000
FXUS63 KGRB 180334
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1034 PM CDT THU APR 17 2014

UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE

.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 252 PM CDT THU APR 17 2014

SEVERAL FCST ISSUES TO DEAL WITH MAINLY DURING THE TNGT PORTION OF
THE FCST. FIRST ISSUE IS THE HANDLING OF CLOUDS AS THE SYSTEM
RESPONSIBLE FOR ALL THE SNOW NORTH CONTS TO PULL AWAY...BUT MID/HI
CLOUDS ASSOCIATED WITH ISEN LIFT TO ALREADY BE KNOCKING ON OUR
DOOR LATER TNGT. SECOND ISSUE IS MIN TEMPS AS ANY PROLONGED
CLEARING SKIES COULD ALLOW READINGS TO FREE-FALL OVER THE NORTH.
THE LAST ISSUE IS WHETHER OR NOT TO MENTION ANY FOG AS WINDS GO
LIGHT AND THERE IS MOISTURE IN THE LOW-LEVELS DUE TO SOME OF THE
NEW SNOW MELTING

THE 19Z MSAS SFC ANALYSIS INDICATED THE CENTER OF THE WEAKENING
AREA OF LOW PRES WAS SITUATED OVER E-CNTRL WI WITH A CDFNT
EXTENDED S-SW INTO THE MID-MS VALLEY. A RDG OF HI PRES WAS LOCATED
OVER THE NRN/CNTRL PLAINS. THE RADAR MOSAIC SHOWED THE BACK EDGE
OF SNOW NOW OVER LAKE SUPERIOR AND PULLING FARTHER AWAY. VSBL SATL
IMAGERY DID SHOW A LOT OF LOW CLOUDS ON THE CYCLONIC SIDE OF THE
DEPARTED SYSTEM WHICH ENCOMPASSES ALL OF WI.

THE NARROW RDG OF HI PRES IS FCST TO MOVE INTO THE WRN GREAT LAKES
TNGT AND PROVIDE FOR AN INITIAL DECREASE IN CLOUDS AND RELATIVELY
LIGHT WINDS. AS A RETURN FLOW SETS UP OVER THE MIDWEST NORTH OF A
WRMFNT...EXPECT TO SEE MID/HI CLOUDS BEGIN TO MAKE A PUSH TOWARD
CNTRL WI AFTER MIDNGT. THESE CLOUDS WL BE A PROBLEM IN TRYING TO
DETERMINE MIN TEMPS...ESPECIALLY OVER THE NORTH WHERE A FRESH FOOT
PLUS OF NEW SNOW FELL. PREFER TO UNDERCUT GUIDANCE WHERE THE SNOW
FELL WITH TEENS NORTH NORTH...BUT ONLY UPR 20S OVER E-CNTRL WI.
ONE OTHER CONCERN FOR TNGT IS THE POTENTIAL FOR FOG ACROSS THE
NORTH DUE TO THE INITIAL CLEARING SKIES...LIGHT WINDS AND LOW-LEVEL
MOISTURE (SNOW). HAVE ADDED AREAS OF FOG GENERALLY NORTH AND WEST
OF A LINE FROM MARATHON COUNTY TO NRN MARINETTE COUNTY IN
COLLABORATION WITH DLH AND ARX.

MID/HI CLOUDS WL CONT TO INCREASE OVER WI ON FRI AS LOW PRES OVER
THE NRN PLAINS GENERATES INCREASING ISEN LIFT ACROSS THE UPR MS
VALLEY. GENERALLY PARTLY SUNNY SKIES EXPECTED...BUT PREVAILING N-NE
WINDS WL PLACE A CAP ON TEMPS...ESPECIALLY NEAR LAKE MI. LOOK FOR
READINGS TO TOP OUT AROUND 40 DEGS N-CNTRL WI TO THE LWR 50S WEST
OF THE FOX VALLEY.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 252 PM CDT THU APR 17 2014

UPPER RIDGING SHOULD PROVIDE FOR DRY WEATHER FRIDAY
NIGHT THROUGH SATURDAY ALONG WITH SEASONABLE TEMPERATURES. AN
UPPER TROUGH MOVING FROM LAKE WINNIPEG TOWARDS JAMES BAY WITH
UPPER DIFFLUENCE OVER THE GREAT LAKES AND LOW LEVEL CONVERGENCE
AND WARM ADVECTION SHOULD BE SUFFICIENT FOR AN AREA OF SHOWERS
SATURDAY NIGHT.

SOME JET ENERGY LIFTING NORTHEAST FROM THE CENTRAL PLAINS MAY
KEEP THE SHOWERS GOING DURING THE MORNING HOURS EASTER SUNDAY. THE
MODELS HAVE VARYING SOLUTION AS TOO HOW MUCH OF A BREAK WE MIGHT
HAVE IN THE RAIN SUNDAY AFTERNOON AND SUNDAY NIGHT BEFORE MORE JET
ENERGY APPROACHES FROM THE SOUTHERN PLAINS AND SOUTHERN CANADA
MONDAY. THE NAM CONTINUES TO BE ADVERTISE A SIGNIFICANT BREAK IN
THE ACTION SUNDAY AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS IN
FROM THE NORTHWEST. THIS SEEMS REASONABLE AS THERE IS A LOT OF
COLD AND DRY AIR UP THERE. THE ECMWF IS NOT AS WET AS YESTERDAY
BUT STILL KEEPS A GOOD CHANCE OF RAIN ACROSS THE AREA SUNDAY
AFTERNOON THROUGH MONDAY. THE GFS IS KIND OF IN BETWEEN.

DRY WEATHER EXPECTED MONDAY NIGHT THROUGH AT LEAST EARLY WEDNESDAY
AS UPPER RIDGING APPROACHES FROM THE PLAINS. TEMPERATURES SHOULD
BE CLOSE TO NORMAL FOR THIS TIME OF THE YEAR.
&&

.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1030 PM CDT THU APR 17 2014

MVFR CIGS SLOWER TO EXIT THE AREA THIS EVENING NORTH AND
WEST OF THE VALLEY. LATEST SATELLITE TRENDS CONTINUE TO SHOW
EASTWARD PUSH OF THE BACK EDGE OF THE CLOUDS. THE BACK EDGE
OF THE CLOUDS SHOULD MOVE EAST OF KRHI/KAUW/KCWA BY 08Z.
ONCE THE CLOUDS CLEAR...AREAS OF FOG WILL DEVELOP ACROSS CENTRAL
AND NORTH-CENTRAL WISCONSIN. DECIDED TO TAKE THE KRHI TAF DOWN TO
A HALF MILE IN FOG TOWARDS SUNRISE DUE TO LIGHT WINDS AND SOME
MELTING SNOW THIS AFTERNOON INTO EARLY THIS EVENING. OTHERWISE...
VFR CONDITIONS SHOULD PREVAIL ON FRIDAY. LIGHT AND VARIABLE OR
LIGHT NORTHWEST WINDS WILL VEER TO THE NORTHEAST AND THEN EAST
FRIDAY AFTERNOON. WINDS MAY BE A LITTLE QUICKER TO VEER ALONG THE
LAKE DUE TO THE LAKE BREEZE AND MAY ARRIVE AN HOUR OR TWO BEFORE
18Z.


&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....KALLAS
LONG TERM......RDM
AVIATION.......ECKBERG