January 6, 2014 Forecast Discussion

000
FXUS61 KALY 061020
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
522 AM EST MON JAN 6 2014

.SYNOPSIS…
LOW PRESSURE WILL DEEPEN AS IT TRACKS NORTHEASTWARD FROM THE EASTERN
GREAT LAKES INTO SOUTHEAST CANADA. THE LOW WILL DRAG AN ARCTIC COLD
FRONT ACROSS THE REGION TODAY. A BITTERLY COLD ARCTIC AIR MASS WILL
SETTLE IN REGION TONIGHT…AND LAST THROUGH THE MIDDLE OF THE WEEK.
THERE WILL BE CONSIDERABLE LAKE EFFECT SNOW DOWNWIND OF LAKE ONTARIO
OVER THE WESTERN ADIRONDACKS AS WELL.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/…
AS OF 430 AM EST…THERE CONTINUES TO BE A WIDE RANGE IN
TEMPERATURES EARLY THIS MORNING…ALTHOUGH MOST OF THE AREA HAS
FINALLY WARMED TO ABOVE FREEZING. SURFACE TEMPERATURES STILL
TEDIOUSLY RISING AND REMAINING CLOSE TO FREEZING FOR A LIMITED AREA
INCLUDING PORTIONS OF SARATOGA…WARREN…WASHINGTON AND EASTERN
WINDHAM COUNTY. ALL OTHER ARES HAVE SEEN TEMPERATURES SURGE INTO THE
UPPER 30S TO LOWER 50S AHEAD OF A COLD FRONT APPROACHING FROM THE
OHIO VALLEY. WILL CONTINUE WINTER WEATHER ADVISORY FOR THIS LIMITED
AREA UNTIL 6 AM…BUT CANCELLED THE ADVISORY FOR OTHER AREAS THAT
ARE WELL ABOVE FREEZING.

A BREAK IN THE STEADY PRECIP WILL OCCUR FOR A FEW MORE HOURS BEFORE
ANOTHER SOLID BATCH OF RAIN MOVES IN FROM THE WEST AHEAD OF AND
ALONG THE COLD FRONT. SO WILL CONTINUE TO MENTION CATEGORICAL POPS
THIS MORNING…THEN TAPER OFF DURING THE AFTERNOON. LAKE EFFECT SNOW
SHOULD ACTUALLY DEVELOP FAIRLY QUICKLY LATER THIS AFTERNOON ONCE
WINDS SHIFT TO THE WEST AND ALIGN. THE LAKE EFFECT SNOW WARNING FOR
THE WESTERN ADIRONDACKS BEGINS AT 6 PM.

TEMPERATURES WILL SPIKE INTO THE UPPER 30S TO LOWER 50S THIS MORNING
AHEAD OF THE COLD FRONT…THEN DROP SIGNIFICANTLY INTO THE TEENS AND
20S BY LATE IN THE DAY BEHIND THE FRONT. ANY WET UNTREATED SURFACES
WILL LIKELY BECOME ICY ONCE THE COLDER AIR SURGES IN LATER TODAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/…
THE MAIN STORIES DURING THIS TIME PERIOD WILL BE BITTERLY COLD AIR
AND LAKE EFFECT SNOW. A DEEP TROUGH WILL SETTLE IN ACROSS THE GREAT
LAKES AND NORTHEAST STARTING TONIGHT…AND LINGERING THROUGH
WEDNESDAY. THE SURFACE PRESSURE FIELD WILL BE QUASI-STATIONARY WITH
DEEP LOW PRESSURE REMAINING WELL NORTH INTO QUEBEC AND HIGH PRESSURE
BUILDING ACROSS THE SOUTHEAST CONUS. THIS WILL SET UP A WELL-ALIGNED
PERSISTENT WESTERLY FLOW REGIME IN THE ARCTIC AIR MASS THAT WILL
RESULT IN WINDY CONDITIONS AND A LONG-DURATION LAKE EFFECT SNOW
EVENT FOR THE WESTERN ADIRONDACKS.

