[LeArc] Forecast Discussion : MLI@ 5/29/02 1:31:34 PM

[learc@mailman.qth.net]

The following weather message is provided by McDonough County E.S.D.A.


FXUS63 KDVN 291831
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
130 PM CDT WED MAY 29 2002

.OVERVIEW...LATE SPRING PATTERN IN EVIDENCE WITH WEAKER SFC AND UPPER
FLOW ACROSS AREA.  BROAD UPPER TROUGH ACROSS CENTRL US SUPPLYING SOME
UPPER LEVEL INSTABILITY AND ALSO WEAK EMBEDDED DISTURBANCES.  LATEST
SFC/RADAR SUGGEST STORM NOW DEVELOPING IN PAST HOUR IN EASTERN IOWA WITH
SFC ANALYSIS SHOWING DECENT INFLOW AND MORE UNSTABLE AIR THAN PROGGED
FOR CONTINUED INTENSIFICATION.

...TIMING AMOUNT AND POTENTIAL SVR NATURE OF STORMS THIS PM AND THEN
MORE SIGNIFICANT STORM POTENTIAL LATER THIS WEEKEND FORECAST ISSUE...

.DIAGNOSIS AND DAYS 1-3...CURRENT CONVECTION POTENTIAL AND INTENSITY
UNDERDONE BY ALL MODELS WITH HIGHER INSTABILITY AND GREATER INFLOW
TOWARD BROAD BOUNDARY IN FAR WEST CWFA AT 18Z PER LAPS/MSAS.  DVN SVR
CHKLST AND BLEP TECHNIQUE SUPPORTS ISOLATED TO WDLY SCT PULSE SVR
POTENTIAL WITH SOME HAIL AND OUTFLOW DOMINATED WINDS OF UP TO ~45 KTS UP
TO NEAR 60-65 KTS WITH OUTFLOW INTERACTION AND SOME ROTATION INTO THIS
EVENING. MIAN THREAT IS WEAK FLOW...SUGGESTING SLOW MOVING STORMS WITH
PW OF 1.40+" FOR HEAVY RAIN CREATING SOME FLOODING CONCERNS.  THUS...
BLENDING NOWCAST TOOLS WITH ETA...WILL TEND TOWARD HIGH SIDE OF POPS
TONIGHT...MAINLY ALONG AND SOUTH OF HIGHWAY 30 THIS EVENING INTO
TONIGHT.  THEN TEMPS NEAR TO SLIGHTLY ABOVE ON HIGH SIDE OF MAV/FWC
BLEND WITH CHANCE POPS THURSDAY PM AND EVENING WITH WEAK FRONT.  APPEARS
MAINLY DRY FRIDAY WITH SOME DRIER AIR THEN LATE FRIDAY NIGHT AND
SATURDAY AS FRONT SLIDES BACK NORTH FOR A PATTERN SUGGESTIVE OF A
FAVORABLE ENVIRONMENT FOR LARGE CONVECTIVE MCS/MCC WITH INSTABILITY
APPROACHING EXTREME LEVELS AND SHEAR PROFILE CONDUCIVE FOR DERECHO
AND/OR INTENSE BOW ECHO EVOLUTION.  KEEP HIGH CHANCE POPS SATURDAY FOR
NOW DUE TO TIMING AND LOCATION OF UNCERTAINTIES. LOOK LIKE NEAR RECORD
COOL PERIOD AT AN END.

.EXTENDED (SUN-TUE)...ALL MODELS SUGGEST E-W BOUNDARY OVER TO JUST SOUTH
OF AREA INTO TUESDAY FOR KEEPING REASONABLE CHANCE POPS THRU PERIOD.
PATTERN IS FAVORABLE FOR HEAVY RAINS WITH SEVERE RISKS...AT LEAST AT TO
ABOVE CLIMATOLOGICAL NORMAL.  CLOUD COVER WILL HAVE GREAT IMPACTS ON
TEMPS AND WILL PLAN TO TRY AND INCORPORATE INTO MEX/FMR GUIDANCE.

.DVN...
IA...NONE.
IL...NONE.
MO...NONE.

NICHOLS