Area Forecast Discussion
Issued by NWS Buffalo, NY

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000
FXUS61 KBUF 141106
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
706 AM EDT MON JUL 14 2014

.SYNOPSIS...
AN UPPER LEVEL TROUGH DEEPENING ACROSS THE GREAT LAKES WILL ALLOW
FOR ANOTHER ROUND OF SCATTERED TO NUMEROUS AFTERNOON SHOWERS AND
THUNDERSTORMS SOUTH OF LAKE ONTARIO...WITH THESE BECOMING A LITTLE
MORE NUMEROUS ON TUESDAY AS A LOW PRESSURE SYSTEM MOVES ACROSS THE
GREAT LAKES. BEHIND THIS LOW...DRIER WEATHER WILL RETURN FOR THE
REMAINDER OF THE WEEK ALONG WITH A PERIOD OF BELOW NORMAL
TEMPERATURES.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 11Z...REGIONAL SURFACE OBS SUGGEST THAT THE WEAK COLD FRONTAL
BOUNDARY IS IN THE PROCESS OF WASHING OUT SOMEWHERE BETWEEN
KBUF/KROC AND KDKK/KDSV. NONETHELESS...THIS FEATURE HAS MANAGED TO
GENERATE A FAIR AMOUNT OF STRATUS OVER THE PAST 3-4 HOURS...WHICH
HAS NECESSITATED BUMPING UP THE CLOUD COVER ACROSS PORTIONS OF THE
THE NIAGARA FRONTIER AND FINGER LAKES REGION EARLY THIS MORNING.
MEANWHILE TO THE SOUTH OF THIS...LOW STRATUS AND/OR FOG IS STILL
FOUND ACROSS THE SOUTHERN TIER. WITH RENEWED DIURNAL HEATING...ALL
OF THIS SHOULD LIFT AND GIVE WAY TO A SCATTERED-BROKEN CU FIELD AND
SOME PARTIAL SUNSHINE THROUGH MID TO LATE THIS MORNING.

OTHERWISE...ANOMALOUSLY DEEP UPPER LEVEL TROUGHING OVER THE UPPER
MISSISSIPPI VALLEY WILL DIG SOUTHEASTWARD ACROSS THE GREAT LAKES
REGION THROUGH THE NEAR TERM PERIOD. FOR TODAY...EXPECT A GENERALLY
DRY AND QUIET MORNING BEFORE DIURNAL HEATING OF OUR WARM AND STILL
SOMEWHAT MOIST AIRMASS GIVES RISE TO INCREASING INSTABILITY
BY MIDDAY/EARLY AFTERNOON SOUTH OF LAKE ONTARIO. AT THE SAME TIME...
DEVELOPING LAKE BREEZE BOUNDARIES WILL ACT TO LIFT THIS MOIST AND
INCREASINGLY UNSTABLE AIRMASS AND EVENTUALLY TRIGGER THE DEVELOPMENT
OF SOME SCATTERED CONVECTION...THE BULK OF WHICH WILL REMAIN FOCUSED
ALONG AND INLAND FROM SAID BOUNDARIES. HAVE ACCORDINGLY RETAINED
SOME MID TO HIGH CHANCE RANGE POPS FOR THIS AFTERNOON FOR MOST
LOCATIONS SOUTH OF LAKE ONTARIO...WITH THE MOST CONCENTRATED AND
NUMEROUS ACTIVITY EXPECTED TO BE FOUND ACROSS THE FINGER LAKES AND
INTERIOR SECTIONS OF THE SOUTHERN TIER/GENESEE VALLEY...WHERE POPS
HAVE BEEN BUMPED UP TO LOW LIKELY. ELSEWHERE...EXPECT MAINLY DRY
WEATHER ACROSS MUCH OF THE NORTH COUNTRY...WHICH WILL BE UNDER THE
INFLUENCE OF SOMEWHAT DRIER AND MORE STABLE AIR.

TONIGHT...ANY DIURNALLY-DRIVEN CONVECTION SHOULD WANE THIS EVENING
WITH THE LOSS OF HEATING AND THE DISSIPATION OF THE LAKE BREEZE
BOUNDARIES...PERHAPS RESULTING IN A BRIEF LULL BEFORE CONVECTIVE
POTENTIAL STARTS TO RISE AGAIN OVERNIGHT IN CONJUNCTION WITH THE
FURTHER DEVELOPMENT/APPROACH OF A WEAK SURFACE WAVE ATTENDANT TO THE
BURGEONING UPPER TROUGH. HAVE CONTINUED TO COVER THIS WITH SOME
CHANCE POPS FOR NOW...WITH THE HIGHEST PROBABILITIES EXTENDING
ACROSS FAR WESTERN NEW YORK AND THE NORTH COUNTRY WITH TIME.

