March 26, 2014 Forecast Discussion

000
FXUS61 KALY 261123
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
723 AM EDT WED MAR 26 2014

.SYNOPSIS…
A VERY INTENSE STORM OFF THE EAST COAST WILL MOVE TO THE CANADIAN
MARITIMES BY LATE THIS AFTERNOON. STRONG NORTHWEST WINDS ON THE
WESTERN SIDE OF THIS STORM WILL AFFECT THE REGION TODAY…AND ALSO
PUSH ANOTHER COLD AIR MASS INTO THE REGION FOR THE MID WEEK PERIOD.
LATER IN THE WEEK…LOW PRESSURE WILL MOVE ACROSS THE GREAT
LAKES…POSSIBLY BRINGING A WINTRY MIX CHANGING TO RAIN ACROSS THE
REGION FOR LATE THURSDAY NIGHT INTO FRIDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/…
AS OF 615 AM…HAVE ONLY MADE SOME MINOR HOURLY TEMP CHANGES TO
ACCOUNT FOR CURRENT CONDITIONS…AND LOWERED POPS OVER WESTERN AREAS
TO BETWEEN 20 AND 30 PERCENT FOR THIS MORNING.

PREV DISCUSSION…
AS OF 430 AM…LITTLE IF ANY SNOW ACROSS THE REGION AT THIS TIME
WITH THE EXCEPTION OF WESTERN AREAS WHERE THERE ARE ISOLD TO SCT
SNOW SHOWERS. WILL CONTINUE WITH NO MORE THAN 20 PERCENT POPS ACROSS
CENTRAL AND EASTERN AREAS DUE TO THE STRONG STORM OFF THE EAST
COAST…AND 20 TO 40 PERCENT POPS WESTERN AREAS DUE TO A WEAKENING
FRONT OVER THAT AREA.

WINDS ARE STILL FAIRLY LIGHT AS OF 430 AM…BUT WILL BE INCREASING
FROM THIS POINT ON…BECOMING QUITE STRONG BY LATE MORNING AND THIS
AFTERNOON. HAVE NOT EXPANDED THE WIND ADVISORY AREA SINCE IT STILL
APPEARS THAT NORTHERN AREAS WILL HAVE WIND SPEEDS THAT ARE 5 TO 10
MPH LESS THAN AREAS FURTHER SOUTH. HIGHS TODAY WILL BE IN THE 20S TO
MID 30S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/…
TONIGHT-THURSDAY…HIGH PRESSURE BUILDS IN FROM THE W TONIGHT…AND
PASSES OVER THE REGION ON THURSDAY. WINDS WILL LIKELY REMAIN QUITE
BRISK THROUGH EARLY TONIGHT…THEN GRADUALLY DIMINISH LATER TONIGHT.
LOWS TONIGHT WILL RANGE FROM AROUND ZERO OVER THE ADIRONDACKS…TO
THE SINGLE DIGITS AND LOW TO MID TEENS ELSEWHERE. HIGHS THURSDAY IN
THE MID 30S TO MID 40S WITH INCREASING CLOUDS EXPECTED LATER IN THE
DAY.

THU NT…A WARM FRONT APPROACHING FROM THE SOUTHWEST/WEST SHOULD
BRING A SURGE OF LIGHT TO MODERATE PRECIPITATION INTO THE REGION…
MAINLY AFTER MIDNIGHT. THERMAL PROFILES SUGGEST THAT AFTER ABOUT 06Z
THE CHOICE FOR PCPN TYPES WILL NARROW TO ONLY RAIN OR FREEZING RAIN
BEING POSSIBLE…WITH UP TO AN EIGHTH OF AN INCH OF ICING FORECAST
WHERE FREEZING RAIN DOES OCCUR. BEFORE 06Z…NORTH AND NORTHWEST
AREAS SHOULD BE COLD ENOUGH FOR SOME SNOW…BUT POPS ARE ONLY IN THE
CHANCE RANGE IN THESE AREAS BEFORE 06Z SO NO SNOW ACCUMULATION WAS
FORECAST. LOWS THURSDAY NIGHT WILL OCCUR AROUND OR A LITTLE AFTER
MIDNIGHT WITH READINGS IN THE UPPER 20S TO LOWER 30S.

