January 5, 2014 Forecast Discussion

000
FXUS61 KALY 060003
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
703 PM EST SUN JAN 5 2014

.SYNOPSIS…
A STORM WILL ORGANIZE IN THE OHIO VALLEY TONIGHT AND
TRACK TO THE SAINT LAWRENCE VALLEY MONDAY…BRINGING RAIN AND A
WINTRY MIX OF PRECIPITATION TO THE REGION. BEHIND IT…ANOTHER
FRIGID SURGE OF ARCTIC AIR WILL MOVE INTO OUR REGION AND LAST
THROUGH THE MIDDLE OF THE WEEK WITH CONSIDERABLE SNOWFALL DOWNWIND
OF LAKE ONTARIO.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/…
FREEZING RAIN ADVISORIES POSTED FOR ULSTER…DUTCHESS AND
LITCHFIELD COS UNTIL 10 PM EST…

WINTER WEATHER ADVISORIES POSTED FOR THE REMAINDER OF THE FA
THROUGH 6 AM MONDAY

AS OF 605 PM EST…THIS UPDATE IS RETOOL THE POPS AND WX BASED ON
THE RADAR TRENDS. ALSO…HOURLY T/TD WERE REDONE BASED ON THE
OBSERVATIONS. SEVERAL REPORTS OF LIGHT FREEZING RAIN HAVE COME IN
THE PAST HOUR IN HERKIMER…DUTCHESS AND ULSTER COUNTIES. SOME
TEMPS HAVE BEEN ABOVE FREEZING…BUT DUE TO DEWPTS IN THE TEENS
AND 20S…WET BULB TEMPS ARE BELOW FREEZING. THE MOST WIDESPREAD
PCPN IS OVER THE LOCATIONS NORTHWEST OF THE CAPITAL REGION…IN
THE W-CNTRL MOHAWK VALLEY…SRN DACKS…AND THE LAKE GEORGE
REGION. THIS PCPN HAS DEVELOPED AHEAD OF A THERMAL TROUGH…AND A
MID LEVEL SHORT-WAVE IN THE SW FLOW ALOFT.

PRECIPITATION WILL CONTINUE TO EXPAND FROM SOUTHWEST TO NORTHEAST
ACROSS THE FA THIS EVENING. WARMING WILL TAKE PLACE RATHER RAPIDLY
ALOFT…HOWEVER COLD AIR WILL REMAIN TRAPPED NEAR THE SURFACE
RESULTING IN A WINTRY MIX OF PCPN BY LATE AFTERNOON. PTYPE WILL
GENERALLY BE FREEZING RAIN WITH SOME SLEET MIXED IN AS WELL.
EXPECT TEMPS TO FALL THROUGH THIS EVENING ONCE THE PCPN STARTS AND
THEN RISE LATER TONIGHT TOWARD MORNING. LOWS ARE EXPECTED TO BE IN
THE UPPER 20S TO LOWER 30S. HOWEVER…SOME THE RIDGE TOPS IN SRN
VT…AND THE ERN CATSKILLS…MAY WARM INTO THE U30S AND L40S
BEFORE FALLING BACK INTO THE 30S WITH THE WET BULB COOLING.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/…
IT WILL BE A VERY TRICKY FORECAST IN TERMS OF TIMING…PTYPE AND
ANOTHER SURGE OF ARCTIC AIR AS WE HEAD INTO MONDAY.

AS THE LOW PRESSURE SYSTEM PASSES BY TO THE NORTHWEST OF THE
FORECAST AREA…IT WILL SWEEP ANOTHER ARCTIC COLD FRONT THROUGH
THE REGION MONDAY MORNING. AS A RESULT…HIGH TEMPS ON MONDAY WILL
OCCUR DURING THE MORNING WITH HIGHS EXPECTED TO BE IN THE MID 30S
TO LOWER 40S AND THEN TEMPS ARE EXPECTED TO DROP TO THE 20S DURING
THE AFTERNOON. THIS WILL CHANGE ANY MIXED PCPN TO SNOW WITH AN
INCH OR SO OF ACCUMULATION POSSIBLE.

