000
FXUS61 KILN 201741
AFDILN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
141 PM EDT MON MAY 20 2013

.SYNOPSIS...
A MID LEVEL RIDGE WILL BUILD ACROSS THE REGION TODAY. THE RIDGE
WILL MOVE EAST TONIGHT AS A LARGE UPPER LEVEL LOW OVER THE
NORTHERN PLAINS BEGINS TO MAKE A SLOW PROGRESSION TO THE EAST.
THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL INCREASE TUESDAY
INTO WEDNESDAY AS THE LOW CONTINUES TOWARD THE GREAT LAKES. A COLD
FRONT WILL EVENTUALLY PUSH THROUGH OUR AREA WEDNESDAY INTO WEDNESDAY
NIGHT. ABOVE NORMAL TEMPERATURES ALONG WITH A HUMID AIRMASS WILL
REMAIN IN PLACE UNTIL AFTER FRONTAL PASSAGE.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HAVE UPDATED POPS TO LIKELY EAST OF COLUMBUS WHERE LINE OF
THUNDERSTORMS DEVELOPED ALONG A WEAK NORTH-SOUTH ORIENTED
BOUNDARY.

FOR THIS AFTERNOON...A VERY WARM AND HUMID AIRMASS WILL PREVAIL.
WITH THE RIDGE IN PLACE...CONVECTION SHOULD BE HELD AT BAY.
HOWEVER...WITH MODERATE TO STRONG INSTABILITY ALONG WITH A VERY
WEAK CAP...IT IS NOT OUT OF THE QUESTION THAT AN ISOLATED SHOWER
OR STORM COULD POP. GIVEN THAT THIS CHANCE IS ABOUT 10
PERCENT...HAVE LEFT THE FORECAST DRY FOR THE AFTERNOON HOURS.
HIGHS TODAY WILL WARM INTO THE UPPER 80S WITH A FEW SPOTS POSSIBLY
REACHING 90 DEGREES BEFORE THE AFTERNOON IS THROUGH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
HAVE USED A BLEND OF THE GFS...CMC AND ECMWF FOR THE SHORT TERM
FORECAST.

MID LVL RIDGE WILL MOVE EAST TONIGHT AS A LARGE UPR LVL LOW OVER
THE NORTHERN PLAINS PUSHES SLOWLY EAST TOWARD THE GREAT LAKES.
CHANCES OF SHOWERS AND THUNDERSTORMS WILL ENCROACH THE WESTERN
ZONES AS MODELS SUGGEST THAT A WEAKENING COMPLEX APPROACHES THE
REGION.

ON TUESDAY...VERY WARM AND HUMID CONDITIONS WILL CONTINUE. TIMING
AND COVERAGE OF CONVECTION WILL BE DEPENDENT ON PREVIOUS FEATURE
MOVING INTO THE AREA WHICH IS STILL SKETCHY AT THIS TIME. AS A
RESULT...HAVE GONE WITH CHANCE POPS. GIVEN INCREASING SHEAR AND
MODERATE TO STRONG INSTABILITY...A FEW SEVERE STORMS WILL BE
POSSIBLE.

FOR TUESDAY NIGHT...THE THREAT FOR SHOWERS/STORMS WILL
CONTINUE...BUT MODELS SUGGEST THAT WE MAY BE IN A RELATIVE LULL
BEFORE A MORE BONAFIDE S/WV AND ASSOCIATED COLD FRONT AFFECT THE
REGION ON WEDNESDAY.

FOR WEDNESDAY INTO WEDNESDAY NIGHT...UPR LVL LOW WILL DROP
SOUTHEAST INTO THE GREAT LAKES. AS MENTIONED...A MORE BONAFIDE
S/WV IS EXPECTED TO ROTATE NE ACROSS THE AREA ALONG WITH A SFC
COLD FRONT. ALTHOUGH SHEAR WILL BE MODERATE...INSTABILITY WILL BE
A LITTLE LESS THAN TUESDAY GIVEN CLOUDS AND SLIGHTLY COOLER
TEMPERATURES. EVEN SO...CAN NOT RULE OUT A FEW SEVERE STORMS
DURING THE AFTERNOON INTO THE EVENING HOURS.

ON THURSDAY...UPR LVL LOW WILL DROP SE INTO OUR AREA. MODELS
SUGGEST THAT A SECONDARY COLD FRONT/TROUGH AXIS WILL APPROACH THE
REGION FROM THE NORTHWEST...KEEPING THE THREAT FOR SHOWERS AND
ISOLATED STORMS. TEMPERATURES WILL BE COOLER GIVEN CLOUDS AND CAA
WITH HIGHS RANGING FROM THE UPPER 60S NW TO THE MID 70S SOUTHEAST.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS THE SECONDARY FRONT/TROUGH AXIS SHIFTS SOUTH THURSDAY NIGHT...
PCPN SHOULD TAPER OFF FROM NORTH TO SOUTH.

HIGH PRESSURE AND A COOLER AIRMASS WILL BUILD DOWN FROM THE NORTH
THROUGH THE DAY ON FRIDAY. THIS WILL LEAD TO SLIGHTLY BELOW NORMAL
TEMPERATURES WITH HIGHS ON FRIDAY IN THE UPPER 60S TO LOWER 70S. THE
AIRMASS WILL THEN SLOWLY MODERATE THROUGH THE WEEKEND AS MID LEVEL
RIDGING BEGINS TO WORK IN FROM THE WEST. BY SUNDAY...TEMPERATURES
WILL BE BACK TO NEAR NORMAL WITH HIGHS PUSHING BACK TOWARD THE MID
70S. WILL MAINTAIN A DRY FORECAST THROUGH THE WEEKEND AT THIS POINT
BUT THE 12Z ECMWF AND TO A LESSER EXTENT THE 12Z GFS ARE HINTING AT
THE POSSIBILITY OF SOME SHORT WAVE ENERGY DROPPING DOWN IN NORTHWEST
FLOW LATE IN THE PERIOD.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
MVFR CEILINGS WILL PERSIST FOR A FEW MORE HOURS UNTIL MIXING
RAISES CLOUD HEIGHTS AND VISIBILITIES LATER THIS AFTERNOON. WINDS
WILL GUST CLOSE TO 20 KNOTS DURING THIS TIME AS WELL. BR MAY FORM
AGAIN TONIGHT AT LUK AND ILN UNDER LIGHT WINDS AND A HUMID AIRMASS.
DAY MAY SEE A FEW SHOWERS TONIGHT IF ACTIVITY TO THE WEST HOLDS
TOGETHER AS INDICATED ON THE NAM AND RAP MODELS. CONVECTION MAY
DEVELOP AT ALL SITES ON TUESDAY AS FORCING INCREASES AHEAD OF A
FRONTAL ZONE...WITH WIND GUSTS OVER 20 KNOTS EXPECTED.

OUTLOOK...THUNDERSTORMS WILL BE POSSIBLE FROM TUESDAY NIGHT THROUGH
THURSDAY.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.

&&

$$
SYNOPSIS...HICKMAN
NEAR TERM...CONIGLIO/HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/JGL
AVIATION...CONIGLIO