FXUS63 KDVN 030944
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
335 AM CST WED MAR 3 2004

.SYNOPSIS...DIRTY...GRUNGY...SURFACE RIDGE IN PLACE OVER THE AREA...
WITH LOTS OF LOW LEVEL TRAPPED MOISTURE IN THE FORM OF THICK STRATUS
OVER MUCH OF THE UPPER MIDWEST.  A SURFACE LOW DEVELOPING OVER THE
SOUTHWEST TX/MEXICO BORDER AREA...WITH A STRONG LEE SIDE TROUGH
EXTENDING NORTH ALONG THE LEE SIDE OF THE ROCKIES.  UPPER LEVELS
SHOWING STRONG SOUTHWEST FLOW ACROSS THE CONUS...WITH SOME PRETTY
DECENT SHORTWAVES AT THE MID AND UPPER LEVELS.  THE MAIN SHORTWAVE
IS MOVING ACROSS WESTERN TEXAS...AND LOTS OF CONVECTION IS ONGOING
ALONG AND NORTH OF THAT WAVE.

&&

.SHORT TERM...(TODAY AND TONIGHT) TODAY...THE BULK OF THE
PRECIPITATION WILL REMAIN TO THE SOUTH OF THE AREA. HOWEVER...A MID
LEVEL WAVE WITH AN AREA OF MID LEVEL WARM AIR ADVECTION...SOME
FRONTOGENETICAL LIFT MAY CAUSE A MESOSCALE BAND TO SET UP SOMEWHERE
ACROSS THE CWA...PROBABLY THIS AFTERNOON AND THIS EVENING.  AM
ACTUALLY LEANING MORE TOWARDS THE NORTHERN THIRD OF THE CWA FOR THE
POSITION OF THIS BAND...AND HAVE HIGHER POPS THERE THAN THE CENTRAL
CWA. TOWARDS MORNING...THIS MESOSCALE BAND SHOULD HAVE MOVED EAST...
AS WELL AS THE MAIN ISENTROPIC UPLIFT BAND WITH THE MAIN VERTICAL
VELOCITIES WILL ALSO HAVE SHIFTED EAST ENOUGH FOR RAIN CHANCES TO BE
OUT OF THE CWA.  TEMPERATURES DURING THIS ENTIRE TIME PERIOD ARE VERY
SLOW TO CHANGE...WITH LOW DIURNAL TEMPERATURE RANGE...RISING ONLY
INTO THE LOW TO MID 40S AND DROPPING INTO THE MID TO UPPER 30S
OVERNIGHT.   ..LE..

&&

.LONGER TERM...(THURSDAY THROUGH TUESDAY) GFS MORE PROGRESSIVE AND
REVVED UP(SOME FEEDBACK ISSUES)...PLUS A BIT FURTHER EAST IN HANDLING
EJECTION PROCESS OF MAJOR VORT FOR THU NIGHT STORM SYSTEM. UKMET MAY
BE THE BEST MEDIUM...AS IT IS FURTHER TO THE WEST AND WEAKER THAN THE
GFS BUT A BIT MORE PROGRESSIVE THAN THE ETA. ANYWAY...EXTENT OF
SOUTHWEST UPPER FLOW ANALYSIS AND ENSEMBLES STILL SUGGEST A STRONG
LATE WINTER SYSTEM TO PULL UP ALMOST RIGHT OVER THE AREA. LATEST
SHORT RANGE MODEL RUN ENSEMBLES STILL SHOW EXTENT OF MID AND UPPER
LEVEL DIFFLUENCE...FORCING AND WARM CONVEYOR IN-FEED TO MAKE FOR A
SIGNIFICANT RAIN EVENT FOR MUCH OF THE CWA. DEPENDING ON FINALIZED
LLVL CYCLONE PATH...IT APPEARS NOW THAT THE WESTERN CWA TO BE AT RISK
OF HEAVY DEF ZONE RAINS...WHILE THE SOUTH AND EAST TO BE GLANCED BY
WARMER SECTOR CONVECTION(ALSO HEAVY RAIN). AN INCH... TO INCH AND A
HALF OVER MUCH OF THE CWA STILL APPEARS REASONABLE LOOKING AT THE
SYNOPTIC SCALE SET-UP THAT WILL AFFECT THE LOCAL AREA. INTERESTING
THOUGH...THAT UKMET'S FURTHER WEST LLVL LOW PATH WOULD WHIRL DRY SLOT
RIGHT UP THROUGH THE CWA FROM THE SOUTHWEST AFTER 06Z FRI...AND WOULD
LIMIT QPF POTENTIAL AFTER THE EVENING RAINS HAVE OCCURRED. SO SOME
QUESTIONS AND UNCERTAINTY FOR LARGE QPF AMOUNTS STILL THERE AT THIS
POINT TO WARRANT ANY KIND OF WATCH AT THIS POINT. EXTENT OF DYNAMICS
AND SHEAR OVER CONTINUED WARMING AND SFC DPT INCREASE IN WARM SECTOR
THU NIGHT MAY FUEL SVR WX/STRAIGHT LINE THREAT...WHICH AGAIN WOULD BE
MAINLY OVER THE SOUTHERN AND EASTERN CWA. BOMBING LOW SWEEPING UP
THROUGH THE AREA AND TIGHTENING GRADIENT WILL MAKE FOR STRONG
GRADIENT WINDS AS WELL...PLUS THE RISK OF EVEN LOWER-TOPPED SHOWERS
MIXING DOWN/ MOMENTUM TRANSFER OF INCREASING 45-55 KT LLVL JET WIND
IN WARM SECTOR(MAINLY EAST OF MS RVR).

BACK TO THURSDAY...EXPECT INCREASING LLVL EAST-NORTHEAST FLOW FETCH
FROM DRIER SOURCE REGION TO RETARD SATURATION AND PRECIP ADVANCEMENT
FROM THE SOUTH OF EJECTING SYSTEM...BUT BY THU NIGHT DYNAMICS AND
GULF FEED TO EASILY WIN OUT EVENTUALLY. THUS BULK OF THU TO BE DRY
UNTIL LATER IN THE AFTERNOON. QUICK LOOK AT BOTH THE ETA AND GFS
300 K SFC ISENTROPIC LIFT AND COND P-DEFS ALSO SHOW THIS DELAY IN
ADEQUATE SATURATION FOR PRECIP TO REACH THE SFC UNTIL LATE IN THE
DAY. THU HIGH TEMPS TO OCCUR ALSO DURING THE EVEING...WITH TEMPS
CONTINUING TO CLIMB OVERNIGHT...ESPECIALLY ACRS THE EASTERN 2/3'S OF
THE CWA. EARLIER DAY SHIFT ALREADY NAILED THIS TREND DOWN.

LITTLE OR NO CHANGES TO LATER PERIODS.   ..12..

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.

&&

$$

LE/12