Area Forecast Discussion
Issued by NWS Buffalo, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KBUF 060742
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
342 AM EDT MON JUL 6 2015

.SYNOPSIS...
SUMMER`S HEAT WILL ARRIVE TODAY AND TOMORROW WITH
TEMPERATURES ABOVE NORMAL AND A HUMID FEEL TO THE AIR. A WEAK
AREA OF LOW PRESSURE WILL SPREAD SEVERAL SHOWERS AND PERHAPS
THUNDERSTORMS ACROSS WESTERN NEW YORK TODAY. MORE WIDESPREAD
SHOWERS AND THUNDERSTORMS WILL ARRIVE ON TUESDAY WHEN A COLD FRONT
CROSSES THE REGION.

&&

.NEAR TERM /THROUGH TONIGHT/...
AN AREA OF HIGH PRESSURE THIS EARLY
MORNING IS SLIDING TOWARDS THE NORTHEAST COASTLINE. MEANWHILE ALOFT
AN AREA OF LOW PRESSURE SPINS OVER THE OHIO VALLEY.

IT WILL BE A WARM START TO THE DAY TODAY WITH AIR TEMPERATURES IN
THE 60S SHORTLY AFTER SUNRISE THIS MORNING...AND DEWPOINTS ALREADY
EDGING TOWARDS 60F. IR SATELLITE IMAGERY DISPLAYS CIRRUS SPREADING
ACROSS THE CWA. THICKER AND LOWER CLOUDS ARE FOUND ACROSS SOUTHERN
PA THIS MORNING...AND THESE CLOUDS WILL EXPAND NORTHWARD THROUGH THE
DAY. TEMPERATURES ALOFT AT 850 HPA WILL WARM TO 15 TO 17C...AND
DAYTIME MIXING TO THIS LEVEL WILL ALLOW FOR A SUMMERY FEEL TO THE
AFTERNOON TEMPERATURES. ADDITIONALLY A SOUTHEAST FLOW DOWNSLOPING
INTO THE VALLEYS...AND ALONG THE LAKE PLAINS WILL GIVE AN EXTRA
BOOST TO THE AIR TEMPERATURES WITH HIGHS RISING INTO THE UPPER 80S
HERE...WHILE LOW TO MID 80S WILL BE FOUND ELSEWHERE. A LIGHT
SOUTHEAST FLOW WILL LIMIT THE INLAND EXTENT OF THE LAKE
BREEZES...WITH JUST THE IMMEDIATE SHORELINES COOLER AND LINGERING IN
THE 70S.

A PLUME OF HIGHER THETA-E AIR WILL EXPAND NORTHWARD TODAY BEHIND THE
DEPARTING SURFACE/MID LEVEL RIDGE AND AHEAD OF THE UPPER LEVEL LOW
OVER THE OHIO VALLEY. DAYTIME INSTABILITY (SBCAPES 500 TO 1000 J/KG)
COUPLED WITH MID LEVEL ASCENT AHEAD OF THE WEAK UPPER LEVEL LOW AND
AN INCREASE IN MOISTURE WILL ALLOW FOR AN ENVIRONMENT FOR SHOWERS
AND THUNDERSTORMS TO FORM THROUGH THE AFTERNOON AND EVENING HOURS.

SHOWERS AND THUNDERSTORMS WILL BE FOUND PRIMARILY ACROSS WESTERN NEW
YORK AND THE SOUTHERN FINGER LAKES REGION...WHERE THE AXIS OF HIGHER
THETA-E AIR WILL BE FOUND. TO THE NORTH OF THE FINGER LAKES AND
ACROSS THE NORTH COUNTRY IT WILL LIKELY REMAIN DRY. SEVERE
PARAMETERS ARE MINIMAL...WITH PERHAPS THE BIGGEST THREAT BEING HEAVY
RAIN FROM SLOW MOVING STORMS.

