593  
FXUS61 KBUF 050758  
AFDBUF  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BUFFALO NY  
358 AM EDT THU MAY 5 2016  
   
SYNOPSIS
 
 
A DEEP UPPER LEVEL TROUGH WILL REMAIN PARKED OVER THE REGION  
THROUGH THE END OF THE WEEK. AS A RESULT...WE CAN EXPECT SOMEWHAT  
UNSETTLED WEATHER TO PERSIST THROUGH THE NEXT COUPLE OF DAYS...  
THOUGH TEMPERATURES WILL REMAIN FAIRLY CLOSE TO NORMAL LEVELS  
FOR EARLY MAY.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
DURING THE COURSE OF TODAY...DEEP UPPER LEVEL TROUGHING WILL  
REMAIN IN PLACE OVERHEAD...WITH AN EMBEDDED CLOSED UPPER LOW  
SLIDING FROM THE LOWER OHIO VALLEY INTO THE CAROLINAS. MEANWHILE  
AT THE SURFACE...A COASTAL LOW WILL LIFT NORTHEASTWARD OFFSHORE OF  
THE EASTERN SEABOARD...WHILE A LINGERING INVERTED TROUGH OVER FAR  
WESTERN NEW YORK SLOWLY DECAYS AND RECEDES SOUTHWARD.  
 
UNDER THIS PATTERN...THE VAST MAJORITY OF ANY DEEP/LARGE-SCALE  
FORCING WILL BE SITUATED WELL TO THE SOUTH AND EAST OF OUR REGION  
TODAY...WITH JUST SOME LINGERING WEAKER LOW-LEVEL CONVERGENCE  
FOUND IN THE VICINITY OF THE SURFACE TROUGH. IN CONJUNCTION WITH  
LINGERING MOISTURE...THIS WILL HELP TO GENERATE SOME SCATTERED  
SHOWERS AT TIMES...WITH THE GREATEST COVERAGE OF THIS ACTIVITY  
AGAIN COMING THIS AFTERNOON IN CONJUNCTION WITH PEAK DIURNAL  
HEATING/ATMOSPHERIC DESTABILIZATION. LOCATION-WISE...EXPECT A FEW  
SHOWERS TO BE POSSIBLE JUST ABOUT ANYWHERE ALONG THE SURFACE  
TROUGH THROUGH EARLY THIS MORNING...WITH THE ACTIVITY THEN LARGELY  
RETREATING TO INTERIOR PORTIONS OF THE SOUTHERN TIER BY THIS  
AFTERNOON...CLOSER TO THE FADING SURFACE BOUNDARY AND AWAY FROM  
THE STABILIZING NORTHEASTERLY FLOW OFF LAKES ERIE AND ONTARIO.  
HAVE RETAINED THE CHANCE POPS FROM CONTINUITY TO COVER THIS  
ACTIVITY...WITH THE HIGHEST PROBABILITIES /HIGH CHANCE/ INDICATED  
THIS AFTERNOON...WHEN THERE MAY AGAIN BE JUST ENOUGH INSTABILITY  
TO POP A THUNDERSTORM ACROSS THE SOUTHERN TIER.  
 
ASIDE FROM THE ABOVE...EXPECT A MAINLY DRY DAY...WITH FAIRLY  
WIDESPREAD EARLY MORNING CLOUD COVER EVENTUALLY GIVING WAY TO SOME  
PARTIAL SUNSHINE ACROSS THE LAKE PLAINS. WITH 850 MB TEMPS RUNNING  
BETWEEN +2C AND +4C...EXPECT HIGHS TO PRIMARILY RANGE FROM THE  
UPPER 50S ACROSS THE HIGHER TERRAIN TO THE LOWER 60S ACROSS THE  
LOWER ELEVATIONS...THOUGH AREAS ALONG THE SOUTH SHORES OF BOTH  
LAKES WILL AGAIN BE COOLER DUE TO THE PREVAILING NORTHEASTERLY  
LOW-LEVEL FLOW. THIS WILL ESPECIALLY BE THE CASE RIGHT ALONG THE  
SOUTH SHORE OF LAKE ONTARIO...WHERE HIGHS WILL AGAIN LIKELY  
STRUGGLE TO REACH ABOVE THE MID TO UPPER 40S.  
 
