FXUS61 KCLE 061155
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
655 AM EST SUN DEC 6 2009
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST OF THE REGION THIS AFTERNOON. A WEAK
AREA OF LOW PRESSURE WILL MOVE OVER THE CENTRAL GREAT LAKES ON MONDAY.
HIGH PRESSURE WILL BRIEFLY BUILD OVER THE FORECAST AREA ON
TUESDAY. A STRONG LOW PRESSURE SYSTEM WILL DEVELOP SOUTHWEST OF
THE REGION WEDNESDAY
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED FOR SKY COVER IN THE MFD AREA AND TO DECREASE THE SNOWFALL
AMOUNT FOR THE SNOW BELT FOR THE MORNING.
SATELLITE IMAGERY AND RADAR SHOW LIGHT LAKE EFFECT SNOW SHOWERS
CONTINUING OVER PORTIONS OF NE OHIO AND NW PA. 850MB TEMPS AROUND
-10C CONTINUE EARLY THIS MORNING. THE 850MB THERMAL TROF WILL NOT
PUSH EAST OF THE REGION UNTIL THIS AFTERNOON. BUFKIT SOUNDINGS
SHOW CONDITIONAL INSTABILITY AT ERI UNTIL 18Z THIS AFTERNOON. AT
THAT TIME WARM AIR ADVECTION WITH THE NEXT SHORT WAVE WILL BECOME
PREDOMINATE. I WILL KEEP SCATTERED SW- IN THE SNOWBELT REGION THIS
MORNING...ENDING IT EARLY THIS AFTERNOON. LITTLE OR NO
ACCUMULATION. ALL OTHER AREAS WILL REMAIN PARTLY CLOUDY. GUIDANCE
TEMPS IN GOOD AGREEMENT WITH HIGHS IN THE UPPER 30S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
HIGH PRESSURE WILL CONTINUE TO WEAKEN TONIGHT. A WEAK RETURN FLOW
AND WARM AIR ADVECTION WILL BEGIN IN ADVANCE OF A WEAK LOW
PRESSURE SYSTEM THAT WILL IMPACT THE REGION ON MONDAY. MODELS ARE
IN GOOD AGREEMENT WITH THIS SYSTEM AS IT MAKES A QUICK APPEARANCE
OVER THE FORECAST AREA MONDAY AFTERNOON INTO MONDAY NIGHT. THE
MODELS SHOW DECENT LIFT AS THE LOW MOVES THROUGH. THE 700-300MB
Q-VECTORS FIELD SHOW GOOD FORCING OVER THE AREA. HOWEVER THE SYSTEM
IS MOISTURE STARVED AND MOVING FAST. I DO EXPECT SCATTERED SNOW
SHOWERS WITH THE LOW BUT LITTLE OR NO ACCUMULATION. COLD ADVECTION
AFTER THE LOW PASSAGE IS WEAK. 850MB TEMPS WILL REMAIN AROUND -6
TO -8C WITH LIMITED MOISTURE. I WILL KEEP SOME SCATTERED SNOW
SHOWERS IN THE SNOWBELT MONDAY NIGHT BUT CONDITIONS ARE EXTREMELY
MARGINAL.
HIGH PRESSURE WILL BRIEFLY ENTER THE REGION TUESDAY BUT CLOUDS
WILL QUICKLY THICKEN AS A STRONG WARM AIR ADVECTION PATTERN WILL
BEGIN TO SETUP IN ADVANCE OF THE NEXT STORM SYSTEM. IT IS POSSIBLE
SOME LIGHT SNOW SHOWERS COULD ENTER THE FAR SOUTHWESTERN SECTIONS
OF THE FORECAST AREA LATE TUESDAY AFTERNOON. LIGHT SNOW SHOULD
SPREAD OVER MUCH OF THE AREA EARLY TUESDAY NIGHT AS A WARM FRONT
ADVANCES ACROSS THE AREA. THE SNOW WILL QUICKLY CHANGE OVER TO
RAIN TUESDAY NIGHT INTO WEDNESDAY AS LOW LEVEL TEMPS AND
THICKNESS VALUES WARM TO LEVELS TO HIGH TO SUPPORT SNOW. RAIN
SHOWERS ARE EXPECTED TO CONTINUE FOR MOST OF THE DAY WEDNESDAY. A
STRONG COLD FRONT WILL SWEEP THROUGH THE FORECAST AREA WED
AFTERNOON. VERY STRONG COLD AIR ADVECTION WILL FOLLOW THIS FRONTAL
PASSAGE. RAIN SHOWERS WILL CHANGE TO SNOW SHOWERS AND WINDS COULD
BECOME VERY STRONG AND GUSTY. MODERATE LAKE EFFECT SNOW SHOWERS
WILL DEVELOP WED NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
STILL SOME QUESTIONS ON THE WIND DIRECTION FOR THURSDAY INTO FRIDAY
AND HOW MUCH LAKE EFFECT. NONE THE LESS IT WILL BE A WESTERLY FLOW
AND THERE WILL BE SOME LAKE EFFECT...THE MORE WESTERLY THE FLOW THE
MORE INLAND IT WILL GET IN THE SNOW BELT. OTHERWISE WITH THE
WESTERLY FLOW THE SNOW BELT SHOULD HAVE MOST OF THE SNOW SHOWERS AND
ELSEWHERE IT WILL BE DRY. THURSDAY WILL STILL BE WINDY ESPECIALLY
NEAR LAKE ERIE.
