

503 

AGNT40 KWNM 080714

MIMATN





MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN 

NWS OCEAN PREDICTION CENTER WASHINGTON DC

315 AM EDT MON 8 AUG 2016 



.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT 

.WEATHER FOR THE NORTH ATLANTIC OCEAN W OF 50W FROM 30N TO 50N. 



0130Z AND 0220Z ASCAT OVERPASSES INDICATED THAT THE W TO SW 20 

KT WINDS WHICH WERE IMMEDIATELY S OF THE STATIONARY FRONT ACROSS 

THE NT2 WATERS HAVE SHIFTED E OF THE OFFSHORE WATERS. ELSWHERE 

WITH BROAD AREA OF LOW PRES IN PLACE ACROSS THE SE US AND HIGH 

PRES RIDGE IN PLACE JUST S OF THE NT2 WATERS...SHIP/BUOY OBS AND 

ASCAT INDICATING S WINDS TO 20 KT OFF SC/GA COASTS EXTENDING E 

INTO ANZ835 WATERS AND EVEN UP TO 25 KT NEAR THE GA COAST. THE 

00Z GFS WINDS APPEAR SLIGHTLY TOO HIGH ACROSS OUTER ANZ925 AND 

ANZ930 WATERS S OF THE FRONT. ELSEWHERE 00Z GFS LOOKS WELL 

INITIALIZED. 

00Z MODELS ARE IN VERY GOOD AGREEMENT ACROSS THE W ATLC FOR THE 

NEXT COUPLE DAYS. MAIN WX FEATURE OVER THE SHORT TERM WILL BE 

THE PERSISTENT STATIONARY FRONT NOTED ABOVE. SCATTERED 

CONVECTION IS CONTINUING ALONG THE STATIONARY BOUNDARY THIS 

MORNING. SPC MESO ANALYSIS INDICATING SB CAPE 1000 TO 1500 J/KG 

INVOF FRONT. HOWEVER SREF PROBABILITIES SUGGEST THAT ENVIRONMENT 

SHOULD BECOME MORE STABLE LATE TONIGHT WITH CONVECTION BECOMING 

MORE LIMITED. AT 06Z A LOW PRES TROUGH EXTENDED ACROSS THE NEW 

ENGLAND WATERS AND MODELS IN AGREEMENT THAT ONCE TROUGH SLIPS SE 

OF THE WATERS HIGH PRES SHOULD BUILD E OFFSHORE TODAY THROUGH 

WED...SHIFTING E OF THE WATERS WED NIGHT. 



TO VARYING DEGREES OVER THE LAST COUPLE DAYS MODELS HAD BEEN 

SHOWING WEAK SURFACE LOW DEVELOPMENT E OF THE BAHAMAS OVER THE 

NEXT FEW DAYS...MOVING NE AND N TO THE SRN NT2 WATERS LATE WED 

NIGHT/THU. MOST RECENT TRENDS IN ECMWF/UKMET/CMC HAVE BEEN 

TOWARD THE GFS WHICH HAS CONSISTENTLY LACKED ANY LOW 

DEVELOPMENT. FOR WIND GRIDS WILL BLEND 50 PERCENT OF THE 00Z 

ECMWF WITH THE PREVIOUS OPC GRIDS...WHICH WILL RESULT IN MORE OF 

AN OPEN WAVE OR LOW PRES TROUGH MOVING INTO THE SRN NT2 WATERS 

VS THE WEAK LOW AS WAS PREVIOUSLY THE CASE. LATER IN THE WEEK 

THE 00Z GFS AND 00Z ECMWF HAVE COME INTO BETTER AGREEMENT WITH 

THE TIMING OF A COLD FRONT MOVING SE TO THE NEW ENGLAND COAST 

LATE THU AND THU NIGHT. THE GFS MOVES THE FRONT A BIT FURTHER 

OFFSHORE THAN THE ECMWF. PLAN TO USE THE SAME BLEND AS MENTIONED 

ABOVE THU THROUGH FRI NIGHT AS APPEARS AS DECENT COMPROMISE 

BETWEEN GFS AND UKMET WITH LOCATION OF FRONT JUST OFF THE MAINE 

COAST THU NIGHT INTO FRI. 



.SEAS...THE 00Z MULTIGRID WAVEWATCH III AND 00Z ECMWF WAM ARE 

BOTH WELL INITIALIZED WITH COASTAL/OFFSHORE WAVE HEIGHTS THIS 

MORNING. THIS GUIDANCE IS OVERALL IN VERY GOOD AGREEMENT OVER 

THE FORECAST PERIOD. TO BE CONSISTENT WITH WINDS POPULATED WITH 

THE 00Z WW3 THROUGH TUE...THE 00Z ECMWF WAM TUE NIGHT THROUGH 

WED NIGHT...THEN A 50/50 BLEND OF THE PREVIOUS GRIDS WITH THE 

00Z ECMWF WAM. 



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



.WARNINGS...PRELIMINARY. 



.NT1 NEW ENGLAND WATERS... 

     NONE. 



.NT2 MID ATLC WATERS... 

     NONE. 



$$ 



.FORECASTER CLARK. OCEAN PREDICTION CENTER.

