FXUS61 KOKX 140041
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE UPTON NY
830 PM EDT MON SEP 13 2004

.SHORT TERM (OVERNIGHT)...SHORTWAVE OVER THE CANADIAN MARITIMES WILL 
CONTINUE TO SLIDE OFFSHORE OVERNIGHT WITH HEIGHTS RISING AS UPPER 
RIDGING BUILDS INTO THE REGION. SURFACE HIGH PRESSURE CENTERED 
OVER SOUTHERN QUEBEC WILL CONTINUE TO BUILD SE OFF THE COAST OF 
MAINE BY DAYBREAK. A WEAK COLD FRONT PASSING JUST SOUTH OF THE AREA 
CURRENTLY WILL PUSH FARTHER SOUTH OVERNIGHT WITH THE NE FLOW BEHIND 
IT PICKING UP TO 10 TO 15 MPH AFTER MIDNIGHT AND THEN TURNING MORE 
EASTERLY BY DAYBREAK. SOME STRATUS HAS DEVELOPED THIS EVENING AS 
LOW-LEVEL COOLING AND SUBSIDENCE ALOFT HAS TRAPPED MOISTURE UNDER A 
WEAK LOW-LEVEL INVERSION. EXPECT THIS TO DISSIPATE TOWARD MIDNIGHT. 
THEN MORE LOW STRATUS DEVELOPING TOWARD DAYBREAK AS TURBULENT MIXING 
POOLS MOISTURE FROM ONSHORE FLOW UNDER A STRENGTHENING INVERSION. NO 
MAJOR CHANGES...JUST TWEAKS TO GRIDS AND ZONES BASED ON LATEST 
SAT/OB/MOD TRENDS.

&&

.MARINE...
LARGE...SPRAWLING SURFACE HIGH EXTENDING SOUTHWARD FROM 
EASTERN CANADA TO ALONG THE EASTERN SEABOARD WILL BE THE DOMINANT 
WEATHER FEATURE TO AFFECT THE COASTAL WATERS THIS PERIOD. BOTH THE 
UPPER RIDGE AND SURFACE HIGH TRANSLATE SLOWLY EASTWARD. SURFACE 
WINDS OVERNIGHT THROUGH THU WILL VEER AROUND FROM THE NE TO SW. 
EXPECTING WINDS AND SEAS TO REMAIN BELOW SMALL CRAFT...BUT COMING 
CLOSE ON TUE DUE TO A STRENGTHENING...LONG FETCH EASTERLY FLOW. THE 
FORECAST GETS A BIT TRICKY IN THE EXTENDED WITH THE FUTURE TRACK OF 
HURRICANE IVAN...WHICH IS FORECAST TO BE WELL INLAND BY THE END OF 
THE PERIOD. WINDS ARE LIKELY TO STRENGTHEN FRI INTO SAT DUE TO A 
TIGHTENING PRESSURE GRADIENT. THIS WOULD BE THE MOST LIKELY TIME 
FOR SEAS AND WINDS TO REACH OR APPROACH SMALL CRAFT CRITERIA.

&&

.AVIATION...VFR CONDITIONS THROUGH ATLEAST FIRST PART OF 
TONIGHT. SOME LOW VFR CLOUD COVER DEVELOPING THIS EVENING MOSTLY 
OVER EASTERN AIRPORTS WITH MOISTURE POOLING UNDER 850 HPA INVERSION. 
THIS SHOULD DISSIPATE AFTER 04Z AS COLUMN COOLS FURTHER. 
THEREAFTER...HAVE CUT BACK TO TEMPO ON LOW MVFR STRATUS TOWARDS 
DAYBREAK. UNCERTAINTY TOO HIGH WITH LOWER DEWPOINT AIR ADVECTING 
INTO THE REGION AND FORECAST SOUNDINGS NOT SHOWING AS STRONG 
INVERSION DEVELOPMENT. THINK THERE IS A BETTER CHANCE OF MVFR 
STRATUS RIGHT AFTER DAYBREAK AS TURBULENT MIXING POOLS MOISTURE 
UNDER A TIGHTENING INVERSION...MOSTLY OVER WESTERN AIRPORTS. 
CONTINUED DAYTIME MIXING AND MORE OF A SE FLOW SHOULD RAISE CIGS TO 
VFR AFTER 15Z FROM EAST TO WEST. CIGS SHOULD SCT BY EARLY AFTERNOON 
OVER EASTERN AIRPORTS UNDER MORE DIRECT INFLUENCE OF SOUTHWARD 
SLIDING HIGH PRESSURE...WHILE WESTERN ZONES WILL NOT SCT TILL LATER. 

