January 2, 2015 Forecast Discussion

000
FXUS61 KALY 030313
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1015 PM EST FRI JAN 2 2015

.SYNOPSIS…
HIGH PRESSURE WILL BRIEFLY BUILD INTO THE REGION AND RESULT IN DRY
AND SEASONABLY COLD TEMPERATURES LATE OVERNIGHT INTO SATURDAY
MORNING. A STORM SYSTEM WILL IMPACT THE AREA LATE SATURDAY INTO
SUNDAY. ALTHOUGH PRECIPITATION IS EXPECTED TO BEGIN AS SNOW…IT
WILL CHANGE TO A WINTRY MIX AND EVENTUALLY RAIN DURING SUNDAY.
ARCTIC CHILL WILL SETTLE IN FOR MOST OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/…
ONLY CHANGES TO THIS UPDATE WAS TO ADD A FEW CLOUDS AND KEEP THE
SNOW SHOWERS/FLURRIES GOING A LITTLE LONGER OVERNIGHT.

AS OF 1015 PM EST…STILL DEALING WITH SOME MINOR LAKE EFFECT SNOW
SHOWERS/FLURRIES WORKING DOWN THE MOHAWK VALLEY INTO THE CAPITAL
REGION AND POINTS TO THE WEST OF THE HUDSON VALLEY ALONG WITH THE
CLOUDS TO GO. TEMPERATURES WERE GENERALLY IN THE 20S. THERE WAS
STILL A BIT OF BREEZE A FEW SPOTS…GUSTING UP TO 15-20 MPH AT
TIMES.

IT WILL TAKE AWHILE FOR THE LAKE EFFECT SNOW SHOWERS/FLURRIES AND
CLOUDS TO DIE OUT. THE SUBSIDENCE INVERSION WILL LOWER AND
EVENTUALLY THERE WILL NO ROOM FOR DENDRITIC GROWTH DEVELOPMENT OF
CRYSTALS. ALSO…THE FLOW WILL WEAKEN AS HIGH PRESSURE CRESTS OVER
THE REGION BY EARLY SATURDAY.

CLOUDS SHOULD DISSIPATE IN MOST AREAS…GIVING US A PARTLY SKY BUT
NOT UNTIL WELL AFTER MIDNIGHT.

HOWEVER…THIS TOO WILL NOT LAST TOO LONG AS HIGHER LEVEL
MOISTURE…ALREADY OBSERVED ON THE SATELLITE IMAGERY…WILL FILTER
INTO THE REGION BY DAYBREAK SATURDAY. THIS WILL BE THE MAIN FORECAST
CHALLENGE WITH RESPECT TO OVERNIGHT LOWS /AND LEADING INTO THE SHORT
TERM FORECAST PERIOD/. PER THE NCEP MODEL MOS AND HOURLY LAMP/LAV
GUIDANCE…WE WILL LEAN TOWARD THE SLIGHTLY COOLER SIDE OF THE
GUIDANCE WITH THE EXPECTATION OF A PARTIALLY CLEAR SKY ALONG WITH
DIMINISHING WINDS. ALSO…THERE APPEARS TO BE A WEAK SECONDARY
BOUNDARY WORKING SOUTH THROUGH THE HUDSON VALLEY…JUST SOUTH OF
GLENS FALLS. THIS WILL SERVE TO DRIVE TEMPERATURES A LITTLE
OVERNIGHT…EVEN IF WE DO NOT COMPLETELY CLEAR OUT.

OVERNIGHT LOWS WILL TRANSLATE TO LOWS IN THE 20S CAPITAL REGION
SOUTH…TEENS HIGHER TERRAIN…AND SINGLE NUMBERS ACROSS MUCH OF THE
ADIRONDACKS.

&&

.SHORT TERM /SATURDAY NIGHT/…
LARGE MULTI HAZARD STORM SYSTEM WILL IMPACT THE ALBANY FORECAST
AREA SATURDAY AFTERNOON INTO SUNDAY.