THE COLDEST TEMPERATURES ALOFT WILL FILTER IN LATE TONIGHT THROUGH
TUESDAY. 850 MB TEMPS ARE FORECAST AT THEIR COLDEST TO BE AROUND
-23C TO -27C. THIS WILL BE AN ADVECTIVE COLD…WITH A WESTERLY
PERSISTING THROUGH THE COLD STRETCH. LEANED TOWARDS COLDER MET/EC
MOS FOR SURFACE TEMPERATURES…AS MAV NUMBERS LOOKED TOO WARM GIVEN
THIS AIR MASS. BY TUESDAY MORNING TEMPS ARE EXPECTED TO DROP INTO
THE SINGLE DIGITS TO SOME BELOW ZERO READINGS WEST OF THE CAPITAL
REGION. WITH THE COLDEST CORE ALOFT OVER US DURING THE DAY TUESDAY
TEMPERATURES WILL NOT RISE MUCH WITH HIGHS AROUND ZERO TO 10 ABOVE.

HOWEVER…WIND CHILLS WILL BE MUCH COLDER IN THE -10 TO -30 RANGE.
THE WORST WIND CHILL VALUES LOOK TO BE FOR AREAS WEST OF THE CAPITAL
REGION WHERE HEADLINES HAVE BEEN ISSUED…WIND CHILL ADVISORIES FROM
SCHOHARIE COUNTY NORTHWARD THROUGH THE MOHAWK VALLEY AND
WESTERN/SOUTHERN ADIRONDACKS…WITH WIND CHILL WARNINGS FOR THE
EASTERN CATSKILLS MAINLY DUE TO SLIGHTLY LOWER CRITERIA BUT
GENERALLY SAME VALUES AS THE ADIRONDACKS. WILL CONTINUE THESE
HEADLINES INTO WEDNESDAY MORNING. FOR THE REST OF THE AREA OUTSIDE
THE WIND CHILL HEADLINES…WILL CONTINUE TO MONITOR TRENDS BUT AT
THIS TIME WIND CHILL ADVISORY CRITERIA IS NOT FORECAST. WILL MENTION
POSSIBLE EXPANSION OF WIND CHILL HEADLINES IN THE HWO.

WITH REGARDS TO THE HEAVY LAKE EFFECT SNOW…THE MAIN AREA OF
CONCERN SHOULD BE RATHER LIMITED COVERAGE OF NORTHERN HERKIMER AND
PORTIONS OF HAMILTON COUNTY…ESPECIALLY NORTHWESTERN HAMILTON
COUNTY ALONG AND NORTH OF ROUTE 28. THIS WILL BE A LONG-DURATION
EVENT DUE TO THE FLOW TRAJECTORY REMAINING BETWEEN 260-265 DEGREES
FROM TONIGHT INTO WEDNESDAY. LAKE-INDUCED INSTABILITY WILL BE IN THE
EXTREME TO MODERATE CATEGORY…WITH CAPPING INVERSION HEIGHTS OF
GENERALLY 3 KM UNTIL LATE TUESDAY NIGHT INTO WEDNESDAY WHEN HEIGHTS
LOWER TO AROUND 1-2 KM. WIND SHEAR SHOULD BE RATHER MINIMAL THROUGH
THE MIXED LAYER IN THE WELL-ALIGNED WESTERLY FLOW. THE LOCAL INLAND
EXTENT TOOL FROM CSTAR RESEARCH INDICATED SIGNIFICANT SNOW BANDS
WILL EASILY BE ABLE TO EXTEND THROUGH NORTHERN HERKIMER AND INTO AT
LEAST THE NORTHWEST PORTION OF HAMILTON COUNTY WITH VERY HEAVY
SNOWFALL AND BLOWING SNOW. THE HIGHEST SNOWFALL TOTALS EXPECTED TO
BE AROUND 1 TO 2+ FEET ESPECIALLY IN NORTHERN HERKIMER COUNTY. LAKE
SNOWS SHOULD PERSIST INTO WEDNESDAY BEFORE WEAKENING AS INVERSION
HEIGHTS LOWER SUBSTANTIALLY.