WITH RESPECT TO TEMPERATURES...850 MB READINGS OF +13C TO +16C
SHOULD SUPPORT HIGHS MOSTLY IN THE LOWER TO MID 80S TODAY...THOUGH
AREAS ALONG THE IMMEDIATE LAKESHORES /ESPECIALLY LAKE ONTARIO/ WILL
BE SOMEWHAT COOLER. FOLLOWING THIS...LOWS TONIGHT WILL FALL BACK
INTO THE LOWER TO MID 60S.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ON TUESDAY MORNING...THE LAST OF A SERIES OF WEAK FRONTAL BOUNDARIES
WILL BE IN THE PROCESS OF CROSSING WESTERN NY...OR IT WILL MOVE INTO
WESTERN NY DURING THE MORNING.  THUS A CONTINUED CHANCE FOR SHOWERS
AND THUNDERSTORMS REMAINS IN THE FORECAST...WITH A SLIGHT DRYING
TREND EXPECTED OVER THE WEST IN THE AFTERNOON AS THE FRONT MOVES
EAST.

TUESDAY NIGHT RELATIVELY COLD AIR ALOFT WILL POUR INTO THE
REGION...WITH 850MB TEMPERATURES DROPPING TO AROUND 7C OVER LAKE
ERIE TOWARD WEDNESDAY MORNING...ABOUT 15C WARMER THAN THE LAKE
TEMPERATURE.  THESE TEMPERATURES ARE ABOUT 2SD BELOW NORMAL FOR THIS
TIME OF YEAR.  THE COLDEST AIR ALOFT SHOULD REMAIN A LITTLE WEST OF
LAKE ONTARIO.  THIS SHOULD RESULT IN AMPLE LAKE EFFECT CLOUD
DEVELOPMENT IN THE MORNING OVER MAINLY LAKE ERIE...WITH SOMEWHAT OF
A HYBRID OF SUMMER LAKE SHADOWS...LAKE EFFECT CLOUDS...AND DAYTIME
INLAND CUMULUS RESULTING IN VARIABLE CLOUD COVER DEPENDING ON TIMING
AND LOCATION...BUT WITH THE MOST CLOUD COVER INLAND.  THERE MAY BE
SOME LAKE EFFECT RAIN SHOWERS DURING THE MORNING...BUT DRY AIR ALOFT
MOVES IN DURING THE DAY...AND THUS EXPECT ANY SHOWERS TO END FAIRLY
QUICKLY.  TEMPERATURES WILL STRUGGLE INTO THE MID TO UPPER 60S.
WITH SOME GUSTY WINDS...RELATIVELY COOL DEWPOINTS...AND VARIABLE
CLOUD COVER...IT MIGHT FEEL MORE LIKE SEPTEMBER RATHER THAN JULY.

THIS WILL SET THE STAGE FOR A DRY NIGHT WEDNESDAY NIGHT AS HIGH
PRESSURE BEGINS TO TAKE HOLD.  THE ONLY SIGNIFICANT WEATHER EXPECTED
IS THE USUAL INLAND VALLEY FOG...WHICH MAY BE A BIT MORE WIDESPREAD
THAN NORMAL FOR THIS TIME OF YEAR.  TEMPERATURES WILL BOTTOM OUT
NEAR 50 ALONG AND NORTH OF THE THRUWAY...AND IN TO THE 40S WELL
INLAND.  THIS IS NEAR RECORD TERRITORY.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
A WEAKENING UPPER LEVEL TROUGH WILL REMAIN OVER QUEBEC ON THURSDAY
WHILE HIGH PRESSURE AT THE SURFACE SLOWLY BUILDS INTO THE OH VALLEY
AND EVENTUALLY LOWER GREAT LAKES REGION.  THIS PATTERN WILL RESULT
IN A DRY DAY FOR THE REGION WITH SOME INLAND CUMULUS DURING THE
AFTERNOON.  DUE TO THE RELATIVELY COOL AIRMASS ALOFT...TEMPERATURES
WILL STILL BE ABOUT 10F BELOW NORMAL WITH HIGHS GENERALLY NEAR OR
JUST BELOW 70F.

HIGH PRESSURE SHOULD BE OVERHEAD FRIDAY WITH NEAR NORMAL
TEMPERATURES.  SOME CIRRUS MAY BE SLOWLY MOVING IN FROM THE
SOUTHWEST AS THE NEXT SYSTEM APPROACHES.

