TO PEAK BETWEEN 1.5 AND 2 FEET...WHICH WOULD RESULT IN MINOR TO MODERATE COASTAL FLOODING. BANDS OF RAIN ARE EXPECTED TO BRING BETWEEN .5 TO 1 INCHES OF RAINFALL OVER MOST OF THE WARNED AREAS...WITH LOCALLY HIGHER AMOUNTS OF 2 TO 3 INCHES POSSIBLE ALONG COASTAL SECTIONS OF NORTH CAROLINA.

SIGNIFICANT SWELLS WILL BRING A HIGH RISK OF STRONG RIP CURRENTS TODAY THROUGH FRIDAY. LARGE BATTERING WAVES WILL ALSO LIKELY PEAK BETWEEN 14 AND 18 FEET IN THE COASTAL WATERS WITH HIGH SURF ALONG THE COAST. THE ANTICIPATED STORM SURGE COMBINED WITH THE HIGH SURF WILL CAUSE SIGNIFICANT BEACH EROSION AND OVERWASH ISSUES ALONG THE MID ATLANTIC COAST...MOST NOTABLY FROM VIRGINIA BEACH SOUTH.

Why didn't Earl weaken but rather than intensify yesterday given the dry air in its surrounding?

(1) It's possible that Earl has/had a double eyewall structure that prevented the inner core from ingesting the extremely dry air surrounding it.

(2) Additionally, there is not alot of shear (winds that change speed and/or direction with height and tend to weaken storms) around Earl (yet), and without environmental winds to help the dry air to get in there, it takes a little longer.

By Capital Weather Gang  | September 2, 2010; 9:30 AM ET
Categories:  Tropical Weather  
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Next: Earl threatens coast from N.C. to New England

Comments

FIRST

Posted by: gjjg4dgd | September 2, 2010 9:40 AM | Report abuse

NC ordered mandatory evac of Dare Co. a couple hours ago, which I think means the 158 bridge is closed to oncoming traffic (so all lanes can accommodate traffic leaving OBX).

Posted by: fleeciewool | September 2, 2010 9:43 AM | Report abuse

If you look to the southeast (here in DC) you can actually see the extreme outer edge of the high clouds associated with Earl starting to creep northward.

Posted by: fleeciewool | September 2, 2010 9:46 AM | Report abuse

There's only 20% chance of even getting some freaking rain?

Posted by: SusanMarie2 | September 2, 2010 10:18 AM | Report abuse

What will winds be line in the chalestown WV area on Saturday?

Posted by: snowlover | September 2, 2010 10:48 AM | Report abuse

What will it be like on the coast of MA? What would be the better day to drive to MA?

Posted by: mmad2 | September 2, 2010 11:10 AM | Report abuse

It certainly appears at this point that Earl will be kept offshore by the Gulf Stream and the trough to the west. Heavy surf and a few tropical rainbands appear to be all that's in the offing. So says this amateur hurricane watcher.

Posted by: herrbrahms | September 2, 2010 11:18 AM | Report abuse

People at work (who live in Crystal City and PG County) are getting text alerts about prepping for the imminent arrival of Earl. I keep trying to tell them that the storm is not moving west and at most we'll get some wind and rain. Anyone else seeing these alerts?

Posted by: phan1 | September 2, 2010 11:19 AM | Report abuse

@snowlover

Could see some gusts to around 25-30 mph on Saturday (mainly a result of flow from the west behind a cold front, but enhanced some by Earl).

@SusanMarie2

Yep ... our forecast for the metro area has been pessimistic on rain chances from Earl for several days now, and that continues. Can't rule out a shower Friday night from a cold front passing through, but even those chances are on the low side.

Posted by: CapitalWeatherGang | September 2, 2010 11:26 AM | Report abuse

@snowlover

Earl will have zero, nada impact on Charleston, WV.

@mmad2

By Saturday afternoon, the worst should be clearing Mass (worst conditions will be Friday night) Stay tuned for an update on New England impacts coming soon...

Posted by: CapitalWeatherGang | September 2, 2010 11:26 AM | Report abuse

The feeder bands for Earl we are seeing so far today are not as distinct as some previous ones. That's quite a sight when they are. Maybe we will see some later on.

Posted by: jaybird926 | September 2, 2010 11:52 AM | Report abuse

Thanks CWG! Wow, without that cool front we could have a major hurricane hit DC!

Posted by: SusanMarie2 | September 2, 2010 12:28 PM | Report abuse

Normally we would get some rain with the frontal passage, as temperatures cool drastically.

What's probably happening is that subsidence of air being thrown outside of Earl is causing the air to heat up and dry out as it descends, thus suppressing precipitation which would normally accompany the frontal passage. However if Earl begins advecting moisture in our direction, this moisture should form rain clouds if it's lifted by the passing front. This explains the 20% to 30% chance of rain being mentioned late tomorrow as the front passes. Such rain would likely occur as isolated frontal thunderstorms. No rain bands from Earl are currently expected this far west.

Posted by: Bombo47jea | September 2, 2010 12:40 PM | Report abuse

That's why we have never had a "major" hurricane hit here. There is always a front of some type that hurricanes bounce off of.

Some might say Hazel was a major hurricane but that one managed to come up the Bay.

Posted by: MKadyman | September 2, 2010 12:43 PM | Report abuse

New post up!

Posted by: snowedin85 | September 2, 2010 1:04 PM | Report abuse

You guys are making me nostalgic-the last time I saw a team forecast (that I can remember) was during snowmageddon, snOMG, and snoverkill. This record hot summer is making me miss those days.

Posted by: BruinGirl2001 | September 2, 2010 1:49 PM | Report abuse

Hoping to fly down tomorrow (Friday) afternoon, from Boston to BWI. Does the CWG have any thoughts on potential travel issues?

Posted by: carolyn2006 | September 2, 2010 2:22 PM | Report abuse

The comments to this entry are closed.

 
 
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