MONDAY NIGHT AND TUESDAY THE ATTENTION TURNS TO A FAIRLY HEAVY
LAKE EFFECT SNOW EVENT ACROSS THE WESTERN ADIRONDACKS WITH A
MULTILAKE CONNECTION WHICH SHOULD RESULT IN A LONG FETCH OFF THE
LAKE. SOME HEAVY ACCUMULATIONS ARE POSSIBLE ESPECIALLY ALONG AND
NORTH OF ROUTE 28 WITH A FOOT TO TWO AND A HALF FEET OF SNOW
POSSIBLE THROUGH WEDNESDAY AFTERNOON. AS A RESULT HAVE ISSUED A
LAKE EFFECT SNOW WARNING FROM 6 PM ON MONDAY TO 1 PM ON WEDNESDAY.
THE REMAINDER OF THE FA WILL REMAIN COLD. EXPECT LOWS MONDAY
NIGHT IN THE 10 BELOW TO 5 ABOVE ZERO RANGE WITH HIGHS ON TUESDAY
IN THE UPPER SINGLE DIGITS TO UPPER TEENS. HAVE ISSUED A WIND
CHILL WATCH FOR AREAS WEST OF THE HUDSON VALLEY…INCLUDING
NORTHERN WARREN COUNTY…WHERE WIND CHILL READINGS MAY DROP TO 30
BELOW ZERO OR LESS LATER MONDAY NIGHT INTO TUESDAY.
ELSEWHERE…WIND CHILL READINGS SHOULD DROP TO ADVISORY LEVELS
DURING THAT TIME PERIOD.

TUESDAY INTO WEDNESDAY THE COLD AIR REMAINS IN PLACE WITH LITTLE
MODERATION EXPECT WINDS TO ONLY GRADUALLY DIMINISH THROUGH
THIS TIME PERIOD WITH THE LAKE EFFECT SNOW CONTINUING DOWNWIND OF
LAKE ONTARIO. HIGHS ON TUESDAY ARE EXPECTED TO BE IN THE UPPER
SINGLE DIGITS TO MID TEENS WITH LOWS TUESDAY NIGHT 5 BELOW TO 5
ABOVE ZERO AND HIGHS ON WEDNESDAY IN THE MID TEENS TO LOWER 20S.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/…
THE EXTENDED FORECAST FEATURES A MODERATING TREND IN TEMPERATURES BY
THE END OF THE WORK WEEK INTO NEXT WEEKEND WITH SOME LIGHT
PRECIPITATION EVENTS.

WPC GUIDANCE WAS FOLLOWED CLOSELY FOR THIS PORTION OF THE FCST WITH
HIGH PRESSURE BUILDING IN FROM NEAR THE MID ATLANTIC REGION…ENDING
THE LAKE EFFECT SNOW SHOWERS…AND YIELDING ONE MORE COLD NIGHT WITH
LOWS FALLING INTO THE SINGLE DIGITS ACROSS MOST OF THE FCST
AREA…WITH A FEW LOWER TEENS OVER THE MID HUDSON VALLEY AND NW CT.

THURSDAY…A WEAK FRONTAL BOUNDARY CROSSES THE REGION DURING THE DAY
WITH HIGH PRESSURE BRIEFLY RIDGING IN…AND THEN THE FRONT STALLS
NEAR THE PA/MD BORDER DURING THE OVERNIGHT PERIOD. SLIGHT CHANCES
OF LIGHT SNOW WERE INCREASED MAINLY FROM THE HUDSON RIVER VALLEY
WESTWARD DURING THE AFTERNOON. H850 TEMPS WILL BE MUCH MORE
SEASONABLE IN THE -8C TO -12C RANGE…BUT WITH THE INCREASE IN
CLOUDS DUE TO STRENGTHENING WARM ADVECTION…MAX TEMPS WILL STILL BE
ABOUT 5 DEGREES OR SO BELOW NORMAL WITH LOWER TO M20S FROM THE
CAPITAL REGION…NRN CATSKILLS…AND NRN BERKSHIRES NORTHWARD…AND
U20S TO L30S TO THE SOUTH AND EAST.

