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000
FXUS63 KIND 232259
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
659 PM EDT THU MAY 23 2013

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 300 PM EDT THU MAY 23 2013

UPPER TROUGH ACROSS THE LOWER GREAT LAKES WILL MOVE SOUTHEAST ACROSS
THE APPALACHIANS ON FRIDAY AS COOL CANADIAN HIGH PRESSURE SETTLES
ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS WILL RESULT IN CLEARING
TONIGHT WITH BELOW TEMPERATURES THROUGH THE MEMORIAL DAY WEEKEND.
SHOWER CHANCES WILL RETURN BY SATURDAY. TEMPERATURES WILL RETURN TO
NEAR NORMAL MEMORIAL DAY AND ABOVE NORMAL BY MIDWEEK NEXT WEEK.
THUNDERSTORM CHANCES WILL ALSO RETURN NEXT WEEK AS GULF MOISTURE
SPREADS NORTH ACROSS THE OHIO VALLEY.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 300 PM EDT THU MAY 23 2013

MAIN CHALLENGES TONIGHT WILL BE TIMING OF END OF SHOWERS...CLEARING
AND FINALLY TEMPERATURES AS AN UPPER LOW DROPS SOUTHEAST ACROSS THE
LOWER GREAT LAKES AND COOL CANADIAN HIGH SURFACE BUILDS IN BEHIND A
COLD FRONT.

MODELS IN GOOD AGREEMENT ON DROPPING AN UPPER TROUGH...ACROSS THE
WESTERN GREAT LAKES THIS AFTERNOON...TO LAKE ERIE BY FRIDAY MORNING.
IN ADDITION...COOL CANADIAN HIGH PRESSURE WILL BUILD IN BEHIND A
COLD FRONT THAT WAS PRESENTLY NEAR AN IND-HUF LINE. THIS WILL ALLOW
CLEARING FROM NORTHWEST TO SOUTHEAST AS WELL AS AN END TO THE
SHOWERS. THE SHOWERS SHOULD ONLY HANG AROUND TIL DARK ACROSS OUR
EASTERN COUNTIES...SO PULLED SLIGHT CHANCE SHOWER POPS AFTER 02Z.
LEANED TOWARD THE COLDER 12Z NAM MOS WHICH WAS BRINGING OVERNIGHT
LOWS IN THE UPPER 30S ACROSS OUR NORTHWEST OVERNIGHT AND 40S
ELSEWHERE. NORTHWEST WINDS WILL DROP TO BELOW 10 KNOTS AT DARK AS
WELL.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
ISSUED AT 300 PM EDT THU MAY 23 2013

MAIN FOCUS TO THE SHORT TERM WILL BE ON POPS FOR THE MEMORIAL DAY
WEEKEND WITH SO MANY OUTDOOR ACTIVITIES ON TAP.

MODELS IN GOOD AGREEMENT ON COOL CANADIAN HIGH PRESSURE...KEEPING
TEMPERATURES BELOW NORMAL THROUGH THE WEEKEND AS UPPER RIDGE CAMPS
OUT ACROSS THE PLAINS. MODEL TIME SECTIONS SUGGEST CLEAR SKIES
FRIDAY AND FRIDAY NIGHT WITH A DRY COLUMN AND HIGH PRESSURE IN
PLACE. HOWEVER...MODELS IN AGREEMENT ON BRINGING QPF TO ALL OR PARTS
OF CENTRAL INDIANA SATURDAY THROUGH SUNDAY AS UPPER WAVES TOP THE
CENTRAL RIDGE AND DROP SOUTHEAST ACROSS CENTRAL INDIANA. IN
ADDITION...305K ISENTROPIC LIFT WILL BE PLACE WITH INCREASING
MOISTURE. THUS...WILL ADD SMALL POPS SATURDAY AND SATURDAY NIGHT
ACROSS ALL BUT NORTHEASTERN PARTS OF THE FORECAST AREA AND RAISE
POPS SLIGHTLY ON SUNDAY WITH GENERALLY CHANCE POPS WEST OF
INTERSTATES 69 AND 65 AND SLIGHT CHANCE POPS EAST. GULF MOISTURE
DOES NOT START INCREASING UNTIL EARLY NEXT WEEK...AND MODEL TIME
SECTIONS ALSO REVEAL DRY AIR BELOW 850 MILLIBARS. SO...AM
COMFORTABLE WITH THE LOWER ALLBLEND POPS. WOULD NOT RULE OUT THUNDER
SUNDAY...BUT BEST INSTABILITY WILL BE WEST OF CENTRAL INDIANA.

