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**Hurricane Dorian Mega Thread**

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Gfs gets Dorian close to Charleston then it kicks northeast towards obx. 

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37 minutes ago, Andrew Maddis said:

I believe we get our rain from the PRE as most, if not all of Dorians rains miss us. 

 

While some upper level jet/trough/TC interaction will occur spreading moisture out ahead of the system, whether or not a true PRE occurs is still up in the air... And assuming it does occur, exactly where is even less certain.

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Excuse my ignorance, I should really know this but what is PRE?

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11 minutes ago, sferic said:

Excuse my ignorance, I should really know this but what is PRE?

Preceding rain event. Usually occurs when deep tropical moisture from the tropical entity begins to get drawn northward and entrained into mid-latitude systems before/in advance of the tropical entity itself.

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Looks to me like 12z operational global models (so far) have wobbled back east and just barely avoid a direct U.S. landfall. Probably model noise at this point, but would be supported by an increasingly more “attractive” appearance of Dorian.

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1 hour ago, 33andrain said:

Dorian fatigue has set in. But, north of FL, into GA and SC especially, residents should remain vigilant. I wouldn't be surprised to see Dorian restrengthen back to a high end cat 3 over the next 20-30 hours. What happens next along the SE coast could be quite the news story.

Dorian fatigue is real, though I question how much the system will be able to officially intensify despite the warm gulf waters. Once the core re-shuffled & that energy was dispersed outward, it became markedly difficult for the system to re-consolidate. That being said, some modest strengthening is possible & any weakening will be delayed now that the eyewall is structurally sound & it has sufficient fuel out ahead. Besides, in my opinion, it's a double edged sword... Considering the track, I'd almost say the expansive windfield is worse due to its reach & exacerbation of storm surge since the on-shore flow occurs over a longer period of time.

 

That & the severe threat/expanded rain shield etc etc as well.

 

At the end of the day, I agree, many people have forgot about the storm/don't care & it'll unfortunately end up being quite the story... There will be some pretty severe effects along the SC/NC coast for sure. I'm particularly concerned about surge in Charleston up to Myrtle Beach due to the geography & angle of approach.

 

image.png

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1:00pm NHC update:

 

Hurricane Dorian Tropical Cyclone Update
NWS National Hurricane Center Miami FL       AL052019
100 PM EDT Wed Sep 04 2019

...DORIAN MOVING PARALLEL TO THE NORTHEASTERN COAST OF FLORIDA...
...RAINBANDS BRINGING HEAVY RAIN AND GUSTY WINDS TO THE SOUTHEAST US
COAST...

A WeatherFlow station in Jacksonville recently reported sustained
winds of 43 mph (69 km/h) with a gust to 55 mph (88 km/h).

An Air Force Reserve Hurricane Hunter aircraft recently reported a
minimum central pressure of 963 mb (28.44 inches).

SUMMARY OF 100 PM EDT...1700 UTC...INFORMATION
----------------------------------------------
LOCATION...30.1N 79.7W
ABOUT 100 MI...160 KM NE OF DAYTONA BEACH FLORIDA
ABOUT 190 MI...305 KM S OF CHARLESTON SOUTH CAROLINA
MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H
PRESENT MOVEMENT...NNW OR 335 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...963 MB...28.44 INCHES

$$
Forecaster Zelinsky

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Latest NHC Hourly Update:

 

000
WTNT65 KNHC 041956
TCUAT5

Hurricane Dorian Tropical Cyclone Update
NWS National Hurricane Center Miami FL       AL052019
400 PM EDT Wed Sep 04 2019

...RAINBANDS OF DORIAN CONTINUE TO BRING HEAVY RAIN AND GUSTY
WINDS TO THE SOUTHEAST U.S. COAST...

A Weatherflow site at Folly Beach Pier, just south of Charleston,
SC, recently measured sustained winds of 39 mph (63 km/h) and a gust
to 51 mph (82 km/h).

The most recent minimum pressure reported by an Air Force Reserve
Hurricane Hunter plane was 962 mb (28.41 inches).

