[LeArc] Forecast Discussion : MLI@ 7/16/2003 3:39:11 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 162030
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
330 PM CDT WED JUL 16 2003

QUIET WEATHER FOR TODAY...WITH JUST SOME CIRRUS DRIFTING OVER THE 
AREA FROM THE CONVECTION OVERNIGHT OVER MN AND SD.  NEW CONVECTION 
VISIBLE ON SATELLITE FINALLY DEVELOPING OVER FAR NORTHWEST CORNER OF 
IA.  RIDGING ALOFT AT ALL LEVELS...WITH VERY DRY CONDITIONS ON THIS 
MORNINGS SOUNDING.  

MAIN CONCERN TONIGHT IS THE INITIATION OF THE NEXT MCS.  BEST 
FACTORS...INCLUDING LOW LEVEL MOISTURE CONVERGENCE...850MB 
WINDS...AND THE DEVELOPING BOUNDARY ACROSS SOUTH DAKOTA AND MN WOULD 
PLACE THE INITIATION REGION ACROSS FAR EASTERN NEBRASKA AND 
SOUTHEASTERN SOUTH DAKOTA...AND A LITTLE OF FAR WESTERN IA.  THIS 
SEEMS TO BE BORNE OUT BY THE CONVECTION DEVELOPING ALONG A LINE 
VISIBLE ON SATELLITE EXTENDING FROM SOUTH CENTRAL SOUTH DAKOTA TO 
FAR NORTHWEST IA.  FOR NOW...THINK THAT THIS WILL HAVE A HARD TIME 
MAKING IT INTO THE CWA BY MORNING...BUT WILL BE RATHER CLOSE AS THE 
850MB JET IS POINTING AT NORTHEAST IA AT 12Z...WITH THE BEST 
MOISTURE STILL OVER CENTRAL IA AND GRADIENT TO THE EAST PRETTY 
STEEP.  IN FACT...HAVE GONE WITH JUST 20 POPS WEST...AND DRY EAST.  

TOMORROW THE PRECIP SHOULD FOCUS ALONG THE FRONT AS IT DROPS SOUTH 
ACROSS THE AREA...BUT DO NOT THINK COVERAGE WILL BE GOOD ENOUGH TO 
GO WITH MORE THAN SCATTERED WORDING...AND WILL BE BEST ACROSS THE 
NORTHERN PORTIONS OF THE CWA.  WITH FRONT LINGERING INTO THE AREA 
THROUGH EARLY EVENING...CONTINUED CHANCE POPS INTO THE EVENING FOR 
THE SOUTHEASTERN THIRD OF THE THE AREA...TAPERING TO DRY NORTHWEST.

SEVERE THREAT FOR TOMORROW AFTERNOON AND EVENING KIND OF IFFY...THE 
FRONT MAY BE TOO FAR AWAY FOR MOST OF THE DAY TO ACT AS A  
TRIGGER...AND STORMS WOULD BE MORE OF AN ISOLATED NATURE.  LATER IN 
THE AFTERNOON AND EVENING WHEN THE FRONT MOVES THROUGH THERE MAY BE 
TOO MUCH DEBRIS...AND THE INSTABILITY MAY BE LACKING.  LATER SHIFTS 
WILL HAVE TO MONTOR FOR FURTHER DETAILS. ...LE

FRIDAY THROUGH SATURDAY...THE GFS AND ETA NOW AGREE ON BRINGING HIGH 
PRESSURE SOUTH THROUGH THE GREAT LAKES LATE THURSDAY...PUSHING THE 
FRONG WELL SOUTH OF THE CWA BY FRIDAY MORNING.  WITH THE HIGH OVER 
LAKE MICHIGAN...WE WILL SEE A COOL EAST FLOW OFF THE LAKE...ALONG 
WITH DRY CONDITIONS.  HAVE REMOVED POPS AND CUT BACK HIGHS TO THE 
MID TO UPPER 70S FOR THIS PERIOD. IF LOW LEVEL MOISTURE IS GREATER 
THAN ANTICIPATED...WILL HAVE TO LOWER HIGHS AGAIN IN FUTURE SHIFTS 
DUE TO MORE CLOUD COVER.  THE NEXT WAVE APPROACHES THE AREA SATURDAY 
NIGHT...AS THE UPPER RIDGING BREAKS DOWN AND A MAJOR COLD FRONT 
BEGINS TO MOVE SOUTH INTO THE CONUS. WILL PUSH TEMPERATURES BACK 
INTO THE LOWER 80S AS SOUTH WINDS RETURN TO THE AREA. 

EXTENDED...SUN-THU
SEASONALLY STRONG COLD FRONT APPEARS ON TRACK FOR PASSING ACROSS THE 
AREA DURING THE DAY OR EARLY EVENING SUNDAY.  MODELS CONTINUE TO 
OFFER A VARIETY OF SOLUTIONS AS TO THE SMALLER DETAILS...MANY OF 
WHICH SEEM DUE TO CONVECTIVE FEEDBACK ISSUES. THIS IS ESPECIALLY 
TRUE WITH REGARD TO THE GFS.  FOR NOW...WILL CONTINUE CHANCE POPS 
SUNDAY AND SUNDAY NIGHT...AND GIVEN THE FROPA WITHIN 4 HOURS OF THE 
DIURNAL MAX HEATING...WILL BUMP UP POPS TO 50 PERCENT. MONDAY...WITH 
COLD POOL OF AIR ALOFT...WILL CONTINUE LOW END CHC POPS FOR SHOWERS 
AND THUNDER UNTIL EARLY EVENING. HIGH PRESSURE SHOULD MOVE INTO THE 
AREA FOR THE REMAINDER OF THE FORECAST PERIOD...WITH BELOW NORMAL 
TEMPERATURES AND DRY WEATHER. ...ERVIN

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

$$