[LeArc] Forecast Discussion : MLI@ 8/5/02 2:36:21 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 051938
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
236 PM CDT MON AUG 5 2002

SHORT TERM...
18Z SURFACE ANALYSIS SHOWS A FRONTAL BOUNDARY JUST SOUTH OF THE
MISSOURI-IOWA BORDER...EXTENDING EAST INTO CENTRAL ILLINOIS AND WEST
INTO NEBRASKA WHERE IT BECOMES A WARM FRONT. DEWPOINTS WERE POOLING
NORTH OF THE FRONT...WITH 75+ DEWPOINTS ACROSS SOUTHERN IOWA INTO
NORTHEAST IOWA AND ACROSS PARTS OF ILLINOIS. UPPER AIR CHARTS SHOW
HIGH PRESSURE AT ALL LEVELS CENTERED OVER MISSOURI WITH H7, H5, AND H2
CHARTS SHOWING RIDGING NORTHWESTWARD INTO SOUTHERN CANADA. THE 850
CHART SHOWS A TROF EXTENDING FROM THE GREAT LAKES SOUTHWESTWARD INTO
NORTHEASTERN NEBRASKA WITH ANOTHER HIGH OVER EASTERN SASKATCHEWAN.
PRESSURE CHARTS SHOW LITTLE IN THE WAY OF PRESSURE CHANGE...EXCEPT FOR
SOME DECENT PRESSURE RISES ASSOCIATED WITH THE RIDGE AT H7 AND H2 OVER
NORTHEAST MANITOBA...AND SOME DECENT PRESSURE FALLS AT H7 OVER THE
NORTHAST U.S. AND THE CANADIAN MARITIME PROVINCES.

FORECAST CHALLENGES INCLUDE RAIN CHANCES THIS EVENING...AND
THUNDERSTORM CHANCES THIS WEEKEND INTO EARLY NEXT WEEK.

VORT MAX OVER EASTERN IOWA CONTINUES TO MOVE EAST-SOUTHEAST OVER THE
WESTERN CWA. THIS VORT MAX WILL CONTINUE MOVING SOUTHEAST OVER THE CWA
THIS EVENING. AS VORT MAX MOVES INTO MORE UNSTABLE AIR...CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL INCREASE. SHOWERS AND THUNDERSTORMS
WILL GRADUALLY AND FROM NORTH TO SOUTH TONIGHT AS THE VORT MAX MOVES
SOUTH AND THE HIGH PRESSURE TO OUR NORTH PUSHES SOUTHWARD.

NORTHERLY WINDS ON TUESDAY INTO WEDNESDAY WILL BRING SOME COOLED AIR
FROM LAKE MICHIGAN INTO OUR AREA. WILL TRIM MAXES BACK SOME IN THE
EASTERN ZONES ON TUESDAY AND WEDNESDAY...AND WILL TRIM BACK MINIMUMS
TUESDAY NIGHT AS WELL.

EXTENDED...
RIDGE BUILDS OVER CENTRAL U.S. THE FIRST PART OF THE PERIOD THEN BREAKS
DOWN AS THE TROF OVER THE WESTERN U.S. COAST RIDES UP IT. TROF THEN
DOMINATES THE CENTRAL U.S. WEATHER THROUGH MONDAY. FAIRLY STRONG
SURFACE SYSTEM FORECAST TO MOVE THROUGH OUR AREA SATURDAY...WITH
ANOTHER ONE ON MONDAY. WILL LEAVE CHANCE OF THUNDERSTORMS IN FOR
SATURDAY AND SUNDAY...AND INTRODUCE A CHANCE ON MONDAY TOO. GOING TEMPS
LOOK GOOD.


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

JAZ