HAMweather.com Area Forecast Discussion for County Warning Area BGM

Thu, 16 Feb 2012 11:58:46 GMT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BINGHAMTON NY
400 AM EST THU FEB 16 2012

.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL PASS THROUGH TODAY...WITH MAINLY A
COLD LIGHT RAIN. THERE MAY BE ENOUGH COLD AIR AT FIRST...FOR THE
PRECIPITATION TO BRIEFLY BEGIN AS A WET SNOW OR LIGHT MIX FOR SOME
LOCATIONS...BEFORE QUICKLY SWITCHING OVER TO RAIN. BEHIND THIS
FEATURE...COLD AIR WILL SETTLE INTO THE REGION WHICH WILL LEAD TO
THE REDEVELOPMENT OF LAKE EFFECT SNOW SHOWERS DOWNWIND OF LAKE
ONTARIO FRIDAY INTO FRIDAY NIGHT. AFTER A MAINLY DRY
SATURDAY...THE EDGE OF A STORM SYSTEM MAY BE CLOSE ENOUGH TO THE
AREA FOR A CHANCE OF SNOW SATURDAY NIGHT INTO SUNDAY.

.NEAR TERM /THROUGH TONIGHT/...
4 AM UPDATE...MAIN CONCERN IS FOR BRIEF POSSIBLE INITIAL MIX OF
PRECIPITATION THIS MORNING BEFORE QUICK TRANSITION TO PLAIN
RAIN. ALSO...PATCHY DRIZZLE IS POSSIBLE AFTER FRONT MOVES THROUGH
TONIGHT...WHICH FOR A FEW LOCATIONS COULD BE PATCHY FREEZING DRIZZLE.

MOST OF THE AREA DROPPED WELL INTO THE 20S OVERNIGHT COURTESY OF
RADIATIONAL COOLING FROM A CLEAR SKY AND BRIEF SURFACE RIDGE OF
HIGH PRESSURE. CLOUD DECK AT ABOUT 10 KFT AGL IS NOW SPREADING IN
FROM THE WEST. OVERNIGHT MINS HAVE ALREADY OCCURRED FOR MAJORITY
OF THE AREA...WITH UPSTREAM TEMPERATURES NOW RISING AS EXPECTED.

ATTENTION TURNS TO SOUTHERN STREAM WAVE CURRENTLY MAKING ITS WAY
UP THE LOWER OHIO VALLEY. HIGH RESOLUTION MODELS HAVE TRENDED TOWARD
INCREASED MOISTURE ON THE WARM AIR ADVECTION SIDE OF THE
SYSTEM...THAT IS...WITH THE BAROCLINIC LIFT. THIS IS SUPPORTED BY
THE WATER VAPOR LOOP SHOWING MOISTURE WELL OUT AHEAD OF THE WAVE
ITSELF...AS WELL AS VIRGA ALREADY BREAKING OUT IN WESTERN NY/PA. I
QUICKENED THE ONSET OF POPS THIS MORNING...TRYING TO BALANCE OUT
THE FASTER TIMING OF THE HIGH RESOLUTION MODELS WITH THE FACT THAT
TOP-DOWN MOISTENING WILL LIKELY TAKE SLIGHTLY LONGER THAN THESE
MODELS SUGGEST...FOR THE PRECIPITATION TO ACTUALLY REACH THE
GROUND.

BECAUSE LIGHT SHIELD OF RAIN WILL BE ARRIVING THIS
MORNING...TEMPERATURES WILL BE VERY TOUCHY AND SO WILL
PRECIPITATION TYPE. OVERALL...LOOKING AT MAINLY A COLD RAIN
TODAY...BUT ANYTHING THAT RUNS OUT AHEAD COULD START OFF AS A
BRIEF WET SNOW OR EVEN FREEZING RAIN BEFORE QUICK TRANSITION TO PLAIN
RAIN. THE FREEZING RAIN PROSPECTS SHOULD BE FAIRLY SPOTTY...BUT WE
WILL MONITOR CONDITIONS CLOSELY. FOR NOW HAVE INCLUDED THE
BRIEF POSSIBILITY IN THE WEATHER GRIDS AND HAZARDOUS WEATHER
OUTLOOK. 

SHORTWAVE ITSELF COMES THROUGH THIS AFTERNOON-EARLY EVENING FOR
ADDITIONAL SHOWERS/RAIN...FOLLOWED BY THE SURFACE COLD FRONT LATE
EVENING. BY THE TIME THE FRONT COMES THROUGH...DEEPER MOISTURE
WILL HAVE SCOOTED EAST WITH THE SHORTWAVE. WHERE CLOUDS ARE DEEP
ENOUGH FOR MEASURABLE PRECIPITATION...CLOUD TOPS WILL ONLY BE AT
MARGINAL TEMPERATURES FOR ICE CRYSTALS...SO PERHAPS SOME VERY
LIGHT SNOW MIXING IN AT BEST. OTHERWISE...LOW CLOUDS AND COLD
LIGHT RAIN/PATCHY DRIZZLE. WITH AMOUNT OF LOW LEVEL MOISTURE...I
STAYED ABOVE GUIDANCE FOR TEMPERATURES TONIGHT...BUT A FEW SPOTS
WILL STILL MANAGE TO GET COLD ENOUGH LATE TONIGHT FOR ANY
LINGERING DRIZZLE TO PERHAPS BRIEFLY BECOME FREEZING DRIZZLE.