TONIGHT...THE CORE OF THE CLOSED LOW WILL SLIDE EAST TO THE  
CAROLINA COASTLINE...WHILE SPURRING THE DEVELOPMENT OF ANOTHER  
MODEST SURFACE LOW OFF THE DELMARVA COAST. THE BULK OF THE LARGER-  
SCALE FORCING WITH THESE FEATURES WILL THUS AGAIN REMAIN WELL TO  
OUR SOUTH AND EAST...WITH JUST SOME LIMITED SHORTWAVE ENERGY  
CIRCULATING AROUND THE NORTHERN EDGE OF THE CLOSED LOW AND  
BRUSHING SOUTHERN/CENTRAL NEW YORK STATE AT TIMES. IN CONJUNCTION  
WITH THE LOSS OF HEATING...THIS SHOULD TRANSLATE INTO A MAINLY DRY  
NIGHT FOR OUR REGION...WITH JUST A LOW CHANCE FOR SOME ADDITIONAL  
SHOWERS FOUND ACROSS THE SOUTHERN TIER AND INTERIOR SECTIONS OF  
THE FINGER LAKES. OTHERWISE EXPECT PARTLY TO MOSTLY CLOUDY SKIES  
TO PREVAIL...WITH OVERNIGHT LOWS MAINLY IN THE MID TO UPPER 40S.  
 

 
   
SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/
 
 
A TYPICAL SPRINGTIME...HIGHLY AMPLIFIED PATTERN WILL BE FOUND ACROSS  
THE COUNTRY TO OPEN THIS PERIOD. LIKE A PAIR OF HEADLIGHTS STARING AT  
YOU...DEEP TWIN CLOSED LOWS WILL BE FOUND ALONG EACH COAST WHILE  
RIDGING WILL BE FOUND ACROSS THE NATIONS MID SECTION. THIS PATTERN  
WILL BREAK DOWN DURING THE COURSE OF THE WEEKEND THOUGH...AS ENERGY  
SPILLING OVER THE MACKENZIE MOUNTAINS IN THE YUKON WILL DIVE  
SOUTHEAST ACROSS THE CANADIAN PRAIRIES TO THE GREAT LAKES BY SUNDAY.  
THIS WILL DISRUPT THE UPPER LEVEL PATTERN OVER THE LOWER 48 BY  
KICKING OUT THE ATLANTIC COAST CLOSED LOW WHILE ESTABLISHING A NEW  
CLOSED CIRCULATION OVER EASTERN CANADA. THE COLD FRONT THAT WILL  
LEAD THIS PATTERN CHANGE WILL END OUR BRIEF TASTE OF EARLY SUMMER  
WEATHER SATURDAY NIGHT BY PLUNGING OUR REGION BACK TO A REGIME OF  
BELOW NORMAL TEMPERATURES FOR SUNDAY AND MONDAY. THE DETAILS...  
 
A BROAD CLOSED LOW CENTERED OVER NORTH CAROLINA FRIDAY MORNING WILL  
SLOWLY DRIFT NORTH ACROSS THE DELMARVA PENINSULA DURING THE MIDDAY  
AND AFTERNOON...WHILE SPOKES OF ENERGY AND PLENTY OF ATLANTIC BASED  
MOISTURE WILL ROTATE BACK ACROSS NEW YORK STATE WITHIN THE RESULTING  
DEEP EASTERLY FLOW. THIS WILL PROMOTE SCATTERED SHOWERS ACROSS MUCH  
OF THE REGION AS WE WORK OUR WAY THROUGH THE DAY...ESPECIALLY OVER  
THE FINGER LAKES REGION WHERE POPS HAVE BEEN RAISED TO LIKELY. AS  
ONE WOULD EXPECT IN A MARINE BASED ERLY FLOW...THERE WILL NOT BE  
ENOUGH INSTABILITY TO ADD ANY THUNDER TO THIS SHOWER ACTIVITY. ODDLY  
ENOUGH...THE EASTERLY FLOW WILL ALSO INCLUDE SOME WARM ADVECTION  
WITH H85 TEMPS NUDGING UP TO ARND 6C. DESPITE THE CLOUD COVER...THIS  
SHOULD SUPPORT FAIRLY WIDESPREAD TEMPERATURES IN THE 60S FOR THE  
AFTERNOON...ESPECIALLY ACROSS THE NORTH COUNTRY WHERE READINGS COULD  
MAKE IT INTO THE UPPER 60S. THE EXCEPTION TO THE MILDER AIR WILL BE  
ACROSS THE HIGHER TERRAIN OF THE SRN TIER.  
 
THE CLOSED LOW WILL BRIEFLY STALL OVER EASTERN PENNSYLVANIA FRIDAY  
NIGHT...WHILE FAIRLY DEEP ATLANTIC MOISTURE WILL REMAIN IN PLACE  
OVER MUCH OF OUR FORECAST AREA. THIS WILL KEEP AT LEAST THE RISK FOR  
SCATTERED SHOWERS IN PLACE...ESPECIALLY EARLY WHEN A LITTLE LEFTOVER  
DIURNAL INSTABILITY WILL ASSIST EMBEDDED SHORTWAVES IN THE EASTERLY  
FLOW.  
 
