[LeArc] Forecast Discussion : MLI@ 6/5/02 1:36:33 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 051833
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
130 PM CDT WED JUN 5 2002

LOTS OF LITTLE THINGS TO KEEP FORECAST CHALLENGING.

18Z VISIBLE SATELLITE SHOWS BACK EDGE OF LOW CLOUDS ROUGHLY JUST SOUTH
OF KDBQ-KIOW-KFFL LINE...MOVING SLOWLY S/E. 12Z UA ANALYSIS
SHOWS BROAD H5 TROUGH FROM UPPER MIDWEST THROUGH CENTRAL PLAINS. 
LOTS OF MID/HIGH CLOUDS BEING THROWN UP OVER REGION 
WITH TROUGH STILL TO OUR WEST. LIGHT PCPN EARLY THIS MORNING HAS SHIFTED
INTO CENTRAL/EASTERN ILLINOIS. PCPN AIDED BY RIGHT ENTRANCE REGION
OF UPPER JET MAX. CLOUDS RESULTING IN UNSEASONABLY COOL 
TEMPS WITH M/U 50S. WHERE SUN HAS FILTERED THROUGH...THE MERCURY HAS
JUMPED INTO M 60S. AT 18Z...SURFACE HIGH PARKED OVER CENTRAL WI 
WITH LIGHT NORTHEAST FETCH OFF LAKE MI RESULTING IN WEAK CONVERGENCE ZONE
IN EASTERN CUTS. THIS WILL PLAY ROLE IN CLOUD FORECAST TNGT-THU.

TONIGHT...WINDS WILL GO LIGHT AND VARIABLE WITH SURFACE RIDGE AXIS LYING
ACROSS REGION. SURFACE HIGH POSITIONED OVER EASTERN WI AND
NORTHERN END OF LAKE MI. FLOW AROUND HIGH TO PRODUCE LIGHT FETCH OFF LAKE
MI WITH NATURAL CONVERGENCE ZONE IN EASTERN HALF OF CWA...THUS
WITH MID/HIGH CLOUD DEBRIS NOT CONFIDENT ON MUCH CLEARING AND WILL SIDE
TOWARD MORE PESSIMISTIC MOCLDY. FURTHER WEST...EXPECT CIRRUS TO THIN
WITH JET MAX AND UPPER TROUGH GRADUALLY SHIFTING EAST...THUS THESE AREAS
COULD GO MOCLEAR. HOWEVER...PLENTY OF RESIDUAL BOUNDARY LAYER MOISTURE
FROM RECENT SIGNIFICANT RAINS. THUS...WITH LIGHT WINDS AND 
ANY CLEARING EXPECT TO SEE FOG/ST FORMATION...MAINLY AFTER MIDNIGHT.
LOOKING AT THIS MORNING SOME AREAS BENEATH RIDGE AXIS GOT DOWN TO AROUND
1/4 MI IN SOUTHERN MN AND NORTHWEST IA. POTENTIAL THERE FOR DENSE FOG
BUT DEPENDENT ON CLOUD TRENDS...THUS WON/T ISSUE ADVISORY...BUT WILL PASS
CONCERNS ON TO EVENING CREW. ATTIM...THINKING NORTHWEST ZONES
MOST FAVORED FOR DENSE FOG GIVEN EXPECTED CLEARING. ELSEWHERE...ESPECIALLY
EAST LOW CLOUDS COULD HINDER FOG FORMATION...BUT ANY CLEARING AND
FOG WILL DEVELOP FAIRLY QUICKLY GIVEN LIGHT FLOW...SO WILL MENTION FOG
BUT NOT ADD DENSE WORDING. MIN TEMPS WILL BE TRICKY WITH POTENTIAL 
FOR BUST WITH CLOUDS AND LAKE FETCH. BELIEVE WE/LL SEE GRADIENT FROM 
NORTHEAST (NR 50 DEGS) TO SOUTHWEST (M50S).  

AREAS OF FOG/STRATUS WILL LINGER INTO THU MID-LATE MORNING...BEFORE 
GRADUALLY GIVING WAY TO SUNSHINE. WITH HIGH JUST PULLING EAST AND 
TRAJECTORY STILL OFF LAKE...NOT THINKING MUCH WARMING...HOWEVER GIVEN
TODAY/S COOL READINGS IT WILL BE WARMER. PLAN TO GO AT OR JUST 
BELOW COOL END OF GUIDANCE ON MAXES (GENERALLY L/M 70S). 

LATE THU-FRI UPPER JET WITH SHORTWAVE PROGGED ACROSS THE NORTHERN STATES
REFLECTED AT SURFACE WITH TROUGH. BEST FORCING NORTHERN PLAINS INTO 
UPPER MIDWEST WHERE SOME CONVECTION EXPECTED. UPPER FLOW WOULD 
TRY TO STEER PCPN TOWARD CWA BUT WITH REGION STILL UNDER INFLUENCE 
OF LLVL RIDGING AND BEST FORCING WELL NORTH
WILL KEEP THINGS DRY. NEXT SHIFT/S CAN RE-EVALUATE POTENTIAL FOR SOME
LEFTOVERS SNEAKING INTO NORTHERN CUTS. TEMPS FRI WILL BE WARMER
WITH WARMUP CONTINUING INTO WEEKEND. 

EXTENDED (SUN-WED)
DIFFERENCES EXIST AMONG MEDIUM RANGE MODELS ON MOVEMENT OF ROCKIES 
TROUGH EASTWARD THROUGH MIDWEST. OVERALL...IT APPEARS MODELS
TRENDING SOMEWHAT SLOWER...THUS INDICATING MORE SUMMERLIKE REGIME WITH
RIDGING AND WARMING ALOFT. RING OF FIRE TO FOCUS PCPN
AROUND PERIPHERY OF UPPER LEVEL HIGH PARKED OVER SOUTHEASTERN US
WITH NOCTURNAL COMPLEXES STAYING TO OUR NORTH. 
OVERALL...VERY WARM/HOT CONDITIONS ALONG WITH HUMID DAYS/MUGGY NIGHTS
SUN-TUE. POTENTIAL TO SQUEEZE OUT DRY WEEKEND FOR UPCOMING 
AIRSHOW WITH BEST PCPN CHCS LOOKING LATE MON-TUE WITH APPROACHING FRONTAL
ZONE.

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

MCCLURE