000
FXUS61 KILN 172321
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
721 PM EDT SAT MAY 17 2008
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL DROP SOUTHEAST ACROSS THE AREA
TONIGHT AND SUNDAY. HIGH PRESSURE AND DRIER AIR WILL MOVE IN FOR
SUNDAY NIGHT INTO MONDAY. ANOTHER AREA OF LOW PRESSURE WILL
AFFECT THE REGION MONDAY NIGHT AND TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SCATTERED SHOWERS AND A FEW THUNDERSTORMS HAVE POPPED UP IN OHIO
ALONG A COLD FRONT. WENT WITH CHANCE OF SHOWERS AND THUNDERSTORMS
ALL ZONES THIS EVENING TO COVER ACTIVITY THAT MAY DEVELOP ALONG
THE FRONT AS IT MOVES SOUTHEAST.
SECOND WAVE OF SHOWERS AND THUNDERSTORMS IS EXPECTED TO A ACCOMPANY
A SHORT WAVE THAT IS PROGGED TO AFFECT THE AREA LATE TONIGHT. THIS
SHORT WAVE IS SIMILAR TO AN ALBERTA CLIPPER...AND IT APPEARS THAT
NORTHERN COUNTIES WILL BE IMPACTED MOST. THEREFORE...RAISED POPS
TO LIKELY IN THE NORTH WITH CHANCE IN THE SOUTH.
TEMPERATURES ARE TRICKY...WITH LOW DEW POINTS OFFSET BY LESS THAN
IDEAL RADIATIONAL COOLING. KEPT LOW TEMPERATURE FORECAST NEAR
GUIDANCE OF AROUND 50.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
EXPECT SHOWERS TO LINGER ON SUNDAY IN MOIST NORTHWEST FLOW AROUND
GREAT LAKES 500 MB LOW. HIGH PRESSURE WILL THEN DOMINATE SUNDAY
NIGHT INTO MONDAY BEFORE THE NEXT AREA OF DISTURBED WEATHER BRINGS
A LOW CHANCE OF SHOWERS MONDAY AFTERNOON. TEMPERATURES WILL BE
RATHER CHILLY DUE TO COLD ADVECTION. READINGS WILL RANGE AROUND
10 DEGREES BELOW AVERAGE...WITH A COOL START OF AROUND 40 ON
MONDAY MORNING.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLY AMPLIFIED MID LEVEL FLOW PATTERN WITH RIDGE OVER THE WEST
AND LONGWAVE TROUGH OVER THE EASTERN US. THIS LONGWAVE TROF WILL
CONTINUE TO INFLUENCE THE WEATHER WITH SEVERAL DISTURBANCES ROTATING
SE THROUGH THE OHIO VALLEY. THIS KEEPS ILN/S FA IN NORTHWESTERLY
FLOW ALOFT THRU MUCH OF THE WEEK WITH HEIGHT RISES AND A WARM UP
EXPECTED FOR NEXT WEEKEND.
BEST CHANCE FOR RAIN WILL BE WITH A CLIPPER SYSTEM MONDAY NIGHT AND
TUESDAY. ALSO HAVE SLIGHT CHC POPS LATE WED AFTN INTO WED EVENING
FOR SYSTEM DROPPING THRU THE GREAT LAKES. BEST CHC FOR A SHOWER
WL BE OVER THE NE WHERE MSTR AND LIFT IS BEST. HAVE DRIED OUT
THURSDAY WITH SFC RIDGING BUILDING IN.
HAVE GENERALLY TRENDED TEMPS CLOSER TO ENSEMBLE MEAN VALUES.
&&
.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
LOW PRESSURE DEVELOPING OVER EASTERN IOWA THIS EVENING WILL TRACK
EAST ACROSS NORTHERN INDIANA AND NORTHERN OHIO OVERNIGHT. THE LOW
WILL BE ASSOCIATED WITH A COLD FRONT...WHICH IS EXPECTED TO
PASS ACROSS THE TAF SITES BETWEEN 09Z AND 12Z. AN UPPER LEVEL
DISTURBANCE...IN CONJUNCTION WITH SUFFICIENT 925 MB-850 MB
CONVERGENCE DUE TO A LOW LEVEL JET...WILL RESULT IN SHOWER
DEVELOPMENT ACROSS ILLINOIS AND INDIANA THIS EVENING...SPREADING
EAST ACROSS THE FORECAST REGION AFTER MIDNIGHT. WIDESPREAD
SHOWERS ARE THUS EXPECTED OVERNIGHT. SOME MVFR CIGS WILL OCCUR
WITH THE SHOWERS...ALONG WITH SOME MVFR VSBYS DUE TO THE PROSPECT
OF MODERATE RAIN. HAVE KEPT THE CB DESCRIPTOR AT ALL TAF SITES
FOR THE POSSIBILITY OF ISOLATED THUNDERSTORMS SINCE FORECAST
MODELS CONTINUE TO INDICATE ELEVATED INSTABILITY. ONCE THE COLD
FRONT PASSES BY...WIDESPREAD PRECIPITATION WILL COME TO AN END.
THE LOWER GREAT LAKES AND OHIO VALLEY REGION WILL REMAIN UNDER A
COOL NORTHWEST FLOW ALOFT THANKS TO A MID LVL LOW PRESSURE SYSTEM
ACROSS SOUTHERN ONTARIO. AS A RESULT...CONSIDERABLE CUMULUS
DEVELOPMENT IS FORECAST IN THE WAKE OF THE COLD FRONT ALONG WITH
THE POSSIBILITY OF SCATTERED LIGHT SHOWERS...MAINLY DUE TO SHALLOW
INSTABILITY. A WEAK RIDGE OF HIGH PRESSURE IS EXPECTED TO BUILD
INTO THE REGION AFTER 00Z MONDAY. WINDS WILL BE GUSTY ON SUNDAY...
PERHAPS AROUND 25 KNOTS BETWEEN 14Z AND 00Z.
OUTLOOK...MVFR CIGS AND VSBYS POSSIBLE MONDAY NIGHT AND TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO
NEAR TERM...CONIGLIO
SHORT TERM...CONIGLIO
LONG TERM...AR
AVIATION...HICKMAN
