March 32, 2013 Forecast Discussion 1

000
FXUS61 KALY 020538
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1238 AM EST SAT MAR 2 2013

.SYNOPSIS…
A SLOW MOVING UPPER LEVEL LOW WILL BE OVER THE REGION OR
IN THE VICINITY THROUGH THE WEEKEND…RESULTING IN CLOUDS AND
SCATTERED SNOW AND RAIN SHOWERS.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/…
AS OF 1230 AM EST…A MOIST CYCLONIC FLOW CONTINUES TO BRING
MOSTLY CLOUDY/OVERCAST SKIES ACROSS THE REGION…ALONG WITH SOME
SCATTERED SNOW SHOWERS AND FLURRIES. TEMPS ARE FALLING VERY
SLOWLY…GENERALLY THROUGH THE LOWER TO MID 30S IN VALLEYS…AND
MID/UPPER 20S ACROSS HIGHER ELEVATIONS E OF THE HUDSON RIVER…AND
LOWER 20S TO THE WEST.

IT STILL APPEARS THAT THE BEST CHANCE FOR MORE PRONOUNCED SNOW
SHOWER ACTIVITY THROUGH DAYBREAK WILL BE TO THE WEST OF THE HUDSON
RIVER…DOWNWIND FROM LAKE ONTARIO…WITH LOWEST CHANCES ACROSS
THE MID HUDSON VALLEY INTO NORTHWESTERN CONNECTICUT. UP TO AN INCH
OF SNOW IS POSSIBLE ACROSS THE WESTERN MOHAWK VALLEY AND WESTERN
ADIRONDACKS…WITH LITTLE TO NO SNOW ACCUMULATION ELSEWHERE.

MIN TEMPS SHOULD FALL ANOTHER 3-5 DEGREES FROM CURRENT
LEVELS…WITH UPPER 20S EXPECTED BY DAYBREAK IN MOST VALLEY
AREAS…AND 20-25 ACROSS HIGHER ELEVATIONS…ALTHOUGH PERHAPS A
BIT COLDER ACROSS HIGHEST ELEVATIONS OF THE WESTERN ADIRONDACKS…AND
EASTERN CATSKILLS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/…
WILL HAVE A DEEP LONGWAVE TROUGH OVER THE EASTERN UNITED STATES.
SHORT WAVE ENERGY WILL CONTINUE TO MOVE THROUGH THE TROUGH DIGGING
IT ALL THE WAY INTO THE GULF OF MEXICO AND FLORIDA. THE TROUGH AXIS
IS FORECAST TO SHIFT EASTWARD AND OFFSHORE ON SUNDAY…HOWEVER MORE
ENERGY WILL DIVE OUT OF CENTRAL CANADA MAINTAINING THE TROUGH OVER
THE REGION…SO NO HEIGHT RISES AND A CONTINUED THREAT OF SHOWERS.
THE STACKED LOW PRESSURE SYSTEM WILL REMAIN OVER/IN THE VICINITY OF
THE REGION DOMINATING OUR WEATHER. WE ARE LOOKING AT LOTS OF CLOUDS
AND THE CONTINUING THREAT OF SCATTERED SHOWERS WITH MAINLY SNOW
SHOWERS ACROSS THE HIGHER TERRAIN WITH RAIN AND SNOW DURING THE DAY
IN THE VALLEYS.

TEMPERATURES GUIDANCE IS IN FAIRLY GOOD AGREEMENT AND NEAR
CLIMATOLOGY HOWEVER WITH EXTENSIVE CLOUDS COVER HAVE GONE A BIT
COLDER THAN GUIDANCE.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/…
CONFIDENCE IN THE EXTENDED PERIOD FORECAST IS RATHER LOW AT THIS
TIME…AS THE TIMING/PLACEMENT OF SEVERAL FEATURES WILL HAVE A BIG
IMPACT ON THE SENSIBLE WEATHER ACROSS THE REGION DURING THIS TIME.

AT THE START OF THE PERIOD…AN UPPER LEVEL LOW WILL FINALLY BE
MOVING AWAY FROM THE REGION…ALLOWING FOR SOME WEAK RIDGING TO
BUILD INTO THE AREA. TEMPS FOR MONDAY NIGHT INTO TUESDAY LOOK TO
AVERAGE CLOSE TO SEASONAL NORMALS…WITH JUST A SLIGHT CHC FOR SOME
LINGERING RAIN/SNOW SHOWERS…MAINLY ACROSS NORTHERN HIGH TERRAIN
AREAS DUE SOME POSITIVE VORTICITY ADVECTION ON THE BACKSIDE OF THE
DEPARTING UPPER LOW.

