April 12, 2012 Forecast Discussion

000
FXUS61 KALY 122049
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
449 PM EDT THU APR 12 2012

.SYNOPSIS…
THE UPPER LEVEL TROUGH WHICH HAS BROUGHT COOL AND SOMEWHAT
UNSETTLED CONDITIONS TO THE REGION WILL MOVE OFF THE NEW ENGLAND
COAST THIS EVENING. HIGH PRESSURE WILL BUILD INTO THE REGION FROM
THE GREAT LAKES LATER TONIGHT INTO FRIDAY…BRINGING FAIR
WEATHER…AND MORE SEASONABLE TEMPERATURES. A WARM FRONT
APPROACHING FROM THE WEST MAY BRING SOME SHOWERS TO THE REGION
SATURDAY NIGHT AND SUNDAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/…
AS OF 445 PM EDT…ISOLATED TO SCATTERED SHOWERS CONTINUE TO
AFFECT THE REGION…ALTHOUGH SOME OF THIS HAS DRIED UP IN VALLEY
REGIONS…WITH ONLY A FEW DROPS REACHING THE GROUND…DESPITE
DECENT FALL STREAKS/VIRGA BENEATH THE CLOUD BASES. A SHORTWAVE HAS
PASSED BY TO OUR E EARLIER THIS AFTERNOON…AND THE SUBSIDENCE IN
THE WAKE OF THIS FEATURE MAY HAVE HELPED STRENGTHENED A MID LEVEL
CAP…AS OVERALL CLOUD DEPTH HAS APPEARS TO DECREASE OVER THE LAST
FEW HOURS.

WE EXPECT THE AREAL COVERAGE OF SHOWERS TO DECREASE SIGNIFICANTLY
EARLY THIS EVENING…ESP AROUND SUNSET…WITH PERHAPS ONLY A FEW
SHOWERS/SPRINKLES REMAINING ACROSS PORTIONS OF THE BERKSHIRES AND
LITCHFIELD HILLS…WHERE SOME SLIGHT CHC POPS WILL BE RETAINED.

OTHERWISE…EXPECT DRY CONDITIONS REGIONWIDE LATER THIS EVENING
INTO THE OVERNIGHT HOURS. CLOUDS SHOULD GRADUALLY DISSIPATE FROM
NW TO SE AS WELL LATER THIS EVENING. THIS SHOULD ALLOW TEMPS TO
FALL INTO THE 20S ACROSS HIGHER ELEVATIONS…AND LOWER TO MID 30S
IN VALLEY REGIONS BY MORNING…AND HAVE FOLLOWED CLOSE TO THE
SLIGHTLY WARMER MET MOS. HOWEVER…SHOULD CLEARING OCCUR MORE
RAPIDLY…SLIGHTLY COLDER MINS AKIN TO THE MAV MOS COULD OCCUR.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/…
FRI-FRI NT…A LOW LEVEL RIDGE OF HIGH PRESSURE WILL GRADUALLY
SLIDE E FROM THE GREAT LAKES/UPPER OHIO VALLEY DURING THIS TIME
FRAME. OTHER THAN SOME PATCHY HIGH CLOUDS…EXPECT GENERALLY CLEAR
SKIES. DEEP MIXING TO AT LEAST 825 MB SHOULD ALLOW MAX TEMPS TO
REACH 60-65 IN VALLEY AREAS…AND 55-60 ACROSS HIGHER ELEVATIONS
FRI AFTN. FRI NT MAY STILL BE CHILLY…ALTHOUGH THERE IS SOME
UNCERTAINTY AS TO HOW MUCH HIGH/MID LEVEL CLOUDS PASS THROUGH.
HAVE GENERALLY SIDED A BIT ABOVE THE MAV/MET MOS FOR FRI NT
MINS…WHICH SHOULD STILL FALL INTO THE LOWER/MID 30S IN MOST
VALLEY AREAS…AND 20S ACROSS HIGHER ELEVATIONS.

