[LeArc] Forecast Discussion : MLI@ 6/13/2003 4:16:46 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 132101
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
400 PM CDT FRI JUN 13 2003

LATEST RADAR AND SATELLITE LOOPS SHOWING SOME NICE LITTLE SHOWERS 
AND THUNDERSTORMS OVER THE FAR WESTERN PORTIONS OF THE 
CWA...GENERALLY WEST OF I-380.  THESE STORMS HAVE ONLY BEEN PUTTING 
OUT SOME SMALL HAIL AND HEAVY RAIN...AND DO NOT EXPECT THEM TO GET 
ANY STRONGER.  THEY SHOULD ALSO FALL APART IN THE 6 TO 8 PM TIME 
FRAME...AS THE DIURNAL HEATING THAT TRIGGERED THEM ON A LITTLE 
CONVERGENCE LINE SHUTS OFF.  UPPER LEVEL FEATURES ARE LOOKING VERY 
SUMMERLIKE...WITH WEAK/SMALL FEATURES...AND NOT A DECENT HEIGHT 
RISE/FALL COUPLET ON THE CHART.  

MAIN CONCERN THIS FORECAST INCLUDES PRECIP CHANCES TONIGHT AND INTO 
THE WEEKEND.

12Z MODELS APPEAR TO HAVE INITIALIZED REASONABLY WELL...AND ARE IN 
GOOD AGREEMENT WITH THE MAIN FEATURES THROUGH THE FORECAST PERIOD. 
HAVE GONE MAINLY WITH A BLEND OF FORECAST MODELS.

HAVE ALREADY MENTIONED THESE LITTLE EVENING POPCORN 
THUNDERSTORMS...WHICH TRIGGERED OFF A LITTLE CONVERGENCE LINE RIGHT 
WHERE THE THUNDERSTORMS ARE...AND WERE ALSO ASSOCIATED WITH A WEAK 
LITTLE VORT MAX THAT HAS BEEN SLOWLY EASING EAST ACROSS THE AREA 
OVER THE LAST 24 HOURS.  THIS VORT MAX SHOULD MOVE EAST TONIGHT AND 
LEAVE THE AREA HIGH AND DRY FOR SATURDAY...THOUGH WOULD NOT BE 
SURPRISED TO SEE MORE THUNDERSTORMS FIRE TO OUR SOUTH AND EAST 
SATURDAY AFTERNOON AND EVENING.  TONIGHT WE SHOULD MANAGE TO CLEAR 
OUT REASONABLY WELL...AND WITH FAIRLY HIGH DEWPOINTS SOME FOG IS 
LIKELY TO APPEAR.  THIS MORNING A NUMBER OF SITES DROPPED TO 2 TO 3 
MILES.  FOR NOW HAVE DECIDED THAT VISIBILITIES SHOULD NOT LOWER ANY 
MORE THAN THEY DID THIS MORNING...AND DOES NOT QUITE WARRANT 
MENTIONING IN THE FORECAST PACKAGE.  THIS WILL NEED TO BE MONITORED 
DURING THE EVENING...AS MUCH DEPENDS ON THE ACTUAL CLEARING THIS 
EVENING.

SUNDAY AND MONDAY...FEATURES ARE VERY SUMMER LIKE...WITH JUST ONE 
WEAK UPPER LEVEL VORT MAX MOVING ACROSS THE AREA SUNDAY 
AFTERNOON/EVENING.  THERE DOES NOT APPEAR TO BE ENOUGH MOISTURE OR 
LOWER LEVEL SUPPORT TO SUPPORT PUTTING IN ANY POPS...BUT WILL PUT IN 
MORE CLOUDS FOR THAT PERIOD.  OTHERWISE....WILL BE GOING WITH LIGHT 
EAST TO NORTHEAST FLOW...SO NO GREAT ADVECTION OR RAINFALL TO 
SUPPORT GOING SIGNIFICANTLY ABOVE OR BELOW GUIDANCE.

EXTENDED...TUESDAY THROUGH FRIDAY
EXTENDED RANGE MODELS IN GENERAL GOOD AGREEMENT THROUGH THE PERIOD 
ON THE MAIN FEATURES...BUT SOME TIMING/LOCATION DISAGREEMENTS ON 
SMALLER FEATURES THAT WILL BE THE MAIN TRIGGER FOR ANY 
PRECIPITATION.  FOR NOW...HAVE STAYED FAIRLY CLOSE TO THE PREVIOUS 
FORECAST FOR THE TUESDAY THROUGH THURSDAY...WITH A WEAK FRONT TO 
MOVE THROUGH LATE WEDENSDAY AND THURSDAY...BRINGING IN A CHANCE OF 
PRECIP FOR THOSE DAYS.  GFS FROM 00Z IS PRETTY CLOSE TO THIS 
SOLUTION...WITH UKMET AND EUROPEAN ONLY A LITTLE FARTHER SOUTH OR 
SLOWER THAN THE GFS SOLUTION.  HAVE DECIDED TO STICK PRETTY CLOSE TO 
THE DRY GFS SOLUTION FOR FRIDAY.   TUESDAY AND WEDNESDAY TEMPS 
PRETTY WARM WITH GOOD SOUTHERLY FLOW...BUT WENT A LITTLE COOLER THAN 
GUIDANCE THURSDAY AND FRIDAY WITH THE NORTHEAST FLOW DEPRESSING 
TEMPS PRETTY WELL WHICH IS NOT TYPICALLY HANDLED WELL BY MODELS.  

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

$$

REA/LE