000
FXUS61 KALY 261147
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
634 AM EST TUE FEB 26 2013
.SYNOPSIS…
HIGH PRESSURE WILL CREST OVER THE REGION TODAY…THEN RETREAT
INTO NORTHERN NEW ENGLAND BY THE EVENING. MEANWHILE…A COMPLEX LOW
PRESSURE SYSTEM WILL BE APPROACHING FROM THE OHIO VALLEY AND MID
ATLANTIC REGION. THIS SYSTEM LOOKS TO BRING SNOW…OR MIXED
PRECIPITATION LATER TONIGHT THROUGH AT LEAST THURSDAY. THE POTENTIAL
IS THERE FOR SIGNIFICANT SNOWFALL ACROSS THE CATSKILLS…SOUTHERN
GREENS AND BERKSHIRES WITH LIGHT TO MODERATE SNOWFALL ACCUMULATIONS
POSSIBLE ACROSS THE REMAINDER OF THE REGION.
&&
.NEAR TERM /THROUGH TODAY/…
AS OF 635 AM…ONLY A FEW MINOR TWEAKS TO THE HOURLY GRIDS TO ADJUST
CLOUDS/TEMPS AND WIND. OTHERWISE…THE CURRENT FORECASTS CARRIES ON.
TEMPERATURES HAVE DIPPED INTO THE 20S MOST PLACES…SOME TEENS
NORTH. WITH SOME SUNSHINE…TEMPERATURES WILL TURN THE CORNER AFTER
SUNRISE AND WARM BACK INTO THE 30S BY NOON.
WE HAVE ISSUED A WINTER STORM WATCH TONIGHT THROUGH EARLY THURSDAY
MORNING FOR OUR EASTERN CATSKILLS…SOUTHERN GREENS AND BERKSHIRES.
HIGH PRESSURE WILL CONTROL OUR WEATHER TODAY. HOWEVER…WE WILL
NOTICE AN INCREASE IN HIGH CLOUDS WELL AHEAD OF A SLOW MOVING STORM
HEADING NORTHEAST FROM SOUTHERN MISSOURI. MORE ABOUT THIS STORM CAN
BE FOUND IN OUR SHORT TERM SECTION.
FOR NOW IT LOOKS LIKE TEMPS WILL TOP OUT IN THE LOWER 40S IN MOST
VALLEY LOCATIONS…WITH 30S IN THE HIGHER TERRAIN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/…
AS OF 630 AM…WE HAVE ISSUED A WINTER STORM WATCH TONIGHT THROUGH
EARLY THURSDAY MORNING FOR OUR EASTERN CATSKILLS…SOUTHERN GREENS
AND BERKSHIRES.
WATER VAPOR LOOP INDICATED A VERY IMPRESSIVE LOOKING STORM OVER
SOUTHERN MISSOURI TRACKING EAST NORTHEAST. EARLIER…THERE WAS
PLENTY OF CONVECTION ASSOCIATED WITH THIS STORM. HOWEVER…LATELY
AN IMPRESSIVE DRY SLOT (MID LEVEL DRYING) WAS EVIDENT…WRAPPING TO
THE EAST AND SOUTH OF THE STORM. THE COLD CLOUDS TOPS WERE HEADING
INTO THE MID ATLANTIC STATES…AND WILL EVENTUALLY HEAD OUR WAY
LATER TODAY.
A QUICK LOOK AT THE 06Z OPERATIONAL NAM AND GFS INDICATED NO REAL
BIG CHANGES IN THE ANTICIPATED EVOLUTION OF THE STORM…QPF AND
TIMING ALTHOUGH IT LOOKED AS IF THE 06Z NAM MIGHT HAVE TRENDED A
LITTLE LOWER ON THE QPF.
THE 00Z MODEL GUIDANCE HAD TRENDED A SHADE COLDER…AT LEAST THROUGH
THE COLUMN. THE EUROPEAN MODEL STILL WAS THE COLDEST BUT EVEN IF WE
BLEND THEM…THERE IS CONCERN THAT SIGNIFICANT SNOW COULD ACCUMULATE
IN THE WATCH AREAS. ALSO…AN ANOMALOUSLY STRONG ESE WIND…REACHING
UP TO 65KTS AT THE H850 LEVEL…AND 40TS AT THE H925…COULD PRODUCE
ENHANCEMENT OF PRECIPITATION AS WELL AS RATHER STRONG GUSTY WINDS.
THE COMBINATION OF THE WIND…SNOW…MIXED WITH SLEET AND PERHAPS A
LITTLE FREEZING RAIN…COULD LEAD TO SCATTERED POWER OUTAGES IN
THESE AREAS.
