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Mesoscale Discussion… for Flooding…

This particular mesoscale discussion is courtesy of the Weather Prediction Center…

mcd0022

MESOSCALE PRECIPITATION DISCUSSION 0022
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
759 AM EDT SUN APR 28 2013

AREAS AFFECTED……NORTHEASTERN AL/NORTHERN GA/EASTERN TN

CONCERNING…HEAVY RAINFALL…FLASH FLOODING POSSIBLE

VALID 281159Z – 281429Z

SUMMARY…STRONG CONVECTION MAINTAINED FROM OVERNIGHT ACTIVITY
WILL BRING A THREAT FOR FLASH FLOODING OVER AREAS OF NORTHERN
GEORGIA THIS MORNING.

DISCUSSION…A NOCTURNAL COMPLEX OF SHOWERS AND THUNDERSTORMS
APPEARS TO HAVE MAINTAINED ITS INTENSITY PER IR SATELLITE TRENDS
AND LIGHTNING DATA. THERE IS LITTLE REASON TO BELIEVE THIS AXIS OF
CONVECTION WILL WEAKEN DURING THE NEXT FEW HOURS AS THE
PRECIPITATION MOVES ACROSS AN AREA OF DIMINISHED 3-HOUR FFG
VALUES. IT APPEARS THIS THREAT SHOULD MOVE JUST TO THE NORTH OF
THE ATLANTA METRO AREA. THE 850-MB FLOW IS FORECAST TO PUMP SOME
OF THE HIGHER MOISTURE CONTENT OUT OF THE GULF OF MEXICO INTO THE
LOWER TENNESSEE VALLEY. ADDITIONALLY…MOST OF THE HIGH-RESOLUTION
GUIDANCE SUGGESTS THIS AREA WILL BE IMPACTED BY 1 TO 2 INCH
RAINFALL TOTALS IN 6 HOURS WITH LOCALIZED HIGHER AMOUNTS. THIS
SUPPORT INCLUDES THE 00Z SPC WRF/00Z HIGH-RES WRF-NMM ALONG WITH
DETERMINISTIC RUNS FROM THE 06Z NAM/GFS.

RUBIN-OSTER
ATTN…WFO…GSP…MRX…FFC…BMX…HUN…

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Labor Day Weekend Rain…

The Hydrometerological Prediction Center has shifted the axis for the rain from Isaac this weekend back into northern Ohio. One thing I caution, though. This projected rainfall forecast could still change.

Stay with Weather or Knot for the latest weather information.

Possible Flooding This Weekend?

HYDROLOGIC OUTLOOK
INC001-003-009-017-033-039-049-053-069-075-085-087-091-099-103-
113-131-141-149-151-169-179-181-183-MIC021-023-027-059-149-OHC003-
039-051-069-125-137-161-171-311115-
ADAMS-ALLEN IN-BLACKFORD-CASS IN-DE KALB-ELKHART-FULTON IN-GRANT-
HUNTINGTON-JAY-KOSCIUSKO-LAGRANGE-LA PORTE-MARSHALL-MIAMI-NOBLE-
PULASKI-ST. JOSEPH IN-STARKE-STEUBEN-WABASH-WELLS-WHITE-WHITLEY-
BERRIEN-BRANCH-CASS MI-HILLSDALE-ST. JOSEPH MI-ALLEN OH-DEFIANCE-
FULTON OH-HENRY-PAULDING-PUTNAM-VAN WERT-WILLIAMS-

HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE NORTHERN INDIANA
356 PM EDT THU AUG 30 2012 /256 PM CDT THU AUG 30 2012/

…POTENTIAL FOR HEAVY RAINFALL THIS WEEKEND FROM ISAAC REMNANTS…

THE REMNANTS FROM TROPICAL STORM ISAAC ARE EXPECTED TO MOVE
ACROSS THE OHIO VALLEY OR LOWER GREAT LAKES REGION THIS HOLIDAY
WEEKEND. A SWATH OF VERY HEAVY RAINFALL IS EXPECTED NEAR THE
CENTER OF THIS SYSTEM. LATEST INDICATIONS ARE THE REMNANT LOW WILL
TRACK EAST FROM CENTRAL ILLINOIS ON SUNDAY TO CENTRAL OHIO ON
TUESDAY. HEAVY RAINFALL IS EXPECTED NEAR AND TO THE EAST OF THE
LOW PRESSURE CENTER. TWO TO FOUR INCHES OF RAIN IS POSSIBLE SOUTH
OF A MONON INDIANA TO VAN WERT OHIO LINE… WITH HEAVIER AMOUNTS
TO THE SOUTH AND LIGHTER AMOUNTS TO THE NORTH. HOWEVER… THERE IS
CONSIDERABLE UNCERTAINTY ON THE TRACK OF THE LOW SO PEOPLE
THROUGHOUT OUR AREA SHOULD PREPARE FOR THE HEAVY RAINFALL
POTENTIAL.

RECENT RAINFALL OVER THE LAST 30 DAYS HAS HELPED DROUGHT
CONDITIONS ACROSS NORTHERN INDIANA…NORTHWEST OHIO AND SOUTHWEST
LOWER MICHIGAN. WHILE MANY STREAMS…CREEKS AND RIVERS REMAIN
LOW…THE TROPICAL NATURE OF THIS SYSTEM COULD BRING HEAVY
RAIN OVER A VERY SHORT PERIOD. THIS COULD STILL LEAD TO FLASH
FLOODING DESPITE THE RECENT DROUGHT AND CURRENT LOW WATER LEVELS.
AREAS THAT RECEIVE THE HEAVY RAIN WILL LIKELY SEE SIGNIFICANT
RISES IN SMALLER STREAMS…CREEKS AND CULVERTS LEADING TO
LOCALIZED FLOODING.

THE FLOODING POTENTIAL OF LARGER RIVERS REMAINS LOW DUE TO THEIR
CURRENT LEVELS AND A SLOWER RESPONSE TIME FROM THE RAIN.
HOWEVER…PEOPLE LIVING NEAR ANY AREA PRONE TO FLOODING SHOULD
CONTINUE TO MONITOR FORECASTS THROUGH THE REMAINDER OF THIS WEEK
AND OVER THE WEEKEND.

IT MUST BE EMPHASIZED THAT THE MOVEMENT OF TROPICAL REMNANTS ARE
DIFFICULT TO FORECAST. A GREAT DEAL OF UNCERTAINTY CONTINUES WITH
THE EVENTUAL TRACK AND LOCATION OF THE HEAVIEST RAIN. FORECASTS
WILL BE REFINED OVER THE NEXT 36 HOURS.

THE LATEST FORECAST INFORMATION FROM THE NATIONAL WEATHER SERVICE
CAN BE FOUND AT HTTP://WWW.WEATHER.GOV/IWX AND UPDATES WILL BE
POSTED VIA FACEBOOK AND TWITTER FOR NWS NORTHERN INDIANA.

Lots of Rain from Isaac Here?

GFS PCPIN forecast valid 12 UTC Sun 02 Sep 2012

The 48-Hour rainfall projected here on the 12z GFS is serious. Those areas in white could see in excess of four to six inches this weekend. This could still change.

Stay with Weather or Knot for continuing coverage of Isaac.

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