THE GFS FLOW BECOMES SOUTHWEST FRIDAY AND
WE LOSE THE LAKE EFFECT WHILE THE ECMWF CONTINUES THE WESTERLY FLOW
INTO SATURDAY. THE TYPICAL PATTERN WOULD FAVOR THE GFS SO WENT
ALONG WITH THAT MODEL. THE GFS TRIES TO DRY THINGS OUT SO JUST WENT
WITH 50 POPS FOR THE SNOW BELT FOR THURSDAY NIGHT AND FRIDAY.
FOR SATURDAY THE MODELS DON'T AGREE THE GFS HAS A NORTHERLY FLOW
WHILE THE ECMWF IS SOUTHWEST. AT THIS TIME CONTINUE A LOW CHANCE POP.
FOLLOWED THE GRIDDED MOS FOR TEMPERATURES WITH JUST SOME MINOR
ADJUSTMENTS...THEY LOOKED REASONABLE.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
EVENTUALLY VFR WILL BE ACROSS THE ENTIRE FORECAST AREA THIS
AFTERNOON AS THE NORTHWEST FLOW BECOMES SOUTHWEST. STRATOCUMULUS
CONTINUES TO FLOW IN FROM THE LAKE INTO NORTHEAST OHIO AND
NORTHWEST PA AND THE CENTRAL HIGHLANDS. AS THE FLOW BECOMES
SOUTHWEST LATTER THIS MORNING AND EARLY AFTERNOON THE LOW CLOUDS
WILL DISSIPATE. ANY FLURRIES AN SNOW SHOWERS THIS MORNING WILL BE
LIGHT AND ONLY LOWER THE VISIBILITY TO MVFR.
SOME CIRRUS AND MID CLOUDS WILL SLOWLY BE INCREASING ACROSS THE
AREA THIS AFTERNOON AND TONIGHT FROM THE WEST AHEAD OF A COLD
FRONT.
.OUTLOOK...NON VFR MONDAY AFTERNOON AND EVENING AND AGAIN TUESDAY
NIGHT THROUGH THURSDAY. STRONG WINDS WEDNESDAY AFTERNOON AND NIGHT.
&&
.MARINE...
HIGH PRESSURE RIDGE SOUTH OF LAKE ERIE WILL WEAKEN TONIGHT. IN THE
MEANTIME THE SOUTHWEST FLOW TODAY COULD GET CLOSE TO 15 TO 25 KNOTS
ON THE EAST END OF LAKE ERIE. AT THIS TIME WILL KEEP IT BELOW SMALL
CRAFT ADVISORY CATEGORY BUT THIS WILL HAVE TO BE MONITORED. A WEAK
COLD FRONT MOVES ACROSS THE LAKE MONDAY FOLLOWED BY MORE HIGH
PRESSURE FOR LATE MONDAY NIGHT INTO TUESDAY. THE WINDS AFTER FROPA
MONDAY EVENING WILL BE CLOSE TO SMALL CRAFT ADVISORY CRITERIA.
THE MAIN CONCERN IS THE STORM FOR WEDNESDAY INTO THURSDAY NIGHT. IN
THE COLD ADVECTION IT LOOKS LIKE A HIGH END GALE BUT THIS WILL HAVE
TO BE MONITORED FOR A POSSIBLE STORM AND WITH THOSE SPEEDS AND THE
DIRECTION LOW WATER ON THE WEST END OF THE LAKE. THE WINDS SHOULD
START TO SETTLE DOWN ON THE LAKE FRIDAY BUT A SMALL CRAFT ADVISORY
WILL LIKELY BE NEEDED.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GARNET
NEAR TERM...GARNET/KIELTYKA
SHORT TERM...GARNET
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