H2O VAPOR LOOP REVEALS A FAIRLY DEEP TROUGH ACROSS THE FOUR
CORNERS REGION AND CENTRAL ROCKIES WITH DEEPER MOISTURE EXTENDING
FROM THE GULF OF MEXICO INTO THE MID MISSISSIPPI RIVER VALLEY AND
OHIO VALLEY. AS THE UPPER LOW OVER THE FOUR CORNERS REGION GETS
INJECTED INTO THE MAIN WESTERLY FLOW WITH THE APPROACH OF THE
PACIFIC JET…SURFACE CYCLOGENESIS WILL COMMENCE OVER THE SOUTHERN
MISSISSIPPI RIVER VALLEY SATURDAY MORNING. PRECEDING THIS WILL BE A
REGION OF HIGH PRESSURE THAT WILL BE DEPARTING TO THE EAST
THROUGH THE DAY. THIS WILL KEEP OUR WEATHER TRANQUIL FOR MOST OF
THE DAY. STRENGTHENING LOW LEVEL JET AND ISENTROPIC LIFT WILL
COMMENCE THROUGH SATURDAY AFTERNOON WITH CLOUDS QUICKLY INCREASING
ALONG WITH HIGHER PROBABILITIES OF SNOW ARRIVING FROM SOUTH TO
NORTH THROUGH THE AFTERNOON. INITIALLY…THE THERMAL COLUMN WILL
SUPPORT SNOW DUE TO WET BULB PROCESSES. AS FOR START
TIMES…EXPECTATIONS ARE SOUTH OF I90 AROUND THE NOON HOUR…THEN
BY LATE AFTERNOON ACROSS THE NORTHERN PORTIONS OF THE CWFA. HIGHS
WILL GENERALLY RANGE FROM 25-35 DEGREES.

SATURDAY NIGHT…THE MAIN HAZARDOUS POTENTIAL IMPACT WILL OCCUR
DURING THIS TIME FRAME. AS MENTIONED IN PREVIOUS EXCELLENT
DISCUSSIONS…THE DEPTH OF MOISTURE STREAMING AHEAD OF DEEPENING
SURFACE CYCLONE WILL BE IMPRESSIVE WITH RESPECTABLE QPF ACROSS THE
REGION. IN FACT…WITH FALLING SHOWALTER VALUES AND MID LEVEL
STEEPENING LAPSE RATES THERE COULD EVEN BE CONVECTIVE ELEMENTS TO
CONTEND WITH SATURDAY NIGHT. THE MAIN FORECAST CHALLENGE WILL BE
PRECIP TYPE/S. SOUTH OF I90…THE STRENGTH OF THE LOW LEVEL JET
AND RISING SURFACE TEMPERATURES SHOULD QUICKLY SEE THE SNOW MIX
WITH A PERIOD OF SLEET/FREEZING RAIN THEN TOO ALL RAIN DURING THE
EVENING HOURS. FOR THE I90 CORRIDOR…THIS TRANSITION WILL TAKE A
LITTLE LONGER TO ACCOMPLISH BUT THIS AREA TOO SHOULD SEE A
TRANSITION TO ALL RAIN. FOR PORTIONS OF THE DACKS…LAKE GEORGE
SARATOGA REGION…WASHINGTON COUNTY INTO PORTIONS OF SOUTHERN
VERMONT…THIS TRANSITION FROM SNOW TO SLEET AND FREEZING RAIN
WILL LIKELY LINGER MOST OF THE NIGHT. NAM12 LOW LEVEL AGEOSTROPHIC
FLOW MAGNITUDES INCREASE FROM THE NORTHEAST WHICH WOULD SUGGEST
THE SURFACE TEMPERATURES MAY STRUGGLE TO CLIMB ABOVE FREEZING
MOST OF THE NIGHT. THIS WOULD RESULT IN A PROLONGED PERIOD OF
SLEET/FZRA. AFTER CLOSE COORDINATION WITH NEIGHBORING WFOS…WE
WILL ISSUE A WINTER WEATHER ADVISORY FOR ALL LOCATIONS BUT KEEP
THE HEADLINE OUT LONGER FOR THE NORTHERN ZONES. IF THE COLDER AIR
REMAINS IN PLACE LONGER ACROSS THE LAKE GEORGE SARATOGA REGION AND
VICINITY…COULD SEE A LOW END WARNING THRESHOLDS BEING
SATISFIED.

