Marine Interpretation Message
Issued by NWS

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AGNT40 KWNM 241316
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
916 AM EDT THU JUL 24 2014

.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT
.WEATHER FOR THE NORTH ATLANTIC OCEAN W OF 50W FROM 30N TO 50N.

A COLD FRONT EXTENDING FROM THE DELMARVA COAST NE ACROSS NT1 WTRS
IS MOVG SLOWLY SE. TSTMS ARE NOTED NR THE FRONT WITH LOCALLY HVY
TSTMS MOVG E OFF THE DELMARVA COAST THIS AM. LOCAL WINDS EXCEEDING
40 KT ARE LKLY WITH THE HEAVIER TSTMS. WE MAY MENTION THE STRONGER
WINDS IN/NR TSTMS IN THE OFF WTRS FCST SHOULD THE ACTIVITY
PERSIST UNTIL FCST ISSUANCE TIME. OTW...WE WILL TWEAK THE PREV
FCST AND ASSOC GRIDS HERE AND THERE TO FIT WITH ADJ CWF AND TAFB
GRIDS. OTW...NO SIG CHANGES APPEAR NEEDED TO THE PREV FCST FOR THE
AM UPDATE. THE COLD FRONT CURRENTLY OVR THE NT1 WTRS WILL CONT TO
MOVE SE TDA INTO FRI. ANOTHER FRONT WILL MOVE OFFSHORE EARLY NEXT
WK. SCTD STRONG TSTMS WILL BE LIKELY NEAR EACH FRONT OVR THE NEXT
FEW DAYS.

SEAS...SEAS HTS RANGE FROM NR 2-3 FT OVR THE GULF OF MAINE OFF
WTRS TO 9-10 FT OVR WTRS WELL OFF THE DELMARVA COAST PER THE
LATEST OBS AND RA1 SEA STATE ANALYSIS. OVERALL...LITTLE CHANGE
WILL BE MADE TO THE PREV FCST FOR THE AM UPDATE.

-----------------------------------------------------------------
PREVIOUS DISCUSSION...

TSTMS WHICH WERE MOVING THRU NEW ENGL LAST EVENING DIMINISHED AS
THEY APPROACHED THE COAST AND MOVED INTO MORE STABLE MARIN
ENVIRONMENT. THE SAME CANNOT BE SAID FOR CONVECTION WHICH EXITED
THE SRN NJ AND DELMARVA COASTS ALTHO LIGHTNING DENSITY INDICATES
IT TOO HAS WEAKEND AS IT PASSED OFFSHORE.

ENHANCEMENT OF SW WINDS UP TO 25 KT LOCALIZED OVER GULF STREAM
WAS OBSERVED IN 01Z AND 02Z HI RES ASCAT-B AND -A OVERPASSES
BETWEEN 73W AND 67W. ELSEWHERE OVER COOLER WATERS N OF GULF
STREAM MAX WINDS WERE UP TO 20 KT OVER GLF OF ME AND 5 TO 15 KT
ELSEWHERE OVER NEW ENGL WATERS. ALSO LATEST HI RES NASA SPORT
SST COMPOSITE INDICATES THERE IS WARM EDDY JUST S OF 1000 FM
OVER WRN PARTS OF ANZ905 WATERS WHERE ASCAT RETURNED LOCALIZED
AREA OF STRONGER SW WINDS UP TO 20 KT. SO FOR PREFRONTAL WINDS
OVER NEXT 24 HRS OR SO AND BASED ON THESE SCATTEROMETER WINDS
WILL CONTINUE TO FAVOR SLIGHTLY HIGHER GFS BOUNDARY LAYER WINDS
OVER WARMER GULF STREAM WATERS AND GFS 10M WINDS ELSEWHERE.

00Z MDLS ARE IN VERY GOOD AGREEMENT OVER NEXT COUPLE DAYS WITH
TIMING AND LOCATION OF COLD FRONT MOVING S THRU NEW ENGL AND NRN
MID ATLC WATERS. COLD FRONT SHOULD STALL JUST N OF CAPE HATTERAS
AND FINALLY WASH OUT SAT EVENING. WILL POPULATE WITH 00Z GFS 10M
WINDS FRI INTO SUN BUT COULD REALLY GO WITH ANY MDL SOLUTION
GIVEN EXCELLENT MDL AGREEMENT. MDLS BEGIN TO DIVERGE WITH
WEAKENING MID/UPPER LVL LOW THRU UPPER GREAT LAKES SUN AND LOWER
GREAT LAKES AND NEW ENGL MON. 00Z GFS AND 00Z UKMET ARE MORE
PROGRESSIVE AND WEAKER THAN 12Z/23 ECMWF. HOWEVER AT THE SFC
REMARKABLY THE MDLS ARE ALL IN DECENT AGREEMENT WITH TIMING OF
INCREASING S TO SW WINDS AND COLD FRONT MOVING OFF NEW ENGL AND
NRN MID ATLC COASTS MON NGT. AS FOR WINDS AS WILL FOLLOW SAME
BLUE PRINT AS IS OCCURRING CURRENTLY FAVORING SLIGHTLY STRONGER
00Z GFS BNDRY LAYER WINDS OVER WARMER GULF STREAM WATERS AND 00Z
GFS 10M WINDS OVER COLDER WATERS N OF GULF STREAM SUN NGT THRU
MON NGT.

00Z MULTIGRID WAVEWATCH III APPEARS AROUND 1 FT TOO HIGH WITH
SIG WV HGTS EARLY THIS MORNING OVER MOST NT1 AND NT2 ZONES. WILL
CONTINUE TO USE THIS GUIDANCE BUT WILL ALSO CONTINUE TO TONE
DOWN THESE SIG WV HGTS BY 10 TO 15 PERCENT TDA INTO TNGT AND
AGAIN SUN/MON.

.EXTRATROPICAL STORM SURGE GUIDANCE...N/A.


.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
     NONE.

.NT2 MID ATLC WATERS...
     NONE.

$$

.FORECASTER MILLS/CLARK. OCEAN PREDICTION CENTER.


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