FXUS61 KCLE 300512
AFDCLE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
1212 AM EST MON NOV 30 2009
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA OVERNIGHT...HOWEVER AN
UPPER TROUGH OF LOW PRESSURE WILL LINGER OVER THE AREA THROUGH
MONDAY. A RIDGE OF HIGH PRESSURE WILL BUILD IN FOR TUESDAY BUT
GIVE WAY TO ANOTHER LOW PRESSURE SYSTEM FOR THE SECOND HALF OF THE
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SHOWERS WILL BE DECREASING FROM THE WEST OVERNIGHT...INDICATED
THAT IN THE UPDATED ZONE/GRIDS. AT 01Z THE COLD FRONT WAS OVER
NORTHWEST OHIO AND IT WAS MOVING SOUTHEAST. IT WILL BE OUT OF THE
FORECAST AREA BY ABOUT 06 OR 07Z. AT THIS TIME IT LOOKS LIKE THE
PRECIPITATION WILL END OR TAPER OFF TONIGHT BEFORE IT IS COLD
ENOUGH TO SNOW. IT WILL BE CLOSE THOUGH. FORECASTED MINIMUM
TEMPERATURES LOOKED GOOD...EXCEPT CLOSE TO LAKE ERIE...MADE SOME
MINOR ADJUSTMENTS.
TOTAL RAINFALL AMOUNTS TONIGHT WILL BE MAINLY UNDER A QUARTER INCH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
BOTH GFS AND NAM SHOWING THE AREA DRYING OUT FROM THE WEST AFTER
12Z TUE AHEAD OF NEXT TROUGH OF LOW PRESSURE THAT IS EXPECTED TO
SWING THROUGH THE AREA LATE MONDAY AND MONDAY NIGHT. WITH THAT
BROUGHT CHC POPS BACK INTO MUCH OF THE AREA MONDAY NIGHT AS ANY
PRECIP WILL BE MORE WIDESPREAD THAN JUST LAKE EFFECT. WITH H850
TEMPS WELL BELOW FREEZING WENT WITH SNOW SHOWERS RATHER THAN
RAIN/SNOW MIX. FORECAST SURFACE TEMPS IN LOWER 30S FOR MUCH OF THE
AREA ALSO SUPPORT ALL SNOW FOR PRECIP.
TROUGH FAIRLY PROGRESSIVE AND MOVES OFF TO THE EAST ON TUESDAY.
BROUGHT DRY CONDITIONS FOR MUCH OF THE AREA WITH HIGH PRESSURE RIDGE
ATTEMPTING TO BUILD IN AND FLOW TURNING MORE WESTERLY. THE ONLY
LOCATIONS LEFT THROUGH TUESDAY WITH CHC POPS ARE FAR NE OH AND NW PA
FOR ANY LINGERING SNOW SHOWERS. HIGH PRESSURE BUILDS OVER THE AREA
TUESDAY NIGHT ALLOWING FOR DRY CONDITIONS THROUGHOUT THE ENTIRE
FORECAST AREA. HAVE TEMPS DROPPING BACK TO LOWER 30S TUESDAY NIGHT
WITH HIGH PRESSURE RIDGE INFLUENCE. TEMPS WARMING ALOFT DURING THIS
TIME BUT CAN SEE A BIT SEE A BIT COOLER IF COLD FRONT FROM THE UPPER
MIDWEST IS SLOWER AND WINDS MORE CALM THAN EXPECTING.
HAVE CONDITIONS DRY FOR WEDNESDAY MORNING BUT THEN IT LOOKS LIKE A
RATHER INTERESTING WEATHER SITUATION MAY SET UP FOR WEDNESDAY
EVENING THROUGH THE END OF THE WEEK. BOTH GFS AND LATEST ECMWF
SHOWING LOW PRESSURE DEVELOPING OVER THE GULF COAST STATES ON
WEDNESDAY AND THEN TRACKING NORTHEASTWARD THROUGH THE APPALACHIANS
AND NEW ENGLAND BY THURSDAY NIGHT. GFS SHOWING LOW PRESSURE TRACKING
RIGHT UP APPALACHIANS. LATEST ECMWF NOW SHOWING SIMILAR SOLUTION BUT
IS A CHANGE FROM THE PREVIOUS RUN WHERE THERE WAS MORE OF A COASTAL
LOW DEVELOPMENT WITH INITIAL LOW PRESSURE WEAKENING JUST TO THE EAST
OF THE AREA. HAVING CONCERNS WITH THE MODELS AT THIS TIME GIVEN THE
DEVELOPMENT AND TRACK OF THE LOW PRESSURE IS CURRENTLY BEING DRIVEN
BY TWO FEATURES. FIRST...UPPER LOW PULLING OUT OF THE SOUTHWEST AND
DEVELOPING SURFACE LOW WELL TO THE SOUTH...AND SECOND NORTHERN
STREAM TROUGH DIGGING SOUTHEAST FROM CANADA IS EXPECTED TO THEN
INTENSIFY LOW PRESSURE AND STEER IT NORTHWARD. CONFIDENCE IN PERFECT
TIMING OF THE TWO FEATURES MERGING TOGETHER AND INTENSIFYING LOW
PRESSURE NEAR OR TO THE EAST OF THE AREA IS SOMEWHAT MARGINAL GIVEN
THIS EVENT IS STILL FIVE DAYS OUT. DESPITE A LACK OF CONFIDENCE IN
INTENSITY AND SPECIFIC TRACK OF THE LOW PRESSURE...MODELS ARE IN THE
BIG PICTURE CONSISTENT WITH THERE BEING A LOW PRESSURE IN THE
VICINITY WITH SOME FORM OF PRECIPITATION AROUND BETWEEN THE
WEDNESDAY NIGHT AND THURSDAY NIGHT PERIOD. WITH THAT ALREADY BROUGHT
POPS UP TO LIKELY ESPECIALLY ACROSS EASTERN PORTIONS OF THE AREA.