SUMMARY OF 400 PM EDT...2000 UTC...INFORMATION
----------------------------------------------
LOCATION...30.4N 79.8W
ABOUT 115 MI...185 KM E OF JACKSONVILLE FLORIDA
ABOUT 165 MI...265 KM S OF CHARLESTON SOUTH CAROLINA
MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H
PRESENT MOVEMENT...NNW OR 340 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...962 MB...28.41 INCHES

$$
Forecaster Zelinsky

As I said above, Dorian needs to make that curve north east very soon to avoid encroaching onto the coast or inland.

 

I don't think anyone posted the discussion from the last full advisory so I'll show this below now + the latest wind warning maps:

 

NHC Discussion from Advisory 45:

615 
WTNT45 KNHC 041458
TCDAT5

Hurricane Dorian Discussion Number  45
NWS National Hurricane Center Miami FL       AL052019
1100 AM EDT Wed Sep 04 2019

Satellite imagery indicates that the cloud tops in the eyewall of
Dorian have cooled significantly during the past few hours, with the
eye becoming better defined in NOAA Doppler radar data.  However,
just-received reports from an Air Force Reserve Hurricane Hunter
aircraft show that the hurricane has changed little in intensity,
with maximum winds remaining near 90 kt and the central pressure
near 964 mb.  The aircraft data show that hurricane-force winds are
roughly 50 n mi offshore of the northeastern Florida peninsula,
while surface observations show that tropical-storm conditions are
affecting portions of the coast of northeastern Florida.

The initial motion is now 335/8.  Dorian is moving around the
western end of the subtropical ridge, and it should recurve
northward and northeastward into the mid-latitude westerlies during
the next 24-48 h.  This motion should bring the center of Dorian
near or over the coast of North Carolina during the 36-48 h period.
After that time, the cyclone is forecast to accelerate northeastward
into the Atlantic toward the Canadian Maritimes, with a quick
northeastward motion continuing for the remainder of the cyclone's
life.  The track guidance is very tightly clustered, and the new
forecast track, which has only minor changes from the previous
forecast, lies in the center of the guidance envelope near the
consensus models. It should be noted that the track is close to and
almost parallel to the coast of the southeastern United State, and
any deviation to the left of the track could bring the center
onshore anywhere in the Carolinas.

Dorian is expected to remain in an environment of light to moderate
vertical wind shear and warm sea surface temperatures during the
next 48 h.  As a result, the hurricane is expected to maintain
Category 2 intensity as it passes near the southeastern United
States coast.  After 48 h, increasing shear and dry air entrainment
should cause a weakening trend.  Extratropical transition should
begin near the 72 h time, and the cyclone is forecast to become a
hurricane-force extratropical low by 96 h near or over Nova Scotia
and Newfoundland.

Since the NHC track prediction continues to take Dorian dangerously
close to the southeast U.S. coast, all interests from northeast
Florida to the Carolinas should remain vigilant to the possibility
of experiencing destructive winds, flooding rains, and life-
threatening storm surges from this hurricane.

Key Messages:

1. Life-threatening storm surge and dangerous winds are expected
along portions of the Florida east coast and the coasts of Georgia,
South Carolina, North Carolina, regardless of the exact track of
Dorian's center.  Water levels could rise well in advance of the
arrival of strong winds.  Residents in these areas should follow
advice given by local emergency officials.

2. The risk of dangerous storm surge, wind, and rain impacts along
portions of the Virginia coast and the southern Chesapeake Bay
continues to increase. Residents in these areas should continue to
monitor the progress of Dorian.

3. Flash flooding will become increasingly likely across coastal
Georgia into the eastern Carolinas tonight into Friday. There is a
high risk of flash flooding over coastal sections of the Carolinas,
where significant, life-threatening, flash flooding is expected.

FORECAST POSITIONS AND MAX WINDS

INIT  04/1500Z 29.8N  79.7W   90 KT 105 MPH
 12H  05/0000Z 30.8N  80.0W   90 KT 105 MPH
 24H  05/1200Z 31.9N  79.8W   85 KT 100 MPH
 36H  06/0000Z 33.1N  78.6W   85 KT 100 MPH
 48H  06/1200Z 34.8N  76.4W   85 KT 100 MPH
 72H  07/1200Z 39.9N  68.2W   75 KT  85 MPH
 96H  08/1200Z 47.5N  59.0W   70 KT  80 MPH...POST-TROP/EXTRATROP
120H  09/1200Z 55.0N  46.0W   60 KT  70 MPH...POST-TROP/EXTRATROP

$$
Forecaster Beven

 

dor100e.JPG

 

dor100f.JPG

 

I'll look at the satellite imagery next. Back shortly.  David :)  

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Dorian is a bit stronger.... and a lot larger in size too as it approaches the SE coast. 961mb/110mph as of the 5:00pm advisory.