WITH TEMPS RISING SLOWLY AFTER MIDNIGHT…EXPECT ALL AREAS TO BE
WARM ENOUGH FOR JUST RAIN WITHIN AN HOUR OR TWO AFTER SUNRISE ON
FRIDAY. THE RAIN WILL CONTINUE THROUGH MOST OF THE DAY AND HAVE
FORECAST LIKELY TO CATEGORICAL POPS ON FRIDAY. HIGHS WILL BE IN THE
MID 40S TO MID 50S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/…
THE PATTERN WILL BECOME MORE ACTIVE WITH A POTENTIAL STORM SYSTEM
BRINGING SIGNIFICANT QPF TO THE REGION OVER THE WEEKEND.

THE PERIOD STARTS OUT WITH LOW PRESSURE MOVING FROM SOUTHEAST QUEBEC
INTO THE CANADIAN MARITIMES…WITH THE SYSTEM/S TRAILING COLD FRONT
PASSING THROUGH OUR REGION FRIDAY EVENING. SO WILL MENTION A CHANCE
OF SHOWERS EARLY…WITH DRYING CONDITIONS OVERNIGHT AS HIGH PRESSURE
BUILDS EASTWARD ACROSS THE UPPER GREAT LAKES AND SOUTHEAST CANADA.
THE COLD FRONT WILL STALL JUST TO OUR SOUTH OVER THE MID ATLANTIC
REGION.

SATURDAY LOOKS TO START OUT DRY…HOWEVER CLOUDS WILL RAPIDLY
THICKEN AHEAD OF A WAVE OF LOW PRESSURE MOVING FROM THE TENNESSEE
VALLEY TO THE OHIO VALLEY DURING THE DAY. THIS SYSTEM IS FORECAST TO
TRACK EASTWARD ALONG THE OLD STALLED OUT FRONTAL BOUNDARY TO OUR
SOUTH. RAIN IS EXPECTED TO OVERSPREAD THE REGION FROM SOUTH TO NORTH
SATURDAY AFTERNOON WITH GOOD ISENTROPIC LIFT NORTH OF THE BOUNDARY.

THERE IS LOW FORECAST CONFIDENCE WITH REGARDS TO THIS SYSTEM…WITH
CONSIDERABLE UNCERTAINTY RESULTING FOR THE REST OF THE LONG TERM
PERIOD AS WELL. MODEL TRENDS SINCE TUESDAY INDICATE THE POTENTIAL
FOR A DEEPER AND POTENTIALLY CUT-OFF UPPER LEVEL LOW…BUT THERE IS
UNCERTAINTY WITH THE TIMING AND POSITION OF THE UPPER LOW CLOSING
OFF. THE 00Z OPERATIONAL GUIDANCE SUCH AS THE GFS/ECMWF/CMC INDICATE
THE MAIN SURFACE WAVE WILL TRACK TO OUR SOUTH…WITH THE GFS
ENSEMBLE MEAN DEPICTING THIS AS WELL. QPF AMOUNTS/LOCATION
VARIES…BUT MOST GUIDANCE SHOWING SIGNIFICANT QPF. THE OTHER ISSUE
IS THAT SINCE THE STORM MAY POTENTIALLY BE TRACKING FARTHER SOUTH
THERMAL PROFILES MAY GRADUALLY BECOME COLD ENOUGH FOR RAIN TO MIX
WITH OR CHANGE TO SNOW SATURDAY NIGHT INTO EARLY SUNDAY. THE BEST
CHANCE FOR SNOW WOULD BE OVER THE HIGHER TERRAIN. VERY DIFFICULT
FORECAST…BUT IT APPEARS TEMPERATURES COULD BE COLDER THAN
PREVIOUSLY THOUGHT…ESPECIALLY FOR SATURDAY NIGHT INTO SUNDAY. WILL
CONTINUE TO MONITOR TRENDS WITH THIS SYSTEM.