FOR SUNDAY…RESIDUAL POCKETS OF FREEZING RAIN COULD LINGER IN
ISOLATED PORTIONS OF THE SOUTHERN ADIRONDACKS AND SOUTHERN VT
THROUGH MID MORNING. OTHERWISE…RAIN SHOULD BECOME MORE SHOWERY
BY AFTERNOON…ALONG WITH SOME AREAS OF DRIZZLE AND FOG. A WARM
FRONT MAY REACH SOUTHERN AREAS SUCH AS THE MID HUDSON VALLEY AND
SOUTHERN LITCHFIELD CO CT LATE SUNDAY MORNING…WHERE TEMPERATURES
ARE FORECAST TO SPIKE INTO THE LOWER 50S. FURTHER N…THE
POTENTIAL FOR THE SFC WARM FRONT PASSING IS LESS…BUT DEEPER
MIXING LATER IN THE DAY WITH THE PASSAGE OF THE OCCLUDED FRONT
SHOULD STILL ALLOW TEMPS TO BRIEFLY RISE INTO THE 40S.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/…
IT WILL BE VERY COLD DURING THE EXTENDED PERIOD…WITH SOME OF THE
COLDEST TEMPERATURES OF THE WINTER THUS FAR.

ARCTIC AIR WILL BEGIN TO BE USHERED INTO THE REGION SUNDAY NIGHT
BEHIND THE WEEKEND STORM ON GUSTY NORTHWEST WINDS. TEMPERATURES WILL
DIP INTO THE TEENS ACROSS THE SOUTHEASTERN ADIRONDACKS…LOWER 20S
MOST OTHER AREAS NORTH OF THE CAPITAL REGION…MID 20S CAPITAL
REGION AND CLOSER TO 30 WELL SOUTH OF THE ALBANY. IT WILL BE RATHER
BLUSTERY AND ONCE AGAIN…LAKE EFFECT SNOW SHOWERS ARE LIKELY MAINLY
ACROSS THE SOUTHEASTERN ADIRONDACKS AND CENTRAL MOHAWK VALLEY. SOME
ACCUMULATIONS ARE POSSIBLE.

IT WILL CONTINUE TO BE WINDY MONDAY WITH TEMPERATURES NOT RISING
MUCH IF AT ALL…DESPITE SOME SUNNY BREAKS. THIS MEAN HIGHS WILL BE
HELD TO THE 30S IN THE VALLEYS…20S HIGHER TERRAIN…EXCEPT TEENS
ACROSS THE ADIRONDACKS. A GUSTY NORTHWEST WIND WILL ADD TO THE CHILL
AND WILL CONTINUE THE LIKELIHOOD OF LAKE EFFECT SNOW SHOWERS ACROSS
THE ADIRONDACKS.

MONDAY NIGHT IT WILL TURN EVEN COLDER WITH LOWS PLUNGING TO NEAR
ZERO ACROSS THE ADIRONDACKS PARK…SINGLE NUMBERS LAKE GEORGE EAST
TO SOUTHERN VERMONT…AROUND 10 DEGREES IN THE CAPITAL REGION AND
SURROUNDING AREAS…TEENS SOUTHWARD. THE WIND WILL DIMINISH BUT NOT
ENTIRELY. THERE STILL COULD BE SOME LAKE EFFECT SNOW
SHOWERS…PRIMARILY TO THE WEST OF THE HUDSON VALLEY. OTHERWISE IT
WILL BE PARTLY CLOUDY AND DRY.