LOW PRESSURE OVER NORTHERN ARKANSAS HAS ALREADY PRODUCED A LEGACY OF
WINTER WEATHER ACROSS PORTIONS OF THE PLAIN…THE SECOND BLIZZARD IN
ABOUT A WEEK!
THIS LOW WILL TRACK INTO THE OHIO VALLEY TODAY. AS IT ENCOUNTERS
SOMEWHAT COLDER AIR AND STRONG HIGH PRESSURE TO THE NORTHEAST…IT
WILL "SPLIT" INTO TWO PIECES OF ENERGY…ONE WHICH WILL SLOWLY
MEANDER INTO NEW YORK STATE BY THURSDAY. HOWEVER…A SECONDARY LOW
PRESSURE WILL FORM ACROSS INTERIOR VA BY THIS EVENING…THEN TRACK
ALONG OR JUST EAST OF THE I-95 CORRIDOR TONIGHT THROUGH WEDNESDAY.
THIS SECONDARY PIECE OF ENERGY WILL BRING THE FIRST ROUND OF
PRECIPITATION TO THE REGION BEGINNING LATER THIS EVENING. A STRONG
LOW LEVEL JET WILL BRING AN EXCEPTIONALLY STRONG U COMPONENT UP TO 5
STANDARD DEVIATIONS ABOVE NORMAL LATE TONIGHT THROUGH WEDNESDAY.
THIS WILL DRAW PWAT VALUES OF NEARLY AN INCH (TWO STANDARDS ABOVE
NORMAL) TOWARD OUR SOUTHEASTERN ZONES.
STRONG UPWARD MOTION LOOKS TO KEEP THE COLUMN COLD ENOUGH FOR MOSTLY
SNOW ACROSS AT LEAST THE HIGHER ELEVATIONS OF THE
CATSKILLS…SOUTHERN GREENS AND BERKSHIRES. THE DEEP MOISTURE DOES
NOT LOOK TO MAKE IT INTO THE ADIRONDACKS SO WHILE IT WILL BE
SLIGHTLY COLDER THERE…SNOWFALL DOES NOT LOOK TO BE ENOUGH TO
JUSTIFY A WATCH.
NORTH/SOUTH VALLEYS LOOK TO HAVE SOME SORT OF SHADOWING…AS THE ESE
WIND WILL RESULT IN SOME DOWNSLOPING OVERNIGHT INTO WEDNESDAY
MORNING…ALTHOUGH THE FLOW DOES NOT LOOK PERFECTLY ORTHOGONAL TO
THE HIGHER TERRAIN. HOWEVER…WE BELIEVE THERE WILL SOME
MINIMIZATION OF THE QPF IN THESE AREAS. ALSO…THIS DOWNSLOPING
WOULD SERVE TO WARM THE LOWEST LEVELS OF THE COLUMN (NAMELY THE
SURFACE) A BIT.
FOR THESE REASONS…WE DO NOT EXPECT A LOT OF SNOW IN THE VALLEYS
DESPITE THE FACT THE SOUNDINGS INDICATE MOSTLY SNOW COULD FALL EVEN
IN PLACES NORTH OF KINGSTON.
HOWEVER…THE TIMING OF THE SNOW…POTENTIALLY HEAVIEST AS WE HEAD
TOWARD THE MORNING DRIVE ON WEDNESDAY…COULD NEVERTHELESS IMPACT
TRAVEL AT THIS TIME. FOR NOW…NO ADVISORIES WILL BE ISSUED BUT
SOMETHING TO MONITOR.
LATER WEDNESDAY…AS SECONDARY LOW MOVES TO OUR EAST…THERE LOOKS
TO BE A TIME WHERE DRIER AIR INTRUDES THE MID LEVELS OF THE
ATMOSPHERE. THIS DRYING WILL LIKELY NOT BE ENOUGH FOR ANY
CLEARING…BUT MOST IF NOT ALL OF THE CLOUDS COULD LOOSE THEIR ICE
BY AFTERNOON…REDUCING PRECIPITATION TO LIGHT RAIN…DRIZZLE OR IN
THE CASE OF THE MOUNTAINS…A LIGHT WINTRY MIX.
TEMPERATURES ON WEDNESDAY WILL START OUT FROM THE MID 20S HIGHER
TERRAIN TO LOWER 30S MOST OF THE VALLEY LOCATIONS ON WEDNESDAY. THEY
SHOULD SLOWLY RISE TO NEAR 40 IN THE VALLEYS…LOWER TO PERHAPS MID
30S HIGHER TERRAIN.