OUTSIDE OF LAKE EFFECT THERE WILL BE MINIMAL SNOW SHOWER ACTIVITY.
BEST CHANCE FOR SOME MINOR ACCUMULATIONS WILL BE OVER THE HIGHER
TERRAIN OF THE TACONICS…BERKSHIRES AND SOUTHERN GREEN MOUNTAINS
WHERE SOME UPSLOPE SNOW SHOWERS ARE EXPECTED. ELSEWHERE MAINLY JUST
A FEW FLURRIES TO DEAL WITH ALONG WITH THE BITTER COLD.

&&

.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.

THE LAKE EFFECT EVENT SHOULD END BY WEDNESDAY EVENING WITH HIGH
PRESSURE IN CONTROL WEDNESDAY NIGHT INTO EARLY THURSDAY. DRY WEATHER
IS FORECAST WITH LOWS WEDNESDAY NIGHT GENERALLY BETWEEN ZERO AND 10
ABOVE.

FOR THURSDAY AFTERNOON INTO FRIDAY…WHAT APPEARS TO BE A WEAK WARM
FRONTAL BAND OF MOISTURE WILL AFFECT THE REGION. PCPN AMOUNTS ARE
VERY LIGHT AND TIMING DIFFERENCES EXIST BETWEEN THE GFS AND ECMWF.
THE GFS BRING THE MOISTURE IN THURSDAY AFTN AND HAS IT EXITING THE
REGION BY FRIDAY MORNING. THE ECMWF BRINGS IT IN LATE THURSDAY NIGHT
AND LINGERS IT OVER THE REGION THROUGH FRIDAY. HAVE FORECAST POPS TO
INCREASE TO ONLY SLIGHT CHANCE THURSDAY AFTN…THEN 30 TO 50 PERCENT
POPS THURSDAY NIGHT AND FRIDAY. TEMPS LOOK COLD ENOUGH FOR SNOW AS
THE PCPN TYPE THURSDAY AFTN AND NIGHT…BUT SHOULD WARM UP ENOUGH ON
FRIDAY FOR ANY PCPN TO MIX WITH OR CHANGE TO RAIN OVER SOUTHERN AND
SOUTHEAST PORTIONS OF THE FORECAST AREA. HIGHS THURSDAY WILL BE IN
THE 20S TO LOWER 30S. LOWS THURSDAY NIGHT IN THE TEENS TO LOWER 20S.
HIGHS FRIDAY IN THE 30S.

A BRIEF PERIOD IN BETWEEN PCPN EVENTS FRIDAY NIGHT WITH ONLY 20
PERCENT POPS FORECAST. LOWS WILL BE IN THE 20S.

A MORE SIGNIFICANT FLOW OF MOISTURE INTO THE REGION WILL OCCUR
SATURDAY AND SATURDAY NIGHT AHEAD OF A FRONTAL BOUNDARY THAT WILL BE
PUSHING TOWARDS THE REGION FROM THE MIDWEST. HAVE FORECAST 30 TO 40
PERCENT POPS DURING THIS PERIOD. HIGHS SATURDAY WILL BE IN THE UPPER
30S TO MID 40S. LOWS SATURDAY NIGHT IN THE LOW OR MID 30S. THE
FORECAST TEMPS AND MODELS SUGGEST MAINLY RAIN ACROSS THE REGION WITH
THIS EVENT.

ONLY SLIGHT CHANCE POPS FORECAST FOR SUNDAY AS HIGH PRESSURE TRIES
TO BUILD IN. HIGHS WILL ONCE AGAIN BE IN THE UPPER 30S TO MID 40S.

