[LeArc] Forecast Discussion : MLI@ 4/2/2003 3:07:00 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 020902
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
300 AM CST WED APR 2 2003

STATIONARY FRONT EXTENDS FROM LOW OVER SOUTH CENTRAL SD ACROSS NRN 
IA INTO NRN IL AT 06Z.  TEMPS REMAIN IN THE UPPER 50S TO LOW 60S 
SOUTH OF THE FRONT WITH MID 40 JUST NORTH OF BOUNDARY.  PCPN REMAINS 
WELL NORTH OF THE FRONT...CLOSER TO THE JET AXIS.  

THE STATIONARY FRONT WILL BE THE MAIN FOCUS OF THE FORECAST THROUGH 
THURSDAY.  THE TIGHT THERMAL GRADIENT IN THE VICNITY OF THE FRONT 
WILL PROVIDE AMPLE OPPURTUNTIES FOR SIGNIFICANT TEMPERATURE BUSTS.
MODELS ARE IN BETTER AGREEMENT TONIGHT AND POSITIONING OF THE 
STATIONARY FRONT THE NEXT 36 HRS. THE GFS HAS BEEN THE MOST 
CONSISTENT KEEPING THE FRONT NORTH OF I80 THROUGH THURSDAY AFTERNOON 
AND WILL RELY ON THE GFS FOR MUCH OF THIS ISSUANCE.  THE ETA...WHICH 
HAS BEEN BOUNCING THE FRONT AROUND IA THE LAST SEVERAL RUNS...IS NOW 
VERY CLOSE TO THE GFS.  THE ETA HAS HAD  BETTER HANDLE ON TEMPS IN 
THE WARM SECTOR...SO WILL CONTINUE TO RELY ON THE MET MOS FOR MAXES 
TODAY AND THURSDAY SOUTH OF THE BOUNDARY.  

MAX TEMPS WILL BE THE BIGGEST CHALLENGE TODAY.  GFS HANGS FRONT UP 
AROUND HIGHWAY 20 TODAY. BASED ON MAX TEMPS NR 70 IN THE VICINITY OF 
THE FRONT ON TUESDAY...WILL GO JUST BELOW THE MET NUMBERS.  SOUTH OF 
THE BOUNDARY...WILL KEEP NUMBERS AT OR A FEW DEGREES BELOW THE MET.  
MODEL SOUNDINGS SUGGEST THAT A STRONG INVERSION BASED NEAR H850 WILL 
LIMIT MIXING AND KEEP TEMPS FROM GETTING AS WARM AS THEY DID ON 
TUESDAY.  MAX TEMPS IN THE UPPER 70S/LOW 80S WILL BE AT LEAST A 
CATEGORY BELOW RECORDS FOR APRIL 2ND.    BY EARLY THURSDAY MODELS 
ARE SUGGESTING THE FRONT WILL MOVE TO A LOCATION BETWEEN HIGHWAY 30 
AND I-80.  TEMPS NORTH OF THE FRONT WILL BE IN THE MID/UPPER 40S 
WITH LOW/MID 50S  TO THE SOUTH. SEVERE THREAT STILL LOOKS OK FOR 
THURSDAY AFTERNOON/EVENING AS SURFACE LOW MOVES EAST ALONG THE 
BOUNDARY IN REPONSE TO S/W ENERGY MOVING THROUGH CENTRAL/NORTHERN 
PLAINS.  ETA SUGGESTING CAPES AROUND 1500 J/KG ALONG AND EAST OF THE 
MISSISSIPPI BY THURSDAY EVENING. LOCATION OF SEVERE WX DEPENDENT ON 
TRACK OF SURFACE LOW.  00Z RUNS WERE FAVORING A MOVEMENT FROM NR 
KCID THROUGH KCWI TO KCHI LATE THURSDAY AFTERNOON AND EVENING.  THE 
06Z META IS NOW INDICATING A TRACK FURTHER N...CLOSER TO HIGHWAY 
20.  SINCE GFS HAS BEEN THE MOST CONSISTENT...WILL FAVOR THE 
SOUTHERN TRACK. TEMPS THEN CRASH BY FRIDAY WITH MAXES PROBABLY SOME 
20 DEGREES COOLER THAN THOSE EXPECTED ON THURSDAY.  ANOTHER SHOT OF 
RAIN POSSIBLE BY FRIDAY...AS GFS MOVES ANOTHER WAVE ALONG 
BOUNDAY...THROUGH CENTRAL MO AND SOUTHERN IL. 

LOOKS LIKE A SIGNIFICANT COOL DOWN FOR THE WEEKEND AND EARLY NEXT 
WEEK.  PRECIPITATION CHANCES ARE IN DOUBT THOUGH.  EUROPEAN MODELS 
ARE DEPICTING A STRONGER HIGH OVER EASTERN CANADA AND ARE PLACING IT 
FURTHER SOUTH THAN THE GFS.  THE MORE SOUTHERN POSITION WAS 
SUPPRESSING THE SURFACE SYSTEMS OVER THE U.S. FURTHER SOUTH.  WILL 
CONTINUE GOING FORECAST WITH LITTLE IF ANY CHANGES MADE.

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

$$
DLF