964 FXUS61 KBGM 300357 AFDBGM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 1157 PM EDT SAT MAR 29 2014 .SYNOPSIS... A STORM SYSTEM MOVING THROUGH THE MIDDLE ATLANTIC STATES HAS CAUSED RAIN TO DEVELOP ACROSS OUR REGION. THE RAIN COULD BE HEAVY AT TIMES OVERNIGHT INTO SUNDAY. COLDER AIR WRAPPING INTO THE SYSTEM WILL ALSO CAUSE THE RAIN TO BECOME A WINTRY MIX IN PARTS OF THE SOUTHERN TIER TO FINGER LAKES TO MOHAWK VALLEY REGIONS OF NEW YORK TONIGHT INTO SUNDAY...ESPECIALLY HIGHER ELEVATIONS. && .NEAR TERM /THROUGH SUNDAY/... 1150 PM UPDATE... FLOOD WATCH WAS EXPANDED WESTWARD DUE TO UP TO AN INCH OF RAIN ALREADY FALLING IN THE CENTRAL SOUTHERN TIER TO FINGER LAKES REGIONS...AND ANOTHER SLUG OF MODERATE RAINFALL HEADING INTO THE AREA THE NEXT FEW HOURS. THIS INITIAL PRECIPITATION MAXIMUM AXIS IS FARTHER WEST THAN WAS EARLIER EXPECTED. IT WILL BE ENOUGH TO CAUSE STRONG RISES AND POSSIBLE FLOODING IN SMALL STREAMS AND CREEKS. SOME ADJUSTMENTS WERE ALSO MADE TO TIMING OF SOME OF THE WINTER WEATHER ADVISORY BASED ON EXPECTED EVOLUTION OF PRECIP TYPE...INCLUDING STARTING THE WESTERN PORTION OF THE ADVISORY NOW INSTEAD OF WAITING TO 06Z. ALMOST EXCLUSIVELY RAIN SO FAR...BUT WESTERN-NORTHWESTERN EDGES OF STEUBEN AND YATES COUNTIES HAVE BEEN MIXING OVER TO SNOW AND PERHAPS SOME FREEZING RAIN. WE HAVE HAD A REPORT OF LIGHT ICING IN ALMOND NY FOR EXAMPLE. ALSO...PATCHY DENSE FOG HAS BEEN ADDED TO THE WEATHER GRIDS IN THE WESTERN ZONES OVERNIGHT. DANSVILLE OBS JUST OUTSIDE STEUBEN COUNTY WAS GETTING BELOW A MILE AT TIMES. PREVIOUS DISCUSSION... A VERY MESSY COMPLEX WINTER STORM WILL IMPACT THE REGION THROUGH SUNDAY NIGHT. RAIN SHOWERS FROM THIS SYSTEM HAVE ALREADY STARTED TO INFILTRATE THE CWA. TEMPS ARE STILL ABOVE FREEZING ACROSS THE CWA THIS AFTERNOON AND EXPECT TEMPS TO HOLD STEADY THROUGH 06Z TONIGHT. CURRENTLY ACTIVITY IS EXPECTED TO REMAIN AS RAIN SHOWERS THROUGH ROUGHLY MIDNIGHT UNTIL SFC TEMPS START TO FALL SHORTLY AFTER. COLDER AIR WILL START TO PUSH INTO THE CWA FROM THE NORTHEAST AND THE SITUATION WILL THEN BECOME ONE CONGLOMERATE MESS. AS THE CAA PUSHES IN FROM THE NORTH/NORTHEAST... RAIN WILL TURN INTO A WINTRY MIX OF POSSIBLY SLEET... FREEZING RAIN... AND SNOW. RAIN WILL TRANSITION OVER TO WINTRY MIX FIRST OVER THE NW PORTIONS OF THE CWA. BY EARLY SUNDAY MORNING MUCH OF CENTRAL NY WILL HAVE A WINTRY MIX AS THE COLD AIR PUSHES FURTHER SOUTH. THERE WILL BE A CHANCE OF A WINTRY MIX FROM THIS SYSTEM THROUGH SUNDAY. DECIDED