461  
FXUS61 KBGM 271226  
AFDBGM  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BINGHAMTON NY  
826 AM EDT MON MAR 27 2017  
   
SYNOPSIS
 
 
AN UPPER-LEVEL DISTURBANCE WILL BRING SHOWERS THIS MORNING. AN  
APPROACHING COLD FRONT WILL BRING ANOTHER ROUND OF SHOWERS ON  
TUESDAY. AN AREA OF HIGH PRESSURE, OVER EASTERN CANADA, WILL  
BUILD ACROSS THE REGION WEDNESDAY AND THURSDAY, TO BRING DRIER  
WEATHER. TEMPERATURES WILL BECOME MILD BOTH TODAY AND TUESDAY,  
THEN TURN A BIT MORE SEASONABLE WEDNESDAY AND THURSDAY.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
820 AM UPDATE... TEMPERATURES HAVE CONTINUED TO RISE SLOWLY  
ACROSS THE REGION...AND ESPECIALLY IN SULLIVAN COUNTY WHERE THE  
FREEZING RAIN ADVISORY HAS BEEN ALLOWED TO EXPIRE. THE THREAT  
FOR FREEZING RAIN HAS ENDED WITH MOST OF THE PRECIPITATION NOW  
IN THE FORM OF RAIN. THE REST OF THE FORECAST LOOKS ON TRACK AT  
THIS POINT.  
 
4 AM UPDATE... BANDS OF SHOWERS WILL ROTATE THROUGH CNY/NEPA  
THIS MORNING, TIED TO A WELL DEFINED SHORT-WAVE CROSSING THE  
REGION. TEMPERATURES ARE STILL HOVERING NEAR 32F AT THIS TIME  
OVER SULLIVAN COUNTY NY, WITH AT LEAST SPOTTY FREEZING RAIN  
LIKELY OCCURRING. ALL AVAILABLE NEAR-TERM TEMPERATURE GUIDANCE  
INDICATES A SLOW RISE OVER THE NEXT FEW HOURS ACROSS THE  
CATSKILLS, SO AN EXPIRATION TIME OF 8 AM FOR THE FREEZING RAIN  
ADVISORY STILL SEEMS REASONABLE.  
 
REGIONAL RADAR LOOPS STILL INDICATE OCCASIONAL BURSTS OF  
MODERATE TO HEAVY RAIN WITH SOME OF THE SHOWERS, BUT MULTI-RADAR  
MULTI-SENSOR DATA, AS WELL AS LOCAL RAIN GAUGE DATA, SHOW HOURLY  
RAINFALL RATES OF 0.1-0.2", AT WORST. WE EXPECT A GENERAL  
0.25-0.5" OF RAIN ACROSS THE REGION THIS MORNING.  
 
DURING THE AFTERNOON, SINKING MOTION BEHIND THE SHORT-WAVE WILL  
PROVIDE GENERALLY RAIN-FREE CONDITIONS, WITH JUST A FEW SPOTTY  
SHOWERS POSSIBLE. AS MOST OF THE AREA EMERGES INTO THE WARM  
SECTOR THIS AFTERNOON, TEMPERATURES WILL BECOME QUITE MILD, WITH  
HIGHS RANGING FROM THE MID 40S OVER SOME OF OUR FAR EASTERN  
ZONES, TO THE MID-UPPER 50S IN MOST OTHER PORTIONS OF CNY/NEPA.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/
 
 
415 AM UPDATE... MOST OF TONIGHT WILL REMAIN RAIN-FREE, WITH  
AGAIN SOME ISOLATED-SCATTERED SHOWERS POSSIBLE, MAINLY IN THE  
PRE-DAWN HOURS. TEMPERATURES WILL STAY MILD, WITH READINGS  
HOLDING UP IN THE 40S-LOWER 50S.  
 
