000
FXUS61 KBUF 041853
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
253 PM EDT FRI JUL 4 2008
.SYNOPSIS...
HIGH PRESSURE WILL SETTLE ACROSS THE GREAT LAKES AND BRING US DRY
WEATHER RIGHT THROUGH NEXT WEEK MONDAY. A COLD FRONT IS THEN
EXPECTED TO SLOWLY DROP SOUTHEAST ACROSS THE GREAT LAKES TUESDAY AND
WEDNESDAY ALONG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS.
FOLLOWING THE FRONT...HIGH PRESSURE WILL BUILD BACK ACROSS THE AREA
NEXT THURSDAY AND FRIDAY...BRINGING A RETURN TO DRIER WEATHER.
&&
.NEAR TERM /THROUGH SATURDAY/...
A FINE MID SUMMER DAY IN PROGRESS ACROSS THE REGION WITH JUST A FEW
AREAS OF HIGH CLOUDS PASSING BY FROM WEST TO EAST AND SOME DIURNAL
CUMULUS BUILDUP. INTERESTINGLY...THE CUMULUS HAVE FORMED
PREFERENTIALLY OVER THE LOWER TERRAIN TODAY...THE OPPOSITE OF A
TYPICAL DAY. PERHAPS THE LOWER ELEVATIONS...BEING A FEW DEGREES
WARMER HAVE REACHED THE CONVECTIVE TEMP WHILE THE HIGHER TERRAIN HAS
NOT. IN ANY EVENT...EXPECT THE DIURNAL CUMULUS TO QUICKLY DISSIPATE
EARLY THIS EVENING WITH LOSS OF DAYTIME HEATING.
OTHERWISE TONIGHT EXPECT MAINLY CLEAR SKIES MOST OF THE TIME AS A
SURFACE RIDGE CRESTS OVER THE LOWER GREAT LAKES. A COMPLEX FRONTAL
ZONE WILL REMAIN WELL SOUTH OF THE REGION FROM THE CENTRAL
APPALACHIANS INTO THE MID ATLANTIC STATES. NUMEROUS MID LEVEL
SHORTWAVES AND MID/UPPER LEVEL JETLETS WILL MOVE BY TO OUR SOUTH
ALONG THIS BAROCLINIC FEATURE. THIS WILL BRING A FEW PERIODS OF HIGH
CIRRUS CLOUDS SPREADING FROM SOUTHWEST TO NORTHEAST ACROSS THE
AREA...MAINLY ACROSS THE SOUTHERN TIER. WITH MAINLY CLEAR SKIES AND
LIGHT WINDS ALONG WITH A RELATIVELY COOL AND DRY AIRMASS...IT WILL
BE ANOTHER GOOD RADIATIONAL COOLING NIGHT WITH AREAS ON THE LAKE
PLAINS DROPPING INTO THE MID/UPPER 50S WITH THE NORMALLY COOLER
SPOTS IN THE SOUTHERN TIER AND EAST OF LAKE ONTARIO DOWN INTO THE
40S ONCE AGAIN. HIGHMARKET ON THE TUG HILL WAS 39 THIS MORNING...AND
WOULD NOT BE SURPRISED TO SEE A FEW SPOTS DOWN INTO THE UPPER 30S
AGAIN ON THE TUG HILL AND WESTERN FOOTHILLS OF THE ADIRONDACKS WITH
A SIMILAR AIRMASS IN PLACE TONIGHT.
ANOTHER FINE DAY IN STORE FOR SATURDAY AS A SURFACE RIDGE SLOWLY
CRESTS OVER THE REGION. EXPECT A FEW MORE HIGH CLOUDS TO SKIRT THE
REGION...ESPECIALLY ACROSS THE SOUTHERN TIER IN CLOSER PROXIMITY TO
THE AFOREMENTIONED FRONTAL ZONE. FORECAST NAM-WRF SOUNDINGS STILL
SUPPORT THE DEVELOPMENT OF A FEW DIURNAL CUMULUS...BUT NOT ENOUGH TO
PREVENT ANOTHER MOSTLY SUNNY DAY. 850MB TEMPS WARM A DEGREE OR TWO
OVER TODAY...AND THIS SHOULD SUPPORT HIGHS INTO THE LOW 80S ACROSS
THE LOWER ELEVATIONS AND UPPER 70S ACROSS THE HIGHER TERRAIN.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
SURFACE-BASED RIDGING OVER OUR AREA AT THE START OF THE PERIOD WILL
GRADUALLY SLIDE EASTWARD...AND MOVE OFF THE ATLANTIC COAST SUNDAY
NIGHT AND MONDAY. MEANWHILE ALOFT...A WEAK UPPER LEVEL TROUGH
CURRENTLY ACROSS THE UPPER MIDWEST AND CENTRAL GREAT LAKES WILL TEND
TO GRADUALLY FILL AND DRIFT EASTWARD WITH TIME...WITH THE AXIS OF
THIS FEATURE SLOWLY OOZING ACROSS THE AREA DURING THE COURSE OF THE
PERIOD.
