January 29, 2013 Post Storm Forecast Discussion

000
FXUS61 KALY 291153
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
653 AM EST TUE JAN 29 2013

.SYNOPSIS…
A WARM FRONT APPROACHING FROM THE SOUTHWEST WILL BECOME NEARLY
STATIONARY ACROSS THE AREA TODAY…THEN LIFT NORTHWARD ON
WEDNESDAY…BRINGING MUCH WARMER TEMPERATURES TO THE REGION. A
STRONG COLD FRONT WILL PASS THROUGH THE AREA WEDNESDAY NIGHT…
ACCOMPANIED BY RAIN SHOWERS…AND FOLLOWED BY MUCH COLDER AND
BLUSTERY CONDITIONS FOR THURSDAY AND FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/…
AS OF 630 AM…KENX RADAR DOES NOT SHOW ANY PCPN…SO THE WINTER
ADVISORY WAS CANCELLED. THE REST OF THE PREVIOUS FORECAST WAS IN
GOOD SHAPE AND HAVE ONLY KEPT AREAS OF FOG INT HE FORECAST FOR A FEW
HOURS THIS MORNING.

.PREVIOUS DISCUSSION…
AS OF 445 AM…TEMPS WERE VERY STUBBORN TO RISE LAST NIGHT…AND
CURRENTLY REMAIN IN THE 20S ACROSS MOST AREAS. ONLY ACROSS PARTS OF
THE EASTERN CATSKILLS…MID HUDSON VALLEY AND LITCHFIELD COUNTY HAVE
TEMPS RISEN TO THE LOWER OR MID 30S. RADAR LOOP SHOWS THE REGION IS
ALMOST ECHO FREE AS OF 500 AM…BUT CHOSE TO KEEP THE WINTER WEATHER
ADVISORY IN EFFECT THROUGH 700 AM FOR NOW SINCE FREEZING DRIZZLE WAS
STILL OCCURRING IN SOME AREAS. WILL REASESS FOR THE 630 AM UPDATE
AND DECIDE WHETHER TO DROP THE ADVISORY AT THAT TIME.

AFTER 7 OR 8 AM…EXPECT DRY CONDITIONS IN TERMS OF PCPN THROUGH AT
LEAST EARLY AFTERNOON. OVERUNNING PCPN ASSOCIATED WITH A WARM FRONT
WILL BEGIN TO SPREAD ACROSS THE FORECAST AREA LATER THIS AFTERNOON
AND THIS EVENING. BY LATE THIS AFTERNOON EXPECT MOST OF THE FORECAST
AREA TO BE ABOVE FREEZING…BUT SOME AREAS FROM THE ADIRONDACKS TO
THE LAKE GEORGE SARATOGA REGION…SOUTHERN VT AND BERKSHIRE COUNTY
COULD COULD STILL BE BELOW FREEZING WHEN THE NEW ROUND OF PCPN
BEGINS. BELIEVE THAT THE COVERAGE OF ANY FREEZING RAIN LATE THIS
AFTN AND EVENING WILL BE MINIMAL AND HAVE NOT ISSUED A FREEZING RAIN
ADVISORY AT THIS TIME. THE FACT THAT A WINTER WEATHER ADVISORY
ALREADY EXISTS FOR THIS MORNING ALSO AFFECTED THAT DECISION SINCE
DOUBLE HEADLINES COULD BE CONFUSING. THE ONLY PLACE WHERE THERE IS A
DECENT CHANCE THAT THE COVERAGE OF ANY FREEZING RAIN WOULD BE ENOUGH
TO WARRANT A FREEZING RAIN ADVISORY WOULD BE WINDHAM COUNTY VT. BUT
PCPN THERE WILL NOT BEGIN UNTIL AFTER SUNSET…SO THERE IS STILL
TIME FOR THE DAYSHIFT TO MONITOR TEMPS TODAY AND ISSUE AN ADVISORY
IF NEEDED.

HIGHS TODAY WILL BE IN THE 30S…WITH TEMPS TONIGHT SLOWLY RISING
THROUGH THE NIGHT. LIKELY REACHING THE MID 30S TO LOWER 40S BY
SUNRISE WEDNESDAY.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY/…
AFTER ANY OVERUNNING PCPN ASSOCIATED WITH THE WARM LIFTS OUT OF THE
REGION EARLY WEDNESDAY MORNING…THERE COULD BE A FEW TO SEVERAL
HOURS OF PCPN FREE WEATHER WEDNESDAY MORNING INTO EARLY AFTN.
HOWEVER…WIDESPREAD RAIN SHOWERS WILL SURGE INTO THE REGION DURING
THE AFTERNOON AND COULD BECOME HEAVY AT TIMES WEDNESDAY EVENING.
PLEASE REFER TO THE HYDROLOGY SECTION CONCERNING THE POTENTIAL FOR
FLOODING WITH THIS EVENT.