THEN…BY WEDNESDAY EVENING…AS WHAT IS LEFT OF THE PLAINS
STORM…MAINLY AN UPPER LEVEL FEATURE…WILL NEVERTHELESS INTERACT
WITH SLOWLY DEEPENING LOW PRESSURE PUSHING NEAR CAPE COD AT THIS
POINT EVENTUALLY FORCING IT TO BECOME STACKED. THIS WILL PRODUCE
SOME SORT OF DEFORMATION PRECIPITATION…LIKELY ENHANCED DUE TO
UPSLOPE AGAINST HIGHER TERRAIN. FOR THIS REASON…WE EXTENDED THE
WINTER STORM WATCH AS ANOTHER ROUND OF SEVERAL INCHES OF SNOW COULD
ACCUMULATE ACROSS THE CATSKILLS/SOUTHERN GREENS AND BERKSHIRES. AN
INCH OR TWO COULD CERTAINLY ACCUMULATE IN VALLEY LOCATIONS AS WELL.
TEMPERATURES WEDNESDAY NIGHT LOOK TO BOTTOM OUT AT OR A BIT BELOW
FREEZING.
RIGHT NOW…THE POTENTIAL IS THERE FOR AT LEAST 6-12 INCHES OF SNOW
ACROSS THE WATCH AREA….MIXED WITH A SOME SLEET AND FREEZING RAIN.
AT THIS TIME…THERMAL PROFILES DID NOT INDICATE AN EXTENDED PERIOD
OF FREEZING RAIN…ALTHOUGH IT IS STILL REMOTELY POSSIBLE. THE SNOW
LOOKS TO BE OF THE WET VARIETY…PROBABLY NOT MUCH DRIFTING BUT IT
WILL BE HEAVY. FACTOR THAT WITH PROJECTED WIND GUSTS APPROACHING 40
MPH AT TIMES…COULD BRING SOME TREES AND WIRES DOWN…PERHAPS
LEADING TO SCATTERED POWER OUTAGES.
WIND WILL BE A CONCERN ACROSS ALL OF THE HIGHER TERRAIN…INCLUDING
THE ADIRONDACKS. HOWEVER…RIGHT NOW WE BELIEVE WIND GUSTS SHOULD
FALL SHORT OF WARNING CRITERIA (58 MPH)…PERHAPS REACHING WIND
ADVISORY THRESHOLDS OF GUSTS TO BETWEEN 40 AND 50 MPH. SINCE THAT IS
THE CASE…WE DECIDED TO HOLD OFF ONE MORE PERIOD TO SEE IF
ADVISORIES WILL REALLY BE NEEDED. WILL CONTINUE TO MENTION THIS
POSSIBILITY IN OUR HAZARDOUS WEATHER OUTLOOK.
IN THE VALLEYS AS WELL AS THE ADIRONDACKS…SNOWFALL LOOKS TO RANGE
FROM 2 TO 6 INCHES…HIGHEST NORTH OF ALBANY. THESE VALUES COULD
REACH ADVISORY THRESHOLDS IN SOME CASES…BUT AGAIN…DECIDED NOT
TO HEADLINE ANY ADVISORIES YET.
THURSDAY WE WILL STILL BE DEALING WITH LEFTOVER LIGHTER
PRECIPITATION IN THE FORM OF SNOW CHANGING TO RAIN SHOWERS IN THE
VALLEYS…OR MAINLY MOUNTAIN SNOW AS THE LARGE STACKED STORM SLOWLY
DRIFTS TO THE GULF OF MAINE. AT THIS POINT…ADDITIONAL
PRECIPITATIONS AMOUNTS LOOK FAIRLY LIGHT ON THURSDAY…WITH PERHAPS
ONE
EXCEPTION…SOUTHERN VERMONT WHERE SNOWFALL COULD BECOME MORE
ENHANCED. HIGH TEMPERATURES LOOK TO REACH 40-45 IN THE HUDSON
VALLEY…WHILE HOLDING IN THE LOWER TO UPPER 30S ACROSS THE HIGHER
TERRAIN.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/…
WE BEGIN WITH THE DEPARTURE OF THE UPPER LOW WITH RESIDUAL UPSLOPE
CONDITIONS FOR A LITTLE ADDITIONAL SNOWFALL ACROSS THE HIGHER
TERRAIN THROUGH THURSDAY NIGHT. THIS TOO WILL DIMINISH THROUGH
FRIDAY…SO MARCH SHOULD START LIKE A LAMB WITH NEAR SEASONABLE
TEMPERATURES UNDER A MOCLDY SKY.
