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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
202 AM EDT FRI SEP 4 2015

.SYNOPSIS...
AN UPPER AIR DISTURBANCE OVER THE NORTHERN GREAT LAKES WILL MOVE
SOUTHEAST AND WEAKEN TONIGHT AND FRIDAY. A BROAD AREA OF HIGH
PRESSURE AT THE SURFACE AND ALOFT FROM THE MIDWEST TO EASTERN
CANADA WILL REMAIN NEARLY STATIONARY THROUGH LABOR DAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WITH SUNSET THE INSTABILITY CONTINUES TO WANE TO UNDER 2000J/KG.
THE THUNDERSTORMS ACROSS THE AREA AND THOSE ADVECTING IN ARE NOT
GROWING AS STRONG AS THE EARLIER STORMS THIS EVENING. HOWEVER SOME
VORT ENERGY ASSOCIATED WITH THE UPPER LEVEL TROUGH OVER MI IS
MOVING OVER THE WESTERN BASIN WITH SOME STRONG STORMS. IR
SATELLITE SHOWS THE COLDEST CLOUD TOPS ARE ENTERING NORTHERN OHIO
FROM THE THE NW...YET STORMS ARE SUB-SEVERE AT THIS TIME. WITH
CAPES DIMINISHING AND NO REAL SHEAR TO SPEAK OF...NOT EXPECTING
ANYMORE SEVERE OVERNIGHT. WITH THE AREA OF UPPER LEVEL DIVERGENCE
SLOWLY SLIDING OVER THE REGION TONIGHT CAN'T RULE OUT SOME POP-UP
SHOWERS AND THUNDERSTORMS. GIVEN DEWPOINTS IN UPPER 60S WITH SOME
SOME DEBRIS CLOUDS LOOKING FOR LOW TEMPS AROUND 70....A COUPLE OF
DEGREES ABOVE GUIDANCE IN MOST AREAS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
THE RIDGE ALOFT IS PROGGED TO BUILD OVER THE WEEKEND. 
UNFORTUNATELY...WE REMAIN IN A SLIGHT WEAKNESS ALOFT BETWEEN THE
HIGHEST HEIGHTS OVER THE WESTERN GREAT LAKES AND EASTERN CANADA. A
FEW MORE STORMS WILL BUBBLE UP FRIDAY. THE PATTERN AGAIN WILL BE
SOMEWHAT UNPREDICTABLE... DEVELOPING ON OUTFLOW BOUNDARIES AND
LAKE BREEZE BOUNDARY ETC. THE AMOUNT OF COVERAGE SHOULD DECREASE
OVER THE WEEKEND AS EVEN WARMER AND SOMEWHAT MORE STABLE AIR FROM
THE MIDWEST SHIFTS INTO THE AREA. CANNOT RULE SOMETHING OUT... BUT
WILL CONTINUE WITH THE TREND OF POPS BELOW THE "SLIGHT CHANCE"
THRESHOLD...ABOUT 10 PERCENT... THROUGH THE WEEKEND.

PERSISTENCE ON TEMPERATURES. IF ANYTHING...TEMPS COULD SNEAK UP A 
DEGREE OR TWO BY THE END OF THE WEEKEND WITH HIGHS NEAR/AROUND 90. DO 
NOT BE SEDUCED BY THE MOS GUIDANCE WHICH TRENDS DOWN THIS TIME OF
YEAR BASED ON CLIMATOLOGY.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
THE LONG TERM MODELS ARE STILL IN AGREEMENT THAT THIS 
UPPER-RIDGE PATTERN WILL HOLD THROUGH LABOR DAY. TEMPERATURES WILL 
BE ABOUT 10 DEGREES ABOVE AVERAGE WITH A MINIMAL CHANCE OF RAIN 
THROUGH MONDAY AFTERNOON. I BELIEVE THAT HIGH TEMPERATURES OF 90 
DEGREES ARE WITHIN REASON FOR MANY INLAND AREAS.