THU NIGHT INTO FRIDAY…PRETTY GOOD AGREEMENT THAT FAST MOVING
POSITIVELY TILTED H500 TROUGH WILL APPROACH FROM THE GREAT LAKES
REGION. THE SFC HIGH QUICKLY RETREATS AT NIGHT WITH INCREASING LOW
AND MID LEVEL WARM ADVECTION. SOME OVER RUNNING LIGHT SNOWFALL IS
EXPECTED ACROSS THE REGION WITH BETTER AGREEMENT ON THE GFS/ECMWF
ON A LIGHT QPF EVENT (UNPHASED PROGRESSIVE OVER RUNNING EVENT). THE
ECMWF WOULD KEEP MOST OF THE OVERNIGHT PERIOD DRY. FAVORED THE
WPC/GFS TIMING WITH CHC POPS BOTH PERIODS WITH A TRANSITION FROM
SNOW…TO SNOW SHOWERS DURING THE DAY. LOWS IN THE TEENS AND
L20S…AND HIGHS RANGING FROM THE LOWER AND M30S FROM THE CAPITAL
REGION NORTH AND WEST…AND U30S TO NEAR 40F FOR THE SRN ZONES.

FRIDAY NIGHT…THE WEAK UPPER TROUGH SHIFTS DOWN STREAM…WITH ONLY
WEAK LOW AND MID LEVEL COLD ADVECTION. THE SNOW SHOWERS END EARLY IN
THE EVENING. HIGH PRESSURE BUILDS IN WITH HEIGHTS ACTUALLY
INCREASING TO START THE WEEKEND. LOWS WILL GENERALLY BE IN THE M20S.

SATURDAY INTO SUNDAY…STRONG SOUTHWESTERLY FLOW SETS UP ALOFT WITH
LOW AND MID LEVEL WARM ADVECTION INCREASING ACROSS THE REGION. H850
TEMPS RISE TO +3C TO +7C WITH THE RIDGING FROM THE SOUTH. MAX TEMPS
COULD REACH THE U30S TO M40S FROM NW TO SE ON SATURDAY. A
DISTURBANCE IN THE SOUTHWEST FLOW COULD BRING A CHANCE OF MAINLY
RAIN/SNOW SHOWERS SATURDAY NIGHT…WITH ONLY A SLIGHT CHC ON
SUNDAY. LOWS WILL LIKELY STAY ABOVE NORMAL IN THE LOWER TO M30S
SATURDAY NIGHT. THE ABOVE NORMAL TEMPS CONTINUE FOR SUNDAY WITH MID
AND U40S FROM THE CAPITAL DISTRICT SOUTH AND EAST…AND U30S TO L40S
NORTH AND WEST.

OVERALL…TEMPS TREND ABOVE NORMAL WITH PCPN BELOW NORMAL IN THE
EXTENDED.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/…
A WARM FRONT AND A LOW PRESSURE SYSTEM WILL IMPACT ERN NY AND WRN
NEW ENGLAND TONIGHT INTO TOMORROW MORNING. THE COLD FRONT TO THE
SYSTEM WILL SWING THROUGH DURING THE EARLY AFTERNOON.

CONDITIONS CONTINUE TO LOWER TO LOW MVFR/IFR LEVELS THIS EVENING.
MIXED PCPN CONTINUES TO IMPACT KGFL WITH FREEZING RAIN THE
PREDOMINANT PTYPE. SPOTTY FREEZING DRIZZLE AND RAIN CONTINUES
SOUTH AND EAST OF KALB. THE PCPN WILL TEND TO BE FREEZING RAIN
FROM KALB-KPSF SOUTH AND EAST PRIOR TO 05Z/MIDNIGHT BASED ON THE
NAM THERMAL PROFILES. SOME PELLETS MAY BRIEFLY MIX IN AT KPSF EARLY ON.
SFC TEMPS SHOULD WARM UP ABOVE 32F IN THE EARLY MORNING FOR RAIN
THE PREDOMINANT PTYPE. HOWEVER…CIGS AND VSBYS WILL BE IN THE IFR
RANGE. KGFL WILL LINGER WITH THE -FZRA UNTIL AT LEAST 07Z…BEFORE
A TRANSITION TO PLAIN RAIN. WIDESPREAD IFR CONDITIONS ARE EXPECTED
UNTIL THE LATE MORNING 14Z-15Z/MON…BEFORE INCREASING TO MVFR
LEVELS. THE ONE EXCEPTION WOULD BE KGFL…WHERE IFR CONDITIONS
WILL PERSIST UNTIL THE EARLY PM. MELTING SNOW WILL ALSO BE AN
ISSUE FOR THE PERSISTENT LOWER VSBYS.

