FXUS61 KCLE 222039
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
339 PM EST TUE DEC 22 2009
.SYNOPSIS...
HIGH PRESSURE TO THE NORTH WILL BUILD SOUTH INTO THE AREA TONIGHT
AND WEDNESDAY. LOW PRESSURE WILL INTENSIFY OVER THE GREAT PLAINS
AND BEGIN MOVING TOWARD THE GREAT LAKES REGION THURSDAY. A COLD
FRONT WILL PASS OVER THE AREA ON FRIDAY...BUT THE LOW PRESSURE
WILL REMAIN OVER THE WESTERN GREAT LAKES INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE DRIER AIR ASSOCIATED WITH HIGH PRESSURE TO THE NORTHEAST WILL
CONTINUE TO SUPPRESS LIGHT SNOW THROUGH THIS EVENING AND GOING
INTO THE OVERNIGHT. LIGHT SNOW ASSOCIATED WITH A FRONTAL BOUNDARY
WILL CONTINUE INTO THE EVENING HOURS...BUT WILL GRADUALLY DIMINISH
AND BECOME CONFINED MORE TO SOUTHWESTERN ZONES. NOT LOOKING FOR
ANY SIGNIFICANT ACCUMULATIONS GOING INTO TONIGHT SO WILL MENTION
LITTLE TO NONE. AT MOST CAN SEE A TRACE TO A TENTH OR TWO SOUTH
AND WEST FROM A TOL-MFD LINE. DIDN/T MAKE MUCH CHANGES TO TEMPS
OVERNIGHT WITH GUIDANCE VALUES MAINLY IN UPPER TEENS TO LOWER 20S
FOR MUCH OF THE AREA. BETTER CLEARING ACROSS NW PA WITH HIGH
PRESSURE INFLUENCE MAY ALLOW FOR SOME RADIATING SO MENTIONED MID
TEENS ACROSS THE INTERIOR THERE.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
HIGH PRESSURE RIDGES INTO THE AREA ON WEDNESDAY AND CONTINUE TO
HOLD ON KEEPING CONDITIONS DRY THROUGH THURSDAY ACROSS THE REGION.
SKIES AT LEAST PARTLY SUNNY ACROSS THE AREA ON WEDNESDAY BUT MAY
SEE HIGHER CLOUDS RETURN AND THICKEN THROUGH THE DAY THURSDAY.
FOCUS IN THE SHORT TERM IS LOW PRESSURE THAT WILL IMPACT THE
REGION ON FRIDAY. MODELS CONTINUING TO TREND ONSET OF PRECIP
ACROSS THE AREA FOR LATE THURSDAY NIGHT/EARLY FRIDAY MORNING.
THERE IS SOME CONCERN ACROSS FAR NE OH/NW PA WITH POSSIBLE MIXED
PRECIP...SNOW/SLEET/FZRA AT ONSET FRIDAY MORNING...BUT MODEL
TRENDS LEANING MORE TOWARDS SOLUTION WHERE BY THE TIME PRECIP
DEVELOPS ACROSS FAR NE ZONES TEMPS WILL HAVE CHANCE TO WARM UP
ABOVE FREEZING BY THEN. FOR NOW ONLY MENTIONED RAIN...BUT THIS
WILL HAVE TO CONTINUE TO BE MONITORED IN FUTURE FORECASTS.
FOR THE REMAINDER OF THE AREA CONDITIONS LOOK PRETTY CLEAR WITH
H850 TEMPS AND THICKNESSES ALL ABOVE THRESHOLDS TO INDICATE
RAINFALL ACROSS THE AREA THROUGH EARLY FRIDAY AFTERNOON. COLD
FRONT PUSHING THROUGH IN THE AFTERNOON AND EVENING WILL GRADUALLY
TRANSITION PRECIP OVER TO A RAIN/SNOW MIX...THEN SNOW SHOWERS
GOING INTO FRIDAY NIGHT WITH COLDER AIR ADVECTION IN AT BOTH
SURFACE AND ALOFT. POPS WILL BE LOWER ACROSS WESTERN AREAS LATER
FRIDAY AND FRIDAY NIGHT WITH DRY SLOT EXPECTED TO MOVE OVER
WESTERN AREAS BEHIND THE COLD FRONT.
