January 30, 2012 Forecast Discussion

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
112 PM EST MON JAN 30 2012

.SYNOPSIS…
A WEAK RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION
TODAY…BEFORE A WARM FRONT APPROACHES FROM THE GREAT LAKES TONIGHT
BRINGING SOME LIGHT SNOW. THE WARM FRONT WILL LIFT NORTH OF THE AREA
ON TUESDAY…ALLOWING FOR A MILD AIR MASS TO SETTLE IN WITH
UNSEASONABLY WARM TEMPERATURES CONTINUING THROUGH WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/…
— Changed Discussion —
AS OF 1 PM EST…LAKE EFFECT BANDS SLOWLY DISSIPATING AND
SHIFTING NORTH. HAVE ALLOWED ADVISORY TO EXPIRE…BUT LIGHT SNOW
SHOWERS WILL CONTINUE TO AFFECT THE MOHAWK VALLEY…ACROSS THE
TACONICS THIS AFTERNOON. WIND DIRECTION SHIFTING MORE SW OUT IN
WESTERN NY…AS WARM FRONT APPROACHES. THIS THIS SHIFT…HAVE
SEEN LAKE ERIE SNOW SHOWERS END…AND LAKE ONTARIO SNOW SHOWERS
WILL EVENTUALLY FOLLOW. CLOUDS CONTINUE OVER MOST OF THE FA…BUT
FEW BREAKS OCCURRING. HAVE ADJUSTED HRLY TEMPS TO SHOW WARMER
TEMPS OCCURRING ESP OVER ADK. OTHERWISE MAX TEMPS IN GOOD SHAPE AS
CLOUDS CONTINUE OVER MOST OF THE FA…BUT DOWNSLOPING IN THE
VALLEY WILL ALLOW MORE BREAKS.

AS OF 845 AM…LAKE EFFECT BANDS WERE TRACKING ACROSS THE MOHAWK
VALLEY AND INTO PORTIONS OF THE CAPITAL REGION. HIRES MODELS DO
SUGGEST THIS BAND WILL STICK AROUND TO AROUND NOON BEFORE THE
LOWERING INVERSIONS AND WARM ADVECTION REGIME UPSTREAM ENCROACHES.
WE HAVE NOT RECEIVED ANY ADDITIONAL SNOWFALL REPORTS BUT BASED ON
WEBCAMS…IT SEEMS PORTIONS OF SOUTHERN HERKIMER COUNTY MAY HAVE
RECEIVED ADVISORY LEVEL SNOW. WE WILL MONITOR TRENDS AND MAY EXTEND
THE ADVISORY FOR SOUTHERN HERKIMER COUNTY BEYOND 10 AM.

AS OF 615 AM…UPDATED TO RAISE POPS AND SNOWFALL AMOUNTS ACROSS
THE NORTHERN/CENTRAL TACONICS…SOUTHERN GREENS AND
BERKSHIRES…AS AREA OF ENHANCEMENT IN SNOW SHOWER ACTIVITY HAS
PERSISTED FOR THE PAST 3-4 HOURS. VSBYS HAVE BEEN LESS THAN ONE
HALF MILE AT TIMES WITH VERY GUSTY WINDS IN EXCESS OF 40 TO 45 MPH
IN THESE AREAS. WINDS ASSOCIATED WITH SNOW SQUALLS SHOULD BE SHORT
LIVED AS SPEEDS DECREASE BY SUNRISE. WILL MENTION SOME 1-2"
ACCUMULATIONS…WHICH IS CONSISTENT WITH A FEW REPORTS WE HAVE
RECEIVED. ELSEWHERE…MAIN LAKE EFFECT SNOW PLUME CONSOLIDATING
WEST OF SOUTHERN HERKIMER COUNTY…ALTHOUGH SOME ACTIVITY IS
EXPECTED TO SCRAPE THE FRINGES OF THE COUNTY. INCREASED POPS OVER
WESTERN SCHOHARIE AND WESTERN GREENE/ULSTER DUE TO BENT BACK LAKE
EFFECT PLUME THAT IS FRAGMENTING.

PREVIOUS NEAR TERM DISCUSSION…

AS OF 445 AM…A VIGOROUS AND COMPACT UPPER LEVEL DISTURBANCE AND
SURFACE COLD FRONT ARE MOVING ACROSS THE EASTERN HALF OF THE AREA
EARLY THIS MORNING. SOME DECENT RADAR RETURNS STILL ONGOING
INDICATING SNOW SHOWERS WITH SOME MINOR ACCUMULATIONS…ESPECIALLY
ACROSS THE TACONICS/SOUTHERN GREENS/BERKSHIRES WHERE AN UPSLOPE
COMPONENT IS AIDING THE ASCENT. THIS SYSTEM WILL QUICKLY SHIFT TO
OUR EAST LATER THIS MORNING…FOLLOWED BY A QUICK SHOT OF COLDER AIR
WITH A GUSTY W-NW WIND DEVELOPING.

