UPDATE: Eye of Sandy now between Jamaica and Cuba
HURRICANE SANDY FORECAST/ADVISORY
NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL AL182012
2100 UTC WED OCT 24 2012
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY…
THE GOVERNMENT OF THE BAHAMAS HAS ISSUED A HURRICANE WARNING FOR THECENTRAL AND NORTHWESTERN BAHAMAS.
A TROPICAL STORM WARNING HAS BEEN ISSUED FOR THE EAST COAST OF
FLORIDA FROM OCEAN REEF TO SEBASTIAN INLET.
THE TROPICAL STORM WATCH HAS BEEN EXTENDED ALONG THE EAST COAST OF
FLORIDA TO FLAGLER BEACH.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT…
A HURRICANE WARNING IS IN EFFECT FOR…
* JAMAICA
* CUBAN PROVINCES OF CAMAGUEY…LAS TUNAS…GRANMA…SANTIAGO DE
CUBA…HOLGUIN…AND GUANTANAMO
* THE CENTRAL BAHAMAS
* THE NORTHWESTERN BAHAMAS
A TROPICAL STORM WARNING IS IN EFFECT FOR…
* HAITI
* FLORIDA EAST COAST FROM OCEAN REEF TO SEBASTIAN INLET
A TROPICAL STORM WATCH IS IN EFFECT FOR…
* THE SOUTHEASTERN BAHAMAS
* FLORIDA EAST COAST FROM NORTH OF SEBASTIAN INLET TO FLAGLER BEACH
* FLORIDA UPPER KEYS FROM OCEAN REEF TO CRAIG KEY
* FLORIDA BAY
HURRICANE SANDY DISCUSSION NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL AL182012
500 PM EDT WED OCT 24 2012
SATELLITE IMAGERY SHOWS THAT THE CENTER OF SANDY MADE LANDFALL OVER SOUTHEASTERN JAMAICA AROUND 1900 UTC. THERE HAS BEEN LITTLE
DEGRADATION TO THE SATELLITE PRESENTATION SINCE LANDFALL…AND THE
INITIAL INTENSITY IS MAINTAINED AT 70 KT FOR THIS ADVISORY. THE
CENTRAL PRESSURE OF 970 MB IS SUPPORTED BY A RECENT OBSERVATION OF
972 MB AT KINGSTON WITH 38 KT OF WIND. ASIDE FROM LAND
INTERACTION…CONDITIONS APPEAR FAVORABLE FOR SANDY TO AT LEAST
MAINTAIN INTENSITY UNTIL IT MOVES ACROSS EASTERN CUBA…WHERE SOME
WEAKENING IS EXPECTED. THE HURRICANE AND GLOBAL MODELS SHOW THE
CYCLONE INTENSIFYING OVER THE BAHAMAS AS IT INTERACTS WITH AN
UPPER-LEVEL TROUGH…AND THE OFFICIAL FORECAST SHOWS SANDY
REGAINING HURRICANE INTENSITY BY 36 HOURS. AFTER THAT TIME…ONLY
A LITTLE WEAKENING IS EXPECTED AS SANDY IS MAINTAINED AS A STRONG
CYCLONE WITH AT LEAST SOME CONTRIBUTION FROM BAROCLINIC PROCESSES
THROUGH DAY 5…WHEN POST-TROPICAL STATUS IS INDICATED.
THE INITIAL MOTION ESTIMATE IS 010/12…AS SANDY IS MOVING NORTHWARD
INTO A BREAK IN THE SUBTROPICAL RIDGE. THE GUIDANCE HAS TRENDED A
LITTLE FASTER IN THE SHORT TERM AND SO HAS THE OFFICIAL FORECAST.
