000
FXUS61 KCLE 201959
AFDCLE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OH
359 PM EDT MON MAY 20 2013

.SYNOPSIS...
THE AIRMASS 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. HIGH PRESSURE WILL RETURN FOR THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A HOT AND HUMID AIRMASS IS IN PLACE OVER THE REGION THIS AFTERNOON
AS WE REMAIN BENEATH THE UPPER LEVEL RIDGE. DEWPOINTS ARE IN THE MID
AND UPPER 60S ACROSS MOST OF THE AREA AND THE SPC RUC ANALYSIS
INDICATES OVER 2000 J/KG OF ML CAPE. DESPITE THIS...SPECIAL 18Z
SOUNDING OUT OF DTX INDICATES A STRONG CAP IS IN PLACE BETWEEN
875-650MB WHICH IS REPRESENTATIVE OF THE AIRMASS ACROSS NRN OHIO.
THE CU FIELD HAS ACTUALLY BEEN CLEARING ACROSS NW OHIO WHERE
DEWPOINTS HAVE MIXED DOWN INTO THE MID 60S. A LINE OF THUNDERSTORMS
IS DEVELOPING ACROSS WESTERN LOWER MICHIGAN AS A SPOKE OF ENERGY
EJECTS OUT OF THE UPPER TROUGH. HI-RES MODELS INDICATE THIS BAND
WILL CONTINUE TO FILL IN TO THE SOUTH ALONG THE ENHANCED CU FIELD TO
THE WEST AND CLIP THE TOLEDO AREA BEFORE MOVING EAST ACROSS LAKE
ERIE BETWEEN 00-03Z. IF THIS OCCURS...THERE IS THE POTENTIAL FOR
SOME THUNDERSTORMS TO BE SEVERE ALTHOUGH INSTABILITY WILL BE
DECREASING AND WIND FIELD IN NW OHIO IS NOT AS FAVORABLE. WILL CARRY
POPS ACROSS MAINLY THE NORTHERN CWA TONIGHT TO ACCOUNT FOR THIS
ACTIVITY WITH POPS INCREASING ACROSS WESTERN AREAS TOWARDS DAWN AS A
LOW LEVEL JET APPROACHES. TEMPERATURES WILL BE MILD OVERNIGHT WITH
LOWS ONLY DROPPING INTO THE UPPER 60S/NEAR 70 DEGREES.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
UPPER LEVEL RIDGE AXIS WILL SHIFT EAST OF THE AREA ON TUESDAY AS THE
APPROACHING LOW PRESSURE SYSTEM MOVES INTO THE WESTERN LAKES REGION.
SHORTWAVE ENERGY IS EXPECTED TO EJECT OUT OF THE TROUGH TOWARDS THE
AREA AND HELP TO INITIATE CONVECTION. MODELS ALSO INDICATE A LOW
LEVEL JET WILL CLIP NW OHIO ON TUESDAY MORNING AND CONVECTION COULD
MOVE INTO THE AREA FROM THE WEST DURING THE MORNING. THERE IS SOME
UNCERTAINTY AS TO HOW ACTIVITY WILL EVOLVE...IF IT WILL CONTINUE
EASTWARD DOWN WIND OF THE LLJ OR IF WAIT UNTIL WE DESTABILIZE TO
INITIATE. CLOUD COVER COULD BE A LIMITING FACTOR FOR DESTABILIZATION
BUT EXPECT WE WILL STILL SEE STRONG WITH TEMPERATURES IN THE LOW 80S
AND DEWPOINTS IN THE 60S. A SPEED MAX AT 500MB WILL ALSO MOVE ACROSS
NW OHIO AND HELP TO SUPPORT CONVECTION. GIVEN THE FAVORABLE SHEAR
AND MODERATE INSTABILITY THE WESTERN HALF OF THE FORECAST AREA IS IN
A SLIGHT RISK FOR SEVERE WEATHER. EXPECTING THE PRIMARY THREAT TO BE
WIND GIVEN THE STRONG FLOW ALOFT. FREEZING LEVELS ARE HIGH NEAR
13.5KFT SO ONLY THE STRONGEST STORMS WILL BE ABLE TO PRODUCE HAIL
AND THE SURFACE FRONT REMAINS TO OUR WEST SO LOW LEVEL SHEAR WILL
NOT BE VERY FAVORABLE FOR TORNADOGENESIS. WITH THAT SAID...A LOW
CHANCE DOES STILL REMAIN FOR BOTH HAIL AND TORNADOES. SHEAR IS
CONSIDERABLY LOWER ACROSS THE EASTERN CWA AND STORM MOTION WILL BE
TO THE NORTHEAST AT ABOUT 35 MPH SO THE SEVERE THREAT WILL BE
LOWER...MAINLY EAST OF I-71.