THE COLD FRONT WILL PASS IN THE 17Z-19Z/MON TIME FRAME. CIGS AND
VSBYS SHOULD QUICKLY INCREASE TO HIGH MVFR/VFR LEVELS WITH THE
FRONTAL PASSAGE AND DEEPER MIXING.

LLWS WILL BE A PROBLEM AT ALL THE TAF SITES THIS EVENING WITH THE
WINDS AT THE 2 KFT AGL LAYER INCREASING TO 40-50 KTS…AND THE SFC
WINDS WILL BE LIGHT FROM THE NE TO S/SE AT 5-10 KTS. THE LLWS WAS
STARTED AT 02Z/MON…AND CONTINUED UNTIL 14-15Z/MON. THE SFC WINDS
WILL VEER TO THE SOUTHWEST TO WEST WITH THE FRONTAL PASSAGE IN THE
LATE MORNING/EARLY PM AT 12-17 KTS WITH SOME GUSTS AROUND 25 KTS
AT KALB AND KPSF.

OUTLOOK…
MONDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
TUESDAY: MODERATE OPERATIONAL IMPACT. WINDY. NO SIG WX.
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
WEDNESDAY TO WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SN.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SN.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.

&&

.HYDROLOGY…
NO WIDESPREAD HYDROLOGIC PROBLEMS ARE EXPECTED OVER THE NEXT FIVE
DAYS.

A STORM WILL ORGANIZE IN THE TENNESSEE VALLEY LATE TODAY AND
TRACK TO THE SAINT LAWRENCE VALLEY MONDAY…BRINGING RAIN AND A
WINTRY MIX OF PRECIPITATION. BEHIND IT ANOTHER FRIGID SURGE OF
ARCTIC AIR WILL MOVE INTO OUR REGION AND LAST THROUGH MID WEEK.
WHILE THERE EXISTS SOME UNCERTAINTY OF TIMING AND PTYPE…EXPECT
ONLY MINOR IMPACTS ON THE RIVERS…EVEN IN AREAS WHERE MOSTLY RAIN
FALLS. THE SNOW COVER SHOULD BE ABLE TO ABSORB MUCH OF THE
RAINFALL…AND TEMPERATURES IN THESE AREAS WILL BE ABOVE FREEZING
FOR LESS THAN 24 HOURS. DURING THE MID WEEK PERIOD ICE ON THE
RIVERS WILL BECOME THICKER AS ANOTHER COLD AIRMASS SETTLES OVER
OUR REGION.

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…FREEZING RAIN ADVISORY UNTIL 10 PM EST THIS EVENING FOR CTZ001-
013.
NY…FREEZING RAIN ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ063>066.
WIND CHILL WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY
AFTERNOON FOR NYZ032-033-038>040-042-047-048-051-058-063-
082.
WINTER WEATHER ADVISORY UNTIL 6 AM EST MONDAY FOR NYZ032-033-
038>043-047>054-058>061-082>084.
LAKE EFFECT SNOW WARNING FROM 6 PM MONDAY TO 1 PM EST
WEDNESDAY FOR NYZ032-033.
MA…WINTER WEATHER ADVISORY UNTIL 6 AM EST MONDAY FOR MAZ001-025.
VT…WINTER WEATHER ADVISORY UNTIL 6 AM EST MONDAY FOR VTZ013>015.

&&

$$
SYNOPSIS…11/WASULA
NEAR TERM…11/WASULA
SHORT TERM…11
LONG TERM…WASULA
AVIATION…WASULA
HYDROLOGY…11

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