CONSENSUS IN THE GLOBAL MODEL DATA AND ENSEMBLE TRENDS CONTINUES TO
FAVOR A DRIER FIRST WEEKEND OF MARCH. QUESTION WILL BE JUST HOW
MUCH CLEARING WILL COMMENCE AS THE GFS/GGEM REMAINS STRONG WITH THE
DRIER SOLUTION WHILE THE ECMWF ATTEMPTS TO WRAP BACK IN SOME
MOISTURE AS THE DEPARTED UPPER LOW RETROGRADES TOWARD NORTHERN NEW
ENGLAND FOR THE END OF THE WEEKEND. FOR NOW…WE WILL KEEP POPS
LOW THROUGH THE WEEKEND AND VARIABLE CLOUDY SKY /IE PTCLDY FOR
VALLEY LOCATIONS AND MOCLDY FOR THE HIGHER TERRAIN/.
THE ECMWF REMAINS PERSISTENT WITH THE WRAP AROUND MOISTURE AS DOES
HPC TO WARRANT MORE CLOUDS AND LOW PROBABILITIES FOR SOME LIGHT
RA/SN SHOWERS.
TEMPERATURES THROUGH THE PERIOD WILL AVERAGE NEAR NORMAL AND
PRECIPITATION NEAR NORMAL.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/…
PESKY STRATUS DECK REMAINS IN PLACE ALTHOUGH RECENT SIGNS IN THE
SATELLITE IMAGERY SUGGESTS SOME IMPROVEMENTS. WE WILL PLACE A TEMPO
GROUP FOR A SCT VFR/MVFR DECK BUT THIS TOO WILL RESULT IN THE
INCREASED POTENTIAL FOR SOME BR/FG. FOR NOW…WE WILL PLACE THIS
VISIBILITY RESTRICTION WITHIN THOSE AFOREMENTIONED TEMPO GROUPS AND
MONITOR TRENDS.
THROUGH THE DAYLIGHT HOURS…CLOUDS WILL BE ON THE INCREASE AS THE
SOUTHERN PLAINS STORM BEGINS ITS TRACK TOWARD THE REGION. IT SEEMS
THE PRECIP POTENTIAL WILL HOLD OFF UNTIL AFTER SUNSET ALONG AND
SOUTH OF I90 HENCE A PROB30 GROUP FOR SN THROUGH THE EVENING HOURS.
OUTLOOK…
TUE NIGHT…MVFR/IFR. RAIN/SNOW DEVELOPING.
WED…MVFR/IFR. SNOW/RAIN…ESPECIALLY IN THE AM…CHANGING TO RA.
WED NIGHT…MVFR/IFR. RAIN/SNOW LIKELY MAINLY IN THE EVENING.
THU-FRI…VFR/MVFR. CHC -SHSN/-SHRA.
SAT…VFR. NO SIG WX EXP AT THIS TIME.
&&
.HYDROLOGY…
DRY CONDITIONS ARE EXPECTED THROUGH TODAY WITH HIGH PRESSURE IN
CONTROL.
A SLOW MOVING STORM SYSTEM WILL POTENTIALLY BRING A HALF TO GREATER
THAN AN INCH OF LIQUID EQUIVALENT QPF WITH SNOW…RAIN AND OR MIXED
PRECIPITATION. THE BEST CHANCE FOR ANY RAIN WILL BE IN VALLEY
LOCATIONS…ESPECIALLY FROM ALBANY SOUTHWARD ON WEDNESDAY.
TEMPERATURES ARE ONLY EXPECTED RISE INTO THE UPPER 30S TO LOWER 40S
FOR HIGHS ON WEDNESDAY…SO EVEN WHERE IT RAINS SNOW MELT AND RUNOFF
WILL NOT BE EXTREME. THERE COULD BE SOME MINOR FLOODING OF POOR
DRAINAGE LOCATIONS…ESPECIALLY WITH FROZEN GROUND. OTHERWISE…MOST
AREAS WITH A SNOW PACK WILL EITHER SEE THE SNOW PACK GROW OR WILL
HAVE RAIN/MIXED PRECIP SOAK IN WITH TEMPERATURES MAINLY IN THE 30S.
SO RUNOFF WILL GENERALLY BE LIMITED TO THE SOUTHEAST HALF OF THE
AREA.
PRECIPITATION COULD CHANGE BACK TO SNOW WEDNESDAY NIGHT INTO
THURSDAY AS THE STORM SYSTEM SLOWLY PULLS AWAY.
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…WINTER STORM WATCH FROM THIS EVENING THROUGH LATE WEDNESDAY
NIGHT FOR NYZ047-051-058-063.
MA…WINTER STORM WATCH FROM THIS EVENING THROUGH LATE WEDNESDAY
NIGHT FOR MAZ001-025.
VT…WINTER STORM WATCH FROM THIS EVENING THROUGH LATE WEDNESDAY
NIGHT FOR VTZ013-014.
&&
$$
SYNOPSIS…HWJIV
NEAR TERM…HWJIV
SHORT TERM…HWJIV
LONG TERM…BGM
AVIATION…BGM
HYDROLOGY…HWJIV/JPV
