January 9, 2014 Forecast Discussion

000
FXUS61 KALY 091737
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1237 PM EST THU JAN 9 2014

.SYNOPSIS…
HIGH PRESSURE OVER THE REGION TODAY…WILL SLIDE EASTWARD OFF THE
NEW ENGLAND COAST TONIGHT INTO FRIDAY. A RETURN SOUTHERLY FLOW OF
MILD AIR AROUND THE DEPARTING HIGH WILL BRING TEMPERATURES BACK TO
NORMAL ON FRIDAY. THE LEADING EDGE OF MILDER AIR IS EXPECTED TO
RESULT IN SOME VERY LIGHT SNOW OR FLURRIES. THEN…A POWERFUL STORM
SYSTEM WILL MOVE INTO THE UPPER GREAT LAKES…ALLOWING A SOUTHERLY
FLOW OF EVEN MILDER AIR TO REACH THE REGION OVER THE WEEKEND…ALONG
WITH A PERIOD OF POTENTIALLY HEAVY RAIN SATURDAY INTO EARLY SUNDAY
AHEAD OF A COLD FRONT.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/…
AS OF 1230 PM EST…SOME LAKE EFFECT CLOUDS…AND FLURRIES
CONTINUE TO AFFECT AREAS ACROSS THE WESTERN AND CENTRAL MOHAWK
VALLEY…WITH SOME FILAMENTS OF CLOUDS OCCASIONALLY EXTENDING INTO
THE CAPITAL REGION. THIS BAND OF CLOUDS/FLURRIES IS EXPECTED TO
GRADUALLY SHIFT NORTHWARD THIS AFTERNOON…AND CONTRACT FURTHER
WEST.

OTHERWISE…MOSTLY SUNNY SKIES WILL PREVAIL ELSEWHERE. BRISK
WEST/NORTHWEST WINDS HAVE DEVELOPED WITHIN PORTIONS OF THE MOHAWK
VALLEY/CAPITAL REGION/BERKSHIRES…WITH SOME GUSTS OF 15-20 MPH.
THESE BRISK WINDS SHOULD GRADUALLY DIMINISH DURING THE MID TO LATE
AFTERNOON HOURS…AS THE SFC HIGH BUILDS ACROSS.

HAVE BOOSTED AFTERNOON MAX TEMPS A BIT…WITH TEMPS EXPECTED TO
REACH 25-30 IN MOST VALLEY AREAS…WITH EVEN SOME LOWER 30S
POSSIBLE ACROSS PORTIONS OF THE MID HUDSON VALLEY. FOR HIGHER
ELEVATIONS…ESP ACROSS THE SOUTHERN ADIRONDACKS…EXPECT MAINLY
UPPER TEENS TO MID 20S FOR MAX TEMPS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/…
CLOUDS WILL START TO INCREASE BY MID TO LATE EVENING…AS WEAK WARM
ADVECTION/ISENTROPIC LIFT DEVELOPS IN THE RETURN FLOW AROUND THE
DEPARTING HIGH. MIN TEMPERATURES WILL OCCUR DURING THE FIRST HALF OF
THE NIGHT…THEN RISE LATE TONIGHT BEFORE SUNRISE. CHANCES FOR LIGHT
SNOW WILL ALSO INCREASE LATE TONIGHT INTO FRIDAY MORNING…WITH SOME
VERY MINOR ACCUMULATIONS OF A DUSTING TO A FEW TENTHS OF AN INCH
POSSIBLE. WILL LOWER POPS TO SLIGHT CHANCE BY FRIDAY AFTERNOON.
PLENTY OF CLOUDS SHOULD PERSIST…BUT TEMPS MAY ACTUALLY NUDGE ABOVE
FREEZING IN VALLEY LOCATIONS FROM ALBANY SOUTHWARD DURING THE
AFTERNOON.

FRIDAY NIGHT INTO EARLY SATURDAY…A POWERFUL STORM SYSTEM WILL
DEVELOP OVER THE MIDWEST AND DEEPEN RAPIDLY AS IT TRACKS INTO THE
UPPER GREAT LAKES REGION. AHEAD OF THIS SYSTEM…SOUTHERLY FLOW WILL
STRENGTHEN CONSIDERABLY ALLOWING FOR SIGNIFICANT WARMING ALOFT OVER
OUR REGION. THIS COULD RESULT IN SOME LIGHT FROZEN PRECIP TO IMPACT
PORTIONS OF THE AREA LATE FRIDAY NIGHT INTO SATURDAY MORNING…AS
SURFACE TEMPS REMAIN COOL DUE TO AN INVERSION. FORTUNATELY QPF LOOKS
TO BE LOW DURING THIS TIME…BUT STILL SOME FREEZING RAIN WILL BE
POSSIBLE AND COULD CAUSE SOME HAZARDOUS TRAVEL. AREAS MOST PRONE TO
PERHAPS SEVERAL HOURS OF LIGHT FREEZING RAIN WILL BE MAINLY NORTH OF
THE CAPITAL REGION…ESPECIALLY IN TYPICALLY SHELTERED VALLEY
LOCATIONS SUCH AS THE UPPER HUDSON VALLEY IN NY AND THE CT RIVER
VALLEY IN SOUTHERN VERMONT. WILL CONTINUE TO MENTION THE POTENTIAL
FOR SOME FREEZING RAIN IN HWO.

