Severe Thunderstorm Warning 41, NWS Quad Cities, IA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
250 AM CDT SUN JUN 6 1999

UPPER AIR ANALYSIS THIS MORNING INDICATING LOW PRESSURE TROUGH
MOVING EAST AWAY FROM THE ROCKIES.  PRESSURE FALLS AHEAD OF SYSTEM
LESS THAN LAST NIGHT...SO EXPECT SOME SLOWING OF FORWARD SPEED IN
THE NEXT 12-24 HRS.  110KT JET INDICATED AT EXTNDG FROM ERN CO THRU
MN...AND NICE DIVERGENT FLOW OVER THE UPPER MIDWEST.  700MB THERMAL
RIDGE STILL IN PLACE OVER THE CWFA...WITH A +13 FROM LOCAL UPPER AIR
RUN.  LIKE LAST NIGHT...THIS SHOULD KEEP THE CURRENT THUNDERSTORM
ACTIVITY TO THE NORTHEAST OVER MINNESOTA AND WISCONSIN...WHERE CAP
IS NOT AS STRONG.  850MB ANALYSIS AND WV IMAGERY INDICATE THAT THIS
SYSTEM IS TAPPING THE GULF...AND THE ONLY THING KEEPING WIDESPREAD
CONVECTION FROM  FORMING IS THE KILLER CAP AT 700MB FROM LA TO IL.
SURFACE ANALYSIS INDICATING WARM FRONT WELL NORTH OF THE CWFA...AND
COLD FRONT STILL EXTENDING FROM KPIR TO KDDC...WELL TO THE WEST.  NO
ACTIVITY LIKELY TO OCCUR UNTIL LATE TODAY.

CONCERN THIS MORNING IS TIMING OF AFTERNOON/EVENING CONVECTION AND
MAX TEMPS TODAY.

MODELS THIS MORNING ARE GENERALLY HANDLING THINGS SIMILARLY...THOUGH
BY 48 DIFFERENCES SEEM TO BE IN THE STRENGTH OF THE EJECTING LOW.
AS OF 06Z THE NGM SEEMED TO BE VERIFYING THE BEST...MAINLY IN THE
POSITIONING OF THE SURFACE LOW...AND THE SHORTWAVE POSITIONING TO
OUR WEST AND NORTHWEST.  HAVE STAYED FAIRLY CLOSE TO IT.  TEMPS WILL
BE CLOSE TO SATURDAYS HIGHS WITH THE CONTINUED WAA COMPENSATING FOR
INCREASED CLOUD COVER- WILL HAVE TO PUT THAT HOT WORD IN THE ZONES.

CONVECTION THIS AFTERNOON HAS SEVERAL THINGS GOING FOR IT.  AT THIS
TIME THE RIGHT REAR QUADRANT OF THE UPR LEVEL JET SHOULD BE OVER THE
AREA.  MODELS INDICATE THE MAIN SHORTWAVE MOVES OVER THE AREA...AND
THAT THE CURRENT CAP WILL HAVE DISSIPATED BY THEN.  WHILE THE COLD
FRONT CURRENTLY OVER THE HIGH PLAINS NEVER APPEARS TO MAKE IT AS FAR
EAST AS THIS CWFA...PLENTY OF OTHER WEAK BOUNDARIES SHOULD BE AROUND
FOR CONVECTION TO FOCUS ON.  SPC DAY ONE OUTLOOK HAS SLIGHT RISK
OVER THE AREA- AND WILL NEED TO WORD THIS AFTERNOON AND TONIGHT IN
THE ZONES ACCORDINGLY.

FROM THEN ON...THE FORECAST APPEARS TO BE DRY UNTIL THE EXTENDED
PERIOD...WITH A SHARP RIDGE BUILDING OVER THE AREA TUESDAY...KEEPING
PRECIP CHANCES LOW UNTIL THURSDAY.  HOWEVER...THE WARM AND MUGGY
CONDITIONS SHOULD CONTINUE...WITH HIGHS CONTINUING TO RANGE IN THE
MID 80S TO NEAR 90.

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

LRE