-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBGM 200900
AFDBGM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BINGHAMTON NY
500 AM EDT THU JUN 20 2013

.SYNOPSIS...
FAIR WEATHER AND WARMING TEMPERATURES WILL CONTINUE INTO FRIDAY
AS HIGH PRESSURE MOVES OFF THE EAST COAST. A SERIES OF WEAK UPPER
LEVEL IMPULSES MAY BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS
THIS WEEKEND...MAINLY OVER CENTRAL NEW YORK.

&&

.NEAR TERM /THROUGH TONIGHT/...
HI PRES CNTRD OVER THE RGN WILL SLOWLY DRIFT TO PSN OFF THE EAST
COAST BY FRI. FAIR WEATHER XPCTD TDA ACRS THE RGN. MDLS SHOW THE
DVLPMNT OF A WEAK INVERTED TROF FROM PA INTO CNTRL NY...WITH
THETA-E AXIS EXTENDING INTO THE SRN TIER AND NE PA LATE TDA. K
INDICES REMAIN LOW TDA AND NOT SUPPORTIVE OF SCT CONVECTION. ALSO
INDICATIONS OF A WEAK CAP AT THE 700-650 MB LVL THIS AFTN...SO
ONLY XPCT SOME ENHANCED CLOUDINESS NEAR THIS FEATURE. FAIR WX
CONTINUES TNGT. MAXES TDA GNRLY M/U70S WITH M50S FOR MINS TNGT.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
LOW LVL THETA-E AXIS REMAINS ACRS THE SRN TIER ON FRI WITH MDLS
SHOWING MODEST CONVERGENCE ALONG A WEAK SFC TROF AXIS. CAN`T RULE
OUT PSBLTY OF AN ISOLD SHRA/TSRA THESE AREAS ON FRI AFTN BUT
AGAIN PROFILES SHOW A WEAK MID LVL CAP SO LEFT FCST DRY. BETTER
CHC FOR SHRA/TSRA WILL LIKELY COME ON SAT NGT. DIFFS PERSIST IN
THE MDLS W/RESPECT TO TIMING BUT MAIN TREND HAS BEEN TO ADVERTISE
HIGHER UPR LVL HGTS...WHICH IS ALSO REFLECTED IN THE LATEST EURO
GDNC. GEM AND UKMET SHOW PSBLTY OF TSRA WORKING INTO NRN ZONES ON
SAT NGT. GIVEN THESE TRENDS...COULD NOT SEE MUCH REASON TO CHG THE
CRNT FCST OF SLGT TO LOW CHC POPS BEGINNING SAT AFTN ACRS NORTHERN
SXNS OF THE CWA...EXPANDING INTO THE SRN TIER SAT NGT. TEMPS
WARMING INTO THE MID AND UPPER 80S BY SAT.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
GRIDS TWEAKED TO ACCOUNT FOR 00Z HPC GUIDANCE. THERE IS STILL
DISAGREEMENT SUNDAY WITH HOW MUCH RIDGING WILL BE IN PLACE...AND
AT 850MB GFS IS STILL WARMER THAN ECMWF MONDAY THROUGH WEDNESDAY.
HOWEVER...GFS/ECMWF ARE AT LEAST ON THE SAME PAGE FOR 500MB
HEIGHTS EDGING A BIT LOWER DURING THIS PERIOD AS THE RIDGE
FLATTENS. THIS LEAVES US VULNERABLE TO MULTIPLE WAVES PASSING
THROUGH THE WESTERLIES...AND THUS MAY BE A FAIRLY BUSY PATTERN FOR
CONVECTION.

PREVIOUS DISCUSSION...
WEAK ANTICYCLONIC FLOW WILL SET UP OVER THE REGION AS A STRONG
UPPER LEVEL RIDGE SLIDES EAST AND SETTLES OVER THE SOUTHEASTERN
CONUS THIS WEEKEND. LARGE DIFFERENCES EXIST BETWEEN THE GFS AND
ECMWF IN THE EXTENDED. WENT WITH THE WPC/ECMWF OUTPUT... AS THIS
IS A TYPICAL PATTERN FOR SHOWERS AND THUNDERSTORMS ACROSS THE CWA.
KEPT SLIGHT TO CHANGE FOR POPS AS EMBEDDED SHORTWAVES ARE EXPECTED
MOVE UP AND AROUND THE OUTER EDGE OF THE RIDGE. THE GFS KEEPS THE
EXTENDED DRY AND VERY WARM WITH 850 MB TEMPS AT 18 DEGREES C. THIS
COULD ALLOW TEMPS TO RISE INTO THE UPPER 80S FOR MUCH OF THE AREA.
AS THIS RIDGE SHIFTS EAST MID NEXT WEEK... IT APPEARS THERE WILL
BE A CHANCE FOR SHOWERS AND THUNDERSTORMS THROUGH THE END OF THE
WEEK.

&&

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
09Z UPDATE...
VERY LIGHT OR CALM BOUNDARY LAYER WIND AND NARROW TEMPERATURE-
DEWPOINT SPREAD IS OFTEN A GOOD SET UP FOR VALLEY FOG AT
KELM...YET IT HAS STRUGGLED TO OCCUR AND CONFIDENCE IN IT STILL
FORMING IS MUCH LOWER. FOR THE 09Z AMENDMENT I HAVE BACKED OFF ON
ITS FORMATION TO ONLY A COUPLE HOUR TEMPO GROUP OF MVFR VIS. FOR
ITH...WITH LIGHT EASTERLY FLOW NEAR THE SURFACE INSTEAD OF NORTH-
NORTHWEST COMING FROM CAYUGA LAKE LIKE 24 HOURS AGO...FOG NOT
EXPECTED TO BE A PROBLEM THIS TIME AND WITH 09Z AMENDMENT I EVEN
REMOVED THE 3 HOUR TEMPO MVFR MIST GROUP. FOR THE OTHER
TERMINALS...NO MIST NOR FOG IMPACTS EXPECTED. DURING THE DAY...VFR
AREAWIDE WITH A FEW-SCT CUMULUS FIELD AROUND 5 KFT AGL AND WSW
WINDS LESS THAN 10 KTS /EXCEPT MORE OF A NORTHERLY COMPONENT FOR
KSYR DUE TO LAKE BREEZE INFLUENCE/. WINDS BECOMING LIGHT AND
VARIABLE THIS EVENING.

OUTLOOK...
LATE THU NIGHT THRU SAT...MAINLY VFR.

SATURDAY NIGHT THRU MON...MAINLY VFR EXCEPT BRIEF RESTRICTIONS ARE
POSSIBLE IN ISOLATED TO SCATTERED SHRA/TSRA.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...PVN
NEAR TERM...CMG/PVN
SHORT TERM...PVN
LONG TERM...KAH/MDP
AVIATION...MDP