NARROW BANDS OF LAKE EFFECT SNOW ARE ALREADY ORGANIZING ACROSS
PORTIONS OF CENTRAL NY WITH A BAND SNAKING SOUTHWARD INTO THE
WESTERN CATSKILLS. AS THE MIXED LAYER FLOW STARTS TO BACK…THIS
ACTIVITY SHOULD SHIFT NORTHWARD INTO SOUTHERN HERKIMER COUNTY…WITH
PIECES OR FRAGMENTS OF BANDS POSSIBLY MAKING IT DOWN PORTIONS OF THE
MOHAWK VALLEY AND EVEN THE CAPITAL REGION LATE MORNING/EARLY
AFTERNOON WITH A 290 FLOW TRAJECTORY. WILL MENTION LIKELY POPS FOR
THE WESTERN/CENTRAL MOHAWK VALLEY AND CHANCE FARTHER WEST. WILL
CANCEL WINTER WEATHER ADVISORY FOR NORTHERN HERKIMER/HAMILTON
COUNTIES BUT WILL KEEP IT GOING FOR SOUTHERN HERKIMER DUE TO A QUICK
TRANSITION TO LAKE EFFECT.

OUTSIDE OF THE LAKE EFFECT…ONCE THE SNOW SHOWERS FROM EARLY THIS
MORNING THERE SHOULD BE LITTLE IF ANY SNOW SHOWER ACTIVITY. EVEN THE
LAKE RESPONSE IS EXPECTED TO DIMINISH THIS AFTERNOON AS INVERSION
HEIGHTS LOWER AND DRIER AIR MOVES IN ASSOCIATED WITH A SMALL AREA OF
HIGH PRESSURE BUILDING IN BRIEFLY. NOT MUCH TEMPERATURE MOVEMENT IS
EXPECTED TODAY…WITH COLD ADVECTION COMMENCING AND SOME LIMITED
WARMING.
— End Changed Discussion —

&&

.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/…
AS OF 445 AM…WITH THE FAST FLOW ALOFT…THE NEXT PRECIPITATION
PRODUCER WILL BE ON OUR DOORSTEP THIS EVENING AS A WARM FRONT
APPROACHES FROM THE GREAT LAKES REGION. ISENTROPIC LIFT ON THE
280-285K SURFACE INCREASES RAPIDLY FROM LATE EVENING THROUGH THE
OVERNIGHT HOURS…WITH THE BEST LIFT MAINLY FROM THE CAPITAL REGION
NORTHWARD. A LIGHT MAINLY 1-2" SNOWFALL IS EXPECTED INTO TUESDAY
MORNING. THERE COULD BE SOME HIGHER 2-4" AMOUNTS ACROSS PORTIONS OF
THE SOUTHERN ADIRONDACKS…BUT THIS LOOKS LIKE A SUB-ADVISORY LIGHT
SNOW EVENT. LESS THAN AN INCH IS EXPECTED SOUTH OF THE IMMEDIATE
CAPITAL REGION…WITH LITTLE IF ANY ACCUMULATION FARTHER SOUTH.
VARIOUS SOURCES OF MODEL GUIDANCE IN GOOD AGREEMENT WITH AROUND ONE
TO TWO TENTH OF AN INCH OF QPF.

THE WARM FRONT IS EXPECTED TO GRADUALLY LIFT NORTH OF THE REGION ON
TUESDAY WITH A FEW LIGHT SNOW SHOWERS LINGERING MAINLY OVER THE
ADIRONDACKS. SOME BREAKS OF SUNSHINE ARE POSSIBLE FROM ALBANY
SOUTHWARD WITH TEMPS RESPONDING BY REACHING THE MID TO UPPER 40S.
COOLER 30S ANTICIPATED TO THE NORTH AS THIS AREA WILL BE CLOSER TO
THE FRONTAL BOUNDARY AND WILL BE SOCKED IN WITH CLOUDS.

TUESDAY NIGHT THERE WILL BE A NARROW WINDOW FOR SOME LIGHT FREEZING
RAIN ACROSS FAR NORTHERN AREAS IF TEMPS DROP TO THE FREEZING MARK.
ANY PRECIP WILL BE LIGHT BUT THERE IS THE POTENTIAL FOR A FEW
POCKETS OF FREEZING RAIN. WILL ADDRESS POTENTIAL IN THE HWO.
OTHERWISE MIN TEMPS SHOULD MAINLY BE IN THE MID TO UPPER 30S.