AN UPPER-LEVEL TROUGH LOOKS TO DIG INTO THE RIDGE ON TUESDAY WITH AN 
ASSOCIATED SURFACE COLD FRONT. THIS TROUGH FEATURE IS CONSISTENT IN 
THE LONG TERM MODELS BUT THE GFS AND THE ECMWF ARE IN DISAGREEMENT 
WITH THE COLD FRONT THAT WOULD APPROACH THE GREAT LAKES ON MONDAY 
NIGHT INTO TUESDAY. THE GFS BRINGS IN THIS COLD FRONT BY 06-12Z 
TUESDAY AND STALLS IT OVER LAKE ERIE. THE ECMWF BRINGS IN THE COLD 
FRONT ALMOST 12-18 HOURS LATER AT THE EARLIEST AND HAS IT MORE 
ALIGNED WITH A SECONDARY UPPER TROUGH THAT MOVES IN FROM THE WEST. 
BOTH MODEL SOLUTIONS WOULD BRING SOME TYPE OF RAIN CHANCE TO THE 
AREA SO HAVE SLIGHT CHANCE POPS BEGINNING EARLY TUESDAY MORNING WITH 
CHANCE POPS ON TUESDAY INTO WEDNESDAY. 

TEMPERATURE SOLUTIONS ARE QUITE DIFFERENT ON THE BACK SIDE OF THE 
COLD FRONT FOR EACH SOLUTION. THE OVERALL TREND WOULD BE TO TREND 
TOWARDS CLIMATOLOGY BUT GENERALLY THINK THAT COLD FRONT IS WEAK AND 
WILL NOT DRASTICALLY DROP TEMPERATURES. THUS...TRENDED TEMPERATURES 
DOWN USING A BLEND OF THE ECMWF AND CLIMATOLOGY.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
A LARGE AREA OF SHOWERS AND THUNDERSTORMS ACROSS NORTH CENTRAL OHIO 
WILL CONTINUE TO MOVE EAST SOUTHEAST OVERNIGHT. EXPECT THE COVERAGE 
OF THUNDERSTORMS TO TEND TO DIMINISH WITH TIME...BUT NOT BEFORE 
BRINGING ANOTHER ROUND OF THUNDERSTORMS TO CLE/MFD/CAK AND POSSIBLY 
THROUGH 09Z WITH LESSER CHANCES AT YNG/ERI IF MCS HOLDS TOGETHER. A 
LOW STRATUS DECK HAS BEEN TRYING TO DEVELOP AND EXPECT THIS TO BE 
SOMEWHAT VARIABLE OVERNIGHT. VISIBILITIES WILL TEND TO SETTLE INTO 
THE MVFR RANGE BUT A FEW SITES WILL LIKELY DIP INTO THE IFR 
VISIBILITY RANGE. 

SCATTERED THUNDERSTORMS EXPECTED TO DEVELOP AGAIN ON FRIDAY BUT 
TIMING WILL AGAIN BE A CHALLENGE. SUFFICIENT INSTABILITY SHOULD BE 
IN PLACE FOR SHOWERS AND THUNDERSTORMS TO FIRE ALONG REMNANT OUTFLOW 
BOUNDARIES BY MID DAY. TIMING THUNDERSTORMS INTO THE INDIVIDUAL 
TERMINALS WILL NEED TO BE REFINED. 

OUTLOOK...AREAS OF NON VFR EACH MORNING IN FOG AND HAZE. ISOLATED
THUNDERSTORMS MAY DEVELOP EACH AFTERNOON/EVENING THROUGH SATURDAY.

&&

.MARINE...
ONGOING SHOWERS AND THUNDERSTORMS SHOULD SUBSIDE BY THIS 
EVENING AND WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT. SOUTH WINDS 
WILL CONTINUE ON FRIDAY THROUGH LABOR DAY MONDAY AS HIGH PRESSURE 
MOVES OVERHEAD BY SUNDAY. WINDS WILL BECOME MORE SOUTHWESTERLY ON 
MONDAY AHEAD OF AN APPROACHING COLD FRONT THAT WILL MOVE THROUGH 
SOMETIME ON LATE TUESDAY/WEDNESDAY. WAVES WILL BE LESS THAN 2 FEET 
THROUGH THE FORECAST PERIOD AND NO SMALL CRAFT ADVISORIES ARE 
ANTICIPATED AT THIS TIME.

&&

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

&&

$$
SYNOPSIS...KOSARIK
NEAR TERM...JAMISON/KOSARIK
SHORT TERM...KOSARIK
LONG TERM...LOMBARDY/SEFCOVIC
AVIATION...KEC
MARINE...LOMBARDY/SEFCOVIC

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