677
FXUS61 KALY 130601
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
201 AM EDT TUE AUG 13 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION ON TUESDAY WITH
SHOWERS AND THUNDERSTORMS. IN ITS WAKE...COOLER AND LESS HUMID AIR
WILL RETURN TO THE REGION FOR WEDNESDAY. THROUGH THE REMAINDER OF
THE WEEK...HIGH PRESSURE WILL ALLOW FOR DRY CONDITIONS...WITH
TEMPERATURES SLOWLY MODERATING BACK TOWARDS NORMAL LEVELS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 200 AM EDT...A FRONTAL BOUNDARY REMAINS WELL TO THE WEST
ACROSS THE GREAT LAKES AND OHIO VALLEY REGION. OUR AREA REMAINS IN
A MOIST SOUTHERLY FLOW AHEAD OF THE APPROACHING STORM SYSTEM. THE
REGIONAL MOSAIC RADAR SHOWS SHOWERS AND THUNDERSTORMS ACROSS
WESTERN NY AND WESTERN PA HEADING TOWARDS OUR AREA. IT SHOULD BE
FAIRLY QUIET ACROSS OUR REGION OVER THE NEXT FEW HOURS...WITH
INCREASING AMOUNTS OF MID AND HIGH LEVEL CLOUDS STREAMING AHEAD OF
THE FRONT AND APPROACHING SHOWERS/STORMS.
SOME OF THOSE SHOWER/THUNDERSTORM ACTIVITY WILL BEGIN TO REACH OUR
FAR WESTERN AREAS /WESTERN ADKS AND WESTERN MOHAWK VALLEY/ JUST
PRIOR TO DAYBREAK. THESE SHOWERS AND THUNDERSTORMS SHOULD MAINTAIN
THEMSELVES AS THEY MOVE ACROSS UPSTATE NY THANKS TO ONGOING WARM AIR
ADVECTION AND SOME ELEVATED INSTABILITY IN PLACE. WHILE POPS ARE
CURRENTLY LOW...THEY RISE TO LIKELY FOR NW PARTS OF THE AREA BY 6
AM...WITH CHC ELSEWHERE.
TEMPS WILL FALL SLOWLY OR HOLD STEADY FOR THE REMAINDER OF THE
NIGHT THANKS TO THE CLOUD COVER AND SOUTHERLY FLOW. MIN TEMPS LOOK TO
RANGE FROM THE MID 50S IN THE ADIRONDACKS TO THE MID 60S IN THE
CAPITAL REGION/MID HUDSON VALLEY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS USUAL...THE PROBLEM IS WHERE THE HEAVIEST QPF WILL BE. THE 12Z
NAM/SREFS AND CMC ALL INDICATED HEAVIER RAIN WOULD FALL FROM THE
CAPITAL DISTRICT NORTHWARD. THE 12Z ECMWF HAS A BROAD AREA OF 1+
INCH RAINFALL ACROSS MOST OF OUR REGION. THE 18Z NAM CAME IN AND
FLIP FLOPPED ITS EARLIER THINKING...NOW CONTAINING THE HEAVIEST
RAINFALL WELL TO OUR SOUTH AND NORTH OF OUR FORECAST AREA.
THE QPF GENERATED BY THE 12Z GFS WAS OVERALL LIGHTER AND REALLY NOT
FOCUSED IN ONE AREA.
BOTTOM LINE...PWATS LOOK TO INCREASE TO ABOUT 1.75 INCHES...FALLING
JUST SHORT OF BEING 70% ABOVE NORMAL. THE K INDEX PEAKS CLOSE TO
35...AND THE H850 WIND ARE BELOW 25KTS ALTHOUGH THE H500 WIND FLOW
IS AROUND 40KTS. MOST OF THESE PARAMETERS FALL BELOW CLASSIC FLASH
FLOOD KEY FACTORS. ALSO...THERE IS NOT CUTOFF LOW UPSTREAM...THE
PATTERN REMAINS PROGRESSIVE.
LOW PRESSURE WILL RE-DEVELOP OVER OUR REGION EARLY TUESDAY...THEN
QUICKLY LIFT NORTHWARD AND DRAG A COLD FRONT THROUGH OUR REGION. THE
WARM FRONT LOOKS TO GET HUNG UP TO OUR SOUTH.