ON TUESDAY A CLIPPER WILL RACE INTO THE REGION…POSSIBLY PRODUCING
A PERIOD OF STEADY LIGHT SNOW OR SNOW SHOWERS EVERYWHERE…AND MORE
LAKE EFFECT SNOWS IN ITS WAKE TO LEE OF ONTARIO…MAINLY THE
ADIRONDACKS AND CENTRAL MOHAWK VALLEY LATE TUESDAY NIGHT INTO
WEDNESDAY.

IN ADDITION…AN ARCTIC FRONT WILL DRIVE THE COLDEST AIRMASS OF THE
REGION WEDNESDAY WITH H850 TEMPERATURES PLUNGING TO -25C IF NOT A
LITTLE LOWER! THIS FRONT COULD BRING MORE SNOW SHOWERS (AND EVEN
SNOW SQUALLS ON ITS OWN).

TEMPERATURES TUESDAY NIGHT WILL NOT BE ALL THE COLD DUE TO CLOUD
COVER DIPPING INTO THE SINGLE NUMBERS NORTH AND TEENS TO AROUND 20
SOUTH.

HIGHS WEDNESDAY WILL BE IN THE TEENS NORTH OF ALBANY…AROUND 20
LOCALLY IN THE CAPITAL REGION…MID 20S SOUTH. BY WEDNESDAY
NIGHT…LOOK FOR LOWS TO PLUMMET TO AROUND ZERO IN THE CAPITAL
REGION…AS LOW AS -15 TO THE NORTH…AND CLOSE TO 5 ABOVE WELL
SOUTH OF ALBANY. WHEN COMBINED WITH A NORTHWEST WIND AVERAGING
AROUND 10 MPH (WITH HIGHER GUSTS) WIND CHILLS WILL LIKELY BE DRIVEN
TO DANGEROUSLY LOW READING (-20 OR LOWER) ACROSS MUCH OF OUR REGION.
WIND CHILL ADVISORIES AND OR WIND CHILL WARNINGS MIGHT BE NEEDED. WE
WILL CONTINUE TO MENTION THIS POSSIBILITY IN OUR HAZARDOUS WEATHER
OUTLOOK (HWO). IN ADDITIONAL…THERE COULD BE SOME LAKE ENHANCED
SNOW SHOWERS ACROSS THE HIGHER TERRAIN.

IT WILL STAY BITTERLY COLD THURSDAY WITH HIGHS HELD TO THE TEENS
FROM ALBANY SOUTHWARD…SINGLE NUMBERS NORTH OF THE CAPITAL REGION.
THERE WILL STILL BE SOME WIND…BUT SHOULD BE SOME SUNSHINE AS WELL.
SNOW SHOWERS (OR FLURRIES) COULD LINGER ACROSS THE HIGHER
TERRAIN.

IT DOES NOT LOOK QUITE AS COLD THURSDAY NIGHT INTO FRIDAY AS THE
CORE OF THE ARCTIC AIR BEGINS TO MOVE AWAY…BUT TEMPERATURES WILL
REMAIN BELOW NORMAL.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/…
VFR FLYING CONDITIONS WILL CONTINUE TO PREVAIL THROUGH MIDDAY
SATURDAY AS HIGH PRESSURE BUILDS ACROSS THE REGION. THEN…A MAJOR
STORM DEVELOPING TONIGHT AND WORKING INTO THE OHIO VALLEY BY LATE
SATURDAY…WILL IMPACT THE TAFS BY SATURDAY AFTERNOON AS CONDITIONS
QUICKLY DROP TO LOW MVFR (EXTRA FUEL REQUIRED) OR IFR WITH
SNOW/SLEET AND LOW CIGS ASSOCIATED WITH A STRONG WARM FRONT.

WE HAVE NO LOW LEVEL WIND SHEAR IN THE TAFS…BUT IT IS POSSIBLE WE
COULD ADD IT LATER ON FOR LATE SATURDAY AS THE WIND INCREASES OFF
THE DECK.