THE MID WEEK PERIOD IS RATHER UNCERTAIN…AS BOTH THE DETERMINISTIC
AND ENSEMBLE MODEL GUIDANCE SHOWS A VARIETY OF SOLUTIONS DURING THIS
TIME. A POTENT CUTOFF LOW LOOKS TO BE TRAVELING FROM THE MID SOUTH
TOWARDS THE SOUTHEAST COAST FOR TUESDAY INTO TUESDAY NIGHT. THE BIG
QUESTION IS IF THIS SYSTEM CAN PHASE WITH A NORTHERN STREAM
SHORTWAVE MOVING ACROSS THE GREAT LAKES FOR WEDNESDAY. WHILE THE 12Z
GFS…12Z GGEM… AND A FEW 12Z GEFS MEMBERS SHOWS THIS…THE 12Z
ECMWF AND MANY OF THE 12Z GEFS MEMBERS SHOW A MORE PROGRESSIVE
PATTERN. ANY PHASING WILL ULTIMATELY DEPEND ON HOW QUICKLY THE EARLY
WEEK UPPER LOW DEPARTS…AND HOW STRONG RIDGING DEVELOPS OVER
SOUTHEASTERN CANADA AND THE WESTERN ATLANTIC. EVEN WITH THE PHASED
SYSTEM DEVELOPING…THE TRACK WOULD BE ANOTHER BIG QUESTION
MARK…AS THE BULK OF THE PRECIP COULD REMAIN SOUTH OF THE REGION
ACROSS THE MID ATLANTIC…AS THE STORM COULD TRACK MORE
EAST-NORTHEAST THAN NORTHEAST.

FOR NOW…WILL GO WITH CHC POPS FOR MAINLY SNOW ACROSS OUR AREA
/PERHAPS SOME RAIN MIXING IN VALLEY AREAS DURING THE DIURNALLY
FAVORED TIME PERIODS/ FOR TUESDAY NIGHT THROUGH THURSDAY. WILL GO
WITH DAYTIME TEMPS A LITTLE BELOW NORMAL DUE TO THE POSSIBLE
PRECIP/CLOUDS…WITH 30S FOR MAX TEMPS IN MOST AREAS FOR WED/THURS.

WITH ALL THE UNCERTAINTY…ESP REGARDING THE STORM FORMATION AND
TRACK…WILL NOT MENTION IN THE HWO STATEMENT QUITE YET…BUT WILL
CONTINUE TO MONITOR MODEL TRENDS.

ONCE THIS SYSTEM EXITS…SOME RIDGING LOOKS TO ESTABLISH ITSELF
ALONG THE EASTERN SEABOARD…WITH A RETURN TO DRIER CONDITIONS AND
NORMAL TEMPS FOR FRIDAY.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/…
FOR THE TAF PERIOD ENDING AT 06Z SUNDAY CIGS WILL BE MAINLY MVFR/VFR
WITH A GRADUAL IMPROVEMENT AFTER SUNRISE. THE EXCEPTION WILL BE AT
KPSF WHERE CIGS WILL BE PRIMARILY IFR/MVFR THROUGH SATURDAY MORNING
AND THEN IMPROVING TO VFR SATURDAY AFTERNOON. EXPECT CIGS TO LOWER
AGAIN TO MVFR SATURDAY EVENING AS ANOTHER SHORT WAVE TROUGH PASSES
THROUGH THE REGION. TIMING OF ANY RAIN OR SNOW SHOWERS ACTIVITY WILL
BE DIFFICULT DURING THE TAF PERIOD…SO WILL CONTINUE TO MENTION
VCSH.

WINDS WILL GENERALLY BE NW AND WILL AVERAGE 6 TO 12 KTS.

OUTLOOK…
SUN…VFR/MVFR. CHC -SHSN/-SHRA WITH A SLIGHT CHC AT KPOU.
MON…VFR/MVFR. CHC -SHSN/-SHRA AT KALB/KGFL/KPSF.
TUE…VFR. SLIGHT CHC -SHSN/-SHRA.
WED…VFR/MVFR. CHC -SN/-RA.

&&

.HYDROLOGY…
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED INTO EARLY NEXT WEEK.
PRECIPITATION WILL BE LIGHT AND SCATTERED. MAIN STEM RIVERS
SHOULD GENERALLY RECEDE INTO EARLY NEXT WEEK.

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…NONE.
MA…NONE.
VT…NONE.

&&

$$
SYNOPSIS…IAA
NEAR TERM…KL/FRUGIS/IAA
SHORT TERM…IAA
LONG TERM…FRUGIS
AVIATION…11/FRUGIS
HYDROLOGY…IAA

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