Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 190947
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
547 AM EDT SAT APR 19 2014

.SYNOPSIS...
ISSUED AT 355 AM EDT SAT APR 19 2014

STRONG HIGH PRESSURE WILL MAINTAIN DRY AND MOSTLY SUNNY CONDITIONS
THROUGH THE WEEKEND. TEMPERATURES TODAY WILL BE IN THE LOW TO MID
60S BUT WILL CLIMB INTO THE LOW TO MID 70S BY SUNDAY AS HIGH
PRESSURE SHIFTS EAST AND SOUTHERLY WINDS INCREASE.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM EDT SAT APR 19 2014

VERY FEW SENSIBLE WEATHER CONCERNS TO DISCUSS THIS SHORT TERM
PERIOD. SOUTHERN GREAT LAKES WILL REMAIN SPLIT BETWEEN PV
ANOMALIES OVER THE SOUTHEAST CONUS AND CANADIAN PRAIRIES. MIDLEVEL
RIDGING IS CURRENTLY ENTERING THE GREAT LAKES AND ASSOCIATED AVA
WILL MAINTAIN A HIGHLY SUBSIDENT/DRY ENVIRONMENT THROUGH TONIGHT.
EXPECT MOSTLY SUNNY SKIES FOR MUCH OF TODAY WITH JUST A FEW HIGH
CLOUDS POSSIBLE...ESPECIALLY BY TONIGHT. MAIN FORECAST CONCERN
WILL BE HOW WARM DO WE GET...MADE SOMEWHAT DIFFICULT BY RECENT
OVERPERFORMANCE OF MAX TEMPS THE PAST TWO DAYS. THERMAL TROUGH
WILL ONLY SLOWLY EXIT THE EASTERN GREAT LAKES BY LATER TODAY.
925MB TEMPS ONLY CLIMB TO AROUND 5C IN OUR FAR NORTHEAST WITH AN
EASTERLY SURFACE WIND MAINTAINING COOL FLOW OFF OF LAKE ERIE.
MIXING DEPTHS WILL ALSO BE CAPPED BY STRONG SUBSIDENCE INVERSION
TODAY. LATEST NAM AND GFS BUFR SOUNDINGS SUGGEST MIXING TO ONLY
ABOUT 900MB. THIS SHOULD KEEP OUR FAR NORTHEAST CONFINED TO AROUND
60F WHILE SOUTHWESTERN COUNTIES COULD APPROACH 70F. INHERITED
FORECAST REFLECTS THIS REASONABLY WELL AND ONLY MINOR CHANGES
MADE. OVERNIGHT LOWS WILL BE A BIT WARMER THAN CURRENT VALUES BUT
CLEAR SKIES AND LIGHT E-SE WINDS COULD STILL PROMOTE DECENT
RADIATIONAL COOLING. DRY AIRMASS AND SLOW GREEN-UP HAVE ALLOWED
FOR SOME IMPRESSIVE DIURNAL SWINGS LATELY AND EXPECT SIMILAR STORY
FOR TODAY AND TONIGHT. LATEST 00Z MOS GUIDANCE ALSO CAME IN A
LITTLE COOLER. THEREFORE LOWERED MIN TEMPS BY A FEW DEGREES WITH
MID TO UPPER 30S IN THE EAST AND UPPER 30S TO LOWER 40S IN THE
WEST.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 355 AM EDT SAT APR 19 2014

A NEARLY PICTURE PERFECT SPRING DAY EXPECTED ON SUNDAY TO START
THE LONG TERM PERIOD. HIGH PRESSURE WILL BE OVER THE REGION WITH
SHORT WAVE RIDGE ALOFT. FORECAST SOUNDINGS SHOW VERY DRY LOWER AND
MID LEVELS WITH HINT AT SOME INCREASING CIRRUS IN THE AFTERNOON.
LARGE DIURNAL SPREADS LIKELY ONCE AGAIN AND AS WE HAVE SEEN LAST
COUPLE DAYS...MAX TEMPS SHOULD EXCEED GUIDANCE IN DRY ATMOSPHERE.
MIX DOWN PROCEDURES STILL YIELD LOW TO MID 70S SUNDAY AND FORECAST
ON TRACK WITH THESE HIGHS.