IN RESPONSE TO THIS FEATURE...THE 12Z RUNS OF THE NAM AND
GFS CONTINUE TO DEVELOP SOME LIMITED CONVECTION ACROSS PORTIONS OF
THE AREA ON BOTH SUNDAY AND MONDAY...WITH ACTIVITY PRIMARILY FOCUSED
ACROSS INTERIOR SECTIONS OF THE SOUTHERN TIER AND FINGER LAKES ON
SUNDAY...THEN A LITTLE FURTHER EAST ON MONDAY AS THE AXIS OF THE
UPPER TROUGH SHIFTS A LITTLE FURTHER EASTWARD. THIS SAID...THE
EXTENT OF THIS SEEMS CONSIDERABLY OVERDONE GIVEN THE RELATIVELY DRY
NATURE OF THE AIRMASS SEEN ON BOTH MODEL PROFILES AND TIME-HEIGHT
SECTIONS FROM THE SAME MODELS...ESPECIALLY ON SUNDAY. FOR THIS
REASON...AM GOING TO STICK WITH CONTINUITY AND KEEP PCPN CHANCES
BELOW THE CHANCE THRESHOLD FOR THIS PERIOD...WITH THE FEELING THAT
AREAS TO OUR SOUTHEAST WILL HAVE A BETTER CHANCE AT SEEING
DIURNALLY-DRIVEN CONVECTION BOTH DAYS.
AS FOR TEMPERATURES...A SOUTHWESTERLY FLOW OF WARMER AIR DEVELOPING
ON THE BACK SIDE OF THE AFOREMENTIONED HIGH WILL RESULT IN A
DAY-TO-DAY WARMING TREND DURING THIS PERIOD...ALONG WITH AN INCREASE
IN HUMIDITY. BY MONDAY...850 MB READINGS WILL LIKELY WARM TO THE +15
TO +16C RANGE...ENOUGH TO SUPPORT WIDESPREAD TEMPERATURES IN THE MID
80S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
DURING THE FIRST HALF OF THIS PERIOD...A COLD FRONT WILL SLOWLY SAG
SOUTHWARD ACROSS THE GREAT LAKES REGION. THIS WILL RESULT IN A
CHANCE OF CONVECTION FOR THE MONDAY NIGHT THROUGH WEDNESDAY TIME
FRAME...WITH THE HIGHEST PROBABILITIES OF PRECIPITATION RESERVED FOR
THE FROPA ITSELF LATER TUESDAY NIGHT AND WEDNESDAY MORNING. GIVEN
OUR STILL RELATIVELY-DISTANT VANTAGE POINT...HAVE OPTED TO LIMIT
PROBABILITIES TO THE MID-CHANCE RANGE FOR NOW.
FOLLOWING THE FRONTAL PASSAGE...HAVE STUCK WITH EXISTING CONTINUITY
AND THE HPC IDEA OF HIGH PRESSURE BUILDING ACROSS THE AREA WITH A
RETURN TO GENERALLY DRY WEATHER...THOUGH AS STATED BEFORE...THIS
SCENARIO IS NOT NECESSARILY A SURE THING WITH THE AFOREMENTIONED
FRONT EXPECTED TO STALL OUT IN THE VICINITY OF THE MASON-DIXON LINE.
AS FOR TEMPERATURES...THE START OF THE PERIOD WILL FEATURE CONTINUED
SUMMERTIME WARMTH AND HUMIDITY IN ADVANCE OF THE COLD FRONTAL
PASSAGE...WITH 850 MB TEMPERATURES OF +16 TO +18C SUPPORTING HIGHS
WELL INTO THE 80S ON TUESDAY. READINGS WILL THEN COOL DOWN A BIT
FOLLOWING THE FRONTAL PASSAGE ON WEDNESDAY...BUT ONLY TO AROUND
NORMAL FOR EARLY JULY /HIGHS NEAR 80 AND LOWS 55-60/.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
DIURNAL CUMULUS CONTINUE TO DEVELOP THIS AFTERNOON ACROSS MUCH OF
WESTERN AND NORTH CENTRAL NEW YORK. THE CUMULUS WILL REMAIN SCT FOR
THE MOST PART...EXCEPT FOR ALONG THE LAKE ONTARIO LAKE BREEZE WHERE
LOW LEVEL CONVERGENCE WILL BE LOCALLY MAXIMIZED AND ALLOW FOR A FEW
AREAS OF BKN COVERAGE. BKN COVERAGE MAY COME INTO KBUF-KIAG-KROC FOR
1 TO 3 HOURS THIS AFTERNOON AS THE LAKE ONTARIO LAKE BREEZE BOUNDARY
OOZES SLOWLY SOUTH. CIGS WILL REMAIN VFR IN ANY EVENT HOWEVER AND
EXPECT DIURNAL CUMULUS TO DISSIPATE THIS EVENING WITH LOSS OF
DAYTIME HEATING. OTHERWISE EXPECT PERIODS OF HIGH CLOUDS TO CROSS
THE REGION FROM SW TO NE THROUGH SATURDAY AS A COMPLEX FRONTAL ZONE
REMAINS PARKED SOUTH OF THE REGION FROM THE LOWER OHIO VALLEY TO THE
MID ATLANTIC. WINDS WILL BE LIGHT THROUGH THE PERIOD AS A SURFACE
HIGH SETTLES OVER THE LOWER GREAT LAKES.
OUTLOOK...
SUNDAY THROUGH MONDAY...VFR.
MONDAY NIGHT THROUGH WEDNESDAY...POSSIBLE MVFR WITH SHOWERS AND
THUNDERSTORMS.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN RIDGED ACROSS THE GREAT LAKES THROUGH
SATURDAY...THEN WILL SLOWLY SHIFT EASTWARD...EVENTUALLY DRIFTING OFF
THE ATLANTIC COAST SUNDAY NIGHT AND MONDAY. THIS FEATURE WILL
MAINTAIN GOOD BOATING CONDITIONS RIGHT THROUGH THE HOLIDAY WEEKEND.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JJR
NEAR TERM...HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...HITCHCOCK
MARINE...JJR
