-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCLE 211737
AFDCLE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
137 PM EDT TUE MAY 21 2013

.SYNOPSIS...
THE AIR MASS WILL BECOME INCREASINGLY MOIST AND UNSTABLE THROUGH MID
WEEK AS AN AREA OF LOW PRESSURE OVER THE UPPER MIDWEST SLOWLY
APPROACHES THE REGION. THIS LOW PRESSURE SYSTEM WILL TRACK THROUGH
THE EASTERN GREAT LAKES LATE WEDNESDAY AND PUSH A COLD FRONT SOUTH
ACROSS THE AREA ON THURSDAY. HIGH PRESSURE WILL RETURN FOR THE END
OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AXIS OF WEAK LIFT MOVING EAST ACROSS THE CENTRAL PART OF THE CWA
ATTM. NEAR TERM MODELS GENERATE CONVECTION FROM THIS FEATURE OVER
THE SNOWBELT AREA BY 17Z WITH THE HRRR BY FAR THE MOST GENEROUS.
SINCE THE HRRR USUALLY TENDS TO BE OVERDONE WITH THIS TYPE OF
CONVECTION WILL ONLY RAMP UP A SLIGHT OR SMALL CHANCE POP FOR THIS.
OTHERWISE WILL GRADUALLY RAMP UP CHANCE POPS FOR SCT CONVECTION TO
DEVELOP DURING THE AFTERNOON BUT NOT SEEING THE COVERAGE AS
WIDESPREAD AS PREVIOUS THINKING. WILL INCREASE TEMPS OVER THE WEST
AND CENTRAL A LITTLE AS MID CLOUDS WILL BE ABSENT OVER THESE AREAS
FOR THE PEAK HEATING HOURS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
SOME LEFT OVER SHOWERS AND THUNDERSTORMS IN THE EVENING AND THEN
THE AREA SHOULD BE IN A LULL FOR MUCH OF TONIGHT AND THEN WAITING
FOR THE NEXT SYSTEM TO AFFECT THE REGION FOR WEDNESDAY INTO
WEDNESDAY NIGHT. THIS WILL BE THE DAY WITH THE BEST CHANCE OF
SEVERE WEATHER. THE COLD FRONT MOVES THROUGH ON THURSDAY. FRIDAY
SHOULD BE DRY AND COOL WITH HIGH PRESSURE BUILDING IN.

THE TEMPERATURE FORECAST IS TOUGH...ESPECIALLY THE HIGHS. IF THE
SHOWERS AND THUNDERSTORMS DEVELOP EARLY OR IF WE HAVE A LOT OF
DEBRIS CLOUDS THAT WILL AFFECT THE HIGHS. USED A BLEND OF GUIDANCE.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
MODELS IN DISAGREEMENT IN THE EXTENDED.  GFS CONTINUES WITH CANADIAN
HIGH PRESSURE OVER THE ENTIRE AREA THROUGH THE WEEKEND.  THE ECMWF
ON THE OTHER HAND HAS ANOTHER FRONT PUSH THROUGH THE AREA ON
SATURDAY...AND IS THUS WETTER AND COOLER.  SINCE THE GFS HAS BEEN
CONSISTENT WITH THIS SOLUTION IGNORED THE ECMWF AND WENT WITH THE
GFS FORECAST.  THIS WILL RESULT IN DRY NORTHERLY FLOW FOR THE AREA
FOR THE ENTIRE WEEKEND AND SLIGHTLY BELOW NORMAL TEMPERATURES.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
MORE UNCERTAINTY TODAY AS FAR AS PRECIP CHANCES GO. MUCH DRIER AIR
HAS WORKED INTO THE WESTERN HALF OF THE AREA WITH DEWPOINTS DOWN
INTO THE 50S. HAVING A TOUGH TIME EVEN GETTING CU THAT AREA AND
PRECIP CHANCES THROUGH THE EVENING HOURS APPEAR MINIMAL. MODELS
SHOWING AN UPPER TROUGH MOVING INTO LOWER MI LATER TODAY WHICH
COULD KICK OFF SOME TSRA ACTIVITY. THIS ACTIVITY COULD COME CLOSE
TO KTOL. FURTHER EAST THE AIRMASS REMAINS MORE UNSTABLE. GUIDANCE
SUGGESTS SOME POP UP STORMS ARE POSSIBLE LATER THIS AFTERNOON.
WILL USE A COMBINATION OF TEMPOS AND VCTS FOR A FEW HOURS THIS
EVENING. THE OVERNIGHT HOURS SHOULD BE DRY WITH JUST PATCHY MVFR
FOG TOWARD DAYBREAK. WEDNESDAY SHOULD BE A MORE ACTIVE DAY AND
WILL BRING MORE PRECIP INTO THE WEST TOWARD MIDDAY. GUSTY S TO SW
FLOW WILL DIMINISH THIS EVENING.

.OUTLOOK...NON VFR PROBABLE IN SHOWERS/THUNDERSTORMS WEDNESDAY AND
THURSDAY.
-- End Changed Discussion --

&&

.MARINE...
SOUTH TO SOUTHWEST FLOW WILL CONTINUE ON THE LAKE THROUGH MID WEEK.
MODELS HAVE BEEN CONSISTENT WITH THE NEXT SYSTEM MOVING ACROSS THE
LAKE ON THURSDAY.  SMALL CRAFT ADVISORY WILL BE NEEDED AS NORTH TO
NORTHWEST WINDS INCREASE TO 15 TO 25 KNOTS IN COLDER AIR.  THE 850MB
TEMPS DIP TO 2C BY THE WEEKEND.  STRONG TO SEVERE STORMS APPEAR
POSSIBLE BOTH TODAY AND WEDNESDAY.  BOATERS WILL NEED TO REMAIN
ALERT.

&&

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

&&

$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...DJB
AVIATION...KUBINA
MARINE...DJB