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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
428 AM EDT SAT APR 18 2015

.SYNOPSIS...
HIGH PRESSURE OVER WESTERN QUEBEC WILL BUILD TO THE EASTERN GREAT 
LAKES BY TONIGHT. LOW PRESSURE WILL TRACK FROM THE GULF COAST TO THE 
CENTRAL GREAT LAKES ON SUNDAY PULLING A WARM FRONT NORTH ACROSS THE 
AREA. A SECONDARY TROUGH WILL PULL A COLD FRONT EAST ACROSS THE AREA 
ON MONDAY. 

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL RIDGE WILL GRADUALLY EXPAND NORTH INTO THE CENTRAL GREAT 
LAKES TODAY. UPSTREAM CIRRUS HAS BEEN DISSIPATING WITHIN THE 
CONFLUENT FLOW ALOFT BUT SHOULD INCREASE TODAY AS THE RIDGE BUILDS 
OVERHEAD. EXPECTING THE CIRRUS TO BE THIN SO WILL CONTINUE WITH A 
MOSTLY SUNNY FORECAST FOR TODAY. AT THE SURFACE...HIGH PRESSURE OVER 
WESTERN QUEBEC WILL BUILD INTO THE CENTRAL GREAT LAKES WITH A LIGHT 
NORTH TO NORTHEAST FLOW OFF LAKE ERIE SETTING UP THIS AFTERNOON. 
THIS WILL HAVE AN EFFECT ON TEMPERATURES ALONG THE IMMEDIATE 
LAKESHORE WITH HIGHS OCCURRING TOWARDS MIDDAY AND THEN FALLING 
DURING THE AFTERNOON. INLAND AREAS SHOULD NOT BE EFFECTED WITH HIGHS 
PEAKING A COUPLE DEGREES HIGHER THAN YESTERDAY. 

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
00Z MODEL SUITE INITIALIZED WITH A 100 KNOT UPPER LEVEL JET MOVING 
NORTHEAST OUT OF MEXICO INTO EASTERN TEXAS. MID AND HIGH CLOUDS WILL 
ARRIVE TONIGHT IN ADVANCE OF THE LEADING JET AND SHORTWAVE ENERGY 
THAT WILL REACH THE AREA ON SUNDAY. CONSIDERABLE MOISTURE ADVECTION 
WILL OCCUR ON SUNDAY AHEAD OF THE SURFACE LOW TRACKING UP THE 
MISSISSIPPI VALLEY. SHOWERS WILL SPREAD NORTH ACROSS THE AREA FROM 
LATE MORNING THROUGH THE AFTERNOON ON SUNDAY. CHANCES FOR 
THUNDERSTORMS APPEAR FAIRLY LOW ON SUNDAY UNTIL THE WARM FRONT 
ARRIVES ON SUNDAY EVENING. BREEZY SOUTHEASTERLY WINDS WILL DEVELOP 
SUNDAY AFTERNOON/SUNDAY EVENING WITH A TIGHT GRADIENT BETWEEN HIGH 
PRESSURE OVER ONTARIO AND THE APPROACHING SURFACE WAVE. THIS WILL
MAINTAIN A BRISK EASTERLY FLOW OFF LAKE ERIE TOWARDS TOLEDO WHICH
WILL LIMIT TEMPERATURES TO THE MID OR UPPER 50S. MID-LEVEL DRY-
SLOT QUICKLY SPREADS NORTH ON SUNDAY NIGHT SO EXPECTING TO SEE A
BREAK IN THE SHOWERS...ESPECIALLY AFTER MIDNIGHT. THE NAM IS
CONSIDERABLY STRONGER WITH THE STRENGTH OF THE APPROACHING SURFACE
LOW...DEEPENING THE SYSTEM TO 987MB OVER NORTHERN INDIANA BY 00Z
MONDAY. THIS IS AN OUTLIER AND WILL LEAN TOWARDS BETTER CONSENSUS
OF GFS/ECMWF...BUT WILL NOT ENTIRELY RULE OUT A SOMEWHAT STRONGER
LOW.

SECONDARY TROUGH AND ASSOCIATED COLD FRONT WILL CROSS THE AREA ON 
MONDAY. MODELS SHOW THE FRONT CLEARING OUR EASTERN AREAS BY LATE 
AFTERNOON WHICH IS A TOUCH ON THE EARLY SIDE FOR MUCH INSTABILITY
TO DEVELOP AHEAD OF THE FRONT. THE WARM SECTOR WILL BE LOCATED ACROSS
EASTERN OHIO WHICH WOULD BE WHERE BEST CHANCES FOR A FEW STRONGER
THUNDERSTORMS COULD DEVELOP. THE STORM PREDICTION CENTER HAS
BROUGHT THE MARGINAL THREAT INTO OUR EXTREME EASTERN COUNTIES ON
MONDAY WHICH SEEMS REASONABLE GIVEN THE SHEER AND DYNAMIC NATURE
OF THIS SYSTEM. HIGHS ON MONDAY WILL DEPEND ON COVERAGE OF
SHOWERS AND TIMING OF FRONT...BUT GENERALLY EXPECTING HIGHS TO
RANGE FROM UPPER 60S EAST TO LOW 60S WEST.