&&

.HYDROLOGY...DRY INTO EARLY THU.  QUESTION REGARDING QPF IS HOW MUCH 
TROPICAL MOISTURE GETS ENTRAINED INTO FRONTAL BOUNDARY WHEN ITS OVER 
OR JUST SOUTH OF CWA.  THINKING THAT WE'LL START SEEING MORE 
MOISTURE STARTING THU NIGHT AND THEN CONTINUING RIGHT INTO WEEKEND.  
KEPT QPF AMOUNTS BELOW 1" IN ANY GIVEN 12 HR PERIOD WITH UNCERTAINTY 
LOCATION OF IVAN'S REMNANTS AND FRONTAL LOCATION.  POTENTIAL THERE 
FOR SOME SOAKING RAINS BUT TOO EARLY TO GET TOO EXCITED JUST YET.

&&

.PREVIOUS DISCUSSION...

LONG TERM (TUE THRU MON)...
WITH THE WINDS BECOMING MORE SOUTHEAST AFTER 14Z EXPECT THE CLOUDS 
TO BREAK...ESPECIALLY OVER THE EASTERN ZONES AND THEN SCATTERED OUT 
TO THE WEST AS THE AFTERNOON PROGRESSES.

GFS AND ETA BOTH PROGGING DECENT S/WV TO MOVE OUT OF OHIO VALLEY 
INTO NEW ENGLAND WED.  NOT SURE 1) HOW MUCH MOISTURE THAT'LL HAVE TO 
WORK WITH AND 2) WHETHER SFC RIDGE WILL HOLD ENOUGH TO KEEP IT AT 
BAY.  WILL HOLD OFF ON ANY PRECIP MENTION FOR NOW PER COLLABORATION 
WITH SURROUNDING WFOS.

NEXT PROBLEMS ARE APPROACHING COLD FRONT FOR FRI AND MOISTURE FROM 
WHATEVER IS LEFT OF IVAN BY THE END OF THE WEEK.  MOISTURE WILL NOT 
BE AN ISSUE WITH THIS...ESPECIALLY AS TIME GOES ON.  GIVEN LATEST 
TPC FORECAST FOR IVAN...WOULD THINK THAT WE'LL START SEEING MORE 
DEEP LAYER MOISTURE GETTING ENTRAINED INTO FRONT FRI OR 
THEREABOUTS.  13/12Z GFS CERTAINLY SHOWS THIS (DESPITE BEING A BIT 
SLOWER AND FURTHER W THAN TPC FORECAST) AND WILL BEEF UP QPF VALUES 
A TAD.  HOWEVER...WITH TREND BEING W WITH IVAN'S TRACK AND PERHAPS 
SLIGHTLY SLOWER...THERE IS A LOT OF UNCERTAINTY WITH THIS FORECAST.  
SLOWER AND FURTHER W COULD ALLOW SFC HIGH MOVING ACROSS NORTHERN 
GREAT LAKES/SOUTHERN ONTARIO PROVINCE OF CANADA TO BUILD MORE INTO 
NEW ENGLAND...WHICH COULD CONCEIVABLY KEEP CWA DRIER TOWARD 
WEEKEND.  WE'LL SEE...  FOR NOW...WILL CONTINUE WITH POPS IN THE 
CHANCE CATEGORY AND SEE HOW THINGS UNFOLD LATER IN THE WEEK BEFORE 
MAKING ANY DRASTIC CHANGES.

*****END OF PREVIOUS DISCUSSION*****

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NJ...NONE. 
NY...NONE.
MARINE...NONE.
&&

$$