MESOSCALE PRECIPITATION DISCUSSION 0876
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
736 AM EDT SUN OCT 08 2017

AREAS AFFECTED...FL PANHANDLE...AL...WESTERN GA...FAR SOUTHERN TN

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 081130Z - 081730Z

SUMMARY...VERY HEAVY RAINFALL ASSOCIATED WITH T.S. NATE WILL
CONTINUE OVER THE NEXT SEVERAL HOURS WITH FLASH FLOODING LIKELY.

DISCUSSION...THE CENTRAL CORE OF T.S. NATE CONTINUES TO LIFT
STEADILY TO THE NORTH-NORTHEAST AND NOW CROSSING INTO FAR WESTERN
AL. DESPITE SOME WARMING OF THE CONVECTIVE CLOUD TOPS NEAR THE
STORM CENTER...THERE REMAINS A STRONG AREA OF CONVECTIVE BANDING
AROUND THE EASTERN SEMICIRCLE OF THE STORM WHERE ENHANCED
MOISTURE/INSTABILITY TRANSPORT ALONG WITH HIGHLY CONVERGENT FLOW
IS IN PLACE.

PWATS ACROSS THE REGION REMAIN VERY HIGH UP BETWEEN 2.5 AND 2.75
INCHES WHICH WILL CONTINUE TO FOSTER ENHANCED RAINFALL RATES OF AS
MUCH AS 3 INCHES/HR...AND ESPECIALLY WITH THE STRONG FORCING AND
VERY COLD CONVECTIVE TOPS AS SUPPORTED BY THE INSTABILITY
TRANSPORT ACROSS THE REGION. MUCAPE VALUES ARE GENERALLY NEAR 1000
J/KG UP ACROSS SOUTHEAST AL AND MUCH OF GA...WITH VALUES CLOSE TO
2000 J/KG OVER THE FL PANHANDLE.

THE MAIN CONCERN OVER THE NEXT SEVERAL HOURS AS T.S. NATE MOVES
QUICKLY TO THE NORTH-NORTHEAST TOWARD SOUTHERN TN WILL BE THE
TRAINING CONVECTIVE BANDS AROUND THE EAST SIDE OF THE CENTER. VERY
HEAVY RAINFALL TOTALS ARE EXPECTED...WITH ADDITIONAL AMOUNTS
THROUGH 18Z OF AS MUCH AS 3 TO 6 INCHES EXPECTED. SOME OF THE
HEAVIEST RAINFALL POTENTIAL WILL BE DOWN ACROSS THE WESTERN FL
PANHANDLE AND UP ACROSS SOUTHEAST AND EAST-CENTRAL AL. THE HIRES
GUIDANCE AND ESPECIALLY THE HRRR APPEAR TO BE A TAD TOO SLOW WITH
THE CONVECTIVE EVOLUTION AND ARE LOCALLY MISHANDLING THE DEGREE OF
STRONG CONVECTIVE BAND EAST OF THE CENTER. ACCOUNTING FOR THE
LATEST SATELLITE AND RADAR TRENDS...VERY HEAVY TOTALS ARE
EXPECTED...AND FLASH FLOODING REMAINS LIKELY.

ORRISON

ATTN...WFO...BMX...FFC...HUN...MOB...MRX...OHX...TAE...

ATTN...RFC...LMRFC...SERFC...

LAT...LON   35298600 34488468 33258424 32258414 30998433
            30338454 29998482 29818514 29898557 30188601
            30298647 30408692 30708694 31038679 31598687
            31868708 32378743 33078797 33748808 34538796
            35218738