WHILE THERE WILL BE SOME WEATHER TO CONTEND WITH EARLY IN THE
UPCOMING WEEK...THERE IS CERTAINLY THE NEED TO MONITOR MODEL TRENDS
AND FUTURE FORECASTS AS THIS STORM SYSTEM DOES HAVE THE POTENTIAL
FOR ACCUMULATING SNOW LATER THIS WEEK.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
STRONG COLD AIR ADVECTION WILL OCCUR OVER MUCH OF THE FORECAST AREA
AS THE EAST COAST LOW PRESSURE SYSTEM MOVES TO THE NORTHEAST. BOTH
GFS AND ECMWF AGREE 850MB AS LOW AS -10-12 WILL ADVECT OVER THE
LAKES THURSDAY NIGHT INTO FRIDAY. THIS COLD AIR COMBINED WITH DEEP
SYNOPTIC LEVEL MOISTURE FROM THE DEPARTING EAST COAST SYSTEM WILL
SETUP A PRIME LAKE EFFECT SNOW SCENARIO. THE LAKE EFFECT SHOULD
BEGIN THURSDAY NIGHT AS THE SYNOPTIC PRECIPITATION ENDS. THE INITIAL
FLOW WILL BE NW WHICH WILL EFFECT THE PRIMARY SNOWBELTS. AT THIS
TIME...THE MODELS SHOW A SHIFT OF THE 850MB FLOW TO A MORE WESTERLY
DIRECTION FOR FRIDAY AND EARLY SATURDAY. THIS WILL SHIFT THE FOCUS
OF THE LAKE EFFECT INTO THE NEAR LAKESHORE AREAS OF LAKE...ASHTABULA
AND ERIE PA. WARM AIR ADVECTION WILL QUICKLY WARM THINGS UP
SATURDAY INTO SUNDAY. THIS WILL BRING AN END TO THE LAKE EFFECT AND
POSSIBLY BRING SOME RAIN SHOWERS TO THE REGION ON SUNDAY.
&&
.AVIATION /05Z MONDAY THROUGH FRIDAY/...
COLD FRONT MOVING THROUGH THE SOUTHERN PORTION OF THE FORECAST
AREA. PLENTY OF MVFR AND IFR CONDITIONS OCCURRING. CONDITIONS WILL
BEGIN TO IMPROVE FROM THE NORTHWEST...CONDITIONS ALREADY IMPROVING
AT TOL. THE SHOWERS WILL BE ENDING BEFORE IT IS COLD ENOUGH FOR SNOW.
CONDITIONS WILL TRY TO BECOME VFR ON MONDAY AND THEN CONDITIONS
WILL GO BACK TO MVFR IN NORTHEAST OHIO AND NORTHWEST PA MONDAY
NIGHT.
.OUTLOOK...NON VFR DEVELOPING WEDNESDAY NIGHT AND CONTINUING INTO
THURSDAY NIGHT.
&&
.MARINE...
SOUTHWEST WINDS CONTINUE OVER THE LAKE WITH MOST LOCATIONS IN THE 10
TO 15 KNOT RANGE. SOUTHWEST WIND WILL CONTINUE THIS EVENING AND
SLIGHTLY INCREASE AS A COLD FRONT APPROACHES THE LAKE. WINDS WILL
SHIFT TO THE NORTHWEST 00Z-06Z ACROSS THE LAKE. WINDS WILL THEN
INCREASE TO 15 TO 25 KNOT RANGE AS COLD AIR ADVECTION MOVES OVER THE
LAKE OVERNIGHT. A RETURN FLOW WILL SETUP QUICKLY ON MONDAY AND WINDS
WILL SHIFT TO THE WEST IN THE AFTERNOON AND EVENTUALLY BACK TO THE
SOUTHWEST BY MONDAY NIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
LEZ142>149.
&&
$$
SYNOPSIS...ABE
NEAR TERM...KIELTYKA
SHORT TERM...ABE
LONG TERM...GARNET
AVIATION...BC/KIELTYKA
MARINE...GARNET
