[LeArc] Forecast Discussion : MLI@ 10/18/02 2:15:04 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 181922
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
220 PM CDT FRI OCT 18 2002

.OVERVIEW...NEXT SHORT WAVE PASSING OVER REGION WITH COLD FRONT AT 18Z
EXTENDING FROM NW WISCONSIN TO NEAR DES MOINES TO NORTHERN KANSAS
MOVING SOUTHEAST AT 15 TO 25 MPH.  LIMITED MOISTURE AHEAD OF SYSTEM
EXCEPT FOR LIFTING UPPER LEVEL STORM SYSTEM IN TEXAS WITH LEADING EDGE
CLOUDS NOW ALONG I-70 MOVING NORTHEAST 15-20 MPH.  JET AXIS NORTH OF
OUR AREA...SUGGESTING ANY PRECIPITATION CHANCES HAVE TO BE ALONG THIS
BOUNDARY OR WITH WARM CONVEYOR BELT.  WEAK BAND OF CLOUDS SUGGESTIVE OF
WARM CONVEYOR BELT AT 18Z RUNNING FROM NORTH OF PIA TO MQB TO IRK.
UPPER AIR HEIGHT RISES SUPPORT LARGE SCALE PROGRESSIVE PATTERN WITH
PHASING OF SOUTHERN SYSTEM WITH WISCONSIN WAVE WITH NICE PRESSURE RISES
ACROSS DAKOTAS TO PUSH FRONT EAST.

...COOL-DOWN AND PRECIP CHANCES THIS EVENING FAR SOUTHEAST NEAR TERM
ISSUES AND THEN PRECIPITATION CHANCES EARLY NEXT WEEK WITH NEXT SHORT
WAVE AND MORE COOL AIR MEDIUM ISSUES...

.DIAGNOSIS AND DAYS 1-3...AVN VERIFIES BEST ON FRONTAL POSITION WITH
ETA AND NGM SLIGHTLY TOO FAST.  THUS...EVENING SHOWERS AND POSSIBLE
EMBEDDED STORMS POSSIBLE TO DEVELOP NEXT SEVERAL HOURS ALONG THE
EXISTING BAND OF WARM CONVEYOR BELT MOISTURE.  THIS CAUSED BY TX SYSTEM
AND FRONT AS THEY PHASE WITH THIS MOISTURE BEFORE HEADING EAST.  WILL
NEED TO MONITOR...BUT RIGHT NOW PLAN FOR 30-40 POPS THIS EVENING SE 3-5
COUNTIES.  GUSTY SW WINDS OVER AREA AT 20 TO 30 MPH ALREADY STARTING TO
WEAKEN WEST AREAS AS FRONT APPROACHES WITH WINDS SHIFTING NW BY EARLY
MORNING WITH SKIES CLEARING.  LOW TEMPS NEAR MAV/FWC/MET EXCEPT SLIGHTLY
BELOW NW AREAS TONIGHT.  SOME FAIR WEATHER CUMULUS TOMORROW BUT
OTHERWISE QUIET AND COOL CONDITIONS THAT WILL PERSIST INTO SUNDAY. WILL
GO NEAR BLEND OF GUIDANCE EXCEPT NW SECTIONS WITH CENTER OF HIGH
LIMITING MIXING AND LOTS OF CAA. LOWS SATURDAY WITH IDEAL RADIATIVE
COOLING AND NEARLY CALM WINDS EXPECT MINS 1-2 CATEGORIES BELOW GUIDANCE
FOR HARD FREEZE ALMOST ALL AREAS THAT WILL PUT END TO ANY REMAINING
OUTDOOR PLANTS.  THEN INCREASING CLOUDS FROM NW SUNDAY AS NEXT SHORT
WAVE APPROACHES WITH SFC HIGH OVERHEAD KEEPING TEMPS ON COOL SIDE.
CHANCE OF LIGHT RAIN OR SNOW NORTH OF HIGHWAY 30 SUNDAY NIGHT WITH
SIGNIFICANT GRADIENT ACROSS AREA WITH NEXT FRONT AND CLOUDS.  KEEP
CHANCE OF LIGHT RAIN OR LIGHT RAIN AND SNOW NEAR HIGHWAY 20 ON MONDAY AS
ETA/AVN AND EVEN UKMET SUPPORT WEAK OVERRUNNING BEHIND SLOW MOVING FRONT
INTO MONDAY NIGHT.

.LONGER RANGE(TUE-FRI)...LATEST AVNXT SHOWS MODERATE WAVE WITH
PRECIPITATION INTO WED WITH NEXT SYSTEM...BUT ALL OTHER MODELS ARE
DRIER AND MORE PROGRESSIVE WITH CENTER OF COLD HIGH OVERHEAD WEDNESDAY
INTO THURSDAY. WILL KEEP THIS CONSENSUS SOLUTION AS NOT ENOUGH EVIDENCE
OF PHASING AS SUGGESTED BY AVN OF RETROGRADING TROUGH OF THIS STRENGTH
APPEARS NOT THAT VIABLE (UNLIKELY)...ANY CHANCES OF THIS HAPPENING
SHOULD BE CLARIFIED PROBABLY ON TONIGHTS RUNS. THUS...KEEP TEMPS FAIRLY
CLOSE TO MEX EXCEPT LOWS WED/THU LOWER WITH NEAR IDEAL RADIATIONAL
COOLING SETUP.

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

NICHOLS