[LeArc] Forecast Discussion : MLI@ 4/14/2003 4:57:18 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 142147
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
400 PM CDT MON APR 14 2003

WARM...WINDY AND SUNNY CONDITIONS ACROSS THE CWA TODAY...WITH
DEWPOINTS HAVING RISEN INTO THE MID TO UPPER 40S ACROSS MOST OF THE
CWA.  UPPER LEVEL ANALYSES INCLUDE A STRONG LONG WAVE RIDGE OVER
THE MIDWEST...WITH GENERALLY DRY CONDITIONS THROUGH MUCH OF THE
ATMOSPHERE.

MAIN CONCERN THIS FORECAST INCLUDES TEMPERATURES TUESDAY AND
WEDNESDAY...AS WELL AS PRECIP CHANCES BEGINNING TUESDAY.

12Z MODELS APPEAR TO HAVE INITIALIZED REASONABLY WELL.  THERE ARE
SOME INTERESTING DIFFERENCES THAT SHOW UP BY THURSDAY 12Z...WITH THE
EUROPEAN AND CANADIAN MODELS KEEPING THE UPPER LEVEL LOW ON A MORE
SOUTHERLY TRACK...AND THE NGM...AVN...AND ETA BRINGING IT FURTHER
NORTH.  FOR NOW...THE DIFFERENCE IS NOT SO GREAT THAT A BLEND
CANNOT BE UTILIZED...AND HAVE DONE SO.  HAVE GONE MAINLY WITH THE
ETA IN THE NEAR TERM...AS IT APPEARS TO BE DOING THE BEST WITH THE
SURFACE FRONT AS IT SAGS SOUTH ACROSS WISCONSIN TO AROUND THE I-80
CORRIDOR BY WEDNESDAY MORNING.

TODAYS HIGHS EXCEEDED EXPECTATIONS...AND I HAD BEEN GOING WELL ABOVE
GUIDANCE FOR THE LAST FEW DAYS ANYHOW.  TOMORROW WILL BE SIMILAR...
BUT WITH THE FRONT A LITTLE FURTHER SOUTH...THE THERMAL RIDGE WILL
BE PROPORTIONATELY FURTHER SOUTH.  CURRENTLY THE WARMEST TEMPS ARE
ACROSS NORTHERN IA...AND SHOULD SHIFT TOWARDS SOUTHERN IOWA FOR
TOMORROW.  HAVE GONE A FEW DEGREES COOLER THAN TODAYS HIGHS IN THE
THERMAL RIDGE DUE TO EXPECTED INCREASE IN CLOUDS.  THE TRICK WILL
BE TIMING IN THE PRECIPITATION.  IT APPEARS THAT THE MAIN FOCUS WILL
BE ALONG THE FRONT TO THE NORTH...AND ALONG THE COLD FRONT TO THE
WEST...AND WITH DEWPOINTS ONLY INCREASING INTO THE LOW 50S...ANY
PRECIP SHOULD STICK TO THESE FOCUS AREAS.  THE SQUALL LINE THAT
DEVELOPS ON THE COLD FRONT SHOULD NOT GET HERE UNTIL AFTER MIDNIGHT
TUESDAY NIGHT...THOUGH IT IS POSSIBLE IT MAY MOVE FASTER THAN
THAT...AND HAVE KEPT PRECIPITATION TO GENERAL NIGHT WORDING.

WEDNESDAY WE COULD SEE SOME LIMITED SEVERE WEATHER...THOUGH SIGNALS
STILL HAVE ENOUGH AMBIGUITY THAT I CHOSE NOT TO MENTION IN THE
ZFP. SPC IS KEEPING THE SLIGHT RISK AREA SOUTH OF THE CWA...AND FOR
NOW AGREE THAT THE HIGHEST RISK IS SOUTH OF THE CWA.  CANNOT RULE
OUT SOME MARGINAL HAIL AND HIGH WIND OCCURRENCES.

EXTENDED...FRIDAY THROUGH MONDAY
MODELS APPEAR TO HAVE SLOWED DOWN THE SATURDAY THROUGH MONDAY SYSTEM
A LITTLE AND PULLED PRECIP OUT OF FRIDAY ENTIRELY.  LITTLE ELSE GOT
CHANGED...WITH ONLY MINOR TWEAKS TO TEMPS. STAYED CLOSE TO GUIDANCE
FOR TEMPS ON MONDAY.

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

$$

LRE