BESIDES ANY FLOOD ISSUES…A STRONG LOW LEVEL SOUTHERLY JET IS
FORECAST FOR THIS EVENT WHICH COULD ALSO PRODUCE STRONG WINDS AHEAD
OF AND ALONG THE FRONT LATE WEDNESDAY AND WEDNESDAY EVENING…WHILE
A STRONG PRESSURE GRADIENT AND GOOD MIXING COULD CONTINUE TO PRODUCE
STRONG WIND GUSTS INTO THURSDAY. THE PRIMARY FACTOR THAT MAY LIMIT
THE WINDS AHEAD OF AND ALONG THE FRONT WOULD BE THE LOW LEVEL
INVERSION FORECAST BY THE MODELS WHICH WOULD PREVENT THE STRONG
WINDS ALOFT FROM REACHING THE GROUND. HOWEVER…BEHIND THE FRONT THE
LOW LEVEL INVERSION QUICKLY DISAPPEARS AND STRONG WIND GUSTS COULD
REACH THE SURFACE AT THAT TIME. HAVE CONTINUED TO HIGHLIGHTED THE
THREAT FOR STRONG WINDS IN THE HWOALY PRODUCT.

TEMPS WEDNESDAY WILL RISE INTO THE MID 40S TO MID 50S AND REMAIN
THAT HIGH INTO WEDNESDAY EVENING. AFTER THE FRONT MOVES THROUGH
TEMPS WILL DROP TO THE UPPER 20S AND 30S BY SUNRISE. ONLY THE
ADIRONDACKS MAY GET COLD ENOUGH FAST ENOUGH FOR A CHANGEOVER TO SNOW
THAT MAY PRODUCE UP TO AN INCH OF SNOW. LITTLE OR NO SNOW
ACCUMULATION EXPECTED ELSEWHERE.

STRONG COLD ADVECTION THURSDAY WILL KEEP TEMPS STEADY OR SLOWLY
FALLING. EXPECT LAKE EFFECT SNOW SHOWERS INTO THE WESTERN
ADIRONDACKS…AND ISOLATED TO SCT SNOW SHOWERS ELSEWHERE.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/…
A SECONDARY COLD FRONT WILL PASS SOUTHWARD THROUGH THE AREA THURSDAY
NIGHT…WITH MAINLY SLIGHT CHANCE TO LOW CHANCE POPS FOR SNOW
SHOWERS EXCEPT LIKELY FOR THE WESTERN ADIRONDACKS DUE TO LAKE
EFFECT/UPSLOPE ENHANCEMENT. SOME LIGHT TO MODERATE ACCUMULATIONS ARE
POSSIBLE IN FAVORED AREAS.

FROM FRIDAY THROUGH THE WEEKEND…LAKE EFFECT SNOW WILL BE THE MAIN
CONCERN…BUT LOCATIONS WHERE POTENTIAL SNOW BANDS SET UP ARE NOT
POSSIBLE TO DETERMINE AT THIS TIME. SUBTLE SHIFTS IN WIND FLOW
TRAJECTORY CAN SIGNIFICANTLY ALTER WHICH AREAS SEE THE MORE
PERSISTENT LAKE BANDS. ALSO PERIODIC PASSAGE OF WEAK DISTURBANCES
WILL FURTHER COMPLICATE THE FORECAST…WITH OSCILLATION AND
WEAKENING/STRENGTHENING OF LAKE BANDS. BOTTOM LINE IS THAT THE
PERIOD WILL BE MAINLY DRY FOR MOST OF THE AREA OUTSIDE OF THE
TYPICAL LAKE EFFECT ZONES. SEEMINGLY ETERNAL CHANCE POPS WILL REMAIN
FOR THE MOHAWK VALLEY AND WESTERN ADIRONDACKS THROUGH MUCH OF THE
PERIOD…WITH SLIGHT CHANCE ELSEWHERE. TEMPERATURES LOOK TO BE NEAR
TO SLIGHTLY BELOW NORMAL.

MODELS START TO DIVERGE SIGNIFICANTLY BY THE END OF THE PERIOD FOR
EARLY NEXT WEEK…WITH THE TRACK OF A POTENTIAL CYCLONE TRACKING
THROUGH THE NORTHERN PLAINS AND GREAT LAKES HIGHLY UNCERTAIN AT THIS
TIME. IT DOES APPEAR THAT SOME MODERATION IN TEMPERATURES MAY OCCUR
WITH SIGNALS FOR THIS CYCLONE TRACKING NORTH AND WEST OF THE REGION.
THIS IS HIGHLY SPECULATIVE AT THIS TIME THOUGH.

&&

.AVIATION /06Z TUESDAY THROUGH FRIDAY/…
A FRONTAL BOUNDARY WILL REMAIN DRAPED OVER THE AREA THROUGH TODAY.
THIS FRONT WILL THEN SURGE NORTHWARD THIS EVENING…BRINGING A
PERIOD OF RAIN TO THE TERMINALS.

