Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 262050
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
450 PM EDT FRI JUN 26 2015

.SYNOPSIS...
ISSUED AT 445 PM EDT FRI JUN 26 2015

AN AREA OF LOW PRESSURE WILL MOVE THROUGH THE OHIO VALLEY TONIGHT
AND SATURDAY...BRINGING MODERATE TO HEAVY RAIN TO MUCH OF THE
FORECAST AREA. AREAS ACROSS THE SOUTHEAST WILL SEE THE MOST
RAIN...AND POTENTIAL FOR FLASH FLOODING. THUNDERSTORMS ARE ALSO
POSSIBLE. LOWS TONIGHT WILL BE AROUND 60. SATURDAY WILL BE COOLER
AND WINDY...WITH HIGHS IN THE MID TO UPPER 60S. RAIN SHOWERS AND
ISOLATED THUNDERSTORMS WILL PERSIST MAINLY IN THE EAST ON
SATURDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 338 PM EDT FRI JUN 26 2015

HEAVY RAIN AND FLOODING IS THE PRIMARY CONCERN FOR THE SHORT TERM
PERIOD AS AN UNSEASONABLY STRONG LOW PRESSURE CENTER TRACKS
THROUGH THE OHIO VALLEY. THIS HIGHLY DYNAMIC SYSTEM COUPLED WITH
PWAT VALUES ABOVE THE 90TH PERCENTILE HAS SET THE STAGE FOR
SEVERAL INCHES OF RAIN ACROSS THE SOUTHERN PORTION OF OUR FORECAST
AREA. UNFORTUNATELY THOSE AREAS HAVE ALREADY SEEN RECORD SETTING
RAINFALL SO FAR IN THE MONTH OF JUNE AND THEREFORE...FLOODING
CONCERNS ARE HIGH.

DIFFUSE SURFACE LOW EXTENDING FROM NEAR KIND TO NORTHERN
TEXAS WILL DEEPEN THIS EVENING ACROSS SOUTHERN ILLINOIS AND TRACK
THROUGH SOUTHERN INDIANA OVERNIGHT. THE RAPID DEEPENING OF
THIS LOW (~9MB/12HR) WILL LEAD TO MAXIMIZED ISENTROPIC LIFT IN OUR
FAR SE CWA...ALONG THE TRACK OF THE 700MB LOW. IN ADDITION TO THE
STRONG DYNAMICS ASSOCIATED WITH THIS SYSTEM...THE UPPER LOW WILL CUT
OFF OVER NORTHERN OHIO ON SATURDAY AND SLOW THE FORWARD PROGRESSION
OF THE LOW CONSIDERABLY. THEREFORE...WHEREVER THE PIVOT POINT SETS
UP NW OF THE LOW TRACK...SIGNIFICANT FLOODING IS LIKELY. INCREASED
QPF SE OF US24 WHERE HEAVY RAIN IS ALREADY FALLING AND THE PIVOT
POINT IS LIKELY TO SET UP. IT IS WORTH MENTIONING THAT MOST OF THE
HIGH RESOLUTION GUIDANCE IS INDICATING STORM TOTAL RAINFALL AMOUNTS
OF 4 TO 5 INCHES OR MORE WHICH CERTAINLY IS NOT OUT OF THE QUESTION
AND WOULD INDICATE THAT SOMEWHERE WITHIN THE FLASH FLOOD WATCH AREA
IS LIKELY TO SEE IN EXCESS OF 3 INCHES OF RAIN.

AS THIS LOW PRESSURE CENTER DEEPENS...NORTHERLY WINDS WILL INCREASE
THROUGH THE DAY ON SATURDAY WITH AFTERNOON WIND GUSTS IN EXCESS OF
35MPH EXPECTED. GIVEN THE EXTREMELY WET SOILS IN OUR EASTERN
COUNTIES WHERE WINDS WILL BE MAXIMIZED...WOULD NOT BE SURPRISED BY
AN ISOLATED REPORT OF AN UPROOTED TREE IN THAT AREA TOMORROW.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 338 PM EDT FRI JUN 26 2015