TEMPERATURES ON TUESDAY WILL DROP BACK ANOTHER 10 DEGREES INTO THE 
50S. DESPITE THE LIMITED MOISTURE WILL CARRY A LOW CHANCE OF 
SHOWERS...MAINLY DURING THE AFTERNOON GIVEN THE STEEP LOW LEVEL 
LAPSE RATES.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
THIS PORTION OF THE FORECAST IS STILL NOT CLEAR AS THE MODELS 
DIVERGE. ON WEDNESDAY WITH A WESTERLY FLOW AND THE LAKE AND 850 MB 
TEMPERATURE DIFFERENCE ALMOST 10C SOME LAKE EFFECT RAIN SHOWERS MAY 
BE OCCURRING MAINLY EAST OF CLEVELAND. WEDNESDAY NIGHT ADDED SOME 
SNOW SHOWERS TO THE MIX AS THE 850 MB TEMPERATURE AND 1000-850 MB 
THICKNESS GETS LOW ENOUGH FOR SOME SNOW EVEN THIS TIME OF YEAR. BY 
WEDNESDAY EVENING THE COLD FRONT WILL BE JUST EAST OF THE AREA. .THE 
GFS MODEL DEVELOPS A WAVE ON THE FRONT AND SPREAD RAIN INTO MUCH OF 
THE FORECAST AREA WEDNESDAY NIGHT. THE ECMWF AND CANADIAN MODELS DO 
NOT DO THIS...SO WILL LEAN THAT DIRECTION.  

THE MODELS AGREE A RIDGE STARTS BUILDING IN THURSDAY NIGHT. THE GFS 
BY LATE FRIDAY SPREADS RAIN BACK INTO THE AREA AHEAD OF STRONG LOW 
MOVING THROUGH THE SOUTHERN PLAINS. UNTIL THE TRENDS BECOME CLEARER 
WILL KEEP FRIDAY DRY.

WENT CLOSE TO WPC GUIDANCE AND A LOCAL SCHEME FOR THE TEMPERATURE 
FORECAST.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS FOR THE TAF PERIOD.

A RIDGE ACROSS THE AREA WILL WEAKEN THIS MORNING AS A WEAK COLD
FRONT MOVES THROUGH FROM THE NORTH AFTER DAYBREAK. FEW TO
SCATTERED CLOUDS AT THE MOST WILL ACCOMPANY THE FRONT. OTHERWISE
SOME CIRRUS. DURING THE AFTERNOON THE NORTHEAST WINDS WILL BE A
LITTLE GUSTY OVER NW OHIO WITH A FLOW OFF THE LAKE.

.OUTLOOK..NON VFR AT TIMES SUNDAY AFTERNOON THROUGH WEDNESDAY.

&&

.MARINE...
UNSETTLED WEATHER WILL BEGIN SUNDAY ON LAKE ERIE AND LAST INTO MID 
WEEK.

A WEAK COLD FRONT WILL MOVE ACROSS THE LAKE AFTER DAYBREAK THIS 
MORNING AND THEN A RIDGE WILL BEGIN TO BUILD IN. AS THIS HAPPENS THE 
FLOW ON THE LAKE WILL BECOME NORTHEAST. THE WINDS MAY INCREASE 
ENOUGH THAT WE COULD BE CLOSE TO SMALL CRAFT ADVISORY CRITERIA 
MAINLY ON THE WEST END OF THE LAKE MAINLY THIS EVENING AND TONIGHT. 

ON SUNDAY AND SUNDAY NIGHT THE FLOW WILL BE SOUTHEAST AND THE WINDS 
WILL BE ON THE INCREASE AS A LOW AND WARM FRONT MOVES THROUGH THE 
SOUTHERN GREAT LAKES. THE WINDS MAY MEET THE CRITERIA FOR A SMALL 
CRAFT ADVISORY...THIS WILL HAVE TO BE WATCHED. LATE MONDAY THE COLD 
FRONT WILL MOVES THROUGH AND CONFIDENCE IS HIGH THAT A SMALL CRAFT 
ADVISORY WILL BE NEEDED IN THE MODERATE COLD ADVECTION. THE THREAT 
FOR A SMALL CRAFT ADVISORY WILL CONTINUE AT TIMES INTO WEDNESDAY 
ESPECIALLY ON THE EAST END OF THE LAKE. THE GRADIENT WILL START TO 
DECREASE BY THE END OF THE WORK WEEK AS THE LOW NORTH OF THE GREAT 
LAKES WEAKENS AND A RIDGE BEGINS TO BUILD IN FROM THE PRAIRIE 
PROVINCES.

&&

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

&&

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

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