AS THE NEXT SHORT-WAVE COMES IN TUESDAY, IT WILL DRIVE A SURFACE  
COLD FRONT INTO NY/PA BY LATE AFTERNOON/EARLY EVENING. SHOWERS  
WILL BECOME FAIRLY WIDESPREAD WITH THESE FEATURES, WITH A FEW  
THUNDERSTORMS NOT OUT OF THE QUESTION, ESPECIALLY ACROSS NEPA.  
WE'RE AGAIN LOOKING AT A 0.25-0.5" OF RAIN ON TUESDAY FOR MUCH  
OF THE SOUTHERN TIER AND NEPA, WITH LESSER AMOUNTS TO THE NORTH.  
ANY ISOLATED CONVECTION COULD BRING LOCALIZED HIGHER AMOUNTS.  
HIGHS TUESDAY AFTERNOON WILL RANGE FROM THE 50S-LOWER 60S AREA-  
WIDE.  
 
TUESDAY NIGHT-WEDNESDAY, DRIER AIR WILL BUILD IN BEHIND THE  
AFOREMENTIONED COLD FRONT, WITH A SURFACE RIDGE ALSO NOSING  
SOUTHWARD OUT OF EASTERN CANADA. TEMPERATURES WILL RETURN TO  
MORE SEASONABLE LEVELS ON WEDNESDAY, WITH HIGHS RANGING MOSTLY  
FROM THE UPPER 30S-MID 40S.  
 

 
   
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
 
 
400 AM EDT UPDATE...  
NO SIGNIFICANT CHANGES WERE MADE TO THE PREVIOUS FORECAST  
DISCUSSION. MODELS ARE COMING TO BETTER AGREEMENT ON THE NEXT  
STORM SYSTEM THAT WILL MOVE INTO THE REGION EARLY FRIDAY MORNING.  
THIS SYSTEM WILL BRING A CHANCE FOR RAIN SHOWERS THROUGH SAT  
AFTERNOON. THE BEST CHANCE FOR PRECIP WILL CONTINUES TO BE  
FRIDAY AFTERNOON AND EVENING. FOR MORE INFORMATION PLEASE READ  
THE PREVIOUS FORECAST DISCUSSION BELOW.  
 
PREVIOUS FORECAST DISCUSSION...  
WEDNESDAY TO THURSDAY HIGH PRESSURE AT THE SURFACE WITH A RIDGE  
ALOFT. TEMPERATURES CLOSE TO NORMAL WITH HIGHS IN THE 40S AND  
LOWS IN THE 20S AND 30S.  
 
FRIDAY WILL BE WATCHING A STRONG STORM FOR RAINFALL AMOUNTS.  
SLOW MOVING STORM WILL MOVE NORTHEAST FROM THE CENTRAL PLAINS  
INTO THE GREAT LAKES FRIDAY. FRIDAY NIGHT IT MOVES OVER OUR  
REGION AND REFORMS ON THE COAST SATURDAY. THE HEAVIEST RAIN WILL  
BE WITH AND AHEAD OF THE LOW FRIDAY AFTERNOON AND NIGHT. COLD  
AIR SHOULD STAY TO THE NORTH KEEPING ALL OF THE PRECIP RAIN EVEN  
WITH THE UPPER LEVEL TROUGH SATURDAY. ANY SNOW LEFT WILL BE  
MELTED WITH WARM MOIST AIR AHEAD OF THIS STORM.  
 
SUNDAY WILL BE IN TRANSITION AS FLOW GOES ZONAL AND ANOTHER  
SHORT WAVE AND WEAK FRONT APPROACHES LATE.  
 

 
   
AVIATION /12Z MONDAY THROUGH FRIDAY/
 
 
A LOW PRESSURE SYSTEM WILL DRIFT TO THE NORTH THIS MORNING AND  
RAIN SHOWERS WILL CONTINUE TO PUSH EAST. EXPECT MOSTLY MVFR  
CEILINGS AND EMBEDDED IFR VISBYS THROUGH THE MORNING, EXCEPT FOR  
KBGM WHICH IS HOLDING AT IFR. FLIGHT CONDITIONS ARE EXPECTED TO  
IMPROVE BY MID MORNING AT ALL TAF SITES AS SHOWERS MOVE EAST OUT  
OF THE AREA. WINDS WILL BECOME LIGHT AND VARIABLE THROUGH THE  
DAY.  
 
