Wednesday, September 30, 2015

Major Hurricane Joaquin (Cat 3) a Potential Long Term Threat to the Region Update Two






000
WTNT41 KNHC 010250
TCDAT1

HURRICANE JOAQUIN DISCUSSION NUMBER  13
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL112015
1100 PM EDT WED SEP 30 2015

Joaquin has rapidly intensified during the past 24 hours with the
satellite presentation continuing to improve this evening.  The eye
has recently become apparent near the center of the very symmetric
central dense overcast.  An Air Force Reserve Hurricane Hunter
aircraft that has been investigating the hurricane this evening has
measured peak 700 mb flight-level winds of 113 kt and 102 kt surface
winds from the SFMR.  These data support an initial intensity of
100 kt, making Joaquin the second major hurricane of the 2015
Atlantic hurricane season. NOTE: Communications problems have
delayed the public release of the Air Force reconnaissance data.

Joaquin continues to move slowly southwestward with an initial
motion estimate of 220/5 kt.  The hurricane is forecast to move
slowly southwestward or west-southwestward for another 24 hours or
so while it remains to the south of a narrow northeast to southwest
oriented ridge.  This ridge is expected to weaken by Friday as a
trough deepens and cuts off over the southeastern United States.
This should cause Joaquin to turn northward within 48 hours. The 18Z
runs of the GFS and HWRF remain in general agreement with the 12Z
UKMET and Canadian models moving Joaquin around the northeastern
portion of the cut-off low and bring the hurricane inland over the
Carolinas or mid-Atlantic states.  The 12Z ECMWF remains the outlier
by showing a track toward the northeast out to sea.  The NHC
forecast continues to follow the trend of the bulk of the guidance
and takes Joaquin toward the U.S east coast. The NHC track is
similar to the previous advisory and is once again east of the
multi-model consensus.  The NOAA G-IV aircraft has recently
completed its synoptic surveillance flight, and data collected
during this mission should be assimilated into the 0000 UTC models,
hopefully reducing the spread of the track guidance.

The upper-level wind pattern over the hurricane is forecast by the
global models to become even more conducive during the next couple
of days.  This favors additional intensification, with the only
possible limiting factors being upwelling of cool SSTs beneath the
slow-moving hurricane and eyewall cycles which could cause some
fluctuations in intensity.  By 72 hours, increasing southwesterly
shear, dry air intrusion, and lower SSTs are expected to cause
gradual weakening.  The updated NHC intensity forecast has been
significantly increased from the previous advisory primarily due to
the higher initial intensity. The official forecast is between the
lower statistical guidance and the higher HWRF during the first
36-48 hours, and is near the SHIPS/LGEM guidance after that time.


KEY MESSAGES:

1.  Preparations to protect life and property within the warning
areas in the Central Bahamas should be completed now.

2.  Confidence in the details of the forecast after 72 hours remains
low, since we have one normally excellent model that keeps Joaquin
far away from the United States east coast.   The range of possible
outcomes is still large, and includes the possibility of a major
hurricane landfall in the Carolinas.

3.  Every effort is being made to provide the forecast models with
as much data as possible.  The NOAA G-IV jet has begun a series of
missions in the storm environment, and the National Weather Service
has begun launching extra balloon soundings.

4.  Because landfall, if it occurs, is still more than three days
away, it's too early to talk about specific wind, rain, or surge
impacts from Joaquin in the United States.  Regardless of Joaquin's
track, strong onshore winds will create minor to moderate coastal
flooding along the coasts of the mid-Atlantic and northeastern
states through the weekend.

5.  A hurricane watch for a portion of the U.S. coast could be
required as early as Thursday evening.

6. Many portions of the eastern U.S. are currently experiencing
heavy rains and gusty winds associated with a frontal system. These
heavy rains are likely to continue for the next few days, even if
the center of Joaquin stays offshore.  The resulting inland flood
potential could complicate preparations for Joaquin should it head
toward the coast, and even more substantial inland flooding is
possible if Joaquin later passes near or over these same areas.