TEMPERATURES SHOULD WARM INTO THE 40S AND EVEN SOME 50S BY SATURDAY
AFTERNOON…AS THE STRONG LOW TRACKS INTO SOUTHEAST CANADA AND
SOUTHERLY WINDS CONTINUE TO STRENGTHEN WITH V-COMPONENT REACHING +3
TO +4 STDEV OVER OUR AREA. THIS SHOULD SCOUR OUT ANY COLD AIR AT THE
SURFACE ENDING THE FREEZING RAIN THREAT. HOWEVER…STRONG MOISTURE
FLUX CONVERGENCE AHEAD OF AND ALONG A COLD FRONT ATTACHED TO THE
CANADIAN LOW…WILL ALLOW FOR A PERIOD OF MODERATE TO POTENTIALLY
HEAVY RAINFALL MAINLY FROM SATURDAY AFTERNOON INTO SATURDAY EVENING.
PWATS ARE FORECAST TO REACH +2 TO +4 STDEV FROM THE GEFS. THERE ARE
SOME MINOR TIMING DIFFERENCES BETWEEN VARIOUS SOURCES OF MODEL
GUIDANCE…BUT GENERALLY AGREE THE BULK OF THE RAIN WILL FALL WITHIN
THE TIME RANGE MENTIONED. QPF COULD BE SUBSTANTIAL…AND ENHANCED BY
SOUTHERLY UPSLOPE FLOW IN FAVORED AREAS. 1-2+ INCHES IS
EXPECTED…WHICH COMBINED WITH SNOW MELT AND POTENTIAL ICE JAMS
COULD LEAD TO SOME FLOODING. WILL CONTINUE TO HIGHLIGHT THIS
POTENTIAL IN THE HWO.

RAIN WILL TAPER OFF TO SHOWERS LATE SATURDAY NIGHT BEHIND THE COLD
FRONT…WITH TEMPERATURES TURNING COLD ENOUGH FOR SOME SNOW SHOWERS
OVER THE WESTERN/SOUTHERN ADIRONDACKS.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/…
ABOVE NORMAL TEMPERATURES CONTINUE THROUGH EARLY IN THE WEEK.

THE SYSTEM THAT BROUGHT THE WARM TEMPERATURES AND RAINFALL TO THE
REGION WILL BE HEADING OFF TO OUR EAST SUNDAY WITH THE UPPER TROUGH
AXIS SWINGING THROUGH. THE ECMWF CONTINUES BE DEEPER AND A BIT
SLOWER THAN THE GFS WITH THE UPPER TROUGH. TO ACCOUNT FOR
DIFFERENCES HAVE LINGERED POPS ACROSS THE FORECAST AREA IN THE
MORNING AND MAINLY TO THE NORTH AND WEST OF THE CAPITAL DISTRICT FOR
THE AFTERNOON. IT WILL COLDER IN THE WAKE OF THE SYSTEM BUT STILL
ABOVE NORMAL WITH HIGHS EXPECTED TO BE IN THE UPPER 30S TO UPPER
40S.

RIDGING WILL BEGIN TO BUILD IN AT THE SURFACE SUNDAY AFTERNOON WITH
HEIGHTS RISING SUNDAY NIGHT. SHOULD HAVE A LULL IN THE PRECIPITATION
AS WE HEAD INTO THE NEW WORK WEEK. BY MONDAY BROAD SOUTHWESTERLY
FLOW WILL DEVELOP ACROSS THE EASTERN UNITED STATES BETWEEN THE
DEPARTING RIDGE AND ADVANCING TROUGH. HENCE THE MILD TEMPERATURES
CONTINUE.

