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SATELLITE PRECIPITATION ESTIMATES..DATE/TIME 09/20/07 1210Z
SATELLITE ANALYSIS BRANCH/NESDIS---NPPU---TEL.301-763-8678
LATEST DATA USED: GOES-12 1145Z  HANNA
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LOCATION...MINNESOTA...SOUTH DAKOTA...NORTH DAKOTA...
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ATTN WFOS...DLH...MPX...FGF...FSD...ABR...BIS...
ATTN RFCS...NCRFC...MBRFC...
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EVENT...ELEVATED CONVECTION WITH LOCALIZED HEAVY RAINFALL
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SATELLITE ANALYSIS AND TRENDS...OVER THE LAST FEW HOURS HAVE NOTED A
RAPID INCREASE IN CONVECTIVE AREAL COVERAGE OVER NE SD/SE ND/W CNTRL MN.
CONVECTION APPEARS TO BE DRIVEN IN LARGE PART BY ISENTROPIC ASCENT,
BEST DEPICTED ON 305K THETA SURFACE, INTO ENTRANCE REGION OF JET STREAK
NEAR THE VIC OF LAKE WINNIPEG.
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EARLY MORNING IR IMAGERY SHOWS VERY PRONOUNCED OVERSHOOTING TOP OVER
THE E PORTION OF DAY COUNTY.  FURTHER TO THE EAST, CONVECTION HAS BEEN
FILLING IN ALONG MESOSCALE BOUNDARY FROM GRANT TO BROOKINGS COUNTY.
THIS CONVECTION HAS BEEN MERGING INTO THE MAIN CONVECTIVE COMPLEX OVER
N GRANT AND S ROBERTS COUNTY.  PRECIPITABLE WATER VALUES HAVE RAPIDLY
INCREASED OVERNIGHT WITH LATEST GOES SOUNDER DPI VALUES RUNNING AROUND
1.25" OVER DISCUSSION AREA.  THIS ALONG WITH POTENT CLOUD TOP COOLING
AND CONVECTIVE MERGERS SHOULD ALLOW FOR LOCAL RAINFALL RATES OF AT LEAST
1.0"/HR WITH EXTREMELY LOCALIZED RAINFALL RATES OF UP TO 2.0"/HR POSSIBLE
IN THE MOST INTENSE CONVECTIVE CORES.
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PROFILER DATA SHOWS THAT STRONG LLJ AS VEERED AROUND TO AROUND 210 AND
THIS TRAJECTORY IS TAPPING RATHER POTENT INSTABILITY RESERVOIR OVER W
SD AND CNTRL NE (CAPES OF AROUND 3000 J/KG).  INSTABILITY TRANSPORT INTO
INTO UPWIND END OF COMPLEX RAISES THE THREAT FOR REGENERATING CONVECTION
ON THE SW END OF COMPLEX WITH SUBSEQUENT DOWNSTREAM TRAINING AS THE
INDIVIDUAL CELLS LIFT NE.  AUTOMATED RAINFALL ESTIMATES GENERALLY RANGING
BETWEEN 1-2" FROM N CLARK COUNTY TO S ROBERTS COUNTY AND CONSIDERING THE
LOW BIAS FOR RAPIDLY DEVELOPING CONVECTION, AS IS CURRENTLY OCCURRING,
BELIEVE THAT LOCAL RAINFALL TOTALS OF OVER 3" NOT OUT OF THE QUESTION.
OVER THE NEXT HOUR OR SO BELIEVE ADDITIONAL LOCALIZED RAINFALL TOTALS
OF 1-3" ARE POSSIBLE ROUGHLY ALONG A LINE FROM 25 MILES NNW OF ATY TO
NEAR ETH.  WILL CONTINUE TO MONITOR.
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SEE NCEP HPC DISCUSSION AND QPF/S FOR FORECAST.
....NESDIS IS A MEMBER OF 12 PLANET....
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SSD/SAB WEB ADDRESS FOR PRECIP ESTIMATES:
HTTP://WWW.SSD.NOAA.GOV/PS/PCPN/
...ALL LOWER CASE EXCEPT /PS/PCPN/
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LAT...LON 4724 9666 4695 9455 4567 9499 4460 9615 4401 9706 4439
9847 4545 9890 4646 9863
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