UNUSUALLY AMPLIFIED PATTERN FOR THIS TIME OF YEAR WILL CONTINUE
THROUGH THE EXTENDED PERIOD FEATURING WESTERN US RIDGE AND EASTERN
TROF WITH 500MB HT ANOMALIES AVERAGING +150M AND -100M
RESPECTIVELY. FORECAST PERIOD TO BEGIN WITH DEEP CLOSED UPPER LOW
EXITING TO THE EAST LEAVING JUST A SMALL CHANCE OF LINGERING
PRECIP AT THE ONSET OF THE FCST PERIOD SATURDAY EVENING. LARGE
SCALE TROF AXIS REMAINS OVER THE REGION AND WILL PROVIDE ONLY A
SMALL WINDOW OF DRY WX ON SUNDAY. NEXT SHORT WAVE WILL BE DROPPING
DOWN INTO THE NORTHERN GREAT LAKES ON SUNDAY AND BRING A WEAK
SURFACE WAVE INTO THE AREA BY SUNDAY EVENING. AS EXPECTED...MODELS
OFFER VARYING SOLNS ON TIMING AND INTENSITY BUT GENERALLY SUGGEST
KEEPING SUNDAY DRY AND HOLD OFF TILL 00Z MON TO BRING POPS BACK
IN. THIS SYSTEM WILL WORK ITS WAY ACROSS THE CWA ON MONDAY
BRINGING WIDESPREAD BUT GENERALLY LIGHT TO MODERATE
RAINFALL...WITH A CHANCE OF CONVECTIVE ELEMENTS EMBEDDED WITHIN.
GIVEN THE CURRENT WET PATTERN SEE NO REASON TO GO ALONG WITH THE
CONSENSUS GUIDANCE AND CARRY LIKELY POPS. DAYS 5-7 BECOME
CHALLENGING AS MEDIUM RANGE MODELS ATTEMPT TO BRING CANADIAN HIGH
PRESSURE INTO THE NORTHERN GREAT LAKES REGION AND SET UP A STRONG
BAROCLINIC ZONE ON ITS SOUTHERN PERIPHERY. UNCERTAINTY LIES IN
WHERE THIS BOUNDARY WILL SET UP...LATEST MODEL RUNS HINTING AT A
MORE SOUTHERLY SOLN AND POTENTIALLY KEEPING A MAJORITY OF THE CWA
DRY UNTIL THE MAIN SURFACE WAVE EJECTS INTO THE OHIO VALLEY TOWARD
THE END OF THE FCST PERIOD. AS EXPECTED...SUPERBLEND WASHES OUT
VARYING SOLNS INTO SMALL CHANCE POPS EVERY SINGLE PERIOD THRU DAY
7. CURRENT GRIDS REFLECT THIS AND WILL RELUCTANTLY YIELD TO THIS
SOLN PENDING A STRONGER MODEL SIGNAL FOR DRY WX. TEMPERATURES WILL
REMAIN AT OR SLIGHTLY BELOW NORMAL THROUGH DAY 7.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 220 PM EDT FRI JUN 26 2015

LIGHT RAIN IS BEGINNING TO SPREAD NORTH AND WILL BECOME MODERATE
INTO THE EVENING. DID NOT BRING LOWER VISIBILITIES INTO KFWA AT
THIS TIME...BUT MAY NEED IFR VISIBILITIES IN LATER TAF ISSUANCES
ONCE THE AXIS OF HEAVIEST RAINFALL BECOMES MORE APPARENT. ISOLATED
THUNDER IS POSSIBLE AT KFWA...BUT CHANCES ARE TOO LOW TO ADD
MENTION IN THE TAF. OTHERWISE...WINDS WILL INTENSIFY OUT OF THE
NORTH THROUGH THE OVERNIGHT AND MAY GUST NEAR 30 KNOTS AT KFWA
TOMORROW AFTERNOON.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR INZ018-022>027-
     032>034.

MI...NONE.
OH...FLASH FLOOD WATCH THROUGH SATURDAY AFTERNOON FOR OHZ004-005-015-
     016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MCD
SHORT TERM...BENTLEY
LONG TERM...JAL
AVIATION...BENTLEY


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