HAVE TEMP MINS EARLIER THURSDAY NIGHT ACROSS THE AREA WILL WARM
AIR ADVECTION TAKING PLACE...AND BRING TEMPS JUST ABOVE FREEZING
ACROSS NE ZONES BY THE TIME HIGH POPS ENTER INTO FORECAST FOR
FRIDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
EXTENDED FORECAST BEGINS ON SATURDAY MORNING WITH MODELS IN GENERAL
AGREEMENT OF FEATURES BUT DIFFERENCES SHOWING UP IN THE DETAILS.
MODELS SHOW DEEP LOW PRESSURE ALOFT OVER WESTERN/SOUTHWEST
WISCONSIN. AT THE SURFACE A COLD FRONT/OCCLUDED FRONT WILL BE EAST
OF THE AREA WITH COLD ADVECTION TAKING PLACE. THE GFS AND ECMWF MOVE
THE LOW ONLY LITTLE THROUGH SUNDAY MORNING WITH DEEP MOISTURE AND
COLD ADVECTION STILL OCCURRING. EXPECT SCATTERED TO NUMEROUS SNOW
SHOWERS ACROSS THE AREA THROUGH SUNDAY NIGHT. SUNDAY 12Z 850MB TEMPS
ARE SIMILAR BETWEEN MODELS WITH BOTH SHOWING -10 TO -12C OVERHEAD.
MONDAY WILL SHAVE POPS TO JUST SE OF THE LAKES IN THE TRADITIONAL
SNOW BELT AS DRIER BUT COLDER AIR MOVES IN. MONDAY THROUGH TUESDAY
THE LOW WILL MOVE ACROSS THE AREA AND THEN PULL NORTHEAST.
DECREASING DYNAMICS AND MOISTURE SO WILL CORRESPONDINGLY LOWER
POPS. ONLY QUESTION WOULD BE THE POTENTIAL FOR LAKE EFFECT AS THE
ECMWF IS A BIT COLDER THAN THE GFS BY DAY 7 AND 8.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
OVERRUNNING MOISTURE STREAMING INTO THE AREA FROM THE WEST THIS
AFTERNOON IS SPREADING VERY LIGHT SNOW ACROSS WESTERN AND CENTRAL
TERMINALS. IN THE NORTHEAST FLOW OFF LAKE ERIE IS ALSO PRODUCING A
LIGHT LAKE EFFECT SNOW. CONDITIONS ACROSS THE REGION ARE WAVERING
BETWEEN IFR AND MVFR MOST AREAS. OVER THE NEXT 24 HOURS THE TREND
IS THAT DRIER AIR WILL BE MOVING IN FROM THE NORTH AND NORTHEAST
WHICH HAS ALREADY STARTED. EXPECT CONDITIONS TO REMAIN MVFR/IFR IN
LOW CIGS AND LIGHT SNOW UNTIL THE DRIER AIR MOVES IN. EXPECT THIS
TO OCCUR ACROSS THE NORTHEAST DURING THE AFTERNOON HOURS AND
THIS EVENING KCAK AND KYNG. OVERNIGHT CONDITIONS WILL SLOWLY
IMPROVE TO VFR AT MFD FDT AND TOL
.OUTLOOK...NON-VFR CONDITIONS THURSDAY THROUGH FRIDAY.
&&
.MARINE...
WINDS ON LAKE ERIE ARE VEERING MORE TOWARD THE NORTHEAST AND WILL
CONTINUE TO DO SO AS HIGH PRESSURE PASSES ACROSS EASTERN CANADA TO
THE NORTH OF THE LAKES. THE FLOW WILL BE FROM THE EAST BY THURSDAY
AND WILL LIKELY REQUIRE A SMALL CRAFT ADVISORY FOR THE WEST HALF OF
THE LAKE SOME TIME ON THURSDAY.
A STRONG LOW PRESSURE CENTER FROM THE SOUTHWESTERN STATES WILL TRACK
NORTHWARD ACROSS THE PLAINS STATES. THE LOW SHOULD BE OVER IOWA
FRIDAY MORNING AND THEN BEGIN TO SLOWLY WEAKEN. THE LOW WILL SLOWLY
DRIFT NORTHEAST CROSSING WISCONSIN ON SATURDAY AND THE NORTHERN
LAKES ON SUNDAY. FORECAST WINDS REMAIN JUST BELOW GALE FORCE BUT A
SMALL CRAFT ADVISORY WILL BE NEEDED LATE IN THE WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ABE
NEAR TERM...ABE
SHORT TERM...ABE
LONG TERM...TK
AVIATION...TK
MARINE...KOSARIK
