January 22, 2012 Forecast Discussion

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
621 AM EST SUN JAN 22 2012

.SYNOPSIS…
A HIGH PRESSURE SYSTEM WILL REMAIN OVER THE NORTHEAST TODAY…SLIDING
OFFSHORE TONIGHT. ON MONDAY…A POWERFUL STORM WILL MOVE FROM THE
UPPER GREAT LAKES REGION INTO WESTERN QUEBEC…LIKELY BRINGING
MIXED PRECIPITATION CHANGING TO RAIN. COLDER MORE SEASONABLE AIR
WILL MOVE INTO THE REGION TUESDAY..AND HIGH PRESSURE WILL BUILD
FROM THE OHIO VALLEY TO THE EASTERN SEABOARD MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/…
AT 620AM FORECAST ON TRACK. ADJUSTED TEMPS TO REFLECT CURRENT
OBS..OTHERWISE NO CHANGES.

LARGE SFC HIGH HAS BUILT OVER S QB AND NY/NEW ENG OVERNIGHT
DOWNSTREAM OF BUILDING 500HPA RIDGE. IT WILL REMAIN IN CONTROL
INTO THIS EVENING KEEPING FAIR AND SEASONABLE CONDITIONS OVER THE
FCA.

OTHER THAN SOME PATCHY MID AND HI CLOUDS IN MID AND HIGH LVL WAA
IT WILL BE MOSTLY SUNNY..AND FAIR INTO THE EVENING. OVERNIGHT THE
SFC HIGH SLIDES OFFSHORE..AND IT SETS UP A LOW LEVEL E-SE FLOW OF
INCRG MOISTURE AND CLOUDS INTO THE RGN. SINCE IT WILL BE MAINLY
CLEAR THE FIRST PART OF THE NIGHT TEMPS WILL PLUNGE. AS ALL THE
MOISTURE IS CONFINED TO LOW LEVELS AND THE MODEL SOUNDINGS DO NOT
SUPPORT ANY ICE CRYSTAL FORMATION…THE RESULTING PCPN WILL BE
CONFINED TO PATCHY -ZL BCMG MORE WIDESPREAD TWRD MORNING. THE
MODELS HAVE BEEN CONSISTENT IN THIS THINKING FOR SVRL DAYS.

MINS WILL OCCUR EARLY IN THE NIGHT AND THE GRIDS WERE POPULATED
WITH 3 HOURLY TEMPS TNGT WITH OUT USING DIURNAL TOOL.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/…
POTENT MISSISSIPPI RIVER VALLEY STORM WILL BECOME VERTICALLY STACKED
OVER THE UPPER GREAT LAKES REGION THROUGH THIS SHORT TERM. ITS
ASSOCIATED COLD FRONTAL BOUNDARY WILL QUICKLY TRACK ACROSS EASTERN
NY AND ADJACENT WESTERN NEW ENGLAND MONDAY AFTERNOON INTO THE EARLY
EVENING HOURS FOR OUR MOST EASTERN ZONES. BOUNDARY LAYER
TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING ON MONDAY WITH
PRECIPITATION ASSOCIATED WITH THE FRONT TO FALL AS RAIN SHOWERS.
WIND GUSTS ARE EXPECTED TO MORE NOTICEABLE ACROSS THE HIGHER TERRAIN
BUT AT THIS TIME WE WILL KEEP THESE VALUES BELOW HEADLINE
THRESHOLDS. HIGH TEMPERATURES MONDAY AFTERNOON ARE EXPECTED TO BE
MAINLY INTO THE LOWER HALF OF THE 40S WITH A FEW POCKETS OF UPPER
30S IN SHELTERED LOCATIONS.

IN THE WAKE OF FROPA…MID LEVEL DRY SLOT AND SUBSIDENCE INVERSION
LOWERS MONDAY NIGHT AS WE WILL DECREASE POPS THROUGH THE NIGHT.
EXCEPTION TO THIS WILL BE DOWNWIND OF LAKE ONTARIO AS MARGINAL LAKE
EFFECT PARAMETERS COULD BRING SOME SNOW SHOWERS TO PORTIONS OF THE
DACKS. DELTA T/S OFF LAKE ONTARIO ARE PROGGED TO BE RIGHT AT 13C
WITH MINIMAL VERTICAL SHEAR BUT INVERSION HEIGHTS AOA 5K FEET.
OVERNIGHT LOWS WILL SETTLE BACK INTO THE 20S AND LOWER 30S UNDER A
VARIABLE CLOUD COVERAGE.