THERE IS SOME UNCERTAINTY FOR THE NEXT WEEKEND WITH THE UPPER LEVEL
TROUGH CURRENTLY OVER THE PACIFIC NORTHWEST.  THIS SYSTEM IS
FORECAST TO BE OVER THE GREAT LAKES REGION ON SATURDAY AND CREATE A
SLOW MOVING SURFACE TROUGH OVER THE MS VALLEY AND THEN INTO THE OH
VALLEY.  WILL INTRODUCE A CHANCE OF SHOWERS AND THUNDERSTORMS FOR
SATURDAY IN ADDITION TO SUNDAY.

&&

.AVIATION /11Z MONDAY THROUGH FRIDAY/...
AS OF 11Z...REGIONAL SURFACE OBS SUGGEST THAT THE WEAK COLD FRONTAL
BOUNDARY IS IN THE PROCESS OF WASHING OUT SOMEWHERE BETWEEN
KBUF/KROC AND KDKK/KDSV. NONETHELESS...THIS FEATURE HAS MANAGED TO
GENERATE A FAIR AMOUNT OF MVFR STRATUS OVER THE PAST 3-4 HOURS.
MEANWHILE TO THE SOUTH OF THIS...LOW STRATUS AND/OR FOG IS STILL
FOUND ACROSS THE SOUTHERN TIER. WITH RENEWED DIURNAL HEATING...ALL
OF THIS SHOULD LIFT AND GIVE WAY TO A SCATTERED-BROKEN CU FIELD AND
SOME PARTIAL SUNSHINE THROUGH MID TO LATE THIS MORNING.

THE ABOVE STATED...THE DIURNAL HEATING WILL ALSO LEAD TO INCREASING
AMOUNTS OF INSTABILITY BY MIDDAY/EARLY AFTERNOON. COUPLED WITH A
CONTINUED WARM AND STILL SOMEWHAT MOIST AIRMASS AND DEVELOPING LAKE
BREEZE CIRCULATIONS... THIS SHOULD LEAD TO THE DEVELOPMENT OF
SCATTERED TO NUMEROUS AFTERNOON SHOWERS AND THUNDERSTORMS SOUTH OF
LAKE ONTARIO...WITH THESE TENDING TO FOCUS ALONG AND INLAND FROM ANY
LAKE BREEZE BOUNDARIES. ANY SHOWERS/STORMS THAT FORM WILL HAVE THE
POTENTIAL TO PRODUCE BRIEF LOCALIZED REDUCTIONS TO MVFR/IFR...WITH
VFR CONDITIONS OTHERWISE PREVAILING.

TONIGHT...EXPECT ANY DIURNALLY-DRIVEN CONVECTION TO QUICKLY WEAKEN
AND DIMINISH IN COVERAGE WITH THE LOSS OF HEATING THIS EVENING...
BEFORE MORE GENERAL CHANCES OF SHOWERS/STORMS RETURN OVERNIGHT AS A
WAVE OF LOW PRESSURE DEVELOPS INTO THE LOWER GREAT LAKES. OVERALL...
EXPECT VFR CONDITIONS TO PREVAIL...WITH IFR/MVFR RESTRICTIONS
POSSIBLE WITHIN ANY CONVECTION.

OUTLOOK...
TUESDAY...VFR/MVFR IN SCATTERED SHOWERS AND THUNDERSTORMS.
WEDNESDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
THURSDAY AND FRIDAY...MAINLY VFR.

&&

.MARINE...
WITH A WEAK PRESSURE GRADIENT REMAINING IN PLACE...GENERALLY LIGHT
FLOW WILL PERSIST OVER THE LAKES THROUGH TONIGHT. THIS WILL ALLOW
FOR THE DEVELOPMENT OF LOCAL LAKE BREEZE CIRCULATIONS THIS AFTERNOON.

AFTER THAT...SOUTHWESTERLY LOW LEVEL FLOW WILL STRENGTHEN AGAIN ON
TUESDAY WITH THE PASSAGE OF A WEAK WAVE OF LOW PRESSURE AND ITS
ATTENDANT COLD FRONT. THIS SHOULD EVENTUALLY REQUIRE ANOTHER ROUND
OF SMALL CRAFT ADVISORIES FOR LAKE ERIE...AND PERHAPS PORTIONS OF
LAKE ONTARIO. BEHIND THIS SYSTEM...WINDS WILL DIMINISH TUESDAY NIGHT
AND WEDNESDAY AS HIGH PRESSURE BUILDS INTO THE LOWER GREAT LAKES.

&&

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

&&

$$

SYNOPSIS...JJR
NEAR TERM...JJR
SHORT TERM...ZAFF
LONG TERM...ZAFF
AVIATION...JJR
MARINE...JJR







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