FXUS61 KILN 300306
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
1006 PM EST SUN NOV 29 2009
.SYNOPSIS...
A COLD FRONT WILL PUSH ACROSS THE REGION TONIGHT BRINGING RAIN
SHOWERS. HIGH PRESSURE WILL THEN BUILD INTO THE AREA LATE MONDAY
INTO TUESDAY....BEFORE A MORE AGGRESSIVE FRONTAL SYSTEM APPROACHES
BY MID WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
A COLD FRONT WILL SLIP SE ACROSS THE REGION OVERNIGHT. LATEST KILN
RADAR WAS SHOWING SHOWERS WELL AHEAD OF THE FRONT ACRS MAINLY THE
ERN FORECAST AREA. THESE SHOWERS WERE OCCURRING IN A ZONE OF 925
MB-850 MB CONVERGENCE. THE BIG DILEMMA OVERNIGHT WILL BE WHAT
HAPPENS TO THE SRN/SERN FORECAST AREA AS AN UPR LVL DISTURBANCE
ROTATES NE FROM THE LOWER MS RIVER VLY TO THE OHIO VLY. MOSAIC
RADAR CONTINUES TO SHOW RAIN ACRS NE ARKANSAS...SE MISSOURI...WRN
KY AND WRN TN. THIS PCPN IS EXPECTED TO RIDE NE ALONG AND AHEAD OF
THE ADVANCING COLD FRONT IN A ZONE OF 850 MB-700 MB CONVERGENCE
ALONG AND JUST BEHIND THE FRONT. HAVE ACCOUNTED FOR THIS PCPN BY
KEEPING LIKELY TO CATEGORICAL POPS ACRS THE FAR SRN AND SERN ZONES
OVERNIGHT. THE REMAINDER OF THE REGION SHOULD SEE SHOWERS END ONCE
FRONT PASSES BY. LOWS WILL RANGE FROM THE LOWER 30S FAR NORTHWEST
TO THE MID 40S FAR SE.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
HAVE TAKEN HIGH TEMPS DOWN A LITTLE FOR MONDAY...AS NW FLOW WORKS
IN. AGAIN STUCK CLOSER TO MAV MOS RATHER THAN NAM NUMBERS. A
QUICKLY MOVING S/WV PUSHES THROUGH MON NIGHT ACROSS THE LOWER
GREAT LAKES...SO HAVE CONTINUED THE SLIGHT CHANCE FOR SHSN IN THE
FAR NORTH.
RIDGING THEN BUILDS IN FOR TUE..BUT AS AGGRESSIVE SPLIT FLOW
PATTERN DEVELOPS IN THE SOUTHERN PLAINS AND NORTHERN
PLAINS...HIGH WILL PUSH PRETTY QUICKLY EAST AHEAD OF THE SOUTHERN
LOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
IN SPLIT FLOW PATTERN SOUTHERN STREAM UPPER LOW OVER TEXAS TO LIFT
NE INTO THE LOWER OHIO VALLEY ON WEDNESDAY AND THEN LIFT INTO THE
OHIO VALLEY WED NIGHT AND MERGE WITH FLOW AHD OF A DIGGING LONG WAVE
TROF. OPERATIONAL NUMERICAL MODEL SOLNS AND SREF MEAN TRENDING A LTL
SLOWER WITH THIS SYSTEM. SO THEREFORE HAVE HELD OFF RAIN UNTIL WED
AFTN WITH PRECIP SPREADING IN FROM THE SOUTH. WITH ASSOCIATED SFC
WAVE TRACKING INTO THE UPR OHIO VALLEY WED NIGHT HAVE INCREASED POPS
TO LKLY ACRS THE SOUTHEAST. ALSO...AS COLDER AIR FUNNELS INTO THE
REGION BEHIND THE LOW EXPECT A CHANGE OVER TO SNOW. WITH MOISTURE
LINGERING AND DIGGING UPR TROF...THIS MAY BE THE FIRST ACCUMULATING
SNOW OF THE SEASON IN MANY LOCATIONS.
DEEP UPPER LEVEL TROF TO SETTLE INTO THE GREAT LAKES ON THURSDAY
WITH CONSIDERABLY COLDER TEMPS EXPECTED. SNOW SHOWERS TO CONTINUE
WITH LAKE ENHANCED SNOW SHOWERS LIKELY LIKELY ACRS W CENTRAL OHIO
WITH FAVORABLE FETCH OFF LAKE MI. WL END ANY MENTION OF SNOW SHOWERS
FRIDAY AS SFC RIDGING BUILDS INTO THE OHIO VLY.
SOLNS SHOW A LARGE DIVERGENCE NEXT WEEKEND WITH ECMWF MAINTAINING THE
UPPER LOW OVER THE GREAT LAKES WHILE THE GFS IS MORE PROGRESSIVE. WL
FOLLOW SOLN CLOSER TO ECMWF WITH CONTD COLD TEMPERATURE BUT DRY
CONDITIONS WITH SNOW SHOWERS EXPECTED TO REMAIN NORTH OF ILN/S FA.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
A COLD FRONT WILL MOVE ACROSS THE TAF SITES BETWEEN 05Z AND 07Z.
SHOWERS WILL ACCOMPANY THE FRONT...BUT SHOULD TAPER OFF ABOUT 2 TO
3 HOURS AFTER FRONTAL PASSAGE. BIGGEST CONCERN OVERNIGHT INTO
MONDAY MORNING WILL BE THE POTENTIAL FOR IFR CIGS. UPSTREAM
OBSERVATIONS WERE INDICATING IFR CIGS ALONG AND BEHIND THE
FRONT...AND MOST MODEL SOUNDINGS SUPPORT THIS. THUS...HAVE PLACED
A 3 TO 4 HOUR PERIOD OF IFR CIGS AT THE TAF SITES. WILL HAVE TO
MONITOR TRENDS SHOULD IFR CONDITIONS LAST LONGER INTO MONDAY MORNING.
OTHERWISE...A SFC RIDGE OF HIGH PRESSURE WILL BUILD INTO THE OHIO
VALLEY ON MONDAY. MVFR CIGS WILL LIFT TO VFR BETWEEN 16Z AND 18Z.
AN UPPER LEVEL WX DISTURBANCE AND ASSOCIATED SFC TROF IS FORECAST
TO MOVE ACROSS THE LOWER GREAT LAKES MONDAY NIGHT. PRECIPITATION
ASSOCIATED WITH THIS FEATURE IS EXPECTED TO REMAIN MAINLY NORTH OF
THE TAF SITES ATTM.
OUTLOOK...MVFR/IFR CIGS/VSBYS POSSIBLE WITH RAIN AND SNOW SHOWERS
WEDNESDAY NIGHT INTO THURSDAY. MVFR CIGS POSSIBLE ON FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...JDR
LONG TERM...AR
AVIATION...HICKMAN