TO ISSUE A WINTER WEATHER ADVISORY TONIGHT BECAUSE COULD SEE UP TO 1 TO 4 INCHES OF SNOW ACROSS THE NORTHWESTERN PART OF THE CWA AND ACCUMULATIONS UP TO A QUARTER OF AN INCH OF ICE. EASTERN PORTIONS OF THE CWA COULD SEE UP TO A QUARTER OF AN INCH OF ICE AS WELL.THE BEST CHANCE FOR ACCUMULATING ICE WILL BE OVER THE HIGHER ELEVATIONS IN CENTRAL NEW YORK. CAN NOT RULE OUT THE LOWER VALLEYS SEEING ICE ACCUMULATIONS EITHER. OVER NORTHEAST PA... EXPECT SHOWERS TO REMAIN MOSTLY RAIN THUS DECIDED TO KEEP OUT OF ADVISORY ATTM. PA MAY SEE A WINTRY MIX LATE SUNDAY NIGHT IF PRECIP LINGERS AS EXPECTED. THE STORM WILL START TO MOVE OUT OF THE CWA SUNDAY NIGHT AND DRY AIR WILL OVERCOME THE REGION BRINGING THE POSSIBILITY FOR DRIZZLE/FREEZING DRIZZLE OVER MUCH OF THE REGION. FLOODING MAY BE AN ISSUE TONIGHT THROUGH SUNDAY. PLEASE SEE HYDROLOGY SECTION BELOW. && .SHORT TERM /SUNDAY NIGHT/... 500 PM EDT UPDATE... MOISTURE MAY LINGER THROUGH SUNDAY NIGHT AND THERE MIGHT BE A CHANCE FOR ADDITIONAL ICE ACCUMULATION OVER THE HIGHER TERRAIN OVER THE EASTERN PORTIONS OF THE CWA. THE CURRENT STORM APPEARS TO TREND SLOWER WITH EACH ADDITIONAL MODEL RUN... THUS A WINTRY MIX MAY CONTINUE THROUGH LATE SUNDAY NIGHT. && .LONG TERM /MONDAY THROUGH SATURDAY/... 230 PM UPDATE... SYSTEM WL BE EXITING STAGE RIGHT TO START OFF THE LONG TERM WITH JUST CHC FOR LGT SNOW SHOWERS IN AREAS EAST OF I-81, THEN EVENTUALLY MIXING WITH RAIN DRG THE AFTN WHEN PCPN PULLS EAST. HIGH PRESSURE WL TAKE HOLD MON NGT AND TUE WITH S/WV RIDGING BUILDING IN FOR TUE. H5 HEIGHTS EXPECTED TO CLIMB TO NR 560DM WITH POSSIBLY WARMEST TEMPS THUS FAR FOR THE MONTH OF MARCH. H8 TEMPS DRG THE DAY WL WARM TO NR +9C, YIELDING HIGHS CLOSE TO 60F. WK CDFNT WL MV THRU WED MRNG KNOCKING H8 TEMPS DOWN A FEW DEGREES WITH HIGHS ON WED ONLY EXPECTED TO CLIMB INTO THE 50S, WHICH IS STILL ABV NORMAL VALUES. MAIN WV WL LIFT NORTH INTO CANADA WITH BEST FRCG ACRS NRN ZONES, THUS WL GO WITH WPC GUIDANCE WITH SLGT/LOCHC POPS FOR RAIN/SNOW TUE NGT. HIPRES WL ONCE AGAIN BUILD IN THRU THUR MRNG WITH NEXT UL TROF APPCHG FM THE WEST WITH CHC RAIN THRU THE END OF NEXT WEEK. TEMPS THRU THE END OF THE WEEK LKLY TO STAY AT TO SLIGHTLY ABV NORMAL. && .AVIATION /04Z SUNDAY THROUGH THURSDAY/... 