FXUS61 KCLE 220429
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
1129 PM EST MON DEC 21 2009
.SYNOPSIS...
A WEAK AREA OF HIGH PRESSURE WILL MOVE SLOWLY EAST ACROSS THE REGION
TONIGHT. THE HIGH WILL DISSIPATE OVER THE AREA TUESDAY NIGHT WHILE
A RIDGE REMAINS STATIONARY OVER THE REGION. A WARM FRONT WILL
APPROACH FROM THE SOUTHWEST ON THURSDAY AND MOVE NORTH ACROSS THE
AREA.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
ANOTHER BATCH OF LAKE EFFECT SNOW WILL BE MOVING INTO THE SNOW
BELT. RAISED POPS A LITTLE. THE SNOWFALL FORECAST LOOKS
REASONABLE. THE LAKE AND 850 MB TEMPERATURE DIFFERENCE IS ONLY
AROUND 13 OR 14C BUT WITH THIS SURGE OF MOISTURE AND THE NORTHWEST FLOW
THAT SHOULD HELP GET THE INTENSITY OF SNOW TO PICK UP. THE
MOISTURE STARTS DECREASING LATE TONIGHT. THE AMOUNTS WILL BE UNDER
ADVISORY CRITERIA. THE LOCAL MODELS CONCUR.
ELSEWHERE CLOUDY WITH A CHANCE OF FLURRIES IN SOME WARM ADVECTION.
WITH THE SOLID CLOUD COVER...RAISED THE LOWS AT LEAST ONE CATEGORY.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
MODELS ARE STILL PERSISTENT IN FORCING LOW PRESSURE SYSTEM TO THE
WEST OF THE FORECAST AREA THURSDAY NIGHT INTO FRIDAY. THE GFS AND
EUROPEAN ARE IN GOOD AGREEMENT WITH THIS TREND AND WILL STICK TO
IT FOR NOW. UNFORTUNATELY...THIS DOES NOT MEAN A WHITE CHRISTMAS
FOR THE FORECAST AREA.
HIGH PRESSURE RIDGE DOMINATES THE FORECAST AREA THROUGH WEDNESDAY
BUT AN UPPER LEVEL DISTURBANCE AND ASSOCIATED MOISTURE WILL RACE
SOUTHEAST TOWARD THE REGION LATE TONIGHT INTO TUESDAY. SOME LIGHT
SNOW WILL DEVELOP ACROSS THE AREA DURING THE MORNING BUT I DONT
ANTICIPATE TO AMOUNT TO MUCH AT ALL IF ANY IN THE WEST AND SOUTH.
SOME LAKE ENHANCEMENT WILL CONTINUE ON TUESDAY WITH THIS FEATURE.
PRECIPITATION FINALLY COMES TO AN END TUESDAY NIGHT OVER THE ENTIRE
AREA THROUGH THURSDAY. PRECIPITATION WILL EVENTUALLY START TO
SPREAD EAST DURING THE NIGHT THURSDAY NIGHT AND START OUT ALL AREAS
IN THE FORM OF RAIN. ONE ISSUE IS COLD EAST WIND AND EVAPORATIVE
COOLING WILL CAUSE TEMPERATURES TO DROP INTO THE MIDDLE 30S MOST
AREAS AND LOWER 30S TO POSSIBLY UPPER 20S IN THE EXTREME NORTHEAST.
THIS COULD CAUSE AN HOUR OR TWO OF FREEZING RAIN BY FRIDAY MORNING.
AS PRECIPITATION MOVES INTO THE REGION THURSDAY NIGHT...EXPECTING
ONE HALF TO THREE QUARTERS OF AN INCH LIQUID PRECIPITATION BY FRIDAY
MORNING.