WEDNESDAY SHOULD BE EVEN MILDER ACROSS THE REGION…AS LOW PRESSURE
TRACKS EASTWARD THROUGH SOUTHERN QUEBEC DRAGGING A COLD FRONT
THROUGH THE AREA DURING THE AFTERNOON. AHEAD OF THE FRONT A MILD
SOUTHWEST FLOW WILL DEVELOP AND POTENTIALLY SEND TEMPS INTO THE
UPPER 40S TO LOWER 50S FROM THE CAPITAL REGION SOUTH AND EAST…WITH
LOWER TO MID 40S NORTH. WILL MENTION CHANCE POPS FOR SHOWERS
ASSOCIATED WITH THE COLD FRONT PASSAGE.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/…
CONFIDENCE IN THE FORECAST FOR MID WEEK INTO THE WEEKEND REMAINS
RATHER LOW AS THERE CONTINUES TO BE SIGNIFICANT MODEL AND ENSEMBLE
SPREAD AND RUN-TO-RUN CONTINUITY CHANGES. OVERALL THE PATTERN NOW
INDICATES MAINLY DRY WEATHER FOR OUR REGION WITH SURFACE RIDGING
DOMINATING AS AN ELONGATED LOW CLOSES OFF BETWEEN THE FOUR CORNERS
AND CENTRAL PLAINS. THE ECMWF HAS TRENDED AWAY FROM BRINGING A
STRONG SOUTHERN STREAM LOW INTO THE REGION OVER THE WEEKEND AND NOW
HAS A NORTHERN STREAM LOW PASSING TO OUR NORTH. WHILE THE GFS HAS A
SOUTHERN STREAM LOW ORIGINATING FROM THE SOUTHERN PLAINS HEADED OUR
WAY. AS FOR TEMPERATURES…EXPECTATION IS FOR COLDER SEASONABLE
READINGS.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/…
KALB REMAINS UNDER THE INFLUENCE WITH LAKE EFFECT SNOW SHOWERS AND
AN OCCASIONAL SQUALL…WITH THE LATEST RADAR TRENDS SHOWING MORE
DISORGANIZATION. EXPECTATIONS ARE FOR A TEMPO GROUP FOR MVFR
CONDITIONS THIS AFTERNOON. TOWARD SUNSET…A PERIOD OF VFR
CONDITIONS BEFORE THE NEXT ROUND OF LIGHT SNOW MOVES INTO THE REGION.

FOR KPOU AND KGFL…EXPECTATIONS ARE FOR VFR CONDITIONS TO PREVAIL
FOR THE BALANCE OF THE AFTERNOON HOURS.

FOR TONIGHT…WARM FRONT APPROACHES WITH A GOOD POTENTIAL FOR LIGHT
SNOW IMPACTING KALB-KGFL WITH IFR CONDITIONS EXPECTED. FOR
KPOU…FORECAST PROFILES SUGGEST THE LOWER LEVELS MAY REMAIN TOO DRY
/ALONG WITH DOWNSLOPING OFF THE CATSKILLS/ TO LIMIT SNOWFALL
POTENTIAL AT THIS TIME. WE WILL PLACE A `VCSH` FOR KPOU TONIGHT AND
MONITOR TRENDS.

OUTLOOK…
TUE…IMPROVING TO VFR/MVFR. SNOW LIKELY TAPERING OFF TO
ISO-SCT -SHRA/-SHSN.
TUE NT..VFR/MVFR. SLIGHT CHC -SHRA/-SHSN AT KGFL.
WED…VFR/MVFR. CHC -SHRA.
WED NT-FRI…VFR. NO SIG WX.

&&

.HYDROLOGY…
RIVER FLOWS CONTINUE TO RECEDE…ALTHOUGH SOME GAGE SITES REMAIN
IMPACTED BY ICE. NO MAJOR PROBLEMS ARE EXPECTED ON THE RIVERS
THROUGH THE WORK WEEK…OTHER THAN THOSE AREAS WHERE BREAK UP ICE
JAMS ARE STILL A POSSIBILITY. A WARM UP IS EXPECTED FOR TUESDAY AND
ESPECIALLY WEDNESDAY…WHICH IS WHEN SOME BREAK UP ICE JAMS MAY
OCCUR. HOWEVER…DUE TO ICE NOT BEING VERY THICK…BREAK UPS WILL
LIKELY NOT CAUSE SIGNIFICANT PROBLEMS.

PRECIPITATION THROUGH TUESDAY MORNING IS EXPECTED TO BE LIGHT AND
AND IN THE FORM OF SNOW. SOME RAIN SHOWERS ARE POSSIBLE TUESDAY
NIGHT THROUGH WEDNESDAY…BUT RAINFALL AMOUNTS WILL BE LIGHT AND
GENERALLY LESS THAN ONE QUARTER INCH.

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…
— Changed Discussion
CT…NONE.
NY…NONE.
MA…NONE.
VT…NONE.
End Changed Discussion —

&&

$$
SYNOPSIS…JPV
NEAR TERM…KGM/BGM/JPV
SHORT TERM…JPV
LONG TERM…IAA
AVIATION…BGM
HYDROLOGY…JPV

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