000
FXUS63 KIWX 250545
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
145 AM EDT FRI JUL 25 2014

.SYNOPSIS...
ISSUED AT 745 PM EDT THU JUL 24 2014

HIGH PRESSURE AND NORTHERLY WINDS WILL BRING COOLER AND DRIER
CONDITIONS TO THE AREA THROUGH FRIDAY. LOWS TONIGHT WILL DROP INTO
THE LOWER AND MIDDLE 50S. HIGHS ON FRIDAY WILL BE IN THE UPPER
70S. THERE IS A CHANCE FOR SHOWERS AND THUNDERSTORMS FROM LATE FRIDAY
NIGHT THROUGH THE WEEKEND.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 305 PM EDT THU JUL 24 2014

FAIR/LOW HUMIDITY WX WILL PERSIST INTO TONIGHT-FRIDAY MORNING AS A
1022 MB SFC HIGH FOLDS SOUTHEAST OVER THE AREA TONIGHT AND TOWARD
THE MID ATLANTIC ON FRIDAY. SFC DEWPOINTS ALREADY MIXING OUT INTO
THE UPPER 40S/LOW 50S THIS AFTERNOON...AND IDEAL RADIATIONAL COOLING
TONIGHT...WILL SUPPORT RELATIVELY COOL MIN TEMPS FOR LATE JULY.

NW FLOW ALOFT WILL DAMPEN INTO FRIDAY AS A RIDGE FLATTENING NEGATIVE
HEIGHT ANOMALY TRANSLATES EAST INTO SOUTHERN SASKATCHEWAN BY 18-00Z.
A WEAK LEAD PERTURBATION IN SEMI-ZONAL FLOW DOWNSTREAM AND RAMP UP
IN LLJ IN ADVANCE OF LEE SIDE TROUGH SHOULD TRIGGER CONVECTION
ACROSS THE UPPER MIDWEST/IOWA LATER TONIGHT-FRIDAY MORNING...LIKELY
DRYING UP WITH SEWD PROGRESSION THEREAFTER INTO DRY/STABLE AIR.
STILL COULD SEE A SHRINKING AREA OF HIGH BASED SHOWERS SURVIVE INTO
OUR FAR WESTERN ZONES BY LATE FRIDAY AFTERNOON GIVEN DEVELOPING
RETURN FLOW/7H THETA-E ADVECTION ON BACKSIDE OF HIGH.
OTHERWISE...EXPECT AN INCREASE IN MID-HIGH LEVEL CLOUDS TOMORROW
WITH HIGHS INTO THE UPPER 70S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 305 PM EDT THU JUL 24 2014

POTENT SW OVR SRN BC THIS AFTN WILL PINWHEEL EWD INTO SAT BFR
MERGING W/DEEP UPR TROUGH DVLPG EWD OF JAMES BAY IN RESPONSE TO
DRAMATIC UPSTREAM BLOCKING DVLPG THROUGH WRN CANADA THANKS IN PART
TO TYPHOON MATMA.

AS THIS EVOLUTION TAKES PLACE...COOL AIR OF LATE WILL ERODE RAPIDLY
AS SW FLW DEEPENS AHD OF A DVLPG FNTL BNDRY FM THE UPR MIDWEST SWWD
THROUGH THE PLAINS. EWD FOLD OF SIG LL THETA-E RIDGE AND EWD ADVTN
OF STOUT EML POINT TO POTENTIAL FOR SVR WX LATER SAT AND AGAIN ON
SUN. BUT AS YET STILL VERY UNCERTAIN TIED TO TIMING OF SEWD
DIG OF ABSORBING SRN CANADA DISTURBANCE...POSITIONING OF SFC FNTL
BNDRY AND NEWD EXTENT OF LL MSTR RTN. WILL CONT W/GENERAL MID RANGE
CHC POPS SAT AFTN THROUGH SUN.

OTRWS ANOTHER UNSEASONABLY COOL AIRMASS TO AGAIN OVERSPREAD THE
LAKES/OH VALLEY EARLY NXT WEEK AS AMPLIFIED BLOCKING PATTN MORE AKIN
TO MID WINTER TAKES SHAPE ACRS NOAM. TEMPS MUCH BLO NORMAL XPCD
MON-TUE BFR MODERATING THEREAFTER.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 138 AM EDT FRI JUL 25 2014

VFR CONDITIONS EXPECTED THROUGH THE PERIOD AS HIGH PRESSURE
CURRENTLY OVERHEAED SLIDES SOUTHEAST INTO THE SMOKIES. EXPECT INCREASED
SSWRLY FLOW ON BACKSIDE OF RIDGE LATER TODAY. SOME CONCERN FOR
UPSTREAM CONVECTION EDGING INTO NWRN IN BY LATE IN THE FORECAST
PERIOD INTO DAYBREAK SAT...THOUGH DECENT DOWNSTREAM STABILITY MAY
PRECLUDE ALL BUT DYING SHRA.

&&

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

$$

SYNOPSIS...LASHLEY
SHORT TERM...STEINWEDEL
LONG TERM...T
AVIATION...MURPHY

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