Marine Interpretation Message
Issued by NWS

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592
AGNT40 KWNM 250048
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
848 PM EDT SUN JUL 24 2016

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

A WEAK COLD FRONT CONTS TO DRIFT S ACRS THE N CNTRL NT2 WTRS WITH
MAX ASCD WINDS NO HIGHER THAN 15-20 KT...PRETTY MUCH AS PREVLY
FCSTD. WITH SUCH LITE WINDS MAX ASCD SEAS ARE ONLY IN THE 3-5 FT
RANGE WHICH ARE BEING HANDLED FINE BY THE 18Z WAVEWATCH III AND
12Z ECMWF WAM MDLS AT THE MOMENT.

OVER THE SHORT TERM...THE 18Z NAM/GFS REMAIN CONSISTENT VS THEIR
PREV RESPECTIVE RUNS AND THE OTHER 12Z GLOBAL MDLS IN FCSTG THE
COLD FRONT TO BCM QSTNRY NR ITS CURRENT POSITION TONITE...THEN
DSIPT MON. THE LATEST MDLS THEN SHARE SMLR FCST TIMING FOR THE
NEXT WEAK COLD FRONT TO PUSH SE INTO THE NT1 WTRS LATE MON
NITE/TUE AND THEN INTO THE NRN NT2 WTRS TUE NITE WITH WEAK ASCD
GRADIENTS (GNRLY IN THE 15-20 KT OR 25 KT RANGE AT MOST). SO PER
THE 18Z NAM/GFS...SEE NO REASON TO MAKE ANY MAJOR CHNGS TO THE
PREVLY USED 12Z GFS 10M BL WINDS THRU TUE NITE OTHER THAN SM MINOR
TWEAKS MAINLY IN DEFERENCE TO THE 12Z ECMWF.

IN THE LONG RANGE...THE LATEST MDLS AGREE THAT A SUMMER-TIME
PATTERN WITH WEAK GRADIENTS AND LITE ASCD WINDS WL CONT. IN GNRL
THE MDLS FCST THE COLD FRONT TO BCM QSTNRY ACRS THE NRN/CNTRL NT2
WTRS WED INTO FRI WITH PRHPS A WEAK SFC LOW(S?) TRACKING NE ALONG
THE FRONT WITH ASCD GRADIENTS REMAINING WEAK (WITH MAX ASCD WINDS
GNRLY IN THE 15-20 KT RANGE). ON FRI/FRI NITE THE DISPARITY DOES
INCREASE BTWN THE LATEST GLOBAL MDLS IN RGRDS TO THE FUTURE
MOVEMENT OF THE FRONT...BUT THEY DO KEEP THE ASCD FCST GRADIENTS
WEAK. AM TEMPTED TO REPOPULATE WITH THE 12Z ECMWF ON THU INTO FRI
NITE. BUT FOR NOW WL STAY THE COURSE WITH THE PREVLY POPULATED
WINDS AND WL JUST MAKE SOME GNRLY MINOR ADDITIONAL EDITS AGAIN IN
DEFERENCE TO THE 12Z ECMWF.




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

AT 18Z A COLD FRONT WAS OVER THE NRN NT2 WATERS...W/A WEAK HIGH
PRES RIDGE ACROSS THE REST OF THE NT1/NT2 WATERS. A 1449Z ASCAT
HIRES PASS REVEALED 10-20 KT WINDS OVER THE NE NT2 WATERS W/AN
AREA OF 25 KT WINDS IN ANZ905.

12Z GUIDANCE WAS IN GOOD AGREEMENT IN THE NEAR TERM W/SOME SLIGHT
DIFFERENCES NOTED WED INTO THU IN REGARDS TO THE EXACT POSITION OF
THE FRONTAL BOUNDARY EXPECTED TO BECOME NEARLY STATIONARY OVER
PARTS OF THE NT2 WATERS. FOR THIS FORECAST PACKAGE DECIDED TO
POPULATE GRIDS THROUGH ABOUT WED 00Z W/12Z GFS 10M WINDS THEN LEFT
EXISTING GRIDS FROM THE 00Z GFS RUN IN PLACE THROUGH THE REST OF
THE PERIOD GIVE SOME UNCERTAINTY IN REGARDS TO EXACT POSITION OF
THE FRONTAL BOUNDARY.

.SEAS...USED 12Z NWW3 THROUGH WED 00Z THEN LEFT IN PRIOR 00Z NWW3
GRIDS THROUGH THE REMAINDER OF THE PERIOD.


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



.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
     NONE.

.NT2 MID ATLC WATERS...
     NONE.

$$

.FORECASTER VUKITS/HOLLEY. OCEAN PREDICTION CENTER.



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