ON DAY 2…A TURN TOWARD THE NORTH-NORTHWEST AND A SLOWER FORWARD SPEED ARE SHOWN AS SANDY INTERACTS WITH THE ABOVE-MENTIONED UPPER-LEVEL TROUGH. AFTER THAT TIME…SANDY IS EXPECTED TO TURN NORTHEASTWARD AS IT BEGINS TO INTERACT WITH A LARGER UPPER-TROUGH MOVING INTO THE EASTERN UNITED STATES. WHILE THERE IS STILL QUITE A BIT OF EAST/WEST SPREAD IN THE GUIDANCE AT DAYS 4 AND 5…THE GFS HAS TRENDED TOWARD THE SCENARIO THAT HAS BEEN SHOWN BY THE ECMWF OF MORE INTERACTION WITH THE TROUGH. WHILE THE GFS TRACK HAS SHIFTED WESTWARD AS A RESULT…THE ECMWF HAS ALSO SHIFTED WESTWARD THIS CYCLE. THE NHC FORECAST HAS BEEN ADJUSTED TO THE LEFT AS WELL…AND LIES ABOUT HALFWAY BETWEEN THE ECMWF AND THE GEFS ENSEMBLE MEAN AND THE FSU SUPER ENSEMBLE AT DAYS 3 THROUGH 5. THE UNCERTAINTY IN THE LONG-RANGE TRACK FORECAST REMAINS VERY HIGH…AND IT IS TOO EARLY TO DETERMINE SPECIFIC IMPACTS FOR THE U.S. EAST COAST NORTH OF FLORIDA.
GIVEN THE NEW NHC FORECAST…A HURRICANE WARNING HAS BEEN ISSUED
FOR THE CENTRAL AND NORTHWESTERN BAHAMAS…AND A TROPICAL STORM
WARNING HAS BEEN ISSUED FOR A PORTION OF THE EAST COAST OF THE
FLORIDA PENINSULA.
FORECAST POSITIONS AND MAX WINDS
INIT 24/2100Z 18.3N 76.6W 70 KT 80 MPH
12H 25/0600Z 20.3N 76.3W 70 KT 80 MPH…INLAND
24H 25/1800Z 23.5N 76.3W 60 KT 70 MPH…OVER WATER
36H 26/0600Z 25.8N 76.8W 65 KT 75 MPH
48H 26/1800Z 27.3N 77.3W 65 KT 75 MPH
72H 27/1800Z 30.0N 76.0W 60 KT 70 MPH
96H 28/1800Z 33.5N 72.5W 60 KT 70 MPH
120H 29/1800Z 37.0N 70.5W 60 KT 70 MPH…POST-TROPICAL
For graphics see bottom of post
Rob Lightbown of Crown Weather said at 6:43 am Wed Oct 24 2012
Based on satellite loops early this morning which clearly shows very deep convection encircling the entire storm and even hints of an eyelike feature, I think that reconnaissance aircraft will find that Sandy is in fact a hurricane with 75 to 80 mph winds. Sandy is tracking almost due north at a forward speed of 13 to 14 mph and will impact Jamaica today with hurricane force winds, heavy rainfall with totals of 8 to 12 inches expected, causing flash flooding and mudslides and very rough seas with heights of up to 15 to 20 feet expected.
This almost due north track is expected to continue right through Thursday and the Bahamas are likely to be impacted with tropical storm force winds with gusts to near hurricane force on Thursday. Additionally, heavy rainfall with totals of 4 to 8 inches are expected across all of the Bahamas on Thursday.
For those of you in southeastern Florida, tropical storm force winds, primarily in gusts are expected on Friday with rainfall totals of 1 to 2 inches expected. Beyond Friday, things are still pretty murky with the potential track of Sandy.
The latest 06Z NAM model 500 millibar map for Saturday afternoon clearly shows Sandy becoming captured and that it looks to become blocked from escaping to the east. This is potentially bad news for the northeastern United States as this could mean a potential major storm late this weekend into early next week. More on that later.