IN THE SHORT TERM (THIS EVENING) WE ARE STILL DEALING WITH LAKE
EFFECT CLOUDS (VFR) AND A FEW POSSIBLE LIGHT SNOW SHOWERS OR
FLURRIES MAINLY AT KALB. EVEN IF SOME FLURRIES OR SNOW SHOWERS WERE
TO HIT THE AIRPORT…IT IS DOUBTFUL CONDITIONS WOULD EVEN DROP TO
MVFR.

ANY RESIDUAL WEST WIND AND GUSTS (MAYBE UP TO 18KTS) SHOULD BECOME
LIGHT AND VARIABLE OVERNIGHT. THEN…THE WIND WILL WORK INTO A
SOUTHEASTERLY COMPONENT 5-10KTS ON SATURDAY AS THE STORM CENTER
PASSES WELL TO OUR WEST.

OUTLOOK…

SATURDAY NIGHT: MAJOR OPERATIONAL IMPACT. DEFINITE RA…SN…SLEET.
SUNDAY: HIGH OPERATIONAL IMPACT. DEFINITE SHRA…RA.
SUNDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA…SHSN.
MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SN.
TUESDAY TO WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.

&&

.HYDROLOGY…
MAINLY DRY AND SEASONABLE COLD CONDITIONS WILL PREVAIL TONIGHT
INTO SATURDAY MORNING. THEN A COMPLEX STORM SYSTEM WITH
POTENTIALLY MODERATE TO HEAVY QPF WILL MOVE ACROSS THE HSA LATE
SATURDAY INTO SATURDAY NIGHT.

ALTHOUGH PRECIPITATION WILL START AS SNOW…IT WILL TRANSITION TO
A WINTRY MIX ON SATURDAY NIGHT…AND EVENTUALLY RAIN BY SUNDAY.
MOST AREAS ARE FORECAST TO RECEIVE 1-1.5 INCHES OF LIQUID
EQUIVALENT PRECIPITATION…WITH LOCALLY UP TO 2 INCHES. THIS WILL
ALLOW FOR SIGNIFICANT RISES ON RIVERS AND STREAMS ON SUNDAY…AS
TEMPERATURES RISE ABOVE FREEZING OVER THE ENTIRE REGION. SOME
MINOR FLOODING IS POSSIBLE AND PER COLLABORATION WITH NERFC…THE
ONLY POINT THAT GOES ABOVE ACTION STAGE IS WILLIAMSTOWN /WILM3/ AT
THIS TIME.

THEREAFTER…BITTER COLD WEATHER IS EXPECTED NEXT WEEK. SOME
FREEZE UP ICE JAMS ARE POSSIBLE ACROSS THE SOUTHWESTERN
ADIRONDACKS AND SOUTHERN VERMONT BY LATE IN THE WEEK.
OTHERWISE…ICE WILL LIKELY DEVELOP AND INCREASE ACROSS RIVERS
AND STREAMS.

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…WINTER WEATHER ADVISORY FROM 4 PM TO 11 PM EST SATURDAY FOR
CTZ001-013.
NY…WINTER WEATHER ADVISORY FROM 4 PM TO 11 PM EST SATURDAY FOR
NYZ047>054-058>061-063>066.
WINTER WEATHER ADVISORY FROM 4 PM SATURDAY TO 6 AM EST SUNDAY
FOR NYZ032-033-038>043-082>084.
MA…WINTER WEATHER ADVISORY FROM 4 PM TO 11 PM EST SATURDAY FOR
MAZ001-025.
VT…WINTER WEATHER ADVISORY FROM 4 PM SATURDAY TO 6 AM EST SUNDAY
FOR VTZ013>015.

&&

$$
SYNOPSIS…HWJIV/BGM
NEAR TERM…HWJIV/BGM
SHORT TERM…SND/BGM
LONG TERM…HWJIV
AVIATION…HWJIV
HYDROLOGY…SND/BGM

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