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THU NGT...MAIN OCCLUDED FRONT FINALLY WORKS THROUGH MUCH OF THE
AREA BY 06Z WHICH WILL RESULT IN PRECIP GENERALLY ENDING FROM WEST
TO EAST THROUGH THE NIGHT. HAVE MAINTAINED SLGT CHC/CHC MENTION
ACROSS THE EASTERN ZONES DUE TO UNCERTAINTY ON HOW QUICKLY FEATURE
MOVES OUT.

FRI...A 270-290 FLOW DEVELOPS, AND BRINGS A LAKE EFFECT SNOW BAND
INTO THE SOUTHERN TUG HILL AND NORTHERN ONEIDA COUNTY. THE SNOW
BAND MAY BE FOCUSED NORTH OF ONEIDA COUNTY FOR A PORTION OF THE
DAYTIME HOURS, AND THERMALS WILL LIKELY PLAY A ROLE IN FIGHTING
THE BAND'S ORGANIZATION EFFORTS.

HOWEVER FLOW DIRECTION, SHEAR, AND INSTABILITY LOOKS PRETTY GOOD
FRIDAY NIGHT FOR NORTHERN ONEIDA COUNTY. CURRENT FORECAST HAS 1 TO
3 INCHES OF SNOW DURING THE OVERNIGHT HOURS, BUT THESE VALUES
COULD CHANGE QUITE A BIT AS MESOSCALE MODEL DATA BECOMES MORE
RELIABLE CLOSER TO THE EVENT.

SAT...A PRETTY GOOD SHORT WAVE AFFECTS THE REGION ON SATURDAY. GFS
IS BACKING OFF ON ITS PERSISTENT INSISTENCE OF A BIG STORM TO THE
WEST, AND ITS PHASING LOOKS MORE REALISTIC. BASICALLY IT IS
QUICKLY ALIGNING ITSELF WITH THE EURO SOLUTION. 

THE NEW GFS AND EURO SOLUTIONS PRODUCE A CYCLONE OVER THE
SOUTHEASTERN U.S., AND TRACK IT EAST TO NC/VA OVERNIGHT SATURDAY.
THE MAIN PRECIP SHIELD REMAINS WELL SOUTH OF OUR FA ON THE EURO,
THOUGH THE GFS PUSHES IT WELL INTO NY. ONCE AGAIN THE GFS SOLUTION
APPEARS LESS LIKELY TO VERIFY.

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
EXTENDED PERIOD BEGINS WITH A COASTAL SYSTEM DRIFTING OUT TO SEA
OFF THE VA COASTLINE. THE PRECIP SHIELD MAY SKIRT OUR SOUTHERN
FA, BUT NO SIGNIFICANT SNOW IS EXPECTED.

BY MONDAY, A STRENGTHENING ANTICYCLONE WILL SLIDE INTO THE OHIO
VALLEY AND GREAT LAKES, EXERTING ITS INFLUENCE DOWN THE MAJORITY
OF THE EASTERN SEABOARD. AT THE SAME TIME, JET ACTIVITY IN THE
SOUTHWESTERN U.S. WILL CARVE OUT ANOTHER WESTERN TROF. THE RESULT
WILL BE UPSTREAM RIDGING INTO THE EASTERN CONUS.

RISING HEIGHTS ALOFT, AND FAIR WEATHER AT THE SURFACE, POINT
TOWARD A WARMING TREND BETWEEN MONDAY AND TUESDAY. A WEAK GREAT
LAKES WAVE WILL FLATTEN THE RIDGE TUESDAY INTO WEDNESDAY,
BRINGING A CHANCE FOR PRECIPITATION AND SLIGHTLY COOLER TEMPS.

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE BRIEFLY IN CHARGE INITIALLY...BUT UPPER SYSTEM ON
ITS WAY IN. VFR THROUGH AT LEAST 13Z AREAWIDE EXCEPT NOTABLE
EXCEPTION OF THE MOHAWK VALLEY /KRME/ WHICH HAD LIGHT
PRECIPITATION WEDNESDAY AFTERNOON...AND NOW HAS MVFR TO IFR VIS
COURTESY OF RADIATIONAL COOLING FROM CLEAR SKY ALLOWING FOR
CONDENSING OF MIST/FOG. UPPER DISTURBANCE IS SET TO BRING RAIN
SOUTHWEST TO NORTHEAST DURING THE DAY. THERE IS SOME QUESTION TO
PRECIPITATION TYPE THIS MORNING ON THE LEADING EDGE OF THE
RAIN...IN THAT THERE MAY BE BRIEF WET SNOW OR EVEN WINTRY MIX.
MAINLY FOR HIGHER ELEVATION TERMINALS...THIS COULD LEAD TO
TEMPORARY SURPRISE IFR IF WET SNOW IS REALIZED. MAINLY MVFR IN
LIGHT RAIN THIS AFTERNOON. COLD FRONT SLIPS IN THIS
EVENING...WHICH WILL LIKELY LOWER CIGS INTO IFR BETWEEN 00Z-06Z
FRIDAY FOR MANY TERMINALS.

.OUTLOOK...

LATE THU NIGHT...MVFR/IFR CIGS.

FRI...MAINLY VFR EXCEPT POSSIBLE MVFR ALONG/NORTH OF KSYR-KRME.

FRI NGT/SAT...MAINLY VFR.

SAT NGT/SUN...MVFR FROM SYSTEM WITH CHANCE OF SNOW...IFR POSSIBLE.

MON...MAINLY VFR.

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.