 

BULLETIN
Hurricane Dorian Advisory Number  46
NWS National Hurricane Center Miami FL       AL052019
500 PM EDT Wed Sep 04 2019

...AIR FORCE HURRICANE HUNTER REPORTS THAT DORIAN HAS STRENGTHENED A
LITTLE...
...EYE NOW EAST OF THE COAST OF SOUTHEASTERN GEORGIA...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...30.6N 79.8W
ABOUT 150 MI...245 KM S OF CHARLESTON SOUTH CAROLINA
ABOUT 275 MI...440 KM SSW OF WILMINGTON NORTH CAROLINA
MAXIMUM SUSTAINED WINDS...110 MPH...175 KM/H
PRESENT MOVEMENT...NNW OR 345 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...961 MB...28.38 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The Storm Surge Warning has been extended northward to Poquoson,
Virginia, including Hampton Roads.

A Tropical Storm Warning has been issued from the North
Carolina/Virginia border to Chincoteague, Virginia, and for the
Chesapeake Bay from Smith Point southward.

A Tropical Storm Watch has been issued from north of Chincoteague,
Virginia, to Fenwick Island, Delaware, for the Chesapeake Bay from
Smith Point to Drum Point, and for the Tidal Potomac River south of
Cobb Island.

The Storm Surge Warning and Tropical Storm Warning have been
discontinued south of the Flagler/Volusia County line.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for...
* Flagler/Volusia County line FL to Poquoson VA
* Pamlico and Albemarle Sounds
* Neuse and Pamlico Rivers
* Hampton Roads

A Hurricane Warning is in effect for...
* North of Savannah River to the North Carolina/Virginia border
* Pamlico and Albemarle Sounds

A Hurricane Watch is in effect for...
* North of Ponte Vedra Beach FL to Savannah River

A Tropical Storm Warning is in effect for...
* Flagler/Volusia County FL line to Savannah River
* North Carolina/Virginia border to Chincoteague VA
* Chesapeake Bay from Smith Point southward

A Tropical Storm Watch is in effect for...
* North of Chincoteague VA to Fenwick Island DE
* Chesapeake Bay from Smith Point to Drum Point
* Tidal Potomac south of Cobb Island

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours in the indicated locations. For a depiction
of areas at risk, please see the National Weather Service Storm
Surge Watch/Warning Graphic, available at hurricanes.gov.  This is a
life-threatening situation.  Persons located within these areas
should take all necessary actions to protect life and property from
rising water and the potential for other dangerous conditions.
Promptly follow evacuation and other instructions from local
officials.

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area.  Preparations to protect life and
property should be rushed to completion.

A Hurricane Watch means that hurricane conditions are possible
within the watch area.  A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
dangerous.

A Tropical Storm Warning means that tropical storm conditions are
expected within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

Interests elsewhere along the Mid-Atlantic coast of the United
States should continue to monitor the progress of Dorian, as
additional watches or warnings may be required later today.
Interests in southeastern New England should also monitor the
progress of the hurricane.

For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.


DISCUSSION AND OUTLOOK
----------------------
At 500 PM EDT (2100 UTC), the center of Hurricane Dorian was located
near latitude 30.6 North, longitude 79.8 West. Dorian is moving
toward the north-northwest near 8 mph (13 km/h).  A turn to the
north is expected tonight, followed by a turn to the north-
northeast on Thursday and a turn toward the northeast on Thursday
night.  A northeastward motion at a faster forward speed is forecast
on Friday.  On the forecast track, the center of Dorian will
approach the coast of South Carolina tonight, move near or over the
coast of South Carolina on Thursday, and move near or over the coast
of North Carolina Thursday night and Friday.

Reports from an Air Force Reserve Hurricane Hunter aircraft
indicate that maximum sustained winds have increased to near 110 mph
(175 km/h) with higher gusts.  Some fluctuations in strength are
possible tonight, followed by slow weakening Thursday through
Friday.