OCCASIONAL FREEZING DRIZZLE WILL OCCUR FOR THE MAJORITY OF THE
TERMINALS THROUGH THE REST OF THE OVERNIGHT HOURS THROUGH AROUND
SUNRISE. THE ONLY EXCEPTION WILL BE AT KPOU…WHICH IS POSITIONED
JUST SOUTH OF THE FRONT AND SHOULD REMAIN DRY. GENERALLY IFR
CONDITIONS WILL PREVAIL THROUGH 12Z AND POSSIBLY LINGERING WELL INTO
THE MORNING AFTER SUNRISE AT ALL TERMINALS. SOME BRIEF OCCASIONAL
MVFR CONDITIONS WILL BE POSSIBLE…SO HAVE ACCOUNTED FOR THIS WITH
TEMPO GROUPS.

FORECAST SOUNDINGS INDICATING THE LOW LEVELS REMAIN MOIST THIS
AFTERNOON…SO WILL CONTINUE TO MENTION OVC SKIES. CONDITIONS SHOULD
GENERALLY IMPROVE TO MVFR RANGE WITH POCKETS OF IFR. AS RAIN MOVES
BACK IN THIS EVENING…CONDITIONS WILL LIKELY DETERIORATE TO IFR
AGAIN. SURFACE WINDS WILL BE LIGHT AND VARIABLE THROUGH THE NEXT 24
HOURS…BUT WILL BE GRADUALLY STRENGTHENING ALOFT SO LOW LEVEL WIND
SHEAR WILL DEVELOP LATE TONIGHT.

OUTLOOK…
TUE NIGHT…MVFR-IFR. -RA LIKELY. LLWS DEVELOPING LATE.
WED…MVFR/IFR. CHC -SHRA IN THE AM AND LIKELY IN THE PM. WED
NIGHT…MVFR/IFR. RA LIKELY. WINDY.
THU…MAINLY VFR. CHC SUB-VFR -SHRA/-SHSN. WINDY.
FRI…MAINLY VFR. SCHC SUB-VFR -SHSN.

&&

.HYDROLOGY…
NO HYDRO PROBLEMS ARE EXPECTED PRIOR TO WEDNESDAY. ABOVE NORMAL
TEMPERATURES WEDNESDAY WILL LIKELY LEAD TO SNOW MELT BEGINNING.
RUNOFF FROM SNOW MELT COMBINED WITH RAINFALL AHEAD OF A COLD FRONT
COULD CAUSE SOME RIVERS AND STREAMS TO RISE TO NEAR OR OVER
BANKFULL.

TODAY INTO WEDNESDAY…TEMPERATURES WILL START TO RUN WELL ABOVE
NORMAL WITH SNOW MELT AN ISSUE WHERE A SIGNIFICANT SNOW PACK STILL
EXISTS. SNOW MELT WILL BE SLOW THROUGH TONIGHT…BUT WILL
ACCELERATE ON WEDNESDAY AS MUCH WARMER TEMPERATURES AND STRONGER
WINDS ARE EXPECTED. THE SNOW LIQUID EQUIVALENT IN THE VALLEYS IS
LESS THAN AN INCH. THE WESTERN/SOUTHERN ADIRONDACKS…SOUTHERN
GREENS…AND BERKSHIRES…GENERALLY HAVE 2 TO 4 INCHES OF SNOW
LIQUID EQUIVALENT. LESS THAN 2 INCHES EXISTS IN THE EASTERN
CATSKILLS. THESE VALUES ARE BELOW NORMAL FOR LATE JANUARY.

THE AMOUNT OF QPF EXPECTED WITH THE COLD FRONT HAS INCREASED BASED
ON THE LATEST MODEL FORECASTS. AT THIS TIME IT APPEARS ONE TO TWO
INCHES OF RAINFALL IS POSSIBLE. THE COMBINATION OF SNOW MELT…DEEP
FROZEN GROUND…AND POTENTIALLY LOCALLY HEAVY RAINFALL COULD RESULT
IN SOME RIVERS RISING OUT OF THEIR BANKS. IF ANY FLOODING DOES OCCUR
DURING THIS PERIOD…IT WOULD NOT OCCUR BEFORE WEDNESDAY NIGHT…SO
IT IS STILL TOO EARLY TO ISSUE A FLOOD WATCH. HOWEVER…THE THREAT
OF FLOODING HAS BEEN HIGHLIGHTED IN THE HWOALY PRODUCT.

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.

&&

.CLIMATE…
RECORD HIGHS FOR JANUARY 30TH…
ALBANY: 54 DEGREES 1974 (RECORDS DATE BACK TO 1874)
GLENS FALLS: 50 DEGREES 1974 (RECORDS DATE BACK TO 1949)
POUGHKEEPSIE: 60 DEGREES 2006 (RECORDS DATE BACK TO 1949)
BENNINGTON: 60 DEGREES 2006 (RECORDS DATE BACK TO 1998)

&&

.ALY WATCHES/WARNINGS/ADVISORIES…
CT…NONE.
NY…NONE.
MA…NONE.
VT…NONE.

&&

$$
SYNOPSIS…GJM
NEAR TERM…GJM
SHORT TERM…GJM
LONG TERM…JPV
AVIATION…JPV
HYDROLOGY…GJM
CLIMATE…WFO STAFF

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