THE UPPER LEVEL LOW WILL WEAKEN OVER OUR REGION TONIGHT AS IT
ENCROACHES UPON THE UPPER LEVEL RIDGE OVER THE EAST COASTLINE.
SHOWERS AND THUNDERSTORMS WILL END THROUGH THE EVENING HOURS WITH
THE LOSS OF DAYTIME HEATING AND THE WEAKENING OF THE UPPER LEVEL LOW
PRESSURE. IT WILL REMAIN MILD OVERNIGHT AS A SOUTHERLY FLOW
CONTINUES AHEAD OF A COLD FRONT THAT WILL REMAIN WELL TO THE WEST OF
THE REGION. OVERNIGHT LOWS WILL GENERALLY BE IN THE 60S...WITH A FEW
70F READINGS ACROSS THE LAKE PLAINS. WEAK LOW LEVEL CONVERGENCE
WITHIN THIS SOUTHERLY FLOW OVER THE FINGER LAKES REGION LATE TONIGHT
MAY PRODUCE A STRAY SHOWER. OTHERWISE THE REGION SHOULD REMAIN DRY
AFTER THE MIDNIGHT HOUR.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
A SHORTWAVE WILL TRACK TO OUR NORTH AND DRAG A COLD FRONT ACROSS THE
REGION TUESDAY NIGHT. 00Z MODEL CONSENSUS HAS CHANGED VERY LITTLE
WITH THE FRONT EXPECTED TO ENTER OUR REGION TUESDAY EVENING AND
REACH THE NY/PA LINE AROUND DAYBREAK WEDNESDAY. THE 00Z NAM IS A
NOTABLE OUTLIER...SINCE IT DEVELOPS AN MCS AND IS CONSIDERABLY
SLOWER COMPARED TO THE GFS/GGEM/ECMWF AND MOST SREF ENSEMBLE
MEMBERS. 00Z HAS GUIDANCE HAS BACKED OFF ON PRE-FRONTAL DIURNAL
CONVECTION...WITH A SOUTHWESTERLY BREEZE SETTING UP AN INITIAL LAKE
SHADOW WHICH SHOULD DELAY CONVECTION. THIS SHOULD KEEP MOST OF THE
AREA DRY DURING MOST OF TUESDAY UNTIL DEEP MOISTURE ERODES THE LAKE
SHADOW TUESDAY EVENING...WITH A BROKEN LINE OF SHOWERS AND
THUNDERSTORM LIKELY TO MOVE ACROSS THE REGION.

TUESDAY SHOULD BE A RATHER MUGGY DAY...WITH TEMPERATURES CLIMBING
WELL INTO THE 80S. THE SW-SSW FLOW SHOULD ALLOW LAKE MODIFIED AIR
ACROSS THE NIAGARA FRONTIER...BUT THIS FLOW WILL DOWNSLOPE ROCHESTER
EAST...WHERE HIGHS SHOULD PUSH 90.

WIND FIELDS AHEAD OF THIS FRONT TUESDAY EVENING ARE FAIRLY MODEST.
GUIDANCE GENERALLY FORECASTS 850MB WINDS INCREASING TO 30 TO 35
KTS... WITH LIMITED DIRECTIONAL SHEAR. THIS IS A MARGINAL WIND FIELD
FOR PRODUCING WIDESPREAD SEVERE WEATHER...BUT IT CAN RESULT IN A FEW
BOWING SEGMENTS OR PULSE STORMS WHEN AMPLE INSTABILITY IS IN PLACE.
ALSO... CANNOT RULE OUT AN MCS DEVELOPING OVER OHIO AND TRACKING
INTO WESTERN NEW YORK AHEAD OF THE COLD FRONT. IF THE MCS
MATERIALIZES... IT WOULD PROVIDE THE BEST OPPORTUNITY TO PRODUCE
DAMAGING WINDS ACROSS THE FORECAST AREA. HOWEVER... FORECAST
CONFIDENCE IN THIS HAPPENING ARE STILL LOW. SPC HAS WESTERN PORTIONS
OF OUR AREA IN A MARGINAL RISK FOR SEVERE WEATHER... WHICH IS IN
LINE WITH THIS THINKING.

IT IS ALSO WORTH NOTING THAT BOTH THE 12Z NAM/GFS FORECAST PWATS
OVER 2 INCHES...WHICH IS EXTREMELY MOIST FOR THE AREA. IF THIS
VERIFIES...THERE IS A POTENTIAL THAT SOME STORMS COULD PRODUCE FLASH
FLOODING. BUFKIT SOUNDINGS SHOW THE POTENTIAL FOR BACKBUILDING CELLS
IN THIS MOISTURE RICH ENVIRONMENT AS WELL. IN EACH CASE...THE
POTENTIAL IS SMALL AND LARGELY DEPENDENT ON THE TIMING AND UPSTREAM
DEVELOPMENT OF CONVECTION ALONG THIS BOUNDARY.