730 PM UPDATE... COMPLICATED FORECAST TONIGHT INTO SUNDAY NIGHT. RAIN HAS MOVED NORTH AHEAD OF A LARGE SLOW MOVING STORM IN VIRGINIA. ALL SITES SHOULD FALL TO IFR CIGS AND VSBYS IN RAIN AND FOG THIS EVENING THEN REMAIN THERE INTO SUNDAY MORNING. SOME IMPROVEMENT AT VALLEY LOCATIONS DURING THE DAY SUNDAY. VSBYS SHOULD IMPROVE MVFR WITH CIGS GOING TO MVFR AT ELM AND AVP. ITH AND BGM SHOULD HAVE THE LOWEST CONDITIONS AND AT TIMES FALLING BELOW AIRPORT MINIMUMS. AROUND 12Z FREEZING RAIN, SNOW, AND SLEET ARE POSSIBLE IN NY EXCEPT BGM. NORTHEAST WINDS 5 TO 10KTS TONIGHT WILL BACK TO THE NORTH AROUND 12Z AND INCREASE TO 10 TO 15 KTS. OUTLOOK... SUN NGT...LINGERING LOW CIGS AND FOG IN MIXED PRECIP. MON...IMPROVING TO VFR. MON NGT THROUGH WED...MAINLY VFR. THUR...RESTRICTIONS POSSIBLE IN LIGHT RAIN. && .HYDROLOGY... 3 PM SATURDAY... THE SITUATION DISCUSSED BELOW STILL APPLIES. HEAVIEST PRECIPITATION WILL OCCUR TONIGHT...CONTINUING YET DIMINISHING SUNDAY INTO SUNDAY NIGHT. 3 PM FRIDAY... SIGNIFICANT AMOUNTS OF RAIN ARE POSSIBLE TONIGHT AND TOMORROW ASSOCIATED WITH A STORM SYSTEM MOVING NORTH ALONG THE COAST. MODERATE TO HEAVY RAINFALL OF 1.5 TO 2.5 INCHES IS EXPECTED ACROSS THE AREA. THE HIGHEST TOTALS ARE LIKELY TO BE SPREAD ACROSS THE UPPER DELAWARE AND NORTHERN SUSQUEHANNA RIVER BASINS. SOME LINGERING SNOW MELTING OUT OF THE HILLS AND MOUNTAINS WILL CONTRIBUTE TO ADDITIONAL RUN OFF. RIVER FORECAST MODELS SUGGESTS SEVERAL FOOT RISES TO NEAR BANKFULL ON AREA RIVERS BY SUNDAY NIGHT OR EARLY MONDAY. FLOOD STAGE MAY BE EXCEEDED AT A FEW POINTS IN THE SUSQUEHANNA BASIN AND DELAWARE BASIN HEADWATERS. SMALLER STREAMS...STORM DRAINS AND STREET FLOODING WILL BE HIGHLY POSSIBLE IN AREAS WHERE THE BULK OF THE RAIN FALLS IN 6 HOURS OR LESS OVERNIGHT TONIGHT. MONITOR THIS SITUATION CLOSELY. RIVER FORECASTS MAY SIGNIFICANTLY CHANGE DUE TO CHANGES IN RAINFALL FORECASTS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH THROUGH LATE SUNDAY NIGHT FOR PAZ038>040-043-044- 047-048-072. WINTER WEATHER ADVISORY FROM 8 PM SUNDAY TO 8 AM EDT MONDAY FOR PAZ039-040-043-044-047-048-072. WINTER WEATHER ADVISORY FROM 6 AM SUNDAY TO 8 AM EDT MONDAY FOR PAZ038. NY...FLOOD WATCH THROUGH LATE SUNDAY NIGHT FOR NYZ036-037-044>046- 055>057-062. WINTER WEATHER ADVISORY UNTIL 8 AM EDT MONDAY FOR NYZ036-037- 044-045. WINTER WEATHER ADVISORY FROM 8 PM SUNDAY TO 8 AM EDT MONDAY FOR NYZ062. WINTER WEATHER ADVISORY FROM 6 AM SUNDAY TO 8 AM EDT MONDAY FOR NYZ046-055>057. WINTER WEATHER ADVISORY UNTIL 8 PM EDT SUNDAY FOR NYZ009- 015>018-022>025. FLOOD WATCH THROUGH SUNDAY MORNING FOR NYZ015>018-022>025. && $$ SYNOPSIS...MDP NEAR TERM...MDP SHORT TERM...KAH LONG TERM...PVN AVIATION...TAC HYDROLOGY...