AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
222 PM CST MON DEC 17 2007

.SHORT TERM...

MODIS 1 KM SNOW/ICE IMAGE DID AN EXCELLENT JOB DEPICTING STRATUS
OVER THE SNOW FIELD. MUCH OF THE SHORT FORECAST PROBLEM WILL DEAL
WITH BOUNDARY LAYER/STRATUS ISSUES.

DURING DAYLIGHT HOURS CRAS FORECAST IMAGERY SEEMS TO GIVE HINT AT
STRATUS MODEL DISTRIBUTION WITH WARMER TEMPS OVER CLEAR AREAS. AS
SUCH CRAS WAS A LITTLE SLOW IN DISSIPATING STRATUS.

NAM SOUNDINGS SHOW SATURATION IN LOWEST 500 FT. HOWEVER WITH
10 TO 15 KNOT WINDS...DOUBT FOG WILL BE AN ISSUE. MOS GUIDANCE
HAS NO INDICATION OF STRATUS...SO WILL BRING TEMPS DOWN A BIT
BELOW GFS MOS. CRAS MODEL HIGH CLOUDS TONIGHT AND TUESDAY MORNING
PRECLUDE ANY INFO ON STRATUS.

WEAK SHORTWAVE MOVING ACROSS THE NORTHERN GREAT LAKES TUESDAY
SHOULD KEEP PRECIPITATION NORTH OF THE FORECAST AREA.
CRAS DOES INDICATE A MORE WESTWARD STRATUS DECK TUESDAY
EVENING...WITH WARMER TEMPS OVER MUCH OF WI...E MN AND FAR E IA.
COLDER TEMPS OVER CLEAR SKIES AND SNOW COVER TO THE WEST OF THIS.
THE STRATUS IS PICKED UP WITH NAM/ETA MOS...BUT GFS MOS DOES NOT
HAVE STRATUS DEVELOPMENT. THIS IS IMPORTANT AS NAM SOUNDINGS SHOW
SOME FLIGHT FREEZING DRIZZLE POTENTIAL TUESDAY NIGHT. WILL
MENTION SOME LIGHT FREEZING DRIZZLE TOWARD FOND DU LAC AND
SHEBOYGAN AND GO WITH MAINLY STRATUS OVER THE REST OF THE FORECAST
AREA.

THEN A SHORTWAVE PUSHES ACROSS THE MID MISSISSIPPI VALLEY
THURSDAY. GFS AND ECMWF VERY SIMILAR WITH A MORE OPEN TROF...WITH
GFS STILL SHOWING MORE OF A CLOSED SURFACE LOW TO THE SOUTH.
ECMWF SPREADS MORE QPF NORTH...ALTHOUGH LESS THAN YESTERDAY...UP
TO 0.08 INCH ACROSS THE IL BORDER...WITH SOME QPF EVEN ACROSS OUR
NORTH AREAS. WILL GO WITH A BLEND THE LESSER GFS PRECIPITATION.

.LONG TERM...

STRONG DYNAMIC SHORTWAVE FOR NEXT WEEKEND WITH BOTH ECMWF AND GFS
HAVING A LOW TRACK THAT WOULD PUT A RAIN SNOW MIX POTENTIAL...OR
JUST RAIN AT LEAST FOR THE SOUTHEAST. WILL ADJUST PRECIPITATION TYPE IN
GRIDS. WITH THIS TRACK SIGNIFICANT SNOW WOULD BE NORTHWEST AND
NORTH OF THE FORECAST AREA.

ECMWF/GFS AND EVEN DGEX IN REASONABLE AGREEMENT IN KEEPING
PROGRESSIVE SHORTWAVES MOVING ACROSS THE U.S. INTO NEXT
WEEK...WITH ANOTHER SHORTWAVE AFFECTING THE UPPER MIDWEST MONDAY
AND TUESDAY.

&&

.AVIATION...
IFR STRATUS DECK FINALLY ERODING ACROSS SOUTHERN
WISCONSIN...WITH MIXING OF DRY AIR JUST ABOVE THE THIN DECK. VFR
CONDITIONS THEN EXPECTED THROUGH TUESDAY. SOME HIGH CLOUDS EXPECTED
LATER TONIGHT INTO TUESDAY...AHEAD OF NEXT SHORTWAVE TROUGH AND
VORTICITY MAXIMUM.

&&

.MARINE...
WINDS AND WAVES REACHING SMALL CRAFT ADVISORY CRITERIA ON
TUESDAY POSSIBLE...AS SURFACE PRESSURE GRADIENT INCREASES AND
SHALLOW MIXING OF 22 TO 25 KNOT WINDS POSSIBLE. OFFSHORE FLOW
SUGGESTS HIGHEST WAVES WOULD BE TOWARDS THE OPEN WATERS.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&

$$

SHORT/LONG TERM...06
AVIATION/MARINE...08