FORECAST POSITIONS AND MAX WINDS

INIT  01/0300Z 23.8N  73.1W  100 KT 115 MPH
12H  01/1200Z 23.5N  73.8W  110 KT 125 MPH
24H  02/0000Z 23.6N  74.5W  120 KT 140 MPH
36H  02/1200Z 24.7N  74.8W  120 KT 140 MPH
48H  03/0000Z 26.6N  74.7W  110 KT 125 MPH
72H  04/0000Z 31.6N  74.7W   95 KT 110 MPH
96H  05/0000Z 36.2N  75.6W   85 KT 100 MPH
120H  06/0000Z 38.5N  76.5W   55 KT  65 MPH

$$
Forecaster Brown
000
FXUS61 KCAR 010319
AFDCAR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
1119 PM EDT WED SEP 30 2015

.SYNOPSIS...
LOW PRESSURE OVER THE GULF OF MAINE WILL EXIT INTO THE MARITIMES
TONIGHT. HIGH PRESSURE FROM CENTRAL CANADA WILL BUILD EASTWARD
NORTH OF MAINE THURSDAY INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH THURSDAY/...
1115 PM UPDATE: DECIDED TO KEEP FLOOD WATCH GOING PER IN-HOUSE
DISCUSSION AS SOME STREAMS AND RIVER STILL RISING SUCH AS THE
PISCATAQUIS RIVER AT DOVER-FOXCROFT AND MEDFORD. THE SAINT CROIX
RIVER IN WASHINGTON COUNTY WAS STILL RISING W/SOME STREAMS NEAR
BANKFUL IN MANY LOCATIONS. RAIN HAS ENDED IN THESE AREAS AND
RIVERS AND STREAMS ARE EXPECTED TO RECEDE OVERNIGHT INTO THURSDAY.
HRLY TEMPS WERE ADJUSTED W/THE FAR W AND NW AREAS SEEING UPPER 30S
BY MORNING.

WINDS WILL SHIFT FROM N TO NW OVRNGT AND REMAIN QUITE BREEZY WITH
AT LEAST PRTL CLRG OVR THE N AND THINNING OVR DOWNEAST AREAS BY
THU MORN. COOLER AND BREEZY CONDITIONS CONT ON THU WELL BEHIND THE
LOW DEPARTING THRU THE MARITIMES AND AHEAD OF SFC HI PRES BUILDING
SE FROM N CNTRL CAN WITH PTLY TO MSLY SUNNY SKIES N AND PTLY TO
MSLY CLDY SKIES OVR CNTRL AND DOWNEAST AREAS.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
THE FRONT WILL CONTINUE TO PUSH EAST OF THE GULF OF MAINE THURSDAY
NIGHT. A LARGE AREA OF CANADIAN HIGH PRESSURE WILL BUILD EAST
LATER THURSDAY NIGHT THROUGH FRIDAY. THIS WILL BRING PARTLY
CLOUDY SKIES TO NORTHERN AREAS WITH PARTLY TO MOSTLY CLOUDY SKIES
CENTRAL AND DOWN EAST. LOW TEMPERATURES THURSDAY NIGHT WILL RANGE
FROM THE LOW 30S ACROSS FAR NORTHWEST AREAS WITH MID TO UPPER 30S
ACROSS NORTHEAST AREAS. LOWS ACROSS CENTRAL AND DOWN EAST WILL
RANGE FROM THE LOW TO MID 40S. HIGHS ON FRIDAY WILL BELOW NORMAL
FOR THIS TIME OF YEAR AND MAINLY IN THE LOW TO MID 50S. THE HIGH
WILL CONTINUE TO BUILD TO OUR NORTH FRIDAY NIGHT THROUGH SATURDAY
WITH CONTINUED DRY WEATHER. A NORTHEAST FLOW AROUND THE HIGH WILL
CONTINUE TO TRANSPORT UNSEASONABLY CHILLY AIR ACROSS THE REGION.
LOWS FRIDAY NIGHT WILL ONCE AGAIN BE IN THE LOW TO MID 30S NORTH
AND LOW TO MID 40S DOWN EAST. HIGHS ON SATURDAY WILL ONCE AGAIN BE
IN THE LOW TO MID 50S.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
STILL PLENTY OF UNCERTAINTY WITH REGARD TO THE LONGER TERM PORTION
OF THE FORECAST AS IT LARGELY HINGES ON THE ULTIMATE TRACK OF
HURRICANE JOAQUIN. OPERATIONAL RUNS OF THE GFS BRING THE SYSTEM
INTO THE SOUTHEASTERN UNITED STATES OVER THE WEEKEND AND THEN ITS
REMNANTS ALONG THE EASTERN SEA BOARD THROUGH EARLY NEXT WEEK
WHICH WOULD KEEP UNSETTLED WEATHER ACROSS THE AREA. ON THE OTHER
HAND...ECMWF CONTINUES TO KEEPS THE SYSTEM WELL EAST OF THE
COAST. HAVE FOLLOWED ALONG WITH A BLENDED MODEL SOLUTION THIS FAR
OUT.

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