Even though the latest GFS model guidance initially shows a storm that tracks east-northeastward well south of Cape Cod, it shows not only an inverted trough of low pressure extending into New England, which would cause very heavy rainfall by Tuesday from southern New England northward into much of New Hampshire and Vermont, it also shows the storm curving back to the northwest to a position near the coast of Nova Scotia by late next week. This causes colder air to be drawn down into northern New England causing rain to change to snow. This is extremely analogous to 1963’s Hurricane Ginny which brought up to one foot of snow to northern Maine around Halloween of 1963.
The Canadian model forecasts that Sandy will track out into the open Atlantic, but some of the energy from Sandy hangs back and causes a second low pressure system to develop near Cape Cod by Monday. This second low pressure system bombs out to 969 millibars in southeastern Massachusetts by Tuesday creating strong winds and heavy rainfall for much of New England from Monday through Wednesday of next week.
The European operational guidance is still pretty extreme and shows Sandy bombing out to 933 millibars just off of the Jersey shore on Monday with hurricane force winds for much of the coastal sections from southern Maine and New Hampshire southward through southern New England and the Mid-Atlantic states. The European ensemble guidance is further north and shows it becoming captured and coming ashore into Cape Cod and eastern Massachusetts on Tuesday.
So, my thinking for an end track and impacts on New England are as follows: So, I think the GFS model may be too far east in its forecast track, especially considering that the teleconnections and analogs point to a storm that should track much closer to southern New England. Additionally, the ensemble guidance members of the GFS model supports the idea of a storm track along the south coast of southern New England by Tuesday.
Bottom line is that this could be a unusual scenario of a hurricane transitioning into an intense low pressure system tracking northwestward into New England by Tuesday morning and remaining nearly stalled over New England through Wednesday and Thursday of next week. This is such an unusual scenario that I have admittedly had a hard time believing and grasping. So, now I am starting to believe the potential for a major storm in New England starting as early as Monday and continuing possibly to Wednesday and Thursday.
Now, do I believe that it will be as strong as the operational European model is forecasting; which is a 933 millibar/27.55 inches central pressure? Not really, but I do think it could be quite strong in nature bringing multiple days of strong winds, coastal flooding and heavy rainfall. Add in the fact of the tidal influences surrounding Monday’s full moon and we could be looking at some potentially significant coastal flooding in New England.
So for all of you across New England, early preparations should begin today as it is never too early to prepare for a storm:
Strong Winds: Coastal sections of New England should be aware that damaging onshore winds with gusts to near hurricane force are possible starting on Monday and continuing through Tuesday and possibly Wednesday.
Coastal Flooding: If you have preparations that take more than a couple of days to complete, you should start them now. These preparations should include protecting your property from battering wave and coastal flooding damage. Multiple days of coastal flooding at high tide from Sunday evening through Tuesday and possibly Wednesday could be in the cards for much of the coastal sections of New England. Additionally, significant beach erosion is possible next week across the beaches of New England.
Mariners: This potential storm has the potential to build up large amounts of ocean water as it tracks from the Caribbean to off of the New England coast. Seas of 20 to 30 feet are likely over a huge area from coastal sections of North Carolina northward to the coastal and offshore waters of New England and the Canadian Maritimes. If you have a boat in the water, you may want to seriously start thinking about pulling it out of the water. Any late season fishing trips should be postponed or cancelled as life threatening seas of at least 20 to 30 feet and very possibly 40 feet could impact coastal and offshore New England waters from Sunday through at least Tuesday or Wednesday.
Heavy Rain Potential: Heavy rainfall with street and basement flooding seems likely starting Sunday night and Monday morning and continuing through Tuesday and Wednesday. River and stream flood potential will have to be monitored closely as we get closer to the event.
So, it is looking more and more likely that Sandy will significantly impact New England for much of next week. Severe coastal damage is a distinct possibility and those of you living in coastal communities in New England, including Portland, Portsmouth, Boston, Chatham, Nantucket and Newport should strongly consider making preparations for this potential storm.
For more on this story go to:
http://www.crownweather.com/?page_id=4557
For up to date information go to:
http://www.nhc.noaa.gov/
