-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBGM 170223
AFDBGM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BINGHAMTON NY
1023 PM EDT THU MAY 16 2013

.SYNOPSIS...
DRY CONDITIONS WILL PERSIST THROUGH AT LEAST SATURDAY MORNING.
CLOUDS WILL DEVELOP OVER THE WEEKEND AS A FRONTAL ZONE SETS UP
NEAR OUR VICINITY. SOME AREAS MAY GET A FEW LIGHT SHOWERS LATE
SATURDAY INTO SUNDAY...WITH BEST CHANCES IN NORTHEAST
PENNSYLVANIA.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
-- Changed Discussion --
1015 PM UPDATE...
WEAK SECONDARY FRONT CONTINUES TO SINK SOUTH ACROSS THE REGION
THIS EVENING WITH UPSTREAM OBSERVATIONS AT ART AND GTB CLEARLY
SHOWING A WINDSHIFT TO THE NORTH. IR SATELLITE IMAGERY A FAIRLY
RAPID DECREASE IN CLOUDS ALONG THIS FEATURE WITH LOSS OF DAYTIME
HEATING AND SKY GRIDS HAVE BEEN ADJUSTED ACCORDINGLY. SOME CONCERN
STILL LINGERS FOR PATCHY FROST ACROSS THE CHEMUNG BASIN AFTER 06Z
BUT OVERALL CONFIDENCE REMAINS MARGINAL AS TEMPS HAVE BEEN SLOW TO
COOL THIS EVENING WITH FRONT STILL TO THE NORTH THIS HR. SINCE WE
CANNOT RULE IT OUT HOWEVER...A PATCHY FROST MENTION HAS BEEN
MAINTAINED FOR NOW. NO OTHER ADJUSTMENTS NEEDED AT THIS TIME.

715 PM UPDATE...
FCST IN GREAT SHAPE THIS EVENING...NO SIGNIFICANT CHANGES NEEDED
AT THE PRESENT TIME. VIS SATELLITE SHOTS STILL SHOWING A FAIRLY
WELL DEFINED AND NARROW CU FIELD ALONG A SOUTHWARD SAGGING SECONDARY
COLD FRONT WHICH NOW STRETCHES FROM NEAR WATERTOWN/FT. DRUM...WEST
THROUGH KINGSTON ONTARIO. FEATURE WILL CONTINUE DIVING SOUTH
THROUGH THE FCST AREA THIS EVENING BEFORE CLEARING THE CWA SHORTLY
AFTER 06Z. ATTENTION THROUGH THE OVERNIGHT WILL REMAIN FOCUSED ON
POSSIBLE FROST POTENTIAL ACROSS THE CHEMUNG RVR VLY. WILL CONTINUE
TO MONITOR TRENDS HOWEVER LATEST MODEL GUIDANCE CONTINUES TO
SUGGEST FAIRLY DRY LOW-LEVEL CONDITIONS WHICH SHOULD KEEP FROST
DEVELOPMENT RATHER ISOLATED AT BEST.

3 PM UPDATE...
JUST A FEW FAIR WEATHER CUMULUS AT 8-10 KFT AGL THIS AFTERNOON
WHICH WILL QUICKLY DISSIPATE. AS EXPECTED...INVERTED-V PROFILE HAS
MIXED DOWN FAIRLY GUSTY WINDS ALONG WITH VERY DRY AIR AND THUS
A MAXIMIZED DIURNAL RANGE. WIDESPREAD 70S WITH SOME LOCATIONS SUCH
AS ELMIRA EVEN TOUCHING 80 DEGREES FOR TEMPERATURES...AND HUMIDITY
VALUES AREAWIDE HAVE MANAGED MAINLY 20S PERCENT RANGE.

SECONDARY COLD FRONT WILL DIP ACROSS THE AREA TONIGHT...AND WITH
SUCH LIMITED MOISTURE...NO PRECIPITATION EXPECTED WHATSOEVER.
LOSS OF DIURNAL HEATING WILL ERODE MUCH OF THE CLOUD COVER
CURRENTLY BEHIND THE FRONT IN CENTRAL ONTARIO AND QUEBEC.
HOWEVER...WRFARW AND RUC SOUNDINGS SHOW THAT BAND OF MOISTURE 4-5
KFT AGL WILL ADVECT IN IMMEDIATELY ALONG THE FRONT ITSELF. SKY
GRIDS THUS REFLECT SOME CLOUDS DROPPING ACROSS THE NORTHERN TO
CENTRAL PART OF THE AREA OVERNIGHT...BEFORE MIXING OUT IN DRY AIR
FRIDAY MORNING.

