Sunday, August 19, 2007

MESO: Mesoscale Discussion 1798

ACUS11 KWNS 190436
SWOMCD
SPC MCD 190436
OKZ000-190730-

MESOSCALE DISCUSSION 1798
NWS STORM PREDICTION CENTER NORMAN OK
1136 PM CDT SAT AUG 18 2007

AREAS AFFECTED...PORTIONS SWRN/CENTRAL OK

CONCERNING...HEAVY RAINFALL

VALID 190436Z - 190730Z

ERN SEMICIRCLE OF REMNANTS OF TC ERIN WILL MOVE NEWD FROM
SWRN-CENTRAL OK AS PARENT CIRCULATION - NOW CENTERED OVER SWRN OK
VICINITY HBR -- CONTINUES MOVING NEWD. MIXTURE OF TSTMS AND
WARM-CLOUD PROCESSES WILL CONTRIBUTE TO RAIN RATES COMMONLY AROUND 2
INCHES/HOUR...WITH LOCAL AMOUNTS TOPPING 3 INCHES/HOUR IN STRONGEST
CORES. SLOW NEWD SHIFT OF PRECIP AREA AND LIKELIHOOD OF
MULTIPLE/TRAINING CORES WILL FURTHER ENHANCE HAZARD FROM THIS HEAVY
RAIN EVENT.

CHARACTERISTICALLY VERY RICH LOW LEVEL MOISTURE WILL CONTINUE TO BE
LIFTED TO LFC OVER BROAD AREA...WITH MODIFIED RAOBS...RUC SOUNDINGS
AND GPS DATA EACH INDICATING 2.25-2.50 INCHES PW. ALTHOUGH LAPSE
RATES ARE ONLY SLIGHTLY GREATER THAN MOIST-ADIABATIC...KEEPING LI
SMALL AT ANY GIVEN LEVEL...GREAT DEPTH OF BUOYANT PROFILE AND LARGE
BOUNDARY LAYER THETAE EACH LEAD TO MLCAPES 1000-1500 J/KG. FURTHER
SUPPORTING CONTINUING POTENTIAL FOR SCATTERED TSTMS EMBEDDED WITHIN
PRECIP AREA IS 40-50 KT LLJ NOW OBSERVED OVER PORTIONS SW/CENTRAL
OK. LLJ IS PROGGED TO VEER AND WEAKEN SLIGHTLY BY AROUND 09Z...BUT
SHOULD REMAIN STRONG WITH ABUNDANT MOISTURE TRANSPORT IN MEANTIME.
IR CLOUD TOP COOLING TRENDS HAVE BEEN QUITE PROMINENT LAST 2-3
HOURS...AS ALSO NOTED BY 408Z NESDIS STATEMENT WXUS20 KNES.

.EDWARDS.. 08/19/2007

..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...OUN...

34499898 34989876 35399886 35529907 35899891 36239816
36119763 35629733 35159734 34859756 34519824

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