000
FXUS61 KCLE 101206
AFDCLE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
706 AM EST WED MAR 10 2010

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH ACROSS THE AREA TODAY. A SERIES OF LOW
PRESSURE SYSTEMS WILL MOVE NORTHEAST TOWARD THE REGION AND THEN
DISSIPATE THROUGH SATURDAY MORNING. LOW PRESSURE WILL DEVELOP ALONG
THE CAROLINA COAST OVER THE WEEKEND AND EXTEND A TROUGH BACK
NORTHWEST OVER THE REGION.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RAIN ASSOCIATED WITH THE WARM FRONT MOVED NORTHEAST ACROSS THE
AREA OVER THE LAST SEVERAL HOURS. SCATTERED RAIN SHOWER ACTIVITY
DEVELOPED ALONG AND BEHIND THE WARM FRONT WITH YET ANOTHER LINE
DEVELOPING FROM SOUTHERN OHIO INTO NORTHEASTERN INDIANA. THIS
ACTIVITY WILL CONTINUE TO MOVE NORTHEAST INTO THE REGION. MODELS
SUGGEST WE WILL SEE REPEATED SHOTS OF POSITIVE VORTICITY ADVECTION
INTO THE AREA THROUGH THE DAY INTO TONIGHT. THIS WILL CONTRIBUTE
TO THE ON AND OFF AGAIN CHANCE FOR SHOWERS THROUGH THE DAY SO WILL
CONTINUE WITH A CHANCE OF SHOWERS ALL DAY.

TEMPERATURES SOUTH OF THE WARM FRONTAL BOUNDARY WERE IN THE LOWER TO
MIDDLE 50S AT THIS HOUR AND THIS WILL LIFT NORTH INTO THE REGION. I
THINK WE SHOULD SEE WARMER TEMPERATURES TODAY COMPARED TO YESTERDAY
DUE TO THE WARM AIR ADVECTION AND THE SOUTH TO SOUTHEAST FLOW.

SO FAR...RIVERS ARE BEHAVING THEMSELVES WITH ONLY KILLBUCK FORECAST
TO REACH FLOOD STAGE.  QUANTITATIVE PRECIPITATION FORECASTS ARE
EXPECTED TO BE AROUND A HUNDREDTH OF AN INCH DURING THE DAY. WARMER
TEMPERATURES WILL ALSO AID IN MELTING OFF SNOW PACK ACROSS THE AREA
AND SLOWLY WHITTLE AWAY AT ANY SURFACE ICE ON THE RIVERS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
FORECAST AREA WILL BE UNDER THE INFLUENCE OF THE WARM AIR ADVECTION
PATTERN THROUGH AT LEAST A PART OF SATURDAY AS THE STORM SYSTEMS
REMAIN MOSTLY WEST OF THE AREA. THE COLD AIR ADVECTION RETURNS ON
SATURDAY WHEN THE EAST COAST LOW BECOMES THE DOMINANT FEATURE.  THE
WARM AIR IN PLACE TONIGHT WILL HELP KEEP TEMPERATURES MUCH WARMER
THAN WE HAVE BEEN FOR HIGH TEMPERATURES OVER THE LAST COUPLE WEEKS.
I WILL KEEP LOWS IN THE LOWER TO MIDDLE 40S OVERNIGHT TONIGHT.

A SERIES OF UPPER LEVEL DISTURBANCES WITH ASSOCIATED MOISTURE
ADVECTION WILL BRING IN PERIODS OF SHOWER ACTIVITY FOLLOWED BY
SUBSIDENCE AND DRY PERIODS.  THE FIRST WAVE IS OVER US AT THIS TIME
FOLLOWED BY A DRY PERIOD FOR THE MOST PART TONIGHT.  ANOTHER SURGE
WILL MOVE INTO THE REGION THURSDAY.

LATEST GUIDANCE FROM SREF HOLDS THUNDERSTORM THREAT OFF UNTIL FRIDAY
AFTERNOON.  THIS IS WHEN THE BEST SURGE OF WARM AIR REACHES THE AREA
CREATING THE BEST INSTABILITY.

EVENTUALLY THE ENTIRE AREA BECOMES ENGULFED IN MOISTURE THURSDAY
NIGHT. THIS COULD BE A PROBLEM FOR THE RIVERS WHEN PRECIPITATION
AMOUNTS REACH A THIRD TO ONE HALF INCH THURSDAY NIGHT.  THIS MAY
CAUSE A RAPID REDUCTION IN THE SNOW PACK AND CAUSE RIVER RISES.
WILL HAVE TO MONITOR THIS SITUATION FOR POSSIBLE FLOOD WATCHES
ACROSS THE FORECAST AREA.