Hurricane-force winds extend outward up to 70 miles (110 km) from
the center and tropical-storm-force winds extend outward up to 195
miles (315 km).  NOAA buoy 41008 near the Georgia coast recently
reported sustained winds of 54 mph (86 km/h) and a wind gust of 60
mph (97 km/h).

The minimum central pressure reported by the Hurricane Hunter is
961 mb (28.38 inches).


HAZARDS AFFECTING LAND
----------------------
WIND:  Tropical storm conditions are currently affecting portions of
the Georgia and southern South Carolina coasts, and should begin
along other portions of the South Carolina coast during the next
several hours.

Tropical storm conditions will begin elsewhere within the Hurricane
Warning area in the Carolinas later today, with hurricane conditions
beginning by late tonight and Thursday.

Tropical storm conditions are expected in the Tropical Storm
Warning area in the Mid-Atlantic states by Friday, with tropical
storm conditions possible in the Tropical Storm Watch area Friday
or Friday night.

Tropical storm conditions along the northeastern Florida coast
should subside tonight.

STORM SURGE:  The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline.  The water could
reach the following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...

Isle of Palms to Myrtle Beach SC...5 to 8 ft
Savannah River to Isle of Palms SC...4 to 7 ft
Myrtle Beach SC to Cape Lookout NC...4 to 7 ft
Cape Lookout NC to Duck NC, including Pamlico and Albemarle Sounds
and the Neuse and Pamlico Rivers...4 to 6 ft
Flagler/Volusia County Line FL to Savannah River...3 to 5 ft
Duck NC to Poquoson VA, including Hampton Roads...2 to 4 ft

Water levels could begin to rise well in advance of the arrival of
strong winds.  The surge will be accompanied by large and
destructive waves.  Surge-related flooding depends on the how close
the center of Dorian comes to the coast, and can vary greatly over
short distances.  For information specific to your area, please see
products issued by your local National Weather Service forecast
office.

RAINFALL:  Dorian is expected to produce the following rainfall
totals through Friday:

Coastal Carolinas...6 to 12 inches, isolated 15 inches.

Far southeast Virginia...3 to 6 inches.

Atlantic Coast from Daytona Beach, Florida to the Georgia-South
Carolina border...2 to 4 inches, isolated 6 inches.

This rainfall may cause life-threatening flash floods.

SURF:  Large swells will affect the northwestern Bahamas, and
the entire southeastern United States coast from Florida through
North Carolina during the next several days.  These swells are
likely to cause life-threatening surf and rip current conditions.
Please consult products from your local weather office.

TORNADOES: A tornado or two are possible along the immediate coast
of Georgia this afternoon. Isolated tornadoes are possible from this
evening through Thursday across the coastal Carolinas.


NEXT ADVISORY
-------------
Next intermediate advisory at 800 PM EDT.
Next complete advisory at 1100 PM EDT.

$$
Forecaster Beven
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Just as @CCB!, Geoff ( @33andrain) and I mentioned in our posts a little earlier, as well as being confirmed by the NHC forecast discussion (advisory 45) and the Tidbits intensities consensus, the latest imagery below also suggests that Dorian is at least maintaining strength if not strengthening again slightly. His eye is becoming better defined again and Dorian is generally looking more robust than he was this morning. Right now he seems to have South Carolina in his path and there is still no sign just yet of that turn north east. Even if he does make that turn, it may be too late to save the Carolinas from more serious impacts.  As I said in one of my posts above the next 6 hours will be critical.  Any more delay in that curve will be serious.  The warnings are all in force.

 

goes16_vis_05L.gif

 

The water vapour view below gives us a few more clues. Dorian encountered the US mainland flow yesterday.  This should continue to undercut his circulation and together with the trough/ridge arrangement (a gap in the ridge to the north) should help him to make that curve, speed up and then be carried quickly north east with steady weakening in about 48 hours or so. We just need to focus on the interim period.  Dorian's immediate circulation is still very dominant. His outer circulation does not yet seem to be suffering from wind sheer.  The light to moderate sheer is not expected to increase that much for another 24 to 36 hours.

goes16_wv-mid_05L (11).gif

I've talked myself into posting wind shear and dry air intrusion charts.  So more from me shortly.  David :) 

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