TEMPERATURES ONCE AGAIN SHOULD REMAIN RATHER STABLE TUESDAY THROUGH
THURSDAY WITH LOWS IN THE 20S AND HIGHS IN THE 30S. I ANTICIPATE
THAT TEMPERATURES WILL DROP DURING THE EVENING THURSDAY NIGHT AND
THEN KIND OF LEVEL OFF. I DECIDED TO GO WITH A NON-DIURNAL
TEMPERATURE THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
NOT MUCH CHANGE IN THE EXTENDED PROGS FROM YDA TO TODAY. THE
EXTENDED PORTION BEGINS FRIDAY MORNING 12Z WITH RAIN ALREADY
OCCURRING ACROSS MUCH OF THE AREA. CURRENT INDICATIONS ARE THAT
SURFACE WINDS WILL BE FROM THE EAST OUT OF NORTHEAST AND NRN PA
THURSDAY NIGHT THROUGH FRIDAY MORNING. THIS WOULD LIKELY BE A COLD
(BELOW 32F) FLOW WITH DEWPOINTS AROUND 20 OR POSSIBLY EVEN A BIT
BELOW. CONCERN HERE IS AS PRECIP FALLS INTO THE DRIER COLD EAST FLOW
IN NERN OH AND NWRN PA PRECIP COULD BEGIN AS A PERIOD FREEZING
RAIN. WILL INCLUDE THIS POSSIBILITY LASTING INTO FRIDAY MORNING.
WARM ADVECTION SHOULD WARM TEMPS ABOVE FREEZING QUICKLY THROUGH THE
MORNING. GIVEN THE MAGNITUDE OF THE SYSTEM...WILL CONTINUE WITH
CATEGORICAL POPS INTO FRIDAY BUT AS THE COLD AIR SWEEPS INTO THE
AREA FROM THE WEST WILL TAPER POPS BACK TO CHANCE AS SNOW MIXES IN
MID/LATE AFTERNOON. WILL CONTINUE WITH CHANCE POPS FRIDAY EVENING
HOWEVER THE GFS SHOWS A SHORT WAVE ROTATING INTO THE WESTERN
COUNTIES THE SECOND HALF OF THE NIGHT. WILL BUMP POPS BACK UP TO
LIKELY FOR SHOW SHOWERS THE SECOND HALF OF FRIDAY NIGHT. SATURDAY
INTO SUNDAY WILL HAVE DIMINISHING POPS FROM CHANCE TO SLIGHT CHANCE
MOST AREAS SUNDAY AND CONTINUING MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
LAKE EFFECT SNOW NOW DEVELOPING SNOWBELT EAST OF CLEVELAND WILL
PRODUCE A FEW INCHES OVERNIGHT. OVERRUNNING SITUATION WILL KICK
OFF SOME SNOW SHOWERS TONIGHT...WITH MOST LOCATIONS ONLY GETTING A
DUSTING. BEST POTENTIAL FOR SNOW WILL BE THE WESTERN LOCATIONS.
EXPECT PREDOMINATELY MVFR CONDITIONS TONIGHT AND TOMORROW...WITH
IFR IN THE HEAVIER SNOW SHOWERS.
.OUTLOOK...NON-VFR CONDITIONS THURSDAY THROUGH FRIDAY.
&&
.MARINE...
WINDS FROM THE WEST WILL SLOWLY VEER TOWARD THE NORTHWEST AND THEN
THE NORTHEAST MID WEEK AS HIGH PRESSURE MOVES FROM NORTHWEST ONTARIO
TO QUEBEC. THE EAST FLOW WILL LIKELY REQUIRE A SMALL CRAFT ADVISORY
IN THE WEST HALF OF LAKE ERIE BY SOMETIME THURSDAY. A STRONG STORM
SYSTEM WILL TRACK FROM THE SOUTHWESTERN STATES TO THE WESTERN GREAT
LAKES LATE IN THE WEEK. THE WIND WILL CONTINUE TO VEER TOWARD THE
SOUTHEAST AND THEN THE SOUTH LATE IN THE WEEK. SMALL CRAFT
ADVISORIES WILL BE NEEDED AND GALE FORCE WINDS ARE NOT OUT OF THE
QUESTION.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...KIELTYKA
SHORT TERM...LOMBARDY
LONG TERM...TK
AVIATION...DJB
MARINE...KOSARIK
