[LeArc] Forecast Discussion : MLI@ 5/30/2003 2:26:40 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 300724
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
223 AM CDT FRI MAY 30 2003

FORECAST CHALLENGE WILL BE CHANCES OF PCPN TODAY AND STRENGTH OF 
WINDS ACROSS ALL OF THE AREA THIS AFTERNOON THROUGH TONIGHT. 

SYNOPSIS-
PERSISTENT LONG WAVE PATTERN IS STILL HOLDING EARLY THIS MORNING 
ACROSS THE NATION.  THE LOCAL AREA CONTINUES TO REMAIN UNDER 
NORTHWEST FLOW ALOFT...WITH SOME MOISTURE NOW RETURNING TO THE 
NORTHERN PLAINS AHEAD OF A RATHER POTENT SHORTWAVE TROF MOVING 
SOUTHEAST FROM SASKATCHEWAN AT 00Z.  A WEAKER WAVE HAS FIRED EVENING 
CONVECTION ALONG THE MISSOURI RIVER INTO MISSOURI WITHIN THIS 
MOISTURE AXIS. 

FORECAST-
CONVECTIVE CHANCES APPEAR TO LIMITED TO PRIOR TO 21Z TODAY AS THE 
MAIN TROF/CDFNT PASSAGE WILL SWEEP THROUGH THE AREA QUICKLY. 
OVERALL...EARLY MORNING PCPN CHANCES WILL LINGER THROUGH 20Z...WITH 
THE BEST COVERAGE IN THE EAST.  SEVERE THREAT APPEARS QUITE 
LOW...DUE TO FORCING COMING THROUGH AT BEFORE INSTABILITY INCREASES. 
CONVECTIVE TRENDS ACROSS CENTRAL IA AND SOUTHEAST MN WILL BE WATCHED 
CLOSELY THROUGH ISSUANCE TIME...AND POPS MAY BE LOCALLY INCREASED IN 
SOME AREAS EARLY THIS MORNING.  ATTENTION THIS AFTERNOON AND TONIGHT 
TURNS TO STRONG NORTHWEST WINDS.   
AS DISCUSSED IN THE PREVIOUS AFD...35-40KT 850MB WINDS WILL MIX DOWN 
TO THE SURFACE INCREASING WELL DURING THE AFTERNOON. BY 00Z 40-50KT 
850MB WINDS WILL CONTINUE TO MIX DOWN...THOUGH NOT AS 
EFFICIENTLY...EVEN SO EXPECT STRONG WINDS TO CONTINUE THROUGH THE 
LATE EVENING.  THIS WIND EVENT WILL COME TO ADVISORY CRITERIA DURING 
THE LATE AFTERNOON AND EVENING...BUT WILL LET DAY SHIFT HANDLE 
THIS.  

COOL HIGH PRESSURE WILL SETTLE IN THROUGH SUNDAY MORNING.  AFTER A 
BREEZY MORNING SATURDAY...CONDITIONS QUIET DOWN SUBSTANTIALLY 
SATURDAY NIGHT.  A SEASONALLY COLD NIGHT LOOKS LIKE A GOOD 
BET...WITH LOWS DROPPING TO THE LOW 40S NORTH TO MID 40S SOUTH.  THE 
UPPER RIDGE BEGINS TO BREAK DOWN/SHIFT WESTWARD LATE SATURDAY.  THIS 
WILL ALLOW SHORT WAVE ENERGY INTERACT WITH MODEST MOIST SOUTHERLY 
FLOW SUNDAY NIGHT.  WILL MAINTAIN CHC POPS FOR SUNDAY NIGHT THROUGH 
MONDAY AS LATEST MODEL RUNS SHOW SOMEWHAT UNSETTLED PERIOD WITH 
SEVERAL SMALL WAVES MOVING THROUGH THE AREA.  

EXTENDED...
GFS CONTINUES TO DROP A MAJOR UPPER LOW INTO THE AREA TUESDAY NIGHT 
INTO EARLY THURSDAY.  CONFIDENCE IS NOT HIGH WITH THIS 
FEATURE...THOUGH THERE SEEMS ENOUGH CONSISTENCY TO SUPPORT LOW CHC 
POPS.  NO SIGNIFICANT CHANGES MADE TO REST OF THE EXTENDED.

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

$$

ERVIN