[LeArc] Forecast Discussion : MLI@ 4/16/2003 3:10:31 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 162007
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
259 PM CDT WED APR 16 2003

H5 LOW OVER E CNTRL KS IS EVIDENT IN THE RADAR COMPOSITE EARLY THIS 
AFTERNOON WITH LARGE PCPN SHIELD ROTATING NORTHEAST THROUGH MO AND
SCATTERED SHRA MOVINE S THROUGH EASTERN KS.  18Z SURFACE ANALYSIS 
HAD SURFACE LOW OVER SERN KS.  BACKDOOR FRONT SNAKING THROUGH NRN IA 
THORUGH NRN IL.  FRONT WAS SHOWING UP ON KDVN 88D AS A FNLN FROM 
JUST N OF KIOW TO JUST S OF KDVN TO JUST S OF KSQI.  TEMPS AHEAD OF 
THE FRONT WERE IN THE LOW 70S...THEN DROP OFF INTO THE MID 50S OVER 
NW IL.  

MODELS WERE IN GOOD AGREEMENT THIS MORNING MOVING THE H5 AND SFC LOW 
E  THROUGH MO TONIGHT AND INTO CENTRAL IL BY EARLY THURSDAY.  SEVERE 
THREAT FOR CWA LOOKS MINIMAL...WITH THE BEST CHANCE ALONG SOUTH OF 
I80 WHERE AIMASS IS THE LEAST STABLE.  META SHOWING SOME DECENT UVV 
DEVELOP BY EARLY THIS EVENING WHICH COULD GENERATE A FEW STRONG 
THUNDERSTORMS ALONG AND SOUTH OF HIGHWAY 34.  THE BIGGEST THREAT 
WOULD BE LARGE HAIL WITH WBZ'S JUST OVER 8K.  DRY AIR BELOW H8 WOULD 
ALSO SUGGEST THE POSSIBLITY OF DOWNBURSTS.  WILL GO WITH CATEGORICAL 
POPS FOR SHRA/TSRA THROUGH MIDNIGHT IN THE SOUTH THEN CUT BACK TO 
LIKELYS OVERNIGHT CWA WIDE.  WILL LEAN TOWARD THE COOLER MAV NUMBERS 
FOR MINS.  COOL MOSIST WRAP AROUND FLOW WILL DOMINATE CWA THURSDAY.  
WILL KEEP CHC POPS IN FOR SOME LINGERING -RA IN THE MORNING.  THERE 
IS SOME DESCREPANCY BETWEEN THE ETA AND GFS ON HOW FAST THE LOW 
LEVELS WILL DRY OUT BEHIND SYSTEM FRIDAY AFTERNOON.  WILL BANK ON 
SOME  LATE AFTERNOON SUN IN THE WEST WITH SUBSIDENCE HELPING BREAK 
UP THE CLOUD DECK WEST OF THE MS.  TEMPS WILL BE A BLEND OF MAV/MET 
NUMBERS.  NEXT SYSTEM MOVES INTO THE CENTRAL PLAINS BY EARLY FRIDAY
WITH MODELS SUGGESTING SOME QPF COULD REACH CWA BY LATE FRIDAY 
AFTERNOON.  WILL INTRODUCE A LOW CHANCE POP OVER THE W FRIDAY 
AFTERNOON.  THERE CONTINUE TO BE SOME TIMING DIFFERENCES WITH SYSTEM 
MOVING ACROSS IA ON SATURDAY.  HOWEVER ALL MODLES KEEP SURFACE LOW 
WEST OF CWA THROUGH SATURDAY AFTERNOON...KEEPING CWA IN THE WARM 
SECTOR. WILL BOOST TEMPS A FEW DEGREES ABOVE THE MEX NUMBERS.  
TIMING OF SYSTEM ALSO SUGGESTS THAT THERE MAY BE A SEVERE THREAT 
SATURDAY AFTERNOON AND EVENING.

EXTENDED...
MODELS STILL HAVING SOME DIFFICULTY WITH WEEKEND SYSTEM. HOWEVER THE 
GFS/UKMET WERE GETTING CLOSER BY SUNDAY EVENING PLACING SURFACE LOW 
OVER NE IOWA /UKMET/ OR E CENTRAL WI /12Z GFS/.  PLACEMENT OF 
SURFACE LOW WILL HAVE A BIG IMPACT ON TEMPS WITH UKMET KEEPING CWA 
IN WARM SECTOR SUNDAY. BOTH MODELS ARE SHOWING A STACKED SYSTEM AND 
WILL TREND TOWARD THE SLOWER UKMET...KEEPING TEMPS SUNDAY A LITTLE 
WARMER THAN THE MEX NUMBERS.  SYSTEM PULLS AWAY FROM REGION BY 
MONDAY AND WILL CUT RAIN CHANCES OFF EARLY IN THE DAY.  NEXT SYSTEM 
APPROACHES REGION FROM THE SOUTHWEST FOR MID-WEEK.  GFS SUGGESTS 
SYSTEM WILL STAY SOUTH OF CWA AND WILL GO WITH A DRY FCST FOR NOW.

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

$$
DLF