[LeArc] Forecast Discussion : MLI@ 4/9/2003 1:59:15 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 090657
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
150 AM CDT WED APR 9 2003

TRANQUIL WX NEXT SEVERAL DAYS. MID/UPPER LEVEL HEIGHT RISES IN PLAINS
SUPPORT MODELS BUILDING UPPER RIDGE EASTWARD...RESULTING IN
WARMING TREND. MAINLY TEMPERATURE FORECAST NEXT FEW DAYS...WITH SOME
CONCERNS WITH DENSE FOG POTENTIAL NEXT FEW NIGHTS.

SURFACE RIDGE AXIS EXTENDS FROM WI THROUGH WESTERN IA AND EASTERN NE
AT 06Z. IMPACTS OF SNOW COVER AND EXCELLENT RADIATIONAL COOLING
BEING FELT WITH DUBUQUE AT 17 DEGS...JUST SHY OF RECORD (16 DEGS IN 
1997)...WHICH SHOULD FALL WITH STILL SEVERAL MORE HOURS OF STRONG 
RADIATIONAL COOLING TO GO. MODELS MOVE RIDGE AXIS SLOWLY S/E THROUGH 
LATE THU. NICE WARMING OCCURS ALOFT WITH H85 TEMPS CLIMBING
TO BETWEEN 6-8C BY 00Z FRI. HOWEVER...SURFACE RIDGE HOVERING 
NEARBY WITH LIMITED MIXING. THIS COUPLED WITH WET GROUND OR RESIDUAL
SNOW COVER NORTH SUGGEST GUIDANCE TOO OPTIMISTIC NORTH AND WILL
UNDERCUT 1-2 CATS INTO THU. ELSEWHERE...WITH LIMITED MIXING WILL SIDE
TOWARD COOLER FWC GUIDANCE. IDEAL RADIATIONAL COOLING TO PERSIST
NEXT FEW NIGHTS. CURRENT TEMPS AT 06Z IN/NEAR RIDGE AXIS IN 
UPPER TEENS TO L20S. FWC ONLY GUIDANCE WHICH SEEMS TO HAVE CLUE...WITH
MAV AND ETA GUIDANCE WAY TOO WARM BASED ON VERIFICATION.
THUS...WILL GO NEAR OR BELOW FWC GUIDANCE ALL LOCATIONS WHICH WILL
PUT RECORDS IN JEOPARDY...AND WILL ADD RECORD/NEAR RECORD
WORDING WHERE APPROPRIATE. NEXT CONCERN IS FOG/DENSE FOG POTENTIAL.
MELTING TODAY WILL INCREASE LLVL MOISTURE...AND BELIEVE
THIS SHOULD AID AREAS OF FOG TO DEVELOP LATE TONIGHT AND EARLY THU
MAINLY NORTH...WITH LOCALLY DENSE FOG POSSIBLE. SHOULD SEE
MORE FOG THU NIGHT WITH SURFACE RIDGE JUST SLIDING S/E. CURRENTLY HAVE
SOME FOG IN MISSOURI RIVER VALLEY ON BACKSIDE OF RIDGE.

MODELS CONTINUE TO ADVERTISE FRONTAL PASSAGE FRI. AVN/GFS HAS BACKED OFF
ON QPF. DRYING TREND LOOKS REASONABLE GIVEN SURFACE RIDGING 
IN THE GULF CUTTING OFF MOISTURE FEED...AND LACK OF FORCING TO OVERCOME
LITTLE MOISTURE. THUS...WILL INCREASE CLOUD WORDING TO P/C AND 
MAINTAIN DRY FORECAST. 

EXTENDED (SAT-TUE)
SURFACE HIGH SHIFTS EAST ON SAT AS WARM FRONT SURGES NORTH BENEATH
BUILDING UPPER RIDGE. AVN/GFS GENERATES LIGHT QPF ACROSS THE
SOUTH LATE SAT AS FRONT LIFTS NORTH. PREVIOUS SHIFT REMOVED POPS AND
WILL NOT REINTRODUCE AT THIS TIME...BUT WILL PASS ON CONCERNS 
TO DAY CREW. 

HOPE TO HAVE FINAL ISC GRIDS OUT BY 0730Z. 

RECORD LOWS APRIL 10TH

DUBUQUE        18  1989
CEDAR RAPIDS   20  1960 AND PREVIOUS 
MOLINE         21  1960
BURLINGTON     20  1960


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

$$

05