&&

.AVIATION /10Z 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 ASSOCIATED
WITH THE SYSTEM WILL SWEEP ACROSS THE KALB/KGFL/KPOU/KPSF TAF SITES
BETWEEN 15Z AND 16Z.

AHEAD OF THE COLD FRONT EXPECT WIDESPREAD IFR/LIFR CIGS/VSBYS AT ALL
THE TAF SITES…WITH ONLY OCCASIONAL IMPROVEMENTS TO MVFR
CONDITIONS. AS OF 06Z…PCPN WAS NOW RAIN AT KALB/KPOU/KPSF…WITH
FZRA CONTINUING AT KGFL. EXPECT THE -FZRA AT KGFL TO LINGER UNTIL
AROUND 09Z…THEN BECOME RAIN THERE AS WELL. AFTER THE COLD FRONT
MOVES…RAIN WILL BECOME MORE SHOWERY AT THE TAF SITES…BUT MAINLY
MVFR CONDITIONS WILL PREVAIL UNTIL 18Z/19Z…AT WHICH TIME
CONDITIONS WILL IMPROVE TO MAINLY VFR AND REMAIN THAT WAY THROUGH
THE END OF THE TAF PERIOD (06Z TUESDAY).

BEFORE THE COLD FRONT PASSES…EXPECT MAINLY SOUTH TO SOUTHEAST
WINDS AT THE TAF SITES AT 5 TO 10 KTS. AT KPSF THE SOUTHEAST WINDS
WILL OCCASIONAL GUSTS TO 20 TO 25 KTS. AFTER THE FRONT THE WINDS
WILL SHIFT TO SOUTHWEST AT 10 TO 14 KTS WITH GUSTS OF 20 KTS OR
MORE..THEN SHIFT TO WESTERLY AFTER 18Z/19Z BEHIND A SECONDARY
BOUNDARY WITH SPEEDS INCREASING 12 TO 16 KTS WITH GUSTS OF 20 TO 30
KTS.

LLWS WILL BE A PROBLEM AT ALL THE TAF SITES UNTIL THE COLD FRONT
MOVES THROUGH…WITH THE WINDS AT THE 2 KFT AGL LAYER AT 40-50
KTS…AND THE SFC WINDS GENERALLY IN THE 5 TO 10 KT RANGE.

OUTLOOK…
LATE 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.

RAINFALL WILL CONTINUE THIS MORNING INTO EARLY AFTERNOON AHEAD OF AN
ARCTIC COLD FRONT THAT WILL MOVE ACROSS THE REGION. BEHIND THIS
FRONT…ANOTHER FRIGID SURGE OF ARCTIC AIR WILL ENVELOPE THE REGION
AND LAST THROUGH MID WEEK. WITH BASIN AVERAGE RAINFALL AMOUNTS OF
AROUND ONE HALF TO THREE QUARTERS OF AN INCH…EXPECTING SOME MINOR
RISES ON AREA RIVERS…BEFORE RAIN ENDS THIS AFTERNOON AND COLDER
AIR FILTERS IN.

THE SNOW COVER SHOULD BE ABLE TO ABSORB MUCH OF THE RAINFALL…AND
TEMPERATURES IN THESE AREAS WILL BE ABOVE FREEZING FOR ONLY A SHORT
TIME UNTIL LATER TODAY. DURING THE MID WEEK PERIOD ICE ON THE RIVERS
WILL BECOME THICKER.

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…WIND CHILL WARNING FROM MIDNIGHT TONIGHT TO 10 AM EST
WEDNESDAY FOR NYZ058-063.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST
WEDNESDAY FOR NYZ032-033-038>040-042-047-048-051-082.
WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
NYZ041>043-050-083-084.
LAKE EFFECT SNOW WARNING FROM 6 PM THIS EVENING TO 1 PM EST
WEDNESDAY FOR NYZ032-033.
MA…NONE.
VT…WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
VTZ015.

&&

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

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