SAT-SAT NT…THE AFOREMENTIONED HIGH WILL GRADUALLY MOVE E OF THE
REGION SAT AFTN…AS A WARM FRONT APPROACHES FROM THE WEST. WE
EXPECT SAT MORNING TO REMAIN MOSTLY SUNNY…BEFORE CLOUDS INCREASE
FROM W TO E FAIRLY RAPIDLY DURING THE MID TO LATE AFTERNOON. SOME
SHOWERS MAY REACH AT LEAST THE WESTERN MOHAWK VALLEY AND
ADIRONDACKS BEFORE SUNSET…WHERE CHC POPS HAVE BEEN INDICATED.
HAVE ALSO INCLUDED SLIGHT CHC POPS AS FAR E AS THE HUDSON
RIVER…IN CASE SHOWERS MOVE A BIT FASTER THAN MODELS CURRENTLY
INDICATE. AT THIS TIME…MOST DETERMINISTIC MODELS…AS WELL AS
THE 09Z AND 15Z SREFS INDICATE SOME SHOWERS FOR SAT NT…WITH THE
GREATEST POTENTIAL FOR AREAS MAINLY FROM THE MOHAWK RIVER
NORTH…INTO THE SOUTHERN ADIRONDACKS. HAVE THEREFORE INDICATED
LIKELY POPS IN THIS REGION…TAPERING TO CHC FURTHER S AND E.
SHOWALTER INDICES DIP INTO THE 0 TO -2 RANGE LATE SAT
NT…COMBINED WITH A HEALTHY SW LOW LEVEL JET…SO HAVE INCLUDED
SLIGHT CHC FOR THUNDER AS WELL.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/…
IT LOOKS AS IF LONG RANGE MODELS ARE IN BETTER AGREEMENT REGARDING
THE LONG TERM. THE BASIC THEME IS A RIDGE WILL BUILD ACROSS THE
SOUTHEAST AND MID ATLANTIC SUNDAY INTO MONDAY. THEN…A COLD FRONT
WILL SLOWLY SINK SOUTHWARD MONDAY NIGHT OR TUESDAY…AND LIKELY
STALL SOMEWHERE TO OUR SOUTH. THE SECOND HALF OF THE FORECAST BEARS
LESS CONFIDENCE DEPENDING ON EXACTLY HOW FAR SOUTH THE FRONT
STALLS…AND ATTEMPTING TO TIME ANY DISTURBANCES THAT WOULD RIDE
ALONG IT…AN ALMOST IMPOSSIBLE FEAT TO ACCOMPLISH AT THIS POINT.

SUNDAY…THE WARM FRONT LOOKS TO PUSH THROUGH THE AREA EARLY IN THE
DAY. ANY SHOWERS ASSOCIATED WITH IT LOOK TO LIFT NORTHWARD BY
MIDDAY. HOWEVER…AS OUR REGION GETS INTO THE WARMER AIR…MORE
SCATTERED SHOWERS AND EVEN THUNDERSTORMS COULD DEVELOP WITH THE
HEATING OF THE AFTERNOON. WILL CONTINUE POPS THAT DAY.

AS THE RIDGE TAKES HOLD SUNDAY NIGHT AND MONDAY…THE THREAT OF
SHOWERS AND THUNDERSTORMS LOOKS TO GREATLY DIMINISH AS THE
ATMOSPHERE WILL LIKELY BECOME CAPPED. THIS MEANS THAT IT WOULD BE
HARD FOR CU TO FORM…EVEN IF THE LOWER LEVELS REMAIN MOIST AND
UNSTABLE. WILL CONTINUE SLIGHT POPS IN OUR NORTHERN AREAS ONLY AS A
STATIONARY FRONT MIGHT NOT BE TOO FAR FROM THESE AREAS.

THEN…AS THE FRONT BEGINS TO PUSH SOUTHWARD AS COLD FRONT
TUESDAY…WE WILL HAVE CHANCE POPS TUESDAY THROUGH WEDNESDAY AS
AGAIN TIMING OF DISTURBANCES AND THE PLACEMENT OF FRONT HAVE YET TO
BE DETERMINED. BY THURSDAY…THE FRONT LOOKS TO BE PUSHED FURTHER
SOUTH BUT WILL CONTINUE WITH SLIGHT POPS.

TEMPERATURES LOOK REACH THE 70S FROM ALBANY SOUTHWARD ON
SUNDAY…60S NORTH. OVERNIGHT LOWS WILL BE IN THE 50S SOUTH…45 TO
50 NORTH. ON MONDAY…LOOK FOR HIGHS TO CRACK THE 80S SOUTH OF
ALBANY…WELL INTO THE 70S CAPITAL DISTRICT AND EVEN NORTH.
OVERNIGHT LOWS MONDAY NIGHT AGAIN MILD IN THE 45 TO 55
RANGE.