THE FORECAST FROM SUNDAY NIGHT THROUGH TUESDAY OF NEXT WEEK IS
HIGHLY QUESTIONABLE AT THIS TIME. THERE IS A POTENTIAL FOR THE
CUT-OFF LOW TO CONTINUE TO IMPACT THE REGION AS THE ECMWF IS
INDICATING…OR FOR THIS SYSTEM TO BE PROGRESSIVE AND TRACK OUT TO
SEA SHOWN BY THE GFS. WILL MENTION GENERALLY SEASONABLE TEMPERATURES
FOR NOW WITH SLIGHT TO CHANCE POPS.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/…
A POWERFUL OCEAN STORM WILL REMAIN WELL OFF-SHORE EAST OF NEW
ENGLAND TODAY AS IT TRACKS NORTHWARD TOWARDS THE CANADIAN
MARITIMES…BUT WILL IMPACT OUR REGION WITH STRONG WINDS. AN UPPER
LEVEL TROUGH WILL CONTINUE TO MOVE ACROSS THE AREA THIS MORNING
BRINGING CONTINUED CLOUD COVER…BUT CIGS SHOULD REMAIN WELL INTO
VFR RANGE. SKIES WILL GRADUALLY CLEAR THIS AFTERNOON AS HIGH
PRESSURE BUILDS EASTWARD FROM THE GREAT LAKES.

NORTHWEST WINDS WILL INCREASE TO 15-20 KT THIS MORNING…AND FURTHER
INCREASING TO 18-23 KT WITH GUSTS OF 30-40 KT THIS AFTERNOON. WIND
SPEEDS WILL GRADUALLY DECREASE AFTER DARK AND ESPECIALLY AFTER
MIDNIGHT.

OUTLOOK…

THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY RA…CHANCE ZR.
FRIDAY: HIGH OPERATIONAL IMPACT. BREEZY. LIKELY RA.
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. LIKELY RA.
SATURDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY RA…SN.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RA.

&&

.FIRE WEATHER…
THE FORECAST AREA IS SNOW COVERED EXCEPT FOR PARTS OF THE MID
HUDSON VALLEY…CAPITAL DISTRICT…AND NW CT. WINDS WILL INCREASE ON
TODAY WITH GUSTS OF 35 TO 50 MPH EXPECTED.

A VERY INTENSE STORM OFF THE EAST COAST WILL MOVE TO THE CANADIAN
MARITIMES BY LATE THIS AFTERNOON. STRONG NORTHWEST WINDS ON THE
WESTERN SIDE OF THIS STORM WILL AFFECT THE REGION TODAY…AND ALSO
PUSH ANOTHER COLD AIR MASS INTO THE REGION FOR THE MID WEEK PERIOD.
LATER IN THE WEEK…LOW PRESSURE WILL MOVE ACROSS THE GREAT
LAKES…POSSIBLY BRINGING A WINTRY MIX CHANGING TO RAIN ACROSS THE
REGION FOR LATE THURSDAY NIGHT INTO FRIDAY.

&&

.HYDROLOGY…
NO HYDROLOGIC PROBLEMS ARE EXPECTED THROUGH THURSDAY.

THE DEEP AND INTENSE OCEANIC LOW MAY BRING SOME SNOW SHOWERS OR
FLURRIES TO THE HSA TODAY WITH LITTLE IF ANY LIQUID EQUIVALENT.

SOMEWHAT MILDER WEATHER WILL RETURN LATE IN THE WEEK INTO THE WEEKEND
WHICH MAY ALLOW FOR SNOW MELT AND OR ICE BREAK UP…COUPLED WITH
ADDITIONAL RUNOFF FROM RAIN SHOWERS FRIDAY INTO SUNDAY.

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…WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR CTZ001-013.
NY…WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NYZ038>040-
047>054-058>061-063>066.
MA…WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MAZ001-025.
VT…WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR VTZ013>015.

&&

$$
SYNOPSIS…GJM
NEAR TERM…GJM
SHORT TERM…GJM
LONG TERM…JPV
AVIATION…KL/JPV
FIRE WEATHER…KL/GJM
HYDROLOGY…KL/GJM

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