ON SATURDAY...THE PERSISTENT UPPER LOW WILL GRADUALLY FILL WHILE  
WEAK RIDGING WILL PUSH ACROSS THE LOWER GREAT LAKES. THIS...IN  
COMBINATION WITH A LITTLE DRYING IN THE MID LEVELS...SHOULD ENABLE  
PARTIAL SUNSHINE TO RETURN TO MUCH OF THE FORECAST AREA WITH MAINLY  
DRY WEATHER ANTICIPATED. THE EXCEPTION COULD BE OVER THE FAR WESTERN  
COUNTIES WHERE THE EFFECTS OF AN APPROACHING COLD FRONT COULD BE  
EXPERIENCED BY DINNER TIME. OTHERWISE...SATURDAY SHOULD BE A FAIRLY  
NICE DAY WITH A SURGE OF 8-10C H85 AIR AHEAD OF THE FRONT  
ENCOURAGING TEMPERATURES TO PEAK IN THE 70S. THE GENESEE VALLEY AND  
SOME OF THE SRN TIER VALLEYS COULD BE IN LINE FOR READINGS IN THE  
MID AND EVEN UPPER 70S...PENDING THE AMOUNT OF SUN WE RECEIVE DURING  
THE MIDDAY AND AFTERNOON. GIVEN THE WEAK SYNOPTIC FLOW...WEAK LAKE  
BREEZES WILL KEEP AREAS WITHIN 5 MILES OR SO OF THE LAKES IN THE 50S  
AND 60S.  
 
THE COLD FRONT WILL MAKE ITS WAY ACROSS WESTERN AND NORTH CENTRAL  
NEW YORK SATURDAY NIGHT. GIVEN THE WAVY NATURE OF THE FRONT (AS PER  
THE PAST SEVERAL RUNS OF THE GFS AND ECMWF) AND SIGNIFICANT HGT  
FALLS...HAVE RAISED POPS TO CATEGORICAL REGIONWIDE FOR SHOWERS AND  
POSSIBLE THUNDERSTORMS. QPF FROM THIS FRONTAL PASSAGE IS FORECAST TO  
RANGE FROM A QUARTER TO AT MOST A HALF INCH.  
 
IN THE WAKE OF THE FRONT...IT WILL BE BREEZY AND NOTABLY COOLER ON  
SUNDAY. H85 TEMPS ARE EXPECTED TO AVERAGE WITHIN A DEGREE OR SO OF  
ZERO C...SO AFTERNOON TEMPERATURES ARE NOT EXPECTED TO CLIMB OUT OF  
THE 50S. WHILE A BRIEF SHOWER CANNOT BE RULED OUT WITHIN THE CHILLY  
CYCLONIC FLOW...SIGNIFICANT DRYING THE MID LEVELS AND RIDGING IN THE  
LOW LEVELS SHOULD PRECLUDE THE DEVELOPMENT OF ANY ORGANIZED/  
WIDESPREAD SHOWERS.  
 

 
   
LONG TERM /MONDAY THROUGH WEDNESDAY/
 
 
WHILE CONFIDENCE IN THE LOW LEVEL FEATURES WILL BE LOWER THAN NORMAL  
DURING THIS PERIOD...CONSISTENCY BETWEEN THE GEFS AND ECMWF  
ENSEMBLES WITH THE OVERLYING JET LEVEL PATTERN WILL SUPPORT  
RELATIVELY HIGH CONFIDENCE WITH THE TEMPERATURE TREND. THIS WILL  
INCLUDE NEAR TO ABOVE NORMAL MERCURY READINGS.  
 
RIDGING OVER THE LOWER GREAT LAKES ON MONDAY WILL SUPPLY OUR  
FORECAST AREA WITH FINE WEATHER...AS AMPLE SUNSHINE WILL HELP TO  
SEND AFTERNOON TEMPERATURES INTO THE LOW-MID 60S FOR MOST AREAS.  
 
THE RIDGE IS FORECAST TO FLATTEN OVER THE REGION MONDAY NIGHT WITH  
FAIRLY STRONG WARM ADVECTION BECOMING ESTABLISHED. THIS COULD SET  
THE STAGE FOR SOME SHOWERS MONDAY NIGHT...ALTHOUGH A HIGHER CHANCE  
FOR PCPN WILL COME ON TUESDAY WHEN THE A TROUGH WILL DIG ACROSS  
QUEBEC AND SOUTHERN ONTARIO.  
 
AS THE TROUGH PUSHES EAST ACROSS THE ST LAWRENCE VALLEY LATE TUESDAY  
NIGHT AND WEDNESDAY...LOW LEVEL RIDGING SHOULD ONCE AGAIN TAKE HOLD  
ACROSS THE LOWER GREAT LAKES TO PROMOTE FAIR WEATHER.  
 

