000 FXUS62 KILM 161643 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 1242 PM EDT MON APR 16 2007 .SYNOPSIS... STRONG NORTHWEST WINDS IN THE WAKE OF AN INTENSE LOW NEARLY STATIONARY IN WESTERN CONNECTICUT...WILL PERSIST THROUGH THIS AFTERNOON. WEAK HIGH PRESSURE WILL FINALLY BUILD INTO THE AREA ON TUESDAY FOLLOWED BY THE NEXT AREA OF LOW PRESSURE LATE WEDNESDAY INTO THURSDAY. HIGH PRESSURE WILL BUILD IN FROM THE GREAT LAKES FRIDAY THROUGH SUNDAY. && .NEAR TERM /THROUGH TODAY/... WINDS PICKED UP OUT OF THE W-NW THIS MORNING WITH DEEP MIXING. THE WINDS ON CHS AND MHX 12Z SOUNDING BOTH HAD 40 KTS AT 1K FT. MAX WIND GUSTS HAVE BEEN UP BETWEEN 35 AND 40 KTS. FORECAST SEEMS IN LINE WITH THIS AND WIND ADVISORY WILL CONTINUE UNTIL 8PM. STRONG AND GUSTY WINDS WILL CONTINUE THROUGH THIS AFTERNOON. FORECAST REMAINED IN LINE WITH PREVIOUS ISSUANCE WITH ADDITION OF SOME PASSING CU AND SMALL ADJUSTMENT OF TEMPS AND DEWPOINTS. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY/... WRAPAROUND MOISTURE FROM THE SPINNING LOW CENTERED OFF NEW JERSEY WILL STAY JUST NORTH AND EAST OF THE ILM CWA THRU TUESDAY NIGHT. A DOWNSLOPE TRAJECTORY IN THE WIND FIELD THRU THE LOWER ATMOSPHERE WILL ALSO AID IN SCOURING OUT ANY LEFTOVER MOISTURE. AS A RESULT...WILL KEEP THE SHARP CONTRAST OF MOISTURE JUST NORTH OF THE ILM CWA...RESULTING IN MOSTLY CLEAR SKIES TONIGHT THROUGH TUESDAY NIGHT. MODELS HAVE SOMEWHAT DIFFERING SOLUTIONS FOR WEDNESDAY WITH AN UPPER S/W TROF IN THE SOUTHERN WESTERLIES AFFECTING THE AREA LATE WEDNESDAY INTO THURSDAY. IN ADDITION AN S/W TROF IN THE NORTHERN WESTERLIES IS FORCED TO DIVE NEARLY SOUTH FROM THE WESTERN GREAT LAKES TO THE CAROLINAS DUE TO THE SLOWLY DEPARTING AND EXTENSIVE LOW OFF THE JERSEY COAST. CULD ONLY GO WITH 20 POPS LATE WED AND WED NITE DUE TO MOISTURE AVAILABILITY. MINS AND MAXES THRU THE SHORT TERM WILL AVERAGE 5 TO AS MUCH AS 10 DEGREES BELOW CLIMO NORMS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... LOW PRESSURE OFF THE NORTHEAST COAST WILL FINALLY PULL ON OUT TO SEA BY EARLY WEDNESDAY. H5 CUTOFF LOW OVER THE MID ATLANTIC STATES WILL DRIFT TO THE SOUTHEAST INTO EASTERN NORTH CAROLINA BY 18Z THURSDAY. COOL POOL ALOFT WILL KEEP TEMPERATURES BELOW NORMAL FOR THE MID WEEK PERIOD WITH SCATTERED SHOWERS. H5 HEIGHTS DROP TO 543-546 ACROSS EASTERN NORTH CAROLINA WITH THE 540 THICKNESS LINE DRAPED ACROSS THE WILMINGTON AREA AT 18Z THURSDAY...MORE OF A WINTER PATTERN THEN SPRINGTIME. H5 LOW CONTINUES TO PULL OUT TO THE SE BEFORE MOVING E THEN NE BY FRIDAY AND NE FLOW AT THE SURFACE DEVELOPS AND PERSIST INTO THE WEEKEND. BEST CHANCE FOR PRECIPITATION WILL BE DURING THE MID WEEK PERIOD ASSOCIATED WITH THIS SYSTEM. PREDOMINATELY NW FLOW ALOFT WILL PERSIST INTO THE WEEKEND WITH A NE FLOW AT THE SURFACE THAT MAY HAVE SOME MARINE IMPLICATIONS LATE IN THE PERIOD AND BEYOND WITH A CONSTANT NE FETCH. FOLLOWED HPC GUIDANCE IN THE EXTENDED WITH THE GFS IN THE MID TERM. WILL LOOK OVER THE 12Z GFS TO MAKE SOME MINOR TWEAKS IN THE EXTENDED. && .AVIATION /18Z MONDAY THROUGH FRIDAY/... MAIN AVIATION CONCERN THIS AFTERNOON IS WINDS. WINDS WILL BE WEST TO NORTHWEST GUSTING 30-40 KNOTS. WINDS SUBSIDE AROUND 01Z AND WILL NEED TO MONITOR FOR POSSIBLE LLWS AT THAT TIME. OTHERWISE VFR EXPECTED WITH SCATTERED CLOUDS AROUND 6K. THIS CLOUD LAYER COULD CONSTITUTE A CEILING AT TIMES THIS AFTERNOON AT ILM. WINDS CONTINUE NORTHWEST AT 20-30 KNOTS TUESDAY MORNING UNDER VFR CONDITIONS. NO SIG WEATHER EXPECTED TUESDAY AFTERNOON THROUGH FRIDAY. && .MARINE... NEAR TERM /THROUGH TODAY/... BASED ON LATEST WRF/GFS/CANADIAN MODELS AND MOS GUIDANCE HAVE DECIDED TO EXTEND GALE WARNING FOR ALL ZONES THRU 00Z. LATER SHIFTS MAY FIND THE IT NEEDS TO BE CONTINUED BEYOND 00Z FOR NC WATERS. INTENSIFYING LOW PRESSURE OFF THE JERSEY COAST WILL TIGHTEN THE SURFACE GRADIENT OVER THE WATERS TODAY. SUSTAINED SPEEDS AT OR ABOVE GALE FORCE EXPECTED WITH GUSTS APPROACHING STORM FORCE POSSIBLE. OFFSHORE TRAJECTORY OF WIND WILL KEEP SEAS MUCH LOWER THAN SPEEDS WOULD SUGGEST...BUT SEAS WILL STILL RUN 8 TO 12 FT. SHORT TERM /TONIGHT THROUGH WEDNESDAY/... A VERY SLOWLY RELAXING SFC PRESSURE GRADIENT WILL BE ONGOING TONIGHT INTO TUESDAY. THIS IN RESPONSE TO THE EXTENSIVE AND INTENSE LOW OFF THE NEW JERSEY COAST THAT WILL SLOWLY FILL IN THROUGH TUESDAY BEFORE FINALLY AND SLOWLY LIFTING EASTWARD BY WEDNESDAY. BORDER LINE GALES TO START THE SHORT TERM...WITH SCA CONDITIONS BECOMING THE PREDOMINATE HAZARD OVERNIGHT TONIGHT INTO TUESDAY. WINDS TO FINALLY SUBSIDE TO 15 KT OR LESS BY TUESDAY NIGHT AND WEDNESDAY...A RESULT OF A TEMPORARY UPPER S/W RIDGE AND A MUCH RELAXED SFC PG. A RANGE OF SHORT PERIOD SEAS WILL OCCUPY THE ILM COASTAL WATERS THRU THE SHORT TERM. THIS A RESULT OF AN OFFSHORE WIND DIRECTION THRU MUCH OF THE SHORT TERM. WILL HAVE TO MONITOR AND SEE IF MODELS PICK UP ANY LONG PERIOD SWELLS THAT MAY AFFECT THE ILM CWA...THAT ORIGINATE FROM THE INTENSE LOW MOVING WELL OFFSHORE FROM NJ. THE ILM WATERS MAY BE BLOCKED BY CAPE LOOKOUT AND CAPE HATTERAS TO OUR NORTH...PREVENTING THE SWELL FROM WRAPPING AROUND AND MAKING IT THIS FAR WEST AND SOUTH. LONG TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... AS AFOREMENTIONED ABOVE IN THE LONG TERM DISCUSSION WITH PERSISTENT NE FLOW TO SET UP ACROSS THE COASTAL WATERS LATE IN THE PERIOD WILL EXPECT TO SEE THE SEA BUILD FROM LATE THURSDAY INTO THE WEEKEND AS UPPER LEVEL CUTOFF LOW MOVES ACROSS THE NORTHERN PORTIONS OF THE COASTAL WATERS. WINDS TO AVERAGE 15 KNOTS OR SO THROUGHOUT THE END OF THE PERIOD WITH SEAS BUILDING TO AROUND 5 FEET. NW WINDS WILL DOMINATE THE MID WEEK PERIOD WITH WIND SPEEDS AROUND 15 KNOTS AND SEAS RUNNING 2 FEET OR SO NEAR SHORE AND 4 FEET OFFSHORE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SCZ017-023-024-032>034-039-046. NC...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NCZ087-096-097-099>101. MARINE...GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR AMZ250-252-254-256. && $$ SYNOPSIS...RGZ AVIATION...MRR NEAR TERM...III SHORT TERM...RGZ LONG TERM...CAROPOLO