PNSPHI/ ON OUR WEB SITE...WWW.WEATHER.GOV/PHI... FOR SNOWFALL AMOUNTS. IT WILL BE QUITE COLD AND SOMEWHAT BRISK OVERNIGHT WITH DECREASING AMOUNTS OF CLOUDINESS. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/... THE LONG WAVE TROUGH LOCATED OVER THE EASTERN STATES THIS WEEKEND SHOULD LIFT TO OUR NORTHEAST EARLY IN THE NEW WEEK. SURFACE HIGH PRESSURE WILL LIKELY BUILD INTO OUR REGION FROM THE WEST. IT WILL REMAIN COLD FROM SUNDAY THROUGH TUESDAY, WITH BELOW NORMAL TEMPERATURES. AN UPPER LEVEL SHORT WAVE IS FORECAST TO APPROACH FROM THE WEST ON TUESDAY. WE MAY SEE AN INCREASE IN HIGH CLOUDS FROM LATE MONDAY INTO MONDAY NIGHT. MID LEVEL CLOUDS SHOULD THEN INVADE FROM THE WEST ON TUESDAY, WITH A SLIGHT CHANCE OF AFTERNOON SNOW SHOWERS, MAINLY IN OUR WESTERN COUNTIES. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... THE OVERALL SYNOPTIC PATTERN CONTINUES TO REMAIN ON THE ACTIVE SIDE AS ENERGY SLIDES INTO THE WESTERN UNITED STATES, THEN TENDS TO REORGANIZE INTO THE PLAINS. A WEAKER SYSTEM LOOKS TO DIVE ACROSS THE AREA TUESDAY INTO WEDNESDAY IN ASSOCIATION WITH THE NORTHERN BRANCH OF THE JET STREAM, AND MAINTAINING AT LEAST SOME TROUGHING IN THE EAST. THE MAIN FEATURE TO WATCH IS THE SOUTHERN STREAM ENERGY AS IT MOVES ACROSS THE PLAINS AND THE GULF COAST REGION. THIS HAS THE POTENTIAL TO BECOME A SIGNIFICANT EAST COAST STORM LATE FRIDAY AND SATURDAY. THE MAIN QUESTION IS JUST HOW FAR NORTH THE SYSTEM CAN MAKE THE TURN, WHICH WILL TEND TO DEPEND ON THE AMPLIFICATION OF THE UPPER-LEVEL TROUGH. THE MODEL GUIDANCE IS ALREADY AT ODDS REGARDING THE FORWARD SPEED OF THE MID LEVEL TROUGH AND ALSO THE POSITIONING OF THE SURFACE HIGH FROM THE MID ATLANTIC TO EASTERN CANADA. THE GFS SUPPRESSES THE STORM TO OUR SOUTH, WHILE THE 12Z ECMWF SLIDES THE SURFACE HIGH OUT OF THE WAY AND WITH MORE TROUGH AMPLIFICATION BRINGS A POTENTIALLY SIGNIFICANT STORM TO OUR AREA. THE GGEM LOOKS TO BE SUPPRESSED AS WELL. THE ECMWF SCENARIO WOULD BRING A WINTRY MIX/SNOW/RAIN TO THE AREA, HOWEVER THE DETAILS IN THE THERMAL FIELDS ARE MORE UNCERTAIN THIS FAR OUT. HPC WENT WITH A ECMWF/GEFS MEAN BLEND FOR TUESDAY AND WEDNESDAY, THEN A BLEND OF THE GEFS MEAN, CANADIAN AND ECMWF ENSEMBLE MEAN FOR THURSDAY THROUGH SATURDAY. HPC DID NOTE THAT THEY LOWERED THE SURFACE PRESSURES AND INCREASED THE GRADIENT WINDS SOME WITH THE SOUTHEAST/MID ATLANTIC REGION POTENTIAL COASTAL STORM FRIDAY AND SATURDAY. WE INITIALIZED THE DATABASE WITH HPC GUIDANCE AND THEN MADE SOME MOSTLY MINOR ADJUSTMENTS BASED ON ADDITIONAL COLLABORATION WITH OUR SURROUNDING OFFICES. THIS PAINTS IN SOME SLIGHT CHC TO LOW CHC POPS TUESDAY NIGHT AS A NORTHERN STREAM SYSTEM MOVES THROUGH AND ANOTHER PIECE OF ENERGY SCOOTS BY TO OUR SOUTH. THERE DOES NOT APPEAR TO BE MUCH IN THE WAY OF MOISTURE WITH THESE FEATURES FOR OUR CWA. WE WENT DRY FOR WEDNESDAY AND THURSDAY AS HIGH PRESSURE SLIDES ACROSS. AS THE ENERGY THEN ORGANIZES ACROSS THE GULF COAST STATES AND MOVES EAST- NORTHEASTWARD, WE WILL BRING SLIGHT CHC TO CHC POPS FROM NORTH TO SOUTH FRIDAY AND SATURDAY. AT THIS POINT, WE WENT WITH RAIN/SNOW AS THE PRECIPITATION TYPE WITH THE GREATER CHC OF ALL SNOW FARTHER INLAND. AS THE SYSTEM MOVES AWAY, COLDER AIR WORKING IN MAY ALLOW ANY MIXED PRECIPITATION/RAIN TO CHANGE TO SNOW BEFORE ENDING. HOWEVER, THERE IS PLENTY OF TIME TO WATCH THE EVOLUTION OF THIS POTENTIAL COASTAL STORM. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. SNOW AT VARYING INTENSITY CONTINUES THIS EVENING AT ALL OUR TERMINALS WITH THE EXCEPTION OF KABE AND KRDG. BASED ON RADAR AND OBSERVATIONAL TRENDS, WE WILL CONTINUE WITH THE SNOW AND SUB-VFR CONDITIONS THROUGH THE NEXT FEW HOURS BEFORE INDICATING MORE OF AN IMPROVEMENT. WHILE THE HEAVIEST SNOW MAY BE OVER WITH, THERE IS THE POSSIBILITY THROUGH ABOUT 02-03Z THAT VISIBILITIES DROP TO AROUND 3/4SM FOR A TIME. THE NORTHEAST TO NORTH WINDS WILL GRADUALLY SHIFT TO NORTH AND NORTHWEST DURING THE NIGHT AND SUNDAY. THE STORM WILL EXIT TO OUR EAST OVERNIGHT WITH DRIER AIR ARRIVING IN ITS WAKE. BY LATER TONIGHT, ITS EFFECTS WILL BE OVER WITH AND ALL TERMINALS SHOULD RETURN TO VFR AND THIS IS EXPECTED TO CONTINUE THROUGH SUNDAY. OUTLOOK... HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN THROUGH MIDWEEK. THERE IS THE POTENTIAL FOR A FEW SNOW SHOWERS LATE TUESDAY INTO EARLY WEDNESDAY, WHICH COULD CAUSE SOME BRIEF RESTRICTIONS. && .MARINE... AN AREA OF LOW PRESSURE IS FCST TO MOVE NEWD AND OUT TO SEA FROM THE NC CST. AS THE LOW MOVES BY, IT IS EXPECTED TO INCREASE WINDS AND SEAS, MAINLY OVER THE SRN AREAS. THE SCA FOR THE SRN WATERS AND DELAWARE BAY WILL BE IN EFFECT THROUGH 11Z SUNDAY. IT IS POSSIBLE THAT A FEW GALE FORCE GUSTS OCCUR ACROSS OUR FAR SOUTHERN WATERS FOR A TIME THIS EVENING, HOWEVER CONFIDENCE IS LOW WITH THE OCCURRENCE AND DURATION THEREFORE WILL MAINTAIN A STRONG SCA FOR NOW. THERE IS MORE UNCERTAINTY AS TO WHETHER WE WILL REACH SCA ACRS THE NRN WATERS. HOWEVER, THINGS WILL BE CLOSE AS THE LOW MOVES BY AND ISSUING AN SCA TO COVER THE REMAINDER OF THE OCEANFRONT SEEMS TO BE THE PRUDENT COURSE OF ACTION AT THIS TIME. HIGH PRESSURE THEN BUILD IN THROUGH MIDWEEK, BRINGING RATHER TRANQUIL CONDS TO THE AREA WATERS. THERE ARE SOME INDICATIONS THAT THERE COULD BE ANOTHER COASTAL STORM LATE TUESDAY INTO EARLY WEDNESDAY. WHAT EFFECTS, IF ANY, IT HAS WILL BE DEPENDENT ON HOW CLOSE TO THE AREA IT GETS, BUT RIGHT NOW IT IS EXPECTED TO REMAIN TO THE S. && .TIDES/COASTAL FLOODING... A COASTAL FLOOD ADVISORY IS IN EFFECT FOR THE COASTAL COUNTIES FOR SUNDAY MORNING`S HIGH TIDE. THE FULL MOON IS TODAY AND TIDES ARE RUNNING HIGH. WITH THE AFOREMENTIONED LOW CHURNING THINGS UP A BIT, IT APPEARS THAT THERE COULD BE SOME MINOR TIDAL FLOODING EARLY SUNDAY MORNING. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...COASTAL FLOOD ADVISORY FROM 9 AM THIS MORNING TO 1 PM EST THIS AFTERNOON FOR NJZ013-014-020-022>027. DE...COASTAL FLOOD ADVISORY FROM 9 AM THIS MORNING TO 1 PM EST THIS AFTERNOON FOR DEZ003-004. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR ANZ431-450>455. && $$ SYNOPSIS...EBERWINE/IOVINO