THE MODEL GUIDANCE CONTINUES TO SHOW A LARGE SPREAD DEALING WITH THE
APPROACHING TROUGH AS THEY DEAL WITH INDIVIDUAL SHORT WAVES AND
THEIR INFLUENCE ON THE AMPLITUDE OF THE PATTERN AND TIMING AND
STRENGTHEN OF ASSOCIATED SYSTEMS. HAVE FAVORED GUIDANCE FROM THE
WEATHER PREDICTION CENTER WHICH WAS PRIMARILY DERIVED FROM THE ECMWF
ENSEMBLE MEAN FOR THIS TIME PERIOD. THE ECMWF SPINS UP A SURFACE LOW
OVER THE SOUTHEASTERN UNITES STATES AND BRINGS IT NORTHWARD UP THE
COAST DRAWING IT TOWARD AN UPPER LOW THAT FORMS THE GREAT LAKES
REGION. THE GFS IS MORE IS NOT AS AMPLIFIED AND DOES DEVELOP A
SECONDARY LOW. TO ACCOUNT FOR THE APPROACHING LOW PRESSURE SYSTEM
FROM THE GREAT LAKES REGION AND THREAT OF SECONDARY LOW HAVE CHANCE
POPS ACROSS THE FORECAST AREA FOR TUESDAY THROUGH WEDNESDAY.
P-TYPES…RAIN VERSUS SNOW SHOWERS…WILL BE DEPENDENT ON THE
BOUNDARY LAYER TEMPERATURES. A COLDER AND MORE SEASONABLE AIRMASS
SHOULD BE USHERED INTO THE REGION IN THE WAKE OF THIS SYSTEM.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/…
VFR CONDITIONS WILL PREVAIL THROUGH TONIGHT…BEFORE MVFR CONDITIONS
ACCOMPANYING A WEAK UPPER-LEVEL DISTURBANCE AND ASSOCIATED SNOW
SHOWERS MOVE ACROSS THE REGION EARLY FRIDAY.

THIS AFTERNOON…OTHER THAN SOME LAKE-EFFECT CLOUDS OFF LAKE ONTARIO
PRODUCING OCCASIONAL SCATTERED STRATOCUMULUS…THE TAF SITES WILL
SEE PRIMARILY SUNNY SKIES THIS AFTERNOON. WINDS WILL BE OUT OF THE
NORTHWEST GENERALLY 5-10 KNOTS…EXCEPT AT KPSF WHERE OCCASIONAL
GUSTS MAY REACH UP TO 20 KNOTS AT TIMES.

TONIGHT INTO FRIDAY…HIGH-LEVEL CLOUDS AHEAD OF AN APPROACHING WEAK
UPPER-LEVEL DISTURBANCE WILL SPREAD ACROSS THE TAF SITES FROM
SOUTHWEST TO NORTHEAST THROUGH THE NIGHT. THESE CLOUDS WILL
GRADUALLY LOWER THROUGHOUT THE NIGHT AS WELL BEFORE LIGHT SNOW
SHOWERS BEGIN IMPACTING THE TAF SITES AFTER 09Z. ACCUMULATIONS WILL
BE LIGHT…RANGING FROM A DUSTING TO UP TO A FEW TENTHS OF AN INCH.

WINDS TONIGHT WILL BE LIGHT AND VARIABLE GENERALLY LESS THAN 5 KNOTS
BEFORE BECOMING SOUTHERLY FRIDAY BETWEEN 5-10 KNOTS.

OUTLOOK…
FRI NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF
RA…SN…FZRA…SLEET.
SAT-SAT NIGHT: HIGH OPERATIONAL IMPACT. BREEZY. RA.
SUN: MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF SHRA.
SUN NIGHT-MON: NO OPERATIONAL IMPACT. NO SIG WX.

&&

.HYDROLOGY…
CONTINUED COLD TEMPERATURES WILL ALLOW FOR RIVER ICE TO THICKEN
THROUGH TONIGHT. TEMPERATURES ARE EXPECTED TO FINALLY MODERATE TO
NORMAL ON FRIDAY…AND WELL ABOVE NORMAL INTO THE WEEKEND.

AN ICE JAM REMAINS IN PLACE ON WAPPINGERS CREEK.

THE NEXT CHANCE OF WIDESPREAD PRECIPITATION WILL BE OVER THE
WEEKEND…STARTING SATURDAY MORNING…THROUGH EARLY SUNDAY
MORNING…WITH THE BULK OF IT EXPECTED TO FALL AS RAIN. THERE
COULD BE SOME SIGNIFICANT RAINFALL AMOUNTS…WITH CURRENT
PROJECTIONS OF 1 TO 1.5 INCHES WITH LOCALLY HIGHER AMOUNTS. THIS
RAINFALL…AND MILDER TEMPERATURES…SHOULD AT LEAST RESULT IN
RISING RIVER LEVELS AND PERHAPS SOME FLOODING. ICE JAM MOVEMENT MAY
FURTHER EXACERBATE HYDROLOGIC ISSUES AS WELL.

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…KL/JPV
NEAR TERM…KL/BGM/JPV
SHORT TERM…JPV
LONG TERM…IAA
AVIATION…IRL/IAA
HYDROLOGY…KL/JPV

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