EXPECTING A LULL IN SHOWERS AND THUNDERSTORMS ON TUESDAY NIGHT SO
WILL JUST HOLD ONTO A CHANCE POP. AN UPPER LEVEL JET WILL ROUND THE
BASE OF THE TROUGH TUESDAY NIGHT WITH THE TROUGH AXIS SWINGING
NORTHEAST TOWARDS THE OHIO VALLEY ON WEDNESDAY. CLOUD COVER IS AGAIN
IN QUESTION BUT LARGE SCALE ASCENT WILL BE STRONGER ON WEDNESDAY AND
EXPECT WIDESPREAD SHOWERS AND THUNDERSTORMS DURING THE DAY. THERE IS
AGAIN A SLIGHT RISK OF SEVERE STORMS ACROSS NEARLY THE ENTIRE
FORECAST AREA WITH BETTER INSTABILITY FOCUSED ACROSS THE EAST.

THE LOW PRESSURE SYSTEM WILL MOVE NORTHEAST THROUGH THE CENTRAL
GREAT LAKES ON WEDNESDAY AND FINALLY PUSH A COLD FRONT SOUTH ACROSS
THE AREA WEDNESDAY NIGHT AND THURSDAY. INSTABILITY AXIS WILL BE TO
OUR EAST FINALLY BY THURSDAY SO ONLY CARRIED THUNDERSTORMS IN THE
SOUTHERN COUNTIES WITH HIGHS NEAR TO JUST SLIGHTLY BELOW NORMAL.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
BY THE START OF THE LONG TERM PERIOD...HIGH PRESSURE IS EXPECTED TO
BE SITUATED OVER THE CENTRAL GREAT LAKES.  THIS WILL RESULT IN DRY
NORTHERLY FLOW FOR THE AREA FOR THE ENTIRE WEEKEND.  THE ENTIRE FOUR
DAY LONG TERM PERIOD SHOULD BE DRY.  TEMPS WILL STRUGGLE TO GET OUT
OF THE MIDDLE 60S ON FRIDAY AND OUT OF THE UPPER 60S BOTH SATURDAY
AND SUNDAY.  READINGS SHOULD RETURN TO CLOSE TO NORMAL ON MONDAY AS
A WARM FRONT APPROACHES FROM THE SOUTH.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
AREA OF STRATUS OVER N-CENTRAL HAS LIFTED TO MVFR AND CONTINUES
TO ERODE FROM THE EDGES. EXPECT ALL AREAS TO BE VFR IN AN HOUR OR
TWO. STILL A LOT OF QUESTIONS ABOUT THUNDERSTORM ACTIVITY DURING
THE PERIOD. BEST GUESS RIGHT NOW IS THAT NW OH COULD SEE SOME
STORMS TOWARD EVENING. WILL GO WITH A MENTION OVER ABOUT THE WEST
HALF OF THE AREA. EASTERN AREAS SHOULD BE CAPPED AND WILL REMAIN
DRY THROUGH 18Z TUESDAY. ANOTHER ROUND OF STORMS COULD AFFECT
WESTERN AREAS BY MIDDAY TUESDAY. S TO SW FLOW WILL CONTINUE.
SPEEDS SHOULD BE 5 KNOTS OR LESS LATER TONIGHT WHICH SHOULD ALLOW
SOME PATCHY MVFR FOG TO DEVELOP BEFORE DAYBREAK. SPEEDS WILL
INCREASE ON TUESDAY MORNING WITH GUSTS TO 20 KNOTS LIKELY. KERI
ALREADLY HAS A LAKE BREEZE. DO NOT THINK IT WILL REACH KCLE TODAY.

.OUTLOOK...NON VFR PROBABLE IN SHOWERS/THUNDERSTORMS OVERNIGHT THROUGH
THURSDAY.

&&

.MARINE...
SOUTH TO SOUTHWEST FLOW WILL CONTINUE ON THE LAKE TILL A COLD FRONT
CROSSES THE LAKE SOMETIME EARLY THURSDAY.  SPEEDS SHOULD MAINLY BE
UNDER 15 KNOTS TILL THE FRONT ARRIVES. ONSHORE FLOW COULD DEVELOP ON
THE NEARSHORE WATERS BOTH TUESDAY AND WEDNESDAY.  STRONG TO SEVERE
STORMS APPEAR POSSIBLE BOTH TUESDAY AND WEDNESDAY.  BOATERS WILL
NEED TO REMAIN ALERT.  SMALL CRAFT ADVISORIES APPEAR LIKELY FOR
THURSDAY AND FRIDAY WITH STRONG NORTHWEST FLOW BEHIND THE FRONT.
SOME SHOWERS ARE LIKELY ON THURSDAY.  FRIDAY AND SATURDAY WILL BE
DRY.

&&

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

&&

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