000
FXUS61 KILN 192358
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
758 PM EDT SAT JUL 19 2008
.SYNOPSIS...
WAVES OF LOW PRESSURE WILL TRACK ACROSS THE GREAT LAKES REGION
THROUGH SUNDAY NIGHT. THESE FEATURES WILL EVENTUALLY CAUSE A COLD
FRONT TO MOVE SOUTHEAST ACROSS THE REGION LATE SUNDAY NIGHT INTO
MONDAY. UNSETTLED WEATHER WILL CONTINUE INTO THE FIRST PART OF
THE WEEK AS AN UPPER LEVEL TROUGH BECOMES ESTABLISHED OVER THE
REGION.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
WITH WEAK UPPER LEVEL FORCING AND LOW LEVEL FORCING...CHC/S FOR
SHOWERS AND THUNDERSTORMS ACRS THE REGION WILL BE SMALL TONIGHT.
LATEST ZONES/GRIDS REFLECT THIS CURRENT THOUGHT. FAR SOUTHERN
ZONES MAY END UP STAYING MOSTLY CLEAR OVERNIGHT. WILL CONTINUE TO
MONITOR SATELLITE/MODEL TRENDS AND WILL UPDATE ZONES/GRIDS IF
NECESSARY. OVERNIGHT LOWS WILL RANGE FROM THE UPPER 60S TO THE
LOWER 70S.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
THE SHORT TERM FORECAST IS MURKY AT BEST IN TERMS OF TRYING TO
PINPOINT THE BEST CHANCE OF RAIN THROUGH MONDAY NIGHT. WILL USE A
BLEND OF THE OPERATIONAL GFS AND OPERATIONAL ECMWF TO COME UP WITH
A DETERMINISTIC SOLUTION.
ON SUNDAY...ANOTHER S/WV IN THE ZONAL FLOW ALOFT WILL MOVE FROM WI
TO MI. THIS SYSTEM WILL PERTURB AN AREA OF SFC LOW PRESSURE WHICH
WILL MOVE ALONG A PREVIOUSLY STALLED OUT FRONTAL BOUNDARY. SINCE
THE MAIN DYNAMICS WITH THE S/WV REMAIN TO THE NORTH...AND ONLY A
SUBTLE LOW LVL CONVERGENCE BOUNDARY IS EXPECTED ACRS OUR FORECAST
AREA DURING THE AFTN/EVENING HOURS...WILL ONLY PLACE A 30 PERCENT
CHC OF SHOWERS AND THUNDERSTORMS IN THE FCST.
FOR SUNDAY INTO SUNDAY NIGHT...WILL DISCOUNT THE NAM/S CONVECTIVE
FEEDBACK SOLUTION OF EXTENSIVE SHOWERS AND THUNDERSTORMS AND WILL
HOLD SWAY WITH THE GFS AND ECMWF. THIS BLENDED SOLUTION BRINGS A COLD
FRONT SLOWLY SE INTO THE FCST AREA BY MONDAY MORNING. AGAIN...WITH
LOSS OF DAYTIME HEATING AND LACK OF SIGNIFICANT DYNAMICS...WILL
ONLY KEEP LOW CHC POPS THROUGH SUNDAY NIGHT ATTM.
FOR MONDAY INTO MONDAY NIGHT...MODELS CONTINUE TO FORECAST A MORE
SIGNIFICANT S/WV TO DIVE SE FROM THE WRN GREAT LAKES TO THE WRN
LOWER GREAT LAKES BY TUESDAY MORNING. THIS WILL HELP PUSH
AFOREMENTIONED COLD FRONT SLOWLY SOUTH OF THE OHIO RIVER THROUGH THE
PERIOD. WITH SOME LOW LVL FORCING INDICATED ALONG AND BEHIND THE
FRONT...ALONG WITH CONSIDERABLE INSTBY OCCURRING ALONG AND BEHIND
THE FRONT ACRS OUR REGION...WILL CONTINUE TO FORECAST AN INCREASE
CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY INTO MONDAY NIGHT. THE
BEST CHANCE APPEARS TO BE MONDAY NIGHT. AS TIME GOES ON AND IF
CONFIDENCE INCREASES...THESE POPS MAY HAVE TO BE RAISED IF IT
BECOMES APPARENT THAT A MORE SIGNIFICANT MCS IS IN THE OFFING.
TEMPERATURES ON SUNDAY WILL AGAIN BE WARM TO HOT...RANGING FROM THE
UPPER 80S NORTH TO THE LOWER 90S SOUTH. TEMPERATURES WILL LOWER ON
MONDAY DUE TO THE INCREASE IN CLOUDS AND THE THREAT FOR PCPN.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
FRONTAL BOUNDARY PUSHES THROUGH AND THEN HANGS UP SOUTH OF FORECAST
AREA BY TUE EVENING THROUGH EARLY THU. KEPT LOW POPS TUE AND
THEN KEPT MIDWEEK DRY...WITH GFS ENS AND ECMWF IN PRETTY GOOD
AGREEMENT THROUGH THIS POINT IN TIME. THEN FOR THU/FRI...MESSY
PATTERNS SETS UP AS S/WV LIFTS INTO AREA FROM CNTRL PLAINS. WHILE
THERE IS A FAIR AMOUNT OF UNCERTAINTY AS FAR AS ANY TIMING...KEPT
LOW POPS THROUGH THU/FRI NIGHT IN ESPECIALLY THE SOUTH WHERE THE SFC
BOUNDARY SEEMS TO HANG UP. BOUNDARY IS FINALLY PUSHED ESE FOR
SATURDAY...SO DRIED OUT AREA HERE. ECMWF TRIES TO HANG UP BOUNDARY A
LITTLE LONGER ACROSS SOUTHERN AREA THAN GFS ENS MEAN. HAVE STUCK
WITH THE MORE PROGRESSIVE SOLUTION FOR THIS FEATURE LATE IN PERIOD.
GENERALLY KEPT WITH ABOVE NORMAL TEMPS THROUGH MID WEEK AND THEN
CLOSER TO NORMAL FOR LATER PART OF WEEK WITH BOUNDARY IN AREA AND
GREATER CHANCE FOR CLOUDS/PRECIP.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
ATTM AREA OF TSTM NR AOH WILL STAY N OF TAFS. THE 18Z NAM APPEARS
TO HAVE BEST HANDLE ON THE CURRENT SITUATION...SO FOLLOWED IT FOR
THE FCST.
BROUGHT IN BKN AC BASED ON CLDS CURRENTLY OVER INDIANA. THESE
CLDS SHOULD MOVE E BY 03Z.
WK H5 S/W MOVES E OVERNIGHT NR THE MI/IN OH BORDER. ASSOCIATED WITH
THIS IS A WK SFC LOW. AHEAD OF LOW IS AREA OF H8 CONVERGENCE AND
HIGHER RH. AM THINKING THAT THIS CONVERGENCE AND RH WILL ONLY BE
REALIZED IN CLDS...SO KEPT FCST DRY OVERNIGHT. BROUGHT 5K FT CIGS
INTO CVG/LUK WITH THIS.
CONVERGENCE BOUNDARY LAYS OUT NR THE OH RIVER BY 12Z...WITH SCT
CONVECTION DEVELOPING ALONG IT IN THE AFTN. PUT PROB30 AT CVG/LUK
AND ONLY CB ELSEWHERE.
OUTLOOK...TSTMS POSSIBLE MONDAY AND TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...JDR
AVIATION...SITES