TEMPERATURES LOOK TO COOL TUESDAY…70S SOUTH…UPPER 50S TO UPPER
60S NORTH…60S SOUTH AND 50S AND EVEN SOME 40S NORTH BY WEDNESDAY
AND THURSDAY FOR DAYTIME HIGHS.

&&

.AVIATION /21Z THURSDAY THROUGH TUESDAY/…

…VFR CONDITIONS WILL PREVAIL THROUGH FRIDAY…

SCATTERED SHOWERS HAVE DEVELOPED COURTESY OF AN UPPER LEVEL
DISTURBANCE THAT HAS PERSISTED FOR DAYS. THESE SHOWERS COULD CONTAIN
SMALL HAIL BUT ONLY BRIEFLY BRING CONDITIONS TO MVFR (LESS THAN 15
MINS IF AT ALL) SO THEREFORE…NO MVFR IN THE TAFS. INCLUDED VCSH IN
THE TAFS.

AFTER SUNDOWN…AS THE UPPER LEVEL DISTURBANCE MOVES
AWAY…CLOUDS…AND SHOWERS WILL DIMINISH. A GUSTY NORTH TO
NORTHWEST WIND WILL DIMINISH AS WELL OVERNIGHT.

ON FRIDAY…CLEAR TO PARTLY CLOUDY SKY…AND THE WIND WILL PICKUP
FROM THE NORTHWEST AROUND 10KTS…GUSTING TO NEAR 20KTS. VISIBILITY
LOOKS UNLIMITED.

.OUTLOOK…
FRI-SAT…VFR. NO SIG WX.
SAT NIGHT-TUE…VFR. CHC -SHRA WITH SUB VFR CONDITIONS.

&&

.FIRE WEATHER…

…LOW RH VALUES OF 20-25 PERCENT RANGE EXPECTED FRI AFTERNOON…
…OCCASIONAL WINDS GUSTS OF 20 TO 25 MPH POSSIBLE FRI AFTERNOON…

HIGH PRESSURE WILL BUILD EAST FROM THE GREAT LAKES TONIGHT INTO
FRIDAY. A WARM FRONT WILL APPROACH THE REGION FROM THE WEST LATE
SATURDAY NIGHT AND SUNDAY…POSSIBLY BRINGING SOME SHOWERS TO THE
REGION.

THE RELATIVE HUMIDITY IS EXPECTED TO RECOVER INTO THE 80-100
PERCENT RANGE TONIGHT…WITH SOME FROST FORMATION POSSIBLE. THE RH
WILL THEN FALL INTO THE 20-25 PERCENT RANGE IN VALLEY AREAS…AND
25-30 PERCENT RANGE ACROSS HIGHER ELEVATIONS FRI AFTERNOON.
RECOVERY TO 70-90 PERCENT IS EXPECTED FRI NT.

NORTH TO NORTHWEST WINDS WILL DECREASE TO 5-10 MPH TONIGHT. WINDS
WILL BECOME NORTHWEST ON FRIDAY…AND INCREASE TO 10-20 MPH BY FRI
AFTERNOON. A FEW WIND GUSTS COULD REACH INTO THE 20-25 MPH RANGE
LATE FRI AFTERNOON…BEFORE WINDS DECREASE RAPIDLY AFTER
SUNSET…TO LESS THAN 5 MPH.

&&

.HYDROLOGY…
NO HYDRO PROBLEMS ARE EXPECTED THE NEXT FEW DAYS. ANY SHOWERS
WHICH OCCURRED TODAY PRODUCED GENERALLY LESS THAN ONE TENTH OF AN
INCH OF RAINFALL.

SHOWERS AND POSSIBLE THUNDERSTORMS ARE EXPECTED TO AFFECT PORTIONS
OF THE REGION SATURDAY NIGHT AND SUNDAY. THIS COULD PRODUCE BASIN
AVERAGE AMTS OF ONE TENTH TO ONE QUARTER OF AN INCH…WITH HIGHER
AMTS POSSIBLE…ESPECIALLY ACROSS THE SOUTHERN ADIRONDACKS.

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…KL
NEAR TERM…KL
SHORT TERM…KL
LONG TERM…HWJIV
AVIATION…HWJIV
FIRE WEATHER…KL
HYDROLOGY…KL

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