AS MENTIONED IN THE NEAR TERM...FLASH FLOOD PARAMETERS...COMPLETED
BY CSTAR RESEARCH...LOOK NOT TO BE QUITE MET. BASICALLY THE COLUMN
DOES NOT GET QUITE AS MOIST AS FRIDAY/S RAINSTORM AND THERE APPEARS
TO BE LITTLE MORE OF A FLOW. AGAIN THOUGH...SOME OF THE POSSIBLE
THUNDERSTORMS COULD CONTAIN HEAVY RAINFALL AND WILL BE MENTIONED IN
OUR HAZARDOUS OUTLOOK PRODUCT.
LOOK FOR OCCASIONAL SHOWERS (OR EVEN RAIN) DURING THE
MORNING...BECOMING SCATTERED BY AFTERNOON. IT IS LATE IN THE
AFTERNOON THAT WE EXPECT THE ACTUAL COLD FRONT WORK THROUGH WITH
PERHAPS MORE SCATTERED SHOWERS AND THUNDERSTORMS.
AT THIS POINT...WE ANTICIPATE LOTS OF CLOUDS AND LIKELY MOST OF OUR
AREA WILL NOT PUNCH THROUGH THE WARM FRONT. THEREFORE THE THREAT OF
SEVERE OR EVEN STRONG THUNDERSTORMS LOOKS FAIRLY LOW AT THIS
POINT.
LOOK FOR HIGHS WEDNESDAY IN THE 70S...UPPER 70S TO THE SOUTH OF
ALBANY...MID 70S CAPITAL DISTRICT AND SURROUNDING AREAS...ONLY LOWER
70S FURTHER NORTH.
THE FRONT WILL SWEEP THROUGH BY TOMORROW EVENING. THE AIR BEHIND
THIS FRONT LOOKS EVEN COOLER THAN PREVIOUS FRONTAL PASSAGES. H850
TEMPS ARE FORECASTED TO DROP TO AROUND +6-7C OVER MUCH OF OUR AREA
COME WEDNESDAY NIGHT!
ON TUESDAY NIGHT LOOKS FOR GRADUAL CLEARING AND A NORTHWEST BREEZE.
LOWS WILL DIP INTO THE 50S.
IT WILL BE BREEZY ON WEDNESDAY WITH SUNSHINE MIXING WITH FAIR
WEATHER CLOUDS...WHICH MIGHT PRODUCE A SPRINKLE OR LIGHT SHOWER OVER
THE ELEVATED TERRAIN. HIGH TEMPERATURES ON WEDNESDAY LOOK TO BE HELD
TO THE LOWER TO MID 70S IN THE VALLEYS...ONLY 65 TO 70 ACROSS THE
ELEVATED TERRAIN. IT WILL DEFINITELY FEEL A LITTLE LIKE
FALL.
LOOK FOR A MOSTLY CLEAR SKY WEDNESDAY NIGHT. HOWEVER...THE BREEZE
MIGHT JUST HOLD ENOUGH TO PREVENT VALLEY FOG OR REALLY LOW
TEMPERATURES. FOR NOW...FOLLOWED GUIDANCE AND WENT WITH LOWS WITHIN
A FEW DEGREES OF 50 MOST PLACES...WELL DOWN INTO THE 40S IN THE
USUAL COLDER SPOTS. NO FROST IS EXPECTED IN THE ADIRONDACKS.
THURSDAY LOOKS LIKE A GRATE LATE SUMMER DAY. AFTER A SOMEWHAT CHILLY
START LOOK FOR LOTS OF SUNSHINE WITH TEMPERATURES RECOVERING BACK
INTO THE 70S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
HIGH PRESSURE AND TRANQUIL CONDITIONS WILL DOMINATE THE LONG TERM
PERIOD.
THE LONG TERM PERIOD WILL BE DOMINATED BY A BROAD AREA OF HIGH
PRESSURE AT THE SURFACE...AND GRADUALLY RISING HEIGHTS ALOFT. THE
END RESULT WITH RIDGING THROUGHOUT THE COLUMN WILL BE DRY AND
PLEASANT MID-AUGUST WEATHER THROUGH THE REMAINDER OF THE WORK WEEK
AND INTO THE WEEKEND. SKIES WILL BE MOSTLY SUNNY TO PARTLY CLOUDY
DURING THE DAY AND MOSTLY CLEAR DURING THE NIGHT.