EXPECTING MAINLY 40S FOR LOWS TONIGHT...BUT FAIR AMOUNT OF
RADIATIONAL COOLING WILL LEAD THE TYPICAL COLDER DRAINAGE-PRONE
SPOTS GETTING INTO THE 30S. PATCHY FROST HAS BEEN ADDED TO A
COUPLE SPOTS IN THE WEATHER GRIDS IN CENTRAL SOUTHERN TIER OF NY
TO BRADFORD COUNTY PA...BUT NOT EXPECTING ENOUGH TO WARRANT FROST
ADVISORY. THE EVENING SHIFT WILL MONITOR THIS CLOSELY IN CASE
EXPECTATIONS SHOULD CHANGE.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
315 PM UPDATE...
HIGH PRESSURE IN CHARGE FRIDAY INTO FRIDAY NIGHT WITH DRY WEATHER
AND TEMPERATURES RIGHT AROUND CLIMATOLOGY. BAROCLINIC ZONE SETS UP
JUST SOUTH AND SOUTHWEST OF OUR VICINITY OVER THE WEEKEND. WHAT
HAS BECOME CLEARER IS THAT CLOUDS WILL DEVELOP AND THICKEN
COURTESY OF MOISTENING BAROCLINIC LIFT...ESPECIALLY CENTRAL TO
SOUTHERN ZONES. HOWEVER...WITH DRY AIR IN THE LOW LEVELS AND FAIRLY
WEAK WAVES ALOFT...PRECIPITATION CHANCES ARE MUCH MORE IFFY.
ALSO...AS HIGH PRESSURE SITUATES OFFSHORE INTO
SUNDAY...STABILIZING COOL ONSHORE SOUTHEAST FLOW WILL DIP
TEMPERATURES ESPECIALLY FROM TWIN TIERS SOUTHWARD. EVER SLOW
SLIGHT YET VERY ELEVATED INSTABILITY ALSO IS SUGGESTED BY THE
SOUNDINGS AT LEAST FOR LATE SATURDAY INTO SATURDAY NIGHT.

OVERALL NOT VERY BULLISH ON RAIN CHANCES BUT HAVE TO RESPECT
PRESENCE OF BAROCLINIC ZONE AND MOISTURE...WHICH SOMETIMES YIELDS
SURPRISES THAT MODELS CAN STRUGGLE WITH. FOR NOW...WENT WITH
SLIGHT TO LOW CHANCE POPS MAINLY WESTERN/SOUTHERN ZONES LATE
SATURDAY...THEN SPREADING OVER REMAINDER OF THE AREA SATURDAY
NIGHT INTO SUNDAY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT THROUGH THIS PERIOD
INDICATING AN UPPER LEVEL RIDGE WILL BUILD OVER THE NORTHEAST
INITIALLY AS AN UPPER LEVEL TROF DIGS INTO THE NORTHERN PLAINS.
TOWARD THE END OF THE PERIOD THE RIDGE WILL FLATTEN THEN AN UPPER
LEVEL TROF DROPPING THROUGH EASTERN CANADA WILL MOVE INTO THE
NORTHEAST.

AT THE SFC, SUNDAY NIGHT INTO MONDAY, HIGH PRES OFF THE NEW
ENGLAND COAST AND A WARM FRONT DRAPED OVER THE MID ATLANTIC WILL
PROVIDE A SOMEWHAT MOIST RETURN FLOW BRINGING PRIMARILY A SLIGHT
CHC FOR SHOWERS OVER CENTRAL NY AND CHC FOR NE PA.

FOR THE REMAINDER OF THE PERIOD WILL CONTINUE TO CARRY CHC POPS
FOR SHOWERS AND THUNDERSTORMS, AS SFC LOW PRES MOVING INTO THE
WESTERN LAKES WILL BRING A WARM FRONT TO THE VCNTY THROUGH
TUESDAY NIGHT WITH THE TRAILING COLD FRONT MOVING THROUGH WED/WED
NIGHT. WILL ADVERTISE CHC/SLIGHT CHC POPS ON THURSDAY, POST FRONTAL
AS UPPER LEVEL TROF RESIDES OVER REGION.

TEMPS THROUGH THE PERIOD WILL RUN 5-10 DEGREES ABOVE NORMAL WITH A
RETURN TO MORE SEASONAL TEMPS BY THURSDAY.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH FRIDAY. SOME MINOR
INCONVENIENCES TO FLIGHT OPS MAY OCCUR ACROSS THE NORTHERN
TERMINALS TONIGHT AS A SECONDARY FRONTAL BOUNDARY DROPS SOUTH WITH
AN ASSOCIATED NORTH WIND SHIFT AND SOME LOWER BKN-OVC VFR CIGS.
THESE ARE EXPECTED TO ERODE SOME WITH A SOUTHWARD MOVEMENT THROUGH
TIME AND LIKELY NOT REACH LOCATIONS FROM KBGM-KELM SOUTH.

GUSTY NW-N WINDS NEXT HOUR OR SO WILL DIMINISH TO UNDER 10 KTS AND
THEN INCREASE AFTER SUNRISE FRIDAY TO AROUND 8-12 KNOTS.

OUTLOOK...

FRI NIGHT THROUGH TUESDAY...PRIMARILY VFR.

&&

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

&&

$$
SYNOPSIS...MDP
NEAR TERM...CMG/MDP
SHORT TERM...MDP
LONG TERM...RRM
AVIATION...JAB