TUESDAY WE ARE EXPECTED TO REMAIN UNDER THE COOLER CYCLONIC FLOW OF
THE SLOWLY DEPARTING VERTICALLY STACKED LOW OVER JAMES BAY AND
TRACKING INTO NORTHERN QUEBEC. MODELS DO DIFFER WITH RESPECT TO HOW
MUCH COLD ADVECTION WILL COMMENCE…NEVERTHELESS…LAKE EFFECT
PARAMETERS REMAIN MARGINALLY FAVORABLE TO CONTINUE LOW CHANCE POPS
DOWNWIND OF THE LAKE. THE BOUNDARY LAYER WINDS ARE EXPECTED TO VEER
TOWARD THE WEST-NORTHWEST TUESDAY AFTERNOON. OTHERWISE…A WIDE
VARIETY OF SKY CONDITIONS ARE EXPECTED WITH A DIVERSE TEMPERATURES
RANGING FROM LOWER 40S IN THE VALLEY LOCATIONS TO 30S FOR THE
TERRAIN. WHERE LAKE SNOWS DO OCCUR…ACCUMULATIONS ARE EXPECTED TO
REMAIN LIGHT.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/…
SOMEWHAT TRANQUIL CONDITIONS ARE EXPECTED THROUGH THURSDAY AS A
BROAD SURFACE RIDGE MOVES ACROSS THE REGION. THERE WILL BE A COUPLE
OF WEAK SHORT WAVES WITHIN THE CONFLUENT FLOW THAT MAY PROVIDE
SCT-BKN CLOUD COVER TO THE REGION. THEN A VERY CHALLENGING FORECAST
TOWARD THE END OF THIS WEEK AND INTO THE WEEKEND.

THURSDAY NIGHT INTO SATURDAY…A FAST MOVING SHORT WAVE WILL MOVE
ACROSS THE GREAT LAKES ON THURSDAY THEN OFF THE NEW ENGLAND COAST
THURSDAY NIGHT. MEANWHILE A CUT OFF UPPER LOW OVER TEXAS EITHER
BEGINS TO TRACK NORTHWARD AND FEEL THE INFLUENCE OF THIS WAVE OR
REMAINS DISCONNECTED. THE ECMWF AND THE CANADIAN ATTEMPT TO OPEN
THIS TEXAS WAVE AND BECOME ENTRAINED WITHIN THE TROUGH AND BRING
ABOUT THE CHANCE FOR PRECIP TO THE REGION FOR THE END OF THIS WEEK.
THE GFS AND TO SOME EXTENT THE DGEX REMAIN LESS PROGRESSIVE WITH THE
MAIN WAVE PASSING BY WELL TO OUR SOUTH THEN BECOMING CAPTURED BY THE
UPPER TROUGH FOR THE WEEKEND. THE ENSEMBLE APPROACH FROM THE GFS
FAVORS THE OPERATIONAL GFS/DGEX WITH THE PREVIOUS HPC EXTENDED
GUIDANCE A FURTHER OFFSHORE SOLUTION. FOR NOW…WE WILL CONTINUE
WITH THE CHANCE FOR SOME PRECIP DURING THE END OF THIS WEEK AND
WEEKEND AS WE CONTINUE TO FOLLOW TRENDS CLOSELY.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/…
HIGH PRESSURE OVER NYS AND NEW ENG. WINDS CALM, SKIES CLR AND VFR
CONDITIONS WILL PERSIST THROUGH THE DAY AND TONIGHT.

OUTLOOK…
MON AM…MAINLY VFR…CHC -FZDZ.
MON AFTN-EVENING…MVFR/IFR…RA LIKELY.
TUE-THU…VFR…NO SIG WX.

&&

.HYDROLOGY…
NO HYDROLOGIC PROBLEMS EXPECTED THROUGH EARLY MONDAY.

A STORM SYSTEM WILL BRING MIXED PRECIPITATION CHANGING TO RAIN
ON MONDAY. A QUICK SHOT OF MODERATE TO HEAVY RAIN IS
POSSIBLE MONDAY WITH A COLD FRONT WITH QPF VALUES BETWEEN ONE
QUARTER TO ONE HALF INCH.

WE MEASURED THE GROUND FROZEN TO A DEPTH OF 13 INCHES HERE AT THE
OFFICE TODAY. SOME LOCALIZED POOR DRAINAGE…URBAN AND SMALL STREAM
FLOODING MAY BE POSSIBLE LATER MONDAY DUE TO ENHANCED RUNOFF FROM
RAIN AND MELT ON FROZEN GROUND.

SOME SIGNIFICANT RISES ON MAIN STEM RIVERS ARE POSSIBLE MONDAY INTO
TUESDAY…BUT LARGER RIVER FLOODING IS NOT EXPECTED AT THIS TIME.
RISES WOULD BE ENOUGH TO BREAK UP WHAT RIVER ICE IS IN PLACE BUT ICE
IS NOT THICK ENOUGH TO CAUSE SIGNIFICANT ICE JAM PROBLEMS.

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…SNYDER
NEAR TERM…SNYDER
SHORT TERM…BGM
LONG TERM…BGM
AVIATION…SNYDER
HYDROLOGY…BGM

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