A STRONG LOW-LVL JET IS PRESENT OVER THE REGION THIS MORNING,  
THUS LLWS WILL BE A THREAT FOR ALL TAF SITES THROUGH AT LEAST  
15Z MON.  
 
OUTLOOK...  
 
MONDAY NIGHT THROUGH TUESDAY...RESTRICTIONS LIKELY FROM WAVES  
OF RAIN AS FRONTAL BOUNDARY WAFFLES OVER THE AREA.  
 
WEDNESDAY/THURSDAY...MAINLY VFR.  
 
THURSDAY NIGHT/FRIDAY...RESTRICTIONS LIKELY IN SHOWERS.  
 

 
   
HYDROLOGY
 
 
245 PM EDT SUNDAY UPDATE...THE RAIN ON SNOW MELT EVENT IS  
UNDERWAY, AND WILL CONTINUE INTO THE UPCOMING WEEK AS  
TEMPERATURES IN THE 50S-60S BECOME MORE WIDESPREAD ACROSS THE  
REGION. THIS WARMTH WILL ALSO BE ACCOMPANIED BY AN INCREASE IN  
SURFACE DEWPOINTS INTO THE 40S.  
 
FUTURE RAINFALL AMOUNTS ARE ROUGHLY THE SAME IN TODAY'S MODEL  
RUNS, WITH BASIN AVERAGED QPF UP TO AN INCH THROUGH WEDNESDAY  
MORNING. THIS ALONG WITH THE RUNOFF OF MOST OF THE 1 TO 3 INCHES  
OF LIQUID WATER CONTENT ACROSS THE HEADWATERS OF THE UPPER  
SUSQUEHANNA, DELAWARE AND THE ONEIDA-SYRACUSE RIVER BASIN WILL  
LEAD TO HIGH FLOWS, AND PROBABLY MINOR FLOODING AT SEVERAL OF  
THE FORECAST GAUGE POINTS IN THE SUSQUEHANNA AND UPPER DELAWARE  
TRIBS.  
 
MMEFS ENSEMBLE SPREADS ARE EVEN MORE AGGRESSIVE THAN OUR LATEST  
OPERATIONAL HYDROLOGIC MODEL RUNS, AND SHOW A POTENTIAL FOR A  
QUICKER MELT ON MONDAY WITH SHARP RISES TO FLOOD STAGE AT THE  
HEADWATER POINTS, FOLLOWED BY SECONDARY CRESTS ON TUESDAY. IN  
SOME CASES, THE MEAN CRESTS ARE TO THE MODERATE FLOOD STAGE.  
THE CONFIDENCE OF A NEAR WORST CASE SCENARIO OUTCOME IS QUITE  
LOW AT THIS TIME, BUT IT WILL BE IMPORTANT TO KEEP THESE CAVEATS  
IN MIND AS THIS EVENT UNFOLDS, AND BE PREPARED TO REACT TO  
LOCALLY HEAVIER RAINFALL AND/OR A RAPID MELT DOWN OF THE SNOW  
COVER.  
 
WITH FORECAST CRESTS STILL OVER 48 HOURS AWAY, THERE IS STILL  
TIME FOR FURTHER ASSESSMENT, AND NO WATCH WILL BE ISSUED AT THIS  
TIME.  
 

 
   
BGM WATCHES/WARNINGS/ADVISORIES
 
 
PA...NONE.  
NY...NONE.  
 

 
 

 
SYNOPSIS...MLJ  
NEAR TERM...BJT/MLJ  
SHORT TERM...MLJ  
LONG TERM...KAH/TAC  
AVIATION...KAH  
HYDROLOGY...  
 
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