NEXT SHORT WAVE APPROACHES ON MONDAY WITH SOME SUBTLE BUT IMPORTANT
DIFFERENCES AMONG MODELS ON TIMING AND STRENGTH. GIVEN LACK OF DEEP
MOISTURE AND ONLY A WEAK TAP INTO SUBTROPICAL MOISTURE PREFER THE
SLOWER MODELS WITH LESS QPF. THIS WILL YIELD ANOTHER MILD DAY FOR
MOST AREAS ON MONDAY WITH SOUNDINGS AGAIN SUPPORTING MID 70S
SOUTHEAST WHERE CLOUDS WILL NOT BE A FACTOR UNTIL LATER IN THE DAY.
UPPER 60S TO LOWER 70S NORTHWEST WITH INCREASING CLOUDS. CHANCE FOR
RAIN WILL INCREASE IN AFTERNOON AS SHORT WAVE NEARS. BEST FORCING
STILL LOOKS TO BE LATE AFTERNOON WEST AND MID TO LATE EVENING EAST.
ALLBLEND GIVING LOW END LIKELY AND CANNOT ARGUE WITH THIS. QPF OF
QUARTER INCH OR LESS GENERALLY EXPECTED.

MUCH COOLER AIR INVADES BEHIND ASSOCIATED COLD FRONT TUESDAY INTO
TUESDAY NIGHT. ECMWF CONTINUES TO INDICATE 850MB TEMPS DROPPING
BELOW 0C TUE NIGHT AND MUCH OF DAY WED BEFORE LATE RECOVERY. WITH
GFS CLOSE AND MEX MOS NUMBERS DROPPING...HAVE LOWERED ALLBLEND TEMPS
TUE NIGHT INTO LOWER AND MIDDLE 30S. FROST AND EVEN SOME FREEZING
TEMPS REMAIN POSSIBLE EARLY WED MORNING. HIGHS ON WED ONLY EXPECTED
TO REBOUND INTO THE 50S.

WARM UP RETURNS THU AND FRI AS RELATIVELY STRONG SYSTEM WILL DEVELOP
IN THE PLAINS AS POTENT PACIFIC SHORT WAVE MOVES OUT OF ROCKIES.
HEIGHT RISES INITIALLY WITH INCREASING LOW LEVEL SOUTHERLY WINDS
SHOULD ALLOW TEMPS TO WARM BACK INTO AT LEAST THE 60S IF NOT WARMER.
POPS INCREASE TO MID AND HIGH CHANCE RANGE THU NIGHT INTO FRIDAY
WITH WARM FRONT AND INCREASING MOISTURE. GIVEN STRENGTH OF SYSTEM
AND INDICATED NEGATIVE TILT WOULD NOT BE SURPRISED TO SEE LATER
MODEL RUNS SLOW EASTWARD PROGRESS AND DELAY OUR PCPN CHANCES EVEN
MORE. HAVE REMOVED SLIGHT CHANCE POPS FROM ALLBLEND WED NIGHT AND
KEPT THU POPS IN LOW CHANCE TO SLIGHT CHANCE RANGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 547 AM EDT SAT APR 19 2014

VFR CONDITIONS ASSURED AS MIDLEVEL RIDGE AND ASSOCIATED SURFACE
HIGH DRIFT OVER THE GREAT LAKES. VERY DRY CONDITIONS THROUGHOUT
THE TROPOSPHERE WILL SUPPORT MOSTLY CLEAR SKIES. LIGHT NE WINDS
WILL GRADUALLY VEER TO THE E/SE THROUGH THE DAY AS SURFACE HIGH
MOVES INTO QUEBEC.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...LASHLEY
AVIATION...AGD


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