FLOOD GUIDANCE...AMOUNT OF RAIN NEEDED TO PRODUCE FLOODING...APPEARS
TO BE QUITE HIGH CONSIDERING GROUND SOIL IS BECOMING SATURATED WITH
SNOW MELT.  THE PRECIPITATION THREAT DIMINISHES FOR A PERIOD FRIDAY
MORNING AS ANOTHER ROUND OF SUBSIDENCE MOVES INTO THE AREA FOLLOWED
BY ANOTHER MOISTURE SURGE AND UPPER LEVEL SUPPORT FRIDAY AFTERNOON
INTO FRIDAY EVENING. I WILL KEEP PRECIPITATION AMOUNTS FAIRLY LOW
BUT POTENTIAL EXISTS SOME LOCATIONS COULD GET QUITE A BIT OF
RAINFALL DURING THE 12 HOUR PERIOD FRIDAY AFTERNOON INTO FRIDAY
EVENING DUE TO THE CONVECTIVE NATURE.

ON THAT NOTE...THE OTHER PROBLEM IS POSSIBILITY FOR SEVERE
THUNDERSTORMS FRIDAY AFTERNOON AND FRIDAY EVENING. CAPES PUSHING
600...LI DROPPING TO CLOSE TO -2 AND TOTAL TOTALS OF 55.  WINDS
ALOFT ARE NOT THAT IMPRESSIVE WITH 30 TO 40 KNOTS BUT FREEZING
LEVELS DOWN AROUND 7000 FEET.  HAIL MAY WIND UP BEING THE MAIN
THREAT AT THIS TIME.

TEMPERATURES DURING THE PERIOD WILL BE IN THE 50S TO LOWER 60S AND
LOWS IN THE 40S THROUGH FRIDAY AND BACK TO THE UPPER 30S AND LOWER
40S SATURDAY MORNING WITH HIGHS IN THE LOWER 50S.

&&

.LONG TERM /SUNDAY THROUGH TUESDAY/...
THE UPPER LOW WILL FINALLY MOVE OUT OF THE REGION ON TUESDAY. SOME
SHOWERS WILL LINGER INTO MONDAY. HOWEVER...RAINFALL AMOUNTS ARE
EXPECTED TO BE LIGHT. RIVERS AND STREAMS WILL BEGIN TO SLOWLY
RECEDE.

WENT A LITTLE COOLER THAN THE MEX MOS WITH A NORTHEASTERLY
FLOW.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SOME LIGHT SHOWERS ASSOCIATED WITH THE WARM FRONT MOVING THROUGH
THE AREA...MAINLY VFR. A DECREASE IN THE SHOWER THREAT WILL OCCUR
LATER TODAY. SOME BRIEF MVFR CEILINGS COULD OCCUR. ON THE EDGE
ABOUT HOW QUICKLY THE MVFR CEILINGS WILL GET INTO THE AREA. THEY
ARE IN INDIANA. THE MODELS ARE ALL OVER THE PLACE ON THIS. WILL GO
WITH THE SREF AND MOVE THE MVFR CEILINGS AND VISIBILITIES IN
SLOWER. SOME QUESTION ABOUT HOW LOW THE VISIBILITIES WILL GO
TONIGHT WITH INCREASING DEW POINTS OVER THE SNOW PACK. THIS WILL
HAVE TO BE MONITORED.

.OUTLOOK...WIDESPREAD NON-VFR THURSDAY THROUGH SUNDAY...CAUSED BY
SURFACE LOW MOVING THROUGH THE REGION.

&&

.MARINE...
EASTERLY WINDS...SHOULD BECOME SOMEWHAT ONSHORE AS A LAKE BREEZE
WILL DEVELOP TODAY. WINDS WILL BECOME SOUTHEAST WITH A WARM FRONT IN
THE AREA FOR THE REST OF THE WORK WEEK. FOR THE WEEKEND A LOW
ASSOCIATED WITH THE WARM FRONT WILL BE AROUND THE GREAT LAKES AND
THAT WILL TIGHTEN THE PRESSURE GRADIENT. THE MODELS ARE IN GENERAL
AGREEMENT ON THIS. SATURDAY NIGHT THE 925 MB WINDS ARE AROUND 50
KNOTS IN WEAK COLD ADVECTION. SOME QUESTION ON WHETHER THIS IS
CORRECT. THE ECMWF AND GEM MODELS ARE NOT AS STRONG BUT NEAR 35
KNOTS. THIS MAY BE BETTER...IT WILL ALL DEPEND ON HOW STRONG THE
SURFACE LOW GETS AND ITS LOCATION. AT THIS TIME WILL HAVE THE MAX
WINDS UP TO 30 KNOTS.

AS THE DEW POINTS START RISING THE NEXT FEW DAYS DENSE FOG MAY BEGIN
DEVELOPING ON THE LAKE. THIS WILL HAVE TO BE MONITORED.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA

NWS CLE Office Area Forecast Discussion