A WEAK FRONTAL BOUNDARY AND WAVE OF LOW PRESSURE MAY DRIFT
NORTHWARDS ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA TOWARDS THE
END OF THE LONG TERM PERIOD...BRINGING THE NEXT CHANCE OF
PRECIPITATION.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
CLOUDS WILL BE IN THE INCREASE OVERNIGHT...THICKENING AND
LOWERING...AS S SURFACE COLD FRONT AND UPPER TROUGH APPROACH FROM
THE GREAT LAKES REGION. SHOWERS ARE EXPECTED TO BECOME LIKELY BY
AROUND 12Z TODAY WITH MVFR CONDITIONS DEVELOPING. DYNAMICS WITH
THIS SYSTEM ARE STRONG ENOUGH THAT AN AREA OF LOW PRESSURE IS
FORMING OVER THE SAINT LAWRENCE RIVER VALLEY AND A SECONDARY AREA OF
LOW PRESSURE IS EXPECTED TO DEVELOP OVER DELMARVA. BOTH LOWS WILL
MOVE NORTHEASTWARD EVENTUALLY CONSOLIDATED INTO ONE LOW OVER NEW
ENGLAND LATE TONIGHT. A PERIOD OF HEAVIER RAINFALL IS EXPECTED LATE
THIS MORNING INTO THE AFTERNOON AND HAVE ADDRESSED THIS WITH A TEMPO
GROUP FOR IFR CONDITIONS. ISOLATED THUNDERSTORMS ARE ALSO EXPECTED
TODAY HOWEVER THEIR LIKELIHOOD IS NOT HIGH ENOUGH TO MENTION IN TAFS
AT THIS TIME. THE SHOWERS WILL TAPER OFF LATE THIS AFTERNOON INTO
THE EVENING AS THE LOWS AND COLD FRONT MOVE OFF TO THE EAST.
CONDITIONS MAY IMPROVE TO VFR FOR A PERIOD THIS EVENING.
LIGHT SOUTHERLY WINDS WILL SHIFT TO THE WEST WITH THE PASSAGE OF THE
LOWS AND FRONTAL BOUNDARY.
OUTLOOK...
WED-SAT: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
A ROUND OF SHOWERS IS ON THE WAY FOR TUESDAY. RAINFALL AMOUNTS
LOOK TO AVERAGE A QUARTER INCH OR MORE MOST PLACES...LOCALLY OVER
AN INCH WHERE HEAVIER SHOWERS OR THUNDERSTORMS TAKE PLACE.
RH VALUES WILL RAMP UP TO NEAR 100 PERCENT OVERNIGHT...AND REMAIN
HIGH THROUGH TUESDAY...ONLY DROPPING TO AROUND 70 PERCENT. THEY
REMAIN ELEVATED TUESDAY NIGHT BUT DROP TO AROUND 50 PERCENT
WEDNESDAY AFTERNOON AND EVEN A LITTLE LOWER THURSDAY AFTERNOON.
A COLD FRONT WILL WORK ACROSS THE REGION TUESDAY...AND SWEEP OUT TO
SEA TUESDAY NIGHT. LARGE CANADIAN HIGH PRESSURE LOOKS TO TAKE
CONTROL OF OUR WEATHER WEDNESDAY THROUGH AT LEAST FRIDAY WITH DRY
WEATHER.
&&
.HYDROLOGY...
AN APPROACHING FRONTAL BOUNDARY WILL BRING A ROUND OF RAIN SHOWERS
AND POSSIBLE THUNDERSTORMS TO THE REGION ON TUESDAY. PWAT VALUES
WILL RISE TO AROUND 1.50-1.75 INCHES INCHES AHEAD OF THE FRONTAL
BOUNDARY. WHILE ANY SHOWER OR THUNDERSTORM WILL BE CAPABLE OF
HEAVY DOWNPOURS...THE ATMOSPHERE IS NOT QUITE AS MOIST AS LATE
LAST WEEK WHEN SOME FLASH FLOODING OCCURRED ACROSS THE MID HUDSON
VALLEY AND NW CT. IN ADDITION...STRONG FLOW ALOFT SHOULD KEEP ANY
SHOWERS OR THUNDERSTORMS MOVING RATHER QUICKLY. AS A
RESULT...FLASH FLOODING IS NOT ANTICIPATED WITH THIS STORM SYSTEM.
SOME MINOR RISES WILL BE POSSIBLE ON AREA RIVERS AND
STREAMS...ESPECIALLY ACROSS THOSE AREAS THAT SAW HEAVIER RAIN LAST
WEEK. THERE STILL COULD BE PONDING ON ROADWAYS AND AREAS OF POOR
DRAINAGE THROUGH TUESDAY EVENING.
DRY WEATHER WILL RETURN BY LATE TUESDAY NIGHT AND CONTINUE THROUGH
THE REMAINDER OF THE WEEK. THIS WILL ALLOW RIVER AND STREAMS LEVELS
TO RECEDE ONCE MORE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...HWJIV
LONG TERM...IRL
AVIATION...IAA
FIRE WEATHER...HWJIV
HYDROLOGY...FRUGIS