SHOWERS SHOULD TAPER OFF FROM N-S LATE TUESDAY NIGHT. THERE MAY BE
SOME FOG WEDNESDAY MORNING WHEN SURFACE TEMPERATURES COOL BEHIND THE
FRONT IN AREAS WHICH JUST GOT RAINFALL. EXPECT A PARTIAL CLEARING
WEDNESDAY...WITH BELOW NORMAL HIGH TEMPERATURES IN THE LOWER TO MID
70S. THEN WEAK HIGH PRESSURE DRIFT ACROSS THE AREA WEDNESDAY NIGHT
WITH FAIR WEATHER FOR MOST OF THE NIGHT.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
MOST 00Z MODEL GUIDANCE DEVELOPS AN MCS ACROSS THE MIDWESTERN STATES
ALONG A STALLED FRONTAL BOUNDARY. THIS IS THEN FORECAST TO WEAKEN
AND EITHER PASS SOUTH OR CLIP SOUTHERN PORTIONS OF OUR CWA ON
THURSDAY INTO THURSDAY NIGHT. WITH LOW FORECAST CONFIDENCE WILL ONLY
CARRY CHANCE POPS FOR THIS FEATURE...MAINLY SOUTH OF BUF-ROC. OUTSIDE
OF THIS...WEAK HIGH PRESSURE WILL BUILD ACROSS THE REGION WITH FAIR
WEATHER. TEMPERATURES SHOULD BE SEASONABLE TO SLIGHTLY BELOW NORMAL
WITH HIGHS IN THE 70S TO NEAR 80 ON THURSDAY AND FRIDAY.

LOOKING AHEAD TO NEXT WEEKEND...FORECAST CONFIDENCE REMAINS BELOW
NORMAL...AS VARIOUS FORECAST MODELS DISAGREE ON THE TIMING OF A
SHORTWAVE THAT COULD BRING INCREASED SHOWER/THUNDERSTORM CHANCES TO
ONE OF THE DAYS OF THE WEEKEND. WHILE SATURDAY OR SUNDAY COULD SEE
SOME SHOWER/THUNDERSTORM ACTIVITY... THE WEEKEND LOOKS FAR FROM A
WASHOUT.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AT 06Z VFR FLIGHT
CONDITIONS WERE FOUND ACROSS THE REGION. CIRRUS WILL CONTINUE TO
SPREAD ACROSS THE TAF REGION OVERNIGHT BEFORE MID LEVEL
MOISTURE/CLOUDS INCREASE DURING THE DAYLIGHT HOURS OF MONDAY.

THIS MOISTURE WILL FUEL A FEW SHOWERS AND PERHAPS A THUNDERSTORM
SOUTH OF LAKE ONTARIO AND MAINLY THIS AFTERNOON AND EVENING. WE DO
NOT EXPECT THIS ACTIVITY TO BE STRONG...BUT ANY STORM COULD DISTRUPT
AN OTHERWISE LIGHT WIND FIELD ACROSS TAF SITES. VFR CIGS SHOULD BE
PREDOMINATE IN ALL PRECIPITATION ACTIVITY THOUGH A
HEAVIER...LOCALIZED STORM MAY DROP VSBYS TO MVFR FOR A BRIEF TIME
PERIOD SOUTH OF LAKE ONTARIO.

PRECIPITATION ACTIVITY WILL END THROUGH THE EVENING HOURS...WITH
SOME PATCHY FOG AND IFR CIGS DEVELOPING OVERNIGHT IN AREAS WHERE
RAIN FELL ACROSS THE INLAND SOUTHERN TIER.

WINDS WILL SLOWLY VEER FROM SOUTHEAST TO SOUTH THROUGH THE TAF
PERIOD.

OUTLOOK...

TUESDAY...MAINLY VFR WITH A CHANCE OF SHOWERS AND THUNDERSTORMS IN
THE AFTERNOON.
TUESDAY NIGHT...AREAS OF MVFR AND BRIEF IFR/GUSTY WINDS WITH SHOWERS
AND THUNDERSTORMS LIKELY. PATCHY FOG/IFR TUESDAY NIGHT INTO
WEDNESDAY MORNING. WEDNESDAY...BY LATE MORNING MAINLY VFR WITH A
CHANCE OF SHOWERS. THURSDAY AND FRIDAY...MAINLY VFR.

&&

.MARINE...
TODAY A LIGHT SOUTHEAST WIND FLOW WILL BE FOUND OVER THE
EASTERN GREAT LAKES REGION. WAVES ON THE LAKES SHOULD LARGELY REMAIN
A FOOT OR LESS THROUGH TONIGHT.

WINDS WILL INCREASE SOME TUESDAY AND TUESDAY NIGHT BOTH AHEAD AND
BEHIND A COLD FRONT...BUT CONDITIONS SHOULD STILL REMAIN BELOW SMALL
CRAFT ADVISORY CRITERIA. OTHERWISE EXPECT FLAT WAVE ACTION TO
CONTINUE THROUGHOUT THE WEEK.

&&

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

&&

$$

SYNOPSIS...THOMAS
NEAR TERM...THOMAS
SHORT TERM...APFFEL
LONG TERM...APFFEL/CHURCH
AVIATION...THOMAS
MARINE...THOMAS


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.