[LeArc] Forecast Discussion : MLI@ 6/6/2003 4:33:34 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 062117
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
400 PM CDT FRI JUN 6 2003

UPPER LOW CHURNING OVER NORTHWEST IA...WITH LEAD VORTIMUS MAXIMUS NEAR STORM
LAKE. COMPLEX SURFACE PATTERN WITH WARM FRONT LIFTING THROUGH
NORTH/EAST SECTIONS WHILE COLD FRONT FAST ON IT/S HEELS ENTERING WESTERN
ZONES ATTIM. BAND OF LOW CIGS/STRATIFORM RAIN/DRIZZLE WITH
WARM FRONT LIFTING THROUGH QUAD CITIES WHILE CONVECTIVE LINE WITH
COLD FRONT MOVING ACROSS WESTERN ZONES ESPECIALLY NORTH OF I-80.
NO REPORTS OF LARGE HAIL OR HIGH WINDS OF LATE. CONVECTION WEAKENING AS IT
IS QUICKLY CATCHING UP TO STRATIFORM RAIN BAND. STILL...CAN/T RULE OUT 
ISOLATED HAIL REPORT OF PENNY TO NICKEL SIZE AND FEW WIND GUSTS OF 50 MPH 
OR SO. KCRG RECENTLY REPORTED A 48 MPH WIND GUST IN DOWNTOWN CEDAR RAPIDS.

NEXT UPPER LOW IN EASTERN MT LOOKS TO REINFORCE TROUGHING OVER THE 
MIDSECTION OF THE COUNTRY NEXT COUPLE OF DAYS...WITH MAIN FOCUS ON PCPN
CHANCES AND TEMPS. 
 
DUMBELL OR PSEUDO FUJIWARA EFFECT PROGGED BY MODELS...WITH INITIAL 
UPPER LOW OVER NORTHWEST IA TO WEAKEN AND LIFT TOWARD GREAT
LAKES WHILE SECOND UPPER LOW DROPS DOWN IN BEHIND REINFORCING TROUGHINESS
IN THE NATION/S MIDSECTION. WEAK COLD FRONT OR WIND SHIFT TO 
SWEEP ACROSS THE CWA TONIGHT. LINE OF CONVECTION EXPECTED TO CONTINUE
WEAKENING AS IT CATCHES UP WITH STRATIFORM RAIN BAND. HAVE PLACED
HIGHEST POPS UNTIL MID EVENING NORTH OF I-80 AND EAST OF I-380...WITH
LOW CHANCE POPS ELSEWHERE. OTHER ACTIVITY IN NORTHERN AND WESTERN IA WITH
UPPER LOW TO WEAKEN AFTER SUNSET WITH LOSS OF SOLAR INSOLATION.
CLOUDS THEN TO GIVE WAY TO SOME CLEARING AND WITH WET GROUND AND LIGHT WIND
MENTIONED PATCHY FOG. 

ON SATURDAY...WEAK MID LEVEL RIDGING DOMINATES EARLY...BUT THEN SHIFTS
EAST IN THE AFTERNOON. MODELS SUGGEST MCV FROM CONVECTION IN PLAINS
OVERNIGHT WILL LIFT TOWARDS THE AREA DURING THE AFTERNOON IN
WEST/SOUTHWEST UPPER FLOW. ATMOSPHERE RELATIVELY UNCHANGED...SO ANTICIPATE
ISOLD/SCT CELLS DEVELOPING DURING THE AFTERNOON MUCH LIKE WE SEE
IN WESTERN IA ATTIM...WITH BEST COVERAGE IN THE NORTH/WEST CLOSER TO 
WEAKENING CIRCULATION AND INCOMING MCV.

PCPN EXPECTED TO INCREASE IN COVERAGE LATE SAT NIGHT AND SUN MORNING WITH
MAIN UPPER LOW. THINK SIMILAR SITUATION TO THIS MORNING WITH LARGE 
STRATIFORM RAIN AREA WITH SOME EMBEDDED THUNDER. LOOKS LIKE A BREAK IN 
THE RAIN MID TO LATE MORNING...THEN PUT IN A CHC OF SHOWERS SUN AFTERNOON WITH
COLD POOL AND UPPER LOW IN VICINITY. 

ON MON...GFS INDICATES VORT MAX DIVING SOUTHEAST ACROSS REGION AND GENERATES 
LIGHT QPF. BEING THAT THE GFS IS ODD MODEL OUT...LEFT OUT MENTION 
OF PCPN ATTIM. 

EXTENDED (TUE-FRI)...NEXT FRONT PROGGED LATE TUE. KEPT MINS AOA MEX GUIDANCE
TUE MORNING WITH SOUTH WINDS AND INCREASING MOISTURE. MAXES TUE WILL BE 
TRICKY AND DEPENDENT ON TIMING OF FRONT/CLOUDS/PCPN. NEXT CONCERN 
IS WITH FRONTAL POSITIONING. MODELS OFFERING A LOT OF DISAGREEMENT ON HOW 
FAR SOUTH FRONT ENDS UP...WHICH WILL IMPACT LOCATION OF CONVECTIVE 
COMPLEXES. GIVEN THE UNCERTAINTY WON/T STRAY MUCH FROM CURRENT FORECAST.

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

$$

M^2