 
   
AVIATION /08Z THURSDAY THROUGH MONDAY/
 
 
FOR THE REMAINDER OF THE NIGHTTIME HOURS...THE MAIN FORECAST  
ISSUE IS THE POTENTIAL FOR THE DEVELOPMENT OF LOWER STRATUS/FOG  
FROM ROUGHLY THE GENESEE VALLEY WESTWARD. WHILE MOST MODEL GUIDANCE  
SUGGESTS THAT THIS WILL OCCUR...IT HAS ALSO BEEN MUCH TOO QUICK  
TO LOWER CIGS SO FAR...WITH REGIONAL SATELLITE IMAGERY/OBS STILL  
INDICATING FAIRLY WIDESPREAD VFR CONDITIONS AS OF THIS WRITING...  
WITH JUST SOME SPOTTY MVFR/IFR NOTED AT TIMES ACROSS FAR INTERIOR  
PORTIONS OF THE SOUTHERN TIER AND GENESEE VALLEY.  
 
THE BETTER THAN MODELED CONDITIONS HAVE SO FAR BEEN DUE TO THE  
PRESENCE OF A FAIR AMOUNT OF MID AND HIGH CLOUDS ACROSS THE REGION  
TO THIS POINT...WHICH HAVE ACTED TO INHIBIT SURFACE COOLING AND  
CONSEQUENTLY THE FORMATION OF ANY APPRECIABLE LOWER STRATUS/FOG.  
IN ORDER FOR THE LATTER TO DEVELOP...THERE WILL LIKELY HAVE TO BE  
SUFFICIENT CLEARING FOR A LONG ENOUGH PERIOD OF TIME...A FACTOR  
THAT IS BECOMING INCREASINGLY QUESTIONABLE AS OF THIS WRITING.  
 
GIVEN THE RESULTING FORECAST UNCERTAINTY AND CURRENT OBSERVATIONAL  
TRENDS...HAVE ELECTED TO HEDGE A LITTLE BIT MORE OPTIMISTIC WITH  
THE 06Z TAF PACKAGE...WHICH STILL ALLOWS FOR THE DEVELOPMENT OF  
SOME STRATUS OVERNIGHT FROM KROC/KDSV WESTWARD...BUT MAINLY OF THE  
MVFR VARIETY AS OPPOSED TO IFR. THIS SAID...IFR CIGS REMAIN A  
POSSIBILITY IF SKIES CAN MANAGE TO CLEAR OUT LONG ENOUGH.  
 
ONCE WE GET INTO THE DAYLIGHT HOURS...WHATEVER LOWER STRATUS/FOG  
THAT MANAGES TO DEVELOP SHOULD MIX OUT BY MID TO LATE MORNING WITH  
RENEWED DIURNAL HEATING. THE DAYTIME HEATING WILL ALSO LEAD TO THE  
DEVELOPMENT OF SOME ADDITIONAL DIURNALLY-DRIVEN SCATTERED SHOWERS  
AND POSSIBLY EVEN A THUNDERSTORM ACROSS THE SOUTHERN TIER DURING  
THE AFTERNOON...ANY OF WHICH COULD PRODUCE SOME BRIEF/LOCALIZED  
REDUCTIONS TO MVFR. OUTSIDE OF THE ABOVE...GENERAL VFR CONDITIONS  
SHOULD PREVAIL.  
 
TONIGHT...EXPECT GENERAL VFR CONDITIONS TO PREVAIL...WITH JUST SOME  
LINGERING SCATTERED SHOWERS/SPOTTY MVFR FOUND ACROSS THE SOUTHERN  
TIER AND INTERIOR PORTIONS OF THE FINGER LAKES.  
 
OUTLOOK...  
FRIDAY...VFR/MVFR WITH SCATTERED TO NUMEROUS SHOWERS...WITH THE  
GREATEST AREAL COVERAGE EXPECTED ACROSS INTERIOR PORTIONS OF THE  
SOUTHERN TIER AND FINGER LAKES.  
SATURDAY...VFR.  
SATURDAY NIGHT...SHOWERS WITH A CHANCE OF THUNDERSTORMS.  
SUNDAY...MAINLY VFR WITH A CHANCE OF MORNING SHOWERS EAST OF KROC/KDSV.  
MONDAY...VFR.  
 

 
   
MARINE
 
 
THE REMAINDER OF THE WEEK WILL FEATURE A RELATIVELY WEAK PRESSURE  
GRADIENT ACROSS THE LOWER LAKES REGION. THIS WILL RESULT IN LIGHT  
TO MODEST WINDS PREDOMINATING...ALONG WITH CORRESPONDINGLY MINIMAL  
WAVES.  
 

 
   
BUF WATCHES/WARNINGS/ADVISORIES
 
 
NY...NONE.  
MARINE...NONE.  
 

 
 

 
 
SYNOPSIS...JJR  
NEAR TERM...JJR  
SHORT TERM...RSH  
LONG TERM...RSH  
AVIATION...JJR  
MARINE...JJR  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab NY Page Main Text Page