ALLBLEND TEMPERATURES RESEMBLE THE CLOSE MOS AND LOOK REASONABLE
WITH THE COOL CANADIAN AIR POISED TO HANG AROUND.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
ISSUED AT 152 AM EDT THU MAY 23 2013

MODELS ARE SIMILAR ENOUGH FOR THE MOST PART THAT THE ALL BLEND
INITIALIZATION WAS USED FOR MOST ITEMS.

A WARM FRONT WILL REMAIN IN THE NEIGHBORHOOD EARLY IN THE
EXTENDED...WHICH WILL ALLOW SOME SHOWERS AND THUNDERSTORMS TO
DEVELOP. LOCATION OF FRONT AND TIMING OF ITS MOVING NORTHEAST
REMAINS SOMEWHAT UNCERTAIN...SO RELUCTANTLY KEPT LOW POPS IN SUNDAY
NIGHT INTO WEDNESDAY /EVEN THOUGH IT LIKELY WILL NOT RAIN EACH
PERIOD/. RIDGING WILL THEN BUILD IN FOR THE END OF THE PERIOD.

TEMPERATURES WILL WARM THROUGH THE PERIOD AS THE FRONT LIFTS
NORTHEAST AND UPPER RIDGING BUILDS IN.

&&

.AVIATION /DISCUSSION FOR 240000Z TAF ISSUANCE/...

ISSUED AT 659 PM EDT THU MAY 23 2013

MVFR CEILINGS TO PERSIST THROUGH THE EVENING...OTHERWISE VFR
CONDITIONS ANTICIPATED.

BROAD AREA OF MVFR STRATOCU REMAINS ACROSS THE ENTIRE FORECAST
AREA EARLY THIS EVENING IN THE WAKE OF THE COLD FRONTAL PASSAGE
EARLIER TODAY. MODEL SOUNDINGS SHOWING A FAIRLY STOUT INVERSION
INITIALLY THIS EVENING THAT GIVES WAY ONLY SLOWLY. THIS COMBINED
WITH N/NE LOW LEVEL FLOW SHOULD ENABLE LOW CLOUDS TO CONTINUE TO
FUNNEL INTO THE REGION FROM THE LOWER MICHIGAN OVER THE NEXT 3-6
HOURS. BEYOND THAT HOWEVER...THE ARRIVAL OF DRIER AIR ASSOCIATED
WITH STRONG CANADIAN HIGH PRESSURE WILL ALLOW FOR SKIES TO
GRADUALLY CLEAR AT ALL TERMINALS BY DAYBREAK OR SHORTLY
THEREAFTER. N/NW WINDS WILL GUST TO AROUND 20KTS THROUGH THE
EVENING...DIMINISHING TO 10KTS OR LESS OVERNIGHT AS THE HIGH
SPREADS IN.

THE HIGH WILL EXPAND ACROSS THE OHIO VALLEY WITH QUIET WEATHER FOR
FRIDAY. PRESENCE OF THE DEPARTING LOW LEVEL THERMAL TROUGH INTO
THE AFTERNOON MAY BE JUST ENOUGH TO GENERATE A FEW CU AT KIND.
OTHERWISE...ANTICIPATE CLEAR SKIES AND NORTHERLY WINDS TO NEAR
10KTS ALL DAY.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...MK
NEAR TERM...MK
SHORT TERM...MK
LONG TERM....50
AVIATION...RYAN

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